Etude de l’impact de la variation de la température sur les activités microbiennes : application à une population de Listeria monocytogenes CIP 7831, Listeria monocytogenes Scott A CIP 103575 et Escherichia coli ATCC 25922

La sécurité sanitaire est un objectif incontournable pour les professionnels de l'agroalimentaire. Pour ce faire, ils doivent, pour chaque procédé de fabrication, pratiquer une démarche d'analyse des dangers et mettre en oeuvre des mesures de prévention pertinentes. Cette approche, appliquée dans son intégralité, nécessite un travail long et fastidieux et demande des personnels hautement qualifiés. Il est désormais nécessaire de dépasser les approches descriptives et de renforcer les approches quantitatives et/ou de modélisation qui répondent donc à la fois aux évolutions internes à la science, au développement des technologies et à des demandes fortes de la société. C’est dans ce contexte que nous avons réalisé une étude de l’influence de la variation de la température sur les activités microbiennes. Elle concerne la réponse à une hausse de la température sur trois souches : Listeria monocytogenes CIP 7831, Listeria monocytogenes Scott A CIP 103575 et Escherichia coli ATCC 25922. Elle consiste en la modélisation de la mortalité induite par une hausse de température. Les résultats ont permis de mettre en évidence la nécessité d’un contrôle strict de la température de stress choisie et de proposer une procédure graphique de choix d’une hausse modérée de la température à appliquer à Listeria monocytogenes CIP 7831, pour obtenir un nombre fixé de bactéries survivantes. © 2013 International Formulae Group. All rights reserved.Mots clés: Microbiologie alimentaire, Sécurité alimentaire, Infections bactériennes, Modélisation mathématique, Biométrie

Farmers knowledge, perceptions and management of Kersting’s groundnut (Macrotyloma geocarpum Harms) insect pests in Benin

Open Access JournalBackground Macrotyloma geocarpum Harms is a neglected and underutilized crop in Benin subject to several constraints including storage insect attacks, which contribute to the decrease in its production. An ethnobotanical survey using a semi-structured questionnaire was conducted in 15 villages in southern and central Benin to document farmers’ perceptions of M. geocarpum storage insect pests and their traditional management practices. Results The results showed that insect pest were the most important storage constraint of M. geocarpum. To overcome this constraint, the promotion of resistant landraces has been proposed by farmers. Six vernaculars names of storage insect pests of M. geocarpum were identified throughout the study area and all corresponding to Callosobruchus maculatus (F.) which proved to be the most abundant insect in the stocks. Palatability and fragility of seeds coat have been identified by farmers as the main factors favoring the infestation by this pest. Various storage containers of M. geocarpum have been inventoried. Our study revealed that education, storage containers, and Kersting’s groundnut landraces significantly influenced farmers’ perceptions of severity of insect pest damages. The use of chemicals and repellent plants were the main control methods used by farmers to protect stocks. Different levels of resistance of M. geocarpum landraces to storage insect pests were reported. Conclusions This study provides baseline information for development of integrated management approaches against storage insect pests of M. geocarpum. The perceived level of resistance to insect damage on Kersting’s groundnut landraces needs to be investigated

Health Effects of Radiation Exposure to Human Sensitive Organs Across Some Selected

The interaction of ionizing radiation with human body, either from external sources (i.e. outside the body) or from internal contamination of the body by radioactive substances, leads to biological effects which may later show up as clinical symptoms. The nature and severity of these symptoms and the time at which they appear depend on the amount of radiation absorbed and the rate at which it is received. This study aimed at assessing the Health Effects of Radiation Exposure to Human Sensitive Organs across Some Selected Mining Sites of Plateau State Nigeria. Finding of this study have revealed that the mean Dorgan values for the lungs, ovaries, bone marrow, testes, kidney, liver and whole body for different mining points of Plateau State are 0.29, 0.26, 0.31, 0.36, 0.28, 0.21 and 0.30 mSv/y respectively. From the findings presented, it can be concluded that the background radiation in Plateau State is not an issue of health concern in regards to sensitive organs and may not course immediate health effect except when accumulated over long period of time which may cause cancer to the indoor members on approximately seventy years of exposure

Effets de l’extrait aqueux de gomphrena celosioides (amaranthaceae) sur les enzymes hépatiques

