The Effects of Oil on Economic Development of Chad

Chad’s oil was extracted in 2003 by consortium oil companies and the World Bank. The World Bank and Chadian government agreed that once Chad starts to export oil to international market, the revenues would be used for development, but today evidence shows that oil production did not improve people’s basic necessities. The country remains one of the poorest countries in the world. This paper critically assesses the resource Curse in Chad by exploring the effects of the oil on Chad’s economic and social development. the finding shows that the declining of oil demand in 2016 has decreased the country’s import and Export due to the fact the country was heavily depend on exporting oil. Many of the Chad’s investments come from oil sector and since the investment in oil has been declining, foreign direct investment (FDI) also has fallen sharply. The paper also finds that rentier economy in Chad has permitted the president Idriss Deby to build a strong political elite that create a huge gap between the government and the civil society. the government uses public funding to support the patronage network, and that scenario has weakened institutions in Chad. The empirical findings have revealed that the oil production has exacerbated the already fragile economic of the country and that the government has no wills of development, this is why oil has a been a curse in Chad.

Creating a framework towards integrated health syndromic surveillance and response in Africa

Background: A substantial part of the population in sub-Saharan Africa live in rural areas characterized by insufficiently equipped health centres and shortages of qualified health workers. These people usually depend on agriculture and livestock but have limited access to social services including health. In Chad, over 78% of the total population lives in rural areas and 3.5% are mobile pastoralists. Previous research has shown that agro-pastoralists suffer from a broad range of diseases of mostly unconfirmed biomedical aetiology. We propose a synergistic approach of integrated “One Health” surveillance-response combining epidemiology, anthropology and advanced biomedical diagnostic with essential complementary elements to anticipate outbreaks of endemic and emerging diseases from perceived illnesses (syndromes). Community-based syndromic surveillance, coupled with mobile technology adapted to the rural agro-pastoralists context, could offer an alternative to existing surveillance systems for humans and animals. Linking such a system with the etiologic confirmation of suspected cases from freshly collected samples would increase the potential of anticipating diseases outbreaks and leads to evidence-based and locally adapted interventions. Such participatory approach to surveillance and intervention could be further used for public and veterinary health service improvement along with zoonosis integration into existing digital and open source health information system application (DHIS2) aiming at their elimination. Aim and objectives: The aim of the thesis was to establish the basis of a culturally adapted and integrated community based human and animal health syndromic surveillance and response system among agro-pastoralists in Chad. We addressed intervention effectiveness, joint human and animal health interventions, zoonosis elimination and basic requirements for syndromic surveillance in remote rural communities using modern information and communication technology. The objectives of the thesis were to: 1. Contribute to health interventions effectiveness evaluation methods; 2. Evaluate One Health approaches (e.g. joint human and animal vaccination) among mobile communities and their potential for integration into the public health system; 3. Establish a basic knowledge on syndromic surveillance and response in order to implement a feasibility study of an integrated human and animal health surveillance and response system; and 4. Estimate the potential of zoonosis elimination in developing countries (the case of bovine tuberculosis in Morocco). Approach: Effectiveness of health interventions: Equity effectiveness of maternal health service coverage in rural Chad: Inequalities and large disparities in the burden of maternal morbidity and mortality still persist within and between different population groups mainly in low income countries. Policies need to be informed by equity sensitive evidence assessing differences in health needs and particularly in the effectiveness of interventions and models of care. The aim of this paper was to assess the community effectiveness of maternal health service coverage for sedentary and mobile populations in two rural districts in Chad. The approach allowed for quantifying the health system’s determinants of effectiveness. Our results provided a baseline to monitor the progress of a health system intervention in these districts focusing on maternal and infant health. Interventions should generally focus in priority on improving community effectiveness through targeting the factors with the highest leverage among specific populations in order to foster effective and equitable health services. Vaccine hesitancy among mobile communities in Chad: Demand side barriers for vaccination among rural and mobile populations in Chad are not yet well understood. We hypothesized that these mobile pastoralists’ communities face specific demand side barriers to access vaccination services. Understanding the factors that caregivers in these communities could take into account, explicitly or implicitly, in order to decide (or not) to vaccinate a child is an essential element to tailor vaccination programmes towards increasing vaccination acceptance and uptake. Our results showed that mobile pastoralist communities face specific demand side barriers to vaccination. Understanding these barriers is essential to reduce vaccine hesitancy and increase vaccination uptake. Local health systems must plan for periodic presence of pastoralist communities in their zones of responsibility and create more mutual trust. One Health methods and approaches: Feasibility and sustainability of joint human and animal vaccination: Joint human and animal vaccination programmes (JHAVP) such as “One Health” approaches have demonstrated to be feasible; to increase health care access to hard-to-reach communities; and to save resources through sharing transport, equipment and logistics in Chad. The main objective of the study was to give an insight to the feasibility and the sustainability of JHAVP integrated as part of the public health system in Chad. Our results showed that even though its integration as a routine activity at the district level depends on the mobilization of additional financial resources, the district could benefit from JHAVP to maintain a contact network with the nomads in order to promote the use of available immunization services at district level in the long term. Trends in health surveillance and service delivery for pastoralists in West and Central Africa: In most sub-Saharan African countries, pastoralism represents an important economic resource and contributes significantly to national growth; however, challenges remain, particularly in providing social services to pastoralists (especially health and education) and in avoiding conflict with local sedentary communities and local authorities. All of this takes place while pastoralists try to maintain their mobile lifestyle within a rapidly changing ecosystem. Although considerable efforts have been made towards integrating mobile pastoralists into social services, obstacles remain to the adoption of a clear, specific and sustainable policy on pastoralism in sub-Saharan Africa. Transmission dynamics and elimination potential of zoonotic tuberculosis in Morocco: A simple compartmental deterministic mathematical model for BTB transmission in cattle and humans have been established to provide a general understanding of BTB, in particular regarding transmission to humans. Differential equations were used to model the different pathways between the compartments for cattle and humans. Scenarios of test and slaughter were simulated to determine the effects of varying the proportion of tested animals (p) on the time to elimination of BTB (individual animal prevalence of less than one in a thousand) in cattle and humans and the economic cost due to elimination

