Is There a General Motor Program for Right Versus Left Hand Throwing in Children?

The purpose of this study was to determine if a general motor program controlled some or all aspects of overhand throwing. Using a 12 camera Vicon motion analysis system to record data from body markers, a group of 30 Australian Aboriginal children 6-10 years of age threw with maximal effort into a large target area. Data were reduced and analysed for numerous variables and correlations were calculated between dominant and non-dominant side variables that were deemed reliable. Results indicated that five variables showed significant dominant to non-dominant correlations. However, only two of the five were entered into both multiple regressions to predict horizontal ball velocity for the dominant vs. non-dominant sides. The variables entered suggested that more gross aspects of the movement (stride distance and pelvis flexion) were both correlated from dominant to non-dominant sides and predicted horizontal ball velocity. Thus, the general motor program does not appear to control the more complex and coordinated parts of the throwing motion

Bi-Polaron and N-Polaron Binding Energies

The binding of polarons, or its absence, is an old and subtle topic. Here we prove two things rigorously. First, the transition from many-body collapse to the existence of a thermodynamic limit for N polarons occurs precisely at U=2\alpha, where U is the electronic Coulomb repulsion and \alpha is the polaron coupling constant. Second, if U is large enough, there is no multi-polaron binding of any kind. Considering the known fact that there is binding for some U>2\alpha, these conclusions are not obvious and their proof has been an open problem for some time.Comment: 4 page

Bioaccessibility performance data for fifty-seven elements in guidance material BGS 102

BGS 102, a guidance material for bioaccessible arsenic (As) and lead (Pb), was produced during validation of the in vitro Unified Bioaccessibility Method (UBM). This paper reports a compilation of reproducible bioaccessible guidance values for fifty-five additional elements in BGS 102, providing guidance for analysts to broaden the scope of UBM analyses for a wider range of elements based on data collected over an average of 60 separate analytical batches per element. Data are presented in categories for both gastric (STOM) and gastrointestinal (STOM + INT) extraction phases, where reproducibility, measured as relative standard deviation (RSD) was; ≤ 10% RSD for 27 elements (Mg, Al, Si, P, Ca, Cr, Mn, Co, Ni, As, Rb, Sr, Y, Ba, La, Ce, Pr, Nd, Sm, Eu, Tb, Gd, Dy, Ho, Er, Tm, Yb); between 10 and 20% RSD for 10 elements (Li, K, V, Fe, Cu, Zn, Cd, Lu, Pb, U); and ≥ 20% RSD for 19 elements in the gastric phase (Be, B, S, Ti, Ga, Se, Zr, Nb, Mo, Ag, Sn, Sb, Cs, Hf, Ta, W, Tl, Bi, Th). Two elements (Mg, Rb) met the ≤ 10% RSD criteria in the UBM gastrointestinal extraction phase due to the alkaline conditions of this phase precipitating out the majority of determinands. Certain elements, including Na, K, Zn and Se, were found to be a significant component of the extraction fluids with proportionally higher concentrations compared to the guidance material. Bioaccessible fractions (%BAF) were also calculated, but were found to be a less reproducible format for confirming the accuracy of measurements. The low concentration of some elements of interest in BGS 102, such as antimony (Sb), justifies the preparation of an alternative certified reference material (CRM). This paper presents an opportunity to broaden the scope of the UBM method to address food security issues (e.g. Fe and Zn micronutrient deficiencies) and contributions to dietary intake from extraneous dust or soil through evidence of the analytical possibilities and current limitations requiring further investigation

BATSE spectroscopy analysis system

The Burst and Transient Source Experiment (BATSE) Spectroscopy Analysis System (BSAS) is the software system which is the primary tool for the analysis of spectral data from BATSE. As such, Guest Investigators and the community as a whole need to know its basic properties and characteristics. Described here are the characteristics of the BATSE spectroscopy detectors and the BSAS

Machine learning reduced workload with minimal risk of missing studies: development and evaluation of an RCT classifier for Cochrane Reviews

BACKGROUND: To describe the development, calibration and evaluation of a machine learning classifier designed to reduce study identification workload in Cochrane for producing systematic reviews. METHODS: A machine learning classifier for retrieving RCTs was developed (the ‘Cochrane RCT Classifier’), with the algorithm trained using a dataset of title-abstract records from Embase, manually labelled by the Cochrane Crowd. The classifier was then calibrated using a further dataset of similar records manually labelled by the Clinical Hedges team, aiming for 99% recall. Finally, the recall of the calibrated classifier was evaluated using records of RCTs included in Cochrane Reviews that had abstracts of sufficient length to allow machine classification. RESULTS: The Cochrane RCT Classifier was trained using 280,620 records (20,454 of which reported RCTs). A classification threshold was set using 49,025 calibration records (1,587 of which reported RCTs) and our bootstrap validation found the classifier had recall of 0.99 (95% CI 0.98 to 0.99) and precision of 0.08 (95% CI 0.06 to 0.12) in this dataset. The final, calibrated RCT classifier correctly retrieved 43,783 (99.5%) of 44,007 RCTs included in Cochrane Reviews but missed 224 (0.5%). Older records were more likely to be missed than those more recently published. CONCLUSIONS: The Cochrane RCT Classifier can reduce manual study identification workload for Cochrane reviews, with a very low and acceptable risk of missing eligible RCTs. This classifier now forms part of the Evidence Pipeline, an integrated workflow deployed within Cochrane to help improve the efficiency of the study identification processes that support systematic review production

The influence of trees, shrubs, and grasses on microclimate, soil carbon, nitrogen, and CO2 efflux:Potential implications of shrub encroachment for Kalahari rangelands

