A biomechanical analysis of the heavy sprint-style sled pull and comparison with the back squat

This study compared the biomechanical characteristics of the heavy sprint-style sled pull and squat. Six experienced male strongman athletes performed sled pulls and squats at 70% of their 1RM squat. Significant kinematic and kinetic differences were observed between the sled pull start and squat at the start of the concentric phase and at maximum knee extension. The first stride of the heavy sled pull demonstrated significantly (

Abating Prejudice With Presence: Dispositional Mindfulness Increases Interracial Helping Behavior

Helping behavior is less frequently shown toward members of social out-groups (Cikra, Bruneau, & Saxe, 2011). Race defines a common source of social division in America and other countries, and although most condemn racial discrimination, helping is undermined in interracial interactions (Saucier, Miller, & Doucet, 2005). Recent theory suggests that mindfulness, a receptive attention to one’s present experience, can attenuate the conceptual boundaries that typically separate and distance oneself from others (Trautwein, Schmidt, & Naranjo, 2014). We designed an experiment to examine whether dispositional mindfulness would be associated with increased helping behavior in interracial contexts. Self-identifying White participants (N = 139) witnessed a confederate in need of help while waiting to participate in a study, and experimenters observed whether participants helped them or not; self-identifying White or Black confederates were randomly assigned to each experimental session. Three-block sequential logistic regression models were constructed to identify predictors of same-race and interracial helping. Overall, dispositional mindfulness, agreeableness, and lower racial prejudice predicted greater helping behavior in same-race interactions (all ps \u3c 0.05). Interestingly, mindfulness moderated the help-reducing effects of racial prejudice in the interracial interactions (p \u3c 0.05). More specifically, high mindfulness was associated with increased helping behavior among those high in racial prejudice. This correlational evidence is consistent with mindfulness theory, which suggests deploying mindful attention dampens psychological barriers between self and others. This study highlights the potential for mindfulness in reducing defensive attitudes and increasing prosocial responsiveness across social lines.https://scholarscompass.vcu.edu/uresposters/1230/thumbnail.jp

Highly Sensitive Dual-Core Photonic Metal Fiber

In this study, we propose an all-solid cladding dual-core metal fiber (DC-MF) filled with toluene and ethanol for temperature sensing applications. Instead of using air holes in the cladding region, we employ fluorine doped silica glass to form an all-solid cladding. By selectively filling toluene and ethanol into three air holes near the core region, we investigate the temperature sensing characteristics numerically. Simulation results demonstrate that the average sensitivity of the temperature sensing can reach -11.64 and -7.41 nm/C within the temperature ranges of 0 to 70 C and -80 to 0 C, respectively, even with a short DC-MF length of 1.6 mm. The maximum sensitivity in the considered temperature ranges can reach up to -15 and -9 nm/C, respectively. Furthermore, the proposed temperature sensor exhibits insensitivity to hydrostatic pressure

Agreement of a Novel Vertical Jump System to Measure Vertical Jump Height: Brower Vertical Jump and Vertec Vertical Jump Systems

Topics in Exercise Science and Kinesiology Volume 2: Issue 1, Article 12, 2021. Validity refers to the ability of a device to measure what it was intended to measure. Therefore, purpose of this study was to assess the validity and reliability of a novel vertical jump height tool designed by Brower Timing Systems (Salt Lake City, Ut). The Brower vertical jump system was compared to the Vertec jump tester. A convenience sample (n=67) of college students performed three maximum countermovement jumps, with the average score being recorded. Data was collected simultaneously for both devices. Results showed a strong and statistically significant correlation between the Vertec vertical jump tester and Brower vertical jump (r = 0.971, p \u3c 0.001.) A paired t-test showed no significant difference (p = 0.170, t = 1.386) between the two systems. An analysis of equivalence was also performed with alpha set at 0.05 and an upper and lower bound set at +/- 0.5. The observed effect was statistically not different from zero and statistically equivalent to zero. Based on the statistical analysis, it can be concluded the Vertec and Brower vertical jump height systems have a high correlation and are equivalent. The Brower system can be an option for assessing vertical jump height, specifically, the Brower system may be useful for high throughput field environments such as testing teams or larger groups to provide valid data

