Refine
Has Fulltext
- yes (486) (remove)
Year of publication
Document Type
- Doctoral Thesis (132)
- Conference Proceeding (122)
- Article (79)
- Postprint (69)
- Working Paper (39)
- Monograph/Edited Volume (16)
- Review (15)
- Preprint (6)
- Master's Thesis (5)
- Habilitation Thesis (2)
Language
- English (486) (remove)
Keywords
- USA (7)
- United States (7)
- Arktis (6)
- climate change (6)
- moderne jüdische Geschichte (6)
- Arctic (5)
- Fernerkundung (5)
- modern Jewish history (5)
- 20. Jahrhundert (4)
- 20th century (4)
- Klimawandel (4)
- Nanopartikel (4)
- remote sensing (4)
- 19. Jahrhundert (3)
- Anden (3)
- Andes (3)
- Atmosphäre (3)
- COVID-19 (3)
- Datenanalyse (3)
- Diversity (3)
- Holozän (3)
- Immunoassay (3)
- Kohlenstoff (3)
- Nachhaltigkeit (3)
- Schadensmodellierung (3)
- Systembiologie (3)
- atmosphere (3)
- carbon (3)
- cluster expansion (3)
- gender (3)
- infinite-dimensional Brownian diffusion (3)
- molecular motors (3)
- molekulare Motoren (3)
- nanoparticles (3)
- sustainability (3)
- uncertainty (3)
- 19th century (2)
- Antarctica (2)
- Antarktis (2)
- Antibiotikaresistenz (2)
- Argentina (2)
- Argentinien (2)
- Deformation (2)
- Energiespeicher (2)
- Erdbeben (2)
- Fluoreszenz-Resonanz-Energie-Transfer (2)
- Focus (2)
- GIS (2)
- Galaxien (2)
- Geodynamik (2)
- German history (2)
- Graphentheorie (2)
- Grenzschicht (2)
- Hochwasserrisiko (2)
- Holocene (2)
- ICT (2)
- Informatics (2)
- Kohlenstoffnitriden (2)
- Korrosion (2)
- Lidar (2)
- Magnetismus (2)
- Magnetohydrodynamik (2)
- Mesokristalle (2)
- Mobilität (2)
- Modellierung (2)
- Modern Jewish history (2)
- N400 (2)
- PUFA (2)
- Paläoklima (2)
- Rheologie (2)
- Rheology (2)
- Seesedimente (2)
- Seismologie (2)
- Spektroskopie (2)
- Subduktion (2)
- Systems Biology (2)
- Unsicherheiten (2)
- Virus (2)
- Vulnerabilität (2)
- Winderosion (2)
- air pollution (2)
- air-water interface (2)
- boundary layer (2)
- carbon nitrides (2)
- carbon pricing (2)
- climate policy (2)
- corrosion (2)
- cosmic rays (2)
- damage modeling (2)
- data analysis (2)
- deutsche Geschichte (2)
- economic impacts (2)
- energy policy (2)
- energy storage (2)
- entrepreneurship (2)
- entropy (2)
- experiment (2)
- fatty acid (2)
- flood risk (2)
- food quality (2)
- galaxies (2)
- gesture (2)
- grammaticalization (2)
- graph theory (2)
- heterogene Photokatalyse (2)
- heterogeneous photocatalysis (2)
- high resolution (2)
- higher education (2)
- hohe Auflösung (2)
- hydraulic fracturing (2)
- immunoassay (2)
- kosmische Strahlung (2)
- machine learning (2)
- magnetohydrodynamics (2)
- mental health (2)
- mesocrystals (2)
- migration (2)
- mobility (2)
- numerical modelling (2)
- numerische Modellierung (2)
- organic synthesis (2)
- organische Synthese (2)
- palaeoclimate (2)
- perovskite (2)
- primary school (2)
- seismology (2)
- self-employment (2)
- spatially explicit model (2)
- stable isotopes (2)
- stochastic processes (2)
- stochastische Prozesse (2)
- virus (2)
- vulnerability (2)
- Ökologie (2)
- (implicit) prosody (1)
- 2D Numerical Modelling (1)
- 315 nm (1)
- 46 (3) 2009 (1)
- 473 nm (1)
- 946 nm (1)
- AC Elektrokinetik (1)
- AC Elektroosmosis (1)
- AC electrokinetics (1)
- AC electroosmosis (1)
- ACIDIFICATION (1)
- AGN (1)
- AMNET (1)
- ARMS (1)
- ASPECT (1)
- ATRP (1)
- Acetobacteraceae (1)
- Active Labor Market Policy (1)
- Adana Basin (1)
- Adana Becken (1)
- Adaptive hypermedia (1)
- Adsorption (1)
- Adverbial Quantification (1)
- Aerosole (1)
- Aerosols (1)
- Africa (1)
- Akan (1)
- Aktiven Galaxienkerne (1)
- Allantoin (1)
- Allgemeine Relativitätstheorie (1)
- Alternative Semantics (1)
- Altiplano (1)
- Aluminiumlegierung (1)
- Alzheimer's Disease (1)
- Amblystegiaceae (1)
- Analyse von Abflussganglinien (1)
- Anaphylatoxin (1)
- Anatomy (1)
- Animal (1)
- Animal personality (1)
- Anpassung (1)
- Antibiotic alternatives (1)
- Antibiotic resistance (1)
- Antibiotikaersatz (1)
- Antikörper (1)
- Antwortmengenprogrammierung (1)
- Archetyp (1)
- Arctic aerosol (1)
- Arctic haze (1)
- Arctic tundra (1)
- Arnos Padiri (1)
- Artificial Intelligence (1)
- Association Rule Mining (1)
- Assoziationsregeln (1)
- Astronomie (1)
- Asynchrone Schaltung (1)
- Asynchronous circuit (1)
- Atmosphärenforschung (1)
- Atmosphärenmodellierung (1)
- Auenbereich (1)
- Ausbreitung (1)
- Ausbreitung der kosmischen Strahlung (1)
- Aussterbeschuld (1)
- Autismus (1)
- Bachelor (1)
- Bachstufen (1)
- Backward ownership (1)
- Bakterien (1)
- Bandenenergien (1)
- Basalt-Vulkane (1)
- Bay of Bengal (1)
- Bayesian Network (1)
- Bayesianisches Netzwerk (1)
- Bayesianism (1)
- Bayesianismus (1)
- Bedingte Inklusionsabhängigkeiten (1)
- Bemessungshochwasser (1)
- Beschichtungen (1)
- Beta-Lactoglobulin (1)
- Beweidung (1)
- Bi2Se3 (1)
- Bi2Te3 (1)
- Big Data Analytics (1)
- Big data mining zu Hochwasserrisiken (1)
- Bildung (1)
- Bindungsinteraktion (1)
- Biochemical analysis (1)
- Biochemie (1)
- Biodiversität (1)
- Biofilm (1)
- Biokonjugate (1)
- Biomoleküle (1)
- Biophotonik (1)
- Bioraffinerie (1)
- Blattverschiebung (1)
- Boden (1)
- Bodenbearbeitung (1)
- Bodenunruhe (1)
- Botanik (1)
- Braunmoose (1)
- Bruchausbreitung (1)
- Bruchmodel (1)
- Bryophyten (1)
- Bryophytes (1)
- Bucht von Bengalen (1)
- Bulge (1)
- CLSM (1)
- CS Ed Research (1)
- CS at school (1)
- CS curriculum (1)
- CSC (1)
- CaM4 (1)
- Caco-2 (1)
- Canonical Gibbs measure (1)
- Capsule (1)
- Carbo-Iron (1)
- Carbon Capture (1)
- Carbon Dioxide Removal (1)
- Cars (1)
- Catecholamine (1)
- Causal structure (1)
- Chaco-Paraná Becken (1)
- Chaco-Paraná basin (1)
- Chalkogenide (1)
- Chaos Theory (1)
- Chaostheorie (1)
- Charnockit (1)
- Chemistry of fresh water (1)
- Chemokinematik der Milchstraße (1)
- Cherenkov telescopes (1)
- Cherenkov-Teleskope (1)
- China (1)
- Chlamydomonas (1)
- Chloroplast transformation (1)
- Chloroplastentransformation (1)
- Citrazinsäure (1)
- Climate Policy (1)
- Climate reconstruction (1)
- Clustering (1)
- Coiled coils (1)
- Color vision Aging (1)
- Comparing programming environments (1)
- Complement system (1)
- Complex networks (1)
- Computational Biology (1)
- Computer Science Education (1)
- Computersimulation (1)
- Conditional Inclusion Dependency (1)
- Confluence (1)
- Constraint Solving (1)
- Continental Rifts (1)
- Controller-Resynthese (1)
- Core-Collapse Supernovae (1)
- Course development (1)
- Course marketing (1)
- Course of Study (1)
- Courses for female students (1)
- Covert Variables (1)
- Covid-19 (1)
- Cu doped InP (1)
- Cu-dotiertes InP (1)
- Curricula Development (1)
- Curriculum analysis (1)
- DAS (1)
- DGVM (1)
- Daphnia (1)
- Dark Matter (1)
- Data Dependency (1)
- Data-Mining (1)
- Datenabhängigkeiten (1)
- Datenintegration (1)
- Deduction (1)
- Deligne Cohomology (1)
- Deligne Kohomologie (1)
- Demokratisierung (1)
- Density modelling (1)
- Deoxyfructosazin (1)
- Diamantstempelzelle (1)
- Diatomeen (1)
- Diatoms (1)
- Dichteeffekte (1)
- Dichtemodellierung (1)
- Dielektrophorese (1)
- Difference-in-Differences (1)
- Digital Rebound (1)
- Digitalisierung (1)
- Diskursverstehen (1)
- Diversität (1)
- Domain Restriction (1)
- Downstep (1)
- Dreissena polymorpha (1)
- Dronning Maud Land (1)
- Dunkle Materie (1)
- Durchmusterung (1)
- Düngung (1)
- E-DSGE (1)
- E. coli (1)
- EAAT1 (1)
- EKP (1)
- EROSION (1)
- ERP (1)
- ERPs (1)
- EVENTS (1)
- Earthquake (1)
- East European Jewish history (1)
- Ecology (1)
- Ecotoxicology (1)
- Einkapselung (1)
- Einwanderungskredit (1)
- Einzelatomkatalyse (1)
- Einzelmolekülkraftspektroskopie (1)
- Einzugsgebietshydrologie (1)
- Eisbohrkern (1)
- Electron acceleration (1)
- Elektronenbeschleunigung (1)
- Emissionslinienklassifikation (1)
- Emotionserkennung (1)
- Employee Training (1)
- Emulsion (1)
- Endophyten (1)
- Energie (1)
- Energieerzeugung (1)
- Energietransfer (1)
- Energy expenditure (1)
- English and Physics teacher trainees (1)
- Entrepreneurship (1)
- Entry deterrence (1)
- Entstehung der Milchstraße (1)
- Epiphyten (1)
- Erdmantel (1)
- Erkennen von Meta-Daten (1)
- Erosion (1)
- Essigsäurebakterien (1)
- Ethics (1)
- Etna (1)
- Europa (1)
- Europe (1)
- European Alps (1)
- European hare (1)
- European history (1)
- Evolution (1)
- Evolution der Milchstraße (1)
- Exoplaneten (1)
- Exoplanetenatmosphären (1)
- Experimental study (1)
- Exploration (1)
- FARIMA (1)
- FastScape (1)
- Ferroperiklas (1)
- Figurative Sprachverarbeitung (1)
- Figurative language processing (1)
- Firm Growth (1)
- Flache Subduktion (1)
- Flat subduction (1)
- Flood Change (1)
- Flood Risk Big Data Mining (1)
- Fluorpolymere (1)
- Foreclosure (1)
- Foreland (1)
- Foreland basin (1)
- Foreland basins (1)
- Forstwirtschaft (1)
- Frucht (1)
- Förster Resonanz Energie Transfer (1)
- GC-MS (1)
- GITEWS (1)
- GPS (1)
- Galaxie: allgemein (1)
- Galaxienhaufen (1)
- Galicia (1)
- Galizien (1)
- Gasgeochemie (1)
- Gebirgsbäche (1)
- Geflügelmist (1)
- Geistesgeschichte (1)
- Gen-Koexpression (1)
- Gender (1)
- Gene co-expression (1)
- General Relativity (1)
- General subject “Information” (1)
- Geodynamic Modelling (1)
- Geodynamics (1)
- Geodynamische Modellierung (1)
- Geomorphologie (1)
- Geothermal monitoring (1)
- Geothermisches Monitoring (1)
- Gerben (1)
- Gerbes (1)
- Gerinne-Hang-Kopplung (1)
- German Jewry (1)
- Geschichte 2003-2006 (1)
- Geschiebetransport (1)
- Geschwindigkeitsmodell (1)
- Gezeitenwechselwirkungen (1)
- Gibbs field (1)
- Gibbs measure (1)
- Gletschervorfeld (1)
- Global Differentialgeometry (1)
- Global Value Chains (1)
- Globale Differentialgeometrie (1)
- Globale Wertschöpfungsketten (1)
- Glucagon (1)
- Glutamat (1)
- Glutamate (1)
- Grabenbrüche (1)
- Grammatica (1)
- Grandonica (1)
- Gravitational Waves (1)
- Gravitationswellen (1)
- Greenhouse Gas Emissions (1)
- Greenland (1)
- Greenland Ice Sheet (1)
- Grenzflächen (1)
- Grenzflächenchemie (1)
- Grundgestein (1)
- Grundwassersanierung (1)
- Grönland (1)
- Grönländisches Eisschild (1)
- Grüne Chemie (1)
- Grünland (1)
- Gyrochronologie (1)
- H/V (1)
- HMA (1)
- HVSR (1)
- HYDROGRAPH SEPARATION (1)
- Halogenbindung (1)
- Hanghydrologie (1)
- Hanxleden (1)
- Hauptfaserbündel (1)
- Hebung des Plateaus (1)
- HepG2 (1)
- Hepatic artery (1)
- Hepatic glucose balance (1)
- Hepatic hemodynamics (1)
- Hepatic lactate balance (1)
- Hepatic nerve (1)
- Heptazine (1)
- High growth firms (1)
- Hochdruck (1)
- Holonomie (1)
- Holonomy (1)
- Horace Kallen (1)
- Horizontal flux (1)
- Human Capital Investments (1)
- Hydrogele (1)
- Hydrograph Analysis (1)
- Hyperakkumulation (1)
- Hysterese (1)
- ICT curriculum (1)
- ISSEP (1)
- Impakt (1)
- Impermanence (1)
- InSAR (1)
- Indian Summer Monsoon (1)
- Indischer Sommermonsun (1)
- Industrial Internet of Things (1)
- Industrie 4.0 (1)
- Industrielles Internet der Dinge (1)
- Industry 4.0 (1)
- Induzierte Seismizität (1)
- Influenza (1)
- Informatics Education (1)
- Informatik (1)
- Informatikdidaktik (1)
- Information Ethics (1)
- Information Processing (1)
- Informations- und Kommunikationstechnologien (1)
- Injektion (1)
- Injektionsschema (1)
- Inlandeis (1)
- Innovation (1)
- Innovationen in den Städten (1)
- Institutions (1)
- Inter-individual differences (1)
- Interacting Diffusion Processes (1)
- Interface-Engineering (1)
- Intersectionality (1)
- Intervention Effect (1)
- Intonation (1)
- Introgression (1)
- Inversion (1)
- Investitionspolitik (1)
- Ionenmobilitätspektrometrie (1)
- Irak (1)
- Isaac Leeser (1)
- Isaac Mayer Wise (1)
- Israel (1)
- JH-III-specific carrier protein (1)
- JUB1 (1)
- Japanese (1)
- Jets (1)
- Job Creation (1)
- Job Search (1)
- Jurkat cells (1)
- Juvenile hormone (1)
- KINETIC-ENERGY (1)
- Karbonnitrid Ionothermalsynthese (1)
- Kathode (1)
- Kausalstruktur (1)
- Kern-Kollaps-Supernovae (1)
- Kern-Mantel Grenze (1)
- Key Competencies (1)
- Kleinwinkelröntgenstreuung (1)
- Klimadaten (1)
- Klimafolgenforschung (1)
- Klimanetzwerke (1)
- Klimaphysik (1)
- Klimarekonstruktion (1)
- Klimavariabilität (1)
- Knochen (1)
- Kohlenstoffdioxid (1)
- Kohlenstoffhaushalt (1)
- Kohlenstoffkreislauf (1)
- Kohlenstoffmaterialien (1)
- Kohlenstoffmodell (1)
- Kohnen (1)
- Komplexe Netzwerke (1)
- Kontaktschichten (1)
- Koordinationskomplexe (1)
- Kultivierung (1)
- Künstliche Intelligenz (1)
- LAEs (1)
- LC/HRMS (1)
- LOC (1)
- LPJ (1)
- Labor Market Mobility (1)
- Lake Constance (1)
- Lake sediments (1)
- Lakunen (1)
- Landnutzung (1)
- Landnutzungshistorie (1)
- Langevin Dynamics (1)
- Lanthanoide (1)
- Laser ablation (1)
- Lateglacial (1)
- Lavafontänen (1)
- Leptinotarsa decemlineata (1)
- Li-Ionen-Akkus (1)
- Li-Ionen-Kondensator (1)
- Li-ion batteries (1)
- Li-ion capacitor (1)
- LiFePO4 (1)
- Lignin (1)
- Link Discovery (1)
- Link-Entdeckung (1)
- Linked Open Data (1)
- Lithosphäre (1)
- Logic Programming (1)
- Logics (1)
- Lokalisierung von Deformation (1)
- Luftverschmutzung (1)
- Lumineszenz (1)
- Lyman Kontinuum (1)
- Lyman alpha (1)
- Lyman continuum (1)
- Lyman-Alpha-Emitter (1)
- Lyman-alpha emitters (1)
- Lysimeter (1)
- MESOSCALE CONVECTIVE COMPLEXES (1)
- MIXTURE (1)
- MSPAC (1)
- Macular pigment (1)
- Magnetfelder (1)
- Magnetoelastizität (1)
- Malliavin calculus (1)
- Manager Decisions (1)
- Markov chains (1)
- Markov-Prozesse (1)
- Markovketten (1)
- Massenspektrometrie (1)
- Massenverlust (1)
- Mechanobiologie (1)
- Meereis (1)
- Meeresspiegelanstieg (1)
- Mehrschichtsysteme (1)
- Memory studies (1)
- Mesoporosity (1)
- Mesoporosität (1)
- Metabolic Modeling (1)
- Metabolism (1)
- Metabolit (1)
- Metabolome (1)
- Metadata Discovery (1)
- Metadatenentdeckung (1)
- Metadatenqualität (1)
- Meteorologie (1)
- Methan (1)
- Methankreislauf (1)
- MiSpEx (1)
- Microsaccades (1)
- Microsaccadic Inhibition (1)
- Microschwimmer (1)
- Middle East (1)
- Mikrokapsel (1)
- Mikroplatte (1)
- Mikrowellensynthese (1)
- Mikrozonierung (1)
- Milky Way chemo-kinematics (1)
- Milky Way evolution (1)
- Milky Way formation (1)
- Minderheit (1)
- Mineralisierung (1)
- Mineralverwitterungsreaktionen (1)
- Minority shareholdings (1)
- Mistausbringung (1)
- Mobile learning (1)
- Model-Daten Integration (1)
- Modeling (1)
- Modelle (1)
- Modellkalibrierung (1)
- Modellvalidierung (1)
- Moden Stabilität (1)
- Moderne jüdische Geschichte (1)
- Mondsee (1)
- Monolayers (1)
- Moorsukzession (1)
- Moos-Mikroben-Interaktion (1)
- Moos-assoziierte Methanoxidation (1)
- Moos-assoziierte Methanproduktion (1)
- Morbus Alzheimer (1)
- Morphologie von Kapseln (1)
- Movement ecology (1)
- Multilayers (1)
- Muttergalaxien (1)
- NP-deletion (1)
- Nanoeisen (1)
- Nanoelektroden (1)
- Natrium-Ionen-Akkumulator (1)
- Naturgefahren (1)
- Navigation (1)
- Nehemia Robinson (1)
- Neodym-YAG-Laser (1)
- Neutronensterne (1)
- Nichtlineare Spektroskopie (1)
- Nichtlineare Wellen (1)
- Nitrogen deposition (1)
- Non-linear Geoscience (1)
- Non-stationary Flood Risk (1)
- Nonlinear waves (1)
- Numerische 2D Modellierung (1)
- ODBA (1)
- Oberflächenchemie (1)
- Oberflächenprozesse (1)
- Oberflächenzustände (1)
- Open Access (1)
- Open Source (1)
- OpenStreetMap (1)
- Optimization (1)
- Optode (1)
- Orogen (1)
- Orthodox Judaism (1)
- Ortscharakterisierung (1)
- Ortseffekte (1)
- Oscillating Bubble (1)
- Oxo-Kohlenstoff (1)
- P-Typ ATPase (1)
- P300 (1)
- P300Psychophysiology (1)
- PBCEC (1)
- PHQ-4 score (1)
- PHREEQC (1)
- PM10 (1)
- PM10, PM2, PM1 (1)
- POC (1)
- PVA (population viability analysis) (1)
- Paleofloods (1)
- Paläohochwasser (1)
- Paläolimnologie (1)
- Partial Little Square (1)
- Partial ownership (1)
- Patent (1)
- Peptid (1)
- Peptid-Polymer-Konjugate (1)
- Peptide (1)
- Perfusion (1)
- Permafrost (1)
- Permafrostdegradation (1)
- Permafrostsedimente (1)
- Permafrostökosysteme (1)
- Perowskit (1)
- Perowskit Solarzellen (1)
- Perowskite (1)
- Petrinetz (1)
- Pflanzenwissenschaften (1)
- Phage lysins (1)
- Phagenlysine (1)
- Phasenraum des Time Delay Embedding (1)
- Photochemische Reaktionen (1)
- Photovoltaik (1)
- Physik (1)
- Piano delle Concazze (1)
- Pitch Reset (1)
- Pkw (1)
- Planetary Rings (1)
- Planing (1)
- Policy Reform (1)
- Politik (1)
- Pollen (1)
- Polyelectrolyte (1)
- Polyelektrolyt (1)
- Polyneuropathie (1)
- Populationsdynamik (1)
- Populationsgefährdungsanalyse (1)
- Portal vein (1)
- Post-Focus Reduction (1)
- Pragmatik (1)
- Preußen (1)
- Primary informatics (1)
- Prinicipal Fibre Bundles (1)
- Privathaushalte (1)
- Problem solving (1)
- Problem solving strategies (1)
- Procrustes rotation analysis (1)
- Programming environments for children (1)
- Programming learning (1)
- Prokrustes Analyse (1)
- Prolog (1)
- Propeller (1)
- Proteom (1)
- Proteomics (1)
- Proxyunsicherheit (1)
- Proxyverständnis (1)
- Prussia (1)
- Pseudodatensätze (1)
- Puna (1)
- Push and Pull Theories (1)
- Pytho n (1)
- QD device (1)
- QD stability (1)
- QD-Gerät (1)
- QD-Stabilität (1)
- QtClassify (1)
- Quadratsäure (1)
- Quality of regional governments (1)
- Quantenpunkt (1)
- Quantificational Variability (1)
- Quantitative Trait Locus (1)
- Quantitative Trait Locus analysis (1)
- RAFT (1)
- RAVE Beobachtungskampagne (1)
- RAVE survey (1)
- Rabbiner (1)
- Random Field Ising Model (1)
- Rare and Unseasonal Flood (1)
- Rat (1)
- Rechtsgeschichte (1)
- Recurrence Plots (1)
- Reform Judaism (1)
- Reformjudentum (1)
- Regions (1)
- Regulation (1)
- Reionisierung (1)
- Reisen (1)
- Rekurrenzanalyse (1)
- Rekurrenzplot (1)
- Relativistische Astrophysik (1)
- Remote Sensing (1)
- Rezeptor (1)
- Rift (1)
- Risk Attitudes (1)
- Roboter (1)
- Rotation (1)
- Runoff and streamflow (1)
- Russia (1)
- Russian Arctic (1)
- Russland (1)
- Röntgenbeugung (1)
- S. 635-644 (1)
- SAR (1)
- SAXS (1)
- SEGUE Beobachtungskampagne (1)
- SEGUE survey (1)
- SOILWATER END-MEMBERS (1)
- SPAC (1)
- STEM (1)
- STG decomposition (1)
- STG-Dekomposition (1)
- STREAMWATER CHEMISTRY (1)
- Salzgestein (1)
- Salzschmelze (1)
- Salzschmelze-Templating (1)
- Sanskrit (1)
- Saprolit (1)
- Sauerstoff (1)
- Schallemissionen (1)
- Schatten eines Schwarzen Lochs (1)
- Schaum (1)
- Scheibe (1)
- Schemaentdeckung (1)
- Schlüsselkompetenzen (1)
- Schwarzes Loch (1)
- Scientific understanding of Information (1)
- Search Frictions (1)
- Sedimentenabfolge (1)
- Segmentierung (1)
- Selbstheilende Beschichtungen (1)
- Selbstorganisation (1)
- Selbstähnlichkeit (1)
- Selen (1)
- Selenonein (1)
- Seneszenz (1)
- Shock waves (1)
- Shortening (1)
- Sierras Pampeanas (1)
- Signalflankengraph (SFG oder STG) (1)
- Silika (1)
- Silizium (1)
- Simulationen (1)
- Simulationsframework (1)
- Skalierung (1)
- Social Cost of Carbon (1)
- Social Identity Theory (1)
- Social impact (1)
- Sociotechnical Design (1)
- Solar corona (1)
- Sonnenkorona (1)
- Space-Time Cluster Expansions (1)
- Spalteneruption (1)
- Spannungsfeld (1)
- Spannungsmessung (1)
- Species richness (1)
- Sphagnum (1)
- Spinpolarisation (1)
- Spleißvariante (1)
- Splice Variant (1)
- Spurengasflüsse (1)
- Spätglazial (1)
- Sri Lanka (1)
- Stabile Isotope (1)
- Stabilität (1)
- Stadtwachstumsraten (1)
- Stakeholder-based Science (1)
- Stakeholder-basierte Forschung (1)
- Stalagmiten (1)
- Starkregen (1)
- Start-Up Subsidies (1)
- Start-up Motivation (1)
- Statistik (1)
- Staubemission (1)
- Steilwinkel-Analyse von PcP (1)
- Stern-Brauner Zwerg Systeme (1)
- Stern-Planet Systeme (1)
- Stern-Planeten-Wechselwirkung (1)
- Sterne: Entfernungen (1)
- Sternentwicklung (1)
- Sternphysik (1)
- Sternwinde (1)
- Stethophyma grossum (1)
- Stimuli (1)
- Stochastic Differential Equation (1)
- Stoffwechsel (1)
- Stoßwellen (1)
- Strahlungstransport (1)
- Strain Localisation (1)
- Strukturgeologie (1)
- Styrol (1)
- Städte (1)
- Subduction (1)
- Subsidenzgeschichte (1)
- Succession (1)
- Sumpfschrecke (1)
- Superconducting gravimetry (1)
- Supernovaüberreste (1)
- Supraleit-Gravimetrie (1)
- Survival (1)
- Synchrotronstrahlung (1)
- Synthese (1)
- Synthesis (1)
- Systeme interagierender Partikel (1)
- Süd-Türkei (1)
- TRACERS (1)
- TRPV1 (1)
- Tandem-Solarzelle (1)
- Tauziehen (1)
- Teaching problem solving strategies (1)
- Team Composition (1)
- Team Development (1)
- Technique (1)
- Tektonik (1)
- Temperaturproxy (1)
- Tensid (1)
- Teukolsky Gleichung (1)
- Teukolsky master equation (1)
- Thermoelektrizität (1)
- Thermokarstprozesse (1)
- Thioester (1)
- Tibet Plateau (1)
- Tibetan Plateau (1)
- Tiefbeben und Kernexplosionen (1)
- Time Embedded Phase Space (1)
- Time series analysis (1)
- Tomate (1)
- Tomato (1)
- Topic (1)
- Torfmoose (1)
- Torsion Experiments (1)
- Torsionsexperimente (1)
- Training Sozialer Kognition (1)
- Trajectories (1)
- Transdisziplinarität (1)
- Transformation (1)
- Transkriptionsfaktor (1)
- Treibhausgase (1)
- Treibhausgasemissionen (1)
- Triazin (1)
- Trockenstress (1)
- Tsunami (1)
- Turbulenz (1)
- Turbulenzparametrisierungen (1)
- UNITED-STATES (1)
- UV-detection (1)
- Ultra-Niedriggeschwindigkeitszonen (1)
- Understorey (1)
- Uniform pricing (1)
- Unintended Consequence (1)
- Union (1)
- Unsicherheit (1)
- Unsicherheitsanalyse (1)
- Urate (1)
- VLT/MUSE (1)
- VOC (1)
- VP-ellipsis (1)
- Variationen terrestrischer Wasserspeicher (1)
- Vascular plants (1)
- Vegetation (1)
- Vegetationsmodell (1)
- Verkürzung (1)
- Vernetzer (1)
- Versöhnung (1)
- Vertical flux (1)
- Vertical integration (1)
- Vertreibung (1)
- Verwitterungsfeedback (1)
- Videoanalyse (1)
- Visual Oddball Paradigm (1)
- Vorland (1)
- Vorlandbecken (1)
- Vulkan Verformung (1)
- Vulkanologie (1)
- Warven (1)
- Warves (1)
- Wasser-Gesteins-Wechselwirkungen (1)
- Wasser/Luft Grenzflächen (1)
- Wasserhaushalt (1)
- Weathering (1)
- Weitwinkelröntgenstreuung (1)
- Wh-question (1)
- Whinterrogatives (1)
- Windböen (1)
- Wirtsspezifität (1)
- Wissenschaftsgeschichte (1)
- Wissensgeschichte (1)
- Women and IT (1)
- Word processing (1)
- Wärmefluss (1)
- Wärmekapazität (1)
- Wärmeleitfähigkeit von Schnee (1)
- X-ray diffraction (1)
- XM (1)
- Zeitpunkt von Störungen (1)
- Zeitreihenanalyse (1)
- Zink (1)
- Zirkulardichroismus (1)
- Zyklone (1)
- Züchtung (1)
- [N]phenylene dyads (1)
- [N]phenylenes (1)
- abrupte Übergänge (1)
- academic leadership (1)
- acclimation (1)
- acoustic emissions (1)
- acoustically levitated droplets (1)
- active galactic nuclei (1)
- ad hoc learning (1)
- ad hoc messaging network (1)
- adaptation (1)
- adsorption (1)
- aerosol: hygroscopic growth (1)
