948 research outputs found
Aspects of the Ecology of the Wood Turtle, Clemmys insculpta (LeConte), in West Virginia
An ecological study of the wood turtle, Clemmys insculpta (LeConte), was conducted in West Virginia from May 1991 to March 1993. Population structure at the primary study area (WV #1) was estimated to be 46% juvenile (H-8 yrs. old), 26% female and 28% male. Total population estimate for WV #1 was 337 wood turtles, with an aquatic density of 1,980 turtles per Hectare of river and a terrestrial density of 22.5 turtles per ha of terrestrial habitat. Growth measurements and estimates indicate rapid initial growth tapering off at year 8 and gradually declining through year 16. Males grow slightly faster than females after the sixth year. Results of movements indicate that wood turtles utilize a wide variety of habitats, including intensively farmed fields. Winter hibernation was found to be strongly centered in a single pool of the WV #1 study area. Analysis of food habits indicates that feeding begins with emergence from water in April. Terrestrial feeding is probably continuous in spring and summer until turtles return to aquatic habitats in October. Reproductive behavior and ectoparasites were noted
Disorder-Induced Order in Quantum XY Chains
We observe signatures of disorder-induced order in 1D XY spin chains with an
external, site-dependent uni-axial random field within the XY plane. We
numerically investigate signatures of a quantum phase transition at T=0, in
particular an upsurge of the magnetization in the direction orthogonal to the
external magnetic field, and the scaling of the block-entropy with the
amplitude of this field. Also, we discuss possible realizations of this effect
in ultra-cold atom experiments
Injuries Following Implementation of a Progressive Load Carriage Program in United States Marine Corps Training
PURPOSE: The overall physical demands placed on recruits completing United States Marine Corps (USMC) training is high and comes concomitantly with high rates of injuries. Load carriage with heavy loads is of particular concern. However, load carriage conditioning, if optimised, can reduce injury risk. METHODS: Retrospective injury data of recruits completing training informed this study. Data were drawn from recruits completing an original load carriage (OLC) program (n=2,363) and those completing a modified load carriage (LCMOD) program (n=681). Musculoskeletal injury data were drawn from the USMC San Diego sports medicine injury database. A population estimate of the OLC:LCMOD relative risk ratio (RR) was calculated. RESULTS: The proportion of injuries sustained by the LCMOD cohort (n=268; 39%) was notably lower than that sustained by the OLC cohort (n=1,372; 58%). The reoccurrence rate *f injury for LCMOD soldiers compared to the OLC was 0.68 (95% CI 0.61 to 0.75). The leading nature of injury (i.e., sprains and strains) was consistent between both cohorts (OLC: n=396; 29% vs. LCMOD: n=66; 25%). Inflammation (n=172; 13%) and fractures (n=144; 11%) were next most common for OLC recruits; while pain (n=58; 22%) and medial tibial stress syndrome (n=18; 8%) were next most common for LCMOD recruits. While stress reactions were proportionally higher in LCMOD (n=17; 6%) when compared to OLC (n=4; 0.3%), stress fractures were proportionality lower (LCMOD: n=9; 3% vs. OLC: n=114; 8%). Pre-existing / chronic injuries were higher in LCMOD (+5%) while new overuse injuries were lower (-7%). Totalling 65% (OLC) and 70% (LCMOD) of reported injuries the knee, lower leg, ankle, and foot were the top 4 bodily sites of injuries, although there were variations in the orders of presentations (See Table 1 for top 10 bodily sites). RELEVANCE: Careful periodisation and planning of a load carriage program can reduce injuries without reducing training outcomes
Origin of intragranular crystallographic misorientations in hot-dip Al-Zn-Si coatings
The origin of intragranular variations of the crystallographic orientation in hot-dip Al-Zn-Si coatings is discussed based on new experimental results and modelling. The solidification microstructure in as-received 55Al-43.4Zn-l.6Si (in wt.%) coatings deposited on steel plates in an industrial production line was analyzed by electron backscattered diffraction, glow-discharge optical emission spectroscopy and atomic force microscopy (AFM). The results were compared with those obtained in coatings re-solidified under different cooling and mechanical loading conditions. Continuous variations of the crystallographic orientation as large as 35 degrees were observed within individual grains of Al-Zn-Si, consistent with previous Studies. However, the mechanisms previously proposed for the origin of intragranular crystallographic misorientations had to be revisited. The new experimental data acquired during this study indicate that the solidification shrinkage accumulating in the area of the grain envelope is the driving Force for the formation of intragranular misorientations. The solidification shrinkage leads to the development of tensile stresses in the oxide film covering the coating while it solidifies. Estimations based on AFM profiles and phase field Simulations of the dendritic structure indicate that the stresses applied on the dendrite network are sufficient to deform plastically the dendrite arms during solidification. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved
