Journal of Next-Generation Research 5.0
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Stratégies d'amélioration de la sécurité d'approvisionnement électrique de la province du Katanga RD/Congo
No full textInternational audienceSummary The province of Katanga, considered as the economic lung of the DRC, is endowed with 24 sites, which can produce an exploitable power of 1952MW. At present, only 4 out of the 24 sites are in exploitation, for an installed power of 468MW. These last years, the province of Katanga has encountered an intensification of industrial activities for the production of raw materials such as copper and cobalt. Furthermore, the urban population is rapidly expanding. These two factors are causes of a constant increase of the demand in electrical energy. The purpose of this paper will be to study strategies for improving the security of electricity supply in Katanga province by local approaches. To reach this goal, a simplified yet sufficiently detailed modeling of the south network was necessary to monitor the evolution of the production fleet and the load over a period of ten years, and the application of the OPF (Optimal Power Flow) tools to this network model allowed us estimating the reliability indicators such as Loss Of Load Probability (LOLP), Loss Of Load Expectation (EENS), and Expected Energy Not Served (EENS). The characterization of the reliability of the electrical system will be limited to hierarchical levels I and II.La province du Katanga étant le poumon économique de la République Démocratique du Congo (RDC) est dotée de 24 sites hydroélectriques pouvant produire une puissance exploitable de 1952 MW, mais actuellement, seulement 4 sites sont en exploitation pour une puissance de 468 MW. Suite à l'intensification d'activités industrielles dans la province du Katanga pour la production de matières premières (cuivre et cobalt essentiellement) ces dernières années et à l'accroissement de la population urbaine, la demande en énergie électrique ne fait qu'augmenter d'année en année. L'objectif de cette communication sera alors d'étudier les stratégies d'amélioration de la sécurité d'approvisionnement électrique de la province du Katanga par des approches locales. Pour arriver à nos objectifs, un modèle simplifié, mais réaliste du réseau katangais a été utilisé pour suivre l'évolution du parc de production et de la charge sur une période de dix ans, et l'application des outils de résolution des OPF (Optimal Power Flow) à ce réseau nous a permis d'estimer les indicateurs de fiabilité tels que LOLP (Loss Of Load Probability), LOLE (Loss Of Load Expectation) EENS (Expected Energy Not Served). La caractérisation de la fiabilité du système électrique a été limitée aux niveaux hiérarchiques I et II
Biogeography of <i>Leptospira</i> in wild animal communities inhabiting the insular ecosystem of the western Indian Ocean islands and neighboring Africa
No full textInternational audienceUnderstanding the processes driving parasite assemblages is particularly important in the context of zoonotic infectious diseases. Leptospirosis is a widespread zoonotic bacterial infection caused by pathogenic species of the genus Leptospira. Despite a wide range of animal hosts, information is still lacking on the factors shaping Leptospira diversity in wild animal communities, especially in regions, such as tropical insular ecosystems, with high host species richness and complex biogeographical patterns. Using a large dataset (34 mammal species) and a multilocus approach at a regional scale, we analyzed the role of both host species diversity and geography in Leptospira genetic diversity in terrestrial small mammals (rodents, tenrecs, and shrews) and bats from 10 different islands/countries in the western Indian Ocean (WIO) and neighboring Africa. At least four Leptospira spp. (L. interrogans, L. borgpetersenii, L. kirschneri, and L. mayottensis) and several yet-unidentified genetic clades contributed to a remarkable regional Leptospira diversity, which was generally related to the local occurrence of the host species rather than the geography. In addition, the genetic structure patterns varied between Leptospira spp., suggesting different evolutionary histories in the region, which might reflect both in situ diversification of native mammals (for L. borgpetersenii) and the more recent introduction of non-native host species (for L. interrogans). Our data also suggested that host shifts occurred between bats and rodents, but further investigations are needed to determine how host ecology may influence these events
Cinquante ans de jurisprudence pour un traité sexagénaire : le façonnage de la structure du Traité Euratom par la Cour de justice
No full textInternational audienc
