Diversité et dynamique des assemblages phytoplanctoniques dans les écosystèmes aquatiques au Sud du Togo

L'étude de la diversité algale de 4 écosystèmes aquatiques du Sud-Ouest du Togo a permis l'identification de 203 espèces dont une centaine est signalée pour la première fois au Togo. Ces espèces sont réparties en 6 embranchements, 29 familles et 85 genres. L’appréciation de la dynamique du phytoplancton a permis de constater que la densité de la population algale est plus importante en grande saison pluvieuse qu’en grande saison sèche. Son importance est encore beaucoup moindre en petite saison sèche qu’en petite saison pluvieuse. Quatre paramètres physico-chimiques sont mesurés. Les analyses multivariées montrent que ces paramètres physico-chimiques affectent plus ou moins la distribution spatiale du peuplement algal. Relativement aux groupes phytoplanctoniques identifiés, plus de 70% des Euglénophytes sont rencontrés dans les mares. Par ailleurs, le peuplement phytoplanctonique lagunaire est à 58% composé des Chromophytes et celui de la rivière est dominé par les Chlorophytes (40%) et les Cyanophytes (30%).Mots-clés : diversité algale, dynamique, paramètres physico-chimiques, écosystèmes aquatiques, Sud du Togo.Diversity and dynamic of phytoplankton assemblages in the aquatic ecosystems in south of TogoThe study of algal diversity of four aquatic ecosystems in Togo’s southwestern led to the identification of 203 species including a hundred which is reported for the first time in Togo. These species are divided into 6 phyla, 29 families and 85 genera. The appreciation of the dynamics of phytoplankton showed that the algal population density is higher in long rainy season than dry season. Its importance is much lower in short dry season than in small rainy season. Four physico-chemical parameters are measured. Multivariate analysis showed that these physico-chemical parameters affect greater or lesser the spatial distribution of algal assemblage. In this study, more than 70% of Euglenophyta met in ponds. In addition, the settlement lagoon phytoplankton is composed of 58% Chromophyta and the river is dominated by Chlorophyta (40%) and Cyanophyta (30%).Keywords : algal diversity, dynamic, physico-chemical parameters, aquatic ecosystems, South of Togo

Présence d\'algues toxiques dans les eaux marines et saumâtres du littoral togolais

Des travaux de recensement de microalgues des eaux marines et saumâtres du littoral togolais pendant une période déterminée de l\'année ont conduit à l\'établissement d\'une liste non exhaustive des espèces phytoplanctoniques potentiellement toxiques du Togo. Cette liste provient de la comparaison de l\'inventaire des microalgues recensées lors de cette étude à celui des espèces toxiques signalées préalablement par différents auteurs. Le prélèvement des eaux marines a été effectué durant la période de juin à septembre 2004 et celui des eaux saumâtres a été réalisé en novembre 2002. Au total, une quarantaine d\'espèces de microalgues toxiques appartenant aux Cyanophycées, Dinoflagellés et Diatomophycées, a été identifiée. Ce travail a permis de mettre en évidence les microalgues toxiques des eaux polluées par les rejets des zones industrielles et les déchets organiquesCensus of marine microalgaes and brackish waters algae on Togolese coastline during a determined period have driven to the establishment of a non exhaustive list of phytoplanktonic toxic species; this list comes from comparison of the inventory of microalgaes identified during the survey time to the one of the toxic species signalized previously by different authors. The samples of marine waters has been done during the period of June to September 2004, and the one of brackish waters has been realised in November 2002. About 40 toxic microalgaes species, belonging to Cyanophyceae, Dinoflagellate and Diatomophyceae have been identified. This work allowed to know toxic microalgaes of waters contaminated by rejections of industrial zones and organic wastes. Keywords: inventaire – microalgues – toxiques - eaux marines - eaux saumâtres; Inventory - Microalgaes - Toxic - Marine waters - Brackish watersAnnales des Sciences Agronomiques du Bénin Vol. 10 (2) 2008: pp. 165-17

Activity and stability of immobilized lipases in lipase-catalyzed modification of peanut oil

