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Found 54 results.

Flowering time, development and yield in oilseed rape (Brassica napus): Sequence diversity in regulatory genes

Flowering time (FTi) genes play a key role as regulators of complex gene expression networks, and the influence of these networks on other complex systems means that FTi gene expression triggers a cascade of regulatory effects with a broad global effect on plant development. Hence, allelic and expression differences in FTi genes can play a central role in phenotypic variation throughput the plant lifecycle. A prime example for this is found in Brassica napus, a phenotypically and genetically diverse species with enormous variation in vernalisation requirement and flowering traits. The species includes oilseed rape (canola), one of the most important oilseed crops worldwide. Previously we have identified QTL clusters related to plant development, seed yield and heterosis in winter oilseed rape that seem to be conserved in diverse genetic backgrounds. We suspect that these QTL are controlled by global regulatory genes that influence numerous traits at different developmental stages. Interestingly, many of the QTL clusters for yield and biomass heterosis appear to correspond to the positions of meta-QTL for FTi in spring-type and/or winter-type B. napus. Based on the hypothesis that diversity in FTi genes has a key influence on plant development and yield, the aim of this study is a detailed analysis of DNA sequence variation in regulatory FTi genes in B. napus, combined with an investigation of associations between FTi gene haplotypes, developmental traits, yield components and seed yield.

Late-Glacial and Holocene vegetational stability of southern South America

This project focuses on the long-term stability (or otherwise) of vegetation, based on a series of multi-proxy records in southern South America. We will build a network of sites suitable for high-resolution reconstructions of changes in vegetation since the Last Glacial Maximum, and use these to test a null hypothesis that changes in vegetation over the past 14,000 years are driven by internal dynamics rather than external forcing factors. The extent to which the null hypothesis can be falsified will reveal the degree to which we can expect to be able to predict how vegetation is affected by external events, including future climate change. The southern fringes of the South American landmass provide a rare opportunity to examine the development of moorland vegetation with sparse tree cover in a wet, cool temperate climate of the Southern Hemisphere. We present a record of changes in vegetation over the past 17,000 years, from a lake in extreme southern Chile (Isla Santa Inés, Magallanes region, 53°38.97S; 72°25.24W; Fontana, Bennett 2012: The Holocene), where human influence on vegetation is negligible. The western archipelago of Tierra del Fuego remained treeless for most of the Lateglacial period. Nothofagus may have survived the last glacial maximum at the eastern edge of the Magellan glaciers from where it spread southwestwards and established in the region at around 10,500 cal. yr BP. Nothofagus antarctica was likely the earlier colonizing tree in the western islands, followed shortly after by Nothofagus betuloides. At 9000 cal. yr BP moorland communities expanded at the expense of Nothofagus woodland. Simultaneously, Nothofagus species shifted to dominance of the evergreen Nothofagus betuloides and the Magellanic rain forest established in the region. Rapid and drastic vegetation changes occurred at 5200 cal. yr BP, after the Mt Burney MB2 eruption, including the expansion and establishment of Pilgerodendron uviferum and the development of mixed Nothofagus-Pilgerodendron-Drimys woodland. Scattered populations of Nothofagus, as they occur today in westernmost Tierra del Fuego may be a good analogue for Nothofagus populations during the Lateglacial in eastern sites. Climate, dispersal barriers and/or fire disturbance may have played a role controlling the postglacial spread of Nothofagus. Climate change during the Lateglacial and early Holocene was a prerequisite for the expansion of Nothofagus populations and may have controlled it at many sites in Tierra del Fuego. The delayed arrival at the site, with respect to the Holocene warming, may be due to dispersal barriers and/or fire disturbance at eastern sites, reducing the size of the source populations. The retreat of Nothofagus woodland after 9000 cal. yr BP may be due to competitive interactions with bog communities. Volcanic disturbance had a positive influence on the expansion of Pilgerodendron uviferum and facilitated the development of mixed Nothofagus-Pilgerodendron-Drimys woodland.

