1,303 research outputs found

    Proton-proton, anti-proton-anti-proton, proton-anti-proton correlations in Au + Au collisions measured by STAR at RHIC

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    The analysis of two-particle correlations provides a powerful tool to study the properties of hot and dense matter created in heavy-ion collisions at ultra-relativistic energies. Applied to identical and non-identical hadron pairs, it makes the study of space-time evolution of the source in femtoscopic scale possible. Baryon femtoscopy allows extraction of the radii of produced sources which can be compared to those deduced from identical pion studies, providing complete information about the source characteristics. In this paper we present the correlation functions obtained for identical and non-identical baryon pairs of protons and anti-protons. The data were collected recently in Au+Au collisions at sNN\sqrt{s_{NN}} =62 GeV and sNN\sqrt{s_{NN}} =200 GeV by the STAR detector at the RHIC accelerator. We introduce corrections to the baryon-baryon correlations taking into account: residual correlations from weak decays, particle identification probability and the fraction of primary baryons. Finally we compare our results to theoretical prediction

    Motivations, perceived risk and behavioural intentions in hard adventure tourism. A natural park case study1

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    Purpose of the paper: This study on consumer behaviour intends to combine two lines of investigation. First, we examine how different motivation factors in adventure tourism affect behavioural intentions. Secondly, in order to provide a better understanding of behavioural intentions we further explore the differences between the groups of individuals\u2019 subjective perception of risk. Design/methodology/approach: A visitor survey was conducted on a sample of hard adventure tourists at the Friuli Dolomiti Alps Natural Park. Factor analysis of motivational items resulted in four dimensions (i.e. nature, risk, contemplation and socialization). In order to discover a relationship between the four motivational factors and the adventure tourists\u2019 behavioural intention, a stepwise regression analysis was conducted. Then, using ANOVA and post hoc analysis (Scheffe\u2019s test), the existing differences between various levels of risk perception of adventure tourists and their response to behavioural intentions were analysed. Findings: The analysis of motivational factors indicates that \u201cactivity related motivations\u201d include four dimensions: nature, risk, contemplation and socialization. The stepwise regression results show that nature is the only motivational factor that affects tourists\u2019 behavioural intention. Originality/value: This paper shows that \u201cnature\u201d is the key motivational factor for adventure tourists to revisit a park. Practical implications: The analysis provides a framework suggesting how organizations might usefully implement a marketing strategy. This study encompasses the risk perception as a motivational factor and tries to discuss how this concept can be operationalized in tourism marketing. Limitations: This paper presents two main limitations. Firstly, the cross sectional nature of the data, and secondly, the hypotheses were tested using a sample from a limited area

    Expression of multiple horizontally acquired genes is a hallmark of both vertebrate and invertebrate genomes.

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    BACKGROUND: A fundamental concept in biology is that heritable material, DNA, is passed from parent to offspring, a process called vertical gene transfer. An alternative mechanism of gene acquisition is through horizontal gene transfer (HGT), which involves movement of genetic material between different species. HGT is well-known in single-celled organisms such as bacteria, but its existence in higher organisms, including animals, is less well established, and is controversial in humans. RESULTS: We have taken advantage of the recent availability of a sufficient number of high-quality genomes and associated transcriptomes to carry out a detailed examination of HGT in 26 animal species (10 primates, 12 flies and four nematodes) and a simplified analysis in a further 14 vertebrates. Genome-wide comparative and phylogenetic analyses show that HGT in animals typically gives rise to tens or hundreds of active 'foreign' genes, largely concerned with metabolism. Our analyses suggest that while fruit flies and nematodes have continued to acquire foreign genes throughout their evolution, humans and other primates have gained relatively few since their common ancestor. We also resolve the controversy surrounding previous evidence of HGT in humans and provide at least 33 new examples of horizontally acquired genes. CONCLUSIONS: We argue that HGT has occurred, and continues to occur, on a previously unsuspected scale in metazoans and is likely to have contributed to biochemical diversification during animal evolution.This work was supported by the European Research Council (AdG233232).This is the final published version. It first appeared at http://genomebiology.com/2015/16/1/50

