Relationship Between Stress-Recovery State and Running Performance in Men\u27s Collegiate Soccer

Purpose: The purpose of this study was to evaluate the relationship between changes in running performance and the stress-recovery state in Division I collegiate soccer players. Methods: Running performance was evaluated in eight NCAA Division I male soccer players (179.39 ± 5.24 cm; 75.46 ± 5.98 kg; 20.37 ± 1.41 yrs.) over the course of 12 games during a single competitive season. The 12 games were divided into four blocks [B1(n=3), B2(n=3), B3(n=3), and B4(n=3)]. Running performance and game load were assessed using a wearable physiological harness and Global Positioning System (GPS) module. Game load, absolute distance, and distance covered while engaging in walking (0.2-2.0 m·s-1; 0.72-7.20 km·h-1), jogging (2.01-3.70 m·s-1; 7.21-13.32 km·h-1), low speed running (3.71-4.99 m·s-1; 13.33-17.99 km·h-1), high speed running (5.0-6.0 m·s-1; 18.0-21.60 km·h-1) sprinting (6.01+ m·s-1; 21.61+ km·h-1), low-intensity running (LIR: 0.2-3.70 m·s-1; 0.72-13.32 km·h-1) and high-intensity running (HIR: \u3e 3.70 m·s-1; \u3e 13.32 km·h-1) were assessed during each block. These variables were also assessed relative to minutes played. Stress-recovery state was assessed using the RESTQ 52 Sport, which was administered to each athlete twice during each block, separated by at least one week. Measures of general stress (GS), general recovery (GR), sport specific stress (SSS), sport specific recovery (SSR), global stress (GLS), global recovery (GLR) and the recovery-stress balance (RSB). Results: Total distance was significantly greater during B4 compared to B1 (p=0.027). Absolute jogging distance and low-speed running distance were significantly greater during B4 compared to all other time points (p’s ≤ 0.05). Absolute LIR distance was significantly greater during B4 compared to B1 (p=0.034). Jogrel was significantly greater during B4 compared to B1 (p=0.001) and B3 (p=0.001). Analysis of correlation coefficients between running performance and RESTQ scales indicate that greater high-speed/HIR is associated with increased stress. Similarly, greater low-speed/LIR is associated with greater recovery. However, changes in SSR did not correlate with changes in running performance from B1 to B4. Conclusions: The results of this study indicate that running performance declined across the season. However, changes in performance were not related to changes in SSR, as determined via the RESTQ 52 Sport questionnaire

Electronic transport in disordered n-alkanes: From fluid methane to amorphous polyethylene

We use a fast Fourier transform block Lanczos diagonalization algorithm to study the electronic states of excess electrons in fluid alkanes (methane, ethane, and propane) and in a molecular model of amorphous polyethylene (PE) relevant to studies of space charge in insulating polymers. We obtain a new pseudopotential for electron–PE interactions by fitting to the electronic properties of fluid alkanes and use this to obtain new results for electron transport in amorphous PE. From our simulations, while the electronic states in fluid methane are extended throughout the whole sample, in amorphous PE there is a transition between localized and delocalized states slightly above the vacuum level (∼+0.06 eV). The localized states in our amorphous PE model extend to −0.33 eV below this level. Using the Kubo–Greenwood equation we compute the zero-field electron mobility in pure amorphous PE to be μ≈2×10−3 cm2/V s. Our results highlight the importance of electron transport through extended states in amorphous regions to an understanding of electron transport in PE.EPSRC through Grants No.GR/R18222 and No. GR/M9442

Differences in muscle oxygenation between young and middle-aged recreationally active men during high-volume resistance exercise

The aim of this study was to compare muscle oxygenation of the vastus lateralis during a high-volume isokinetic resistance exercise protocol (HVP) between young adult (YA) and middle-aged adult (MA) men. Twenty recreationally trained men were assigned to either the YA (age 21.8±2.0 years, body mass 90.7±11.6 kg, body height 179±4.7 cm) or MA (age 47.0±4.4 years, body mass 96.1±21.6 kg, body height 177±7.7 cm) group. The HVP consisted of eight sets of 10 repetitions of unilateral isokinetic concentric knee extension and eccentric knee flexion at 60°·s-1. Changes in tissue hemoglobin saturation index (TSI), tissue oxygenated hemoglobin concentration (O2Hb), deoxygenated hemoglobin (HHb), and muscle oxidation index (O2Hb-HHb) were measured during the exercise session using the near-infrared spectroscopy (NIRS). Data were analyzed using two-way mix factorial analyses of variance. Prior to exercise, TSI was significantly greater (p=.024) for YA compared to MA. Significant decreases in O2Hb and O2Hb-HHb and increases in HHb were observed during each of the eight sets relative to the rest periods (p<.05) for both groups. The average change during the eight sets of the HVP revealed a significantly higher (p=.036) level of HHb and a lower (p=.029) level of O2Hb-HHb for MA compared to YA. A significant negative correlation was also noted at baseline between O2Hb-HHb index and the cross-sectional area of the vastus lateralis muscle (r=-.45, p=.045). During a high- volume resistance exercise, MA experienced reduced muscle oxygen saturation levels compared to YA. These results may be attributed to reductions in local tissue oxidative capacity and reduced blood delivery occurring during middle-age, and possibly due to group differences in muscle morphology

