21 research outputs found

    NFDI4Microbiota – national research data infrastructure for microbiota research

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    Microbes – bacteria, archaea, unicellular eukaryotes, and viruses – play an important role in human and environmental health. Growing awareness of this fact has led to a huge increase in microbiological research and applications in a variety of fields. Driven by technological advances that allow high-throughput molecular characterization of microbial species and communities, microbiological research now offers unparalleled opportunities to address current and emerging needs. As well as helping to address global health threats such as antimicrobial resistance and viral pandemics, it also has a key role to play in areas such as agriculture, waste management, water treatment, ecosystems remediation, and the diagnosis, treatment and prevention of various diseases. Reflecting this broad potential, billions of euros have been invested in microbiota research programs worldwide. Though run independently, many of these projects are closely related. However, Germany currently has no infrastructure to connect such projects or even compare their results. Thus, the potential synergy of data and expertise is being squandered. The goal of the NFDI4Microbiota consortium is to serve and connect this broad and heterogeneous research community by elevating the availability and quality of research results through dedicated training, and by facilitating the generation, management, interpretation, sharing, and reuse of microbial data. In doing so, we will also foster interdisciplinary interactions between researchers. NFDI4Microbiota will achieve this by creating a German microbial research network through training and community-building activities, and by creating a cloud-based system that will make the storage, integration and analysis of microbial data, especially omics data, consistent, reproducible, and accessible across all areas of life sciences. In addition to increasing the quality of microbial research in Germany, our training program will support widespread and proper usage of these services. Through this dual emphasis on education and services, NFDI4Microbiota will ensure that microbial research in Germany is synergistic and efficient, and thus excellent. By creating a central resource for German microbial research, NDFDI4Microbiota will establish a connecting hub for all NFDI consortia that work with microbiological data, including GHGA, NFDI4Biodiversity, NFDI4Agri and several others. NFDI4Microbiota will provide non-microbial specialists from these consortia with direct and easy access to the necessary expertise and infrastructure in microbial research in order to facilitate their daily work and enhance their research. The links forged through NFDI4Microbiota will not only increase the synergy between NFDI consortia, but also elevate the overall quality and relevance of microbial research in Germany

    Detecting Multi-layered Forest Stands Using High Density Airborne LiDAR Data. GI_Forum|GI_Forum 2015 – Geospatial Minds for Society|

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    Since two decades, the use of terrestrial laser scanning (TLS) and Airborne Light Detection and Ranging (LIDAR) has become very prominent in analysing 3D forest structures (AKAY et al. 2009). The potential of full waveform analysis of high density Airborne LiDAR data (ALS) for the detection and structural analysis of multi-layered forest stands is not yet well investigated (JASKIERNIAK et al. 2011), although ALS data provide exact information on tree heights of multi-layered forest stands using particular laser pulse characteristics (GAULTON & MALTHUS 2010). Since the mid-19th century, managed forests in Brandenburg have been dominated by Scots pine monocultures. In the last fifteen to twenty years many forest stands were converted into multi-layered mixed forests by silvicultural conversion of forests and natural succession (MLUR 2004). Today, the majority of forest stands in the federal state of Brandenburg remain dominated by Scots pine (Pinus sylvestris) in the canopy layer, while European beech (Fagus sylvatica) or Sessile oak (Quercus petraea) are predominant in the understorey. In this study, we investigate and discuss the potential of full waveform high density airborne LiDAR data (ALS) for detecting, classifying, and stratifying discrete vegetation layers at forest stand level, based on 0.1ha investigation plots. Full waveform high density ALS data on each 5th percentile level was used in combination with binary logistic regressions to discover the structural layer type of multi-layered forest stands from normalized discrete ALS pulses. The results of the descriptive statistics of ALS point clouds and binary logistic regression models produce particular forest layer profile indices of understorey vegetation and canopy layer. Such parameters can further be used as variables for forest structure analysis algorithms, and can be empirically tested against stand characteristics. The validation of ALS data and model results is tested against empirical forest mensuration data of the “Datenspeicher Wald 2 (DSW 2-Forest inventory data)” and field survey reference points using error matrices. We demonstrate that binary logistic regression analyses are functional for establishing a prediction model. The model was applied successfully on larger forest stands and forest areas, and can become useful for identifying and separating single from multi-layered forest stands using percentiles of total amounts of ALS return pulses on a 10x10m raster size with a high overall accuracy of 90%. The established model has the potential for a broad range of forest management applications, such as timber inventory evaluation, forest growth modelling, monitoring of vegetation dynamic and succession, as well as ecological classifications and the detection of deadwood in forest stands (KIM et al. 2009)

    Biochemical Characterization of the Ran-RanBP1-RanGAP System: Are RanBP Proteins and the Acidic Tail of RanGAP Required for the Ran-RanGAP GTPase Reaction?

