Refine
Has Fulltext
- yes (122) (remove)
Year of publication
- 2020 (122) (remove)
Document Type
- Doctoral Thesis (122) (remove)
Is part of the Bibliography
- yes (122)
Keywords
- Maschinelles Lernen (3)
- Anden (2)
- Andes (2)
- Arktis (2)
- Boden (2)
- Chemometrie (2)
- Datenassimilation (2)
- Diffusion (2)
- Galaktische Archäologie (2)
- Geomagnetic activity (2)
- Geomagnetische Aktivität (2)
- Geophysik (2)
- ICP-OES (2)
- Klima (2)
- Nanopartikel (2)
- Nährelemente (2)
- PCA (2)
- PLSR (2)
- Paleoclimatology (2)
- Paläoklimatologie (2)
- Perowskit (2)
- Photochemie (2)
- Porous carbon (2)
- RFA (2)
- Rashba effect (2)
- Rashba-Effekt (2)
- Solarzellen (2)
- Spaltsätze (2)
- Stratigraphy (2)
- Translation (2)
- XRF (2)
- clefts (2)
- diffusion (2)
- emulsion (2)
- machine learning (2)
- memory (2)
- remote sensing (2)
- solar cells (2)
- 3D field calculations (1)
- 3D-Feldsimulationen (1)
- A-bar movement (1)
- A-quer-Bewegung (1)
- AM1 (1)
- AM1/FOMO (1)
- AM1/FOMO-CI (1)
- ARPES (1)
- ATPS (1)
- Abgleich von Abhängigkeiten (1)
- Adipositas (1)
- Adressnormalisierung (1)
- Affekt (1)
- Aid Effectiveness (1)
- Akan (1)
- Algorithmen (1)
- Algorithms (1)
- Alpine Fault (1)
- Altitude (1)
- Ammonia (1)
- Ammoniak (1)
- Analogmodell (1)
- Analogue Model (1)
- Anfoderungsprofil Judo (1)
- Anregungsspektren (1)
- Anreicherungsmethoden (1)
- Antikörper-Färbung (1)
- Anwendungsbedingungen (1)
- Aptamer (1)
- Aptamers (1)
- Arbeitgeberattraktivität (1)
- Archaeolithoporella (1)
- Archäomagnetismus (1)
- Arctic (1)
- Arctic-midlatitude linkages (1)
- Argentina (1)
- Argentinien (1)
- Array-Entwurf (1)
- Arrhenius (1)
- Asia (1)
- Asien (1)
- Astronomical instrumentation (1)
- Astrophysik (1)
- Astroteilchenphysik (1)
- Atmosphäre (1)
- Atomic Force Microscope (1)
- Aufbau Ost (1)
- Automatizität (1)
- Autotropher Nitrat-Aufnahme in Gewässernetzen (1)
- Autotrophic nitrate uptake in river networks (1)
- Azobenzene (1)
- Azobenzene containing surfactant (1)
- Azobenzol (1)
- Azobenzol enthaltende Moleküle (1)
- Azobenzol enthaltendes Tensid (1)
- B3LYP (1)
- BCH code (1)
- BCH-Code (1)
- Bacteria (1)
- Bakterien (1)
- Bank filtration (1)
- Bayesian Inference (1)
- Beanspruchungsfolgen (1)
- Bending energy (1)
- Benetzung (1)
- Beratungssituationen (1)
- Berny-Algorithmus (1)
- Berufliche Wiedereingliederung (1)
- Bestandsparameter (1)
- Beugungseffizienz (1)
- Biegeenergie (1)
- Big Data (1)
- Bildlinguistik (1)
- Bildungstechnologien (1)
- Biochemie (1)
- Biofilme (1)
- Biogeochemie (1)
- Biogeochemistry (1)
- Biogeographie (1)
- Biokompatibilität (1)
- Biomasse (1)
- Biotop (1)
- Bioverfügbarkeit (1)
- Blickbewegungen (1)
- Bodenanalytik (1)
- CO2 degassing (1)
- CO2-Entgasung (1)
- Calculus of Variation (1)
- Caldera-ähnliche Topographie (1)
- Candidate Journey (1)
- Canopy parameters (1)
- Carbonate-Silicate reactions (1)
- Cardinality estimation (1)
- Caribbean (1)
- Carrara marble (1)
- Carrara-marmor (1)
- Catchment and in-stream water quality (1)
- Cell-cell adhesion (1)
- Central Andes (1)
- Change Data Capture (1)
- Chemerin (1)
- Chemometrics (1)
- Chemotaxis (1)
- Chloroplast gene expression (1)
- Chloroplasten-Genexpression (1)
- Climate (1)
- Cluster (1)
- Codierungstheorie (1)
- Coding theory (1)
- Cognitive linguistics (1)
- Coiled Coil (1)
- Cone sheet (1)
- Conic compartments (1)
- Contamination Control (1)
- Crowd Resourcing (1)
- Cyanobacteria (1)
- Cyanobakterien (1)
- Cybersecurity e-Learning (1)
- Cybersicherheit E-Learning (1)
- D3 (1)
- DFT (1)
- DRYM (1)
- Data Assimilation (1)
- Data Integration (1)
- Data Mining (1)
- Data Profiling (1)
- Data assimilation (1)
- Data profiling (1)
- Data quality (1)
- Data-Driven Methods (1)
- Daten Assimilation (1)
- Datenabgleich (1)
- Datenaufbereitung (1)
- Datenbereinigung (1)
- Datengetriebene Methoden (1)
- Datenintegration (1)
- Datenqualität (1)
- Datensatzverknüpfung (1)
- Decolmation (1)
- Defektchemie (1)
- Defekte (1)
- Deformationsmechanismen (1)
- Dekolmation (1)
- Der Rückzug aus dem Gazastreifen (1)
- Deutsch (1)
- Development Aid (1)
- Dichtefunktionaltheorie (1)
- Dielektrophorese (1)
- Differential Geometrie (1)
- Differential Geometry (1)
- Digital Multimodal Linguistics (1)
- Digital education (1)
- Digitale Bildung (1)
- Digitale multimodale Linguistik (1)
- Direkte Manipulation (1)
- Dispersionskorrektur (1)
- Djerba (1)
- Doppelpuls (1)
- Drogenhandel (1)
- Drought tolerance (1)
- Duplikaterkennung (1)
- Dwarf galaxies (1)
- Dynamic Data (1)
- Düngeempfehlung (1)
- E-Z Isomerisierung (1)
- EEG (1)
- EKP (1)
- ERP (1)
- Early Earth (1)
- Early Starvation 1 (1)
- Early starvation protein (1)
- Earth's magnetic field (1)
- Earth's mantle (1)
- Economics of Convention (1)
- Education technologies (1)
- Einschätzung der Diffusion (1)
- Einzel-Objekt-Nachweis (1)
- Einzelmolekül-Biosensor (1)
- Einzelmolekülkraftspektroskopie (1)
- Einzelzellbewegung (1)
- El Niño-Southern Oscillation (ENSO) (1)
- El Niño-Südliche Oszillation (1)
- Electrocatalysis (1)
- Elektret (1)
- Elektrochemie (1)
- Elektrokatalyse (1)
- Elektronenstrukturrechnung (1)
- Emotion (1)
- Employer Branding (1)
- Emulsion (1)
- Emulsionen (1)
- Energieumwandlung (1)
- Englisch (1)
- English (1)
- Entitätsauflösung (1)
- Entlastungsspannung (1)
- Entwicklungszusammenarbeit (1)
- Eocene (1)
- Eozän (1)
- Epistemologie (1)
- Erdbeben (1)
- Erdbebenkatalogdaten (1)
- Erdbebenquellen-Array (1)
- Erdmagnetfeld (1)
- Erdmantel (1)
- Erdrutsche (1)
- Erinnerung (1)
- Erinnerungskultur (1)
- Eutrophierung (1)
- Exhaustivitätsinferenz (1)
- Experimental Physics (1)
- Experimentalphysik (1)
- Experimente (1)
- Expert interviews (1)
- Experteninterview (1)
- Exploration (1)
- Extremniederschläge (1)
- Eye movements (1)
- Eyetracking (1)
- Eyring (1)
- FELS (1)
- FGF21 (1)
- FRAP (1)
- Fachkräftemangel (1)
- Fahrkompetenz (1)
- Fault Healing (1)
- Fehlende Werte (1)
- Feldmaus (1)
- Fernerkundung (1)
- Fernerkundungsprodukte (1)
- Fibre-fed spectroscopy (1)
- Flagella (1)
- Flagellen (1)
- Flow (1)
- Fluid-Gesteins-Wechselwirkung (1)
- Fluorchemie (1)
- Fluorescence fluctuation spectroscopy (1)
- Fluoreszenz-Mikroskopie (1)
- Fluoreszenzfluktuationsspektroskopie (1)
- Fluoreszenzproteine (1)
- Fokus (1)
- Forecasting (1)
- Foreign Keys (1)
- Foreign Keys Discovery (1)
- Formgleichungen von Vesikeln (1)
- Forschend Entdeckendes Lernen (1)
- Fotografieforschung (1)
- Fotogrammetrie (1)
- Fractals (1)
- Fraktale (1)
- Frame Analyse; Französische Entwicklungsagentur (1)
- Frame Analysis (1)
- Französisch (1)
- Frauen (1)
- French (1)
- French Development Agency (1)
- Frequenzverdopplung (1)
- Frühe Erdgeschichte (1)
- Fulgimide (1)
- Fully distributed nitrate modeling (1)
- Functional dependencies (1)
- Funktionale Abhängigkeiten (1)
- Funktionalisierung (1)
- Förster Resonanz Energie Transfer (FRET) (1)
- Förster resonance energy transfer (FRET) (1)
- GAUSSIAN (1)
- GPI (1)
- Galactic Archaeology (1)
- Galactic archaeology (1)
- Galaxien (1)
- Galaxienbalken (1)
- Galaxienbulges (1)
- Galaxienentwicklung (1)
- Galaxienstruktur (1)
- Gammastrahlung (1)
- Gammastrahlungsastronomie (1)
- Gedächtnis (1)
- Gelatine-Analogmodellierung (1)
- Genomic Mining (1)
- Genomics (1)
- Genomik (1)
- Geodynamik (1)
- Geological heterogeneity (1)
- Geologie (1)
- Geologische Heterogenität (1)
- Geology (1)
- Geomagnetic index (1)
- Geomagnetic observatory (1)
- Geomagnetischer Index (1)
- Geomagnetisches Observatorium (1)
- Geometric Analysis (1)
- Geometric Data Analysis (1)
- Geometrieoptimierung (1)
- Geometrische Analysis (1)
- Geometrische Datenanalyse (1)
- Geomicrobiology (1)
- Geomikrobiologie (1)
- Geomorphologie (1)
- Geophysics (1)
- Geosciences (1)
- Geowissenschaften (1)
- German (1)
- German Studies (1)
- Germanistica (1)
- Germanistik (1)
- Gitterdynamik (1)
- Glissant (1)
- Glucan water dikinase (1)
- Glucan-Wasser-Dikinase (1)
- Glukose Oxidation (1)
- Glykolipide (1)
- Graphbedingungen (1)
- Graphen (1)
- Graphtransformationen (1)
- Graphtransformationssysteme (1)
- Grasland (1)
- Grenzflächen (1)
- Grenzflächenrekombination (1)
- Groundwater modelling (1)
- Grundwassermodellierung (1)
- Grundwasserneubildung (1)
- Grüne Infrastruktur (1)
- Habitat (1)
- Halachic (1)
- Halo der Milchstraße (1)
- Halogenid-Perowskite (1)
- Hartree Fock (1)
- Hasserkennung (1)
- Heat transport (1)
- Herdzeit Parameter Abschätzung (1)
- Herzentwicklung (1)
- Herzklappe (1)
- Heterogene Einzugsgebietsreaktionen (1)
- Heterogeneous catchement responses (1)
- Heterogenität (1)
- High-frequency data (1)
- Hill Youth (1)
- Histidin-Metall Koordination (1)
- Hochdurchsatzsequenzierung (1)
- Hochfrequenzdaten (1)
- Hochtemperatur Gesteinsdeformtion (1)
- Hydrogel (1)
- Hydrologie (1)
- Hydrophobic and hydrophillic interactions (1)
- Hydrophobizität (1)
- Hyperpolarisierbarkeit (1)
- Hyperspektral (1)
- Höhe (1)
- ICON (1)
- IMAGE EUV (1)
- IR laser (1)
- Iconolinguistica (1)
- Identitätsorientierte Unternehmensführung (1)
- Igbo (1)
- Image studies (1)
- Inclusion Dependency (1)
- Inclusion Dependency Discovery (1)
- Incremental Discovery (1)
- Incrementally Inclusion Dependencies Discovery (1)
- Index (1)
- Inklusionsabhängigkeiten (1)
- Inklusionsabhängigkeiten Entdeckung (1)
- Inner magnetosphere (1)
- Innere Magnetosphäre (1)
- Institutional Complexity (1)
- Institutionelle Komplexität (1)
- Integrale Feldspektroskopie (1)
- Ionenmobilitätsspektrometrie (1)
- Ionic liquids (1)
- Ionische Flüssigkeiten (1)
- Ionosphäre (1)
- Isomerisierung Kinetik (1)
- Jahreszeitenvorhersage (1)
- Janus colloids (1)
- Janus-Kolloid (1)
- Kalfon, Mosheh, ha-Kohen (1)
- Kalman Filter (1)
- Kalman filter (1)
- Kampfsport (1)
- Kant (1)
- Karbonat-Silikat-Reaktionen (1)
- Kardinalitätsschätzung (1)
- Kardiologische Rehabilitation (1)
- Karibik (1)
- Kartierung (1)
- Kartographie (1)
- Kegelförmige Geometrien (1)
- Kern-Schale Aufkonvertierende Nanopartikel (1)
- Kinetics of photoisomerization (1)
- Klimapolitik (1)
- Klimatologie (1)
- Kognitive Linguistik (1)
- Kohlenhydrate (1)
- Kohn Sham (1)
- Kolonialismus (1)
- Kontaminationskontrolle (1)
- Kp index (1)
- Kp-Index (1)
- Kritik der Urteilskraft (1)
- Kugelflächenfunktionen (1)
- Körper (1)
- LDDO (1)
- LDPC code (1)
- LDPC-Code (1)
- LIBS (1)
- Ladungsspeicherung und -transport (1)
- Landschaft (1)
- Landschaftsökologie (1)
- Landwirtschaft (1)
- Lascar Volcano (1)
- Laser induzierte Breakdown Spektroskopie (1)
- Lava dome (1)
- Lavadom (1)
- Learning Analytics (1)
- Learning experience (1)
- Lebendigkeit (1)
- Leistungsrückmeldung (1)
- Lernerlebnis (1)
- Lernumgebung (1)
- Lesen (1)
- Licht-Materie-Wechselwirkung (1)
- Light-Matter Coupling (1)
- Like-Early Starvation 1 (1)
- Like-Early starvation protein (1)
- Linguistica cognitiva (1)
- Linguistica del testo (1)
- Linguistica digitale multimodale (1)
- Lipide (1)
- Local adaptation (1)
- Lokalisierte Deformation (1)
- Lokalisierung von Verformung (1)
- Luteinester (1)
- MOOC (1)
- MOOCs (1)
- MP2 (1)
- Machine learning (1)
- Magellanic Clouds (1)
- Magellansche Wolken (1)
- Mapping (1)
- Marronage (1)
- Maschinen- und Anlagenbau (1)
- Massenaussterben (1)
- Massive Open Online Courses (1)
- Mathematical Physics (1)
- Mathematische Physik (1)
- Mbembe (1)
- Meaning Structure (1)
- Mechanical engineering (1)
- Mechanosensation (1)
- Mediengebrauch (1)
- Medienpraxeologie (1)
- Medienwissenschaft (1)
- Medizinisch-beruflich orientierte Rehabilitation (MBOR) (1)
- Melt inclusions (1)
- Membran (1)
- Metadata Discovery (1)
- Metadaten Entdeckung (1)
- Metal-poor stars (1)
- Metallarme Sterne (1)
- Metamorphism (1)
- Metamorphose (1)
- Metanome (1)
- Metasomatism (1)
- Metasomatose (1)
- Meteorologie (1)
- Methane (1)
- Methanogene (1)
- Methanotrophe (1)
- Microbial communities (1)
- Microtus arvalis (1)
- Mikrobielle Gemeinschaften (1)
- Mikrobieller Abbau von organischen Material (1)
- Mikrogel (1)
- Mikrostrukturen (1)