Gomphrena celosioides est une plante utilisée en médecine traditionnelle dans le traitement des maladies hépatiques. Le tétrachlorure de carbone (CCl4) a été utilisé pour induire une hépato toxicité chez les rats. Ce hépatotoxique provoque une montée significative des taux des enzymes hépatiques et de la bilirubine. Les différents traitements avec l’extrait aqueux de Gomphrena celosioides (EAG) à la dose de 500 mg/kg de Poids Vif (PV) et de la silymarine (SIL) reconnue pour ses propriétés hépatotoxiques, à la dose de 300 mg/kg PV entrainent une baisse des taux de ces paramètres. Les traitements préventifs des animaux avec l’EAG et la SIL ont entraîné une baisse du taux des transaminases sériques, des phosphatases alcalines et de la bilirubine avec une protection de 65,06 % pour l’EAG et 78,34 % pour la SIL en ce qui concerne l’Alanine amino transférase (ALAT). Les traitements curatifs des animaux à l’EAG et à la SIL ont donné une protection de 56,35 % pour l’EAG contre 70,45% pour la SIL en ce qui concerne l’ALAT. L’activité hépato protectrice de l’EAG est donc plus protective que curative. Cette activité est comparable à celle de la SIL. Les mécanismes possibles de cette activité peuvent être dus à l’action des antioxydants contenus dans les flavonoïdes, présents dans l’EAG.Mots-clés : affections hépatiques, silymarine, médecine traditionnelle, hépato toxicité, flavonoïdes.The aqueous extract effect of Gomphrena celosioides in liver enzymes Gomphrena celosioides is a plant used in traditional medicine in the treatment of liver disease. Carbon tetrachloride (CCl4) was used to induce hepatotoxicity in rats. This hepatotoxic causes a significant rise in liver enzymes and bilirubin. The various treatments with the aqueous extract of Gomphrena celosioides (EAG) at a fixed dose of 500 mg/kg body weight (bw) and silymarin (SIL), which is known for its hepatoprotective properties, at a fixed dose of 300 mg/kg bw, decrease the activity of these parameters. Preventive treatments of animals with EAG and SIL resulted in a decrease in serum transaminases, alkaline phosphatase and bilirubin with the protection of 65, 06 % for EAG and 78, 34 % for SIL in Alanine Amino Transferase (ALT) respectively. With regards to ALT, curative treatments with EAG and SIL gave a protection of 56, 35 % for EAG against 70, and 45 % for SIL. The activity of EAG is more protective than curative. This activity is comparable to that of SIL. Possible mechanisms of this activity may be due to the action of antioxidants in flavonoids, whose presence is known in EAG.Keywords : liver disease, silymarin, traditional medicine, hepatotoxicity, flavonoids

Analysis of gender and governance of value chainbased systems on rice and vegetable crops in southern Benin and Mali

Published Online June 2015This present study analyses gender and governance in the rice and vegetable-based value chain systems in 3 lowlands of southern Benin and 2 lowlands in Southern Mali. A sample of 243 farmers, 1 modern processing unit, 18 traditional processors, 76 traders and 8 national institutions were interviewed in Benin and Mali. Descriptive statistics and Harvard analytical framework were used for the analysis of governance and gender respectively in the value chains. The majority of farmers have access to the use of land. Women produce up to 80% of basic foods for household consumption and sale. However they don’t have the control of these resources (capital and land). Decision making in relation to resources (land, water labor, credit) is under the control of men and natives. The governance analysis showed that the products of lowlands are not subject to quality control, with no public inspection for health and product quality. There is no input subsidy for actors in both countries. There are informal contracts between actors of the rice based systems in Mali and Benin. The markets are open for all the products and credit systems do exist. Some structures are involved in upstream and downstream chain components for training in various activitiesThis present study analyses gender and governance in the rice and vegetable-based value chain systems in 3 lowlands of southern Benin and 2 lowlands in Southern Mali. A sample of 243 farmers, 1 modern processing unit, 18 traditional processors, 76 traders and 8 national institutions were interviewed in Benin and Mali. Descriptive statistics and Harvard analytical framework were used for the analysis of governance and gender respectively in the value chains. The majority of farmers have access to the use of land. Women produce up to 80% of basic foods for household consumption and sale. However they don’t have the control of these resources (capital and land). Decision making in relation to resources (land, water labor, credit) is under the control of men and natives. The governance analysis showed that the products of lowlands are not subject to quality control, with no public inspection for health and product quality. There is no input subsidy for actors in both countries. There are informal contracts between actors of the rice based systems in Mali and Benin. The markets are open for all the products and credit systems do exist. Some structures are involved in upstream and downstream chain components for training in various activitie

