Efficacy of two plant powders as cowpea grain protectants against Callosobruchus maculatus Fabricius (Coleoptera, Chrysomelideae: Bruchinae)

Objective: This study was carried out to study insecticidal effect of powders from Chenopodium ambrosioides leaves and Aframomum melegueta seeds on cowpea weevil Callosobruchus maculatus.Methodology and Results: 5g of both powders of A. melegueta and C. ambrosioides were used in the proportions of C. ambrosioides 100%:A. melegueta 0%, C. ambrosioides 0%: A. melegueta 100%, C. ambrosioides 30%: A. melegueta 70%, C. ambrosioides 70%: A. melegueta 30% and C. ambrosioides 50%: A. melegueta 50%. Plant powders were added to 20g of cowpea grains. Bioassays were conducted at 26.64±0.74°C and 72.55±4.38% relative humidity. Insect mortality was evaluated from 24 to 144 hours after treatment. Results obtained indicated that plant powders had significant effect on C. maculatus mortality. The highest mortality rate (70.00±26.45%) was recorded in jar treated with C. ambrosioides.Conclusion and application of findings: Either plant powders, alone or mixed had high insecticidal effect on C. maculatus. Because of their effectiveness, these plant powders could be recommended as grain protectants against C. maculatus.Key words: Chenopodium ambrosioides, Aframomum melegueta, Callosobruchus maculatus, Insecticidal activit

Efficacy of mixed powders of Piper guineense and Zingiber officinale as maize grain protectants against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)

This study was carried out to evaluate the effects of mixed powders of Piper guineense (Piperaceae) and Zingiber officinale (Zingiberaceae) on Sitophilus zeamais population and seed weight loss percentage of stored maize. Experiment was conducted under laboratory conditions (26.94 ± 0.81 °C, 74.76 ± 4.51% r.h. and 12 h photoperiod). In a completely randomized design with three replications, powders of P. guineense and Z. officinale were applied separately and in mixtures at the ratios of Zg100%:Pg0% (T1), Zg0%:Pg100% (T2), Zg30%:Pg70% (T3), Zg70%:Pg30% (T4) and Zg50%:Pg50% (T5), respectively. The mortality rate of S. zeamais adults was recorded and compared with the control at 24, 48, 72, 96, 120 and 168 hours after treatment. Maize grain damage and seed weight loss percentage were determined. Results showed highly significant differences with S. zeamais mortality rate between treatments, treatment exposure duration and their interactions (p<0.001). P. guineense, alone, showed the best efficacy (mortality rate = 96.66 ± 5.77% at 96 hours after treatment) and mixed with Z. officinale at the ratio 70%Pg: 30Zo (mortality rate = 93.33 ± 5.77%). Taking into account this high performance of P. guineense seed powder, it can be recommended as stored maize grain protectants.Keywords: Botanical insecticides, maize storage, Sitophilus zeamais, weight loss, mortality rate

Evaluation of Extra-early Maturing Maize Genotypes for Grain Yield and Stability in the Groundnut Basin Agro-ecological Zone of Senegal

Maize is a highly valuable staple food crop in Sub-Saharan Africa regions. Its production is hampered by both biotic and abiotic stress. Early-maturing genetic resources appear as an excellent choice to manage adverse climatic change’s effects. This study aimed to find the best extra-early maize genotypes based on genotype by environment interactions in the groundnut agro-ecological zone of Senegal. The trials were conducted in Paoskoto, Ndiedieng, Nioro and Keur Sene during the rainy seasons of 2016 and 2017. Six extra-early maize genotypes were evaluated following a randomized complete block design with three replications. Data on grain yield were recorded and analysed using additive main effect and multiplicative interaction and genotype plus genotype by environment biplot methods. Analysis of variance revealed a significant (P < 0.01) genotype by environment effect on grain yield. The sum of squares variation was higher (77.2%) explained by the environment effect. The genotype 2008-TZEE-W-STR showed the highest yield performance (3299 kg ha-1) and lowest yield stability index (3). This genotype can be suggested to farmers for its cultivation and a good candidate for early maturing maize breeding program in Senegal

Evaluation of Extra-early Maturing Maize Genotypes for Grain Yield and Stability in the Groundnut Basin Agro-ecological Zone of Senegal

