165 research outputs found

    eSport : an analysis of the relevant market

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    Die vorliegende Bachelorarbeit gibt einen Überblick den elektronischen Sport eSports im Bezug auf den ihm zugrunde liegenden Markt. Dabei wurde zunächst das Phänomen eSports genauer beleuchtet. Anschließend wurde der eSport in den Kontext von Porters Branchenstrukturanalyse gestellt. Diese Arbeit baut auf der theoretischen Grundlage von Porter auf und gibt Erkenntnisse über die aktuelle Lage des eSports am relevanten Markt

    Nutrients cause grassland biomass to outpace herbivory

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    Human activities are transforming grassland biomass via changing climate, elemental nutrients, and herbivory. Theory predicts that food-limited herbivores will consume any additional biomass stimulated by nutrient inputs ('consumer-controlled'). Alternatively, nutrient supply is predicted to increase biomass where herbivores alter community composition or are limited by factors other than food ('resource-controlled'). Using an experiment replicated in 58 grasslands spanning six continents, we show that nutrient addition and vertebrate herbivore exclusion each caused sustained increases in aboveground live biomass over a decade, but consumer control was weak. However, at sites with high vertebrate grazing intensity or domestic livestock, herbivores consumed the additional fertilization-induced biomass, supporting the consumer-controlled prediction. Herbivores most effectively reduced the additional live biomass at sites with low precipitation or high ambient soil nitrogen. Overall, these experimental results suggest that grassland biomass will outstrip wild herbivore control as human activities increase elemental nutrient supply, with widespread consequences for grazing and fire risk

    Enhancing the relevance of Shared Socioeconomic Pathways for climate change impacts, adaptation and vulnerability research

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    This paper discusses the role and relevance of the shared socioeconomic pathways (SSPs) and the new scenarios that combine SSPs with representative concentration pathways (RCPs) for climate change impacts, adaptation, and vulnerability (IAV) research. It first provides an overview of uses of social–environmental scenarios in IAV studies and identifies the main shortcomings of earlier such scenarios. Second, the paper elaborates on two aspects of the SSPs and new scenarios that would improve their usefulness for IAV studies compared to earlier scenario sets: (i) enhancing their applicability while retaining coherence across spatial scales, and (ii) adding indicators of importance for projecting vulnerability. The paper therefore presents an agenda for future research, recommending that SSPs incorporate not only the standard variables of population and gross domestic product, but also indicators such as income distribution, spatial population, human health and governance

    Assessing the role of large herbivores in the structuring and functioning of freshwater and marine angiosperm ecosystems

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    2 figuras, 3 tablasWhile large herbivores can have strong impacts on terrestrial ecosystems, much less is known of their role in aquatic systems. We reviewed the literature to determine: (1) which large herbivores (>10 kg) have a (semi-)aquatic lifestyle and are important consumers of submerged vascular plants, (2) their impact on submerged plant abundance and species composition and (3) their ecosystem functions. We grouped herbivores according to diet, habitat selection and movement ecology: (1) Fully aquatic species, either resident or migratory (manatees, dugongs, turtles), (2) Semi-aquatic species that live both in water and on land, either resident or migratory (swans), (3) Resident semi-aquatic species that live in water and forage mainly on land (hippopotamuses, beavers, capybara), (4) Resident terrestrial species with relatively large home ranges that frequent aquatic habitats (cervids, water buffalo, lowland tapir). Fully aquatic species and swans have the strongest impact on submerged plant abundance and species composition. They may maintain grazing lawns. Because they sometimes target belowground parts, their activity can result in local collapse of plant beds. Semi-aquatic species and turtles serve as important aquatic-terrestrial linkages, by transporting nutrients across ecosystem boundaries. Hippopotamuses and beavers are important geomorphological engineers, capable of altering the land and hydrology at landscape scales. Migratory species and terrestrial species with large home ranges are potentially important dispersal vectors of plant propagules and nutrients. Clearly, large aquatic herbivores have strong impacts on associated species and can be critical ecosystem engineers of aquatic systems, with the ability to modify direct and indirect functional pathways in ecosystems. While global populations of large aquatic herbivores are declining, some show remarkable local recoveries with dramatic consequences for the systems they inhabit. A better understanding of these functional roles will help set priorities for the effective management of large aquatic herbivores along with the plant habitats they rely on.This research was funded by the Spanish Ministry of Science and Innovation (CTM2013-48027-C3-3-R), an Intramural Project from the Spanish National Research Council (CSIC, 201330E062) and the Pew Marine Fellowship.Peer reviewe

    The Numbers Behind Mushroom Biodiversity

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    Fungi are among the most diverse groups of organisms on Earth. with a global diversity estimated at 0.8 million to 5.1 million species. They play fundamental ecological roles as decomposers, mutualists, and pathogens, growing in almost all habitats and being important as sources of food and health benefits, income, and to maintain forest health. Global assessment of wild edible fungi indicate the existence of 2327 useful wild species; 2166 edible and 1069 used as food; 470 medicinal species. Several million tonnes are collected, consumed, and sold each year in over 80 countries. The major mushroom-producing countries in 2012 were China, Italy, USA, and The Netherlands, with 80% of the world production, 64% of which came from China. The European Union produces 24% of the world production. Italy is the largest European producer, Poland is the largest exporter, UK the largest importer.Fungi are difficult to preserve and fossilize and due to the poor preservation of most fungal structures, it has been difficult to interpret the fossil record of fungi. Hyphae, the vegetative bodies of fungi, bear few distinctive morphological characteristicss, and organisms as diverse as cyanobacteria, eukaryotic algal groups, and oomycetes can easily be mistaken for them (Taylor & Taylor 1993). Fossils provide minimum ages for divergences and genetic lineages can be much older than even the oldest fossil representative found. According to Berbee and Taylor (2010), molecular clocks (conversion of molecular changes into geological time) calibrated by fossils are the only available tools to estimate timing of evolutionary events in fossil‐poor groups, such as fungi. The arbuscular mycorrhizal symbiotic fungi from the division Glomeromycota, generally accepted as the phylogenetic sister clade to the Ascomycota and Basidiomycota, have left the most ancient fossils in the Rhynie Chert of Aberdeenshire in the north of Scotland (400 million years old). The Glomeromycota and several other fungi have been found associated with the preserved tissues of early vascular plants (Taylor et al. 2004a). Fossil spores from these shallow marine sediments from the Ordovician that closely resemble Glomeromycota spores and finely branched hyphae arbuscules within plant cells were clearly preserved in cells of stems of a 400 Ma primitive land plant, Aglaophyton, from Rhynie chert 455–460 Ma in age (Redecker et al. 2000; Remy et al. 1994) and from roots from the Triassic (250–199 Ma) (Berbee & Taylor 2010; Stubblefield et al. 1987).info:eu-repo/semantics/publishedVersio