Éléments de conception d’un générateur électrique pour l’alimentation d’un dispositif à décharge à barrière diélectrique (DBD)

Ce travail traite de la conception de générateur alimentant une lampe DBD destinée à la production de rayonnement UV. Cette alimentation doit permettre un contrôle efficace du rayonnement, grâce aux degrés de liberté apportés par le contrôle du générateur (fréquence, amplitude du courant injecté dans la lampe). Le modèle électrique de la lampe est utilisé pour prédire l’impact des caractéristiques du générateur sur le rayonnement UV produit. Une synthèse des interrupteurs de puissance du convertisseur statique permettant le contrôle du courant injecté est proposée et des solutions d’implémentation sont étudiées. Une démarche de conception en vue de l’optimisation du transformateur haute tension est proposée, notamment en ce qui concerne la valeur de ses éléments parasites. L’ensemble de ces travaux est étayé par des réalisations expérimentales. ABSTRACT : This work presents the concept of a generator supplying a DBD lamp for UV radiation production purpose. This supply permits effective control of radiation based on degree-of-freedom provided by generator control system (lamp current frequency and ampli-tude). Lamp electrical model is used to predict the impact of power source characteristics on the produced UV radiation. A synthesis of the switching devices of power converter for current lamp control is pro-posed and the implemented solutions are studied. A design procedure for high voltage transformer optimization is proposed in particular concerning parasitic elements. The entire work is supported by experimentations

Distribution des ligneux sur le tracé de la grande muraille verte : cas de batha et de wadi-fira Ouest au Tchad

