Resistance training practices of Brazilian Olympic sprint and jump coaches: toward a deeper understanding of their choices and insights (part III)

In the final part of this three-article collection on the training strategies of Brazilian Olympic sprint and jump coaches, we provide a detailed description of the resistance training methods and exercises most commonly employed by these speed experts. Always with the objective of maximizing the sprint and jump capabilities of their athletes, these experienced coaches primarily utilize variable, eccentric, concentric, machine-based, isometric, complex, and isoinertial resistance training methods in their daily practices. Squats (in their different forms), Olympic weightlifting, ballistics, hip thrusts, lunges, calf raises, core exercises, leg curls, stiff-leg deadlifts, and leg extension are the most commonly prescribed exercises in their training programs, during both the preparatory and competitive periods. Therefore, the current manuscript comprehensively describes and examines these methods, with the additional aim of extrapolating their application to other sports, especially those where sprint speed is a key performance factor

High-energy spectroscopic study of the III-V nitride-based diluted magnetic semiconductor Ga1−x_{1-x}Mnx_{x}N

We have studied the electronic structure of the diluted magnetic semiconductor Ga$_{1-x}$Mn$_{x}$N ($x$ = 0.0, 0.02 and 0.042) grown on Sn-doped $n$-type GaN using photoemission and soft x-ray absorption spectroscopy. Mn $L$-edge x-ray absorption have indicated that the Mn ions are in the tetrahedral crystal field and that their valence is divalent. Upon Mn doping into GaN, new state were found to form within the band gap of GaN, and the Fermi level was shifted downward. Satellite structures in the Mn 2$p$ core level and the Mn 3$d$ partial density of states were analyzed using configuration-interaction calculation on a MnN$_{4}$ cluster model. The deduced electronic structure parameters reveal that the $p$-$d$ exchange coupling in Ga$_{1-x}$Mn$_{x}$N is stronger than that in Ga$_{1-x}$Mn$_{x}$As.Comment: 6pages, 10figures. To be published to Phys. Rev.

A randomised controlled trial of personalised decision support delivered via the internet for bowel cancer screening with a faecal occult blood test: the effects of tailoring of messages according to social cognitive variables on participation

BACKGROUND: In Australia, bowel cancer screening participation using faecal occult blood testing (FOBT) is low. Decision support tailored to psychological predictors of participation may increase screening. The study compared tailored computerised decision support to non-tailored computer or paper information. The primary outcome was FOBT return within 12 weeks. Additional analyses were conducted on movement in decision to screen and change on psychological variables. METHODS: A parallel, randomised controlled, trial invited 25,511 people aged 50-74 years to complete an eligibility questionnaire. Eligible respondents (n = 3,408) were assigned to Tailored Personalised Decision Support (TPDS), Non-Tailored PDS (NTPDS), or Control (CG) (intention-to-treat, ITT sample). TPDS and NTPDS groups completed an on-line baseline survey (BS) and accessed generic information. The TPDS group additionally received a tailored intervention. CG participants completed a paper BS only. Those completing the BS (n = 2270) were mailed an FOBT and requested to complete an endpoint survey (ES) that re-measured BS variables (per-protocol, PP sample). RESULTS: FOBT return: In the ITT sample, there was no significant difference between any group (χ (2)(2) = 2.57, p = .26; TPDS, 32.5%; NTPDS, 33%; and CG, 34.5%). In the PP sample, FOBT return in the internet groups was significantly higher than the paper group (χ (2)(2) = 17.01, p < .001; TPDS, 80%; NTPDS, 83%; and CG, 74%). FOBT completion by TPDS and NTPDS did not differ (χ (2)(1) = 2.23, p = .13). Age was positively associated with kit return. Decision to screen: 2227/2270 of the PP sample provided complete BS data. Participants not wanting to screen at baseline (1083/2227) and allocated to TPDS and NTPDS were significantly more likely to decide to screen and return an FOBT than those assigned to the CG. FOBT return by TPDS and NTPDS did not differ from one another (OR = 1.16, p = .42). Change on psychosocial predictors: Analysis of change indicated that salience and coherence of screening and self-efficacy were improved and faecal aversion decreased by tailored messaging. CONCLUSIONS: Online information resources may have a role in encouraging internet-enabled people who are uncommitted to screening to change their attitudes, perceptions and behaviour. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12610000095066.Carlene J Wilson, Ingrid HK Flight, Deborah Turnbull, Tess Gregory, Stephen R Cole, Graeme P Young, and Ian T Zaja

Analysis of lower limb internal kinetics and electromyography in elite race walking.

The aim of this study was to analyse lower limb joint moments, powers and electromyography patterns in elite race walking. Twenty international male and female race walkers performed at their competitive pace in a laboratory setting. The collection of ground reaction forces (1000 Hz) was synchronised with two-dimensional high-speed videography (100 Hz) and electromyography of seven lower limb muscles (1000 Hz). As well as measuring key performance variables such as speed and stride length, normalised joint moments and powers were calculated. The rule in race walking which requires the knee to be extended from initial contact to midstance effectively made the knee redundant during stance with regard to energy generation. Instead, the leg functioned as a rigid lever which affected the role of the hip and ankle joints. The main contributors to energy generation were the hip extensors during late swing and early stance, and the ankle plantarflexors during late stance. The restricted functioning of the knee during stance meant that the importance of the swing leg in contributing to forward momentum was increased. The knee flexors underwent a phase of great energy absorption during the swing phase and this could increase the risk of injury to the hamstring muscles

