Die Bildung der Eis Phase in der Troposphäre stellt einen wichtigen Fokus der aktuellen Atmosphärenforschung dar. Durch heterogene Nukleation entstehen bei Temperaturen oberhalb von -37°C primäre Eiskristalle an sogenannten eiskeimbildenden Partikeln (INP, engl, ice nucleating particles). Die räumliche Verteilung der INP und deren Quellen variieren stark. In der Atmosphäre finden sich INP nur in sehr geringer Anzahlkonzentration, oft weniger als ein Partikel pro Liter, und sie stellen nur eine kleine Untergruppe des gesamten atmosphärischen Aerosols dar. Ziel dieses Antrages ist es die Anzahlkonzentrationen von eiskeimbildenden Partikeln und deren Variabilität in der Atmosphäre zu messen. Außerdem sind Laborstudien geplant, in denen unser Verständnis über die chemischen und biologischen Eigenschaften der Partikel, die die Eisbildung initiieren, verbessert werden soll. Mit dem von unserer Arbeitsgruppe entwickelten Eiskeimzahler FINCH (Fast Ice Nucleaus CHamber) sollen die atmosphärischen Anzahlkonzentrationen von INP bei verschiedenen Gefriertemperaturen und Übersättigungen an mehreren Standorten gemessen werden. Die Kopplung von FINCH mit einem virtuellen Gegenstromimpaktor (CVI, engl, counter-flow virtual impactor, Kooperation mit RP2), die während lNUIT-1 entwickelt und getestet wurde, soll nun weiter charakterisiert und Messungen damit fortgesetzt werden. Bei dieser Methode werden die Eispartikel, die in FINCH gebildet werden, von den unterkühlten Tröpfchen und inaktivierten Partikeln separiert und mit weiteren Messmethoden untersucht. In Kooperation mit RP2 und RP8 planen wir hierbei die Charakterisierung der INP mittels Größen- und Aerosolmassenspektrometer sowie die Sammlung der INP auf Filtern oder Impaktorplatten zur anschließenden Analyse mit einem Elektronenmikroskop (ESEM, engl. DFG fomi 54.011 -04/14 page 3 of 6 Environmental Scanning Electron Microscopy). Die Feldmessdaten werden von umfangreichen Laborstudien an den Forschungseinrichtungen AIDA (RP6) und LACIS (RP7) ergänzt. Dort soll das Immersionsgefrieren von verschiedenen Testpartikeln aus biologischem Material (z.B. Zellulose), porösem Material (z.B. Zeolith) und Mineralstaub mit geringem organischem Anteil im Detail untersucht werden. Des Weiteren planen wir Labormessungen, bei denen eine verbesserte Charakterisierung der Messunsicherheiten von FINCH erarbeitet werden soll. Außerdem werden regelmäßige Tests und Kalibrierungen mit FINCH durchgeführt, für die Standardroutinen festgelegt werden sollen. Um die Rolle der INP bei der Wolken- und Niederschlagsbildung sowie bei den Wolkeneigenschaften abzuschätzen, werden die gewonnenen Messergebnisse am Ende als Eingabeparameter für erweiterte Wolkenmodelle (Kooperation mit WP-M) dienen.
The development of sustainable and efficient energy conversion processes at interfaces is at the center of the rapidly growing field of basic energy science. How successful this challenge can be addressed will ultimately depend on the acquired degree of molecular-level understanding. In this respect, the severe knowledge gap in electro- or photocatalytic conversions compared to corresponding thermal processes in heterogeneous catalysis is staggering. This discrepancy is most blatant in the present status of predictive-quality, viz. first-principles based modelling in the two fields, which largely owes to multifactorial methodological issues connected with the treatment of the electrochemical environment and the description of the surface redox chemistry driven by the photo-excited charges or external potentials.Successfully tackling these complexities will advance modelling methodology in (photo)electrocatalysis to a similar level as already established in heterogeneous catalysis, with an impact that likely even supersedes the one seen there in the last decade. A corresponding method development is the core objective of the present proposal, with particular emphasis on numerically efficient approaches that will ultimately allow to reach comprehensive microkinetic formulations. Synergistically combining the methodological expertise of the two participating groups we specifically aim to implement and advance implicit and mixed implicit/explicit solvation models, as well as QM/MM approaches to describe energy-related processes at solid-liquid interfaces. With the clear objective to develop general-purpose methodology we will illustrate their use with applications to hydrogen generation through water splitting. Disentangling the electro- resp. photocatalytic effect with respect to the corresponding dark reaction, this concerns both the hydrogen evolution reaction at metal electrodes like Pt and direct water splitting at oxide photocatalysts like TiO2. Through this we expect to arrive at a detailed mechanistic understanding that will culminate in the formulation of comprehensive microkinetic models of the light- or potential-driven redox process. Evaluating these models with kinetic Monte Carlo simulations will unambiguously identify the rate-determining and overpotential-creating steps and therewith provide the basis for a rational optimization of the overall process. As such our study will provide a key example of how systematic method development in computational approaches to basic energy sciences leads to breakthrough progress and serves both fundamental understanding and cutting-edge application.
