66 research outputs found
M87, Globular Clusters, and Galactic Winds: Issues in Giant Galaxy Formation
New VRI photometry is presented for the globular clusters in the innermost
140'' of the M87 halo. The results are used to discuss several issues
concerning the formation and evolution of globular cluster systems in
supergiant ellipticals like M87. (1) we find no significant change in the
globular cluster luminosity function (GCLF) with galactocentric radius, for
cluster masses M < 10^5 solar masses, indicating that the main effects of
dynamical evolution may be only on lower-mass clusters. (2) Within the core
radius (1') of the globular cluster system, the metallicity distribution is
uniform, but at larger radii the mean metallicity declines steadily as Z ~
r^-0.9. (3) The various options for explaining the existence of high specific
frequency galaxies like M87 are evaluated, and scaling laws for the GCSs in
these galaxies are given. Interpretations involving secondary evolution
(formation of many globular clusters during mergers, intergalactic globular
clusters, etc.) are unlikely to be the primary explanation for high-S_N
galaxies. (4) We suggest that central-supergiant E galaxies may have formed in
an exceptionally turbulent or high-density environment in which an early,
powerful galactic wind drove out a high fraction of the protogalactic gas, thus
artificially boosting the specificComment: 67 pages, 17 figures. To appear in Astronomical Journal, in press for
May 1998. Preprints also available from W.Harris; send e-mail request to
[email protected]
The Magnitude of Global Marine Species Diversity
Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered.
Results: There are âŒ226,000 eukaryotic marine species described. More species were described in the past decade (âŒ20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are âŒ170,000 synonyms, that 58,000â72,000 species are collected but not yet described, and that 482,000â741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7â1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science.
Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century
Automated telephone communication systems for preventive healthcare and management of long-term conditions
Background
Automated telephone communication systems (ATCS) can deliver voice messages and collect health-related information from patients
using either their telephoneâs touch-tone keypad or voice recognition software. ATCS can supplement or replace telephone contact
between health professionals and patients. There are four different types of ATCS: unidirectional (one-way, non-interactive voice
communication), interactive voice response (IVR) systems, ATCS with additional functions such as access to an expert to request advice
(ATCS Plus) and multimodal ATCS, where the calls are delivered as part of a multicomponent intervention.
Objectives
To assess the effects of ATCS for preventing disease and managing long-term conditions on behavioural change, clinical, process,
cognitive, patient-centred and adverse outcomes.
Search methods
We searched 10 electronic databases (the Cochrane Central Register of Controlled Trials; MEDLINE; Embase; PsycINFO; CINAHL;
Global Health; WHOLIS; LILACS; Web of Science; and ASSIA); three grey literature sources (Dissertation Abstracts, Index to Theses,
Australasian Digital Theses); and two trial registries (www.controlled-trials.com; www.clinicaltrials.gov) for papers published between
1980 and June 2015.
Selection criteria
Randomised, cluster- and quasi-randomised trials, interrupted time series and controlled before-and-after studies comparing ATCS
interventions, with any control or another ATCS type were eligible for inclusion. Studies in all settings, for all consumers/carers, in any
preventive healthcare or long term condition management role were eligible.
Data collection and analysis
We used standard Cochrane methods to select and extract data and to appraise eligible studies.
Main results
We included 132 trials (N = 4,669,689). Studies spanned across several clinical areas, assessing many comparisons based on evaluation
of different ATCS types and variable comparison groups. Forty-one studies evaluated ATCS for delivering preventive healthcare, 84 for
managing long-term conditions, and seven studies for appointment reminders. We downgraded our certainty in the evidence primarily
because of the risk of bias for many outcomes. We judged the risk of bias arising from allocation processes to be low for just over half
the studies and unclear for the remainder. We considered most studies to be at unclear risk of performance or detection bias due to
blinding, while only 16% of studies were at low risk. We generally judged the risk of bias due to missing data and selective outcome
reporting to be unclear.
