342 research outputs found
Health-Related Fitness and Energy Expenditure in Recreational Youth Rock Climbers 8-16 Years of Age
International Journal of Exercise Science 8(2): 174-183, 2015. Information on the characteristics of youth rock climbers is minimal. The purpose was to 1) Determine the influence of a three-month program of bouldering and vertical rock climbing on the anthropometry and health-related physical fitness of relatively novice youth climbers, and 2) determine whether rock climbing and bouldering in novice youth climbers can provide adequate levels of moderate to vigourous physical activity (US DHHS, 2008). Fifteen participants (11 males and 4 females; mean age = 11.5 ± 2.3 years) from a newly established youth climbing team were assessed twice weekly during their normal two-hour training sessions at a local rock gym. Body composition, flexibility, grip strength, and anthropometric estimates of somatotype were measured in August and November. Heart rate (HR) monitors recorded average activity heart rate (AHR), peak heart rate (HRpeak), and estimated energy expended (EE-kcals) during each climbing session. Basic descriptive statistics were run; repeat measure ANOVAs were used to assess changes between times. Estimated percent body fat did not change, but individual skinfolds (biceps and supraspinale) decreased significantly (
Field-scale evaluation of biosolids-derived organomineral fertilizers applied to winter wheat in England
Field-scale experiments in four crop seasons established the agronomic performance of biosolids-derived organomineral fertilizers (OMF) for winter wheat (Triticum aestivum L.) production in England. Two OMF formulations (OMF10 10:4:4 and OMF15 15:4:4) were compared with urea and biosolids granules (≈5:6:0.2) to determine crop responses and fertilizer effects on soil chemical properties. Fertilizers were applied at N rates between 0 and 250 kg ha–1 at regular increments of 50 kg ha–1 N. Average grain yields with OMF10 and OMF15 were higher than with biosolids granules, but lower than with urea (P < 0.05). The optimum N application rates, and corresponding grain yields, were 245 and 7900 kg ha–1 for biosolids, 257 and 9100 kg ha–1 for OMF10, 249 and 9500 kg ha–1 for OMF15, and 225 and 10350 kg ha–1 for urea, respectively. Differences in grain yield between fertilizer treatments were explained by differences in yield components, particularly number of grains and thousand-grain-weight. Grain-N recoveries were 31% for biosolids, ≈40% for OMF, and 52% for urea. Organomineral fertilizers-induced changes in soil extractable P and soil P Index were not significant. Thus, application of OMF replenished P offtake by the crop and therefore supported the choice of the proposed OMF formulations. By contrast, extractable P increased in biosolids and decreased in urea-treated soils, respectively. Heavy metals in soil were unaffected by fertilizer treatment and lower than permissible limit values. The use of OMF for winter wheat production appears to be a sustainable approach to recycling biosolids to land
A polygenic basis for birth weight in a wild population of red deer ( Cervus elaphus )
The genetic architecture of traits under selection has important consequences for the response to selection and potentially for population viability. Early QTL mapping studies in wild populations have reported loci with large effect on trait variation. However, these results are contradicted by more recent genome-wide association analyses, which strongly support the idea that most quantitative traits have a polygenic basis. This study aims to re-evaluate the genetic architecture of a key morphological trait, birth weight, in a wild population of red deer (Cervus elaphus), using genomic approaches. A previous study using 93 microsatellite and allozyme markers and linkage mapping on a kindred of 364 deer detected a pronounced QTL on chromosome 21 explaining 29% of the variance in birth weight, suggesting that this trait is partly controlled by genes with large effects. Here, we used data for more than 2,300 calves genotyped at >39,000 SNP markers and two approaches to characterise the genetic architecture of birth weight. First, we performed a genome-wide association (GWA) analysis, using a genomic relatedness matrix to account for population structure. We found no SNPs significantly associated with birth weight. Second, we used genomic prediction to estimate the proportion of variance explained by each SNP and chromosome. This analysis confirmed that most genetic variance in birth weight was explained by loci with very small effect sizes. Third, we found that the proportion of variance explained by each chromosome was slightly positively correlated with its size. These three findings highlight a highly polygenic architecture for birth weight, which contradicts the previous QTL study. These results are probably explained by the differences in how associations are modelled between QTL mapping and GWA. Our study suggests that models of polygenic adaptation are the most appropriate to study the evolutionary trajectory of this trait
The Full-sky Astrometric Mapping Explorer -- Astrometry for the New Millennium
FAME is designed to perform an all-sky, astrometric survey with unprecedented
accuracy. It will create a rigid astrometric catalog of 4x10^7 stars with 5 <
m_V < 15. For bright stars, 5 < m_V < 9, FAME will determine positions and
parallaxes accurate to < 50 microarcseconds, with proper motion errors < 50
microarcseconds/year. For fainter stars, 9 < m_V < 15, FAME will determine
positions and parallaxes accurate to < 500 microarcseconds, with proper motion
errors < 500 microarcseconds/year. It will also collect photometric data on
these 4 x 10^7 stars in four Sloan DSS colors.Comment: 6 pages, 4 figures, to appear in "Working on the Fringe
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Evaluation of ingredients for the development of new insensitive munitions.
