Efficacite agronomique du compost a base de la biomasse du « neem » et de l’anacarde sur des cultures maraicheres dans la zone des Niayes au Senegal

Dans la zone des Niayes au Sénégal, les sols sont pauvres en matières organiques et en éléments nutritifs nécessaires aux plantes. Les engrais chimiques utilisés pour améliorer les rendements ont engendré une forte pollution des sols et de la  nappe phréatique. L’objectif de cette étude est d’évaluer la valeur agronomique du compost fabriqué à base des feuilles de neem et d’anacarde, de fiente de volaille et de la cendre de bois. Le compost obtenu présente un rapport C/N de 15,49 et des teneurs en N - P - K de 9,1, 14,8 et 7,3 mg/kg, respectivement. Les différentes doses du compost testées  sur  des  cultures  maraichères  ont  révélé  des  performances  agronomiques  meilleures par rapport aux témoins. La dose T3 (30 t/ha) a induit les meilleurs rendements pour la tomate (27,213 t/ha) et l’oignon (105,263 t/ha). Pour le chou et la pomme de terre, la dose T1 (10 t/ha) a permis d’obtenir les meilleurs rendements (144,533 t/ha et 55,163 t/ha, respectivement). Par contre pour le poivron, la dose T2 (20 t/ha) a favorisé les meilleurs rendements (32,534 t/ha) avec un poids moyen (81,748g) et un nombre de fruits/récolte considérablement plus élevé. Ce compost pourrait constituer une alternative réelle à l’utilisation abusive de l’engrais minéral dans la zone agricole des Niayes.Mots clés : Compost, Neem, Feuilles d’anacarde, Maraichage, Sénéga

Experimental study of slow sand filtration for the treatment of various wastewaters in tropical environment

Wastewater treatment by slow sand filtration is a biological process which consists in filtering wastewater through a porous media. The objective of this study was to evaluate the performances of this biotechnology under tropical climate. Three sand filters were monitored at ONAS (Cambérène wastewater treatment plant in Dakar, Senegal). The filters were built with local materials, and were constituted with a feeding tank of approximately 180 litters, a column (two meters high and 30-25 cm diameter). The filters were filled with sand (75 cm), gravel (25 cm) and wastewater (90 cm). The results showed that with sand of d10 equal to 0.58 mm and flow rate of 0.05 m/h, the filtration cycle was relatively long for the first run with pretreated wastewater. At the level of the primary settling tank, with flow a rate of 0.08 m/h, the removal rates were about 12.75%, 16.31%, 12.92%, 5.45%, 7.09% and 10.50% for TSS, COD, BOD5, nitrogen phosphorus and faecal coliforms respectively. At the level of the clarifier, with a filtration of 0.15 m/h, the removals were 1.4% for TSS, 1.84% for COD, 1.09% for BOD5 11.38% for nitrogen, 5.18% for phosphorus and 1.74% of faecal coliforms.Keywords: Flow rate; filtration cycle, removal; sand filtration; tropical climate, wastewater

Grain yield response of Fonio (Digitaria exilis) varieties to fertilizer and cost- effectiveness under two different production systems in the Gambia

Fonio is an easy crop to grow because it grows well even on poor sandy soils, as well as in areas with low rainfall. The crop can withstand long dry  spells during the production season which are becoming a common occurrence in the West African subregion. In The Gambia, the common name  for the crop is “Findi”. It is commonly grown in fields that were previously cultivated with groundnut. Fonio is one of the oldest cereal crops grown in  the country; however, its cultivation has drastically declined to the extent that it is currently considered a minor crop in the country. Fonio is a very  fast-growing crop and matures earlier than most cereals. Its ability to withstand dry spells and its high nutritive value makes it an ideal climate-  smart crop. For this reason, there is renewed momentum in promoting the crop in the country. Despite these renewed efforts in its promotion,  there still exists a huge gap in terms of information on improved production practices that could help uplift the existing low yields. Appropriate  agronomic practices that can boost fonio productivity are not well documented at national level. To gather information on the input requirements  and utilizations, adaptability and productivity of fonio in The Gambia, experiments were conducted in 2018 and 2019 with the aim of generating  important production information that could guide efficient production and enhance productivity. Results obtained showed that fonio responded  positively to application of fertilizer. Application of 100 kg ha -1 comprising half NPK (15-15-15) and half urea was sufficient to produce financially  beneficial yields. Results also indicated that “Findiba”, which is a landrace may not be suitable for cultivation anymore due to its long growth period  amidst the short and erratic nature of the rainfall. The Momo and the Momosato varieties which are of shorter durations and high-yielding are more  suitable in the existing climatic conditions of the country