Les déficits pluviométriques combinés à l’action anthropique ont entrainé une dégradation des ressources naturelles à partir desquelles les paysans tchadiens tirent leurs moyens de subsistance. Cette étude avait pour objectif de déterminer la composition floristique, la circonférence et la hauteur des peuplements ligneux dans deux sites de la Grande Muraille Verte du Tchad (Batha et Wadi-Fira Ouest). Pour cela, nous avons utilisé la méthode des relevés floristiques et des mesures dendrométriques pour caractériser lavégétation. Cette méthode nous a permis d’inventorier 15 espèces réparties en 11 genres et 6 familles. Les espèces les plus dominantes sont Balanites aegyptiaca (Delile), Acacia tortilis (Forssk.) Hayne subsp. raddiana (Savi) Brenan et Capparis decidua Edgew (Forssk.). La répartition des individus selon la grosseur et la hauteur permettent d’établir la structure du peuplement ligneux. Ainsi, dans le Batha, le peuplement ligneux ainsi que les espèces dominantes (Balanites aegyptiaca, Acacia raddiana et Capparis decidua) est constitué de cinquante-deux virgule seize pour cent (52,16%) d’individus qui ont une circonférence comprise entre 10 et 50 cm. Au niveau de Wadi-Fira Ouest, le peuplement est dominé par des individus de circonférence comprise entre 20 et 60 cm. Le peuplement du Batha renferme des individus qui ont une hauteur comprise entre 1 et 14 m. Quatre-vingt-six virgule soixante-sept pour cent (86,67%) des espèces ont une hauteur inférieure ou égale à 7 m. Tandis que dans le Wadi-Fira Ouest, la hauteur des individus du peuplement varie de 0,9 à 12 m et quatrevingt-dix pour cent (90%) des individus ont une hauteur comprise entre 0,9 et 7 m. La strate ligneuse estdominée par des arbustes en grande partie. L’étude a permis de mettre en évidence que les facteurs d’ordre climatique et anthropique ont un impact sur l’environnement des sites.Mots clés : Ligneux, Circonférence, Hauteur, Batha, Wadi-Fira Ouest, Tcha

Influence des bulles gazeuses et des préparations fermentatives complexes sur la viscosité des mélasses de betterave à sucre

La mélasse est le coproduit de la fabrication du sucre de canne ou de betterave et dont la composition varie en fonction des conditions climatiques de production de la matière première et du processus de fabrication mis en place par la sucrerie. Elle se présente sous la forme d’un liquide épais, homogène, de couleur marron. Sa forte viscosité limite sa fluidité et son transport dans les tuyauteries et l’abaissement de cette viscosité par réchauffage engendre des coûts élevés d’énergie. L’objectif de cette étude est la mise en oeuvre d’une méthodologie efficace permettant de diminuer la viscosité de la mélasse par l’usage des solutions liquéfiantes (ferments) sans toutefois augmenter la température. Cette diminution évitera à l’usine de dépenser énormément d’énergie pour baisser sa viscosité et faciliter sa fluidité dans les tuyauteries. Les travaux ont été réalisés en utilisant cinq (5) différentes préparations fermentatives liquides de masse volumique 1,2 g/ cm³ fabriquées dans une firme Danoise Novo-Nordisk et qui sont destinées à la transformation des produits céréaliers pour la production des boissons. Il s’agit notamment de : Ultraflo-L, Cereflo- 200L, Thermamyl-120L, Fungamyl-800L et Ceremix- 6 XL. A travers cette recherche, il a été utilisé une mélasse, de pureté 55% laquelle, dans 100 kg de matière sèche retient 55 kg de saccharose et 45 kg de matières organiques et non organiques. Cette mélasse a été ensuite intensivement mélangée à l’aide d’un malaxeur mécanique, et périodiquement par intervalle d’un quart d’heure, des échantillons ont été prélevés et dont la masse volumique a été mesurée. Il ressort des expériences que les masses volumiques de ces échantillons diminuent respectivement en passant de 1,360 à 1,320 ; 1,250 et 1,200 g/ cm³. A la température constante de 60 °C, maintenue à l’aide d’un ultra thermostat, la viscosité des échantillons a été mesurée. Les résultats obtenus ont montré que les viscosités finales de la mélasse de concentration 60% ont varié dans l’amplitude 10,5 à 15,3 m.Pa.s. Pour une thermo stabilité de la mêlasse avec un pH neutre des préparations fermentatives comme l’ultraflo- L et le cereflo -200L permettent de diminuer la viscosité de la mêlasse de 20-35%.© 2016 International Formulae Group. All rights reserved.Mots clés: Mélasses, betterave, viscosité, température, fermentsEnglish Title: Influence of gaz bubbles and complex fermentative preparation on the viscosity of the sugar beet molassesEnglish AbstractMolasses is the product of the manufacture of sugar cane or beet whose composition changes depending on the climatic conditions of de production of the raw materials and of the process of manufacture set up by the sugar refinery. It comes as a thick, homogenous, and brown liquid. Its fluidity is limited by its strong viscosity,  hence the high cost of energy needed for its conveyance in the pipes, caused by the diminution of that viscosity through reheating. The aim of this study is the implementation of an efficient methodology allowing to lowering the viscosity of the molasses by the use of liquefying solutions without, however, increasing the temperature. This diminution will enable the factory not to use a lot of energy to lower the viscosity so as to ease fluidity in the pipes. The works have been carried out by using five (5) different liquid fermentative preparations of 1.2 g/cm³ relative density made in a Danish Novo-Nordisk firm intended to the transformation of cereal products for the production of drinks. It is basically about: Ultraflo-L; Cereflo- 200L; Thermamyl- 120L; Ffungamyl-800L and Ceremix-6XL. In carrying out this scientific research, we have used the molasses of beet, of 55% purity, which in 100 g of dried matters retain 55 kg of sucrose and 45 kg of organic and inorganic matters. This molasses has been then intensively mixed with a mechanic mixer, and periodically, at 15mn intervals, samples have been taken the relative density of which has been measured. It follows from our experiences that the relative densities of theses samples diminishes respectively , passing from 1.360 to 1.320; 1.250 and 1.200 g/cm³. Densities of these samples taken respectively reduce from 1,360; 1,320; 1,250; 1,200 g/cm3. At constant temperature of 60 °C, Kept by an Ultra thermostat, the viscosity of samples have been measured. The results have shown that final viscosities of molasses of 60% concentration have varied from 10.5 to 15.3 m. Pa in terms of amplitude. Thus, the thermo stability of the molasses with a neutral pH and a weak dose of fermentative preparations, like the Ultraflo-L and Cereflo-200L, allow the reduction of the viscosity of molasses to 20-35%.© 2016 International Formulae Group. All rights reserved.Keywords: Molasses, beet, viscosity, temperature, ferment

