5,466 research outputs found
The colour-magnitude relations of ClJ1226.9+3332, a massive cluster of galaxies at z=0.89
(Abridged) The colour-magnitude relations of one of the most massive, high
redshift clusters of galaxies known have been studied. Photometry has been
measured in the V, R, I, z, F606W, F814W, J and K bands to a depth of K*+2.5
and spectroscopy confirms 27 K band selected cluster members. The V-K colours
are equivalent to a rest-frame colour of ~2700A-J, and provide a very sensitive
measure of star-formation activity. HST ACS imaging has been used to
morphologically classify the galaxies.
The cluster has a low early-type fraction compared to nearby clusters, with
only 33% of the cluster members having types E or S0. The early-type member
galaxies form a clear red-sequence in all colours. The scatter and slope of the
relations show no evolution compared to the equivalent Coma cluster relations,
suggesting the stellar populations are already very old. The normalisation of
the relations has been compared to models based on synthetic stellar
populations, and are most consistent with stellar populations forming at z>3.
Some late-type galaxies were found to lie on the red-sequence, suggesting that
they have very similar stellar populations to the early-types.
These results present a picture of a cluster in which the early-type galaxies
are all old, but in which there must be future morphological transformation of
galaxies to match the early-type fraction of nearby clusters. In order to
preserve the tight colour-magnitude relation of early-types seen in nearby
clusters, the late-type galaxies must transform their colours, through the
cessation of star-formation, before the morphological transformation occurs.
Such evolution is observed in the late-types lying on the colour-magnitude
relation.Comment: Accepted for publication in MNRAS. 14 pages, 5 figure
How Dry Are Red Mergers?
The focus of current research in galaxy evolution has increasingly turned to
understanding the effect that mergers have on the evolution of systems on the
red sequence. For those interactions purported to occur dissipationlessly (so
called "dry mergers"), it would appear that the role of gas is minimal.
However, if these mergers are not completely dry, then even low levels of gas
may be detectable. The purpose of our study is to test whether early type
galaxies with HI in or around them, or "wet" ellipticals, would have been
selected as dry mergers by the criteria in van Dokkum (2005, AJ, 130, 2647). To
that end, we examine a sample of 20 early types from the HI Rogues Gallery with
neutral hydrogen in their immediate environs. Of these, the 15 brightest and
reddest galaxies match the optical dry merger criteria, but in each case, the
presence of HI means that they are not truly dry.Comment: 8 pages plus 1 table and 5 figures; accepted for publication in A
Vitamin D supplementation does not improve human skeletal muscle contractile properties in insufficient young males
Vitamin D may be a regulator of skeletal muscle function, although human trials investigating this hypothesis are limited to predominantly elderly populations. We aimed to assess the effect of oral vitamin D3 in healthy young males upon skeletal muscle function
Hypoalbuminaemia predicts outcome in adult patients with congenital heart disease
Background In patients with acquired heart failure, hypoalbuminaemia is associated with increased risk of death. The prevalence of hypoproteinaemia and hypoalbuminaemia and their relation to outcome in adult patients with congenital heart disease (ACHD) remains, however, unknown. Methods Data on patients with ACHD who underwent blood testing in our centre within the last 14 years were collected. The relation between laboratory, clinical or demographic parameters at baseline and mortality was assessed using Cox proportional hazards regression analysis. Results A total of 2886 patients with ACHD were included. Mean age was 33.3 years (23.6–44.7) and 50.1% patients were men. Median plasma albumin concentration was 41.0 g/L (38.0–44.0), whereas hypoalbuminaemia (<35 g/L) was present in 13.9% of patients. The prevalence of hypoalbuminaemia was significantly higher in patients with great complexity ACHD (18.2%) compared with patients with moderate (11.3%) or simple ACHD lesions (12.1%, p<0.001). During a median follow-up of 5.7 years (3.3–9.6), 327 (11.3%) patients died. On univariable Cox regression analysis, hypoalbuminaemia was a strong predictor of outcome (HR 3.37, 95% CI 2.67 to 4.25, p<0.0001). On multivariable Cox regression, after adjusting for age, sodium and creatinine concentration, liver dysfunction, functional class and disease complexity, hypoalbuminaemia remained a significant predictor of death. Conclusions Hypoalbuminaemia is common in patients with ACHD and is associated with a threefold increased risk of risk of death. Hypoalbuminaemia, therefore, should be included in risk-stratification algorithms as it may assist management decisions and timing of interventions in the growing ACHD population
'Selling it as a holistic health provision and not just about condoms ?' Sexual health services in school settings: current models and their relationship with sex and relationships education policy and provision
