3,835 research outputs found

    High-Risk Environmental Conditions Attenuates Performance Efficiency Index in NCAA DI Female Soccer Players

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    International Journal of Exercise Science 15(6): 442-454, 2022. The purpose of this study was to evaluate the effects of environmental conditions on running performance and performance efficiency index (Effindex). Performance data recorded using Polar Team Pro sensors from eight collegiate female soccer players in nine matches were analyzed during the 2019 competitive season. Effindex and running performance, including total distance covered (TDREL) and distance covered in five speed thresholds relative to minutes played, were examined for indications of fatigue with respect to environmental conditions, including ambient temperature and relative humidity. Matches were separated into three groups based on environmental conditions: Low-Risk (n = 2 matches), Moderate-Risk (n = 3 matches), or High-Risk (n = 4 matches). Speed thresholds were grouped as follows: walking (WALKREL), jogging (JOGREL), low-speed running (LSRREL), high-speed running (HSRREL), and sprinting (SPRINTREL). A significant effect was observed for TDREL in all environmental conditions (η2 = 0.614). TDREL was significantly lower in the High-Risk (p = 0.002; 95.32 ± 12.04 m/min) and Moderate-Risk conditions (p = 0.004; 94.85 ± 9.94 m/min) when compared to Low-Risk (105.61 ± 9.95 m/min). WALKREL (p = 0.005), JOGREL (p = 0.005) LSRREL (p = 0.001), HSRREL (p = 0.035), SPRINTREL (p = 0.017), and Effindex (p = 0.0004) were significantly greater in Low-Risk conditions when compared to Moderate-Risk conditions. WALKREL (p = 0.005), HSRREL (p = 0.029), SPRINTREL (p = 0.005), and Effindex (p = 0.0004) were significantly greater in Low-Risk conditions when compared to High-Risk conditions. High-Risk environmental conditions may result in adverse performance in female collegiate soccer players

    Mediators of Monocyte Migration in Response to Recovery Modalities following Resistance Exercise

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    Mediators of monocyte migration, complement receptor-3 (CR3), and chemokine ligand-4 (CCL4) were measured in response to recovery modalities following resistance exercise. Thirty resistance-trained men (23.1 +/- 2.9 y; 175.2 +/- 7.1 cm; 82.1 +/- 8.4 kg) were given neuromuscular electric stimulation (NMES), cold water immersion (CWI), or control (CON) treatments immediately following resistance exercise. Blood samples were obtained preexercise (PRE), immediately (IP), 30 minutes (30 P), 24 hours (24 H), and 48 hours (48 H) after exercise for measurement of circulating CCL4 and CR3 expression on CD14+ monocytes, by assay and flow cytometry. Circulating CCL4 showed no consistent changes. Inferential analysis indicated that CR3 expression was likely greater in CON at 30 P than NMES (90.0%) or CWI (86.8%). NMES was likely lower than CON at 24H (92.9%) and very likely lower at 48H (98.7%). Expression of CR3 following CWI was very likely greater than CON (96.5%) at 24H. The proportion of CR3+ monocytes was likely greater following CWI than NMES (85.8%) or CON (85.2%) at 24 H. The change in proportion of CR3+ monocytes was likely (86.4%) greater following NMES than CON from IP to 30 P. The increased expression of CR3 and increased proportion of CR3+ monocytes following CWI at 24 H indicate a potentially improved ability for monocyte adhesion to the endothelium, possibly improving phagocytosis of damaged tissues

    Identification of single-site gold catalysis in acetylene hydrochlorination

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    There remains considerable debate over the active form of gold under operating conditions of a recently validated gold catalyst for acetylene hydrochlorination. We have performed an in situ x-ray absorption fine structure study of gold/carbon (Au/C) catalysts under acetylene hydrochlorination reaction conditions and show that highly active catalysts comprise single-site cationic Au entities whose activity correlates with the ratio of Au(I):Au(III) present. We demonstrate that these Au/C catalysts are supported analogs of single-site homogeneous Au catalysts and propose a mechanism, supported by computational modeling, based on a redox couple of Au(I)-Au(III) species. View Full Tex