- aerosol: hygroskopisches Wachstum (1)
- aerosol: optical properties (1)
- aerosol: optische Eigenschaften (1)
- affect (1)
- agricultural (1)
- airborne bacteria (1)
- aktive Galaxienkerne (1)
- akustisch schwebende Tropfen (1)
- alga (1)
- alpha (1)
- aluminum alloy (1)
- ambient vibration (1)
- ambiguity attitudes (1)
- anaerobe Inkubationensexperimente (1)
- anaerobic incubation experiments (1)
- angle resolved photoelectron spectroscopy (1)
- answer set programming (1)
- anterior PNP (1)
- antibiotic resistance (1)
- antibody (1)
- archetype (1)
- arctic (1)
- arktische Tundra (1)
- arktischer Dunst (1)
- arktisches Aerosol (1)
- astronomy (1)
- atmospheric modelling (1)
- atmospheric science (1)
- autism (1)
- bacteria (1)
- basaltic volcanoes (1)
- basement rock (1)
- bedload transport (1)
- behavioral economics (1)
- behaviour (1)
- benchmarking (1)
- bidirectional intracellular transport (1)
- bidirektionaler intrazellulärer Transport (1)
- bild (1)
- binding interactions (1)
- biochemistry (1)
- bioconjugate (1)
- biofilm (1)
- biohybrid molecules (1)
- biomolecule (1)
- biophotonics (1)
- biorefinery (1)
- black hole (1)
- black hole shadows (1)
- black holes (1)
- blended learning (1)
- bone (1)
- bottom–up (1)
- breeding (1)
- brown mosses (1)
- bryophytes (1)
- built–in predicates (1)
- bulge (1)
- business services (1)
- calmodulin (1)
- canonical discretization schemes (1)
- capacity building (1)
- capillary electrophoresis (1)
- capsule morphology (1)
- carbon cycle (1)
- carbon cycling (1)
- carbon debt (1)
- carbon dioxide (1)
- carbon emissions (1)
- carbon materials (1)
- carbon nitride (1)
- carbon price (1)
- carbon removal (1)
- cartel (1)
- catchment hydrology (1)
- cathode (1)
- central Andes (1)
- central-eastern Beringia (1)
- chalcogenide (1)
- channel steps (1)
- channel-hillslope coupling (1)
- charnockite (1)
- chemical weathering (1)
- chemische Verwitterung (1)
- childcare provision (1)
- chlorbenzol (1)
- chronic pain (1)
- chronischer Schmerz (1)
- circular dichroism (1)
- citrazinic acid (1)
- climate (1)
- climate data (1)
- climate impact research (1)
- climate networks (1)
- climate physics (1)
- closed chamber method (1)
- clustering (1)
- coating (1)
- coherence (1)
- coiled coils (1)
- collaboration (1)
- colloidal quantum dot (1)
- collusion (1)
- colonization credit (1)
- color change (1)
- communication (1)
- community (1)
- commuting (1)
- competence (1)
- complement (1)
- completion rates (1)
- complex emulsion (1)
- complex systems (1)
- complexity (1)
- composition (1)
- computational thinking (1)
- computer science (1)
- computergestützte Biologie (1)
- computing science education (1)
- concept of algorithm (1)
- conditioned (1)
- conditioned Feller diffusion (1)
- conjunction (1)
- constrained Hamiltonian systems (1)
- constraint (1)
- constructionism (1)
- consumer (1)
- contact layers (1)
- control resynthesis (1)
- cooperative phenomena (1)
- cooperative transport (1)
- coordination complexes (1)
- core-mantle boundary (1)
- cosmic ray propagation (1)
- covalent frameworks (1)
- critical and subcritical Dawson-Watanabe process (1)
- critical collapse (1)
- critical zone (1)
- crops (1)
- crosslinker (1)
- crowding out (1)
- cultivation (1)
- cultural pluralism (1)
- cyclones (1)
- damage modelling (1)
- data integration (1)
- data profiling (1)
- data-mining (1)
- decomposition (1)
- decomposition methods (1)
- deductive databases (1)
- deep earthquakes and nuclear explosions (1)
- deep eutectic solvents (1)
- definite descriptions (1)
- deformation (1)
- density effects (1)
- density-driven flow (1)
- deoxyfructosazine (1)
- derivational complexity (1)
- detailed balance equation (1)
- deutsch-jüdische Geschichte (1)
- developing country cities (1)
- diamond anvil cell (1)
- dichlorbenzol (1)
- dichlorobenzene (1)
- dichtegetriebene Strömung (1)
- dielectrophoresis (1)
- differential-algebraic equations (1)
- digitalization (1)
- disc (1)
- discotics (1)
- discourse comprehension (1)
- discrete choice (1)
- discrimination (1)
- dispersal (1)
- displacement (1)
- disturbance timing (1)
- diversity (1)
- doctoral studies (1)
- double dividend (1)
- drought stress (1)
- drug delivery (1)
- dust emission (1)
- dwarf spheroidal galaxies (1)
- dünne Filme (1)
- e-learning platform (1)
- early indicators for SLI (1)
- earth mantle (1)
- earthquakes (1)
- ecology (1)
- ecophysiology (1)
- education (1)
- efficiency (1)
- elastic coupling (1)
- elastische Kopplung (1)
- electrochemistry (1)
- emergency-aid (1)
- emission line classification (1)
- emotion recognition (1)
- employment precariousness (1)
- emulsion (1)
- enantioselectivity (1)
- encapsulation (1)
- endophytes (1)
- energy (1)
- energy expenditure (1)
- energy levels (1)
- engaged computing (1)
- enhanced geothermal system (1)
- enhanced geothermal systems (EGS) (1)
- entrepreneurship policy (1)
- environmental tax reform (1)
- environmental upgrading (1)
- enzymatic conjugation (1)
- epiphytes (1)
- equity crowdfunding (1)
- erosion (1)
- europe (1)
- european (1)
- europäische Geschichte (1)
- ex-situ focus (1)
- exoplanet atmospheres (1)
- exoplanets (1)
- extensions of logic programs (1)
- extinction debt (1)
- family (1)
- feature selection (1)
- fecal contamination (1)
- ferropericlase (1)
- fertilization (1)
- finance (1)
- financial access and inclusion (1)
- firn (1)
- fissure eruption (1)
- flexibility (1)
- flooding (1)
- flow (1)
- fluorescence immunoassay (1)
- fluorinated polymers (1)
- foam (1)
- focus (1)
- focus marker (1)
- focus marking (1)
- focus movement (1)
- food prices (1)
- forestry (1)
- forward / backward chaining (1)
- fracture growth (1)
- fruit (1)
- function symbols (1)
- fundamental parameters (1)
- fundamentale Parameter (1)
- fäkale Kontamination (1)
- galactic astronomy (1)
- galactic magnetic fields (1)
- galaktische Astronomie (1)
- galaktische Magnetfelder (1)
- galaxy clusters (1)
- galaxy: general (1)
- gas geochemistry (1)
- gefangene lichtartige Kurven (1)
- gemeinsame Inversion (1)
- gender pay gap (1)
- general secondary education (1)
- generalized difference-in-difference (1)
- generalized logic programs (1)
- geodynamics (1)
- geographische Großstudie (1)
- geomorphology (1)
- geothermal exploration (1)
- geothermal monitoring (1)
- geothermische Exploration (1)
- geothermische Überwachung (1)
- gepulster DPSS Laser (1)
- geschlossene Haubenmessmethode (1)
- glacier forefield (1)
- global change (1)
- global flood model (1)
- global hydrological modeling (1)
- globale hydrologische Modellierung (1)
- globales Überschwemmungsmodell (1)
- glucose (1)
- goal-setting (1)
- grafting-from (1)
- grassland (1)
- grazer (1)
- grazing (1)
- green chemistry (1)
- greenhouse gases (1)
- gridded data (1)
- großräumige Struktur des Universums (1)
- gyrochronology (1)
- habit formation (1)
- halogen bonding (1)
- hard core potential (1)
- hate crime (1)
- heat capacity (1)
- heat flux (1)
- heptazine (1)
- herbivore (1)
- heteroatom-doped carbons (1)
- heteroatom-dotierte Kohlenstoffe (1)
- heterogene Katalyse (1)
- heterogeneous catalysis (1)
- hierarchical porosity (1)
- hierarchische Porosität (1)
- high pressure (1)
- high-redshift (1)
- hillslope hydrology (1)
- history of science (1)
- hoher Rotverschiebung (1)
- home office (1)
- horizontal equity (1)
- horizontal-vertikales Spektralverhältnis (1)
- horizontaler Fluss (1)
- host galaxies (1)
- host-specificity (1)
- human capital (1)
- human excised skin (1)
- hydraulische Risserzeugung (1)
- hydraulisches Aufbrechen (1)
- hydro-meteorological risk (1)
- hydro-meteorologische Risiken (1)
- hydrodynamic modeling (1)
- hydrodynamische Modellierung (1)
- hydrogels (1)
- hydrolysis (1)
- hyperaccumulation (1)
- hyperspectral remote sensing (1)
- hyperspektral Fernerkundung (1)
- hyporheic zone (1)
- hyporheische Zone (1)
- hysteresis (1)
- ice core (1)
- ice sheet (1)
- ice-flow modeling (1)
- image (1)
- imaging spectroscopy (1)
- impact (1)
- income (1)
- induced seismicity (1)
- inequality (1)
- inequality of opportunity (1)
- influenza (1)
- informatics curricula (1)
- informatics education (1)
- informatics in upper secondary education (1)
- information and communication technologies (1)
- information structure (1)
- injection (1)
- injection scheme (1)
- innovations in the city (1)
- inorganic ions (1)
- instruction (1)
- instrumental variables (1)
- integration by parts formula (1)
- intellectual history (1)
- interacting particle systems (1)
- interface engineering (1)
- interfaces (1)
- international comparison (1)
- international cooperation (1)
- international study (1)
- internationalisation for higher education (1)
- interreligious dialogue (1)
- interreligiöser Dialog (1)
- intonation (1)
- intracellular transport (1)
- intracluster medium (1)
- intrazellulärer Transport (1)
- inversion (1)
- ion mobility spectrometry (1)
- ionothermal synthesis (1)
- isotope variations (1)
- job characteristics (1)
- joint inversion (1)
- just transition (1)
- jüdische Orthodoxie (1)
- knowledge representation (1)
- kolloidaler Quantenpunkt (1)
- komplexe Emulsion (1)
- komplexe Systeme (1)
- konfokales Laser-Scanning-Mikroskop (1)
- kooperative Phänomene (1)
- kooperativer Transport (1)
- kovalente Rahmenbedingungen (1)
- kritische Zone (1)
- kritischer Kollaps (1)
- kultureller Pluralismus (1)
- lab-on-chip (1)
- labor productivity (1)
- labour migration (1)
- lactate output (1)
- lacunae (1)
- lacuno-canalicular network (1)
- lake sediments (1)
- lakuno-kanaliculäres Netzwerk (1)
- land use (1)
- land use history (1)
- landwirtschaftlich (1)
- langreichweitige Korrelationen (1)
- language acquisition (1)
- large marsh grasshopper (1)
- large-scale structure (1)
- large-scale study (1)
- late talker (1)
- lava fountains (1)
- layered compounds (1)
- leadership (1)
- lebende Materialien (1)
- legal history (1)
- lesson (1)
- life history (1)
- light-programmable viscosity (1)
- lignin (1)
- linked employer-employee data (1)
- liquid crystals (1)
- lithosphere (1)
- living materials (1)
- logic programming (1)
- logical signaling networks (1)
- logische Signalnetzwerke (1)
- long-memory (1)
- long-range dependence (1)
- long-term effects (1)
- low back pain (1)
- low-cost sensor (1)
- lubricant (1)
- luftgetragene Bakterien (1)
- lysimeter (1)
- ländliche Entwicklung (1)
- lösungsmittelfreie Synthese (1)
- magnetic fields (1)
- magnetism (1)
- magnetoelasticity (1)
- mandatory computer science foundations (1)
- manure application (1)
- market-entry game (1)
- markov processes (1)
- maschinelles Lernen (1)
- mass loss (1)
- mass spectrometry (1)
- massereiche Sterne (1)
- massive stars (1)
- mechanics (1)
- mechanische Stabilität (1)
- mechanobiology (1)
- medical (1)
- medizinisch (1)
- mehrfache Stressfaktoren (1)
- mehrschichtige Verbindungen (1)
- memory studies (1)
- mesoporous (1)
- mesoporös (1)
- meta-analysis (1)
- metabolic genomics (1)
- metabolische Modellierung (1)
- metabolite breeding (1)
- metabolite profiling (1)
- metabolome (1)
- metadata discovery (1)
- metadata quality (1)
- metamorphosis (1)
- meteorology (1)
- methane (1)
- methane cycle (1)
- methanogenic archaea (1)
- methanotrophic bacteria (1)
- methanoxidierende Bakterien (1)
- methanproduzierende Archaeen (1)
- miRNA (1)
- micro- and nanotechnologies (1)
- microbial communities (1)
- microbial processes (1)
- microplate (1)
- microswimmers (1)
- microwave synthesis (1)
- microzonation (1)
- mikrobielle Gemeinschaften (1)
- mikrobielle Moor-Kerngemeinschaft (1)
- mikrobielle Prozesse (1)
- mineral weathering reactions (1)
- mineralization (1)
- misconceptions (1)
- mixed methods (1)
- mixture of bridges (1)
- mock data catalogues (1)
- modality (1)
- mode stability (1)
- model calibration (1)
- model validation (1)
- model-data integration (1)
- modelling (1)
- models (1)
- modifizierte räumliche Autkorrelationsmethode (1)
- molecular biomarkers (1)
- molekulare Biomarker (1)
- monensin (1)
- monochlorobenzene (1)
- monosaccharides (1)
- moss-associated archaea (1)
- moss-associated bacteria (1)
- moss-associated methanogenesis (1)
- moss-associated methanotrophy (1)
- moss-microbe-interactions (1)
- mother’s labor supply (1)
- mountain rivers (1)
- multi-valued logic (1)
- multi-valued treatment (1)
- multidisciplinary intervention (1)
- multiple stress factors (1)
- multiresponsiv (1)
- multiresponsive (1)
- multitype measure-valued branching processes (1)
- nZVI (1)
- nachhaltige Energiespeichermaterialien (1)
- nachhaltige Stadtentwicklung (1)
- nachhaltige industrielle Entwicklung (1)
- nachhaltiges Lieferkettenmanagement (1)
- nano zero-valent iron (1)
- nanoelectrodes (1)
- nanogels (1)
- nanoporous carbon particles (1)
- nanoporöser Kohlenstoffpartikel (1)
- narrative structure (1)
- national multiplication training (1)
- national quality assurance agency in Guinea (1)
- natural field experiment (1)
- natural hazards (1)
- net-negative emissions (1)
- neutron stars (1)
- nicht-thermische Strahlung (1)
- nichtgenestete Modellselektion (1)
- nichtlineare Geowissenschaften (1)
- nichtlineare Zeitreihenanalyse (1)
- nichtstationäres Hochwasserrisiko (1)
- nineteenth century (1)
- noise (1)
- non-Ricardian households (1)
- non-manuals (1)
- non-nested model selection (1)
- non-thermal radiation (1)
- nonlinear dynamics (1)
- nonlinear optics (1)
- nonlinear time series analysis (1)
- northern peatlands (1)
- numerical astrophysics (1)
- numerical relativity (1)
- numerische Astrophysik (1)
- numerische Relativitätstheorie (1)
- nördliche Moore (1)
- obesity (1)
- objective health measures (1)
- offene Daten (1)
- open data (1)
- optical properties (1)
- optische Eigenschaften (1)
- optode (1)
- organic matter (1)
- organic-inorganic hybrids (1)
- organisch-anorganische Hybride (1)
- organische Bodensubstanz (1)
- organisches Material (1)
- ortsverteile faseroptische Dehnungsmessung (1)
- oscillating bubble (1)
- osteuropäisch-jüdische Geschichte (1)
- oxocarbon (1)
- oxygen (1)
- p-type ATPase (1)
- paleolimnology (1)
- paraconsistency (1)
- participatory didactics (1)
- patent (1)
- peacebuilding (1)
- peatland core microbiome (1)
- peatland development (1)
- peptide (1)
- peptide synthesis (1)
- peptide-polymer conjugate (1)
- peptides (1)
- periglacial landscape evolution (1)
- periglacial landscapes (1)
- periglaziale Landschaften (1)
- periglaziale Landschaftsentwicklung (1)
- permafrost (1)
- permafrost degradation (1)
- permafrost ecosystems (1)
- permafrost sediments (1)
- perovskite solar cells (1)
- personal initiative (1)
- pervasive learning (1)
- petri net (1)
- petrothermales System (EGS) (1)
- phase synchronization (1)
- photochemical reactions (1)
- photoinduced electron transfer (1)
- photoresponse (1)
- photosynthesis (1)
- photovoltaic (1)
- physical activity (1)
- physics (1)
- physiology (1)
- plant science (1)
- plateau uplift (1)
- pluvial flooding (1)
- point-of-care (1)
- policy (1)
- political ideology (1)
- political opportunism (1)
- political speech (1)
- pollution (1)
- polymerization (1)
- polyneuropathy (1)
- population density (1)
- population dynamics (1)
- porous materials (1)
- poröse Materialien (1)
- post-depositional (1)
- posterior P600 (1)
- poultry manure (1)
- pragmatics (1)
- predictability (1)
- print culture (1)
- private households (1)
- probabilistic (1)
- probabilistic approach (1)
- probabilistic processing (1)
- probabilistischer Ansatz (1)
- processing (1)
- processing of phonological details (1)
- productivity slowdown (1)
- programmable friction (1)
- promises (1)
- propellers (1)
- property taxes (1)
- proposal writing (1)
- prostaglandin-f2-alpha (1)
- protein (1)
- proteome (1)
- proxy uncertainty (1)
- proxy understanding (1)
- public good (1)
- public universities in Kenya (1)
- pulsed DPSS laser (1)
- quality assurance (1)
- quality assurance in Guinean higher education (1)
- quality assurance structures (1)
- quality culture (1)
- quality evaluation (1)
- quality in higher education (1)
- quasiparticle interactions (1)
- rabbis (1)
- radiative transfer (1)
- reactive transport (1)
- reaktiver Transport (1)
- receptor (1)
- reciprocal processes (1)
- reciprocal relationship (1)
- recombinant inbred line (1)
- reconciliation (1)
- recurrence analysis (1)
- redistribution (1)
- reflective breadth (1)
- reflective depth (1)
- reflective skills (1)
- refugees (1)
- regime shifts (1)
- reionization (1)
- relative clause (1)
- relativistic hydrodynamics (1)
- relativistische Hydrodynamik (1)
- religious education (1)
- religiöse Bildung (1)
- remediation (1)
- removal subsidies (1)
- renewable energy (1)
- renewable energy subsidies (1)
- representative longitudinal survey data (1)
- representative real-time survey data (1)
- resilience (1)
- return level estimation (1)
- returns to education (1)
- revenue recycling (1)
- reversible measure (1)
- rift (1)
- riparian zone (1)
- rising bubble (1)
- risk attitudes (1)
- robot (1)
- rotation (1)
- rural development (1)
- russische Arktis (1)
- räumlich explizit (1)
- räumlich explizites Modell (1)
- räumliche Analyse (1)
- räumliche Autkorrelationsmethode (1)
- räumliche Autokorrelation (1)
- salt melt (1)
- salt melt templating (1)
- salt rock (1)
- sandige Böden (1)
- sandy soils (1)
- saprolite (1)
- scaling (1)
- schema discovery (1)
- school health examinations (1)
- schwarze Löcher (1)
- science (1)
- sea ice (1)
- sea-level rise (1)
- seasonality (1)
- sedimentary record (1)
- segmentation (1)
- seismic noise (1)
- seismisches Rauschen (1)
- selenium (1)
- selenoneine (1)
- self-assembly (1)
- self-employed (1)
- self-healing coatings (1)
- self-organization (1)
- self-rated health (1)
- self-similarity (1)
- selfefficacy (1)
- seltenes und saisonunübliches Hochwasser (1)
- semantic incongruity (1)
- semantics (1)
- senescence (1)
- seston (1)
- sign languages (1)
- signal transition graph (1)
- silica nanoparticles (1)
- silicon (1)
- simulation (1)
- simulation framework (1)
- single-atom catalysis (1)
- single-molecule force spectroscopy (1)
- site characterization (1)
- site effects (1)
- situated learning (1)
- skin penetration (1)
- snow thermal conductivity (1)
- social capital (1)
- social cognition training (1)
- social network (1)
- social networking (1)
- sodium-ion batteries (1)
- soft and hard templating (1)
- soft information (1)
- soil (1)
- soil analysis (1)
- soil organic matter (1)
- solvent-free reactions (1)
- sortagging (1)
- sortaseA (1)
- sorting (1)
- source model (1)
- southern Turkey (1)
- space-time Gibbs field (1)
- spatial analyses (1)
- spatial autocorrelation (1)
- spatially explicit (1)
- species richness (1)
- spectroscopy (1)
- speed independent (1)
- sphäroidische Zwerggalaxien (1)
- spin resolved photoelectron spectroscopy (1)
- spin-orbit coupling (1)
- spinaufgelöste Photoelektronenspektroskopie (1)
- spindown (1)
- spiropyran copolymer (1)
- spoken discourse (1)
- spreadsheets (1)
- squaric acid (1)
- stabile Isotope (1)
- stabile Schichtung (1)
- stability (1)
- stable stratification (1)
- stag-hunt game (1)
- stalagmites (1)
- star-brown dwarf systems (1)
- star-planet interaction (1)
- star-planet systems (1)
- stark eutektisches Lösungsmittel (1)
- stars: distances (1)
- statistical physics (1)
- statistics (1)
- statistische Physik (1)
- steep-angle analysis of PcP (1)
- steigende Blasen (1)
- stellar content (1)
- stellar evolution (1)
- stellar physics (1)
- stellar winds (1)
- stellarer Inhalt (1)
- stimuli (1)
- stochastic bridge (1)
- stocking capacity (1)
- strategic-uncertainty attitudes (1)
- stratification (1)
- stress field (1)
- stress measurement (1)
- strike-slip (1)
- structural and operational changes (1)
- structural geology (1)
- styrene (1)
- subduction (1)
- subjective survival probability (1)
- subsidence history (1)
- supercritical carbon dioxide (scCO₂) (1)
- supernova remnants (1)
- surface chemistry (1)
- surface processes (1)
- surface rheology (1)
- surface states (1)
- surfactants (1)
- survey (1)
- sustainable development (1)
- sustainable energy storage materials (1)
- sustainable industrial development (1)
- sustainable supply chain management (1)
- switchSENSE (1)
- switchSENSE Technologie (1)
- symplectic methods (1)
- synchrotron radiation (1)
- systems biology (1)
- sättigbarer Absorber (1)
- tacrolimus formulation (1)
- tandem solar cell (1)
- tax competition (1)
- taxpayer subsidies (1)
- teacher (1)
- teacher education (1)
- teacher training (1)
- teaching material (1)
- tectonics (1)
- temperature proxy (1)
- temperature variability (1)
- terms-of-trade effects (1)
- terrestrial water storage variation (1)
- test items (1)
- thermoelectricity (1)
- thermokarst processes (1)
- theta (1)
- thin films (1)
- thioester (1)
- tidal interactions (1)
- tillage (1)
- time reversal (1)
- time reversal symmetry (1)
- tone languages (1)
- topics (1)
- topography (1)
- topological insulators (1)
- topologische Isolatoren (1)
- top– down (1)
- trace gas fluxes (1)
- trade (1)
- training for sustainability (1)
- training programme (1)
- transatlantic history (1)
- transatlantische Geschichte (1)
- transcription factor (1)
- transdisciplinary (1)
- transformation (1)
- transformation products (1)
- transformative justice (1)
- transition economy (1)
- transition metals (1)
- transitional justice (1)
- trapping (1)
- travel (1)
- treatment effects (1)
- triazine (1)
- tug-of-war (1)
- turbulence (1)
- turbulence parameterizations (1)
- two-dimensional (1)
- typology (1)
- ultra-high energy cosmic rays (1)
- ultra-low velocity zones (1)
- ultrafast (1)
- ultrahochenergetische kosmische Strahlung (1)
- ultraschnell (1)
- uncertainty analysis (1)
- unemployment (1)
- unilateral climate policy (1)
- university leadership in Malaysia (1)
- university management (1)
- urban (1)
- urban growth (1)
- vegetation (1)
- vegetation model (1)
- velocity model (1)
- verbal irony (1)
- verbale Ironie (1)
- verbesserte geothermische Systeme (1)
- vertikaler Fluss (1)
- veterinary drugs (1)
- video analysis (1)
- vocational education (1)
- volcanic tremor (1)
- volcano deformation (1)
- volcanology (1)
- voting (1)
- voucher (1)
- vulkanischer Tremor (1)
- water balance (1)
- water rock interactions (1)
- wealth (1)
