L'INTERNATIONALISATION ESTELLE CREATRICE DE VALEUR ?

La diversification géographique est elle source de valeur pour la firme ? Cette étude se place dans le cadre de la théorie de l'internalisation selon lequel une entreprise, qui possède des actifs intangibles spécifiques, peut tirer avantages de sa multinationalisation par le biais des transactions qu'elle réalise en interne, entre la société mère et ses filiales étrangères. Les résultats empiriques montrent que l'influence positive, que peut avoir l'internationalisation sur la valeur de la société, est fonction du degré d'implantation à l'étranger de la firme.multinationales ; création de valeur ; diversification géographique

Normes comptables internationales et capital immatériel : une étude exploratoire à partir de deux cas de la "nouvelle économie"

Cette recherche, de nature exploratoire, s'est intéressée aux politiques comptables en matière d'immatériels de deux entreprises françaises de la nouvelle économie. Les études de cas, conduites essentiellement à partir des états financiers consolidés de 1998 à 2002, soulèvent la question de la justification, dans le cas de la nouvelle économie, de l'activation des immatériels. Il semble que les futures normes IAS/IFRS devraient permettre une comptabilisation plus pertinente des intangibles.immatériels; nouvelle économie; normes comptables; études de cas

Risk assessment of spreading Banana streak viruses in the Dominican Republic through large scale cultivation of plantain cultivars and hybrids harbouring infectious eBSVs. [O.33]

Most cultivated plantains are interspecific cultivars or hybrids: they harbour Musa acuminata (A) genomes and Musa balbisiana (B) genomes which hosts infectious endogenous Banana streak virus sequences (eBSVs). Spontaneous infections can arise in plantains following activation of these sequences by biotic and abiotic stresses, such as tissue culture and temperature differences, while several mealybug species can transmit BSV horizontally. The level of activation of infectious eBSVs by tissue culture has been quantified for several plantain cultivars and hybrids [1, 2], but virtually nothing is known about activation levels under field conditions, thus preventing the assessment of the risk of spreading BSV through large scale cultivation of plantains. This question was addressed in the Dominican Republic, using the most widely cultivated plantain types in the country: triploid AAB cultivar Macho x Hembra (MxH) and tetraploid AAAB hybrid FHIA21. Both carry infectious eBSV alleles OL1 and GF7 of the two distinct BSV species BSOLV and BSGFV, respectively, but are devoid of infectious eBSVs of species BSIMV. Firstly, a nationwide survey was conducted throughout all Dominican banana growing areas. A total of 590 leaf samples of FHIA21 and MxH were collected from 36 locations reflecting the diversity of banana cultivation conditions in the country (temperature, irrigation, type of planting material, presence of mealybugs...). Samples were indexed for viral species BSOLV, BSGFV and BSIMV. Based on these results, two locations were selected for an in depth survey: 100 FHIA21 and 100 MxH leaf samples were collected from nearby plots in each location, and mealybug samples were also collected on sampled plants. All plant samples were indexed for viral species BSOLV, BSGFV and BSIMV, whereas total DNA was extracted from mealybugs and used to type mealybug species and search for BSV in mealybugs. Results from indexings and molecular analyses were used in a multifactorial statistical analysis taking into account environmental factors. Overall, results suggest that in the Dominican Republic, BSV infections in plantains MxH and FHIA21 result from the activation of infectious eBSVs rather than from horizontal transmission by mealybug vectors. They show that infection levels are significantly more important in FHIA21 than in MxH, highlighting the importance of genetic background in eBSV activation processes. Activation of infectious eBSVs was also assessed experimentally in FHIA21 and MxH. To this end, an experimental plot was set up under field culture conditions, using FHIA21 and MxH plants produced either by tissue culture or by suckers. Mealybugs and ants were controlled by insecticide treatment throughout the experiment, therefore ensuring that BSV infections could only arise from the activation of infectious eBSVs. All 484 plants of the plot were indexed regularly for BSV species BSOLV, BSGFV and BSIMV. Indexing results were used in a multifactorial statistical analysis, providing the first comparative risk assessment of spreading Banana streak viruses through cultivation of plantain cultivars and hybrids originating from tissue culture or suckers. (Résumé d'auteur

Comparative study of the prevalence and diversity of Banana streak viruses (BSV) in plantain interspecific hybrids in the Dominican Republic

Banana and plantain (Musa spp.) are major staple food and cash crops in the Dominican Republic. However, production suffers from Black Sigatoka disease (BSD), a severe foliar disease caused by the fungus MycosphaerellafijiensisMorelet. Several BSD-resistant interspecific Musa acuminata(A) x Musa balbisiana(B) bananaand plantain hybrid varieties were introduced in the late 1990sin the Dominican Republic as an alternative to chemical control of M. fijiensis, especially plantain hybrid species FHIA21.However, it was later shown that M. balbisiana(B) progenitors harbor infectious endogenous sequences of Banana streak virus (eBSV) [1] and that these sequences can lead to spontaneous infections in created and natural interspecific hybrids, following abiotic stresses including cell culture and temperature differences [2]. In order to assess the risk of spreading BSV in the Dominican Republicthrough large scale distributions of created plantain interspecific hybrids, apreliminary survey was conducted in order to compare the prevalence and diversity of BSV species in hybrid FHIA21 (AAAB) and a local plantain cultivar, Macho X Hembra (AAB), which is a natural interspecific hybrid. Samples were collected in a selection of plots located in the main production area of plantain in the Dominican Republic and representative of the diversity of environmental and growing conditions (temperature, rainfall).All samples were indexed for the four main BSV species, including BSOLV, BSImV and BSGFV for which the existence of infectious eBSVs has been demonstrated. eBSV signatures were established for each sample group and correlated to indexing results. The presence of mealybugs (Planococcus ssp.), which are BSV natural vectors, was monitored on each sampling site and taken into account in a multifactor analysis. Results show that the level of prevalence of some BSVspecies is significantly higher in FHIA21 than in Macho X Hembra, and suggest that this difference results from increased activation of infectious eBSVs in FHIA21. (Texte intégral

LA VERIFICATION VOLONTAIRE DES INFORMATIONS SOCIETALES: LA STRUCTURE DE PROPRIETE ET LE CONSEIL D'ADMINISTRATION ONT-ILS UNE INFLUENCE SUR LA DECISION DE L'ENTREPRISE ?

