7 research outputs found

    Diversité des trypanosomes, évidence d'espèces zoonotiques potentielles chez l'homme, le bétail et les tsé-tsé au Tchad : les foyers de maladie du sommeil du Mandoul et du Maro

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    Molecular studies of circulating trypanosomes in Chad remain insufficient, particularly in a priming time of the disease elimination involving tsetse control and human screenings and treatments campaigns. Trypanosomes are responsible for Human African Trypanosomiasis (HAT) and Animal African Trypanosomiasis (AAT). Trypanosoma brucei gambiense and T. b. rhodesiense are the species responsible for the HAT forms (i.e. sleeping sickness). In contrast, T. b. brucei, T. congolense, and T. vivax are the most pathogenic African livestock species. The parasites are transmitted by bites of infected tsetse, flies of the genus Glossina, the most prominent vector for AAT and HAT. This study aimed to investigate the circulating trypanosomes, including potential zoonotic species in two HAT/AAT foci in Southern Chad, Mandoul and Maro. As for tsetse habitat, the Mandoul HAT/AAT focus represents an isolated ecological island. Tsetse control started in 2014 and human screenings and treatments campaigns were ongoing before 2014. In contrast, the Maro HAT/AAT focus is an area bordering the Central African Republic (CAR) where anti-tsetse campaigns had not started when this study was undertaken and represented an open area for tsetse reinvasions. 889 humans and 540 cattle were recruited, and 177 tsetse were caught to investigate the circulating trypanosome species in both foci. During the surveys on humans, organised in 2017 and 2018 in nomadic and sedentary settlements, questionnaires related to demographic data, anthropometric measurements, health and nutritional status, literacy, and knowledge on parasitic vector diseases were recorded, besides the blood and urine sample collections. Also, cattle blood samples were collected, and questionnaires linked to the settlement systems (nomadic or sedentary), common animal diseases, and animal health status, were filled, and the PCVs measured. During the entomological surveys, alive tsetse were dissected in wings, legs, and proboscis, and gut tissues. As an outcome, the surveyed human groups showed different responses on the social determinant of health (SDOH), on which the vulnerability to infectious diseases and non-communicable diseases depend. The low education level and the lack of sensitisation hampered the understanding of vector-borne parasitic diseases and the preventive measures to be adopted. Interestingly, only a few people are obese, or in overweight range in these areas, with few who presented a high glycemia and high blood pressure. Looking at the entomological data, tsetse are rare in Mandoul where only one fly was caught. In contrast, in Maro, their presence was farther noticed. Extracted DNA samples screened using nested PCR targeting the internal transcribed spacer I (ITS1) supported by the glycosomal glyceraldehyde- 3-phosphate dehydrogenase (gGAPDH)-PCR, and sequencing revealed different trypanosomes diversity according to focus. In Mandoul, there is no evidence of T. b. gambiense and T. congolense neither in humans nor in cattle. Since only one fly was collected here, no statement on presence of trypanosomes in tsetse can be made. However, an unknown Trypanosoma species (Trypanosoma-sp.-129-H) was identified in one person, and a high prevalence of T. theileri in cattle, besides few T. vivax and T. simiae. In contrast, in Maro, T. b. gambiense was identified in humans, as well as evidence for T. congolense DNA. Furthermore, in this focus, sample from cattle and tsetse showed evidence for a high diversity of trypanosomes. This includes pathogenic, non-pathogenic, and unknown species. The diversity of trypanosome species in Maro is linked to the relatively high number of tsetse observed. Consequently, tsetse are vectoring trypanosomes in this focus. This is influenced mainly by the missing tsetse control, besides pastoralist transhumance activities from and to CAR. Whereas in Mandoul, the campaigns are ongoing since 2014 (i.e., three years before and during the surveys). They have reduced the tsetse populations and the pathogenic trypanosome species. However, the other species identified in this focus could be transmitted by other vectors such as tabanid and Stomoxys. Regarding the evidence of T. congolense in humans, it was also confirmed when performing the ELISA assay to investigate the anti-TconTS (anti-T. congolense Trans-sialidase), an enzyme produced during infection with this species. The assay showed a high number of people having an immune response against this parasite exposure. It could be due to a current or cleared infection. The evidence of zoonotic trypanosomes in humans need to be monitored in the field, and the pathogenicity studied in case of non-transient infection. For this purpose, loop-mediated isothermal amplification (LAMP) techniques were optimised for both human and animal pathogenic Trypanosoma species. The assays were successfully tested in the field for the identification of T. congolense in cattle. This thesis gives an insight into the circulating trypanosomes in the Mandoul and the Maro HAT/AAT foci in these cited hosts. It provides a better understanding of the genetic of trypanosomes to support elimination goals. In conclusion, there is evidence of the diversity of trypanosomes and emerging zoonotic species in the study sites. Thus, we suggest widening the study to other mammalian hosts, vectors, and involving other areas, as well as joining efforts with CAR in terms of tsetse control operation and disease elimination in these areas. We also suggest investigating the potentials of emerging zoonotic trypanosomes

    Towards Automation of the FORM/BCS Method

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    The software industry is facing more complex computer systems, with short development and sustainability issues. To deliver good software with these constraints, software reuse has become a central concept for minimizing design and realization costs. This study improves upon Feature-Oriented Reuse Method with Business Component Semantics (FORM/BCS), a software development method that produces adaptable architectures from reusable domain components. This is a promising method for reusable software assets and model creation. The objective of the FORM/BCS is to bring the industrial production chain to the software. This study proposes a model to automatically transform the FORM/BCS business subsystem component into a process business component. Two metamodels for business subsystems and process business components were developed. In addition, this study establishes correspondences between the source metamodel and target metamodel classes, transformation rules, and the instance of the source metamodel and generates the target metamodel instance. Detailed findings can help practitioners reduce software design costs and development time, and contribute to the advancement of knowledge in software engineering

