302 research outputs found

    Caffeine increases strength and power performance in resistance‐trained females during early follicular phase

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    The effects of 4 mg·kg‐1caffeine ingestion on strength and power were investigated for the first time, in resistance‐trained females during the early follicular phase utilizing a randomized, double‐blind, placebo‐controlled, crossover design. Fifteen females (29.8±4.0 years, 63.8±5.5 kg [mean±SD]) ingested caffeine or placebo 60 minutes before completing a test battery separated by 72 hours. One‐repetition maximum (1RM), repetitions to failure (RTF) at 60% of 1RM, were assessed in the squat and bench press. Maximal voluntary contraction torque (MVC) and rate of force development (RFD) were measured during isometric knee‐extensions, while utilizing interpolated twitch technique to measure voluntary muscle activation. Maximal power and jump height were assessed during countermovement jumps (CMJ). Caffeine metabolites were measured in plasma. Adverse effects were registered after each trial. Caffeine significantly improved squat (4.5±1.9%, effect size [ES]: 0.25) and bench press 1RM (3.3±1.4%, ES: 0.20), and squat (15.9±17.9%, ES: 0.31) and bench press RTF (9.8±13.6%, ES: 0.31), compared to placebo. MVC torque (4.6±7.3%, ES: 0.26), CMJ height (7.6±4.0%, ES: 0.50) and power (3.8±2.2%, ES: 0.24) were also significantly increased with caffeine. There were no differences in RFD or muscle activation. Plasma [caffeine] was significantly increased throughout the protocol and mild side‐effects of caffeine were experienced by only 3 participants. This study demonstrated that 4 mg·kg‐1 caffeine ingestion enhanced maximal strength, power and muscular endurance in resistance‐trained and caffeine‐habituated females during the early follicular phase, with few adverse effects. Female strength and power athletes may consider using this dose pre‐competition and ‐training as an effective ergogenic aid

    Capturing metal-support interactions in situ during the reduction of a Re promoted Co/γ-Al<sub>2</sub>O<sub>3</sub> catalyst

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    The diffusion of Co2+ cations into the γ-Al2O3 support is probed during the reduction of a Re/Co/γ-Al2O3 catalyst by in situ by synchrotron X-ray powder diffraction resulting in the expansion of its crystal lattice.</p

    Antithrombotic treatment after intracerebral hemorrhage: Surveys among stroke physicians in Scandinavia and the United Kingdom

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    BACKGROUND AND AIMS: It is unclear whether patients with previous intracerebral hemorrhage (ICH) should receive antithrombotic treatment to prevent ischemic events. We assessed stroke physicians' opinions about this, and their views on randomizing patients in trials assessing this question. METHODS: We conducted three web‐based surveys among stroke physicians in Scandinavia and the United Kingdom. RESULTS: Eighty‐nine of 205 stroke physicians (43%) responded to the Scandinavian survey, 161 of 180 (89%) to the UK antiplatelet survey, and 153 of 289 (53%) to the UK anticoagulant survey. In Scandinavia, 19 (21%) stroke physicians were uncertain about antiplatelet treatment after ICH for ischemic stroke or transient ischemic attack (TIA) and 21 (24%) for prior myocardial infarction. In the United Kingdom, 116 (77%) were uncertain for ischemic stroke or TIA and 115 (717%) for ischemic heart disease. In Scandinavia, 32 (36%) were uncertain about anticoagulant treatment after ICH for atrial fibrillation, and 26 (29%) for recurrent deep vein thrombosis or pulmonary embolism. In the United Kingdom, 145 (95%) were uncertain about anticoagulants after ICH in at least some cases. In both regions combined, 191 of 250 (76%) would consider randomizing ICH survivors in a trial of starting versus avoiding antiplatelets, and 176 of 242 (73%) in a trial of starting versus avoiding anticoagulants. CONCLUSION: Considerable proportions of stroke physicians in Scandinavia and the United Kingdom were uncertain about antithrombotic treatment after ICH. A clear majority would consider randomizing patients in trials assessing this question. These findings support the need for such trials

    The stroke oxygen pilot study: a randomized control trial of the effects of routine oxygen supplementation early after acute stroke--effect on key outcomes at six months

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    Introduction: Post-stroke hypoxia is common, and may adversely affect outcome. We have recently shown that oxygen supplementation may improve early neurological recovery. Here, we report the six-month outcomes of this pilot study. Methods: Patients with a clinical diagnosis of acute stroke were randomized within 24 h of admission to oxygen supplementation at 2 or 3 L/min for 72 h or to control treatment (room air). Outcomes (see below) were assessed by postal questionnaire at 6 months. Analysis was by intention-to-treat, and statistical significance was set at p#0.05. Results: Out of 301 patients randomized two refused/withdrew consent and 289 (148 in the oxygen and 141 in the control group) were included in the analysis: males 44%, 51%; mean (SD) age 73 (12), 71 (12); median (IQR) National Institutes of Health Stroke Scale score 6 (3, 10), 5 (3, 10) for the two groups respectively. At six months 22 (15%) patients in the oxygen group and 20 (14%) in the control group had died; mean survival in both groups was 162 days (p= 0.99). Median (IQR) scores for the primary outcome, the modified Rankin Scale, were 3 (1, 5) and 3 (1, 4) for the oxygen and control groups respectively. The covariate-adjusted odds ratio was 1.04 (95% CI 0.67, 1.60), indicating that the odds of a lower (i.e. better) score were non-significantly higher in the oxygen group (p= 0.86). The mean differences in the ability to perform basic (Barthel Index) and extended activities of daily living (NEADL), and quality of life (EuroQol) were also non-significant. Conclusions: None of the key outcomes differed at 6 months between the groups. Although not statistically significant and generally of small magnitude, the effects were predominantly in favour of the oxygen group; a larger trial, powered to show differences in longer-term functional outcomes, is now on-going. Trial Registration: Controlled-Trials.com ISRCTN12362720; Eudract.ema.europa.eu 2004-001866-4

    Long‐distance dispersal in the short‐distance dispersing house sparrow ( Passer domesticus )

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    The house sparrow (Passer domesticus) is a small passerine known to be highly sedentary. Throughout a 30‐year capture–mark–recapture study, we have obtained occasional reports of recoveries far outside our main metapopulation study system, documenting unusually long dispersal distances. Our records constitute the highest occurrence of long‐distance dispersal events recorded for this species in Scandinavia. Such long‐distance dispersals radically change the predicted distribution of dispersal distances and connectedness for our study metapopulation. Moreover, it reveals a much greater potential for colonization than formerly recorded for the house sparrow, which is an invasive species across four continents. These rare and occasional long‐distance dispersal events are challenging to document but may have important implications for the genetic composition of small and isolated populations and for our understanding of dispersal ecology and evolution
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