Maize is a highly valuable staple food crop in Sub-Saharan Africa regions. Its production is hampered by both biotic and abiotic stress. Early-maturing genetic resources appear as an excellent choice to manage adverse climatic change’s effects. This study aimed to find the best extra-early maize genotypes based on genotype by environment interactions in the groundnut agro-ecological zone of Senegal. The trials were conducted in Paoskoto, Ndiedieng, Nioro and Keur Sene during the rainy seasons of 2016 and 2017. Six extra-early maize genotypes were evaluated following a randomized complete block design with three replications. Data on grain yield were recorded and analysed using additive main effect and multiplicative interaction and genotype plus genotype by environment biplot methods. Analysis of variance revealed a significant (P < 0.01) genotype by environment effect on grain yield. The sum of squares variation was higher (77.2%) explained by the environment effect. The genotype 2008-TZEE-W-STR showed the highest yield performance (3299 kg ha-1) and lowest yield stability index (3). This genotype can be suggested to farmers for its cultivation and a good candidate for early maturing maize breeding program in Senegal

Bridging the gap in African biodiversity genomics and bioinformatics:Open Institute of the African BioGenome Project:

The Open Institute of the African BioGenome Project empowers African scientists and institutions with the skill sets, capacity and infrastructure to advance scientific knowledge and innovation and drive economic growth

Production of food nanomaterials by specialized equipment

In the past decade, there has been a great interest in using nanotechnology by different industries, including food, pharmaceutical, and beauty. Nanotechnology provides many advantages to produce functional compounds which tend to be delivered for desired properties, such as protection from the environment or food matrix, controlled release, and increased bioavailability and bioaccessibility (Muhammad et al., 2019, Sedaghat Doost et al., 2019b, Sedaghat Doost et al., 2018c). There is a variety of methods to prepare food nanomaterials. Specialized equipment is frequently employed for the production of efficient nano-delivery systems, which is the focus of this chapter; the basic principle of conventional and recent techniques, as well as their advantages and disadvantages are described

Informal economy in Benin : occupational exposures and health consequences for tinsmiths in Cotonou