Spatially explicit modelling of tree–grass interactions in fire-prone savannas: A partial differential equations framework
No full textInternational audienceLong term tree–grass dynamics is an important issue in many places around the world. Especially, if we intend to take into account environmental and human perturbations, like fire events, herbivory, etc. In this paper, we complete and extend temporal models developed in recent papers by Yatat et al. (2014, 2017) and Tchuinte Tamen et al. (2014), using diffusion operators, into spatio-temporal models, in order to study the long term dynamics of a mosaic of forest and grassland in a humid context of Central Africa. We take into account local biomass diffusion, as well as local tree–grass competition for nutrients and light. For this model, we carry out a qualitative analysis that highlights some ecological thresholds shaping the dynamics of the system. In addition, we show that monostable and bistable travelling wave solutions may exist. We illustrate some of our theoretical results with numerical simulations, and, also explore the use of impulsive fires on the dynamics of a mosaic of forest and grassland in a humid savanna. We found that depending on fire-return time as well as difference in diffusion potential of woody and herbaceous vegetation, fire events are able to greatly slow down or even stop the progression of forest in humid regions
A pantropically introduced tree is followed by specific ectomycorrhizal symbionts due to pseudo-vertical transmission
No full textInternational audienceGlobal trade increases plant introductions, but joint introduction of associated microbes is overlooked. We analyzed the ectomycorrhizal fungi of a Caribbean beach tree, seagrape (Coccoloba uvifera, Polygonacaeae), introduced pantropically to stabilize coastal soils and produce edible fruits. Seagrape displays a limited symbiont diversity in the Caribbean. In five regions of introduction (Brazil, Japan, Malaysia, Reunion and Senegal), molecular barcoding showed that seagrape mostly or exclusively associates with Scleroderma species (Basidiomycota) that were hitherto only known from Caribbean seagrape stands. An unknown Scleroderma species dominates in Brazil, Japan and Malaysia, while Scleroderma bermudense exclusively occurs in Reunion and Senegal. Population genetics analysis of S. bermudense did not detect any demographic bottleneck associated with a possible founder effect, but fungal populations from regions where seagrape is introduced are little differentiated from the Caribbean ones, separated by thousands of kilometers, consistently with relatively recent introduction. Moreover, dry seagrape fruits carry Scleroderma spores, probably because, when drying on beach sand, they aggregate spores from the spore bank accumulated by semi-hypogeous Scleroderma sporocarps. Aggregated spores inoculate seedlings, and their abundance may limit the founder effect after seagrape introduction. This rare pseudo-vertical transmission of mycorrhizal fungi likely contributed to efficient and repeated seagrape/Scleroderma co-introductions
The One health concept : 10 years old and a long road ahead
No full textOver the past decade, a significant increase in the circulation of infectious agents was observed. With the spread and emergence of epizootics, zoonoses, and epidemics, the risks of pandemics became more and more critical. Human and animal health has also been threatened by antimicrobial resistance, environmental pollution, and the development of multifactorial and chronic diseases. This highlighted the increasing globalization of health risks and the importance of the human-animal-ecosystem interface in the evolution and emergence of pathogens. A better knowledge of causes and consequences of certain human activities, lifestyles, and behaviors in ecosystems is crucial for a rigorous interpretation of disease dynamics and to drive public policies. As a global good, health security must be understood on a global scale and from a global and crosscutting perspective, integrating human health, animal health, plant health, ecosystems health, and biodiversity. In this study, we discuss how crucial it is to consider ecological, evolutionary, and environmental sciences in understanding the emergence and re-emergence of infectious diseases and in facing the challenges of antimicrobial resistance. We also discuss the application of the "One Health" concept to non-communicable chronic diseases linked to exposure to multiple stresses, including toxic stress, and new lifestyles. Finally, we draw up a list of barriers that need removing and the ambitions that we must nurture for the effective application of the "One Health" concept. We conclude that the success of this One Health concept now requires breaking down the interdisciplinary barriers that still separate human and veterinary medicine from ecological, evolutionary, and environmental sciences. The development of integrative approaches should be promoted by linking the study of factors underlying stress responses to their consequences on ecosystem functioning and evolution. This knowledge is required for the development of novel control strategies inspired by environmental mechanisms leading to desired equilibrium and dynamics in healthy ecosystems and must provide in the near future a framework for more integrated operational initiatives
