Evaluation de la qualité physico-chimique et de la pollution métallique du lac Guidimouni site RAMSAR au Niger : qualité du milieu de vie pour les organismes aquatiques

Au Niger les plans d’eau sont soumis à des perturbations physique et chimiques, origine de la dégradation de leur qualité. La présente étude fait un diagnostic des perturbations de la qualité des eaux dues aux activités anthropiques sur le lac Guidimouni en se basant l’état physico-chimique et la pollution métallique. A cet effet, des mesures sur les eaux ont été réalisé In-situ : T°, CE, TDS, pH, OD et Au laboratoire : MES, Cl-, SO42-, HCO3-, CO3-, NO3-, NO2-, NH4+, P, Pb, Zn, Cu, Fe et Cd. Pour les sédiments, la granulométrie et le taux de matière organique ont été déterminés.  Les résultats montrent une eau alcaline en saison froide (pH 9,3) (risque de toxicité du NH3), une charge organique plus élevée en saison chaude et pluvieuse (NH4+ 2,9 mg/L et phosphore 23,8mg/L) indiquant un risque élevé d’eutrophisation avec un niveau très bas d’OD 3mg/L (risque asphyxie) en saison pluvieuse. Une pollution anthropique modérée à forte (chlorure 100,7mg/L). Tous les ETM analysés dans les eaux et sédiments ont été détecté, toutefois à des teneurs conformes aux normes sauf pour le Pb (51,26 à 63,82µg/L), ce qui montre un début de pollution métallique du lac. Des mesures correctives doivent être envisager afin de préserver la biodiversité locale.   In Niger, water bodies are subject to physical and chemical disturbances, which is the origine of their quality deterioration. The aim of this study was to diagnose the disturbances in water quality caused by anthropic activities on Lake Guidimouni, based on the physicochemical state and metal pollution. In this order, measurements were carried out on water and sediments in situ: T°, CE, TDS, pH, OD and in the laboratory: SM, Cl-, SO42-, HCO3-, CO3-, NO3-, NO2-, NH4+, P, Pb, Zn, Cu, Fe and Cd. For the sediments, the granulometry and the organic matter content were determined. The results showed alkaline water in the cold season (pH 9.3) (risk of NH3 toxicity), a higher organic load in the hot and rainy season (NH4+ 2.9 mg/L and phosphorus 23.8 mg/L), indicating a high risk of eutrophication with a very low level of DO 3 mg/L (risk of asphyxiation) in the rainy season. Moderate to high anthropogenic pollution (chloride 100.7 mg/L). All the MTE analyzed in the water and sediments were detected, however, at levels in accordance with the standards except for Pb (51.26 to 63.82 µg/L), which shows the beginning of metallic pollution of the lake. Corrective measures must be considered in order to preserve local biodiversity

Caractéristiques structurales et écologiques des populations d’espèces d’arbres à valeur commerciale des forêts classées de Sota et de Wari-Maro au Bénin

Les populations des espèces à valeur commerciale subissent généralement des pressions. Cette étude vise à analyser la structure des populations de quelques espèces dans les forêts du Bénin en vue de leur conservation. Elle a été menée en zone soudano-guinéenne (forêt classée Wari-Maro) et en zone soudanienne (forêt de Sota). Le diamètre de tous les arbres a été mesuré dans des placeaux de 0,25 ha installés dans ces forêts. Une analyse de correspondance détendue (DCA) suivie d’une analyse en composantes principales (ACP) réalisée sur les indices de valeur d’importance (IVI) ont permis de comparer la composition floristique des forêts. Les indices de diversité, les paramètres dendrométriques et les densités de régénération ont été calculés ; les structures en diamètre ont été réalisées. Au vu des IVI, Isoberlinia doka et Anogeissus leiocarpa étaient plus importantes dans la forêt classée de Wari-Maro tandis que Afzelia africana, Prosopis africana et Pterocarpus erinaceus étaient plus importantes dans la forêt classée de Sota. Pseudocedrela kotschyi et Diospyros mespiliformis avaient des IVI faibles dans toutes les forêts. Au vu des structures en diamètre et des densités de régénération, des problèmes de remplacement des arbres se poseront à long terme dans les populations de ces espèces.   Populations of commercially valuable species are generally under pressure. This study aims to analyze the population structure of a few species in the forests of Benin with a view to their conservation. It was conducted in the Sudano-Guinean zone (Wari-Maro classified forest) and in the Sudanian zone (Sota forest). The diameter of all trees was measured in 0.25 ha plots located in these forests. A relaxed correspondence analysis (RCA) followed by a principal component analysis (PCA) carried out on the importance value indices (IVI) made it possible to compare the floristic composition of the forests. Diversity indices, dendrometric parameters and regeneration densities were calculated; diameter structures were made. Based on the IVIs, Isoberlinia doka and Anogeissus leiocarpa were more important in the Wari-Maro classified forest while Afzelia africana, Prosopis africana and Pterocarpus erinaceus were more important in the Sota classified forest. Pseudocedrela kotschyi and Diospyros mespiliformis had low IVIs in all the forests. Based on the diameter structures and regeneration densities, the study concludes that tree replacement problems will arise in the long term in the populations of these species

