901 research outputs found
The Integrated Sachs-Wolfe Signal from BOSS Super-Structures
Cosmic structures leave an imprint on the microwave background radiation
through the integrated Sachs-Wolfe effect. We construct a template map of the
linear signal using the SDSS-III Baryon Acoustic Oscillation Survey at redshift
0.43 < z < 0.65. We verify the imprint of this map on the Planck CMB
temperature map at the 97% confidence level and show consistency with the
density-temperature cross-correlation measurement. Using this ISW
reconstruction as a template we investigate the presence of ISW sources and
further examine the properties of the Granett-Neyrinck-Szapudi supervoid and
supercluster catalogue. We characterise the three-dimensional density profiles
of these structures for the first time and demonstrate that they are
significant structures. Model fits demonstrate that the supervoids are
elongated along the line-of-sight and we suggest that this special orientation
may be picked out by the void-finding algorithm in photometric redshift space.
We measure the mean temperature profiles in Planck maps from public void and
cluster catalogues. In an attempt to maximise the stacked ISW signal we
construct a new catalogue of super-structures based upon local peaks and
troughs of the gravitational potential. However, we do not find a significant
correlation between these structures and the CMB temperature.Comment: Updated to match journal articl
Effective dark matter power spectra in f(R) gravity
Using N-body simulations, we measure the power spectrum of the effective dark matter density field, which is defined through the modified Poisson equation in f(R) cosmologies. We find that, when compared to the conventional dark matter power spectrum, the effective power spectrum deviates more significantly from the ÎCDM model. For models with fR0=â10â4, the deviation can exceed 150%, while the deviation of the conventional matter power spectrum is less than 50%. Even for models with fR0=â10â6, for which the conventional matter power spectrum is very close to the ÎCDM prediction, the effective power spectrum shows sizeable deviations. Our results indicate that traditional analyses based on the dark matter density field may seriously underestimate the impact of f(R) gravity on galaxy clustering. We therefore suggest the use of the effective density field in such studies. In addition, based on our findings, we also discuss several possible methods of making use of the differences between the conventional and effective dark matter power spectra in f(R) gravity to discriminate the theory from the ÎCDM model
Effective dark matter halo catalog in f(R) gravity
We introduce the idea of an effective dark matter halo catalog in f(R) gravity, which is built using the effective density field. Using a suite of high resolution N-body simulations, we find that the dynamical properties of halos, such as the distribution of density, velocity dispersion, specific angular momentum and spin, in the effective catalog of f(R) gravity closely mimic those in the cold dark matter model with a cosmological constant (ÎCDM). Thus, when using effective halos, an f(R) model can be viewed as a ÎCDM model. This effective catalog therefore provides a convenient way for studying the baryonic physics, the galaxy halo occupation distribution and even semianalytical galaxy formation in f(R) cosmologies
Motivation to Learn, Quality of Life and Estimated Academic Achievement: Medical Students Studying in New Zealand
The quality of life of medical students and their motivation to learn are critical factors that have an impact on their ability to learn. The aim of this study was to investigate the associations between medical students' perceptions of their quality of life, motivation to learn, and estimated grade at the end of the academic year. Two hundred and seventy-four medical students at years four and five of medical school participated in the study. Students filled in a demographic survey form, and shortened versions of the World Health Organization Quality of Life Questionnaire and the Motivated Strategies for Learning Questionnaire. Significant correlations between quality of life and motivation to learn measures were obtained. Second, students who scored high on aspects of quality of life and motivation to learn also scored significantly higher on estimates of written grade. In conclusion, the results suggest that medical studentsâ perceptions about quality of life and motivation to learn are linked to estimation of academic achievement. The findings of this study further resonate with a key conceptual model in the motivation literature, which promotes the importance of creating opportunities for mastery learning, engaging task value, producing optimal learning contexts, and creating mechanisms for coping with and managing the inevitable anxiety-provoking learning experiences that medical students face.The quality of life of medical students and their motivation to learn are critical factors that have an impact on
their ability to learn. The aim of this study was to investigate the associations between medical studentsâ
perceptions of their quality of life, motivation to learn, and estimated grade at the end of the academic year. Two hundred and seventy-four medical students at years four and five of medical school participated in the study. Students filled in a demographic survey form, and shortened versions of the World Health Organization Quality of Life Questionnaire and the Motivated Strategies for Learning Questionnaire. Significant correlations between quality of life and motivation to learn measures were obtained. Second, students who scored high on aspects of quality of life and motivation to learn also scored significantly higher on estimates of written grade. In conclusion, the results suggest that medical studentsâ perceptions about quality of life and motivation to learn are linked to estimation of academic achievement. The findings of this study further resonate with a key conceptual model in the motivation literature, which promotes the importance of creating opportunities for mastery learning, engaging task value, producing optimal learning contexts, and creating mechanisms for coping with and managing the inevitable anxiety-provoking learning experiences that medical students face
