18 research outputs found
Vitamin A and zinc supplementation among pregnant women to prevent placental malaria: a randomized, double-blind, placebo-controlled trial in Tanzania
BACKGROUND: Malaria causes nearly 200 million clinical cases and approximately half a million deaths each year, primarily in sub-Saharan Africa.1 The risk of malaria increases during pregnancy,2 a period during which its prevention is especially important. Not only do pregnant women experience greater severity of illness compared with nonpregnant women,2 but studies have shown strong associations between prenatal malaria and maternal anemia,2 fetal loss, low birthweight, and infant mortality.2 Improving preventive
measures that specifically target malaria in pregnancy is a global health priority.3
METHODS: Study design and participants. This randomized, doubleblind, placebo-controlled trial was implemented at 8 antenatal care clinics in the urban Temeke and Ilala districts of Dar es Salaam, Tanzania. The trial was registered
RESULTS: A total of 2,500 screened participants were enrolled in the trial. The trial profile is shown in Figure 1. It was not possible to collect placentas from 875 participants for the following reasons: miscarriages (fetal loss before 28 weeks of gestation) (N = 234), delivery outside of Dar es Salaam or at a non-study hospital (N = 577), or withdrawal from the study (N = 34). Of the remaining 1,589 women, 1,404 placental
samples were obtained (88%); histology results were available for 1,361 participants. PCR results were available for 1,158 participants, and 1,404 participants had either histology or PCR results available.
CONCLUSION: This study is the first to examine the impact of vitamin A and zinc supplementation starting in early pregnancy on placental malaria. We observed that supplementation with 25 mg zinc per day from the first trimester until delivery was associated with a 36% (95% CI = 9–56%) reduced risk of histopathology-positive placental infection, but not PCRpositive infection. Vitamin A supplementation had no impact on placental malaria, but was associated with an increased risk for severe anemia
Integrating control design and real-time computing : a robust control approach
International audienceControl systems running on a computer are subject to timing disturbances coming from implementation constraints. Fortunately closed-loop systems behave robustly w.r.t. modelling errors and disturbances, and the controller design can be performed to explicitly enhance robustness against specific uncertainties. On one hand robustness in process controllers can be used to comply with weakly modelled timing uncertainties. On the other hand, the principle of robust closed-loop control can also be applied to the real-time scheduler to provide on-line adaption of some scheduling parameters, with the objective of controlling the computing resource allocation. As varying sampling appears to be a key actuator to control the computing resource, a varying sampling control design based on LPV gain scheduling design is provided. The feasibility of the approach is assessed through several examples using simulation and real experiments
Longitudinal estimation of Plasmodium falciparum prevalence in relation to malaria prevention measures in six sub-Saharan African countries.
BACKGROUND: Plasmodium falciparum prevalence (PfPR) is a widely used metric for assessing malaria transmission intensity. This study was carried out concurrently with the RTS,S/AS01 candidate malaria vaccine Phase III trial and estimated PfPR over ≤ 4 standardized cross-sectional surveys. METHODS: This epidemiology study (NCT01190202) was conducted in 8 sites from 6 countries (Burkina Faso, Gabon, Ghana, Kenya, Malawi, and Tanzania), between March 2011 and December 2013. Participants were enrolled in a 2:1:1 ratio according to age category: 6 months-4 years, 5-19 years, and ≥ 20 years, respectively, per year and per centre. All sites carried out surveys 1-3 while survey 4 was conducted only in 3 sites. Surveys were usually performed during the peak malaria parasite transmission season, in one home visit, when medical history and malaria risk factors/prevention measures were collected, and a blood sample taken for rapid diagnostic test, microscopy, and haemoglobin measurement. PfPR was estimated by site and age category. RESULTS: Overall, 6401 (survey 1), 6411 (survey 2), 6400 (survey 3), and 2399 (survey 4) individuals were included in the analyses. In the 6 months-4 years age group, the lowest prevalence (assessed using microscopy) was observed in 2 Tanzanian centres (4.6% for Korogwe and 9.95% for Bagamoyo) and Lambaréné, Gabon (6.0%), while the highest PfPR was recorded for Nanoro, Burkina Faso (52.5%). PfPR significantly decreased over the 3 years in Agogo (Ghana), Kombewa (Kenya), Lilongwe (Malawi), and Bagamoyo (Tanzania), and a trend for increased PfPR was observed over the 4 surveys for Kintampo, Ghana. Over the 4 surveys, for all sites, PfPR was predominantly higher in the 5-19 years group than in the other age categories. Occurrence of fever and anaemia was associated with high P. falciparum parasitaemia. Univariate analyses showed a significant association of anti-malarial treatment in 4 surveys (odds ratios [ORs]: 0.52, 0.52, 0.68, 0.41) and bed net use in 2 surveys (ORs: 0.63, 0.68, 1.03, 1.78) with lower risk of malaria infection. CONCLUSION: Local PfPR differed substantially between sites and age groups. In children 6 months-4 years old, a significant decrease in prevalence over the 3 years was observed in 4 out of the 8 study sites. Trial registration Clinical Trials.gov identifier: NCT01190202:NCT. GSK Study ID numbers: 114001
Longitudinal estimation of Plasmodium falciparum prevalence in relation to malaria prevention measures in six sub-Saharan African countries
Integrating control design and real-time computing : a robust control approach
International audienceControl systems running on a computer are subject to timing disturbances coming from implementation constraints. Fortunately closed-loop systems behave robustly w.r.t. modelling errors and disturbances, and the controller design can be performed to explicitly enhance robustness against specific uncertainties. On one hand robustness in process controllers can be used to comply with weakly modelled timing uncertainties. On the other hand, the principle of robust closed-loop control can also be applied to the real-time scheduler to provide on-line adaption of some scheduling parameters, with the objective of controlling the computing resource allocation. As varying sampling appears to be a key actuator to control the computing resource, a varying sampling control design based on LPV gain scheduling design is provided. The feasibility of the approach is assessed through several examples using simulation and real experiments
Crisis group project : governance, reform and Islamism in the Middle East and North Africa; implementation: 1 February 2008 to 31 January 2010 - final technical report
Fieldwork was conducted on a continuous basis by a team of seven analysts based in Beirut, Paris and Jerusalem, as well as deputy program directors based in Washington, DC and Damascus. The team traveled extensively throughout the Middle East and North Africa, including Iraq and the Occupied Territories, conducting hundreds of face-to-face interviews. The report outlines advocacy activities, outputs, outreach and research findings. The Crisis Group publishes reports and generates practical policy recommendations to assist governments, the UN and other international organizations to respond to conflict in the Middle East and North Africa