University Students’ Perceptions of a CLIL-Based Model in Teaching Aviation English Listening Skills

The study investigates university students’ perceptions of using a Content and Language Integrated Learning (CLIL) approach to teach Aviation English listening skills. The integration of content knowledge with language acquisition has gained momentum in English for Specific Purposes (ESP), particularly in aviation training contexts where comprehension of authentic radio communication is critical. A mixed-methods design was employed involving 60 undergraduate aviation students at Georgian Aviation University. Data were collected via a perception questionnaire and semi-structured interviews. Results indicate that the majority of students viewed the CLIL-based approach positively, citing improved comprehension, contextual vocabulary acquisition, and increased engagement. However, some challenges, such as cognitive overload and unfamiliar terminology, were also reported. These findings suggest that CLIL holds promise for Aviation English instruction, provided that pedagogical scaffolding and appropriate materials are in place

Aspects cliniques et thérapeutiques du strabisme divergent intermittent de l'enfant à Abidjan

Introduction : Le strabisme divergent intermittent (SDI) est une entité clinique fréquente en ophtalmologie pédiatrique, associée à des altérations fonctionnelles et esthétiques significatives. Cette étude vise à décrire les caractéristiques cliniques et thérapeutiques du SDI chez l'enfant. Méthode : Une analyse rétrospective a été menée sur une population pédiatrique d’Afrique subsaharienne ayant un SDI en évaluant les données sociodémographiques, les caractéristiques du strabisme, les amétropies associées, la stratégie de prise en charge. Résultat : La prévalence hospitalière du strabisme de l’enfant était de 9,75% dont 57,74% de SDI. La moyenne d’âge était de 3,47 ± 2,48 ans dont 52,8% âgé de 2 à 6 ans. Ce strabisme était précoce dans 35,8% et tardif dans 34,1%. Le SDI était unilatéral dans 43,1% associé à une amétropie dans 36,6% et une anisométropie dans 22,8%. On notait un astigmatisme myopique dans 42,3% majoritairement de degré faible à modéré. L’anisométropie astigmatisme représentait 50%. L’amblyopie qui s’y associait dans 14,6% était d’origine fonctionnelle chez 88,9 % des patients. Elle était profonde dans 33,3% et modérée dans 50% des cas. La correction optique totale a été prescrite chez tous les enfants. Conclusion : Le diagnostic tardif observé souligne la nécessité d'un dépistage précoce. L'association fréquente du SDI et des vices réfractifs dans notre contexte africain justifie une correction optique totale systématique. La variabilité des approches thérapeutiques reflète l'absence de consensus sur les critères de prise en charge.           Introduction: Intermittent divergent strabismus (IDS) is a common clinical condition in paediatric ophthalmology, associated with meaningful functional and aesthetic alterations. This study aims to describe the clinical and therapeutic characteristics of IDS in children. Method: A retrospective analysis was conducted on a paediatric population in sub-Saharan Africa with IDS, evaluating sociodemographic data, strabismus characteristics, associated ametropia, and management strategy. Results: The hospital prevalence of strabismus in children was 9.75%, of which 57.74% were IDS. The average age was 3.47 ± 2.48 years, with 52.8% aged between two and six years. This strabismus had an early onset in 35.8% and a late onset in 34.1%. IDS was unilateral in 43.1% of cases, associated with ametropia in 36.6% and anisometropia in 22.8%. Myopic astigmatism was noted in 42.3% of cases, mostly mild to moderate. Anisometropia astigmatism accounted for 50%. Amblyopia, which was associated with it in 14.6% of cases, was functional in 88.9% of patients. It was profound in 33.3% and moderate in 50% of cases. Total optical correction was prescribed for all children. Conclusion: The late diagnosis observed highlights the need for early screening. The frequent association of IDS and refractive errors in our African context justifies systematic total optical correction. The variability of therapeutic approaches reflects the lack of consensus on management criteria.                            &nbsp

