Refine
Year of publication
- 2007 (487) (remove)
Document Type
- Article (213)
- Doctoral Thesis (105)
- Conference Proceeding (65)
- Monograph/Edited Volume (40)
- Part of a Book (17)
- Postprint (12)
- Preprint (10)
- Master's Thesis (7)
- Other (6)
- Review (6)
- Habilitation Thesis (3)
- Working Paper (3)
Language
- English (487) (remove)
Keywords
- focus (5)
- Arabidopsis thaliana (4)
- Focus (4)
- Japanese (3)
- Seismologie (3)
- Synchronisation (3)
- Synchronization (3)
- Topic (3)
- contrastive focus (3)
- AMNET (2)
- Diversität (2)
- Erdbeben (2)
- Indischer Ozean (2)
- Information Structure (2)
- Intonation (2)
- Klimawandel (2)
- Modellierung (2)
- Perception (2)
- Raman (2)
- Transkriptionsfaktoren (2)
- Tsunami (2)
- ad hoc learning (2)
- ad hoc messaging network (2)
- cleft constructions (2)
- diversity (2)
- e-learning platform (2)
- eye movements (2)
- givenness (2)
- information structure (2)
- prosody (2)
- scope of focus (2)
- synchronization (2)
- transcription factors (2)
- (Statement-Question Matching) (1)
- (implicit) prosody (1)
- 3D Linsen (1)
- 3D lenses (1)
- Abflussbildung (1)
- Aboutness Topics (1)
- Accretion (1)
- Active Galactic Nuclei (1)
- Adsorption (1)
- Agent (1)
- Agrarökosystem (1)
- Akkretion (1)
- Aktive Galaxienkerne (1)
- Alternative Semantics (1)
- Alzheimer's Disease (1)
- Anden (1)
- Andes (1)
- Antarctic (1)
- Antarktis (1)
- Anthropometrie (1)
- Antwortmengenprogrammierung (1)
- Atomwaffen (1)
- Atomwaffensperrvertrag (1)
- Attention (1)
- Aufmerksamkeit (1)
- Australia (1)
- Australien (1)
- Automated Theorem Proving (1)
- Automatisches Beweisen (1)
- Bedeutung (1)
- Bemessungshochwasser (1)
- Bias (1)
- Bilddatenanalyse (1)
- Bildgeschichtenaufgabe (1)
- Bilirubin oxidase (1)
- Biogenic amine (1)
- Biosensor (1)
- Blickbewegung (1)
- Blickbewegungen (1)
- Blickbewegungskontrolle (1)
- Bodenhydrologie (1)
- Bologna process (1)
- Brain Code (1)
- Bruchausbreitung (1)
- Calorimetry (1)
- Cell cycle (1)
- Celtic languages (1)
- Chaos (1)
- Chemotaxis (1)
- Chile (1)
- Chilean Andes (1)
- Christian Hebraists (1)
- Clause Learning (1)
- Climate (1)
- Climate change (1)
- Cloze predictability (1)
- Cloze-Vorhersagbarkeit (1)
- Colombia (1)
- Complex Speech Acts (1)
- Context (1)
- Continental Celtic (1)
- Contrast (1)
- Correlation Analysis (1)
- Corynephorus canescens (1)
- Cosmic Dust (1)
- Covalent imprinting (1)
- Cretaceous (1)
- Cytochrome c (1)
- DGVM (1)
- DPLL (1)
- Daten Analyse (1)
- Deduction (1)
- Deligne Cohomology (1)
- Deligne Kohomologie (1)
- Democracy Promotion (1)
- Demokratieförderung (1)
- Demokratisierung (1)
- Development (1)
- Dezentralisierung (1)
- Diversity (1)
- Divisionsbäume (1)
- Domänen (1)
- Downstep (1)
- Dynamics (1)
- Dynamik (1)
- EAAT1 (1)
- Earthquake (1)
- East Prussia (1)
- Echtzeitanwendung (1)
- Electron acceleration (1)
- Electron transfer (1)
- Elektronenbeschleunigung (1)
- Energieerzeugung (1)
- Entwicklung (1)
- Equisetum hyemale (1)
- Erzählungen (1)
- Etablierung (1)
- European Foreign Policy (1)
- European Neighbourhood Policy (1)
- European Union (1)
- Europäische Außenpolitik (1)
- Europäische Nachbarschaftspolitik (1)
- Europäische Union (1)
- Evolution of Language (1)
- Eye movement (1)
- F-marking (1)
- FARIMA (1)
- Faltungsdynamik (1)
- Filament-Bündel (1)
- Filamente (1)
- Fiscal decentralisation (1)
- Fluss-Seen (1)
- Foodo (1)
- Fore-Arc (1)
- Fructose (1)
- Fructosyl valine (1)
- G protein-coupled receptor (1)
- G-marking (1)
- GITEWS (1)
- Gender (1)
- Gene expression profiling (1)
- Genetic transformation (1)
- Geochemie (1)
- Geometrieerzeugung (1)
- George W. Bush (1)
- Geostatistik (1)
- Gerben (1)
- Gerbes (1)
- Geschichte 2003-2006 (1)
- Geschlecht (1)
- Geschwindigkeit (1)
- Gewässerökologie (1)
- Givenness (1)
- Gleichgewicht der Kräfte (1)
- Global Differentialgeometry (1)
- Globale Differentialgeometrie (1)
- Glutamat (1)
- Glutamate (1)
- Glycated hemoglobin (1)
- Gravitational Wave (1)
- Gravitationswellen (1)
- HMA (1)
- Habitatmodell (1)
- Handedness (1)
- Hangstabilität (1)
- Hauptfaserbündel (1)
- HbA1c (1)
- Holonomie (1)
- Holonomy (1)
- Hsp (1)
- Human-Eco-System (1)
- Hydrodynamischer Fluss (1)
- Hydrologic Modeling (1)
- Hydrologische Modellierung (1)
- Hyperakkumulation (1)
- I/O-effiziente Algorithmen (1)
- IASP Program of the DAAD (1)
- Identity (1)
- Identität (1)
- Immunhistochemie (1)
- Indefinites (1)
- India (1)
- Indian Ocean (1)
- Indien (1)
- Indonesia (1)
- Information (1)
- Information Processing (1)
- Inselkeltisch (1)
- Insular Celtic (1)
- Intervention Effect (1)
- Investitionspolitik (1)
- Irak (1)
- Jets (1)
- Jhabua (1)
- Joint study programs (1)
- Judaism (1)
- Judentum (1)
- Jugendliche (1)
- Kinesin (1)
- Klausellernen (1)
- Klima (1)
- Kohlenstoffhaushalt (1)
- Kohlenstoffmaterialien (1)
- Kohlenstoffmodell (1)
- Kolokalisation (1)
- Kolumbien (1)
- Konditionalregeln (1)
- Konkomba (1)
- Kontext (1)
- Kontinentalkeltisch (1)
- Kosmischer Staub (1)
- Kreide (1)
- Kuramoto Modell (1)
- Kuramoto model (1)
- Künstliche Intelligenz (1)
- LPJ (1)
- Landnutzungswandel (1)
- Latent Semantic Analysis (1)
- Latente-Semantische-Analyse (1)
- Laufzeitresiduen (1)
- Leaf trichomes (1)
- Left-Dislocation (1)
- Literatur (1)
- Literature (1)
- Logarithmic Sobolev inequality (1)
- Logisches Denken (1)
- MCHR-1 (1)
- MHD (1)
- MIP sensor (1)
- Maaseh Book (1)
- Maassebuch (1)
- Madhya Pradesh (1)
- Magmatismus (1)
- Magnetohydrodynamics (1)
- Magnetohydrodynamik (1)
- Mais (1)
- Maize (1)
- Management (1)
- Marokko (1)
- Mars (1)
- Massenbewegung (1)
- Massenverlust (1)
- Maysebuch (1)
- Maßstabsabhängigkeit (1)
- Meaning (1)
- Melampyrum pratense (1)
- Membran (1)
- Mentale Modell Theorie (1)
- Mergel (1)
- Mesoporosity (1)
- Mesoporosität (1)
- Metabolism (1)
- Methankreislauf (1)
- Microalgae (1)
- Mikroalgen (1)
- Mikrotomographie (1)
- Minderheit (1)
- Mobile learning (1)
- Monte Carlo (1)
- Morbus Alzheimer (1)
- Morocco (1)
- Musterbildung (1)
- N400 (1)
- Nachhaltigkeit (1)
- Nation (1)
- Negative (1)
- Networks (1)
- Netzwerk (1)
- Neuronsreliabilität (1)
- Neuropeptides (1)
