3,165 research outputs found
Developmental Improvements in Perceptual Restoration: Can Young Children Reconstruct Missing Sounds in Noisy Environments?
Young children are frequently exposed to sounds such as speech and music in noisy listening conditions, which have the potential to disrupt their learning. Missing input that is masked by louder sounds can, under the right conditions, be ‘filled in’ by the perceptual system using a process known as perceptual restoration. This experiment compared the ability of 4- to 6-year-old children, 9- to 11-year-old children and adults to complete a melody identification task using perceptual restoration. Melodies were presented either intact (complete input), with noise-filled gaps (partial input; perceptual restoration can occur) or with silence-filled gaps (partial input; perceptual restoration cannot occur). All age groups could use perceptual restoration to help them interpret partial input, yet perception was the most detrimentally affected by the presentation of partial input for the youngest children. This implies that they might have more difficulty perceiving sounds in noisy environments than older children or adults. Young children had particular difficulty using partial input for identification under conditions where perceptual restoration could not occur. These findings suggest that perceptual restoration is a crucial mechanism in young children, where processes that fill in missing sensory input represent an important part of the way meaning is extracted from a complex sensory world. Copyright © 2011 John Wiley & Sons, Lt
The Recurrent Nova Candidate M31N 1966-08a = 1968-10c is a Galactic Flare Star
A spectrum of the quiescent counterpart of the Recurrent Nova candidate M31N 1966-08a (= M31N 1968-10c) obtained with LRS2 on the Hobby-Eberly Telescope reveals the object to be a foreground Galactic dMe flare star, and not a nova in M31
Health literacy, health status, and healthcare utilization of Taiwanese adults: results from a national survey
Abstract Background Low health literacy is considered a worldwide health threat. The purpose of this study is to assess the prevalence and socio-demographic covariates of low health literacy in Taiwanese adults and to investigate the relationships between health literacy and health status and health care utilization. Methods A national survey of 1493 adults was conducted in 2008. Health literacy was measured using the Mandarin Health Literacy Scale. Health status was measured based on self-rated physical and mental health. Health care utilization was measured based on self-reported outpatient clinic visits, emergency room visits, and hospitalizations. Results Approximately thirty percent of adults were found to have low (inadequate or marginal) health literacy. They tended to be older, have fewer years of schooling, lower household income, and reside in less populated areas. Inadequate health literacy was associated with poorer mental health (OR, 0.57; 95% CI, 0.35-0.91). No association was found between health literacy and health care utilization even after adjusting for other covariates. Conclusions Low (inadequate and marginal) health literacy is prevalent in Taiwan. High prevalence of low health literacy is not necessarily indicative of the need for interventions. Systematic efforts to evaluate the impact of low health literacy on health outcomes in other countries would help to illuminate features of health care delivery and financing systems that may mitigate the adverse health effects of low health literacy.http://deepblue.lib.umich.edu/bitstream/2027.42/78252/1/1471-2458-10-614.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78252/2/1471-2458-10-614.pdfPeer Reviewe
Cross-species gene expression analysis of species specific differences in the preclinical assessment of pharmaceutical compounds
Animals are frequently used as model systems for determination of safety and efficacy in pharmaceutical research and development. However, significant quantitative and qualitative differences exist between humans and the animal models used in research. This is as a result of genetic variation between human and the laboratory animal. Therefore the development of a system that would allow the assessment of all molecular differences between species after drug exposure would have a significant impact on drug evaluation for toxicity and efficacy. Here we describe a cross-species microarray methodology that identifies and selects orthologous probes after cross-species sequence comparison to develop an orthologous cross-species gene expression analysis tool. The assumptions made by the use of this orthologous gene expression strategy for cross-species extrapolation is that; conserved changes in gene expression equate to conserved pharmacodynamic endpoints. This assumption is supported by the fact that evolution and selection have maintained the structure and function of many biochemical pathways over time, resulting in the conservation of many important processes. We demonstrate this cross-species methodology by investigating species specific differences of the peroxisome proliferatoractivator receptor (PPAR) a response in rat and human
Sculpting oscillators with light within a nonlinear quantum fluid
Seeing macroscopic quantum states directly remains an elusive goal. Particles
with boson symmetry can condense into such quantum fluids producing rich
physical phenomena as well as proven potential for interferometric devices
[1-10]. However direct imaging of such quantum states is only fleetingly
possible in high-vacuum ultracold atomic condensates, and not in
superconductors. Recent condensation of solid state polariton quasiparticles,
built from mixing semiconductor excitons with microcavity photons, offers
monolithic devices capable of supporting room temperature quantum states
[11-14] that exhibit superfluid behaviour [15,16]. Here we use microcavities on
a semiconductor chip supporting two-dimensional polariton condensates to
directly visualise the formation of a spontaneously oscillating quantum fluid.