Multibody dynamics analysis (MDA) as a numerical modelling tool to reconstruct the function and palaeobiology of extinct organisms

Recent advances in computer technology have substantially changed the field of palaeontology in the last two decades. Palaeontologists now have a whole new arsenal of powerful digital techniques available to study fossil organisms in unprecedented detail and to test hypotheses regarding function and behaviour. Multibody dynamics analysis (MDA) is one of these techniques and although it originated as a tool used in the engineering and automotive industry, it holds great potential to address palaeontological questions as well. MDA allows the simulation of dynamic movements in complex objects consisting of multiple linked components. As such, this technique is ideally suited to model biological structures and to obtain quantifiable results that can be used to test the function of musculoskeletal systems rigorously. However, despite these advantages, MDA has seen a slow uptake by the palaeontological community. The most likely reason for this lies in the steep learning curve and complexity of the method. This paper provides an overview of the underlying principles of MDA and outlines the main steps involved in conducting analyses. A number of recent studies using MDA to reconstruct the palaeobiology of fossil organisms are presented and the potential for future studies is discussed. Similar to other computational techniques, including finite element analysis and computational fluid dynamics, the non‐invasive and exploratory power of MDA makes it ideally suited to study the form and function in vertebrates for which no modern analogues exist

Local Density Approximation for proton-neutron pairing correlations. I. Formalism

In the present study we generalize the self-consistent Hartree-Fock-Bogoliubov (HFB) theory formulated in the coordinate space to the case which incorporates an arbitrary mixing between protons and neutrons in the particle-hole (p-h) and particle-particle (p-p or pairing) channels. We define the HFB density matrices, discuss their spin-isospin structure, and construct the most general energy density functional that is quadratic in local densities. The consequences of the local gauge invariance are discussed and the particular case of the Skyrme energy density functional is studied. By varying the total energy with respect to the density matrices the self-consistent one-body HFB Hamiltonian is obtained and the structure of the resulting mean fields is shown. The consequences of the time-reversal symmetry, charge invariance, and proton-neutron symmetry are summarized. The complete list of expressions required to calculate total energy is presented.Comment: 22 RevTeX page

Bone microarchitecture in transgender adults: a cross-sectional study

First published: 03 January 2022Gender-affirming hormone therapy aligns physical characteristics with an individual’s gender identity, but sex hormones regulate bone remodeling and influence bonemorphology. Wehypothesized that transmen receiving testosterone have compromised bonemorphology because of suppression of ovarian estradiol production, whereas trans women receiving estradiol, with or without anti-androgen therapy, have preserved bonemicroarchitecture.We compared distal radial and tibial microarchitecture using high-resolution peripheral quantitative computed tomography images in a cross-sectional study of 41 trans men with 71 cis female controls, and 40 trans women with 51 cismale controls. Between-group differences were expressed as standardized deviations (SD) fromthemean in age-matched cisgender controls with 98% confidence intervals adjusted for cross-sectional area (CSA) and multiple comparisons. Relative to cis women, trans men had 0.63 SD higher total volumetric bone mineral density (vBMD; both p = 0.01). Cortical vBMD and cortical porosity did not differ, but cortices were 1.11 SD thicker (p < 0.01). Trabeculae were 0.38 SD thicker (p = 0.05) but otherwise no different. Compared with cismen, trans women had 0.68 SD lower total vBMD (p=0.01). Cortical vBMD was 0.70 SD lower (p < 0.01), cortical thicknesswas 0.51 SD lower (p = 0.04), and cortical porosity was 0.70 SD higher (p < 0.01). Trabecular bone volume (BV/TV) was 0.77 SD lower (p < 0.01),with 0.57 SD fewer (p < 0.01) and 0.30 SD thicker trabeculae (p = 0.02). There was 0.56 SD greater trabecular separation (p = 0.01). Findings at the distal radius were similar. Contrary to each hypothesis, bonemicroarchitecture was not compromised in trans men, perhaps because aromatization of administered testosterone prevented bone loss. Trans women had deteriorated bone microarchitecture either because of deficits in microstructure before treatment or because the estradiol dosage was insufficient to offset reduced aromatizable testosterone. Prospective studies are needed to confirm these findings.Ingrid Bretherton, Ali Ghasem-Zadeh, Shalem Y Leemaqz, Ego Seeman, Xiaofang Wang, Thomas McFarlane, Cassandra Spanos, Mathis Grossmann, Jeffrey D Zajac, and Ada S Cheun

The complex TIE between macrophages and angiogenesis

Macrophages are primarily known as phagocytic immune cells, but they also play a role in diverse processes, such as morphogenesis, homeostasis and regeneration. In this review, we discuss the influence of macrophages on angiogenesis, the process of new blood vessel formation from the pre-existing vasculature. Macrophages play crucial roles at each step of the angiogenic cascade, starting from new blood vessel sprouting to the remodelling of the vascular plexus and vessel maturation. Macrophages form promising targets for both pro- and anti-angiogenic treatments. However, to target macrophages, we will first need to understand the mechanisms that control the functional plasticity of macrophages during each of the steps of the angiogenic cascade. Here, we review recent insights in this topic. Special attention will be given to the TIE2-expressing macrophage (TEM), which is a subtype of highly angiogenic macrophages that is able to influence angiogenesis via the angiopoietin-TIE pathway