236 research outputs found

    The effects of physical contact type on the internal and external demands during a rugby league match simulation protocol.

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Sports Sciences on 09/02/2016, available online: DOI: 10.1080/02640414.2016.1140907This study investigated how the type of contact influences physiological, perceptual and locomotive demands during a simulated rugby league match. Eleven male university rugby league players performed two trials of the rugby league movement simulation protocol for forwards (RLMSP-i) with a traditional soft tackle bag (BAG) and a weighted tackle sled (SLED) to replicate contact demands. Locomotive rate, sprint speed, tackle intensity, heart rate, rating of perceived exertion and blood lactate concentration were analysed in four periods during the first and second bout of both trials. Countermovement jump (CMJ) was measured before and immediately after each trial. More time was spent in heart rate zone between 90 – 100% HRpeak during the first (effect size ± 95% confidence interval: 0.44 ± 0.49) and second bout (0.44 ± 0.43), and larger (0.6 ± 0.69) decrements in CMJ performance were observed during SLED (5.9, s = 4.9%) compared to BAG (2.6, s = 5.4%). Sprint into contact speed was faster during BAG compared to SLED in the first (1.10 ± 0.92) and second bout (0.90 ± 0.90), which impaired high intensity running ability but did not increase physiological strain. Changing the type of contact during the match simulation subtly altered both the internal and external load on participants. These findings indicate that tackle training apparatus should be considered regarding the outcome of a training session

    Relation of C-reactive protein to body fat distribution and features of the metabolic syndrome in Europeans and South Asians.

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    OBJECTIVE: To investigate the association between circulating C-reactive protein (CRP) concentrations and indices of body fat distribution and the insulin resistance syndrome in South Asians and Europeans. DESIGN: : Cross-sectional study. SUBJECTS: A total of 113 healthy South Asian and European men and women in West London (age 40-55 y, body mass index (BMI) 17-34 kg/m(2)). MEASUREMENTS: Fatness and fat distribution parameters (by anthropometry, dual-energy X-ray absorptiometry and abdominal CT scan); oral glucose tolerance test with insulin response; modified fat tolerance test; and CRP concentration by sensitive ELISA. RESULTS: Median CRP level in South Asian women was nearly double that in European women (1.35 vs 0.70 mg/1, P=0.05). Measures of obesity and CRP concentration were significantly associated in both ethnic groups. The correlation to CRP was especially strong among South Asians (P0.15). CONCLUSION: We suggest that adiposity and in particular visceral adipose tissue is a key promoter of low-grade chronic inflammation. This observation may in part account for the association of CRP with markers of the metabolic syndrome. Future studies should confirm whether CRP concentrations are elevated in South Asians and whether losing weight by exercise or diet, or reduction in visceral fat mass, is associated with reduction in plasma CRP concentrations

    Dynamics of transmission of Plasmodium falciparum by Anopheles arabiensis and the molecular forms M and S of Anopheles gambiae in Dielmo, Senegal

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    <p>Abstract</p> <p>Background</p> <p>The adaptation of <it>Anopheles gambiae </it>to humans and its environment involves an ongoing speciation process that can be best demonstrated by the existence of various chromosomal forms adapted to different environments and of two molecular forms known as incipient taxonomic units.</p> <p>Methods</p> <p>The aim of this study was to compare the epidemiologic role of <it>Anopheles arabiens </it>is and the molecular forms M and S of <it>Anopheles gambiae </it>in the transmission of Plasmodium in a rural areas of southern Senegal, Dielmo. The sampling of mosquitoes was carried out monthly between July and December 2004, during the rainy season, by human volunteers and pyrethrum spray catches.</p> <p>Results</p> <p><it>Anopheles arabiensis</it>, <it>An. gambiae </it>M and S forms coexisted during the rainy season with a predominance of the M form in September and the peak of density being observed in August for the S form. Similar parity rates were observed in <it>An. arabiensis </it>[70.9%] (n = 86), <it>An</it>. <it>gambiae </it>M form [68.7%] (n = 64) and <it>An</it>. <it>gambiae </it>S form [81.1%] (n = 156). The circumsporozoite protein (CSP) rates were 2.82% (n = 177), 3.17% (n = 315) and 3.45% (n = 405), with the mean anthropophilic rates being 71.4% (n = 14), 86.3% (n = 22) and 91.6% (n = 24) respectively for <it>An</it>. <it>arabiensis </it>and <it>An</it>. <it>gambiae </it>M and S forms. No significant difference was observed either in host preference or in <it>Plasmodium falciparum </it>infection rates between sympatric M and S populations.</p> <p>Conclusion</p> <p>No difference was observed either in host preference or in <it>Plasmodium falciparum </it>infection rates between sympatric M and S populations, but they present different dynamics of population. These variations are probably attributable to different breeding conditions.</p

    Using Population Genetic Theory and DNA Sequences for Species Detection and Identification in Asexual Organisms