Coordination and administration of the priority programme SPP 1315 Biogeochemical Interfaces in Soil, Biotic and abiotic factors that dive the function of microbial communities at biogeochemical interfaces in different soils (BAMISO)

Biogeochemical interfaces shape microbial community function in soil. On the other hand microbial communities influence the properties of biogeochemical interfaces. Despite the importance of this interplay, basic understanding of the role of biogeochemical interfaces for microbial performance is still missing. We postulate that biogeochemical interfaces in soil are important for the formation of functional consortia of microorganisms, which are able to shape their own microenvironment and therefore influence the properties of interfaces in soil. Furthermore biogeochemical interfaces act as genetic memory of soils, as they can store DNA from dead microbes and protect it from degradation. We propose that for the formation of functional biogeochemical interfaces microbial dispersal (e.g. along fungal networks) in response to quality and quantity of bioavailable carbon and/or water availability plays a major role, as the development of functional guilds of microbes requires energy and depends on the redox state of the habitat.To address these questions, hexadecane degradation will be studied in differently developed artificial and natural soils. To answer the question on the role of carbon quantity and quality, experiments will be performed with and without litter material at different water contents of the soil. Experiments will be performed with intact soil columns as well as soil samples where the developed interface structure has been artificially destroyed. Molecular analysis of hexadecane degrading microbial communties will be done in vitro as well as in situ. The corresponding toolbox has been successfully developed in the first phase of the priority program including methods for genome, transcriptome and proteome analysis.

Development of an integrated forest carbon monitoring system with field sampling and remote sensing for tropical forests in Indonesia

Forests play a relevant role in mitigation of climate change. A major issue, however, is the scientifically well founded, transparent and verifyable monitoring of achievements in forest carbon sequestration through reduction of deforestation and forest degradation, and through fostering sustainable forest management. Monitoring is particularly difficult in diverse and inaccessible humid tropical forest areas. The proposed research will contribute to the improvement of forest carbon monitoring under the challenging conditions of humid tropical forests. Sample based field observations and model based biomass predictions will be linked to area-wide satellite remote sensing imagery (RapidEye) and to strip samples of LiDAR imagery. Techniques of linking these data sources will be further developed and analysed with respect to (1) precision of carbon estimation and (2) accuracy of carbon regionalization. The proposed project implies research on methodological improvements of both sample based forest inventories (resampling techniques for biomass, imputation of non-response) and remote sensing application to forest monitoring (regionalization, sample based application of LiDAR data). At the core of this research is the analysis of the error variance components that each data source brings into the system. Such error analysis will allow identifying optimal resource allocation for the efficient improvement of forest carbon monitoring systems.

Omongwa Pan, Namibia (June 2015) - an EnMAP Preparatory Flight Campaign

The dataset is composed of Neo HySpex (VNIR/SWIR) hyperspectral imagery acquired during airplane overflights on June 6th, 2015 covering the Omongwa Pan located in the South-West Kalahari, Namibia. The dataset includes three cloud-free flight lines with 408 spectral bands ranging from VNIR to SWIR wavelength regions (0.4-2.5 µm). The dataset also includes Level 2A EnMAP-like imagery simulated using the end-to-end Simulation tool (EeteS). The overall goal of the campaign was to acquire imagery over the Omongwa Pan and use the spectral reflectance for the analyses of surface sediments, specifically the mineralogical composition of exposed surface evaporites / salts on the airborne and spaceborne scale. The data are highly novel and can be used to test estimation of surface sediment properties in a highly saline and dynamic environment.

Anthropogenic carbon and heat uptake by the Southern Ocean

Heat and carbon dioxide exchange between the atmosphere and ocean is a major control on Earths climate and increasing atmospheric carbon dioxide (CO2) and concomitant global warming stimulate uptake of both heat and CO2 by the ocean. The Southern Ocean south of 30 S, occupying just over 1/4 of the surface ocean area, accounts for a disproportionate share of the vertical exchange of properties between the deep and surface waters of the ocean and between the surface ocean and the atmosphere. On average, the Southern Ocean absorbs 70Prozent of anthropogenic heat and 42Prozent of anthropogenic carbon in a new set of climate model simulations. This region thus plays a central role in determining the rate of climate change. However, the exact processes governing the magnitude and regional distribution of heat and carbon uptake remain poorly understood with models showing the largest disagreement in Southern Ocean anthropogenic air-sea heat and CO2 fluxes due to their widely divergent representation of physical circulation and atmosphere-ocean interactions. Indeed, the fraction of the simulated uptake within the Southern Ocean ranges between 30 to 160Prozent for excess heat and between 38 to 47Prozent for anthropogenic carbon. Natural unforced variability in models and observations further complicates the detection and attribution of changes. We will investigate anthropogenic ocean heat and carbon uptake with our main objectives being: (i) intercomparing ocean heat and carbon uptake in Earth System Model (ESM) simulations conducted for the Coupled Model Intercomparison Project Phase 5 (CMIP5), (ii) assessing the contribution of internal variability to model-model and model-data differences in anthropogenic heat and carbon uptake, and (iii) quantifying the contribution of differences in basic atmospheric forcing, model parameterizations, sea ice representation and model resolution to differences in heat and carbon uptake and distribution, and disagreements between models. This will be achieved through a series of process-perturbation experiments and ensemble simulations with an Earth System Model configured for transient climate change that help in attributing variations over the Southern Ocean. We will also contribute to the broader community goal in interpreting projections of IPCC AR5 coupled climate models. Ultimately, the project leads to a better understanding of Southern Ocean biogeochemical processes, thereby pinning down one of the greatest sources of uncertainty in predictions of the fate of anthropogenic carbon and of the climate.

