98 research outputs found
The effect of carbohydrate ingestion on the motor skill proficiency of soccer players
This study examined the effects of ingesting a glucose-polymer (GP) solution on the motor skill proficiencies of association football (soccer) players from two teams playing during two matches in a cool environment. Fifteen minutes before each match and at halftime, players from both teams ingested 5 ml/kg of either placebo or a 6.9% GP solution. GP ingestion did not improve tackling, heading, dribbling, or shooting ability. On the contrary, the mean of successful tackles was lower with GP ingestion than with placebo. The success rate for heading, dribbling, and shooting also tended to be lower in the GP than in the placebo condition. In contrast, success in passing and ball control was similar in the two conditions. Improvements in passing and ball control may have been related to a decrease in the intensity of play in the second half of the game. These data indicate that there are no measurable benefits of GP ingestion for the motor skill proficiencies of soccer players during games played in a cool environment.IS
Split-off dimer defects on the Si(001)2x1 surface
Dimer vacancy (DV) defect complexes in the Si(001)2x1 surface were
investigated using high-resolution scanning tunneling microscopy and first
principles calculations. We find that under low bias filled-state tunneling
conditions, isolated 'split-off' dimers in these defect complexes are imaged as
pairs of protrusions while the surrounding Si surface dimers appear as the
usual 'bean-shaped' protrusions. We attribute this to the formation of pi-bonds
between the two atoms of the split-off dimer and second layer atoms, and
present charge density plots to support this assignment. We observe a local
brightness enhancement due to strain for different DV complexes and provide the
first experimental confirmation of an earlier prediction that the 1+2-DV
induces less surface strain than other DV complexes. Finally, we present a
previously unreported triangular shaped split-off dimer defect complex that
exists at SB-type step edges, and propose a structure for this defect involving
a bound Si monomer.Comment: 8 pages, 7 figures, submitted to Phys. Rev.
Glacier Calving Rates Due to Subglacial Discharge, Fjord Circulation, and Free Convection
Tidewater glacier calving provides the most direct mechanism of ice transfer from land to the ocean. However, the physical melt processes influencing calving remain challenging to constrain. In this study we focus on calving rates at Kongsbreen, a tidewater glacier in Svalbard, due to three mechanisms of submarine melt: (1) free convection, (2) horizontal fjord circulation, and (3) meltwater discharge. To calculate an overall calving rate, we measure glacier velocity and terminus change using Sentinel imagery. We calculate free convection, fjord circulation, and meltwater discharge calving using mooring data for mid-fjord ocean temperature (30ā80Ā m depth), reanalysis results for meltwater runoff, and georectified time-lapse imagery to track icebergs and infer surface circulation. Results show that the total glacier calving rate is highly correlated with ocean temperature during the 2016 melt season. When runoff was present, we found that subglacial discharge accounted for calving rates an order of magnitude greater than the maximum calving rates assigned to the other two melting mechanisms combined. Further, subglacial discharge at Kongsbreen was more efficient in inducing calving later in the season than earlier in the season, implying that the increase in ocean temperatures, the timing of meltwater discharge within a melt season, and/or the development of discrete meltwater exit channels are critical components to calving rates. As the recent atmospheric warming trend and subsequent increase in meltwater discharge is expected to continue, it is essential to understand the processes contributing to an increase in glacier calving and incorporate these processes into predictive models
The Emergence of Hospital Federations: An Integration of Perspectives from Organizational Theory
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68464/2/10.1177_107755878704400206.pd
Can we IMPROVE cardiovascular outcomes through phosphate lowering in CKD? Rationale and protocol for the IMpact of Phosphate Reduction on Vascular End-points in Chronic Kidney Disease (IMPROVE-CKD) study
Introduction: Patients with chronic kidney disease (CKD) are at heightened cardiovascular risk, which has been associated with abnormalities of bone and mineral metabolism. A deeper understanding of these abnormalities should facilitate improved treatment strategies and patient-level outcomes, but at present there are few large, randomised controlled clinical trials to guide management. Positive associations between serum phosphate and fibroblast growth factor 23 (FGF-23) and cardiovascular morbidity and mortality in both the general and CKD populations have resulted in clinical guidelines suggesting that serum phosphate be targeted towards the normal range, although few randomised and placebo-controlled studies have addressed clinical outcomes using interventions to improve phosphate control. Early preventive measures to reduce the development and progression of vascular calcification, left ventricular hypertrophy and arterial stiffness are crucial in patients with CKD. Methods and analysis: We outline the rationale and protocol for an international, multicentre, randomised parallel-group trial assessing the impact of the non-calcium-based phosphate binder, lanthanum carbonate, compared with placebo on surrogate markers of cardiovascular