- weathering feedback (1)
- weiche und harte Templatierung (1)
- welfare and gender regimes (1)
- wh-ex-situ (1)
- wh-in-situ (1)
- wh-questions (1)
- wide-angle x-ray scattering (1)
- wind erosion (1)
- wind gusts (1)
- winderosion (1)
- windfall gains (1)
- winkelaufgelöste Photoelektronenspektroskopie (1)
- zentral-östliches Beringia (1)
- zentralen Anden (1)
- zinc (1)
- µCT (1)
- Änderungen des Hochwassers (1)
- Ätna (1)
- Ökotoxikologie (1)
- Übergangsjustiz (1)
- Übergangsmetalle (1)
- Überschwemmungen (1)
- Þeistareykir Iceland (1)
- Þeistareykir Island (1)
- ökologisches Upgrading (1)
- ökonomische Auswirkungen (1)
- überkritisches Kohlendioxid (scCO₂) (1)
Institute
- Extern (486) (remove)
The large literature that aims to find evidence of climate migration delivers mixed findings. This meta-regression analysis i) summarizes direct links between adverse climatic events and migration, ii) maps patterns of climate migration, and iii) explains the variation in outcomes. Using a set of limited dependent variable models, we meta-analyze thus-far the most comprehensive sample of 3,625 estimates from 116 original studies and produce novel insights on climate migration. We find that extremely high temperatures and drying conditions increase migration. We do not find a significant effect of sudden-onset events. Climate migration is most likely to emerge due to contemporaneous events, to originate in rural areas and to take place in middle-income countries, internally, to cities. The likelihood to become trapped in affected areas is higher for women and in low-income countries, particularly in Africa. We uniquely quantify how pitfalls typical for the broader empirical climate impact literature affect climate migration findings. We also find evidence of different publication biases.
Biofilms are complex living materials that form as bacteria get embedded in a matrix of self-produced protein and polysaccharide fibres. The formation of a network of extracellular biopolymer fibres contributes to the cohesion of the biofilm by promoting cell-cell attachment and by mediating biofilm-substrate interactions. This sessile mode of bacteria growth has been well studied by microbiologists to prevent the detrimental effects of biofilms in medical and industrial settings. Indeed, biofilms are associated with increased antibiotic resistance in bacterial infections, and they can also cause clogging of pipelines or promote bio-corrosion. However, biofilms also gained interest from biophysics due to their ability to form complex morphological patterns during growth. Recently, the emerging field of engineered living materials investigates biofilm mechanical properties at multiple length scales and leverages the tools of synthetic biology to tune the functions of their constitutive biopolymers.
This doctoral thesis aims at clarifying how the morphogenesis of Escherichia coli (E. coli) biofilms is influenced by their growth dynamics and mechanical properties. To address this question, I used methods from cell mechanics and materials science. I first studied how biological activity in biofilms gives rise to non-uniform growth patterns. In a second study, I investigated how E. coli biofilm morphogenesis and its mechanical properties adapt to an environmental stimulus, namely the water content of their substrate. Finally, I estimated how the mechanical properties of E. coli biofilms are altered when the bacteria express different extracellular biopolymers.
On nutritive hydrogels, micron-sized E. coli cells can build centimetre-large biofilms. During this process, bacterial proliferation and matrix production introduce mechanical stresses in the biofilm, which release through the formation of macroscopic wrinkles and delaminated buckles. To relate these biological and mechanical phenomena, I used time-lapse fluorescence imaging to track cell and matrix surface densities through the early and late stages of E. coli biofilm growth. Colocalization of high cell and matrix densities at the periphery precede the onset of mechanical instabilities at this annular region. Early growth is detected at this outer annulus, which was analysed by adding fluorescent microspheres to the bacterial inoculum. But only when high rates of matrix production are present in the biofilm centre, does overall biofilm spreading initiate along the solid-air interface. By tracking larger fluorescent particles for a long time, I could distinguish several kinematic stages of E. coli biofilm expansion and observed a transition from non-linear to linear velocity profiles, which precedes the emergence of wrinkles at the biofilm periphery. Decomposing particle velocities to their radial and circumferential components revealed a last kinematic stage, where biofilm movement is mostly directed towards the radial delaminated buckles, which verticalize. The resulting compressive strains computed in these regions were observed to substantially deform the underlying agar substrates. The co-localization of higher cell and matrix densities towards an annular region and the succession of several kinematic stages are thus expected to promote the emergence of mechanical instabilities at the biofilm periphery. These experimental findings are predicted to advance future modelling approaches of biofilm morphogenesis.
E. coli biofilm morphogenesis is further anticipated to depend on external stimuli from the environment. To clarify how the water could be used to tune biofilm material properties, we quantified E. coli biofilm growth, wrinkling dynamics and rigidity as a function of the water content of the nutritive substrates. Time-lapse microscopy and computational image analysis revealed that substrates with high water content promote biofilm spreading kinetics, while substrates with low water content promote biofilm wrinkling. The wrinkles observed on biofilm cross-sections appeared more bent on substrates with high water content, while they tended to be more vertical on substrates with low water content. Both wet and dry biomass, accumulated over 4 days of culture, were larger in biofilms cultured on substrates with high water content, despite extra porosity within the matrix layer. Finally, the micro-indentation analysis revealed that substrates with low water content supported the formation of stiffer biofilms. This study shows that E. coli biofilms respond to the water content of their substrate, which might be used for tuning their material properties in view of further applications.
Biofilm material properties further depend on the composition and structure of the matrix of extracellular proteins and polysaccharides. In particular, E. coli biofilms were suggested to present tissue-like elasticity due to a dense fibre network consisting of amyloid curli and phosphoethanolamine-modified cellulose. To understand the contribution of these components to the emergent mechanical properties of E. coli biofilms, we performed micro-indentation on biofilms grown from bacteria of several strains. Besides showing higher dry masses, larger spreading diameters and slightly reduced water contents, biofilms expressing both main matrix components also presented high rigidities in the range of several hundred kPa, similar to biofilms containing only curli fibres. In contrast, a lack of amyloid curli fibres provides much higher adhesive energies and more viscoelastic fluid-like material behaviour. Therefore, the combination of amyloid curli and phosphoethanolamine-modified cellulose fibres implies the formation of a composite material whereby the amyloid curli fibres provide rigidity to E. coli biofilms, whereas the phosphoethanolamine-modified cellulose rather acts as a glue. These findings motivate further studies involving purified versions of these protein and polysaccharide components to better understand how their interactions benefit biofilm functions.
All three studies depict different aspects of biofilm morphogenesis, which are interrelated. The first work reveals the correlation between non-uniform biological activities and the emergence of mechanical instabilities in the biofilm. The second work acknowledges the adaptive nature of E. coli biofilm morphogenesis and its mechanical properties to an environmental stimulus, namely water. Finally, the last study reveals the complementary role of the individual matrix components in the formation of a stable biofilm material, which not only forms complex morphologies but also functions as a protective shield for the bacteria it contains. Our experimental findings on E. coli biofilm morphogenesis and their mechanical properties can have further implications for fundamental and applied biofilm research fields.
In this talk, I would like to share my experiences gained from participating in four CSP solver competitions and the second ASP solver competition. In particular, I’ll talk about how various programming techniques can make huge differences in solving some of the benchmark problems used in the competitions. These techniques include global constraints, table constraints, and problem-specific propagators and labeling strategies for selecting variables and values. I’ll present these techniques with experimental results from B-Prolog and other CLP(FD) systems.
In the present thesis I investigate the lattice dynamics of thin film hetero structures of magnetically ordered materials upon femtosecond laser excitation as a probing and manipulation scheme for the spin system. The quantitative assessment of laser induced thermal dynamics as well as generated picosecond acoustic pulses and their respective impact on the magnetization dynamics of thin films is a challenging endeavor. All the more, the development and implementation of effective experimental tools and comprehensive models are paramount to propel future academic and technological progress.
In all experiments in the scope of this cumulative dissertation, I examine the crystal lattice of nanoscale thin films upon the excitation with femtosecond laser pulses. The relative change of the lattice constant due to thermal expansion or picosecond strain pulses is directly monitored by an ultrafast X-ray diffraction (UXRD) setup with a femtosecond laser-driven plasma X-ray source (PXS). Phonons and spins alike exert stress on the lattice, which responds according to the elastic properties of the material, rendering the lattice a versatile sensor for all sorts of ultrafast interactions. On the one hand, I investigate materials with strong magneto-elastic properties; The highly magnetostrictive rare-earth compound TbFe2, elemental Dysprosium or the technological relevant Invar material FePt. On the other hand I conduct a comprehensive study on the lattice dynamics of Bi1Y2Fe5O12 (Bi:YIG), which exhibits high-frequency coherent spin dynamics upon femtosecond laser excitation according to the literature. Higher order standing spinwaves (SSWs) are triggered by coherent and incoherent motion of atoms, in other words phonons, which I quantified with UXRD. We are able to unite the experimental observations of the lattice and magnetization dynamics qualitatively and quantitatively. This is done with a combination of multi-temperature, elastic, magneto-elastic, anisotropy and micro-magnetic modeling.
The collective data from UXRD, to probe the lattice, and time-resolved magneto-optical Kerr effect (tr-MOKE) measurements, to monitor the magnetization, were previously collected at different experimental setups. To improve the precision of the quantitative assessment of lattice and magnetization dynamics alike, our group implemented a combination of UXRD and tr-MOKE in a singular experimental setup, which is to my knowledge, the first of its kind. I helped with the conception and commissioning of this novel experimental station, which allows the simultaneous observation of lattice and magnetization dynamics on an ultrafast timescale under identical excitation conditions. Furthermore, I developed a new X-ray diffraction measurement routine which significantly reduces the measurement time of UXRD experiments by up to an order of magnitude. It is called reciprocal space slicing (RSS) and utilizes an area detector to monitor the angular motion of X-ray diffraction peaks, which is associated with lattice constant changes, without a time-consuming scan of the diffraction angles with the goniometer. RSS is particularly useful for ultrafast diffraction experiments, since measurement time at large scale facilities like synchrotrons and free electron lasers is a scarce and expensive resource. However, RSS is not limited to ultrafast experiments and can even be extended to other diffraction techniques with neutrons or electrons.
The Greenland Ice Sheet is the second-largest mass of ice on Earth. Being almost 2000 km long, more than 700 km wide, and more than 3 km thick at the summit, it holds enough ice to raise global sea levels by 7m if melted completely. Despite its massive size, it is particularly vulnerable to anthropogenic climate change: temperatures over the Greenland Ice Sheet have increased by more than 2.7◦C in the past 30 years, twice as much as the global mean temperature. Consequently, the ice sheet has been significantly losing mass since the 1980s and the rate of loss has increased sixfold since then. Moreover, it is one of the potential tipping elements of the Earth System, which might undergo irreversible change once a warming threshold is exceeded. This thesis aims at extending the understanding of the resilience of the Greenland Ice Sheet against global warming by analyzing processes and feedbacks relevant to its centennial to multi-millennial stability using ice sheet modeling.
One of these feedbacks, the melt-elevation-feedback is driven by the temperature rise with decreasing altitudes: As the ice sheet melts, its thickness and surface elevation decrease, exposing the ice surface to warmer air and thus increasing the melt rates even further. The glacial isostatic adjustment (GIA) can partly mitigate this melt-elevation feedback as the bedrock lifts in response to an ice load decrease, forming the negative GIA feedback. In my thesis, I show that the interaction between these two competing feedbacks can lead to qualitatively different dynamical responses of the Greenland Ice Sheet to warming – from permanent loss to incomplete recovery, depending on the feedback parameters. My research shows that the interaction of those feedbacks can initiate self-sustained oscillations of the ice volume while the climate forcing remains constant.
Furthermore, the increased surface melt changes the optical properties of the snow or ice surface, e.g. by lowering their albedo, which in turn enhances melt rates – a process known as the melt-albedo feedback. Process-based ice sheet models often neglect this melt-albedo feedback. To close this gap, I implemented a simplified version of the diurnal Energy Balance Model, a computationally efficient approach that can capture the first-order effects of the melt-albedo feedback, into the Parallel Ice Sheet Model (PISM). Using the coupled model, I show in warming experiments that the melt-albedo feedback almost doubles the ice loss until the year 2300 under the low greenhouse gas emission scenario RCP2.6, compared to simulations where the melt-albedo feedback is neglected,
and adds up to 58% additional ice loss under the high emission scenario RCP8.5. Moreover, I find that the melt-albedo feedback dominates the ice loss until 2300, compared to the melt-elevation feedback.
Another process that could influence the resilience of the Greenland Ice Sheet is the warming induced softening of the ice and the resulting increase in flow. In my thesis, I show with PISM how the uncertainty in Glen’s flow law impacts the simulated response to warming. In a flow line setup at fixed climatic mass balance, the uncertainty in flow parameters leads to a range of ice loss comparable to the range caused by different warming levels.
While I focus on fundamental processes, feedbacks, and their interactions in the first three projects of my thesis, I also explore the impact of specific climate scenarios on the sea level rise contribution of the Greenland Ice Sheet. To increase the carbon budget flexibility, some warming scenarios – while still staying within the limits of the Paris Agreement – include a temporal overshoot of global warming. I show that an overshoot by 0.4◦C increases the short-term and long-term ice loss from Greenland by several centimeters. The long-term increase is driven by the warming at high latitudes, which persists even when global warming is reversed. This leads to a substantial long-term commitment of the sea level rise contribution from the Greenland Ice Sheet.
Overall, in my thesis I show that the melt-albedo feedback is most relevant for the ice loss of the Greenland Ice Sheet on centennial timescales. In contrast, the melt-elevation feedback and its interplay with the GIA feedback become increasingly relevant on millennial timescales. All of these influence the resilience of the Greenland Ice Sheet against global warming, in the near future and on the long term.
Integration of digital elevation models and satellite images to investigate geological processes.
(2006)
In order to better understand the geological boundary conditions for ongoing or past surface processes geologists face two important questions: 1) How can we gain additional knowledge about geological processes by analyzing digital elevation models (DEM) and satellite images and 2) Do these efforts present a viable approach for more efficient research. Here, we will present case studies at a variety of scales and levels of resolution to illustrate how we can substantially complement and enhance classical geological approaches with remote sensing techniques. Commonly, satellite and DEM based studies are being used in a first step of assessing areas of geologic interest. While in the past the analysis of satellite imagery (e.g. Landsat TM) and aerial photographs was carried out to characterize the regional geologic characteristics, particularly structure and lithology, geologists have increasingly ventured into a process-oriented approach. This entails assessing structures and geomorphic features with a concept that includes active tectonics or tectonic activity on time scales relevant to humans. In addition, these efforts involve analyzing and quantifying the processes acting at the surface by integrating different remote sensing and topographic data (e.g. SRTM-DEM, SSM/I, GPS, Landsat 7 ETM, Aster, Ikonos…). A combined structural and geomorphic study in the hyperarid Atacama desert demonstrates the use of satellite and digital elevation data for assessing geological structures formed by long-term (millions of years) feedback mechanisms between erosion and crustal bending (Zeilinger et al., 2005). The medium-term change of landscapes during hundred thousands to millions years in a more humid setting is shown in an example from southern Chile. Based on an analysis of rivers/watersheds combined with landscapes parameterization by using digital elevation models, the geomorphic evolution and change in drainage pattern in the coastal Cordillera can be quantified and put into the context of seismotectonic segmentation of a tectonically active region. This has far-reaching implications for earthquake rupture scenarios and hazard mitigation (K. Rehak, see poster on IMAF Workshop). Two examples illustrate short-term processes on decadal, centennial and millennial time scales: One study uses orogen scale precipitation gradients derived from remotely sensed passive microwave data (Bookhagen et al., 2005a). They demonstrate how debris flows were triggered as a response of slopes to abnormally strong rainfall in the interior parts of the Himalaya during intensified monsoons. The area of the orogen that receives high amounts of precipitation during intensified monsoons also constitutes numerous landslide deposits of up to 1km<sup>3 volume that were generated during intensified monsoon phase at about 27 and 9 ka (Bookhagen et al., 2005b). Another project in the Swiss Alps compared sets of aerial photographs recorded in different years. By calculating high resolution surfaces the mass transport in a landslide could be reconstructed (M. Schwab, Universität Bern). All these examples, although representing only a short and limited selection of projects using remote sense data in geology, have as a common approach the goal to quantify geological processes. With increasing data resolution and new sensors future projects will even enable us to recognize more patterns and / or structures indicative of geological processes in tectonically active areas. This is crucial for the analysis of natural hazards like earthquakes, tsunamis and landslides, as well as those hazards that are related to climatic variability. The integration of remotely sensed data at different spatial and temporal scales with field observations becomes increasingly important. Many of presently highly populated places and increasingly utilized regions are subject to significant environmental pressure and often constitute areas of concentrated economic value. Combined remote sensing and ground-truthing in these regions is particularly important as geologic, seismicity and hydrologic data may be limited here due to the recency of infrastructural development. Monitoring ongoing processes and evaluating the remotely sensed data in terms of recurrence of events will greatly enhance our ability to assess and mitigate natural hazards. <hr> Dokument 1: Foliensatz | Dokument 2: Abstract <hr> Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
In this paper, we present a finite-state approach to constituency and therewith an analysis of coordination phenomena involving so-called non-constituents. We show that non-constituents can be seen as parts of fully-fledged constituents and therefore be coordinated in the same way. We have implemented an algorithm based on finite state automata that generates an LFG grammar assigning valid analyses to non-constituent coordination structures in the German language.
