141 research outputs found
What turns galaxies off? The different morphologies of star-forming and quiescent galaxies since z~2 from CANDELS
We use HST/WFC3 imaging from the CANDELS Multicycle Treasury Survey, in
conjunction with the Sloan Digital Sky Survey, to explore the evolution of
galactic structure for galaxies with stellar masses >3e10M_sun from z=2.2 to
the present epoch, a time span of 10Gyr. We explore the relationship between
rest-frame optical color, stellar mass, star formation activity and galaxy
structure. We confirm the dramatic increase from z=2.2 to the present day in
the number density of non-star-forming galaxies above 3e10M_sun reported by
others. We further find that the vast majority of these quiescent systems have
concentrated light profiles, as parametrized by the Sersic index, and the
population of concentrated galaxies grows similarly rapidly. We examine the
joint distribution of star formation activity, Sersic index, stellar mass,
inferred velocity dispersion, and stellar surface density. Quiescence
correlates poorly with stellar mass at all z<2.2. Quiescence correlates well
with Sersic index at all redshifts. Quiescence correlates well with `velocity
dispersion' and stellar surface density at z>1.3, and somewhat less well at
lower redshifts. Yet, there is significant scatter between quiescence and
galaxy structure: while the vast majority of quiescent galaxies have prominent
bulges, many of them have significant disks, and a number of bulge-dominated
galaxies have significant star formation. Noting the rarity of quiescent
galaxies without prominent bulges, we argue that a prominent bulge (and
perhaps, by association, a supermassive black hole) is an important condition
for quenching star formation on galactic scales over the last 10Gyr, in
qualitative agreement with the AGN feedback paradigm.Comment: The Astrophysical Journal, in press; 20 pages with 13 figure
Interphase cytogenetics of multicentric renal cell tumours confirm associations of specific aberrations with defined cytomorphologies
To demonstrate associations of certain chromosomal aberrations with defined renal cell tumour (RCT) subtypes, we analysed 239 tumour nephrectomy cases for specimens with multicentric tumours. Chromosomal in situ hybridization was then performed on 15 cases with 34 foci (16 conventional renal cell carcinomas (RCCs), and 18 papillary RCTs (11 carcinomas and seven adenomas) for specific chromosomal aberrations, using α-satellite probes for chromosomes 3, 7 or 17. Particular preference was given to cases which had separate foci with different cytomorphologies. Furthermore, we compared aberrations in relation to tumour size, stage, grade and between different foci in a specimen. Thirty-four cases had multiple tumours. Forty-seven per cent of the multicentric tumours were conventional RCCs and 53% papillary RCTs (against 83% solitary conventional RCCs and 5% solitary papillary RCTs). Three conventional RCCs sized 8 mm (G3), 13 cm (pT2, G2) and 15 cm (pT3b, G3), respectively, revealed monosomy 3, and 13 were disomic. Seventeen papillary RCTs (11 carcinomas and six adenomas) displayed trisomy 17, irrespective of size or grade. Four papillary carcinomas and six papillary adenomas had trisomy 7, and the rest (seven papillary carcinomas and one papillary adenoma) revealed disomy 7. In conclusion, papillary RCTs were tendentially multicentric. Although specific for conventional RCCs heedless of size, monosomy 3 was only observed in high-grade and/or advanced tumours. Trisomy 17 was only detectable in papillary RCTs irrespective of tumour state, showing increased copies with tumour growth. Papillary RCTs also appeared to lose some copies of chromosome 7 with tumour progress, possibly reflecting malignancy. © 2000 Cancer Research Campaig
Efficacy of nonsurgical interventions for anterior knee pain: Systematic review and meta-analysis of randomized trials
Anterior knee pain is a chronic condition that presents frequently to sports medicine clinics, and can have a long-term impact on participation in physical activity. Conceivably, effective early management may prevent chronicity and facilitate physical activity. Although a variety of nonsurgical interventions have been advocated, previous systematic reviews have consistently been unable to reach conclusions to support their use. Considering a decade has lapsed since publication of the most recent data in these reviews, it is timely to provide an updated synthesis of the literature to assist sports medicine practitioners in making informed, evidence-based decisions. A systematic review and meta-analysis was conducted to evaluate the evidence for nonsurgical interventions for anterior knee pain
Mental health training programmes for non-mental health trained professionals coming into contact with people with mental ill health: a systematic review of effectiveness
