1,110 research outputs found
Redshift Evolution in the Iron Abundance of the Intracluster Medium
Clusters of galaxies provide a closed box within which one can determine the
chemical evolution of the gaseous baryons with cosmic time. We studied this
metallicity evolution in the hot X-ray emitting baryons through an analysis of
XMM-Newton observations of 29 galaxy clusters in the redshift range 0.3 < z <
1.3. Taken alone, this data set does not show evidence for significant
evolution. However, when we also include a comparable sample of 115 clusters
observed with Chandra (Maughan et al. 2008) and a lower redshift sample of 70
clusters observed with XMM at z < 0.3 (Snowden et al. 2008), there is
definitive evidence for a decrease in the metallicity. This decrease is
approximately a factor of two from z = 0 to z \approx 1, over which we find a
least-squares best-fit line Z(z) / Z_{\odot} = (0.46 \pm 0.05) - (0.38 \pm
0.03)z. The greatest uncertainty in the evolution comes from poorly constrained
metallicities in the highest redshift bin
Extending pharmacy services to the point of discharge
Aim: The aim of this study was to determine the impact of introducing a clinical pharmacist led discharge service on medication safety at the point of discharge and its acceptability to healthcare staff. Methods: A retrospective chart review to identify medication discrepancies was undertaken before and after the introduction of a pharmacist led discharge service. An evaluation was undertaken by means of a questionnaire to community pharmacists, GPs and hospital clinicians. Results: The pharmacist led discharge service significantly reduced errors from 50% (n=17) to 7% (n=2) of patients (p<0.001) and 10% (n=22) to 1% (n=2) of medication orders (p=0.001). The evaluation revealed that the majority of clinicians found the service useful, had the potential to reduce errors and improve communication. Conclusion: Pharmacist involvement at the point of discharge had a significant impact on medication safety. Crucially, in this project, we show the service was received well by medical personnel and improved communication between primary and secondary care, enhancing implementation potential
Change Matters: Binge Drinking and Drugging Victimization over Time in Three College Freshman Cohorts
The âonce bitten, twice shyâ (OBTS) hypothesis argues that crime victims who change their involvement in risky lifestyle behaviors reduce their likelihood of experiencing repeat victimization. Tests of this hypothesis have yielded weak to mixed results, which may be due to methodological issues. We address these methodological issues by testing the OBTS hypothesis for repeat drugging victimization with survey data from a panel of three freshman cohorts at three large, public universities. Supportive of the OBTS hypothesis, the multivariate results show that, on average, those not drugged at Time 1 or Time 2 and those drugged at Time 1 and Time 2 increased the number of days they binge drank in the past month significantly more than those who were drugged at Time 1 only. Our findings have implications for both victimology theory and drugging prevention programming
Orbital Instabilities in a Triaxial Cusp Potential
This paper constructs an analytic form for a triaxial potential that
describes the dynamics of a wide variety of astrophysical systems, including
the inner portions of dark matter halos, the central regions of galactic
bulges, and young embedded star clusters. Specifically, this potential results
from a density profile of the form , where the radial
coordinate is generalized to triaxial form so that . Using the resulting analytic form of the potential, and the
corresponding force laws, we construct orbit solutions and show that a robust
orbit instability exists in these systems. For orbits initially confined to any
of the three principal planes, the motion in the perpendicular direction can be
unstable. We discuss the range of parameter space for which these orbits are
unstable, find the growth rates and saturation levels of the instability, and
develop a set of analytic model equations that elucidate the essential physics
of the instability mechanism. This orbit instability has a large number of
astrophysical implications and applications, including understanding the
formation of dark matter halos, the structure of galactic bulges, the survival
of tidal streams, and the early evolution of embedded star clusters.Comment: 50 pages, accepted for publication in Ap
Impact of program characteristics on weight loss in adult behavioral weight management interventions: systematic review and component network meta-analysis
Objective: Behavioral weight management programs (BWMPs) for adults lead to greater weight loss at 12 months than minimal-intervention control treatments. However, there is considerable heterogeneity in the content of BWMPs and outcomes of treatment. This study assessed the contribution of individual components of BWMPs, using Bayesian component network meta-analysis.
Methods:Â Randomized controlled trials of BWMPs in adults were identified (latest search: December 2019) and arms coded for presence or absence of 29 intervention components grouped by type, content, provider, mode of delivery, and intensity.
Results:Â A total of 169 studies (41 judged at high risk of bias) were included in the main analysis. Six components had effect estimates indicating clinically significant benefit and credible intervals (CrIs) excluding no difference: change in diet (mean difference [MD] =Â â1.84 kg, 95% CrI: â2.91 to â0.80); offering partial (MDÂ =Â â2.12 kg, 95% CrI: â3.39 to â0.89) or total meal replacements (MD = â2.63 kg, 95% CrI: â4.58 to â0.73); delivery by a psychologist/counselor (MDÂ =Â â1.45 kg, 95% CrI: â2.81 to â0.06) or dietitian (MDÂ =Â â1.31 kg, 95% CrI: â2.40 to â0.24); and home setting (MDÂ =Â â1.05 kg, 95% CrI: â2.02 to â0.09).
