Background: A 17-year-old boy on long-term immunosuppression following renal transplantation for chronic kidney disease (CKD), the result of dysplastic kidneys, initially presented with a swelling in his neck while attending hospital for an unrelated problem. A clinical diagnosis of tonsillitis was made, and he was treated with broad-spectrum antibiotics. Over a few days, his condition deteriorated, and he developed multiple vesicopustular skin lesions and required an emergency tonsillectomy due to respiratory distress.
View Article and Find Full Text PDFSalmonid alphavirus subtype 3 (SAV3) causes pancreas disease (PD) and adversely affects salmonid aquaculture in Europe. A better understanding of disease transmission is currently needed in order to manage PD outbreaks. Here, we demonstrate the relationship between viral dose and the outcome of SAV3 infection in Atlantic salmon post-smolts using a bath challenge model.
View Article and Find Full Text PDFDespite the Système International d'Unitès (SI) that was published in 1960, there continues to be widespread misuse of the terms and nomenclature of mechanics in descriptions of exercise performance. Misuse applies principally to failure to distinguish between mass and weight, velocity and speed, and especially the terms "work" and "power." These terms are incorrectly applied across the spectrum from high-intensity short-duration to long-duration endurance exercise.
View Article and Find Full Text PDFAviat Space Environ Med
September 2014
Introduction: Women increasingly occupy manual labor jobs. However, research examining women working under hot-humid conditions is lacking. Therefore, the purpose of our study was to assess how increasing relative humidity (RH) affects women's thermoregulation during low-intensity exercise characteristic of 8 h self-paced manual labor.
View Article and Find Full Text PDFThe aim of this investigation was to determine and compare current and projected expenditure associated with chronic kidney disease (CKD), renal replacement therapy (RRT), and cardiovascular disease (CVD) in Australia. Data published by Australia and New Zealand Dialysis and Transplant Registry, Australian Institute of Health and Welfare, and World Bank were used to compare CKD-, RRT-, and CVD-related expenditure and prevalence rates. Prevalence and expenditure predictions were made using a linear regression model.
View Article and Find Full Text PDFObjectives: Infective endocarditis (IE) is a feared complication in up to 38% of cases of Staphylococcus aureus bacteraemia (SAB). BSAC guidelines recommend echocardiography in all cases of SAB. The aim of this study was to determine the incidence of IE in SAB using transoesophageal echocardiography (TOE) as the first step in diagnostic imaging.
View Article and Find Full Text PDFThe purpose of this study was to determine whether improvements in endurance exercise performance elicited by strength training were accurately reflected by changes in parameters of the power-duration hyperbola for high-intensity exercise. Before and after 8 weeks of strength training (N = 14) or no exercise, control (N = 5), 19 males (age: 20.6 ± 2.
View Article and Find Full Text PDFJ Sports Sci
September 2013
The "Critical Power" (CP) model of human bioenergetics provides a valuable way to identify both limits of tolerance to exercise and mechanisms that underpin that tolerance. It applies principally to cycling-based exercise, but with suitable adjustments for analogous units it can be applied to other exercise modalities; in particular to incremental ramp exercise. It has not yet been applied to decremental ramps which put heavy early demand on the anaerobic energy supply system.
View Article and Find Full Text PDFThe study examined the maintenance of VO(2max) using VO(2max) as the controlling variable instead of power. Therefore, ten subjects performed three exhaustive cycling exercise bouts: (1) an incremental test to determine VO(2max) and the minimal power at VO(2max) (PVO(max)), (2) a constant-power test at PVO(max) and (3) a variable-power test (VPT) during which power was varied to control VO(2) at VO(2max). Stroke volume (SV) was measured by impedance in each test and the stroke volume reserve was calculated as the difference between the maximal and the average 5-s SV.
View Article and Find Full Text PDFMed Sci Sports Exerc
August 2012
Purpose: This study was designed to determine whether V˙O(2) reaches a maximum, equivalent to that attained in an incremental exercise test to exhaustion, during "submaximal" fatigue-inducing constant-power exercise bouts above critical power (CP).
Methods: Nine males (age = 24.6 ± 3.
For any athlete competing at the highest level it is vital to understand the components that lead to successful performance. World cup cross-country mountain biking is a complex sport involving large numbers of athletes (100-200) competing for positional advantage over varied off-road terrain. The start has been deemed a major part of performance outcome in such races.
View Article and Find Full Text PDFPurpose: This study tested the relevance of the critical power (CP) model for explaining exercise tolerance during intermittent high-intensity exercise with different recovery intensities.
Methods: After estimation of CP and W' from a 3-min all-out test, seven male subjects completed, in randomized order, a cycle test to exhaustion at a severe-intensity constant-work-rate (S-CWR) and four cycle tests to exhaustion using different intermittent ("work-recovery") protocols (i.e.