    Machine Learning Approaches for Prediction of the Compressive Strength of Alkali Activated Termite Mound Soil

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    Earth-based materials have shown promise in the development of ecofriendly and sustainable construction materials. However, their unconventional usage in the construction field makes the estimation of their properties difficult and inaccurate. Often, the determination of their properties is conducted based on a conventional materials procedure. Hence, there is inaccuracy in understanding the properties of the unconventional materials. To obtain more accurate properties, a support vector machine (SVM), artificial neural network (ANN) and linear regression (LR) were used to predict the compressive strength of the alkali-activated termite soil. In this study, factors such as activator concentration, Si/Al, initial curing temperature, water absorption, weight and curing regime were used as input parameters due to their significant effect in the compressive strength. The experimental results depict that SVM outperforms ANN and LR in terms of R2 score and root mean square error (RMSE)

    Molecular detection of Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts in wild population of tsetse flies collected in Cameroon, Chad and Nigeria

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    Abstract Background Tsetse flies are cyclical vectors of African trypanosomiasis (AT). The flies have established symbiotic associations with different bacteria that influence certain aspects of their physiology. Vector competence of tsetse flies for different trypanosome species is highly variable and is suggested to be affected by bacterial endosymbionts amongst other factors. Symbiotic interactions may provide an avenue for AT control. The current study provided prevalence of three tsetse symbionts in Glossina species from Cameroon, Chad and Nigeria. Results Tsetse flies were collected and dissected from five different locations. DNA was extracted and polymerase chain reaction used to detect presence of Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts, using species specific primers. A total of 848 tsetse samples were analysed: Glossina morsitans submorsitans (47.52%), Glossina palpalis palpalis (37.26%), Glossina fuscipes fuscipes (9.08%) and Glossina tachinoides (6.13%). Only 95 (11.20%) were infected with at least one of the three symbionts. Among infected flies, six (6.31%) had Wolbachia and Spiroplasma mixed infection. The overall symbiont prevalence was 0.88, 3.66 and 11.00% respectively, for Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts. Prevalence varied between countries and tsetse fly species. Neither Spiroplasma species nor S. glossinidius were detected in samples from Cameroon and Nigeria respectively. Conclusion The present study revealed, for the first time, presence of Spiroplasma species infections in tsetse fly populations in Chad and Nigeria. These findings provide useful information on repertoire of bacterial flora of tsetse flies and incite more investigations to understand their implication in the vector competence of tsetse flies

    Abstracts of the 1st International Colloquium in Mine & Society

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    This book presents the abstracts of the selected contributions to the First International Colloquium on Mines and Society (CIMS) organized by The Higher Institute of Mining and Geology of Boke. The theme of this colloquium was "Mining and Sustainable Development, a major challenge for an Emerging Africa" which aims to bring together teachers, researchers, and Professionals from different backgrounds in order to exchange the results of their research work, share their points of view on the issue of mining and sustainable development. It also aims to define, in a collaborative and inclusive manner, research prospects or future projects between all the actors involved in this field. Colloquium Title: 1st International Colloquium in Mine & SocietyTheme: Mining and Sustainable Development, A Major Challenge for an Emerging AfricaColloquium Date: 20-22 May 2022Colloquium Location: A L’Hôtel Rio Nunez de BokeColloquium Organizer: The Higher Institute of Mining and Geology of Bok

    Le projet majeur africain de la Grande Muraille Verte

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    L’initiative de la Grande Muraille Verte (GMV), projet transcontinental, est une réponse de l’Afrique à la désertification, à la pauvreté et au changement climatique. Elle repose sur une approche concertée, multisectorielle, mettant en synergie des actions de lutte contre ces trois fléaux majeurs pour le continent africain. La particularité de la GMV est, tout en créant et consolidant une ligne de défense par des activités de reboisement et d’aménagement, de contribuer efficacement au développement intégré des zones rurales et d’aider à la lutte contre la pauvreté dans le cadre d’un développement durable. Il s’agit de l’installation et de la mise en valeur intégrée d’espèces végétales à valeur économique adaptées aux terres arides et aux particularités locales, de bassins de rétention, de systèmes de production agricoles et autres activités génératrices de revenus. La GMV intègre ainsi plusieurs systèmes des plantations artificielles anciennes ou nouvelles, des unités agro-sylvo-pastorales. Des zones de parcours villageoises ou intercommunautaires, des parcs animaliers, des réserves communautaires et des couloirs de migration de faune. Cet édifice transcontinental est une référence de modèle d’intégration sous-régional mettant en exergue une initiative originale initiée par des pays fortement assujettis aux phénomènes de désertification et de changement climatique Il constitue un Modèle Multisectoriel de Développement Intégré des Zones Andes (MDI/ZA). Dédié à la lutte contre tes effets et l’avancée de la désertification, à la restauration et la mise en valeur des zones dégradées et au mécanisme de développement propre dû à sa forte capacité de séquestration de carbone. L’ouvrage vise un large public, notamment les scientifiques, enseignants, décideurs, techniciens charges de la mise en œuvre de la GMV et permet d’apprécier l’originalité du projet dans son approche concertée et multisectorielle et ses résultats dans le développement intégré des zones arides a semi-arides