586 research outputs found

    Nitrate stable isotopes and major ions in snow and ice samples from four Svalbard sites

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    Increasing reactive nitrogen (N-r) deposition in the Arctic may adversely impact N-limited ecosystems. To investigate atmospheric transport of N-r to Svalbard, Norwegian Arctic, snow and firn samples were collected from glaciers and analysed to define spatial and temporal variations (1 10 years) in major ion concentrations and the stable isotope composition (delta N-15 and delta O-18) of nitrate (NO3-) across the archipelago. The delta N-15(NO3-) and delta O-18(NO3-) averaged -4 parts per thousand and 67 parts per thousand in seasonal snow (2010-11) and -9 parts per thousand and 74 parts per thousand in firn accumulated over the decade 2001-2011. East-west zonal gradients were observed across the archipelago for some major ions (non-sea salt sulphate and magnesium) and also for delta N-15(NO3-) and delta O-18(NO3-) in snow, which suggests a different origin for air masses arriving in different sectors of Svalbard. We propose that snowfall associated with long-distance air mass transport over the Arctic Ocean inherits relatively low delta N-15(NO3-) due to in-transport N isotope fractionation. In contrast, faster air mass transport from the north-west Atlantic or northern Europe results in snowfall with higher delta N-15(NO3-) because in-transport fractionation of N is then time-limited

    The efficacy of a β-hydroxy-β-methylbutyrate supplementation on physical capacity, body composition and biochemical markers in elite rowers: a randomised, double-blind, placebo-controlled crossover study

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    BACKGROUND: β-hydroxy-β-methylbutyric acid (HMB) is an interesting supplement in sports. However, literature sources present a limited number of studies that verify the efficacy of HMB intake over a longer time period among endurance athletes. For this reason, the aim of this study was to assess the effect of HMB supplementation on physical capacity, body composition and levels of biochemical markers in rowers. METHODS: Sixteen elite male rowers were administered a 12-week HMB supplementation (3×1 g(HMB) · day(−1)) and placebo administration (PLA) following the model of a randomised, placebo controlled, double-blind crossover study with a 10 days washout period. Over the course of the experiment, aerobic (maximal oxygen uptake, ventilatory threshold) and anaerobic (anaerobic power indices) capacity were determined, while analyses were conducted on body composition as well as levels of creatine kinase, lactate dehydrogenase, testosterone, cortisol and the T/C ratio. A normal distribution of variables was tested using the paired 2-tailed t-tests; the Mann–Whitney U-test or the Wilcoxon-signed rank test were applied for non-normally distributed variables. RESULTS: Following HMB supplementation, [Formula: see text] increased (+2.7 mL · min(−1) · kg(−1)) significantly (p < 0.001) in comparison to its reduction after PLA (−1.0 mL · min(−1) · kg(−1)). In turn, at the ventilatory threshold, a longer time was required to reach this point (+1.2 min(HMB) vs. −0.2 min(PLA), p = 0.012), while threshold load (+0.42 W · kg(−1)(HMB) vs. −0.06 W · kg(−1)(PLA), p = 0.002) and threshold heart rate (+9 bpm(HMB) vs. +1 bpm(PLA), p < 0.001) increased. After HMB supplementation, fat mass decreased (−0.9 kg(HMB) vs. +0.8 kg(PLA), p = 0.03). In relation to the initial values after HMB supplementation, the refusal time to continue in the progressive test was extended (p = 0.04), maximum load (p = 0.04) and anaerobic peak power (p = 0.02) increased. However, in relation to the placebo, no differences were observed in anaerobic adaptation or blood marker levels. CONCLUSIONS: The results indicate that HMB intake in endurance training has an advantageous effect on the increase in aerobic capacity and the reduction of fat mass. It may also stimulate an increase in peak anaerobic power, while it seems to have no effect on other indices of anaerobic adaptation and levels of investigated markers in the blood

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    Zorganizowana skrzeplina w lewej komorze powstała po zabiegu przezskórnej angioplastyki wieńcowej mimo stosowanej podwójnej terapii przeciwpłytkowej

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    Myocardial infarction is an acute condition which can lead to many complications in a postinfarct period (MI, myocardial infarction). Left ventricular thrombus formation after successful primary percutaneous coronary intervention (PCI) with stenting and treating with dual antiplatelet therapy nowadays is a less common finding especially in absence of severe left ventricular dysfunction associated with MI. Case of 70-year-old male who was admitted to the Emergency Department with severe MI treating with successful primary PCI with stenting and dual antiplatelet therapy with a new unexpected finding of thrombus in the left ventricular apex observed in control of the echocardiography examination during hospitalisation despite dual antiplatelet therapy.Zawał serca jest stanem ostrym, który może prowadzić do licznych powikłań we wczesnym okresie pozawałowym.Występowanie skrzepliny w lewej komorze u pacjentów po skutecznej pierwotnej przezskórnej angioplastyce (PCI) z implantacją stentu i zastosowaniu podwójnej terapii przeciwpłytkowej (DAPT) w obecnych czasach jest mniej powszechnym zjawiskiem, zwłaszcza u osób bez ciężkiej pozawałowej dysfunkcji mięśnia lewej komory. Zaprezentowano przypadek 70-letniego mężczyzny, przyjętego do kliniki z prezentacją ostrego zespołu wieńcowego leczonego skuteczną pierwotną PCI z implantacją stentu i zastosowaniem DAPT, u którego, mimo zastosowanej terapii, w kolejnych badaniach echokardiograficznych podczas hospitalizacji obserwowano skrzeplinę w koniuszku lewej komory

    Jumping abilities in elite female volleyball players: comparative analysis among age categories

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    The aim of the study was to examine age-related differences in the maximal power and height of rise of the body’s centre of mass, measured in the counter-movement jump (CMJ) and the spike jump (SPJ), between elite cadet, junior and senior female volleyball players. The study was conducted on elite cadet (n=39), junior (n=8) and senior (n=23) female volleyball players. The maximal power and height of jumps were measured for CMJ and SPJ. Cadets had a significantly smaller maximal relative power output (40.92±8.10 W • kg–1) than junior (49.47±6.47 W • kg–1) and senior (46.70±8.95 W • kg–1) volleyball players during SPJ. The height of rise of the centre of mass measured in CMJ and SPJ were similar between groups. Our research has shown that age-related differences were observed only in power output of SPJ. The differences between elite cadet, junior and senior female volleyball players were not statistically significant in relation to height of jumps (both CMJ and SPJ), and maximal power in CMJ

    Changes in physiological and biomechanical variables in women practicing the Power Yoga system

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    Study aim: To investigate changes in selected indices of anaerobic capacity, the ability to maintain body balance and the height of elevating body’s centre of mass, and maximum power output in lower limbs during countermovement jump (CMJ) after 6 months of participation in yoga classes in Ashtanga Vinyasa system (Power Yoga). Material and methods: The study included 24 untrained women who volunteered to participate in a half-year experiment. The analysis focused on 12 women who participated in the classes until the experiment ended. The Wingate test was used to evaluate anaerobic capacity. In order to measure the functional state of vestibular organ the authors used a stabilographic method. Measurements of power output in the lower limbs and the height of elevation of the centre of mass in CMJ jumps were carried out using a dynamometric platform. Results: The 6 months of training in the Power Yoga system considerably improved the height of CMJ jumps from 0.276 ± 0.048 m to 0.308 ± 0.038 m (p0.05). Conclusions: Practicing Power Yoga does not induce changes in the anaerobic capacity and the functional state of the vestibular organ in women
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