- Mikroviskosität (1)
- Milchstraße (1)
- Milky Way (1)
- Milky Way Halo (1)
- Min-Proteine (1)
- Min-proteins (1)
- Mind2 (1)
- Mineralzusammensetzung (1)
- Missing values (1)
- Modal expansion method (1)
- Modeling (1)
- Modellieren (1)
- Modellierung (1)
- Molecular motors (1)
- Molekular-dynamik (1)
- Molekulare Motoren (1)
- Moleküle in äußeren Feldern (1)
- Monsoon (1)
- Monsun (1)
- Morphologie (1)
- Motivation (1)
- Multi-object spectroscopy (1)
- Multimode fibres (1)
- Multiple Correspondence Analysis (1)
- Multiple Korrespondenzanalyse (1)
- Myodus glareolus (1)
- Nachhaltige Entwicklung (1)
- Nachhaltiges Finanzwesen (1)
- Nachhaltigkeitstransformation (1)
- Nahrunsgergänzungsmittel (1)
- Namibia (1)
- Nano-Elektroden (1)
- Nanoparticle (1)
- Nanoparticles (1)
- Nanoplättchen (1)
- Narcocultura (1)
- Natural Products (1)
- Naturstoffe (1)
- Neural networks (1)
- Neuronale Netze (1)
- Neutronen Diffraktion (1)
- Neutronen Reflektometrie (1)
- Neutronen aus kosmischer Höhenstrahlung (1)
- Nitrogen Physisorption (1)
- Nordostbrasilien (1)
- Normalmodenanalyse (1)
- Nostoc punctiforme (1)
- Nutrients (1)
- Nutzerinteraktion (1)
- Oberflächenelektromyographie (1)
- Oberflächengitter (1)
- Oberflächentopografie (1)
- Oberfächen (1)
- Obesity (1)
- Oculomotor control (1)
- Okulomotorik (1)
- Online-Lernen (1)
- Optical remote sensing (1)
- Optische Fernerkundung (1)
- Ordnung der Partikel auf der Oberfläche (1)
- Organic matter mineralization (1)
- Ornstein-Uhlenbeck Process (1)
- Ornstein-Uhlenbeck Prozess (1)
- P2P (1)
- PEG brushes (1)
- PEG-Funktionalisierung (1)
- PNIPAM (1)
- Pachkungsdichte (1)
- Paleogeography (1)
- Paläogeographie (1)
- Paläomagnetismus (1)
- Pantoea stewartii (1)
- Partial Differential Equations (1)
- Partielle Differential Gleichungen (1)
- Partikelverben (1)
- Peer Assessment (1)
- Perceived Relevance (1)
- Percolation (1)
- Perkolation (1)
- Perm (1)
- Permafrostdegradation (1)
- Permian (1)
- Perovskite (1)
- Perowskit Solarzellen (1)
- Petrologie (1)
- Petrology (1)
- Pflanzen (1)
- Philosophie der Biologie (1)
- Phosphoglucan water dikinase (1)
- Phosphoglucan-Wasser-Dikinase (1)
- Phosphorylation process (1)
- Phosphorylierungsprozess (1)
- Photochemistry (1)
- Photogrammetry (1)
- Photokatalyse (1)
- Photopolymer (1)
- Photostrukturierung von Polymerfilmen (1)
- Photovoltaik (1)
- Physics Education (1)
- Physics Problems (1)
- Physikaufgaben (1)
- Physikdidaktik (1)
- Planungsstrategien (1)
- Plasmasphere (1)
- Plasmasphäre (1)
- Plasmonen (1)
- Plasmons (1)
- Playa (1)
- Politics (1)
- Politik (1)
- Politolinguistica (1)
- Politolinguistics (1)
- Politolinguistik (1)
- Polyelektrolyt-Multischichten (1)
- Polymere (1)
- Polypropylen (1)
- Polystyrol Nano-Sphären (1)
- Populationsanalyse (1)
- Porous silica particles (1)
- Poröser Kohlenstoff (1)
- Postcolonial (1)
- Postkolonial (1)
- Pragmatica (1)
- Pragmatics (1)
- Pragmatik (1)
- Preaktivierung (1)
- Precision Agriculture (1)
- Preisschild (1)
- Price Tag (1)
- Prognose (1)
- Programmieren (1)
- Protein (1)
- Protein complex assembly (1)
- Proteinkomplexassemblierung (1)
- Prädikatsinterpretation (distributiv vs. nicht-distributiv) (1)
- QM/MM (1)
- Qualitative content analysis (1)
- Quantenausbeute (1)
- Quantenpunkte (1)
- Quantifizierung von Unsicherheit (1)
- Quantumdots (1)
- Quell-Array optimales Design (1)
- R-PE (1)
- REM (1)
- Random Environments (1)
- Random Walk (1)
- Rasterkraftmikroskopie (1)
- Raumplanung (1)
- Reading (1)
- Reconstruction of eastern Germany (1)
- Redox (1)
- Redoxchemie (1)
- Relation (1)
- Relativsätze (1)
- Religious Zionism (1)
- Religiöser Zionismus (1)
- Repertory Grid (1)
- Resonante Energie Transfer (1)
- Results-Based Management (1)
- Return to work (1)
- Rheologie (1)
- Ribosome profiling (1)
- Riff (1)
- Ringstromelektronen (1)
- Romance Studies (1)
- Romanistica (1)
- Romanistik (1)
- Rothberg (1)
- Rumpfkraft (1)
- Räumlich verteilte Nitratmodellierung (1)
- Räumliche und zeitliche Nitratvariabilität (1)
- Rötelmaus (1)
- Rückgabe (1)
- S-indd++ (1)
- SAM (1)
- SAXS (1)
- SEM (1)
- SFG (1)
- SHG (1)
- Salt pan (1)
- Salzpfanne (1)
- Satellitenmission Swarm (1)
- Satzverarbeitung (1)
- Scalability (1)
- Schema discovery (1)
- Schema-Entdeckung (1)
- Scherzonen (1)
- Schimmelpilze (1)
- Schmelzeinschlüsse (1)
- Schädel (1)
- Seasonal prediction (1)
- Secondary Metabolites (1)
- Sedimente (1)
- Sedimentologie (1)
- Sedimentology (1)
- Seismizitätsmodellierung (1)
- Seismologie (1)
- Seismology (1)
- Seismotektonik (1)
- Sekundärmetabolite (1)
- Selbstwirsamkeitserwartungen (1)
- Semantica (1)
- Semantics (1)
- Semantik (1)
- Semiotic Testology (1)
- Semiotica (1)
- Semiotics (1)
- Semiotik (1)
- Semiotische Textologie (1)
- Settlers (1)
- Shape equations of vesicles (1)
- Siedler (1)
- Signalübertragung (1)
- Simulation (1)
- Single-cell motility (1)
- Skalierbarkeit (1)
- Skalierungsmethode von Champagne (1)
- Skriptsprachen (1)
- Smartphone (1)
- Soil (1)
- South Africa (1)
- Soziale Arbeit (1)
- Soziale Medien (1)
- Space climate (1)
- Space weather (1)
- Spatial and temporal nitrate variability (1)
- Spin Textur (1)
- Sport (1)
- Spread F (1)
- Sprungwahrscheinlichkeit (1)
- Spröde Vorläufer (1)
- Squeak/Smalltalk (1)
- Standort des Streuers (1)
- Starch metabolism (1)
- Sterne (1)
- Sternenpopulationen (1)
- Stickstoff Physisorption (1)
- Strahlungsgürtel (1)
- Stratigrafie (1)
- Stratigraphie (1)
- Stratosphere-troposphere coupling (1)
- Stratospheric polar vortex (1)
- Stratosphären-Troposphären-Kopplung (1)
- Stratosphärischer Polarwirbel (1)
- Streuresonanzen (1)
- Strukturgeologie (1)
- Stärkestoffwechsel (1)
- Störungszonenarchitektur (1)
- Subduktion (1)
- Subjektivitäten (1)
- Submarine permafrost (1)
- Submariner Permafrost (1)
- Subsea permafrost (1)
- Supernovaüberrest (1)
- Surface Relief Grating (SRG) (1)
- Svalbard (1)
- Südafrika (1)
- TDDFT (1)
- Tansania (1)
- Tanzania (1)
- Teamarbeit (1)
- Teilchenbeschleunigung (1)
- Tektonik (1)
- Tensor (1)
- Testologia semiotica (1)
- Text Linguistics (1)
- Textklassifikation (1)
- Textlinguistik (1)
- The disengagement from Gaza Strip (1)
- Topological Crystalline Insulator (1)
- Topological Insulator (1)
- Topologischer Isolator (1)
- Topologischer kristalliner Isolator (1)
- Touchpoint Management (1)
- Trajektorien (1)
- Translation feedback regulation (1)
- Translationsfeedbackregulation (1)
- Translationstheorie (1)
- Trockentoleranz (1)
- Tully-Algorithmus (1)
- Uferfiltration (1)
- Uncertainty Quantification (1)
- Unsicherheiten (1)
- Urban (1)
- Validation (1)
- Validierung (1)
- Variabilität (1)
- Variationsrechung (1)
- Verbindungspfade zwischen der Arktis und den mittleren Breiten (1)
- Verifikation induktiver Invarianten (1)
- Verteilungsmuster (1)
- Verwerfungen (1)
- Virtual Laboratory (1)
- Virtuelles Labor (1)
- Volcano (1)
- Vorhersagen (1)
- Vorlanddeformation (1)
- Vulkan (1)
- Vulkan Lascar (1)
- Vulkan-Überwachung (1)
- Vulnerabilität (1)
- WAXS (1)
- War for Talents (1)
- Wasser-in-Wasser (1)
- Wellen-Teilchen Wechselwirkungen (1)
- Wellengleichung (1)
- Weltraumklima (1)
- Weltraumwetter (1)
- Werkzeugbau (1)
- Werteprofil (1)
- Wirksamkeit von Entwicklungszusammenarbeit (1)
- Wirkstoff-Freisetzun (1)
- Wirkungsorientiertes Management (1)
- Wismut (1)
- Wuchiapingian (1)
- Wuchiapingium (1)
- Wärmetransport (1)
- Yamabe problem (1)
- Yamabe-Problem (1)
- Z-E Isomerisierung (1)
- Zebrafisch (1)
- Zeitaufgelöste Lumineszenz (1)
- Zell-zell Adhäsion (1)
- Zentralanden (1)
- Zufällige Stochastische Irrfahrt (1)
- Zufällige Umgebungen (1)
- Zwei-Prozess (1)
- Zwerg Galaxien (1)
- address normalization (1)
- aesthetics (1)
- affect (1)
- agriculture (1)
- algorithmic image recognition (1)
- algorithmische Bilderkennung (1)
- anaphoric existence presupposition (1)
- anaphorische Existenzpräsupposition (1)
- antibody staining (1)
- application conditions (1)
- archeomagnetism (1)
- arctic (1)
- array design (1)
- assessment of the diffusion (1)
- astroparticle physics (1)
- astrophysics (1)
- athletic performance (1)
- atmosphere (1)
- authigene Mineralbildung (1)
- authigenic mineral formation (1)
- automatic (1)
- azobenzene containing molecules (1)
- bayessche Inferenz (1)
- belowground herbivory (1)
- beobachtende Seismologie (1)
- bioavailability (1)
- biochemistry (1)
- biocompatibility (1)
- biofilm (1)
- biofilms (1)
- biogeography (1)
- biological membranes (1)
- biologische Membranen (1)
- biomass (1)
- biotope (1)
- bismuth (1)
- blended learning (1)
- body (1)
- brittle deformation (1)
- brittle precursors (1)
- caldera-like topography (1)
- carbohydrates (1)
- carbon nitride (1)
- cardiac rehabilitation (1)
- cardiac valves (1)
- charge storage and transport (1)
- chemische Oberflächen-Modifikationen (1)
- chiral separation (1)
- chirale Trennung (1)
- chloroplast (1)
- circumferential dike (1)
- cis-trans Isomerisierung (1)
- climate (1)
- climate policy (1)
- climatology (1)
- close packing (1)
- coarse grained Molekulardynamiken (1)
- coarse grained molecular dynamics (1)
- coarse-graining (1)
- coiled coil (1)
- collaborative learning (1)
- collaborative work (1)
- colonialism (1)
- combat sport (1)
- cone sheet (1)
- core-shell UCNP (1)
- cosmic-ray neutron sensing (1)
- counseling at schools (1)
- critique of judgement (1)
- cuerpo (1)
- data assimilation (1)
- data cleaning (1)
- data matching (1)
- data preparation (1)
- decolonial (1)
- deep biosphere (1)
- deep convection (1)
- defect chemistry (1)
- definite Pseudospaltsätze (1)
- definite pseudoclefts (1)
- deformation mechanisms (1)
- dekolonial (1)
- demands (1)
- detecção de nêutrons de raios cósmicos (1)
- dichteste Packung (1)
- dielectrophoresis (1)
- dietary supplements (1)
- diffraction efficiency (1)
- diffusioosmotic flow (1)
- diffusioosmotischer Fluss (1)
- digital learning (1)
- digital media (1)
- digitale Medien (1)
- digitales Lernen (1)
- direct manipulation (1)
- distribution pattern (1)
- driving competence (1)
- drug release (1)
- drug trafficking (1)
- dual-process (1)
- duplicate detection (1)
- dynamic hyperpolarizability (1)
- dynamische Hyperpolarisierbarkeit (1)
- eLearning (1)
- earthquake (1)
- earthquake bulletin data (1)
- earthquake source array (1)
- eastern south–central Andes (1)
- ecological modelling (1)
- electret (1)
- electric and magnetic fields (1)
- electrical switches (1)
- electrochemistry (1)
- elektrische und magnetische Felder (1)
- elektronische Schalter (1)
- emotion (1)
- energy conversion (1)
- enrichments methods (1)
- entity resolution (1)
- epistemology (1)
- equatorial plasma depletions (1)
- eutrophication (1)
- exercise (1)
- exhaustive inference (1)
- exopolysaccharide (1)
- experiment (1)
- experimental studies (1)
- experimentelle Studien (1)
- exploration (1)
- extreme rainfall (1)
- eye tracking (1)
- fMRI (1)
- fMRT (1)
- fault healing (1)
- fault zone architecture (1)
- faults (1)
- first passage (1)
- fluid rock interaction (1)
- fluorescence microscopy (1)
- fluorescent proteins (1)
- fluorous chemistry (1)
- focus (1)
- foreland deformation (1)
- formal verification (1)
- formale Verifikation (1)
- freie Aktivierungsenthalpie (1)
- functionalization (1)
- galaxies (1)
- galaxy bars (1)
- galaxy bulges (1)
- galaxy evolution (1)
- galaxy structure (1)
- gamma rays (1)
- gamma-ray astronomy (1)
- gelatin analogue modeling (1)
- genocide (1)
- geodynamic modeling (1)
- geodynamics (1)
- geodynamische Modellierung (1)
- geomorphology (1)
- geophysics (1)
- gestreute Phasen (1)
- global-hyperbolisch (1)
- globally hyperbolic (1)
- glucose oxidation (1)
- glycolipids (1)
- graph constraints (1)
- graph transformation systems (1)
- graph transformations (1)
- graphene (1)
- grassland (1)
- green infrastructure (1)
- green investments (1)
- grobkörnig (1)
- groundwater recharge (1)
- grüne Investitionen (1)
- habitat (1)
- halide perovskite (1)
- hate speech detection (1)
- heart development (1)