Nested complementation plays an important role in expressing counter- i.e. star-free and first-order definable languages and their hierarchies. In addition, methods that compile phonological rules into finite-state networks use double-nested complementation or “double negation”. This paper reviews how the double-nested complementation extends to a relatively new operation, generalized restriction (GR), coined by the author (Yli-Jyrä and Koskenniemi 2004). This operation encapsulates a double-nested complementation and elimination of a concatenation marker, diamond, whose finite occurrences align concatenations in the arguments of the operation. The paper demonstrates that the GR operation has an interesting potential in expressing regular languages, various kinds of grammars, bimorphisms and relations. This motivates a further study of optimized implementation of the operator.
Generalized Two-Level Grammar (GTWOL) provides a new method for compilation of parallel replacement rules into transducers. The current paper identifies the role of generalized lenient composition (GLC) in this method. Thanks to the GLC operation, the compilation method becomes bipartite and easily extendible to capture various application modes. In the light of three notions of obligatoriness, a modification to the compilation method is proposed. We argue that the bipartite design makes implementation of parallel obligatoriness, directionality, length and rank based application modes extremely easy, which is the main result of the paper.
Inverted perovskite solar cells still suffer from significant non-radiative recombination losses at the perovskite surface and across the perovskite/C₆₀ interface, limiting the future development of perovskite-based single- and multi-junction photovoltaics. Therefore, more effective inter- or transport layers are urgently required. To tackle these recombination losses, we introduce ortho-carborane as an interlayer material that has a spherical molecular structure and a three-dimensional aromaticity. Based on a variety of experimental techniques, we show that ortho-carborane decorated with phenylamino groups effectively passivates the perovskite surface and essentially eliminates the non-radiative recombination loss across the perovskite/C₆₀ interface with high thermal stability. We further demonstrate the potential of carborane as an electron transport material, facilitating electron extraction while blocking holes from the interface. The resulting inverted perovskite solar cells deliver a power conversion efficiency of over 23% with a low non-radiative voltage loss of 110 mV, and retain >97% of the initial efficiency after 400 h of maximum power point tracking. Overall, the designed carborane based interlayer simultaneously enables passivation, electron-transport and hole-blocking and paves the way toward more efficient and stable perovskite solar cells.
We analyze anaphoric phenomena in the context of building an input understanding component for a conversational system for tutoring mathematics. In this paper, we report the results of data analysis of two sets of corpora of dialogs on mathematical theorem proving. We exemplify anaphoric phenomena, identify factors relevant to anaphora resolution in our domain and extensions to the input interpretation component to support it.
Basaltic fissure eruptions, such as on Hawai'i or on Iceland, are thought to be driven by the lateral propagation of feeder dikes and graben subsidence. Associated solid earth processes, such as deformation and structural development, are well studied by means of geophysical and geodetic technologies. The eruptions themselves, lava fountaining and venting dynamics, in turn, have been much less investigated due to hazardous access, local dimension, fast processes, and resulting poor data availability.
This thesis provides a detailed quantitative understanding of the shape and dynamics of lava fountains and the morphological changes at their respective eruption sites. For this purpose, I apply image processing techniques, including drones and fixed installed cameras, to the sequence of frames of video records from two well-known fissure eruptions in Hawai'i and Iceland. This way I extract the dimensions of multiple lava fountains, visible in all frames. By putting these results together and considering the acquisition times of the frames I quantify the variations in height, width and eruption velocity of the lava fountains. Then I analyse these time-series in both time and frequency domains and investigate the similarities and correlations between adjacent lava fountains. Following this procedure, I am able to link the dynamics of the individual lava fountains to physical parameters of the magma transport in the feeder dyke of the fountains.
The first case study in this thesis focuses on the March 2011 Pu'u'O'o eruption, Hawai'i, where a continuous pulsating behaviour at all eight lava fountains has been observed. The lava fountains, even those from different parts of the fissure that are closely connected, show a similar frequency content and eruption behaviour. The regular pattern in the heights of lava fountain suggests a controlling process within the magma feeder system like a hydraulic connection in the underlying dyke, affecting or even controlling the pulsating behaviour.
The second case study addresses the 2014-2015 Holuhraun fissure eruption, Iceland. In this case, the feeder dyke is highlighted by the surface expressions of graben-like structures and fault systems. At the eruption site, the activity decreases from a continuous line of fire of ~60 vents to a limited number of lava fountains. This can be explained by preferred upwards magma movements through vertical structures of the pre-eruptive morphology. Seismic tremors during the eruption reveal vent opening at the surface and/or pressure changes in the feeder dyke. The evolving topography of the cinder cones during the eruption interacts with the lava fountain behaviour. Local variations in the lava fountain height and width are controlled by the conduit diameter, the depth of the lava pond and the shape of the crater. Modelling of the fountain heights shows that long-term eruption behaviour is controlled mainly by pressure changes in the feeder dyke.
This research consists of six chapters with four papers, including two first author and two co-author papers. It establishes a new method to analyse lava fountain dynamics by video monitoring. The comparison with the seismicity, geomorphologic and structural expressions of fissure eruptions shows a complex relationship between focussed flow through dykes, the morphology of the cinder cones, and the lava fountain dynamics at the vents of a fissure eruption.
We have used techniques of nonlinear dynamics to compare a special model for the reversals of the Earth's magnetic field with the observational data. Although this model is rather simple, there is no essential difference to the data by means of well-known characteristics, such as correlation function and probability distribution. Applying methods of symbolic dynamics we have found that the considered model is not able to describe the dynamical properties of the observed process. These significant differences are expressed by algorithmic complexity and Renyi information.
Multiple hierarchies
(2005)
In this paper, we present the Multiple Annotation approach, which solves two problems: the problem of annotating overlapping structures, and the problem that occurs when documents should be annotated according to different, possibly heterogeneous tag sets. This approach has many advantages: it is based on XML, the modeling of alternative annotations is possible, each level can be viewed separately, and new levels can be added at any time. The files can be regarded as an interrelated unit, with the text serving as the implicit link. Two representations of the information contained in the multiple files (one in Prolog and one in XML) are described. These representations serve as a base for several applications.
STG decomposition is a promising approach to tackle the complexity problems arising in logic synthesis of speed independent circuits, a robust asynchronous (i.e. clockless) circuit type. Unfortunately, STG decomposition can result in components that in isolation have irreducible CSC conflicts. Generalising earlier work, it is shown how to resolve such conflicts by introducing internal communication between the components via structural techniques only.
Spatial and temporal temperature and moisture patterns across the Tibetan Plateau are very complex. The onset and magnitude of the Holocene climate optimum in the Asian monsoon realm, in particular, is a subject of considerable debate as this time period is often used as an analogue for recent global warming. In the light of contradictory inferences regarding past climate and environmental change on the Tibetan Plateau, I have attempted to explain mismatches in the timing and magnitude of change. Therefore, I analysed the temporal variation of fossil pollen and diatom spectra and the geochemical record from palaeo-ecological records covering different time scales (late Quaternary and the last 200 years) from two core regions in the NE and SE Tibetan Plateau. For interpretation purposes I combined my data with other available palaeo-ecological data to set up corresponding aquatic and terrestrial proxy data sets of two lake pairs and two sets of sites. I focused on the direct comparison of proxies representing lacustrine response to climate signals (e.g., diatoms, ostracods, geochemical record) and proxies representing changes in the terrestrial environment (i.e., terrestrial pollen), in order to asses whether the lake and its catchments respond at similar times and magnitudes to environmental changes. Therefore, I introduced the established numerical technique procrustes rotation as a new approach in palaeoecology to quantitatively compare raw data of any two sedimentary records of interest in order to assess their degree of concordance. Focusing on the late Quaternary, sediment cores from two lakes (Kuhai Lake 35.3°N; 99.2°E; 4150 m asl; and Koucha Lake 34.0°N; 97.2°E; 4540 m asl) on the semi-arid northeastern Tibetan Plateau were analysed to identify post-glacial vegetation and environmental changes, and to investigate the responses of lake ecosystems to such changes. Based on the pollen record, five major vegetation and climate changes could be identified: (1) A shift from alpine desert to alpine steppe indicates a change from cold, dry conditions to warmer and more moist conditions at 14.8 cal. ka BP, (2) alpine steppe with tundra elements points to conditions of higher effective moisture and a stepwise warming climate at 13.6 cal. ka BP, (3) the appearance of high-alpine meadow vegetation indicates a further change towards increased moisture, but with colder temperatures, at 7.0 cal. ka BP, (4) the reoccurrence of alpine steppe with desert elements suggests a return to a significantly colder and drier phase at 6.3 cal. ka BP, and (5) the establishment of alpine steppe-meadow vegetation indicates a change back to relatively moist conditions at 2.2 cal. ka BP. To place the reconstructed climate inferences from the NE Tibetan Plateau into the context of Holocene moisture evolution across the Tibetan Plateau, I applied a five-scale moisture index and average link clustering to all available continuous pollen and non-pollen palaeoclimate records from the Tibetan Plateau, in an attempt to detect coherent regional and temporal patterns of moisture evolution on the Plateau. However, no common temporal or spatial pattern of moisture evolution during the Holocene could be detected, which can be assigned to the complex responses of different proxies to environmental changes in an already very heterogeneous mountain landscape, where minor differences in elevation can result in marked variations in microenvironments. Focusing on the past 200 years, I analysed the sedimentary records (LC6 Lake 29.5°N, 94.3°E, 4132 m asl; and Wuxu Lake 29.9°N, 101.1°E, 3705 m asl) from the southeastern Tibetan Plateau. I found that despite presumed significant temperature increases over that period, pollen and diatom records from the SE Tibetan Plateau reveal only very subtle changes throughout their profiles. The compositional species turnover investigated over the last 200 years appears relatively low in comparison to the species reorganisations during the Holocene. The results indicate that climatically induced ecological thresholds are not yet crossed, but that human activity has an increasing influence, particularly on the terrestrial ecosystem. Forest clearances and reforestation have not caused forest decline in our study area, but a conversion of natural forests to semi-natural secondary forests. The results from the numerical proxy comparison of the two sets of two pairs of Tibetan lakes indicate that the use of different proxies and the work with palaeo-ecological records from different lake types can cause deviant stories of inferred change. Irrespective of the timescale (Holocene or last 200 years) or region (SE or NE Tibetan Plateau) analysed, the agreement in terms of the direction, timing, and magnitude of change between the corresponding terrestrial data sets is generally better than the match between the corresponding lacustrine data sets, suggesting that lacustrine proxies may partly be influenced by in-lake or local catchment processes whereas the terrestrial proxy reflects a more regional climatic signal. The current disaccord on coherent temporal and spatial climate patterns on the Tibetan Plateau can partly be ascribed to the complexity of proxy response and lake systems on the Tibetan Plateau. Therefore, a multi-proxy, multi-site approach is important in order to gain a reliable climate interpretation for the complex mountain landscape of the Tibetan Plateau.
With Arctic ground as a huge and temperature-sensitive carbon reservoir, maintaining low ground temperatures and frozen conditions to prevent further carbon emissions that contrib-ute to global climate warming is a key element in humankind’s fight to maintain habitable con-ditions on earth. Former studies showed that during the late Pleistocene, Arctic ground condi-tions were generally colder and more stable as the result of an ecosystem dominated by large herbivorous mammals and vast extents of graminoid vegetation – the mammoth steppe. Characterised by high plant productivity (grassland) and low ground insulation due to animal-caused compression and removal of snow, this ecosystem enabled deep permafrost aggrad-ation. Now, with tundra and shrub vegetation common in the terrestrial Arctic, these effects are not in place anymore. However, it appears to be possible to recreate this ecosystem local-ly by artificially increasing animal numbers, and hence keep Arctic ground cold to reduce or-ganic matter decomposition and carbon release into the atmosphere.
By measuring thaw depth, total organic carbon and total nitrogen content, stable carbon iso-tope ratio, radiocarbon age, n-alkane and alcohol characteristics and assessing dominant vegetation types along grazing intensity transects in two contrasting Arctic areas, it was found that recreating conditions locally, similar to the mammoth steppe, seems to be possible. For permafrost-affected soil, it was shown that intensive grazing in direct comparison to non-grazed areas reduces active layer depth and leads to higher TOC contents in the active layer soil. For soil only frozen on top in winter, an increase of TOC with grazing intensity could not be found, most likely because of confounding factors such as vertical water and carbon movement, which is not possible with an impermeable layer in permafrost. In both areas, high animal activity led to a vegetation transformation towards species-poor graminoid-dominated landscapes with less shrubs. Lipid biomarker analysis revealed that, even though the available organic material is different between the study areas, in both permafrost-affected and sea-sonally frozen soils the organic material in sites affected by high animal activity was less de-composed than under less intensive grazing pressure. In conclusion, high animal activity af-fects decomposition processes in Arctic soils and the ground thermal regime, visible from reduced active layer depth in permafrost areas. Therefore, grazing management might be utilised to locally stabilise permafrost and reduce Arctic carbon emissions in the future, but is likely not scalable to the entire permafrost region.
The optical density of human macular pigment was measured for 50 observers ranging in age from 10 to 90 years. The psychophysical method required adjusting the radiance of a 1°, monochromatic light (400–550 nm) to minimize flicker (15 Hz) when presented in counterphase with a 460 nm standard. This test stimulus was presented superimposed on a broad-band, short-wave background. Macular pigment density was determined by comparing sensitivity under these conditions for the fovea, where macular pigment is maximal, and 5° temporally. This difference spectrum, measured for 12 observers, matched Wyszecki and Stiles's standard density spectrum for macular pigment. To study variation in macular pigment density for a larger group of observers, measurements were made at only selected spectral points (460, 500 and 550 nm). The mean optical density at 460 nm for the complete sample of 50 subjects was 0.39. Substantial individual differences in density were found (ca. 0.10–0.80), but this variation was not systematically related to age.
The spectral efficiency of blackness induction was measured in three normal trichromatic observers and in one deuteranomalous observer. The psychophysical task was to adjust the radiance of a monochromatic 60–120′ annulus until a 45′ central broadband field just turned black and its contour became indiscriminable from a dark surrounding gap that separated it from the annulus. The reciprocal of the radiance required to induce blackness with annulus wavelengths between 420 and 680 nm was used to define a spectral-efficiency function for the blackness component of the achromatic process. For each observer, the shape of this blackness-sensitivity function agreed with the spectral-efficiency function based on heterochromatic flicker photometry when measured with the same 60–120′ annulus. Both of these functions matched the Commission Internationale de l'Eclairage Vλ function except at short wavelengths. Ancillary measurements showed that the latter difference in sensitivity can be ascribed to nonuniformities of preretinal absorption, since the annular field excluded the central 60′ of the fovea. Thus our evidence indicates that, at least to a good first approximation, induced blackness is inversely related to the spectral-luminosity function. These findings are consistent with a model that separates the achromatic and the chromatic pathways.
Cosmic rays (CRs) constitute an important component of the interstellar medium (ISM) of galaxies and are thought to play an essential role in governing their evolution. In particular, they are able to impact the dynamics of a galaxy by driving galactic outflows or heating the ISM and thereby affecting the efficiency of star-formation. Hence, in order to understand galaxy formation and evolution, we need to accurately model this non-thermal constituent of the ISM. But except in our local environment within the Milky Way, we do not have the ability to measure CRs directly in other galaxies. However, there are many ways to indirectly observe CRs via the radiation they emit due to their interaction with magnetic and interstellar radiation fields as well as with the ISM.
In this work, I develop a numerical framework to calculate the spectral distribution of CRs in simulations of isolated galaxies where a steady-state between injection and cooling is assumed. Furthermore, I calculate the non-thermal emission processes arising from the modelled CR proton and electron spectra ranging from radio wavelengths up to the very high-energy gamma-ray regime.
I apply this code to a number of high-resolution magneto-hydrodynamical (MHD) simulations of isolated galaxies, where CRs are included. This allows me to study their CR spectra and compare them to observations of the CR proton and electron spectra by the Voyager-1 satellite and the AMS-02 instrument in order to reveal the origin of the measured spectral features.
Furthermore, I provide detailed emission maps, luminosities and spectra of the non-thermal emission from our simulated galaxies that range from dwarfs to Milk-Way analogues to starburst galaxies at different evolutionary stages. I successfully reproduce the observed relations between the radio and gamma-ray luminosities with the far-infrared (FIR) emission of star-forming (SF) galaxies, respectively, where the latter is a good tracer of the star-formation rate. I find that highly SF galaxies are close to the limit where their CR population would lose all of their energy due to the emission of radiation, whereas CRs tend to escape low SF galaxies more quickly. On top of that, I investigate the properties of CR transport that are needed in order to match the observed gamma-ray spectra.
Furthermore, I uncover the underlying processes that enable the FIR-radio correlation (FRC) to be maintained even in starburst galaxies and find that thermal free-free-emission naturally explains the observed radio spectra in SF galaxies like M82 and NGC 253 thus solving the riddle of flat radio spectra that have been proposed to contradict the observed tight FRC.
Lastly, I scrutinise the steady-state modelling of the CR proton component by investigating for the first time the influence of spectrally resolved CR transport in MHD simulations on the hadronic gamma-ray emission of SF galaxies revealing new insights into the observational signatures of CR transport both spectrally and spatially.
This paper introduces a novel measure to assess similarity between event hydrographs. It is based on Cross Recurrence Plots and Recurrence Quantification Analysis which have recently gained attention in a range of disciplines when dealing with complex systems. The method attempts to quantify the event runoff dynamics and is based on the time delay embedded phase space representation of discharge hydrographs. A phase space trajectory is reconstructed from the event hydrograph, and pairs of hydrographs are compared to each other based on the distance of their phase space trajectories. Time delay embedding allows considering the multi-dimensional relationships between different points in time within the event. Hence, the temporal succession of discharge values is taken into account, such as the impact of the initial conditions on the runoff event. We provide an introduction to Cross Recurrence Plots and discuss their parameterization. An application example based on flood time series demonstrates how the method can be used to measure the similarity or dissimilarity of events, and how it can be used to detect events with rare runoff dynamics. It is argued that this methods provides a more comprehensive approach to quantify hydrograph similarity compared to conventional hydrological signatures.
The NAC transcription factor (TF) JUNGBRUNNEN1 (JUB1) is an important negative regulator of plant senescence, as well as of gibberellic acid (GA) and brassinosteroid (BR) biosynthesis in Arabidopsis thaliana. Overexpression of JUB1 promotes longevity and enhances tolerance to drought and other abiotic stresses. A similar role of JUB1 has been observed in other plant species, including tomato and banana. Our data show that JUB1 overexpressors (JUB1-OXs) accumulate higher levels of proline than WT plants under control conditions, during the onset of drought stress, and thereafter. We identified that overexpression of JUB1 induces key proline biosynthesis and suppresses key proline degradation genes. Furthermore, bZIP63, the transcription factor involved in proline metabolism, was identified as a novel downstream target of JUB1 by Yeast One-Hybrid (Y1H) analysis and Chromatin immunoprecipitation (ChIP). However, based on Electrophoretic Mobility Shift Assay (EMSA), direct binding of JUB1 to bZIP63 could not be confirmed. Our data indicate that JUB1-OX plants exhibit reduced stomatal conductance under control conditions. However, selective overexpression of JUB1 in guard cells did not improve drought stress tolerance in Arabidopsis. Moreover, the drought-tolerant phenotype of JUB1 overexpressors does not solely depend on the transcriptional control of the DREB2A gene. Thus, our data suggest that JUB1 confers tolerance to drought stress by regulating multiple components. Until today, none of the previous studies on JUB1´s regulatory network focused on identifying protein-protein interactions. We, therefore, performed a yeast two-hybrid screen (Y2H) which identified several protein interactors of JUB1, two of which are the calcium-binding proteins CaM1 and CaM4. Both proteins interact with JUB1 in the nucleus of Arabidopsis protoplasts. Moreover, JUB1 is expressed with CaM1 and CaM4 under the same conditions. Since CaM1.1 and CaM4.1 encode proteins with identical amino acid sequences, all further experiments were performed with constructs involving the CaM4 coding sequence. Our data show that JUB1 harbors multiple CaM-binding sites, which are localized in both the N-terminal and C-terminal regions of the protein. One of the CaM-binding sites, localized in the DNA-binding domain of JUB1, was identified as a functional CaM-binding site since its mutation strongly reduced the binding of CaM4 to JUB1. Furthermore, JUB1 transactivates expression of the stress-related gene DREB2A in mesophyll cells; this effect is significantly reduced when the calcium-binding protein CaM4 is expressed as well. Overexpression of both genes in Arabidopsis results in early senescence observed through lower chlorophyll content and an enhanced expression of senescence-associated genes (SAGs) when compared with single JUB1 overexpressors. Our data also show that JUB1 and CaM4 proteins interact in senescent leaves, which have increased Ca2+ levels when compared to young leaves. Collectively, our data indicate that JUB1 activity towards its downstream targets is fine-tuned by calcium-binding proteins during leaf senescence.
Transitional Justice
(2022)
This publication deals with the topic of transitional justice. In six case studies, the authors link theoretical and practical implications in order to develop some innovative approaches. Their proposals might help to deal more effectively with the transition of societies, legal orders and political systems.
Young academics from various backgrounds provide fresh insights and demonstrate the relevance of the topic. The chapters analyse transitions and conflicts in Sierra Leone, Argentina, Nicaragua, Nepal, and South Sudan as well as Germany’s colonial genocide in Namibia. Thus, the book provides the reader with new insights and contributes to the ongoing debate about transitional justice.
Informatics as a school subject has been virtually absent from bilingual education programs in German secondary schools. Most bilingual programs in German secondary education started out by focusing on subjects from the field of social sciences. Teachers and bilingual curriculum experts alike have been regarding those as the most suitable subjects for bilingual instruction – largely due to the intercultural perspective that a bilingual approach provides. And though one cannot deny the gain that ensues from an intercultural perspective on subjects such as history or geography, this benefit is certainly not limited to social science subjects. In consequence, bilingual curriculum designers have already begun to include other subjects such as physics or chemistry in bilingual school programs. It only seems a small step to extend this to informatics. This paper will start out by addressing potential benefits of adding informatics to the range of subjects taught as part of English-language bilingual programs in German secondary education. In a second step it will sketch out a methodological (= didactical) model for teaching informatics to German learners through English. It will then provide two items of hands-on and tested teaching material in accordance with this model. The discussion will conclude with a brief outlook on the chances and prerequisites of firmly establishing informatics as part of bilingual school curricula in Germany.
The most massive stars are those with the shortest but most active life. One group of massive stars, the Luminous Blue Variables (LBVs), of which only a few objects are known, are in particular of interest concerning the stability of stars. They have a high mass loss rate and are close to being instable. This is even more likely as rotation becomes an important factor in stellar evolution of these stars. Through massive stellar winds and sometimes giant eruptions, LBV nebulae are formed. Various aspects in the evolution in the LBV phase lead, beside the large scale morphological and kinematical differences, to a diversity of small structures like clumps, rims, and outflows in these nebulae.
Mothers of Seafaring
(2023)
The article aims to trace the contribution of Jewish women in the Yishuv’s maritime history. Taking the example of Henrietta Diamond, a founding member and chairperson of the Zebulun Seafaring Society, the article seeks to explore the representation and role of women in a growing Jewish maritime domain from the 1930s to the 1950s. It examines Zionist narratives on the ‘New Jew’ and the Jewish body and studies their relevance for the emerging field of maritime activities in the Yishuv. By contextualizing the work and depiction of Henrietta Diamond, the article sheds new light on the gendered notions that underlay the emergence of the Jewish maritime domain and illustrates the patterns of inclusion and exclusion in it.
