A Selected Ion Flow Tube Study of the Reactions of Several Cations with the Group 6B Hexafluorides SF6, SeF6, and TeF6

The first investigation of the ion chemistry of SeF$_6$ and TeF$_6$ is presented. Using a selected ion flow tube, the thermal rate coefficients and ion product distributions have been determined at 300 K for the reactions of fourteen atomic and molecular cations, namely H$_3$O$^+$, CF$_3^+$, CF$^+$, CF$_2^+$, H$_2$O$^+$, N$_2$O$^+$, O$^+$, CO$_2^+$, CO$^+$, N$^+$, N$_2^+$, Ar$^+$, F$^+$ and Ne$^+$ (in order of increasing recombination energy), with SeF$_6$ and TeF$_6$. The results are compared with those from the reactions of these ions with SF$_6$, for which the reactions with CF$^+$, CF$_2^+$, N$_2$O$^+$ and F$^+$ are reported for the first time. Several distinct processes are observed amongst the large number of reactions studied, including dissociative charge transfer, and F$^-$, F, F$_2^-$ and F$_2$ abstraction from the neutral reactant molecule to the reagent ion. The dissociative charge transfer channels are discussed in relation to vacuum ultraviolet photoelectron and threshold photoelectron-photoion coincidence spectra of XF$_6$ (X = S, Se, and Te). For reagent ions whose recombination energies lie between the first dissociative ionisation limit, XF$_6$ $\rightarrow$ XF$_5^+$ + F + e$^-$, and the onset of ionisation of the XF$_6$ molecule, the results suggest that if dissociative charge transfer occurs, it proceeds via an intimate encounter. For those reagent ions whose recombination energies are greater than the onset of ionisation, long-range electron transfer may occur depending on whether certain physical factors apply, for example non-zero Franck-Condon overlap. From the reaction kinetics, limits for the heats of formation of SeF$_4$, SeF$_5$, TeF$_4$ and TeF$_5$ at 298 K have been obtained; $\Delta_f$H$^o$(SeF$_4$) < -369 kJ mol$^{-1}$, $\Delta_f$H$^o$(SeF$_5$) < -621 kJ mol$^{-1}$, $\Delta_f$H$^o$(TeF$_4$) > -570 kJ mol$^{-1}$, and $\Delta_f$H$^o$(TeF$_5$) < -822 kJ mol$^{-1}$

Epidemiology of Injury in Women’s Super League Football: A Cohort Study

Introduction: The epidemiology of injury in male professional football has been well documented (Ekstrand, Hägglund, & Waldén, 2011) and used as a basis to understand injury trends for a number of years. The prevalence and incidence of injuries occurring in women’s super league football is unknown. The aim of this study is to estimate the prevalence and incidence of injury in an English Super League Women’s Football squad. Methods: Following ethical approval from Leeds Beckett University, players (n = 25) signed to a Women’s Super League Football club provided written informed consent to complete a self-administered injury survey. Measures of exposure, injury and performance over a 12-month period was gathered

The evolution of gregariousness in parasitoid wasps

Data are assembled on the clutch-size strategies adopted by extant species of parasitoid wasp. These data are used to reconstruct the history of clutch-size evolution in the group using a series of plausible evolutionary assumptions. Extant families are either entirely solitary, both solitary and gregarious, or else clutch size is unknown. Parsimony analysis suggests that the ancestors of most families were solitary, a result which is robust to different phylogenetic relationships and likely data inadequacies. This implies that solitariness was ubiquitous throughout the initial radiation of the group, and that transitions to gregariousness have subsequently occurred a minimum of 43 times in several, but not all lineages. Current data suggest that species-rich and small-bodied lineages are more likely to have evolved gregariousness, and contain more species with small gregarious brood sizes. I discuss the implications of these data for clutch-size theory