- heterogene Katalyse (1)
- heterogeneous catalysis (1)
- high light (1)
- high temperature rock deformation (1)
- histidine-metal coordination (1)
- human remains (1)
- hydraulische Bodeneigenschaften (1)
- hydrological modelling (1)
- hydrologische Modellierung (1)
- hydrology (1)
- hydrophoben und hydrophile Wechselwirkungen (1)
- hydrophobicity (1)
- hyperpolarizability (1)
- immediacy (1)
- index (1)
- inductive invariant checking (1)
- inquiry based learning (1)
- integral field spectroscopy (1)
- interfacial recombination (1)
- intraspecific trait variation (1)
- intraspezifische Merkmalsvariation (1)
- ion mobility spectrometry (1)
- ionic defects (1)
- ionosphere (1)
- judo-specific pulling movement (1)
- judospezifische Anrissbewegung (1)
- k-Induktion (1)
- k-induction (1)
- k-inductive invariant (1)
- k-induktive Invariante (1)
- kollaboratives Arbeiten (1)
- kollaboratives Lernen (1)
- landscape (1)
- landscape ecology (1)
- landslides (1)
- laser induced breakdown spectroscopy (1)
- laser-geheizte Diamantstempelzelle (1)
- laser-heated Diamond Anvil Cell (1)
- lattice dynamics (1)
- learning environment (1)
- lipids (1)
- liveness (1)
- localized deformation (1)
- lokale Anpassung (1)
- lutein esters (1)
- market-based view (1)
- martini (1)
- mass extinction (1)
- massive open online courses (1)
- matching dependencies (1)
- mathematical modeling (1)
- mathematische Modellierung (1)
- mechanical and acoustical properties (1)
- mechanische und akustische Eigenschaften (1)
- mechanosensation (1)
- media praxeology (1)
- media studies (1)
- media use (1)
- membrane (1)
- menschliche Überreste (1)
- metalorganic frameworks (1)
- meteorology (1)
- methane (1)
- methanogens (1)
- methanotrophs (1)
- microbial activity (1)
- microbial community (1)
- microgel (1)
- microstructures (1)
- microviscosity (1)
- mikrobielle Aktivität (1)
- mikrobielle Gemeinschaft (1)
- mineral composition (1)
- modelling (1)
- mold fungi (1)
- molecular dynamics (1)
- molekularer Abstand (1)
- morphological impairments (1)
- morphologische Störungen (1)
- morphology (1)
- motivation (1)
- mujeres (1)
- mulifractional diffusion (1)
- multi-fraktionelle Diffusion (1)
- muscle activity (1)
- nano-electrodes (1)
- nanoscale heat transfer (1)
- nanoskaliger Wärmetransport (1)
- narcocultura (1)
- narcoculture (1)
- narcotráfico (1)
- needs analysis judo (1)
- neutron diffraction (1)
- neutron reflectometry (1)
- next generation sequencing (1)
- nicht-lineare Optik (1)
- nichtadiabatische Kopplung (1)
- nichtadibatische Dynamik (1)
- nichtlineare Optik (1)
- nichtstrahlende Verluste (1)
- non-adiabatic coupling (1)
- non-adiabatic dynamic (1)
- non-gaussianity (1)
- non-linear optics (1)
- nonradiative losses (1)
- nordeste do Brasil (1)
- northeast of Brazil (1)
- numerical modeling (1)
- numerische Modellierung (1)
- observational seismology (1)
- off-specular scattering (1)
- online learning (1)
- optimal array configuration (1)
- optimale Array-Konfiguration (1)
- ordering of particles on the surface (1)
- organic chemistry (1)
- oxidative Proteinmodifikationen (1)
- oxidative protein modifications (1)
- paleomagnetism (1)
- parallel immobilization of biomolecules (1)
- parallele Immobilisierung von Biomolekülen (1)
- particle acceleration (1)
- particle verbs (1)
- peer assessment (1)
- performance feedback (1)
- permafrost degradation (1)
- perovskite (1)
- perovskite solar cells (1)
- philosophy of biology (1)
- photo-structuring of polymer films (1)
- photocatalysis (1)
- photography research (1)
- photoredox catalysis (1)
- photosensitive Polymer (1)
- phreatic eruption (1)
- phreatische Eruption (1)
- physics education (1)
- planning strategies (1)
- plants (1)
- polyelectrolyte multilayers (1)
- polymers (1)
- polypropylene (1)
- polystyrene nano-spheres (1)
- poröse Kohlenstoffmaterialien (1)
- poröse Siliciumdioxidpartikel (1)
- post-translational modifications (1)
- postcolonial (1)
- postkolonial (1)
- posttranslationale Modifikationen (1)
- power spectral analysis (1)
- practical driving (1)
- praktische Fahrerlaubnisprüfung (1)
- preactivation (1)
- predicate interpretation (distributive vs. non-distributive) (1)
- prediction (1)
- programming (1)
- propriedades hidráulicas do solo (1)
- protein (1)
- qualitative Inhaltsanalyse (1)
- quantum yield (1)
- radiation belts (1)
- random diffusivity (1)
- randomisierte kontrollierte Studie (RCT) (1)
- randomized controlled trial (1)
- raumbezogene Ökologie (1)
- recarga de águas subterrâneas (1)
- record linkage (1)
- redox (1)
- redox chemistry (1)
- reef (1)
- relativization (1)
- reliability (1)
- repatriation (1)
- resonance energy transfer (1)
- rheology (1)
- ribosome profiling (1)
- ring current electrons (1)
- räumlich und zeitlich kontrollierte Wirkstoff-Freisetzung (1)
- scattered phases (1)
- scatterer location (1)
- scattering resonances (1)
- scripting languages (1)
- second harmonic generation (1)
- sediments (1)
- seismic activity (1)
- seismic array (1)
- seismic event localization (1)
- seismic source-time function estimation (1)
- seismicity modelling (1)
- seismische Aktivität (1)
- seismische Ereignislokalisierung (1)
- seismisches Array (1)
- selbstassemblierende Monolagen (1)
- selbstbestimmtes Lesen (1)
- selbstorganisierte Einzelschichten (1)
- self-assembled monolayer (1)
- self-assembled monolayers (1)
- self-efficacy (1)
- self-paced reading (1)
- sensoriamento remoto (1)
- sentence processing (1)
- shear zones (1)
- signalling (1)
- simulation (1)
- single-molecule biosensor (1)
- single-molecule force spectroscopy (1)
- single-object detection (1)
- skull (1)
- social media (1)
- social uses (1)
- social work (1)
- soil analysis (1)
- soil hydraulic properties (1)
- source array optimal design (1)
- soziale Gebrauchsweisen (1)
- spatial ecology (1)
- spatial planning (1)
- spatially and temporally controlled drug release (1)
- spektrale Leistungsdichte (1)
- spezifisches Krafttraining (1)
- spherical harmonics (1)
- spin texture (1)
- sport-specific resistance training (1)
- sportliche Leistung (1)
- spread F (1)
- spröde Deformation (1)
- starker Konvektion (1)
- stars (1)
- static hyperpolarizability (1)
- statische Hyperpolarisierbarkeit (1)
- stellar populations (1)
- stewartan (1)
- strain localization (1)
- structural geology (1)
- sub-diffraction gratings (1)
- subduction (1)
- subjectivities (1)
- subjetividades (1)
- supernova remnant (1)
- surface chemical treatment (1)
- surface topography (1)
- surfaces and interfaces (1)
- sustainability transformation (1)
- sustainable development (1)
- sustainable finance (1)
- swarm mission (1)
- synthetic array beam power (1)
- synthetische Array-Strahlleistung (1)
- teamwork (1)
- tectonics (1)
- text classification (1)
- theoretische Chemie (1)
- tiefe Biosphäre (1)
- time-resolved luminescence (1)
- tool building (1)
- trajectory (1)
- trajectory surface hopping (1)
- trans-cis Isomerisierung (1)
- transcrystalline polypropylene (1)
- transition state (1)
- transkristallines Polypropylen (1)
- translation (1)
- trunk muscle strength (1)
- ultrafast magnetism (1)
- ultrafast x-ray diffraction (1)
- ultraschnelle Röntgendiffraktion (1)
- ultraschneller Magnetimus (1)
- umlaufender Deich (1)
- uncertainties (1)
- unloading stress (1)
- unterirdische Pflanzenfresser (1)
- upconverting nanoparticles (1)
- urban (1)
- user interaction (1)
- variability (1)
- visual word recognition (1)
- visuelle Worterkennung (1)
- volcanic plumbing system (1)
- volcano monitoring (1)
- volcano seismology (1)
- vulkanische Seismologie (1)
- vulkanisches System (1)
- vulnerability (1)
- water-in-water (1)
- wave equation (1)
- wave-particle interactions (1)
- western Eger Rift (1)
- westlichen Eger-Graben (1)
- wetting (1)
- women (1)
- work-related medical rehabilitation (1)
- zebrafish (1)
- zufälligen Diffusivität (1)
- Ärztemangel (1)
- Ästhetik (1)
- Ökonomie der Konventionen (1)
- Übergangszustand (1)
- äquatorialen Plasma-Verarmungen (1)
- ökologische Modellierung (1)
- östlich-südzentrale Anden (1)
- ג'רבה (1)
- הכהן, משה כלפון בן שלום דניאל יהודה, (1)
- הלכתית (1)
- התנתקות מרצועת עזה (1)
- מתנחלים (1)
- נוער הגבעות (1)
- ציונות דתית (1)
- תג מחיר (1)
- wahrgenommene Relevanz (1)
Institute
- Institut für Physik und Astronomie (26)
- Institut für Geowissenschaften (20)
- Institut für Biochemie und Biologie (18)
- Institut für Chemie (13)
- Hasso-Plattner-Institut für Digital Engineering GmbH (8)
- Institut für Umweltwissenschaften und Geographie (7)
- Department Psychologie (3)
- Institut für Mathematik (3)
- Department Linguistik (2)
- Department Sport- und Gesundheitswissenschaften (2)
In nature, bacteria are found to reside in multicellular communities encased in self-produced extracellular matrices. Indeed, biofilms are the default lifestyle of the bacteria which cause persistent infections in humans. The biofilm assembly protects bacterial cells from desiccation and limits the effectiveness of antimicrobial treatments. A myriad of biomolecules in the extracellular matrix, including proteins, exopolysaccharides, lipids, extracellular DNA and other, form a dense and viscoelastic three dimensional network. Many studies emphasized that a destabilization of the mechanical integrity of biofilm architectures potentially eliminates the protective shield and renders bacteria more susceptible to the immune system and antibiotics. Pantoea stewartii is a plant pathogen which infects monocotyledons such as maize and sweet corn. These bacteria produce dense biofilms in the xylem of infected plants which cause wilting of plants and crops. Stewartan is an exopolysaccharide which is produced by Pantoea stewartii and secreted as the major component to the extracellular matrix. It consists of heptasaccharide repeating units with a high degree of polymerization (2-4 MDa). In this work, the physicochemical properties of stewartan were investigated to understand the contributions of this exopolysaccharide to the mechanical integrity and cohesiveness of Pantoea stewartii biofilms. Therefore, a coarse-grained model of stewartan was developed with computational techniques to obtain a model for its three dimensional structural features. Here, coarse-grained molecular dynamic simulations revealed that the exopolysaccharide forms a hydrogel in which the exopolysaccharide chains arrange into a three dimensional mesh-like network. Simulations at different concentrations were used to investigate the influence of the water content on the network formation. Stewartan was further purified from 72 h grown Pantoea stewartii biofilms and the diffusion of bacteriophage and differently-sized nanoparticles (which ranged from 1.1 to 193 nm diameter) was analyzed in reconstituted stewartan solutions. Fluorescence correlation spectroscopy and single-particle tracking revealed that the stewartan network impeded the mobility of a set of differently-sized fluorescent particles in a size-dependent manner. Diffusion of these particles became more anomalous, as characterized by fitting the diffusion data to an anomalous diffusion model, with increasing stewartan concentrations. Further bulk and microrheological experiments were used to analyze the transitions in stewartan fluid behavior and stewartan chain entanglements were described. Moreover, it was noticed, that a small fraction of bacteriophage particles was trapped in small-sized pores deviating from classical random walks which highlighted the structural heterogeneity of the stewartan network. Additionally, the mobility of fluorescent particles
also depended on the charge of the stewartan exopolysaccharide and a model of a molecular sieve for the stewartan network was proposed. The here reported structural features of the stewartan polymers were used to provide a detailed description of the mechanical properties of typically glycan-based biofilms such as the one from Pantoea stewartii.
