The Stellar Populations of Low-redshift Clusters

We present some preliminary results from an on-going study of the evolution of stellar populations in rich clusters of galaxies. This sample contains core line-strength measurements from 183 galaxies with b_J <= 19.5 from four clusters with ~0.04. Using predictions from stellar population models to compare with our measured line strengths we can derive relative luminosity-weighted mean ages and metallicities for the stellar populations in each of our clusters. We also investigate the Mgb'-sigma and Hbeta_G'-sigma scaling relations. We find that, consistent with previous results, Mgb' is correlated with sigma, the likely explanation being that larger galaxies are better at retaining their heavier elements due to their larger potentials. Hbeta', on the other hand, we find to be anti-correlated with sigma. This result implies that the stellar populations in larger galaxies are older than in smaller galaxies.Comment: 3 pages, 2 figures, to appear in the Proceedings of IAU Colloquium 195: "Outskirts of Galaxy Clusters: intense life in the suburbs", Torino Italy, March 12-16 200

Daily Fluctuations in Hormonal and Performance Markers in Collegiate Weightlifters

The purpose of this study was to assess relationships between daily fluctuations in hormonal and performance markers in weightlifters. Nine male collegiate weightlifters gave daily pre-practice salivary samples for one week and were tested daily for standing broad jump distance; first jump (BJ1) and best jump (BJB) were recorded. Volume-load was heavy on Monday (47%), light on Tuesday (13%), and medium-heavy on Wednesday (40%). To determine if variables differed by day, RM ANOVAs were used with partial-eta squared effect sizes (η2 p) to calculate meaningful changes. RM ANOVA models suggest daily differences occurred for T (F=4.027, p=.024, η2 p =.402), T/C (F=11.735, p=.019, η2 p =.898), and BJ1 (F=6.229, p=.004, η2 p =.509), but not for C (F=1.623, p=.219, η2 p =.213) nor BJB (F=1.088, p=.379, η2 p =.154). Daily fluctuations in BJ1 shared a moderate inverse relationship with daily fluctuations in C (r = -0.42), whereas BJB revealed no association with hormonal markers. T, T/C, and BJ1 appeared to be meaningfully affected by the previous day’s training stress in collegiate weightlifters, suggesting that BJ1 may be indicative of hormonal status and that a one-day reduction in VL may enhance acute athlete readiness

Epidemiologic evidence for physical activity as a preventative factor for metabolic syndrome and frailty: the Health ABC Study

The presence of metabolic syndrome (MS) or frailty aligns an older adult with increased risk for health decline. Physical activity is an important part of health maintenance in older adults, but optimal doses of physical activity are unclear with these two health conditions. This study examined the longitudinal associations between different doses and types of physical activity and incidence of MS and frailty. Participants from the Health, Aging and Body Composition Study were followed for six years to ascertain long-term MS and frailty status. Physical activity doses at baseline included weekly time (low, recommended, high), intensity (sedentary, light, moderate, vigorous) and type (sedentary, lifestyle active, exercise active). In MS as the outcome, in men, dose-response curves generally were linear, with increasingly lower doses of time, intensity and activity type resulting in a higher incidence of MS. In women, intermediate doses of time and intensity were associated with the lowest incidence of MS, indicating a U-shaped dose-response curve. Results also indicated that the time and intensity physical activity doses were not associated with frailty; however, being exercise active was associated with reduced risk for frailty. In those who had progressed to frailty within six years, we found that the sedentary and lifestyle active participants were at increased risk for severe frailty compared to the exercise active in a dose-response manner. The optimal dose of physical activity for reducing the risk of MS in older men is spending, iv on average, more than thirty minutes per day in vigorous activities. The optimal dose of physical activity for reducing the risk of MS in older women is meeting the current recommendations for time spent in weekly physical activity in activities of light intensity such as light housework, shopping, or volunteering. Expending 1000 kcals/week in physical activities that are done with the intent of exercising, such as walking for exercise, strength training or aerobic dance, can reduce the risk of frailty onset and severity in older adults

Single-Cell RNA-seq Reveals Profound Alterations in Mechanosensitive Dorsal Root Ganglion Neurons with Vitamin E Deficiency.

