50 research outputs found
Performance of self-reported HIV status in determining true HIV status among older adults in rural South Africa: a validation study
Introduction: In South Africa, older adults make up a growing proportion of people living with HIV. HIV programmes are likely to reach older South Africans in home-based interventions where testing is not always feasible. We evaluate the accuracy of self-reported HIV status, which may provide useful information for targeting interventions or offer an alternative to biomarker testing.
Methods: Data were taken from the Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) baseline survey, which was conducted in rural Mpumalanga province, South Africa. A total of 5059 participants aged ≥40 years were interviewed from 2014 to 2015. Self-reported HIV status and dried bloodspots for HIV biomarker testing were obtained during at-home interviews. We calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for self-reported status compared to “gold standard” biomarker results. Log-binomial regression explored associations between demographic characteristics, antiretroviral therapy (ART) status and sensitivity of self-report.
Results: Most participants (93%) consented to biomarker testing. Of those with biomarker results, 50.9% reported knowing their HIV status and accurately reported it. PPV of self-report was 94.1% (95% confidence interval (CI): 92.0–96.0), NPV was 87.2% (95% CI: 86.2–88.2), sensitivity was 51.2% (95% CI: 48.2–54.3) and specificity was 99.0% (95% CI: 98.7–99.4). Participants on ART were more likely to report their HIV-positive status, and participants reporting false-negatives were more likely to have older HIV tests.
Conclusions: The majority of participants were willing to share their HIV status. False-negative reports were largely explained by lack of testing, suggesting HIV stigma is retreating in this setting, and that expansion of HIV testing and retesting is still needed in this population. In HIV interventions where testing is not possible, self-reported status should be considered as a routine first step to establish HIV status.This study was funded by the National Institute on Aging (NIA) of the
National Institutes of Health (NIH) [P01-AG041710] and is nested within the MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt) and funded by Wellcome Trust [058893/Z/99/A; 069683/Z/02/Z; 085477/Z/08/Z; 085477/B/08/Z] with important contributions from the
University of the Witwatersrand and the South African Medical Research
Council. Till Bärnighausen was supported by the Alexander von Humboldt
Foundation through the Alexander von Humboldt Professor award, funded by the German Federal Ministry of Education and Research. He is also supported by the Wellcome Trust, the European Commission, the Clinton Health Access Initiative and NICHD of NIH [R01-HD084233], NIAID of NIH [R01-AI124389 and R01-AI112339] and FIC of NIH [D43-TW009775]
Tracing shadows: How gendered power relations shape the impacts of maternal death on living children in Sub-Saharan Africa
Driven by the need to better understand the full and intergenerational toll of maternal mortality (MM), a mixed-methods study was conducted in four countries in sub-Saharan Africa to investigate the impacts of maternal death on families and children. The present analysis identifies gender as a fundamental driver not only of maternal, but also child health, through manifestations of gender inequity in house- hold decision making, labor and caregiving, and social norms dictating the status of women. Focus group discussions were conducted with community members, and in depth qualitative interviews with key- informants and stakeholders, in Tanzania, Ethiopia, Malawi, and South Africa between April 2012 and October 2013. Findings highlight that socially constructed gender roles, which define mothers as care- givers and fathers as wage earners, and which limit women's agency regarding childcare decisions, among other things, create considerable gaps when it comes to meeting child nutrition, education, and health care needs following a maternal death. Additionally, our findings show that maternal deaths have differential effects on boy and girl children, and exacerbate specific risks for girl children, including early marriage, early pregnancy, and school drop-out. To combat both MM, and to mitigate impacts on children, investment in health services interventions should be complemented by broader interventions regarding social protection, as well as aimed at shifting social norms and opportunity structures regarding gendered divisions of labor and power at household, community, and society levels.Web of Scienc
Towards ecosystem-based management: identifying operational food-web indicators for marine ecosystems
Modern approaches to Ecosystem-Based Management and sustainable use of marine resources must account for the myriad of pressures
(interspecies, human and environmental) affecting marine ecosystems. The network of feeding interactions between co-existing species and populations (food webs) are an important aspect of all marine ecosystems and biodiversity. Here we describe and discuss a process to evaluate the selection of operational food-web indicators for use in evaluating marine ecosystem status. This process brought together experts in food-web ecology, marine ecology, and resource management, to identify available indicators that can be used to inform marine management.
Standard evaluation criteria (availability and quality of data, conceptual basis, communicability, relevancy to management) were implemented to identify practical food-web indicators ready for operational use and indicators that hold promise for future use in policy and management. The major attributes of the final suite of operational food-web indicators were structure and functioning. Indicators that represent resilience of the marine ecosystem were less developed. Over 60 potential food-web indicators were evaluated and the final selection of operational food-web indicators includes: the primary production required to sustain a fishery, the productivity of seabirds (or charismatic megafauna), zooplankton indicators, primary productivity, integrated trophic indicators, and the biomass of trophic guilds. More efforts should be made to develop thresholds-based reference points for achieving Good Environmental Status. There is also a need for international collaborations to develop indicators that will facilitate management in marine ecosystems used by multiple countries.JRC.D.2-Water and Marine Resource
Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial
Background:
Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke.
Methods:
We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515.
Findings:
Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p<0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (<1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (<1%) deaths in the albiglutide group.
Interpretation:
In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes.