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    It is widely agreed that species are fundamental units of biology, but there is little agreement on a definition of species or on an operational criterion for delimiting species that is applicable to all organisms.We focus on asexual eukaryotes as the simplest case for investigating species and speciation. We describe a model of speciation in asexual organisms based on basic principles of population and evolutionary genetics. The resulting species are independently evolving populations as described by the evolutionary species concept or the general lineage species concept. Based on this model, we describe a procedure for using gene sequences from small samples of individuals to assign them to the same or different species. Using this method of species delimitation, we demonstrate the existence of species as independent evolutionary units in seven groups of invertebrates, fungi, and protists that reproduce asexually most or all of the time.This wide evolutionary sampling establishes the general existence of species and speciation in asexual organisms. The method is well suited for measuring species diversity when phenotypic data are insufficient to distinguish species, or are not available, as in DNA barcoding and environmental sequencing. We argue that it is also widely applicable to sexual organisms

    First evidence of Renlandian (c. 950–940 Ma) orogeny in mainland Scotland:Implications for the status of the Moine Supergroup and circum-North Atlantic correlations

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    Central problems in the interpretation of the Neoproterozoic geology of the North Atlantic region arise from uncertainties in the ages of, and tectonic drivers for, Tonian orogenic events recorded in eastern Laurentia and northern Baltica. The identification and interpretation of these events is often problematic because most rock units that record Tonian orogenesis were strongly reworked at amphibolite facies during the Ordovician-Silurian Caledonian orogeny. Lu-Hf and Sm-Nd geochronology and metamorphic modelling carried out on large (>1 cm) garnets from the Meadie Pelite in the Moine Nappe of the northern Scottish Caledonides indicate prograde metamorphism between 950 and 940 Ma at pressures of 6–7 kbar and temperatures of 600 °C. This represents the first evidence for c. 950 Ma Tonian (Renlandian) metamorphism in mainland Scotland and significantly extends its geographic extent along the palaeo-Laurentian margin. The Meadie Pelite is believed to be part of the Morar Group within the Moine Supergroup. If this is correct: 1) the Morar Group was deposited between 980 ± 4 Ma (age of the youngest detrital zircon; Peters, 2001, youngest published zircon date is 947 ± 189 (Friend et al., 2003)) and c. 950 Ma (age of regional metamorphism reported here), 2) an orogenic unconformity must separate the Morar Group from the 883 ± 35 Ma (Cawood et al., 2004) Glenfinnan and Loch Eil groups, and 3) the term ‘Moine Supergroup’ may no longer be appropriate. The Morar Group is broadly correlative with similar aged metasedimentary successions in Shetland, East Greenland, Svalbard, Ellesmere Island and northern Baltica. All these successions were deposited after c. 1030 Ma, contain detritus from the Grenville orogen, and were later deformed and metamorphosed at 950–910 Ma during accretionary Renlandian orogenesis along an active plate margin developed around this part of Rodinia

    Neoproterozoic to early Paleozoic extensional and compressional history of East Laurentian margin sequences: The Moine Supergroup, Scottish Caledonides

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    Neoproterozoic siliciclastic-dominated sequences are widespread along the eastern margin of Laurentia and are related to rifting associated with the breakout of Laurentia from the supercontinent Rodinia. Detrital zircons from the Moine Supergroup, NW Scotland, yield Archean to early Neoproterozoic U-Pb ages, consistent with derivation from the Grenville-Sveconorwegian orogen and environs and accumulation post–1000 Ma. U-Pb zircon ages for felsic and associated mafic intrusions confirm a widespread pulse of extension-related magmatism at around 870 Ma. Pegmatites yielding U-Pb zircon ages between 830 Ma and 745 Ma constrain a series of deformation and metamorphic pulses related to Knoydartian orogenesis of the host Moinerocks. Additional U-Pb zircon and monazite data, and 40Ar/39Ar ages for pegmatites and host gneisses indicate high-grade metamorphic events at ca. 458–446 Ma and ca. 426 Maduring the Caledonian orogenic cycle.The presence of early Neoproterozoic silici clastic sedimentation and deformation in the Moine and equivalent successions around the North Atlantic and their absence along strike in eastern North America reflect contrasting Laurentian paleogeography during the breakup of Rodinia. The North Atlantic realm occupied an external location on the margin of Laurentia, and this region acted as a locus for accumulation of detritus (Moine Supergroup and equivalents) derived from the Grenville-Sveconorwegian orogenic welt, which developed as a consequence of collisional assembly of Rodinia. Neoproterozoic orogenic activity corresponds with theinferred development of convergent platemargin activity along the periphery of the supercontinent. In contrast in eastern North America, which lay within the internal parts of Rodinia, sedimentation did not commence until the mid-Neoproterozoic (ca. 760 Ma) during initial stages of supercontinent fragmentation. In the North Atlantic region, this time frame corresponds to a second pulse of extension represented by units such as the Dalradian Supergroup, which unconformably overlies the predeformed Moine succession
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