This system is created on the fly by injecting polaritons at two or more
spatially-separated pump spots. Although oscillating at tuneable THz-scale
frequencies, a simple optical microscope can be used to directly image their
stable archetypal quantum oscillator wavefunctions in real space. The
self-repulsion of polaritons provides a solid state quasiparticle that is so
nonlinear as to modify its own potential. Interference in time and space
reveals the condensate wavepackets arise from non-equilibrium solitons. Control
of such polariton condensate wavepackets demonstrates great potential for
integrated semiconductor-based condensate devices.Comment: accepted in Nature Physic
Exploring differential item functioning in the Western Ontario and McMaster Universities osteoarthritis index (WOMAC)
Background: The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a widely used patient reported outcome in osteoarthritis. An important, but frequently overlooked, aspect of validating health outcome measures is to establish if items exhibit differential item functioning (DIF). That is, if respondents have the same underlying level of an attribute, does the item give the same score in different subgroups or is it biased towards one subgroup or another. The aim of the study was to explore DIF in the Likert format WOMAC for the first time in a UK osteoarthritis population with respect to demographic, social, clinical and psychological factors. Methods: The sample comprised a community sample of 763 people with osteoarthritis who participated in the Somerset and Avon Survey of Health. The WOMAC was explored for DIF by gender, age, social deprivation, social class, employment status, distress, body mass index and clinical factors. Ordinal regression models were used to identify DIF items. Results: After adjusting for age, two items were identified for the physical functioning subscale as having DIF with age identified as the DIF factor for 2 items, gender for 1 item and body mass index for 1 item. For the WOMAC pain subscale, for people with hip osteoarthritis one item was identified with age-related DIF. The impact of the DIF items rarely had a significant effect on the conclusions of group comparisons. Conclusions: Overall, the WOMAC performed well with only a small number of DIF items identified. However, as DIF items were identified in for the WOMAC physical functioning subscale it would be advisable to analyse data taking into account the possible impact of the DIF items when weight, gender or especially age effects, are the focus of interest in UK-based osteoarthritis studies. Similarly for the WOMAC pain subscale in people with hip osteoarthritis it would be worthwhile to analyse data taking into account the possible impact of the DIF item when age comparisons are of primary interest
Incidence of seed migration to the chest, abdomen, and pelvis after transperineal interstitial prostate brachytherapy with loose 125I seeds
<p>Abstract</p> <p>Background</p> <p>The aim was to determine the incidence of seed migration not only to the chest, but also to the abdomen and pelvis after transperineal interstitial prostate brachytherapy with loose <sup>125</sup>I seeds.</p> <p>Methods</p> <p>We reviewed the records of 267 patients who underwent prostate brachytherapy with loose <sup>125</sup>I seeds. After seed implantation, orthogonal chest radiographs, an abdominal radiograph, and a pelvic radiograph were undertaken routinely to document the occurrence and sites of seed migration. The incidence of seed migration to the chest, abdomen, and pelvis was calculated. All patients who had seed migration to the abdomen and pelvis subsequently underwent a computed tomography scan to identify the exact location of the migrated seeds. Postimplant dosimetric analysis was undertaken, and dosimetric results were compared between patients with and without seed migration.</p> <p>Results</p> <p>A total of 19,236 seeds were implanted in 267 patients. Overall, 91 of 19,236 (0.47%) seeds migrated in 66 of 267 (24.7%) patients. Sixty-nine (0.36%) seeds migrated to the chest in 54 (20.2%) patients. Seven (0.036%) seeds migrated to the abdomen in six (2.2%) patients. Fifteen (0.078%) seeds migrated to the pelvis in 15 (5.6%) patients. Seed migration occurred predominantly within two weeks after seed implantation. None of the 66 patients had symptoms related to the migrated seeds. Postimplant prostate D90 was not significantly different between patients with and without seed migration.</p> <p>Conclusion</p> <p>We showed the incidence of seed migration to the chest, abdomen and pelvis. Seed migration did not have a significant effect on postimplant prostate D90.</p
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