La double correction comme solution à l’évaluation du baccalauréat tchadien

Résumé : Cet article vise à analyser la portée et la fonction de la double correction qui est une réforme pour la crédibilité, la réputation, la transparence et la justice dans l’évaluation des candidats au baccalauréat tchadien. L’analyse de cette réforme est faite grâce aux données statistiques des trois années consécutives à savoir 2019,2020 et 2021. Les théories sur les évaluations et celles de la méritocratie nous ont servi de cadre théorique. De nature quantitative, cette recherche s’est basée sur les statistiques de l’Office National des Examens et Concours du Supérieur (ONECS) et complétées par nos propres observations en tant que responsables impliqués dans cette structure en charge de l’organisation du baccalauréat. Les résultats font état de ce que la double correction a apporté une amélioration considérable en termes de succès au baccalauréat. Après comparaison des prestations des titulaires de la licence à celles des titulaires du CAPEL (Certificat d’Aptitude Professionnelle pour l’Enseignement aux Lycées), les résultats sont profondément édifiants : il ressort de notre analyse que les enseignants certifiés commettent plus de maladresses que ceux issus des universités avec une Licence. Cette conclusion est due au fait que les licenciés n’aient pas bénéficié de formation professionnelle au cours de leur parcours. En revanche, les enseignants certifiés, eux, ont suivi une formation professionnelle dans les écoles de formation. Dès lors, une formation supplémentaire, notamment un recyclage serait important et bénéfique pour tous les enseignants licenciés. Il serait également intéressant pour notre pays de continuer à professionnaliser les enseignements dispensés dans les institutions académiques.   Mots-clés : Baccalauréat tchadien, double correction, docimologie, évaluation, ONEC

Phase II study of paclitaxel combined with capecitabine as second-line treatment for advanced gastric carcinoma after failure of cisplatin-based regimens

Purpose To determine the safety and the efficacy of paclitaxel and capecitabine as second-line combination chemotherapy after failure of platinum regimens in advanced gastric cancer. Methods Patients with histologically proven gastric cancer and measurable metastatic disease received capecitabine 825 mg/m2 twice daily (1,650 mg/m2 per day) on days 1–14 and paclitaxel 175 mg/m2 by intravenous infusion on day 1 every 3 weeks until disease progression or unacceptable toxicities. Results Between June 2003 and October 2005, 26 patients, of median age 59 years (range 41–84 years) were included in the study and were treated by paclitaxel/capecitabine combination. Overall response rate was 34.6% (95%CI = 17.2–55.7%) with one complete response and 42.3% (95%CI = 17.2–55.7%) of patients achieved a stable disease. Median progression-free survival was 4.5 months (95%CI = 4–4.5 months). Median overall survival was 7.5 months (95%CI = 6–10 months). Cumulated overall survival including cisplatin regimens was 15.5 months (95%CI = 11–18 months). Grade 3/4 adverse events included alopecia (30.8%), neutropenia (11.5%), hand foot skin reaction (11.5%), neuropathy (11.5%), arthralgias (7.5%), and anemia (3.8%). Conclusions Paclitaxel and capecitabine combination was safe and effective in advanced gastric cancer after failure of cisplatin regimens. The cumulated overall survival of 15.5 months suggests a particular interest of taxanes in second-line treatment after failure of platinum salts

