346 research outputs found
Rapid assessment of drug use and sexual HIV risk patterns among vulnerable drugusing populations in Cape Town, Durban and Pretoria, South Africa
This exploratory study examines the links between drug use and high-risk sexual practices and HIV in vulnerable drug-using populations in South Africa, including commercial sex workers (CSWs), men who have sex with men (MSM), injecting drug users (IDUs) and non-injecting drug users who are not CSWs or MSM (NIDUs). A rapid assessment ethnographic study was undertaken using observation, mapping, key informant interviews and focus groups in known ‘hotspots\' for drug use and sexual risk in Cape Town, Durban and Pretoria. Key informant (KI) and focus group interviews involved drug users and service providers. Purposeful snowball sampling and street intercepts were used to recruit drug users. Outcome measures included drug-related sexual HIV risk behaviour, and risk behaviour related to injection drug use, as well as issues relate to service use. HIV testing of drug-using KIs was conducted using the SmartCheck Rapid HIV-1 Antibody Test. Non-injection drug use (mainly cannabis, methaqualone, crack cocaine and crystal methamphetamine) and injection drug use (mainly heroin) was occurring in these cities. Drug users report selling sex for money to buy drugs, and CSWs used drugs before, during and after sex. Most (70%) of the drug-using KIs offered HIV testing accepted and 28% were positive, with rates highest among CSWs and MSM. IDUs reported engaging in needle sharing and needle disposal practices that put them and others at risk for contracting HIV. There was a widespread lack of awareness about where to access HIV treatment and preventive services, and numerous barriers to accessing appropriate HIV and drug- intervention services were reported. Multiple risk behaviours of vulnerable populations and lack of access to HIV prevention services could accelerate the diffusion of HIV. Targeted interventions could play an important role in limiting the spread of HIV in and through
these under-reached and vulnerable populations. Keywords: Drug use, sexual risk behaviour, HIV/AIDS, South Africa.SAHARA-J Vol. 5 (3) 2008: pp. 113-11
Continuum variational and diffusion quantum Monte Carlo calculations
This topical review describes the methodology of continuum variational and
diffusion quantum Monte Carlo calculations. These stochastic methods are based
on many-body wave functions and are capable of achieving very high accuracy.
The algorithms are intrinsically parallel and well-suited to petascale
computers, and the computational cost scales as a polynomial of the number of
particles. A guide to the systems and topics which have been investigated using
these methods is given. The bulk of the article is devoted to an overview of
the basic quantum Monte Carlo methods, the forms and optimisation of wave
functions, performing calculations within periodic boundary conditions, using
pseudopotentials, excited-state calculations, sources of calculational
inaccuracy, and calculating energy differences and forces
Shoreline Management Plan with Habitat Enhancement for Town of Saxis, Virginia
The goal of the present study is to identify the best course of action to manage shoreline erosion in Saxis and to provide a detailed Shoreline Management Plan with Habitat Enhancement which can be presented to potential State and Federal funding agencies. While the Plan itself will not resolve the erosion conditions in Saxis, it will allow the Town to market its need and the method of resolution of this need, to agencies and leaders with the resources to implement the Plan’s suggested actions. The shoreline management plan will provide the necessary level of shoreline stabilization while minimizing adverse impacts to estuarine habitat and providing maximum habitat enhancement opportunities. The habitats needed to fulfill the life history requirements of target species desirable for Saxis Island were emphasized in the Plan. The Plan also will present opportunities to enhance local fisheries and provide increased opportunities in eco-tourism
Software engineering to sustain a high-performance computing scientific application: QMCPACK
We provide an overview of the software engineering efforts and their impact
in QMCPACK, a production-level ab-initio Quantum Monte Carlo open-source code
targeting high-performance computing (HPC) systems. Aspects included are: (i)
strategic expansion of continuous integration (CI) targeting CPUs, using GitHub
Actions runners, and NVIDIA and AMD GPUs in pre-exascale systems, using
self-hosted hardware; (ii) incremental reduction of memory leaks using
sanitizers, (iii) incorporation of Docker containers for CI and
reproducibility, and (iv) refactoring efforts to improve maintainability,
testing coverage, and memory lifetime management. We quantify the value of
these improvements by providing metrics to illustrate the shift towards a
predictive, rather than reactive, sustainable maintenance approach. Our goal,
in documenting the impact of these efforts on QMCPACK, is to contribute to the
body of knowledge on the importance of research software engineering (RSE) for
the sustainability of community HPC codes and scientific discovery at scale.Comment: Accepted at the first US-RSE Conference, USRSE2023,
https://us-rse.org/usrse23/, 8 pages, 3 figures, 4 table
The Coupled Electronic-Ionic Monte Carlo Simulation Method
Quantum Monte Carlo (QMC) methods such as Variational Monte Carlo, Diffusion
Monte Carlo or Path Integral Monte Carlo are the most accurate and general
methods for computing total electronic energies. We will review methods we have
developed to perform QMC for the electrons coupled to a classical Monte Carlo
simulation of the ions. In this method, one estimates the Born-Oppenheimer
energy E(Z) where Z represents the ionic degrees of freedom. That estimate of
the energy is used in a Metropolis simulation of the ionic degrees of freedom.
