The efficacy of caffeine supplementation in collegiate tennis players and the magnitude of improvement in tennis skill mediated by caffeine influenced by a polymorphism of the CYP1A2 gene

Purpose: This study examined the efficacy of caffeine supplementation on tennis performance in male and female collegiate tennis players and whether a polymorphism of the CYP1A2 gene influenced the ergogenic response to caffeine. Methods: Eighteen collegiate tennis players (9 male; 9 female) completed two separate trials. Each test occurred one hour after the administration of either 6 mg/kg of caffeine or a placebo, administered in double-blind fashion. The treadmill portion was comprised of 15 minutes at a velocity corresponding with 50% VO2max followed by 30 minutes of intermittent sprints (5 seconds at 80% VO2max, 15 seconds at 50% VO2max). 90 second resting periods were administered after the 18th sprint and every twelve sprints thereafter, mirroring the discontinuous nature of tennis. RPE and HR was taken before each 90 second resting period. 120 seconds following the treadmill test, the tennis skills test was administered. A 6-ball drill comprised with 4 groundstrokes, 1 approach shot and 1 volley were fed, followed by a 20 second resting period. The 6-ball drill was repeated 6 times, and every 2 sessions were followed by a 90 second break. Nine full sessions were performed with RPE and HR recorded prior to resting periods. Subjects completed these methods for both treatments, in a randomly counterbalanced, double-blind protocol. DNA was obtained from whole blood samples and analyzed for presence of the C variant using polymerase chain reaction with allele-specific primers. Subjects were classified as AA homozygotes (N=7) or C allele carriers (N=9). Results: Caffeine significantly (P=0.029) improved performance during the Tennis Skills test. There was no genotype effect (P=.454), regardless of gender. There was no main effect for treatment on RPE during the treadmill portion of the test and no significant main effects or interaction effects for RPE following ingestion of caffeine during the Tennis Skills Test. A significant gender effect existed during the treadmill portion of the test (P=0.020) and Tennis Skills test (P=0.027) for RPE with women exhibiting a lower RPE men. Furthermore, on average, caffeine elevated peak HR in AA homozygotes and lowered peak HR for C allele carriers. Conclusion: Caffeine supplementation positively impacts tennis performance regardless of genotype

Transient changes in blood-brain barrier integrity, thermotolerance, and heat shock protein expression following brief, hyperthermia in an in vitro model

Hyperthermia is being studied as a means of disrupting blood-brain barrier (BBB) integrity. An in vitro BBB model was exposed to 10 s of 45, 48, or 51°C, or 5 s of 54°C, and TEER was used to assess integrity. Loss of BBB integrity increased as temperature increased (r = 0.88, P\u3c0.0001). Thermotolerance was examined by applying a second hyperthermia to models 24 h afterward. Models demonstrated thermotolerance, indicated by less loss (P\u3c0.001) of integrity compared to controls. The degree of thermotolerance increased as pre-conditioning temperature increased (r = 0.42, P\u3c0.0001). Hsp27 and Hsp70 were analyzed by Western blot to examine their contribution to this thermotolerance. Hsp27 was not changed (P\u3e0.10) by the pre-conditioning heat treatments. Hsp70 expression increased (P\u3c0.05) in response to pre-conditioning for 5 s at 54°C. This thermotolerance cannot be explained by changes in Hsp27 (r = 0.17, P\u3e0.10) and Hsp70 (r = -0.17, P\u3e0.10)

Measuring DHEA-S in saliva: time of day differences and positive correlations between two different types of collection methods

