14,171 research outputs found
Mosquito production in sewage lagoons
Four sewage lagoons are described that illustrate in varying degree conditions that encourage mosquito production. Steps are outlined by which mosquito breeding in ponds can be prevented
Quantifying frequency of use of methods of body mass loss in competing UK powerlifters
Previous research in Powerlifting (PL) has qualitatively investigated rapid weight-loss (RWL) in PL athletes and body image, however limited research exists in quantifying such methods adopted in PL. This study aimed to assess the frequency of RWL methods are adopted by male and female PL athletes in the United Kingdom (UK) during competition preparation. A total of n = 37 (n = 19 female, n = 18 male) competitive powerlifters completed an anonymous online questionnaire assessing RWL methods. A Chi-square cross tabulation was utilised to identify any significant differences between independent and dependent variables. Multiple regression analyses were then conducted to assess the contribution of biological sex and PL category on RWL methods. Commonly reported methods of weight loss were gradual dieting (49%), fluid restriction (46%), and water loading (51%). Differences between PL category (Junior, Open, Masters One) and adopting RWL were observed (X2 =4.220, p<0.05). PL category was a predictor of undertaking RWL (R2adj = 0.160, F(2, 34) = 4.429, p ≤ 0.05), whilst biological sex was a predictor of timeframe of undertaking RWL (R2adj = 0.123, F(2, 34) = 3.534, p ≤ 0.05). RWL strategies are adopted by PL athletes in order to make weight for competition. Despite known effects of RWL on strength performance, limited research currently exists on these strategies specifically within PL, therefore this may be a consideration for future research. Practitioners working with PL athletes may wish to consider appropriate nutrition and weight loss strategies in preparation for PL competitions
Investigating the prevalence of low energy availability, disordered eating and eating disorders in competitive and recreational female endurance runners
Eating disorders (ED), disordered eating (DE) and low energy availability (LEA) can be detrimental to health and performance. Previous studies have independently investigated prevalence of ED, DE or LEA, however limited studies have combined methods identifying risk within female runners. The aim of this study was to identify prevalence of ED, DE and LEA in United Kingdom-based female runners and associations between age, competition level and running distance. The Female Athlete Screening Tool (FAST) and Low Energy Availability in Females Questionnaire (LEAF-Q) were used in a cross-sectional study design. A total of n = 524 responses eligible for analysis were received. A total of n = 248 (47.3%), n = 209 (40%) and n = 49 (9.4%) athletes were at risk of LEA, DE and ED, respectively. LEAF-Q scores differed based upon age (Age: H(3) = 23.998, p≤0.05) and competitive level (Comp: H(1) = 7.682, p≤0.05) whereas FAST scores differed based on age (Age: F(3,523) = 4.753, p≤0.05). Tukey's post-hoc tests showed significantly higher FAST scores in 18-24 years compared to all other age categories (p≤0.05). Stepwise multiple regression demonstrated age and competitive level modestly predicted LEAF-Q scores (R2adj = 0.047, F(2,523) = 13.993, p≤0.05, VIF = 1.0) whereas age modestly predicted FAST scores (R2adj = 0.022, F(1,523) = 12.711, p≤0.05, VIF = 1.0). These findings suggest early identification, suitable screening methods and educational intervention programmes should be aimed at all levels of female endurance runners
A feynman path integral representation for elastic wave scattering by anisotropic weakly perturbations
We write a space-time Feynman path integral representation for scattered
elastic wave fields from a weakly compact supported anisotropic
non-homogeneity.Replacement by a new version where We (I!) propose a new
tomographic inversion methodology based solely in the wave sampling of the Ray
paths through Monte Carlo path integral sampling Holding thus great
potentiality for Navy's advanced Sonar detection .Comment: 8 page
Gauge covariance and the fermion-photon vertex in three- and four- dimensional, massless quantum electrodynamics
In the quenched approximation, the gauge covariance properties of three
vertex Ans\"{a}tze in the Schwinger-Dyson equation for the fermion self energy
are analysed in three- and four- dimensional quantum electrodynamics. Based on
the Cornwall-Jackiw-Tomboulis effective action, it is inferred that the
spectral representation used for the vertex in the gauge technique cannot
support dynamical chiral symmetry breaking. A criterion for establishing
whether a given Ansatz can confer gauge covariance upon the Schwinger-Dyson
equation is presented and the Curtis and Pennington Ansatz is shown to satisfy
this constraint. We obtain an analytic solution of the Schwinger-Dyson equation
for quenched, massless three-dimensional quantum electrodynamics for arbitrary
values of the gauge parameter in the absence of dynamical chiral symmetry
breaking.Comment: 17 pages, PHY-7143-TH-93, REVTE
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