- Nichtlineare Wellen (1)
- Nichtverbreitung von Kernwaffen (1)
- Nitrat (1)
- Nitrate (1)
- Noise (1)
- Nonlinear waves (1)
- Nuclear non-proliferation (1)
- Nährstoffe (1)
- Oberflächengitter (1)
- Oculomotor control (1)
- On.Line Monitoring (1)
- Ostpreußen (1)
- P-Typ ATPase (1)
- Partition (1)
- Pattern-oriented parameter estimation (1)
- Permafrostökosysteme (1)
- Persistenzlänge (1)
- Phase (1)
- Phase Diffusion (1)
- Phasen-Gleichungen (1)
- Phasen-Oszillatoren (1)
- Phasendiffusion (1)
- Photon density waves (1)
- Photonendichtewellen (1)
- Pitch Reset (1)
- Plant hormones (1)
- Plastid (1)
- Point Process (1)
- Polar Questions (1)
- Politikdiffusion (1)
- Politiktransfer (1)
- Polizeireform (1)
- Polydispersität (1)
- Polyelectrolyte (1)
- Polymere (1)
- Post-Focus Reduction (1)
- Prinicipal Fibre Bundles (1)
- Probabilistische Theorie (1)
- Prosody (1)
- Protein Multilayer (1)
- Proteinfaltung (1)
- Proximity-Effekt (1)
- Präferenzen (1)
- Quantificational Variability Effects (1)
- Quasar (1)
- Quasare (1)
- Ramsey test (1)
- Ramsey-Test (1)
- Ratte (1)
- Rauschen (1)
- Recurrence Plot (1)
- Recursivity (1)
- Regeneratin (1)
- Regeneration (1)
- Reliability of Neurons (1)
- Rollende Adhäsion (1)
- Rupture Propagation (1)
- Röntgenbeugung (1)
- Röntgenhintergrund (1)
- SAT (1)
- SAXS (1)
- SDRT (1)
- SWAP (1)
- Saccade (1)
- Sakkade (1)
- Saturation model (1)
- Saturn (1)
- Schleifenschließung (1)
- Schwefel (1)
- Second Occurrence Focus (1)
- Seen (1)
- Segmentierung (1)
- Seismology (1)
- Seismotektonik (1)
- Semi-arid (1)
- Shader (1)
- Shock waves (1)
- Shrub encroachment (1)
- Signal transfer chain (1)
- Siliciumdioxid (1)
- Simulationen (1)
- Simulations (1)
- Simulationsmodell (1)
- Single cell level (1)
- Skelettberechnung (1)
- Social Identity Theory (1)
- Solar corona (1)
- Sonne (1)
- Sonnenkorona (1)
- Southeast Asia (1)
- Spielleistung (1)
- Spleißvariante (1)
- Splice Variant (1)
- Sprachkontakt (1)
- Spurengasflüsse (1)
- Sternwinde (1)
- Stochastics (1)
- Stochastik (1)
- Stochastische Prozesse (1)
- Stochastischer Prozess (1)
- Stoffwechsel (1)
- Stokesion Dynamics (1)
- Stokessche Dynamik (1)
- Stoßwellen (1)
- Strahlungstransport (1)
- Strike-Slip Störungen (1)
- Stäbchen (1)
- Subduktionszone (1)
- Substrat (1)
- Sukzession (1)
- Sun (1)
- Surface characterization (1)
- Surrogate Data (1)
- Synchrony (1)
- Südostasien (1)
- Tachocline (1)
- Tachokline (1)
- Tag Questions (1)
- Taylor-Couette (1)
- Team Composition (1)
- Team Development (1)
- Testen (1)
- Tetration (1)
- Thermistor (1)
- Tone (language) (1)
- Topic/Comment (1)
- Transatlantic Degree Program (TDP) (1)
- Transport (1)
- TreeNet (1)
- Trichome initial cells (1)
- Tropen (1)
- Type I AGN (1)
- Type II AGN (1)
- US foreign policy (1)
- US-Außenpolitik (1)
- Understanding (1)
- Unilateralismus (1)
- Unsicherheitsanalyse (1)
- Upper Limit (1)
- Vegetationsmodell (1)
- Verhältnis der Struktur und Funktion (1)
- Verstehen (1)
- Vesikel (1)
- Vietnamese (1)
- Virtuelles 3D Stadtmodell (1)
- Visualisierung (1)
- Visualisierungsmodell (1)
- Volleyball (1)
- WASA (1)
- WOFOST (1)
- WRKY (1)
- Wahlen (1)
- Wahlmuster (1)
- Wahlverhalten (1)
- Wahrnehmung (1)
- Wassergüte (1)
- Weglänge (1)
- Weitwinkelröntgenstreuung (1)
- Weißstorch (1)
- Wellengeschwindigkeiten (1)
- Wh-question (1)
- Whinterrogatives (1)
- Wide Scope (1)
- Wiederkehrverhalten (1)
- Winterschachtelhalm (1)
- Wittgenstein (1)
- Wort-n-Gramme-Wahrscheinlichkeit (1)
- X-ray background (1)
- Zelladhäsion (1)
- Zink (1)
- Zusammenarbeit in Sicherheitsfragen (1)
- [N]phenylene dyads (1)
- [N]phenylenes (1)
- adolescents (1)
- adsorption (1)
- adverbial quantification (1)
- alternative semantics presupposition projection (1)
- answer set programming (1)
- anthropometry (1)
- antioxidant response (1)
- arid (1)
- artificial intelligence (1)
- asymptotic stable (1)
- attractive interaction (1)
- attraktive Wechselwirkung (1)
- azobenzene polymer (1)
- azobenzenhaltige Polymere (1)
- balance of power (1)
- bild (1)
- biodiversity (1)
- breadth of focus (1)
- c-Fos (1)
- carbon cycle (1)
- carbon materials (1)
- cell adhesion (1)
- cell cycle (1)
- chilenische Anden (1)
- chloroplast (1)
- christliche Hebraisten (1)
- ciconia ciconia (1)
- climate change (1)
- clitic doubling (1)
- colocalisation study (1)
- community (1)
- complex brain networks (1)
- complexity (1)
- conditional reasoning (1)
- conjunction (1)
- contrastive topic (1)
- corrective focus (1)
- data analysis (1)
- de Sitter model ; Fundamental solutions ; Decay estimates (1)
- de-accenting (1)
- decentralization (1)
- deep-seated landslide (1)
- definites (1)
- degenerate elliptic equations (1)
- democratization (1)
- discourse expectability (1)
- division trees (1)
- domains (1)
- economic transformation (1)
- economics curriculum (1)
- elections (1)
- electoral patterns (1)
- emphasis (1)
- erzeugte Kraft (1)
- establishment (1)
- event-related potentials (ERP) (1)
- exhaustive identification (1)
- external memory algorithms (1)
- eye-movements (1)
- filament bundles (1)
- filaments (1)
- fiscal federalism (1)
- fiscal policy (1)
- fixation durations (1)
- focus ambiguity (1)
- focus anaphoricity (1)
- focus constructions (1)
- focus intonation (1)
- focus meaning (1)
- focus position (1)
- focus type (1)
- focus types (1)
- folding dynamics (1)
- fore-arc (1)
- freshwater ecology (1)
- generated force (1)
- genetische Manipulation (1)
- geochemistry (1)
- geometry generation (1)
- geostatistics (1)
- geovisualization (1)
- global change (1)
- global solution (1)
- governance (1)
- hierarchical model (1)
- hierarchical porosity (1)
- hierarchische Porosität (1)
- hierarchisches Model (1)
- higher operations (1)
- hydrodynamic flow (1)
- hydrodynamic modeling (1)
- hydrodynamische Modellierung (1)
- hydrological processes (1)
- hydrologische Prozesse (1)
- hyperaccumulation (1)
- höhere Operationen (1)
- image (1)
- image data analysis (1)
- immunohistochemistry (1)
- implicit motives (1)
- implizite Motive (1)
- individual-based model (1)
- informational focus (1)
- insect (1)
- interface (1)
