1,558 research outputs found

    Saturation of Transverse Energy per Charged Hadron and Freeze-Out Criteria in Heavy-Ion Collisions

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    For beam energies from SPS to RHIC, the transverse energy per charged particle, ET/NchE_T/N_{\textrm{ch}}, saturates at a value of approximately 0.8 GeV. A direct connection between this value and the freeze-out criterium E/N1E/N \approx 1 GeV for the primordial energy and particle number in the hadronic resonance gas model is established.Comment: 7pages 5 figure

    Questioning policy, youth participation and lifestyle sports

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    Young people have been identified as a key target group for whom participation in sport and physical activity could have important benefits to health and wellbeing and consequently have been the focus of several government policies to increase participation in the UK. Lifestyle sports represent one such strategy for encouraging and sustaining new engagements in sport and physical activity in youth groups, however, there is at present a lack of understanding of the use of these activities within policy contexts. This paper presents findings from a government initiative which sought to increase participation in sport for young people through provision of facilities for mountain biking in a forest in south-east England. Findings from qualitative research with 40 young people who participated in mountain biking at the case study location highlight the importance of non-traditional sports as a means to experience the natural environments through forms of consumption which are healthy, active and appeal to their identities. In addition, however, the paper raises questions over the accessibility of schemes for some individuals and social groups, and the ability to incorporate sports which are inherently participant-led into state-managed schemes. Lifestyle sports such as mountain biking involve distinct forms of participation which present a challenge for policy-makers who seek to create and maintain sustainable communities of youth participants

    The fescue fungus problem

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    "Tall fescue has been widely accepted as a forage plant. It is particularly well adapted to the southern portion of the cornbelt where it has been planted on millions of acres of pasture lands."--First page.H.N. Wheaton and D.A. Sleper (Department of Agronomy) and Einar Palm (Department of Pathology, College of Agriculture)New 10/84/20

    Obtaining Personal Jurisdiction over Alien Corporations--A Survey of U.S. Practice

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    With the increase in international trade, civil litigation between persons of different nationalities has become increasingly important. Today alien and foreign corporations are being brought before American courts to defend actions arising out of products liability, contract, and tort. There is considerable authority holding alien and foreign corporations amenable to jurisdiction on the basis of a single act or business transaction. The states themselves are affecting international trade since state law is chosen to determine the amenability of alien and foreign corporations to suit in diversity actions in federal court. This survey presents a cross-section of recent cases and attempts to distinguish the treatment given alien corporations from the treatment given foreign corporations. While a variety of actions is represented, the majority of the cases deal with products liability. Generally, these cases concern an alien corporation\u27s contacts with a particular state, although some courts might look to contacts with the United States as a whole in determining whether to assume jurisdiction in some types of cases. Recurrent considerations which appear throughout include: (1) whether the corporation has availed itself of the privilege of conducting business within the forum state; (2) whether the corporation knew its product was destined for the forum state; (3) whether the assumption of jurisdiction would violate traditional notions of fair play; (4) whether the plaintiff could realistically bring suit in the alien forum; (5) whether the alien corporation set its product in the normal stream of commerce; and (6) whether an American corporation is an alter ego of the alien corporation. While these considerations are largely derived from the major cases in which suit was brought against foreign corporations in a particular state, the courts balance the same considerations and apply the same standards to alien corporations in determining whether jurisdiction is proper. However, it has been advocated that a different standard should be applied in cases where alien corporations are involved

    Effects of waterlogging on crop and pasture production in the Upper Great Southern, Western Australia

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    Separate estimates of the effect of waterlogging on cereal yields were made using rainfall and crop yield statistics, and remote sensing. Both methods showed that waterlogging costs tens of millions of dollars each year in lost crop production in the Upper Great Southern Statistical Division. The costs will be over $100 m in wet years. Losses in pasture production are likely to be of a similar magnitude, but are harder to quantify

    The natural hallucinogen 5-MeO-DMT, component of Ayahuasca, disrupts cortical function in rats: reversal by antipsychotic drugs

