171 research outputs found

    Extreme heat events, high ambient temperatures and human morbidity and mortality in Africa: A systematic review

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    Temperature extremes vary across Africa. A continent-wide examination of the impacts of heat on health in Africa, and a synthesis of Africa-informed evidence is, however, lacking. A systematic review of articles published in peer-reviewed journals between January 1992 and April 2019 was conducted. To be eligible, articles had to be Africa-specific, in English, and focused on how heatwaves and high ambient temperatures affect morbidity and mortality. A secondary systematic analysis on policies and interventions comprising 17 studies was also conducted, and the findings synthesised together with those of the 20 primary studies. Eleven studies showed that high ambient temperatures and heat waves are linked with increased mortality rates in Africa. These linkages are characterised by complex, linear and non-linear (J or U) relationships. Eight of the nine primary studies of morbidity outcome reported that an increase in temperature was accompanied by raised disease incidence. Children and the elderly were the population groups most vulnerable to extreme heat exposure. Location-specific interventions and policy suggestions include developing early warning systems, creating heat-health plans, changing housing conditions and implementing heat-health awareness campaigns. In summary, this review demonstrates that, while heat-health relationships in Africa are complex, extreme temperatures are associated with high mortality and morbidity, especially amongst vulnerable populations. As temperatures increase across Africa, there is an urgent need to develop heat-health plans and implement interventions. Future studies must document intervention effectiveness and quantify the costs of action and inaction on extreme heat-related mortality and morbidity. Significance: Empirical evidence shows that the relationship between heat and human health is complex in the African context. This complexity has implications for the development of interventions and policies for heathealth on the continent. This review is important for African policymakers, practitioners and others who support Africa’s adaptation to climate change. Through this review, a compendium of Africa-specific and relevant empirical information is aggregated and made readily available to various interested and affected parties

    Extreme heat events, high ambient temperatures and human morbidity and mortality in Africa : a systematic review

    Get PDF
    Temperature extremes vary across Africa. A continent-wide examination of the impacts of heat on health in Africa, and a synthesis of Africa-informed evidence is, however, lacking. A systematic review of articles published in peer-reviewed journals between January 1992 and April 2019 was conducted. To be eligible, articles had to be Africa-specific, in English, and focused on how heatwaves and high ambient temperatures affect morbidity and mortality. A secondary systematic analysis on policies and interventions comprising 17 studies was also conducted, and the findings synthesised together with those of the 20 primary studies. Eleven studies showed that high ambient temperatures and heat waves are linked with increased mortality rates in Africa. These linkages are characterised by complex, linear and non-linear (J or U) relationships. Eight of the nine primary studies of morbidity outcome reported that an increase in temperature was accompanied by raised disease incidence. Children and the elderly were the population groups most vulnerable to extreme heat exposure. Location-specific interventions and policy suggestions include developing early warning systems, creating heat-health plans, changing housing conditions and implementing heat-health awareness campaigns. In summary, this review demonstrates that, while heat-health relationships in Africa are complex, extreme temperatures are associated with high mortality and morbidity, especially amongst vulnerable populations. As temperatures increase across Africa, there is an urgent need to develop heat-health plans and implement interventions. Future studies must document intervention effectiveness and quantify the costs of action and inaction on extreme heatrelated mortality and morbidity. SIGNIFICANCE : • Empirical evidence shows that the relationship between heat and human health is complex in the African context. This complexity has implications for the development of interventions and policies for heathealth on the continent. • This review is important for African policymakers, practitioners and others who support Africa’s adaptation to climate change. Through this review, a compendium of Africa-specific and relevant empirical information is aggregated and made readily available to various interested and affected parties.http://www.sajs.co.zahj2022Geography, Geoinformatics and Meteorolog

    Clinical and epidemiological aspects of a hepatitis E outbreak in Bangui, Central African Republic

