750 research outputs found
Discovery of the Acoustic Faraday Effect in Superfluid 3He-B
We report the discovery of the acoustic Faraday effect in superfluid 3He-B.
The observation of this effect provides the first direct evidence for
propagating transverse acoustic waves in liquid 3He, a mode first predicted by
Landau in 1957. The Faraday rotation is large and observable because of
spontaneously broken spin-orbit symmetry in 3He-B. We compare the experimental
observations with a simulation of the transverse acoustic impedance that
includes the field-induced circular birefringence of transverse waves.Comment: 4 pages in RevTex plus 3 postscript figures; new version includes:
minor corrections to the text and an updated of list of reference
The contribution of multiple long-term conditions to widening inequalities in disability-free life expectancy over two decades: Longitudinal analysis of two cohorts using the Cognitive Function and Ageing Studies.
BACKGROUND: : Disability-free life expectancy (DFLE) inequalities by socioeconomic deprivation are widening, alongside rising prevalence of multiple long-term conditions (MLTCs). We use longitudinal data to assess whether MLTCs contribute to the widening DFLE inequalities by socioeconomic deprivation. METHODS: : The Cognitive Function and Ageing Studies (CFAS I and II) are large population-based studies of those ≥65 years, conducted in three areas in England. Baseline occurred in 1991 (CFAS I, n=7635) and 2011 (CFAS II, n=7762) with two-year follow-up. We defined disability as difficulty in activities of daily living, MLTCs as the presence of at least two of nine health conditions, and socioeconomic deprivation by area-level deprivation tertiles. DFLE and transitions between disability states and death were estimated from multistate models. FINDINGS: : For people with MLTCs, inequalities in DFLE at age 65 between the most and least affluent widened to around 2.5 years (men:2.4 years, 95% confidence interval (95%CI) 0.4-4.4; women:2.6 years, 95%CI 0.7-4.5) by 2011. Incident disability reduced for the most affluent women (Relative Risk Ratio (RRR):0.6, 95%CI 0.4-0.9), and mortality with disability reduced for least affluent men (RRR:0.6, 95%CI 0.5-0.8). MLTCs prevalence increased only for least affluent men (1991: 58.8%, 2011: 66.9%) and women (1991: 60.9%, 2011: 69.1%). However, DFLE inequalities were as large in people without MLTCs (men:2.4 years, 95%CI 0.3-4.5; women:3.1 years, 95% CI 0.8-5.4). INTERPRETATION: : Widening DFLE inequalities were not solely due to MLTCs. Reduced disability incidence with MLTCs is possible but was only achieved in the most affluent
Population structure and connectivity of tiger sharks (Galeocerdo cuvier) across the Indo-Pacific Ocean basin
Population genetic structure using nine polymorphic nuclear microsatellite loci was assessed for the tiger shark () at seven locations across the Indo-Pacific, and one location in the southern Atlantic. Genetic analyses revealed considerable genetic structuring ( > 0.14,
The Structure of the Non-SUSY Baryonic Branch of Klebanov-Strassler
We study the two-dimensional space of supergravity solutions corresponding to
non-supersymmetric deformations of the baryonic branch of Klebanov-Strassler.
By combining analytical methods with a numerical survey of the parameter space,
we find that this solution space includes as limits the softly-broken N=1
solutions of Gubser et al. and those of Dymarsky and Kuperstein. We also
identify a one-dimensional family of solutions corresponding to a natural
non-supersymmetric generalisation of Klebanov-Strassler, and one corresponding
to the limit in which supersymmetry is completely absent, even in the far UV.
