5,395 research outputs found
Estimates of genetic parameters of distal limb fracture and superficial digital flexor tendon injury in UK Thoroughbred racehorses
A retrospective cohort study of distal limb fracture and superficial digital flexor tendon (SDFT) injury in Thoroughbred racehorses was conducted using health records generated by the British Horseracing Authority (BHA) between 2000 and 2010. After excluding records of horses that had both flat and jump racing starts, repeated records were reduced to a single binary record per horse (<i>n</i> = 66,507, 2982 sires), and the heritability of each condition was estimated using residual maximum likelihood (REML) with animal logistic regression models. Similarly, the heritability of each condition was estimated for the flat racing and jump racing populations separately. Bivariate mixed models were used to generate estimates of genetic correlations between SDFT injury and distal limb fracture.
The heritability of distal limb fracture ranged from 0.21 to 0.37. The heritability of SDFT injury ranged from 0.31 to 0.34. SDFT injury and distal limb fracture were positively genetically correlated. These findings suggest that reductions in the risk of the conditions studied could be attempted using targeted breeding strategies
Detection Of KOI-13.01 Using The Photometric Orbit
We use the KOI-13 transiting star-planet system as a test case for the
recently developed BEER algorithm (Faigler & Mazeh 2011), aimed at identifying
non-transiting low-mass companions by detecting the photometric variability
induced by the companion along its orbit. Such photometric variability is
generated by three mechanisms, including the beaming effect, tidal ellipsoidal
distortion, and reflection/heating. We use data from three Kepler quarters,
from the first year of the mission, while ignoring measurements within the
transit and occultation, and show that the planet's ephemeris is clearly
detected. We fit for the amplitude of each of the three effects and use the
beaming effect amplitude to estimate the planet's minimum mass, which results
in M_p sin i = 9.2 +/- 1.1 M_J (assuming the host star parameters derived by
Szabo et al. 2011). Our results show that non-transiting star-planet systems
similar to KOI-13.01 can be detected in Kepler data, including a measurement of
the orbital ephemeris and the planet's minimum mass. Moreover, we derive a
realistic estimate of the amplitudes uncertainties, and use it to show that
data obtained during the entire lifetime of the Kepler mission, of 3.5 years,
will allow detecting non-transiting close-in low-mass companions orbiting
bright stars, down to the few Jupiter mass level. Data from the Kepler Extended
Mission, if funded by NASA, will further improve the detection capabilities.Comment: Accepted to AJ on October 4, 2011. Kepler Q5 Long Cadence data will
become publicly available on MAST by October 23. Comments welcome (V2: minor
changes, to reflect proof corrections
Using Geographic Information Systems to investigate variations in accessibility to ‘extended hours’ primary healthcare provision
There are ongoing policy concerns surrounding the difficulty in obtaining timely appointments to primary healthcare services and the potential impact on, for example, attendance at accident and emergency services and potential health outcomes. Using the case study of potential access to primary healthcare services in Wales, Geographic Information System (GIS)‐based tools that permit a consideration of population‐to‐provider ratios over space are used to examine variations in geographical accessibility to general practitioner (GP) surgeries offering appointment times outside of ‘core’ operating hours. Correlation analysis is used to explore the association of accessibility scores with potential demand for such services using UK Population Census data. Unlike the situation in England, there is a tendency for accessibility to those surgeries offering ‘extended’ hours of appointment times to be better for more deprived census areas in Wales. However, accessibility to surgeries offering appointments in the evening was associated with lower levels of working age population classed as ‘economically active’; that is, those who could be targeted beneficiaries of policies geared towards ‘extended’ appointment hours provision. Such models have the potential to identify spatial mismatches of different facets of primary healthcare, such as ‘extended’ hours provision available at GP surgeries, and are worthy of further investigation, especially in relation to policies targeted at particular demographic groups
N-terminal pro-B-type natriuretic peptide and the prediction of primary cardiovascular events: results from 15-year follow-up of WOSCOPS
<b>Aims:</b>To test whether N-terminal pro-B-type natriuretic peptide (NT-proBNP) was independently associated with, and improved the prediction of, cardiovascular disease (CVD) in a primary prevention cohort.
