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

Identification des usages de Sclerocarya birrea (A. Rich) hoscht dans la zone du Ferlo (Senegal) et evaluation du potentiel biochimique et nutritionnel de son fruit

Le prunier d’Afrique ou Sclerocarya birrea est un arbre fruitier de la famille des Anacardiaceae, qui fournit aux populations des fruits consommables pendant la période de soudure. Bien que présente dans les régions à climat soudano-sahélien du Sénégal, sa zone de prédilection demeure le Ferlo. Elle y fait l’objet de réhabilitation dans la mise en place du programme de l’Union Africaine dite de la muraille verte. Malheureusement, peu d’études scientifiques n’ont encore fait mention de la composition nutritive des fruits issus de cette zone. Dans le cadre de la reconstitution du couvert végétal des zones arides, la connaissance des relations entre l’homme et son milieu s’avère importante. Ainsi, la présente étude est entreprise dans le but de connaître les usages de Sclerocarya birrea et les potentialités qu’offre son fruit. Des enquêtes ethnobotaniques ont permis de recueillir les connaissances sur les usages de l’espèce dans la zone du Ferlo (Sénégal). Des échantillons de fruits mûrs récoltés ont été analysés grâce à des techniques de dosages normalisés et conventionnelles. Les résultats révèlent que les populations du Ferlo connaissent bien S. birrea, dont l’usage médicinal est de loin le plus important (79%). En usage médicinal, les organes végétaux les plus utilisés sont les écorces et les feuilles. Les résultats obtenus sur la pulpe du fruit montrent qu'elle constitue une bonne source en vitamine C, en sucres, en Calcium, Magnésium, Potassium, Sodium et en Polyphénols totaux. L'huile de l'amande présente des caractéristiques qui dans l'ensemble restent dans la norme admise pour les huiles alimentaires. Ces résultats sont marqués par une forte variabilité de la composition physico-chimique qui semble être liées aux variations des conditions édaphiques et climatiques. Il ressort de cette analyse que le fruit de S. birrea constitue une excellente source de nutriments et peut valablement combler certaines carences nutritionnelles des populations autochtones. Par ailleurs, le fruit présente aussi des potentialités de transformation et de conservation qui doivent être explorées.Mots clés:  Sclerocarya birrea, fruits, usages, valeurs nutritionnelles, polyphénols, vitamine C, variabilité, FerloEnglish AbstractThe present study was undertaken to know the uses and some nutritional potentials of Sclerocarya birrea. The African plum tree called Sclerocarya birrea is a fruit tree of the Anacardiaceae family, which provides populations some consumable fruits during the lean season. Although it is present in Sudano-Sahelian regions of Senegal, its favorite repartition zone is the Ferlo. Sclerocarya birrea is being rehabilitated in the framework of the implementation of the African Union program called the “Green Wall”. Unfortunately, no scientific studies have mentioned the nutritional content of fruits coming from this area. In the context of the reconstitution of the vegetation cover, knowledge of the relations between man and his environment is important. Thus, the present study is undertaken with the aim of knowing the uses of Sclerocarya birrea and its fruits attibutes. According to that, ethnobotanical surveys have gathered knowledge on the species' uses in the Ferlo area (Senegal). Samples of ripe fruits harvested were analyzed using standard and conventional assay techniques. The results revealed that the populations of the Ferlo are well acquainted with Sclerocarya birrea and that its medicinal use is by far the most important (79%). In medicinal use, the most commonly used plant organs are barks and leaves. The results obtained on the pulp of the fruit showed that it is a good source of vitamin C, sugars, Calcium, Magnesium, Potassium, Sodium and total polyphenols. The almond oil has characteristics that remain within the accepted food standards. These results are marked by a high variability in the physicochemical composition, which appears to be linked to variations in edaphic and climatic conditions. The analysis shows that the fruit of Sclerocarya birrea is an excellent source of nutrients and can validly fill certain nutritional deficiencies of indigenous peoples. The fruit also has potential for transformation that needs to be explored.Keywords: Sclerocarya birrea, fruits, uses, nutritional values, polyphenols, vitamin C, variability, Ferl

Calf muscle stimulation with the Veinoplus device results in a significant increase in lower limb inflow without generating limb ischemia or pain in patients with peripheral artery disease

