Insights into Long-Lasting Protection Induced by RTS,S/AS02A Malaria Vaccine: Further Results from a Phase IIb Trial in Mozambican Children

Background: The pre-erythrocytic malaria vaccine RTS,S/AS02A has shown to confer protection against clinical malaria for at least 21 months in a trial in Mozambican children. Efficacy varied between different endpoints, such as parasitaemia or clinical malaria; however the underlying mechanisms that determine efficacy and its duration remain unknown. We performed a new, exploratory analysis to explore differences in the duration of protection among participants to better understand the protection afforded by RTS,S. Methodology/Principal Findings: The study was a Phase IIb double-blind, randomized controlled trial in 2022 children aged 1 to 4 years. The trial was designed with two cohorts to estimate vaccine efficacy against two different endpoints: clinical malaria (cohort 1) and infection (cohort 2). Participants were randomly allocated to receive three doses of RTS,S/AS02A or control vaccines. We did a retrospective, unplanned sub-analysis of cohort 2 data using information collected for safety through the health facility-based passive case detection system. Vaccine efficacy against clinical malaria was estimated over the first six-month surveillance period (double-blind phase) and over the following 12 months (single-blind phase), and analysis was per-protocol. Adjusted vaccine efficacy against first clinical malaria episodes in cohort 2 was of 35.4% (95% CI 4.5-56.3; p = 0.029) over the double-blind phase and of 9.0% (230.6-36.6; p = 0.609) during the single-blind phase. Conclusions/Significance: Contrary to observations in cohort 1, where efficacy against clinical malaria did not wane over time, in cohort 2 the efficacy decreases with time. We hypothesize that this reduced duration of protection is a result of the early diagnosis and treatment of infections in cohort 2 participants, preventing sufficient exposure to asexual-stage antigens. On the other hand, the long-term protection against clinical disease observed in cohort 1 may be a consequence of a prolonged exposure to low-dose blood-stage asexual parasitaemia

The limited importance of size-asymmetric light competition and growth of pioneer species in early secondary forest succession in Vietnam

It is generally believed that asymmetric competition for light plays a predominant role in determining the course of succession by increasing size inequalities between plants. Size-related growth is the product of size-related light capture and light-use efficiency (LUE). We have used a canopy model to calculate light capture and photosynthetic rates of pioneer species in sequential vegetation stages of a young secondary forest stand. Growth of the same saplings was followed in time as succession proceeded. Photosynthetic rate per unit plant mass (Pmass: mol C g−1 day−1), a proxy for plant growth, was calculated as the product of light capture efficiency [Φmass: mol photosynthetic photon flux density (PPFD) g−1 day−1] and LUE (mol C mol PPFD−1). Species showed different morphologies and photosynthetic characteristics, but their light-capturing and light-use efficiencies, and thus Pmass, did not differ much. This was also observed in the field: plant growth was not size-asymmetric. The size hierarchy that was present from the very early beginning of succession remained for at least the first 5 years. We conclude, therefore, that in slow-growing regenerating vegetation stands, the importance of asymmetric competition for light and growth can be much less than is often assumed

Rural-to-Urban Labor Migration, Household Livelihoods, and the Rural Environment in Chongqing Municipality, Southwest China

Rural migration and its relationship to the rural environment have attracted increasing research interest in recent decades. Rural migration constitutes a key component of human population movement, while rural areas contain most of the world’s natural resources such as land and forests. This study empirically evaluates a conceptual framework incorporating rural household livelihoods as an integrative mediating factor between rural migration and the rural environment in the context of rural-to-urban labor migration in Chongqing Municipality, Southwest China. The analysis draws on data collected through household surveys and key informant interviews from four villages. Results confirm the hypothesis that labor-migrant and non-labor-migrant households differ significantly in livelihood activities including agricultural production, agricultural technology use, income and consumption, and resource use and management. Implications for the subsequent environmental outcomes of rural labor out-migration and corresponding natural resource management and policy in rural origin areas are discussed

Activity and Habitat Use of Chimpanzees (Pan troglodytes verus) in the Anthropogenic Landscape of Bossou, Guinea, West Africa

Many primate populations inhabit anthropogenic landscapes. Understanding their long-term ability to persist in such environments and associated real and perceived risks for both primates and people is essential for effective conservation planning. Primates in forest–agricultural mosaics often consume cultivars to supplement their diet, leading to potentially negative encounters with farmers. When crossing roads, primates also face the risk of encounters with people and collision with vehicles. Chimpanzees (Pan troglodytes verus) in Bossou, Guinea, West Africa, face such risks regularly. In this study, we aimed to examine their activity budget across habitat types and the influence of anthropogenic risks associated with cultivated fields, roads, and paths on their foraging behavior in noncultivated habitat. We conducted 6-h morning or afternoon follows daily from April 2012 to March 2013. Chimpanzees preferentially used forest habitat types for traveling and resting and highly disturbed habitat types for socializing. Wild fruit and crop availability influenced seasonal habitat use for foraging. Overall, chimpanzees preferred mature forest for all activities. They showed a significant preference for foraging at >200 m from cultivated fields compared to 0–100 m and 101–200 m, with no effect of habitat type or season, suggesting an influence of associated risk. Nevertheless, the chimpanzees did not actively avoid foraging close to roads and paths. Our study reveals chimpanzee reliance on different habitat types and the influence of human-induced pressures on their activities. Such information is critical for the establishment of effective land use management strategies in anthropogenic landscapes

Economic Globalization, Nutrition and Health: a review of quantitative evidence

BACKGROUND: Unhealthy dietary patterns have in recent decades contributed to an endemic-level burden from non-communicable disease (NCDs) in high-income countries. In low- and middle-income countries rapid changes in diets are also increasingly linked to malnutrition in all its forms as persistent undernutrition and micronutrient deficiencies continue to coexist with a rising prevalence of obesity and associated NCDs. Economic globalization and trade liberalization have been identified as potentially important factors driving these trends, but the mechanisms, pathways and actual impact are subject to continued debate. METHODS: We use a ‘rigorous review’ to synthesize evidence from empirical quantitative studies analysing the links between economic globalization processes and nutritional outcomes, with a focus on impact as well as improving the understanding of the main underlying mechanisms and their interactions. FINDINGS: While the literature remains mixed regarding the impacts of overall globalization, trade liberalization or economic globalization on nutritional outcomes, it is possible to identify different patterns of association and impact across specific sub-components of globalization processes. Although results depend on the context and methods of analysis, foreign direct investment (FDI) appears to be more clearly associated with increases in overnutrition and NCD prevalence than to changes in undernutrition. Existing evidence does not clearly show associations between trade liberalization and NCD prevalence, but there is some evidence of a broad association with improved dietary quality and reductions in undernutrition. Socio-cultural aspects of globalization appear to play an important yet under-studied role, with potential associations with increased prevalence of overweight and obesity. The limited evidence available also suggests that the association between trade liberalization or globalization and nutritional outcomes might differ substantially across population sub-groups. Overall, our findings suggest that policymakers do not necessarily face a trade-off when considering the implications of trade or economic liberalization for malnutrition in all its forms. On the contrary, a combination of nutrition-sensitive trade policy and adequate regulation of FDI could help reduce all forms of malnutrition. In the context of trade negotiations and agreements it is fundamental, therefore, to protect the policy space for governments to adopt nutrition-sensitive interventions