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Ökologische Bewertungskriterien für Desinfektionsmittel und deren Adaptierung in der Desinfektionsmittel-Datenbank der Stadt Wien

Das Projekt ÖkoKauf der Stadt Wien hat es sich zum Ziel gesetzt, durch die Erstellung von ökologischen Kriterien, Pilotprojekte und durch Bewusstseinsarbeit das Beschaffungswesen im Magistrat Wien weiter zu ökologisieren. In diesem Rahmen widmete sich der Arbeitskreis 'Desinfektionsmittel unter der Leitung der Wiener Umweltanwaltschaft (WUA) der Aufgabe, für Hygienefachleute ein Instrument zur Beurteilung der Auswirkungen von Desinfektionsmitteln auf Gesundheit und Umwelt zu erstellen. Das Österreichische Ökologie-Institut führte eine Daten- und Literaturrecherche durch, das Umweltbundesamt nahm ergän-zende ökotoxikologische Tests an Wirkstoffen und -produkten vor und 'die umweltberatung ermittelte stationsbezogene Desinfektionsmittelverbräuche in Wiener Krankenanstalten. Die Recherche- und Testergebnisse zu Desinfektionsmittelwirkstoffen und -produkten wurden in einer vom IFZ konzipierten und von der Magistratsabteilung 14 realisierten Datenbank zusammengefasst. Um die ökotoxikologischen Produkteigenschaften vergleichbar zu machen, wurde vom IFZ ein Bewertungsraster entwickelt und in die Datenbank integriert. Dabei werden nachteilige Wirkungen auf die Gesundheit anhand von vier Wirkungskategorien erfasst: Akute Giftigkeit; Reizwirkung auf die Haut; Sensibilisierung, allergenes Potenzial sowie Erbgutschädigende, krebserzeugende und fruchtschädigende Eigenschaften. Zusammen mit der Berücksichtigung des Verhaltens in Oberflächengewässern (Abbauverhalten, Bioakkumulationspotenzial, Toxizität für Wasserorganismen) sowie dem Verhalten in Kläranlagen werden insgesamt sechs Bewertungszahlen generiert, die auf einer Skala von 1 (vernachlässigbar) bis 5 (sehr hoch) das gesamte Gefährdungsprofil des Stoffes beschreiben sollen. Das Gefährdungsprofil eines Handelsproduktes errechnet sich aus den Gefährdungsprofilen der darin enthaltenen Wirkstoffe anhand eines Algorithmus: Dabei wird die Annahme getroffen, dass die Produkteigenschaften von der Konzentration der darin enthaltenen Wirkstoffe abhängen. Bei der Bewertung ist außerdem zu gewährleisten, dass ein Wirkstoff mit einem hohen Gefährdungspotenzial angemessen berücksichtigt wird, auch und gerade wenn seine Konzentration im Produkt gering ist. In der Literatur wird dazu eine logarithmische Skalierung vorgeschlagen. Die Bewertung berücksichtigt derzeit die Wirkstoffe sowie Anwendungsverdünnungen. Die Zusammenfassung der Produkte in Verwendungs- bzw. Expositionskategorien ermöglicht letztlich eine vergleichende Bewertung. Da das Bewertungsraster gerade auf eine vergleichende Bewertung von Produkten abzielt, unterliegt er einer ständigen kritischen Diskussion, die auch häufig von den Herstellern geführt wird. Dieser Umstand sowie das Faktum von Produktlebenszyklen erfordern ein ständiges Update der in der Datenbank enthaltenen Informationen und eine Anpassung des Bewertungsmodells an den aktuellen Stand von Forschung sowie Standards der Stoff- und Produktpolitik.