<p>Abstract</p> <p>Background</p> <p>The anabolic steroid, dehydroepiandosterone sulfate (DHEA-S), is secreted from the adrenal cortex. It plays a significant role in the body as a precursor to sex steroids as well as a lesser known role in the hypothalamic pituitary adrenal axis (HPA) response to stress. DHEA-S can be measured reliably in saliva, making saliva collection a valuable tool for health research because it minimizes the need for invasive sampling procedures (e.g., blood draws). Typical saliva collection methods include the use of plain cotton swab collection devices (e.g., Salivette^®) or passive drool. There has been some speculation that the plain saliva cotton collection device may interfere with determination of DHEA-S by enzyme immunoassay (EIA) bringing this saliva collection method into question. Because of the increasing popularity of salivary biomarker research, we sought to determine whether the cotton swab interferes with DHEA-S determination through EIA techniques.</p> <p>Findings</p> <p>Fifty-six healthy young adult men and women aged 18-30 years came to the lab in the morning (0800 hrs; 14 men, 14 women) or late afternoon (1600 hrs; 14 men, 14 women) and provided saliva samples via cotton Salivette and passive drool. Passive drool collection was taken first to minimize particle cross contamination from the cotton swab. Samples were assayed for DHEA-S in duplicate using a commercially available kit (DSL, Inc., Webster, TX). DHEA-S levels collected via Salivette and passive drool were positively correlated (r = + 0.83, p < 0.05). Mean DHEA-S levels were not significantly different between collection methods. Salivary DHEA-S levels were significantly higher in males than in females, regardless of saliva collection method (p < 0.05), and morning DHEA-S values were higher than evening levels (p < 0.05).</p> <p>Conclusions</p> <p>Results suggest that DHEA-S can be measured accurately using passive drool or cotton Salivette collection methods. Results also suggest that DHEA-S levels change across the day and that future studies need to take this time of day difference into account when measuring DHEA-S.</p

Shaking Up Traditional Training With Lynda.com

Supporting the diverse technology training needs on campus while resources continue to dwindle is a challenge many of us continue to tackle. Institutions from small liberal arts campuses to large research universities are providing individualized training and application support 24/7 by subscribing to the lynda.com Online Training Library(r) and marketing the service to various combinations of faculty, staff and students. As a supplemental service on most of our campuses, lynda.com has allowed us to extend support to those unable to attend live lab-based training, those who want advanced level training, those who want training on specialized applications, and those who want to learn applications that are not in high demand. The service also provides cost effective professional development opportunities for everyone on campus, from our own trainers and technology staff who are developing new workshops, learning new software versions or picking up new areas of expertise from project management to programming, to administrative and support staff who are trying to improve their skills in an ever-tighter economic environment. On this panel discussion, you will hear about different licensing approaches, ways of raising awareness about lynda.com on our campuses, lessons learned through implementation, reporting capabilities, and advice we would give for other campuses looking to offer this service

\u27Terroristic Threats\u27 and COVID-19: A Guide for the Perplexed

The first few months of the COVID-19 outbreak in the United States saw the rise of a troubling sort of behavior: people would cough or spit on people or otherwise threaten to spread the COVID-19 virus, resulting in panic and sometimes thousands of dollars’ worth of damages to businesses. Those who have been caught doing this — or have filmed themselves doing it — have been charged under so-called “terroristic threat” statutes. But what is a terroristic threat, and is it an appropriate charge in these cases? Surprisingly little has been written about these statutes given their long history and regular use by states. Our article is one of the first to look systematically at these statutes, and we do so in light of the rash of these charges during the recent pandemic.Our argument begins with the premise that these statutes typically contemplate a “core case” of terroristic threatening, e.g., someone calls in a bomb threat which forces the evacuation of a building. But these statutes have been variously revised and repurposed over the years, most notably to mass shootings, and more problematically to those who threaten to give others HIV. The recent COVID-19 charges seem to involve facts that are outside the “core case,” so that even if terroristic threatening is a permissible charge in these cases, it is often not the most appropriate one. We conclude by suggesting that in many of the COVID-19 cases other charges should be made (criminal mischief, disorderly conduct, false reporting, etc.) instead of terroristic threatening, and that a lot of the expressive and deterrence benefits of more serious charges can be accomplished just as well by social disapproval

Testosterone Trajectories and Reference Ranges in a Large Longitudinal Sample of Male Adolescents