- intergalactic medium (1)
- intergalaktisches Medium (1)
- intergovernmental relations (1)
- intonation (1)
- intonation (language) (1)
- job characteristics (1)
- keltische Sprachen (1)
- kinesin (1)
- komplexe Hirnnetzwerke (1)
- lakes (1)
- landslide hydrology (1)
- landuse change (1)
- langreichweitige Korrelationen (1)
- language contact (1)
- lexical tone (1)
- local and regional autonomy (1)
- local jurisdictions (1)
- logic programming (1)
- logische Programmierung (1)
- long-memory (1)
- long-range dependence (1)
- loop closure (1)
- magmatism (1)
- management (1)
- marls (1)
- mass loss (1)
- massereiche Sterne (1)
- massive stars (1)
- mean first passage times (1)
- medical (1)
- medizinisch (1)
- membrane (1)
- mental modell theory (1)
- methane cycle (1)
- micro- and nanotechnologies (1)
- microbial processes (1)
- microtomography (1)
- mikrobielle Prozesse (1)
- mobile learning (1)
- modeling (1)
- morphological focus marking (1)
- nachhaltige Landnutzung (1)
- negative polarity item (NPI) (1)
- neogene (1)
- neuropeptides (1)
- nichtgenestete Modellselektion (1)
- non-nested model selection (1)
- nonlinear dynamics (1)
- nuclear non-proliferation treaty (1)
- nuclear weapons (1)
- numerical models (1)
- numerische Modelle (1)
- nutrients (1)
- overgrazing (1)
- oxidative stress (1)
- p-type ATPase (1)
- parafoveal-on-foveal effects (1)
- path analysis (1)
- pattern formation (1)
- performance (1)
- permafrost ecosystems (1)
- persistence length (1)
- personal goals (1)
- personal initiative (1)
- persönliche Ziele (1)
- pervasive learning (1)
- phase equations (1)
- phase oscillators (1)
- photoinduced electron transfer (1)
- picture story exercise (1)
- pitch accent (1)
- police reform (1)
- policy diffusion (1)
- policy transfer (1)
- polydispersity (1)
- polymers (1)
- predictive habitat model (1)
- preferences (1)
- presentational constructions (1)
- pressure propagation (1)
- presupposition (1)
- preview benefit (1)
- priorities (1)
- probabilistic theory (1)
- processing (1)
- prosodic phrasing (1)
- protein folding (1)
- proximity effect (1)
- prozeß-basierte Modellierung (1)
- quasar (1)
- quasars (1)
- quasiperiodic dynamical systems (1)
- quasiperiodisches dynamisches System (1)
- radiative transfer (1)
- rapid serial visual presentation (RSVP) (1)
- rat (1)
- reading (1)
- real-time application (1)
- reciprocal relationship (1)
- reconstruction (1)
- recurrence (1)
- recurrence plots (1)
- referential competence (1)
- referentielle Kompetenz (1)
- regional modeling (1)
- regionales Modell (1)
- reptiles (1)
- residuals (1)
- return level estimation (1)
- revenue sharing (1)
- river-lake systems (1)
- rods (1)
- rolling adhesion (1)
- run length (1)
- runoff generation (1)
- räumliche Analyse (1)
- salivary gland (1)
- scale dependence (1)
- scrambling (1)
- second occurrence focus (1)
- secondary metabolism (1)
- secretion (1)
- security cooperation (1)
- seed dispersal (1)
- segmentation (1)
- seismology (1)
- seismotectonics (1)
- selbst-attribuierte Motive (1)
- self-attributed motives (1)
- self-organization (1)
- selfefficacy (1)
- sentence reading (1)
- shader (1)
- silica (1)
- similarity measures (1)
- simulation model (1)
- situation variables (1)
- skeletonization (1)
- soft and hard templating (1)
- soil hydrology (1)
- spatial analysis (1)
- spatially explicit modelling (1)
- state and local budgets (1)
- stellar winds (1)
- stochastic gradient boosting (1)
- stochastic process (1)
- stochastic processes (1)
- stories (1)
- strike-slip faults (1)
- structur-function relationship (1)
- structured numbers (1)
- strukturierte Zahlen (1)
- subduction zone (1)
- substrate (1)
- succession (1)
- sulphur (1)
- surface relief grating (1)
- sustainable management (1)
- syntactic focus marking (1)
- syntax (1)
- tax distribution (1)
- testing (1)
- tetration (1)
- topic (1)
- topic affixes (1)
- topic-comment (1)
- topicalization (1)
- trace gas fluxes (1)
- transition economy (1)
- transition metals (1)
- transition state (1)
- transport (1)
- traveltime (1)
- tropics (1)
- tuition fees (1)
- type I AGN (1)
- type II AGN (1)
- uncertainty analysis (1)
- unilateralism (1)
- universal quantifiers (1)
- vegetation model (1)
- velocity (1)
- verb-initial (1)
- verb-initial cleft constructions (1)
- vesicle (1)
- virtual 3D city model (1)
- virtual corporation (1)
- viscoplastic theory (1)
- viskoplastische Theorie (1)
- visualization (1)
- volleyball (1)
- voting behaviour (1)
- water quality (1)
- weiche und harte Templatierung (1)
- wh-question (1)
- white stork (1)
- wide-angle x-ray scattering (1)
- word n-gram probability (1)
- zinc (1)
- Ähnlichkeit-Masse (1)
- Übergangsmetalle (1)
- Übergangszustand (1)
Institute
- Extern (78)
- Institut für Biochemie und Biologie (71)
- Institut für Physik und Astronomie (68)
- Department Linguistik (51)
- Institut für Informatik und Computational Science (36)
- Institut für Chemie (31)
- Institut für Anglistik und Amerikanistik (30)
- Wirtschaftswissenschaften (28)
- Department Psychologie (24)
- Institut für Mathematik (22)
Focus presuppositions
(2007)
This paper reviews notions related to focus and presupposition and addresses the hypothesis that focus triggers an existential presupposition. Presupposition projection behavior in certain examples appears to favor a presuppositional analysis of focus. It is argued that these examples are open to a different analysis using givenness theory. Overall, the analysis favors a weak semantics for focus not including an existential presupposition.