Several ingredients being considered by the U.S. Army for the development of new insensitive munitions have been examined. One set of ingredients consists of 2,4-dinitrophenylhydrazine (DNPH) and hexahydro-1,3,5-trinitro-s-triazine (RDX). In this set, the decomposition of the mixture was examined to determine whether adding DNPH to RDX would generate a sufficient quantity of gas to rupture the case of a munition prior to the onset of the rapid reaction of RDX, thus mitigating the violence of reaction. The second set of ingredients consists of three different reduced sensitivity RDX (RS-RDX) powders manufactured by SNPE and Dyno-Nobel. In this set, the objective was to determine properties of RS-RDX powders that may distinguish them from normal RDX powder and may account for their reduced shock sensitivity. The decomposition reactions and sublimation properties of these materials were examined using two unique instruments: the simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) instrument and the Fourier Transform ion cyclotron resonance (FTICR) mass spectrometry instrument. These instruments provide the capability to examine the details of decomposition reactions in energetic materials. DNPH does not appear to be a good candidate to mitigate the violence of the RDX reaction in a munition. DNPH decomposes between 170 C and 180 C. When mixed with RDX it decomposes between 155 C and 170 C. It decomposes to form 1,3-dintrobenzene (DNB), ammonia, water and nitrogen. Of these compounds only nitrogen and ammonia are capable of generating high pressures within a munition. When DNPH is mixed with RDX, the DNB formed in the decomposition of DNPH interacts with RDX on the surface of the RDX powder leading to a higher rate of formation of CH2O and N2O. The CH2O is consumed by reaction with DNPH to form 2-methylene-1-(2,4-dintrophenyl)hydrazine. As a result, DNPH does not generate a large quantity of gas that will lead to rupture of a munition case. Another compound to consider as an additive is 2-oxo-1,3,5-trinitro-1,3,5-triazacyclohexane (K-6), which generates more gas in the required temperature range. Examination of several different RS-RDX materials has shown that their sublimation rates and decomposition behavior differ from Holston grade RDX. The results suggest that insensitive RDX materials from both SNPE and Dyno-Nobel may have a shell-like structure of RDX on the surface of the particles that is less stable and more reactive than the material in the core of the particles. The origin of this shell-like RDX structure is uncertain, but may be due to some aspect of the manufacturing process. It is possible that this less stable RDX on the surface of the particles may be more fluid than the interior of the particles, allowing more slip between the surface of the particles under impact or shock. This may play a role in the reduced shock sensitivity of the insensitive RDX materials. The results of over 50 experiments with DNPH, mixtures of DNPH and RDX and insensitive RDX are presented. The results characterize the decomposition behavior of each of these materials
Microwave, infrared and Raman spectra, r0 structural parameters, ab initio calculations and vibrational assignment of 1-fluoro-1-silacyclopentanea)
The microwave spectrum (6500–18 500 MHz) of 1-fluoro-1-silacyclopentane, c-C4H8SiHF has been recorded and 87 transitions for the 28Si, 29Si, 30Si, and 13C isotopomers have been assigned for a single conformer. Infrared spectra (3050-350 cm−1) of the gas and solid and Raman spectrum (3100-40 cm−1) of the liquid have also been recorded. The vibrational data indicate the presence of a single conformer with no symmetry which is consistent with the twist form. Ab initio calculations with a variety of basis sets up to MP2(full)/aug-cc-pVTZ predict the envelope-axial and envelope-equatorial conformers to be saddle points with nearly the same energies but much lower energy than the planar conformer. By utilizing the microwaverotational constants for seven isotopomers (28Si, 29Si, 30Si, and four 13C) combined with the structural parameters predicted from the MP2(full)/6–311+G(d,p) calculations, adjusted r0 structural parameters have been obtained for the twist conformer. The heavy atom distances in Å are: r0(SiC2) = 1.875(3); r0(SiC3) = 1.872(3); r0(C2C4) = 1.549(3); r0(C3C5) = 1.547(3); r0(C4C5) = 1.542(3); r0(SiF) = 1.598(3) and the angles in degrees are: ∠CSiC = 96.7(5); ∠SiC2C4 = 103.6(5); ∠SiC3C5 = 102.9(5); ∠C2C4C5 = 108.4(5); ∠C3C5C4 = 108.1(5); ∠F6Si1C2 = 110.7(5); ∠F6Si1C3 = 111.6(5). The heavy atom ring parameters are compared to the corresponding rs parameters. Normal coordinate calculations with scaled force constants from MP2(full)/6–31G(d) calculations were carried out to predict the fundamental vibrational frequencies, infrared intensities, Raman activities, depolarization values, and infrared band contours. These experimental and theoretical results are compared to the corresponding quantities of some other five-membered rings