For almost all of the parameter space we find indications that much of the
structure of the supersymmetric baryonic branch survives.Comment: 29 pages plus appendices, 11 figure
Get screened: a pragmatic randomized controlled trial to increase mammography and colorectal cancer screening in a large, safety net practice
Abstract Background Most randomized controlled trials of interventions designed to promote cancer screening, particularly those targeting poor and minority patients, enroll selected patients. Relatively little is known about the benefits of these interventions among unselected patients. Methods/Design "Get Screened" is an American Cancer Society-sponsored randomized controlled trial designed to promote mammography and colorectal cancer screening in a primary care practice serving low-income patients. Eligible patients who are past due for mammography or colorectal cancer screening are entered into a tracking registry and randomly assigned to early or delayed intervention. This 6-month intervention is multimodal, involving patient prompts, clinician prompts, and outreach. At the time of the patient visit, eligible patients receive a low-literacy patient education tool. At the same time, clinicians receive a prompt to remind them to order the test and, when appropriate, a tool designed to simplify colorectal cancer screening decision-making. Patient outreach consists of personalized letters, automated telephone reminders, assistance with scheduling, and linkage of uninsured patients to the local National Breast and Cervical Cancer Early Detection program. Interventions are repeated for patients who fail to respond to early interventions. We will compare rates of screening between randomized groups, as well as planned secondary analyses of minority patients and uninsured patients. Data from the pilot phase show that this multimodal intervention triples rates of cancer screening (adjusted odds ratio 3.63; 95% CI 2.35 - 5.61). Discussion This study protocol is designed to assess a multimodal approach to promotion of breast and colorectal cancer screening among underserved patients. We hypothesize that a multimodal approach will significantly improve cancer screening rates. The trial was registered at Clinical Trials.gov NCT00818857http://deepblue.lib.umich.edu/bitstream/2027.42/78264/1/1472-6963-10-280.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78264/2/1472-6963-10-280.pdfPeer Reviewe
Grouping practices in the primary school: what influences change?
During the 1990s, there was considerable emphasis on promoting particular kinds of pupil grouping as a means of raising educational standards. This survey of 2000 primary schools explored the extent to which schools had changed their grouping practices in responses to this, the nature of the changes made and the reasons for those changes. Forty eight percent of responding schools reported that they had made no change. Twenty two percent reported changes because of the literacy hour, 2% because of the numeracy hour, 7% because of a combination of these and 21% for other reasons. Important influences on decisions about the types of grouping adopted were related to pupil learning and differentiation, teaching, the implementation of the national literacy strategy, practical issues and school self-evaluation
Bell Correlations and the Common Future
Reichenbach's principle states that in a causal structure, correlations of
classical information can stem from a common cause in the common past or a
direct influence from one of the events in correlation to the other. The
difficulty of explaining Bell correlations through a mechanism in that spirit
can be read as questioning either the principle or even its basis: causality.
In the former case, the principle can be replaced by its quantum version,
accepting as a common cause an entangled state, leaving the phenomenon as
mysterious as ever on the classical level (on which, after all, it occurs). If,
more radically, the causal structure is questioned in principle, closed
space-time curves may become possible that, as is argued in the present note,
can give rise to non-local correlations if to-be-correlated pieces of classical
information meet in the common future --- which they need to if the correlation
is to be detected in the first place. The result is a view resembling Brassard
and Raymond-Robichaud's parallel-lives variant of Hermann's and Everett's
relative-state formalism, avoiding "multiple realities."Comment: 8 pages, 5 figure
Age-related changes in global motion coherence: conflicting haemodynamic and perceptual responses
