222 research outputs found

    One-repetition-maximum measures or maximum bar-power output: which Is more related to sport performance?

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    Purpose: This study compared the associations between optimum power loads and 1-repetition maximum (1RM) values (assessed in half-squat [HS] and jump squat [JS] exercises) and multiple performance measures in elite athletes. Methods: Sixty-one elite athletes (fifteen Olympians) from four different sports (track and field [sprinters and jumpers], rugby sevens, bobsled, and soccer) performed squat and countermovement jumps, HS exercise (for assessing 1RM), HS and JS exercises (for assessing bar-power output), and sprint tests (60-m for sprinters and jumpers and 40-m for the other athletes). Pearson’s product moment correlation test was used to determine relationships between 1RM and bar-power outputs with vertical jumps and sprint times in both exercises. Results: Overall, both measurements were moderately to near perfectly related to speed performance (r values varying from -0.35 to -0.69 for correlations between 1RM and sprint times, and from -0.36 to -0.91 for correlations between bar-power outputs and sprint times; P< 0.05). However, on average, the magnitude of these correlations was stronger for power-related variables, and only the bar-power outputs were significantly related to vertical jump height. Conclusions: The bar-power outputs were more strongly associated with sprint-speed and power performance than the 1RM measures. Therefore, coaches and researchers can use the bar-power approach for athlete testing and monitoring. Due to the strong correlations presented, it is possible to infer that meaningful variations in bar-power production may also represent substantial changes in actual sport performance

    Mjerenje radona u vodi radi predviđanja potresa u Sloveniji

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    Radon (222Rn) concentration in water of several thermal springs was measured with the aim of obtaining a correlation with the seismic activity of the region. Though a qualitative correlation was found for a spring with deep water circulation, we are far from being able to predict either the time or the place of an earthquake. An additional study with more relevant sampling sites and more frequent water analyses would be necessary to achieve this.Mjerili smo količinu radona (222Rn) u vodi iz više izvora radi utvrđivanja moguće korelacije sa seizmičkom aktivnosti u Sloveniji. Iako smo našli kvalitativnu korelaciju za jedan izvor s dubokim kruženjem vode, nismo još u mogućnosti predvidjeti mjesto ili vrijeme potresa. Za to su potrebna proširena mjerenja na više mjesta i sa češćim uzorkovanjem vode

    Mjerenje radona u vodi radi predviđanja potresa u Sloveniji

    Get PDF
    Radon (222Rn) concentration in water of several thermal springs was measured with the aim of obtaining a correlation with the seismic activity of the region. Though a qualitative correlation was found for a spring with deep water circulation, we are far from being able to predict either the time or the place of an earthquake. An additional study with more relevant sampling sites and more frequent water analyses would be necessary to achieve this.Mjerili smo količinu radona (222Rn) u vodi iz više izvora radi utvrđivanja moguće korelacije sa seizmičkom aktivnosti u Sloveniji. Iako smo našli kvalitativnu korelaciju za jedan izvor s dubokim kruženjem vode, nismo još u mogućnosti predvidjeti mjesto ili vrijeme potresa. Za to su potrebna proširena mjerenja na više mjesta i sa češćim uzorkovanjem vode

    Personality Traits in Miners with Past Occupational Elemental Mercury Exposure

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    In this study, we evaluated the impact of long-term occupational exposure to elemental mercury vapor (Hg(0)) on the personality traits of ex-mercury miners. Study groups included 53 ex-miners previously exposed to Hg(0) and 53 age-matched controls. Miners and controls completed the self-reporting Eysenck Personality Questionnaire and the Emotional States Questionnaire. The relationship between the indices of past occupational exposure and the observed personality traits was evaluated using Pearson’s correlation coefficient and on a subgroup level by machine learning methods (regression trees). The ex-mercury miners were intermittently exposed to Hg(0) for a period of 7–31 years. The means of exposure-cycle urine mercury (U-Hg) concentrations ranged from 20 to 120 μg/L. The results obtained indicate that ex-miners tend to be more introverted and sincere, more depressive, more rigid in expressing their emotions and are likely to have more negative self-concepts than controls, but no correlations were found with the indices of past occupational exposure. Despite certain limitations, results obtained by the regression tree suggest that higher alcohol consumption per se and long-term intermittent, moderate exposure to Hg(0) (exposure cycle mean U-Hg concentrations > 38.7 < 53.5 μg/L) in interaction with alcohol remain a plausible explanation for the depression associated with negative self-concept found in subgroups of ex-mercury miners. This could be one of the reason for the higher risk of suicide among miners of the Idrija Mercury Mine in the last 45 years