    Pratiques agricoles et propriétés agro-écologiques des prairies dans un processus d’intensification écologique : le cas de l’élevage bovin dans le Vercors

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    National audienceL'élevage bovin pour la production laitière est la composante agricole majeure sur le territoire des Quatre Montagnes dans le massif du Vercors. Sur ce territoire, un enjeu fort soulevé par une grande partie des agriculteurs concerne la question de l'autonomie fourragère. Cet aspect de la production est d'autant plus central qu'il est fortement dépendant des caractéristiques des prairies qui permettent d'assurer la production de fourrage en dépit d'aléas de plus en plus contraignants (sécheresses, dégâts de campagnols…). Comprendre comment maintenir un niveau de production suffisant en s'appuyant sur les propriétés écosystémiques des prairies relève du contexte de l'intensification écologique en abordant les relations entre l'organisation des systèmes d'élevage (usages à l'échelle des parcelles, diversité des types de parcelles au sein des exploitations, distribution au sein du paysage) et les valeurs d'usage et services écosystémiques fournis par les prairies. Au sein du projet multi-sites ANR-SYSTERRA MOUVE (Les interactions Elevage et Territoire dans la mise en mouvement de l’intensification écologique), le territoire des Quatre Montagnes constitue l'un des terrains d'approfondissement pour analyser comment l'évolution des pratiques dans le sens de l'intensification écologique peut permettre d'augmenter le niveau des services écologiques et d'améliorer les capacités d'adaptation des élevages. En nous appuyant sur une typologie préétablie des prairies, basée le type d'usage (fauche, pâturage) et la composition simplifiée de la végétation nous avons mesuré un large panel de propriétés écosystémiques sur un échantillon de 50 parcelles représentant la diversité des types d'usage sur le territoire. Les propriétés mesurée couvrent notamment la structure spécifique (diversité, hétérogénéité) et fonctionnelle des communautés (traits foliaires, structuraux, phénologiques), les caractéristiques agronomiques (teneur en N, C, P…) et écologique (biomasse et diversité microbienne) du sol et du fourrage (production, qualité), autant de proxys pour les grands types de services reconnus : (i) services intrants, (ii) services de production fourragère et (iii) services en lien avec la valeur écologique des prairies. Les premiers résultats révèlent le rôle prépondérant de deux facteurs liés aux usages pour les propriétés agro-écologiques des prairies : la date de première fauche ou pâturage et le caractère temporaire ou permanent des prairies (date du dernier retournement). Les prairies temporaires offrent un bon niveau de services intrant (fertilité, matière organique) et de production et qualité fourragère mais une faible valeur écologique (faible diversité). Cette distinction sur la base des propriétés agro-écologiques est d'autant plus intéressante que les entretiens auprès des éleveurs ont souligné l'importance de la place des prairies temporaires comme une des clés pour l'autonomie fourragère. Ces prairies productives étant également les plus sensibles aux aléas et offrant une moindre souplesse d'utilisation. A terme, notre objectif est d'identifier les compromis, synergies et antagonismes entre les différents types de services rendus (agronomiques, écologiques) en fonction de différents scénarios d'intensification écologique à l'échelle du territoire

    The impact of quantitative optimization of hybridization conditions on gene expression analysis.