Statistical methods for analyzing immunosignatures

<p>Abstract</p> <p>Background</p> <p>Immunosignaturing is a new peptide microarray based technology for profiling of humoral immune responses. Despite new challenges, immunosignaturing gives us the opportunity to explore new and fundamentally different research questions. In addition to classifying samples based on disease status, the complex patterns and latent factors underlying immunosignatures, which we attempt to model, may have a diverse range of applications.</p> <p>Methods</p> <p>We investigate the utility of a number of statistical methods to determine model performance and address challenges inherent in analyzing immunosignatures. Some of these methods include exploratory and confirmatory factor analyses, classical significance testing, structural equation and mixture modeling.</p> <p>Results</p> <p>We demonstrate an ability to classify samples based on disease status and show that immunosignaturing is a very promising technology for screening and presymptomatic screening of disease. In addition, we are able to model complex patterns and latent factors underlying immunosignatures. These latent factors may serve as biomarkers for disease and may play a key role in a bioinformatic method for antibody discovery.</p> <p>Conclusion</p> <p>Based on this research, we lay out an analytic framework illustrating how immunosignatures may be useful as a general method for screening and presymptomatic screening of disease as well as antibody discovery.</p

Body Composition of Utah Highway Patrol Officers: No Difference Between Air Displacement Plethysmography and Alternative Tools for Measurement and Prediction.

Topics in Exercise Science and Kinesiology Volume 3: Issue 1, Article 6, 2022. Different techniques exist for examining body composition. The purpose of this study was to examine differences in body fat percentage as measured by air displacement plethysmography (ADP), body adiposity index (BAI), bioelectrical impedance (BIA), a body mass index conversion equation (BMID), and skinfolds (SKF). Twenty-one male Utah Highway Patrol Officers participated in this study (age 35.19 ± 10.32 years, 1.79 ± 0.09 m tall, 92.20 ± 14.56 kg in weight, and 105.52 ± 10.01 cm hip circumference). All measurements were taken during a single visit and performed in the same order for all participants beginning with BIA, followed by ADP, and SKF. The BAI and BMI conversion equation were later calculated. For ADP and SKF the Brozek equation was used to convert body density to percent body fat (%BF). No significant differences were found among the different measurement techniques. No significant correlations were found between ADP, BAI, BIA, BMID, and SKF. Bland-Altman plots revealed small levels of bias, however, the upper and lower limits of agreement were large for all measures. Prediction equations such as BAI and BMID may be cheaper and faster for assessing large populations when compared with traditional laboratory techniques. This study found no significant different among the measurement techniques. Despite the non-significant differences, the authors suggest using a single measurement technique and not using techniques interchangeably

The Binary Fraction of Low Mass White Dwarfs

We describe spectroscopic observations of 21 low-mass (<0.45 M_sun) white dwarfs (WDs) from the Palomar-Green Survey obtained over four years. We use both radial velocities and infrared photometry to identify binary systems, and find that the fraction of single, low-mass WDs is <30%. We discuss the potential formation channels for these single stars including binary mergers of lower-mass objects. However, binary mergers are not likely to explain the observed number of single low-mass WDs. Thus additional formation channels, such as enhanced mass loss due to winds or interactions with substellar companions, are likely.Comment: 9 pages, accepted to Ap

Susceptibility of North American Ducks and Gulls to H5N1 Highly Pathogenic Avian Influenza Viruses

Species-related differences in clinical response and duration and extent of viral shedding exist between North American ducks and gulls infected with H5N1 HPAI viruses

Formation and Disruption of W-Phase in High-Entropy Alloys

High-entropy alloys (HEAs) are single-phase systems prepared from equimolar or near-equimolar concentrations of at least five principal elements. The combination of high mixing entropy, severe lattice distortion, sluggish diffusion and cocktail effect favours the formation of simple phases—usually a bcc or fcc matrix with minor inclusions of ordered binary intermetallics. HEAs have been proposed for applications in which high temperature stability (including mechanical and chemical stability under high temperature and high mechanical impact) is required. On the other hand, the major challenge to overcome for HEAs to become commercially attractive is the achievement of lightweight alloys of extreme hardness and low brittleness. The multicomponent AlCrCuScTi alloy was prepared and characterized using powder X-ray diffraction (PXRD), scanning-electron microscope (SEM) and atomic-force microscope equipped with scanning Kelvin probe (AFM/SKP) techniques. Results show that the formation of complex multicomponent ternary intermetallic compounds upon heating plays a key role in phase evolution. The formation and degradation of W-phase, Al2Cu3Sc, in the AlCrCuScTi alloy plays a crucial role in its properties and stability. Analysis of as-melted and annealed alloy suggests that the W-phase is favoured kinetically, but thermodynamically unstable. The disruption of the W-phase in the alloy matrix has a positive effect on hardness (890 HV), density (4.83 g·cm−3) and crack propagation. The hardness/density ratio obtained for this alloy shows a record value in comparison with ordinary heavy refractory HEAs