464 research outputs found

    The evolution of masturbation is associated with postcopulatory selection and pathogen avoidance in primates

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    Masturbation occurs throughout the animal kingdom. At first glance, however, the fitness benefits of this self-directed behaviour are unclear. Regardless, several drivers have been proposed. Non-functional hypotheses posit that masturbation is either a pathology, or a byproduct of high underlying sexual arousal, whereas functional hypotheses argue an adaptive benefit. The Postcopulatory Selection Hypothesis states that masturbation aids the chances of fertilization, while the Pathogen Avoidance Hypothesis states that masturbation helps reduce host infection by flushing pathogens from the genital tract. Here, we present comprehensive new data documenting masturbation across the primate order and use these, in conjunction with phylogenetic comparative methods, to reconstruct the evolutionary pathways and correlates of masturbation. We find that masturbation is an ancient trait within the primate order, becoming a more common aspect of the haplorrhine behavioural repertoire after the split from tarsiers. Our analyses provide support for both the Postcopulatory Selection and Pathogen Avoidance Hypotheses in male primates, suggesting that masturbation may be an adaptive trait, functioning at a macroevolutionary scale

    Quality of life and physical activity in long-term (≄5 years post-diagnosis) colorectal cancer survivors - systematic review

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    Background: Due to the increasing number of long-term (≄5 years post diagnosis) colorectal cancer survivors, long-term quality of life of these patients is highly relevant. Several studies have reported a positive association between physical activity and quality of life in colorectal cancer survivors, however, so far no systematic review has been published which focuses on long-term colorectal cancer survivors. Material and methods: A systematic review was conducted using the databases PubMed, Web of Science, PsychINFO, and CINAHL. Studies which investigated associations between physical activity and quality of life in long-term colorectal cancer survivors were included. Results and conclusion: Ten articles based on seven studies were identified. Long-term colorectal cancer survivors who were physically active reported better quality of life than long-term survivors who were not physically active. Both, moderate to vigorous physical activity and lower levels like light physical activity were associated with higher quality of life. Most studies assessed the association between physical activity and quality of life cross-sectionally but one prospective study which measured physical activity and quality of life at three different points in time also found associations between physical activity and quality of life. The association between physical activity and quality of life seemed to be stronger among women than among men. The findings of this systematic review support an association between physical activity and quality of life in long-term colorectal cancer survivors. However, the evidence is limited as most studies were based on cross-sectional and observational design

    Untersuchungen zum Amphibienbestand eines Feuchtgebietes in OsnabrĂŒck : mit 2 Tabellen

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    Im Rahmen der Projekt-Lehrveranstaltung "Angewandte Biotopforschung" an der UniversitĂ€t OsnabrĂŒck wurden im Jahre 1987 in einem kleinen Feuchtgebiet des OsnabrĂŒkker Stadtteils Atter Untersuchungen an den dortigen AmphibienbestĂ€nden durchgefĂŒhrt. Dabei konnten 9 Arten nachgewiesen werden: Erdkröte (Bufo bufo), Grasfrosch (Rana temporaria), Moorfrosch (Rana arvalis), Wasserfrosch (Rana esculenta), Laubfrosch (Hyla arborea), Teichmolch (Triturus vulgaris), Fadenmolch (T. helveticus), Bergmolch (T. alpestris) und Kammolch (T. cristatus). 4 der Arten stehen auf der Roten Liste. Bedingt durch das kalte FrĂŒhjahr 1987 erfolgten die Wanderungen zu den LaichgewĂ€ssern sehr spĂ€t. Negative Entwicklungen und EinflĂŒsse, die im Gebiet beobachtbar sind, sollten durch die Ausweisung als "FlĂ€chenhaftes Naturdenkmal" eingedĂ€mmt werden. Über einen Pflege- und Entwicklungsplan wĂ€re das GelĂ€nde zu verbessern

    Dynamische Zeiten - langsamer Wandel: betriebliche Kompetenzentwicklung von FachkrÀften in zentralen TÀtigkeitsfeldern der deutschen Wirtschaft

