63 research outputs found

    COVID-19 lockdown : a global study investigating athletes’ sport classification and sex on training practices

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    PURPOSE : To investigate differences in athletes’ knowledge, beliefs, and training practices during COVID-19 lockdowns with reference to sport classification and sex. This work extends an initial descriptive evaluation focusing on athlete classification. METHODS : Athletes (12,526; 66% male; 142 countries) completed an online survey (May–July 2020) assessing knowledge, beliefs, and practices toward training. Sports were classified as team sports (45%), endurance (20%), power/technical (10%), combat (9%), aquatic (6%), recreational (4%), racquet (3%), precision (2%), parasports (1%), and others (1%). Further analysis by sex was performed. RESULTS : During lockdown, athletes practiced body-weight-based exercises routinely (67% females and 64% males), ranging from 50% (precision) to 78% (parasports). More sport-specific technical skills were performed in combat, parasports, and precision (∌50%) than other sports (∌35%). Most athletes (range: 50% [parasports] to 75% [endurance]) performed cardiorespiratory training (trivial sex differences). Compared to prelockdown, perceived training intensity was reduced by 29% to 41%, depending on sport (largest decline: ∌38% in team sports, unaffected by sex). Some athletes (range: 7%–49%) maintained their training intensity for strength, endurance, speed, plyometric, change-of-direction, and technical training. Athletes who previously trained ≄5 sessions per week reduced their volume (range: 18%–28%) during lockdown. The proportion of athletes (81%) training ≄60 min/session reduced by 31% to 43% during lockdown. Males and females had comparable moderate levels of training knowledge (56% vs 58%) and beliefs/attitudes (54% vs 56%). CONCLUSIONS : Changes in athletes’ training practices were sport-specific, with few or no sex differences. Team-based sports were generally more susceptible to changes than individual sports. Policy makers should provide athletes with specific training arrangements and educational resources to facilitate remote and/or home-based training during lockdown-type events.https://journals.humankinetics.com/view/journals/ijspp/ijspp-overview.xmlhj2023Sports Medicin

    Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star

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    Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

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    Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≀0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

    Ultralight vector dark matter search using data from the KAGRA O3GK run

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    Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

    Murder and Mutilation in Early-Stuart England: A Case Study in Crime Reporting

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    Although historians have long recognized that crime pamphlet authors were not very faithful reporters, it has been difficult for them to establish precisely how much fiction this literature contained because of the limited availability of other sources with which to compare them. Using a case study approach, this essay examines two murder pamphlets, both written in 1606, that describe the murder of a young boy, Anthony James, the mutilation of his sister, Elizabeth, and the conviction and execution of their alleged assailants, Agnes and George Dell. The presence of two pamphlets describing the same series of crimes was unusual, and, through a process of detailed comparison and critical interpretation, provides us with an opportunity to reflect further on the accuracy and purpose of crime reporting in early modern England. The two versions contain a great deal of contradictory information, were seemingly written for very different audiences, served a variety of functions for contemporary readers, and raise the question of whether the authors believed that justice was done in this case.Les historiens savent depuis longtemps que les auteurs de rĂ©cits de crime ne rapportaient pas fidĂšlement les faits, mais il demeure difficile pour eux d’estimer prĂ©cisĂ©ment la part de fiction dans ces Ă©crits en raison du manque de sources susceptibles d’en fournir une base comparative. Par une Ă©tude de cas, cet article se propose d’examiner deux brochures datĂ©es de 1606 relatant le meurtre d’un jeune garçon, Anthony James, la mutilation de sa soeur Elizabeth, de mĂȘme que la conviction et l’exĂ©cution de leurs supposĂ©s assaillants, Agnes et George Dell. La coexistence de deux brochures dĂ©crivant la mĂȘme sĂ©rie de crimes est inhabituelle; l’analyse comparative minutieuse et l’interprĂ©tation critique de ces rĂ©cits permettront de poursuivre la rĂ©flexion sur les notions d’exactitude et de pertinence dans la couverture des procĂšs criminels en Angleterre Ă  l’époque moderne. Les deux versions contenaient de nombreux dĂ©tails contradictoires; elles ciblaient de toute Ă©vidence des publics fort diffĂ©rents, remplissant une panoplie de fonctions pour les lecteurs contemporains, et, ultimement, soulĂšvent la question de savoir si les auteurs ont cru, en ce cas, que justice fut faite

    Strategic Culture:Framework for Analysis

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    https://thekeep.eiu.edu/den_1916_dec/1001/thumbnail.jp
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