Effets des Déterminants du Prix International de Référence du Coton en FCFA sur la Compétitivité de l’Afrique de l’Ouest et du Centre

L’objet de ce chapitre est d’analyser les effets des déterminants de l’indice A en FCFA sur la compétitivité de l’AOC évaluée à travers la part de marché et le profit. Après la détection de relations de cointégration par le test de cointégration aux bornes, l’estimation du modèle à correction d’erreur ARDL-ECR est validé par une force de rappel de -0.990695, un R2 de 86,84%, des tests de diagnostic de résidus réussis et le test de stabilité du modèle. Sur la part de marché et de façon significative, la dynamique de l’indice A Cotlook en FCFA se manifeste à court terme par des effets positifs du taux de change dollar-FCFA et des effets négatifs de la volatilité et de l’élasticité-prix de l’indice A en FCFA, de la rupture (dévaluation) survenue en 1994. A long terme et toujours de façon significative, elle se manifeste par des effets positifs du taux de change dollar-FCFA. Les déterminants de l’indice eux se manifestent à court terme par des effets positifs de la production de l’AOC, de la consommation et du stock du monde ; et des effets négatifs du stock de l’AOC et de la production mondiale. A long terme, ces déterminants se manifestent par des effets positifs de la production de l’AOC, des pandémies ; et des effets négatifs du stock de l’AOC. Sur le Profit, le modèle Probit validé par les tests de diagnostics des résidus révèle uniquement des effets significatifs et positif de la production de l’AOC. Face aux effets négatifs de la volatilité et de la dévaluation, l’AOC se trouve démunie et ne peut réagir. Par contre, les effets de sa production sont bénéfices sur la part de marché et le profit et ouvrent des champs possibles d’amélioration de sa compétitivité. Il s’agit (1) de la création d’une place de marché propre avec des institutions permettant de moins s’exposer aux impacts négatifs de la dynamique des cours internationaux et de mieux valoriser ses avantages comparatifs ; (2) de l’amélioration continue de la performance opérationnelle des systèmes de production aussi bien agricoles qu’industriels ; et (3) de la meilleure valorisation de la qualité de la fibre par le passage du classement manuel en œuvre à l’AOC au classement instrumental utilisé par le reste du monde.   The purpose of this chapter is to analyse the effects of the dynamics and determinants of the index A in FCFA on the competitiveness of the AOC evaluated through market share and profit. After the detection of cointegration relations by the cointegration test at the terminals, the estimation of the error-corrected model ARDL-ECR is validated by a recall force of -0.990695, an R2 of 86,84%, successful residue diagnostic tests and model stability test. In terms of market share and significantly, the dynamics of the A Cotlook index in FCFA are reflected in the short term by positive effects of the dollar-FCFA exchange rate and the negative effects of the volatility and price elasticity of the A index in FCFA, the break-up (devaluation) in 1994. In the long term, and still significantly, it is reflected in the positive effects of the dollar-FCFA exchange rate. The determinants of the index are manifested in the short term by positive effects of the production of the AOC, the consumption and the world stock; and the negative effects of the AOC stock and world production. In the long term, these determinants manifest themselves in positive effects of the production of AOC, pandemics; and negative effects of the AOC stock. On Profit, the Probit model validated by the residue diagnostic tests only reveals significant and positive effects of AOC production. Our hypothesis is thus confirmed. Faced with the negative effects of volatility and devaluation, the AOC finds itself deprived and unable to react. On the other hand, On the other hand, the effects of its production are beneficial on market share and profit and open up possible fields for improving its competitiveness.. It concerns (1) the creation of a market place with its own institutions allowing less exposure to the negative impacts of the dynamics of international prices and to better value its comparative advantages; (2) continuous improvement in the operational performance of both agricultural and industrial production systems; and (3) the best enhancement of the quality of the fiber by the transition from the manual classification in use to the AOC to the instrumental classification used by the rest of the world

Effets des Déterminants du Prix International de Référence du Coton en FCFA sur la Compétitivité de l’Afrique de l’Ouest et du Centre