Feeding on exudates and leaves of cassava cultivars with varying cyanogenic Potentials: Implications for the Biology of Typhlodromalus aripo, a key biocontrol agent of cassava green mite in Africa

The predatory mite Typhlodromalus aripo, a key biological control agent of the cassava green mite in Africa, is known to feed on cassava exudates and, in the absence of prey, directly on cassava leaves. While cassava cultivars differ greatly in cyanogenic potential (CNP), the consequences of feeding on exudates and leaves from cultivars with different CNP levels for T. aripo biology remain unknown. We conducted laboratory experiments to evaluate several life history parameters of T. aripo on exudates and leaf discs of three cassava cultivars – TME1 (low CNP), TMS91934 (moderate CNP), and TMS82/00661 (high CNP). T. aripo completed its development on exudates of all three cultivars, being faster with higher survival on exudate of TMS82/00661 (6.8 days, 68.2%) compared with TME1 (7.9 days, 53.8%) and TMS91934 (8.2 days, 56.8%). None of the exudates supported oviposition, although adult female survivorship was highest on TMS82/00661. T. aripo was unable to develop beyond the deutonymph stage on the leaf discs of all three cassava cultivars. However, juvenile and adult longevity were greater on TME1 compared with the two other cultivars. Exudates were free of cyanogenic glycosides with similar amino acid concentrations; however, sugar content was twice as high in exudates of TMS8200661 compared with the other cultivars. These findings highlight the importance of cassava exudate quality for predator persistence and biological control success

Activité anti-anémique de l'extrait aqueux des feuilles de Syzygium guineense (Myrtaceae) chez le rat