In addition, the mechanical properties of the biofilm architecture are permanently sensed by the embedded bacteria and enzymatic modifications of the extracellular matrix take place to address environmental cues. Hence, in this work the influence of enzymatic degradation of the stewartan exopolysaccharides on the overall exopolysaccharide network structure was analyzed to describe relevant physiological processes in Pantoea stewartii biofilms. Here, the stewartan hydrolysis kinetics of the tailspike protein from the ΦEa1h bacteriophage, which is naturally found to infect Pantoea stewartii cells, was compared to WceF. The latter protein is expressed from the Pantoea stewartii stewartan biosynthesis gene cluster wce I-III. The degradation of stewartan by the ΦEa1h tailspike protein was shown to be much faster than the hydrolysis kinetics of WceF, although both enzymes cleaved the β D GalIII(1→3)-α-D-GalI glycosidic linkage from the stewartan backbone. Oligosaccharide fragments which were produced during the stewartan cleavage, were analyzed in size-exclusion chromatography and capillary electrophoresis. Bioinformatic studies and the analysis of a WceF crystal structure revealed a remarkably high structural similarity of both proteins thus unveiling WceF as a bacterial tailspike-like protein. As a consequence, WceF might play a role in stewartan chain length control in Pantoea stewartii biofilms.
In recent years people have realised non-renewability of our modern society which relays on spending huge amounts of energy mostly produced from fosil fuels, such as oil and coal, and the shift towards more sustainable energy sources has started. However, sustainable sources of energy, such as wind-, solar- and hydro-energy, produce primarily electrical energy and can not just be poured in canister like many fosil fuels, creating necessity for rechragable batteries. However, modern Li-ion batteries are made from toxic heavy metals and sustainable alternatives are needed. Here we show that naturally abundant catecholic and guaiacyl groups can be utilised to replace heavy metals in Li-ion batteries.
Foremost vanillin, a naturally occurring food additive that can be sustainably synthesised from industrial biowaste, lignin, was utilised to synthesise materials that showed extraordinary performance as cathodes in Li-ion batteries. Furthermore, behaviour of catecholic and guiacyl groups in Li-ion system was compared, confirming usability of guiacayl containing biopolymers as cathodes in Li-ion batteries. Lastly, naturally occurring polyphenol, tannic acid, was incorporated in fully bioderived hybrid material that shows performance comparable to commercial Li-ion batteries and good stability.
This thesis presents an important advancement in understanding of biowaste derived cathode materials for Li-ion batteries. Further research should be conducted to better understand behaviour of guaiacyl groups during Li-ion battery cycling. Lastly, challenges of incorporation of lignin, an industrial biowaste, have to be addressed and lignin should be incorporated as a cathode material in Li-ion batteries.
La cabrona aquí soy yo
(2020)
La última década ha visto un interés creciente en el fenómeno del narcotráfico en México a nivel global. Las diversas expresiones de violencia extrema que acompañan al negocio ilegal de drogas se narran en artefactos mediáticos que provocan fascinación e intriga. Así, la literatura y el cine, la música y la televisión presentan imágenes e historias sobre el narcotráfico que alimentan el imaginario colectivo. En este contexto, a nivel global hay representaciones mediáticas de la mujer mexicana narcotraficante que reproducen estereotipos femeninos donde la mujer se cosifica, exagerando los atributos sexuales del cuerpo de las mujeres. Esta representación cultural hace de la mujer un objeto de deseo, cuya belleza sirve como una marca de prestigio y ostentación para el hombre narcotraficante. La cultura del narcotráfico impone a las mujeres un ideal estético particular distintivo, que las mujeres reproducen meticulosamente para emular esta representación. Aunado a la belleza física, la mujer es retratada violenta y sin escrúpulos, usa su belleza y poder de seducción para acumular dinero y poder a costa de los hombres que conquista. Para los que no pertenecen al mundo del narcotráfico, este tipo de mujer, hipersexualizada, inspira juicios negativos, discriminación, desconfianza y temor. La intención de la pregunta y objetivos de investigación de este trabajo fue rebasar estas representaciones para observar las complejidades de las experiencias de vida de estas mujeres. El propósito de esta tesis de doctorado fue explorar cómo cambian las vidas de las mujeres mexicanas cuando se involucran en la narcocultura, en la frontera México-Estados Unidos. En específico, la investigación analizó las transformaciones en la corporalidad y en las subjetividades de estas mujeres, y cómo estas transformaciones influían en el lugar que ocupan en el espacio social y cultural que configura el narcotráfico. Además, se analizó qué márgenes de negociación tienen las mujeres en la narcocultura, para poder actuar y definirse a sí mismas. Las preguntas que guiaron el trabajo indagaban sobre cómo las mujeres cambiaban su cuerpo para encarnar el ideal estético y qué significados se atribuían a estos cambios. Fue importante analizar qué dinámicas de poder se ponían en juego a partir de estos cuerpos femeninos, en las relaciones con los hombres y con otras mujeres. También, otro objetivo fue qué procesos de subjetivación operaban en las mujeres que participan en la narcocultura, y qué márgenes de negociación tenían para actuar y definirse a sí mismas. Esta es una investigación inscrita dentro de los estudios culturales y con una perspectiva feminista interseccional. La investigación se realizó en la frontera mexicana con Estados Unidos, en el noroeste, específicamente en las ciudades de Mexicali, Tijuana y San Diego, California. La frontera, en esta tesis, se observa como un espacio con múltiples contextos de interpretación, polisémico y heterogéneo. Estas cualidades hacen que los fenómenos culturales que ocurren en él sean diversos y contradictorios. Para entender los fenómenos culturales que emergen de la frontera norte de México, fue útil el concepto de transfrontera de José Valenzuela Arce (2014). La propuesta de este académico es que las transfronteras son “espacios que se niegan a una sola de las condiciones o los lados que la integran” (p. 9). Así, el concepto habla de los procesos de conectividad y simultaneidad que la globalización genera y que redefinen a los Estados-territorio. Al mismo tiempo, habla también de los límites que estos mismos Estados utilizan para sostener narrativas nacionales que son “referentes organizadores de adscripciones identitarias y culturales” (p. 18) que crean diferencias y desigualdades. Si esto es así, una frontera no se explica completamente desde la demarcación territorial o desde la diferenciación jerárquica que incluye a algunos y excluye a otros, pero tampoco puede entenderse si nos concentramos solamente en los procesos de hibridación cultural que ocurren en esos espacios. Por eso, para Valenzuela las fronteras son entre espacios y entre tiempos. Este concepto ayuda a entender cómo se intersecta lo global y local en los sistemas semióticos que componen el universo cultural del narcotráfico mexicano, al mismo tiempo que explica cómo se estructuran mecanismos de exclusión y jerarquías a partir del género, la posición social y otras marcas de diferenciación social. En última instancia, ayuda a localizar estos procesos culturales, materializados en el cuerpo de las mujeres. El concepto de narcocultura también fue una herramienta heurística útil. La cultura aquí se entiende como un proceso de producción y reproducción de modelos simbólicos, materializados en artefactos o representaciones y, además, interiorizados en lógicas de vida, sistemas de valores y creencias, que circulan a través de las prácticas individuales y colectivas de mujeres y hombres, en contextos históricos y espaciales específicos. La narcocultura sería entonces el sistema semiótico producido en torno al negocio transnacional de tráfico ilegal de drogas, tal como se vive en la frontera norte de México. La narcocultura, tal como se define en este trabajo es un sistema semiótico con límites difusos. Así, las distinciones entre el mundo ilegal del narcotráfico y el mundo de la legalidad externo a este negocio, en el mejor de los casos son borrosas, en el peor, ficticias. La narcocultura trasciende límites territoriales, es un fenómeno cultural transnacional. Fue necesario delinear las características de los estudios culturales latinoamericanos y los Kulturwissenschaften en Alemania, para distinguir las genealogías de estas dos diferentes perspectivas, entender sus diferencias, pero, sobre todo, encontrar los puntos en común entre ellas. La coincidencia central fue el carácter transdisciplinario de estas dos tradiciones académicas. Los estudios culturales entonces se entienden como un espacio de articulación entre disciplinas (Castro Gómez, 2002), que no tiene como objetivo la unificación sino la pluralización de significados, actitudes y modos de percepción (Bachmann-Medick, 2016). La transdisciplina permite trazar las complejidades de los fenómenos culturales, creando puentes entre diferentes formas de conocimiento y prácticas de investigación. El feminismo interseccional es una perspectiva central en el trabajo de investigación. Una contribución del feminismo a los estudios culturales que influye en esta investigación es cuestionar “Hombre” y “Mujer” como esencias naturales dadas e inmutables, desde la premisa que “los signos "hombre" y "mujer" son construcciones discursivas que el lenguaje de la cultura proyecta e inscribe en el escenario de los cuerpos, disfrazando sus montajes de signos tras la falsa apariencia de que lo masculino y lo femenino son verdades naturales, ahistóricas” (Richard, 2009, p. 77). Los estudios culturales feministas suponen que estos signos se construyen en un sistema de representaciones que articulan subjetividades en mundos culturales concretos. Su objetivo entonces es develar en las prácticas significantes, los elementos ideológicos que configuran los signos y los conflictos que se suscitan a través del uso e interpretación de éstos. Estos signos adquieren múltiples significados y lecturas de acuerdo con especificidades que se distinguen en la diferencia. La interseccionalidad, dentro del feminismo es un discurso teórico y metodológico que aboga por reconocer que el signo “mujer” no es una categoría absoluta, y por lo tanto no puede explicar por sí misma las variadas experiencias vitales de las mujeres. Las diferencias se vuelven legibles cuando se ponen en juego con otras categorías sociales como la posición social, la raza, la edad y la discapacidad. Las diferencias sociales están fincadas en diferentes discursos que naturalizan los diferentes atributos de estas categorías sociales cuando, para esta perspectiva, son socialmente construidos y cambiantes. El objetivo de una perspectiva interseccional es identificar cómo interactúan diferentes categorías sociales en instituciones, prácticas y subjetividades, para entender cómo se materializan las desigualdades a través del tiempo. Los conceptos teóricos que guían esta tesis son cuerpo y subjetividad. Para esta tesis, el cuerpo se entiende como un sitio de articulación, donde se materializan códigos culturales y el orden social. El cuerpo puede entenderse como una frontera dinámica y mutable, donde convergen lo físico, lo simbólico y lo social. Sujeto y cuerpo son mutuamente constitutivos; el cuerpo es el medio a través del cual el sujeto vive experiencias en el mundo social, y son esas experiencias las que llevan al sujeto a encarnar las diferencias sociales, materializadas en género, sexo, clase social y raza. A pesar de esta relación indisociable, para facilitar el análisis, una parte se concentra en el cuerpo y otra en la subjetividad. Así, para entender la dimensión corporal se puso en tensión la representación con la experiencia vivida, a través del análisis audiovisual y la observación etnográfica leída en conjunto. En el caso de la subjetividad, se puso en tensión la vida en la narrativa de ficción con las narraciones de vida en entrevistas, para también encontrar los puentes entre las representaciones y la experiencia vital. Esta investigación fue un estudio cualitativo y transdisciplinario. Se utilizaron diversos recursos metodológicos para construir el análisis. Se realizó observación etnográfica en diversos bares y clubs a ambos lados de la frontera, que son frecuentados por personas que se adscriben al mundo de la narcocultura o bien, que trabajan dentro de las redes del narcotráfico. En las incursiones a estos sitios, se observó el físico de las mujeres: su manera de vestir, su arreglo personal, sus formas corporales. Se observó la conducta: las gestualidades y las interacciones con otros sujetos en el espacio. Además, se observó el espacio, para ver cómo se establecían reglas, límites y jerarquizaciones en la disposición física de los lugares visitados. Se analizaron tres videos de narcocorridos a través de la video hermenéutica, para determinar cómo se representan las mujeres en estos artefactos culturales, usando los mismos criterios físicos y conductuales que mencioné anteriormente. El análisis de los videos de la mano del trabajo etnográfico ayudó a profundizar en los significados atribuidos a la corporalidad femenina, y también a los impactos que estos significados tienen en las vivencias y relaciones de estas mujeres. Se realizaron 5 entrevistas semi estructuradas con mujeres que se identificaban con la narcocultura. Algunas sólo simpatizan con el estilo de vida, otras estuvieron involucradas de alguna manera en el negocio ilegal de drogas. En las entrevistas se exploraron narraciones sobre sus vidas donde se revelaban discursos sobre qué es lo femenino, qué significa ser mujer y cómo se vive el ser mujer en el mundo del narcotráfico. Adicionalmente, utilicé las narraciones de dos textos literarios de la narrativa sobre narcotráfico del norte de México. En estos dos textos, los personajes principales son mujeres. Analicé cómo se construye al sujeto femenino en la narración y qué discursos se transparentan en el texto sobre la feminidad y ser una mujer en el mundo del narco. Aquí también se puso en tensión la representación y la experiencia de vida, buscando en el análisis de la narración literaria y las experiencias narradas por las mujeres, discursos comunes que explicaran los procesos de subjetivación femenina dentro de la narcocultura mexicana. La primera parte del análisis articuló la observación etnográfica con el material audiovisual para entender las exigencias estéticas que la narcocultura demanda a las mujeres y las maneras en que ellas transforman su cuerpo para complacer esta demanda. La narcocultura impone a las mujeres un ideal estético que se convierte en un medio de acceso a un tipo de poder. Este ideal exige un tipo particular de fisonomía y de apariencia personal, que las mujeres intentan reproducir a través de intervenciones en el cuerpo, con el maquillaje y el peinado y/o la cirugía estética. Además, demanda cierto estilo de moda, en ropa y accesorios, de marcas de lujo de consumo global. Entre más fielmente se reproduzca este ideal, las mujeres están en posibilidad de acceder a beneficios económicos y sociales que les dan márgenes de acción dentro de este entorno social. El cuerpo de las mujeres se convierte en el recurso primario para la movilidad social y la agencia dentro de este mundo. El cuerpo es el signo principal para determinar el lugar de las mujeres dentro de los sistemas de jerarquización, de inclusión y exclusión en los espacios físicos y sociales que fabrica el narcotráfico. Estos mecanismos de diferencia reproducen las desigualdades sociales, de género, edad, posición social y raza que se observan en otros ámbitos de la sociedad mexicana. La observación etnográfica y el análisis audiovisual revelan que las posibilidades para performar la feminidad está confinado a limites muy estrechos. Alicia Gaspar de Alba llama a esto The Three Maria Syndrome, que ella define como “the patriarchal social discourse of Chicano/Mexicano culture that constructs women’s gender and sexuality according to three Biblical archetypes -virgins, mothers and whores-” (Gaspar de Alba, 2014, pos.3412). Estas representaciones femeninas son alegorías a las constricciones que la cultura machista mexicana impone sobre las mujeres, sometiéndolas