921 research outputs found

    Reid on knowledge and justification in Physical Education

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    [FIRST PARAGRAPHS] To my knowledge, very little has been written on the educational justification of PE activities for the last decade. Since PE now does have a place on the National Curriculum, albeit arguably a minor one, the justification issue does seem to have been put on the back burner by the profession. In a recent and welcome addition to the literature, Reid revisits the debate, outlining two ‘conventional assumptions’ made by what he calls the ‘new orthodoxy’ in PE: 1. The ‘early Hirstian’ account3, which sees knowledge as propositional, and education as academic. When applied to PE, this suggests: 2. The distinction between practical performance and the ‘theory’ related to it - i.e. the propositional knowledge of Human Movement Science (HMS). The paper is a critique of these two assumptions, and a defence of the claim that PE ‘can indeed satisfy the knowledge requirements of education; but ... without making claims to academic significance’ (p95)

    Evidence for a Complex Mosaic Genome Pattern in a Full-length Hepatitis C Virus Sequence

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    The genome of the hepatitis C virus (HCV) exhibits a high genetic variability. This remarkable heterogeneity is mainly attributed to the gradual accumulation of mutational changes, whereas the contribution of recombination events to the evolution of HCV remains controversial so far. While performing phylogenetic analyses including a large number of sequences deposited in the GenBank, we encountered a full-length HCV sequence (AY651061) that showed evidence for inter-subtype recombination and was, therefore, subjected to a detailed analysis of its molecular structure. The obtained results indicated that AY651061 does not represent a “simple” HCV 1c isolate, but a complex 1a/1c mosaic genome, showing five putative breakpoints in the core to NS3 regions. To our knowledge, this is the first report on a mosaic HCV full-length sequence with multiple breakpoints. The molecular structure of AY651061 is reminiscent of complex homologous recombinant variants occurring among other members of the flaviviridae family, e.g. GB virus C, dengue virus, and Japanese encephalitis virus. Our finding of a mosaic HCV sequence may have important implications for many fields of current HCV research which merit careful consideration

    Evidence for the production of copper-complexing ligands by marine phytoplankton in the subarctic northeast Pacific

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    The availability and toxicity of copper (Cu) to marine phytoplankton involve complexation of Cu by dissolved organic ligands of uncertain origin and structure. As part of a GEOTRACES process study we used immobilized copper(II)-ion affinity chromatography (IMAC) to isolate and obtain information about the distribution and potential sources of Cu-complexing ligands along Line P in the subarctic northeast Pacific. Filtered seawater samples were collected from up to five stations during cruises in June 2016, June 2017, August 2017, and September 2018. Copper ligand concentrations were consistently higher at coastal station P4 than at other stations, particularly in surface waters. Ligand concentrations in the upper 40 m at station P26 increased between 2016 and 2018 following the 2014–2016 warming anomaly in the northeast Pacific, whereas an increase in ligand concentration from June to August 2017 coincided with seasonal increases in dissolved organic carbon (DOC) and net community production. At all stations, the depth of highest ligand concentration and maximum chlorophyll concentration coincided. A positive linear correlation between ligand and chlorophyll concentrations suggests that marine phytoplankton are a significant source of Cu ligands along Line P. The lower than expected ligand concentrations at station P26 in June 2016 are consistent with changes in phytoplankton ecology associated with the 2014–2016 warming anomaly. Comparing results from coastal and oceanic waters with those obtained previously in the Canadian Arctic suggests that terrigenous organic matter and marine humic substances contribute to the pool of Cu ligands captured by IMAC

    Seasonal occurrence of balanomorph barnacle nauplius larvae in the region of the Antarctic Peninsula

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    Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Experimental Marine Biology and Ecology 392 (2010): 125-128, doi:10.1016/j.jembe.2010.04.016.Plankton samples taken along the west coast of the Antarctic Peninsula and in Bransfield Strait show widespread occurrence of Bathylasma corolliforme nauplius larvae during the austral spring, mid-October to the third week of December. During autumn, between the first week of May and early June there was a complete absence of balanomorph nauplii. This evidence shows periodicity in reproduction. There is a seemingly close correlation between the presence of these nauplii and the published data on phytoplankton biomass and seawater surface temperature.The research was supported by grants from the U.S. National Science Foundation Office of Polar Programs

