Etude de quelques facteurs influençant la biologie et le comportement de Bruchidius atrolineatus Pic. (Coleoptera-Bruchinae), ravageur du niébe(VIGNA UNGUICULATA (L.) Walp en zone sahelienne

Bruchidius atrolineatus Pic. est le principal ravageur du niébé en culture et en début de stockage. Au cours de cette étude, certains facteurs susceptibles d’influencer sa biologie, son développement et son comportement dans les cultures de niébé ont été étudiés. Pour ce faire, l’influence de l’alimentation des adultes de cet insecte à base de fleurs de trois espèces végétales, à savoir Balanites aegyptiaca, Neocarya macrophylla, Acacia seyal et Bauhinia rufescens sur sa durée de vie d’une part et, d’autre part, les paramètres biologiques et la capacité de discrimination de l’insecte en présence de trois variétés de niébé (une variété locale, KVX et HTR) ont été étudiés. Pour tous les paramètres étudiés, l’expérience est réalisée avec des insectes âgés d’au plus 24 h. L’analyse des résultats obtenus montre que la durée de vie est prolongée de 02 à 08 jours lorsque les insectes sont nourris comparativement au témoin négatif. Pour le témoin positif qui a consisté à nourrir les insectes d’eau saccharosée, la durée de survie est de 35 jours. Par ailleurs, l’activité de ponte de B. atrolineatus est relativement influencée par la taille des graines de la variété. En effet, les résultats révèlent que plus la taille de la graine est importante plus le nombre d’oeufs déposés est élevé. Le taux de survie larvaire et le taux d’émergence des adultes sont plus faibles sur les graines des variétés améliorées que sur celle de la variété locale. Ainsi, les facteurs comme l’alimentation au dépend des fleurs et les variétés de niébé utilisées influencent la biologie, le développement et le comportement de B. atrolineatus.Mots clé : Bruchidius atrolineatus, niébé, paramètres biologiques, alimentation , capacité de discrimination.English AbstractStudy of some factors influencing the biology and behavior of  Buchidius atrolineatus pic.(Coleoptera-bruchinae), pest of cowpea (Vigna unguiculata (l.) Walp in the Sahelian zoneBruchidius atrolineatus Pic. is the main pest of Cowpea in field and beginning of storage. Some factors that may influence its biology, its development and its behavior in Cowpea field were studied. So the influence of the diet of this species based on flower on its life duration on one hand and, on the other hand, the biological parameters and discrimination ability of the insect in the presence of three cowpea varieties have been studied. The analysis of the results obtained shows that the life duration is extended from 02 to 08 days when the insects are fed compared to the negative control. For the positive control fed on water saccharosee, the survival time is 35 days. Otherwise, the ovipositor activity of B. atrolineatus is relatively influenced by the size of the seeds of the variety. Indeed, the results show that more the size of the seeds is important more the number of eggs laid is high. Larval survival and adult emergence rate are lower on the seeds of  improved varieties than on the local variety. Factors like flowers and varieties influence biology, development and behaviour of B. atrolineatus.Keywords : Bruchidius atrolineatus, cowpea, biological parameters, power; capacity of discriminat

Toxicity and persistence of Boscia senegalensis Lam. (Ex Poir.) (Capparaceae) leaves on Callosobruchus maculatus Fab. (Coleoptera:Bruchidae)

In this study, we examined the toxicity and persistence of ground fresh leaves of B. senegalensis on the development of Callosobruchus maculatus, major insect pest of cowpea (V. unguiculata) in the sahelian area. The effect of the product has been evaluated over the three developmental stages (egg, larvae and adult) of C. maculatus. At high concentration (4 g/l of ground leaves), 100 % of adults were killed within 24 h of exposure to the leaf extract, and the development of newly laid eggs and neonate larvae was also inhibited. However, the ground leaves of B. senegalensis have a variable efficacy against the bruchid instars larva. The 2nd larvae stage (L2) of C. maculatus developing inside the seeds have proved to be highly susceptible while the 4th larval stage was relatively tolerant. The study of the toxicity persistence of the leaves of B. senegalensis showed that whatever its concentration, the efficacy of crushed leaves of B. senegalensis decreased with the storage time. At a concentration of 20 g/l, the effect of B. seneglensis can persist up to 7 days.Keywords: Biopesticides, Bruchids, cowpea, pest control, Nige

AMMA dust experiment : an overview of measurements performed during the dry season special observation period (SOP0) at the Banizoumbou (Niger) supersite - art. no. D00C14

