154 research outputs found
Sweet potato development and delivery in sub-Saharan Africa
n sub-Saharan Africa, more than 40% of children under five years of age suffer from vitamin A deficiency. Among several interventions in place to address vitamin A deficiency is biofortification, breeding vitamin A into key staple crops. Staple crops biofortified with beta-carotene, the precursor to vitamin A, are orange in color. Given the natural occurrence of high levels of beta-carotene in many sweet potato varieties, breeding progress for biofortified orange sweet potato (OSP) has been much faster than for the other vitamin A enhanced staples. Nearly 3 million households have been reached with OSP. This paper reviews key factors influencing the uptake of OSP, the breeding investment, five key delivery approaches that have been tested in the region and efforts to broaden government and other stakeholder engagement
Origin and putative colonization routes for invasive rodent taxa in the democratic Republic of Congo
The threat posed by biological invasions is well established. An important consideration in preventing the spread of invasives and also subsequent introductions lies in understanding introduction pathways. The Democratic Republic of the Congo (DRC) houses a large percentage of the world's biodiversity, yet no national strategy exists to deal with the growing number of invasive alien species. Amongst these are the house mouse and ship and Norwegian rats. By comparing our result to published data, we show that species were possibly introduced into the DRC via two routes. The first is via the western seaport at Kinshasa where specimens of M. m. domesticus and R. rattus on the western and northwestern side of the DRC show ties with European haplotypes. The second is via the east where specimens of R. rattus appear linked to Arab and southeast Asian haplotypes. Future work should consider more comprehensive sampling throughout the DRC to more accurately investigate the occurrence of invasive species throughout the country as well as extend sampling to other African countries
Everything you ever wanted to know about sweetpotato: Reaching agents of change ToT manual. 3: Sweetpotato seed systems.
Community knowledge, attitude and practice towards Sexually Transmitted Diseases and HIV infection in Biharamulo and Muleba districts in Kagera Region, Tanzania
Abstract: The study was conducted to determine knowledge, attitude and practice towards Sexually Transmitted Diseases and HIV infections among communities in Biharamulo and Muleba districts, Kagera Tanzania. A total of 915 study participants were recruited and most of them (96.3%) knew that there are diseases which could be transmitted through sexual contact. Seventy one percent of participants thought STDs could be acquired through sharing a towel while fifty percent thought HIV could be transmitted through insect bites. Eighty five percent of school pupils who participated in the study reported to have been taught about AIDS and less than 30% on sex and pregnancy. Sixty three percent of study participants were of the opinion that a girl or woman should not refuse to have sex after being given a gift, and having sex with an elder partner was thought to be acceptable by almost fifty percent of participants. Over 50% percent of interviewees thought a girl or woman should not refuse to have sex with their friends. Although 99% of interviewees reported to have ever heard about condoms, only 28% reported to have ever used them irrespective of been affordable. Most schoolboys and about 50% of schoolgirls reported to have experienced sex by the time of the study. Thirty eight percent of girls reported to have first sex at the age of 14 years. Nine percent of the participants who reported to have experienced sex were forced to do so. Knowledge regarding STDs and HIV/AIDS was high among participants, but a sizeable proportion report misconception on transmission of STDs/HIV such as through sharing a towel and insect bites. Therefore it is recommended that S&RH intervention programme should address these misconceptions in order to match knowledge and practice, and achieve the intended objectives
Cluster-randomized non-inferiority trial to compare supplement consumption and adherence to different dosing regimens for antenatal calcium and iron-folic acid supplementation to prevent preeclampsia and anaemia: rationale and design of the Micronutrient Initiative study