Sonderforschungsbereich Transregio 38 (SFB TRR): Strukturen und Prozesse der initialen Ökosystementwicklung in einem künstlichen Wassereinzugsgebiet; Structures and Processes of the Initial Ecosystem Development Phase in an Artificial Water Catchment, Teilprojekt C 04: Hydrologische Oberflächenprozesse während der Entwicklungsphase eines künstlichen Einzugsgebiets

Das Hauptziel des Projekts ist die Untersuchung und die Entwicklung von Methoden nicht nur zur punktuellen, sondern auch zur flächenhaften Bestimmung der Bodenfeuchte. Zur Anwendung sollen Geländetechniken wie Time-Domain Reflectrometry (TDR), Georadar (GPR), Elektrische Widerstand (ER), Elektromagnetische Induktion (EMI) sowie GNSS Scatterometry kommen. Eine der methodischen Hauptfragen ist die Nutzung der GNSS Scatterometry zur Ermittlung der Bodenfeuchte im Feldmaßstab. Eine weitere grundlegende Forschungsfrage wird die weitere Entwicklung der elektrischen und elektromagnetischen geophysikalischen Techniken für bodenkundliche Anwendungen sein.

The role of turgor in rain-cracking of sweet cherry fruit

Rain-cracking limits the production of many soft and fleshy fruit including sweet cherries world wide. Cracking is thought to result from increased water uptake through surface and pedicel. Water uptake increases fruit volume, and hence, turgor of cells (Pcell) and the pressure inside the fruit (Pfruit) and subjects the skin to tangential stress and hence, strain. When the strain exceeds the limits of extensibility the fruit cracks. This hypothesis is referred to as the Pfruit driven strain cracking. Based on this hypothesis cracking is related to two independent groups of factors: (1) water transport characteristics and (2) the intrinsic cracking susceptibility of the fruit defined as the amount of cracking per unit water uptake. The intrinsic cracking susceptibility thus reflects the mechanical constitution of the fruit. Most studies focussed on water transport through the fruit surface (factors 1), but only little information is available on the mechanical constitution (i.e., Pfruit and Pcell, tensile properties such as fracture strain, fracture pressure and modulus of elasticity of the exocarp; factors 2). The few published estimates of Pfruit in sweet cherry are all obtained indirectly (calculated from fruit water potential and osmotic potentials of juice extracts) and unrealistically high. They exceed those measured by pressure probe techniques in mature grape berry by several orders of magnitude. The objective of the proposed project is to test the hypothesis of the Pfruit driven strain cracking. Initially we will focus on establishing systems of widely differing intrinsic cracking susceptibility by varying species (sweet and sour cherry, Ribes and Vaccinium berries, plum, tomato), genotype (within sweet cherry), stage of development and temperature. These systems will then be used for testing the hypothesis of Pfruit driven strain cracking. We will quantify Pfruit und Pcell by pressure probe techniques and compression tests and the mechanical properties of the exocarp using biaxial tensile tests. When the presence of high Pfruit and Pcell is confirmed by direct measurements, subsequent studies will focus on the mode of failure of the exocarp (fracture along vs. across cell walls) and the relationship between failure thresholds and morphometric characteristics of the exocarp. However, when Pfruit und Pcell are low, the hypothesis of Pfruit driven strain cracking must be rejected and the mechanistic basis for low pressures (presence of apoplastic solutes) clarified on a temporal (in the course of development) and a spatial scale (exocarp vs. mesocarp). We focus on sweet cherry, because detailed information on this species and experience in extending the short harvest period is available. Where appropriate, other cracking susceptible species (sour cherry, plum, Vaccinium, Ribes, tomato) will be included to further extend the experimental period and to maximize the range in intrinsic cracking susceptibility.

Biogenic soil structures: feedbacks between bioactivity and spatial heterogeneity of water storage and fluxes from plot to hillslope scale

Soil structure determines a large part of the spatial heterogeneity in water storage and fluxes from the plot to the hillslope scale. In recent decades important progress in hydrological research has been achieved by including soil structure in hydrological models. One of the main problems herein remains the difficulty of measuring soil structure and quantifying its influence on hydrological processes. As soil structure is very often of biogenic origin (macropores), the main objective of this project is to use the influence of bioactivity and resulting soil structures to describe and support modelling of hydrological processes at different scales. Therefore, local scale bioactivity will be linked to local infiltration patterns under varying catchment conditions. At hillslope scale, the spatial distribution of bioactivity patterns will be linked to connectivity of subsurface structures to explain subsurface stormflow generation. Then we will apply species distribution modelling of key organisms in order to extrapolate the gained knowledge to the catchment scale. As on one hand, bioactivity influences the hydrological processes, but on the other hand the species distribution also depends on soil moisture contents, including the feedbacks between bioactivity and soil hydrology is pivotal for getting reliable predictions of catchment scale hydrological behavior under land use change and climate change.

