La Massification Dans L’enseignement Supérieur : Contours, Enjeux Et Solutions Possibles

La massification dans l enseignement sup rieur du Cameroun et des autres pays membres du CAMES s inscrit dans une mouvance mondiale Au minimum trois axes demande offre et produits services contribuent l alimenter Elle est susceptible d ancrage dans diverses th ories conomiques et le taux de croissance de la proportion des tudiants sup rieur au double de celui de la population totale en est un fait stylis Cette massification emporte la fois des enjeux connotation p jorative et des enjeux connotation m liorative Pour y faire face les solutions explor es pr sent es et explorables sugg r es ont globalement pour finalit de sauvegarder la pertinence et la qualit des prestations offerte

Hydrocarbon influence on denitrification in bioturbated Mediterranean coastal sediments

An in situ experiment has been carried out inbioturbated Mediterranean coastal marine sediments (Gulfof Fos) in order to study the influence of hydrocarbons ondenitrification after 1, 4 and 6 months. In theabsence of hydrocarbons in the control sediments, the presenceof macrofauna stimulated denitrificationby 160%. This stimulation is induced by sediment reworkingthat favours both direct NO-3 supply fromthe water column and the penetration of O{2}, which in turnstimulated nitrification, the other source ofNO-3 in sediment. The presence of hydrocarbons in theexperimental sediments either stimulated orinhibited the denitrification. The denitrification response tothe presence of hydrocarbon is dependent onthe quantity of matter buried by the macrofauna activity. Insmall quantities, the organic matter relatedto hydrocarbons 120% enhanced the denitrification compared tothe controls. On the other hand, whenburied hydrocarbon concentrations were higher (>100 mgsaturated hydrocarbon fraction kg-1 drysediment), the denitrification was inhibited.On the basis of the results obtained, a descriptive model ofthe patterns of denitrification in relation to the presence ofmacrofauna and the distribution of hydrocarbons in sediments is proposed

Maximal stability region of a perturbed nonnegative matrix

For a class of positive matrices A + K with a stable positive nominal part A and a structured positive perturbation part K, we address the problem of finding the largest set of admissible perturbations such that the global matrix remains stable. Theoretical bounds are derived and an algorithm for constructing this set is presented. As an example, this algorithm is applied to the regulation of water flow in open channels

Turquie, France : le voyage des mots

De “sofa” à “kefta”, de nombreux mots, issus ou passant par le monde turc, sont entrés dans la langue française. Petite histoire des emprunts lexicaux au carrefour des imaginaires en provenance de l’Orient

Perspectives paysagères. La recherche en questions

Serge Briffaud, organisateur de ces Journées doctorales en paysage, m’a proposé de rédiger une sorte de « postface », ce qui ne veut rien dire… ou tout dire s’il s’agit de ménager un espace de libre réflexion à partir des travaux présentés et, si possible, d’élargir le panorama. Une occasion unique de mettre des recherches paysagères récentes en perspective générale. En effet, ce ne peut être un bilan : celui-ci relève collectivement du conseil scientifique de cette manifestation. Une analyse..

Digital divides in Sub-Saharan Africa: Gender issues and evidence from Cameroon

This study aims at answering two questions: Do women have the same determinants of Internet adoption as men? Do they adopt it for the same uses? The answers are mainly positive. However, in the adoption decision, women are different from men mainly due to the negative effects of age and unemployment; these effects being positive for men. Moreover, women have a relatively lesser intensity of use. Age remains a hindering factor while high computer skills and high frequency of computer use improves the intensity of Internet use. This recommends homogeneous policies while especially encouraging young women to use ICT and not to drop out as they grow in age.Keywords: Gender; Digital divide; Internet adoption; Internet use

Alteration and release of aliphatic compounds by the polychaete Nereis virens (Sars) experimentally fed with hydrocarbons

In the laboratory, marine worms were fed with a mixture of algae and several aliphatic hydrocarbons for 15 days. After ingestion by the worms, 34.9% of hydrocarbons are found in the faeces and only 3.1% accumulated in the gut. The comparison between the initial mixture and the faeces shows that the worm’s digestive process lead to changes in the distribution of the n-alkane mixture. These changes are different from those only due to physical processes in the experimental conditions. In our experiment, no variation in the distribution of hydrocarbons in faeces with time and no microbial hydrocarbon biodegradation were evidenced. Our results suggest that marine worm feeding can substantially affect the fate of hydrocarbons in the sedimentary marine ecosystem by predominantly stimulating dissolution processes

Inhibition of denitrification by hydrocarbons in marine sediments. Role of Nereis diversicolor

An in vitro experiment has been carried out in order to illustrate the influence of the burrowing polychaete Nereis diversicolor on denitrification in hydrocarbon-loaded sediments. After 15 and 45 days, the denitrification activity in the different contaminated or non-contaminated control (without macro-fauna) and experimental (colonized by polychaetes) sediments was compared. In control contaminated sediments, the inhibition of denitrification is solely located in the surface layer (0–2 cm). In the presence of polychaetes, the hydrocarbon buried in the burrows extends the inhibition of denitrification in the sediment. As a function of the quantity of buried hydrocarbon, the inhibition of denitrification is observed up to a depth of 6 and 10 cm, after 15 and 45 days, respectively