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    <p>Abstract</p> <p>Background</p> <p>Outbreaks of hepatitis E frequently occur in tropical developing countries during the rainy season due to overflowing drains, short-circuiting of networks of clean water and use of contaminated water from wells. Hepatitis E virus (HEV) infections are usually accompanied by general symptoms of acute liver disease. This study was conducted to define the clinical and epidemiological aspects of the HEV outbreak that occurred in May 2004 in Bangui.</p> <p>Methods</p> <p>Blood samples were collected from 411 patients aged 1-87 years, most of whom presented with jaundice, asthenia or signs of uncomplicated malaria, for a transversal study from June 2004 to September 2005. Patients were recruited at 11 health care centres, including two referral hospitals, after they had given informed consent. The diagnosis of HEV was made with a commercial ELISA test to detect IgM and/or IgG antibodies. HEV RNA was amplified by RT-PCR to confirm the presence of the viral genome.</p> <p>Results</p> <p>The most frequent clinical signs found were jaundice (93.4%), vomiting (50.7%), hepatalgia (47.4%), hepatomegaly (30.9%) and asthenia (26.8%), which are the general clinical signs of hepatic disease. Acute hepatitis E was found in 213 patients (51.8%) who were positive for HEV IgM antibodies. The IgG anti-HEV seroprevalence during this outbreak was high (79.5%). The age group 18-34 years was more frequently infected (91.2%) than those aged 1-17 (78.0%) or over 34 (64.9%) (p < 10<sup>-6</sup>). RT-PCR performed on 127 sera from the 213 IgM-HEV-positive patients was amplified, and the presence of the viral genome was found in 65 samples.</p> <p>Conclusion</p> <p>Although no specific clinical signs exist for hepatitis E infection, people presenting with jaundice, vomiting, hepatalgia, asthenia, hepatomegaly or distended abdomen with no signs of uncomplicated malaria in tropical developing countries should be sent to a laboratory for testing for hepatitis E.</p

    New Strategies in Modeling Electronic Structures and Properties with Applications to Actinides

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    This chapter discusses contemporary quantum chemical methods and provides general insights into modern electronic structure theory with a focus on heavy-element-containing compounds. We first give a short overview of relativistic Hamiltonians that are frequently applied to account for relativistic effects. Then, we scrutinize various quantum chemistry methods that approximate the NN-electron wave function. In this respect, we will review the most popular single- and multi-reference approaches that have been developed to model the multi-reference nature of heavy element compounds and their ground- and excited-state electronic structures. Specifically, we introduce various flavors of post-Hartree--Fock methods and optimization schemes like the complete active space self-consistent field method, the configuration interaction approach, the Fock-space coupled cluster model, the pair-coupled cluster doubles ansatz, also known as the antisymmetric product of 1 reference orbital geminal, and the density matrix renormalization group algorithm. Furthermore, we will illustrate how concepts of quantum information theory provide us with a qualitative understanding of complex electronic structures using the picture of interacting orbitals. While modern quantum chemistry facilitates a quantitative description of atoms and molecules as well as their properties, concepts of quantum information theory offer new strategies for a qualitative interpretation that can shed new light onto the chemistry of complex molecular compounds.Comment: 43 pages, 3 figures, Version of Recor

    Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.

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    BACKGROUND: Child stunting reduces survival and impairs neurodevelopment. We tested the independent and combined effects of improved water, sanitation, and hygiene (WASH), and improved infant and young child feeding (IYCF) on stunting and anaemia in in Zimbabwe. METHODS: We did a cluster-randomised, community-based, 2 × 2 factorial trial in two rural districts in Zimbabwe. Clusters were defined as the catchment area of between one and four village health workers employed by the Zimbabwe Ministry of Health and Child Care. Women were eligible for inclusion if they permanently lived in clusters and were confirmed pregnant. Clusters were randomly assigned (1:1:1:1) to standard of care (52 clusters), IYCF (20 g of a small-quantity lipid-based nutrient supplement per day from age 6 to 18 months plus complementary feeding counselling; 53 clusters), WASH (construction of a ventilated improved pit latrine, provision of two handwashing stations, liquid soap, chlorine, and play space plus hygiene counselling; 53 clusters), or IYCF plus WASH (53 clusters). A constrained randomisation technique was used to achieve balance across the groups for 14 variables related to geography, demography, water access, and community-level sanitation coverage. Masking of participants and fieldworkers was not possible. The primary outcomes were infant length-for-age Z score and haemoglobin concentrations at 18 months of age among children born to mothers who were HIV negative during pregnancy. These outcomes were analysed in the intention-to-treat population. We estimated the effects of the interventions by comparing the two IYCF groups with the two non-IYCF groups and the two WASH groups with the two non-WASH groups, except for outcomes that had an important statistical interaction between the interventions. This trial is registered with ClinicalTrials.gov, number NCT01824940. FINDINGS: Between Nov 22, 2012, and March 27, 2015, 5280 pregnant women were enrolled from 211 clusters. 3686 children born to HIV-negative mothers were assessed at age 18 months (884 in the standard of care group from 52 clusters, 893 in the IYCF group from 53 clusters, 918 in the WASH group from 53 clusters, and 991 in the IYCF plus WASH group from 51 clusters). In the IYCF intervention groups, the mean length-for-age Z score was 0·16 (95% CI 0·08-0·23) higher and the mean haemoglobin concentration was 2·03 g/L (1·28-2·79) higher than those in the non-IYCF intervention groups. The IYCF intervention reduced the number of stunted children from 620 (35%) of 1792 to 514 (27%) of 1879, and the number of children with anaemia from 245 (13·9%) of 1759 to 193 (10·5%) of 1845. The WASH intervention had no effect on either primary outcome. Neither intervention reduced the prevalence of diarrhoea at 12 or 18 months. No trial-related serious adverse events, and only three trial-related adverse events, were reported. INTERPRETATION: Household-level elementary WASH interventions implemented in rural areas in low-income countries are unlikely to reduce stunting or anaemia and might not reduce diarrhoea. Implementation of these WASH interventions in combination with IYCF interventions is unlikely to reduce stunting or anaemia more than implementation of IYCF alone. FUNDING: Bill & Melinda Gates Foundation, UK Department for International Development, Wellcome Trust, Swiss Development Cooperation, UNICEF, and US National Institutes of Health.The SHINE trial is funded by the Bill & Melinda Gates Foundation (OPP1021542 and OPP113707); UK Department for International Development; Wellcome Trust, UK (093768/Z/10/Z, 108065/Z/15/Z and 203905/Z/16/Z); Swiss Agency for Development and Cooperation; US National Institutes of Health (2R01HD060338-06); and UNICEF (PCA-2017-0002)