Геоботанічні аспекти екотонізації природних ландшафтів

Vegetation is one of the main criteria for landscape differentiation of the Earth surface. The main morphological feature of the landscape is the presence or absence of the forest that is, and the gradual character of the boundaries between the natural zones causes the formation of fairly wide transitional zones bands – ecotones. They have become one of the most common subjects in landscape research in recent years. This is natural in view of the insufficient localization of ecotones and their constant drift in the light of gradual changes in climate and degradation of soil cover. In modern studies, structural-geographical ecotones are considered not as clear sharp boundaries, but as rather wide transitional bands. There are four natural zones (mixed coniferous-deciduous forests, deciduous forests, forest-steppe and steppe) and three structural and geographical strips – pasture, forest and field districted in the plain part of Ukraine. If the physical-geographical boundary of the forest-steppe and steppe is traditionally drawn along the Balta – Kropyvnytskyi – Dnipro – Izyum – Kup'yansk line, from the standpoint of constructive geography, the area of continuous predominance of the field landscapes is shifted to the north by almost 100 km. In general, the territory of the traditionally separated southern sub-zone of the forest-steppe objectively reaching the steppe zone is today. Anthropogenic factor makes its adjustments to the holding of ecotones, in particular through deforestation. The action of natural and anthropogenic factors is synergistic. On the one hand, the natural process of the steppe on the forest continues; on the other hand, one actively promotes deforestation. Therefore, the boundaries of Polissya and the Forest-Steppe are becoming less clear. Ecotones are manifested not only on the interzonal (macro- and meso scale) but also on the intra-zonal, within landscape complexes (micro levels). A striking example would be the ecotones in forest landscapes. In general, the continuous changes of the landscape environment, caused nowadays by both natural and anthropogenic factors, inevitably cause the displacement of both geobotanical and physical-geographical boundaries. However, most landscape systems are not homogeneous in their typological characteristics; the transitions between them are rather blurred. This further complicates the boundaries and suggests the leading importance of ecotones in the terrestrial landscape organization.Відзначено, що більшість сучасних ландшафтів – як натуральних природних, так і антропогенних – мають характер екотонів. Наголошено, що екотонізація виразно позначається на педобіогенному компоненті-чинникові ландшафту. Зауважено, що формування екотонів відбувається як на макро- й мезо-, так і на мікрорівні організації рослинного компоненту. Проілюстровано, що явище поступового переходу від однієї фізико-географічної зони до іншої яскраво проявляється на прикладах лісостепу Правобережної України – як у межах екотону "зона мішаних лісів" – "лісостеп", так і в смузі екотону "лісостеп" – "степ". Наголошено, що процесам екотонізації ландшафтів істотно сприяє втручання антропогенного чинника. Розглянуто різні варіанти екотонізації лісових фітоценозів, зокрема висвітлено особливості природних і антропогенних екотонів "ліс – галявина", "ліс – прогалина", "ліс – узлісся", "ліс – зруб" тощо. Відзначено високий рівень біорізноманіття, властивий лісовим ландшафтам завдяки їхній екотонізації. Проаналізовано феномен "екотону в часі", що проявляється на сукцесійних стадіях розвитку лісових фітоценозів. Окреслено основний зміст концепцій змін порід деревної лісової рослинності відповідно до поглядів В. П. Кучерявого та Г. Ф. Морозова. Зауважено, що сукупна дія природних і антропогенних чинників увиразнює розмитість меж природних регіонів і в такий спосіб підсилює екотонізацію ландшафтів, зокрема лісових. Наголошено, що дослідження екотонів становить комплексну міждисциплінарну наукову проблему, що перебуває на пограниччі географії, геоботаніки, лісознавства, ландшафтної та соціоекології