Background: To prevent pre-eclampsia in populations with insufficient dietary calcium (Ca) intake, the World Health Organisation (WHO) recommends routine Ca supplementation during antenatal care (ANC). WHO guidelines suggest a complex dosing regimen, requiring as many as 5 pill-taking events per day when combined with iron and folic acid (IFA) supplements. Poor adherence may undermine public health effectiveness, so simpler regimens may be preferable. This trial will compare the effect of the WHO-recommended (higher-dose) regimen vs. a simpler, lower-dose regimen on supplement consumption and pill-taking behaviours in Kenyan ANC clients. Design and methods: This is a parallel, non-inferiority, cluster-randomized trial; we examined 16 primary care health facilities in Kenya, 1047 pregnant women between 16-30 weeks gestational age. Higher-dose regimen: 1.5 g elemental calcium in 3 separate doses (500 mg Ca/pill) and IFA (60 mg Fe + 400 μg folic acid) taken with evening dose. Lower-dose regimen: 1.0 g calcium in 2 separate doses (500 mg Ca/pill) with IFA taken as above. Measurements: Primary outcome is Ca pills consumed per day, measured by pill counts. Secondary outcomes include IFA pills consumed per day, client knowledge, motivation, social support, and satisfaction, measured at 4 to 10 weeks post-enrolment. Statistical analyses: Unit of randomization is the health-care facility; unit of analysis is individual client. Intent-to-treat analysis will be implemented with multi-level models to account for clustering. Expected public health impact: If pregnant women prescribed lower doses of Ca ingest as many pills as women prescribed the WHO-recommended regimen, developing a lower-dose recommendation for antenatal Ca and IFA supplementation programs could save resources
Diagnosing Severe Falciparum Malaria in Parasitaemic African Children: A Prospective Evaluation of Plasma PfHRP2 Measurement.
In African children, distinguishing severe falciparum malaria from other severe febrile illnesses with coincidental Plasmodium falciparum parasitaemia is a major challenge. P. falciparum histidine-rich protein 2 (PfHRP2) is released by mature sequestered parasites and can be used to estimate the total parasite burden. We investigated the prognostic significance of plasma PfHRP2 and used it to estimate the malaria-attributable fraction in African children diagnosed with severe malaria. Admission plasma PfHRP2 was measured prospectively in African children (from Mozambique, The Gambia, Kenya, Tanzania, Uganda, Rwanda, and the Democratic Republic of the Congo) aged 1 month to 15 years with severe febrile illness and a positive P. falciparum lactate dehydrogenase (pLDH)-based rapid test in a clinical trial comparing parenteral artesunate versus quinine (the AQUAMAT trial, ISRCTN 50258054). In 3,826 severely ill children, Plasmadium falciparum PfHRP2 was higher in patients with coma (p = 0.0209), acidosis (p<0.0001), and severe anaemia (p<0.0001). Admission geometric mean (95%CI) plasma PfHRP2 was 1,611 (1,350-1,922) ng/mL in fatal cases (n = 381) versus 1,046 (991-1,104) ng/mL in survivors (n = 3,445, p<0.0001), without differences in parasitaemia as assessed by microscopy. There was a U-shaped association between log(10) plasma PfHRP2 and risk of death. Mortality increased 20% per log(10) increase in PfHRP2 above 174 ng/mL (adjusted odds ratio [AOR] 1.21, 95%CI 1.05-1.39, p = 0.009). A mechanistic model assuming a PfHRP2-independent risk of death in non-malaria illness closely fitted the observed data and showed malaria-attributable mortality less than 50% with plasma PfHRP2≤174 ng/mL. The odds ratio (OR) for death in artesunate versus quinine-treated patients was 0.61 (95%CI 0.44-0.83, p = 0.0018) in the highest PfHRP2 tertile, whereas there was no difference in the lowest tertile (OR 1.05; 95%CI 0.69-1.61; p = 0.82). A limitation of the study is that some conclusions are drawn from a mechanistic model, which is inherently dependent on certain assumptions. However, a sensitivity analysis of the model indicated that the results were robust to a plausible range of parameter estimates. Further studies are needed to validate our findings. Plasma PfHRP2 has prognostic significance in African children with severe falciparum malaria and provides a tool to stratify the risk of "true" severe malaria-attributable disease as opposed to other severe illnesses in parasitaemic African children
Elimination of Schistosomiasis Transmission in Zanzibar: Baseline Findings before the Onset of a Randomized Intervention Trial.