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    BACKGROUND: With the growing availability of entire genome sequences, an increasing number of scientists can exploit oligonucleotide microarrays for genome-scale expression studies. While probe-design is a major research area, relatively little work has been reported on the optimization of microarray protocols. RESULTS: As shown in this study, suboptimal conditions can have considerable impact on biologically relevant observations. For example, deviation from the optimal temperature by one degree Celsius lead to a loss of up to 44% of differentially expressed genes identified. While genes from thousands of Gene Ontology categories were affected, transcription factors and other low-copy-number regulators were disproportionately lost. Calibrated protocols are thus required in order to take full advantage of the large dynamic range of microarrays.For an objective optimization of protocols we introduce an approach that maximizes the amount of information obtained per experiment. A comparison of two typical samples is sufficient for this calibration. We can ensure, however, that optimization results are independent of the samples and the specific measures used for calibration. Both simulations and spike-in experiments confirmed an unbiased determination of generally optimal experimental conditions. CONCLUSIONS: Well calibrated hybridization conditions are thus easily achieved and necessary for the efficient detection of differential expression. They are essential for the sensitive pro filing of low-copy-number molecules. This is particularly critical for studies of transcription factor expression, or the inference and study of regulatory networks.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Multiple functionally divergent and conserved copies of alpha tubulin in bdelloid rotifers.

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    BACKGROUND: Bdelloid rotifers are microscopic animals that have apparently survived without sex for millions of years and are able to survive desiccation at all life stages through a process called anhydrobiosis. Both of these characteristics are believed to have played a role in shaping several unusual features of bdelloid genomes discovered in recent years. Studies into the impact of asexuality and anhydrobiosis on bdelloid genomes have focused on understanding gene copy number. Here we investigate copy number and sequence divergence in alpha tubulin. Alpha tubulin is conserved and normally present in low copy numbers in animals, but multiplication of alpha tubulin copies has occurred in animals adapted to extreme environments, such as cold-adapted Antarctic fish. Using cloning and sequencing we compared alpha tubulin copy variation in four species of bdelloid rotifers and four species of monogonont rotifers, which are facultatively sexual and cannot survive desiccation as adults. Results were verified using transcriptome data from one bdelloid species, Adineta ricciae. RESULTS: In common with the typical pattern for animals, monogonont rotifers contain either one or two copies of alpha tubulin, but bdelloid species contain between 11 and 13 different copies, distributed across five classes. Approximately half of the copies form a highly conserved group that vary by only 1.1% amino acid pairwise divergence with each other and with the monogonont copies. The other copies have divergent amino acid sequences that evolved significantly faster between classes than within them, relative to synonymous changes, and vary in predicted biochemical properties. Copies of each class were expressed under the laboratory conditions used to construct the transcriptome. CONCLUSIONS: Our findings are consistent with recent evidence that bdelloids are degenerate tetraploids and that functional divergence of ancestral copies of genes has occurred, but show how further duplication events in the ancestor of bdelloids led to proliferation in both conserved and functionally divergent copies of this gene.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    PENGARUH KINERJA KEUANGAN TERHADAP PROFITABILITAS BANK BTN SEBELUM DAN SESUDAH SEKURITISASI ASET

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    ABSTRACTRumah layak huni dan terjangkau bagi PNS (Pegawai Negeri Sipil/ASN) dan masyarakat berpenghasilan rendah (MBR) merupakan permasalahan yang hingga kini belum dapat diatasi secara tuntas. Meskipun berbagai program telah digulirkan pemerintah untuk menyelesaikannya namun jumlah backlog perumahan semakin bertambah (kebutuhan saat ini mencapai 13,5 juta unit , sedangkan pembangunan rumah baru hanya sekitar 300-400 ribu unit per tahun)(Sumber Bappenas & BPS Tahun 2015). Adapun kendala pembiayaan pemerintah melalui APBN sangat terbatas, alokasi anggaran perumahan FLPP (Fasilitas Likuiditas Pembiayaan Perumahan) yaitu Rp 9 T di tahun 2015 atau hanya sekitar 0.375% dari APBN 2400 T (atau kurang dari ½ %). Untuk itu , Bank BTN ditunjuk sebagai Bank Penyalur program kredit perumahan rakyat (KPR-Bersubsidi FLPP) oleh Pemerintah , hasil kinerja keuangan Bank BTN sebelum dan sesudah sekuritisasi asset akan dikaji lebih lanjut, sekaligus dapat memberikan masukan kepada seluruh stakeholders agar solusi backlog dan pembiayaan perumahan dapat memberi kontribusi mengatasi permasalahan perumahan.
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