Socio-Behavioural Barriers to Viral Suppression in the Older Adult Population in Rural South Africa.

South Africa has the largest share of people living with HIV in the world and this population is ageing. The social context in which people seek HIV care is often ignored. Apart from clinical interventions, socio-behavioural factors impact successful HIV care outcomes for older adults living with HIV. We use cross-sectional data linked with demographic household surveillance data, consisting of HIV positive adults aged above 40, to identify socio-behavioural predictors of a detectable viral load. Older adults were more likely to have a detectable viral load if they did not disclose their HIV positive status to close family members (aOR 2.56, 95% CI 1.89-3.46), resided in the poorest households (aOR 1.98, 95% CI 1.23-3.18), or were not taking medications other than ART (aOR 1.83, 95% CI 1.02-1.99) likely to have a detectable. Clinical interventions in HIV care must be supported by understanding the socio-behavioural barriers that occur outside the health facility. The importance of community health care workers in bridging this gap may offer more optimum outcomes for older adults ageing with HIV.

Probabilistic Assessment of the Failure Risk of the Europa Clipper Spacecraft due to Radiations.

The Europa mission approved in 2019 is still in the development phase. It is designed to conduct a detailed reconnaissance of that moon of Jupiter as it could possibly support life as we know it. This article is based on a top-down approach (mission → system → subsystems → components) to model the probability of mission failure. The focus here is on the case where the (uncertain) radiation load exceeds the (uncertain) capacity of critical subsystems of the spacecraft. The model is an illustrative quantification of the uncertainties about (1) the complex external radiation environment in repeated exposures, (2) the effectiveness of the shielding in different zones of the spacecraft, and (3) the components' capacities, by modeling all three as dynamic random variables. A simulation including a sensitivity analysis is used to obtain the failure probability of the whole mission in forty-five revolutions around Jupiter. This article illustrates how probabilistic risk analysis based on engineering models, test results and expert opinions can be used in the early stages of the design of space missions when uncertainties are large. It also describes the optimization of the spacecraft design, taking into account the decisionmakers' risk attitude and the mission resource constraints.

Cyber Risk Management for Critical Infrastructure: A Risk Analysis Model and Three Case Studies.

Managing cyber security in an organization involves allocating the protection budget across a spectrum of possible options. This requires assessing the benefits and the costs of these options. The risk analyses presented here are statistical when relevant data are available, and system-based for high-consequence events that have not happened yet. This article presents, first, a general probabilistic risk analysis framework for cyber security in an organization to be specified. It then describes three examples of forward-looking analyses motivated by recent cyber attacks. The first one is the statistical analysis of an actual database, extended at the upper end of the loss distribution by a Bayesian analysis of possible, high-consequence attack scenarios that may happen in the future. The second is a systems analysis of cyber risks for a smart, connected electric grid, showing that there is an optimal level of connectivity. The third is an analysis of sequential decisions to upgrade the software of an existing cyber security system or to adopt a new one to stay ahead of adversaries trying to find their way in. The results are distributions of losses to cyber attacks, with and without some considered countermeasures in support of risk management decisions based both on past data and anticipated incidents.

Supermassive black holes do not correlate with galaxy disks or pseudobulges.

The masses of supermassive black holes are known to correlate with the properties of the bulge components of their host galaxies. In contrast, they seem not to correlate with galaxy disks. Disk-grown 'pseudobulges' are intermediate in properties between bulges and disks; it has been unclear whether they do or do not correlate with black holes in the same way that bulges do. At stake in this issue are conclusions about which parts of galaxies coevolve with black holes, possibly by being regulated by energy feedback from black holes. Here we report pseudobulge classifications for galaxies with dynamically detected black holes and combine them with recent measurements of velocity dispersions in the biggest bulgeless galaxies. These data confirm that black holes do not correlate with disks and show that they correlate little or not at all with pseudobulges. We suggest that there are two different modes of black-hole feeding. Black holes in bulges grow rapidly to high masses when mergers drive gas infall that feeds quasar-like events. In contrast, small black holes in bulgeless galaxies and in galaxies with pseudobulges grow as low-level Seyfert galaxies. Growth of the former is driven by global processes, so the biggest black holes coevolve with bulges, but growth of the latter is driven locally and stochastically, and they do not coevolve with disks and pseudobulges.

Asteroid Risk Assessment: A Probabilistic Approach.

