1,026 research outputs found
B-virus from pet macaque monkeys: an emerging threat in the United States?
Of primary concern when evaluating macaque bites are bacterial and B-virus infections. B-virus infection is highly prevalent (80% to 90%) in adult macaques and may cause a potentially fatal meningoencephalitis in humans. We examined seven nonoccupational exposure incidents involving 24 persons and eight macaques. Six macaques were tested for herpes B; four (67%) were seropositive. A common observation was that children were more than three times as likely to be bitten than adults. The virus must be assumed to be a potential health hazard in macaque bite wounds; this risk makes macaques unsuitable as pets
Cognitive performance in light current users and ex-users of ecstasy (MDMA) and controls
Previous research has shown that heavy users of ecstasy may suffer impaired cognitive functioning, and the present study set out to investigate whether such impairment might also be found in light users or ex-users of ecstasy. Sixty subjects, comprising 20 current light users, 20 ex-users, and 20 non-users of ecstasy, were tested on an extensive battery of cognitive tests. Current light users of ecstasy achieved significantly lower scores on the overall cognitive test battery than did the non-users (p=0.011), though there were no significant differences on any individual subtests. However, the scores obtained by the ex-users of ecstasy did not differ significantly from those of the non-users. It was concluded that current light users of ecstasy show a small but significant cognitive impairment, but that no such impairment is detectable in ex-users who had abstained from the drug for at least 6 months
Cost-effectiveness of strategies to improve delivery of brief interventions for heavy drinking in primary care: results from the ODHIN trial
Background: Screening and brief interventions (SBIs) for heavy drinking are an effective and cost-effective approach to reducing alcohol-related harm, yet delivery rates remain low. This study uses trial data to estimate the cost-effectiveness of alternative strategies to increase SBI delivery. Methods: Data from a large cluster-randomized trial were combined with the Sheffield Alcohol Policy Model, a policy appraisal tool, to estimate the cost-effectiveness of eight strategies to increase SBI delivery in primary care in England, Poland and the Netherlands: care as usual (control), training and support (TS), financial reimbursement (FR), referral of patients to an online brief intervention (eBI) and all combinations of TS, FR and eBI. cost-effectiveness was assessed from a healthcare perspective by comparing health benefits (measured in Quality-Adjusted Life Years) with total implementation costs and downstream healthcare savings for each strategy over a 30-year horizon and calculating Incremental cost-effectiveness ratios (ICERs). Results: All trialled strategies were cost-effective compared to control. TS combined with FR was the most cost-effective approach in England (more effective and less costly than control) and Poland (ICER €4632 vs. next-best strategy). This combination is not cost-effective in the Netherlands, where TS alone is the most cost-effective approach (ICER €3386 vs. next-best strategy). Conclusions: Structured TS, financial incentives and access to online interventions are all estimated to be cost-effective methods of improving delivery of alcohol brief interventions. TS and FR together may be the most cost-effective approach, however this is sensitive to country characteristics and alternative BI effect assumptions. Trial registration: ClinicalTrials.gov trial identifier: NCT01501552
The visibility of IQHE at sharp edges: Experimental proposals based on interactions and edge electrostatics
The influence of the incompressible strips on the integer quantized Hall
effect (IQHE) is investigated, considering a cleaved-edge overgrown (CEO)
sample as an experimentally realizable sharp edge system. We propose a set of
experiments to clarify the distinction between the large-sample limit when bulk
disorder defines the IQHE plateau width and the small-sample limit smaller than
the disorder correlation length, when self-consistent edge electrostatics
define the IQHE plateau width. The large-sample or bulk QH regime is described
by the usual localization picture, whereas the small-sample or edge regime is
discussed within the compressible/incompressible strips picture, known as the
screening theory of QH edges. Utilizing the unusually sharp edge profiles of
the CEO samples, a Hall bar design is proposed to manipulate the edge potential
profile from smooth to extremely sharp. By making use of a side-gate
perpendicular to the two dimensional electron system, it is shown that the
plateau widths can be changed or even eliminated altogether. Hence, the
visibility of IQHE is strongly influenced when adjusting the edge potential
profile and/or changing the dc current direction under high currents in the
non-linear transport regime. As a second investigation, we consider two
different types of ohmic contacts, namely highly transmitting (ideal) and
highly reflecting (non-ideal) contacts. We show that if the injection contacts
are non-ideal, however still ohmic, it is possible to measure directly the
non-quantized transport taking place at the bulk of the CEO samples. The
results of the experiments we propose will clarify the influence of the edge
potential profile and the quality of the contacts, under quantized Hall
conditions.Comment: Substantially revised version of manuscript arXiv:0906.3796v1,
including new figures et
Bridging Time Scales in Cellular Decision Making with a Stochastic Bistable Switch
Cellular transformations which involve a significant phenotypical change of
the cell's state use bistable biochemical switches as underlying decision
systems. In this work, we aim at linking cellular decisions taking place on a
time scale of years to decades with the biochemical dynamics in signal
transduction and gene regulation, occuring on a time scale of minutes to hours.
We show that a stochastic bistable switch forms a viable biochemical mechanism
to implement decision processes on long time scales. As a case study, the
mechanism is applied to model the initiation of follicle growth in mammalian
ovaries, where the physiological time scale of follicle pool depletion is on
the order of the organism's lifespan. We construct a simple mathematical model
for this process based on experimental evidence for the involved genetic
mechanisms. Despite the underlying stochasticity, the proposed mechanism turns
out to yield reliable behavior in large populations of cells subject to the
considered decision process. Our model explains how the physiological time
constant may emerge from the intrinsic stochasticity of the underlying gene
regulatory network. Apart from ovarian follicles, the proposed mechanism may
also be of relevance for other physiological systems where cells take binary
decisions over a long time scale.Comment: 14 pages, 4 figure
Duration of shedding of respiratory syncytial virus in a community study of Kenyan children
Background: Our understanding of the transmission dynamics of respiratory syncytial virus (RSV) infection will be better informed with improved data on the patterns of shedding in cases not limited only to hospital admissions.