Étude hydrogéochimique des eaux des aquifères de fractures du socle Paléoprotérozoïque du Nord-Est de la Côte d’Ivoire : Cas de la région de Bondoukou

La région de Bondoukou, objet de cette étude est une zone soumise à un problème crucial d’approvisionnement en eau potable. Cette étude se propose d’améliorer les connaissances sur les nappes souterraines et de déterminer l’origine de la minéralisation des eaux souterraines de la région à partir d’une combinaison des méthodes hydro-chimiques et de l’Analyse en Composantes Principales. L’étude hydro-chimique montre que les eaux de la région sont agressives, avec un pH qui varie de 5,62 à 7,47, pour une moyenne de 6,23. A l’exception des localités de Motiamo (1236 µS/cm) et Malaga (1175 µS/cm) où sont observées de fortes conductivités, ces eaux sont dans l’ensemble faiblement minéralisées, avec une conductivité électrique qui varie de 134 à 1236 µS/cm, pour une moyenne de 347,55 µS/cm. Les eaux souterraines de la région sont bicarbonatées calciques (93,75%) et chlorurées calciques (6,25%). On note dans l’ensemble que les eaux des aquifères de fractures sont sous-saturées en calcite et en dolomite. La minéralisation des eaux souterraines de la région a pour origine, l’altération des roches, l’hydrolyse des minéraux silicatés tels que l’anorthite dans les plagioclases et la décomposition des minéraux ferromagnésiens comme la biotite et l’amphibole. A cela s’ajoute le pluviolessivage des sols et une pollution liée aux activités anthropiques.Mots-clés : aquifère, Bondoukou, eaux souterraines, hydrochimie, minéralisation.Hydrogeochimistry study of water from fractured aquifers of the Paeleoproterozoic in the North-East of Côte d’Ivoire: Case of the area of BondoukouThe area of Bondoukou where the study takes place has a problem of assess of clean water. The main objective of this study is to improve the knowledge of the phenomena of mineralization of groundwater of the region of Bondoukou. The method used for this study is the hydrochemistry method and the multivariate analysis such as Principal Component Analysis. Hydrochemistry analysis show that the pH of groundwater are acids and range from 5.62 to 7.47, with an average of 6.23. Except, Motiamo (1236 µS/cm) and Malaga (1175 µS/cm) where high electrical conductivities are found, groundwater of the area have low electrical conductivities. Those conductivities varied from 134 to 1236 µS/cm, with an average of 347.55 µS/cm. In this region, groundwater are bicarbonated and calcic (93.75%) and chlorured and calcic (6.25%). Water from rock aquifer are undersatured in calcite and dolomite.The mineralisation of the water are associated with wereathing, hydrolysis of silicates minerals such as anorthite and biotite. Water take also mineral element from antropogenic activities.Keywords : aquifer, Bondoukou, groundwater, hydrochemistry, mineralization

Termites (Blattodea: Termitidae) diversity and assemblages in different yam fields habitats in central Benin

Open Access JournalTermites are known to cause significant economic losses in yam fields. Therefore, assessing diversity and abundance of termites in yam fields is critical for their control. In this study, we compared the specific richness, abundance, and diversity of functional groups of termite pests in upland and lowland yam fields, across 15 villages using the standardized belt transect method. The specific termite diversity encountered in yam fields was compared with that of the Agoua classified forest. In general, eight genera classified into four subfamilies (Nasutitermitinae, Macrotermitinae, Amitermitinae and Coptotermitinae) grouped into two families (Termitidae and Rhinotermitidae) were identified. The highest number of the species (13) were identified in upland fields while the lowest number (10) were identified in the lowlands. Termite fauna collected from yam fields and from the Agoua forest were distinct, as showed by the similarity index. Amitermes evuncifer (Silvestri) was the most widely distributed and the most dominant termite species in upland yam fields while in lowland yam fields it was Macrotermes subhyalinus (Rambur). Three functional groups were observed with humus feeders only found in upland yam fields. Principal component analysis classified the 24 sampled transects into four groups with different termites feeding groups. The dominance of non-fungus-growers was observed in the groups mostly composed of transects in uplands yam fields. Three nesting habitats were represented (epigeal mound, wood, and subterranean). The results of this present research could help to develop efficient strategies against the identified key yam termite pests

Does R&D, human capital and FDI matter for TFP in OECD countries?