a un repertorio restringido de opciones de vida y al control social de su sexualidad. Las mujeres dentro de la narcocultura tienen un lugar en él en función de su belleza física, el cuerpo es el referente principal para definirse como sujetos. Las mujeres son objetos de deseo, cuya belleza es una joya más para la corona de un narcotraficante, una posesión más para ostentar su poderío. Al mismo tiempo, aparecen cada vez más las representaciones femeninas como sujetos activos, participando del negocio y de la violencia a la par de los hombres. Se observan transgresiones al ideal de feminidad que se exige a la mujer tradicional en la cultura mexicana. La docilidad, la suavidad y la sumisión que se espera, el recato y la compostura, no está presente. Las mujeres adoptan cualidades consideradas masculinas, tomando para sí el ejercicio de la violencia y la agresividad sexual para demostrar que ellas también pueden navegar un mundo agresivo e hipermasculino. A pesar de esto, esta mujer guerrera y valiente está dentro de los confines limitados que la cultura patriarcal impone al régimen heterosexual. Siguen al pie de la letra la prescripción del Three Maria Syndrome. Esto queda patente un sistema de jerarquización a través de la cual se evalúa a las mujeres dentro de la narcocultura. Las mujeres son juzgadas a partir de criterios que intersectan componentes raciales, de género y de clase. Aunque las maneras en las que estas marcas de diferencia se encarnan en un cuerpo femenino de manera muy diversa, se puede identificar, a través de las representaciones y la observación etnográfica, que las mujeres más privilegiadas, son mujeres que encarnan los signos de una posición económica alta: tienen tez clara, son atractivas y cuidan su apariencia para presentar signos de feminidad de manera discreta, y su conducta proyecta compostura y respetabilidad, en función de su restricción, particularmente en la expresión de la sexualidad. A las mujeres que encarnan estos signos de feminidad se les respeta y se consideran valiosas. Su valor se formaliza a través de la respetabilidad del contrato matrimonial: este tipo de performance de género lo reproducen, por lo general, mujeres esposas de narcotraficantes. En el otro extremo del espectro están las mujeres menos valoradas: son mujeres morenas, que utilizan una estética asociada con la clase trabajadora, por lo general ostentosa y recargada de decoraciones. La conducta de estas mujeres se juzga como vulgar y sin restricciones. A las mujeres que encarnan este tipo de feminidad se les discrimina y cosifica, son las más vulnerables a la violencia en función del poco valor que tienen dentro del mundo del narcotráfico. La buchona representa una versión devaluada de la feminidad, que choca con el decoro y la discreción que exigen las normas tradicionales de género. Son mujeres que se consideran vulgares, porque sus cuerpos portan signos de una sexualidad agresiva, porque adoptan conductas que irrumpen las restricciones sociales impuestas a las mujeres, porque sus prácticas y consumos culturales están asociadas a las clases trabajadoras y rurales. En las mujeres que entrevisté hay un conflicto entre la atractiva libertad que promete la transgresión de ser buchona y el deseo de respetabilidad que otorga ser una mujer que cumple con lo que la sociedad exige. Uno de los dilemas al centro de performar el cuerpo buchón es la batalla entre una feminidad aceptada socialmente, pero restrictiva y una feminidad que otorga poder, pero castiga. Por este motivo, las mujeres que entrevisté rechazaban ser nombradas como buchonas y preferían llamarse a sí mismas cabronas. En este contexto particular, la palabra cabrona es una resignificación de un término coloquial castellano, usado para ofender. Aquí, la mujer cabrona se convierte en un eje articulador para la constitución de subjetividades femeninas dentro de la narcocultura. La cabrona es un tropo femenino que entrelaza narrativas sobre ser mujer que circulan a nivel global con narrativas locales sobre la feminidad. Asumirse “cabrona”, se convierte en un recurso para enfrentar un mundo violento y encontrar estrategias de acción en un espacio claramente dominado por los hombres. La cabrona representa independencia y fuerza, autonomía y acción. La cabrona confronta los discursos tradicionales de una feminidad abnegada y dócil, con diferentes matices, aparentemente interpelando la dominación masculina. Por lo mismo, carga un fuerte estigma. La cultura de masas también produce representaciones sobre la cabrona. Se transmiten en discursos de género que circulan a través de imágenes en las redes sociales, en libros y workshops del mercado de autoayuda en el mundo entero, y que promueven una idea de mujer indócil frente a la gente de su entorno, suscrita al consumo y al individualismo de la cultura capitalista. En estas representaciones culturales contemporáneas, la mujer es fuerte e insumisa, pero conservando códigos corporales y prácticas femeninas. En el contexto concreto de la narcocultura, los discursos globales sobre una mujer fuerte e independiente con poder económico y a cargo de su sexualidad, se encuentran con las condiciones particulares del norte mexicano. La violencia extrema, el machismo, las desigualdades sociales pronunciadas y la crisis de legitimidad del Estado intervienen para que estos discursos globales sobre la mujer muten en la representación de la buchona y la cabrona, interpretaciones locales de un discurso de género global. Para las mujeres, asumirse cabrona es un recurso para enfrentar un mundo violento y encontrar estrategias de acción en un espacio claramente dominado por los hombres. Ayuda a enfrentar la violencia perpetrada sobre ella, abre la posibilidad a ser la victimaria. La cabrona es la reacción que provoca el cuerpo femenino vulnerable y vulnerado, pero también, es la posibilidad de apropiarse de la violencia para ejercerla sobre otros cuerpos. Implica independencia, libertad sexual y éxito económico, evidenciadas por el consumo y el estilo de vida. Cuando niegan ser buchonas, están rechazando todos los estigmas que acarrea la palabra. No se reconocen en la discriminación de clase, las connotaciones raciales y los prejuicios sexistas que contiene. Prefieren cabrona porque es una manera de escindirse de los discursos negativos que se vuelcan sobre ellas, es un camino de acceso a una feminidad global que los medios de comunicación masiva presentan como ideal. El análisis exploró qué elementos componían este tropo femenino a través de las entrevistas a mujeres y de personajes femeninos en novelas sobre narcotráfico, para encontrar puentes entre la ficción y la experiencia vital. La belleza y la capacidad de seducir tiene una utilidad ambivalente. Por un lado, todo el tiempo, dinero y cuidado que se invierte en apropiarse de un ideal estético, es para convertirse en una mujer que un narco pueda presumir. Para las mujeres es un motivo de orgullo saberse deseadas y puestas en aparador. Las mujeres están sometidas a las presiones que genera la creencia de que, para sobrevivir, hay que ser bella. En los textos literarios y en las entrevistas, se transparenta una naturalización del lugar de la mujer como objeto de ostentación para el hombre y, además, la validación que sienten las mujeres al ser reconocidas como bellas. La ficción y la vida nos presentan la precaria condición del sujeto femenino en la narcocultura. Es una subjetividad anclada a los discursos que demandan un ideal de belleza imposible para las mujeres y que encajonan el ser mujer a los caprichos y necesidades del hombre. Sin embargo, la belleza femenina tiene otra faceta. La subjetividad femenina en la narcocultura no sólo es resultado del sometimiento de la mujer a los discursos que regulan su apariencia y su conducta. La belleza también es un instrumento al servicio de las mujeres para acceder a dinero y poder. La belleza y el poder de seducción femenino se convierten en estrategias de subsistencia, y esto transforma a la mujer de un objeto sometido a un sujeto que somete. La belleza y la seducción podrán dar a las mujeres ciertos márgenes de acción, pero esto tiene límites muy claros. Aunque estas estrategias femeninas muevan la balanza de poder hacía el sujeto femenino, hay que recordar el contexto. Están insertas en un mundo violento y machista, así que ejercer ese poder es un ejercicio de equilibrio muy delicado y arriesgado. Las mujeres que habitan la narcocultura están inmersas es un mundo de violencia, y no conocer y respetar las reglas y límites significa un riesgo de muerte. La muerte violenta es una consecuencia muy real por cometer errores en este mundo. Esto lleva a tercer componente de ser cabrona: el riesgo. Para los hombres y mujeres que se involucran en el mundo cultural del narcotráfico, perseguir el riesgo es parte integral de vivir y es una parte importante de la constitución de subjetividades en la narcocultura. En las narraciones de las entrevistas y en las narraciones literarias, hay muchos momentos donde las mujeres viven situaciones de riesgo que ponen en peligro hasta sus vidas. A través de las narraciones se asoma la manera en qué ellas interpretan su papel en la situación y cómo se ven a sí mismas en función de esas experiencias. El riesgo le da sentido al carácter recio y atrevido que demanda asumir el rol de una cabrona, pero también expone la vulnerabilidad de la condición de las mujeres en un mundo violento. Tomar riesgos es otra manera de afirmarse como mujeres fuertes y poner distancia con las disposiciones de género que les exigen ser dóciles y pasivas. Tienen que demostrar lo que valen frente a un mundo dominado por hombres y el control de sus emociones juega un rol fundamental en lograr esto. Sin embargo, el reconocimiento del miedo y vulnerabilidad es, paradójicamente, lo que las ayuda a sobrevivir. Detrás de los discursos de fuerza y poder femenino, se revela la fragilidad de unas vidas sumergidas en un mundo donde la violencia y el machismo deja a las mujeres en el filo de la vida y de la muerte. Para el caso que nos compete, el vacío institucional para garantizar seguridad a las mujeres en México deja a estas mujeres absolutamente expuestas, y cobra sentido la adopción del discurso de la cabrona como estrategia de persistencia. Al investirse como cabronas, encuentran una manera de enfrentarse al mundo violento al que deciden pertenecer, aunque al final de cuentas, permanecen atrapadas en él.
The goal of this thesis was to thoroughly investigate the behavior of multimode fibres to aid the development of modern and forthcoming fibre-fed spectrograph systems. Based on the Eigenmode Expansion Method, a field propagation model was created that can emulate effects in fibres relevant for astronomical spectroscopy, such as modal noise, scrambling, and focal ratio degradation. These effects are of major concern for any fibre-coupled spectrograph used in astronomical research. Changes in the focal ratio, modal distribution of light or non-perfect scrambling limit the accuracy of measurements, e.g. the flux determination of the astronomical object, the sky-background subtraction and detection limit for faint galaxies, or the spectral line position accuracy used for the detection of extra-solar planets.
Usually, fibres used for astronomical instrumentation are characterized empirically through tests. The results of this work allow to predict the fibre behaviour under various conditions using sophisticated software tools to simulate the waveguide behaviour and mode transport of fibres.
The simulation environment works with two software interfaces. The first is the mode solver module FemSIM from Rsoft. It is used to calculate all the propagation modes and effective refractive indexes of a given system. The second interface consists of Python scripts which enable the simulation of the near- and far-field outputs of a given fibre. The characteristics of the input field can be manipulated to emulate real conditions. Focus variations, spatial translation, angular fluctuations, and disturbances through the mode coupling factor can also be simulated.
To date, complete coherent propagation or complete incoherent propagation can be simulated. Partial coherence was not addressed in this work. Another limitation of the simulations is that they work exclusively for the monochromatic case and that the loss coefficient of the fibres is not considered. Nevertheless, the simulations were able to match the results of realistic measurements.
To test the validity of the simulations, real fibre measurements were used for comparison. Two fibres with different cross-sections were characterized. The first fibre had a circular cross-section, and the second one had an octagonal cross-section. The utilized test-bench was originally developed for the prototype fibres of the 4MOST fibre feed characterization. It allowed for parallel laser beam measurements, light cone measurements, and scrambling measurements. Through the appropriate configuration, the acquisition of the near- and/or far-field was feasible.
By means of modal noise analysis, it was possible to compare the near-field speckle patterns of simulations and measurements as a function of the input angle. The spatial frequencies that originate from the modal interference could be analyzed by using the power spectral density analysis. Measurements and simulations yielded similar results. Measurements with induced modal scrambling were compared to simulations using incoherent propagation and once again similar results were achieved. Through both measurements and simulations, the enlargement of the near-field distribution could be observed and analyzed. The simulations made it possible to explain incoherent intensity fluctuations that appear in real measurements due to the field distribution of the active propagation modes.
By using the Voigt analysis in the far-field distribution, it was possible to separate the modal diffusion component in order to compare it with the simulations. Through an appropriate assessment, the modal diffusion component as a function of the input angle could be translated into angular divergence. The simulations gave the minimal angular divergence of the system. Through the mean of the difference between simulations and measurements, a figure of merit is given which can be used to characterize the angular divergence of real fibres using the simulations. Furthermore, it was possible to simulate light cone measurements. Due to the overall consistent results, it can be stated that the simulations represent a good tool to assist the fibre characterization process for fibre-fed spectrograph systems.
This work was possible through the BMBF Grant 05A14BA1 which was part of the phase A study of the fibre system for MOSAIC, a multi-object spectrograph for the Extremely Large Telescope (ELT-MOS).
Eine sportartspezifische Anforderungsanalyse ist die Grundlage für die Leistungsdiagnostik und eine wichtige Voraussetzung für die Trainingssteuerung im Spitzensport. Im Rahmen der Leistungsdiagnostik in der Zweikampfsportart Judo besitzen judospezifische Anrissleistungen bei Anrissbewegungen ein hohes Potenzial, um Defizite im Kraft-Weg-Verlauf bzw. in den kinetischen Parametern (z. B. mechanische Arbeit, dynamische Maximalkraft) zu identifizieren und ableitend daraus entsprechende trainingsmethodische Anpassungen zur Verbesserung vorzunehmen. Die Rumpfstabilität und die Rumpfkraft stellen wichtige Leistungsvoraussetzungen für sportliche Bewegungen dar, um den optimalen Transfer von Kräften und Drehmomenten von den unteren Extremitäten über den stabilen Rumpf hin zu den oberen Extremitäten zu ermöglichen. Im Trainingsprozess der Judoka erfährt das spezifische Krafttraining immer mehr Aufmerksamkeit, um die sportartrelevanten Muskelgruppen zu entwickeln und somit die finale Effektivität einer Wurftechnik zu verbessern.
Die wesentliche Zielstellung dieser Arbeit bestand darin, die Leistungsdiagnostik im Judo zu optimieren und effektive Trainingsprogramme zur Verbesserung von judospezifischen Anrissbewegungen zu entwickeln. Im Einzelnen wurde dafür eine systematische Anforderungsanalyse für die Sportart Judo erarbeitet. Basierend auf dieser Analyse wurden die Validität und die Reliabilität von kinetischen Parametern während Anrissbewegungen mit einem judospezifischen Ergometer-System (JERGo) untersucht. Zudem wurden die Zusammenhänge zwischen der Rumpfkraft und kinetischen Parametern bei judospezifischen Anrissbewegungen analysiert. Schließlich wurde die Wirksamkeit eines spezifischen Anrisstrainings am JERGo-System gegenüber einem Anrisstraining mit Partner auf kinetische Parameter und Muskelaktivität überprüft.