The aim of this work was the generation of carbon materials with high surface area, exhibiting a hierarchical pore system in the macro- and mesorange. Such a pore system facilitates the transport through the material and enhances the interaction with the carbon matrix (macropores are pores with diameters > 50 nm, mesopores between 2 – 50 nm). Thereto, new strategies for the synthesis of novel carbon materials with designed porosity were developed that are in particular useful for the storage of energy. Besides the porosity, it is the graphene structure itself that determines the properties of a carbon material. Non-graphitic carbon materials usually exhibit a quite large degree of disorder with many defects in the graphene structure, and thus exhibit inherent microporosity (d < 2nm). These pores are traps and oppose reversible interaction with the carbon matrix. Furthermore they reduce the stability and conductivity of the carbon material, which was undesired for the proposed applications. As one part of this work, the graphene structures of different non-graphitic carbon materials were studied in detail using a novel wide-angle x-ray scattering model that allowed precise information about the nature of the carbon building units (graphene stacks). Different carbon precursors were evaluated regarding their potential use for the synthesis shown in this work, whereas mesophase pitch proved to be advantageous when a less disordered carbon microstructure is desired. By using mesophase pitch as carbon precursor, two templating strategies were developed using the nanocasting approach. The synthesized (monolithic) materials combined for the first time the advantages of a hierarchical interconnected pore system in the macro- and mesorange with the advantages of mesophase pitch as carbon precursor. In the first case, hierarchical macro- / mesoporous carbon monoliths were synthesized by replication of hard (silica) templates. Thus, a suitable synthesis procedure was developed that allowed the infiltration of the template with the hardly soluble carbon precursor. In the second case, hierarchical macro- / mesoporous carbon materials were synthesized by a novel soft-templating technique, taking advantage of the phase separation (spinodal decomposition) between mesophase pitch and polystyrene. The synthesis also allowed the generation of monolithic samples and incorporation of functional nanoparticles into the material. The synthesized materials showed excellent properties as an anode material in lithium batteries and support material for supercapacitors.
Development and application of novel genetic transformation technologies in maize (Zea mays L.)
(2007)
Plant genetic engineering approaches are of pivotal importance to both basic and applied research. However, rapid commercialization of genetically engineered crops, especially maize, raises several ecological and environmental concerns largely related to transgene flow via pollination. In most crops, the plastid genome is inherited uniparentally in a maternal manner. Consequently, a trait introduced into the plastid genome would not be transferred to the sexually compatible relatives of the crops via pollination. Thus, beside its several other advantages, plastid transformation provides transgene containment, and therefore, is an environmentally friendly approach for genetic engineering of crop plants. Reliable in vitro regeneration systems allowing repeated rounds of regeneration are of utmost importance to development of plastid transformation technologies in higher plants. While being the world’s major food crops, cereals are among the most difficult-to-handle plants in tissue culture which severely limits genetic engineering approaches. In maize, immature zygotic embryos provide the predominantly used material for establishing regeneration-competent cell or callus cultures for genetic transformation experiments. The procedures involved are demanding, laborious and time consuming and depend on greenhouse facilities. In one part of this work, a novel tissue culture and plant regeneration system was developed that uses maize leaf tissue and thus is independent of zygotic embryos and greenhouse facilities. Also, protocols were established for (i) the efficient induction of regeneration-competent callus from maize leaves in the dark, (ii) inducing highly regenerable callus in the light, and (iii) the use of leaf-derived callus for the generation of stably transformed maize plants. Furthermore, several selection methods were tested for developing a plastid transformation system in maize. However, stable plastid transformed maize plants could not be yet recovered. Possible explanations as well as suggestions for future attempts towards developing plastid transformation in maize are discussed. Nevertheless, these results represent a first essential step towards developing chloroplast transformation technology for maize, a method that requires multiple rounds of plant regeneration and selection to obtain genetically stable transgenic plants. In order to apply the newly developed transformation system towards metabolic engineering of carotenoid biosynthesis, the daffodil phytoene synthase (PSY) gene was integrated into the maize genome. The results illustrate that expression of a recombinant PSY significantly increases carotenoid levels in leaves. The beta-carotene (pro-vitamin A) amounts in leaves of transgenic plants were increased by ~21% in comparison to the wild-type. These results represent evidence for maize to have significant potential to accumulate higher amounts of carotenoids, especially beta-carotene, through transgenic expression of phytoene synthases. Finally, progresses were made towards developing transformation technologies in Peperomia (Piperaceae) by establishing an efficient leaf-based regeneration system. Also, factors determining plastid size and number in Peperomia, whose species display great interspecific variation in chloroplast size and number per cell, were investigated. The results suggest that organelle size and number are regulated in a tissue-specific manner rather than in dependency on the plastid type. Investigating plastid morphology in Peperomia species with giant chloroplasts, plasmatic connections between chloroplasts (stromules) were observed under the light microscope and in the absence of tissue fixation or GFP overexpression demonstrating the relevance of these structures in vivo. Furthermore, bacteria-like microorganisms were discovered within Peperomia cells, suggesting that this genus provides an interesting model not only for studying plastid biology but also for investigating plant-microbe interactions.