International audienceIn the frame of the African Monsoon Multidisciplinary Analysis-Special Observation Period 0 (AMMA SOP0) field campaign, a sophisticated instrumental setup specially designed for documenting the characteristics of aerosols in the surface boundary layer has been operated for 1 month (13 January to 13 February 2006) at the Banizoumbou supersite in Niger. The analysis of the long-term routine sunphotometer measurements shows that the intensive measurements were performed during a transition phase between a period when biomass burning aerosols are present in the atmospheric column and another when mineral dust is clearly predominant. On the basis of ground-level observations, three types of events can be defined. (1) Type B events are those corresponding to advection of Biomass burning plumes from southern Sahel. They represent only 3% of the measurement period. (2) Type D events are those during which mineral dust concentrations are larger than 200 mu g m(-3). They represent 35% of the measuring time, and coincide with advection of mineral dust from distant sources to the measurement site. The composition of the dust differs significantly from one episode to the other, depending on the trajectory of air mass that transported it. (3) Type L events are those that can be explained by occurrence of local erosion and that are of short duration. During them, the aerosol size distribution is dominated by a coarser mode (9 mu m) than during the events of the D type dominated by a finer mode (4.5 mu m). Elemental analysis also shows that mineral dust is relatively rich in Fe and poor in Ca, which is typical of the Sahelian aerosols

Gender and neglected tropical disease front-line workers: Data from 16 countries.

BackgroundDelivery of preventive chemotherapy (PC) through mass drug administration (MDA) is used to control or eliminate five of the most common neglected tropical diseases (NTDs). The success of an MDA campaign relies on the ability of drug distributors and their supervisors-the NTD front-line workers-to reach populations at risk of NTDs. In the past, our understanding of the demographics of these workers has been limited, but with increased access to sex-disaggregated data, we begin to explore the implications of gender and sex for the success of NTD front-line workers.Methodology/principal findingsWe reviewed data collected by USAID-supported NTD projects from national NTD programs from fiscal years (FY) 2012-2017 to assess availability of sex-disaggregated data on the workforce. What we found was sex-disaggregated data on 2,984,908 trainees trained with financial support from the project. We then analyzed the percentage of males and females trained by job category, country, and fiscal year. During FY12, 59% of these data were disaggregated by sex, which increased to nearly 100% by FY15 and was sustained through FY17. In FY17, 43% of trainees were female, with just four countries reporting more females than males trained as drug distributors and three countries reporting more females than males trained as trainers/supervisors. Except for two countries, there were no clear trends over time in changes to the percent of females trained.Conclusions/significanceThere has been a rapid increase in availability of sex-disaggregated data, but little increase in recruitment of female workers in countries included in this study. Women continue to be under-represented in the NTD workforce, and while there are often valid reasons for this distribution, we need to test this norm and better understand gender dynamics within NTD programs to increase equity

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications. Methods: ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery. Results: The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784. Conclusions: This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance. © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Medical Research Council of South Africa gran

Maternal and neonatal outcomes after caesarean delivery in the African Surgical Outcomes Study: a 7-day prospective observational cohort study.

BACKGROUND: Maternal and neonatal mortality is high in Africa, but few large, prospective studies have been done to investigate the risk factors associated with these poor maternal and neonatal outcomes. METHODS: A 7-day, international, prospective, observational cohort study was done in patients having caesarean delivery in 183 hospitals across 22 countries in Africa. The inclusion criteria were all consecutive patients (aged ≥18 years) admitted to participating centres having elective and non-elective caesarean delivery during the 7-day study cohort period. To ensure a representative sample, each hospital had to provide data for 90% of the eligible patients during the recruitment week. The primary outcome was in-hospital maternal mortality and complications, which were assessed by local investigators. The study was registered on the South African National Health Research Database, number KZ_2015RP7_22, and on ClinicalTrials.gov, number NCT03044899. FINDINGS: Between February, 2016, and May, 2016, 3792 patients were recruited from hospitals across Africa. 3685 were included in the postoperative complications analysis (107 missing data) and 3684 were included in the maternal mortality analysis (108 missing data). These hospitals had a combined number of specialist surgeons, obstetricians, and anaesthetists totalling 0·7 per 100 000 population (IQR 0·2-2·0). Maternal mortality was 20 (0·5%) of 3684 patients (95% CI 0·3-0·8). Complications occurred in 633 (17·4%) of 3636 mothers (16·2-18·6), which were predominantly severe intraoperative and postoperative bleeding (136 [3·8%] of 3612 mothers). Maternal mortality was independently associated with a preoperative presentation of placenta praevia, placental abruption, ruptured uterus, antepartum haemorrhage (odds ratio 4·47 [95% CI 1·46-13·65]), and perioperative severe obstetric haemorrhage (5·87 [1·99-17·34]) or anaesthesia complications (11·47 (1·20-109·20]). Neonatal mortality was 153 (4·4%) of 3506 infants (95% CI 3·7-5·0). INTERPRETATION: Maternal mortality after caesarean delivery in Africa is 50 times higher than that of high-income countries and is driven by peripartum haemorrhage and anaesthesia complications. Neonatal mortality is double the global average. Early identification and appropriate management of mothers at risk of peripartum haemorrhage might improve maternal and neonatal outcomes in Africa. FUNDING: Medical Research Council of South Africa.Medical Research Council of South Africa