Fatty acid release during lipolysis of peanut oil using microbial free and immobilized lipases in aqueous media was developed. Immobilized lipase from Rhizomucor miehei (RML) gave the best result from its ability to clive different fatty acids from peanut oil in such media. In organic solvent, interesterification of peanut oil with tricaprylin using immobilized lipases from RML, Chromobacterium viscosum (CVL) and Candida rugosa (CRL) was performed. The best substrate molar ratio of tricaprylin to peanut oil found was in the range 0.7 to 0.8. Using substrate molar ratio 0.7, high amount of structured triglyceride ST (about 35% MLM, 44% LML triglyceride fractions) was obtained with lipase from RML in n-hexane. The results found in solvent free system were in some cases quite similar to that obtained in organic solvent. In nine successive batch interesterification in solvent free medium using immobilized RML and CRL, no significant loss of amount of both produced triacylglycerol fractions until batch 7 was observed with RML

Activity and stability of immobilized lipases in lipase-catalyzed modification of peanut oil

Fatty acid release during lipolysis of peanut oil using microbial free and immobilized lipases in aqueous media was developed. Immobilized lipase from Rhizomucor miehei (RML) gave the best result from its ability to clive different fatty acids from peanut oil in such media. In organic solvent, interesterification of peanut oil with tricaprylin using immobilized lipases from RML, Chromobacterium viscosum (CVL) and Candida rugosa (CRL) was performed. The best substrate molar ratio of tricaprylin to peanut oil found was in the range 0.7 to 0.8. Using substrate molar ratio 0.7, high amount of structured triglyceride ST (about 35% MLM, 44% LML triglyceride fractions) was obtained with lipase from RML in n-hexane. The results found in solvent free system were in some cases quite similar to that obtained in organic solvent. In nine successive batch interesterification in solvent free medium using immobilized RML and CRL, no significant loss of amount of both produced triacylglycerol fractions until batch 7 was observed with RML

Le contrôle de terrain par la méthode des transects en classification d'image HRV

(J. de la Recherche Scientifique de l'Université de Lomé, 2000, 4(1): 103-112

Connaissances, attitudes et pratiques des mesures barrieres contre la COVID-19 en milieu scolaire : Cas du Lycee Agoe-Nyive Centre a Lome (Togo) : Knowledge, attitudes and practices on barrier measures against COVID-19 in school: Case of Agoe-Nyive Center high school in Lome (Togo)

Introduction : Les établissements scolaires ont été l'un des milieux de vie les plus impactés par la COVID-19. L’objectif de notre étude était d’évaluer les connaissances, attitudes et pratiques des mesures barrières contre la COVID-19 chez les élèves et enseignants du lycée Agoe-Nyivé Centre à Lomé.Méthode : Il s’agissait d’une étude transversale menée du 11 mai au 14 juin 2021 au lycée Agoe-Nyivé Centre à Lomé. Un échantillonnage systématique de 80 élèves a été réalisé et 40 enseignants disponibles ont été sélectionnés. Un questionnaire a été administré en entretien face à face aux élèves. Les enseignants l’ont rempli eux-mêmes.Résultats : L’âge moyen des élèves et des enseignants était respectivement de 17,8 ± 2,0 ans et 38,9 ± 8,1 ans. Le sex-ratio (H/F) était de 1,2 chez les élèves et 9 chez les enseignants. Les principales sources d’information sur la COVID-19 et ses mesures barrières étaient la télévision (93,3%), la radio (75,8%) et les réseaux sociaux (68,3%). Les modes de transmission de la COVID-19 étaient connus dans plus de 80% des cas. Les symptômes de la COVID-19 les plus connus étaient les difficultés respiratoires (97,5%), la toux (95,8%) et la fièvre (95,0%). Tous les élèves et les enseignants estimaient important le respect des mesures barrières contre la COVID-19. Lorsqu’ils présenteraient des signes de la COVID-19, ils appelleraient le numéro vert 111 (84,2%), iraient à l’hôpital (58,3%) ou resteraient en isolement à la maison (45,8%). Les mesures barrières systématiquement pratiquées au sein de l’établissement étaient le port de masque (98,3%), le lavage des mains (82,5%) et le respect de la distanciation physique (60,8%). Le matériel de lavage des mains à leur disposition était les dispositifs de lave-mains (90,8%) et la solution hydro-alcoolique (75,0%). Les masques les plus utilisés étaient de type chirurgical (75,0%) et en tissu (55,8%).Conclusion : l’étude a révélé de bonnes connaissances, des attitudes positives et de bonnes pratiques sur les mesures barrières contre la COVID-19, bien que certaines insuffisances existent. Il est important de continuer par diffuser les messages de sensibilisation contre la COVID-19 au Togo. Introduction: Schools have been one of the living environments most affected by COVID-19. The objective of our study was to assess the knowledge, attitudes and practices of barrier measures against COVID-19 among students and teachers in Agoe-Nyivé Center high school in Lomé.Method: This was a cross-sectional study conducted from May 11 to June 14, 2021 in Agoe-Nyivé Center high school in Lomé. A systematic sampling of 80 students was carried out and 40 available teachers were selected. A questionnaire was administered in a face-to-face interview with the students. The teachers filled it out themselves.Results: The mean age of students and teachers was 17.8 ± 2.0 years and 38.9 ± .1 years, respectively. The sex ratio (M/F) was 1.2 for students and 9 for teachers. The main sources of information on COVID-19 and its barrier measures were television (93.3%), radio (75.8%) and social networks (68.3%). The modes of transmission were known in more than 80% of cases. The most well-known symptoms of COVID-19 were difficulty breathing (97.5%), cough (95.8%) and fever (95.0%). All students and teachers estimated important to respect the barrier measures against COVID-19. If they have symptoms of COVID-19, they would call the free number 111 (84.2%), go to hospital (58.3%) or stay in isolation at home (45.8%). Barrier measures systematically practiced in the school were to wear masks (98.3%), hand washing (82.5%) and respect of physical distancing (60.8%). The hand washing materials available were hand washing devices (90.8%) and alcohol-based hand rub (75.0%).The most widely used masks were surgical (75.0%) and fabric (55.8%).Conclusion: the study showed good knowledge, positive attitudes and good practices on barrier measures against COVID-19, although some insufficiencies exist. It is important to continue by diffusing sensitization spots against COVID- 19 in Togo