    Interior Train Design of Commuter Trains: Standing Seats, and Consideration for Persons with Reduced Mobility

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    Testy bezpieczeństwa typowych stołów wykorzystywanych w pociągach

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    Increasingly, urban and high speed trains are incorporating tables (workstations) as common railway vehicle interior furniture because passengers prefer seating by bay tables. Among table design characteristics, the most challenging is meeting crashworthiness requirements. Past accident data and sled test results have shown that in the event of railway vehicle frontal impact, occupants located in the bay seating are exposed to chest and abdominal injuries upon contact with tables resulting from secondary collision. In some cases tables have tended to be structurally weak; they easily detach from the side walls and/or floor mounting. Subsequently these become unguided missiles that strike occupants, resulting in injuries. This paper presents an analysis of the crash performance of a typical bay table. The results provide some understanding of the table’s crash safety, giving an indication of its impact aggression. Table materials are characterised using quasi-static compressive tests. In addition, experimental dynamic (impact) tests are conducted using a pendulum representing a body block (mass). The results provide information about the possible loading of the table on the occupant in the event of a crash. Contact forces are compared with chest and abdominal injury tolerance thresholds to infer the collision injury potential. Recommendations are then made on design of bay tables to meet the “functional-strength-and-safety balance”.Coraz częściej zarówno w pociągach miejskich, jak i pociągach dużych prędkości wprowadza się do wyposażenia stoły. Wynika to z wymagań pasażerów, którzy to preferują siedzenie przy stołach. Wśród cech konstrukcyjnych stołów, największym wyzwaniem jest spełnienie wymagań wytrzymałości zderzeniowej. Wcześniejsze informacje dotyczące wypadków i wyniki badań wykazały, że w przypadku czołowego zderzenia pojazdów kolejowych pasażerowie, znajdujący się w sąsiedztwie stołów, są narażeni na urazy klatki piersiowej i brzucha na skutek wtórnej kolizji. W niektórych przypadkach stoły miały słabą strukturę; w prosty sposób można je było odłączyć od ścian bocznych i/lub podłogi, do których były przymocowane. W następstwie stawały się one niekontrolowanymi pociskami, które uderzały pasażerów i powodowały ich obrażenia. W artykule przedstawiono analizę wyników wypadku dla typowego stołu. Wyniki dostarczają wiedzę o bezpieczeństwie w razie zaistnienia 98 E. Matsika, Q. Peng wypadku z udziałem stołu, podają informacje o skutkach. Materiały stosowane na stoły zostały zbadane za pomocą quasi-statycznych testów ściskających. Ponadto, przeprowadzono eksperymentalne dynamiczne testy wykorzystujące wahadło. Wyniki dostarczają informacji na temat potencjalnego oddziaływania stołu na pasażera w momencie zderzenia. Siły kontaktowe są porównywalne z progami tolerancji, odpowiadającym klatce piersiowej i jamie brzusznej, w wyniku czego można przewidzieć skutki kolizji. W związku z tym zaleca się wykonanie stołów z zachowaniem „równowagi funkcjonalności, wytrzymałości i bezpieczeństwa”

    Rail Station Boarding Systems for Persons with Reduced Mobility (PRMs)

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