Funding:
GlaxoSmithKline
Performance of self-reported HIV status in determining true HIV status among older adults in rural South Africa: a validation study
Abstract Introduction:: In South Africa, older adults make up a growing proportion of people living with HIV. HIV programmes are likely to reach older South Africans in home-based interventions where testing is not always feasible. We evaluate the accuracy of self-reported HIV status, which may provide useful information for targeting interventions or offer an alternative to biomarker testing. Methods:: Data were taken from the Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) baseline survey, which was conducted in rural Mpumalanga province, South Africa. A total of 5059 participants aged ≥40 years were interviewed from 2014 to 2015. Self-reported HIV status and dried bloodspots for HIV biomarker testing were obtained during at-home interviews. We calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for self-reported status compared to “gold standard” biomarker results. Log-binomial regression explored associations between demographic characteristics, antiretroviral therapy (ART) status and sensitivity of self-report. Results:: Most participants (93%) consented to biomarker testing. Of those with biomarker results, 50.9% reported knowing their HIV status and accurately reported it. PPV of self-report was 94.1% (95% confidence interval (CI): 92.0–96.0), NPV was 87.2% (95% CI: 86.2–88.2), sensitivity was 51.2% (95% CI: 48.2–54.3) and specificity was 99.0% (95% CI: 98.7–99.4). Participants on ART were more likely to report their HIV-positive status, and participants reporting false-negatives were more likely to have older HIV tests. Conclusions:: The majority of participants were willing to share their HIV status. False-negative reports were largely explained by lack of testing, suggesting HIV stigma is retreating in this setting, and that expansion of HIV testing and retesting is still needed in this population. In HIV interventions where testing is not possible, self-reported status should be considered as a routine first step to establish HIV status
One health, une seule santé
One Health, « Une seule santé », est une stratégie mondiale visant à développer les collaborations interdisciplinaires pour la santé humaine, animale et environnementale. Elle promeut une approche intégrée, systémique et unifiée de la santé aux échelles locale, nationale et mondiale, afin de mieux affronter les maladies émergentes à risque pandémique, mais aussi s'adapter aux impacts environnementaux présents et futurs. Bien que ce mouvement s’étende, la littérature en français reste rare. Traduit de l’anglais, coordonné par d’éminents épidémiologistes et s'appuyant sur un large panel d' approches scientifiques rarement réunies autour de la santé, cet ouvrage retrace les origines du concept et présente un contenu pratique sur les outils méthodologiques, la collecte de données, les techniques de surveillance et les plans d’étude. Il combine recherche et pratique en un seul volume et constitue un ouvrage de référence unique pour la santé mondiale
An All-Optical 4-Bit Adder Composed of Fabry-Perot Devices
This work models an all-optical 4-bit adder comprised of Fabry-Perot devices. Each device is composed of 2 silver mirrors on either side of a cavity made of a nonlinear Kerr material. These devices are optically bistable and suitable for fast logic operations on the order of picoseconds. An amplifying buffer is used between devices to adjust the transmitted signal’s amplitude to the desired value, and to provide control for logic operations. This work uses the method of finite-difference time-domain (FDTD) in one-dimensional (1D) space to demonstrate the feasibility of the proposed idea.doctoral, Ph.D., Electrical and Computer Engineering -- University of Idaho - College of Graduate Studies, 2023-0
Time-Domain Simulation of the Quantum Magnetic Dipole Moment
In this thesis, the Finite-Difference Time Domain (FDTD) method is used to implement the Schrödinger equation in Python. This method is used to find the ground eigenstate and to simulate an electron within a three-dimensional torus. The magnetic dipole moment operator is developed, both with and without an applied magnetic field, and the equations describing a magnetic field applied to the torus are developed using the FDTD method. The magnetic dipole moment operator and implementation of a magnetic field are verified using a classical method. The magnetic dipole moment operator is used to calculate the magnetic susceptibility of a grated torus.masters, M.S., Electrical and Computer Engineering -- University of Idaho - College of Graduate Studies, 201
Size-structured modelling tools for an ecosystems approach to fisheries
This thesis informs an ecosystem approach to fisheries management (EAFM) through the development and application of three relevant. novel size-based modelling case studies that demonstrate the importance of considering trophic interactions when managing fisheries. EAFM, which considers ecological interactions between and within fish populations, allows for better fisheries management because these interactions can cause complex changes in ecosystem structure with changing fishing pressure. This size-based modelling approach informs EAFM through the model's ability to accurately represent size-structured fish community dynamics. I refine the model's ecological representation and explore its properties in order to make it more operational for EAFM. I take a test Signal approach to examine the performance of a suite of fish community indicators proposed as being useful for fisheries management. I show that fish community indicators are differentially and nonlinearly sensitive to fishing and that indicators are generally, though not equally, specific to fishing. I examine how fisheries for forage and predator fish populations interact I show that trade-offs occur among yield, spawning stock biomass, and collapse of forage and predator fish populations due to underlying trophic interactions. I examine ecological seal-fishery interactions in southwest Irish waters using a modelling scenario based on fish community survey data, grey and harbour seal diet and population data, and fisheries catch and discard data. I specify seal diet preference for fish prey using a diet correction method. I find that under the modelled circumstances, seals do not have a major direct or indirect impact on the main modelled commercial fish species, but they do have a negative impact on salmonids, which are vulnerable group. These case studies illustrate that the model used in this thesis is a useful tool that shows how trophic interactions cause ecosystem change with changing fishing pressure, which has policy implications for fisheries management.EThOS - Electronic Theses Online ServiceGBUnited Kingdo