Die sportartspezifische Anforderungsanalyse wurde unter Berücksichtigung der metabolischen und muskulären Anforderungen sowie sportartspezifischen Verletzungsrisiken erarbeitet. An den zwei Querstudien bzw. einer Längsschnittstudie nahmen gesunde männliche Judoka mit unterschiedlichem Expertiseniveau teil. Die kinetischen Parameter bei judospezifischen Anrissbewegungen wurden mit dem JERGo-System in allen Experimentalstudien erfasst. Die Rumpfkraft wurde mit einem isokinetischen Dynamometer gemessen, um Assoziationen zwischen der Rumpfkraft und judospezifischen Anrissleistungen zu bestimmen. Zudem wurde die Aktivität ausgewählter Rumpf-/Schultermuskeln bei der Anrissbewegung im Standfür die Validierung des JERGo-Systems und für die Überprüfung der Effekte eines Anrisstrainings erfasst. Die Ermittlung von sportmotorischen Leistungen erfolgte durch die Übungen Liegend-Anreißen und Klimmziehen, um die Wirkungen eines judospezifischen Anrisstrainings auf sportartunspezifische Kraftleistungen zu untersuchen.
Unter Berücksichtigung der muskulären Anforderungen im Judo wird die Ausführung einer explosiven Anrissbewegung bzw. Wurftechnik durch die koordinierte Aktivität vieler Muskelgruppen und vor allem durch die unteren Extremitäten sowie den Rumpf realisiert. Aus trainingswissenschaftlicher Sicht ist das JERGo-System ein valides und reliables Messinstrument für die Diagnostik von kinetischen Parametern während judospezifischer Anrissbewegungen. Die Rumpfkraft, insbesondere bei der Rumpfrotation, ist mit kinetischen Parametern bei judospezifischen Anrissbewegungen assoziiert. Ein Anrisstraining am JERGo-System zeigt in den kinetischen Parametern und Muskelaktivierungen vor allem bei der Anrissbewegung im Stand signifikant größere Zuwachsraten im Vergleich zu einem Anrisstraining mit Partner.
Die Ergebnisse dieser Arbeit zeigen, dass die Verbesserung der muskulären Leistungsfähigkeit (z. B. Explosivkraft) in den unteren Extremitäten und der Rumpfmuskulatur eine wichtige Basis für judospezifische Anrissleistungen bei Anrissbewegungen und Wurftechniken darstellt. Zudem empfiehlt es sich, dass JERGo-System zur Diagnostik von kinetischen Parametern bei judospezifischen Anrissbewegungen in die judospezifische Testbatterie einzubinden. Weiterhin kann davon ausgegangen werden, dass durch rumpfextensions- und vor allem durch rumpfrotationskräftigende Übungen unter maximal schellkräftigender Muskelaktivierung Einfluss auf kinetische Parameter bei judospezifischen Anrissbewegungen genommen wird. Letztendlich empfiehlt es sich, ein Antrisstraining am JERGo-System in den judospezifischen Trainingsprozess zu integrieren.
The field of gamma-ray astronomy opened a new window into the non-thermal universe that allows studying the acceleration sites of cosmic rays and the role of cosmic rays on evolutionary processes in galaxies. The detection of almost one hundred Galactic very-high-energy (VHE: 0.1−100TeV) gamma-ray sources in the Milky Way demonstrates that particle acceleration up to tens of TeV energies is a common phenomenon. Furthermore, the detection of VHE gamma rays from other galaxies has confirmed that cosmic rays are not exclusively accelerated in the Milky Way. The rapid development of gamma-ray astronomy in the past two decades has led to a transition from the detection and study of individual sources to source population studies. To answer the question, whether the VHE gamma-ray source population of the Milky Way is unique, observations of galaxies, for which individual sources can be resolved, are required. Such galaxies are the Magellanic Clouds, two satellite galaxies of the Milky Way, which have been surveyed by the H.E.S.S. experiment in the last decade. In this thesis, data from a total of 450 hours of H.E.S.S. observations towards the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC) are presented. During the analysis of the data sets, special emphasis is put on the evaluation of systematic uncertainties of the experiment in order to assure an unbiased flux estimation of the potential VHE gamma-ray sources of the Magellanic Clouds. A detailed analysis of the survey data revealed the detection of the gamma-ray binary LMCP3, the most powerful gamma-ray binary known so far, that is located in the LMC, and thus, increases the number of known VHE gamma-ray sources in the LMC to four. No other VHE gamma-ray source is detected in the Magellanic Clouds and integral flux upper limits are estimated. These flux upper limits are used to perform a source population study based on known VHE source classes and existing multi-wavelength catalogues. A comparison of the source populations of the Magellanic Clouds and the Milky Way revealed that no other source in the Magellanic Clouds is as bright as the most luminous VHE gamma-ray source in the LMC: the pulsar wind nebula N 157B, and that one-third of the source population of the Magellanic Clouds is less luminous than the other known VHE gamma-ray sources in the LMC. For only a couple of sources luminosity levels of Galactic VHE sources, that are more than one order of magnitude fainter than the detected sources in the LMC, are constrained. Based on the flux upper limits, differences on the TeV source populations in the Magellanic Clouds and the Milky Way as well as the importance of the source environments will be discussed.
Single-column data profiling
(2020)
The research area of data profiling consists of a large set of methods and processes to examine a given dataset and determine metadata about it. Typically, different data profiling tasks address different kinds of metadata, comprising either various statistics about individual columns (Single-column Analysis) or relationships among them (Dependency Discovery). Among the basic statistics about a column are data type, header, the number of unique values (the column's cardinality), maximum and minimum values, the number of null values, and the value distribution. Dependencies involve, for instance, functional dependencies (FDs), inclusion dependencies (INDs), and their approximate versions.
Data profiling has a wide range of conventional use cases, namely data exploration, cleansing, and integration. The produced metadata is also useful for database management and schema reverse engineering. Data profiling has also more novel use cases, such as big data analytics. The generated metadata describes the structure of the data at hand, how to import it, what it is about, and how much of it there is. Thus, data profiling can be considered as an important preparatory task for many data analysis and mining scenarios to assess which data might be useful and to reveal and understand a new dataset's characteristics.
In this thesis, the main focus is on the single-column analysis class of data profiling tasks. We study the impact and the extraction of three of the most important metadata about a column, namely the cardinality, the header, and the number of null values.
First, we present a detailed experimental study of twelve cardinality estimation algorithms. We classify the algorithms and analyze their efficiency, scaling far beyond the original experiments and testing theoretical guarantees. Our results highlight their trade-offs and point out the possibility to create a parallel or a distributed version of these algorithms to cope with the growing size of modern datasets.
Then, we present a fully automated, multi-phase system to discover human-understandable, representative, and consistent headers for a target table in cases where headers are missing, meaningless, or unrepresentative for the column values. Our evaluation on Wikipedia tables shows that 60% of the automatically discovered schemata are exact and complete. Considering more schema candidates, top-5 for example, increases this percentage to 72%.
Finally, we formally and experimentally show the ghost and fake FDs phenomenon caused by FD discovery over datasets with missing values. We propose two efficient scores, probabilistic and likelihood-based, for estimating the genuineness of a discovered FD. Our extensive set of experiments on real-world and semi-synthetic datasets show the effectiveness and efficiency of these scores.
Ammonia is a chemical of fundamental importance for nature`s vital nitrogen cycle. It is crucial for the growth of living organisms as well as food and energy source. Traditionally, industrial ammonia production is predominated by Haber- Bosch process (HBP) which is based on direct conversion of N2 and H2 gas under high temperature and high pressure (~500oC, 150-300 bar). However, it is not the favorite route because of its thermodynamic and kinetic limitations, and the need for the energy intense production of hydrogen gas by reforming processes. All these disfavors of HBP open a target to search for an alternative technique to perform efficient ammonia synthesis via electrochemical catalytic processes, in particular via water electrolysis, using water as the hydrogen source to save the process from gas reforming.
In this study, the investigation of the interface effects between imidazolium-based ionic liquids and the surface of porous carbon materials with a special interest in the nitrogen absorption capability. As the further step, the possibility to establish this interface as the catalytically active area for the electrochemical N2 reduction to NH3 has been evaluated. This particular combination has been chosen because the porous carbon materials and ionic liquids (IL) have a significant importance in many scientific fields including catalysis and electrocatalysis due to their special structural and physicochemical properties. Primarily, the effects of the confinement of ionic liquid (EmimOAc, 1-Ethyl-3-methylimidazolium acetate) into carbon pores have been investigated. The salt-templated porous carbons, which have different porosity (microporous and mesoporous) and nitrogen species, were used as model structures for the comparison of the IL confinement at different loadings. The nitrogen uptake of EmimOAc can be increased by about 10 times by the confinement in the pores of carbon materials compared to the bulk form. In addition, the most improved nitrogen absorption was observed by IL confinement in micropores and in nitrogen-doped carbon materials as a consequence of the maximized structural changes of IL. Furthermore, the possible use of such interfaces between EmimOAc and porous carbon for the catalytic activation of dinitrogen during the kinetically challenging NRR due to the limited gas absorption in the electrolyte, was examined. An electrocatalytic NRR system based on the conversion of water and nitrogen gas to ammonia at ambient operation conditions (1 bar, 25 °C) was performed in a setup under an applied electric potential with a single chamber electrochemical cell, which consists of the combination of EmimOAc electrolyte with the porous carbon-working electrode and without a traditional electrocatalyst. Under a potential of -3 V vs. SCE for 45 minutes, a NH3 production rate of 498.37 μg h-1 cm-2 and FE of 12.14% were achieved. The experimental observations show that an electric double-layer, which serves the catalytically active area, occurs between a microporous carbon material and ions of the EmimOAc electrolyte in the presence of sufficiently high provided electric potential. Comparing with the typical NRR systems which have been reported in the literature, the presented electrochemical ammonia synthesis approach provides a significantly higher ammonia production rate with a chance to avoid the possible kinetic limitations of NRR. In terms of operating conditions, ammonia production rate and the faradic efficiency without the need for any synthetic electrocatalyst can be resulted of electrocatalytic activation of nitrogen in the double-layer formed between carbon and IL ions.
After endosymbiosis, chloroplasts lost most of their genome. Many former endosymbiotic genes are now nucleus-encoded and the products are re-imported post-translationally. Consequently, photosynthetic complexes are built of nucleus- and plastid-encoded subunits in a well-defined stoichiometry. In Chlamydomonas, the translation of chloroplast-encoded photosynthetic core subunits is feedback-regulated by the assembly state of the complexes they reside in. This process is called Control by Epistasy of Synthesis (CES) and enables the efficient production of photosynthetic core subunits in stoichiometric amounts. In chloroplasts of embryophytes, only Rubisco subunits have been shown to be feedback-regulated. That opens the question if there is additional CES regulation in embryophytes. I analyzed chloroplast gene expression in tobacco and Arabidopsis mutants with assembly defects for each photosynthetic complex to broadly answer this question. My results (i) confirmed CES within Rubisco and hint to potential translational feedback regulation in the synthesis of (ii) cytochrome b6f (Cyt b6f) and (iii) photosystem II (PSII) subunits. This work suggests a CES network in PSII that links psbD, psbA, psbB, psbE, and potentially psbH expression by a feedback mechanism that at least partially differs from that described in Chlamydomonas. Intriguingly, in the Cyt b6f complex, a positive feedback regulation that coordinates the synthesis of PetA and PetB was observed, which was not previously reported in Chlamydomonas. No evidence for CES interactions was found in the expression of NDH and ATP synthase subunits of embryophytes. Altogether, this work provides solid evidence for novel assembly-dependent feedback regulation mechanisms controlling the expression of photosynthetic genes in chloroplasts of embryophytes.
In order to obtain a comprehensive inventory of the rbcL and psbA RNA-binding proteomes (including factors that regulate their expression, especially factors involved in CES), an aptamer based affinity purification method was adapted and refined for the specific purification these transcripts from tobacco chloroplasts. To this end, three different aptamers (MS2, Sephadex ,and streptavidin binding) were stably introduced into the 3’ UTRs of psbA and rbcL by chloroplast transformation. RNA aptamer based purification and subsequent chip analysis (RAP Chip) demonstrated a strong enrichment of psbA and rbcL transcripts and currently, ongoing mass spectrometry analyses shall reveal potential regulatory factors. Furthermore, the suborganellar localization of MS2 tagged psbA and rbcL transcripts was analyzed by a combined affinity, immunology, and electron microscopy approach and demonstrated the potential of aptamer tags for the examination of the spatial distribution of chloroplast transcripts.
In this dissertation, I describe the mechanisms involved in magmatic plumbing system establishment and evolution. Magmatic plumbing systems play a key role in determining volcanic activity style and recognizing its complexities can help in forecasting eruptions, especially within hazardous volcanic systems such as calderas. I explore the mechanisms of dike emplacement and intrusion geometry that shape magmatic plumbing systems beneath caldera-like topographies and how their characteristics relate to precursory activity of a volcanic eruption. For this purpose, I use scaled laboratory models to study the effect of stress field reorientation on a propagating dike induced by caldera topography. I construct these models by using solid gelatin to mimic the elastic properties of the earth's crust with a caldera on the surface. I inject water as the magma analog and track the evolution of the experiments through qualitative (geometry and stress evolution) and quantitative (displacement and strain computation) descriptions. The results show that a vertical dike deviates towards and outside of the caldera-like margin due to stress field reorientation beneath the caldera-like topography. The propagating intrusion forms a circumferential-eruptive dike when the caldera-like size is small, whereas a cone sheet develops beneath the large caldera-like topography.
To corroborate the results obtained from the experimental models, this thesis also describes the results of a case study utilizing seismic monitoring data associated with the unrest period of the 2015 phreatic eruption of Lascar volcano. Lascar has a crater with a small-scale caldera-like topography and exhibited long-lasting anomalous evolution of the number of long-period (LP) events preceding the 2015 eruption. I apply seismic techniques to constrain the hypocentral locations of LP events and characterize their spatial distribution, obtaining an image of Lascar's plumbing system. I observe an agreement in shallow hypocentral locations obtained through four different seismic techniques; nevertheless, the cross-correlation technique provides the best results. These results depict a plumbing system with a narrow sub-vertical deep conduit and a shallow hydrothermal system, where most LP events are located. These two regions are connected through an intermediate region of path divergence, whose geometry and orientation likely is influenced by stress reorientation due to topographic effects of the caldera-like crater.
Finally, in order to further enhance the interpretations of the previous case study, the seismic data was analyzed in tandem with a complementary multiparametric monitoring dataset. This complementary study confirms that the anomalous LP activity occurred as a sign of unrest in the preparatory phase of the phreatic eruption. In addition, I show how changes observed in other monitored parameters enabled to detect further signs of unrest in the shallow hydrothermal system. Overall, this study demonstrates that detecting complex geometric regions within plumbing systems beneath volcanoes is fundamental to produce an effective forecast of eruptions that from a first view seem to occur without any precursory activity.
Furthermore, through the development of this research I show that combining methods that include both observations and models allows one to obtain a more precise interpretation of the volcanic processes.
