The validity of capillary blood sampling in the determination of human growth hormone concentration during exercise in men

This is an open access article - Copyright © 2004 BMJ Publishing Group LtdBACKGROUND: Studies measuring human growth hormone (hGH) in blood during exercise have mainly used venous sampling. The invasive nature of this procedure makes evaluation of hGH impossible in various exercise environments. OBJECTIVE: To determine whether capillary sampling could offer an alternative sampling method. METHODS: Capillary and venous blood samples were collected for determination of hGH at the end of each exercise stage during an incremental exercise test in 16 male club level competitive cyclists (mean (SD) age 30.8 (8.0) years, body mass 72.2 (7.1) kg, body fat 12.9 (3.5)%, peak oxygen consumption 4.18 (0.46) l⋅min−1). Linear regression, from a plot of venous v capillary blood hGH concentration, showed a correlation coefficient of r = 0.986 (p<0.001). When geometric means and log transformations were used, a coefficient of variation of 14.2% was demonstrated between venous and capillary flow for hGH concentration. The mean ratio limits of agreement were 0.62 (1.72)—that is, 95% of the ratios were contained between 0.36 and 1.07, with a mean of 0.62. CONCLUSIONS: Capillary blood sampling is an acceptable alternative to venous sampling for determining hGH concentration during rest and exercise. Sample sites should not be used interchangeably: one site should be chosen and its use standardised

South Asian Children Have Increased Body Fat in Comparison to White Children at the Same Body Mass Index.

The ability of body mass index (BMI) to predict excess fat in South Asian children is unknown. This cross-sectional study examines the influence of ethnicity on body fatness in children. Weight status and body fat were determined using BMI, waist circumference (WC), two skinfold sites (SF; triceps and subscapula) and leg-to-leg bioelectrical impedance analysis (BIA; Tanita BF350, Tanita, Tokyo, Japan) in 194 children aged 8.47 ± 0.50 years from Coventry, United Kingdom. Biological maturity was also determined. Analysis of covariance (ANCOVA) identified significant differences between ethnic (p 0.05). To conclude, the findings suggest that BMI cut-points may need to be lowered in South Asian children, and thus age-by-sex-by-ethnicity specific BMI cut-points are needed in children. Further research examining body composition with health parameters in this population is needed

Reproducibility of body volume assessments in survival clothing in fixed and portable scanning systems.

The recent development of portable 3D scanning systems for industries such as animation and museum artefact digitisation have considerable potential for applications involving human body measurement. However, this requires a system for validation of measurements against a criterion, which this study aimed to provide. Forty four adult males were scanned in duplicate in both a fixed Hamamatsu and portable Artec L scanning systems in two postures and two different clothing assemblages. Following inspection of all scans, complete data for duplicate scans of 38 participants were available for the study. Both scanners demonstrated good precision, however significant differences in body volume prevailed for both egress and scanner postures in form-fitting clothing and the scanner posture in survival suit scans, with the Hamamatsu providing greater volumes than the Artec system (by 2.7, 2.8 and 2.1 litres respectively). Regression analysis indicated the results from the portable scanner explained between 96 and 98% of the variability in the results from the fixed scanner. The biases in body volume probably relate to different software approaches to its calculation, and a possible interaction with posture and clothing. Validation of the Artec against the Hamamatsu system provides valuable information for its use in field and industrial settings

Effect of exercise on postprandial endothelial function in adolescent boys

The ingestion of high-fat meals induces a state of endothelial dysfunction in adults. This dysfunction is attenuated by prior exercise. The response of young people to these nutritional and physiological stressors has not been established. Thus, the purpose of the present study was to investigate if a bout of moderate-intensity exercise influenced endothelial function (as indicated by flow-mediated dilation (FMD)) following the ingestion of a high-fat breakfast and lunch in adolescent boys (aged 12·6–14·3 years). Two, 2 d main trials (control and exercise) were completed by thirteen adolescent boys in a counter-balanced, cross-over design. Participants were inactive on day 1 of the control trial, but completed 60 min of walking at 60% peak oxygen uptake in the exercise trial. On day 2, endothelial function was assessed via FMD prior to, and following, ingestion of a high-fat breakfast and lunch. There was no difference in fasting FMD between the control and exercise trial (P¼0·449). In the control trial, FMD was reduced by 32% following consumption of the high-fat breakfast and by 24% following lunch. In the exercise trial, the corresponding reductions were 6 and 10 %, respectively (main effect trial, P¼0·002). These results demonstrate that moderate-intensity exercise can attenuate the decline in FMD seen following the consumption of high-fat meals in adolescent boys