The central melanin-concentrating hormone (MCH) system has been intensively studied for its involvement in the regulation of feeding behaviour and body weight regulation. The importance of the neuropeptide MCH in the control of energy balance has been underlined by MCH knock out and Melanin-concentrating hormone receptor subtype 1 (MCHR-1) knock-out animals. The anorectic and anti-obesity effects of selective MCHR-1 antagonists have confirmed the notion that pharmacological blockade of MCHR-1 is a potential therapeutic approach for obesity. First aim of this work is to study the neurochemical “equipment” of MCHR-1 immunoreactive neurons by double-labelling immunohistochemistry within the rat hypothalamus. Of special interest is the neuroanatomical identification of other hypothalamic neuropeptides that are co-distributed with MCHR-1. A second part of this study deals with the examination of neuronal activation patterns after pharmacological or physiological, feeding-related stimuli and was introduced to further understand central regulatory mechanisms of the MCH system. In the first part of work, I wanted to neurochemically characterize MCHR-1 immunoreactive neurons in the rat hypothalamus for colocalisation with neuropeptides of interest. Therefore I performed an immunohistochemical colocalisation study using a specific antibody against MCHR-1 in combination with antibodies against hypothalamic neuropeptides. I showed that MCHR-1 immunoreactivity (IR) was co-localised with orexin A in the lateral hypothalamus, and with adrenocorticotropic hormone and neuropeptide Y in the arcuate nucleus. Additionally, MCHR-1 IR was co-localised with the neuropeptides vasopressin and oxytocin in magnocellular neurons of the supraoptic and paraventricular hypothalamic nucleus and corticotrophin releasing hormone in the parvocellular division of the paraventricular hypothalamic nucleus. Moreover, for the first time MCHR-1 immunoreactivity was found in both the adenohypophyseal and neurohypophyseal part of the rat pituitary. These results provide the neurochemical basis for previously described potential physiological actions of MCH at its target receptor. In particular, the MCHR-1 may be involved not only in food intake regulation, but also in other physiological actions such as fluid regulation, reproduction and stress response, possibly through here examined neuropeptides. Central activation patterns induced by pharmacological or physiological stimulation can be mapped using c-Fos immunohistochemistry. In the first experimental design, central administration (icv) of MCH in the rat brain resulted in acute and significant increase of food and water intake, but this animal treatment did not induce a specific c-Fos induction pattern in hypothalamic nuclei. In contrast, sub-chronic application of MCHR-1 antagonist promoted a significant decrease in food- and water intake during an eight day treatment period. A qualitative analysis of c-Fos immunohistochemistry of sections derived from MCHR-1 antagonist treated animals showed a specific neuronal activation in the paraventricular nucleus, the supraoptic nucleus and the dorsomedial hypothalamus. These results could be substantiated by quantitative evaluation of an automated, software-supported analysis of the c-Fos signal. Additionally, I examined the activation pattern of rats in a restricted feeding schedule (RFS) to identify pathways involved in hunger and satiety. Animals were trained for 9 days to feed during a three hour period. On the last day, food restricted animals was also allowed to feed for the three hours, while food deprived (FD) animals did not receive food. Mapping of neuronal activation showed a clear difference between stareved (FD) and satiated (FR) rats. FD animals showed significant induction of c-Fos in forebrain regions, several hypothalamic nuclei, amygdaloid thalamus and FR animals in the supraoptic nucleus and the paraventricular nucleus of the hypothalamus, and the nucleus of the solitary tract. In the lateral hypothalamus of FD rats, c-Fos IR showed strong colocalisation for Orexin A, but no co-staining for MCH immunoreactivity. However, a large number of c-Fos IR neurons within activated regions of FD and FR animals was co-localised with MCHR-1 within selected regions. To conclude, the experimental set-up of scheduled feeding can be used to induce a specific hunger or satiety activation pattern within the rat brain. My results show a differential activation by hunger signals of MCH neurons and furthermore, demonstrates that MCHR-1 expressing neurons may be essential parts of downstream processing of physiological feeding/hunger stimuli. In the final part of my work, the relevance of here presented studies is discussed with respect to possible introduction of MCHR-1 antagonists as drug candidates for the treatment of obesity.
This paper describes the proof calculus LD for clausal propositional logic, which is a linearized form of the well-known DPLL calculus extended by clause learning. It is motivated by the demand to model how current SAT solvers built on clause learning are working, while abstracting from decision heuristics and implementation details. The calculus is proved sound and terminating. Further, it is shown that both the original DPLL calculus and the conflict-directed backtracking calculus with clause learning, as it is implemented in many current SAT solvers, are complete and proof-confluent instances of the LD calculus.
Intonation and discourse
(2007)
This paper surveys a range of constructions in which prosody affects discourse function and discourse structure.We discuss English tag questions, negative polar questions, and what we call “focus” questions. We postulate that these question types are complex speech acts and outline an analysis in Segmented Discourse Representation Theory (SDRT) to account for the interactions between prosody and discourse.
The cytoskeletal motor protein kinesin-1 (conventional kinesin) is the fast carrier for intracellular cargo transport along microtubules. So far most studies aimed at investigating the transport properties of individual motor molecules. However, the transport in cells usually involves the collective work of more than one motor. In the present work, we have studied the movement of beads as artificial loads/organelles pulled by several kinesin-1 motors in vitro. For a wide range of motor coverage of the beads and different bead (cargo) sizes the transport parameters walking distance or run length, velocity and force generation are measured. The results indicate that the transport parameters are influenced by the number of motors carrying the bead. While the transport velocity slightly decreases, an increase in the run length was measured and higher forces are determined, when more motors are involved. The effective number of motors pulling a bead is estimated by measuring the change in the hydrodynamic diameter of kinesin-coated beads using dynamic light scattering. The geometrical constraints imposed by the transport system have been taken into account. Thus, results for beads of different size and motor-surface coverage could be compared. In addition, run length-distributions obtained for the smallest bead size were matched to theoretically calculated distributions. The latter yielded an average number of pulling motors, which is in agreement with the effective motor numbers determined experimentally.
