405 research outputs found

    Approaches to Assess the Suitability of Zooplankton for Bioregenerative Life Support Systems

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    Future manned space exploration will send humans farther away from Earth than ever before (e.g., to Mars), leading to extended mission durations and thus to a higher demand for essentials such as food, water and oxygen. As resupplying these items from Earth is nearly impossible, aquatic bioregenerative life support systems (BLSS) appear to be a promising solution. Due to its central role in aquatic ecosystems, zooplankton could act as a key player in aquatic BLSS, linking oxygen liberating, autotrophic producers and higher trophic levels. However, prior to the utilization of BLSS in space, organisms proposed to inhabit these systems have to be studied thoroughly to evaluate any space-borne adverse traits, which may impede a proper function of the system. To investigate the impact of microgravity (ÎĽg), in particular, several platforms are available, providing ÎĽg periods ranging from seconds (Bremen drop tower and parabolic flights), to minutes (sounding rockets), up to even days and months (space flights and the International Space Station (ISS)). Furthermore, ground-based facilities, such as clinostats, enable the of candidate organisms to variable periods of simulated/functional ÎĽg. In this book chapter, research on zooplankton utilizing these methods is summarized

    State-dependencies of learning across brain scales

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    Learning is a complex brain function operating on different time scales, from milliseconds to years, which induces enduring changes in brain dynamics. The brain also undergoes continuous “spontaneous” shifts in states, which, amongst others, are characterized by rhythmic activity of various frequencies. Besides the most obvious distinct modes of waking and sleep, wake-associated brain states comprise modulations of vigilance and attention. Recent findings show that certain brain states, particularly during sleep, are essential for learning and memory consolidation. Oscillatory activity plays a crucial role on several spatial scales, for example in plasticity at a synaptic level or in communication across brain areas. However, the underlying mechanisms and computational rules linking brain states and rhythms to learning, though relevant for our understanding of brain function and therapeutic approaches in brain disease, have not yet been elucidated. Here we review known mechanisms of how brain states mediate and modulate learning by their characteristic rhythmic signatures. To understand the critical interplay between brain states, brain rhythms, and learning processes, a wide range of experimental and theoretical work in animal models and human subjects from the single synapse to the large-scale cortical level needs to be integrated. By discussing results from experiments and theoretical approaches, we illuminate new avenues for utilizing neuronal learning mechanisms in developing tools and therapies, e.g., for stroke patients and to devise memory enhancement strategies for the elderly

    POLES-JRC model documentation

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    This report is a public manual of the POLES-JRC model, the in-house tool of the European Commission for global and long-term analysis of GHG mitigation policies and evolution of energy markets. The model includes a comprehensive description of the energy system and related GHG emissions for a large set of significant economies and residual regions, covering the World and including international bunkers. Through linkage with specialized tools it also provides a full coverage of GHG emissions, including from land use and agriculture, as well as of air pollutants emissions. The POLES-JRC model builds on years of development of the POLES model (Prospective Outlook on Long-term Energy Systems) while adding specific features developed internally to the JRC. Latest modelling upgrades - compared to the 2017 edition of the model documentation - include final energy demand, electricity production, the role of hydrogen as an energy vector, the oil, gas and coal international markets and GHG emission projections. This document presents the Prospective Outlook on Long-term Energy Systems (POLES) model of the Joint Research Centre, as used in the 2018 edition of the Global Energy and Climate Outlook (GECO).JRC.C.6-Economics of Climate Change, Energy and Transpor

    Global Energy and Climate Outlook 2018: Sectoral mitigation options towards a low-emissions economy