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    RanBP type proteins have been reported to increase the catalytic efficiency of the RanGAP-mediated GTPase reaction on Ran. Since the structure of the Ran-RanBP1-RanGAP complex showed RanBP1 to be located away from the active site, we reinvestigated the reaction using fluorescence spectroscopy under pre-steady-state conditions. We can show that RanBP1 indeed does not influence the rate-limiting step of the reaction, which is the cleavage of GTP and/or the release of product P(i). It does, however, influence the dynamics of the Ran-RanGAP interaction, its most dramatic effect being the 20-fold stimulation of the already very fast association reaction such that it is under diffusion control (4.5 × 10(8) M(−1) s(−1)). Having established a valuable kinetic system for the interaction analysis, we also found, in contrast to previous findings, that the highly conserved acidic C-terminal end of RanGAP is not required for the switch-off reaction. Rather, genetic experiments in Saccharomyces cerevisiae demonstrate a profound effect of the acidic tail on microtubule organization during mitosis. We propose that the acidic tail of RanGAP is required for a process during mitosis

    Mineralogical and geochemical analyses of Antarctic lake sediments: A study of reflectance and Mössbauer spectroscopy and C, N, and S isotopes with applications for remote sensing on Mars

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    We analyzed lake-bottom sediments from the Dry Valleys region of Antarctica to study the influence of water chemistry on the mineralogy and geochemistry of these sediments, as well as to evaluate techniques for remote spectral identification of potential biomarker minerals on Mars. Lakes from the Dry Valleys region of Antarctica have been investigated as possible analogs for extinct lake environments on early Mars. Sediment cores were collected in the present study from perennially ice-covered Lake Hoare in the Taylor Valley. These sediments were taken from a core in an oxic region of the lake and another core in an anoxic zone. Differences between the two cores were observed in the sediment color, Fe(II)/Fe(III) ratio, the presence of pyrite, the abundance of Fe, S, and some trace elements, and the C, N, and S isotope fractionation patterns. The results of visible-infrared reflectance spectroscopy (0.3-25 μm), Mössbauer spectroscopy (77 and 4 K), and X-ray diffraction are combined to determine the mineralogy and composition of these samples. The sediments are dominated by plagioclase, K-feldspar, quartz, and pyroxene. Algal mats grow on the bottom of the lake and organic material has been found throughout the cores. Calcite is abundant in some layers of the sediment core from the shallow, oxic region, and pyrite is abundant in the upper sediment layers of the core from the deep, anoxic region of Lake Hoare, Analysis of the spectroscopic features due to organics and carbonates with respect to the abundance of organic C and carbonate contents was performed in order to select optimal spectral bands for remote identification of these components in planetary regoliths. Carbonate bands near 4 and 6.8 μm (∼ 2500 and 1500 cm-1) were detected for carbonate abundances as low as 0.1 wt% CO2. Organic features at 3.38, 3.42, and 3.51 μm (2960, 2925, and 2850 cm-1) were detected for organic C abundances as low as 0.06 wt% C. The δ13C and δ15N trends show a more complex organic history for the anoxic region sediments than for the oxic region sediments. The biogenic pyrite found in the core from the anoxic zone is associated with depleted δ34S values and high organic C levels and could be used as a potential biomarker mineral for paleolakes on Mars. Copyright © 2001 Elsevier Science Ltd

    Stability of high-entropy alloys under electrocatalytic conditions

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    Summary: High-entropy alloys are claimed to possess superior stability due to thermodynamic contributions. However, this statement mostly lies on a hypothetical basis. In this study, we use on-line inductively coupled plasma mass spectrometer to investigate the dissolution of five representative electrocatalysts in acidic and alkaline media and a wide potential window targeting the most important applications. To address both model and applied systems, we synthesized thin films and carbon-supported nanoparticles ranging from an elemental (Pt) sample to binary (PtRu), ternary (PtRuIr), quaternary (PtRuIrRh), and quinary (PtRuIrRhPd) alloy samples. For certain metals in the high-entropy alloy under alkaline conditions, lower dissolution was observed. Still, the improvement was not striking and can be rather explained by the lowered concentration of elements in the multinary alloys instead of the synergistic effects of thermodynamics. We postulate that this is because of dissolution kinetic effects, which are always present under electrocatalytic conditions, overcompensating thermodynamic contributions

    Isopropanol electro-oxidation on Pt-Ru-Ir: A journey from model thin-film libraries towards real electrocatalysts

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    Liquid fuels are considered a promising alternative to hydrogen in proton exchange membrane fuel cells. In particular, isopropanol, which can be selectively oxidised to acetone and further hydrogenated back to isopropanol using electrochemical and heterogeneous catalysis routes, respectively, opens the possibility of zero-emission fuel cell operation without complex management of molecular H2. However, the maximum electric power of such fuel cells is still relatively low, which is attributed to the poisoning of state-of-the-art Pt-Ru electrocatalysts by adsorbed acetone and/or Ru oxide/hydroxide. Here, in order to mitigate Pt-Ru poisoning at higher anodic potentials during isopropanol oxidation in acidic media, the effect of the addition of Ir, a less oxophilic element than Ru, on the activity and stability during dynamic experiments of Pt-Ru is systematically investigated. To identify the most active compositions, Pt-Ru-Ir thin-film material libraries are prepared using magnetron co-sputtering. The electrocatalytic activity of the libraries is screened using a high-throughput scanning flow cell setup. Catalysts with the highest activity are further synthesised in the form of carbon-supported nanoparticles. Comparing the two systems, similar trends are observed, highlighting the model material libraries being an excellent starting point for novel catalyst development. Besides electrocatalytic activity, catalyst shelf-life and dissolution stability are studied. While significant ageing in the air is found, partial reactivation is possible using a reductive treatment. The dissolution of the most promising nanoparticulate electrocatalyst is evaluated using online inductively coupled plasma mass spectrometry to assess the effect of Ir addition on Pt and Ru stability. No significant stabilising role of Ir, however, is observed. Hence, further optimisation of Pt-Ru or Pt-Ru-Ir is still needed to improve isopropanol fuel cell performance
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