Exploring elections features from a geographical perspective is the focus of this study. Its primary objective is to develop a scientific approach based on geoinformation technology (GIT) that promotes deeper understanding how geographical settings affect the spatial and temporal variations of voting behaviour and election outcomes. For this purpose, the five parliamentary elections (1991-2005) following the political turnaround in 1990 in the South East European reform country Albania have been selected as a case study. Elections, like other social phenomena that do not develop uniformly over a territory, inherit a spatial dimension. Despite of fact that elections have been researched by various scientific disciplines ranging from political science to geography, studies that incorporate their spatial dimension are still limited in number and approaches. Consequently, the methodologies needed to generate an integrated knowledge on many facets that constitute election features are lacking. This study addresses characteristics and interactions of the essential elements involved in an election process. Thus, the baseline of the approach presented here is the exploration of relations between three entities: electorate (political and sociodemographic features), election process (electoral system and code) and place (environment where voters reside). To express this interaction the concept of electoral pattern is introduced. Electoral patterns are defined by the study as the final view of election results, chiefly in tabular and/or map form, generated by the complex interaction of social, economic, juridical, and spatial features of the electorate, which has occurred at a specific time and in a particular geographical location. GIT methods of geoanalysis and geovisualization are used to investigate the characteristics of electoral patterns in their spatial and temporal distribution. Aggregate-level data modelled in map form were used to analyse and visualize the spatial distribution of election patterns components and relations. The spatial dimension of the study is addressed in the following three main relations: One, the relation between place and electorate and its expression through the social, demographic and economic features of the electorate resulting in the profile of the electorate’s context; second, the electorate-election interaction which forms the baseline to explore the perspective of local contextual effects in voting behaviour and election results; third, the relation between geographical location and election outcomes reflecting the implication of determining constituency boundaries on election results. To address the above relations, three types of variables: geo, independent and dependent, have been elaborated and two models have been created. The Data Model, developed in a GIS environment, facilitates structuring of election data in order to perform spatial analysis. The peculiarity of electoral patterns – a multidimensional array that contains information on three variables, stored in data layers of dissimilar spatial units of reference and scales of value measurement – prohibit spatial analysis based on the original source data. To perform a joint spatial analysis it is therefore mandatory to restructure the spatial units of reference while preserving their semantic content. In this operation, all relevant electoral as well as socio-demographic data referenced to different administrative spatial entities are re-referenced to uniform grid cells as virtual spatial units of reference. Depending on the scale of data acquisition and map presentation, a cell width of 0.5 km has been determined. The resulting fine grid forms the basis of subsequent data analyses and correlations. Conversion of the original vector data layers into target raster layers allows for unification of spatial units, at the same time retaining the existing level of detail of the data (variables, uniform distribution over space). This in turn facilitates the integration of the variables studied and the performance of GIS-based spatial analysis. In addition, conversion to raster format makes it possible to assign new values to the original data, which are based on a common scale eliminating existing differences in scale of measurement. Raster format operations of the type described are well-established data analysis techniques in GIT, yet they have rarely been employed to process and analyse electoral data. The Geovisualization Model, developed in a cartographic environment, complements the Data Model. As an analog graphic model it facilitates efficient communication and exploration of geographical information through cartographic visualization. Based on this model, 52 choropleth maps have been generated. They represent the outcome of the GIS-based electoral data analysis. The analog map form allows for in-depth visual analysis and interpretation of the distribution and correlation of the electoral data studied. For researchers, decision makers and a wider public the maps provide easy-to-access information on and promote easy-to-understand insight into the spatial dimension, regional variation and resulting structures of the electoral patterns defined.
Bacteria play a key role in the world's oceans, supporting nutrient remineralisation and mediating carbon transfer. Little is known about annual changes in bacterial concentration, production and metabolism during the extreme seasonal changes in biological productivity in Antarctic waters. We measured rates of bacterial production, concentrations of viruses and bacteria and environmental parameters between February 2004 and January 2005 at an Antarctic coastal site. Concentrations of total bacteria and viruses were obtained using 4', 6-diamidino-2- phenylindole (DAPI) and SYBR Green I (Molecular Probes), respectively. Populations of bacteria in different metabolic states were estimated using vital stains. Concentrations of bacteria with intact or compromised plasma membranes were estimated using BacLight (Molecular Probes) and active cells estimated using 6-carboxyfluorescein diacetate (6CFDA). Our study showed 6CFDA and BacLight gave rapid and ecologically valuable insights into bacterial physiology, production and growth in natural Antarctic communities that were poorly represented by changes in total cell concentrations. Concentrations of total, active and intact bacteria declined rapidly at the end of summer probably owing to viral infection and microheterotrophic grazing. The decline continued over winter, likely owing to substrate limitation, and concentrations only increased after the phytoplankton bloom in spring and summer. Bacterial abundance was positively correlated with particulate organic carbon (POC) and nitrogen (PON), but not dissolved organic carbon (DOC), reflecting the refractory nature of the DOC pool. Only active and intact bacteria were significantly correlated with concentrations of chl a and rates of bacterial production. Furthermore, the obtained rates of [H-3]thymidine uptake suggest that bacterial growth rates can be sustained by the populations identified as intact or by active cells alone.
Sulphur, a macronutrient essential for plant growth, is among the most versatile elements in living organisms. Unfortunately, little is known about regulation of sulphate uptake and assimilation by plants. Identification of sulphate signalling processes will allow to control sulphate acquisition and assimilation and may prove useful in the future to improve sulphur-use efficiency in agriculture. Many of genes involved in sulphate metabolism are regulated on transcriptional level by products of other genes called transcription factors (TF). Several published experiments revealed TF genes that respond to sulphate deprivation, but none of these have been so far been characterized functionally. Thus, we aimed at identifying and characterising transcription factors that control sulphate metabolism in the model plant Arabidopsis thaliana. To achieve that goal we postulated that factors regulating Arabidopsis responses to inorganic sulphate deficiency change their transcriptional levels under sulphur-limited conditions. By comparing TF transcript profiles from plants grown on different sulphate regimes, we identified TF genes that may specifically induce or repress changes in expression of genes that allow plants to adapt to changes in sulphate availability. Candidate genes obtained from this screening were tested by reverse genetics approaches. Transgenic plants constitutively overproducing selected TF genes and mutant plants, lacking functional selected TF genes (knock out), were used. By comparing metabolite and transcript profiles from transgenic and wild type plants we aimed at confirming the role of selected AP2 TF candidate genes in plant adaptation to sulphur unavailability. After preliminary characterisation of WRKY24 and MYB93 TF genes, we postulate that these factors are involved in a complex multifactorial regulatory network, in which WRKY24 and MYB93 would act as superior factors regulating other transcription factors directly involved in the regulation of S-metabolism genes. Results obtained for plants overproducing TOE1 and TOE2 TF genes suggests that these factors may be involved in a mechanism, which is promoting synthesis of an essential amino acid, methionine, over synthesis of another amino acid, cysteine. Thus, TOE1 and TOE2 genes might be a part of transcriptional regulation of methionine synthesis. Approaches creating genetically manipulated plants may produce plant phenotypes of immediate biotechnological interest, such as plants with increased sulphate or sulphate-containing amino acid content, or better adapted to the sulphate unavailability.