Following the 2013 Chelyabinsk event, the risks posed by asteroids attracted renewed interest, from both the scientific and policy-making communities. It reminded the world that impacts from near-Earth objects (NEOs), while rare, have the potential to cause great damage to cities and populations. Point estimates of the risk (such as mean numbers of casualties) have been proposed, but because of the low-probability, high-consequence nature of asteroid impacts, these averages provide limited actionable information. While more work is needed to further refine its input distributions (e.g., NEO diameters), the probabilistic model presented in this article allows a more complete evaluation of the risk of NEO impacts because the results are distributions that cover the range of potential casualties. This model is based on a modularized simulation that uses probabilistic inputs to estimate probabilistic risk metrics, including those of rare asteroid impacts. Illustrative results of this analysis are presented for a period of 100 years. As part of this demonstration, we assess the effectiveness of civil defense measures in mitigating the risk of human casualties. We find that they are likely to be beneficial but not a panacea. We also compute the probability-but not the consequences-of an impact with global effects ("cataclysm"). We conclude that there is a continued need for NEO observation, and for analyses of the feasibility and risk-reduction effectiveness of space missions designed to deflect or destroy asteroids that threaten the Earth.

Providing HIV Treatment during community-wide flooding: experiences of clients and Health Care Workers in Malawi.

Background: In Malawi, community wide flooding, especially in high HIV burdened districts, continues to affect continuity of care and access to facilities. We explored the lived experiences of clients and healthcare workers (HCWs) to gain understanding of challenges and to propose interventions for improved ART care delivery. Methods: Participants came six health facilities and surrounding communities impacted by flooding between Dec 2021-Apr 2022 in Chikwawa, Nsanje and Mulanje districts in Malawi. Facilities are supported by Partners in Hope, a local NGO and PEPFAR/USAID partner.We conducted In-depth interviews with (IDIs) ART clients identified through medical chart reviews and focus group discussions (FGDs) with HCWs. IDIs and FGDs were coded using inductive and deductive methods in Atlas.ti. Results: We conducted IDIs with 23 respondents, of which, ten were women, ten experienced treatment interruption (>28 days without medication) and 17 relocated from their homes. The Six FGDs involved 37 HCWs. (21 ART providers; 16 lay cadre).In IDIs, most clients who relocated and lost livestock, possessions and ART medications. They travelling for income generation. Barriers to care included dangerous travel conditions, competing needs for time and fear of ill treatment at facilities. Some outreach clinics did not provide ART. Respondents were motivated to remain on care and motivators included fear of developing illnesses and HIV-status acceptance.All providers said that lack of standardized guidelines affected preparedness and response and they advocated for guidelines, stakeholder coordination and adequate resources. Most also reported personal physical exhaustion, damage to their own houses and property, and drug stock-outs. Documentation due to loss of registers was also mostly mentioned. Discussion: Clients motivated to remain in care but face barriers and challenges. National flooding protocols, adequate resource planning and seasonal 6-month ART dispensing may improve ART outcomes.

Gender inequality: Bad for men's health.

Men's increased risk of death in ART programmes in sub-Saharan Africa is widely reported but poorly understood. Some studies have attributed this risk to men's poorer health-seeking behaviour, which may prevent them from accessing ART, being adherent to treatment, or remaining in care. In a multicentre analysis of 46 201 adults starting ART in urban and rural settings in South Africa, these factors only partly explained men's increased mortality while receiving ART. Importantly, the gender difference in mortality among patients receiving ART (31% higher for men than women) was substantially smaller than that among HIV-negative South Africans, where men had twice the risk of death compared with women. Yet, this extreme gender inequality in mortality, both within and outside of ART programmes, has not given rise to widespread action. Here it is argued that, despite their dominance in society, men may be subject to a wide range of unfair discriminatory practices, which negatively affect their health outcomes. The health needs of men and boys require urgent attention.

South Africa's male homicide epidemic hiding in plain sight: exploring sex differences and patterns in homicide risk in a retrospective descriptive study of postmortem investigations.

