39 research outputs found
NeXSPheRIO Results on Elliptic-Flow Fluctuations at RHIC
By using the NexSPheRIO code, we study the elliptic-flow fluctuations in
Au+Au collisions at 200A GeV. It is shown that, by fixing the parameters of the
model to correctly reproduce the charged pseudo-rapidity and the
transverse-momentum distributions, reasonable agreement of with data is
obtained, both as function of pseudo-rapidity as well as of transverse
momentum, for charged particles. Our results on elliptic-flow fluctuations are
in good agreement with the recently measured data in experiments.Comment: 12 pages, 6 figures, prepared for the Workshop "Relativistic Nuclear
Physics: from Nuclotron to LHC Energies", June 18-22, 2007 (BITP, Kiev,
Ukraine
Qatar-1b: a hot Jupiter orbiting a metal-rich K dwarf star
We report the discovery and initial characterisation of Qatar-1b, a hot
Jupiter orbiting a metal-rich K dwarf star, the first planet discovered by the
Alsubai Project exoplanet transit survey. We describe the strategy used to
select candidate transiting planets from photometry generated by the Alsubai
Project instrument. We examine the rate of astrophysical and other false
positives found during the spectroscopic reconnaissance of the initial batch of
candidates. A simultaneous fit to the follow-up radial velocities and
photometry of Qatar-1b yield a planetary mass of 1.09+/-0.08 Mjup and a radius
of 1.16+/-0.05 Rjup. The orbital period and separation are 1.420033 days and
0.0234 AU for an orbit assumed to be circular. The stellar density, effective
temperature and rotation rate indicate an age greater than 4 Gyr for the
system.Comment: 8 pages, 5 figures, submitted to Monthly Notices of the Royal
Astronomical Societ
Quality of Reporting and Study Design of CKD Cohort Studies Assessing Mortality in the Elderly Before and After STROBE:A Systematic Review
BACKGROUND:The STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) statement was published in October 2007 to improve quality of reporting of observational studies. The aim of this review was to assess the impact of the STROBE statement on observational study reporting and study design quality in the nephrology literature. STUDY DESIGN:Systematic literature review. SETTING & POPULATION:European and North American, Pre-dialysis Chronic Kidney Disease (CKD) cohort studies. SELECTION CRITERIA FOR STUDIES:Studies assessing the association between CKD and mortality in the elderly (>65 years) published from 1st January 2002 to 31st December 2013 were included, following systematic searching of MEDLINE & EMBASE. PREDICTOR:Time period before and after the publication of the STROBE statement. OUTCOME:Quality of study reporting using the STROBE statement and quality of study design using the Newcastle Ottawa Scale (NOS), Scottish Intercollegiate Guidelines Network (SIGN) and Critical Appraisal Skills Programme (CASP) tools. RESULTS:37 papers (11 Pre & 26 Post STROBE) were identified from 3621 potential articles. Only four of the 22 STROBE items and their sub-criteria (objectives reporting, choice of quantitative groups and description of and carrying out sensitivity analysis) showed improvements, with the majority of items showing little change between the period before and after publication of the STROBE statement. Pre- and post-period analysis revealed a Manuscript STROBE score increase (median score 77.8% (Inter-quartile range [IQR], 64.7-82.0) vs 83% (IQR, 78.4-84.9, p = 0.05). There was no change in quality of study design with identical median scores in the two periods for NOS (Manuscript NOS score 88.9), SIGN (Manuscript SIGN score 83.3) and CASP (Manuscript CASP score 91.7) tools. LIMITATIONS:Only 37 Studies from Europe and North America were included from one medical specialty. Assessment of study design largely reliant on good reporting. CONCLUSIONS:This study highlights continuing deficiencies in the reporting of STROBE items and their sub-criteria in cohort studies in nephrology. There was weak evidence of improvement in the overall reporting quality, with no improvement in methodological quality of CKD cohort studies between the period before and after publication of the STROBE statement
Using functional data analysis to understand daily activity levels and patterns in primary school-aged children: Cross-sectional analysis of a UK-wide study
Temporal characterisation of physical activity in children is required for effective strategies to increase physical activity (PA). Evidence regarding determinants of physical activity in childhood and their time-dependent patterns remain inconclusive. We used functional data analysis (FDA) to model temporal profiles of daily activity, measured objectively using accelerometers, to identify diurnal and seasonal PA patterns in a nationally representative sample of primary school-aged UK children. We hypothesised that PA levels would be lower in girls than boys at play times and after school, higher in children participating in social forms of exercise (such as sport or play), and lower among those not walking to school.Children participating in the UK-wide Millennium Cohort Study wore an Actigraph GT1M accelerometer for seven consecutive days during waking hours. We modelled 6,497 daily PA profiles from singleton children (3,176 boys; mean age: 7.5 years) by means of splines, and used functional analysis of variance to examine the cross-sectional relation of time and place of measurement, demographic and behavioural characteristics to smoothed PA profiles.Diurnal and time-specific patterns of activity showed significant variation by sex, ethnicity, UK country and season of measurement; girls were markedly less active than boys during school break times than boys, and children of Indian ethnicity were significantly less active during school hours (9:30-12:00). Social activities such as sport clubs, playing with friends were associated with higher level of PA in afternoon (15:00-17:30) and early evenings (17:30-19:30). Lower PA levels between 8:30-9:30 and 17:30-19:30 were associated with mode of travel to and from school, and number of cars in regular use in the household.Diminished PA in primary school aged children is temporally patterned and related to modifiable behavioural factors. FDA can be used to inform and evaluate public health policies to promote childhood PA
Genetic parameters for milk urea and its relationship with milk yield and compositions in Holstein dairy cows
peer reviewe
Induction of altered gene expression profiles in cultured bovine granulosa cells at high cell density
Empowering the frontline: internal and external organizational antecedents of teacher empowerment
Although frontline empowerment is central to managerial reform, few scholars have explored the conditions which effectively promote empowerment. We argue that empowerment is linked to inherent organizational features. To investigate this, we consider six sub-dimensions of empowerment: a) decision-making, b) professional growth, c) supportive culture, d) self-efficacy, e) work autonomy, and f) use of performance information. Findings from a panel survey of all public-school teachers in North Carolina show the singular importance of responsive leadership for fostering empowerment, but also show that other organizational factors, such as organizational type, structure, size, and prior performance, explain significant variation in empowerment.1