Approche spatiale des inégalités d'exposition environnementale et socioéconomiques Quelle influence sur les inégalités de cancer ? Projet Cancer inégalités régionales, cantonales et environnement (CIRCE)

National audienceINTRODUCTION. La progression de l'incidence du cancer en France et dans les pays développés suscite une interrogation sur l'origine de cette croissance et notamment sur l'importance de la composante environnementale de cette croissance. Les études de corrélations écologiques utilisant les Systèmes d'information géographique (SIG) peuvent apporter un éclairage nouveau sur la relation entre cancer et facteurs environnementaux et socio-économiques. Les objectifs sont de 1) Proposer une méthodologie utilisant des indicateurs permettant de mettre en évidence les inégalités spatiales d'exposition environnementale, de niveau socio-économique et de mortalité par cancer et 2) Comprendre les relations entre cancer et facteurs environnementaux et socioéconomiques en croisant ces données par une étude de corrélation écologique à l'échelle cantonale. MATERIEL/METHODES. A partir des bases de données descriptives de l'environnement, des indicateurs de l'exposition environnementale sont proposés : un indicateur de pollution de l'air à partir du registre européen d'émission des polluants (European pollutant emission register, EPER) pour une cinquantaine de polluants, un indicateur général de contamination des sols à partir de BASIAS, un indicateur de pollution agricole ou urbaine à partir de Corine Land Cover. A partir du recensement INSEE descriptif de la population, l'indice de défaveur sociale de Townsend peut être construit. A partir des données du Centre d'épidémiologie sur les causes médicales de décès (CépiDc) de l'Inserm, le risque relatif de mortalité par cancer a pu être défini. RESULTATS. La région Nord-Pas-de-Calais a été choisie pour illustrer les résultats. Chacun des indicateurs est cartographié à l'échelle des cantons mettant en évidence des disparités géographiques plus ou moins importantes. La carte de l'indice de Townsend fait ressortir la région Lilloise ainsi que le bassin minier comme les zones les plus défavorisées socialement. La cartographie des indices généraux d'exposition environnementale semble faire ressortir ces mêmes zones. Les indicateurs d'exposition à partir d'EPER mettent en évidence de fortes disparités spatiales de l'exposition, et des différences importantes suivant le polluant considéré. Concernant le cancer, les résultats sont variables selon la localisation cancéreuse analysée ; dans le Nord-Pas-de-Calais, les situations récurrentes de surmortalité sont localisées autour des grands pôles. Certains cantons semblent cumuler les inégalités sociales, environnementales et sanitaires. Le croisement de ces données spatialisées par canton permettra de définir les liens éventuels entre cancer, environnement et niveau socio-économique. DISCUSSION ET CONCLUSION. Bien que cette approche comporte quelques limites comme la non prise en compte de la mobilité à court et long terme des populations ou encore les temps de latence relativement long pour le cancer, l'utilisation des SIG dans le cadre d'études de corrélations écologiques apporte une vision nouvelle des disparités spatiales et permettent de mieux comprendre la complexité du lien environnement, social et sant

Nutritional status and disease severity in children acutely presenting to a primary health clinic in rural Gambia