    Muon content of ultra-high-energy air showers: Yakutsk data versus simulations

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    We analyse a sample of 33 extensive air showers (EAS) with estimated primary energies above 2\cdot 10^{19} eV and high-quality muon data recorded by the Yakutsk EAS array. We compare, event-by-event, the observed muon density to that expected from CORSIKA simulations for primary protons and iron, using SIBYLL and EPOS hadronic interaction models. The study suggests the presence of two distinct hadronic components, ``light'' and ``heavy''. Simulations with EPOS are in a good agreement with the expected composition in which the light component corresponds to protons and the heavy component to iron-like nuclei. With SYBILL, simulated muon densities for iron primaries are a factor of \sim 1.5 less than those observed for the heavy component, for the same electromagnetic signal. Assuming two-component proton-iron composition and the EPOS model, the fraction of protons with energies E>10^{19} eV is 0.52^{+0.19}_{-0.20} at 95% confidence level.Comment: 8 pages, 3 figures; v2: replaced with journal versio

    Post‐activation potentiation: is there an optimal training volume and intensity to Induce improvements in vertical jump ability in highly‐trained subjects?

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    The aim of this study was to compare the acute effects of performing half squats (HSs) with different loading intensities (1, 3, and 5 repetitions maximum [RM], and 60% 1RM) and a different number of sets (1, 2, and 3) on the countermovement jump (CMJ) performance of 18 highly‐trained male subjects. Participants were submitted to four experimental conditions (1RM, 3RM, 5RM, and 60% 1RM) in randomized order. The CMJ was assessed before and after each set. Differences in CMJ performance between the distinct experimental conditions and individual responses in CMJ performance induced by the different protocols were analyzed via the magnitude‐based inference method. Overall, significant improvements were detected in individual CMJ heights after each activation protocol. It can be concluded that the use of 1 to 3 sets of HSs performed at moderate‐to‐high loads may be an effective strategy to improve jump performance in highly‐trained subjects. Nonetheless, despite the high efficiency of the protocols tested here, coaches and researchers are strongly encouraged to perform individualized assessments within the proposed range of loads and sets, to find optimal and tailored post‐activation potentiation protocols

    Post-activation potentiation: is there an optimal training volume and intensity to induce improvements in vertical jump ability in highly-trained subjects?

    Get PDF
    The aim of this study was to compare the acute effects of performing half squats (HSs) with different loading intensities (1, 3, and 5 repetitions maximum [RM], and 60% 1RM) and a different number of sets (1, 2, and 3) on the countermovement jump (CMJ) performance of 18 highly-trained male subjects. Participants were submitted to four experimental conditions (1RM, 3RM, 5RM, and 60% 1RM) in randomized order. The CMJ was assessed before and after each set. Differences in CMJ performance between the distinct experimental conditions and individual responses in CMJ performance induced by the different protocols were analyzed via the magnitude-based inference method. Overall, significant improvements were detected in individual CMJ heights after each activation protocol. It can be concluded that the use of 1 to 3 sets of HSs performed at moderate-to-high loads may be an effective strategy to improve jump performance in highly-trained subjects. Nevertheless, despite the high efficiency of the protocols tested here, coaches and researchers are strongly encouraged to perform individualized assessments within the proposed range of loads and sets, to find optimal and tailored post-activation potentiation protocols

    PHOTON BEAMLINE CONTROL SYSTEM AS A PRODUCT

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    Abstract Every beamline is different, which makes it impossible to buy a control system off the shelf. Nevertheless well tested and customizable building blocks can be prepared, which are then put together according to customer requirements. Delivering a fully operational control system is not just software development, but also gathering specifications, writing documentation, testing the hardware and trimming the software on site. Based on the delivery of a number of working beamline control systems, this paper will prove that we have optimized all stages and can guarantee that the purchased control system will be delivered on time, will work according to specifications and will be properly documented. The customers can also count on support

    Dissociated Representations of Pleasant and Unpleasant Olfacto-Trigeminal Mixtures: An fMRI Study

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    How the pleasantness of chemosensory stimuli such as odorants or intranasal trigeminal compounds is processed in the human brain has been the focus of considerable recent interest. Yet, so far, only the unimodal form of this hedonic processing has been explored, and not its bimodal form during crossmodal integration of olfactory and trigeminal stimuli. The main purpose of the present study was to investigate this question. To this end, functional magnetic resonance imaging (fMRI) was used in an experiment comparing brain activation related to a pleasant and a relatively unpleasant olfacto-trigeminal mixture, and to their individual components (CO2 alone, Orange alone, Rose alone). Results revealed first common neural activity patterns in response to both mixtures in a number of regions: notably the superior temporal gyrus and the caudate nucleus. Common activations were also observed in the insula, although the pleasant mixture activated the right insula whereas the unpleasant mixture activated the left insula. However, specific activations were observed in anterior cingulate gyrus and the ventral tegmental area only during the perception of the pleasant mixture. These findings emphasized for the firs time the involvement of the latter structures in processing of pleasantness during crossmodal integration of chemosensory stimuli
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