Hydrologic Prediction in Alpine Environments II

Proposed research: This research programme proposes to analyze the predictability of the hydrologic behaviour of Alpine ecosystems at the spatio-temporal scales relevant for water management, i.e. at spatial scales of between 200 km2 (e.g. a hydropower production catchment) and around 5000 km2 (e.g. flood management of the Swiss Rhone catchment) and at temporal scales ranging from hours to seasons. Research context: Quantitative stream flow predictions are essential for the sustainable management of our natural and man-made environment and for the prevention of natural hazards. Despite of ever better insights into the involved physical processes at the point scale, many existing catchment scale runoff prediction models still show a lack of reliability for stream flow prediction. The present research programme addresses this foremost issue in Alpine environments, which are the source of many major European rivers and play a dominant role for hydropower production and flood protection. Stream flow prediction in such environments is particularly challenging due to the high spatial variability of the meteorological driving forces opposed to notorious data scarcity in remote and high elevation areas. Project context: The present proposal is a follow-up proposal of the Ambizione project Hydrologic Prediction in Alpine Environments. During the main phase of the project (3 years), certain essential research objectives could not be reached, due namely to the maternity leave of the principal investigator (PI), but also due to additional research questions that emerged at the very beginning of this research. The present follow-up project proposes to complete the research programme during a complementary project phase (2 years). Objectives: The main objective of this research programme is to assess under which conditions simple hydrological models can give reliable stream flow predictions in Alpine environments. This objective will be reached based on an analysis of the variability of natural flow generation processes and of the variability of corresponding state-of-the-art hydrological model outputs. During the main phase of the project, the research was concentrated on the analysis of flow generation processes related to snowmelt, which in Alpine areas dominate the hydrological response over a large part of the year. The achieved results include a new hourly snowmelt model combined to a spatially-explicit precipitation-runoff model, an improved snowfall-limit prediction method for hydrological models and a weather generator that produces coupled temperature and prediction scenarios to analyze how these two meteorological variables integrate to the snow-hydrological response.(...)

Rethinking globalisation in the light of contraction and Convergence (CONVERGE)

Objective: The CONVERGE project will build from the concept of 'contraction and convergence' that informed the Kyoto process. C&C linked the key social concept of equal rights to emissions with the key ecological need for reduced emissions to issue a challenge to economic systems to develop fair processes for emissions reduction. CONVERGE aims to re-think globalisation by developing our understanding of convergence beyond emissions-trading across wider social, economic and ecological dimensions of sustainability. CONVERGE will research, develop and test the processes of contraction, convergence and divergence in current forms of globalisation. The research will be based on systems science to integrate social, scientific and economic disciplines in order to create coherent solutions to complex problems. Key to the success of this study is the interdisciplinary approach and working with stakeholders from civil society, government and business. CONVERGE seeks to explore convergent sustainability relationships across different scales from local, national, global-regional to global. CONVERGE will research current examples of convergence in communities, policies and indicators moving towards sustainability. The project will develop a convergence frame for understanding and development in civil society and policy communities; accessible publications providing guidance and tools for the use of this framework; a set of Convergence indicators, quantitative and qualitative, that will be used to test and model the processes of convergence including development of a Computer Programme; and recommendations to assist policy makers to integrate C&C into the decision making process. CONVERGE will play a significant role in achieving the strategic objective of EUs global partnership: 'to promote sustainable development actively worldwide and ensure that the European Union's internal and external policies are consistent with global sustainable development and its international commitments.'

