333 research outputs found

    CENTRAL FATIGUE AFTER PROLONGED RUNNING

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    Fatigue can be caused by a failure in neural activation (central) and/or in force generating capacity of the muscle (peripheral). Using the twitch interpolation technique, central fatigue was demonstrated after prolonged running in the knee extensors (Millet et al., 2003), but not in the plantar flexor muscle group (Finni et al., 2003; Racinais et al., 2006) despite marked involvement in running propulsion. However, the paradigm in the latter studies appears to have limited the testing only to parts of the triceps surae. Therefore, the aim of this study was to use the twitch interpolation technique to investigate central and peripheral fatigue in the entire plantar flexor muscle group after prolonged running

    Regionalization of Flood Data Using Probability Distributions and Their Parameters

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    The U. S. Geological survey recently used the method of residuals to delineate seven flood regions for the State of Kentucky. As an alternative approach, the FASTCLUS clustering procedure of the Statistical Analysis system (SAS) is used in this study to delineate five to six cluster regions in conjunction with statistical properties of the AMF series, like the coefficient of variation as estimated using method of L-moments, LCV, the parameters of the EVl and GEV flood frequency distributions, and the specific mean annual flood, QSP. For both cluster and USGS flood regions, regionalized flood frequency growth curves are developed and their performance evaluated using Monte Carlo simulation techniques. Flood regions are.then evaluated and compared ·using trends in the hydrological characteristics of important.variables, performance of the regionalized flood frequency growth curves, discriminant analysis and regression equations relating flood quantiles to watershed physical characteristics. Results show that the cluster regions are more distinguishable in terms of their flood characteristics than the USGS regions. The.regionalized flood frequency growth curves of the EVl and GEV model are more distinct for the cluster regions than the USGS regions, although their performance in terms of bias and RMSE are comparable. The standard errors associated with the regression equations, developed for predicting the EVl and GEV flood quantiles, are similar for cluster and USGS regions

    Parameter-sparse modification of Fourier methods to analyse the shape of closed contours with application to otolith outlines

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    -Elliptical Fourier descriptors (EFDs) have been used extensively in shape analysis of closed contours and have a range of marine applications, such as automatic identification of fish species and discrimination between fish stocks based on EFDs of otolith contours. A recent method (the ‘MIRR’ method) transforms the two-dimensional contour to a one-dimensional function by mirroring (reflecting) the lower half of the contour around a vertical axis at the right end of the contour. MIRR then applies the fast Fourier transform (FFT) to the vertical contour points corresponding to equidistant coordinate values along the horizontal axis. MIRR has the advantage of reducing the number of Fourier coefficients to two coefficients per frequency component compared with four EFDs. However, both Fourier methods require several frequency components to reproduce a pure ellipse properly. This paper shows how the methods can be easily modified so that a virtually perfect reproduction of a pure ellipse is obtained with only one frequency component. In addition, real otolith examples for cod (Gadus morhua) and Greenland halibut (Reinhardtius hippoglossoides) are used to demonstrate that the modified methods give better approximations to the large-scale shape of the original contour with fewer coefficients than the traditional Fourier methods, with negligible additional computing time

    Reading religion in Norwegian textbooks: are individual religions ideas or people?

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    Different religions are treated in different ways in Norwegian sixth form textbooks. We carried out an exhaustive content analysis of the chapters devoted to individual religions in textbooks for the Religion and Ethics course currently available in Norway, using rigorous indicators to code each word, image and question according to whether they were treated the religion as a set of ideas or a group of people. After adjusting for trends in the different kinds of data (word, image, question), we found that Buddhism and Christianity receive significantly more attention for their ideas than Hinduism, Islam and Judaism, which are treated more as people. This difference cannot be explained by the national syllabus or the particularities of the individual religions. The asymmetry also has implications for the pupils’ academic, moral and pedagogical agency for which teachers play a critical role in compensating.acceptedVersio

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration
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