<b>Methods and results:</b> In the West of Scotland Coronary Prevention Study (WOSCOPS), a cohort of middle-aged men with hypercholesterolaemia at a moderate risk of CVD, we related the baseline NT-proBNP (geometric mean 28 pg/mL) in 4801 men to the risk of CVD over 15 years during which 1690 experienced CVD events. Taking into account the competing risk of non-CVD death, NT-proBNP was associated with an increased risk of all CVD [HR: 1.17 (95% CI: 1.11–1.23) per standard deviation increase in log NT-proBNP] after adjustment for classical and clinical cardiovascular risk factors plus C-reactive protein. N-terminal pro-B-type natriuretic peptide was more strongly related to the risk of fatal [HR: 1.34 (95% CI: 1.19–1.52)] than non-fatal CVD [HR: 1.17 (95% CI: 1.10–1.24)] (P= 0.022). The addition of NT-proBNP to traditional risk factors improved the C-index (+0.013; P < 0.001). The continuous net reclassification index improved with the addition of NT-proBNP by 19.8% (95% CI: 13.6–25.9%) compared with 9.8% (95% CI: 4.2–15.6%) with the addition of C-reactive protein. N-terminal pro-B-type natriuretic peptide correctly reclassified 14.7% of events, whereas C-reactive protein correctly reclassified 3.4% of events. Results were similar in the 4128 men without evidence of angina, nitrate prescription, minor ECG abnormalities, or prior cerebrovascular disease.
<b>Conclusion:</b> N-terminal pro-B-type natriuretic peptide predicts CVD events in men without clinical evidence of CHD, angina, or history of stroke, and appears related more strongly to the risk for fatal events. N-terminal pro-B-type natriuretic peptide also provides moderate risk discrimination, in excess of that provided by the measurement of C-reactive protein
The Impact of Parents’ Categorization of Their Own Weight and Their Child’s Weight on Healthy Lifestyle Promoting Beliefs and Practices
Objective. To evaluate parents’ beliefs and practices related to childhood obesity and determine if these are influenced by parent’s perception of their own weight or their child’s weight.
Methods. Parents of obese ( = 689) or normal weight ( = 1122) children 4–15 years in Georgia, USA, were randomly selected to complete a telephone survey. Frequency of child obesity-related perceptions, beliefs, and practices were assessed, stratified by parent-perceived self-weight and child weight status, and compared using Chisquared tests and multivariate logistic regression.
Results. Most parents, regardless of perceived child weight, agreed that child overweight/obesity can cause serious illness (95%) but only one-half believed it was a problem in Georgia. Many (42.4%) failed to recognize obesity in their own children. More parents who perceived their child as overweight versus normal weight reported concern about their child’s diet and activity and indicated readiness for lifestyle change. Parents’ perception of their own weight had little additional impact.
Conclusions. While awareness of child overweight as a modifiable health risk is high, many parents fail to recognize it in their own families and communities, reducing the likelihood of positive lifestyle change. Additional efforts to help parents understand their role in facilitating behavior change and to assist them in identifying at-risk children are required
Reduced executive and default network functional connectivity in cigarette smokers
Altered functional connectivity has been associated with acute and chronic nicotine use. Connectivity alterations, specifically in the right and left executive control networks (RECN/LECN) and the default mode network (DMN), may contribute to the addiction cycle. The objective of this study was to determine if executive control network (ECN) and DMN connectivity is different between non‐smokers and smokers and whether reductions in connectivity are related to chronic cigarette use. The RECN, LECN, and DMN were identified in resting state functional magnetic resonance imaging data in 650 subjects. Analyses tested for group differences in network connectivity strength, controlling for age and alcohol use. There was a significant group effect on LECN and DMN connectivity strength with smokers (n = 452) having lower network strengths than non‐smokers (n = 198). Smokers had lower connectivity than non‐smokers associated with key network hubs: the dorsolateral prefrontal cortex, and parietal nodes within ECNs. Further, ECN connectivity strength was negatively associated with pack years of cigarette use. Our data suggest that chronic nicotine use negatively impacts functional connectivity within control networks that may contribute to the difficulty smokers have in quitting. Hum Brain Mapp 36:872–882, 2015. © 2014 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110754/1/hbm22672.pd
On the Reliability of Cross Correlation Function Lag Determinations in Active Galactic Nuclei
Many AGN exhibit a highly variable luminosity. Some AGN also show a
pronounced time delay between variations seen in their optical continuum and in
their emission lines. In effect, the emission lines are light echoes of the
continuum. This light travel-time delay provides a characteristic radius of the
region producing the emission lines. The cross correlation function (CCF) is
the standard tool used to measure the time lag between the continuum and line
variations. For the few well-sampled AGN, the lag ranges from 1-100 days,
depending upon which line is used and the luminosity of the AGN. In the best
sampled AGN, NGC 5548, the H_beta lag shows year-to-year changes, ranging from
about 8.7 days to about 22.9 days over a span of 8 years. In this paper it is
demonstrated that, in the context of AGN variability studies, the lag estimate
using the CCF is biased too low and subject to a large variance. Thus the
year-to-year changes of the measured lag in NGC 5548 do not necessarily imply
changes in the AGN structure. The bias and large variance are consequences of
finite duration sampling and the dominance of long timescale trends in the
light curves, not due to noise or irregular sampling. Lag estimates can be
substantially improved by removing low frequency power from the light curves
prior to computing the CCF.Comment: To appear in the PASP, vol 111, 1999 Nov; 37 pages; 10 figure
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