Restauration de plages nues d’une brousse tachetée au Niger

Un essai de restauration de plages nues dfune brousse tachetee degradee du Parc National du W au sudouest du Niger a ete installe en 2007. Cet article etablit le bilan de cette restauration realisee par la plantation dfespeces locales dans des ouvrages antierosifs du type tranchees sylvopastorales. Dans la zonetemoin et dans la zone mise en defens par une cloture, le taux de survie des plants mis en place, leur croissance en hauteur et en diametre, la composition et la diversite floristique des herbacees ont ete suivis pendant trois ans (2007-2009). Lfeffet des ouvrages antierosifs sur lfhumidite du sol a ete evalue pendant lapremiere annee. Les analyses demontrent une amelioration nette des conditions ecologiques du site dfexperimentation, qui evolue progressivement vers lfetat dfune brousse tachetee, qui est lfecosysteme de reference. Lfamelioration de lfhumidite du sol induit des conditions beaucoup plus favorables pour la couverture vegetale. La richesse floristique dans la zone-temoin est passee en trois annees de 16 a 49, la diversite ƒ¿ de 2,1 a 4,42 et lfequitabilite de Pielou de 0,59 a 0,78. Dans la zone cloturee (mise en defens), la richesse floristique, la diversite ƒ¿ et lfequitabilite de Pielou sont respectivement passees en trois ans de 14 a 43, de 2,26 a 4,22 et de 0,53 a 0,79, ce qui traduit une amelioration progressive de la flore. Acacia senegal et Bauhinia rufescens ont enregistre les plus forts taux de survie et les plus importantes croissances en hauteur et en diametre. Les mortalites elevees des A. seyal et Ziziphus mauritiana sont vraisemblablement liees a la forte concentration de rongeurs que la presence dfune cloture ne gene guere. La pose couteuse dfune cloture nfest efficace que contre les grands mammiferes, ce qui se traduit toujourspar une croissance en diametre et en hauteur superieure pour la zone cloturee.Mots-cles : restauration ecologique, brousse tachetee, Acacia senegal, Acacia seyal, Bauhinia rufescens, Ziziphus mauritiana, ouvrage antierosif

Antiprotozoal activity of natural products from Nigerien plants used in folk medicine

In the course of the screening of plants from Niger for antiprotozoal activity, the methanol extract of Cassia sieberiana, and the dichloromethane extracts of Ziziphus mauritiana and Sesamun alatum were found to be active against protozoan parasites, namely Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani and/or Plasmodium falciparum. Myricitrin (1), quercitrin (2) and 1-palmitoyl-lysolecithin (3) were isolated from C. sieberiana. From Z. mauritiana, the three triterpene derivatives 13, 15, and 16 are described here for the first time. Their chemical structures were determined by 1D and 2D NMR experiments, UV, IR and HRESIMS data. The absolute configurations were assigned via comparison of the experimental and calculated ECD spectra. In addition, eight known cyclopeptide alkaloids (4, 5, 7-12), and five known triterpenoids (6, 14, 17-19) were isolated. The antiprotozoal activity of the isolated compounds, as well as of eleven quinone derivatives (20-30) previously isolated from S. alatum was determined in vitro. The cytotoxicity in L6 rat myoblast cells was also evaluated. Compound 18 showed the highest antiplasmodial activity (IC(50) = 0.2 microm) and compound 24 inhibited T. b. rhodesiense with an IC(50) value of 0.007 microM. However, it also displayed significant cytotoxicity in L6 cells (IC(50) = 0.4 microm)

Bethe lattice approach study of the mixed spin-1/2 and spin-7/2 Ising model in a longitudinal magnetic field

The magnetic properties of the mixed spin-1/2 and spin-7/2 Ising model with a crystal-field in a longitudinal magnetic field are investigated on the Bethe lattice using exact recursion relations. The ground-state phase diagram is constructed. The temperature-dependent one is displayed in the case of uniform crystal-field on the (k_BT/|J|, D/|J|) plane in the absence of the external constraint for lattice coordination numbers z=3,4,6. The order parameters and corresponding response functions as well as the internal energy are calculated and examined in detail in order to feature the real nature of phase boundaries and corresponding temperatures. The thermal variations of the average magnetization are classified according to the Néel nomenclature

Pyridine-4(1H)-one alkaloids from Waltheria indica as antitrypanosomatid agents

Twelve new pyridine-4(1H)-one derivatives, namely, 8-demethoxywaltherione F (1), waltheriones R-V (2, 6, 7, 10, and 11), 1-methoxywaltherione O (3), (S)-15-hydroxywaltherione G (4), (8R)-8-hydroxywaltherione M (5), (9S,13S)-2-hydroxymethylwaltherione C (8), (9S,10S,13S)-10-hydroxywaltherione C (9), and (S)-13-methoxywaltherione V (12), as well as melovinone (13) and 5'-methoxywaltherione A (14) were isolated from the CH2Cl2 extract of the aerial parts of Waltheria indica. Their chemical structures were determined by means of a comprehensive analysis including (1)H NMR, DEPTQ, HSQC, HMBC, (1)H-(1)H COSY, ROESY, and HRESIMS data. The absolute configurations were assigned via comparison of the experimental and calculated ECD data. In addition, the isolated constituents as well as the known waltheriones M-Q were evaluated for their in vitro antitrypanosomal activity. Compounds 2, 5, and 7 as well as waltheriones M, P, and Q showed potent growth inhibition toward Trypanosoma cruzi with IC50 values of 2.1, 0.8, 2.1, 1.3, 0.5, and 0.1 muM, respectively, and selectivity indices of >12, >33, >13, 5, 25, and 14. These findings further demonstrate that the waltheriones are a promising class of antichagasic compounds worthy of further investigations

