Different Patterns of HIV Expansion Between High-income and Non-rich Countries and the Potential Drivers during the 1980s

Disease dynamics theory predicts that after the introduction of an infected individual into a susceptible population, the number of infected individuals will grow exponentially until a point at which the depletion of the susceptible class starts to affect the rate of increase of the infectious class. The disease then starts to self-limit its own rate of increase towards an equilibrium with the size of the infectious population. Here, we explored whether the HIV dynamics described exponential growth as theoretically predicted during the 1980s decade for 64 countries.  We focused on the HIV population rate of change per infectious individual ( RHIV ) of the infectious class. We used nonlinear regression between HIV infectious class size and RHIV to determine the dynamic behavior of HIV. The prevalence of HIV increased exponentially in most countries, except for high-income countries. The world during the 1980s could be separated into two groups based on HIV dynamics at the country scale. We performed a multivariate analysis with variables mentioned in the HIV literature to explore the preexisting scenarios that could influence this global separation with regard to HIV dynamics. Poverty levels, malaria burden, the prevalence of men who have sex with men, the prevalence of sex workers, the modes of transmission (HIV subtypes) and the urbanization process could interact to explain the differences among countries with regard to HIV dynamics. The results suggest that during the 1980s, we could divide the world into two groups based on the HIV exponential (non-rich countries) and logistic growth patterns (high-income countries)

MACROINVERTEBRADOS AQUÁTICOS COMO BIOINDICADORES NO PROCESSO DE LICENCIAMENTO AMBIENTAL NO BRASIL

Licenciamento ambiental no Brasil é um procedimento com vários níveis e etapas, concebido como ferramenta preventiva aos potenciais danos ambientais causados pela implantação de empreendimentos. Embora este procedimento seja obrigatório desde meados da década de 1980, ainda é limitado no que diz respeito ao uso de informações biológicas para a avaliação e o monitoramento de ambientes aquáticos. Neste processo, o órgão licenciador (federal, estadual ou municipal) define as variáveis a serem medidas, tendo como referência o tipo e a magnitude do empreendimento e as características específicas do local proposto para sua instalação. Respostas biológicas devem ser usadas para medir os impactos sobre ecossistemas aquáticos e os macroinvertebrados constituem um grupo que apresenta vantagens como bioindicadores, sendo os mais utilizados para este fim. Em 2011, o Grupo de Trabalho Intersetorial em Biomonitoramento foi criado para discutir o uso de macroinvertebrados em programas de monitoramento. Este trabalho apresenta as reflexões e propostas deste grupo e fornece subsídios para a inclusão destes organismos nos termos de referência a serem aplicados nos processos de licenciamento ambiental no Brasil

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.

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)

Porque o mundo é verde, o mar azul e a cadeia trófica de pequenos rios tropicais baseia-se em microalgas crípticas?