Effects of a Nighttime Multi-Ingredient Supplement on Recovery from a Damaging Exercise Protocol

International Journal of Exercise Science 9(4): 471-481, 2016. The purpose of this study was to determine the efficacy of a nighttime multi-ingredient supplement on noninvasive markers of recovery in resistance trained and untrained individuals. Forty-nine participants, both trained (n=25) and untrained (n=24) completed the randomized, double blind, placebo-controlled study. Trained participants were randomly divided into supplement (n=12) and placebo (n=13) groups. Untrained participants were randomly divided into supplement (n=14) and placebo (n=10) groups. Two, 2 (supplement group) x 2 (training status) x 5 (time points) repeated measures analysis of variance (ANOVA) were utilized to determine if an interaction for supplement group and training status existed for peak force (PForce) and delayed onset muscle soreness (DOMS). Four, 2 (supplement group) x 2 (training status) x 4 (time points) repeated measures ANOVAs was employed for SWVL-Long, SWVL-Tera, SWVL-Trans and ROM to determine interactions for supplement group and training status. For significant main effects, pairwise comparisons were utilized to determine at what time-points significant differences occurred. There were no significant interactions for either DOMS or PForce. However, significant main effects of time were observed for both variables (p\u3c0.001). No significant interactions were determined for either training group, or supplement group for SWVL-Tera, SWVL-Trans, SWVL-Long, or ROM. Although the SWVL-Long had a significant main effect of time (p=0.033), post-hoc pairwise comparisons revealed no significant differences between time points. There was no effect of the nighttime multi-ingredient supplement for attenuation of symptoms associated with acute exercise induced muscle damage

Wavefront sensing and control in space-based coronagraph instruments using Zernike’s phase-contrast method

Future space telescopes with coronagraph instruments will use a wavefront sensor (WFS) to measure and correct for phase errors and stabilize the stellar intensity in high-contrast images. The HabEx and LUVOIR mission concepts baseline a Zernike wavefront sensor (ZWFS), which uses Zernike’s phase contrast method to convert phase in the pupil into intensity at the WFS detector. In preparation for these potential future missions, we experimentally demonstrate a ZWFS in a coronagraph instrument on the Decadal Survey Testbed in the High Contrast Imaging Testbed facility at NASA’s Jet Propulsion Laboratory. We validate that the ZWFS can measure low- and mid-spatial frequency aberrations up to the control limit of the deformable mirror (DM), with surface height sensitivity as small as 1 pm, using a configuration similar to the HabEx and LUVOIR concepts. Furthermore, we demonstrate closed-loop control, resolving an individual DM actuator, with residuals consistent with theoretical models. In addition, we predict the expected performance of a ZWFS on future space telescopes using natural starlight from a variety of spectral types. The most challenging scenarios require ∼1  h of integration time to achieve picometer sensitivity. This timescale may be drastically reduced by using internal or external laser sources for sensing purposes. The experimental results and theoretical predictions presented here advance the WFS technology in the context of the next generation of space telescopes with coronagraph instruments

Independent mechanisms target SMCHD1 to trimethylated histone H3 lysine 9-modified chromatin and the inactive X chromosome

The chromosomal protein SMCHD1 plays an important role in epigenetic silencing at diverse loci, including the inactive X chromosome, imprinted genes, and the facioscapulohumeral muscular dystrophy locus. Although homology with canonical SMC family proteins suggests a role in chromosome organization, the mechanisms underlying SMCHD1 function and target site selection remain poorly understood. Here we show that SMCHD1 forms an active GHKL-ATPase homodimer, contrasting with canonical SMC complexes, which exist as tripartite ring structures. Electron microscopy analysis demonstrates that SMCHD1 homodimers structurally resemble prokaryotic condensins. We further show that the principal mechanism for chromatin loading of SMCHD1 involves an LRIF1-mediated interaction with HP1γ at trimethylated histone H3 lysine 9 (H3K9me3)-modified chromatin sites on the chromosome arms. A parallel pathway accounts for chromatin loading at a minority of sites, notably the inactive X chromosome. Together, our results provide key insights into SMCHD1 function and target site selection

Summary report : universal fuel processor.

