Effet d'un amendement organique sur l'infiltration, les coefficients de transferts hydriques, et l'évaporation d'un sol sableux dégradé du Nord-Sénégal

Dans le cadre d'un essai agronomique de longue durée portant sur les possibilités de régénération de sols sableux totalement dégradés du Nord-Sénégal par amendement organique, on a pu observer de très forts contrastes de cinétique d'humectation du sol en saison des pluies à partir de mesures de profils hydriques effectuées par humidimétrie neutronique sous culture d'arachide sur le traitement avec apport de matière organique et sur témoin. Deux types d'expérimentations ont été effectués pour déterminer si cet effet provenait d'une modification des propriétés de rétention et de conductivité hydrique du sol par la matière organique : - Essais de caractérisation hydrodynamiques classiques, par infiltration sous charge constante suivie de drainage interne. Aucun effet significatif n'a pu être obtenu ni sur les paramètres des lois d'infiltration, ni sur les relations caractéristiques K(i) et h(i). En outre, ces essais mettent en évidence une trés forte hystérésis de succion qui montre clairement la difficulté d'utiliser une courbe de drainage obtenue en laboratoire pour caractériser un comportement de terrain. - Suivi de l'évaporation sur sol nu immédiatement après semis. Là encore les résultats obtenus sur le témoin et sur l'essai, ne conduisent à aucune différenciation. Ces essais permettent en outre de proposer une loi de paramétrisation simple liant l'évaporation à la teneur en eau du sol. On montre, dans un autre article publié par ailleurs sur l'aspect agronomique de l'expérimentation, que les effets constatés s'expliquent essentiellement par une trés forte différence de colonisation du sol par le système racinaire des cultures étudiées. (Résumé d'auteur

KC 5.1: Traditional Systems and Methods of Rural LandsConservation in Mali and Africa // Systemes et Methodes Traditionnels de Preservations des Paysages Ruraux au Mali et en Afrique