L'objectif de cette étude était de déterminer les effets anti-anémiques des extraits aqueux des feuilles de Syzygium guineense (Myrtaceae), utilisées en médecine traditionnelle pour le traitement de l'anémie. Le criblage phytochimique de l'extrait aqueux des feuilles de Syzygium guineense a révélé la présence de stérols, de polyterpènes, de polyphénols, de tanins catéchiques, d'alcaloïdes, de quinones et de saponosides. Une étude de la toxicité aiguë de l'extrait aqueux des feuilles de Syzygium guineense chez des souris femelles a permis d'estimer, conformément aux lignes directrices de l'Organisation de coopération et de développement économiques 423, la dose létale à 50 %. Les résultats montrent que l'administration de l'extrait aqueux de feuilles de Syzygium guineense à une dose de 2000 mg/kg de poids corporel puis à une dose de 5000 mg/kg de poids corporel n'a provoqué aucune mortalité chez les animaux. Cela montre que l'extrait aqueux de feuilles de Syzygium guineense n'est pas toxique par voie orale. L'anémie a été induite chez des rats Wistar par l'administration orale de chlorhydrate de phénylhydrazine. L'administration orale de l'extrait aqueux de Syzygium guineense à des doses de 200, 1000 et 2000 mg/kg de poids corporel à des rats anémiques a entraîné une normalisation des taux de globules rouges, de la concentration d'hémoglobine, du taux d'hématocrite, du volume corpusculaire moyen, de la concentration corpusculaire moyenne d'hémoglobine et du contenu corpusculaire moyen d'hémoglobine, similaire à l'action anti-anémique du Ranferon® (70 mg/kg de poids corporel). Ces résultats montrent que les métabolites révélés dans cet extrait pourraient être responsables de ses effets anémiants. Ceci pourrait justifier l'utilisation de cette plante dans le traitement de l'anémie.   The aim of this study was to determine the anti-anaemic effects of aqueous extracts of Syzygium guineense (Myrtaceae) leaves, used in traditional medicine for the treatment of anaemia. Phytochemical screening of the aqueous extract of Syzygium guineense leaves revealed the presence of sterols, polyterpenes, polyphenols, catechic tannins, alkaloids, quinones, and saponosides. A study of the acute toxicity of the aqueous extract of Syzygium guineense leaves in female mice gave an estimate, in accordance with Organisation for Economic Co-operation and Development 423 guidelines, of the 50% lethal dose. The results show that administration of the aqueous extract of leaves of Syzygium guineense at a dose of 2000 mg/kg body weight, then at a dose of 5000 mg/kg body weight, did not cause any mortality in the animals. This shows that the aqueous extract of Syzygium guineense leaves is not toxic by the oral route. Anaemia was induced in Wistar rats by oral administration of phenylhydrazine hydrochloride. Oral administration of Syzygium guineense aqueous extract at doses of 200, 1000 and 2000 mg/kg body weight to anaemic rats resulted in normalisation of red blood cell levels, haemoglobin concentration, haematocrit level, mean corpuscular volume, mean corpuscular haemoglobin concentration and mean corpuscular haemoglobin content similar to the anti-anaemic action of Ranferon® (70 mg/kg body weight). These results show that the metabolites revealed in this extract could be responsible for its anaemic effects. This could justify the use of this plant in the treatment of anaemia

From Truman to Reagan: The Evolution of U.S. Nuclear Policy in the Cold War Context

Since the beginning of the nuclear era, the United States' nuclear policy has exerted substantial influence on international security and the intricacies of the Cold War. This scholarly work analyzes the evolution of United States nuclear policy throughout the Cold War period, from the presidency of Harry Truman to that of Ronald Reagan. Ranging from President Harry Truman’s decisive deployment of atomic weapons to President Ronald Reagan’s dedication to modernization and arms reduction, successive administrations have adapted their strategic approaches in response to emerging threats, technological advancements, and changing diplomatic contexts. This paper offers a comprehensive qualitative analysis of the progression of U.S. nuclear policy from 1945 to 1988, scrutinizing presidential doctrines, arms control negotiations, and the persistent tension between deterrence and disarmament. The study synthesizes primary and secondary sources to underscore pivotal moments and strategic shifts, considering both American and Soviet perspectives. The research illustrates how nuclear policy has both influenced and reflected broader transformations in U.S. grand strategy, culminating in landmark treaties that contributed to the termination of the Cold War

Determinants of Competitiveness Among Georgian Commercial Banks in the Financial Market

This study investigates the competitiveness of Georgian commercial banks by examining their financial performance, market positioning, and the role of innovation in achieving and maintaining market leadership. A stable and efficient banking sector is fundamental to a country’s economic health, as commercial banks facilitate the allocation of financial resources and support sustainable growth. However, bank failures can pose systemic risks and undermine public trust. The research employs a mixed-method approach, combining quantitative analysis of key financial indicators with qualitative assessment through structured interviews with banking professionals. The financial data was collected from annual reports and official statistics of leading Georgian banks, while interviews provided insights into strategic management practices and innovation-driven competitiveness. The results indicate that JSC TBC Bank and JSC Bank of Georgia have maintained strong market positions through diversified financial services, customer-centric innovations, and strategic segmentation. Furthermore, banks like JSC ProCredit Bank and JSC Credo Bank have established niche competitiveness by focusing on SME lending and inclusive finance models. The findings highlight that technological adaptation, effective risk management, and customer satisfaction are critical determinants of competitiveness in the Georgian banking sector. In conclusion, the study reveals that both financial robustness and non-financial capabilities, such as innovation and managerial efficiency, contribute significantly to the sustained competitiveness of Georgian commercial banks in an increasingly dynamic and globalized financial market