BACKGROUND: Accurate and timely data on the health of a population are key for evidence-based decision making at both the policy and programmatic level. In many low-income settings, such data are unavailable or outdated. Using an electronic medical records system, we determined the association between nutritional status and severe illness and mortality among young children presenting to a rural primary health care facility in the Gambia. METHODS: Clinical data collected over five years (2010-2014) on children aged under 60 months making acute visits to a primary health care clinic in the rural Gambian district of Kiang West were retrospectively extracted from the medical records system. Generalised estimating equation models were used to investigate associations between nutritional status and illness severity, accounting for repeat visits, gender, age and access to transport to the clinic. The Population Attributable Fraction (PAF) was used to determine the proportion of severe illness likely attributable to different grades of malnutrition. RESULTS: 3839/5021 (77%) children under 60 months of age living in Kiang West presented acutely to the clinic at least once, yielding 21,278 visits (47% girls, median age 20.2 months (Interquartile Range (IQR) 23.92 months)) and 26,001 diagnoses, 86% being infectious diseases. Severe illness was seen in 4.5% of visits (961/21,278). Wasting was associated with an increased risk of severe illness in a dose-dependent manner, ('WHZ < -1' adjusted Odds Ratio (aOR) 1.68, 95% CI:1.43-1.98, p < 0.001, 'WHZ <-2 and ≥-3' aOR 2.78, 95% CI:2.31-3.36, p < 0.001 and 'WHZ < -3' aOR 7.82, 95% CI:6.40-9.55, p < 0.001) the PAF for wasting (WHZ < -2) was 0.21 (95% CI: 0.18-0.24). Stunting, even in the most severe form (HAZ < -3), was not significantly associated with severe illness (aOR 1.19 95% CI:0.94-1.51) but was associated with a significantly increased risk of death (aOR 6.04 95% CI:1.94-18.78). CONCLUSION: In this population-based cohort of young children in rural Gambia, wasting was associated with disease severity in a dose-dependent manner. Further research is needed into strategies to identify and reach these children with effective interventions to improve their nutritional status

Reduced postprandial energy expenditure and increased exogenous fat oxidation in young woman after ingestion of test meals with a low protein content

<p>Abstract</p> <p>Background</p> <p>Macronutrient composition of diets can influence energy balance in humans. We tested the hypothesis whether low protein content in single meals may induce lower values of energy expenditure (EE) and fat oxidation (FO) as compared to adequate protein content.</p> <p>Methods</p> <p>Indirect calorimetry was combined with a breath test using naturally ¹³C-enriched corn oil to differentiate between postprandial exogenous and endogenous FO. Young women ingested single meals containing either 3.9% (low protein, LP) or 11.4% (adequate protein, AP) of total energy (~3100 kJ) as protein.</p> <p>Results</p> <p>Postprandial EE was 160 kJ/6 h lower (p < 0.01) after LP meals and diet induced thermogenesis (DIT) increased less (p < 0.001) as compared to AP meals. Total postprandial FO was not significantly different between meals (~17 g/6 h). However, exogenous postprandial FO was significantly (p < 0.01) higher (4.28 ± 1.57 g/6 h) after exposure to LP meals as compared to AP meals (1.87 ± 1.00 g/6 h). Less than 10% of ingested fat (50 g) was oxidized in the postprandial phase. The overall postprandial fat balance was approximately + 33 g.</p> <p>Conclusion</p> <p>Breath tests using naturally ¹³C-labeled corn oil mirror exogenous FO. Low protein meals resulted in reduced postprandial EE and increased exogenous FO as compared to adequate protein meals without differences in total FO.</p

Changes in the Molecular Epidemiology of Pediatric Bacterial Meningitis in Senegal After Pneumococcal Conjugate Vaccine Introduction.

BACKGROUND: Bacterial meningitis is a major cause of mortality among children under 5 years of age. Senegal is part of World Health Organization-coordinated sentinel site surveillance for pediatric bacterial meningitis surveillance. We conducted this analysis to describe the epidemiology and etiology of bacterial meningitis among children less than 5 years in Senegal from 2010 and to 2016. METHODS: Children who met the inclusion criteria for suspected meningitis at the Centre Hospitalier National d'Enfants Albert Royer, Senegal, from 2010 to 2016 were included. Cerebrospinal fluid specimens were collected from suspected cases examined by routine bacteriology and molecular assays. Serotyping, antimicrobial susceptibility testing, and whole-genome sequencing were performed. RESULTS: A total of 1013 children were admitted with suspected meningitis during the surveillance period. Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus accounted for 66% (76/115), 25% (29/115), and 9% (10/115) of all confirmed cases, respectively. Most of the suspected cases (63%; 639/1013) and laboratory-confirmed (57%; 66/115) cases occurred during the first year of life. Pneumococcal meningitis case fatality rate was 6-fold higher than that of meningococcal meningitis (28% vs 5%). The predominant pneumococcal lineage causing meningitis was sequence type 618 (n = 7), commonly found among serotype 1 isolates. An ST 2174 lineage that included serotypes 19A and 23F was resistant to trimethoprim-sulfamethoxazole. CONCLUSIONS: There has been a decline in pneumococcal meningitis post-pneumococcal conjugate vaccine introduction in Senegal. However, disease caused by pathogens covered by vaccines in widespread use still persists. There is need for continued effective monitoring of vaccine-preventable meningitis