Das BfG-GNSS-Messnetzes besteht aus über 50 GNSS-Stationen im Bereich der Nord- und Ostsee. Primärer Zweck ist die Georeferenzierung von Pegeln der Wasserstraßen- und Schifffahrtsverwaltung (WSV). Die Rohdaten umfassen die kontinuierlichen Beobachtungsdaten der Satellitensysteme GPS, Glonass, Galileo und Beidou. Der Höhenunterschied 'dH1' zwischen dem jeweiligen Referenzpunkt der GNSS-Antenne und den zugehörigen Pegelfestpunkten (PFP) kann dem Sitelog der Permanentstation entnommen werden. Der Sollhöhenunterschied 'dH2' zwischen den Pegelfestpunkten und dem Pegelnullpunkt (PNP) wird durch das zuständige Wasserstraßen- und Schifffahrtsamt geführt.
Cydia pomonella granulovirus (CpGV, Baculoviridae) is one of the most important agents for the control of codling moth (CM, Cydia pomonella, L.) in both biological and integrated pest management. The rapid emergence of resistance against CpGV-M, which was observed in about 40 European CM field populations from 2003 on, could be traced back to a single, dominant, sex-linked gene. Since then, resistance management has been based on mixtures of new CpGV isolates (CpGV-I12, -S), which are able to overcome this resistance. Recently, resistance even to these novel isolates was observed in CM field populations. This resistance does not follow the described dominant, sex-linked inheritance trait. At the same time, another isolate CpGV-V15 was identified showing high virulence against these resistant populations. To elucidate this novel resistance mechanism and to identify the resistance gene(s) involved, we propose a comprehensive analysis of this resistance on the cellular and genomic level of codling moth. Because of the lack of previous knowledge of the molecular mechanisms of virus resistance in insects, several different and complementary approaches will be pursued. This study will not only give an in-depth insight into the genetic possibilities for development of baculovirus resistance in CM field populations and how the virus overcomes it, but can also serve as an important model for other baculovirus-host interaction systems.
In the Bavarian Forest National Park a brief, but intense storm event on 1 August 1983 created large windfall areas. The windfall ecosystems within the protection zone of the park were left develop without interference; outside this zone windfall areas were cleared of dead wood but not afforested. A set of permanent plots (transect design with 10 to 10 m plots) was established in 1988 in spruce forests of wet and cool valley bottoms in order to document vegetation development. Resampling shall take place every five years; up to now it was done in 1993 and 1998. On cleared areas an initial raspberry (Rubus idaeus) shrub community was followed by pioneer birch (Betula pubescens, B. pendula) woodland, a sequence well known from managed forest stands. In contrast to this, these two stages were restricted to root plates of fallen trees in uncleared windfalls; here shade-tolerant tree species of the terminal forest stages established rather quickly from saplings that had already been present in the preceeding forest stand. Soil surface disturbances are identified to be causal to the management pathway of forest development, wereas the untouched pathway is caused by relatively low disturbance levels. The simulation model FORSKA-M is used to analyse different options of further stand development with a simulation time period of one hundred years.
Changes in agroecosystem management (e.g. landscape diversity, management intensity) affect the natural control of pests. The effects of agricultural change on this ecosystem service, however, are not universal and the mechanisms affecting it remain to be understood. As biological control is effectively the product of networks of interactions between pests and their natural enemies, food web analysis provides a versatile tool to address this gap of knowledge. The proposed project will utilize a molecular food web approach and examine, for the first time, how changes in plant fertilisation and landscape complexity affect quantitative aphid-parasitoid-hyperparasitoid food webs on a species-specific level to unravel how changes in food web interactions affect parasitoid aphid control. Based on the fieldderived data, cage experiments will be conducted to assess how parasitoid diversity and identity affect parasitoid interactions and pest control, complementing the field results. The work proposed here will take research on parasitoid aphid control one step further, as it will provide a clearer understanding of how plant fertilization affects whole aphid-parasitoid food webs in both simple and complex landscapes, allowing for further improvements in natural pest control.