This study investigates the interplay between research and development (R&D), human capital (HC), foreign direct investment (FDI) and total factor productivity (TFP) in OECD countries. We divide the sample into two sub-groups; the European and the non-European states so as to account for underlying country heterogeneity. The analysis follows a panel data approach over the period 1995–2015, taking into account the modelling on non-stationarity, long-run relationships and short-run dynamics with a panel VAR. Both R&D and HC have a positive effect on TFP, whilst FDI has a positive and significant effect only in the case of non-European countries. Moreover, the contribution of R&D is higher than that of HC and FDI in all cases. Thus, based on these findings, policymakers should design and implement policies to increase resources invested in R&D, with a consistent ongoing spending review, to attract foreign direct investment, especially for the majority of the European and some of the non-European countries and to improve education system on a more productive innovation and research base

White Guinea yam (Dioscorea rotundata Poir.) landraces trait profiling and setting benchmark for breeding programs in the Republic of Benin

Open Access Journal; Published online: 17 Aug 2022To meet the high demand for white Guinea yam, there is a need to develop and release improved varieties to farmers. Unfortunately, low rate of adoption of most of the improved yam varieties by both producers and consumers was observed. Information regarding agronomic characteristics and food qualities of popular white Guinea yam landraces with high market value are not available to establish minimum standards to be considered by breeding programs. To fill this gap, surveys using rural appraisal tools were carried out in 20 villages and 16 markets throughout Benin. Data on the agronomic performance suggested that for an improved variety to be adopted by Beninese farmers it should have a minimum yield of 4.16 ± 0.15 kg per mound, and average number of marketable tubers of 1.23 ± 0.05, a mean tuber length of 36.41 ± 1.22 cm, and a minimum diameter of 25.44 ± 1.16 cm. The sensorial attributes for boiled and pounded tubers of this improved variety should have minimum score of 3.16 for texture, 0.75 for softness, 3.75 for elasticity, and 1.34 for colour during the sensory evaluation. The improved variety must also have a minimum average severity score of 1.1 for yam mosaic virus disease, 1.33 for anthracnose and 1 for nematodes. Landraces Amoula, Laboko, and Djilaadja should be considered as the standard for yield, sensory attributes, and tolerance to pest and diseases while landraces Danwari, Kodjewe, Mondji, and Gnidou should be characterized as possessing good flowering and fruit setting capacities for breeding programs

Diversity of white Guinea yam (Dioscorea rotundata Poir.) cultivars from Benin as revealed by agro-morphological traits and SNP markers

Open Access Article; Published online: 18 Oct 2021White Guinea yam (Dioscorea rotundata Poir.) is indigenous to West Africa, a region that harbours the crop's tremendous landrace diversity. The knowledge and understanding of local cultivars’ genetic diversity are essential for properly managing genetic resources, conservation, sustainable use and their improvement through breeding. This study aimed to dissect phenotypic and molecular diversity of white yam cultivars from Benin using agro-morphological and single nucleotide polymorphism (SNP) markers. Eighty-eight Beninese white Guinea yam cultivars collected through a countrywide ethnobotanical survey were phenotyped with 53 traits and genotyped with 9725 DArT-SNP. Multivariate analysis using phenotypic traits revealed 30 traits as most discriminative and explained up to 80.78% of cultivars’ phenotypic variation. Assessment of diversity indices such as Shannon–Wiener (H′), inverse Shannon (H.B.), Simpson's (λ) index and Pilou evenness (J) based molecular and phenotypic data depicted a moderate genetic diversity in Beninese white Guinea yam cultivars. Genetic differentiation of cultivars among country production zones was low due to the high exchange of planting materials among farmers of different regions. However, there was high genetic diversity within regions. Hierarchical clusters (HCs) on phenotypic data revealed the presence of two groups while HCs based on the SNP markers and the combined analysis identified three genetic groups. Our result provided valuable insights into the Beninese white Guinea yam diversity for its proper conservation and improvement through breeding