Background The police and others in occupations where they come into close contact with people experiencing/with mental ill health, often have to manage difficult and complex situations. Training is needed to equip them to recognise and assist when someone has a mental health issue or learning/intellectual disability. We undertook a systematic review of the effectiveness of training programmes aimed at increasing knowledge, changing behaviour and/or attitudes of the trainees with regard to mental ill health, mental vulnerability, and learning disabilities. Methods Databases searched from 1995 onwards included: ASSIA, Cochrane Central Register of Controlled Clinical Trials (CENTRAL), Criminal Justice Abstracts, Embase, ERIC, MEDLINE, PsycINFO, Social Science Citation Index. Courses, training, or learning packages aimed at helping police officers and others who interact with the public in a similar way to deal with people with mental health problems were included. Primary outcomes were change in practice and change in outcomes for the groups of people the trainees come into contact with. Systematic reviews, randomised controlled trials (RCTs) and non- randomised controlled trials (non-RCTs) were included and quality assessed. In addition non-comparative evaluations of training for police in England were included. Results From 8578 search results, 19 studies met the inclusion criteria: one systematic review, 12 RCTs, three prospective non-RCTs, and three non-comparative studies. The training interventions identified included broad mental health awareness training and packages addressing a variety of specific mental health issues or conditions. Trainees included police officers, teachers and other public sector workers. Some short term positive changes in behaviour were identified for trainees, but for the people the trainees came into contact with there was little or no evidence of benefit. Conclusions A variety of training programmes exist for non-mental health professionals who come into contact with people who have mental health issues. There may be some short term change in behaviour for the trainees, but longer term follow up is needed. Research evaluating training for UK police officers is needed in which a number of methodological issues need to be addressed
Sexual dimorphism in cancer.
The incidence of many types of cancer arising in organs with non-reproductive functions is significantly higher in male populations than in female populations, with associated differences in survival. Occupational and/or behavioural factors are well-known underlying determinants. However, cellular and molecular differences between the two sexes are also likely to be important. In this Opinion article, we focus on the complex interplay that sex hormones and sex chromosomes can have in intrinsic control of cancer-initiating cell populations, the tumour microenvironment and systemic determinants of cancer development, such as the immune system and metabolism. A better appreciation of these differences between the two sexes could be of substantial value for cancer prevention as well as treatment
Stress hormones and posttraumatic stress symptoms following paediatric critical illness: an exploratory study
Association Between Chromosome 9p21 Variants and the Ankle-Brachial Index Identified by a Meta-Analysis of 21 Genome-Wide Association Studies
Genetic determinants of peripheral arterial disease (PAD) remain largely unknown. To identify genetic variants associated with the ankle-brachial index (ABI), a noninvasive measure of PAD, we conducted a meta-analysis of genome-wide association study data from 21 population-based cohorts
The Effect of Diacutaneous Fibrolysis on Patellar Position Measured Using Ultrasound Scanning in Patients With Patellofemoral Pain Syndrome
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Regional grid refinement in an Earth system model: Impacts on the simulated Greenland surface mass balance
In this study, the resolution dependence of the simulated Greenland ice sheet surface mass balance (GrIS SMB) in the variable-resolution Community Earth System Model (VR-CESM) is investigated. Coupled atmosphere-land simulations are performed on two regionally refined grids over Greenland at 0.5° (∼55km) and 0.25° (∼28km), maintaining a quasi-uniform resolution of 1° (∼111km) over the rest of the globe. On the refined grids, the SMB in the accumulation zone is significantly improved compared to airborne radar and in situ observations, with a general wetting (more snowfall) at the margins and a drying (less snowfall) in the interior GrIS. Total GrIS precipitation decreases with resolution, which is in line with best-available regional climate model results. In the ablation zone, CESM starts developing a positive SMB bias with increased resolution in some basins, notably in the east and the north. The mismatch in ablation is linked to changes in cloud cover in VR-CESM, and a reduced effectiveness of the elevation classes subgrid parametrization in CESM. Overall, our pilot study introduces VR-CESM as a new tool in the cryospheric sciences, which could be used to dynamically downscale SMB in scenario simulations and to force dynamical ice sheet models through the CESM coupling framework
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