Pubertal dynamics plays an important role in physical and psychological development of children and adolescents. We aim to provide reference ranges of plasma testosterone in a large longitudinal sample. Furthermore, we describe a measure of testosterone trajectories during adolescence that can be used in future investigations of development.We carried out longitudinal measurements of plasma testosterone in 2,216 samples obtained from 513 males (9 to 17 years of age) from the Avon Longitudinal Study of Parents and Children. We used integration of a model fitted to each participant's testosterone trajectory to calculate a measure of average exposure to testosterone over adolescence. We pooled these data with corresponding values reported in the literature to provide a reference range of testosterone levels in males between the ages of 6 and 19 years.The average values of total testosterone in the ALSPAC sample range from 0.82 nmol/L (Standard Deviation [SD]: 0.09) at 9 years of age to 16.5 (SD: 2.65) nmol/L at 17 years of age; these values are congruent with other reports in the literature. The average exposure to testosterone is associated with different features of testosterone trajectories such as Peak Testosterone Change, Age at Peak Testosterone Change, and Testosterone at 17 years of age as well as the timing of the growth spurt during puberty.The average exposure to testosterone is a useful measure for future investigations using testosterone trajectories to examine pubertal dynamics

Evidence for downflows in the narrow plasma sheet of 2017 September 10 and their significance for flare reconnection

This work was supported partly by a grant from NASA's Heliophysics Supporting Research (HSR) program and partly by a grant from NSF/AGS's Research Experiences for Undergraduates (REU) program.Current sheets are believed to form in the wakes of erupting flux ropes and to enable the magnetic reconnection responsible for an associated flare. Multiwavelength observations of an eruption on 2017 September 10 show a long, linear feature widely taken as evidence of a current sheet viewed edge-on. The relation between the high-temperature, high-density plasma thus observed and any current sheet is not yet entirely clear. We estimate the magnetic field strength surrounding the sheet and conclude that approximately one-third of all flux in the active region was opened by the eruption. Subsequently decreasing field strength suggests that the open flux closed down over the next several hours through reconnection at a rate Mx s−1. We find in AIA observations evidence of downward-moving, dark structures analogous to either supra-arcade downflows, more typically observed above flare arcades viewed face-on, or supra-arcade downflowing loops, previously reported in flares viewed in this perspective. These features suggest that the plasma sheet is composed of the magnetic flux retracting after being reconnected high above the arcade. We model flux tube retraction following reconnection to show that this process can generate high densities and temperatures as observed in the plasma sheet. The retracting flux tubes reach their highest temperatures at the end of their retraction, well below the site of reconnection, consistent with previous analysis of AIA and EIS data showing a peak in the plasma temperature near the base of this particular sheet.Publisher PDFPeer reviewe

A Pilot Search for Gravitational Self-Lensing Binaries with the Zwicky Transient Facility

Binary systems containing a compact object may exhibit periodic brightening episodes due to gravitational lensing as the compact object transits the companion star. Such "self-lensing" signatures have been detected before for white dwarf binaries. We attempt to use these signatures to identify detached stellar-mass neutron star and black hole binaries using data from the Zwicky Transient Facility (ZTF). We present a systematic search for self-lensing signals in Galactic binaries from a subset of high-cadence ZTF data taken in 2018. We identify 19 plausible candidates from the search, although because each candidate is observed to only brighten once, other origins such as stellar flares are more likely. We discuss prospects for more comprehensive future searches of the ZTF data.Comment: 12 pages. Submitted to the Open Journal of Astrophysic

Resonance energy transfer sensitises and monitors in situ switching of LOV2-based optogenetic actuators

Engineered light-dependent switches provide uniquely powerful opportunities to investigate and control cell regulatory mechanisms. Existing tools offer high spatiotemporal resolution, reversibility and repeatability. Cellular optogenetics applications remain limited with diffusible targets as the response of the actuator is difficult to independently validate. Blue light levels commonly needed for actuation can be cytotoxic, precluding long-term experiments. We describe a simple approach overcoming these obstacles. Resonance energy transfer can be used to constitutively or dynamically modulate actuation sensitivity. This simultaneously offers on-line monitoring of light-dependent switching and precise quantification of activation-relaxation properties in intact living cells. Applying this approach to different LOV2-based switches reveals that flanking sequences can lead to relaxation times up to 11-fold faster than anticipated. In situ-measured parameter values guide the design of target-inhibiting actuation trains with minimal blue-light exposure, and context-based optimisation can increase sensitivity and experimental throughput a further 10-fold without loss of temporal precision