Human influences on forests in southern Ethiopia: the case of Shashemane-Munessa-forest

Especially during the last decades, the natural forests of Ethiopia have been heavily disturbed by human activities. Some forests have been totally cleared and converted into fields for agricultural use, other suffered from different influences, such as heavy grazing and selective logging. The ongoing research in the Shashemane-Munessa-study area (Gu 406/8-1,2) showed clearly that, in spite of interdiction and control, forests continue to be cleared and degraded. However, it is not yet sufficiently known, how and why these processes are still going on. Growing population pressure and economic constraints for the people living in and around the forests contribute to the actual situation but allow no final answers to the complex situation. Concerning a sustainable management of the forests there is to no solid basis for recommendations from the socioeconomic and socio-cultural view. Therefore, a comprehensive analysis of the traditional needs and forms of forest use, including all forest products, is necessary. The objective of this project is, to achieve this basis by carrying out intensive field observations, the consultation of aerial photographs, satellite imagery and above all semi-structured interviews with the population in the study area in order to contribute to the recommendations for a sustainable use of the Munessa Shasemane forests.

Schwerpunktprogramm (SPP) 1488: Planetary Magnetism (PlanetMag), Mineral magnetism of shocked ferrimagnetic minerals

Magnetic properties of ferrimagnetic minerals depend on their crystal lattice, anisotropy, chemical composition and grain size. The latter parameter is strongly controlled by microstructures, which are significant for the interpretation of the magnetic properties of shocked magnetic minerals. Fracturing and lattice defects are the main causes for magnetic domain size reduction and generate an increase in coercivity and the suppression of magnetic transitions (e.g. 34 K transition in pyrrhotite, Verwey transition in magnetite).Especially for an adequate investigation of shock-induced modifications in ferromagnetic minerals, a combination of microstructural and magnetic measurements is therefore essential.This project focusses on two significant aspects of extreme conditions - the consequence of shock waves on natural material on Earth and on the magnetic mineralogy of exotic magnetic minerals in iron meteorites. In order to obtain general correlations between deformation structures and magnetic properties, the specific magnetic properties and carriers as well as microstructures of samples from two impact structures in marine targets (Lockne and Chesapeake Bay) will be compared with shocked magnetite ore and magnetite-bearing target lithologies from outside the crater (Lockne) as well as from undeformed megablocks within the crater (Chesapeake Bay). We will test the hypothesis if shock-related microstructures and associated magnetic properties can significantly be overprinted by postshock hydrothermal alteration. We especially want to focus on the Verwey transition (TV) as lower TVs are described for shocked impact lithologies. Hence, the main focus of this study lies on magneto-mineralogical investigations which combine low- and high-temperature magnetic susceptibility and saturation isothermal remanent magnetization with mineralogical and microstructural investigations. The same methods will then be used for the investigation of iron meteorites, whose magnetic properties are often controled by exotic magnetic minerals like cohenite, schreibersite and daubreelite in addition to the metal phases. Magnetic transition temperatures of those phases are poorly documented in relation to their chemical composition as well as to their crystallographic and microstructural configuration. For a general understanding of shock-related magnetization processes in extraterrestrial and terrestrial material, however, it is crucial to obtain a general correlation between the initial 'unshocked' state and the subsequent shock- and alteration-related overprints.

Schwerpunktprogramm (SPP) 2238: Dynamik der Erzmetallanreicherung, Überquerung der magmatisch-hydrothermalen Grenzschicht innerhalb lagerstättenbildender Systeme mit numerischen Modellen