Syntax
(2007)
Morphology
(2007)
We explored the extent of interspecific hybridisation between alien and native plant species in Germany with a special focus on the potential threat for native biodiversity. In total we listed 134 hybrids which are interpreted as products of hybridisation between 81 alien and 109 native plant species (including 13 archeophytes) that occur in Germany Seventy-five of these hybrids have been recorded in Germany, while the remaining 59 hybrids have not been detected in Germany yet, although both parental species currently occur in Germany. Interspecific hybridisation between abundant alien and rare native species can threaten populations of the native species through outbreeding depression and/ or through high rates of gene flow swamping native populations. We identified 37 threatened native plant species which hybridise with aliens. Seventeen of these threatened plant species may suffer from outbreeding depression when hybridising with a more abundant alien invader (minority disadvantage). Using hybrid abundance as an indicator of hybrid fitness we argue that introgression of alien genes may affect the gene pool of eight threatened native plant species. Consequently, hybridisation with aliens has to be considered as an additional risk potentially leading to a loss of biodiversity and should be included in the repertoire of causes for rare species extinction in German Red Lists of threatened plant species.
The acinar salivary gland of the cockroach, Periplaneta americana, is innervated by dopaminergic and serotonergic nerve fibers. Stimulation of the glands by serotonin (5-hydroxytryptamine, 5-HT) results in the production of a protein-rich saliva, whereas stimulation by dopamine results in saliva that is protein-free. Thus, dopamine acts selectively on ion-transporting peripheral cells within the acini, and 5-HT acts on protein-producing central cells. We have investigated the pharmacology of the 5-HT-induced secretory activity of isolated salivary glands of P. americana by testing several 5-HT receptor agonists and antagonists. The effects of 5-HT can be mimicked by the non-selective 5-HT receptor agonist 5-methoxytryptamine. All tested agonists that display at least some receptor subtype specificity in mammals, i.e., 5-carboxamidotryptamine, (+/-)-8-OH-DPAT, (+/-)-DOI, and AS 19, were ineffective in stimulating salivary secretion. 5-HT-induced secretion can be blocked by the vertebrate 5-HT receptor antagonists methiothepin, cyproheptadine, and mianserin. Our pharmacological data indicate that the pharmacology of arthropod 5-HT receptors is remarkably different from that of their vertebrate counterparts. (C) 2007 Elsevier Ltd. All rights reserved.
Interaction between CRHR1 gene and stressful life events predicts adolescent heavy alcohol use
(2007)
Background: Recent animal research suggests that alterations in the corticotropin releasing hormone receptor 1 (CRHR1) may lead to heavy alcohol use following repeated stress. The aim of this study was to examine interactions between two haplotype-tagging single nucleotide polymorphisms (SNPs) covering the CRHR1 gene and adverse life events on heavy drinking in adolescents. Methods: Data were available from the Mannheim Study of Children at Risk, an ongoing cohort study of the long-term outcome of early risk factors followed since birth. At age 15 years, 280 participants (135 males, 145 females) completed a self-report questionnaire measuring alcohol use and were genotyped for two SNPs (rs242938, rs1876831) of CRHR1. Assessment of negative life events over the past three years was obtained by a standardized interview with the parents. Results: Adolescents homozygous for the C allele of rs1876831 drank higher maximum amounts of alcohol per occasion and had greater lifetime rates of heavy drinking in relation to negative life events than individuals carrying the T allele. No gene X environment interactions were found for regular drinking and between rs242938 and stressful life events. Conclusions: These findings provide first evidence in humans that the CRHR1 gene interacts with exposure to stressful life events to predict heavy alcohol use in adolescents.
We have analyzed the spectra of seven Galactic O4 supergiants, with the NLTE wind code CMFGEN. For all stars, we have found that clumped wind models match well lines from different species spanning a wavelength range from FUV to optical, and remain consistent with Hα data. We have achieved an excellent match of the P V λλ1118, 1128 resonance doublet and N IV λ1718, as well as He II λ4686 suggesting that our physical description of clumping is adequate. We find very small volume filling factors and that clumping starts deep in the wind, near the sonic point. The most crucial consequence of our analysis is that the mass loss rates of O stars need to be revised downward significantly, by a factor of 3 and more compared to those obtained from smooth-wind models.
We report the influence of different nutritional modes-autotrophy, mixotrophy, and heterotrophy-on the fatty acid and sterol composition of the freshwater flagellate Ochromonas sp. and discuss the ecological significance of our results with respect to the resource competition theory (rct). Polyunsaturated fatty acids (PUFAs) are the most efficient biochemical variable distinguishing between nutritional modes of Ochromonas sp. Decreasing concentrations of PUFAs were observed in the order autotrophs, mixotrophs, heterotrophs. In mixotrophs and heterotrophs, concentrations of saturated fatty acids were higher than those of monounsaturated fatty acids and PUFAs as a result of bacterivory. Stigmasterol was the main sterol in Ochromonas sp., regardless of nutritional mode. Mixotrophs showed higher growth rates than heterotrophs, which could not be explained by rct. Heterotrophs, in turn, exhibited higher growth rates than autotrophs, which were cultured under the same light conditions as mixotrophs. Mixotrophs can synthesize PUFAs, which are important for many physiological functions such as membrane permeability and growth. Thus, mixotrophy facilitated efficient growth as well as the ability to synthesize complex and essential biomolecules. These strong synergetic effects are due to the combination of biochemical benefits of heterotrophic and autotrophic metabolic pathways and cannot be predicted by rct.