Rural landscapes in Africa and elsewhere constitute a precious heritage for rural communities, which have since the onset of time been able to develop endogenous techniques, systems and practices for the development and preservation of natural and cultural landscapes. Within African territorial entities, culture and nature are harmoniously interconnected and their management and preservation are based on systems created and transmitted from generation to generation according to socio-cultural environments and contexts. Based on ancestral social and religious practices, traditional systems and methods for preserving rural landscapes are more focused on a community-oriented approach. Several traditional methods, systems, practices and approaches to the management and preservation of rural landscapes exist in Mali and other African countries. Among them we can mention: - The sanctuarization of certain areas as places of initiation and sacred rituals: woods, forests and sacred ponds..... This practice, governed by numerous prohibitions, has proved to be very successful in the sustainable conservation of rural areas that contribute to the protection of rare animal and plant species. - The sacralization of landscapes considered as havens of supernatural beings (including the souls of deceased ancestors), protective genies or evil spirits is a method that has proven its efficiency in the preservation of several African ecosystems and rural landscapes. - The consecration of passages, places and spaces dedicated to the celebration of certain ritual ceremonies linked to the tradition of masks and other religious practices is in line with the same principle of respect and safeguarding of spaces by local communities. - The development and implementation of certain local conventions governing pastoral, agricultural and forestry calendars (specific transhumance corridors, harvest and consumption periods for new cereals produced, etc.). This is the case of the tradition of pastoralism in the Niger River delta, developed and carried out under the theocratic empire of the Macina (1820 - 1862). Beyond funeral and agrarian ritual ceremonies, some intangible cultural heritage elements play a cardinal role in the preservation of ecosystems and rural landscapes within territories. Among the practical measures is the protection of vulnerable ecosystems within landscapes. The initiation companies, associations and brigades play an essential role in the protection of landscapes and the environment, which is part of their priority mission. Nowadays, it has to be said that the development of new information technologies and globalisation, climate change, are having a dangerous impact on traditional systems and methods for preserving rural landscapes and constitute obstacles to their sustainability. Their revitalization and adaptation to the current context would certainly contribute to the sustainable conservation of the vital spaces that feed the local community, despite growing anthropic pressure. ________________________________________________________________ Les paysages ruraux en Afrique et ailleurs constituent un patrimoine précieux pour les communautés rurales qui depuis la nuit des temps ont su développer des techniques, systèmes et pratiques endogènes d’aménagement et de préservation des paysages naturels et culturels. Au sein des entités territoriales africaines, culture et nature s’imbriquent harmonieusement et leur gestion et préservation reposent sur des systèmes créés et transmis de génération en génération suivant les milieux et les contextes socioculturels. Basée sur les pratiques sociales et religieuses ancestrales les systèmes et méthodes traditionnels de préservation des paysages ruraux privilégient l’approche communautaire. Plusieurs méthodes, systèmes, pratiques et approches traditionnels de gestion et de préservation des paysages ruraux existent au Mali et dans d’autres pays africains. Parmi ceux-ci on peut citer: La sanctuarisation de certains espaces en lieux d’initiation et de rites sacrés: bois, forêts et mares sacrés…. Cette pratique, régie par des nombreux interdits, s’est avérée efficace pour la conservation durable d’espaces ruraux qui contribuent à la protection d’espèces animales et végétales rares. La sacralisation de paysages considérés comme des repaires d’êtres surnaturels (notamment les âmes des ancêtres défunts), de génies protecteurs ou de mauvais esprits est une méthode qui a fait ses preuves dans la préservation de plusieurs écosystèmes et paysages ruraux africains. La consécration de passages, lieux et espaces dédiés à la célébration de certaines cérémonies rituelles liées à la tradition des masques et d’autres pratiques cultuels, s’inscrit dans le même principe de respect et de sauvegarde des espaces par les communautés locales. L’élaboration et l’application de certaines conventions locales qui régissent les calendriers pastoraux, agricoles et forestiers (couloirs déterminés de transhumance, périodes de récoltes et de consommation des nouvelles céréales produites, etc.). C’est le cas de la tradition du pastoralisme dans le delta du fleuve Niger, élaborée et exécutée sous l’empire théocratique du Macina (1820 – 1862). Au-delà des cérémonies rituelles funéraires et agraires, certains éléments du patrimoine culturel immatériel jouent un rôle cardinal dans la préservation des écosystèmes et des paysages ruraux au sein des territoires. Parmi les mesures pratiques figure la mise en défens des écosystèmes fragiles au sein des paysages. Les sociétés initiatiques, associations et brigades jouent un rôle essentiel dans la protection des paysages et de l\u27environnement qui relève de leur mission prioritaire. De nos jours, force est de constater que le développement des nouvelles technologies de l\u27information et de la globalisation, le changement climatique influent dangereusement sur les systèmes et méthodes traditionnels de préservation des paysages ruraux et constituent des menaces pour leur pérennisation. Leur revitalisation et adaptation au contexte actuel contribueraient à coup sûr à la conservation durable des espaces vitaux qui nourrissent la communauté locale, malgré la pression anthropique grandissante

Changing patterns of malaria during 1996-2010 in an area of moderate transmission in Southern Senegal

<p>Abstract</p> <p>Background</p> <p>Malaria is reportedly receding in different epidemiological settings, but local long-term surveys are limited. At Mlomp dispensary in south-western Senegal, an area of moderate malaria transmission, year-round, clinically-suspected malaria was treated with monotherapy as per WHO and national policy in the 1990s. Since 2000, there has been a staggered deployment of artesunate-amodiaquine after parasitological confirmation; this was adopted nationally in 2006.</p> <p>Methods</p> <p>Data were extracted from clinic registers for the period between January 1996 and December 2010, analysed and modelled.</p> <p>Results</p> <p>Over the 15-year study period, the risk of malaria decreased about 32-times (from 0.4 to 0.012 episodes person-year), while anti-malarial treatments decreased 13-times (from 0.9 to 0.07 treatments person-year) and consultations for fever decreased 3-times (from 1.8 to 0.6 visits person-year). This was paralleled by changes in the age profile of malaria patients so that the risk of malaria is now almost uniformly distributed throughout life, while in the past malaria used to concern more children below 16 years of age.</p> <p>Conclusions</p> <p>This study provides direct evidence of malaria risk receding between 1996-2010 and becoming equal throughout life where transmission used to be moderate. Infection rates are no longer enough to sustain immunity. Temporally, this coincides with deploying artemisinin combinations on parasitological confirmation, but other contributing causes are unclear.</p

