| 1. |
- Joffrin, E., et al.
(författare)
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Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Forskningsöversikt (refereegranskat)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
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| 2. |
- Abolfathi, Bela, et al.
(författare)
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The LSST DESC DC2 Simulated Sky Survey
- 2021
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Ingår i: Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 253:31
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Tidskriftsartikel (refereegranskat)abstract
- We describe the simulated sky survey underlying the second data challenge (DC2) carried out in preparation for analysis of the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) by the LSST Dark Energy Science Collaboration (LSST DESC). Significant connections across multiple science domains will be a hallmark of LSST; the DC2 program represents a unique modeling effort that stresses this interconnectivity in a way that has not been attempted before. This effort encompasses a full end-to-end approach: starting from a large N-body simulation, through setting up LSST-like observations including realistic cadences, through image simulations, and finally processing with Rubin's LSST Science Pipelines. This last step ensures that we generate data products resembling those to be delivered by the Rubin Observatory as closely as is currently possible. The simulated DC2 sky survey covers six optical bands in a wide-fast-deep area of approximately 300 deg2, as well as a deep drilling field of approximately 1 deg2. We simulate 5 yr of the planned 10 yr survey. The DC2 sky survey has multiple purposes. First, the LSST DESC working groups can use the data set to develop a range of DESC analysis pipelines to prepare for the advent of actual data. Second, it serves as a realistic test bed for the image processing software under development for LSST by the Rubin Observatory. In particular, simulated data provide a controlled way to investigate certain image-level systematic effects. Finally, the DC2 sky survey enables the exploration of new scientific ideas in both static and time domain cosmology.
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| 3. |
- Durevall, Dick, 1954, et al.
(författare)
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Associations of Social Support with Sexual Practices, Health Behaviours, and Health Outcomes Among Adolescent Girls and Young Women: Evidence From a Longitudinal Study in KwaZulu-Natal, South Africa
- 2023
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Ingår i: International Journal of Behavioral Medicine. - 1070-5503 .- 1532-7558.
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Tidskriftsartikel (refereegranskat)abstract
- Background Several studies have reported on the benefits of social support for health behaviour, including risky sex. Social support may thus be an important resource for promoting individual health and well-being, particularly in regions where HIV rates are high and healthcare resources are scarce. However, prior research on the implications of social support for the health behaviour of young women has yielded mixed and inconclusive findings. Using prospective data from young women in South Africa, this study examines the associations of social support with subsequent sexual practices, health behaviour, and health outcomes. Methods We used two rounds of longitudinal data from a sample of n=1446 HIV-negative emerging adult women, aged 18 to 29 years, who participated in a population-based HIV study in KwaZulu-Natal, South Africa. Applying the analytic template for outcome-wide longitudinal designs, we estimated the associations between combinations of social support (i.e., tangible, educational, emotional) and ten HIV-risk related outcomes. Results Combinations of tangible, educational, and emotional support, as well as tangible support by itself, were associated with lower risk for several outcomes, whereas educational and emotional support, by themselves or together, showed little evidence of association with the outcomes. Conclusions This study highlights the protective role of tangible support in an environment of widespread poverty, and the additional effect of combining tangible support with non-tangible support. The findings strengthen recent evidence on the benefits of combining support in the form of cash and food with psychosocial care in mitigating risk behaviours associated with HIV and negative health outcomes among young women.
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| 4. |
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| 5. |
- George, Gavin, et al.
(författare)
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Exposure to comprehensive sexuality education in schools in South Africa : the implications on the uptake of HIV testing services among HIV positive adolescent girls
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Ingår i: AIDS Care - Psychological and Socio-Medical Aspects of AIDS/HIV. - 0954-0121.
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Tidskriftsartikel (refereegranskat)abstract
- Comprehensive sexuality education (CSE) is seen as a key instrument through which to affect behaviour and improve sexual and reproductive health (SRH) outcomes amongst adolescents. However, few studies have to date evaluated key SRH outcomes following exposure to CSE within a school setting. This study estimates the association between CSE and HIV testing and HIV testing self-efficacy amongst HIV positive adolescent girls. Data were collected from a cross-sectional survey administered in four high HIV prevalence districts. Independent variables included exposure to CSE, with outcome variables measuring uptake of HIV testing in the 12 months preceding the survey, and HIV testing self-efficacy. The sample comprised 505 HIV positive adolescent girls aged 12–19. Attending CSE was associated with both; being more confident to get an HIV test (AOR: 2.44, 95% CI: 1.47-4.06, p < 0.001) and having ever tested for HIV (AOR: 2.15, 95% CI: 1.39-3.33, p < 0.001) while controlling for numerous variables. Results suggest CSE can play an important role in not only affecting HIV-related behaviours themselves, but also critical factors that affect HIV behaviours, including self-efficacy.
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| 6. |
- George, Gavin, et al.
(författare)
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Greater risk for more money: the economics of negotiating condom use amongst sex workers in South Africa
- 2019
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Ingår i: AIDS Care - Psychological and Socio-Medical Aspects of AIDS/HIV. - : Informa UK Limited. - 0954-0121 .- 1360-0451. ; 31:9, s. 1168-1171
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Tidskriftsartikel (refereegranskat)abstract
- © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group. The economics of sex work and the effect on safe sex practices remain understudied. This research contributes to a better understanding of how economic opportunity and vulnerability place sex workers (SWs) at an increased risk of STI infection. Using quantitative and qualitative methods, we investigated the role of economic incentives in determining condom use among SWs. The data reveals that SWs are on average, nearly doubling their rates for condomless sex. Our findings that SWs are engaging in condomless sex to increase their earnings, illustrates the point that the context in which they operate influences condom negotiation and consequently, increases risky sexual behaviour.