Breeding practices and morphometric indicators of the dairy performance of Kouri cattle according to farmers in Niger

In the Diffa region of Niger, a survey was carried out in 140 farms to analyze the breeding practices and dairy perfor­mance of Kouri cattle. In addition, morphometric traits that were indicators of dairy performance according to the farmers were documented. Most of the herders were sedentary and the majority of herds were medium-sized (36 ± 30 head per farm). For cows with the most recent complete lactations, milk pro­duction per cow was on average 2.7 ± 1.4 liters per day for an average lactation duration of 7.2 ± 2.8 months. For cows considered as the best dairy cows, milk production per cow was 4.2 ± 1.5 liters per day for an average lactation duration of 8.9 ± 2.7 months. Although breeding practices were similar for many aspects in the different ethnic groups, morphomet­ric selection criteria for Kouri dairy cows varied according to the ethnic group. The phenotypic characteristics thus associ­ated with the Kouri breed in the identified ethnic groups were mainly the pelvic length, chest width, teat length, withers height, and tail length. It is important to consider endogenous knowledge of genetic improvement because the morphomet­ric parameters identified in this study as performance indica­tors were not unanimously accepted within the ethnic groups

Strengthen digestive surgical emergency care: experience of an action-research in Zinder National Hospital, Niger

info:eu-repo/semantics/publishe

Caracteristiques ecologiques et impacts socio-economiques de l’exploitation de Azadirachta indica A. Juss dans la commune de Glazoue au Benin, Afrique de l’Ouest

Cette étude vise à documenter les utilisations locales et l’importance socio-économique de Azadirachta indica dans la Commune de Glazoué au Centre du Bénin. A cet effet, treize (13) villages de la Commune ont été sélectionnés pour servir de cadre d’étude. Les méthodes utilisées sont basées sur des enquêtes socio-économiques et des inventaires phytoécologiques. L’approche phytoécologique a permis d’obtenir 3 groupements de distribution de cette espèce. Dans ces différents groupements (jachères, champs et zones habitées) les densités moyennes des individus de la catégorie des régénérations sont respectivement 10,29 ± 25,87 ; 7,77 ± 13,9 et 0,68 ± 2,69 individus/ha. Celle des individus adultes sont respectivement 23,30 ± 21,77 ; 26,66 ± 18,29 et 19,50 ± 14,26 individus/ha. Il est ressorti de cette étude que 90 % des populations enquêtées ont de bonnes connaissances sur l’utilité de l’espèce. Pour les femmes, la collecte des graines de l’espèce constitue une source de génération de revenu notamment pendant les périodes de soudure. Ces résultats révèlent l’importance de cette espèce sur le plan social qu’économique. La valorisation des sous produits de cette essence constitue une opportunité majeure pour sa domestication, sa protection et sa conservation à long terme.Mots clés: Impact, socio-économique, exploitation, Azadirachta indica, GlazouéEnglish Title: Ecological characteristics and socio-economic impacts of the exploitation of Azadirachta indica A. Juss in the commune of Glazoue in Benin, west AfricaEnglish AbstractThis study aims at documenting the local uses and the socioeconomic importance of Azadirachta indica in the Municipality of Glazoué in the central Benin. For this purpose, thirteen (13) villages of the Municipality were selected to serve as the study area. The methods used were based on the socioeconomic surveys and on a phytoecologic inventory. The phytoecologic approach used, allowed obtaining 3 species distribution groups. In each group (fallows, fields and inhabited zones), the average densities of the individuals of the category of regenerations are respectively 10.29 ± 25.87; 7.77 ± 13.9 and 0.68 ± 2.69 individuals / ha. The groups with elder individuals are respectively 23.30 ± 21.77; 26.66 ± 18.29 and 19.50 ± 14.26 individuals / ha. It results from this study that 90% of the investigated populations have good knowledge on the utility of the tree species. For women, the collection of the neem seeds constitutes a source of income generation in particular during the dry periods. These results reveal the importance of this Azadirachta indica species on the economic and social plan. This represents a major opportunity for its domestication, its protection and its long-term preservation.Keywords: Impact, socioeconomic, exploitation, Azadirachta indica, Glazou

Typology of Fermented Porridges and Socio-demographic Characteristics of Respondents in the Northern Part of Benin

Fermentation is an ancestral process and one of the most used economic methods in the preservation and transformation of cereal-based food raw materials. They are essentially rich in carbohydrates, but they can also be a source of micronutrients such as iron and are used in many traditional culinary preparations, in particular fermented porridges. The aim of this study is to identify the variability of fermented cereal-based porridges produced and consumed in northern Benin. Thus, 315 producers and consumers were randomly interviewed in nine localities of northern Benin. First, field surveys were carried out in the traditional areas of porridge production and consumption in the northern region of Benin in order to establish the consumption map of fermented porridges. Secondly, interviews and occasional conversations were used for sample collection as well as occasional interviews (individual survey). During our investigation, eight (koko, bobossou, gbangba, apkan, sagagnega, akloui, bita and fourra) porridge were reported. Corn, millet and sorghum are cereals that are used for proceeding those porridges. The interviewed people are predominantly (35.53%) between 18 and 25 years old of age followed by those aged between 25 and 31 years old (30.82%). Mostly (63.21%) women were interviewed with a sex ratio (M/F = 0.58) and involved in the production of traditional porridge. More than 36% of respondents had at least secondary education, 30.82% are uneducated, 22.64% have primary education and 10.06% had at least university level. A significant association was observed between the cereal used and the type of porridge (p<0.001). It can be seen that the marketing and consumption of different porridges is associated with different communes in northern Benin. The method of preserving these porridges and their processing differs from one producer to another or from one consumer to another. It also differs from one municipality to another