Implementation of intermittent preventive treatment in pregnancy with sulphadoxine/pyrimethamine (IPTp-SP) at a district health centre in rural Senegal

<p>Abstract</p> <p>Background</p> <p>Intermittent preventive treatment with <it>s</it>ulphadoxine-pyrimethamine (SP) is recommended for reducing the risk of malaria in pregnancy and its consequences on mothers and babies (IPTp-SP). Indicators of implementation and effects of IPTp-SP were collected in a rural clinic in Southern Senegal.</p> <p>Methods</p> <p>Women seen routinely at the antenatal clinic (ANC) of a rural dispensary during 2000–2007. Deployment of IPTp-SP started in January 2004. Inspection of antenatal and outpatient clinic registries of the corresponding period.</p> <p>Results</p> <p>Between 1^stJanuary 2000 and 30^thApril 2007, 1,781 women of all gravitidities and parities attended the ANC with 965 deliveries (606 and 398 respectively since 1^stJanuary 2004, when IPTp-SP was started.) 69% of women were seen ≥ 3 times; 95% received at least one dose and 70% two doses of SP (from 61% in 2004 to 86% in 2007). The first visit, first and second dose of SP occurred at a median week 20, 22 and 31. The probability of receiving two doses was > 80% with ≥ 3 antenatal visits and a first dose of SP by week 20.</p> <p>The prevalence of maternal malaria was low and similar pre- (0.7%) and during IPTp (0.8%). Effects on of low birth weight (LBW, < 2.5 kg) were non-statistically significant. The prevalence of LBW was 10.8% pre- and 7.7% during IPTp deployment (29% risk reduction, p = 0.12).</p> <p>Unfavourable pregnancy outcomes numbered 72 (7.5% of pregnancies with known outcome), including 30 abortions and 42 later deaths (late foetal deaths, stillbirth, peri-natal) of which 13 with one or more malformations (1.35% of all recorded deliveries).</p> <p>Conclusion</p> <p>The implementation of IPTp-SP was high. Early attendance to ANC favours completion of IPTp-SP. The record keeping system in place is amenable to data extraction and linkage. A model was developed that predicts optimal compliance to two SP doses, and could be tested in other settings. Maternal malaria was infrequent and unaffected by IPTp-SP. The risk of LBW was lower during IPT implementation but the difference was non-significant and could have other explanations.</p

Resource management research in- semi-arid West Africa: Challenges and new opportunities

Thls paper revlews part themes and results of resource management research and the con$- tralnt, lo adoptlon It proposer future theme, and approaches to tncreue resource managcmnt cffecuveness The key themes for future rescarch In resource management m duclng mineral ien~ltsatronc oqts, lncreaslng plant nutnent and water uptake, lncreaslng the organlc matter m the systems and cxplonng the posrlb~i~tlcfro r small-rcale supplemntary lrngatlon Multtd~x~plmaryap proaches muql play an lncrcaslng role as must new technlques In madelltng and spaual analyses Exploltlng the erlstlng capenmental databases wtll pcmul qutcker prngres, at lower cos

GENETIC POLYMORPHISM OF REVERSE TRANSCRIPTASE AND PROTEASE ASSOCIATED WITH THE ANTIRETROVIRAL (ARV) INEFFICIENCY IN PEOPLE LIVING WITH HUMAN IMMUNODEFICIENCY VIRUS TYPE-2 (HIV-2) IN ABIDJAN, CÔTE D’IVOIRE