Integration of complete chloroplast genome sequences with small amplicon datasets improves phylogenetic resolution in Acacia

Combining whole genome data with previously obtained amplicon sequences has the potential to increase the resolution of phylogenetic analyses, particularly at low taxonomic levels or where recent divergence, rapid speciation or slow genome evolution has resulted in limited sequence variation. However, the integration of these types of data for large scale phylogenetic studies has rarely been investigated. Here we conduct a phylogenetic analysis of the whole chloroplast genome and two nuclear ribosomal loci for 65 Acacia species from across the most recent Acacia phylogeny. We then combine this data with previously generated amplicon sequences (four chloroplast loci and two nuclear ribosomal loci) for 508 Acacia species. We use several phylogenetic methods, including maximum likelihood bootstrapping (with and without constraint) and ExaBayes, in order to determine the success of combining a dataset of 4000 bp with one of 189,000 bp. The results of our study indicate that the inclusion of whole genome data gave a far better resolved and well supported representation of the phylogenetic relationships within Acacia than using only amplicon sequences, with the greatest support observed when using a whole genome phylogeny as a constraint on the amplicon sequences. Our study therefore provides methods for optimal integration of genomic and amplicon sequences

Inconsistency of decision-making, the Achilles heel of referees

This is an accepted manuscript of an article published by Taylor & Francis in Journal of Sports Sciences on 12/12/2016, available online: https://doi.org/10.1080/02640414.2016.1265143 The accepted version of the publication may differ from the final published version.This study assessed whether decisions made by six qualified referees were consistent when watching the live 2016 televised Champions League Final. Referees were paired off into three separate rooms. Two referees watched the game with no supporters present. Two watched the game surrounded by Real Madrid supporters, and the remaining two watched the game surrounded by Athletic Madrid supporters. Referees were asked to decide whether each decision made by the on-field referee was either correct or incorrect. Results identified two types of refereeing inconsistency. The first type was a systematic tendency of the supporting crowds (both rooms) to influence the adjudicating referees to make fewer incorrect (disagree with the on-field referee) decisions (8 and 5) than referees in the “no supporters” room (19) (χ2 = 11.22 [df = 2], P = 0.004). The second type of inconsistency was the home advantage “bias”, where the surrounding crowd influenced the adjudicating referees to favour their team, by disagreeing with the decision made by the on-field referee (χ2 = 6.0 [df = 2], P = 0.0498). One explanation for these inconsistencies is that referees adopt a coping strategy of “avoidance”, i.e., when faced with difficult decisions, referees simply avoid making unpopular decisions by waving “play on”

An Evaluation of Prediction Equations for the 6 Minute Walk Test in Healthy European Adults Aged 50-85 Years