Associations between informal care costs, care quality, carer rewards, burden and subsequent grief:the international, access, rights and empowerment mortality follow-back study of the last 3Â months of life (IARE I study)
Drivers of care costs and quality in the last three months of life among older people receiving palliative care:a multinational mortality follow-back survey across England, Ireland and the USA
Effects of increased body mass index on employment status:a Mendelian randomisation study
Background:
The obesity epidemic may have substantial implications for the global workforce, including causal effects on employment, but clear evidence is lacking. Obesity may prevent people from being in paid work through poor health or through social discrimination. We studied genetic variants robustly associated with body mass index (BMI) to investigate its causal effects on employment.
Dataset/methods:
White UK ethnicity participants of working age (men 40–64 years, women 40–59 years), with suitable genetic data were selected in the UK Biobank study (N = 230,791). Employment status was categorised in two ways: first, contrasting being in paid employment with any other status; and second, contrasting being in paid employment with sickness/disability, unemployment, early retirement and caring for home/family. Socioeconomic indicators also investigated were hours worked, household income, educational attainment and Townsend deprivation index (TDI). We conducted observational and two-sample Mendelian randomisation (MR) analyses to investigate the effect of increased BMI on employment-related outcomes.
Results:
Regressions showed BMI associated with all the employment-related outcomes investigated. MR analyses provided evidence for higher BMI causing increased risk of sickness/disability (OR 1.08, 95% CI 1.04, 1.11, per 1 Kg/m2 BMI increase) and decreased caring for home/family (OR 0.96, 95% CI 0.93, 0.99), higher TDI (Beta 0.038, 95% CI 0.018, 0.059), and lower household income (OR 0.98, 95% CI 0.96, 0.99). In contrast, MR provided evidence for no causal effect of BMI on unemployment, early retirement, non-employment, hours worked or educational attainment. There was little evidence for causal effects differing by sex or age. Robustness tests yielded consistent results.
Discussion:
BMI appears to exert a causal effect on employment status, largely by affecting an individual’s health rather than through increased unemployment arising from social discrimination. The obesity epidemic may be contributing to increased worklessness and therefore could impose a substantial societal burden
VAST: An ASKAP Survey for Variables and Slow Transients
The Australian Square Kilometre Array Pathfinder (ASKAP) will give us an
unprecedented opportunity to investigate the transient sky at radio
wavelengths. In this paper we present VAST, an ASKAP survey for Variables and
Slow Transients. VAST will exploit the wide-field survey capabilities of ASKAP
to enable the discovery and investigation of variable and transient phenomena
from the local to the cosmological, including flare stars, intermittent
pulsars, X-ray binaries, magnetars, extreme scattering events, interstellar
scintillation, radio supernovae and orphan afterglows of gamma ray bursts. In
addition, it will allow us to probe unexplored regions of parameter space where
new classes of transient sources may be detected. In this paper we review the
known radio transient and variable populations and the current results from
blind radio surveys. We outline a comprehensive program based on a multi-tiered
survey strategy to characterise the radio transient sky through detection and
monitoring of transient and variable sources on the ASKAP imaging timescales of
five seconds and greater. We also present an analysis of the expected source
populations that we will be able to detect with VAST.Comment: 29 pages, 8 figures. Submitted for publication in Pub. Astron. Soc.
Australi
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