Our aim was to use both behavioural and neuroimaging data to identify indicators of perceptual decline in motion processing. We employed a global motion coherence task and functional Near Infrared Spectroscopy (fNIRS). Healthy adults (n = 72, 18-85) were recruited into the following groups: young (n = 28, mean age = 28), middle-aged (n = 22, mean age = 50), and older adults (n = 23, mean age = 70). Participants were assessed on their motion coherence thresholds at 3 different speeds using a psychophysical design. As expected, we report age group differences in motion processing as demonstrated by higher motion coherence thresholds in older adults. Crucially, we add correlational data showing that global motion perception declines linearly as a function of age. The associated fNIRS recordings provide a clear physiological correlate of global motion perception. The crux of this study lies in the robust linear correlation between age and haemodynamic response for both measures of oxygenation. We hypothesise that there is an increase in neural recruitment, necessitating an increase in metabolic need and blood flow, which presents as a higher oxygenated haemoglobin response. We report age-related changes in motion perception with poorer behavioural performance (high motion coherence thresholds) associated with an increased haemodynamic response
Population-based estimates of the prevalence of FMR1 expansion mutations in women with early menopause and primary ovarian insufficiency
PURPOSE: Primary ovarian insufficiency before the age of 40 years affects 1% of the female population and is characterized by permanent cessation of menstruation. Genetic causes include FMR1 expansion mutations. Previous studies have estimated mutation prevalence in clinical referrals for primary ovarian insufficiency, but these are likely to be biased as compared with cases in the general population. The prevalence of FMR1 expansion mutations in early menopause (between the ages of 40 and 45 years) has not been published. METHODS: We studied FMR1 CGG repeat number in more than 2,000 women from the Breakthrough Generations Study who underwent menopause before the age of 46 years. We determined the prevalence of premutation (55–200 CGG repeats) and intermediate (45–54 CGG repeats) alleles in women with primary ovarian insufficiency (n = 254) and early menopause (n = 1,881). RESULTS: The prevalence of the premutation was 2.0% in primary ovarian insufficiency, 0.7% in early menopause, and 0.4% in controls, corresponding to odds ratios of 5.4 (95% confidence interval = 1.7–17.4; P = 0.004) for primary ovarian insufficiency and 2.0 (95% confidence interval = 0.8–5.1; P = 0.12) for early menopause. Combining primary ovarian insufficiency and early menopause gave an odds ratio of 2.4 (95% confidence interval = 1.02–5.8; P = 0.04). Intermediate alleles were not significant risk factors for either early menopause or primary ovarian insufficiency. CONCLUSION: FMR1 premutations are not as prevalent in women with ovarian insufficiency as previous estimates have suggested, but they still represent a substantial cause of primary ovarian insufficiency and early menopause
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The use of phylogeny to interpret cross-cultural patterns in plant use and guide medicinal plant discovery: an example from Pterocarpus (Leguminosae)
The study of traditional knowledge of medicinal plants has led to discoveries that have helped combat diseases and improve healthcare. However, the development of quantitative measures that can assist our quest for new medicinal plants has not greatly advanced in recent years. Phylogenetic tools have entered many scientific fields in the last two decades to provide explanatory power, but have been overlooked in ethnomedicinal studies. Several studies show that medicinal properties are not randomly distributed in plant phylogenies, suggesting that phylogeny shapes ethnobotanical use. Nevertheless, empirical studies that explicitly combine ethnobotanical and phylogenetic information are scarce.In this study, we borrowed tools from community ecology phylogenetics to quantify significance of phylogenetic signal in medicinal properties in plants and identify nodes on phylogenies with high bioscreening potential. To do this, we produced an ethnomedicinal review from extensive literature research and a multi-locus phylogenetic hypothesis for the pantropical genus Pterocarpus (Leguminosae: Papilionoideae). We demonstrate that species used to treat a certain conditions, such as malaria, are significantly phylogenetically clumped and we highlight nodes in the phylogeny that are significantly overabundant in species used to treat certain conditions. These cross-cultural patterns in ethnomedicinal usage in Pterocarpus are interpreted in the light of phylogenetic relationships.This study provides techniques that enable the application of phylogenies in bioscreening, but also sheds light on the processes that shape cross-cultural ethnomedicinal patterns. This community phylogenetic approach demonstrates that similar ethnobotanical uses can arise in parallel in different areas where related plants are available. With a vast amount of ethnomedicinal and phylogenetic information available, we predict that this field, after further refinement of the techniques, will expand into similar research areas, such as pest management or the search for bioactive plant-based compounds
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