The role of dissolved organic matter as an antioxidant in triplet-induced oxidation reactions

Dissolved organic matter (DOM), ubiquitous in natural waters, can both accelerate and inhibit the transformation of organic contaminants under the action of sunlight. In this project we relate the inhibition effect of DOM to its antioxidant capacity. Background Triplet-induced oxidation of several organic contaminants is likely to play a significant role for their fate in the aquatic environment. DOM carries not only photosensitizer moieties, able to form excited triplet states with oxidizing character, but also moieties that may be considered as antioxidants. Thus, DOM can act as a light-activated oxidant as well as a reductant. In a preceding project, we employed model aromatic ketones as the photosensitizers to disentangle this dual chemical nature and study the possible inhibition of triplet-induced oxidation. We could show that DOM is able to inhibit (or, in other words; slow down the rate of) triplet-induced oxidation of several organic contaminants, but especially those containing aniline functionalities. Various phenolic compounds, used as model antioxidants to mimic the corresponding moieties of DOM, were also shown to inhibit triplet-induced oxidation. The basic hypothesis, still valid at the present state of knowledge, is that oxidation intermediates of the target contaminant interact with model antioxidants or antioxidant moieties of the DOM, leading to reduction of the oxidation intermediates with consequent regeneration of the parent compound. However, the reason why certain contaminants undergo inhibition while others don't is still open. Objectives and methods We now intend to improve our understanding of the mechanisms that govern triplet-induced oxidation of contaminants and its inhibition by DOM. The two main objectives and the corresponding experimental methods are: 1. Detection, by nanosecond laser flash photolysis, of the oxidation intermediates of a few selected aniline derivatives and investigation of their decay kinetics in the presence of DOM and model antioxidants. 2. Study of the relationships between extent of inhibition of triplet-induced oxidation and electron donating capacity of different types of DOM to narrow down the suite of possible antioxidant moieties in DOM responsible for the observed inhibition of oxidation. Electrochemical measurements and selective oxidation of DOM by various chemical oxidants (ozone, chlorine, chlorine dioxide) will be used as additional experimental tools. Significance The results are anticipated to provide quantitative methods to assess the photoinduced degradation of a wide class of organic contaminants containing aniline moieties, including sulfonamide antibiotics, in natural waters.

WTZ Südliches Afrika SPACES: GeoArchives II - Signale des Klima- und Landschaftswandels konserviert in Geoarchives des südlichen Afrika, Vorhaben: Hänge, Schwemmfächer und Flussterrassen als Geoarchive; Rekonstruktion der Paläoumwelt- und Paläoklimasignale (SP2; SP4)

1. Vorhabenziel: Die Untersuchung von mikrobiellen Gemeinschaften in Salzpfannen im südwestlichen Afrika über die Zeit birgt das Potential, wertvolle Informationen über die mit den Mikroorganismen assoziierten Klima- und Umweltbedingungen der Vergangenheit zu erhalten. In der GeoArchives II Phase wollen wir neue mikrobiologische Ansätze und Methoden anwenden, um die Änderungen der mikrobiellen Gemeinschaften mit der Zeit zu dokumentieren (Kultivierungsexperimente von Schlüsselorganismen, externe DNA als Schlüssel zur Vergangenheit), die gewonnenen Daten mit biogeochemischen Methoden (mikrobielle Biomarker) zu validieren und Klimainformationen aus den Daten abzuleiten. Außerdem wollen wir die Wechselwirkung von Mikroorganismen mit Gesteinsoberflächen im Zuge von bodenbildenden Verwitterungsprozessen in der Region untersuchen. Weiterhin sollen mit Hilfe geochronologischer Datierungsansätze relevante Landschaftsformen (Salzpfannen, Hänge, Schwemmfächer und Terrassen) in ihrer Genese datiert werden, um aktuelle Fragen nach den Auswirkungen des Klima- und Nutzungswandels auf die heutigen Landschaftsökosysteme zu beantworten. 2. Arbeitsplanung: Im Projekt sollen zwei Probenahmen durchgeführt werden. Die Salzpfannen werden Ende 2016 Gegenstand der ersten Kampagne sein. Die Salzpfannenproben sollen für die Kultivierungsexperimente und die Studien zur extrazellularen DNA verwendet werden. In der zweiten Kampagne soll im Frühjahr 2017 im Tsauchab-Tal Material für die Untersuchung der Verwitterungsprozesse gewonnen werden. Des Weiteren sollen Altersdatierung von Hangsedimenten, Schwemmfächern, Flussterrassen und Talbodenverschüttungen vorgenommen werden, um die Stabilität und das Potenzial dieser Flächen für die Landnutzung unter dem Einfluss des Klimawandels zu bewerten.

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