Methods: In a household study, children testing RSV positive by direct immunofluorescent antibody test (DFA) were enrolled. Nasal washings were scheduled right away, then every three days until day 14, every 7 days until day 28 and every 2 weeks until a maximum of 16 weeks, or until the first DFA negative RSV specimen. The relationship between host factors, illness severity and viral shedding was investigated using Cox regression methods.
Results: From 151 families a total of 193 children were enrolled with a median age of 21 months (range 1-164 months), 10% infants and 46% male. The rate of recovery from infection was 0.22/person/day (95% CI 0.19-0.25) equivalent to a mean duration of shedding of 4.5 days (95%CI 4.0-5.3), with a median duration of shedding of 4 days (IQR 2-6, range 1-14). Children with a history of RSV infection had a 40% increased rate of recovery i.e. shorter duration of viral shedding (hazard ratio 1.4, 95% CI 1.01-1.86). The rate of cessation of shedding did not differ significantly between males and females, by severity of infection or by age.
Conclusion: We provide evidence of a relationship between the duration of shedding and history of infection, which may have a bearing on the relative role of primary versus re-infections in RSV transmission in the community
Perovskite-perovskite tandem photovoltaics with optimized bandgaps
We demonstrate four and two-terminal perovskite-perovskite tandem solar cells
with ideally matched bandgaps. We develop an infrared absorbing 1.2eV bandgap
perovskite, , that can deliver 14.8 %
efficiency. By combining this material with a wider bandgap
material, we reach monolithic two
terminal tandem efficiencies of 17.0 % with over 1.65 volts open-circuit
voltage. We also make mechanically stacked four terminal tandem cells and
obtain 20.3 % efficiency. Crucially, we find that our infrared absorbing
perovskite cells exhibit excellent thermal and atmospheric stability,
unprecedented for Sn based perovskites. This device architecture and materials
set will enable 'all perovskite' thin film solar cells to reach the highest
efficiencies in the long term at the lowest costs
Effects of e-cigarettes vs usual care for smoking cessation when offered at homeless centres: protocol for a cluster randomised controlled trial.
A study protocol to assess the feasibility of conducting an evaluation trial of the ADVANCE integrated intervention to address both substance use and intimate partner abuse perpetration to men in substance use treatment.
Strong evidence exists that substance use is a contributory risk factor for intimate partner abuse (IPA) perpetration. Men in substance use treatment are more likely to perpetrate IPA than men from the general population. Despite this, referral pathways are lacking for this group. This trial will assess the feasibility of conducting an evaluation trial of a tailored integrated intervention to address substance use and IPA perpetration to men in substance use treatment. ADVANCE is a multicentre, parallel-group individually randomised controlled feasibility trial, with a nested formative evaluation, comparing an integrated intervention to reduce IPA + substance use treatment as usual (TAU) to TAU only. One hundred and eight men who have perpetrated IPA in the past 12 months from community substance use treatment in London, the West Midlands, and the South West will be recruited. ADVANCE is a manualised intervention comprising 2-4 individual sessions (2 compulsory) with a keyworker to set goals, develop a personal safety plan and increase motivation and readiness, followed by a 12-session weekly group intervention delivered in substance use services. Men will be randomly allocated (ratio 1:1) to receive the ADVANCE intervention + TAU or TAU only. Men's female (ex) partners will be invited to provide outcome data and offered support from integrated safety services (ISS). Regular case management meetings between substance use and ISS will manage risk. Outcome measures will be obtained at the end of the intervention (approximately 4 months post-randomisation) for all male and female participants. The main objective of this feasibility trial is to estimate parameters required for planning a definitive trial including rates of consent, recruitment, and follow-up by site and group allocation. Nested formative evaluation including focus groups and in-depth interviews will explore the intervention's acceptability to participants, group facilitators, keyworkers and ISS workers. Secondary outcomes include substance use, IPA, mental health, self-management, health and social care service use, criminal justice contacts, and quality of life. Findings from this feasibility trial will inform the design of a multicentre randomised controlled trial evaluating the efficacy and cost-effectiveness of the ADVANCE intervention for reducing IPA and improving the well-being of female (ex)partners
Stability and change the role of keepsakes and family homes in the lives of parentally bereaved young adults in the Netherlands 1
This paper examines the loss of a parent in young adulthood, showing how this emergent and distinctive life stage shapes Dutch young people’s experience of bereavement. Youth material cultures have commonly been analysed in terms of the construction and expression of youth identities, for example, through style, music and leisure. In this research, we highlight three themes in young people’s relationship to material culture as part of their everyday lived experience of parental loss: first, the parental home as a space of departure, memory and return, and the potential for conflict, destabilisation and misunderstanding when the remaining parent transforms the home or embarks on a new relationship; second, the different strategies young adults use to commemorate their parent in their own temporary or shared accommodation and online space; and third, the role of small, portable but effective keepsakes and adornment, such as jewellery or tattoos, that meet their need for the emotional experience of closeness with the memory of their parent. A focus on the material trajectories of grief grants insights into how young adults cope with loss in their everyday life, generating understanding of the ways young people may support themselves and be supported by others in the context of parental bereavement
- …