702 research outputs found
Physical activity and sedentary behaviour in 12-13 year old children, stratified by sex, school type and residential deprivation score
Many children are insufficiently active for good health. Factors affecting childhood physical activity and sedentary behaviour levels have been identified, including residential and school factors. Three schools in Sheffield, UK were recruited. Data were collected from children aged 12-13 years on their physical activity and sedentary behaviours using the Youth Physical Activity Questionnaire. Data were analysed using univariate (t-test), non-parametric (X2, Krusall Wallis), and regression models adjusted for school type, sex and residential deprivation score. Children (n=189) attending the independent schools had higher MVPA levels (p<0.008; 95% CI 348-2289 extra minutes per week), and were more likely to meet the physical activity guidelines; this association was particularly strong for boys (boys at independent schools 7.8x more likely). Sex and residential deprivation score were not statistically significantly associated with MVPA or meeting physical activity guidelines. Children in affluent areas had the highest sedentary behaviour levels (p=0.021; 95% CI -1171 to -98). School type and sex were not statistically significantly associated with sedentary behaviour, after adjusting for the other factors. This study found that independent school children, particularly boys, were more active across the whole day, when compared with their state school counterparts. They were also more likely to meet the government’s physical activity guidelines. There was no significant difference in the amount of time girls and boys spent in sedentary activities, but the types of sedentary activity differed between sexes. Children from less deprived areas reported more time spent in sedentary activities
Electrical transport studies of quench condensed Bi films at the initial stage of film growth: Structural transition and the possible formation of electron droplets
The electrical transport properties of amorphous Bi films prepared by
sequential quench deposition have been studied in situ. A
superconductor-insulator (S-I) transition was observed as the film was made
increasingly thicker, consistent with previous studies. Unexpected behavior was
found at the initial stage of film growth, a regime not explored in detail
prior to the present work. As the temperature was lowered, a positive
temperature coefficient of resistance (dR/dT > 0) emerged, with the resistance
reaching a minimum before the dR/dT became negative again. This behavior was
accompanied by a non-linear and asymmetric I-V characteristic. As the film
became thicker, conventional variable-range hopping (VRH) was recovered. We
attribute the observed crossover in the electrical transport properties to an
amorphous to granular structural transition. The positive dR/dT found in the
amorphous phase of Bi formed at the initial stage of film growth was
qualitatively explained by the formation of metallic droplets within the
electron glass.Comment: 7 pages, 6 figure
Reframing e-assessment: building professional nursing and academic attributes in a first year nursing course
This paper documents the relationships between pedagogy and e-assessment in two nursing courses offered at the University of Southern Queensland, Australia. The courses are designed to build the academic, numeracy and technological attributes student nurses need if they are to succeed at university and in the nursing profession. The paper first outlines the management systems supporting the two courses and how they intersect with the e-learning and e-assessment components of course design. These pedagogical choices are then reviewed. While there are lessons to be learnt and improvements to be made, preliminary results suggest students and staff are extremely supportive of the courses. The e-assessment is very positively received with students reporting increased confidence and competency in numeracy, as well as IT, academic, research and communication skills
Microevolution during the emergence of a monophasic Salmonella Typhimurium epidemic in the United Kingdom
Microevolutionary events associated with the emergence and clonal expansion of new 27 epidemic clones of bacterial pathogens hold the key to understanding the drivers of 28 epidemiological success. We describe a comparative whole genome sequence and 29 phylogenomic analysis of monophasic Salmonella Typhimurium isolates from the UK 30 and Italy from 2005-2012. Monophasic isolates from this time formed a single clade 31 distinct from recent monophasic epidemic clones described previously from North 32 America and Spain. The current UK monophasic epidemic clones encode a novel 33 genomic island encoding resistance to heavy metals (SGI-3), and composite transposon 34 encoding antibiotic resistance genes not present in other Typhimurium isolates, that 35 may have contributed to the epidemiological success. We also report a remarkable 36 degree of genotypic variation that accumulated during clonal expansion of a UK 37 epidemic including multiple independent acquisitions of a novel prophage carrying the 38 sopE gene and multiple deletion events affecting the phase II flagellin locus
Translational neuroscience: the state of the nation (a PhD student perspective)
Many brain disorders are currently untreatable. It has been suggested that taking a ‘translational’ approach to neuroscientific research might change this. We discuss what ‘translational neuroscience’ is and argue for the need to expand the traditional translational model if we are to make further advances in treating brain disorders