L’Afrique de l’ouest et du Centre (AOC) est le 3e exportateur de coton sur le marché mondial et y exporte la quasi-totalité de sa production. A cet effet, la maîtrise indispensable des déterminants du prix indiciel mondial qui sert de référence à ses contrats de vente constitue l’objectif de cette étude axée sur la compétitivité et dans laquelle sont expliqués la Part de marché et le Profit de l’AOC grâce aux modèles Auto Regressive Distributed Lag (ARDL) et Probit. Sur la part de marché, les tests révèlent à court terme des effets positifs du taux de change dollar-FCFA, de la production de l’AOC, de la consommation et du stock du monde ; et des effets négatifs de la volatilité et de l’élasticité-prix de l’indice A en FCFA, de la dévaluation de 1994, du stock de l’AOC et de la production mondiale. A long terme, on observe des effets positifs du taux de change dollar-FCFA, de la production de l’AOC, des pandémies ; et des effets négatifs du stock de l’AOC. Sur le Profit, on observe des effets positifs de la production de l’AOC. Ainsi pour croitre sa compétitivité, l’AOC doit améliorer son système de production et créer sa propre place de marché pour mieux maîtriser les prix et valoriser ses avantages comparatifs.   West and Central Africa (WCA) is the 3rd cotton exporter on the world market and exports almost all of its production there. To this end, the essential mastery of the determinants of the world index price which serves as a reference for its sales contracts constitutes the objective of this study focused on competitiveness and in which the Market Share and Profit of the AOC are explained thanks to Auto Regressive Distributed Lag (ARDL) and Probit models. On the market share, the tests reveal in the short-term positive effects of the dollar-FCFA exchange rate, of the production of the AOC, of ​​the consumption and of the world stock; and the negative effects of the volatility and price elasticity of the A index in FCFA, the 1994 devaluation, the AOC stock and world production. In the long term, there are positive effects of the dollar-FCFA exchange rate, AOC production, pandemics; and negative effects of the AOC stock. On the Profit, we observe positive effects of the production of the AOC. Thus, to increase its competitiveness, the AOC must improve its production system and create its own market place to better control prices and enhance its comparative advantages

Effets des Déterminants du Prix International de Référence du Coton en FCFA sur la Compétitivité de l’Afrique de l’Ouest et du Centre

L’objet de ce chapitre est d’analyser les effets des déterminants de l’indice A en FCFA sur la compétitivité de l’AOC évaluée à travers la part de marché et le profit. Après la détection de relations de cointégration par le test de cointégration aux bornes, l’estimation du modèle à correction d’erreur ARDL-ECR est validé par une force de rappel de -0.990695, un R2 de 86,84%, des tests de diagnostic de résidus réussis et le test de stabilité du modèle. Sur la part de marché et de façon significative, la dynamique de l’indice A Cotlook en FCFA se manifeste à court terme par des effets positifs du taux de change dollar-FCFA et des effets négatifs de la volatilité et de l’élasticité-prix de l’indice A en FCFA, de la rupture (dévaluation) survenue en 1994. A long terme et toujours de façon significative, elle se manifeste par des effets positifs du taux de change dollar-FCFA. Les déterminants de l’indice eux se manifestent à court terme par des effets positifs de la production de l’AOC, de la consommation et du stock du monde ; et des effets négatifs du stock de l’AOC et de la production mondiale. A long terme, ces déterminants se manifestent par des effets positifs de la production de l’AOC, des pandémies ; et des effets négatifs du stock de l’AOC. Sur le Profit, le modèle Probit validé par les tests de diagnostics des résidus révèle uniquement des effets significatifs et positif de la production de l’AOC. Face aux effets négatifs de la volatilité et de la dévaluation, l’AOC se trouve démunie et ne peut réagir. Par contre, les effets de sa production sont bénéfices sur la part de marché et le profit et ouvrent des champs possibles d’amélioration de sa compétitivité. Il s’agit (1) de la création d’une place de marché propre avec des institutions permettant de moins s’exposer aux impacts négatifs de la dynamique des cours internationaux et de mieux valoriser ses avantages comparatifs ; (2) de l’amélioration continue de la performance opérationnelle des systèmes de production aussi bien agricoles qu’industriels ; et (3) de la meilleure valorisation de la qualité de la fibre par le passage du classement manuel en œuvre à l’AOC au classement instrumental utilisé par le reste du monde.   The purpose of this chapter is to analyse the effects of the dynamics and determinants of the index A in FCFA on the competitiveness of the AOC evaluated through market share and profit. After the detection of cointegration relations by the cointegration test at the terminals, the estimation of the error-corrected model ARDL-ECR is validated by a recall force of -0.990695, an R2 of 86,84%, successful residue diagnostic tests and model stability test. In terms of market share and significantly, the dynamics of the A Cotlook index in FCFA are reflected in the short term by positive effects of the dollar-FCFA exchange rate and the negative effects of the volatility and price elasticity of the A index in FCFA, the break-up (devaluation) in 1994. In the long term, and still significantly, it is reflected in the positive effects of the dollar-FCFA exchange rate. The determinants of the index are manifested in the short term by positive effects of the production of the AOC, the consumption and the world stock; and the negative effects of the AOC stock and world production. In the long term, these determinants manifest themselves in positive effects of the production of AOC, pandemics; and negative effects of the AOC stock. On Profit, the Probit model validated by the residue diagnostic tests only reveals significant and positive effects of AOC production. Our hypothesis is thus confirmed. Faced with the negative effects of volatility and devaluation, the AOC finds itself deprived and unable to react. On the other hand, On the other hand, the effects of its production are beneficial on market share and profit and open up possible fields for improving its competitiveness.. It concerns (1) the creation of a market place with its own institutions allowing less exposure to the negative impacts of the dynamics of international prices and to better value its comparative advantages; (2) continuous improvement in the operational performance of both agricultural and industrial production systems; and (3) the best enhancement of the quality of the fiber by the transition from the manual classification in use to the AOC to the instrumental classification used by the rest of the world