Seroprevalence and associated risk factors of brucellosis, Rift Valley fever and Q fever among settled and mobile agro-pastoralist communities and their livestock in Chad.

Brucellosis, Rift Valley fever (RVF) and Q fever are zoonoses prevalent in many developing countries, causing a high burden on human and animal health. Only a few studies are available on these among agro-pastoralist communities and their livestock in Chad. The objective of our study was to estimate brucellosis, RVF and Q fever seroprevalence among Chadian agro-pastoralist communities and their livestock, and to investigate risk factors for seropositivity. We conducted a multi-stage cross-sectional serological survey in two rural health districts, Yao and Danamadji (966 human and 1041 livestock (cattle, sheep, goat and equine) samples)). The true seroprevalence were calculated applying a Bayesian framework to adjust for imperfect diagnostic test characteristics and accounting for clustering in the study design. Risk factors for each of the zoonotic diseases were estimated using mixed effects logistic regression models. The overall prevalence for brucellosis, Q fever and RVF combined for both regions was estimated at 0.2% [95% credibility Interval: 0-1.1], 49.1% [%CI: 38.9-58.8] and 28.1% [%CI: 23.4-33.3] in humans, and 0.3% [%CI: 0-1.5], 12.8% [%CI: 9.7-16.4] and 10.2% [%CI: 7.6-13.4] in animals. Risk factors correlating significantly with the respective disease seropositivity were sex for human brucellosis, sex and Q fever co-infection for animal brucellosis, age for human Q fever, species and brucellosis co-infection for animal Q fever, age and herd-level animal RVF seroprevalence within the same cluster for human RVF, and cluster-level human RVF seroprevalence within the same cluster for animal RVF. In Danamadji and Yao, Q fever and RVF are notably seroprevalent among agro-pastoralist human and animal communities, while brucellosis appears to have a low prevalence. Correlation between the seroprevalence between humans and animals living in the same communities was detected for RVF, highlighting the interlinkage of human and animal transmissible diseases and of their health, highlighting the importance of a One Health approach

Evaluation of the feasibility and sustainability of the joint human and animal vaccination and its integration to the public health system in the Danamadji health district, Chad

Background:One Health approaches such as the Joint human and animal vaccination programmes (JHAVP) are shown to be feasible and to increase health care access to hard-to-reach communities such as mobile pastoralists. However, the financial sustainability and the integration into the public health systems at the district level of such programmes are still challenging. The main objective of the present study was to give insight to the feasibility and financial sustainability of JHAVP integrated as part of the public health system in Chad.Methods:We conducted a mixed methods study using semi-structured key informant interviews, focus group discussions and budget impact analysis. Strengths, weaknesses, opportunities, and threats were analysed regarding the feasibility and sustainability of the implementation of JHAVP in Danamadji health district in Chad. Feasibility was further analysed using three dimensions: acceptability, implementation, and adaptation. Financial sustainability of JHAVP was analysed through budget impact analysis of implementation of the programme at district level.Results:The acceptability of this approach was regularly assessed by immunization campaign teams through evalua-tion meetings which included pastoralists. The presence of authorities in the meetings and workshops of the pro-gramme had an incentive effect since they represent a mark of consideration these populations generally declared to be lacking. The coordination between the public health and veterinary services at central and decentralized level seemed to be a key element in the success of the implementation of the programme. Regarding financial sustainabil-ity, the total incremental budget impact was 27% slightly decreasing to 26% after five years, which accounts for up to one third of the total budget of the district health office. Also, given that most of the costs for each round are recur-rent costs, efficiency gains from scale effects over time are limited.Conclusion:Based on these findings, we conclude that for JHAVP to be routinely delivered at the district health level, a considerable increase in financial resources would be required. The district could benefit from joint immunization to maintain contact with mobile pastoralists to promote the use of available immunization services at district level