Etiology of Pediatric Meningitis in West Africa Using Molecular Methods in the Era of Conjugate Vaccines against Pneumococcus, Meningococcus, and Haemophilus influenzae Type b

Despite the implementation of effective conjugate vaccines against the three main bacterial pathogens that cause meningitis, Streptococcus pneumoniae, Haemophilus influenzae type b (Hib), and Neisseria meningitidis serogroup A, the burden of meningitis in West Africa remains high. The relative importance of other bacterial, viral, and parasitic pathogens in central nervous system infections is poorly characterized. Cerebrospinal fluid (CSF) specimens were collected from children younger than 5 years with suspected meningitis, presenting at pediatric teaching hospitals across West Africa in five countries including Senegal, Ghana, Togo, Nigeria, and Niger. Cerebrospinal fluid specimens were initially tested using bacteriologic culture and a triplex real-time polymerase chain reaction (PCR) assay for N. meningitidis, S. pneumoniae, and H. influenzae used in routine meningitis surveillance. A custom TaqMan Array Card (TAC) assay was later used to detect 35 pathogens including 15 bacteria, 17 viruses, one fungus, and two protozoans. Among 711 CSF specimens tested, the pathogen positivity rates were 2% and 20% by the triplex real-time PCR (three pathogens) and TAC (35 pathogens), respectively. TAC detected 10 bacterial pathogens, eight viral pathogens, and Plasmodium. Overall, Escherichia coli was the most prevalent (4.8%), followed by S. pneumoniae (3.5%) and Plasmodium (3.5%). Multiple pathogens were detected in 4.4% of the specimens. Children with human immunodeficiency virus (HIV) and Plasmodium detected in CSF had high mortality. Among 220 neonates, 17% had at least one pathogen detected, dominated by gram-negative bacteria. The meningitis TAC enhanced the detection of pathogens in children with meningitis and may be useful for case-based meningitis surveillance

The relationship between wasting and stunting: a retrospective cohort analysis of longitudinal data in Gambian children from 1976 to 2016

Background: The etiologic relationship between wasting and stunting is poorly understood, largely because of a lack of high-quality longitudinal data from children at risk of undernutrition. Objectives: The aim of this study was to describe the interrelationships between wasting and stunting in children aged <2 y. Methods: This study involved a retrospective cohort analysis, based on growth-monitoring records spanning 4 decades from clinics in rural Gambia. Anthropometric data collected at scheduled infant welfare clinics were converted to z scores, comprising 64,342 observations on 5160 subjects (median: 12 observations per individual). Children were defined as "wasted" if they had a weight-for-length z score <-2 against the WHO reference and "stunted" if they had a length-for-age z score <-2. Results: Levels of wasting and stunting were high in this population, peaking at approximately (girls-boys) 12-18% at 10-12 months (wasted) and 37-39% at 24 mo of age (stunted). Infants born at the start of the annual wet season (July-October) showed early growth faltering in weight-for-length z score, putting them at increased risk of subsequent stunting. Using time-lagged observations, being wasted was predictive of stunting (OR: 3.2; 95% CI: 2.7, 3.9), even after accounting for current stunting. Boys were more likely to be wasted, stunted, and concurrently wasted and stunted than girls, as well as being more susceptible to seasonally driven growth deficits. Conclusions: We provide evidence that stunting is in part a biological response to previous episodes of being wasted. This finding suggests that stunting may represent a deleterious form of adaptation to more overt undernutrition (wasting). This is important from a policy perspective as it suggests we are failing to recognize the importance of wasting simply because it tends to be more acute and treatable. These data suggest that stunted children are not just short children but are children who earlier were more seriously malnourished and who are survivors of a composite process