    Evaluating the effects of PeakATP® supplementation on visuomotor reaction time and cognitive function following high-intensity sprint exercise

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    The purpose of this study was to examine the effects of 14-days adenosine 5′-triphosphate (ATP) supplementation (PeakATP®) on reaction time (RT), multiple object tracking speed (MOT), mood and cognition. Twenty adults (22.3 ± 4.4 yrs., 169.9 ± 9.5 cm, 78.7 ± 14.6 kg) completed two experimental trials in a double-blind, counter-balanced, crossover design. Subjects were randomized to either PeakATP® (400 mg) or placebo (PLA) and supplemented for 14-days prior to each trial. During each trial, subjects completed a three-minute all-out test on a cycle ergometer (3MT), with measures of visuomotor RT [Dynavision D2 Proactive (Mode A) and Reactive (Mode B) tasks], MOT (Neurotracker), mood (Profile of Mood States Questionnaire; POMS) and cognition (Automated Neuropsychological Assessment Metrics; ANAM) occurring before (PRE), immediately post (IP) and 60 min post-3MT (60P). Subjects ingested an acute dose of the assigned supplement 30 min prior to completing PRE assessments for each trial. Trials were separated by a 14-day washout period. PeakATP® significantly attenuated declines in hits (p = 0.006, ηp2 = 0.235) and average RT (AvgRT, p = 0.006, ηp2 = 0.236) in Mode A, significantly improved AvgRT (p = 0.039, ηp2 = 0.174) in Mode B, and significantly reduced the total number of misses (p = 0.005, ηp2 = 0.343) in Mode B. No differences between treatments were noted for MOT, POMS or ANAM variables. In conclusion, these results indicate that PeakATP® maintains proactive RT and improves reactive RT following high-intensity sprint exercise suggesting that supplemental ATP may mitigate exercise induced cognitive dysfunction

    Cycle-based high-intensity sprint exercise elicits acute cognitive dysfunction in psychomotor and memory task performance

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    PurposeTo examine the impact of an acute high-intensity sprint exercise protocol (HISEP) for eliciting post-exercise cognitive dysfunction in psychomotor, attentional, executive, and memory tasks.MethodsTwenty-four recreationally active adults (22 ± 4 yrs, 169.39 ± 10.07 cm, 75.80 ± 14.73 kg, 27.03 ± 9.55 BF%) performed a HISEP on a cycle ergometer. Average psychomotor reaction time (avgRT; Dynavision D2 Mode A & Mode B), mood (Profile of Mood States Questionnaire; POMS), and cognition (Automated Neuropsychological Assessment Metrics; ANAM) were assessed pre- (PRE), post- (POST) and 60-min post (60POST) HISEP. One-way repeated measures ANOVAs were used to assess changes across time.ResultsFatigue (main effect: p < 0.001, ηp2 = 0.309) was significantly higher at POST compared to PRE (p = 0.007). Tension (main effect: p = 0.021, ηp2 = 0.154) was significantly lower at 60POST compared to PRE (p = 0.029). Mode A avgRT (main effect: p = 0.022, ηp2 = 0.153) was significantly slower at POST compared to PRE (p = 0.026). Throughput (TP) scores for ANAM code substitution-delayed (CSD) task (main effect: p < 0.001, ηp2 = 0.284) and matching to sample (M2S) tasks (main effect: p = 0.014, ηp2 = 0.169) were significantly lower at POST compared to PRE (p = 0.001 and p = 0.025, respectively), while mathematical processing (main effect: p = 0.002, ηp2 = 0.232) was significantly higher at 60POST compared to both PRE (p = 0.019) and POST (p = 0.005). No other significant changes in cognitive task performance were observed (p's > 0.05).ConclusionsThe HISEP is a feasible and time-effective fatiguing exercise stimulus capable of eliciting acute cognitive dysfunction in psychomotor and memory task performance. NCT05100589