The study examined whether or not acute exposure to unfamiliar hot or cold conditions impairs performance of highly skilled coordinative activities and whether prior physical self-efficacy beliefs were associated with task completion. Nineteen volunteers completed both Guitar Hero and Archery activities as a test battery using the Nintendo Wii console in cold (2 degrees C), neutral (20 degrees C), and hot (38 degrees C) conditions. Participants all completed physical self-efficacy questionnaires following experimental familiarization.
View Article and Find Full Text PDFBr J Sports Med
January 2012
Reports on reproducibility of lactate markers usually considered only two trials. The authors assessed reproducibility of power output at seven markers in 11 fit subjects over at least six trials under tightly controlled conditions. Subjects undertook incremental exercises (50 W start, +50 W every 3 min to exhaustion) on a cycle ergometer.
View Article and Find Full Text PDFExperimental studies have consistently reported higher peak power outputs at the termination of steeper ramp exercises. One explanation can be deduced from oxygen uptake kinetics. This short communication offers an alternative explanation based on the "critical power" concept of human bioenergetics.
View Article and Find Full Text PDFThis study evaluated exercise modality [i.e. self-paced (SP) or fixed-intensity (FI) exercise] as a modulator of body temperature regulation under uncompensable heat stress.
View Article and Find Full Text PDFPoor nutrient intake during pregnancy can adversely affect both infant and maternal health. The aim was to investigate the efficacy of multiple-micronutrient supplementation during pregnancy in a socially deprived population in the developed world. We conducted a randomised, double-blind, placebo-controlled trial of multiple-micronutrient supplementation including 20 mg Fe and 400 microg folic acid, from the first trimester of pregnancy in 402 mothers, in East London, UK.
View Article and Find Full Text PDFMed Sci Sports Exerc
October 2010
For high-intensity muscular exercise, the time-to-exhaustion (t) increases as a predictable and hyperbolic function of decreasing power (P) or velocity (V ). This relationship is highly conserved across diverse species and different modes of exercise and is well described by two parameters: the "critical power" (CP or CV), which is the asymptote for power or velocity, and the curvature constant (W') of the relationship such that t = W'/(P - CP). CP represents the highest rate of energy transduction (oxidative ATP production, V˙O2) that can be sustained without continuously drawing on the energy store W' (composed in part of anaerobic energy sources and expressed in kilojoules).
View Article and Find Full Text PDFThe tolerable duration (t) of high-intensity cycle ergometry is well characterized by a hyperbolic function of power output (P) with an asymptote (termed the critical power (CP)) and a curvature constant (denoted W'). The purpose of this study was to investigate the effect of prior heavy exercise (W-up) that specifically engenders an acidosis on CP and W'. Eight healthy subjects performed 2 sets of 4 high-intensity square-wave exercise bouts on a bicycle ergometer to estimate CP and W', with (W-up) and without (control) prior exercise, respectively.
View Article and Find Full Text PDFAn isoperformance curve (or surface) defines combinations of two (or more) physiological attributes of individuals such that equal performances for a specified event would be expected of them. Parameters from the two- and three-parameter critical power models are used to illustrate the concept. There are a number of sporting races where teams of individuals compete simultaneously as a unit.
View Article and Find Full Text PDFFormation of biofilms in dairy membrane plants causes membrane pore blocking, product contamination and subsequent economic loss. To investigate the biofilm growth, two Klebsiella oxytoca strains, K. B006 and TR002, previously isolated from New Zealand dairy membrane plants, were grown both individually and combined on three types of ultrafiltration (UF) membranes in different concentrations of whey medium in biofilm reactors (CBR 90, BioSurface Technologies, Bozeman, USA).
View Article and Find Full Text PDFThis study examined the hypothesis that running speed over 800- and 1,500-m races is regulated by the prevailing anaerobic (oxygen independent) store (ANS) at each instant of the race up until the all-out phase of the race over the last several meters. Therefore, we hypothesized that the anaerobic power that allows running above the speed at maximal oxygen uptake (VO2max) is regulated by ANS, and as a consequence the time limit at the anaerobic power (tlim PAN=ANS/PAN) is constant until the final sprint. Eight 800-m and seven 1,500-m male runners performed an incremental test to measure VO2max and the minimal velocity associated with the attainment of VO2max (vVO2max), referred to as maximal aerobic power, and ran the 800-m or 1,500-m race with the intent of achieving the lowest time possible.
View Article and Find Full Text PDFProtein is often considered the most satiating macronutrient. The objective was to determine the short-term effect of mixtures of whey protein and glycomacropeptide (GMP) versus a carbohydrate control on satiety in healthy adult humans. The study was a randomised crossover Latin Square design.
View Article and Find Full Text PDFIt is common for athletes striving to achieve maximal effort to exercise in the presence of a visible clock. It is implicitly assumed that calibration of the clock is normal (i.e.
View Article and Find Full Text PDFFelinine is a branched-chain sulfur amino acid present in the urine of certain Felidae, including domestic cats. The objective of the present study was to determine if additional cystine and/or dietary N would increase felinine and N-acetylfelinine excretion by intact male cats fed a low-protein(LP) diet. Feeding five adult intact male cats an LP diet (18.
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