The site of confluence of the artery and the portal vein in the liver still appears to be controversial. Anatomical studies suggested a presinusoidal or an intrasinusoidal confluence in the first, second or even final third of the sinusoids. The objective of this investigation was to study the problem with functional biochemical techniques. Rat livers were perfused through the hepatic artery and simultaneously either in the orthograde direction from the portal vein to the hepatic vein or in the retrograde direction from the hepatic vein to the portal vein. Arterial how was linearly dependent on arterial pressure between 70 cm H2O and 120 cm H2O at a constant portal or hepatovenous pressure of 18 cm H2O. An arterial pressure of 100 cm H2O was required for the maintenance of a homogeneous orthograde perfusion of the whole parenchyma and of a physiologic ratio of arterial to portal how of about 1:3. Glucagon was infused either through the artery or the portal vein and hepatic vein, respectively, to a submaximally effective ''calculated'' sinusoidal concentration after mixing of 0.1 nmol/L. During orthograde perfusions, arterial and portal glucagon caused the same increases in glucose output. Yet during retrograde perfusions, hepatovenous glucagon elicited metabolic alterations equal to those in orthograde perfusions, whereas arterial glucagon effected changes strongly reduced to between 10% and 50%. Arterially infused trypan blue was distributed homogeneously in the parenchyma during orthograde perfusions, whereas it reached clearly smaller areas of parenchyma during retrograde perfusions. Finally, arterially applied acridine orange was taken up by all periportal hepatocytes in the proximal half of the acinus during orthograde perfusions but only by a much smaller portion of periportal cells in the proximal third of the acinus during retrograde perfusions. These findings suggest that in rat liver, the hepatic artery and the portal vein mix before and within the first third of the sinusoids, rather than in the middle or even last third.
During the National Multiplication Training in Kenya in 2018, participants raised concerns about attrition, completion rates and quality of PhD programmes in Kenya’s public universities. This led the authors of this article to further examine the question of PhD completion rates. Available data underlined that PhD students across various disciplines in Kenya’s public universities take unnecessarily long to complete their studies due to a myriad of factors that are related to their supervisors, university guidelines for post-graduate studies, or the students themselves. This article examines inertia areas along the PhD training pathway at three public universities in Kenya and provides suggestions on structural and operational changes universities must make to shorten completion periods.
Jacob Brandon Maduro’s Memoirs and Related Observations (Havana, 1953) speak to the lasting yet malleable legacy of Jewish Caribbean/Atlantic mercantile communities that defined early modern settlement in the Americas. A close reading of the Memoirs, alongside relevant archival records and community narratives, lends new perspectives to scholarship on Port Jewries and the Atlantic Diaspora. Specifically concerned with Jacob’s adoption of such leading intellectual and political tropes as the Monroe doctrine, José Martí’s Nuestra America, and a Zionism that evolved from an ideology to a reality, the Memoirs reveal a narrative at once defined by the tremendous upheavals of the first half of the 20th century, and an enduring sense of Jewish diasporic peoplehood defined through a Port Jew paradigm whereby the preservation of Jewish ethnicity is understood as synonymous with the championing of modernity.
INTEGRAL tripled the number of super-giant high-mass X-ray binaries (sgHMXB) known in the Galaxy by revealing absorbed and fast transient (SFXT) systems. Quantitative constraints on the wind clumping of massive stars can be obtained from the study of the hard X-ray variability of SFXT. A large fraction of the hard X-ray emission is emitted in the form of flares with a typical duration of 3 ksec, frequency of 7 days and luminosity of $10^{36}$ erg/s. Such flares are most probably emitted by the interaction of a compact object orbiting at $\sim10~R_*$ with wind clumps ($10^{22 ... 23}$ g) representing a large fraction of the stellar mass-loss rate. The density ratio between the clumps and the inter-clump medium is $10^{2 ... 4}$. The parameters of the clumps and of the inter-clump medium, derived from the SFXT flaring behavior, are in good agreement with macro-clumping scenario and line-driven instability simulations. SFXT are likely to have larger orbital radius than classical sgHMXB.
The Arctic plays a key role in Earth’s climate system as global warming is predicted to be most pronounced at high latitudes and because one third of the global carbon pool is stored in ecosystems of the northern latitudes. In order to improve our understanding of the present and future carbon dynamics in climate sensitive permafrost ecosystems, the present study concentrates on investigations of microbial controls of methane fluxes, on the activity and structure of the involved microbial communities, and on their response to changing environmental conditions. For this purpose an integrated research strategy was applied, which connects trace gas flux measurements to soil ecological characterisation of permafrost habitats and molecular ecological analyses of microbial populations. Furthermore, methanogenic archaea isolated from Siberian permafrost have been used as potential keystone organisms for studying and assessing life under extreme living conditions. Long-term studies on methane fluxes were carried out since 1998. These studies revealed considerable seasonal and spatial variations of methane emissions for the different landscape units ranging from 0 to 362 mg m-2 d-1. For the overall balance of methane emissions from the entire delta, the first land cover classification based on Landsat images was performed and applied for an upscaling of the methane flux data sets. The regionally weighted mean daily methane emissions of the Lena Delta (10 mg m-2 d-1) are only one fifth of the values calculated for other Arctic tundra environments. The calculated annual methane emission of the Lena Delta amounts to about 0.03 Tg. The low methane emission rates obtained in this study are the result of the used remotely sensed high-resolution data basis, which provides a more realistic estimation of the real methane emissions on a regional scale. Soil temperature and near soil surface atmospheric turbulence were identified as the driving parameters of methane emissions. A flux model based on these variables explained variations of the methane budget corresponding to continuous processes of microbial methane production and oxidation, and gas diffusion through soil and plants reasonably well. The results show that the Lena Delta contributes significantly to the global methane balance because of its extensive wetland areas. The microbiological investigations showed that permafrost soils are colonized by high numbers of microorganisms. The total biomass is comparable to temperate soil ecosystems. Activities of methanogens and methanotrophs differed significantly in their rates and distribution patterns along both the vertical profiles and the different investigated soils. The methane production rates varied between 0.3 and 38.9 nmol h-1 g-1, while the methane oxidation ranged from 0.2 to 7.0 nmol h-1 g-1. Phylogenetic analyses of methanogenic communities revealed a distinct diversity of methanogens affiliated to Methanomicrobiaceae, Methanosarcinaceae and Methanosaetaceae, which partly form four specific permafrost clusters. The results demonstrate the close relationship between methane fluxes and the fundamental microbiological processes in permafrost soils. The microorganisms do not only survive in their extreme habitat but also can be metabolic active under in situ conditions. It was shown that a slight increase of the temperature can lead to a substantial increase in methanogenic activity within perennially frozen deposits. In case of degradation, this would lead to an extensive expansion of the methane deposits with their subsequent impacts on total methane budget. Further studies on the stress response of methanogenic archaea, especially Methanosarcina SMA-21, isolated from Siberian permafrost, revealed an unexpected resistance of the microorganisms against unfavourable living conditions. A better adaptation to environmental stress was observed at 4 °C compared to 28 °C. For the first time it could be demonstrated that methanogenic archaea from terrestrial permafrost even survived simulated Martian conditions. The results show that permafrost methanogens are more resistant than methanogens from non-permafrost environments under Mars-like climate conditions. Microorganisms comparable to methanogens from terrestrial permafrost can be seen as one of the most likely candidates for life on Mars due to their physiological potential and metabolic specificity.
Unity in diversity
(2005)
This paper describes the creation and preparation of TUSNELDA, a collection of corpus data built for linguistic research. This collection contains a number of linguistically annotated corpora which differ in various aspects such as language, text sorts / data types, encoded annotation levels, and linguistic theories underlying the annotation. The paper focuses on this variation on the one hand and the way how these heterogeneous data are integrated into one resource on the other hand.
The factors that determine the efficiency of energy transfer in aquatic food webs have been investigated for many decades. The plant-animal interface is the most variable and least predictable of all levels in the food web. In order to study determinants of food quality in a large lake and to test the recently proposed central importance of the long-chained eicosapentaenoic acid (EPA) at the pelagic producer-grazer interface, we tested the importance of polyunsaturated fatty acids (PUFAs) at the pelagic producerconsumer interface by correlating sestonic food parameters with somatic growth rates of a clone of Daphnia galeata. Daphnia growth rates were obtained from standardized laboratory experiments spanning one season with Daphnia feeding on natural seston from Lake Constance, a large pre-alpine lake. Somatic growth rates were fitted to sestonic parameters by using a saturation function. A moderate amount of variation was explained when the model included the elemental parameters carbon (r2 = 0.6) and nitrogen (r2 = 0.71). A tighter fit was obtained when sestonic phosphorus was incorporated (r2 = 0.86). The nonlinear regression with EPA was relatively weak (r2 = 0.77), whereas the highest degree of variance was explained by three C18-PUFAs. The best (r2 = 0.95), and only significant, correlation of Daphnia's growth was found with the C18-PUFA α-linolenic acid (α-LA; C18:3n-3). This correlation was weakest in late August when C:P values increased to 300, suggesting that mineral and PUFA-limitation of Daphnia's growth changed seasonally. Sestonic phosphorus and some PUFAs showed not only tight correlations with growth, but also with sestonic α-LA content. We computed Monte Carlo simulations to test whether the observed effects of α-LA on growth could be accounted for by EPA, phosphorus, or one of the two C18-PUFAs, stearidonic acid (C18:4n-3) and linoleic acid (C18:2n-6). With >99 % probability, the correlation of growth with α-LA could not be explained by any of these parameters. In order to test for EPA limitation of Daphnia's growth, in parallel with experiments on pure seston, growth was determined on seston supplemented with chemostat-grown, P-limited Stephanodiscus hantzschii, which is rich in EPA. Although supplementation increased the EPA content 80-800x, no significant changes in the nonlinear regression of the growth rates with α-LA were found, indicating that growth of Daphnia on pure seston was not EPA limited. This indicates that the two fatty acids, EPA and α-LA, were not mutually substitutable biochemical resources and points to different physiological functions of these two PUFAs. These results support the PUFA-limitation hypothesis for sestonic C:P < 300 but are contrary to the hypothesis of a general importance of EPA, since no evidence for EPA limitation was found. It is suggested that the resource ratios of EPA and α-LA rather than the absolute concentrations determine which of the two resources is limiting growth.
Significant seasonal variation in size at settlement has been observed in newly settled larvae of Dreissena polymorpha in Lake Constance. Diet quality, which varies temporally and spatially in freshwater habitats, has been suggested as a significant factor influencing life history and development of freshwater invertebrates. Accordingly, experiments were conducted with field-collected larvae to test the hypothesis that diet quality can determine planktonic larval growth rates, size at settlement and subsequent post-metamorphic growth rates. Larvae were fed one of two diets or starved. One diet was composed of cyanobacterial cells which are deficient in polyunsaturated fatty acids (PUFAs), and the other was a mixed diet rich in PUFAs. Freshly metamorphosed animals from the starvation treatment had a carbon content per individual 70% lower than that of larvae fed the mixed diet. This apparent exhaustion of larval internal reserves resulted in a 50% reduction of the postmetamorphic growth rates. Growth was also reduced in animals previously fed the cyanobacterial diet. Hence, low food quantity or low food quality during the larval stage of D. polymorpha lead to irreversible effects for postmetamorphic animals, and is related to inferior competitive abilities.
We present the results of Monte Carlo mass-loss predictions for massive stars covering a wide range of stellar parameters. We critically test our predictions against a range of observed massloss rates – in light of the recent discussions on wind clumping. We also present a model to compute the clumping-induced polarimetric variability of hot stars and we compare this with observations of Luminous Blue Variables, for which polarimetric variability is larger than for O and Wolf-Rayet stars. Luminous Blue Variables comprise an ideal testbed for studies of wind clumping and wind geometry, as well as for wind strength calculations, and we propose they may be direct supernova progenitors.
Deciphering the functioning of biological networks is one of the central tasks in systems biology. In particular, signal transduction networks are crucial for the understanding of the cellular response to external and internal perturbations. Importantly, in order to cope with the complexity of these networks, mathematical and computational modeling is required. We propose a computational modeling framework in order to achieve more robust discoveries in the context of logical signaling networks. More precisely, we focus on modeling the response of logical signaling networks by means of automated reasoning using Answer Set Programming (ASP). ASP provides a declarative language for modeling various knowledge representation and reasoning problems. Moreover, available ASP solvers provide several reasoning modes for assessing the multitude of answer sets. Therefore, leveraging its rich modeling language and its highly efficient solving capacities, we use ASP to address three challenging problems in the context of logical signaling networks: learning of (Boolean) logical networks, experimental design, and identification of intervention strategies. Overall, the contribution of this thesis is three-fold. Firstly, we introduce a mathematical framework for characterizing and reasoning on the response of logical signaling networks. Secondly, we contribute to a growing list of successful applications of ASP in systems biology. Thirdly, we present a software providing a complete pipeline for automated reasoning on the response of logical signaling networks.
This chapter deals with the problem that theories of peace building, conflict resolution and reconciliation were predominately created in the West and, therefore, do not necessarily fit the understanding of peace, conflict, and resolution in non-Western societies and cultures. Within these societies, the acceptance of suffering may also be higher, which leads to different priorities of conflict resolution approaches. Furthermore, this chapter deals with the question of whether the current understanding of wars and the nature of conflict change the basis of established conflict theories. These theoretical approaches are then applied in Sierra Leone as a non-Western negotiation scenario.
The process of introducing compulsory ICT education at primary school level in the Czech Republic should be completed next year. Programming and Information, two topics from the basics of computer science have been included in a new textbook. The question is whether the new chapters of the textbook are comprehensible for primary school teachers, who have undergone no training in computer science. The paper reports on a pilot verification project in which pre-service primary school teachers were trained to teach these informatics topics.
It has recently been demonstrated that the presentation of a rare target in a visual oddball paradigm induces a prolonged inhibition of microsaccades. In the field of electrophysiology, the amplitude of the P300 component in event-related potentials (ERP) has been shown to be sensitive to the stimulus category (target vs. non target) of the eliciting stimulus, its overall probability, and the preceding stimulus sequence. In the present study we further specify the functional underpinnings of the prolonged microsaccadic inhibition in the visual oddball task, showing that the stimulus category, the frequency of a stimulus and the preceding stimulus sequence influence microsaccade rate. Furthermore, by co-recording ERPs and eye-movements, we were able to demonstrate that, despite being largely sensitive to the same experimental manipulation, the amplitude of P300 and the microsaccadic inhibition predict each other very weakly, and thus constitute two independent measures of the brain’s response to rare targets in the visual oddball paradigm.
Recent studies of massive O-type stars present clear evidences of inhomogeneous and clumped winds. O-type (H-rich) central stars of planetary nebulae (CSPNs) are in some ways the low mass–low luminosity analogous of those massive stars. In this contribution, we present preliminary results of our on-going multi-wavelength (FUV, UV and optical) study of the winds of Galactic CSPNs. Particular emphasis will be given to the clumping factors derived by means of optical lines (Hα and Heii 4686) and “classic” FUV (and UV) lines.
Foam fractionation of surfactant and protein solutions is a process dedicated to separate surface active molecules from each other due to their differences in surface activities. The process is based on forming bubbles in a certain mixed solution followed by detachment and rising of bubbles through a certain volume of this solution, and consequently on the formation of a foam layer on top of the solution column. Therefore, systematic analysis of this whole process comprises of at first investigations dedicated to the formation and growth of single bubbles in solutions, which is equivalent to the main principles of the well-known bubble pressure tensiometry. The second stage of the fractionation process includes the detachment of a single bubble from a pore or capillary tip and its rising in a respective aqueous solution. The third and final stage of the process is the formation and stabilization of the foam created by these bubbles, which contains the adsorption layers formed at the growing bubble surface, carried up and gets modified during the bubble rising and finally ends up as part of the foam layer.
Bubble pressure tensiometry and bubble profile analysis tensiometry experiments were performed with protein solutions at different bulk concentrations, solution pH and ionic strength in order to describe the process of accumulation of protein and surfactant molecules at the bubble surface. The results obtained from the two complementary methods allow understanding the mechanism of adsorption, which is mainly governed by the diffusional transport of the adsorbing protein molecules to the bubble surface. This mechanism is the same as generally discussed for surfactant molecules. However, interesting peculiarities have been observed for protein adsorption kinetics at sufficiently short adsorption times. First of all, at short adsorption times the surface tension remains constant for a while before it decreases as expected due to the adsorption of proteins at the surface. This time interval is called induction time and it becomes shorter with increasing protein bulk concentration. Moreover, under special conditions, the surface tension does not stay constant but even increases over a certain period of time. This so-called negative surface pressure was observed for BCS and BLG and discussed for the first time in terms of changes in the surface conformation of the adsorbing protein molecules. Usually, a negative surface pressure would correspond to a negative adsorption, which is of course impossible for the studied protein solutions. The phenomenon, which amounts to some mN/m, was rather explained by simultaneous changes in the molar area required by the adsorbed proteins and the non-ideality of entropy of the interfacial layer. It is a transient phenomenon and exists only under dynamic conditions.
The experiments dedicated to the local velocity of rising air bubbles in solutions were performed in a broad range of BLG concentration, pH and ionic strength. Additionally, rising bubble experiments were done for surfactant solutions in order to validate the functionality of the instrument. It turns out that the velocity of a rising bubble is much more sensitive to adsorbing molecules than classical dynamic surface tension measurements. At very low BLG or surfactant concentrations, for example, the measured local velocity profile of an air bubble is changing dramatically in time scales of seconds while dynamic surface tensions still do not show any measurable changes at this time scale. The solution’s pH and ionic strength are important parameters that govern the measured rising velocity for protein solutions. A general theoretical description of rising bubbles in surfactant and protein solutions is not available at present due to the complex situation of the adsorption process at a bubble surface in a liquid flow field with simultaneous Marangoni effects. However, instead of modelling the complete velocity profile, new theoretical work has been started to evaluate the maximum values in the profile as characteristic parameter for dynamic adsorption layers at the bubble surface more quantitatively.
The studies with protein-surfactant mixtures demonstrate in an impressive way that the complexes formed by the two compounds change the surface activity as compared to the original native protein molecules and therefore lead to a completely different retardation behavior of rising bubbles. Changes in the velocity profile can be interpreted qualitatively in terms of increased or decreased surface activity of the formed protein-surfactant complexes. It was also observed that the pH and ionic strength of a protein solution have strong effects on the surface activity of the protein molecules, which however, could be different on the rising bubble velocity and the equilibrium adsorption isotherms. These differences are not fully understood yet but give rise to discussions about the structure of protein adsorption layer under dynamic conditions or in the equilibrium state.
The third main stage of the discussed process of fractionation is the formation and characterization of protein foams from BLG solutions at different pH and ionic strength. Of course a minimum BLG concentration is required to form foams. This minimum protein concentration is a function again of solution pH and ionic strength, i.e. of the surface activity of the protein molecules. Although at the isoelectric point, at about pH 5 for BLG, the hydrophobicity and hence the surface activity should be the highest, the concentration and ionic strength effects on the rising velocity profile as well as on the foamability and foam stability do not show a maximum. This is another remarkable argument for the fact that the interfacial structure and behavior of BLG layers under dynamic conditions and at equilibrium are rather different. These differences are probably caused by the time required for BLG molecules to adapt respective conformations once they are adsorbed at the surface.
All bubble studies described in this work refer to stages of the foam fractionation process. Experiments with different systems, mainly surfactant and protein solutions, were performed in order to form foams and finally recover a solution representing the foamed material. As foam consists to a large extent of foam lamella – two adsorption layers with a liquid core – the concentration in a foamate taken from foaming experiments should be enriched in the stabilizing molecules. For determining the concentration of the foamate, again the very sensitive bubble rising velocity profile method was applied, which works for any type of surface active materials. This also includes technical surfactants or protein isolates for which an accurate composition is unknown.
Magnetic fields influence the dynamics of hot-star winds and create large scale structure. Based on numerical magnetohydrodynamic (MHD) simulations, we model the wind of θ¹ Ori C, and then use the SEI method to compute synthetic line profiles for a range of viewing angles as function of rotational phase. The resulting dynamic spectrum for a moderately strong line shows a distinct modulation, but with a phase that seems at odds with available observations.
Climate change is one of the greatest challenges to humanity in this century, and most noticeable consequences are expected to be impacts on the water cycle – in particular the distribution and availability of water, which is fundamental for all life on Earth. In this context, it is essential to better understand where and when water is available and what processes influence variations in water storages. While estimates of the overall terrestrial water storage (TWS) variations are available from the GRACE satellites, these represent the vertically integrated signal over all water stored in ice, snow, soil moisture, groundwater and surface water bodies. Therefore, complementary observational data and hydrological models are still required to determine the partitioning of the measured signal among different water storages and to understand the underlying processes. However, the application of large-scale observational data is limited by their specific uncertainties and the incapacity to measure certain water fluxes and storages. Hydrological models, on the other hand, vary widely in their structure and process-representation, and rarely incorporate additional observational data to minimize uncertainties that arise from their simplified representation of the complex hydrologic cycle.
In this context, this thesis aims to contribute to improving the understanding of global water storage variability by combining simple hydrological models with a variety of complementary Earth observation-based data. To this end, a model-data integration approach is developed, in which the parameters of a parsimonious hydrological model are calibrated against several observational constraints, inducing GRACE TWS, simultaneously, while taking into account each data’s specific strengths and uncertainties. This approach is used to investigate 3 specific aspects that are relevant for modelling and understanding the composition of large-scale TWS variations.
The first study focusses on Northern latitudes, where snow and cold-region processes define the hydrological cycle. While the study confirms previous findings that seasonal dynamics of TWS are dominated by the cyclic accumulation and melt of snow, it reveals that inter-annual TWS variations on the contrary, are determined by variations in liquid water storages. Additionally, it is found to be important to consider the impact of compensatory effects of spatially heterogeneous hydrological variables when aggregating the contribution of different storage components over large areas. Hence, the determinants of TWS variations are scale-dependent and underlying driving mechanism cannot be simply transferred between spatial and temporal scales. These findings are supported by the second study for the global land areas beyond the Northern latitudes as well.
This second study further identifies the considerable impact of how vegetation is represented in hydrological models on the partitioning of TWS variations. Using spatio-temporal varying fields of Earth observation-based data to parameterize vegetation activity not only significantly improves model performance, but also reduces parameter equifinality and process uncertainties. Moreover, the representation of vegetation drastically changes the contribution of different water storages to overall TWS variability, emphasizing the key role of vegetation for water allocation, especially between sub-surface and delayed water storages. However, the study also identifies parameter equifinality regarding the decay of sub-surface and delayed water storages by either evapotranspiration or runoff, and thus emphasizes the need for further constraints hereof.
The third study focuses on the role of river water storage, in particular whether it is necessary to include computationally expensive river routing for model calibration and validation against the integrated GRACE TWS. The results suggest that river routing is not required for model calibration in such a global model-data integration approach, due to the larger influence other observational constraints, and the determinability of certain model parameters and associated processes are identified as issues of greater relevance. In contrast to model calibration, considering river water storage derived from routing schemes can already significantly improve modelled TWS compared to GRACE observations, and thus should be considered for model evaluation against GRACE data.
Beyond these specific findings that contribute to improved understanding and modelling of large-scale TWS variations, this thesis demonstrates the potential of combining simple modeling approaches with diverse Earth observational data to improve model simulations, overcome inconsistencies of different observational data sets, and identify areas that require further research. These findings encourage future efforts to take advantage of the increasing number of diverse global observational data.
The most recent trend in the studies of LF intervention effects makes crucial reference to focusing effects on the interveners, and this paper critically examines the representative analyses of the focus-based approach. While each analysis has its own merits and shortcomings, I argue that a pragmatic analysis that does not make appeal to syntactic configurations is better equipped to deal with many of the complex and delicate facts surrounding intervention effects.
When the Jewish Theological Seminary in Breslau opened its doors in 1854, it established a novel form of rabbinical education: the systematic combination of Jewish studies at the seminary in parallel with university studies. The Breslau seminary became the model for most later institutions for rabbinical training in Europe and the United States. The seminaries were the new sites of modern Jewish scholarship, especially the academic study of Judaism (Wissenschaft des Judentums). Their function and goal were to preserve, (re)organize, and transmit Jewish knowledge in the modern age. As such, they became central nodes in Jewish scholarly networks. This case study highlights the multi-nodal connections between the Conservative seminaries in Breslau, Philadelphia, New York, Budapest, and Vienna. At the same time, it is intended to provide an example of the potential of transnational and transfer studies for the history of the Jewish religious learning in Europe and the United States.
We investigate whether political ideology has an observable effect on decarbonization ambition, renewable power aims, and preferences for power system balancing technologies in four European countries. Based on the Energy Logics framework, we identify ideologically different transition strategies (state-centered, market-centered, grassroots-centered) contained in government policies and opposition party programs valid in 2019. We compare these policies and programs with citizen poll data. We find that ideology has a small effect: governments and political parties across the spectrum have similar, and relatively ambitious, decarbonization and renewables targets. This mirrors citizens' strong support for ambitious action regardless of their ideological self-description. However, whereas political positions on phasing out fossil fuel power are clear across the policy space, positions on phasing in new flexibility options to balance intermittent renewables are vague or non-existent. As parties and citizens agree on strong climate and renewable power aims, the policy ambition is likely to remain high, even if governments change.