    Type 5 secretion system antigens as vaccines against Gram-negative bacterial infections

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    Infections caused by Gram-negative bacteria are leading causes of mortality worldwide. Due to the rise in antibiotic resistant strains, there is a desperate need for alternative strategies to control infections caused by these organisms. One such approach is the prevention of infection through vaccination. While live attenuated and heat-killed bacterial vaccines are effective, they can lead to adverse reactions. Newer vaccine technologies focus on utilizing polysaccharide or protein subunits for safer and more targeted vaccination approaches. One promising avenue in this regard is the use of proteins released by the Type 5 secretion system (T5SS). This system is the most prevalent secretion system in Gram-negative bacteria. These proteins are compelling vaccine candidates due to their demonstrated protective role in current licensed vaccines. Notably, Pertactin, FHA, and NadA are integral components of licensed vaccines designed to prevent infections caused by Bordetella pertussis or Neisseria meningitidis. In this review, we delve into the significance of incorporating T5SS proteins into licensed vaccines, their contributions to virulence, conserved structural motifs, and the protective immune responses elicited by these proteins

    Effects of beta-Hydroxy-beta-methylbutyrate Free Acid Ingestion and Resistance Exercise on the Acute Endocrine Response

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    Objective. To examine the endocrine response to a bout of heavy resistance exercise following acute beta-hydroxy-beta-methylbutyrate free acid (HMB-FA) ingestion. Design. Twenty resistance trained men were randomized and consumed either 1 g of HMB-FA (BetaTor) or placebo (PL) 30 min prior to performing an acute heavy resistance exercise protocol. Blood was obtained before (PRE), immediately after (IP), and 30 min after exercise (30P). Circulating concentrations of testosterone, growth hormone (GH), insulin-like growth factor (IGF-1), and insulin were assayed. Data were analyzed with a repeated measures ANOVA and area under the curve (AUC) was analyzed by the trapezoidal rule. Results. The resistance exercise protocol resulted in significant elevations from PRE in testosterone (P \u3c 0.01), GH (P \u3c 0.01), and insulin (P = 0.05) at IP, with GH (P \u3c 0.01) and insulin (P \u3c 0.01) remaining elevated at 30P. A significant interaction was noted between groups in the plasma GH response at IP, which was significantly higher following HMB-FA compared to PL (P \u3c 0.01). AUC analysis revealed an elevated GH and IGF-1 response in the HMB-FA group compared to PL. Conclusion. HMB-FA prior to resistance exercise augments the GH response to high volume resistance exercise compared to PL. These findings provide further support for the potential anabolic benefits associated with HMB supplementation

    Operando Label-free Optical Imaging of Solution-Phase Ion Transport and Electrochemistry

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    Ion transport is a fundamental process in many physical, chemical, and biological phenomena, and especially in electrochemical energy conversion and storage. Despite its immense importance, demonstrations of label-free, spatially and temporally resolved ion imaging in the solution phase under operando conditions are not widespread. Here we spatiotemporally map ion concentration gradient evolution in solution and yield ion transport parameters by refining interferometric reflection microscopy, obviating the need for absorptive or fluorescent labels. As an example, we use an electrochemical cell with planar electrodes to drive concentration gradients in a ferricyanide-based aqueous redox electrolyte, and we observe the lateral spatiotemporal evolution of ions via concentration-dependent changes to the refractive index. Analysis of an evolving spatiotemporal ion distribution directly yields the diffusivity of the redox-active species. The simplicity of this approach makes it amenable to probing local ion transport behavior in a wide range of electrochemical, bioelectronic, and electrophysiological systems.Comment: includes supporting informatio
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