Ferruginous conditions were a prominent feature of the oceans throughout the Precambrian Eons and thus throughout much of Earth’s history. Organic matter mineralization and diagenesis within the ferruginous sediments that deposited from Earth’s early oceans likely played a key role in global biogeochemical cycling. Knowledge of organic matter mineralization in ferruginous sediments, however, remains almost entirely conceptual, as modern analogue environments are extremely rare and largely unstudied, to date. Lake Towuti on the island of Sulawesi, Indonesia is such an analogue environment and the purpose of this PhD project was to investigate the rates and pathways of organic matter mineralization in its ferruginous sediments.
Lake Towuti is the largest tectonic lake in Southeast Asia and is hosted in the mafic and ultramafic rocks of the East Sulawesi Ophiolite. It has a maximum water depth of 203 m and is weakly thermally stratified. A well-oygenated surface layer extends to 70 m depth, while waters below 130 m are persistently anoxic. Intensive weathering of the ultramafic catchment feeds the lake with large amounts of iron(oxy)hydroxides while the runoff contains only little sulfate, leading to sulfate-poor (< 20 µM) lake water and anoxic ferruginous conditions below 130 m. Such conditions are analogous to the ferruginous water columns that persisted throughout much of the Archean and Proterozoic eons. Short (< 35 cm) sediment cores were collected from different water depths corresponding to different bottom water redox conditions. Also, a drilling campaign of the International Continental Scientific Drilling Program (ICDP) retrieved a 114 m long sediment core dedicated for geomicrobiological investigations from a water depth of 153 m, well below the depth of oxygen penetration at the time of sampling. Samples collected from these sediment cores form the fundament of this thesis and were used to perform a suite of biogeochemical and microbiological analyses.
Geomirobiological investigations depend on uncontaminated samples. However, exploration of subsurface environments relies on drilling, which requires the use of a drilling fluid. Drilling fluid infiltration during drilling can not be avoided. Thus, in order to trace contamination of the sediment core and to identify uncontaminated samples for further analyses a simple and inexpensive technique for assessing contamination during drilling operations was developed and applied during the ICDP drilling campaign. This approach uses an aqeous fluorescent pigment dispersion commonly used in the paint industry as a particulate tracer. It has the same physical properties as conventionally used particulate tracers. However, the price is nearly four orders of magnitude lower solving the main problem of particulate tracer approaches. The approach requires only a minimum of equipment and allows for a rapid contamination assessment potentially even directly on site, while the senstitivity is in the range of already established approaches. Contaminated samples in the drill core were identified and not included for further geomicrobiological investigations.
Biogeochemical analyses of short sediment cores showed that Lake Towutis sediments are strongly depleted in electron acceptors commonly used in microbial organic matter mineralization (i.e. oxygen, nitrate, sulfate). Still, the sediments harbor high microbial cell densities, which are a function of redox conditions of Lake Towuti’s bottom water. In shallow water depths bottom water oxygenation leads to a higher input of labile organic matter and electron acceptors like sulfate and iron, which promotes a higher microbial abundance. Microbial analyses showed that a versatile microbial community with a potential to perform metabolisms related to iron and sulfate reduction, fermentation as well as methanogenesis inhabits Lake Towuti’s surface sediments.
Biogeochemical investigations of the upper 12 m of the 114 m sediment core showed that Lake Towuti’s sediment is extremely rich in iron with total concentrations up to 2500 µmol cm-3 (20 wt. %), which makes it the natural sedimentary environment with the highest total iron concentrations studied to date. In the complete or near absence of oxygen, nitrate and sulfate, organic matter mineralization in ferruginous sediments would be expected to proceed anaerobically via the energetically most favorable terminal electron acceptors available - in this case ferric iron. Astonishingly, however, methanogenesis is the dominant (>85 %) organic matter mineralization process in Lake Towuti’s sediment. Reactive ferric iron known to be available for microbial iron reduction is highly abundant throughout the upper 12 m and thus remained stable for at least 60.000 years. The produced methane is not oxidized anaerobically and diffuses out of the sediment into the water column. The proclivity towards methanogenesis, in these very iron-rich modern sediments, implies that methanogenesis may have played a more important role in organic matter mineralization thoughout the Precambrian than previously thought and thus could have been a key contributor to Earth’s early climate dynamics.
Over the whole sequence of the 114 m long sediment core siderites were identified and characterized using high-resolution microscopic and spectroscopic imaging together with microchemical and geochemical analyses. The data show early diagenetic growth of siderite crystals as a response to sedimentary organic matter mineralization. Microchemical zoning was identified in all siderite crystals. Siderite thus likely forms during diagenesis through growth on primary existing phases and the mineralogical and chemical features of these siderites are a function of changes in redox conditions of the pore water and sediment over time. Identification of microchemical zoning in ancient siderites deposited in the Precambrian may thus also be used to infer siderite growth histories in ancient sedimentary rocks including sedimentary iron formations.
The Willmore functional is a function that maps an immersed Riemannian manifold to its total mean curvature. Finding closed surfaces that minimizes the Willmore energy, or more generally finding critical surfaces, is a classic problem of differential geometry.
In this thesis we will develop the concept of generalized Willmore functionals for surfaces in Riemannian manifolds. We are guided by models in mathematical physics, such as the Hawking energy of general relativity and the bending energies for thin membranes.
We prove the existence of minimizers under area constraint for these generalized Willmore functionals in a suitable class of generalized surfaces. In particular, we construct minimizers of the bending energy mentioned above for prescribed area and enclosed volume.
Furthermore, we prove that critical surfaces of generalized Willmore functionals with prescribed area are smooth, away from finitely many points. These results and the following are based on the existing theory for the Willmore functional.
This general discussion is succeeded by a detailed analysis of the Hawking energy. In the context of general relativity the surrounding manifold describes the space at a given time, hence we strive to understand the interplay between the Hawking energy and the ambient space. We characterize points in the surrounding manifold for which there are small critical spheres with prescribed area in any neighborhood. These points are interpreted as concentration points of the Hawking energy.
Additionally, we calculate an expansion of the Hawking energy on small, round spheres. This allows us to identify a kind of energy density of the Hawking energy.
It needs to be mentioned that our results stand in contrast to previous expansions of the Hawking energy. However, these expansions are obtained on spheres along the light cone at a given point. At this point it is not clear how to explain the discrepancy.
Finally, we consider asymptotically Schwarzschild manifolds. They are a special case of asymptotically flat manifolds, which serf as models for isolated systems. The Schwarzschild spacetime itself is a classical solution to the Einstein equations and yields a simple description of a black hole.
In these asymptotically Schwarzschild manifolds we construct a foliation of the exterior region by critical spheres of the Hawking energy with prescribed large area. This foliation can be seen as a generalized notion of the center of mass of the isolated system. Additionally, the Hawking energy of grows along the foliation as the area of the surfaces grows.
Cardiac valves are essential for the continuous and unidirectional flow of blood throughout the body. During embryonic development, their formation is strictly connected to the mechanical forces exerted by blood flow. The endocardium that lines the interior of the heart is a specialized endothelial tissue and is highly sensitive to fluid shear stress. Endocardial cells harbor a signal transduction machinery required for the translation of these forces into biochemical signaling, which strongly impacts cardiac morphogenesis and physiology. To date, we lack a solid understanding on the mechanisms by which endocardial cells sense the dynamic mechanical stimuli and how they trigger different cellular responses. In the zebrafish embryo, endocardial cells at the atrioventricular canal respond to blood flow by rearranging from a monolayer to a double-layer, composed of a luminal cell population subjected to blood flow and an abluminal one that is not exposed to it. These early morphological changes lead to the formation of an immature valve leaflet. While previous studies mainly focused on genes that are positively regulated by shear stress, the mechanisms regulating cell behaviors and fates in cells that lack the stimulus of blood flow are largely unknown. One key discovery of my work is that the flow-sensitive Notch receptor and Krüppel-like factor (Klf) 2, one of the best characterized flow-regulated transcriptional factors, are activated by shear stress but that they function in two parallel signal transduction pathways. Each of these two pathways is essential for the rearrangement of atrioventricular cells into an immature double-layered valve leaflets. A second key discovery of my study is the finding that both Notch and Klf2 signaling negatively regulate the expression of the angiogenesis receptor Vegfr3/Flt4, which becomes restricted to abluminal endocardial cells of the valve leaflet. Within these cells, Flt4 downregulates the expressions of the cell adhesion proteins Alcam and VE-cadherin. A loss of Flt4 causes abluminal endocardial cells to ectopically express Notch, which is normally restricted to luminal cells, and impairs valve morphology. My study suggests that abluminal endocardial cells that do not experience mechanical stimuli loose Notch expression and this triggers expression of Flt4. In turn, Flt4 negatively regulates Notch on the abluminal side of the valve leaflet. These antagonistic signaling activities and fine-tuned gene regulatory mechanisms ultimately shape cardiac valve leaflets by inducing unique differences in the fates of endocardial cells.
Understanding how organisms adapt to their local environment is a major focus of evolutionary biology. Local adaptation occurs when the forces of divergent natural selection are strong enough compared to the action of other evolutionary forces. An improved understanding of the genetic basis of local adaptation can inform about the evolutionary processes in populations and is of major importance because of its relevance to altered selection pressures due to climate change. So far, most insights have been gained by studying model organisms, but our understanding about the genetic basis of local adaptation in wild populations of species with little genomic resources is still limited.
With the work presented in this thesis I therefore set out to provide insights into the genetic basis of local adaptation in populations of two voles species: the common vole (Microtus arvalis) and the bank vole (Myodes glareolus). Both voles species are small mammals, they have a high evolutionary potential compared to their dispersal capabilities and are thus likely to show genetic responses to local conditions, moreover, they have a wide distribution in which they experience a broad range of different environmental conditions, this makes them an ideal species to study local adaptation.
The first study focused on producing a novel mitochondrial genome to facilitate further research in M. arvalis. To this end, I generated the first mitochondrial genome of M. arvalis using shotgun sequencing and an iterative mapping approach. This was subsequently used in a phylogenetic analysis that produced novel insights into the phylogenetic relationships of the Arvicolinae.
The following two studies then focused on the genetic basis of local adaptation using ddRAD-sequencing data and genome scan methods. The first of these involved sequencing the genomic DNA of individuals from three low-altitude and three high-altitude M. arvalis study sites in the Swiss Alps. High-altitude environments with their low temperatures and low levels of oxygen (hypoxia) pose considerable challenges for small mammals. With their small body size and proportional large body surface they have to sustain high rates of aerobic metabolism to support thermogenesis and locomotion, which can be restricted with only limited levels of oxygen available. To generate insights into high-altitude adaptation I identified a large number of single nucleotide polymorphisms (SNPs). These data were first used to identify high levels of differentiation between study sites and a clear pattern of population structure, in line with a signal of isolation by distance. Using genome scan methods, I then identified signals of selection associated with differences in altitude in genes with functions related to oxygen transport into tissue and genes related to aerobic metabolic pathways. This indicates that hypoxia is an important selection pressure driving local adaptation at high altitude in M. arvalis. A number of these genes were linked with high-altitude adaptation in other species before, which lead to the suggestion that high-altitude populations of several species have evolved in a similar manner as a response to the unique conditions at high altitude
The next study also involved the genetic basis of local adaptation, here I provided insights into climate-related adaptation in M. glareolus across its European distribution. Climate is an important environmental factor affecting the physiology of all organisms. In this study I identified a large number of SNPs in individuals from twelve M. glareolus populations distributed across Europe. I used these, to first establish that populations are highly differentiated and found a strong pattern of population structure with signal of isolation by distance. I then employed genome scan methods to identify candidate loci showing signals of selection associated with climate, with a particular emphasis on polygenic loci. A multivariate analysis was used to determine that temperature was the most important climate variable responsible for adaptive genetic variation among all variables tested. By using novel methods and genome annotation of related species I identified the function of genes of candidate loci. This showed that genes under selection have functions related to energy homeostasis and immune processes. Suggesting that M. glareolus populations have evolved in response to local temperature and specific local pathogenic selection pressures.
The studies presented in this thesis provide evidence for the genetic basis of local adaptation in two vole species across different environmental gradients, suggesting that the identified genes are involved in local adaptation. This demonstrates that with the help of novel methods the study of wild populations, which often have little genomic resources available, can provide unique insights into evolutionary processes.
Die Entwicklung nachhaltiger Bewirtschaftungs- und Produktionsmethoden ist eine der zentralen Fragestellungen der modernen Agrarwirtschaft. Die vorliegende Arbeit beschäftigt sich mit zwei Forschungsthemen, die das Konzept Nachhaltigkeit beinhalten. In beiden Fällen werden analytische Grundlagen für die Entwicklung entsprechender landwirtschaftlicher Arbeitsmethoden gelegt.
Das erste Thema ist an den sogenannten Präzisionsackerbau angelehnt. Bei diesem wird die Bearbeitung von Agrarflächen ortsabhängig ausgeführt. Das heißt, die Ausbringung von Saatgut, Dünger, Bewässerung usw. richtet sich nach den Eigenschaften des jeweiligen Standortes und wird nicht pauschal gleichmäßig über ein ganzes Feld verteilt. Voraussetzung hierfür ist eine genaue Kenntnis der Bodeneigenschaften. In der vorliegenden Arbeit sollten diese Parameter mittels der analytischen Technik der Laser-induzierten Breakdown Spektroskopie (LIBS), die eine Form der Elementaranalyse darstellt, bestimmt werden. Bei den hier gesuchten Bodeneigenschaften handelte es sich um die Gehalte von Nährstoffen sowie einige sekundäre Parameter wie den Humusanteil, den pH-Wert und den pflanzenverfügbaren Anteil einzelner Nährstoffe. Diese Eigenschaften wurden durch etablierte Referenzanalysen bestimmt. Darauf aufbauend wurden die Messergebnissen der LIBS-Untersuchungen durch verschiedene Methoden der sogenannten multivariaten Datenanalyse (MVA) ausgewertet. Daraus sollten Modelle zur Vorhersage der Bodenparameter in zukünftigen LIBS-Messungen erarbeitet werden. Die Ergebnisse dieser Arbeit zeigten, dass mit der Kombination von LIBS und MVA sämtliche Bodenparameter erfolgreich vorhergesagt werden konnten. Dies beinhaltete sowohl die tatsächlich messbaren Elemente als auch die sekundären Eigenschaften, welche durch die MVA mit den Elementgehalten in Zusammenhang gebracht wurden.