Differences in intestinal size, structure, and function contributing to feed efficiency in broiler chickens reared at geographically distant locations
The contribution of the intestinal tract to differences in residual feed intake (RFI) has been inconclusively studied in chickens so far. It is also not clear if RFI-related differences in intestinal function are similar in chickens raised in different environments. The objective was to investigate differences in nutrient retention, visceral organ size, intestinal morphology, jejunal permeability and expression of genes related to barrier function, and innate immune response in chickens of diverging RFI raised at 2 locations (L1: Austria; L2: UK). The experimental protocol was similar, and the same dietary formulation was fed at the 2 locations. Individual BW and feed intake (FI) of chickens (Cobb 500FF) were recorded from d 7 of life. At 5 wk of life, chickens (L1, n = 157; L2 = 192) were ranked according to their RFI, and low, medium, and high RFI chickens were selected (n = 9/RFI group, sex, and location). RFI values were similar between locations within the same RFI group and increased by 446 and 464 g from low to high RFI in females and males, respectively. Location, but not RFI rank, affected growth, nutrient retention, size of the intestine, and jejunal disaccharidase activity. Chickens from L2 had lower total body weight gain and mucosal enzyme activity but higher nutrient retention and longer intestines than chickens at L1. Parameters determined only at L1 showed increased crypt depth in the duodenum and jejunum and enhanced paracellular permeability in low vs. high RFI females. Jejunal expression of IL1B was lower in low vs. high RFI females at L2, whereas that of TLR4 at L1 and MCT1 at both locations was higher in low vs. high RFI males. Correlation analysis between intestinal parameters and feed efficiency metrics indicated that feed conversion ratio was more correlated to intestinal size and function than was RFI. In conclusion, the rearing environment greatly affected intestinal size and function, thereby contributing to the variation in chicken RFI observed across locations
Cylindrical, periodic surface lattice â theory, dispersion analysis, and experiment
A two-dimensional surface lattice of cylindrical topology obtained via perturbing the inner surface of a cylinder is considered. Periodic perturbations of the surface lead to observation of high-impedance, dielectric-like media and resonant coupling of surface and non-propagating volume fields. This allows synthesis of tailored-for-purpose "coating" material with dispersion suitable, for instance, to mediate a Cherenkov type interaction. An analytical model of the lattice is discussed and coupled-wave equations are derived. Variations of the lattice dispersive properties with variation of parameters are shown, illustrating the tailoring of the structure's electromagnetic properties. Experimental results are presented showing agreement with the theoretical model
PUK30 Elicitation of Health-Related Quality of Life Concepts Associated with Overactive Bladder
Movement control of the trunk and pelvis in cerebral palsy diplegia
Core control was quantified using performance measures derived from a computer game driven by rotation and tilt of the trunk and pelvis. Baseline results showed reduced control of tilt in comparison to rotation, and cephalo-caudal reduction of control. Training of pelvic tilt control may improve pelvic kinematics, reducing the risk of developing low back pain
Maintenance inhaler therapy preferences of patients with asthma or chronic obstructive pulmonary disease:a discrete choice experiment
Background A variety of maintenance inhaler therapies are available to treat asthma and COPD. Patient-centric treatment choices require understanding patient preferences for the alternative therapies. Methods A self-completed web-based discrete choice experiment was conducted to elicit patient preferences for inhaler device and medication attributes. Selection of attributes was informed by patient focus groups and literature review. Results The discrete choice experiment was completed by 810 patients with asthma and 1147 patients with COPD. Patients with asthma most valued decreasing the onset of action from 30 to 5 min, followed by reducing yearly exacerbations from 3 to 1. Patients with COPD most and equally valued decreasing the onset of action from 30 to 5 min and reducing yearly exacerbations from 3 to 1. Both patients with asthma and patients with COPD were willing to accept an additional exacerbation in exchange for a 15 min decrease in onset of action and a longer onset of action in exchange for a lower risk of adverse effects from inhaled corticosteroids. Patients with asthma and COPD valued once-daily over twice-daily dosing, pressurised inhalers over dry powder inhalers and non-capsule priming over single-use capsules, although these attributes were not valued as highly as faster onset of action or reduced exacerbations. Conclusions The most important maintenance inhaler attributes for patients with asthma and COPD were fast onset of symptom relief and a lower rate of exacerbations. Concerns about safety of inhaled corticosteroids and device convenience also affected patient preferences but were less important
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