This study compared actual 6 minute walk test (6MWT) performance with predicted 6MWT using previously validated equations and then determined whether allometric modelling offers a sounder alternative to estimating 6MWT in adults aged 50-80 years.We compared actual 6MWT performance against predicted 6MWT in 125 adults aged 50-85 years (62 male, 63 female). In a second sample of 246 adults aged 50-85 years (74 male, 172 female), a new prediction equation for 6MWT performance was developed using allometric modelling. This equation was then cross validated using the same sample that the other prediction equations were compared with.Significant relationships were evident between 6MWT actual and 6MWT predicted using all of the commonly available prediction equations (all P<0.05 or better) with the exception of the Alameri et al prediction equation (P>0.05). A series of paired t-tests indicated significant differences between 6MWT actual and 6MWT predicted for all available prediction equations (all P<0.05 or better) with the exception of the Iwama et al equation (P = .540). The Iwama et al equation also had similar bias (79.8m) and a coefficient of variation of over 15%. Using sample 2, a log-linear model significantly predicted 6MWT from the log of body mass and height and age (P = 0.001, adjusted R2 = .526), predicting 52.6% of the variance in actual 6MWT. When this allometric equation was applied to the original sample, the relationship between 6MWT actual and 6MWT predicted was in excess of values reported for the other previously validated prediction equations (r = .706, P = 0.001). There was a significant difference between actual 6MWT and 6MWT predicted using this new equation (P = 0.001) but the bias, standard deviation of differences and coefficient of variation were all less than for the other equations.Where actual assessment of the 6MWT is not possible, the allometrically derived equation presented in the current study, offers a viable alternative which has been cross validated and has the least SD of differences and smallest coefficient of variation compared to any of the previously validated equations for the 6MWT

Does the Brief Self-Control Scale Assess Relatively Stable Individual Differences in Self-Control Among Endurance Athletes?

Endurance athletes are a population where self-control in the form of following training plans, race plans, and pacing schedules is key to performing successfully. A valid and stable measure of self-control has theoretical and applied value through the ability to identify athletes who might be susceptible to poor self-control. The present study reports the test-retest stability of the Brief Self-Control Scale (BSCS). 132 endurance athletes (18-65 years) completed the 13-item BSCS on two occasions, separated by two weeks. Stability was measured by calculating the test-retest differences for each questionnaire item, with a stable item showing 90% of respondents’ test-retest differences within a reference value of ±1. Analyses revealed seven items to be stable with the question, Q11 = “I am able to work effectively toward long-term goals”, demonstrating greatest stability (96.3%). In contrast, six items showed relatively poor stability with test-retest difference scores ranging from 83.4-89.4%. Chi-square tests of independence revealed no associations with categorical levels of age, gender, sport, and training habits. In the context of the current findings, we argue that the six unstable items do not represent dispositional self-control behaviours among endurance athletes. Future researchers are encouraged to assess the stability of individual items rather than favoring a summary statistic, particularly when developing trait measures

Relaxation mechanism for electron spin in the impurity band of n-doped semiconductors

We propose a mechanism to describe spin relaxation in n-doped III-V semiconductors close to the Mott metal-insulator transition. Taking into account the spin-orbit interaction induced spin admixture in the hydrogenic donor states, we build a tight-binding model for the spin-dependent impurity band. Since the hopping amplitudes with spin flip are considerably smaller than the spin conserving counterparts, the resulting spin lifetime is very large. We estimate the spin lifetime from the diffusive accumulation of spin rotations associated with the electron hopping. Our result is larger but of the same order of magnitude than the experimental value. Therefore the proposed mechanism has to be included when describing spin relaxation in the impurity band.Comment: 4 page

An investigation of home advantage in the Summer Paralympic Games

Purpose: There is a paucity of home advantage research set in the context of para-sport events. It is this gap in the knowledge that this paper addresses by investigating the prevalence and size of home advantage in the Summer Paralympic Games. Methods: Using a standardised measure of success, we compared the performances of nations when competing at home with their own performances away from home in the competition between 1960 and 2016. Both country level and individual sport level analysis was conducted for this time frame. A Wilcoxon signed rank test was used to determine whether there was a genuine difference in nations' performance under host and non-host conditions. Spearman's rank-order correlation was run to assess the relationship between nation quality and home advantage. Results: Strong evidence of a home advantage effect in the Summer Paralympic Games was found at country level (p 0.10). Conclusion: While our results confirm that home advantage is prevalent in the Summer Paralympic Games at an overall country level and within specific sports, they do not explain fully why such an effect does exist. Future studies should investigate the causes of home advantage in the competition and also draw comparisons with the Summer Olympic Games in order to explore any differences between para-sport events and able-bodied events