Ethnobotanical study of medicinal plants used by traditional healers for the treatment of oxidative stress-related diseases in the Congo Basin
No full textInternational audienceThis paper identifies the medicinal plants used for the treatment of oxidative stress-related diseases by the Congolese population. The objective of the present survey was to list the major plants used in Congolese traditional folk medicine for the treatment of oxidative stress-related diseases as well as to review the phytogeographical distribution of these plants, their natural habitats, plant parts used, routes of administration and administered doses. Several methods have been used to fulfil the aim of the study: an ethnobotanical survey, observation of the practices of traditional healers, and bibliographical research focused on the ethnobotany and antioxidant power of sub-Saharan African medicinal plants. From a questionnaire, a guided semi-structured interview was carried out to obtain information from independent traditional healers in the Republic of the Congo. A total of 70 plants distributed among 47 families were identified. These plants were mainly employed to treat hypertension, diabetes, and anaemia, but they also were used to a lesser extent for fighting other pathologies such as infertility, asthma, ulcer, cough, and viral hepatitis. Analgesic, antiseptic, and aphrodisiac activities of the medicinal plants as well as their ability to improve visual acuity were also reported. Most of the plant preparations were taken orally as a decoction or infusion or taken directly as a powder. Treatments generally involved only one plant but mixtures of several plants were also used. Other ingredients, such as lemon, milk and honey were sometimes added to preparations to facilitate their ingestion. Among the total of 70 species of plants that were identified in the study, it is noteworthy that three plants (Syzygium brazzavillense Aubrev. & Pellegr., Parinari congensis Didr., and Croton dybowskii Hutch.) have never been studied for their medicinal properties. According to the traditional healers, these plants showed efficacy in the treatment of oxidative stress-related pathologies. The reported dosage of the plant preparations depends on several factors, particularly plant type, amounts of powder and water used for its reconstitution (i.e. powder to water ratio), and patient age. Treatments were reported to last a maximum of one month. The current ethnobotanical study allowed the identification of some plants which are endemic to the Republic of the Congo (e.g., Syzygium brazzavillense Aubrev. & Pellegr.) and some growing only in a specific zone of the country (e.g., Croton dybowskii Hutch.). The traditional knowledge of these plants will guide future research of the antioxidant power of African plant powders
Fenêtre sur la femme indienne au début de l'époque coloniale française d'après le journal d'Ananda Ranga Pillai (1736-1761)
No full textThis thesis reviews the status of Indian women and the start of various changes under French rule in India, in light of the diary of Ananda Ranga Pillai, Dubâsh for the French East India Company, between 1736 and 1761. Through his daily chronicles in this decisive period of colonization, being both an observer and an actor, the diarist displays his constant concern for women, far from the romantic considerations. The study of the place and the role of the Indian women is made possible in the fields of politics through the lens of war, highlighting their involvement in the socio-economic sphere and its impact in their private life, by shedding a more internal light on global colonial society during this first half of the 18th century.Cette thèse étudie la condition féminine indienne et les prémices des différentes mutations opérées par la présence française en Inde, à la lumière du journal d’Ananda Ranga Pillai, Dubâsh pour le compte de la Compagnie française des Indes Orientales entre 1736 et 1761. Grâce à ses chroniques quotidiennes en cette époque décisive de la colonisation, observateur et acteur à la fois, le diariste témoigne d’un intérêt constant pour la gent féminine, loin des considérations romanesques. Il rend possible l’étude de la place et du rôle des femmes indiennes en politique sous le prisme de la guerre, la mise en évidence de leur implication dans la sphère socio-économique et les répercussions dans leur vie privée, apportant un éclairage interne plus global sur la société coloniale dans cette première moitié du XVIIIe siècle