The stable isotope composition of organic and inorganic fossils in lake sediment records: current understanding, challenges, and future directions
This paper provides an overview of stable isotope analysis (H, C, N, O, Si) of the macro and microscopic remains from aquatic organisms found in lake sediment records and their application in (palaeo)environmental science. Aquatic organisms, including diatoms, macrophytes, invertebrates, and fish, can produce sufficiently robust remains that preserve well as fossils and can be identified in lake sediment records. Stable isotope analyses of these remains can then provide valuable insights into habitat-specific biogeochemistry, feeding ecology, but also on climatic and hydrological changes in and around lakes. Since these analyses focus on the remains of known and identified organisms, they can provide more specific and detailed information on past ecosystem, food web and environmental changes affecting different compartments of lake ecosystems than analyses on bulk sedimentary organic matter or carbonate samples. We review applications of these types of analyses in palaeoclimatology, palaeohydrology, and palaeoecology. Interpretation of the environmental ‘signal’ provided by taxon-specific stable isotope analysis requires a thorough understanding of the ecology and phenology of the organism groups involved. Growth, metabolism, diet, feeding strategy, migration, taphonomy and several other processes can lead to isotope fractionation or otherwise influence the stable isotope signatures of the remains from aquatic organisms. This paper includes a review of the (modern) calibration, culturing and modeling studies used to quantify the extent to which these factors influence stable isotope values and provides an outlook for future research and methodological developments for the different examined fossil groups
Prenatal cortisol exposure impairs adrenal function but not glucose metabolism in adult sheep
Adverse environmental conditions before birth are known to program adult metabolic and endocrine phenotype in several species. However, whether increments in fetal cortisol
concentrations of the magnitude commonly seen in these conditions can cause
developmental programming remains unknown. Thus, this study investigated the outcome
of physiological increases in fetal cortisol concentrations on glucose-insulin dynamics and
pituitary-adrenal function in adult sheep. Compared to saline treatment, intravenous fetal
cortisol infusion for 5 days in late gestation did not affect birthweight but increased lamb
body weight at 1-2 weeks after birth. Adult glucose dynamics, insulin sensitivity and insulin
secretion were unaffected by prenatal cortisol overexposure, assessed by glucose tolerance
tests, hyperinsulinaemic-euglycaemic clamps and acute insulin administration. In contrast,
prenatal cortisol infusion induced adrenal hypo-responsiveness in adulthood with
significantly reduced cortisol responses to insulin-induced hypoglycaemia and exogenous
adrenocorticotropic hormone (ACTH) administration relative to saline treatment. The area of
adrenal cortex expressed as a percentage of the total cross-sectional area of the adult adrenal
gland was also lower after prenatal cortisol than saline infusion. In adulthood, basal
circulating ACTH but not cortisol concentrations were significantly higher in the cortisol than
saline treated group. The results show that cortisol overexposure before birth programs
pituitary-adrenal development with consequences for adult stress responses. Physiological
variations in cortisol concentrations before birth may, therefore, have an important role in
determining adult phenotypical diversity and adaptability to environmental challenges
The Mathematical Universe
I explore physics implications of the External Reality Hypothesis (ERH) that
there exists an external physical reality completely independent of us humans.
I argue that with a sufficiently broad definition of mathematics, it implies
the Mathematical Universe Hypothesis (MUH) that our physical world is an
abstract mathematical structure. I discuss various implications of the ERH and
MUH, ranging from standard physics topics like symmetries, irreducible
representations, units, free parameters, randomness and initial conditions to
broader issues like consciousness, parallel universes and Godel incompleteness.
I hypothesize that only computable and decidable (in Godel's sense) structures
exist, which alleviates the cosmological measure problem and help explain why
our physical laws appear so simple. I also comment on the intimate relation
between mathematical structures, computations, simulations and physical
systems.Comment: Replaced to match accepted Found. Phys. version, 31 pages, 5 figs;
more details at http://space.mit.edu/home/tegmark/toe.htm
The First VERITAS Telescope
The first atmospheric Cherenkov telescope of VERITAS (the Very Energetic
Radiation Imaging Telescope Array System) has been in operation since February
2005. We present here a technical description of the instrument and a summary
of its performance. The calibration methods are described, along with the
results of Monte Carlo simulations of the telescope and comparisons between
real and simulated data. The analysis of TeV -ray observations of the
Crab Nebula, including the reconstructed energy spectrum, is shown to give
results consistent with earlier measurements. The telescope is operating as
expected and has met or exceeded all design specifications.Comment: Accepted by Astroparticle Physic
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