For preventive healthcare, ATCS (ATCS Plus, IVR, unidirectional) probably increase immunisation uptake in children (risk ratio (RR)
1.25, 95% confidence interval (CI) 1.18 to 1.32; 5 studies, N = 10,454; moderate certainty) and to a lesser extent in adolescents (RR
1.06, 95% CI 1.02 to 1.11; 2 studies, N = 5725; moderate certainty). The effects of ATCS in adults are unclear (RR 2.18, 95% CI
0.53 to 9.02; 2 studies, N = 1743; very low certainty).
For screening, multimodal ATCS increase uptake of screening for breast cancer (RR 2.17, 95% CI 1.55 to 3.04; 2 studies, N = 462;
high certainty) and colorectal cancer (CRC) (RR 2.19, 95% CI 1.88 to 2.55; 3 studies, N = 1013; high certainty) versus usual care.
It may also increase osteoporosis screening. ATCS Plus interventions probably slightly increase cervical cancer screening (moderate
certainty), but effects on osteoporosis screening are uncertain. IVR systems probably increase CRC screening at 6 months (RR 1.36,
95% CI 1.25 to 1.48; 2 studies, N = 16,915; moderate certainty) but not at 9 to 12 months, with probably little or no effect of IVR
(RR 1.05, 95% CI 0.99, 1.11; 2 studies, 2599 participants; moderate certainty) or unidirectional ATCS on breast cancer screening.
Appointment reminders delivered through IVR or unidirectional ATCS may improve attendance rates compared with no calls (low
certainty). For long-term management, medication or laboratory test adherence provided the most general evidence across conditions
(25 studies, data not combined). Multimodal ATCS versus usual care showed conflicting effects (positive and uncertain) on medication
adherence. ATCS Plus probably slightly (versus control; moderate certainty) or probably (versus usual care; moderate certainty) improves
medication adherence but may have little effect on adherence to tests (versus control). IVR probably slightly improves medication
adherence versus control (moderate certainty). Compared with usual care, IVR probably improves test adherence and slightly increases
medication adherence up to six months but has little or no effect at longer time points (moderate certainty). Unidirectional ATCS,
compared with control, may have little effect or slightly improve medication adherence (low certainty). The evidence suggested little or
no consistent effect of any ATCS type on clinical outcomes (blood pressure control, blood lipids, asthma control, therapeutic coverage)
related to adherence, but only a small number of studies contributed clinical outcome data.
The above results focus on areas with the most general findings across conditions. In condition-specific areas, the effects of ATCS
varied, including by the type of ATCS intervention in use.
Multimodal ATCS probably decrease both cancer pain and chronic pain as well as depression (moderate certainty), but other ATCS
types were less effective. Depending on the type of intervention, ATCS may have small effects on outcomes for physical activity,
weight management, alcohol consumption, and diabetes mellitus. ATCS have little or no effect on outcomes related to heart failure,
hypertension, mental health or smoking cessation, and there is insufficient evidence to determine their effects for preventing alcohol/
substance misuse or managing illicit drug addiction, asthma, chronic obstructive pulmonary disease, HIV/AIDS, hypercholesterolaemia,
obstructive sleep apnoea, spinal cord dysfunction or psychological stress in carers.
Only four trials (3%) reported adverse events, and it was unclear whether these were related to the intervention
Understanding the medicines information-seeking behaviour and information needs of South African long-term patients with limited literacy skills:
Although much health informationâseeking behaviour (HISB) research has been reported in patients with good literacy skills, little is known about HISB in patients with limited literacy skills served by underâresourced healthâcare systems. To investigate medicine informationâseeking behaviour and information needs in patients with limited literacy
Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors
Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Aging and the oral cavity
Geriatric Medicinehttps://nsuworks.nova.edu/hpd_cdm_facbooks/1012/thumbnail.jp
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