The United States produces only about 1/3 of the more than 20 million barrels of petroleum that it consumes daily. Oil imports into the country are roughly equivalent to the amount consumed in the transportation sector. Hence the nation in general, and the transportation sector in particular, is vulnerable to supply disruptions and price shocks. The situation is anticipated to worsen as the competition for limited global supplies increases and oil-rich nations become increasingly willing to manipulate the markets for this resource as a means to achieve political ends. The goal of this project was the development and improvement of technologies and the knowledge base necessary to produce and qualify a universal fuel from diverse feedstocks readily available in North America and elsewhere (e.g. petroleum, natural gas, coal, biomass) as a prudent and positive step towards mitigating this vulnerability. Three major focus areas, feedstock transformation, fuel formulation, and fuel characterization, were identified and each was addressed. The specific activities summarized herein were identified in consultation with industry to set the stage for collaboration. Two activities were undertaken in the area of feedstock transformation. The first activity focused on understanding the chemistry and operation of autothermal reforming, with an emphasis on understanding, and therefore preventing, soot formation. The second activity was focused on improving the economics of oxygen production, particularly for smaller operations, by integrating membrane separations with pressure swing adsorption. In the fuel formulation area, the chemistry of converting small molecules readily produced from syngas directly to fuels was examined. Consistent with the advice from industry, this activity avoided working on improving known approaches, giving it an exploratory flavor. Finally, the fuel characterization task focused on providing a direct and quantifiable comparison of diesel fuel and JP-8

The contribution of macroalgae-associated fishes to small-scale tropical reef fisheries

Macroalgae-dominated reefs are a prominent habitat in tropical seascapes that support a diversity of fishes, including fishery target species. To what extent, then, do macroalgal habitats contribute to small-scale tropical reef fisheries? To address this question we: (1) Quantified the macroalgae-associated fish component in catches from 133 small-scale fisheries, (2) Compared life-history traits relevant to fishing (e.g. growth, longevity) in macroalgal and coral-associated fishes, (3) Examined how macroalgae-associated species can influence catch diversity, trophic level and vulnerability and (4) Explored how tropical fisheries change with the expansion of macroalgal habitats using a case study of fishery-independent data for Seychelles. Fish that utilised macroalgal habitats comprise 24% of the catch, but very few fished species relied entirely on macroalgal or coral habitats post-settlement. Macroalgal and coral-associated fishes had similar life-history traits, although vulnerability to fishing declined with increasing contribution of macroalgae association to the catch, whilst mean trophic level and diversity peaked when macroalgal-associated fish accounted for 20%-30% of catches. The Seychelles case study revealed similar total fish biomass on macroalgal and coral reefs, although the biomass of primary target species increased as macroalgae cover expanded. Our findings reinforce that multiple habitat types are needed to support tropical fishery stability and sustainability. Whilst coral habitats have been the focus of tropical fisheries management, we show the potential for macroalgae-associated fish to support catch size and diversity in ways that reduce vulnerability to overfishing. This is pertinent to seascapes where repeated disturbances are facilitating the replacement of coral reef with macroalgal habitats

Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-line Analysis for NGC 5548

We present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part of a larger multiwavelength reverberation mapping campaign. The campaign spanned 6 months and achieved an almost daily cadence with observations from five ground-based telescopes. The Hβ and He ii λ4686 broad emission-line light curves lag that of the 5100 +-optical continuum by 4.17+0.36-0.36 and 0.79+0.35-0.34 days, respectively. The Hβ lag relative to the 1158 ultraviolet continuum light curve measured by the Hubble Space Telescope is ∼50% longer than that measured against the optical continuum, and the lag difference is consistent with the observed lag between the optical and ultraviolet continua. This suggests that the characteristic radius of the broad-line region is ∼50% larger than the value inferred from optical data alone. We also measured velocity-resolved emission-line lags for Hβ and found a complex velocity-lag structure with shorter lags in the line wings, indicative of a broad-line region dominated by Keplerian motion. The responses of both the Hβ and He ii emission lines to the driving continuum changed significantly halfway through the campaign, a phenomenon also observed for C iv, Lyα, He ii(+O iii]), and Si iv(+O iv]) during the same monitoring period. Finally, given the optical luminosity of NGC 5548 during our campaign, the measured Hβ lag is a factor of five shorter than the expected value implied by the R BLR-L AGN relation based on the past behavior of NGC 5548