Contexte et objectifs : Au Bénin, le « secteur informel » représente près de 80 % des travailleurs avec une prédominance d’acteurs dans l’artisanat, suivi par le secteur privé moderne (11 %) et la fonction publique (9 %). La situation socio-professionnelle des artisans est caractérisée par l’absence d’équipements de protection, par l’exposition à des nuisances physiques et chimiques et par l’absence de sécurité sociale. L’objectif principal de ce travail de thèse était d’étudier l’impact des conditions de travail sur la santé des forgerons-ferblantiers exerçant dans le cadre de l’économie informelle, à Cotonou au Bénin. Ce travail a permis également d’évaluer l’imprégnation sanguine en éléments traces métalliques chez les ferblantiers par comparaison avec les concentrations observées dans la population masculine de Cotonou, non exposée professionnellement. Cette partie de l’étude a nécessité la mise en place d’une première enquête en population générale, chez 70 donneurs de sang à Cotonou afin de proposer des valeurs de référence pour 29 éléments traces métalliques.Méthode : Une étude transversale a été réalisée à Midombô sur le site des artisans ferblantiers dans le 3ème arrondissement de Cotonou au Bénin. Au total, 84 responsables d’atelier sur 102 ont donné leur accord de participation pour l’étude des postes et conditions de travail, soit un taux de participation de 82,4 %. Parmi les 251 personnes travaillant dans les 102 ateliers investigués, 135 ferblantiers ont accepté de venir au centre de santé Erasme (53,8 %) pour bénéficier d’un entretien médical gratuit. Dans cette population, 31 personnes étaient des apprentis (23,0 %) et 104 étaient des artisans ou maitres-artisans (77,0 %). Résultats : Il a été observé des niveaux de bruit supérieurs à 85 décibels dans 58,3 % des ateliers, avec une durée du travail en moyenne de 10 h par jour pouvant être à l’origine des déficits auditifs (légers à sévères) observés dans 99,3% des cas. L’exposition directe aux fumées et poussières métalliques (38,52 %) et la consommation d’aliments au poste de travail seraient à l’origine d’une imprégnation métallique. Pour 6 éléments traces, plus de 20 % des ferblantiers présentaient des concentrations sanguines supérieures aux valeurs de référence de la population générale. Par ordre croissant de niveau d’imprégnation, il s’agissait du molybdène, du cuivre, du strontium, de l’étain, de l’antimoine, et du plomb. Environ 71 % des ferblantiers présentaient des plombémies supérieures au 95ème percentile des concentrations retrouvées en population non exposée à Cotonou. Pour les moins de 18 ans, la prévalence des travailleurs ayant une plombémie ≥ 100 μg/L était de 83 %. Une baisse de l’acuité visuelle non corrigée (> 20 %) et une hypertension artérielle non traitée (27,4 %) ont été dépistées chez les ferblantiers participants. Conclusion : Les travailleurs informels sont dans une situation de grande vulnérabilité du fait d’une faible couverture en matière de protection sociale et d’un niveau élevé d’exposition aux risques professionnels. Compte tenu du grand nombre de travailleurs dans l’économie informelle, l’amélioration de la santé et de la sécurité au travail des acteurs de ce secteur, devrait permettre un renforcement du capital humain et la réduction des maladies professionnelles encore mal documentées.Context and objectives: In Benin, the "informal sector" represents almost 80% of workers with a predominance of craftsmen, followed by the modern private sector (11%) and the civil service (9%). The socio-professional situation of craftsmen is characterized by the lack of personal or collective protective equipment, exposure to physical and harmful chemical substances and a lack of social security. The main objective of this thesis was to study the impact of working conditions on the health of tinsmiths in the informal economy in Cotonou, Benin. This research also allowed us to evaluate the blood impregnation of trace elements in tinsmiths compared to the background levels of the non-occupationally exposed male population of Cotonou. This part of the study required a first survey of 70 blood donors in Cotonou, in order to propose reference values for 29 trace elements. Method: A cross-sectional study was carried out in Midombô on the site of the tinsmiths in the 3rd district of Cotonou in Benin. Study population: A total of 84 workshop managers out of 102 gave their agreement to participate in the study of work places and conditions (participation rate of 82.4 %). Among the 251 tinsmiths working in the 102 workshops investigated, 135 agreed to go to the “Erasmus” health center (53.8%) for free medical care. In this population, there were 31 apprentices (23.0 %) and 104 craftsmen or master craftsmen (77.0 %). Results: Noise levels greater than 85 decibels were observed in 58.3% of the workshops, with an average working time of 10 hours per day. This exposure can be the cause of hearing impairment (mild to severe) observed in 99, 3% of the cases. Direct exposure to metal fumes and dust (38.52 %) and the consumption of food at the workplace are the cause of metallic impregnation. For 6 trace elements, more than 20 % of the tinsmiths had blood concentrations above the reference values of the general population. These elements, classified from the lowest to the highest level of impregnation were molybdenum, copper, strontium, tin, antimony, and lead, respectively. Approximately 71% of the tinsmiths had lead levels above the 95th percentile of concentrations found in unexposed populations in Cotonou. 83% of the workers who were under 18 years of age had blood lead levels ≥ 100 μg / L. Uncorrected visual acuity (> 20%) and untreated arterial hypertension (27.4 %) were detected in the participating tinsmiths. Conclusion: Informal workers are in a very vulnerable situation due to poor social protection and a high level of exposure to occupational risks. Given the large number of employees in the informal sector, improving the occupational health and safety of these workers should help to strengthen human capital and reduce the incidence of occupational diseases that are still poorly documented

Travail informel au Bénin : Expositions professionnelles et conséquences sanitaires chez les forgerons-ferblantiers à Cotonou