Epidemiology of Injury in English Women's Super league Football: A Cohort Study

INTRODUCTION: The epidemiology of injury in male professional football has been well documented (Ekstrand, Hägglund, & Waldén, 2011) and used as a basis to understand injury trends for a number of years. The prevalence and incidence of injuries occurring in womens super league football is unknown. The aim of this study is to estimate the prevalence and incidence of injury in an English Super League Women’s Football squad. METHODS: Following ethical approval from Leeds Beckett University, players (n = 25) signed to a Women’s Super League Football club provided written informed consent to complete a self-administered injury survey. Measures of exposure, injury and performance over a 12-month period was gathered. Participants were classified as injured if they reported a football injury that required medical attention or withdrawal from participation for one day or more. Injuries were categorised as either traumatic or overuse and whether the injury was a new injury and/or re-injury of the same anatomical site RESULTS: 43 injuries, including re-injury were reported by the 25 participants providing a clinical incidence of 1.72 injuries per player. Total incidence of injury was 10.8/1000 h (95% CI: 7.5 to 14.03). Participants were at higher risk of injury during a match compared with training (32.4 (95% CI: 15.6 to 48.4) vs 8.0 (95% CI: 5.0 to 10.85)/1000 hours, p 28 days) of which there were three non-contact anterior cruciate ligament (ACL) injuries. The epidemiological incidence proportion was 0.80 (95% CI: 0.64 to 0.95) and the average probability that any player on this team will sustain at least one injury was 80.0% (95% CI: 64.3% to 95.6%) CONCLUSION: This is the first report capturing exposure and injury incidence by anatomical site from a cohort of English players and is comparable to that found in Europe (6.3/1000 h (95% CI 5.4 to 7.36) Larruskain et al 2017). The number of ACL injuries highlights a potential injury burden for a squad of this size. Multi-site prospective investigations into the incidence and prevalence of injury in women’s football are require

Threats from the air: damselfly predation on diverse prey taxa

To understand the diversity and strength of predation in natural communities, researchers must quantify the total amount of prey species in the diet of predators. Metabarcoding approaches have allowed widespread characterization of predator diets with high taxonomic resolution. To determine the wider impacts of predators, researchers should combine DNA techniques with estimates of population size of predators using mark–release–recapture (MRR) methods, and with accurate metrics of food consumption by individuals. Herein, we estimate the scale of predation exerted by four damselfly species on diverse prey taxa within a well‐defined 12‐ha study area, resolving the prey species of individual damselflies, to what extent the diets of predatory species overlap, and which fraction of the main prey populations are consumed. We identify the taxonomic composition of diets using DNA metabarcoding and quantify damselfly population sizes by MRR. We also use predator‐specific estimates of consumption rates, and independent data on prey emergence rates to estimate the collective predation pressure summed over all prey taxa and specific to their main prey (non‐biting midges or chironomids) of the four damselfly species. The four damselfly species collectively consumed a prey mass equivalent to roughly 870 (95% CL 410–1,800) g, over 2 months. Each individual consumed 29%–66% (95% CL 9.4–123) of its body weight during its relatively short life span (2.1–4.7 days; 95% CL 0.74–7.9) in the focal population. This predation pressure was widely distributed across the local invertebrate prey community, including 4 classes, 19 orders and c. 140 genera. Different predator species showed extensive overlap in diets, with an average of 30% of prey shared by at least two predator species. Of the available prey individuals in the widely consumed family Chironomidae, only a relatively small proportion (0.76%; 95% CL 0.35%–1.61%) were consumed. Our synthesis of population sizes, per‐capita consumption rates and taxonomic distribution of diets identifies damselflies as a comparatively minor predator group of aerial insects. As the next step, we should add estimates of predation by larger odonate species, and experimental removal of odonates, thereby establishing the full impact of odonate predation on prey communities.Peer reviewe

Doing audio-visual montage to explore time and space: The everyday rhythms of Billingsgate Fish Market

This article documents, shows and analyses the everyday rhythms of Billingsgate, London’s wholesale fish market. It takes the form of a short film based an audio-visual montage of time-lapse photography and sound recordings, and a textual account of the dimensions of market life revealed by this montage. Inspired by Henri Lefebvre’s Rhythmanalysis, and the embodied experience of moving through and sensing the market, the film renders the elusive quality of the market and the work that takes place within it to make it happen. The composite of audio-visual recordings immerses viewers in the space and atmosphere of the market and allows us to perceive and analyse rhythms, patterns, flows, interactions, temporalities and interconnections of market work, themes that this article discusses. The film is thereby both a means of showing market life and an analytic tool for making sense of it. This article critically considers the documentation, evocation and analysis of time and space in this way

Movement velocity as a measure of exercise intensity in three lower limb exercises

