Entre individualisation et responsabilités familiales : les mobilités des jeunes de la région de Kayes au Mali

Cet article porte sur les jeunes des villages de la région de Kayes, au Mali, confrontés à la nécessité de prendre leurs responsabilités d’adultes au sein de leur groupe familial et, plus largement, de leur collectivité. Or, la crise de l’agriculture au Sahel fait que celle-ci ne suffit plus aux besoins alimentaires et ne représente plus un métier. Si leurs aînés ont passé ce cap en émigrant vers la France, les nouvelles générations sont face à une alternative, celle d’émigrer à leur tour ou d’étudier afin de se professionnaliser au Mali. Mais cette dernière éventualité demeure fragile. La frontière entre les deux groupes, candidats à l’émigration ou élèves et étudiants, apparaît alors ténue. Quoi qu’il en soit, le projet de mobilité sociale auquel aspire l’ensemble de ces jeunes s’accompagne d’une nécessaire mobilité spatiale : que ce soit vers la capitale nationale (Bamako) pour y étudier ; ou vers un pays d’émigration pour y travailler.This article examines the case of young adults coming from villages in the region of the Kayes in Mali. They are faced up to the necessity of taking their responsibilities as adults in the family and in the community. However, the Sahelian agriculture is in crisis and do not meet any longer the needs of food or of employment. If their elders overcome this obstacle by migration to France, new generations are now facing another alternative: in their turn migrating, or, studying in order to be more professional in Mali. But this second possibility remains an uncertain option. There is a fine boundary between these two groups: being a potential candidate for emigration or for studies. In any case, the project of social mobility these young adults aspire to, goes along with a necessary spatial mobility, either towards the national capital (Bamako) to study or to any country of migration to work there.Este artículo trata de los jóvenes de los pueblos de la región de Kayes, en Mali, enfrentados a la necesidad de tomar sus responsabilidades de adultos en el seno de su grupo familiar y, más ampliamente, en el seno de su colectividad. Con todo, la crisis de la agricultura en el Sahel ha hecho que ésta haya dejado de ser suficiente para cubrir las necesidades alimentarias y ha dejado de ser un oficio. Si sus mayores pasaron este trance emigrando hacia Francia, las nuevas generaciones se hallan frente a una alternativa, la de emigrar también, o la de estudiar con el fin de profesionalizarse en Mali. Pero esta última eventualidad sigue siendo frágil. La frontera entre ambos grupos, ya sean los candidatos a la emigración o los alumnos y estudiantes, resulta tenue. Sea como fuere, el proyecto de movilidad social al cual aspira el conjunto de estos jóvenes se acompaña de una necesaria movilidad y espacial: ya sea hacia la capital nacional (Bamako) para estudiar allí o hacia un país de emigración para trabajar

Lock-in thermography as a rapid and reproducible thermal characterization method for magnetic nanoparticles

Lock-in thermography (LIT) is a sensitive imaging technique generally used in engineering and materials science (e.g. detecting defects in composite materials). However, it has recently been expanded for investigating the heating power of nanomaterials, such as superparamagnetic iron oxide nanoparticles (SPIONs). Here we implement LIT as a rapid and reproducible method that can evaluate the heating potential of various sizes of SPIONs under an alternating magnetic field (AMF), as well as the limits of detection for each particle size. SPIONs were synthesized via thermal decomposition and stabilized in water via a ligand transfer process. Thermographic measurements of SPIONs were made by stimulating particles of varying sizes and increasing concentrations under an AMF. Furthermore, a commercially available SPION sample was included as an external reference. While the size dependent heating efficiency of SPIONs has been previously described, our objective was to probe the sensitivity limits of LIT. For certain size regimes it was possible to detect signals at concentrations as low as 0.1 mg Fe/mL. Measuring at different concentrations enabled a linear regression analysis and extrapolation of the limit of detection for different size nanoparticles

A Novel Gene, fudoh, in the SCCmec Region Suppresses the Colony Spreading Ability and Virulence of Staphylococcus aureus

Staphylococcus aureus colonies can spread on soft agar plates. We compared colony spreading of clinically isolated methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). All MSSA strains showed colony spreading, but most MRSA strains (73%) carrying SCCmec type-II showed little colony spreading. Deletion of the entire SCCmec type-II region from these MRSA strains restored colony spreading. Introduction of a novel gene, fudoh, carried by SCCmec type-II into Newman strain suppressed colony spreading. MRSA strains with high spreading ability (27%) had no fudoh or a point-mutated fudoh that did not suppress colony spreading. The fudoh-transformed Newman strain had decreased exotoxin production and attenuated virulence in mice. Most community-acquired MRSA strains carried SCCmec type-IV, which does not include fudoh, and showed high colony spreading ability. These findings suggest that fudoh in the SCCmec type-II region suppresses colony spreading and exotoxin production, and is involved in S. aureus pathogenesis

Conserved white-rot enzymatic mechanism for wood decay in the Basidiomycota genus Pycnoporus

White-rot (WR) fungi are pivotal decomposers of dead organic matter in forest ecosystems and typically use a large array of hydrolytic and oxidative enzymes to deconstruct lignocellulose. However, the extent of lignin and cellulose degradation may vary between species and wood type. Here, we combined comparative genomics, transcriptomics and secretome proteomics to identify conserved enzymatic signatures at the onset of wood-decaying activity within the Basidiomycota genus Pycnoporus. We observed a strong conservation in the genome structures and the repertoires of protein-coding genes across the four Pycnoporus species described to date, despite the species having distinct geographic distributions. We further analysed the early response of P. cinnabarinus, P. coccineus and P. sanguineus to diverse (ligno)-cellulosic substrates. We identified a conserved set of enzymes mobilized by the three species for breaking down cellulose, hemicellulose and pectin. The co-occurrence in the exo-proteomes of H2O2-producing enzymes with H2O2-consuming enzymes was a common feature of the three species, although each enzymatic partner displayed independent transcriptional regulation. Finally, cellobiose dehydrogenase-coding genes were systematically co-regulated with at least one AA9 lytic polysaccharide monooxygenase gene, indicative of enzymatic synergy in vivo. This study highlights a conserved core white-rot fungal enzymatic mechanism behind the wood-decaying process.Peer reviewe

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Les émigrés, passeurs de culture ?

International audienc

L’autonomisation des cadets sociaux de la région de Kayes : entre trajectoires migratoires et formations ?

International audienc

Émigrer depuis le Mali : contextes régionaux contrastés et trajectoires migratoires particulières.

International audienc

Développement des pays d'origine et flux migratoires : la nécessaire déconnexion

Le lien établi par la politique gouvernementale française en matière d'émigration entre développement des pays d'origine et maîtrise des flux migratoires est-il valide ? Ne convient-il pas plutôt de rechercher une autre articulation entre ressources humaines et accumulation de capital ? Une réelle prise en compte des immigrés comme acteurs du développement semble nécessaire , basée sur les expériences accumulées dans ce domaine depuis une quinzaine d'années.Daum Christophe. Développement des pays d'origine et flux migratoires : la nécessaire déconnexion. In: Hommes et Migrations, n°1214, Juillet-août 1998. Migrants et solidarités nord-sud. pp. 58-72