Approche de la complexité des risques sanitaires hydriques dans les quartiers précaires d'Antananarivo : la notion de contexte à l'épreuve des pratiques et représentations citadines
No full textThe geographical study of the health risks related to water in Antananarivo, metropolitan capital of Madagascar, a tropical country with a low level development, is articulated through the access conditions to the water resources, the evaluation of supplied water quality and the domestic practices performed until its consumption. This thesis seeks to illustrate via the hydric determinant how complex are the issues at the intersection of health and environment in an urban developing area. This complexity is due to the integration of the various components of the pathogenic system and the connections between them. In Antananarivo, our analyses show that the disparities of health as regards hydric risks are the reflection of a dichotomic social configuration inherited between the lower and the upper city and thus strongly impregnated by the social representations. To understand the mechanisms at the origin of these disparities of health, life environment in the precarious districts of Antananarivo is studied as a risk factor. These places are subjected to effects which are identified in the literature like contextual effects (relating to the characteristics of the territory) and compositional effects (relating to the characteristics of the individuals). In Antananarivo, the quantitative approach confirms the predominance of the contextual effects over the compositional effects. However, our fieldwork moderates this static and deterministic vision of the surveyed territories through the observation of the coping strategies developed by the populations to mitigate the failures of the urban services of health, water and sanitation. In agreement with recent publications, this research, argues that it exists a more complex and retroactive relation between the practices of the populations and the territories. This relation is in perpetual evolution. The individuals by their practices adapt and modify the configuration of the territories and conversely.L’étude géographique des risques sanitaires hydriques à Antananarivo, capitale métropolitaine de Madagascar, pays tropical et au niveau de développement faible, s’articule à travers les conditions d’accès à la ressource, l’évaluation de la qualité de l’eau distribuée mais également à travers les pratiques domestiques accomplies jusqu’à sa consommation. Cette thèse cherche à illustrer via le déterminant hydrique combien les questions au croisement de la santé et de l’environnement sont, dans un milieu urbain en développement, des questions complexes. Cette complexité est engendrée par les différentes composantes du système pathogène à intégrer et les relations entre elles. À Antananarivo, nos analyses montrent que les disparités de santé en matière de risques hydriques sont le reflet d’une configuration sociale dichotomique héritée entre ville basse et ville haute et donc fortement imprégnée par les représentations. Comprendre les mécanismes à l’origine de ces disparités de santé, conduit à interroger les milieux de vie comme facteur risque, ici les quartiers précaires d’Antananarivo. Ces lieux sont soumis à des effets qui sont identifiés dans la littérature comme des effets de contexte (relatifs aux caractéristiques du territoire) et des effets de composition (relatifs aux caractéristiques des individus). À Antananarivo, l’approche quantitative confirme la prédominance des effets de contexte sur les effets de compositions. Pourtant, notre travail de terrain à travers la démonstration des pratiques et des compétences citadines mises en œuvre par les populations pour pallier, notamment les défaillances des services urbains de santé, de l’eau et de l’assainissement, nuance cette vision statique et déterministe des territoires enquêtés. En accord avec de récentes publications, cette recherche avec les difficultés que peuvent représenter les études un milieu urbain en développement, soutient qu’il existe une relation plus complexe et rétroactive entre les pratiques des populations et les territoires et que cette relation est en perpétuelle évolution. Les individus par leurs pratiques s’approprient et modifient la configuration des territoires et inversement