In this article we discuss the findings from a recent study of UK policy and practice in relation to sexual health services for young people, based in - or closely linked with - schools. This study formed part of a larger project, completed in 2009, which also included a systematic review of international research. The findings discussed in this paper are based on analyses of interviews with 51 service managers and questionnaire returns from 205 school nurses. Four themes are discussed. First, we found three main service permutations, in a context of very diverse and uneven implementation. Second, we identified factors within the school context that shaped and often constrained service provision; some of these also have implications for sex and relationships education (SRE). Third, we found contrasting approaches to the relationship between SRE input and sexual health provision. Fourth, we identified some specific barriers that need to be addressed in order to develop 'young people friendly' services in the school context. The relative autonomy available to school head teachers and governors can represent an obstacle to service provision - and inter-professional collaboration - in a climate where, in many schools, there is still considerable ambivalence about discussing 'sex' openly. In conclusion, we identify areas worthy of further research and development, in order to address some obstacles to sexual health service and SRE provision in schools
Suggestions for a way forward to further evaluate ageing error for Southern Hemisphere minke whales.
Paper SC/59/O8 provides a very helpful perspective and suggestions to help clarify the use of Antarctic minke whale age data in the commercial and research permit periods. On the basis of the paper, some areas for further work suggest themselves and these are outlined below. We recognise that these involve, in some cases, quite substantial additional work but believe that this will assist considerably in addressing the issues raised inter alia at the JARPA review meeting as well as during past IA sub-committee meetings and allow the valuable analyses involving both commercial and scientific permit data to be undertaken. The second experiment is designed to confirm the proposal in SC/59/O8 to limit analyses to using only data for animals aged six years and over
Metrics to evaluate research performance in academic institutions: A critique of ERA 2010 as applied in forestry and the indirect H2 index as a possible alternative
Excellence for Research in Australia (ERA) is an attempt by the Australian
Research Council to rate Australian universities on a 5-point scale within 180
Fields of Research using metrics and peer evaluation by an evaluation
committee. Some of the bibliometric data contributing to this ranking suffer
statistical issues associated with skewed distributions. Other data are
standardised year-by-year, placing undue emphasis on the most recent
publications which may not yet have reliable citation patterns. The
bibliometric data offered to the evaluation committees is extensive, but lacks
effective syntheses such as the h-index and its variants. The indirect H2 index
is objective, can be computed automatically and efficiently, is resistant to
manipulation, and a good indicator of impact to assist the ERA evaluation
committees and to similar evaluations internationally.Comment: 19 pages, 6 figures, 7 tables, appendice
Changes in whole body bone mineral composition in a community-based pilot study designed for Mexican-American women at risk for type II diabetes
Changes in whole body bone mineral composition in a community-based pilot study designed for Mexican-American women at risk for type II diabetes
David C. Castillo, B.S., Maria G. Placeres, B.S., Arely Perez, M.S., Danielle M. Bravo, B.S., Donovan L. Fogt, Ph.D., Zenong Yin, Ph.D.
Mobile Health Laboratory, Department of Health and Kinesiology
The University of Texas at San Antonio
Classification of First Author (Master’s)
Background: Osteoporosis is a serious public health concern in the United States that is expected to increase over the next several years, especially in women. The US Surgeon General’s Report on Bone Health states that individuals can decrease the risk of developing osteoporosis with proper combinations of nutrition and physical activity. Diet and exercise are two important factors that have been shown to prevent or delay the onset of type II diabetes, another national top health concern. Intensive lifestyle interventions, such as The Diabetes Prevention Program have shown that type II diabetes can be delayed or prevented by losing moderate amounts of weight through dietary changes and increased physical activity. It is not clear if a lifestyle intervention can impact bone health.
Purpose: This pilot study examined the effects of lifestyle intervention (dietary and physical activity behavior modification) on bone mineral density (BMD) and bone mineral content (BMC). The intervention was a 14-week community-based pilot study, based on The Diabetes Prevention Program, designed to reduce risk for type II diabetes in high-risk Mexican American women.