    The influence of the PI3-kinase pathway on the regulation of of alternative HIV-1 pre-mRNA splicing

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    In der vorliegenden Arbeit wurden ausgehend von HIV-1 basierten Minigenkonstrukten und der proviralen NL4-3 DNA die Einflüsse der PI3K Signalwegmodulation auf das alternative Spleißen der HIV-1 prä-mRNA sowie auf die Virus Replikation untersucht. Mittels RT-PCR Analysen konnte gezeigt werden, dass die PI3K Inhibition im Falle der HIV-1 basierten Minigenkonstrukte in einer erhöhten Abundanz ungespleißter bzw. intronhaltiger mRNAs resultierte, während im Kontext des Virus die Induktion alternativer Tat Transkriptvarianten nachgewiesen werden konnte. Als Folge der Inhibition des PI3K Signalwegs kam es zu einem vermehrten Einschluss der HIV-1 Leader Exone2/2b und 3. Da der Einschluss dieser Exone durch die hnRNP A/B- und F/H-abhängigen Silencer Elemente ESSV und GI2-1 negativ reguliert wird, wurde vermutet, dass die PI3K Inhibition mit der Funktionalität dieser spleißregulatorischen Aktivität interferiert. Unterstützt wurde diese Hypothese durch Replikationsexperimente mit ESSV und GI2-1 Mutanten in Gegenwart und Abwesenheit des PI3K-Inhibitors. Zusätzlich wurde auch der Einfluss des Inhibitors unter Überexpressionsbedingungen von hnRNP H auf das alternative HIV-1 Spleißen analysiert. In dieser Arbeit konnte ebenfalls gezeigt werden, dass die PI3K Inhibition ein verändertes hnRNP H Spleißmuster bedingt sowie die SR-Protein Phosphorylierung und Expression beeinflusst. Des Weiteren war es im Verlauf der vorliegenden Arbeit möglich, eine Interferenz der PI3K Modulation mit der Virus Replikation nachzuweisen. Die Überexpression der aktivierten Akt-Kinase lies hier nur eine sehr geringe Virus Produktion zu während die PI3K Inhibition diese auf ca. die Hälfte reduzierte. Weiterführende Experimente zeigten, dass die Überexpression der aktivierten Akt-Kinase den nuklearen Export Rev-abhängiger HIV-1 mRNAs zu blockieren scheint. Darüber hinaus beeinflusste die PI3K Inhibition neben dem alternativen HIV-1 Spleißen auch die virale Transkription sowie die zelluläre Translation. Zusammen könnten diese Effekte die reduzierte virale Replikation erklären. Der PI3K Signalweg spielt somit eine zentrale Rolle bei dem alternativen HIV-1 Spleißen und der viralen Replikation und bietet so die Möglichkeit der Entwicklung neuer Ansätze einer antiviralen Therapie.  In this thesis outgoing from HIV-1 based minigenes and the proviral NL4-3 DNA the influences of the PI3K signaling modulation on the alternative HIV-1 pre-mRNA splicing and also the viral replication were investigated. By performing RT-PCR analysis it could be shown that in the case of the minigene experiments the PI3K inhibition displayed an increased amount of unspliced or intron containing mRNAs, while the production of alternative Tat variants was demonstrated in the context of the virus. As a result of the PI3K inhibition an increased inclusion of the HIV-1 leader exons2/2b and 3 was observed. Because the inclusion of these exons is negatively regulated by the hnRNP H/F- and hnRNP A/B-dependent silencere elements ESSV and GI2-1, it was suggested that the PI3K inhibition interferes with the functionality of this splicing regulatory activity. Replication experiments either with GI2-1 or ESSV mutants in the presence or absence of the PI3K-Inhibitior supported this hypothesis. In addition, the influence of the inhibitor on the alternative HIV-1 splicing was analyzed under hnRNP H overexpression conditions. Furthermore, it was shown that the hnRNP H splicing pattern as well as the SR-protein phosphorylation and expression were altered as a consequence of the PI3K inhibition. During this thesis an interference of the PI3K modulation with the viral replication was also shown. The overexpression of the activated Akt kinase nearly prevented viral production while the PI3K inhibition reduced viral production by half. In further experiments it was shown that the overexpression of the activated Akt kinase seems to block the nuclear export of Rev-dependent HIV-1 mRNAs. In addition, beside the effect on the viral splicing pattern the PI3K inhibition also showed an influence on the viral transcription and the cellular translation suggesting that the sum of all these effects could contribute to the reduced virus production. These findings demonstrate that the PI3K signaling pathway has indeed a central influence on the alternative HIV-1 splicing as well as on the viral replication and may offer a new approach for antiviral therapy
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