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    Der Bericht befasst sich mit den Perspektiven betrieblicher Kompetenzentwicklung in zentralen Bereichen der deutschen Wirtschaft. Eine beschleunigte Innovationsdynamik, eine gestiegene VolatilitĂ€t von MĂ€rkten, verschĂ€rfte Wettbewerbsbedingungen und erhöhte AnsprĂŒche von Kunden stellen Industrie- und Dienstleistungsunternehmen vor neue Herausforderungen gerade auch im Hinblick auf die Optimierung ihres Kompetenzstocks im Sinne der Erschließung und Weiterentwicklung der Wissens- und Kompetenzpotentiale ihrer Belegschaften. Methodisch lĂ€sst sich den aufgeworfenen Fragen nur durch eine vertiefte, qualitativ angelegte Empirie nachgehen. Eine solche haben wir durch Auswahl von insgesamt 25 BetriebsfĂ€llen in drei Kernsektoren der deutschen Wirtschaft - dem Verarbeitenden Gewerbe (KFZ- und Zulieferindustrie, Maschinenbau, Pharmazeutische Industrie), dem traditionellen Dienstleistungssektor (Handel, Banken und Versicherungen) und dem Feld wissensintensiver Dienstleistungen (Unternehmensberatungen, IT- und Multimediadienstleistungen, Entwicklungs- und Konstruktionsdienstleistungen) - und dort mit einer Fokussierung auf jeweils typische FachkrĂ€fte- und TĂ€tigkeitsgruppen realisieren können. Auf der Basis von insgesamt 163 qualitativen Experteninterviews, einer standardisierten schriftlichen Befragung von insgesamt 555 Facharbeitern, Fach- und hochqualifizierten Angestellten können wir bei aller Vorsicht, die angesichts der von uns in den empirischen Fallstudien nachgezeichneten, teilweise spezifischen VerĂ€nderungsdynamiken angezeigt ist, einige allgemeine Aussagen zum gegenwĂ€rtigen Stand und zu möglichen Trends im Feld der betrieblichen Kompetenzentwicklung treffen. (ICD2

    Assessment of injury severity of nearside occupants in pole impacts to side of passenger cars in European traffic accidents - analysis of German and UK in-depth data

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    The national accident statistics demonstrate that the situation of passenger car side impacts is dominated by car to car accidents. Car side to pole impacts are relatively infrequent events. However the importance of car side to pole impacts is significantly increasing with fatal and seriously injured occupants. For the present study the German in-depth database GIDAS (German In-Depth-Accident Study) and the UK database CCIS (Co-operative Crash Injury Study) were used. Two approaches were undertaken to better understand the scenario of car to pole impacts. The first part is a statistical analysis of passenger car side to pole impacts to describe the characteristics and their importance relevant to other types of impact and to get further knowledge about the main factors influencing the accident outcome. The second part contains a case by case review on passenger cars first registered 1998 onwards to further investigate this type of impact including regression analysis to assess the relationship between injury severity and pole impact relevant factors

    Identification of a novel Rev-interacting cellular protein

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    BACKGROUND: Human cell types respond differently to infection by human immunodeficiency virus (HIV). Defining specific interactions between host cells and viral proteins is essential in understanding how viruses exploit cellular functions and the innate strategies underlying cellular control of HIV replication. The HIV Rev protein is a post-transcriptional inducer of HIV gene expression and an important target for interaction with cellular proteins. Identification of Rev-modulating cellular factors may eventually contribute to the design of novel antiviral therapies. RESULTS: Yeast-two hybrid screening of a T-cell cDNA library with Rev as bait led to isolation of a novel human cDNA product (16.4.1). 16.4.1-containing fusion proteins showed predominant cytoplasmic localization, which was dependent on CRM1-mediated export from the nucleus. Nuclear export activity of 16.4.1 was mapped to a 60 amino acid region and a novel transport signal identified. Interaction of 16.4.1 with Rev in human cells was shown in a mammalian two-hybrid assay and by colocalization of Rev and 16.4.1 in nucleoli, indicating that Rev can recruit 16.4.1 to the nucleus/nucleoli. Rev-dependent reporter expression was inhibited by overexpressing 16.4.1 and stimulated by siRNAs targeted to 16.4.1 sequences, demonstrating that 16.4.1 expression influences the transactivation function of Rev. CONCLUSION: These results suggest that 16.4.1 may act as a modulator of Rev activity. The experimental strategies outlined in this study are applicable to the identification and biological characterization of further novel Rev-interacting cellular factors

    Mineralogical characterization of scalings formed in geothermal sites in the Upper Rhine Graben before and after the application of sulfate inhibitors