Ninety percent of Americans consume less than the estimated average requirements of dietary vitamin E (vitE). Severe vitE deficiency due to genetic mutations in the tocopherol transfer protein (TTPA) in humans results in ataxia with vitE deficiency (AVED), with proprioceptive deficits and somatosensory degeneration arising from dorsal root ganglia neurons (DRGNs). Single-cell RNA-sequencing of DRGNs was performed in Ttpa-/- mice, an established model of AVED. In stark contrast to expected changes in proprioceptive neurons, Ttpa-/- DRGNs showed marked upregulation of voltage-gated Ca2+ and K+ channels in mechanosensitive, tyrosine-hydroxylase positive (TH+) DRGNs. The ensuing significant conductance changes resulted in reduced excitability in mechanosensitive Ttpa-/- DRGNs. A highly supplemented vitE diet (600 mg dl-α-tocopheryl acetate/kg diet) prevented the cellular and molecular alterations and improved mechanosensation. VitE deficiency profoundly alters the molecular signature and functional properties of mechanosensitive TH+ DRGN, representing an intriguing shift of the prevailing paradigm from proprioception to mechanical sensation

Arctic–CHAMP: A program to study Arctic hydrology and its role in global change

The Arctic constitutes a unique and important environment that is central to the dynamics and evolution of the Earth system. The Arctic water cycle, which controls countless physical, chemical, and biotic processes, is also unique and important. These processes, in turn, regulate the climate, habitat, and natural resources that are of great importance to both native and industrial societies. Comprehensive understanding of water cycling across the Arctic and its linkage to global biogeophysical dynamics is a scientific as well as strategic policy imperative

Arctic–CHAMP: A program to study Arctic hydrology and its role in global change

The Arctic constitutes a unique and important environment that is central to the dynamics and evolution of the Earth system. The Arctic water cycle, which controls countless physical, chemical, and biotic processes, is also unique and important. These processes, in turn, regulate the climate, habitat, and natural resources that are of great importance to both native and industrial societies. Comprehensive understanding of water cycling across the Arctic and its linkage to global biogeophysical dynamics is a scientific as well as strategic policy imperative

The relationship between ventilatory threshold and repeated-sprint ability in competitive male ice hockey players

Background/objective The relationship between ventilatory threshold (VT1, VT2) and repeated-sprint ability (RSA) in competitive male ice hockey players was investigated. Methods Forty-three male ice hockey players aged 18–23 years competing in NCAA Division I, NCAA Division III, and Junior A level participated. Participants performed an incremental graded exercise test on a skate treadmill to determine V˙ role= presentation style= box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 14.4px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative; \u3eV˙O2peak, VT1, and VT2 using MedGraphics Breezesuit™ software (v-slope). Participants performed an on-ice repeated shift (RSA) test consisting of 8-maximal skating bouts, lasting approximately 25 s and interspersed with 90 s of passive recovery, to determine first gate, second gate, and total sprint decrement (%dec). Pearson product-moment correlations and multiple regressions were used to assess relationships between ventilatory threshold variables (VT1, VT2, Stage at VT1, and Stage at VT2) and RSA (first gate, second gate, and total course decrement). Results Stage at VT2 was the only variable substantially correlated with first gate (r = −0.35; P \u3c 0.05), second gate (r = −0.58; P \u3c 0.001) and total course decrement (r = −0.42; P \u3c 0.05). Conclusion The results of this study demonstrated that VT is substantially associated with RSA, and VT2 is more strongly correlated with RSA than V˙ role= presentation style= box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 14.4px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative; \u3eV˙O2peak. This study suggests that longer duration high-intensity interval training at intensities that increase workrate at VT2 may lead to possible improvements in RSA

Design and Implementation of Views: Isolated Perspectives of a File System for Regulatory Compliance

We present Views, a file system architecture designed to meet the role-based access control (RBAC) requirement of federal regulations, such as those in HIPAA. Views allows for discrete IO entities, such as users, groups or processes, to have a logically complete but isolated perspective of the file system. Entities may perform IO using the standard system call interface without affecting the views of other entities. Views is designed to be file system independent, extremely easy to use and manage, and flexible in defining isolation and sharing polices. Our implementation of Views is built on ext3cow, which additionally provides versioning capabilities to all entities. Preliminary results show the performance of Views is comparable with other traditional disk file systems.The Johns Hopkins Universit