Conclusions:Â Future program development should consider including these components; other approaches continue to warrant evaluation of effectiveness
Framingham risk score and alternatives for prediction of coronary heart disease in older adults
Background
Guidelines for the prevention of coronary heart disease (CHD) recommend use of Framingham-based risk scores that were developed in white middle-aged populations. It remains unclear whether and how CHD risk prediction might be improved among older adults. We aimed to compare the prognostic performance of the Framingham risk score (FRS), directly and after recalibration, with refit functions derived from the present cohort, as well as to assess the utility of adding other routinely available risk parameters to FRS.
Methods
Among 2193 black and white older adults (mean age, 73.5 years) without pre-existing cardiovascular disease from the Health ABC cohort, we examined adjudicated CHD events, defined as incident myocardial infarction, CHD death, and hospitalization for angina or coronary revascularization.
Results
During 8-year follow-up, 351 participants experienced CHD events. The FRS poorly discriminated between persons who experienced CHD events vs. not (C-index: 0.577 in women; 0.583 in men) and underestimated absolute risk prediction by 51% in women and 8% in men. Recalibration of the FRS improved absolute risk prediction, particulary for women. For both genders, refitting these functions substantially improved absolute risk prediction, with similar discrimination to the FRS. Results did not differ between whites and blacks. The addition of lifestyle variables, waist circumference and creatinine did not improve risk prediction beyond risk factors of the FRS.
Conclusions
The FRS underestimates CHD risk in older adults, particularly in women, although traditional risk factors remain the best predictors of CHD. Re-estimated risk functions using these factors improve accurate estimation of absolute risk
Identifications of Five INTEGRAL Sources via Optical Spectroscopy
The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) is discovering
hundreds of new hard X-ray sources, many of which remain unidentified. We
report on optical spectroscopy of five such sources for which X-ray
observations at lower energies (~0.5-10 keV) and higher angular resolutions
than INTEGRAL have allowed for unique optical counterparts to be located. We
find that IGR J16426+6536 and IGR J22292+6647 are Type 1 Seyfert active
galactic nuclei (with IGR J16426+6536 further classified as a Seyfert 1.5)
which have redshifts of z=0.323 and z=0.113, respectively. IGR J18308-1232 is
identified as a cataclysmic variable (CV), and we confirm a previous
identification of IGR J19267+1325 as a magnetic CV. IGR J18214-1318 is
identified as an obscured high mass X-ray binary (HMXB), which are systems
thought to have a compact object embedded in the stellar wind of a massive
star. We combine Chandra fluxes with distances based on the optical
observations to calculate X-ray luminosities of the HMXB and CVs, finding
L_(0.3-10 keV)=5e36 erg s^-1 for IGR J18214-1318, L_(0.3-10 keV)=1.3e32 erg
s^-1 for IGR J18308-1232, and L_(0.3-10 keV)=6.7e32 erg s^-1 for IGR
J19267+1325.Comment: 8 pages, 5 figures, accepted for publication by Ap
Group acceptance and commitment therapy for patients and caregivers in psychosis services: Feasibility of training and a preliminary randomized controlled evaluation
Objective: Psychological interventions reduce the impact of psychosis, but widescale implementation is problematic. We tested the feasibility of group acceptance and commitment therapy for Psychosis (G-ACTp), delivered by frontline staff, and co-facilitated by service-user experts-by-experience (SU-EbyE), for service-users and informal caregivers (ISRCTN: 68540929). We estimated recruitment/retention rates and outcome variability for future evaluation. Methods: Staff and SU-EbyE facilitators completed 1-day workshops, then delivered closely supervised G-ACTp, comprising four sessions (weeks 1â4) and two boosters (10 and 12 weeks). Participants recruited from adult community psychosis services were randomized to receive G-ACTp immediately or after 12 weeks, completing outcome assessments at 0, 4, and 12 weeks. Service-use/month was calculated for 1-year pre-randomization, weeks 0â12, and 5-year uncontrolled follow-up. Results: Of 41 facilitators trained (29 staff, 12 SU-EbyE), 29 (71%; 17 staff, 12 SU-EbyE) delivered 18 G-ACTp courses. Participant refusal rates were low (9% of service-users [10/112]; 5% of caregivers [4/79]); 60% of those invited to participate attended â„1 G-ACTp session (64% of service-users [39/61]; 56% of caregivers [35/63]). Randomization of facilitators and participants proved problematic and participant follow-up was incomplete (78% [66/85]; 82% of service-users [36/44]; 73% of caregivers [30/41]). Effect sizes ranged from very small to large mostly favouring treatment. Service-use reductions require cautious interpretation, as very few participants incurred costs. Conclusions: Implementation appears feasible for service-users; for caregivers, retention needs improving. Outcome variability indicated n = 100â300/arm followed up (α = 0.05, 90% power). Methodological limitationsâ mean replication is needed: identified sources of potential bias may be reduced in a cluster randomized design with sessional outcome completion. Practitioner points: Group acceptance and commitment therapy can be successfully adapted for people with psychosis and their caregivers. Implementation (training and delivery) is possible in routine community mental health care settings. Clinical and economic outcomes are promising, but replication is needed. Recommendations are made for future studies
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