Important aspects of this method are how to deal with the noise, which QMC
method and which trial function to use, how to deal with generalized boundary
conditions on the wave function so as to reduce the finite size effects. We
discuss some advantages of the CEIMC method concerning how the quantum effects
of the ionic degrees of freedom can be included and how the boundary conditions
can be integrated over. Using these methods, we have performed simulations of
liquid H2 and metallic H on a parallel computer.Comment: 27 pages, 10 figure
From research to practice: Lay adherence counsellors' fidelity to an evidence-based intervention for promoting adherence to antiretroviral treatment in the Western Cape, South Africa
In the Western Cape, lay counsellors are tasked
with supporting antiretroviral (ARV) adherence in public
healthcare clinics. Thirty-nine counsellors in 21 Cape
Town clinics were trained in Options for Health (Options),
an evidence-based intervention based on motivational
interviewing (MI). We evaluated counsellors’ ability to
deliver Options for addressing poor adherence following
5 days training. Audio-recordings of counselling sessions
collected following training were transcribed and translated
into English. Thirty-five transcripts of sessions conducted
by 35 counsellors were analysed for fidelity to the Options
protocol, and using the Motivational Interviewing
Treatment and Integrity (MITI) code. Counsellors struggled
with some of the strategies associated with MI, such as
assessing readiness-to-change and facilitating change talk.
Overall, counsellors failed to achieve proficiency in the
approach of MI according to the MITI. Counsellors were
able to negotiate realistic plans for addressing patients’
barriers to adherence. Further efforts aimed at strengthening
the ARV adherence counselling programme are
needed.Department of HE and Training approved lis
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Assessing the Quality of Goal Setting in Behavioural Support for Smoking Cessation and its Association with Outcomes
BACKGROUND: Smoking cessation behavioural support can be effective but practitioners differ markedly in effectiveness, possibly due to variation in the quality of delivery of key behaviour change techniques, such as goal setting (i.e. setting a quit date).
OBJECTIVES: This study aimed to (i) develop a reliable method for assessing the quality of practitioners' support in setting quit dates and (ii) assess whether quality predicts initiation of abstinence as a first step to quitting.
METHODS: A scale for scoring the quality of goal setting was developed from national guidance documents and applied to 85 transcribed behavioural support sessions. Inter-rater reliability was assessed. Associations between quality scores and quit attempts were assessed.
RESULTS: The 10-item scale produced had good inter-rater reliability (Kappa = 0.68). Higher quality goal setting was associated with increased self-reported quit attempts (p < .001; OR = 2.60, 95 % CI 1.54-4.40). The scale components 'set a clear quit date' (χ (2) (2, N = 85) = 22.3, p < .001) and 'within an appropriate timeframe' (χ (2) (2, N = 85) = 15.5, p < .001) were independently associated with quit attempts.
CONCLUSIONS: It is possible to reliably assess the quality of goal setting in smoking cessation behavioural support. Higher quality of goal setting is associated with greater likelihood of initiating quit attempts
Facilitation skills: the catalyst for increased effectiveness in consultant practice and clinical systems leadership
Consultant practitioner is the pinnacle of the clinical career ladder for all health care disciplines in the United Kingdom. Consultant nurse, midwife and health visitor roles build on the clinical credibility and expertise characteristic of advanced level practice, but also possess expertise in: clinical systems leadership and the facilitation of culture change, learning and development; advanced consultancy approaches, and research and evaluation to prioritise person-centred, safe and effective care across patient pathways.
This project aimed to help new and emerging consultants to become more effective in their role through a programme of support to develop their expertise.
Emancipatory action research, supported by claims, concerns and issues tool, derived from Stakeholder Evaluation, and other methods (active learning, action learning, collaborative workshops and individual tools e.g. qualitative 360 degree feedback and reflective reviews) comprised the supportive intervention which enabled participants to research their own practice.
The programme’s methodology and methods helped participants to: research their own practice; theorise from practice; grow the facilitation skills needed to develop and demonstrate their own effectiveness; foster the effectiveness of others and; transform practice culture. Greater effectiveness in their multiple roles was demonstrated, as was the impact of this on others, services and organisations.
The study concludes that the support programme augmented by the methodology, facilitation skills and the 10 principles derived from a concept analysis of work-based learning is central to achieving improved effectiveness and transformation of others, services and organisations. Theoretical insights at collective/community levels also resulted. Key recommendations are identified for commissioners, higher education and research
How do we get there? Effects of cognitive aging on route memory
© 2017 The Author(s) Research into the effects of cognitive aging on route navigation usually focuses on differences in learning performance. In contrast, we investigated age-related differences in route knowledge after successful route learning. One young and two groups of older adults categorized using different cut-off scores on the Montreal Cognitive Assessment (MoCA), were trained until they could correctly recall short routes. During the test phase, they were asked to recall the sequence in which landmarks were encountered (Landmark Sequence Task), the sequence of turns (Direction Sequence Task), the direction of turn at each landmark (Landmark Direction Task), and to identify the learned routes from a map perspective (Perspective Taking Task). Comparing the young participant group with the older group that scored high on the MoCA, we found effects of typical aging in learning performance and in the Direction Sequence Task. Comparing the two older groups, we found effects of early signs of atypical aging in the Landmark Direction and the Perspective Taking Tasks. We found no differences between groups in the Landmark Sequence Task. Given that participants were able to recall routes after training, these results suggest that typical and early signs of atypical aging result in differential memory deficits for aspects of route knowledge
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