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    Scale formation processes in the surface installations of geothermal power plants may have a negative effect on power plant performance. In addition, scales formed within the geothermal water circuit frequently accumulate natural radionuclides. Consequently, scale formation may lead to radiation dose rates, which are of radiological concern, and deposits, which may have to be disposed as radioactive waste. In order to minimize these problems and to foster geothermal power plant availability, it is of major interest to understand scale formation processes and to develop methods for their inhibition. One important pre-requisite towards this goal is a sound mineralogical and geochemical characterization of the formed material. Geothermal brines at sites in the Upper Rhine Graben are in general highly mineralized and become, upon cooling in the heat exchanger, supersaturated with respect to sulfate solid-solutions, e.g. (Ba,Sr)SO4, and other mineral phases. Some geothermal power plants very successfully tested the application of sulfate scaling inhibitors. Here we present mineralogical analyses of scale samples from geothermal power plants in the Upper Rhine Valley deposited in absence and presence of sulfate scaling inhibitors. Solid samples are investigated using wet-chemistry (after digestion), XRPD, SEM-EDX, XPS, EA-IRMS, Raman spectroscopy, and XANES (for explanation of abbreviations, see main text). Samples of scales deposited in the absence of a sulfate scaling inhibitor mainly consist of two phases. The largest part is made up of a barite type (Ba,Sr,Ca)SO4 solid-solution. Traces of Ra occurring in the scaling are assumed to be incorporated in the barite type solid solution. Further minor phases are sulfide phases, either an Xray amorphous nano-particulate phase or galena (PbS). Since the application of the sulfate inhibitor, sulfate minerals are no longer detectable in the scale samples. Subsequent scalings are Pb-dominated and consist mainly of galena (PbS), elemental lead (Pb), arsenic (As) and antimony (Sb). As and Sb are likely present as a nanocrystalline intermetallic mixed compound ((Sb, As) or Pb3(Sb,As)2S3). The absence of barite-type minerals demonstrates the success of the application of the sulfate inhibitor. The precipitation of elemental Pb, As, and Sb, which are more noble than iron, may enhance the corrosion of mild steel pipes in the geothermal water circuit. Elution tests and oxidation of the scalings upon storage at atmospheric conditions demonstrate that proper disposal of the toxic heavy metal and metalloid containing scalings may be challenging

    Banks' risk assessment of Swedish SMEs

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    Building on the literatures on asymmetric information and risk taking, this paper applies conjoint experiments to investigate lending officers' probabilities of supporting credit to established or existing SMEs. Using a sample of 114 Swedish lending officers, we test hypotheses concerning how information on the borrower's ability to repay the loan; alignment of risk preferences; and risk sharing affect their willingness to grant credit. Results suggest that features that reduce the risk to the bank and shift the risk to the borrower have the largest impact. The paper highlights the interaction between factors that influence the credit decision. Implications for SMEs, banks and research are discussed

    Die wirtschaftliche Lage Rußlands: MonetĂ€re Orientierungslosigkeit und realwirtschaftlicher Aktionismus. Dritter Bericht

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    Die beteiligten Institute legen hiermit ihren dritten Bericht ĂŒber die Wirtschaft Rußlands vor. Der Bericht ist in zwei Teile gegliedert. Im ersten Teil wird der aktuelle Stand der Wirtschaftsentwicklung und der Reformpolitik dargestellt. Seit der Fertigstellung des zweiten Berichts hat sich die politische und wirtschaftliche Lage in der Russischen Föderation nicht grundlegend geĂ€ndert. Die politische Blockade zwischen Legislative und Exekutive lĂ€hmt weiterhin den Reformprozeß; eine Wende zum Besseren ist nicht zu erkennen. Der zweite Teil des Berichts beschĂ€ftigt sich schwerpunktmĂ€ĂŸig mit der sozialen Lage der Bevölkerung. Gegenstand der Analyse sind die Entwicklung von Einkommen und Verbrauch, das System der sozialen Sicherung sowie das Angebotspotential fĂŒr die Versorgung der Bevölkerung mit GĂŒtern und Dienstleistungen. Nach wie vor werden die Analysen durch die unsichere politische Lage, den institutionellen Umbruch und das unzuverlĂ€ssige Berichtssystem erheblich erschwert. Die statistische Berichterstattung hat sich im Zeitablauf sogar noch verschlechtert. Vor allem die AktivitĂ€ten des sich neu entwickelnden privaten Sektors werden kaum erfaßt. InformationslĂŒcken konnten nur zu einem geringen Teil durch Befragung staatlicher Stellen und russischer Wissenschaftler vor Ort geschlossen werden, so daß erhebliche Unsicherheiten ĂŒber den tatsĂ€chlichen Ablauf des Transformationsprozesses verbleiben. --

    Different Modelling Purposes

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    How one builds, checks, validates and interprets a model depends on its ‘purpose’. This is true even if the same model code is used for different purposes. This means that a model built for one purpose but then used for another needs to be re-justified for the new purpose and this will probably mean it also has to be re-checked, re-validated and maybe even re-built in a different way. Here we review some of the different purposes for a simulation model of complex social phenomena, focusing on seven in particular: prediction, explanation, description, theoretical exploration, illustration, analogy, and social interaction. The paper looks at some of the implications in terms of the ways in which the intended purpose might fail. This analysis motivates some of the ways in which these ‘dangers’ might be avoided or mitigated. It also looks at the ways that a confusion of modelling purposes can fatally weaken modelling projects, whilst giving a false sense of their quality. These distinctions clarify some previous debates as to the best modelling strategy (e.g. KISS and KIDS). The paper ends with a plea for modellers to be clear concerning which purpose they are justifying their model against
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