The purpose of this study was to investigate the relationship between movement velocity and relative load in three lower limbs exercises commonly used to develop strength: Leg Press, Full Squat, and Half Squat. The percentage of one Repetition Maximum (%1RM) has typically been used as the main parameter to control resistance training, however more recent research has proposed movement velocity as an alternative. Fifteen participants performed a load progression with a range of loads until they reached their one repetition maximum (1RM). Maximum instantaneous velocity V max) and mean propulsive velocity (MPV) of the knee extension phase of each exercise were assessed. For all exercises, a strong relationship between V max and the %1RM was found: Leg Press (r2adj=0.96; 95% CI for slope is [-0.0244,-0.0258], p<0.0001), Full Squat (r2adj=0.94; 95% CI for slope is [-0.0144, -0.0139], p<0.0001), and Half Squat (r2adj=0.97; 95% CI for slope is [-0.0135, -0.00143], p<0.0001), and for MPV, Leg Press (r2adj=0.96; 95% CI for slope is [- 0.0169, -0.0175], p<0.0001, Full Squat (r2adj=0.95; 95% CI for slope is [-0.0136, -0.0128], p<0.0001), and Half Squat (r2adj=0.96; 95% CI for slope is [-0.0116, 0.0124], p<0.0001). The 1RM was attained with a MPV and Vmax of 0.21±0.06 ms-1 and 0.63±0.15 ms-1, 0.29±0.05 ms-1 and 0.89±0.17 ms-1, 0.33±0.05 ms-1, and 0.95±0.13 ms-1 for Leg Press, Full Squat and Half Squat respectively. Results indicate that it is possible to determine an exercise-specific %1RM by measuring movement velocity for that exercise

Agenda setting and framing of gender-based violence in Nepal: how it became a health issue.

: Gender-based violence (GBV) has been addressed as a policy issue in Nepal since the mid 1990s, yet it was only in 2010 that Nepal developed a legal and policy framework to combat GBV. This article draws on the concepts of agenda setting and framing to analyse the historical processes by which GBV became legitimized as a health policy issue in Nepal and explored factors that facilitated and constrained the opening and closing of windows of opportunity. The results presented are based on a document analysis of the policy and regulatory framework around GBV in Nepal. A content analysis was undertaken. Agenda setting for GBV policies in Nepal evolved over many years and was characterized by the interplay of political context factors, actors and multiple frames. The way the issue was depicted at different times and by different actors played a key role in the delay in bringing health onto the policy agenda. Women's groups and less powerful Ministries developed gender equity and development frames, but it was only when the more powerful human rights frame was promoted by the country's new Constitution and the Office of the Prime Minister that legislation on GBV was achieved and a domestic violence bill was adopted, followed by a National Plan of Action. This eventually enabled the health frame to converge around the development of implementation policies that incorporated health service responses. Our explicit incorporation of framing within the Kindgon model has illustrated how important it is for understanding the emergence of policy issues, and the subsequent debates about their resolution. The framing of a policy problem by certain policy actors, affects the development of each of the three policy streams, and may facilitate or constrain their convergence. The concept of framing therefore lends an additional depth of understanding to the Kindgon agenda setting model.<br/

Spermatogenesis and sertoli cell activity in mice lacking Sertoli cell receptors for follicle stimulating hormone and androgen

Spermatogenesis in the adult male depends on the action of FSH and androgen. Ablation of either hormone has deleterious effects on Sertoli cell function and the progression of germ cells through spermatogenesis. In this study we generated mice lacking both FSH receptors (FSHRKO) and androgen receptors on the Sertoli cell (SCARKO) to examine how FSH and androgen combine to regulate Sertoli cell function and spermatogenesis. Sertoli cell number in FSHRKO-SCARKO mice was reduced by about 50% but was not significantly different from FSHRKO mice. In contrast, total germ cell number in FSHRKO-SCARKO mice was reduced to 2% of control mice (and 20% of SCARKO mice) due to a failure to progress beyond early meiosis. Measurement of Sertoli cell-specific transcript levels showed that about a third were independent of hormonal action on the Sertoli cell, whereas others were predominantly androgen dependent or showed redundant control by FSH and androgen. Results show that FSH and androgen act through redundant, additive, and synergistic regulation of spermatogenesis and Sertoli cell activity. In addition, the Sertoli cell retains a significant capacity for activity, which is independent of direct hormonal regulation