disease in a predialysis CKD populationāthe IM pact of P hosphate R eduction O n V ascular E nd-points (IMPROVE)-CKD study. The primary objective of the IMPROVE-CKD study is to determine if the use of lanthanum carbonate reduces the burden of cardiovascular disease in patients with CKD stages 3b and 4 when compared with placebo. The primary end-point of the study is change in arterial compliance measured by pulse wave velocity over a 96-week period. Secondary outcomes include change in aortic calcification and biochemical parameters of serum phosphate, parathyroid hormone and FGF-23 levels. Ethics and dissemination: Ethical approval for the IMPROVE-CKD trial was obtained by each local Institutional Ethics Committee for all 17 participating sites in Australia, New Zealand and Malaysia prior to study commencement. Results of this clinical trial will be published in peer-reviewed journals and presented at conferences.Nicole Lioufas, Nigel D Toussaint, Eugenia Pedagogos, Grahame Elder, Sunil V Badve, Elaine Pascoe, Andrea Valks, Carmel Hawley, Geoffrey A Block, Neil C Boudville, Katrina Campbell, James D Cameron, Sylvia S M Chen, Randall J Faull, Stephen G Holt, Lai S Hooi, Dana Jackson, Meg J Jardine, David W Johnson, Peter G Kerr, Kenneth K Lau, Alicia Morrish, Vlado Perkovic, Kevan R Polkinghorne, Carol A Pollock, Donna Reidlinger, Laura Robison, Edward R Smith, Robert J Walker, Angela Yee Moon Wang
CCD photometry of late-type stars in the young open cluster ICĀ 2602
We present the results of VRI photometry of the young open cluster
ICĀ 2602. Two \rm 15\hbox{^\prime}\times 15\hbox{^\prime} fields were observed in
February and May 1991 using the 1-m Swope telescope at Las Campanas. Using
theoretical isochrones obtained from D'Antona & Mazzitelli
(1994), and allowing for observational and other
uncertainties, we identify 78 primary candidate members with
from their positions on colour-magnitude diagrams. We compare
the cluster field with an offset field of similar galactic latitude and
estimate the contamination due to background stars to be large,
, as might be expected given its low galactic latitude. We
also compare our photometry with that given for the X-ray detected
stars of Randich et al. (1995). We present complimentary
narrow band photometry for a subset of the stars
CCD photometry and proper motions of lateātype stars in the young open cluster StockĀ 2
ā©We present the results of the first CCD BVRI photometric
and proper motion study of late-type stars
in the young open cluster StockĀ 2.ā©Twentyāone fields of approximately size
have been observed photometrically, from which we have identified 118
candidate members based on their positions on colourāmagnitude diagrams
relative to
theoretical isochrones.
From a comparison of the known star density of the
Pleiades, we estimate the contamination of this selection
process due to background
stars to be as large as .
However, only 22 of those 118 candidate members
have proper motions consistent with
membership,
suggesting that the contamination is of the order of . ā©Additional candidate members were found by means of a proper motion analysis of
Schmidt plate material for a
field containing the cluster.
The cluster proper motion allows us to separate members
from background and foreground stars.
We have found 634 stars
with a membership probability down to a limiting magnitude of
, corresponding to lateāM dwarfs at the distance
of StockĀ 2.ā©
Thiol-based antioxidant supplementation alters human skeletal muscle signaling and attenuates its inflammatory response and recovery after intense eccentric exercise
Background: The major thiol-disulfide couple of reduced glutathione (GSH) and oxidized glutathione is a key regulator of major transcriptional pathways regulating aseptic inflammation and recovery of skeletal muscle after aseptic injury. Antioxidant supplementation may hamper exercise-induced cellular adaptations. Objective: The objective was to examine how thiol-based antioxidant supplementation affects skeletal muscle's performance and redox-sensitive signaling during the inflammatory and repair phases associated with exercise-induced microtrauma. Design: In a double-blind, crossover design, 10 men received placebo or N-acetylcysteine (NAC; 20 mg ā„ kg-1 ā„ d-1) after muscledamaging exercise (300 eccentric contractions). In each trial, muscle performance was measured at baseline, after exercise, 2 h after exercise, and daily for 8 consecutive days. Muscle biopsy samples from vastus lateralis and blood samples were collected before exercise and 2 h, 2 d, and 8 d after exercise. Results: NAC attenuated the elevation of inflammatory markers of muscle damage (creatine kinase activity, C-reactive protein, proinflammatory cytokines), nuclear factor ĪŗB phosphorylation, and the decrease in strength during the first 2 d of recovery. NAC also blunted the increase in phosphorylation of protein kinase B, mammalian target of rapamycin, p70 ribosomal S6 kinase, ribosomal protein S6, and mitogen activated protein kinase p38 at 2 and 8 d after exercise. NAC also abolished the increase in myogenic determination factor and reduced tumor necrosis factor-Ī± 8 d after exercise. Performance was completely recovered only in the placebo group. Conclusion: Although thiol-based antioxidant supplementation enhances GSH availability in skeletal muscle, it disrupts the skeletal muscle inflammatory response and repair capability, potentially because of a blunted activation of redox-sensitive signaling pathways. This trial was registered at clinicaltrials.gov as NCT01778309. Copyright Ā© 2013 American Society for Nutrition
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