Energy cost and knee extensor strength changes following multiple day military load carriage.

Military exercises and recruit training requires soldiers, including new recruits, to undergo multiple days of substantial physical stress. The aim of this study was to evaluate the physiological impact of multiple days of military load carriage by addressing the hypothesis: A second day of load carriage increases oxygen uptake and reduces knee extensor torque compared to a single day of load carriage. A load carriage group (n = 12) (carrying 32 kg) and unloaded group (n = 14) walked on a treadmill for 2 h on two consecutive days. Knee extensor and flexor torque were assessed by dynamometry at speeds of: 0°·s ,60°·s and 180°·s before and after load carriage on day one and two, and 24 h following day 2. Oxygen uptake was assessed via respiratory gas assessment at the 6th and 119th minute of load carriage on day one and two. When assessed by mixed methods ANOVA (alpha: 0.05), an interaction effect was observed for oxygen uptake (p < 0.001), with post hoc assessment highlighting second day of load carriage significantly increased oxygen uptake compared to day one post in the loaded group (28.9(3.0) vs 25.8(3.4), p = 0.048). An interaction effect was observed for all knee extensor variables (all p < 0.05). All knee extensor peak torque variables were significantly associated to oxygen uptake at 0°s (r = -0.576, p < 0.05), 60°s (r = -0.552, p < 0.05), and 180°s (r = -0.589, p < 0.05). Two days of load carriage significantly increases oxygen uptake and reduces knee extensor and flexor torque compared to a single day of load carriage. Subsequently, physical training programmes aimed at increasing knee extensor strength may protect against increases in oxygen uptake. [Abstract copyright: Copyright © 2021 Elsevier Ltd. All rights reserved.

The Correlation of Dyslipidemia with the Extent of Coronary Artery Disease in the Multiethnic Study of Atherosclerosis.

BackgroundThe extent of coronary artery calcium (CAC) improves cardiovascular disease (CVD) risk prediction. The association between common dyslipidemias (combined hyperlipidemia, simple hypercholesterolemia, metabolic Syndrome (MetS), isolated low high-density lipoprotein cholesterol, and isolated hypertriglyceridemia) compared with normolipidemia and the risk of multivessel CAC is underinvestigated.ObjectivesTo determine whether there is an association between common dyslipidemias compared with normolipidemia, and the extent of coronary artery involvement among MESA participants who were free of clinical cardiovascular disease at baseline.MethodsIn a cross-sectional analysis, 4,917 MESA participants were classified into six groups defined by specific LDL-c, HDL-c, or triglyceride cutoff points. Multivessel CAC was defined as involvement of at least 2 coronary arteries. Multivariate Poisson regression analysis evaluated the association of each group with multivessel CAC after adjusting for CVD risk factors.ResultsUnadjusted analysis showed that all groups except hypertriglyceridemia had statistically significant prevalence ratios of having multivessel CAC as compared to the normolipidemia group. The same groups maintained statistical significance prevalence ratios with multivariate analysis adjusting for other risk factors including Agatston CAC score [combined hyperlipidemia 1.41 (1.06-1.87), hypercholesterolemia 1.55 (1.26-1.92), MetS 1.28 (1.09-1.51), and low HDL-c 1.20 (1.02-1.40)].ConclusionCombined hyperlipidemia, simple hypercholesterolemia, MetS, and low HDL-c were associated with multivessel coronary artery disease independent of CVD risk factors and CAC score. These findings may lay the groundwork for further analysis of the underlying mechanisms in the observed relationship, as well as for the development of clinical strategies for primary prevention

Force-time characteristics of repeated bouts of depth jumps and the effects of compression garments

No studies have reported ground-reaction force (GRF) profiles of the repeated depth-jump (DJ) protocols commonly used to study exercise-induced muscle damage (EIMD). Furthermore, whilst compression garments (CG) may accelerate recovery from EIMD, any effects on the repeated-bout effect are unknown. Therefore, we investigated the GRF profiles of two repeated bouts of damage-inducing DJs, and the effects of wearing CG for recovery. Non-resistance trained males randomly received CG (n=9) or placebo (n=8) for 72 h recovery, following 20 x 20 m sprints and 10 x 10 DJs from 0.6 m. Exercise was repeated after 14 days. Using a three-way (set x bout x group) design, changes in GRF were assessed with ANOVA and statistical parametric mapping (SPM). Jump height, reactive strength, peak and mean propulsive forces declined between sets (p&lt;0.001). Vertical stiffness, contact time, force at zero velocity and propulsive duration increased (p&lt;0.05). According to SPM, braking (17–25% of the movement), and propulsive forces (58–81%) declined (p&lt;0.05). During the repeated bout, peak propulsive force and duration increased (p&lt;0.05), whilst mean propulsive force (p&lt;0.05) and GRF from 59–73% declined (p&lt;0.001). A repeated bout of DJs differed in propulsive GRF, without changes to the eccentric phase, or effects from CG