Das zweite Thema beschäftigt sich mit der Vermeidung von Verlusten durch Schädlingsbefall bei der Getreidelagerung. Hier sollten mittels der Ionenmobilitätsspektrometrie (IMS) Schimmelpilzkontaminationen detektiert werden. Dabei wurde nach den flüchtigen Stoffwechselprodukten der Pilze gesucht. Die durch Referenzmessungen mit Massenspektrometern identifizierten Substanzen konnten durch IMS im Gasvolumen über den Proben, dem sogenannten Headspace, nachgewiesen werden. Dabei wurde nicht nur die Anwesenheit einer Kontamination festgestellt, sondern diese auch charakterisiert. Die freigesetzten Substanzen bildeten spezifische Muster, anhand derer die Pilze identifiziert werden konnten. Hier wurden sowohl verschiedene Gattungen als auch einzelne Arten unterschieden. Die Messungen fanden auf verschiedenen Nährböden statt um den Einfluss dieser auf die Stoffwechselprodukte zu beobachten. Auch die sekundären Stoffwechselprodukte der Schimmelpilze, die Mykotoxine, konnten durch IMS detektiert werden.
Beide in dieser Arbeit vorgestellten Forschungsthemen konnten erfolgreich abgeschlossen werden. Sowohl LIBS als auch IMS erwiesen sich für den Nachweis der jeweiligen Analyten als geeignet, und der Einsatz moderner computergestützter Auswertemethoden ermöglichte die genaue Charakterisierung der gesuchten Parameter. Beide Techniken können in Form von mobilen Geräten verwendet werden und zeichnen sich durch eine schnelle und sichere Analyse aus. In Kombination mit entsprechenden Modellen der MVA sind damit alle Voraussetzungen für Vor-Ort-Untersuchungen und damit für den Einsatz in der Landwirtschaft erfüllt.
With rising complexity of today's software and hardware systems and the hypothesized increase in autonomous, intelligent, and self-* systems, developing correct systems remains an important challenge. Testing, although an important part of the development and maintainance process, cannot usually establish the definite correctness of a software or hardware system - especially when systems have arbitrarily large or infinite state spaces or an infinite number of initial states. This is where formal verification comes in: given a representation of the system in question in a formal framework, verification approaches and tools can be used to establish the system's adherence to its similarly formalized specification, and to complement testing.
One such formal framework is the field of graphs and graph transformation systems. Both are powerful formalisms with well-established foundations and ongoing research that can be used to describe complex hardware or software systems with varying degrees of abstraction. Since their inception in the 1970s, graph transformation systems have continuously evolved; related research spans extensions of expressive power, graph algorithms, and their implementation, application scenarios, or verification approaches, to name just a few topics.
This thesis focuses on a verification approach for graph transformation systems called k-inductive invariant checking, which is an extension of previous work on 1-inductive invariant checking. Instead of exhaustively computing a system's state space, which is a common approach in model checking, 1-inductive invariant checking symbolically analyzes graph transformation rules - i.e. system behavior - in order to draw conclusions with respect to the validity of graph constraints in the system's state space. The approach is based on an inductive argument: if a system's initial state satisfies a graph constraint and if all rules preserve that constraint's validity, we can conclude the constraint's validity in the system's entire state space - without having to compute it.
However, inductive invariant checking also comes with a specific drawback: the locality of graph transformation rules leads to a lack of context information during the symbolic analysis of potential rule applications. This thesis argues that this lack of context can be partly addressed by using k-induction instead of 1-induction. A k-inductive invariant is a graph constraint whose validity in a path of k-1 rule applications implies its validity after any subsequent rule application - as opposed to a 1-inductive invariant where only one rule application is taken into account. Considering a path of transformations then accumulates more context of the graph rules' applications.
As such, this thesis extends existing research and implementation on 1-inductive invariant checking for graph transformation systems to k-induction. In addition, it proposes a technique to perform the base case of the inductive argument in a symbolic fashion, which allows verification of systems with an infinite set of initial states. Both k-inductive invariant checking and its base case are described in formal terms. Based on that, this thesis formulates theorems and constructions to apply this general verification approach for typed graph transformation systems and nested graph constraints - and to formally prove the approach's correctness.
Since unrestricted graph constraints may lead to non-termination or impracticably high execution times given a hypothetical implementation, this thesis also presents a restricted verification approach, which limits the form of graph transformation systems and graph constraints. It is formalized, proven correct, and its procedures terminate by construction. This restricted approach has been implemented in an automated tool and has been evaluated with respect to its applicability to test cases, its performance, and its degree of completeness.
Living cells rely on transport and interaction of biomolecules to perform their diverse functions. A powerful toolbox to study these highly dynamic processes in the native environment is provided by fluorescence fluctuation spectroscopy (FFS) techniques. In more detail, FFS takes advantage of the inherent dynamics present in biological systems, such as diffusion, to infer molecular parameters from fluctuations of the signal emitted by an ensemble of fluorescently tagged molecules. In particular, two parameters are accessible: the concentration of molecules and their transit times through the observation volume. In addition, molecular interactions can be measured by analyzing the average signal emitted per molecule - the molecular brightness - and the cross-correlation of signals detected from differently tagged species.
In the present work, several FFS techniques were implemented and applied in different biological contexts. In particular, scanning fluorescence correlation spectroscopy (sFCS) was performed to measure protein dynamics and interactions at the plasma membrane (PM) of cells, and number and brightness (N&B) analysis to spatially map molecular aggregation. To account for technical limitations and sample related artifacts, e.g. detector noise, photobleaching, or background signal, several correction schemes were explored. In addition, sFCS was combined with spectral detection and higher moment analysis of the photon count distribution to resolve multiple species at the PM.
Using scanning fluorescence cross-correlation spectroscopy and cross-correlation N&B, the interactions of amyloid precursor-like protein 1 (APLP1), a synaptic membrane protein, were investigated. It is shown for the first time directly in living cells, that APLP1 undergoes specific interactions at cell-cell contacts. It is further demonstrated that zinc ions induce formation of large APLP1 clusters that enrich at contact sites and bind to clusters on the opposing cell. Altogether, these results provide direct evidence that APLP1 is a zinc ion dependent neuronal adhesion protein.
In the context of APLP1, discrepancies of oligomeric state estimates were observed, which were attributed to non-fluorescent states of the chosen red fluorescent protein (FP) tag mCardinal (mCard). Therefore, multiple FPs and their performance in FFS based measurements of protein interactions were systematically evaluated. The study revealed superior properties of monomeric enhanced green fluorescent protein (mEGFP) and mCherry2. Furthermore, a simple correction scheme allowed unbiased in situ measurements of protein oligomerization by quantifying non-fluorescent state fractions of FP tags. The procedure was experimentally confirmed for biologically relevant protein complexes consisting of up to 12 monomers.
In the last part of this work, fluorescence correlation spectroscopy (FCS) and single particle tracking (SPT) were used to characterize diffusive transport dynamics in a bacterial biofilm model. Biofilms are surface adherent bacterial communities, whose structural organization is provided by extracellular polymeric substances (EPS) that form a viscous polymer hydrogel. The presented study revealed a probe size and polymer concentration dependent (anomalous) diffusion hindrance in a reconstituted EPS matrix system caused by polymer chain entanglement at physiological concentrations. This result indicates a meshwork-like organization of the biofilm matrix that allows free diffusion of small particles, but strongly hinders diffusion of larger particles such as bacteriophages. Finally, it is shown that depolymerization of the matrix by phage derived enzymes rapidly facilitated free diffusion. In the context of phage infections, such enzymes may provide a key to evade trapping in the biofilm matrix and promote efficient infection of bacteria. In combination with phage application, matrix depolymerizing enzymes may open up novel antimicrobial strategies against multiresistant bacterial strains, as a promising, more specific alternative to conventional antibiotics.
Since the golden era of antibiotics natural products are of ever growing interest to both basic research and applied sciences as they are the main source of new bioactive compounds delivering lead structures for new pharmaceuticals with potent antibiotic, anti-inflammatory or anti-cancer activities. Alongside the technological advances in high-throughput genome sequencing and the better understanding of the general organization of those modular biosynthetic assembly lines of secondary metabolites, there was also a shift from wet-lab screening of active cell extracts towards algorithm-based in silico screening for new natural product biosynthesis gene clusters (BGCs). Although the increasing availability of full genome sequences revealed that such non-ribosomal peptide synthetases (NRPS), polyketide synthases (PKS) and ribosomally synthesized and post-translationally modified peptides (RiPPs) can be found in all three kingdoms of life, certain phyla like actinobacteria and cyanobacteria show a very high density of these secondary metabolite BGCs.
The facultative symbiotic, N2-fixing model organism N. punctiforme PCC73102 is a terrestrial type IV cyanobacterium that not only dedicates are very large fraction of its genome to secondary metabolite production but is also amenable to genetic modification. AntiSMASH analysis of the genome showed that there are sixteen potential secondary metabolite BGCs encoded in N. punctiforme, but until now there were only two compounds assigned to their respective BGC leaving the remaining fourteen orphan. This makes the organism a perfect subject for the establishment of a novel combinatorial genomic mining approach for the detection of new natural products.
In the course of this study a combinatorial approach of genomic mining, independent monitoring techniques and alteration of cultivation conditions lead to new insights in cyanobacterial natural product biosynthesis and ultimately to the description of a novel compound produced by N. punctiforme. With the generation and investigation of a reporter strain library consisting of CFP-producing transcriptional reporter mutants for every predicted secondary metabolite BGC of N. punctiforme, it could be shown that natural product expression is in fact not silent for all those BGCs where no compound can be detected. Instead several distinct expression patterns could be described highlighting that secondary metabolite production is under tight regulation and only a minor fraction of these BGCs is in fact silent under standard laboratory conditions. Furthermore, increasing light intensity and carbon dioxide availability and cultivating N. punctiforme to very high cell densities had a tremendous impact on the overall metabolic activity of the organism. Investigation of high density cultivated cell extracts ultimately lead to the detection of a so far undescribed set of microviridins with unusual extended peptide sequences named Microviridin N3 – N9. Both cultivation of the transcriptional reporter mutants as well as RTqPCR-based detection of secondary metabolite BGC transcription levels revealed that in fact 50% of N. punctiforme’s natural product BGCs are upregulated under high cell density conditions. In contrast to this very broad response, co-cultivation of N. punctiforme in chemical or physical contact with a N-deprived host plant (Blasia pusilla) lead to a very specific upregulation of two natural product BGCs, namely RIPP3 and RIPP4. Although this response could be confirmed by various independent monitoring techniques and heavy analytical efforts were spent, no compound could be assigned to either of these BGCs.
This study is the first in-depth systematic investigation of a cyanobacterial secondary metabolome by a combinatorial approach of genome mining and independent monitoring techniques that can serve as a new strategic approach to gain further insight into natural product synthesis of various organisms. Although there are single well described examples of secondary metabolites like the cell differentiation factor PatS in Anabaena sp. strain PCC 7120, the level and extent of regulation observed in this study is unprecedented and understanding of these mechanisms might be the key to streamline natural product discovery. However, the results of this study also highlight that induction of secondary metabolite BGCs is not the real challenge. Instead the new insights point towards analytical issues being a severe hurdle and finding reliable strategies to overcome these problems might as well drive natural product discovery.
Cleft exhaustivity
(2020)
In this dissertation a series of experimental studies are presented which demonstrate that the exhaustive inference of focus-background it-clefts in English and their cross-linguistic counterparts in Akan, French, and German is neither robust nor systematic. The inter-speaker and cross-linguistic variability is accounted for with a discourse-pragmatic approach to cleft exhaustivity, in which -- following Pollard & Yasavul 2016 -- the exhaustive inference is derived from an interaction with another layer of meaning, namely, the existence presupposition encoded in clefts.
Over the last decades, the Arctic regions of the earth have warmed at a rate 2–3 times faster than the global average– a phenomenon called Arctic Amplification. A complex, non-linear interplay of physical processes and unique pecularities in the Arctic climate system is responsible for this, but the relative role of individual processes remains to be debated. This thesis focuses on the climate change and related processes on Svalbard, an archipelago in the North Atlantic sector of the Arctic, which is shown to be a "hotspot" for the amplified recent warming during winter. In this highly dynamical region, both oceanic and atmospheric large-scale transports of heat and moisture interfere with spatially inhomogenous surface conditions, and the corresponding energy exchange strongly shapes the atmospheric boundary layer. In the first part, Pan-Svalbard gradients in the surface air temperature (SAT) and sea ice extent (SIE) in the fjords are quantified and characterized. This analysis is based on observational data from meteorological stations, operational sea ice charts, and hydrographic observations from the adjacent ocean, which cover the 1980–2016 period. It is revealed that typical estimates of SIE during late winter range from 40–50% (80–90%) in the western (eastern) parts of Svalbard. However, strong SAT warming during winter of the order of 2–3K per decade dictates excessive ice loss, leaving fjords in the western parts essentially ice-free in recent winters. It is further demostrated that warm water currents on the west coast of Svalbard, as well as meridional winds contribute to regional differences in the SIE evolution. In particular, the proximity to warm water masses of the West Spitsbergen Current can explain 20–37% of SIE variability in fjords on west Svalbard, while meridional winds and associated ice drift may regionally explain 20–50% of SIE variability in the north and northeast. Strong SAT warming has overruled these impacts in recent years, though.
In the next part of the analysis, the contribution of large-scale atmospheric circulation changes to the Svalbard temperature development over the last 20 years is investigated. A study employing kinematic air-back trajectories for Ny-Ålesund reveals a shift in the source regions of lower-troposheric air over time for both the winter and the summer season. In winter, air in the recent decade is more often of lower-latitude Atlantic origin, and less frequent of Arctic origin. This affects heat- and moisture advection towards Svalbard, potentially manipulating clouds and longwave downward radiation in that region. A closer investigation indicates that this shift during winter is associated with a strengthened Ural blocking high and Icelandic low, and contributes about 25% to the observed winter warming on Svalbard over the last 20 years. Conversely, circulation changes during summer include a strengthened Greenland blocking high which leads to more frequent cold air advection from the central Arctic towards Svalbard, and less frequent air mass origins in the lower latitudes of the North Atlantic. Hence, circulation changes during winter are shown to have an amplifying effect on the recent warming on Svalbard, while summer circulation changes tend to mask warming.
An observational case study using upper air soundings from the AWIPEV research station in Ny-Ålesund during May–June 2017 underlines that such circulation changes during summer are associated with tropospheric anomalies in temperature, humidity and boundary layer height.
In the last part of the analysis, the regional representativeness of the above described changes around Svalbard for the broader Arctic is investigated. Therefore, the terms in the diagnostic temperature equation in the Arctic-wide lower troposphere are examined for the Era-Interim atmospheric reanalysis product. Significant positive trends in diabatic heating rates, consistent with latent heat transfer to the atmosphere over regions of increasing ice melt, are found for all seasons over the Barents/Kara Seas, and in individual months in the vicinity of Svalbard. The above introduced warm (cold) advection trends during winter (summer) on Svalbard are successfully reproduced. Regarding winter, they are regionally confined to the Barents Sea and Fram Strait, between 70°–80°N, resembling a unique feature in the whole Arctic. Summer cold advection trends are confined to the area between eastern Greenland and Franz Josef Land, enclosing Svalbard.