Background: South Africa has homicide rates six times the global average, predominantly among men, but little is known about male victims. As part of the country's first ever study of male homicide we compared 2017 male and female victim profiles for selected covariates, against global averages and previous estimates for 2009. Methods: We conducted a retrospective descriptive study of routine data collected through postmortem investigations, calculating age-standardised mortality rates for manner of death by age, sex and province and male-to-female incidence rate ratios with 95% confidence intervals. We then used generalised linear models and linear regression models to assess the association between sex and victim characteristics including age and mechanism of injury (guns, stabs and blunt force) within and between years. Findings: 87% of 19,477 homicides in 2017 were males, equating to seven male deaths for every female, with sharp force and firearm discharge the most common external causes. Rates were higher among males than females at all ages, and up to eight times higher among males aged 15-44 years. Provincial rates varied overall and by sex, with the highest comparative risk for men vs. women in the Western Cape Province (11.4 males for every 1 female). Male homicides peaked during December and were highest on weekends, underscoring the prominent role of alcohol as a risk factor. Significantly more males tested positive for alcohol than females. Interpretation: The massive, disproportionate and enduring homicide risk borne by adult South African men highlights the negligible prevention response. Only through challenging the normative perception of male invulnerability can we begin to address the enormous burden of violence impacting men. There is an urgent need to address the insidious effect of such societal norms alongside implementing structural interventions to overcome the root causes of poverty and inequality and better control alcohol and firearms. Funding: South African Medical Research Council and Ford Foundation.

Effect of increasing the organic loading rate on the co-digestion and mono-digestion of cattle slurry and maize.

Co-digestion of cattle slurry and maize has been shown to have benefits for both, improving the biogas yield of the slurry and stability of digestion of the maize. The effect of increasing the total loading rate from 3 to 6 g VS l(-1) day(-1) on the co-digestion of cattle slurry and maize, mixed at equal volatile solids volumes, was investigated in laboratory-scale continuously stirred digesters. These were compared with similar digesters evaluating the increase of 1.5 to 3 g VS l(-1) day(-1) loading rates of slurry and maize digested separately. Compared with mono-digestion of the substrates, where the digestion of maize failed at loading rates greater than 2.5 g VS l(-1) day(-1), the co-digestion of cattle slurry and maize was feasible at all the loading rates tested with an increase in the volumetric methane yield occurring with loading rate. Even at the lowest rate of loading, the addition of equal amounts of volatile solids of maize to slurry leads to an increase in volumetric methane yield of 219%.

The treatment gap for mental disorders in adults enrolled in HIV treatment programmes in South Africa: a cohort study using linked electronic health records.

AIMS: Mental disorders are common in people living with HIV (PLWH) but often remain untreated. This study aimed to explore the treatment gap for mental disorders in adults followed-up in antiretroviral therapy (ART) programmes in South Africa and disparities between ART programmes regarding the provision of mental health services. METHODS: We conducted a cohort study using ART programme data and linked pharmacy and hospitalisation data to examine the 12-month prevalence of treatment for mental disorders and factors associated with the rate of treatment for mental disorders among adults, aged 15-49 years, followed-up from 1 January 2012 to 31 December 2017 at one private care, one public tertiary care and two pubic primary care ART programmes in South Africa. We calculated the treatment gap for mental disorders as the discrepancy between the 12-month prevalence of mental disorders in PLWH (aged 15-49 years) in South Africa (estimated based on data from the Global Burden of Disease study) and the 12-month prevalence of treatment for mental disorders in ART programmes. We calculated adjusted rate ratios (aRRs) for factors associated with the treatment rate of mental disorders using Poisson regression. RESULTS: In total, 182 285 ART patients were followed-up over 405 153 person-years. In 2017, the estimated treatment gap for mental disorders was 40.5% (95% confidence interval [CI] 19.5-52.9) for patients followed-up in private care, 96.5% (95% CI 95.0-97.5) for patients followed-up in public primary care and 65.0% (95% CI 36.5-85.1) for patients followed-up in public tertiary care ART programmes. Rates of treatment with antidepressants, anxiolytics and antipsychotics were 17 (aRR 0.06, 95% CI 0.06-0.07), 50 (aRR 0.02, 95% CI 0.01-0.03) and 2.6 (aRR 0.39, 95% CI 0.35-0.43) times lower in public primary care programmes than in the private sector programmes. CONCLUSIONS: There is a large treatment gap for mental disorders in PLWH in South Africa and substantial disparities in access to mental health services between patients receiving ART in the public vs the private sector. In the public sector and especially in public primary care, PLWH with common mental disorders remain mostly untreated.

Organizational aspects of engineering system safety: the case of offshore platforms.

Organizational errors are often at the root of failures of critical engineering systems. Yet, when searching for risk management strategies, engineers tend to focus on technical solutions, in part because of the way risks and failures are analyzed. Probabilistic risk analysis allows assessment of the safety of a complex system by relating its failure probability to the performance of its components and operators. In this article, some organizational aspects are introduced to this analysis in an effort to describe the link between the probability of component failures and relevant features of the organizaton. Probabilities are used to analyze occurrences of organizational errors and their effects on system safety. Coarse estimates of the benefits of certain organizational improvements can then be derived. For jacket-type offshore platforms, improving the design review can provide substantial reliability gains, and the corresponding expense is about two orders of magnitude below the cost of achieving the same result by adding steel to structures.