Shrub encroachment is a well-documented phenomenon affecting many of the world's drylands. The alteration of vegetation structure and species composition can lead to changes in local microclimate and soil properties which in turn affect carbon cycling. The objectives of this paper were to quantify differences in air temperatures, soil carbon, nitrogen, and CO2 efflux under trees (Vachellia erioloba), shrubs (Grewia flava), annual and perennial grasses (Schmidtia kalahariensis and Eragrostis lehmanniana) collected over three seasons at a site in Kgalagadi District, Botswana, in order to determine the vegetation-soil feedback mechanism affecting the carbon cycle. Air temperatures were logged continuously and soil CO2 efflux was determined throughout the day and evening using closed respiration chambers and an infrared gas analyser. There were significant differences in soil carbon, total nitrogen, CO2 efflux, light and temperatures beneath the canopies of trees, shrubs and grasses. Daytime air temperatures beneath shrubs and trees were cooler compared to grass sites, particularly in summer months. Night time air temperatures under shrubs and trees were, however, warmer than at the grass sites. There was also significantly more soil carbon, nitrogen and CO2 efflux under shrubs and trees compared to grasses. Whilst the differences observed in soils and microclimate may reinforce the competitive dominance of shrubs and present challenges to strategies designed to manage encroachment they should not be viewed as entirely negative. Our findings highlight some of the dichotomies and challenges to be addressed before interventions aiming to bring about more sustainable land management can be implementedpublishersversionPeer reviewe

The effects of oral contraceptives on exercise performance in women: a systematic review and meta-analysis

Background: Oral contraceptive pills (OCPs) are double agents, which downregulate endogenous concentrations of oestradiol and progesterone whilst simultaneously providing daily supplementation of exogenous oestrogen and progestin during the OCP-taking days. This altered hormonal milieu differs significantly from that of eumenorrheic women and might impact exercise performance, due to changes in ovarian hormone-mediated physiological processes. Objective: To explore the effects of OCPs on exercise performance in women and to provide evidence-based performance recommendations to users. Methods: This review complied with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A between-group analysis was performed, wherein performance of OCP users was compared with naturally menstruating women, and a within-group analysis was conducted, wherein performance during OCP consumption was compared with OCP withdrawal. For the between-group analysis, women were phase matched in two ways: (1) OCP withdrawal versus the early follicular phase of the menstrual cycle and (2) OCP consumption versus all phases of the menstrual cycle except for the early follicular phase. Study quality was assessed using a modified Downs and Black Checklist and a strategy based on the recommendations of the Grading of Recommendations Assessment Development and Evaluation working group. All meta-analyses were conducted within a Bayesian framework to facilitate probabilistic interpretations. Results: 42 studies and 590 participants were included. Most studies (83%) were graded as moderate, low or very low quality, with 17% achieving high quality. For the between-group meta-analysis comparing OCP users with naturally menstruating women, posterior estimates of the pooled effect were used to calculate the probability of at least a small effect (d ≥ 0.2). Across the two between-group comparison methods, the probability of a small effect on performance favouring habitual OCP users was effectually zero (p < 0.001). In contrast, the probability of a small effect on performance favouring naturally menstruating women was moderate under comparison method (1) (d ≥ 0.2; p = 0.40) and small under comparison method (2) (d ≥ 0.2; p = 0.19). Relatively large between-study variance was identified for both between-group comparisons (0.5 = 0.16 [95% credible interval (CrI) 0.01-0.44] and 0.5 = 0.22 [95% CrI 0.06-0.45]). For the within-group analysis comparing OCP consumption with withdrawal, posterior estimates of the pooled effect size identified almost zero probability of a small effect on performance in either direction (d ≥ 0.2; p ≤ 0.001). Conclusions: OCP use might result in slightly inferior exercise performance on average when compared to naturally menstruating women, although any group-level effect is most likely to be trivial. Practically, as effects tended to be trivial and variable across studies, the current evidence does not warrant general guidance on OCP use compared with non-use. Therefore, when exercise performance is a priority, an individualised approach might be more appropriate. The analysis also indicated that exercise performance was consistent across the OCP cycle

Policy, Performativity and Partnership: an Ethical Leadership Perspective

This article identifies the need to think differently about educational partnerships in a changing and turbulent post compulsory policy environment in England. The policy and institutional contexts in which universities and colleges currently operate seem to be fuelling performativity at the expense of educational values. There appears to be a sharp interruption in the steady increase in educational partnerships as a vehicle for increasing and widening participation in higher education. We are witnessing a marked change in university / college relationships that appears to be a consequence of government calling a halt to increased participation in higher education, creating an increasingly competitive market for a more limited pool of student places. The implication that educational policy at the national level determines a particular pattern or mode of leadership decision making throughout an institution should however be resisted. Policy developments that challenge the moral precepts of education should not be allowed to determine how a leader acts, rather they should prompt actions that are truly educational, rooted in morality, and atached to identifiable educational values. Educational leaders have agency to resist restricted discourses in favour of ethical and principled change strategies that are a precondition for sustainable transformative partnerships in post compulsory education. University leaders in particular are called upon to use their considerable influence to resist narrow policy or managerial instrumentalism or performativity and embrace alternatives that are both educationally worthwhile and can enhance institutional resilience

Horava-Lifshitz gravity: a status report

This is intended to be a brief introduction and overview of Horava-Lifshitz gravity. The motivation and all of the various version of the theory (to date) are presented. The dynamics of the theory are discussed in some detail, with a focus on low energy viability and consistency, as these have been the issues that attracted most of the attention in the literature so far. Other properties of the theory and developments within its framework are also covered, such as: its relation to Einstein-aether theory, cosmology, and future perspectives.Comment: 17 pages, no figures, based on talk given at the 14th Conference on Recent Developments in Gravity (NEBXIV), Ioannina, Greece, 8-11 Jun 2010; v2: minor changes to match published version, references adde