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    This report analyses global transition pathways to a low Greenhouse Gas (GHG) emissions economy The main scenarios presented have been designed to be compatible with the 2°C and 1.5°C temperature targets put forward in the UNFCCC Paris Agreement, in order to minimise irreversible climate damages. Reaching these targets requires action from all world countries and in all economic sectors. Global net GHG emissions would have to drop to zero by around 2080 to limit temperature increase to 2°C above pre-industrial levels (by around 2065 for the 1.5°C limit). The analysis shows that this ambitious low-carbon transition can be achieved with robust economic growth, implying small mitigation costs. Results furthermore highlight that the combination of climate and air policies can contribute to improving air quality across the globe, thus enabling progress on the UN Sustainable Development Goals for climate action, clean energy and good health. Key uncertainties in future pathways related to the availability of future technological options have been assessed for Carbon Capture and Sequestration (CCS) and bioenergy. If CCS technologies would not develop, a 2°C pathway would have a similar mitigation trajectory in the first half of the century as a 1.5°C scenario with CCS.JRC.C.6-Economics of Climate Change, Energy and Transpor

    Coregulator Control of Androgen Receptor Action by a Novel Nuclear Receptor-Binding Motif

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    The androgen receptor (AR) is a ligand-activated transcription factor that is essential for prostate cancer development. It is activated by androgens through its ligand-binding domain (LBD), which consists predominantly of 11 α-helices. Upon ligand binding, the last helix is reorganized to an agonist conformation termed activator function-2 (AF-2) for coactivator binding. Several coactivators bind to the AF-2 pocket through conserved LXXLL or FXXLF sequences to enhance the activity of the receptor. Recently, a small compound-binding surface adjacent to AF-2 has been identified as an allosteric modulator of the AF-2 activity and is termed binding function-3 (BF-3). However, the role of BF-3 in vivo is currently unknown, and little is understood about what proteins can bind to it. Here we demonstrate that a duplicated GARRPR motif at the N terminus of the cochaperone Bag-1L functions through the BF-3 pocket. These findings are supported by the fact that a selective BF-3 inhibitor or mutations within the BF-3 pocket abolish the interaction between the GARRPR motif(s) and the BF-3. Conversely, amino acid exchanges in the two GARRPR motifs of Bag-1L can impair the interaction between Bag-1L and AR without altering the ability of Bag-1L to bind to chromatin. Furthermore, the mutant Bag-1L increases androgen-dependent activation of a subset of AR targets in a genome-wide transcriptome analysis, demonstrating a repressive function of the GARRPR/BF-3 interaction. We have therefore identified GARRPR as a novel BF-3 regulatory sequence important for fine-tuning the activity of the AR

    Partial Regulatory T Cell Depletion Prior to Acute Feline Immunodeficiency Virus Infection Does Not Alter Disease Pathogenesis

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    Feline immunodeficiency virus (FIV) infection in cats follows a disease course similar to HIV-1, including a short acute phase characterized by high viremia, and a prolonged asymptomatic phase characterized by low viremia and generalized immune dysfunction. CD4+CD25hiFoxP3+ immunosuppressive regulatory T (Treg) cells have been implicated as a possible cause of immune dysfunction during FIV and HIV-1 infection, as they are capable of modulating virus-specific and inflammatory immune responses. Additionally, the immunosuppressive capacity of feline Treg cells has been shown to be increased during FIV infection. We have previously shown that transient in vivo Treg cell depletion during asymptomatic FIV infection reveals FIV-specific immune responses suppressed by Treg cells. In this study, we sought to determine the immunological influence of Treg cells during acute FIV infection. We asked whether Treg cell depletion prior to infection with the highly pathogenic molecular clone FIV-C36 in cats could alter FIV pathogenesis. We report here that partial Treg cell depletion prior to FIV infection does not significantly change provirus, viremia, or CD4+ T cell levels in blood and lymphoid tissues during the acute phase of disease. The effects of anti-CD25 mAb treatment are truncated in cats acutely infected with FIV-C36 as compared to chronically infected cats or FIV-naĂŻve cats, as Treg cell levels were heightened in all treatment groups included in the study within two weeks post-FIV infection. Our findings suggest that the influence of Treg cell suppression during FIV pathogenesis is most prominent after Treg cells are activated in the environment of established FIV infection

    Mathematische Spieltheorie

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