Context and objectives: In Benin, the "informal sector" represents almost 80% of workers with a predominance of craftsmen, followed by the modern private sector (11%) and the civil service (9%). The socio-professional situation of craftsmen is characterized by the lack of personal or collective protective equipment, exposure to physical and harmful chemical substances and a lack of social security. The main objective of this thesis was to study the impact of working conditions on the health of tinsmiths in the informal economy in Cotonou, Benin. This research also allowed us to evaluate the blood impregnation of trace elements in tinsmiths compared to the background levels of the non-occupationally exposed male population of Cotonou. This part of the study required a first survey of 70 blood donors in Cotonou, in order to propose reference values for 29 trace elements. Method: A cross-sectional study was carried out in Midombô on the site of the tinsmiths in the 3rd district of Cotonou in Benin. Study population: A total of 84 workshop managers out of 102 gave their agreement to participate in the study of work places and conditions (participation rate of 82.4 %). Among the 251 tinsmiths working in the 102 workshops investigated, 135 agreed to go to the “Erasmus” health center (53.8%) for free medical care. In this population, there were 31 apprentices (23.0 %) and 104 craftsmen or master craftsmen (77.0 %). Results: Noise levels greater than 85 decibels were observed in 58.3% of the workshops, with an average working time of 10 hours per day. This exposure can be the cause of hearing impairment (mild to severe) observed in 99, 3% of the cases. Direct exposure to metal fumes and dust (38.52 %) and the consumption of food at the workplace are the cause of metallic impregnation. For 6 trace elements, more than 20 % of the tinsmiths had blood concentrations above the reference values of the general population. These elements, classified from the lowest to the highest level of impregnation were molybdenum, copper, strontium, tin, antimony, and lead, respectively. Approximately 71% of the tinsmiths had lead levels above the 95th percentile of concentrations found in unexposed populations in Cotonou. 83% of the workers who were under 18 years of age had blood lead levels ≥ 100 μg / L. Uncorrected visual acuity (> 20%) and untreated arterial hypertension (27.4 %) were detected in the participating tinsmiths. Conclusion: Informal workers are in a very vulnerable situation due to poor social protection and a high level of exposure to occupational risks. Given the large number of employees in the informal sector, improving the occupational health and safety of these workers should help to strengthen human capital and reduce the incidence of occupational diseases that are still poorly documented.Contexte et objectifs : Au Bénin, le « secteur informel » représente près de 80 % des travailleurs avec une prédominance d’acteurs dans l’artisanat, suivi par le secteur privé moderne (11 %) et la fonction publique (9 %). La situation socio-professionnelle des artisans est caractérisée par l’absence d’équipements de protection, par l’exposition à des nuisances physiques et chimiques et par l’absence de sécurité sociale. L’objectif principal de ce travail de thèse était d’étudier l’impact des conditions de travail sur la santé des forgerons-ferblantiers exerçant dans le cadre de l’économie informelle, à Cotonou au Bénin. Ce travail a permis également d’évaluer l’imprégnation sanguine en éléments traces métalliques chez les ferblantiers par comparaison avec les concentrations observées dans la population masculine de Cotonou, non exposée professionnellement. Cette partie de l’étude a nécessité la mise en place d’une première enquête en population générale, chez 70 donneurs de sang à Cotonou afin de proposer des valeurs de référence pour 29 éléments traces métalliques.Méthode : Une étude transversale a été réalisée à Midombô sur le site des artisans ferblantiers dans le 3ème arrondissement de Cotonou au Bénin. Au total, 84 responsables d’atelier sur 102 ont donné leur accord de participation pour l’étude des postes et conditions de travail, soit un taux de participation de 82,4 %. Parmi les 251 personnes travaillant dans les 102 ateliers investigués, 135 ferblantiers ont accepté de venir au centre de santé Erasme (53,8 %) pour bénéficier d’un entretien médical gratuit. Dans cette population, 31 personnes étaient des apprentis (23,0 %) et 104 étaient des artisans ou maitres-artisans (77,0 %). Résultats : Il a été observé des niveaux de bruit supérieurs à 85 décibels dans 58,3 % des ateliers, avec une durée du travail en moyenne de 10 h par jour pouvant être à l’origine des déficits auditifs (légers à sévères) observés dans 99,3% des cas. L’exposition directe aux fumées et poussières métalliques (38,52 %) et la consommation d’aliments au poste de travail seraient à l’origine d’une imprégnation métallique. Pour 6 éléments traces, plus de 20 % des ferblantiers présentaient des concentrations sanguines supérieures aux valeurs de référence de la population générale. Par ordre croissant de niveau d’imprégnation, il s’agissait du molybdène, du cuivre, du strontium, de l’étain, de l’antimoine, et du plomb. Environ 71 % des ferblantiers présentaient des plombémies supérieures au 95ème percentile des concentrations retrouvées en population non exposée à Cotonou. Pour les moins de 18 ans, la prévalence des travailleurs ayant une plombémie ≥ 100 μg/L était de 83 %. Une baisse de l’acuité visuelle non corrigée (> 20 %) et une hypertension artérielle non traitée (27,4 %) ont été dépistées chez les ferblantiers participants. Conclusion : Les travailleurs informels sont dans une situation de grande vulnérabilité du fait d’une faible couverture en matière de protection sociale et d’un niveau élevé d’exposition aux risques professionnels. Compte tenu du grand nombre de travailleurs dans l’économie informelle, l’amélioration de la santé et de la sécurité au travail des acteurs de ce secteur, devrait permettre un renforcement du capital humain et la réduction des maladies professionnelles encore mal documentées