Gaining and sustaining control of schistosomiasis and, whenever feasible, achieving local elimination are the year 2020 targets set by the World Health Organization. In Zanzibar, various institutions and stakeholders have joined forces to eliminate urogenital schistosomiasis within 5 years. We report baseline findings before the onset of a randomized intervention trial designed to assess the differential impact of community-based praziquantel administration, snail control, and behavior change interventions. In early 2012, a baseline parasitological survey was conducted in ∼20,000 people from 90 communities in Unguja and Pemba. Risk factors for schistosomiasis were assessed by administering a questionnaire to adults. In selected communities, local knowledge about schistosomiasis transmission and prevention was determined in focus group discussions and in-depths interviews. Intermediate host snails were collected and examined for shedding of cercariae. The baseline Schistosoma haematobium prevalence in school children and adults was 4.3% (range: 0-19.7%) and 2.7% (range: 0-26.5%) in Unguja, and 8.9% (range: 0-31.8%) and 5.5% (range: 0-23.4%) in Pemba, respectively. Heavy infections were detected in 15.1% and 35.6% of the positive school children in Unguja and Pemba, respectively. Males were at higher risk than females (odds ratio (OR): 1.45; 95% confidence interval (CI): 1.03-2.03). Decreasing adult age (OR: 1.04; CI: 1.02-1.06), being born in Pemba (OR: 1.48; CI: 1.02-2.13) or Tanzania (OR: 2.36; CI: 1.16-4.78), and use of freshwater (OR: 2.15; CI: 1.53-3.03) showed higher odds of infection. Community knowledge about schistosomiasis was low. Only few infected Bulinus snails were found. The relatively low S. haematobium prevalence in Zanzibar is a promising starting point for elimination. However, there is a need to improve community knowledge about disease transmission and prevention. Control measures tailored to the local context, placing particular attention to hot-spot areas, high-risk groups, and individuals, will be necessary if elimination is to be achieved
Chapter 4: Water
This chapter assesses observed and projected climate-induced changes in the water cycle, their current impacts and future risks on human and natural systems and the benefits and effectiveness of water-related adaptation efforts now and in the future
EVALUATION OF BIOSSAYS FOR TESTING Bt SWEETPOTATO EVENTS AGAINST SWEETPOTATO WEEVILS
Sweetpotato weevil ( Cylas puncticollis ) Boheman is a serious pest
throughout Sub-Saharan Africa region and is a big threat to sweetpotato
cultivation. Ten transgenic sweetpotato events expressing Cry7Aa1,
Cry3Ca1, and ET33-34 proteins from Bacillus thuringiensis (Bt) were
evaluated for resistance against C. puncticollis. Four bioassays used
were: (i) 1st instar larva in an artificial diet using root powder of
transgenic events, (ii) whole root of transgenic events infested with
female adults, (iii) root chip, and (iv) small root of transgenic
events both infested with egg-plugs. DAS-ELISA analysis showed
variation in Cry protein concentration among the events that ranged
between 0.1 and 0.394 \ub5g g-1 of root fresh weight. The highest
protein quantity was observed in the event carrying the ET33-34
transcript. In general, transgenic events had no significant effect on
larval survival (P = 0.28) and pupal (P = 0.86) development, though
maximum pupation of 96% was observed on event CIP410009.12 that had
very low expression levels of cry3Ca1 gene. Root chips were prone to
damage by fungi and desiccation especially during the first larval
instar. The whole root bioassay had less handling injuries to weevils
compared with other methods. However, it requires a large number of
adult females for oviposition and roots per event to be tested to
obtain efficacy results with statistical rigour. The small root egg
plug bioassay required much fewer roots and experimental insects to
assess larval mortality and development. The root chip method was the
least desirable because of susceptibility to fungal and bacterial
contamination. In addition, this method was the most labour intensive
in terms of frequent replacement of root chips for weevil development.