Barley (Hordeum vulgare) is an important cereal grain which serves as major animal fodder crop as well as basis for malt beverages or staple food. Currently barley is ranked fourth in terms of quantity of cereal crops produced worldwide. In times of a constantly growing world population in conjunction with an unforeseeable climate change and groundwater depletion, the accumulation of knowledge concerning cereal growth and rate of yield gain is important. The Nordic Genetic Resource Center holds a major collection of barley mutants produced by irradiation or chemical treatment. One phenotypic group of barley varieties are dwarf mutants (erectoides, brachytic, semidwarf, uzu). They are characterized by a compact spike and high rate of yield while the straw is short and stiff, enhancing the lodging resistance of the plant. Obviously they are of applied interest, but they are also of scientific interest as virtually nothing is known about the genes behind the development of plant dwarfism. The aim of this project is to identify and isolate the genes carrying the mutations by using state of the art techniques for gene cloning at the Carlsberg Laboratory. The identified genes will be connected with the mutant phenotype to reveal the gene function in general. One or two genes will be overexpressed and the resulting recombinant proteins will be biochemically and structurally characterized. The insights how the mutation effects the protein will display the protein function in particular. Identified genes and their mutant alleles will be tested in the barley breeding program of the Carlsberg brewery.
Evidence is compelling for a positive correlation between urbanisation and increment of allergic sensitisation and diseases. The reason for this association is not clear to date. Some data point to a pro-allergic effect of anthropogenic factors on susceptible individuals. Data analysing the impact of environmental - natural and anthropogenic - factors on the allergenicity of allergen carriers such as pollen grains are scarce, and if applicable only taken from in vitro experimental designs. This study will analyse one of the most common allergy inducers in northern Europe - the birch pollen. Under natural exposure conditions, birch pollen will be analysed with respect to their allergenicity. Within an interdisciplinary research team this study will evaluate the effect of natural (e.g. soil, climate, genetic background) and anthropogenic (e.g. traffic pollutants) factors on birch pollen in a holistic approach including analysis of allergen bioavailability, release of pollen associated lipid mediators from birch pollen grains, in vitro immunostimulatory activity and in vivo allergenic potential. These data collected in the time course of three years will significantly add to our understanding how urbanisation and climate change influence the allergenicity of birch pollen and will help us in the future to set up primary prevention studies.
Agriculture is the major contributor of nitrogen to ecosystems, both by organic and inorganic fertilizers. Percolation of nitrate to groundwater and further transport to surface waters is assumed to be one of the major pathways in the fate of this nitrogen. The quantification of groundwater and associated nitrate flux to streams is still challenging. In particular because we lack understanding of the spatial distribution and temporal variability of groundwater and associated NO3- fluxes. In this preliminary study we will focus on the identification and quantification of groundwater and associated nitrate fluxes by combining high resolution distributed fiber-optic temperature sensing (DTS) with in situ UV photometry (ProPS). DTS is a new technique that is capable to measure temperature over distances of km with a spatial resolution of ca1 m and an accuracy of 0.01 K. It has been applied successfully to identify and quantify sources of groundwater discharge to streams. ProPS is a submersible UV process photometer, which uses high precision spectral analyses to provide single substance concentrations, in our case NO3-, at minute intervals and a detection limit of less than 0.05 mg l-1 (ca.0.01 mg NO3--Nl-1). We will conduct field experiments using artificial point sources of lateral inflow to test DTS and ProPS based quantification approaches and estimate their uncertainty. The selected study area is the Schwingbach catchment in Hessen, Germany, which has a good monitoring infrastructure. Preliminary research on hydrological fluxes and field observations indicate that the catchment favors the intended study.
Farm structures are often characterized by regional heterogeneity, agglomeration effects, sub-optimal farm sizes and income disparities. The main objective of this study is to analyze whether this is a result of path dependent structural change, what the determinants of path dependence are, and how it may be overcome. The focus is on the German dairy sector which has been highly regulated and subsidized in the past and faces severe structural deficits. The future of this sector in the process of an ongoing liberalization will be analyzed by applying theoretical concepts of path dependence and path breaking. In these regards, key issues are the actual situation, technological and market trends as well as agricultural policies. The methodology will be based on a participative use of the agent-based model AgriPoliS and participatory laboratory experiments. On the one hand, AgriPoliS will be tested as a tool for stakeholder oriented analysis of mechanisms, trends and policy effects. This part aims to analyze whether and how path dependence of structural change can be overcome on a sector level. In a second part, AgriPoliS will be extended such that human players (farmers, students) can take over the role of agents in the model. This part aims to compare human agents with computer agents in order to overcome single farm path dependence.