The research questions were: Did the lifestyle intervention affect the outcome measures (BMC and BMD)? Were there differences in BMC and BMD between age groups (low-age ≤45 yrs. vs. high-age \u3e45 yrs.)? Were there differences in BMC and BMD between body weight groups (≤78 kg vs. \u3e78.1 kg)?
Methods: The study used a one-group pre- and post-test design. Twenty-five non-diabetic Mexican-American females (average age = 45, SD = 10.9; BMI 25-40) participated in a 14-week lifestyle intervention pilot study. Changes in BMD (g/cm2) and BMC (g) were measured at baseline and 14 weeks after baseline using whole body dual-energy x-ray absorptiometry (DXA).
Results: results of paired t-test showed a significant increase in whole body BMC (p\u3c .0001) and a marginally significant increase in whole body BMD (p\u3c .06). Results of Analysis of Covariance revealed no significant difference in BMC between age groups and a marginally significant increase of BMD (p\u3c .07) in younger participants compared to older participants, after controlling pretest measure. There was a significant increase in BMC (p\u3c .01) and a marginally significant increase in BMD (p\u3c .08) in the high-body weight group compared to the low weight group after controlling for pretest measure.
Conclusions: A lifestyle intervention that utilized a combination of physical activity and dietary modification showed great promise toward preventing the onset of osteoporosis, especially in heavier Mexican-American women
Evaluating an interactive acceptance and commitment therapy (ACT) workshop delivered to trained therapists working with cancer patients in the United Kingdom: a mixed methods approach
Background
SURECAN (SUrvivors’ Rehabilitation Evaluation after CANcer) is a multi-phase study developing and evaluating an Acceptance and Commitment Therapy (ACT) intervention integrated with exercise and work when highly valued (thus we called the intervention ACT+), for people who have completed treatment for cancer but who have low quality of life. We developed a training programme for therapists working in different psychological services to be delivered over 2–3 days. Our aim was to evaluate the extent to which the training could improve therapists’ knowledge and confidence to deliver ACT+ to cancer patients in a trial setting.
Methods
Three interactive workshops were delivered to 29 therapists from three clinical settings in London and in Sheffield. A mixed-methods approach was used. Questionnaires were designed to assess knowledge and confidence in using ACT+ with people who have low quality of life after cancer treatment. They were self-administered immediately prior to and after each workshop. Open text-based questions were used to elicit feedback about the workshops alongside a satisfaction scale. Semi-structured interviews were conducted with a purposive sample of therapists (n = 12) to explore their views about the training more deeply, and how it might be optimised.
Results
Quantitative analysis showed that knowledge of ACT, as well as confidence in using the ACT+ intervention in this setting increased significantly after training (28.6 and 33.5% increase in the median score respectively). Qualitative analysis indicated that most therapists were satisfied with the content and structure of the programme, valued the rich resources provided and enjoyed the practice-based approach. Potential barriers/facilitators to participation in the trial and to the successful implementation of ACT+ were identified. For some therapists, delivering a manualised intervention, as well as supporting exercise- and work-related goals as non-specialists was seen as challenging. At the same time, therapists valued the opportunity to be involved in research, whilst training in a new therapy model.
Conclusions
Training can effectively improve the knowledge and confidence of therapists from different clinical backgrounds to deliver a modified ACT intervention to cancer patients in a trial setting
Iso-singlet Down Quark Mixing And CP Violation Experiments
We confront the new physics models with extra iso-singlet down quarks in the
new CP violation experimental era with and
measurements, events, and
limits. The closeness of the new experimental results to the standard
model theory requires us to include full SM amplitudes in the analysis. In
models allowing mixing to a new isosinglet down quark, as in E, flavor
changing neutral currents are induced that allow a mediated contribution
to mixing and which bring in new phases. In ,
, and plots we still find much
larger regions in the four down quark model than in the SM, reaching down to
, , , and down to zero, all at 1. We elucidate
the nature of the cancellation in an order four down quark mixing
matrix element which satisfies the experiments and reduces the number of
independent angles and phases. We also evaluate tests of unitarity for the
CKM submatrix.Comment: 14 pages, 16 figures, REVTeX
- …