OBJECTIVE: Increase in arterial inflow to the lower limbs is important to obtain functional improvement in peripheral artery disease (PAD) patients with claudication. The aim of this study was to assess the effect of electrical stimulation of calf muscles on arterial inflow and tissue oxygen content in PAD in the area of stimulation.METHODS: Fifteen adult patients [mean (standard deviation) age, 62 (12 ) years; height, 165 (8)cm; weight, 76 (13) kg; lowest ankle-brachial index 0.66 (0.19)] with stable arterial claudication were recruited. All patients performed a treadmill test (3.2 km/h, 10% slope) associated with a transcutaneous oximetry test expressed as decrease from rest of oxygen pressure (DROP) index values (calf changes minus chest changes from rest) with a maximum walking distance (median [25th/75th percentiles]) of 295 [133-881] m. The DROP index on the symptomatic side was -25 [-18/-34] mm Hg. On another day the patients underwent electrical stimulation in the seated position on the leg that was the most symptomatic on the treadmill. After resting values were recorded, the gastrocnemius was stimulated for 20minutes at increasing contraction rates at 5-minute steps of 60, 75, 86, and 100bpm on the most symptomatic side. Arterial blood inflow with duplex Doppler ultrasound scanning of the femoral artery, DROP transcutaneous oxygen pressure value, and oxygen concentration (O2Hb) from the near-infrared spectroscopic signal of the calf were recorded on both sides. Patients were instructed to report eventual contraction-induced pain in the stimulated calf. Results are given as mean (standard deviation) or median [25th/75th percentiles] according to distribution, and the level of statistical significance was set at P < .05 on two-tailed tests. RESULTS: Lower limb inflow (mL/min) was 64 [48/86] vs 63 [57/81] (P> .05) before stimulation, 123 [75/156] vs 57 [44/92] (P < .01) at 60bpm, 127 [91/207] vs 49 [43/68] (P < .01) at 75bpm, 140 [84/200] vs 57 [45/71] (P < .01) at 86bpm, and 154 [86/185] vs 55 [46/94] (P < .01) at 100bpm on the stimulated vs nonstimulated limb, respectively. No apparent decrease or significant leg difference was observed in DROP index or O2Hb values. None of the patients reported contraction-induced pain in the leg. CONCLUSIONS: Electrical stimulation of calf muscle with the Veinoplus device results in a significant increase of arterial inflow without measurable muscle ischemia or pain. Potential use of this device as an adjuvant treatment to improve walking capacity in PAD patients remains to be evaluated

An evaluation of groundwater vulnerability assessment methods in a rapidly urbanizing city: evidence from Dakar, Senegal

In rapidly growing cities in the tropics, unregulated urban development presents a major risk to groundwater quality. Here, we assess the vulnerability of an unconfined aquifer of Quaternary sands in the Thiaroye area of Dakar (Senegal) to contamination using four GIS-based indices (DRASTIC, DRASTIC_N, SINTACS, SI). Our correlation of assessed vulnerability to observed impact is semi-quantitative, relating observed groundwater quality, based on nitrate concentrations and tryptophan-like fluorescence to vulnerability degrees (i.e. coincidence rates). We show that considerably more of the Thiaroye area has a “very high vulnerability” according to SI (36%) relative to DRASTIC (5%) and SINTACS (9%); “high vulnerability” is estimated using DRASTIC_N (100%), DRASTIC (66%) and SINTACS (69%). Single-parameter sensitivity tests show that groundwater depth, soil, topography, land use and redox parameters strongly influence assessments of groundwater vulnerability. Correlation with observed nitrate concentrations reveals aquifer vulnerability is better represented by SI (coincidence rates of 56%) relative to DRASTIC_N (43%), SINTACS (38%) and DRASTIC (34%). The underestimation of groundwater vulnerability in Dakar using DRASTIC, DRASTIC_N and SINTACS is attributed to their reliance on an assumed capacity of the unsaturated zone to attenuate surface or near-surface contaminant loading, which in the low-income (Thiaroye) area of Dakar is thin and affords limited protection. The inclusion of a land-use parameter in SI improves the characterization of groundwater vulnerability in this low-income, rapidly urbanizing area of Dakar

Intestinal parasite infections and associated risk factors in communities exposed to wastewater in urban and peri-urban transition zones in Hanoi, Vietnam

