Following the droughts that occurred in the Sahel during the 1970s, the Senegalese grasshopper Oedaleus senegalensis (Krauss 1877) suddenly became the main pest grasshopper species in this region, where it regularly causes serious damage to crops, especially millet. The lifecycle of O. senegalensis refl ects the precariousness of the Sahelian environment. The lifecycle and survival strategies of O. senegalensis have evolved to include migration following shifts in the intertropical convergence zone (ITCZ) and embryonic diapause in the dry season. It is thus able to cope with its natural hostile environment and remain in the most suitable ecological conditions for as long as possible. The alternation between outbreaks and recession periods seems to be related to the high spatiotemporal rainfall variability in the Sahel. Senegalese grasshopper outbreaks depend on the rainy season chronological pattern and on the initial quantity of diapaused eggs in the soil. Since the 1970s, many studies have been conducted on this species in the Sahel. Various models designed to monitor the population dynamics of this species have been published. However, some key factors that could explain the variability in outbreaks have not been seriously investigated. The present bibliographical review provides an overview on current knowledge while proposing some avenues for future research to enhance the sustainable management of this major Sahelian pest. Résumé. Ecologie et contrôle du criquet sénégalais Oedalus senegalensis (Krauss 1877) (Orthoptera : Acrididae) en Afrique Occidentale : revue et perspectives. Depuis les années 1970, le criquet sénégalais-Oedaleus senegalensis (Krauss 1877)-est devenu l'un des principaux criquets ravageurs des cultures vivrières du Sahel africain. Il cause régulièrement des dégâts considérables, en particulier sur le mil. Le cycle biologique de ce criquet refl ète la précarité de l'environnement sahélien. Cette espèce a développé un cycle biologique et une stratégie de survie incluant à la fois des migrations saisonnières suivant le déplacement du Front Intertropical (FIT) et une diapause embryonnaire pendant la saison sèche. Cela lui permet de faire face à un environnement souvent hostile et, pendant la saison des pluies, de se maintenir dans les conditions écologiques les plus favorables possibles. La succession de périodes de pullulations et d'accalmie est liée à la forte variabilité spatiale et temporelle de la pluviométrie et à l'abondance du stock d'oeufs en diapause dans le sol en fi n de saison sèche. Les nombreux travaux conduits au Sahel depuis les années 1970 ont permis une meilleure compréhension de l'écologie de cette espèce. Divers modèles ont été proposés pour suivre la dynamique de ses populations. Cependant, certains facteurs clés pouvant permettre d'expliquer les pullulations demeurent peu ou pas étudiés. La présente revue bibliographique fait le point sur les connaissances actuelles et propose des voies de recherche pour une gestion durable de ce ravageur.
We describe the outcomes of second-line drug resistance profiles and predict the efficacy of drugs for third-line therapy in patients monitored without the benefit of plasma HIV-1 RNA viral load (VL) or resistance testing. Methods: We recruited 106 HIV-1-infected patients after second-line treatment failure in Mali. VL was determined by the Abbott RealTime system and the resistance by the ViroSeq HIV-1 genotyping system. The resistance testing was interpreted using the latest version of the Stanford algorithm. Results: Among the 106 patients, 93 had isolates successfully sequenced. The median age, VL and CD4 cells were respectively 35 years, 72 000 copies/mL and 146 cells/mm 3. Patients were exposed to a median of 4 years of treatment and to six antiretrovirals. We found 20% of wild-type viruses. Resistance to etravirine was noted in 38%, to lopinavir in 25% and to darunavir in 12%. The duration of prior nucleos(t)ide reverse transcriptase inhibitor exposure was associated with resistance to abacavir (P,0.0001) and tenofovir (P ¼ 0.0001), and duration of prior protease inhibitor treatment with resistance to lopinavir (P,0.0001) and darunavir (P ¼0.06). Conclusion: Long duration of therapy prior to failure was associated with high levels of resistance and is directly related to limited access to VL monitoring and delayed switches to second-line treatment, precluding efficacy of drugs for third-line therapy. This study underlines the need for governments and public health organizations to recommend the use of VL monitoring and also the availability of darunavir and raltegravir for third-line therapies in the context of limited-resource settings.
This study demonstrated a high level of resistance to NRTIs and NNRTIs, compromising second-generation NNRTIs, for patients who stayed on long-term first-line regimens. It is crucial to expand the accessibility of virological testing in resource-limited settings to limit the expansion of resistance and preserve second-line treatment efficacy.
Sorghum is a good candidate crop for breeding to increase provitamin A, i.e., biofortification. Yellow endosperm sorghums contain carotenoids, including precursors of vitamin A, and sorghum is a major staple crop in areas of Asia and Africa where vitamin A deficiency is prevalent. Our objective was to collect and characterize yellow endosperm sorghums as a potential new source of genetic diversity to increase provitamin A content. A set of 164 landraces were collected from southern Niger and northern Nigeria. The most important use of these cultivars was as food. The endosperm exhibited a significant variation in yellow intensity. Lutein, zeaxanthin and b-carotene were the most abundant carotenoids in the ten landraces with the most intense yellow color. Cluster analysis, principal coordinate analysis and population differentiation test revealed that this set of 164 landraces represent a new genetic pool that might increase the genetic diversity of yellow endosperm sorghums in applied breeding programs.
Objectives We assessed cumulative incidence rates of and factors associated with re-engagement in HIV care for PLHIV lost to follow-up in Mali. Methods HIV-1-infected individuals lost to follow-up before 31/12/2013, � 18 years old, who started ART from 2006 to 2012 at one of 16 care centres were considered. Loss to follow-up (LTFU) was defined as an interruption of � 6 months during follow-up. The re-engagement in care in PLHIV lost to follow-up before 31/12/2013 was defined as having at least one clinical visit after LTFU. The cumulative incidence rates of re-engagement in care was estimated by Kaplan-Meier and its predictive factors were assessed using Cox models. Socio-demographic characteristics, clinical and immune status, period, region, centre expertise level, and distance from home at the start of ART plus a combined variable of duration of ART until LTFU and 12-month change in CD4 count were assessed. Multiple imputation was used to deal with missing data. Results We included 3,650 PLHIV lost to follow-up before December 2013, starting ART in nine outpatient clinics and seven hospitals (5+2 in Bamako and 4+5 in other regions): 35% male, median (IQR) age 35 (29-43), and duration of ART until LTFU 11 months (5-22). Among these PLHIV, 1,975 (54%) were definitively LTFU and 1,675 (46%) subsequently returned to care. The cumulative incidence rates of re-engagement in care rose from 39.0% at one
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