Average flow constraints and stabilizability in uncertain production-distribution systems

We consider a multi-inventory system with controlled flows and uncertain demands (disturbances) bounded within assigned compact sets. The system is modelled as a first-order one integrating the discrepancy between controlled flows and demands at different sites/nodes. Thus, the buffer levels at the nodes represent the system state. Given a long-term average demand, we are interested in a control strategy that satisfies just one of two requirements: (i) meeting any possible demand at each time (worst case stability) or (ii) achieving a predefined flow in the average (average flow constraints). Necessary and sufficient conditions for the achievement of both goals have been proposed by the authors. In this paper, we face the case in which these conditions are not satisfied. We show that, if we ignore the requirement on worst case stability, we can find a control strategy driving the expected value of the state to zero. On the contrary, if we ignore the average flow constraints, we can find a control strategy that satisfies worst case stability while optimizing any linear cost on the average control. In the latter case, we provide a tight bound for the cost

Energy poverty, shack fires and childhood burns

Burn injuries are a persisting challenge in South Africa. Energy poverty, prevalent in under-resourced communities, is a key contributor to the problem. The energy-poor rely on solid fuels and flammable hydrocarbons, such as paraffin, for energy services. The fuels are burnt in inefficient, leaky and unstable appliances, leading to health losses from pollutant emissions, burns, and conflagrations. Within cramped informal home settings, using flammable fuels and risky combustion technologies, the situation can become devastating, especially for young children. Those who survive fiery incidents have to contend with trauma and property losses that may lead to further impoverishment. Proactive intervention strategies are required and should include the broadening of access to safe and sustainable energy. We advocate greater enforcement of home appliance standards and targeted support for the distribution of proven alternative energy technologies, such as liquefied petroleum gas and solar power. Support and advocacy from professional and citizen groups would be necessary to ensure that government prioritises the safe energy requirements of poor citizens

Paraffin dangers, health and socioeconomic consequences: Urgent need for policy action

Illuminating paraffin (kerosene) is the primary cooking fuel for approximately two million South Africans. The highly flammable and toxic fuel is burnt in poorly made stoves that are prone to malfunction and are associated with accidental fires, burns and household air pollution. However, the fuel continues to be used as it is easily decanted, widely available in neighbourhood outlets, perceived as affordable, and often the only available option for low-income urban settlements. It is anticipated that increased and enforced home congestion during COVID-19 lockdowns will exacerbate exposure of homebound families to unsafe energy, especially during the cold winter months. Based on an accumulation of evidence on the health and socioeconomic impacts of paraffin, this article advocates for its expedited phase-out and substitution with safer energy

Burns, scalds and poisonings from household energy use in South Africa: Are the energy poor at greater risk?

Household energy related accidents such as burns and poisonings are not included amongst the causes of health burdens from residential energy use in the Global Burden of Disease (GBD) and other similar assessments. This is a serious omission in the case of transitional developmental states, such as South Africa, where these can be significant. This study analyses the risks associated with burns, scalds and poisonings from the use of household fuels in South Africa, adopting an environmental risk transition framework. We employ quantitative data from a nationally representative household energy consumption survey and hospital treatment data on energy incident injuries from a sample of 17 hospitals around South Africa to assess the relationship between the risk of these accidents, household income and energy poverty. Previous research on risk transitions provides clear evidence of a transition away from risks associated with household pollution with rising income, and also suggests that the evidence regarding injuries appears to decrease with rising income. We, however, find that in the case of South Africa, the relationship between poverty and burn and poison incidents due to household energy use may be non-linear. The results of our analysis suggest that the risks of burn incidents and fires initially rise with income only to decrease at higher income levels. Moreover, for households below an energy poverty threshold, the risks of energy related accidents rise with an increase in household energy use, but falls once households cross this threshold. This suggests that a pro-poor approach is needed in designing programmes that lower the overall risk of these incidents. In addition, more rapid household energy transitions that displace paraffin with LPG and candles with electricity or solar power can help reduce the incidence and burden of these accidents

Perceived social influences on women’s decisions to use medications not studied in pregnancy: a qualitative ethical analysis of PrEP implementation research in Kenya

Implementation research ethics can be particularly challenging when pregnant women have been excluded from earlier clinical stages of research given greater uncertainty about safety and efficacy in pregnancy. The evaluation of HIV pre-exposure prophylaxis (PrEP) during pregnancy offered an opportunity to understand important ethical considerations and social influences shaping women’s decisions to participate in evaluation of PrEP and investigational drugs during pregnancy. We conducted interviews with women (n=51), focus groups with male partners (5 FGDs), interviews with health providers (n=45), 4 FGDs with pregnant/postpartum adolescents and 4 FGDs with young women. Data were analyzed using thematic content analysis, including ethical aspects of the data. Our study reveals that women navigate a complex network of social influences, expectations, support, and gender roles, not only with male partners, but with clinicians, family, and friends when making decisions about PrEP or other drugs that lack complete safety data during pregnancy