Why NERICA is a successful innovation for African farmers

This paper responds to ‘Funding international agricultural research and the need to be noticed: a case study of NERICA rice’ by Stuart Orr, James Sumberg, Olaf Erenstein and Andreas Oswald, published in this issue of Outlook on Agriculture. In summary, the article by Orr et al, based on an internal WARDA document written in November 2003 and augmented with results from Internet searches, is outdated and does not seem to be fair, objective or useful. We invite the authors to visit WARDA or any of its partners in Sub-Saharan Africa for evidence of the impact of NERICA varieties or the other improved varieties and technologies that have been developed and disseminated by WARDA in recent years

Malaria Risk Factors in Dielmo, A Senegalese Malaria-Endemic Village, Between October and November of 2013: A Case-Control Study

International audienceThe incidence of malaria has decreased recently in parts of Africa, coinciding with the widespread use of long-lasting insecticide-treated nets (LLINs) and artemisinin-based combination therapy (ACT). This reduction was also observed in Dielmo, our study area, and it was associated with the use of ACT as the first-line treatment against malaria beginning in 2006 and the implementation of LLINs in 2008. However, an unexplained slight increase in malaria incidence was observed in October and November of 2013. The aim of this study was to identify individual and environmental risk factors for malaria using a case-control study approach. Thirty cases and sixty controls were investigated. The use of LLINs was protective against malaria (adjusted odds ratio [AOR] = 0.10; 95% confidence interval [95% CI] = 0.02–0.45; P = 0.003). The risk of malaria transmission was high among villagers who watched television outside the house or the bedroom during the night (AOR = 8.83; 95% CI = 1.39–56.22; P = 0.021). The use of LLINs should be reinforced by the use of individual protection measures to avoid malaria transmission outside of the home. BACKGROUN

Heart of endosymbioses : transcriptomics reveals a conserved genetic program among arbuscular mycorrhizal, actinorhizal and legume-rhizobial symbioses

To improve their nutrition, most plants associate with soil microorganisms, particularly fungi, to form mycorrhizae. A few lineages, including actinorhizal plants and legumes are also able to interact with nitrogen-fixing bacteria hosted intracellularly inside root nodules. Fossil and molecular data suggest that the molecular mechanisms involved in these root nodule symbioses (RNS) have been partially recycled from more ancient and widespread arbuscular mycorrhizal (AM) symbiosis. We used a comparative transcriptomics approach to identify genes involved in establishing these 3 endosymbioses and their functioning. We analysed global changes in gene expression in AM in the actinorhizal tree C. glauca. A comparison with genes induced in AM in Medicago truncatula and Oryza sativa revealed a common set of genes induced in AM. A comparison with genes induced in nitrogen-fixing nodules of C. glauca and M. truncatula also made it possible to define a common set of genes induced in these three endosymbioses. The existence of this core set of genes is in accordance with the proposed recycling of ancient AM genes for new functions related to nodulation in legumes and actinorhizal plants

Aménagements hydro-agricoles et santé (vallée du fleuve Sénégal)

La transmission du paludisme dans le delta du fleuve Sénégal a été étudiée dans trois villages, deux villages de riziculture irriguée dont un d'aménagement récent et un village de culture pluviale traditionnelle. La riziculture irriguée a entraîné une pullulation de moustiques et principalement d'#Anopheles pharoensis. La densité de ses populations est très importante et liée aux cycles des cultures dans la zone rizicole, son indice d'anthropophilie est élevé mais la longévité des femelles est très faible. #An. gambiae s.l. vecteur majeur du paludisme au Sénégal est, dans le delta, remplacé par #An. pharoensis$, vecteur secondaire dont l'aptitude à assurer une bonne transmission n'est pas prouvée. La riziculture irriguée n'a pas entraîné une augmentation de la transmission du paludisme. (Résumé d'auteur

No Difference in the Incidence of Malaria in Human-Landing Mosquito Catch Collectors and Non-Collectors in a Senegalese Village with Endemic Malaria

International audienceBackground The human landing catches is the gold standard method used to study the vectors of malaria and to estimate their aggressiveness. However, this method has raised safety concerns due to a possible increased risk of malaria or other mosquito-borne diseases among the mosquito collectors. The aim of this study was to evaluate the incidence of malaria attacks among mosquito collectors and to compare these results with those of non-collectors in a Senegalese village. Methods From July 1990 to December 2011, a longitudinal malaria study involving mosquito collectors and non-collectors was performed in Dielmo village, Senegal. During the study period, 4 drugs were successively used to treat clinical malaria, and long-lasting insecticide-treated nets were offered to all villagers in July 2008. No malaria chemoprophylaxis was given to mosquito collectors. Incidence of uncomplicated clinical malaria and asymptomatic malaria infection were analyzed among these two groups while controlling for confounding factors associated with malaria risk in random effects negative binomial and logistic regression models, respectively. Results A total of 3,812 person-trimester observations of 199 adults at least 15 years of age were analyzed. Clinical malaria attacks accounted for 6.3% both in collectors and non-collectors, and asymptomatic malaria infections accounted for 21% and 20% in collectors and non-collectors, respectively. A non-significant lower risk of malaria was observed in the collector group in comparison with the non-collector group after adjusting for other risk factors of malaria and endemicity level (Clinical malaria: adjusted incidence rate ratio = 0.89; 95% confidence interval = 0.65-1.22; p= 0.47). Conclusion Being a mosquito collector in Dielmo was not significantly associated with an increased risk of malaria both under holoendemic, mesoendemic and hypoendemic conditions of malaria epidemiology. This result supports the view that HLC, the most accurate method for evaluating malaria transmission, may be used without health concerns in Dielmo