Claiming that cross-speaker "but" can signal correction in dialogue, we start by describing the types of corrections "but" can communicate by focusing on the Speech Act (SA) communicated in the previous turn and address the ways in which "but" can correct what is communicated. We address whether "but" corrects the proposition, the direct SA or the discourse relation communicated in the previous turn. We will also briefly address other relations signalled by cross-turn "but". After presenting a typology of the situations "but" can correct, we will address how these corrections can be modelled in the Information State model of dialogue, motivating this work by showing how it can be used to potentially avoid misunderstandings. We wrap up by showing how the model presented here updates beliefs in the Information State representation of the dialogue and can be used to facilitate response deliberation.
The Voyager 2 Photopolarimeter experiment has yielded the highest resolved data of Saturn's rings, exhibiting a wide variety of features. The B-ring region between 105000 km and 110000 km distance from Saturn has been investigated. It has a high matter density and contains no significance features visible by eye. Analysis with statistical methods has let us to the detection of two significant events. These features are correlated with the inner 3:2 resonances of the F-ring shepherd satellites Pandora and Prometheus, and may be evidence of large ring paricles caught in the corotation resonances.
We present a system for the linguistic exploration and analysis of lexical cohesion in English texts. Using an electronic thesaurus-like resource, Princeton WordNet, and the Brown Corpus of English, we have implemented a process of annotating text with lexical chains and a graphical user interface for inspection of the annotated text. We describe the system and report on some sample linguistic analyses carried out using the combined thesaurus-corpus resource.
What are the consequences of unemployment and precarious employment for individuals' health in Europe? What are the moderating factors that may offset (or increase) the health consequences of labor-market risks? How do the effects of these risks vary across different contexts, which differ in their institutional and cultural settings? Does gender, regarded as a social structure, play a role, and how? To answer these questions is the aim of my cumulative thesis. This study aims to advance our knowledge about the health consequences that unemployment and precariousness cause over the life course. In particular, I investigate how several moderating factors, such as gender, the family, and the broader cultural and institutional context, may offset or increase the impact of employment instability and insecurity on individual health.
In my first paper, 'The buffering role of the family in the relationship between job loss and self-perceived health: Longitudinal results from Europe, 2004-2011', I and my co-authors measure the causal effect of job loss on health and the role of the family and welfare states (regimes) as moderating factors. Using EU-SILC longitudinal data (2004-2011), we estimate the probability of experiencing 'bad health' following a transition to unemployment by applying linear probability models and undertake separate analyses for men and women. Firstly, we measure whether changes in the independent variable 'job loss' lead to changes in the dependent variable 'self-rated health' for men and women separately. Then, by adding into the model different interaction terms, we measure the moderating effect of the family, both in terms of emotional and economic support, and how much it varies across different welfare regimes. As an identification strategy, we first implement static fixed-effect panel models, which control for time-varying observables and indirect health selection—i.e., constant unobserved heterogeneity. Secondly, to control for reverse causality and path dependency, we implement dynamic fixed-effect panel models, adding a lagged dependent variable to the model.
We explore the role of the family by focusing on close ties within households: we consider the presence of a stable partner and his/her working status as a source of social and economic support. According to previous literature, having a partner should reduce the stress from adverse events, thanks to the symbolic and emotional dimensions that such a relationship entails, regardless of any economic benefits. Our results, however, suggest that benefits linked to the presence of a (female) partner also come from the financial stability that (s)he can provide in terms of a second income. Furthermore, we find partners' employment to be at least as important as the mere presence of the partner in reducing the negative effect of job loss on the individual's health by maintaining the household's standard of living and decreasing economic strain on the family. Our results are in line with previous research, which has highlighted that some people cope better than others with adverse life circumstances, and the support provided by the family is a crucial resource in that regard.
We also reported an important interaction between the family and the welfare state in moderating the health consequences of unemployment, showing how the compensation effect of the family varies across welfare regimes. The family plays a decisive role in cushioning the adverse consequences of labor market risks in Southern and Eastern welfare states, characterized by less developed social protection systems and –especially the Southern – high level of familialism.
The first paper also found important gender differences concerning job loss, family and welfare effects. Of particular interest is the evidence suggesting that health selection works differently for men and women, playing a more prominent role for women than for men in explaining the relationship between job loss and self-perceived health. The second paper, 'Gender roles and selection mechanisms across contexts: A comparative analysis of the relationship between unemployment, self-perceived health, and gender.' investigates more in-depth the gender differential in health driven by unemployment.
Being a highly contested issue in literature, we aim to study whether men are more penalized than women or the other way around and the mechanisms that may explain the gender difference. To do that, we rely on two theoretical arguments: the availability of alternative roles and social selection. The first argument builds on the idea that men and women may compensate for the detrimental health consequences of unemployment through the commitment to 'alternative roles,' which can provide for the resources needed to fulfill people's socially constructed needs. Notably, the availability of alternative options depends on the different positions that men and women have in society.
Further, we merge the availability of the 'alternative roles' argument with the health selection argument. We assume that health selection could be contingent on people's social position as defined by gender and, thus, explain the gender differential in the relationship between unemployment and health. Ill people might be less reluctant to fall or remain (i.e., self-select) in unemployment if they have alternative roles. In Western societies, women generally have more alternative roles than men and thus more discretion in their labor market attachment. Therefore, health selection should be stronger for them, explaining why unemployment is less menace for women than for their male counterparts.
Finally, relying on the idea of different gender regimes, we extended these arguments to comparison across contexts. For example, in contexts where being a caregiver is assumed to be women's traditional and primary roles and the primary breadwinner role is reserved to men, unemployment is less stigmatized, and taking up alternative roles is more socially accepted for women than for men (Hp.1). Accordingly, social (self)selection should be stronger for women than for men in traditional contexts, where, in the case of ill-health, the separation from work is eased by the availability of alternative roles (Hp.2).
By focusing on contexts that are representative of different gender regimes, we implement a multiple-step comparative approach. Firstly, by using EU-SILC longitudinal data (2004-2015), our analysis tests gender roles and selection mechanisms for Sweden and Italy, representing radically different gender regimes, thus providing institutional and cultural variation. Then, we limit institutional heterogeneity by focusing on Germany and comparing East- and West-Germany and older and younger cohorts—for West-Germany (SOEP data 1995-2017). Next, to assess the differential impact of unemployment for men and women, we compared (unemployed and employed) men with (unemployed and employed) women. To do so, we calculate predicted probabilities and average marginal effect from two distinct random-effects probit models. Our first step is estimating random-effects models that assess the association between unemployment and self-perceived health, controlling for observable characteristics. In the second step, our fully adjusted model controls for both direct and indirect selection. We do this using dynamic correlated random-effects (CRE) models. Further, based on the fully adjusted model, we test our hypotheses on alternative roles (Hp.1) by comparing several contexts – models are estimated separately for each context. For this hypothesis, we pool men and women and include an interaction term between unemployment and gender, which has the advantage to allow for directly testing whether gender differences in the effect of unemployment exist and are statistically significant. Finally, we test the role of selection mechanisms (Hp.2), using the KHB method to compare coefficients across nested nonlinear models. Specifically, we test the role of selection for the relationship between unemployment and health by comparing the partially-adjusted and fully-adjusted models. To allow selection mechanisms to operate differently between genders, we estimate separate models for men and women.
We found support to our first hypotheses—the context where people are embedded structures the relationship between unemployment, health, and gender. We found no gendered effect of unemployment on health in the egalitarian context of Sweden. Conversely, in the traditional context of Italy, we observed substantive and statistically significant gender differences in the effect of unemployment on bad health, with women suffering less than men. We found the same pattern for comparing East and West Germany and younger and older cohorts in West Germany.
On the contrary, our results did not support our theoretical argument on social selection. We found that in Sweden, women are more selected out of employment than men. In contrast, in Italy, health selection does not seem to be the primary mechanism behind the gender differential—Italian men and women seem to be selected out of employment to the same extent. Namely, we do not find any evidence that health selection is stronger for women in more traditional countries (Hp2), despite the fact that the institutional and the cultural context would offer them a more comprehensive range of 'alternative roles' relative to men. Moreover, our second hypothesis is also rejected in the second and third comparisons, where the cross-country heterogeneity is reduced to maximize cultural differences within the same institutional context. Further research that addresses selection into inactivity is needed to evaluate the interplay between selection and social roles across gender regimes.
While the health consequences of unemployment have been on the research agenda for a pretty long time, the interest in precarious employment—defined as the linking of the vulnerable worker to work that is characterized by uncertainty and insecurity concerning pay, the stability of the work arrangement, limited access to social benefits, and statutory protections—has emerged only later. Since the 80s, scholars from different disciplines have raised concerns about the social consequences of de-standardization of employment relationships. However, while work has become undoubtedly more precarious, very little is known about its causal effect on individual health and the role of gender as a moderator. These questions are at the core of my third paper : 'Bad job, bad health? A longitudinal analysis of the interaction between precariousness, gender and self-perceived health in Germany'. Herein, I investigate the multidimensional nature of precarious employment and its causal effect on health, particularly focusing on gender differences.
With this paper, I aim at overcoming three major shortcomings of earlier studies: The first one regards the cross-sectional nature of data that prevents the authors from ruling out unobserved heterogeneity as a mechanism for the association between precarious employment and health. Indeed, several unmeasured individual characteristics—such as cognitive abilities—may confound the relationship between precarious work and health, leading to biased results. Secondly, only a few studies have directly addressed the role of gender in shaping the relationship. Moreover, available results on the gender differential are mixed and inconsistent: some found precarious employment being more detrimental for women's health, while others found no gender differences or stronger negative association for men. Finally, previous attempts to an empirical translation of the employment precariousness (EP) concept have not always been coherent with their theoretical framework. EP is usually assumed to be a multidimensional and continuous phenomenon; it is characterized by different dimensions of insecurity that may overlap in the same job and lead to different "degrees of precariousness." However, researchers have predominantly focused on one-dimensional indicators—e.g., temporary employment, subjective job insecurity—to measure EP and study the association with health. Besides the fact that this approach partially grasps the phenomenon's complexity, the major problem is the inconsistency of evidence that it has produced. Indeed, this line of inquiry generally reveals an ambiguous picture, with some studies finding substantial adverse effects of temporary over permanent employment, while others report only minor differences.
To measure the (causal) effect of precarious work on self-rated health and its variation by gender, I focus on Germany and use four waves from SOEP data (2003, 2007, 2011, and 2015). Germany is a suitable context for my study. Indeed, since the 1980s, the labor market and welfare system have been restructured in many ways to increase the German economy's competitiveness in the global market. As a result, the (standard) employment relationship has been de-standardized: non-standard and atypical employment arrangements—i.e., part-time work, fixed-term contracts, mini-jobs, and work agencies—have increased over time while wages have lowered, even among workers with standard work. In addition, the power of unions has also fallen over the last three decades, leaving a large share of workers without collective protection. Because of this process of de-standardization, the link between wage employment and strong social rights has eroded, making workers more powerless and more vulnerable to labor market risks than in the past. EP refers to this uneven distribution of power in the employment relationship, which can be detrimental to workers' health. Indeed, by affecting individuals' access to power and other resources, EP puts precarious workers at risk of experiencing health shocks and influences their ability to gain and accumulate health advantages (Hp.1).
Further, the focus on Germany allows me to investigate my second research question on the gender differential. Germany is usually regarded as a traditionalist gender regime: a context characterized by a configuration of roles. Here, being a caregiver is assumed to be women's primary role, whereas the primary breadwinner role is reserved for men. Although many signs of progress have been made over the last decades towards a greater equalization of opportunities and more egalitarianism, the breadwinner model has barely changed towards a modified version. Thus, women usually take on the double role of workers (the so-called secondary earner) and caregivers, and men still devote most of their time to paid work activities. Moreover, the overall upward trend towards more egalitarian gender ideologies has leveled off over the last decades, moving notably towards more traditional gender ideologies.
In this setting, two alternative hypotheses are possible. Firstly, I assume that the negative relationship between EP and health is stronger for women than for men. This is because women are systematically more disadvantaged than men in the public and private spheres of life, having less access to formal and informal sources of power. These gender-related power asymmetries may interact with EP-related power asymmetries resulting in a stronger effect of EP on women's health than on men's health (Hp.2).
An alternative way of looking at the gender differential is to consider the interaction that precariousness might have with men's and women's gender identities. According to this view, the negative relationship between EP and health is weaker for women than for men (Hp.2a). In a society with a gendered division of labor and a strong link between masculine identities and stable and well-rewarded job—i.e., a job that confers the role of primary family provider—a male worker with precarious employment might violate the traditional male gender role. Men in precarious jobs may perceive themselves (and by others) as possessing a socially undesirable characteristic, which conflicts with the stereotypical idea of themselves as the male breadwinner. Engaging in behaviors that contradict stereotypical gender identity may decrease self-esteem and foster feelings of inferiority, helplessness, and jealousy, leading to poor health.
I develop a new indicator of EP that empirically translates a definition of EP as a multidimensional and continuous phenomenon. I assume that EP is a latent construct composed of seven dimensions of insecurity chosen according to the theory and previous empirical research: Income insecurity, social insecurity, legal insecurity, employment insecurity, working-time insecurity, representation insecurity, worker's vulnerability. The seven dimensions are proxied by eight indicators available in the four waves of the SOEP dataset. The EP composite indicator is obtained by performing a multiple correspondence analysis (MCA) on the eight indicators. This approach aims to construct a summary scale in which all dimensions contribute jointly to the measured experience of precariousness and its health impact.
Further, the relationship between EP and 'general self-perceived health' is estimated by applying ordered probit random-effects estimators and calculating average marginal effect (further AME). Then, to control for unobserved heterogeneity, I implement correlated random-effects models that add to the model the within-individual means of the time-varying independent variables. To test the significance of the gender differential, I add an interaction term between EP and gender in the fully adjusted model in the pooled sample.
My correlated random-effects models showed EP's negative and substantial 'effect' on self-perceived health for both men and women. Although nonsignificant, the evidence seems in line with previous cross-sectional literature. It supports the hypothesis that employment precariousness could be detrimental to workers' health. Further, my results showed the crucial role of unobserved heterogeneity in shaping the health consequences of precarious employment. This is particularly important as evidence accumulates, yet it is still mostly descriptive.
Moreover, my results revealed a substantial difference among men and women in the relationship between EP and health: when EP increases, the risk of experiencing poor health increases much more for men than for women. This evidence falsifies previous theory according to whom the gender differential is contingent on the structurally disadvantaged position of women in western societies. In contrast, they seem to confirm the idea that men in precarious work could experience role conflict to a larger extent than women, as their self-standard is supposed to be the stereotypical breadwinner worker with a good and well-rewarded job. Finally, results from the multiple correspondence analysis contribute to the methodological debate on precariousness, showing that a multidimensional and continuous indicator can express a latent variable of EP.
All in all, complementarities are revealed in the results of unemployment and employment precariousness, which have two implications: Policy-makers need to be aware that the total costs of unemployment and precariousness go far beyond the economic and material realm penetrating other fundamental life domains such as individual health. Moreover, they need to balance the trade-off between protecting adequately unemployed people and fostering high-quality employment in reaction to the highlighted market pressures. In this sense, the further development of a (universalistic) welfare state certainly helps mitigate the adverse health effects of unemployment and, therefore, the future costs of both individuals' health and welfare spending. In addition, the presence of a working partner is crucial for reducing the health consequences of employment instability. Therefore, policies aiming to increase female labor market participation should be promoted, especially in those contexts where the welfare state is less developed.
Moreover, my results support the significance of taking account of a gender perspective in health research. The findings of the three articles show that job loss, unemployment, and precarious employment, in general, have adverse effects on men's health but less or absent consequences for women's health. Indeed, this suggests the importance of labor and health policies that consider and further distinguish the specific needs of the male and female labor force in Europe. Nevertheless, a further implication emerges: the health consequences of employment instability and de-standardization need to be investigated in light of the gender arrangements and the transforming gender relationships in specific cultural and institutional contexts. My results indeed seem to suggest that women's health advantage may be a transitory phenomenon, contingent on the predominant gendered institutional and cultural context. As the structural difference between men's and women's position in society is eroded, egalitarianism becomes the dominant normative status, so will probably be the gender difference in the health consequences of job loss and precariousness. Therefore, while gender equality in opportunities and roles is a desirable aspect for contemporary societies and a political goal that cannot be postponed further, this thesis raises a further and maybe more crucial question: What kind of equality should be pursued to provide men and women with both good life quality and equal chances in the public and private spheres? In this sense, I believe that social and labor policies aiming to reduce gender inequality in society should focus on improving women's integration into the labor market, implementing policies targeting men, and facilitating their involvement in the private sphere of life. Equal redistribution of social roles could activate a crucial transformation of gender roles and the cultural models that sustain and still legitimate gender inequality in Western societies.
Luminous Blue Variables show strong changes in their stellar wind on time scales of typically years to decades when they expand and contract radially at approximately constant luminosity. Micro-variability on shorter time scales and amplitudes can be observed superimposed to the larger scale radial changes. I will show long-term time series of high resolution spectra which we have collected in the past 20 years for many of the well known LBVs together with a few time series of weekly sampling (HR Car, R40, R71, R110, R127, S Dor) covering a time windows of up to a few months. Wind variability is seen on short and intermediate time scales with the line profiles changing from P Cygni to inverse P Cygni and double peeked profiles sometimes for the same star and spectral line. On longer time scales the ionisation levels for all chemical elements change drastically due to the strong change of the temperature on the stellar surface. While on the long term the characteristic radial changes may have impact on the over all mass loss rates, the variabilities and asymmetries on short and intermediate time scales may cause false estimates of the mass loss rates when confronting models with the observed line profiles
The potential increase in frequency and magnitude of extreme floods is currently discussed in terms of global warming and the intensification of the hydrological cycle. The profound knowledge of past natural variability of floods is of utmost importance in order to assess flood risk for the future. Since instrumental flood series cover only the last ~150 years, other approaches to reconstruct historical and pre-historical flood events are needed. Annually laminated (varved) lake sediments are meaningful natural geoarchives because they provide continuous records of environmental changes > 10000 years down to a seasonal resolution. Since lake basins additionally act as natural sediment traps, the riverine sediment supply, which is preserved as detrital event layers in the lake sediments, can be used as a proxy for extreme discharge events. Within my thesis I examined a ~ 8.50 m long sedimentary record from the pre-Alpine Lake Mondsee (Northeast European Alps), which covered the last 7000 years. This sediment record consists of calcite varves and intercalated detrital layers, which range in thickness from 0.05 to 32 mm. Detrital layer deposition was analysed by a combined method of microfacies analysis via thin sections, Scanning Electron Microscopy (SEM), μX-ray fluorescence (μXRF) scanning and magnetic susceptibility. This approach allows characterizing individual detrital event layers and assigning a corresponding input mechanism and catchment. Based on varve counting and controlled by 14C age dates, the main goals of this thesis are (i) to identify seasonal runoff processes, which lead to significant sediment supply from the catchment into the lake basin and (ii) to investigate flood frequency under changing climate boundary conditions. This thesis follows a line of different time slices, presenting an integrative approach linking instrumental and historical flood data from Lake Mondsee in order to evaluate the flood record inferred from Lake Mondsee sediments. The investigation of eleven short cores covering the last 100 years reveals the abundance of 12 detrital layers. Therein, two types of detrital layers are distinguished by grain size, geochemical composition and distribution pattern within the lake basin. Detrital layers, which are enriched in siliciclastic and dolomitic material, reveal sediment supply from the Flysch sediments and Northern Calcareous Alps into the lake basin. These layers are thicker in the northern lake basin (0.1-3.9 mm) and thinner in the southern lake basin (0.05-1.6 mm). Detrital layers, which are enriched in dolomitic components forming graded detrital layers (turbidites), indicate the provenance from the Northern Calcareous Alps. These layers are generally thicker (0.65-32 mm) and are solely recorded within the southern lake basin. In comparison with instrumental data, thicker graded layers result from local debris flow events in summer, whereas thin layers are deposited during regional flood events in spring/summer. Extreme summer floods as reported from flood layer deposition are principally caused by cyclonic activity from the Mediterranean Sea, e.g. July 1954, July 1997 and August 2002. During the last two millennia, Lake Mondsee sediments reveal two significant flood intervals with decadal-scale flood episodes, during the Dark Ages Cold Period (DACP) and the transition from the Medieval Climate Anomaly (MCA) into the Little Ice Age (LIA) suggesting a linkage of transition to climate cooling and summer flood recurrences in the Northeastern Alps. In contrast, intermediate or decreased flood episodes appeared during the MWP and the LIA. This indicates a non-straightforward relationship between temperature and flood recurrence, suggesting higher cyclonic activity during climate transition in the Northeast Alps. The 7000-year flood chronology reveals 47 debris flows and 269 floods, with increased flood activity shifting around 3500 and 1500 varve yr BP (varve yr BP = varve years before present, before present = AD 1950). This significant increase in flood activity shows a coincidence with millennial-scale climate cooling that is reported from main Alpine glacier advances and lower tree lines in the European Alps since about 3300 cal. yr BP (calibrated years before present). Despite relatively low flood occurrence prior to 1500 varve yr BP, floods at Lake Mondsee could have also influenced human life in early Neolithic lake dwellings (5750-4750 cal. yr BP). While the first lake dwellings were constructed on wetlands, the later lake dwellings were built on piles in the water suggesting an early flood risk adaptation of humans and/or a general change of the Late Neolithic Culture of lake-dwellers because of socio-economic reasons. However, a direct relationship between the final abandonment of the lake dwellings and higher flood frequencies is not evidenced.
Desperados at Sea
(2023)
Pirates are fortune-seeking fighters at sea. Their exploits fire the imaginations of their victims and admirers, drawing a veil over individuals who rarely bear a real name and pursue their adventurous occupations as buccaneers, filibusters, freebooters, privateers, pirates, or corsairs. Piracy, corsairing, and contraband trade were epidemic among the Egyptians and the Phoenicians, the Greeks and the Vikings, the Spaniards and the Ottomans, the Muslims, and the Christians. And the Jews.
Intuitively, strongly constraining contexts should lead to stronger probabilistic representations of sentences in memory. Encountering unexpected words could therefore be expected to trigger costlier shifts in these representations than expected words. However, psycholinguistic measures commonly used to study probabilistic processing, such as the N400 event-related potential (ERP) component, are sensitive to word predictability but not to contextual constraint. Some research suggests that constraint-related processing cost may be measurable via an ERP positivity following the N400, known as the anterior post-N400 positivity (PNP). The PNP is argued to reflect update of a sentence representation and to be distinct from the posterior P600, which reflects conflict detection and reanalysis. However, constraint-related PNP findings are inconsistent. We sought to conceptually replicate Federmeier et al. (2007) and Kuperberg et al. (2020), who observed that the PNP, but not the N400 or the P600, was affected by constraint at unexpected but plausible words. Using a pre-registered design and statistical approach maximising power, we demonstrated a dissociated effect of predictability and constraint: strong evidence for predictability but not constraint in the N400 window, and strong evidence for constraint but not predictability in the later window. However, the constraint effect was consistent with a P600 and not a PNP, suggesting increased conflict between a strong representation and unexpected input rather than greater update of the representation. We conclude that either a simple strong/weak constraint design is not always sufficient to elicit the PNP, or that previous PNP constraint findings could be an artifact of smaller sample size.
The requirements of modern e-learning techniques change. Aspects such as community interaction, flexibility, pervasive learning and increasing mobility in communication habits become more important. To meet these challenges e-learning platforms must provide support on mobile learning. Most approaches try to adopt centralised and static e-learning mechanisms to mobile devices. However, often technically it is not possible for all kinds of devices to be connected to a central server. Therefore we introduce an application of a mobile e-learning network which operates totally decentralised with the help of an underlying ad hoc network architecture. Furthermore the concept of ad hoc messaging network (AMNET) is used as basis system architecture for our approach to implement a platform for pervasive mobile e-learning.
Background
Animal personality has emerged as a key concept in behavioral ecology. While many studies have demonstrated the influence of personality traits on behavioral patterns, its quantification, especially in wild animal populations, remains a challenge. Only a few studies have established a link between personality and recurring movements within home ranges, although these small-scale movements are of key importance for identifying ecological interactions and forming individual niches. In this regard, differences in space use among individuals might reflect different exploration styles between behavioral types along the shy-bold continuum.