Temperature dependent energy-dispersive X-ray diffraction and magnetic study of Fe/Al interface
(2007)
In situ temperature dependent energy-dispersive structural and magnetic study of electron beam evaporated Fe/Al multilayer sample (MLS) has been investigated. The structural studies show the formation of an intermixed FeAl transition layer of a few nanometers thick at the interface during deposition, which on annealing at 300 degrees C transforms to B2FeAl intermetallic phase. Magnetization decreases with increase in temperature and drops to minimum above 300 degrees C due to increase in anti-ferromagnetic interlayer coupling and formation of nonmagnetic FeAl phase at the interface. The Curie temperature (T-c) is found to be 288 degrees C and is much less than that of bulk bcc Fe.
Als die SED-Diktatur zusammenbrach, übte der Glanz der ostdeutschen Medaillen nach wie vor eine große Anziehungskraft aus, vor allem auf westdeutsche Sportpolitiker. Der Sport war ein Spezialfall der deutschen Vereinigung, da hier der Westen vom Osten zu lernen hoffte. Bald jedoch wurden die dunklen Seiten des DDR-Sports offensichtlich: die Verstrickung mit dem Ministerium für Staatsicherheit ebenso wie das staatlich forcierte Zwangsdoping. Bis heute gehen die Meinungen über den DDR-Sport weit auseinander: während die Einen ihn als repressiv und unmenschlich verurteilen, wird er von den Anderen gleichzeitig als Organisationsvorbild für die Zukunft gehandelt.
We summarize Chandra observations of the emission line profiles from 17 OB stars. The lines tend to be broad and unshifted. The forbidden/intercombination line ratios arising from Helium-like ions provide radial distance information for the X-ray emission sources, while the H-like to He-like line ratios provide X-ray temperatures, and thus also source temperature versus radius distributions. OB stars usually show power law differential emission measure distributions versus temperature. In models of bow shocks, we find a power law differential emission measure, a wide range of ion stages, and the bow shock flow around the clumps provides transverse velocities comparable to HWHM values. We find that the bow shock results for the line profile properties, consistent with the observations of X-ray line emission for a broad range of OB star properties.
The major aim of this thesis was to study the effect of nitrate on primary metabolism and in development of the model plant Arabidopsis thaliana. The present work has two separate topics. First, to investigate the GDH family, a small gene family at the interface between nitrogen and carbon metabolisms. Second, to investigate the mechanisms whereby nitrogen is regulating the transition to flowering time in Arabidopsis thaliana. To gain more insights into the regulation of primary metabolism by the functional characterization of the glutamate dehydrogenase (GDH) family, an enzyme putatively involved in the metabolism of amino acids and thus suggested to play different and essential roles in carbon and nitrogen metabolism in plants, knock out mutants and transgenic plants carrying RNA interference construct were generated and characterized. The effect of silencing GDH on carbon and nitrogen metabolisms was investigated, especially the level of carbohydrates and the amino acid pool were further analysed. It has been shown that GDH expression is regulated by light and/or sugar status therefore, phenotypic and metabolic analysis were developed in plants grown at different points of the diurnal rhythm and in response to an extended night period. In addition, we are interested in the effect of nutrient availability in the transition from vegetative growth to flowering and especially in nitrate as a metabolite that triggers widespread and coordinated changes in metabolism and development. Nutrient availability has a dramatic effect on flowering time, with a marked delay of flowering when nitrate is supplied (Stitt, 1999). The use of different mutants and transgenic plants impaired in flowering signalling pathways was crucial to evaluate the impact of different nitrate concentrations on flowering time and to better understand the interaction of nitrate-dependent signals with other main flowering signalling pathways. Plants were grown on glutamine as a constitutive source of nitrogen, and the nitrate supply varied. Low nitrate led to earlier flowering. The response to nitrate is accentuated in short days and in the CONSTANS deficient co2 mutant, whereas long days or overexpression of CONSTANS overrides the nitrate response. These results indicate that nitrates acts downstream of the known flowering signalling pathways for photoperiod, autonomy, vernalization and gibberellic acid. Global analyses of gene expression of two independent flowering systems, a light impaired mutant (co2tt4) and a constitutive over-expresser of the potent repressor of flowering (35S::FLC), were to be investigated under two different concentrations of nitrate in order to identify candidate genes that may be involved in the regulation of flowering time by nitrate.
We consider a class of ergodic Hamilton-Jacobi-Bellman (HJB) equations, related to large time asymptotics of non-smooth multiplicative functional of difusion processes. Under suitable ergodicity assumptions on the underlying difusion, we show existence of these asymptotics, and that they solve the related HJB equation in the viscosity sense.
A multitype Dawson-Watanabe process is conditioned, in subcritical and critical cases, on non-extinction in the remote future. On every nite time interval, its distribution law is absolutely continuous with respect to the law of the unconditioned process. A martingale problem characterization is also given. The explicit form of the Laplace functional of the conditioned process is used to obtain several results on the long time behaviour of the mass of the conditioned and unconditioned processes. The general case is considered first, where the mutation matrix which modelizes the interaction between the types, is irreducible. Several two-type models with decomposable mutation matrices are also analysed.
We study the time variability of emission lines in three WNE stars : WR 2 (WN2), WR 3 (WN3ha) and WR152 (WN3). While WR 2 shows no variability above the noise level, the other stars do show variation, which are like other WR stars in WR 152 but very fast in WR 3. From these motions, we deduce a value of β ∼1 for WR 3 that is like that seen in O stars and β ∼2–3 for WR 152, that is intermediate between other WR stars and WR 3.
By quantitatively fitting simple emission line profile models that include both atomic opacity and porosity to the Chandra X-ray spectrum of ζ Pup, we are able to explore the trade-offs between reduced mass-loss rates and wind porosity. We find that reducing the mass-loss rate of ζ Pup by roughly a factor of four, to 1.5 × 10−6 M⊙ yr−1, enables simple non-porous wind models to provide good fits to the data. If, on the other hand, we take the literature mass-loss rate of 6×10−6 M⊙ yr−1, then to produce X-ray line profiles that fit the data, extreme porosity lengths – of h∞ ≈ 3 R∗ – are required. Moreover, these porous models do not provide better fits to the data than the non-porous, low optical depth models. Additionally, such huge porosity lengths do not seem realistic in light of 2-D numerical simulations of the wind instability.
We examined relations between eye movements (single-fixation durations) and RSVP-based event-related potentials (ERPs; N400’s) recorded during reading the same sentences in two independent experiments. Longer fixation durations correlated with larger N400 amplitudes. Word frequency and predictability of the fixated word as well as the predictability of the upcoming word accounted for this covariance in a path-analytic model. Moreover, larger N400 amplitudes entailed longer fixation durations on the next word, a relation accounted for by word frequency. This pattern offers a neurophysiological correlate for the lag-word frequency effect on fixation durations: Word processing is reliably expressed not only in fixation durations on currently fixated words, but also in those on subsequently fixated words.