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    5-Methoxy-N, N-dimethyltryptamine (5-MeO-DMT) is a natural hallucinogen component of Ayahuasca, an Amazonian beverage traditionally used for ritual, religious and healing purposes that is being increasingly used for recreational purposes in US and Europe. 5MeO-DMT is of potential interest for schizophrenia research owing to its hallucinogenic properties. Two other psychotomimetic agents, phencyclidine and 2,5-dimethoxy-4-iodo-phenylisopropylamine (DOI), markedly disrupt neuronal activity and reduce the power of low frequency cortical oscillations (<4Hz, LFCO) in rodent medial prefrontal cortex (mPFC). Here we examined the effect of 5-MeO-DMT on cortical function and its potential reversal by antipsychotic drugs. Moreover, regional brain activity was assessed by blood-oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI). 5-MeO-DMT disrupted mPFC activity, increasing and decreasing the discharge of 51 and 35% of the recorded pyramidal neurons, and reducing (-31%) the power of LFCO. The latter effect depended on 5-HT1A and 5-HT2A receptor activation and was reversed by haloperidol, clozapine, risperidone, and the mGlu2/3 agonist LY379268. Likewise, 5-MeO-DMT decreased BOLD responses in visual cortex (V1) and mPFC. The disruption of cortical activity induced by 5-MeO-DMT resembles that produced by phencyclidine and DOI. This, together with the reversal by antipsychotic drugs, suggests that the observed cortical alterations are related to the psychotomimetic action of 5-MeO-DMT. Overall, the present model may help to understand the neurobiological basis of hallucinations and to identify new targets in antipsychotic drug development.Peer Reviewe

    Crystal Structure and Computational Analysis of a Two-Dimensional Coordination Polymer, BiI3(DppeO2)3/2

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    Catena-poly[fac-triiodobismuth(III)-tris-(µ-ethane-1,2-diylbis(diphenylphosphane oxide-κ2O,O′))], a 2-D sheet network of BiI3 was synthesized from BiI3 and ethane-1,2-diylbis(diphenylphosphane oxide) (DppeO2) in tetrahydrofuran. The crystal structure revealed a trigonal structure with three-fold symmetry at Bi. Bismuth centers show fac-BiI3O3 coordination, with Bi–I = 2.9416(2) Å and Bi–O = 2.4583(17) Å. The I–Bi–I and O–Bi–O angles (95.520(7)° and 79.04(6)°, respectively) indicate trigonal distortion in the Bi octahedron. Bridging DppeO2 ligands centered on inversion centers give rise to a 2-D sheet polymer. The 8.3 Å thick sheets consist of three layers in a sandwich structure. The outer layers are composed of phenyl rings and BiI3 groups with the iodide atoms pointing outward. The central layer consists of the O=PCH2CH2P=O bridging groups. Computational results suggest that semi-conducting behavior arises from Bi(III) centers. A halide to DppeO2 π* transition is suggested by theoretical results

    Modelling Braided River Morphodynamics Using a Particle Travel Length Framework

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    Numerical models that predict channel evolution are an essential tool for investigating processes that occur over timescales which render field observation intractable. The current generation of morphodynamic models, however, either oversimplify the relevant physical processes or, in the case of more physically complete codes based on computational fluid dynamics (CFD), have computational overheads that severely restrict the space–time scope of their application. Here we present a new, open-source, hybrid approach that seeks to reconcile these modelling philosophies. This framework combines steady-state, two-dimensional CFD hydraulics with a rule-based sediment transport algorithm to predict particle mobility and transport paths which are used to route sediment and evolve the bed topography. Data from two contrasting natural braided rivers (Rees, New Zealand, and Feshie, United Kingdom) were used for model verification, incorporating reach-scale quantitative morphological change budgets and volumetric assessment of different braiding mechanisms. The model was able to simulate 8 of the 10 empirically observed braiding mechanisms from the parameterized bed erosion, sediment transport, and deposition. Representation of bank erosion and bar edge trimming necessitated the inclusion of a lateral channel migration algorithm. Comparisons between simulations based on steady effective discharge versus event hydrographs discretized into a series of model runs were found to only marginally increase the predicted volumetric change, with greater deposition offsetting erosion. A decadal-scale simulation indicates that accurate prediction of event-scale scour depth and subsequent deposition present a methodological challenge because the predicted pattern of deposition may never “catch up” to erosion if a simple path-length distribution is employed, thus resulting in channel over-scouring. It may thus be necessary to augment path-length distributions to preferentially deposit material in certain geomorphic units. We anticipate that the model presented here will be used as a modular framework to explore the effect of different process representations, and as a learning tool designed to reveal the relative importance of geomorphic transport processes in rivers at multiple timescales
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