Zukünftige Explorationen für metallische Ressourcen werden auf größere Tiefen und untermeerische Bereiche abzielen, was kostspielig und technisch herausfordernd ist. Für diese Entwicklung benötigen wir belastbare Vorhersagemodelle, welche die entscheidenden Prozesse innerhalb ganzer lagerstättenbildender Systeme abbilden können. Magmatisch-hydrothermale Lagerstätten bilden unsere größten Ressourcen für Cu, Mo, Sn und W und entstehen durch Fluidentmischung aus magmatischen Intrusionen in ein Hydrothermalsystem im Umgebungsgestein. Das Potential, riesige ('world-class') Lagerstätten bilden zu können, hängt wesentlich von Fluidflüssen über diese magmatisch-hydrothermale Grenzschicht hinweg ab, welche jedoch die größte Unbekannte in unserem derzeitigen Verständnis dieser Lagerstätten darstellten und bislang in numerischen Simulationen lediglich parameterisiert werden können. Um diese Grenzprozesse abbilden zu können, benötigt es einen fundamental neuen Modellieransatz mit einem Kontinuum, das über die Tiefenbereiche von Hydrothermalsystemen hinaus reicht und die Lücke zwischen Fluidfluss und Magmadynamik überbrückt. Das Projekt CROWN wird neue Wege beschreiten, indem es eine konsistente Formulierung für Fluidgenese und -transport in einem gekoppelten Modell für viskoses Fliessen gemäß der Navier-Stokes-Gleichungen und poröses Fliessen nach dem Darcy Gesetz entwickelt. Außerdem, und sehr wichtig für die geologische Realitätsnähe, simuliert das Modell dynamische Permeabitätsänderungen und fokussiertes Fliessen entlang von Störungsbahnen. Die Simulationen richten sich an konzeptuellen Modellen aus der Literatur aus - darunter auch neue eigene Arbeit. Der Projektantrag hebt auch angedachte direkte Zusammenarbeiten mit anderen Projekten, die sich mit magmatisch-hydrothermalen Lagerstätten beschäftigen und für das DOME SPP beantragt wurden, hervor. Das Thema hat auch Verbindungen zu anderen SPP-Anträgen, welche sich mit Laborexperimenten beschäftigen, was noch weitere Möglichkeiten zur Zusammenarbeit eröffnet.

Carbon acquisition during pathogenic development of Ustilago maydis and Colletotrichum graminicola

The biotrophic fungus Ustilago maydis infects corn and induces the formation of tumors. In order for the fungus to proliferate in the infected tissue, U. maydis has to redirect the metabolism of the host to the site of infection. We wish to elucidate how this is accomplished. To this end we will perform transcript profiling during the time course of infection for both, the fungus and the maize plant. This will be complemented by metabolome analysis of different tissues during infection as well as by apoplastic fluid analysis. The goals will be to identify the carbon sources taken up by the fungus during biotrophic growth, to identify the transporters required for uptake, determine their specificity and elucidate how these carbon sources are provided by the plant. Fungal mutants affected in discrete stages of pathogenic development will be included in these studies. Likely candidate genes for carbon uptake/supply as well as for redirecting host metabolism will be functionally characterized by generating knockouts in the fungus and by isolating plants carrying mutations in respective genes or by generating transgenic plants expressing RNAi constructs.

Between Path Dependence and Path Creation: The Impact of Farmers' Behavior and Policies on Structural Change in Agriculture

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.

Dissolved organic matter driven changes in minerals and organic-mineral interactions during paddy soil development

Previous studies indicated that the development and biogeochemistry of paddy soils relates to the parent material, thus the original soil paddies derive from. The proposed research focuses on redox-mediated changes in mineral composition and mineral-associated organic matter (OM) during paddy transformation of different soils. We plan to subject soil samples to a series of redox cycles, in order to mimic paddy soil formation and development. Soils with strongly different properties and mineral composition as well as at different states of paddy transformation; ranging from unchanged soils to fully developed paddy soils, are to be included. We hypothesize that dissolved organic matter is one key driver in redox-mediated transformations, serving as an electron donator as well as interacting with dissolved metals and minerals. The extent of effects shall depend on the parent soil's original mineral assemblage and organic matter and their mutual interactions. The experimental paddy soil transformation will tracked by analyses of soil solutions, of the (re-)distribution of carbon (by addition of 13C-labelled rice straw), of indicative biomolecules (sugars, amino sugars, fatty acids, lignin) and of minerals (including the redox state of Fe). For analyses of organic matter as well as of mineral characteristics we plan to utilize EXAFS and XPS, for Fe-bearing minerals also Mößbauer spectroscopy. This approach of experimental pedology seems appropriate to give insight into the major factors during paddy soil formation and development.

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