Hence, the most appropriate method for testing Bt efficacy in
sweetpotato is the small root egg-plug bioassay. Nonetheless, none of
the transgenic events tested provided weevil control probably because
of low Cry protein expression in storage roots.La charan\ue7on de la patate douce ( Cylas puncticollis ) Boheman
constitue une importante peste \ue0 travers la r\ue9gion
d\u2019Afrique sub-saharienne et une grande contrainte \ue0 la
production de la culture. Dix patate douce transg\ue9niques
d\u2019\ue9v\ue9n\ue9ments exprimant les prot\ue9ines Cry7Aa1,
Cry3Ca1, et ET33-34 des Bacillus thuringiensis (Bt) \ue9taient
\ue9valu\ue9es pour r\ue9sistance contre C. puncticollis. Quatre
bioassais utilis\ue9s \ue9taient: (i) une larve de premier instar
dans une alimentation artificielle utilisant une poudre racinaire
d\u2019\ue9v\ue9nement transg\ue9nique, (ii) racine entire
d\u2019\ue9v\ue9nement transg\ue9niques infest\ue9s avec
adultes femelles, (iii) un morceau racinaire, et (iv) petite racine
d\u2019\ue9v\ue9nements transg\ue9niques tous infest\ue9s avec
des oeufs. L\u2019analyse DAS-ELISA a montr\ue9 une variation dans
la concentration en protein Cry parmi les \ue9v\ue9nements variant
de 0.1 \ue0 0.394 \ub5g g-1 de poids de raciness fra\ueeches. La
quqntit\ue9 la plus \ue9lev\ue9e de prot\ue9ines \ue9tait
observ\ue9e dans l\u2019\ue9v\ue9nement portant le relev\ue9
ET33-34. En g\ue9n\ue9ral, les \ue9v\ue9nements
transg\ue9niques n\u2019avaient aucun effet significatif sur la
survie de larves (P = 0.28) et le d\ue9veloppement de la nimphe (P =
0.86), bien que la pupation maximale de 96% \ue9tait observ\ue9e
sur l\u2019\ue9v\ue9nement CIP410009.12 qui avait un tr\ue8s bas
niveau d\u2019expression du g\ue8ne cry3Ca1. Les morceaux de
raciness \ue9taient susceptibles d\u2019\ueatre endommag\ue9s
par les champignons et la dessication sp\ue9cialement durant le
premier instar larvaire. La racine enti\ue8re bioassay \ue9tait
moins affct\ue9e par la charan\ue7on et avait moins de blessures en
comparaison \ue0 d\u2019autres m\ue9thodes. Par ailleurs, il
n\ue9cessite un grand nombre d\u2019adultes femelles pour
l\u2019oviposition et raciness par \ue9v\ue9nement devrant
\ueatre test\ue9s pour obtenir des r\ue9sultats efficaces avec
rigueur statistique. Le bioassai de petits oeufs racinaires ongt
n\ue9cessit\ue9 un peu moins de raciness et insectes
exp\ue9rimentaux pour \ue9valuer la mortalit\ue9 larvaire et leur
d\ue9veloppement. La m\ue9thode de morceaux racinaires \ue9tait
la moins desirable \ue0 cause de la contamination fongique et
bact\ue9rienne. En plus, cette m\ue9thode exigeait plus de travail
intensif en terme remplacement fr\ue9quent de morceaux de racines
pour le d\ue9veloppement de charan\ue7on. Ainsi, la m\ue9thode la
plus appropri\ue9e pour tester l\u2019efficacit\ue9 du Bt dans la
patate douce est le bioassai de petis oeufs racinaires. N\ue9amoins,
aucun des \ue9v\ue9nements transg\ue9niques test\ue9s n\u2019a
fourni un control probable de la charan\ue7on suite \ue0 une basse
expression de la protein Cry dans les raciness de stockage
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