Factors associated with unprotected anal intercourse among men who have sex with men in Douala, Cameroon

Objectives Research on men who have sex with men (MSM) in sub-Saharan Africa was neglected for a long time. The objective of this study was to understand factors associated with unprotected anal intercourse (UAI) with male partners among a group of MSM living in the city of Douala, Cameroon. Methods In 2008, a survey on the sexual activity and practices of MSM was set up in Douala in collaboration with a local community-based organisation. Data were collected among a convenience sample of 168 MSM during face-to-face interviews with trained interviewers. Results A total of 142 individuals reported sexual activity during the previous 6 months, among whom 80 (57%) reported UAI with male partners. In a multivariate logistic regression model adjusted for the frequency of sexual intercourse, not having had access to prevention interventions and not knowing any HIV-infected person were both independently associated with a higher risk of UAI. Other factors associated with this higher risk included having had a stable male partnership at some point in one's life and not having been out of Douala for more than 4 weeks during the previous year. Conclusions This community-based research is the first study of MSM in Cameroon and the HIV transmission risks they face. Results show the importance of HIV prevention interventions from peers, and underline the need to maintain efforts to develop specific interventions targeting MSM more efficiently in the African context

Second-trimester amniotic fluid proteins changes in subsequent spontaneous preterm birth

IntroductionThe global sequence of the pathogenesis of preterm labor remains unclear. This study aimed to compare amniotic fluid concentrations of extracellular matrix-related proteins (procollagen, osteopontin and IL-33), and of cytokines (IL-19, IL-6, IL-20, TNF alpha, TGF beta, and IL-1 beta) in asymptomatic women with and without subsequent spontaneous preterm delivery. Material and methodsWe used amniotic fluid samples of singleton pregnancy, collected by amniocentesis between 16 and 20 weeks' gestation, without stigmata of infection (i.e., all amniotic fluid samples were tested with broad-range 16 S rDNA PCR to distinguish samples with evidence of past bacterial infection from sterile ones), during a randomized, double-blind, placebo-controlled trial to perform a nested case-control laboratory study. Cases were women with a spontaneous delivery before 37 weeks of gestation (preterm group). Controls were women who gave birth at or after 39 weeks (full term group). Amniotic fluid concentrations of the extracellular matrix-related proteins and cytokines measured by immunoassays were compared for two study groups. : NCT00718705. ResultsBetween July 2008 and July 2011, in 12 maternal-fetal medicine centers in France, 166 women with available PCR-negative amniotic fluid samples were retained for the analysis. Concentrations of procollagen, osteopontin, IL-19, IL-6, IL-20, IL-33, TNF alpha, TGF beta, and IL-1 beta were compared between the 37 who gave birth preterm and the 129 women with full-term delivery. Amniotic fluid levels of procollagen, osteopontin, IL-19, IL-33, and TNF alpha were significantly higher in the preterm than the full-term group. IL-6, IL-20, TGF beta, and IL-1 beta levels did not differ between the groups. ConclusionsIn amniotic fluid 16 S rDNA PCR negative samples obtained during second-trimester amniocentesis, extracellular matrix-related protein concentrations (procollagen, osteopontin and IL-33), together with IL-19 and TNF alpha, were observed higher at this time in cases of later spontaneous preterm birth

Addressing ethical challenges in the Genetics Substudy of the National Eye Survey of Trinidad and Tobago (GSNESTT).