    Approach to the semiconductor cavity QED in high-Q regimes with q-deformed boson

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    The high density Frenkel exciton which interacts with a single mode microcavity field is dealed with in the framework of the q-deformed boson. It is shown that the q-defomation of bosonic commutation relations is satisfied naturally by the exciton operators when the low density limit is deviated. An analytical expression of the physical spectrum for the exciton is given by using of the dressed states of the cavity field and the exciton. We also give the numerical study and compare the theoretical results with the experimental resultsComment: 6 pages, 2 figure

    Electronic and Structural Properties of a 4d-Perovskite: Cubic Phase of SrZrO3_3

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    First-principles density functional calculations are performed within the local density approximation to study the electronic properties of SrZrO3_3, an insulating 4d-perovskite, in its high-temperature cubic phase, above 1400 K, as well as the generic 3d-perovskite SrTiO3_3, which is also a d^0-insulator and cubic above 105 K, for comparison reasons. The energy bands, density of states and charge density distributions are obtained and a detailed comparison between their band structures is presented. The results are discussed also in terms of the existing data in the literature for both oxides.Comment: 5 pages, 2 figure

    Host resistance to rat cytomegalovirus (RCMV) and immune function in adult PVG rats fed herring from the contaminated Baltic Sea

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    The immunotoxic potential of many classes of environmental contaminants has been well established in laboratory studies, with much attention being focussed on aryl hydrocarbon (Ah)-receptor binding polychlorinated biphenyl (PCB), polychlorinated dibenzo-p-dioxin (PCDD), and polychlorinated dibenzofuran (PCDF) congeners. In a semi-field study, we previously showed that harbour seals (Phoca vitulina) fed herring from the contaminated Baltic Sea had lower natural killer cell activity, T-lymphocyte functionality and delayed-type hypersensitivity responses than seals fed herring from the relatively uncontaminated Atlantic Ocean. While ethical and practical constraints preclude in-depth studies in seals, specific reagents and a wider array of immune function tests allow such studies in laboratory rats. We therefore carried out a feeding study in rats aimed at extending our observations of contaminant-induced immunosuppression in harbour seals. The same two herring batches used in the seal study were freeze-dried, supplemented and fed. to female adult PVG rats for a period of 4 1/4 months. Daily contaminant intakes of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalents (TEQ) were estimated to be 0.3 ng/kg body weight and 1.6 ng/kg in the Atlantic and Baltic groups, respectively. At the end of the feeding experiment, no contaminant-related changes in spleen CD4+/CD8+cellularity, natural killer cell activity, or mitogen-induced proliferative responses of thymus or spleen cells could be detected. However, total thymocyte numbers and thymus CD4+/CD8+ratios were reduced in the Baltic group. A novel model was established to assess the specific T-cell response to rat cytomegalovirus (RCMV). When applied to the feeding study, no differences between the Atlantic and Baltic groups in the RCMV-induced proliferative T-lymphocyte responses could be detected, but virus titres in salivary glands of infected rats of the Baltic Sea group were higher. These elevated RCMV titres and changes in thymus cellularity suggest that the dietary exposure to low levels of contaminants may have been immunotoxic at a level which our immune function test could not otherwise detect. While the herring diet per se appeared to have an effect on several immune function parameters, lower plasma thyroid hormone levels in the Baltic Sea group of rats confirmed that exposure to the environmental mixture of contaminants led to adverse PHAH-related health effects

    The Gluon Impact Factors

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    We calculate in the next-to-leading approximation the non-forward gluon impact factors for arbitrary color state in the tt-channel. In the case of the octet state we check the so-called "second bootstrap condition" for the gluon Reggeization in QCD, using the integral representation for the impact factors. The condition is fulfilled in the general case of an arbitrary space-time dimension and massive quark flavors for both helicity conserving and non-conserving parts.Comment: 32 pages, LaTeX, 1 EPS figure, uses epsf.sty and axodraw.st
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