International audienceWhat is the influence of ownership structure and composition of the Board of Directors on the voluntary verification, by an outside third party, of the sustainability information disclosed? This paper is an attempt to answer this research question. The empirical study focuses on the CAC40 companies. The results show that the majority of these companies checked their voluntarily sustainability information in 2007 and 2008. The nature of ownership and the non-overlapping mandates of CEO and Chairman of the Board are determinants of sustainability verification. In addition, firm size is an important explanatory factor of the verification. This verification is primarily implemented by larger companies, i.e. those able to bear the costs of such activity.Quelle est l'influence de la structure de propriété et de la composition du conseil d'administration (CA) sur la vérification volontaire, par un tiers extérieur, des informations sociétales divulguées ? C'est à cette question de recherche que nous tentons ici de répondre. L'étude empirique porte sur les entreprises du CAC40. Les résultats montrent que la majorité de ces entreprises vérifie volontairement leurs informations sociétales en 2007 et 2008. La nature de l'actionnariat ainsi que le non cumul des mandats de directeur général et président du CA constituent des déterminants de la vérification sociétale. En outre, la taille de l'entreprise est un facteur explicatif important de la vérification. Celle-ci est avant tout mise en place par les plus grandes entreprises, c'est-à-dire celles qui sont susceptibles de supporter les coûts d'une telle activité

Communication environnementale et coût des fonds propres : Le cas des entreprises du SBF120

Quel est l'impact sur le coût des fonds propres des divulgations volontaires d'informations environnementales ? C'est à cette question de recherche que nous tentons ici de répondre. L'étude empirique porte sur un échantillon de 119 entreprises cotées du SBF120. La majorité de ces entreprises consacre en 2006 un chapitre ou une partie au domaine environnemental dans leur rapport annuel tandis que 20% publient un rapport spécifiquement dédié au développement durable. Quel que soit le support choisi, les thèmes environnementaux les plus documentés concernent la pollution, les ressources naturelles et le recyclage. L'étude met en exergue l'absence d'impact de la communication environnementale sur le coût des fonds propres des entreprises émettrices. Une gestion environnementale transparente ne semble donc pas à l'origine d'une baisse du coût des ressources de financement.Communication environnementale; divulgation volontaire; coût des fonds propres

LA VERIFICATION VOLONTAIRE DES INFORMATIONS SOCIETALES: LA STRUCTURE DE PROPRIETE ET LE CONSEIL D'ADMINISTRATION ONT-ILS UNE INFLUENCE SUR LA DECISION DE L'ENTREPRISE ?

Quelle est l'influence de la structure de propriété et de la composition du conseil d'administration (CA) sur la vérification volontaire, par un tiers extérieur, des informations sociétales divulguées ? C'est à cette question de recherche que nous tentons ici de répondre. L'étude empirique porte sur les entreprises du CAC40. Les résultats montrent que la majorité de ces entreprises vérifie volontairement leurs informations sociétales en 2007 et 2008. La nature de l'actionnariat ainsi que le non cumul des mandats de directeur général et président du CA constituent des déterminants de la vérification sociétale. En outre, la taille de l'entreprise est un facteur explicatif important de la vérification. Celle-ci est avant tout mise en place par les plus grandes entreprises, c'est-à-dire celles qui sont susceptibles de supporter les coûts d'une telle activité.Vérification volontaire, informations sociétales, gouvernance interne

Multiple effects of silymarin on the hepatitis C virus lifecycle

Silymarin, an extract from milk thistle (Silybum marianum), and its purified flavonolignans have been recently shown to inhibit hepatitis C virus (HCV) infection, both in vitro and in vivo. In the current study, we further characterized silymarin's antiviral actions. Silymarin had antiviral effects against hepatitis C virus cell culture (HCVcc) infection that included inhibition of virus entry, RNA and protein expression, and infectious virus production. Silymarin did not block HCVcc binding to cells but inhibited the entry of several viral pseudoparticles (pp), and fusion of HCVpp with liposomes. Silymarin but not silibinin inhibited genotype 2a NS5B RNA-dependent RNA polymerase (RdRp) activity at concentrations 5 to 10 times higher than required for anti-HCVcc effects. Furthermore, silymarin had inefficient activity on the genotype 1b BK and four 1b RDRPs derived from HCV-infected patients. Moreover, silymarin did not inhibit HCV replication in five independent genotype 1a, 1b, and 2a replicon cell lines that did not produce infectious virus. Silymarin inhibited microsomal triglyceride transfer protein activity, apolipoprotein B secretion, and infectious virion production into culture supernatants. Silymarin also blocked cell-to-cell spread of virus. CONCLUSION: Although inhibition of in vitro NS5B polymerase activity is demonstrable, the mechanisms of silymarin's antiviral action appear to include blocking of virus entry and transmission, possibly by targeting the host cell