Methods
We assessed among-individual differences in behavior in the European hare (Lepus europaeus), a characteristic mammalian herbivore in agricultural landscapes using a standardized box emergence test for captive and wild hares. We determined an individuals’ degree of boldness by measuring the latencies of behavioral responses in repeated emergence tests in captivity. During capture events of wild hares, we conducted a single emergence test and recorded behavioral responses proven to be stable over time in captive hares. Applying repeated novel environment tests in a near-natural enclosure, we further quantified aspects of exploration and activity in captive hares. Finally, we investigated whether and how this among-individual behavioral variation is related to general activity and space use in a wild hare population. Wild and captive hares were treated similarly and GPS-collared with internal accelerometers prior to release to the wild or the outdoor enclosure, respectively. General activity was quantified as overall dynamic body acceleration (ODBA) obtained from accelerometers. Finally, we tested whether boldness explained variation in (i) ODBA in both settings and (ii) variation in home ranges and core areas across different time scales of GPS-collared hares in a wild population.
Results
We found three behavioral responses to be consistent over time in captive hares. ODBA was positively related to boldness (i.e., short latencies to make first contact with the new environment) in both captive and wild hares. Space use in wild hares also varied with boldness, with shy individuals having smaller core areas and larger home ranges than bold conspecifics (yet in some of the parameter space, this association was just marginally significant).
Conclusions
Against our prediction, shy individuals occupied relatively large home ranges but with small core areas. We suggest that this space use pattern is due to them avoiding risky, and energy-demanding competition for valuable resources. Carefully validated, activity measurements (ODBA) from accelerometers provide a valuable tool to quantify aspects of animal personality along the shy-bold continuum remotely. Without directly observing—and possibly disturbing—focal individuals, this approach allows measuring variability in animal personality, especially in species that are difficult to assess with experiments. Considering that accelerometers are often already built into GPS units, we recommend activating them at least during the initial days of tracking to estimate individual variation in general activity and, if possible, match them with a simple novelty experiment. Furthermore, information on individual behavioral types will help to facilitate mechanistic understanding of processes that drive spatial and ecological dynamics in heterogeneous landscapes.
Arctic warming has implications for the functioning of terrestrial Arctic ecosystems, global climate and socioeconomic systems of northern communities. A research gap exists in high spatial resolution monitoring and understanding of the seasonality of permafrost degradation, spring snowmelt and vegetation phenology. This thesis explores the diversity and utility of dense TerraSAR-X (TSX) X-Band time series for monitoring ice-rich riverbank erosion, snowmelt, and phenology of Arctic vegetation at long-term study sites in the central Lena Delta, Russia and on Qikiqtaruk (Herschel Island), Canada. In the thesis the following three research questions are addressed:
• Is TSX time series capable of monitoring the dynamics of rapid permafrost degradation in ice-rich permafrost on an intra-seasonal scale and can these datasets in combination with climate data identify the climatic drivers of permafrost degradation?
• Can multi-pass and multi-polarized TSX time series adequately monitor seasonal snow cover and snowmelt in small Arctic catchments and how does it perform compared to optical satellite data and field-based measurements?
• Do TSX time series reflect the phenology of Arctic vegetation and how does the recorded signal compare to in-situ greenness data from RGB time-lapse camera data and vegetation height from field surveys?
To answer the research questions three years of TSX backscatter data from 2013 to 2015 for the Lena Delta study site and from 2015 to 2017 for the Qikiqtaruk study site were used in quantitative and qualitative analysis complimentary with optical satellite data and in-situ time-lapse imagery.
The dynamics of intra-seasonal ice-rich riverbank erosion in the central Lena Delta, Russia were quantified using TSX backscatter data at 2.4 m spatial resolution in HH polarization and validated with 0.5 m spatial resolution optical satellite data and field-based time-lapse camera data. Cliff top lines were automatically extracted from TSX intensity images using threshold-based segmentation and vectorization and combined in a geoinformation system with manually digitized cliff top lines from the optical satellite data and rates of erosion extracted from time-lapse cameras. The results suggest that the cliff top eroded at a constant rate throughout the entire erosional season. Linear mixed models confirmed that erosion was coupled with air temperature and precipitation at an annual scale, seasonal fluctuations did not influence 22-day erosion rates. The results highlight the potential of HH polarized X-Band backscatter data for high temporal resolution monitoring of rapid permafrost degradation.
The distinct signature of wet snow in backscatter intensity images of TSX data was exploited to generate wet snow cover extent (SCE) maps on Qikiqtaruk at high temporal resolution. TSX SCE showed high similarity to Landsat 8-derived SCE when using cross-polarized VH data. Fractional snow cover (FSC) time series were extracted from TSX and optical SCE and compared to FSC estimations from in-situ time-lapse imagery. The TSX products showed strong agreement with the in-situ data and significantly improved the temporal resolution compared to the Landsat 8 time series. The final combined FSC time series revealed two topography-dependent snowmelt patterns that corresponded to in-situ measurements. Additionally TSX was able to detect snow patches longer in the season than Landsat 8, underlining the advantage of TSX for detection of old snow. The TSX-derived snow information provided valuable insights into snowmelt dynamics on Qikiqtaruk previously not available.
The sensitivity of TSX to vegetation structure associated with phenological changes was explored on Qikiqtaruk. Backscatter and coherence time series were compared to greenness data extracted from in-situ digital time-lapse cameras and detailed vegetation parameters on 30 areas of interest. Supporting previous results, vegetation height corresponded to backscatter intensity in co-polarized HH/VV at an incidence angle of 31°. The dry, tall shrub dominated ecological class showed increasing backscatter with increasing greenness when using the cross polarized VH/HH channel at 32° incidence angle. This is likely driven by volume scattering of emerging and expanding leaves. Ecological classes with more prostrate vegetation and higher bare ground contributions showed decreasing backscatter trends over the growing season in the co-polarized VV/HH channels likely a result of surface drying instead of a vegetation structure signal. The results from shrub dominated areas are promising and provide a complementary data source for high temporal monitoring of vegetation phenology.
Overall this thesis demonstrates that dense time series of TSX with optical remote sensing and in-situ time-lapse data are complementary and can be used to monitor rapid and seasonal processes in Arctic landscapes at high spatial and temporal resolution.
Prediction of hybrid biomass in Arabidopsis thaliana by selected parental SNP and metabolic markers
(2009)
A recombinant inbred line (RIL) population, derived from two Arabidopsis thaliana accessions, and the corresponding testcrosses with these two original accessions were used for the development and validation of machine learning models to predict the biomass of hybrids. Genetic and metabolic information of the RILs served as predictors. Feature selection reduced the number of variables (genetic and metabolic markers) in the models by more than 80% without impairing the predictive power. Thus, potential biomarkers have been revealed. Metabolites were shown to bear information on inherited macroscopic phenotypes. This proof of concept could be interesting for breeders. The example population exhibits substantial mid-parent biomass heterosis. The results of feature selection could therefore be used to shed light on the origin of heterosis. In this respect, mainly dominance effects were detected.
Salt deposits offer a variety of usage types. These include the mining of rock salt and potash salt as important raw materials, the storage of energy in man-made underground caverns, and the disposal of hazardous substances in former mines. The most serious risk with any of these usage types comes from the contact with groundwater or surface water. It causes an uncontrolled dissolution of salt rock, which in the worst case can result in the flooding or collapse of underground facilities. Especially along potash seams, cavernous structures can spread quickly, because potash salts show a much higher solubility than rock salt. However, as their chemical behavior is quite complex, previous models do not account for these highly soluble interlayers. Therefore, the objective of the present thesis is to describe the evolution of cavernous structures along potash seams in space and time in order to improve hazard mitigation during the utilization of salt deposits.
The formation of cavernous structures represents an interplay of chemical and hydraulic processes. Hence, the first step is to systematically investigate the dissolution and precipitation reactions that occur when water and potash salt come into contact. For this purpose, a geochemical reaction model is used. The results show that the minerals are only partially dissolved, resulting in a porous sponge like structure. With the saturation of the solution increasing, various secondary minerals are formed, whose number and type depend on the original rock composition. Field data confirm a correlation between the degree of saturation and the distance from the center of the cavern, where solution is entering. Subsequently, the reaction model is coupled with a flow and transport code and supplemented by a novel approach called ‘interchange’. The latter enables the exchange of solution and rock between areas of different porosity and mineralogy, and thus ultimately the growth of the cavernous structure. By means of several scenario analyses, cavern shape, growth rate and mineralogy are systematically investigated, taking also heterogeneous potash seams into account. The results show that basically four different cases can be distinguished, with mixed forms being a frequent occurrence in nature. The classification scheme is based on the dimensionless numbers Péclet and Damköhler, and allows for a first assessment of the hazard potential. In future, the model can be applied to any field case, using measurement data for calibration.
The presented research work provides a reactive transport model that is able to spatially and temporally characterize the propagation of cavernous structures along potash seams for the first time. Furthermore, it allows to determine thickness and composition of transition zones between cavern center and unaffected salt rock. The latter is particularly important in potash mining, so that natural cavernous structures can be located at an early stage and the risk of mine flooding can thus be reduced. The models may also contribute to an improved hazard prevention in the construction of storage caverns and the disposal of hazardous waste in salt deposits. Predictions regarding the characteristics and evolution of cavernous structures enable a better assessment of potential hazards, such as integrity or stability loss, as well as of suitable mitigation measures.
“Domestic Foreigners”
(2024)
This paper examines the relationship between the Sephardic Jewish community of Vienna and the Ottoman and Habsburg Empires in the latter half of the 19th century. The community’s legal status was transformed following the emancipation of Austrian Jews, but very few first-hand accounts of these changes exist today. The primary sources analyzed in this paper are Judezmo-language newspapers published in Vienna at that time. The paper emphasizes the historical and political contexts surrounding these sources, particularly the community’s close ties to the Ottoman and Habsburg regimes.
In the present thesis, AC electrokinetic forces, like dielectrophoresis and AC electroosmosis, were demonstrated as a simple and fast method to functionalize the surface of nanoelectrodes with submicrometer sized biological objects. These nanoelectrodes have a cylindrical shape with a diameter of 500 nm arranged in an array of 6256 electrodes. Due to its medical relevance influenza virus as well as anti-influenza antibodies were chosen as a model organism. Common methods to bring antibodies or proteins to biosensor surfaces are complex and time-consuming. In the present work, it was demonstrated that by applying AC electric fields influenza viruses and antibodies can be immobilized onto the nanoelectrodes within seconds without any prior chemical modification of neither the surface nor the immobilized biological object. The distribution of these immobilized objects is not uniform over the entire array, it exhibits a decreasing gradient from the outer row to the inner ones. Different causes for this gradient have been discussed, such as the vortex-shaped fluid motion above the nanoelectrodes generated by, among others, electrothermal fluid flow. It was demonstrated that parts of the accumulated material are permanently immobilized to the electrodes. This is a unique characteristic of the presented system since in the literature the AC electrokinetic immobilization is almost entirely presented as a method just for temporary immobilization. The spatial distribution of the immobilized viral material or the anti-influenza antibodies at the electrodes was observed by either the combination of fluorescence microscopy and deconvolution or by super-resolution microscopy (STED). On-chip immunoassays were performed to examine the suitability of the functionalized electrodes as a potential affinity-based biosensor. Two approaches were pursued: A) the influenza virus as the bio-receptor or B) the influenza virus as the analyte. Different sources of error were eliminated by ELISA and passivation experiments. Hence, the activity of the immobilized object was inspected by incubation with the analyte. This resulted in the successful detection of anti-influenza antibodies by the immobilized viral material. On the other hand, a detection of influenza virus particles by the immobilized anti-influenza antibodies was not possible. The latter might be due to lost activity or wrong orientation of the antibodies. Thus, further examinations on the activity of by AC electric fields immobilized antibodies should follow. When combined with microfluidics and an electrical read-out system, the functionalized chips possess the potential to serve as a rapid, portable, and cost-effective point-of-care (POC) device. This device can be utilized as a basis for diverse applications in diagnosing and treating influenza, as well as various other pathogens.
We report on new mass-loss rate estimates for O stars in six massive binaries using the amplitude of orbital-phase dependent, linear-polarimetric variability caused by electron scattering off free electrons in the winds. Our estimated mass-loss rates for luminous O stars are independent of clumping. They suggest similar clumping corrections as for WR stars and do not support the recently proposed reduction in mass-loss rates of O stars by one or two orders of magnitude.
The James Webb Space Telescope (JWST) is a large, infrared-optimized space telescope scheduled for launch in 2013. JWST will find the first stars and galaxies that formed in the early universe, connecting the Big Bang to our own Milky Way galaxy. JWST will peer through dusty clouds to see stars forming planetary systems, connecting the MilkyWay to our own Solar System. JWST’s instruments are designed to work primarily in the infrared range of 1 - 28 μm, with some capability in the visible range. JWST will have a large mirror, 6.5 m in diameter, and will be diffraction-limited at 2 μm (0.1 arcsec resolution). JWST will be placed in an L2 orbit about 1.5 million km from the Earth. The instruments will provide imaging, coronography, and multi-object and integral-field spectroscopy across the 1 - 28 μm wavelength range. The breakthrough capabilities of JWST will enable new studies of massive star winds from the Milky Way to the early universe.
I discuss observational evidence – independent of the direct spectral diagnostics of stellar winds themselves – suggesting that mass-loss rates for O stars need to be revised downward by roughly a factor of three or more, in line with recent observed mass-loss rates for clumped winds. These independent constraints include the large observed mass-loss rates in LBV eruptions, the large masses of evolved massive stars like LBVs and WNH stars, WR stars in lower metallicity environments, observed rotation rates of massive stars at different metallicity, supernovae that seem to defy expectations of high mass-loss rates in stellar evolution, and other clues. I pay particular attention to the role of feedback that would result from higher mass-loss rates, driving the star to the Eddington limit too soon, and therefore making higher rates appear highly implausible. Some of these arguments by themselves may have more than one interpretation, but together they paint a consistent picture that steady line-driven winds of O-type stars have lower mass-loss rates and are significantly clumped.
Business process management experiences a large uptake by the industry, and process models play an important role in the analysis and improvement of processes. While an increasing number of staff becomes involved in actual modeling practice, it is crucial to assure model quality and homogeneity along with providing suitable aids for creating models. In this paper we consider the problem of offering recommendations to the user during the act of modeling. Our key contribution is a concept for defining and identifying so-called action patterns - chunks of actions often appearing together in business processes. In particular, we specify action patterns and demonstrate how they can be identified from existing process model repositories using association rule mining techniques. Action patterns can then be used to suggest additional actions for a process model. Our approach is challenged by applying it to the collection of process models from the SAP Reference Model.
Business process management aims at capturing, understanding, and improving work in organizations. The central artifacts are process models, which serve different purposes. Detailed process models are used to analyze concrete working procedures, while high-level models show, for instance, handovers between departments. To provide different views on process models, business process model abstraction has emerged. While several approaches have been proposed, a number of abstraction use case that are both relevant for industry and scientifically challenging are yet to be addressed. In this paper we systematically develop, classify, and consolidate different use cases for business process model abstraction. The reported work is based on a study with BPM users in the health insurance sector and validated with a BPM consultancy company and a large BPM vendor. The identified fifteen abstraction use cases reflect the industry demand. The related work on business process model abstraction is evaluated against the use cases, which leads to a research agenda.
Contents: Chapter 1. Introduction 1 Information Structure 2 Grammatical Correlates of Information Structure 3 Structure of the Questionnaire 4 Experimental Tasks 5 Technicalities 6 Archiving 7 Acknowledgments Chapter 2. General Questions 1 General Information 2 Phonology 3 Morphology and Syntax Chapter 3. Experimental tasks 1 Changes (Given/New in Intransitives and Transitives) 2 Giving (Given/New in Ditransitives) 3 Visibility (Given/New, Animacy and Type/Token Reference) 4 Locations (Given/New in Locative Expressions) 5 Sequences (Given/New/Contrast in Transitives) 6 Dynamic Localization (Given/New in Dynamic Loc. Descriptions) 7 Birthday Party (Weight and Discourse Status) 8 Static Localization (Macro-Planning and Given/New in Locatives) 9 Guiding (Presentational Utterances) 10 Event Cards (All New) 11 Anima (Focus types and Animacy) 12 Contrast (Contrast in pairing events) 13 Animal Game (Broad/Narrow Focus in NP) 14 Properties (Focus on Property and Possessor) 15 Eventives (Thetic and Categorical Utterances) 16 Tell a Story (Contrast in Text) 17 Focus Cards (Selective, Restrictive, Additive, Rejective Focus) 18 Who does What (Answers to Multiple Constituent Questions) 19 Fairy Tale (Topic and Focus in Coherent Discourse) 20 Map Task (Contrastive and Selective Focus in Spontaneous Dialogue) 21 Drama (Contrastive Focus in Argumentation) 22 Events in Places (Spatial, Temporal and Complex Topics) 23 Path Descriptions (Topic Change in Narrative) 24 Groups (Partial Topic) 25 Connections (Bridging Topic) 26 Indirect (Implicational Topic) 27 Surprises (Subject-Topic Interrelation) 28 Doing (Action Given, Action Topic) 29 Influences (Question Priming) Chapter 4. Translation tasks 1 Basic Intonational Properties 2 Focus Translation 3 Topic Translation 4 Quantifiers Chapter 5. Information structure summary survey 1 Preliminaries 2 Syntax 3 Morphology 4 Prosody 5 Summary: Information structure Chapter 6. Performance of Experimental Tasks in the Field 1 Field sessions 2 Field Session Metadata 3 Informants’ Agreement
The increasing demand for energy in the current technological era and the recent political decisions about giving up on nuclear energy diverted humanity to focus on alternative environmentally friendly energy sources like solar energy. Although silicon solar cells are the product of a matured technology, the search for highly efficient and easily applicable materials is still ongoing. These properties made the efficiency of halide perovskites comparable with silicon solar cells for single junctions within a decade of research. However, the downside of halide perovskites are poor stability and lead toxicity for the most stable ones.
On the other hand, chalcogenide perovskites are one of the most promising absorber materials for the photovoltaic market, due to their elemental abundance and chemical stability against moisture and oxygen. In the search of the ultimate solar absorber material, combining the good optoelectronic properties of halide perovskites with the stability of chalcogenides could be the promising candidate.
Thus, this work investigates new techniques for the synthesis and design of these novel chalcogenide perovskites, that contain transition metals as cations, e.g., BaZrS3, BaHfS3, EuZrS3, EuHfS3 and SrHfS3. There are two stages in the deposition techniques of this study: In the first stage, the binary compounds are deposited via a solution processing method. In the second stage, the deposited materials are annealed in a chalcogenide atmosphere to form the perovskite structure by using solid-state reactions.
The research also focuses on the optimization of a generalized recipe for a molecular ink to deposit precursors of chalcogenide perovskites with different binaries. The implementation of the precursor sulfurization resulted in either binaries without perovskite formation or distorted perovskite structures, whereas some of these materials are reported in the literature as they are more favorable in the needle-like non-perovskite configuration.
Lastly, there are two categories for the evaluation of the produced materials: The first category is about the determination of the physical properties of the deposited layer, e.g., crystal structure, secondary phase formation, impurities, etc. For the second category, optoelectronic properties are measured and compared to an ideal absorber layer, e.g., band gap, conductivity, surface photovoltage, etc.
Dryland vulnerability : typical patterns and dynamics in support of vulnerability reduction efforts
(2011)
The pronounced constraints on ecosystem functioning and human livelihoods in drylands are frequently exacerbated by natural and socio-economic stresses, including weather extremes and inequitable trade conditions. Therefore, a better understanding of the relation between these stresses and the socio-ecological systems is important for advancing dryland development. The concept of vulnerability as applied in this dissertation describes this relation as encompassing the exposure to climate, market and other stresses as well as the sensitivity of the systems to these stresses and their capacity to adapt. With regard to the interest in improving environmental and living conditions in drylands, this dissertation aims at a meaningful generalisation of heterogeneous vulnerability situations. A pattern recognition approach based on clustering revealed typical vulnerability-creating mechanisms at global and local scales. One study presents the first analysis of dryland vulnerability with global coverage at a sub-national resolution. The cluster analysis resulted in seven typical patterns of vulnerability according to quantitative indication of poverty, water stress, soil degradation, natural agro-constraints and isolation. Independent case studies served to validate the identified patterns and to prove the transferability of vulnerability-reducing approaches. Due to their worldwide coverage, the global results allow the evaluation of a specific system’s vulnerability in its wider context, even in poorly-documented areas. Moreover, climate vulnerability of smallholders was investigated with regard to their food security in the Peruvian Altiplano. Four typical groups of households were identified in this local dryland context using indicators for harvest failure risk, agricultural resources, education and non-agricultural income. An elaborate validation relying on independently acquired information demonstrated the clear correlation between weather-related damages and the identified clusters. It also showed that household-specific causes of vulnerability were consistent with the mechanisms implied by the corresponding patterns. The synthesis of the local study provides valuable insights into the tailoring of interventions that reflect the heterogeneity within the social group of smallholders. The conditions necessary to identify typical vulnerability patterns were summarised in five methodological steps. They aim to motivate and to facilitate the application of the selected pattern recognition approach in future vulnerability analyses. The five steps outline the elicitation of relevant cause-effect hypotheses and the quantitative indication of mechanisms as well as an evaluation of robustness, a validation and a ranking of the identified patterns. The precise definition of the hypotheses is essential to appropriately quantify the basic processes as well as to consistently interpret, validate and rank the clusters. In particular, the five steps reflect scale-dependent opportunities, such as the outcome-oriented aspect of validation in the local study. Furthermore, the clusters identified in Northeast Brazil were assessed in the light of important endogenous processes in the smallholder systems which dominate this region. In order to capture these processes, a qualitative dynamic model was developed using generalised rules of labour allocation, yield extraction, budget constitution and the dynamics of natural and technological resources. The model resulted in a cyclic trajectory encompassing four states with differing degree of criticality. The joint assessment revealed aggravating conditions in major parts of the study region due to the overuse of natural resources and the potential for impoverishment. The changes in vulnerability-creating mechanisms identified in Northeast Brazil are well-suited to informing local adjustments to large-scale intervention programmes, such as “Avança Brasil”. Overall, the categorisation of a limited number of typical patterns and dynamics presents an efficient approach to improving our understanding of dryland vulnerability. Appropriate decision-making for sustainable dryland development through vulnerability reduction can be significantly enhanced by pattern-specific entry points combined with insights into changing hotspots of vulnerability and the transferability of successful adaptation strategies.
Among the multitude of geomorphological processes, aeolian shaping processes are of special character, Pedogenic dust is one of the most important sources of atmospheric aerosols and therefore regarded as a key player for atmospheric processes. Soil dust emissions, being complex in composition and properties, influence atmospheric processes and air quality and has impacts on other ecosystems. In this because even though their immediate impact can be considered low (exceptions exist), their constant and large-scale force makes them a powerful player in the earth system. dissertation, we unravel a novel scientific understanding of this complex system based on a holistic dataset acquired during a series of field experiments on arable land in La Pampa, Argentina. The field experiments as well as the generated data provide information about topography, various soil parameters, the atmospheric dynamics in the very lower atmosphere (4m height) as well as measurements regarding aeolian particle movement across a wide range of particle size classes between 0.2μm up to the coarse sand.
The investigations focus on three topics: (a) the effects of low-scale landscape structures on aeolian transport processes of the coarse particle fraction, (b) the horizontal and vertical fluxes of the very fine particles and (c) the impact of wind gusts on particle emissions.
Among other considerations presented in this thesis, it could in particular be shown, that even though the small-scale topology does have a clear impact on erosion and deposition patterns, also physical soil parameters need to be taken into account for a robust statistical modelling of the latter. Furthermore, specifically the vertical fluxes of particulate matter have different characteristics for the particle size classes. Finally, a novel statistical measure was introduced to quantify the impact of wind gusts on the particle uptake and its application on the provided data set. The aforementioned measure shows significantly increased particle concentrations during points in time defined as gust event.
With its holistic approach, this thesis further contributes to the fundamental understanding of how atmosphere and pedosphere are intertwined and affect each other.