Thermodynamics of Hydroxyapatite Surfaces

A new model for equilibria at the interface of a sparingly soluble crystal is reviewed. It provides that several kinds of equilibria are present and each type is characterized by (i) a set of species that are transported across the phase boundary, (ii) a set · of chemical reactions which describe this transport process, and (iii) a set of thermodynamic expressions which define equilibrium. Three types are envisaged: 1. Stoichiometric equilibrium provides the thermodynamic communication between the lattice and the bulk solution, occurs at a kink site, preserves the composition of the solid phase, defines a solubility product, leads to an isotherm in the phase diagram, and is unaffected by Galvani potentials. The equilibrium is defined by a single equation. 2. Gibbsian equilibrium in which the chemical potential of each component is stated to be equal across the phase boundary, but does not define an actual chemical process. There is one such equation for each component in the system. 3. Electrochemical equilibrium provides thermodynamic communication between ions in the bulk phase and those in the outer layer of the crystal, is nonstoichiometric, is profoundly affected by Galvani potentials, does not lead to a solubility product constant nor to an isotherm, and requires one more equilibrium condition than there are components in the system. Equilibrium between the lattice and the surface is limited to reactions via the aqueous phase, one of which is stoichiometric and the other nonstoichiometric. This model provides a clarity of description of interfacial events heretofore unattainable

Numerical investigation into the combustion behavior of an inlet-fueled thermal-compression-like scramjet

A numerical study on the combustion behavior of an inlet-fueled three-dimensional nonuniform-compression scramjet is presented. This paper is an extension to previous work on the combustion processes in a premixed three-dimensional nonuniform-compression scramjet, where thermal compression was shown to enhance combustion. This paper demonstrates how thermal compression can be used in a generic scramjet configuration with a realistic fuel-injection method to enhance performance at high flight Mach numbers. Such a scramjet offers an extra degree of freedom in the design process of fixed-geometry scramjets that must operate over a range of flight Mach numbers. In this study, how the combustion processes are affected is investigated, with the added realism of inlet porthole fuel injection. Ignition is established from within a shock-induced boundary-layer separation at the entrance to the combustor. Radicals that form upstream of the combustor within the inlet, from the injection method, enhance combustion. Coupling of the inlet-induced spanwise gradients and thermal compression improves combustion. The results highlight that, although the fuel-injection method imparts local changes to the flow structures, the global flow behavior does not change compared to previous premixed results. This combustion behavior will be reproduced when using other fueling methods that deliver partially premixed fuel and air to the combustor entrance

A Deficiency of Donors or an Abundance of Barriers? Title IX Fundraising Challenges from the Perspective of Athletic Department Fundraisers

This paper explores how Title IX effects college athletic fundraising, particularly how athletic fundraisers creates an unfair environment for non-football and basketball programs. Using distributive justice as a theoretical lens, we examine the perspective of athletic department fundraisers working at NCAA, Power Five athletic departments. Interviews from participants gleaned insights into only meeting the minimum legal requirements of Title IX, fighting between non-revenue programs for remaining resources, elevated requirements for program success for non-football and basketball programs, and more. This paper aims at providing insight into a distinct context of fundraising, which often avoids Title IX scrutiny, but is the primary outlet for athletic departments to raise additional funds for their sport programs

A PRELIMINARY STUDY: EXPLORING THE MUSCULAR CHANGES BETWEEN PARTIAL AND FULL SHOTS DURING THE DOWNSWING IN GOLF UTILISING STATISTICAL PARAMETRIC MAPPING

The purpose of this study was to assess the feasibility of using Statistical Parametric Mapping (SPM) data analysis techniques on golf swing electromyographic (EMG) data and to explore any muscular changes that might occur between full and partial golf shots. Three male golfers completed the testing. The results of the ANOVA suggest that two muscles show a significant decrease in muscle activation between the shot conditions, Right Medial Gastrocnemius (RMG)(p\u3c0.001) and Right Rectus Abdominus (RRA) (p\u3c0.001). The post-hoc analysis suggests that RMG and RRA both decrease activation to perform partial shots. The results suggest that SPM analysis is a useful tool for golf swing research and that specific muscles might show activation changes associated with reducing shot distance

Semantic Analysis: Can MD&A Word Choice Increase Stock Price of American Publicly Traded Banks Disseminating Using Twitter?

Social media has become a part of the International framework. Use has risen exponentially and organizations that have relied on traditional channels of communication are considering its use. Researchers studied the impact of semantics on organizations disseminating financial information using Twitter. This study sought to understand the impact of word strength in communicating with investors. This study included 34 American publicly traded banks over four quarters or a sample size of 136. Seventeen used Twitter while seventeen did not. The researchers analyzed the semantic content of these messages. Using a predictive model, researchers compared the cumulative abnormal returns associated with the announcement. Researchers concluded that using Twitter did not positively impact stock price. Researchers also found that banks using Twitter used more powerful words in communicating. This research advances understanding the role social media and semantics can play to disseminate financial informatio