Effect of solid and liquid retention times on hydrolysis of maize.

First stage hydrolysis/acidification, using maize as the substrate, was carried out both in single pass (SP) reactors at different hydraulic retention times (HRT) and in hydraulic flush (HF) reactors in which the solids and liquid retention time were uncoupled. The HF reactors were operated at two different loadings (2 and 4 g VS l(-1) d(-1)) and at liquid retention times between 2-16 days with solids held for 20 days. The volatile solids destruction (VS(destroyed) d(-1)) and specific methane potential (l CH(4) g VS(added) d(-1)) of the intermediate products formed in the SP reactors both decreased with increasing retention and showed a maximum VS destruction of 55.6% at a 2-day HRT. The HF reactors showed a slightly lower VS destruction at the same loading but the methane potential was slightly higher as the intermediate COD produced had a greater proportion of volatile fatty acids (VFA) present. At the loading used it was necessary to operate the HF reactors at a HRT of less than 8 days to have any benefit over the SP reactors.

Engineering risk analysis of a hospital oxygen supply system.

Reports from the Food and Drug Administration (FDA) and the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) have emphasized the potential for injury to patients caused by failures in oxygen supply systems. This article presents a model of patient risk related to the process of supplying oxygen at a single university hospital. One of the goals of the article is to illustrate how probabilistic risk analysis (PRA) can be used by hospitals to assess and mitigate risk and, therefore, to meet JCAHO requirements. PRA techniques are useful to 1) model the reliability of a complex system and 2) assess the cost-effectiveness of different risk mitigation measures. The authors focus on the risk estimation step, describing in detail their modeling of the oxygen supply system and analysis of the results. For the hospital that the authors study (20,000 admissions yearly), the total expected number of fatalities from oxygen system failure is 44 over a 30-year time horizon. The greatest contribution to the risk (94% of the expected number of fatalities) comes from problems that involve the supply network (e.g., damage to structure and poisoning) as opposed to incidents that occur inside patient rooms. Although the threat to patient safety is not dramatic, health care organizations should be concerned about potential failures of their oxygen system because improving this system could avoid low-probability, high-consequence failures at a low cost.

The Drosophila melanogaster Suppressor of deltex gene, a regulator of the Notch receptor signaling pathway, is an E3 class ubiquitin ligase.

During development, the Notch receptor regulates many cell fate decisions by a signaling pathway that has been conserved during evolution. One positive regulator of Notch is Deltex, a cytoplasmic, zinc finger domain protein, which binds to the intracellular domain of Notch. Phenotypes resulting from mutations in deltex resemble loss-of-function Notch phenotypes and are suppressed by the mutation Suppressor of deltex [Su(dx)]. Homozygous Su(dx) mutations result in wing-vein phenotypes and interact genetically with Notch pathway genes. We have previously defined Su(dx) genetically as a negative regulator of Notch signaling. Here we present the molecular identification of the Su(dx) gene product. Su(dx) belongs to a family of E3 ubiquitin ligase proteins containing membrane-targeting C2 domains and WW domains that mediate protein-protein interactions through recognition of proline-rich peptide sequences. We have identified a seven-codon deletion in a Su(dx) mutant allele and we show that expression of Su(dx) cDNA rescues Su(dx) mutant phenotypes. Overexpression of Su(dx) also results in ectopic vein differentiation, wing margin loss, and wing growth phenotypes and enhances the phenotypes of loss-of-function mutations in Notch, evidence that supports the conclusion that Su(dx) has a role in the downregulation of Notch signaling.

Intravenous pamidronate reduces osteoporosis and improves formation of the regenerate during distraction osteogenesis. A study in immature rabbits.

We examined the effect on bone mineral density (BMD) of a single dose of 3 mg/kg of the bisphosphonate, pamidronate (Novartis) in distraction osteogenesis in immature rabbits. Seventeen rabbits (9 control, 8 given pamidronate) were examined by dual-energy x-ray absorptiometry. There was a significant increase in the BMD in the pamidronate group compared with the control animals. The mean areal BMD (g/cm2) in the bone proximal and distal to the regenerate was increased by 40% and 39%, respectively, compared with the control group (p < 0.05). The BMD of the regenerate bone was increased by a mean of 43% (p < 0.05). There was an increase of 22% in the mean area of regenerate formed in the pamidronate group (p < 0.05). Histological examination of bone in nine rabbits (5 control, 4 pamidronate) showed an increase in osteoblastic rimming and mineralisation of the regenerate, increased formation of bone around the pin sites and an increase in the cortical width of the bone adjacent to the regenerate in the rabbits given pamidronate. Pamidronate had a markedly positive effect. It reduced the disuse osteoporosis normally associated with lengthening using an external fixator and increased the amount and density of the regenerate bone. Further study is required to examine the mechanical properties of the regenerate after the administration of pamidronate.