Objectives:&nbsp;To analyse the genetic polymorphism of reverse transcriptase and protease genes in patients living with HIV-2, to search for possible mutations preventing the effectiveness of antiretroviral drugs (ARVs). Methods:&nbsp;RNA Viral was extracted after lysis of the virus particles and purified on filter columns (Qiagen). After their extraction, DNA fragments were amplified by the method of reverse transcription/polymerase chain reaction (RT/PCR) on one hand and by the PCR method enchase on the other hand. The study of genetic polymorphisms in reverse transcriptase and protease was performed after sequencing of amplicons. Results:&nbsp;A significant polymorphism was observed in positions involved in resistance to antiretrovirals. The most frequent was mutations M 46 I, M 36 I/V, V82I, L 89 I on protease and Y 181 I, Y 188 L, G 190A on reverse transcriptase. Conclusion:&nbsp;Polymorphic mutations were observed in the genes of the protease and reverse transcriptase and could be involved in the HIV-2 resistance to antiretrovirals (ARVs). It would be desirable to do the quantification of DNA provirus of HIV-2 in the other for a durable therapeutic monitoring of patients having HIV-2

Phosphorus recovery: a need for an integrated approach

Increasing cost of phosphate fertilizer, a scarcity of high quality phosphate rock (PR)and increasing surface water pollution are driving aneed to accelerate the recovery and re-use ofphosphorus (P) from various waste sectors. Options to recover P occur all along the open P cycle from mining to households to oceans. However, P recovery as a regional and global strategy towards P sustainability and future food, bio energy and water security is in its infancy because of a number of technological, socio-economic and institutional constraints. There is no single solution and resolving these constraints requires concerted collaboration betweenrelevant stakeholders and an integrated approach combiningsuccessful business models withsocio-economic and institutional change. We suggest that an operational framework is developed for fast tracking cost-effective recovery options

Zona planto-pédieux révélateur de l’infection à VIH

Le zona est une dermatose virale qui peut intéresser n’importe quelle partie du corps. La plus part des personnes atteintes d’un zona ont entre 50 à 70 ans. Toutefois son apparition chez le sujet jeune doit fait rechercher une immunodépression à VIH. Nous rapportons un cas atypique de zona révélant l’infection à VIH chez une patiente de 25 ans présentant une éruption vésiculeuse, douloureuse reposant sur un fond érythémateux localisé sur la plante du pied gauche. Le diagnostic du zona a été évoqué grâce aux éléments cliniques et réconforté par le cytodiagnostic et l’histologie. Cette localisation atypique nous a incités à demander une sérologie à VIH qui est revenue positive

Effects of climatic factors on diarrheal diseases among children below 5 years of age at national and subnational levels in Nepal: an ecological study

INTRODUCTION: The incidence of diarrhea, a leading cause of morbidity and mortality in low-income countries such as Nepal, is temperature-sensitive, suggesting it could be associated with climate change. With climate change fueled increases in the mean and variability of temperature and precipitation, the incidence of water and food-borne diseases are increasing, particularly in sub-Saharan Africa and South Asia. This national-level ecological study was undertaken to provide evidence linking weather and climate with diarrhea incidence in Nepal. METHOD: We analyzed monthly diarrheal disease count and meteorological data from all districts, spanning 15 eco-development regions of Nepal. Meteorological data and monthly data on diarrheal disease were sourced, respectively, from the Department of Hydrology and Meteorology and Health Management Information System (HMIS) of the Government of Nepal for the period from 2002 to 2014. Time-series log-linear regression models assessed the relationship between maximum temperature, minimum temperature, rainfall, relative humidity, and diarrhea burden. Predictors with p-values < 0.25 were retained in the fitted models. RESULTS: Overall, diarrheal disease incidence in Nepal significantly increased with 1 degrees C increase in mean temperature (4.4%; 95% CI: 3.95, 4.85) and 1 cm increase in rainfall (0.28%; 95% CI: 0.15, 0.41). Seasonal variation of diarrheal incidence was prominent at the national level (11.63% rise in diarrheal cases in summer (95% CI: 4.17, 19.61) and 14.5% decrease in spring (95% CI: -18.81, -10.02) compared to winter season). Moreover, the effects of temperature and rainfall were highest in the mountain region compared to other ecological regions of Nepal. CONCLUSION: Our study provides empirical evidence linking weather factors and diarrheal disease burden in Nepal. This evidence suggests that additional climate change could increase diarrheal disease incidence across the nation. Mountainous regions are more sensitive to climate variability and consequently the burden of diarrheal diseases. These findings can be utilized to allocate necessary resources and envision a weather-based early warning system for the prevention and control of diarrheal diseases in Nepal