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| 7. |
- Govender, Kaymarlin, et al.
(författare)
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Depression symptoms, HIV testing, linkage to ART, and viral suppression among women in a high HIV burden district in KwaZulu-Natal, South Africa: A cross-sectional household study.
- 2022
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Ingår i: Journal of Health Psychology. - : SAGE Publications. - 1461-7277 .- 1359-1053. ; 27:4, s. 935-945
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Tidskriftsartikel (refereegranskat)abstract
- Achieving the UNAIDS 90-90-90 targets by 2020 is contingent on identifying and addressing mental health challenges that may affect HIV testing and treatment-related behaviors. This study is based on survey data from KwaZulu-Natal, South Africa (2014-2015). HIV positive women who reported higher depression scores had a lower odds of having tested previously for HIV (15-25years: AOR=0.90, 95% CI [0.83, 0.98]; 26-49years: AOR=0.90, 95% CI [0.84, 0.96]). Because HIV testing behavior represents a gateway to treatment, the findings suggest mental health may be one challenge to attaining the UNAIDS 90-90-90 targets.
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| 8. |
- Govender, Kaymarlin, et al.
(författare)
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Effects of a Short Message Service(SMS) Intervention on Reduction of HIV Risk Behaviours and Improving HIV Testing RatesAmong Populationslocated near Roadside Wellness Clinics: A Cluster Randomised Controlled Trial in South Africa, Zimbabwe and Mozambique
- 2019
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Ingår i: AIDS and behavior. - : Springer Science and Business Media LLC. - 1573-3254 .- 1090-7165. ; 23:11, s. 3119-3128
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Tidskriftsartikel (refereegranskat)abstract
- Short Message Service (SMS) offers an innovative method of promoting sexual health to key and vulnerable populations who are users of mobile phones and are at high risk of HIV infection. This cluster randomised control trial tests the effectiveness of a SMS intervention in reducing HIV risk behaviours and improving HIV testing behaviours among truck drivers, sex workers and community residents located near Roadside Wellness Clinics (RWCs)in three southern African countries. The SMS arm received 35 HIV risk reduction and HIV testing SMSs over a 6-month period. The SMS intervention had no significant impact on sexual risk behaviours. However, participants in the SMS arm were more likely to have tested for HIV in the previous 6 months (86.1% vs. 77.7%; AOR 1.71, 95% CI 1.11-2.66). The results indicate that the general SMS intervention, which provide health promoting information, improved HIV testing rates in key and vulnerable populations in southern Africa.
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| 9. |
- Lewis, Lara, et al.
(författare)
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HIV incidence and associated risk factors in adolescent girls and young women in South Africa : A population-based cohort study
- 2022
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 17:12 December
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Tidskriftsartikel (refereegranskat)abstract
- Background In sub-Saharan Africa, high HIV incidence rates in adolescent girls and young women (AGYW) persist despite extensive HIV prevention efforts. Methods A prospective cohort of 2,710 HIV-negative AGYW (15–24 years) in KwaZulu-Natal, South Africa were interviewed at baseline and followed-up approximately 18 months later (2014–2017). Associations between HIV seroconversion and socio-demographic and behavioural variables measured at baseline and follow-up were examined using Cox regression and a proximate determinants framework. Inter-relationships between determinants were measured using logistic regression. Separate models were built for 15–19 and 20-24-year-olds. Results Weighted HIV incidence was 3.92 per 100 person-years (95% confidence interval: 3.27–4.69; 163 seroconversions over 4,016 person-years). Among 15-19-year-olds, absence of family support (adjusted hazards ratio (aHR): 3.82 (1.89–7.72)), having a circumcised partner (aHR: 0.5 (0.27–0.94)) or one who was HIV-positive and not on antiretroviral therapy (ART) (aHR: 6.21 (2.56–15.06)) were associated with HIV incidence. Those reporting an absence of family support were also more likely to report >1 partner during follow-up (odds ratio (OR): 2.7(1.11–6.57)). Among 20-24-year-olds, failure to complete secondary school (aHR: 1.89 (1.11–3.21)), inconsistent condom use (aHR: 3.01 (1.14–7.96)) and reporting partner(s) who were HIV-positive and not on ART (aHR: 7.75 (3.06–19.66)) were associated with HIV incidence. Failure to complete secondary school among 20-24-year-olds was associated with inconsistent condom use (OR: 1.82 (1.20–2.77)) and reporting an HIV-positive partner not on ART (OR: 3.53(1.59–7.82)) or an uncircumcised partner (OR: 1.39 (1.08–1.82). Conclusion Absence of family support and incomplete schooling are associated with risky sexual behaviours and HIV acquisition in AGYW. In addition, partner-level prevention—condom use, medical circumcision, and viral suppression–continue to play an important role in reducing HIV risk in AGYW. These findings support the use of combination HIV prevention programs that consider structural as well as biological and behavioural HIV risk factors in their design.
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