Improved Traditional Drugs: State of knowledge for the sustainable management of gastrointestinal parasitic nematodes of small ruminants

This article aims to present the current state of the fight against gastrointestinal parasites in small ruminants from Improved Traditional Drugs (DTI). A host of scientific documents were consulted by means of search engines to gather the information useful for this synthesis. The failure of conventional treatments has led to the use of new methods to treat digestive pathologies due to internal parasitism in herds of sheep and goats. These include, among others, herbal medicine, homeopathy, aromatherapy, the mixed grazing system for small and large ruminants, ... All plant parts of plants can be used in the preparation of remedies. Several scientific studies show that plants are full of chemical compounds that cause anthelmintic effects on gastrointestinal parasites in small ruminants. Literature searches have revealed that studies on DTIs in the management of gastrointestinal nematodes in small ruminants are non-existent. In addition to the forms (decocted, macerated, infused, etc.) traditionally used by breeders, there are other forms that can be used to make DTIs from plant extracts. There are capsules, capsules, tablets etc. The placing on the market of DTIs requires official authorization based on the safety and reproducibility of the products. From the documents consulted, it appears that scientific research has not yet focused on the formulation of DTIs for the treatment of gastrointestinal parasitic nematodes in small ruminants. It will be useful to manufacture them to facilitate access to veterinary care and the sustainable management of animal health. Keywords: Improved Traditional Drugs; Gastrointestinal nematodes; Small ruminants, West Africa; Central Africa

Biome reconstruction from pollen and plant macrofossil data for Africa and the Arabian peninsula at 0 and 6000 years

Biome reconstruction from pollen and plant macrofossil data provides an objective method to reconstruct past vegetation. Biomes for Africa and the Arabian peninsula have been mapped for 6000 years sp and provide a new standard for the evaluation of simulated palaeovegetation distributions. A test using modern pollen data shows the robustness of the biomization method, which is able to predict the major vegetation types with a high confidence level. The application of the procedure to the 6000 years data set (pollen and plant macrofossil analyses) shows systematic differences from the present that are consistent with the numerous previous regional and continental interpretations, while providing a more extensive and more objective basis for such interpretations. Madagascar, eastern, southern and central Africa show only minor changes in terms of biomes, compared to present. Major changes in biome distributions occur north of 15 degrees N, with steppe in many low-elevation sites that are now desert, and temperate xerophytic woods/scrub and warm mixed forest in the Saharan mountains. These shifts in biome distributions, imply significant changes in climate, especially precipitation, between 6000 years and present, reflecting a change in monsoon extent combined with a southward expansion of Mediterranean influence. [References: 170