BACKGROUND: Infections with intestinal parasites (helminths and intestinal protozoa) are endemic in Southeast Asia and inappropriate management and reuse of wastewater might exacerbate the risk of human infections. In rapidly growing urban settings, little is known about the extent of intestinal parasite infections. We assessed the point-prevalence and risk factors of intestinal parasite infections in population groups differently exposed to wastewater in urban and peri-urban transition zones in Hanoi, the capital of Vietnam. METHODS: A cross-sectional survey was carried out between April and June 2014 in people aged ≥ 18 years at risk of wastewater exposure from To Lich River: workers maintaining wastewater treatment facilities; urban farmers reusing wastewater; and urban dwellers at risk of flooding events. For comparison, two peri-urban population groups living in close proximity to the Red River were chosen: farmers using river water for irrigation purposes; and people living in the same communities. A single stool sample was subjected to Kato-Katz and formalin-ether concentration methods for the diagnosis of helminth and intestinal protozoa infections. A questionnaire was administered to determine risk factors and self-reported signs and symptoms. RESULTS: A total of 681 individuals had complete data records. Highest point-prevalence rates of intestinal parasite infections were observed for peri-urban farmers (30 %). Hookworm and Trichuris trichiura were the predominant helminth species (25 % and 5 %, respectively). Peri-urban farmers were at higher odds of infection with intestinal parasites than any other groups (adjusted odds ratio 5.8, 95 % confidence interval 2.5 to 13.7). Lack of access to improved sanitation and not receiving deworming within the past 12 months were associated with higher infection risk, while higher educational attainment and socioeconomic status were negatively associated with intestinal parasite infections. CONCLUSIONS: Our results suggest that exposure to wastewater was not directly associated with infection with helminths and intestinal protozoa in different population groups in Hanoi. These findings might be explained by a high level of awareness of health risks and access to safe sanitary infrastructure in urban areas. The high prevalence rates observed in peri-urban farmers call for specific interventions targeting this population group

Acceptance of exotic beverages with health benefits in Europe: a crosscountry comparison of hibiscus products

info:eu-repo/semantics/publishedVersio

"Climate change and health?": Knowledge and perceptions among key stakeholders in Puducherry, India

Climate change has far-reaching impacts on human health, with low- and middle-income countries, including India, being particularly vulnerable. While there have been several advances in the policy space with the development of adaptation plans, little remains known about how stakeholders who are central to the strengthening and implementation of these plans perceive this topic. We conducted a qualitative study employing key interviews with 16 medical doctors, researchers, environmentalists and government officials working on the climate change agenda from Puducherry, India. The findings were analysed using the framework method, with data-driven thematic analysis. We elucidated that despite elaborating the direct and indirect impacts of climate change on health, there remains a perceived gap in education and knowledge about the topic among participants. Knowledge of the public health burden and vulnerabilities influenced the perceived health risks from climate change, with some level of scepticism on the impacts on non-communicable diseases, such as cardiovascular diseases. There was also a felt need for multi-level awareness and intervention programmes targeting all societal levels along with stakeholder recommendations to fill these gaps. The findings of this study should be taken into consideration for strengthening the region's climate change and health adaptation policy. In light of limited research on this topic, our study provides an improved understanding of how key stakeholders perceive the impacts of climate change on health in India

OmpA family proteins and Pmp-like autotransporter: new adhesins of Waddlia chondrophila.

Waddlia chondrophila is a obligate intracellular bacterium belonging to the Chlamydiales order, a clade that also includes the well-known classical Chlamydia responsible for a number of severe human and animal diseases. Waddlia is an emerging pathogen associated with adverse pregnancy outcomes in humans and abortion in ruminants. Adhesion to the host cell is an essential prerequisite for survival of every strict intracellular bacteria and, in classical Chlamydia, this step is partially mediated by polymorphic outer membrane proteins (Pmps), a family of highly diverse autotransporters that represent about 15% of the bacterial coding capacity. Waddlia chondrophila genome however only encodes one putative Pmp-like protein. Using a proteomic approach, we identified several bacterial proteins potentially implicated in the adhesion process and we characterized their expression during the replication cycle of the bacteria. In addition, we demonstrated that the Waddlia Pmp-like autotransporter as well as OmpA2 and OmpA3, two members of the extended Waddlia OmpA protein family, exhibit adhesive properties on epithelial cells. We hypothesize that the large diversity of the OmpA protein family is linked to the wide host range of these bacteria that are able to enter and multiply in various host cells ranging from protozoa to mammalian and fish cells