PORQUE O MUNDO É VERDE, O MAR AZUL E A CADEIA TRÓFICA DE PEQUENOS RIOS TROPICAIS BASEIA-SE EM MICROALGAS CRÍPTICAS? A questão �Porque o mundo é verde?� tem sido debatida e pesquisada desde a publicação seminal de Hairston et al.(1960). Três principais hipóteses foram levantadas para explicar porque uma grande parte da biomassa de plantas terrestres não é comida por herbívoros: (1) predadores controlam herbívoros (especialmente folívoros), (2) defesas das plantas inibem herbívoros e tornam a biomassa relativamente não disponível e, (3) diferentes controles operam em regiões com produtividades diferentes.Sistemas aquáticos, especialmente os de plâncton, tendem a ter muito menos biomassa de plantas que sistemas terrestres e, geralmente, uma porção bem maior da biomassa viva é consumida por herbívoros.Daí sistemas de águas abertas parecerem azul ou verde transparente. Tais sistemas muitas vezes mostram relações em cascata nas quais as mudanças em um nível trófico têm efeitos em dois ou mais níveis abaixo. A regra geral em pequenos rios sombreados de floresta é que recebam muita matéria orgânica proveniente da floresta ao redor, e isto fornece a fonte principal de energia e material para a rede trófica. Pesquisas recentes em pequenos rios tropicais mostram que microalgas fornecem uma parte maior da fonte primária do que a matéria alóctone.Isto pode ser um fenômeno especificamente tropical, ou talvez uma tendência, mais acentuada nos trópicos.Experimentos de exclusão mostram cascatas tróficas e interações fortes entre fauna (especialmente camarões) e substrato alóctone.Mas as interações funcionais (e.g., rasgar serapilheira, remover matéria bêntica) não são tróficas � os animais são herbívoros ou predadores de herbívoros baseados em microalgas. Podemos especular que o desperdício aparente de matéria alóctone se deva em parte aos custos inerentes que o detritívoro teria que arcar por processar uma fonte menos tratável e menos nutritiva (serapilheira) em condições de predação e competição maiores, que possivelmente são mais exigentes nos trópicos. Palavras chaves: Rede trófica, Controle de herbívoro, Defesa de planta, Isótopos estáveis, Ecossistema de córrego

Reviewing carbon spiraling approach to understand organic matter movement and transformation in lotic ecosystems

Abstract: Aim Understanding riverine carbon cycling is a major issue for stream ecologists. Over the past 60 years, important advance in carbon dynamics and ecosystem energy flow have been made mainly through the Budget and Metabolism approaches. However, much less focus has been given to the quantification of longitudinal movement of organic matter. The concept “Organic Carbon Spiraling” (SOC) was formulated in the early 80s, and represented a substantial advance in the understanding of the longitudinal flow of elements in lotic systems. Methods In this review, we summarize the history behind the SOC concept, cover the major advances at the time of its creation, describe the operational variables and the equation for SOC calculation, and discuss future directions and current applications of this approach. Results/Conclusions We emphasize the need for integrating the C spiraling approach in other regions of the globe, given that measurements are almost exclusive of North America. Such comparative studies can elucidate important drivers of C export, storage and oxidation. Advance in dissolved organic carbon characterization, and improvements in heterotrophic respiration measurements are required to improve SOC accuracy, as well as realistic estimates of benthic stock. With the current interest in examining how lotic systems contribute to regional and global C budgets, we argue that SOC is an effective way to achieve this goal and answer classical questions in stream ecology

Baseline Body Mass Index Does Not Significantly Affect Outcomes After Pulmonary Thromboendarterectomy

BACKGROUND: Obesity is a common comorbidity of patients with chronic thromboembolic pulmonary hypertension referred for pulmonary thromboendarterectomy, yet the effect of obesity on pulmonary thromboendarterectomy outcomes has not been well described. METHODS: We conducted a retrospective cohort study in which 476 consecutive surgeries over a 3.5 year period were examined to determine the effects of obesity on outcomes. Patients were grouped into four categories based on bass mass index (BMI <22 kg/m(2), BMI 22-30 kg/m(2), 30-40 kg/m(2), and BMI >40 kg/m(2)). RESULTS: There were important differences in baseline pulmonary hemodynamics with obese patients having significantly lower pulmonary vascular resistances than non-obese patients. All patients achieved a significant reduction in PVR, though the improvement was greatest in the lower BMI groups. The overall in-hospital mortality was 0.8% and there were no differences in risk among BMI groups. Among the BMI groups, there were no differences in incidence of postoperative complications including atrial fibrillation (overall 24.8%), reperfusion lung injury (overall 23.1%), and surgical site infection (overall 4.4%) or median lengths of stay (including ventilator days, ICU days, and postoperative length of stay). CONCLUSIONS: Pulmonary thromboendarterectomy outcomes have continued to improve and this surgery can safely be completed in obese patients, previously deemed to be at high risk for poor outcomes