Gender differences in injuries sustained during United States Marine Corps training
Aim: To investigate gender-specific differences in injuries in United States Marine Corps (USMC) trainees.Design: Retrospective cohort study.Method: Point-of-care injury data for USMC recruits (females=94; males=681) completing training were drawn from the Marine Corps Recruit Depot San Diego sports medicine injury database and analysed descriptively. The male: female incidence rate ratio (IRR) was calculated.Results: Male trainees suffered more injuries (male=268; 39%; female n=22; 23%; IRR=1.68 (95% CI 1.33 to 2.1)). Sprains and strains were the leading nature of injury (female=41%; male=25%) followed by pain(female=23%; male=22%). The leading type of injury was ‘new overuse injuries’ for both genders (54% each). Female trainees experienced more acute injuries (36% versus 26%). While female (55%) and male (58%)rates of ‘moderate’ injuries were similar, female trainees experienced more ‘mild’ injuries (36% versus 25%). The knee (female=27%: male=23%) and lower leg (female=23%: male=21%) were the leading injury sites. All injuries were to the lower limbs in female trainees; male trainees also reported injuries to the upper limb (12%) and trunk (8%).Conclusion: Female trainees experienced fewer injuries than male trainees, with more being mild. Both genders had similar natures of injuries in similar body sites except that male trainees reported some upper body and trunk injuries.</div
Disorder-induced phase control in superfluid fermi-bose mixtures
Abstract -We consider a mixture of a superfluid Fermi gas of ultracold atoms and a BoseEinstein condensate of molecules possessing a continuous U (1) (relative phase) symmetry. We study the effects of a spatially random photo-associative-dissociative symmetry-breaking coupling of the systems. Such coupling allows one to control the relative phase between a superfluid order parameter of the Fermi system and the condensate wave function of molecules for temperatures below the Bardeen-Cooper-Schriefer critical temperature. The presented mechanism of phase control belongs to the general class of phenomena in which disorder interacts with continuous symmetry. Our results show the robustness and wide range of applicability of disorder-induced order and are valid for both disordered and regular couplings. Here, the effect is studied in the case of interacting fermionic and bosonic gases in the superfluid phase
Cholesterol-lowering properties of Ganoderma lucidum in vitro, ex vivo, and in hamsters and minipigs
INTRODUCTION: There has been renewed interest in mushroom medicinal properties. We studied cholesterol lowering properties of Ganoderma lucidum (Gl), a renowned medicinal species. RESULTS: Organic fractions containing oxygenated lanosterol derivatives inhibited cholesterol synthesis in T9A4 hepatocytes. In hamsters, 5% Gl did not effect LDL; but decreased total cholesterol (TC) 9.8%, and HDL 11.2%. Gl (2.5 and 5%) had effects on several fecal neutral sterols and bile acids. Both Gl doses reduced hepatic microsomal ex-vivo HMG-CoA reductase activity. In minipigs, 2.5 Gl decreased TC, LDL- and HDL cholesterol 20, 27, and 18%, respectively (P < 0.05); increased fecal cholestanol and coprostanol; and decreased cholate. CONCLUSIONS: Overall, Gl has potential to reduce LDL cholesterol in vivo through various mechanisms. Next steps are to: fully characterize bioactive components in lipid soluble/insoluble fractions; evaluate bioactivity of isolated fractions; and examine human cholesterol lowering properties. Innovative new cholesterol-lowering foods and medicines containing Gl are envisioned
Transport regimes of cold gases in a two-dimensional anisotropic disorder
We numerically study the dynamics of cold atoms in a two-dimensional
disordered potential. We consider an anisotropic speckle potential and focus on
the classical regime, which is relevant to some recent experiments. First, we
study the behavior of particles with a fixed energy and identify different
transport regimes. For low energy, the particles are classically localized due
to the absence of a percolating cluster. For high energy, the particles undergo
normal diffusion and we show that the diffusion constants scale algebraically
with the particle energy, with an anisotropy factor which significantly differs
from that of the disordered potential. For intermediate energy, we find a
transient sub-diffusive regime, which is relevant to the time scale of typical
experiments. Second, we study the behavior of a cold-atomic gas with an
arbitrary energy distribution, using the above results as a groundwork. We show
that the density profile of the atomic cloud in the diffusion regime is
strongly peaked and, in particular, that it is not Gaussian. Its behavior at
large distances allows us to extract the energy-dependent diffusion constants
from experimental density distributions. For a thermal cloud released into the
disordered potential, we show that our numerical predictions are in agreement
with experimental findings. Not only does this work give insights to recent
experimental results, but it may also serve interpretation of future
experiments searching for deviation from classical diffusion and traces of
Anderson localization.Comment: 19 pages, 16 figure
Increasing galactose consumption by Saccharomyces cerevisiae through metabolic engineering of the GAL gene regulatory network
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