Management Errors and System Reliability: A Probabilistic Approach and Application to Offshore Platforms.

Probabilistic risk analysis, based on the identification of failure modes, points to technical malfunctions and operator errors that can be direct causes of system failure. Yet component failures and operator errors are often rooted in management decisions and organizational factors. Extending the analysis to identify these factors allows more effective risk management strategies. It also permits a more realistic assessment of the overall failure probability. An implicit assumption that is often made in PRA is that, on the whole, the system has been designed according to specified norms and constructed as designed. Such an analysis tends to overemphasize scenarios in which the system fails because it is subjected to a much higher load than those for which it was designed. In this article, we find that, for the case of jacket-type offshore platforms, this class of scenarios contributes only about 5% of the failure probability. We link the PRA inputs to decisions and errors during the three phases of design, construction, and operation of platforms, and we assess the contribution of different types of error scenarios to the overall probability of platform failure. We compute the benefits of improving the design review, and we find that, given the costs involved, improving the review process is a more efficient way to increase system safety than reinforcing the structure.

The pentothal test in the management of orthopaedic patients with hysterical illness.

Hysterical illness may be defined as symptoms normally associated with disease without pathological basis. Orthopaedics attracts more of these patients than most specialties. They are intensively and expensively investigated, yet clinicians remain anxious they are missing genuine pathology. We use examination under pentothal, without analgesia, to help distinguish real from imagined symptoms. The results of a review of patients evaluated under pentothal over the past two years are presented.

The emerging role of HDL cholesterol. Is it time to focus more energy on raising high-density lipoprotein levels?

Low HDL cholesterol levels have been found to be a risk factor for CAD. To date, the focus of treating hyperlipidemia has been on lowering LDL cholesterol levels. Now, as more and more compelling data are reported, it is time to begin focusing more energy on how to raise HDL cholesterol levels. If exercise, smoking cessation, and moderate alcohol consumption fail to achieve HDL cholesterol goals, niacin, fibric acid derivatives, or statin drugs may prove helpful in patients at high risk of CAD.

The cooperative care concept: a care partner's perspective.

Today's acute care facilities are facing the most serious crisis in health care history. They have been challenged with providing high quality services with good patient outcomes at competitive prices. The Cooperative Care Concept is an alternative that strives to meet this challenge by delivering hospital care in a unique way. This innovation is described through the care partner's eyes by a health care professional who has recently lived the experience.

Longitudinal developmental profile of children from low socio-economic circumstances in Cape Town, using the 1996 Griffiths Mental Development Scales.

BACKGROUND: The Griffiths Mental Development Scales (GMDS) have not been standardised in South African children Neurodevelopmental scores of infants from deprived environments decline with age, but there is no evidence on how young South African children from such backgrounds perform on serial assessments. AIM: To describe the longitudinal developmental profile of infants from low socio-economic backgrounds at Tygerberg Children's Hospital by comparing the GMDS scores performed at 10 - 12 months and 20 - 22 months. METHODS: Infants born to HIV-uninfected women attending the public service programme were recruited from a vaccine study in Cape Town, South Africa. The GMDS 0 - 2 years and a neurological examination were performed between 10 and 12 months and between 20 and 22 months. RESULTS: Thirty-one infants (14 girls, 17 boys) were assessed. Their mean (standard deviation (SD)) age was 11.6 (0.8) months and 21.0 (0.5) months at the first and second assessments, respectively. The mean (SD) general quotient decreased significantly from 107.3 (11.7) to 95.0 (11.0) (p<0.001). All sub-quotients decreased significantly except for locomotor. The hearing and language sub-quotient was most affected, with a decrease in mean quotients from 113.0 to 93.2 (p<0.001). There was no evidence of intercurrent events to explain the decline. INTERPRETATION: Scores on the GMDS of this group of children from low socio-economic backgrounds were normal at 11 months and, other than locomotor, decreased significantly at 21 months, with language the most affected. Further research is needed to determine the specific reasons for the decline.