Adult Phyllophaga ephilida host plant feeding preference

Limited biological information about Phyllophaga ephilida, a major sweet potato pest in Louisiana, is available. In 2001 and 2002, a study was conducted in the laboratory to investigate the feeding preference of adult Phyllophaga ephilida (Say) (Coleoptera: Scarabaeidae) for the foliage of eight woody plant species: water oak (Quercus nigra L.), live oak (Quercus virginiana Mill.), red maple (Acer rubrum L.), slash pine (Pinus caribaea Morelet), pecan (Carya illinoensis (Wangenh) K. Koch), sweetgum (Liquidambar styraciflua L.), southern magnolia (Magnolia grandiflora L.), and American elm (Ulmus americana L.). Beetles were placed in an arena with the eight host plants and allowed to feed for 24 h (choice test). Leaf area consumed and change in leaf weight were recorded. In 2001 and 2002, host plant had a significant effect on both leaf area and weight consumed. In 2001, mean leaf area (mm2) consumed was pecan (504), followed by elm (314), water oak (237), maple (176), live oak (38.0), and sweetgum (4.00). Southern magnolia and slash pine were not consumed. In 2002, mean leaf area (mm2) consumed was pecan (628), followed by elm (390), water oak (204), maple (75.0), and live oak (30.0). Southern magnolia, sweetgum, and slash pine were not consumed. In 2001, mean leaf consumption (mg) was pecan (8.400), water oak (3.700), maple (3.500), live oak (1.300), elm (0.300), and sweetgum (0.060). Southern magnolia and slash pine were not consumed. In 2002, mean leaf consumption (mg) was pecan (10.00), elm (4.200), water oak (3.200), maple (1.500), and live oak (1.000). Southern magnolia, sweetgum, and slash pine were not consumed. Phyllophaga ephilida exhibited a preference for pecan, oak, and elm. They avoided slash pine and southern magnolia

Postpartum maternal morbidity requiring hospital admission in Lusaka, Zambia – a descriptive study

Background: Information on the extent of postpartum maternal morbidity in developing countries is extremely limited. In many settings, data from hospital-based studies is hard to interpret because of the small proportion of women that have access to medical care. However, in those areas with good uptake of health care, the measurement of the type and incidence of complications severe enough to require hospitalisation may provide useful baseline information on the acute and severe morbidity that women experience in the early weeks following childbirth. An analysis of health services data from Lusaka, Zambia, is presented. Methods: Six-month retrospective review of hospital registers and 4-week cross-sectional study with prospective identification of postpartum admissions. Results: Both parts of the study identified puerperal sepsis and malaria as, respectively, the leading direct and indirect causes of postpartum morbidity requiring hospital admission. Puerperal sepsis accounted for 34.8% of 365 postpartum admissions in the 6-month period. Malaria and pneumonia together accounted for one-fifth of all postpartum admissions (14.5% & 6% respectively). At least 1.7% of the postpartum population in Lusaka will require hospital-level care for a maternal morbidity. Conclusions: In developing country urban settings with high public health care usage, meticulous review of hospital registers can provide baseline information on the burden of moderate-to-severe postpartum morbidity. © 2005 Vallely et al; licensee BioMed Central Ltd

Are the “100 of the world’s worst” invasive species also the costliest?

Biological invasions are increasing worldwide, damaging ecosystems and socioeconomic sectors. Two decades ago, the “100 of the world’s worst” invasive alien species list was established by the IUCN to improve communications , identifying particularly damaging ‘flagship’ invaders globally (hereafter, worst). Whilst this list has bolstered invader awareness, whether worst species are especially economically damaging and how they compare to other invaders (hereafter, other) remain unknown. Here, we quantify invasion costs using the most comprehensive global database compiling them (InvaCost). We compare these costs between worst and other species against sectorial, taxonomic and regional descriptors, and examine temporal cost trends. Only 60 of the 100 worst species had invasion costs considered as highly reliable and actually observed estimates (median: US$43 million). On average, these costs were significantly higher than the 463 other invasive species recorded in InvaCost (median: US$ 0.53 million), although some other species had higher costs than most worst species. Damages to the environment from the worst species dominated, whereas other species largely impacted agriculture. Disproportionately highest worst species costs were incurred in North America, whilst costs were more evenly distributed for other species; animal invasions were always costliest. Proportional management expenditures were low for the other species, and surprisingly, over twice as low for the worst species. Temporally, costs increased more for the worst than other taxa; however, management spending has remained very low for both groups. Nonetheless, since 40 species had no robust and/or reported costs, the “true” cost of “some of the world’s worst” 100 invasive species still remains unknown