A degree course in IT and business administration solely for women (FIW) has been offered since 2009 at the HTW Berlin – University of Applied Sciences. This contribution discusses student motivations for enrolling in such a women only degree course and gives details of our experience over recent years. In particular, the approach to attracting new female students is described and the composition of the intake is discussed. It is shown that the women-only setting together with other factors can attract a new clientele for computer science.
“Creating a Maritime Future”
(2023)
This article explores the importance of the port city of Hamburg in the evolving discourses on the creation of a maritime future, a vision which became influential in the 1930s, 1940s and 1950s. While some Jewish representatives in the city aimed at preserving and intertwining Hanseatic and Jewish traditions in order to secure a Jewish presence in the port city under the pressure of the Nazi regime and thereafter, others wanted to create new emigration opportunities, especially to Mandatory Palestine, and create a Jewish maritime future in Eretz Israel. Different Zionist organizations supported the newly evolving maritime ideas, such as the “conquest of the sea”, and promoted the image of a Jewish seafaring nation. Despite the difficulties in the 1940s, these concepts gained influence post-1945 and led to the foundation of the fishery kibbutz “Zerubavel” in Blankenese/Hamburg. However, the idea of a Hanseatic Jewish future also remained influential and illustrates how differently a “Jewish maritime future” was imagined and used to link past, present and future.
Natural extreme events are an integral part of nature on planet earth. Usually these events are only considered hazardous to humans, in case they are exposed. In this case, however, natural hazards can have devastating impacts on human societies. Especially hydro-meteorological hazards have a high damage potential in form of e.g. riverine and pluvial floods, winter storms, hurricanes and tornadoes, which can occur all over the globe. Along with an increasingly warm climate also an increase in extreme weather which potentially triggers natural hazards can be expected. Yet, not only changing natural systems, but also changing societal systems contribute to an increasing risk associated with these hazards. These can comprise increasing exposure and possibly also increasing vulnerability to the impacts of natural events. Thus, appropriate risk management is required to adapt all parts of society to existing and upcoming risks at various spatial scales. One essential part of risk management is the risk assessment including the estimation of the economic impacts. However, reliable methods for the estimation of economic impacts due to hydro-meteorological hazards are still missing. Therefore, this thesis deals with the question of how the reliability of hazard damage estimates can be improved, represented and propagated across all spatial scales. This question is investigated using the specific example of economic impacts to companies as a result of riverine floods in Germany.
Flood damage models aim to describe the damage processes during a given flood event. In other words they describe the vulnerability of a specific object to a flood. The models can be based on empirical data sets collected after flood events. In this thesis tree-based models trained with survey data are used for the estimation of direct economic flood impacts on the objects. It is found that these machine learning models, in conjunction with increasing sizes of data sets used to derive the models, outperform state-of-the-art damage models. However, despite the performance improvements induced by using multiple variables and more data points, large prediction errors remain at the object level. The occurrence of the high errors was explained by a further investigation using distributions derived from tree-based models. The investigation showed that direct economic impacts to individual objects cannot be modeled by a normal distribution. Yet, most state-of-the-art approaches assume a normal distribution and take mean values as point estimators. Subsequently, the predictions are unlikely values within the distributions resulting in high errors. At larger spatial scales more objects are considered for the damage estimation. This leads to a better fit of the damage estimates to a normal distribution. Consequently, also the performance of the point estimators get better, although large errors can still occur due to the variance of the normal distribution. It is recommended to use distributions instead of point estimates in order to represent the reliability of damage estimates.
In addition current approaches also mostly ignore the uncertainty associated with the characteristics of the hazard and the exposed objects. For a given flood event e.g. the estimation of the water level at a certain building is prone to uncertainties. Current approaches define exposed objects mostly by the use of land use data sets. These data sets often show inconsistencies, which introduce additional uncertainties. Furthermore, state-of-the-art approaches also imply problems of missing consistency when predicting the damage at different spatial scales. This is due to the use of different types of exposure data sets for model derivation and application. In order to face these issues a novel object-based method was developed in this thesis. The method enables a seamless estimation of hydro-meteorological hazard damage across spatial scales including uncertainty quantification. The application and validation of the method resulted in plausible estimations at all spatial scales without overestimating the uncertainty.
Mainly newly available data sets containing individual buildings make the application of the method possible as they allow for the identification of flood affected objects by overlaying the data sets with water masks. However, the identification of affected objects with two different water masks revealed huge differences in the number of identified objects. Thus, more effort is needed for their identification, since the number of objects affected determines the order of magnitude of the economic flood impacts to a large extent.
In general the method represents the uncertainties associated with the three components of risk namely hazard, exposure and vulnerability, in form of probability distributions. The object-based approach enables a consistent propagation of these uncertainties in space. Aside from the propagation of damage estimates and their uncertainties across spatial scales, a propagation between models estimating direct and indirect economic impacts was demonstrated. This enables the inclusion of uncertainties associated with the direct economic impacts within the estimation of the indirect economic impacts. Consequently, the modeling procedure facilitates the representation of the reliability of estimated total economic impacts. The representation of the estimates' reliability prevents reasoning based on a false certainty, which might be attributed to point estimates. Therefore, the developed approach facilitates a meaningful flood risk management and adaptation planning.
The successful post-event application and the representation of the uncertainties qualifies the method also for the use for future risk assessments. Thus, the developed method enables the representation of the assumptions made for the future risk assessments, which is crucial information for future risk management. This is an important step forward, since the representation of reliability associated with all components of risk is currently lacking in all state-of-the-art methods assessing future risk.
In conclusion, the use of object-based methods giving results in the form of distributions instead of point estimations is recommended. The improvement of the model performance by the means of multi-variable models and additional data points is possible, but small. Uncertainties associated with all components of damage estimation should be included and represented within the results. Furthermore, the findings of the thesis suggest that, at larger scales, the influence of the uncertainty associated with the vulnerability is smaller than those associated with the hazard and exposure. This leads to the conclusion that for an increased reliability of flood damage estimations and risk assessments, the improvement and active inclusion of hazard and exposure, including their uncertainties, is needed in addition to the improvements of the models describing the vulnerability of the objects.
The origin and structure of magnetic fields in the Galaxy are largely unknown. What is known is that they are essential for several astrophysical processes, in particular the propagation of cosmic rays. Our ability to describe the propagation of cosmic rays through the Galaxy is severely limited by the lack of observational data needed to probe the structure of the Galactic magnetic field on many different length scales. This is particularly true for modelling the propagation of cosmic rays into the Galactic halo, where our knowledge of the magnetic field is particularly poor.
In the last decade, observations of the Galactic halo in different frequency regimes have revealed the existence of out-of-plane bubble emission in the Galactic halo. In gamma rays these bubbles have been termed Fermi bubbles with a radial extent of ≈ 3 kpc and an azimuthal height of ≈ 6 kpc. The radio counterparts of the Fermi bubbles were seen by both the S-PASS telescopes and the Planck satellite, and showed a clear spatial overlap. The X-ray counterparts of the Fermi bubbles were named eROSITA bubbles after the eROSITA satellite, with a radial width of ≈ 7 kpc and an azimuthal height of ≈ 14 kpc. Taken together, these observations suggest the presence of large extended Galactic Halo Bubbles (GHB) and have stimulated interest in exploring the less explored Galactic halo.
In this thesis, a new toy model (GHB model) for the magnetic field and non-thermal electron distribution in the Galactic halo has been proposed. The new toy model has been used to produce polarised synchrotron emission sky maps. Chi-square analysis was used to compare the synthetic skymaps with the Planck 30 GHz polarised skymaps. The obtained constraints on the strength and azimuthal height were found to be in agreement with the S-PASS radio observations.
The upper, lower and best-fit values obtained from the above chi-squared analysis were used to generate three separate toy models. These three models were used to propagate ultra-high energy cosmic rays. This study was carried out for two potential sources, Centaurus A and NGC 253, to produce magnification maps and arrival direction skymaps. The simulated arrival direction skymaps were found to be consistent with the hotspots of Centaurus A and NGC 253 as seen in the observed arrival direction skymaps provided by the Pierre Auger Observatory (PAO).
The turbulent magnetic field component of the GHB model was also used to investigate the extragalactic dipole suppression seen by PAO. UHECRs with an extragalactic dipole were forward-tracked through the turbulent GHB model at different field strengths. The suppression in the dipole due to the varying diffusion coefficient from the simulations was noted. The results could also be compared with an analytical analogy of electrostatics. The simulations of the extragalactic dipole suppression were in agreement with similar studies carried out for galactic cosmic rays.
.NET Gadgeteer Workshop
(2013)
A wide range of additional forward chaining applications could be realized with deductive databases, if their rule formalism, their immediate consequence operator, and their fixpoint iteration process would be more flexible. Deductive databases normally represent knowledge using stratified Datalog programs with default negation. But many practical applications of forward chaining require an extensible set of user–defined built–in predicates. Moreover, they often need function symbols for building complex data structures, and the stratified fixpoint iteration has to be extended by aggregation operations. We present an new language Datalog*, which extends Datalog by stratified meta–predicates (including default negation), function symbols, and user–defined built–in predicates, which are implemented and evaluated top–down in Prolog. All predicates are subject to the same backtracking mechanism. The bottom–up fixpoint iteration can aggregate the derived facts after each iteration based on user–defined Prolog predicates.
Mathematical modeling of biological phenomena has experienced increasing interest since new high-throughput technologies give access to growing amounts of molecular data. These modeling approaches are especially able to test hypotheses which are not yet experimentally accessible or guide an experimental setup. One particular attempt investigates the evolutionary dynamics responsible for today's composition of organisms. Computer simulations either propose an evolutionary mechanism and thus reproduce a recent finding or rebuild an evolutionary process in order to learn about its mechanism. The quest for evolutionary fingerprints in metabolic and gene-coexpression networks is the central topic of this cumulative thesis based on four published articles. An understanding of the actual origin of life will probably remain an insoluble problem. However, one can argue that after a first simple metabolism has evolved, the further evolution of metabolism occurred in parallel with the evolution of the sequences of the catalyzing enzymes. Indications of such a coevolution can be found when correlating the change in sequence between two enzymes with their distance on the metabolic network which is obtained from the KEGG database. We observe that there exists a small but significant correlation primarily on nearest neighbors. This indicates that enzymes catalyzing subsequent reactions tend to be descended from the same precursor. Since this correlation is relatively small one can at least assume that, if new enzymes are no "genetic children" of the previous enzymes, they certainly be descended from any of the already existing ones. Following this hypothesis, we introduce a model of enzyme-pathway coevolution. By iteratively adding enzymes, this model explores the metabolic network in a manner similar to diffusion. With implementation of an Gillespie-like algorithm we are able to introduce a tunable parameter that controls the weight of sequence similarity when choosing a new enzyme. Furthermore, this method also defines a time difference between successive evolutionary innovations in terms of a new enzyme. Overall, these simulations generate putative time-courses of the evolutionary walk on the metabolic network. By a time-series analysis, we find that the acquisition of new enzymes appears in bursts which are pronounced when the influence of the sequence similarity is higher. This behavior strongly resembles punctuated equilibrium which denotes the observation that new species tend to appear in bursts as well rather than in a gradual manner. Thus, our model helps to establish a better understanding of punctuated equilibrium giving a potential description at molecular level. From the time-courses we also extract a tentative order of new enzymes, metabolites, and even organisms. The consistence of this order with previous findings provides evidence for the validity of our approach. While the sequence of a gene is actually subject to mutations, its expression profile might also indirectly change through the evolutionary events in the cellular interplay. Gene coexpression data is simply accessible by microarray experiments and commonly illustrated using coexpression networks where genes are nodes and get linked once they show a significant coexpression. Since the large number of genes makes an illustration of the entire coexpression network difficult, clustering helps to show the network on a metalevel. Various clustering techniques already exist. However, we introduce a novel one which maintains control of the cluster sizes and thus assures proper visual inspection. An application of the method on Arabidopsis thaliana reveals that genes causing a severe phenotype often show a functional uniqueness in their network vicinity. This leads to 20 genes of so far unknown phenotype which are however suggested to be essential for plant growth. Of these, six indeed provoke such a severe phenotype, shown by mutant analysis. By an inspection of the degree distribution of the A.thaliana coexpression network, we identified two characteristics. The distribution deviates from the frequently observed power-law by a sharp truncation which follows after an over-representation of highly connected nodes. For a better understanding, we developed an evolutionary model which mimics the growth of a coexpression network by gene duplication which underlies a strong selection criterion, and slight mutational changes in the expression profile. Despite the simplicity of our assumption, we can reproduce the observed properties in A.thaliana as well as in E.coli and S.cerevisiae. The over-representation of high-degree nodes could be identified with mutually well connected genes of similar functional families: zinc fingers (PF00096), flagella, and ribosomes respectively. In conclusion, these four manuscripts demonstrate the usefulness of mathematical models and statistical tools as a source of new biological insight. While the clustering approach of gene coexpression data leads to the phenotypic characterization of so far unknown genes and thus supports genome annotation, our model approaches offer explanations for observed properties of the coexpression network and furthermore substantiate punctuated equilibrium as an evolutionary process by a deeper understanding of an underlying molecular mechanism.
As mid-19th-century American Jews introduced radical changes to their religious observance and began to define Judaism in new ways, to what extent did they engage with European Jewish ideas? Historians often approach religious change among Jews from German lands during this period as if Jewish immigrants had come to America with one set of ideas that then evolved solely in conversation with their American contexts. Historians have similarly cast the kinds of Judaism Americans created as both unique to America and uniquely American. These characterizations are accurate to an extent. But to what extent did Jewish innovations in the United States take place in conversation with European Jewish developments? Looking to the 19th-century American Jewish press, this paper seeks to understand how American Jews engaged European Judaism in formulating their own ideas, understanding themselves, and understanding their place in world Judaism.
To achieve a sustainable energy economy, it is necessary to turn back on the combustion of fossil fuels as a means of energy production and switch to renewable sources. However, their temporal availability does not match societal consumption needs, meaning that renewably generated energy must be stored in its main generation times and allocated during peak consumption periods. Electrochemical energy storage (EES) in general is well suited due to its infrastructural independence and scalability. The lithium ion battery (LIB) takes a special place, among EES systems due to its energy density and efficiency, but the scarcity and uneven geological occurrence of minerals and ores vital for many cell components, and hence the high and fluctuating costs will decelerate its further distribution.
The sodium ion battery (SIB) is a promising successor to LIB technology, as the fundamental setup and cell chemistry is similar in the two systems. Yet, the most widespread negative electrode material in LIBs, graphite, cannot be used in SIBs, as it cannot store sufficient amounts of sodium at reasonable potentials. Hence, another carbon allotrope, non-graphitizing or hard carbon (HC) is used in SIBs. This material consists of turbostratically disordered, curved graphene layers, forming regions of graphitic stacking and zones of deviating layers, so-called internal or closed pores.
The structural features of HC have a substantial impact of the charge-potential curve exhibited by the carbon when it is used as the negative electrode in an SIB. At defects and edges an adsorption-like mechanism of sodium storage is prevalent, causing a sloping voltage curve, ill-suited for the practical application in SIBs, whereas a constant voltage plateau of relatively high capacities is found immediately after the sloping region, which recent research attributed to the deposition of quasimetallic sodium into the closed pores of HC.
Literature on the general mechanism of sodium storage in HCs and especially the role of the closed pore is abundant, but the influence of the pore geometry and chemical nature of the HC on the low-potential sodium deposition is yet in an early stage. Therefore, the scope of this thesis is to investigate these relationships using suitable synthetic and characterization methods. Materials of precisely known morphology, porosity, and chemical structure are prepared in clear distinction to commonly obtained ones and their impact on the sodium storage characteristics is observed. Electrochemical impedance spectroscopy in combination with distribution of relaxation times analysis is further established as a technique to study the sodium storage process, in addition to classical direct current techniques, and an equivalent circuit model is proposed to qualitatively describe the HC sodiation mechanism, based on the recorded data. The obtained knowledge is used to develop a method for the preparation of closed porous and non-porous materials from open porous ones, proving not only the necessity of closed pores for efficient sodium storage, but also providing a method for effective pore closure and hence the increase of the sodium storage capacity and efficiency of carbon materials.
The insights obtained and methods developed within this work hence not only contribute to the better understanding of the sodium storage mechanism in carbon materials of SIBs, but can also serve as guidance for the design of efficient electrode materials.
A numerical bifurcation analysis of the electrically driven plane sheet pinch is presented. The electrical conductivity varies across the sheet such as to allow instability of the quiescent basic state at some critical Hartmann number. The most unstable perturbation is the two-dimensional tearing mode. Restricting the whole problem to two spatial dimensions, this mode is followed up to a time-asymptotic steady state, which proves to be sensitive to three-dimensional perturbations even close to the point where the primary instability sets in. A comprehensive three-dimensional stability analysis of the two-dimensional steady tearing-mode state is performed by varying parameters of the sheet pinch. The instability with respect to three-dimensional perturbations is suppressed by a sufficiently strong magnetic field in the invariant direction of the equilibrium. For a special choice of the system parameters, the unstably perturbed state is followed up in its nonlinear evolution and is found to approach a three-dimensional steady state.
This PhD thesis presents the spatio-temporal distribution of terrestrial carbon fluxes for the time period of 1982 to 2002 simulated by a combination of the process-based dynamic global vegetation model LPJ and a 21-year time series of global AVHRR-fPAR data (fPAR – fraction of photosynthetically active radiation). Assimilation of the satellite data into the model allows improved simulations of carbon fluxes on global as well as on regional scales. As it is based on observed data and includes agricultural regions, the model combined with satellite data produces more realistic carbon fluxes of net primary production (NPP), soil respiration, carbon released by fire and the net land-atmosphere flux than the potential vegetation model. It also produces a good fit to the interannual variability of the CO2 growth rate. Compared to the original model, the model with satellite data constraint produces generally smaller carbon fluxes than the purely climate-based stand-alone simulation of potential natural vegetation, now comparing better to literature estimates. The lower net fluxes are a result of a combination of several effects: reduction in vegetation cover, consideration of human influence and agricultural areas, an improved seasonality, changes in vegetation distribution and species composition. This study presents a way to assess terrestrial carbon fluxes and elucidates the processes contributing to interannual variability of the terrestrial carbon exchange. Process-based terrestrial modelling and satellite-observed vegetation data are successfully combined to improve estimates of vegetation carbon fluxes and stocks. As net ecosystem exchange is the most interesting and most sensitive factor in carbon cycle modelling and highly uncertain, the presented results complementary contribute to the current knowledge, supporting the understanding of the terrestrial carbon budget.
A constraint programming system combines two essential components: a constraint solver and a search engine. The constraint solver reasons about satisfiability of conjunctions of constraints, and the search engine controls the search for solutions by iteratively exploring a disjunctive search tree defined by the constraint program. The Monadic Constraint Programming framework gives a monadic definition of constraint programming where the solver is defined as a monad threaded through the monadic search tree. Search and search strategies can then be defined as firstclass objects that can themselves be built or extended by composable search transformers. Search transformers give a powerful and unifying approach to viewing search in constraint programming, and the resulting constraint programming system is first class and extremely flexible.
This thesis is focussed on the electronic properties of the new material class named topological insulators. Spin and angle resolved photoelectron spectroscopy have been applied to reveal several unique properties of the surface state of these materials. The first part of this thesis introduces the methodical background of these quite established experimental techniques.
In the following chapter, the theoretical concept of topological insulators is introduced. Starting from the prominent example of the quantum Hall effect, the application of topological invariants to classify material systems is illuminated. It is explained how, in presence of time reversal symmetry, which is broken in the quantum Hall phase, strong spin orbit coupling can drive a system into a topologically non trivial phase. The prediction of the spin quantum Hall effect in two dimensional insulators an the generalization to the three dimensional case of topological insulators is reviewed together with the first experimental realization of a three dimensional topological insulator in the Bi1-xSbx alloys given in the literature.
The experimental part starts with the introduction of the Bi2X3 (X=Se, Te) family of materials. Recent theoretical predictions and experimental findings on the bulk and surface electronic structure of these materials are introduced in close discussion to our own experimental results. Furthermore, it is revealed, that the topological surface state of Bi2Te3 shares its orbital symmetry with the bulk valence band and the observation of a temperature induced shift of the chemical potential is to a high probability unmasked as a doping effect due to residual gas adsorption.
The surface state of Bi2Te3 is found to be highly spin polarized with a polarization value of about 70% in a macroscopic area, while in Bi2Se3 the polarization appears reduced, not exceeding 50%. We, however, argue that the polarization is most likely only extrinsically limited in terms of the finite angular resolution and the lacking detectability of the out of plane component of the electron spin. A further argument is based on the reduced surface quality of the single crystals after cleavage and, for Bi2Se3 a sensitivity of the electronic structure to photon exposure.
We probe the robustness of the topological surface state in Bi2X3 against surface impurities in Chapter 5. This robustness is provided through the protection by the time reversal symmetry. Silver, deposited on the (111) surface of Bi2Se3 leads to a strong electron doping but the surface state is observed up to a deposited Ag mass equivalent to one atomic monolayer. The opposite sign of doping, i.e., hole-like, is observed by exposing oxygen to Bi2Te3. But while the n-type shift of Ag on Bi2Se3 appears to be more or less rigid, O2 is lifting the Dirac point of the topological surface state in Bi2Te3 out of the valence band minimum at $\Gamma$. After increasing the oxygen dose further, it is possible to shift the Dirac point to the Fermi level, while the valence band stays well beyond. The effect is found reversible, by warming up the samples which is interpreted in terms of physisorption of O2.
For magnetic impurities, i.e., Fe, we find a similar behavior as for the case of Ag in both Bi2Se3 and Bi2Te3. However, in that case the robustness is unexpected, since magnetic impurities are capable to break time reversal symmetry which should introduce a gap in the surface state at the Dirac point which in turn removes the protection. We argue, that the fact that the surface state shows no gap must be attributed to a missing magnetization of the Fe overlayer. In Bi2Te3 we are able to observe the surface state for deposited iron mass equivalents in the monolayer regime. Furthermore, we gain control over the sign of doping through the sample temperature during deposition.
Chapter6 is devoted to the lifetime broadening of the photoemission signal from the topological surface states of Bi2Se3 and Bi2Te3. It is revealed that the hexagonal warping of the surface state in Bi2Te3 introduces an anisotropy for electrons traveling along the two distinct high symmetry directions of the surface Brillouin zone, i.e., $\Gamma$K and $\Gamma$M. We show that the phonon coupling strength to the surface electrons in Bi2Te3 is in nice agreement with the theoretical prediction but, nevertheless, higher than one may expect. We argue that the electron-phonon coupling is one of the main contributions to the decay of photoholes but the relatively small size of the Fermi surface limits the number of phonon modes that may scatter off electrons. This effect is manifested in the energy dependence of the imaginary part of the electron self energy of the surface state which shows a decay to higher binding energies in contrast to the monotonic increase proportional to E$^2$ in the Fermi liquid theory due to electron-electron interaction.
Furthermore, the effect of the surface impurities of Chapter 5 on the quasiparticle life- times is investigated. We find that Fe impurities have a much stronger influence on the lifetimes as compared to Ag. Moreover, we find that the influence is stronger independently of the sign of the doping. We argue that this observation suggests a minor contribution of the warping on increased scattering rates in contrast to current belief. This is additionally confirmed by the observation that the scattering rates increase further with increasing silver amount while the doping stays constant and by the fact that clean Bi2Se3 and Bi2Te3 show very similar scattering rates regardless of the much stronger warping in Bi2Te3.
In the last chapter we report on a strong circular dichroism in the angle distribution of the photoemission signal of the surface state of Bi2Te3. We show that the color pattern obtained by calculating the difference between photoemission intensities measured with opposite photon helicity reflects the pattern expected for the spin polarization. However, we find a strong influence on strength and even sign of the effect when varying the photon energy. The sign change is qualitatively confirmed by means of one-step photoemission calculations conducted by our collaborators from the LMU München, while the calculated spin polarization is found to be independent of the excitation energy. Experiment and theory together unambiguously uncover the dichroism in these systems as a final state effect and the question in the title of the chapter has to be negated: Circular dichroism in the angle distribution is not a new spin sensitive technique.
We present preliminary results of a tailored atmosphere analysis of six Galactic WC stars using UV, optical, and mid-infrared Spitzer IRS data. With these data, we are able to sample regions from 10 to 10³ stellar radii, thus to determine wind clumping in different parts of the wind. Ultimately, derived wind parameters will be used to accuratelymeasure neon abundances, and to so test predicted nuclear-reaction rates.