BACKGROUND: The conduct of international collaborative genomics research raises distinct ethical challenges that require special consideration, especially if conducted in settings that are research-naïve or resource-limited. Although there is considerable literature on these issues, there is a dearth of literature chronicling approaches taken to address these issues in the field. Additionally no previous ethical guidelines have been developed to support similar research in Trinidad and Tobago. METHODS: A literature review was undertaken to identify strategies used to address common ethical issues relevant to human genetics and genomics research in research-naïve or resource-limited settings. Strategies identified were combined with novel approaches to develop a culturally appropriate, multifaceted strategy to address potential challenges in the Genetics Substudy of the National Eye Survey of Trinidad and Tobago (GSNESTT). RESULTS: Regarding the protection of study participants, we report a decision to exclude children as participants; the use of a Community Engagement and Sensitization Strategy to increase the genetic literacy of the target population; the involvement of local expertise to ensure cultural sensitivity and to address potential comprehension barriers in informed consent; and an audit of the informed consent process to ensure valid consent. Concerning the regulation of the research, we report on ethics approvals from relevant authorities; a Materials Transfer Agreement to guide sample ownership and export; and a Sample Governance Committee to oversee data use and data access. Finally regarding the protection of the interests of scientists from the host country, we report on capacity building efforts to ensure that local scientists have access to data collected through the project and appropriate recognition of their contributions in future publications. CONCLUSION: This paper outlines an ethical framework for the conduct of population-based genetics and genomics research in Trinidad and Tobago; highlights common issues arising in the field and strategies to address these

Cyclic-di-AMP synthesis by the diadenylate cyclase CdaA is modulated by the peptidoglycan biosynthesis enzyme GlmM in lactococcus lactis

© 2016 John Wiley & Sons Ltd. The second messenger cyclic-di-adenosine monophosphate (c-di-AMP) plays important roles in growth, virulence, cell wall homeostasis, potassium transport and affects resistance to antibiotics, heat and osmotic stress. Most Firmicutes contain only one c-di-AMP synthesizing diadenylate cyclase (CdaA); however, little is known about signals and effectors controlling CdaA activity and c-di-AMP levels. In this study, a genetic screen was employed to identify components which affect the c-di-AMP level in Lactococcus. We characterized suppressor mutations that restored osmoresistance to spontaneous c-di-AMP phosphodiesterase gdpP mutants, which contain high c-di-AMP levels. Loss-of-function and gain-of-function mutations were identified in the cdaA and gdpP genes, respectively, which led to lower c-di-AMP levels. A mutation was also identified in the phosphoglucosamine mutase gene glmM, which is commonly located within the cdaA operon in bacteria. The glmM I154F mutation resulted in a lowering of the c-di-AMP level and a reduction in the key peptidoglycan precursor UDP-N-acetylglucosamine in L. lactis. C-di-AMP synthesis by CdaA was shown to be inhibited by GlmMI154F more than GlmM and GlmMI154F was found to bind more strongly to CdaA than GlmM. These findings identify GlmM as a c-di-AMP level modulating protein and provide a direct connection between c-di-AMP synthesis and peptidoglycan biosynthesis. c-di-AMP is an essential signalling molecule which affects peptidoglycan homeostasis and resistance against various stressors, however little is known regarding how the c-di-AMP level is regulated in the cell. Here we identify the peptidoglycan biosynthesis enzyme GlmM as a modulator of c-di-AMP synthesis through its regulation of diadenylate cyclase enzyme CdaA activity in Lactococcus lactis

Protecting and Evaluating Genomic Privacy in Medical Tests and Personalized Medicine

In this paper, we propose privacy-enhancing technologies for medical tests and personalized medicine methods that use patients' genomic data. Focusing on genetic disease-susceptibility tests, we develop a new architecture (between the patient and the medical unit) and propose a "privacy-preserving disease susceptibility test" (PDS) by using homomorphic encryption and proxy re-encryption. Assuming the whole genome sequencing to be done by a certified institution, we propose to store patients' genomic data encrypted by their public keys at a "storage and processing unit" (SPU). Our proposed solution lets the medical unit retrieve the encrypted genomic data from the SPU and process it for medical tests and personalized medicine methods, while preserving the privacy of patients' genomic data. We also quantify the genomic privacy of a patient (from the medical unit's point of view) and show how a patient's genomic privacy decreases with the genetic tests he undergoes due to (i) the nature of the genetic test, and (ii) the characteristics of the genomic data. Furthermore, we show how basic policies and obfuscation methods help to keep the genomic privacy of a patient at a high level. We also implement and show, via a complexity analysis, the practicality of PDS

Current Antiviral Therapy of Chronic Hepatitis B: Efficacy and Safety

The treatment of chronic hepatitis B is in constant evolution. Interferon, the first agent licensed for chronic hepatitis B treatment, has been superseded by the growing popularity of nucleoside/nucleotide analogues (NA). However, resistance to these agents is a major challenge. Newer NAs, such as entecavir and tenofovir dipivoxil fumarate, have very low resistance rates and favorable safety profiles. Long-term use of these agents can effectively suppress hepatitis B virus DNA, leading to decrease in incidence of hepatitic flares, as well as in the development of cirrhosis and hepatocellular carcinoma. The efficacy and safety of various antiviral agents is discussed in this review