Nutrient fluxes on an intertidal mudflat in Marennes-Oleron Bay, and influence of the emersion period

Fluxes of nutrients (NH sub(4) super(+), NO sub(3) super(-), PO sub(4) super(3-) and Si(OH) sub(4)) were studied on an intertidal mudflat in Marennes-Oleron Bay, France, at two different seasons and at different times of the emersion period. Fluxes through the sediment-water interface were both calculated from vertical profiles of nutrient concentration in pore-water (diffusive fluxes, JD) and measured in light and dark benthic mini-chambers (measured fluxes, J sub(0)). Results indicate that ammonia was mainly released in summer while nitrate was mainly taken up in late winter. This uptake from the overlying water was probably due to the coupling of nitrification-denitrification within the sediment. The J sub(0) /J sub(D) ratio further indicates that bioturbation likely enhanced ammonia release in summer. Concerning phosphate, the comparison of diffusive and measured fluxes suggests that PO sub(4) super(3-) could be assimilated by the biofilm in winter while it was released in summer at a high rate due to both bioturbation and desorption because of the relative summer anoxic conditions. Silica was always released by the sediment, but at a higher rate in summer. Statistically significant differences in measured fluxes were detected in dark chambers at different times of low tide, thus suggesting a short-term variability of fluxes. Microphytobenthos preferred ammonia to nitrate, but assimilated nitrate when ammonia was not available. It also turned out that benthic cells could be limited in nitrogen during low tide in late winter. In summer, ammonia was not limiting and microphytobenthic activity significantly decreased the measured flux of NH sub(4) super(+) in the middle of low tide when its photosynthetic capacity was highest.

L'habitat à Niamey

L'accélération rapide de la croissance urbaine est l'une des caractéristiques les plus spectaculaires de l'Afrique actuelle. Elle détermine une nouvelle distribution du peuplement. Le glissement de population des villages vers les centres urbains entretient, d'une manière continue, le développement des capitales et la multiplication des "petites" villes. Elle impose un remaniement rapide des structures sociales, Elle contribue à l'élaboration d'une nouvelle culture africaine, "Le milieu urbain est le chantier où se construisent les sociétés africaines modernes". Étudier, dans ce processus d'accélération, les conditions de l'habitat et son évolution, ainsi que le rapport habitat-population, me paraît donc important, d'actualité et d'avenir. Le terrain choisi pour cette étude est celui de Niamey, capitale de la République du Niger. Village encore en 1927, agglomération urbaine approchant les 100 000 habitants aujourd'hui, peut-être métropole de 500 000 habitants en l'an 2000, Niamey, comme toutes les villes africaines, a grandi trop rapidement et, parfois, d'une façon anarchique. Une prise de conscience du développement rapide de cette ville a déjà provoqué des études de sociologie et d'urbanisme, des plans d'aménagement de l'espace urbain ont été élaborés (dès 1930) et souvent corrigés et améliorés, des projets d'avenir prennent corps avec le nouveau Conseil Municipal. Cette étude voudrait situer les problèmes de la population de Niamey face à son habitat dans un grand mouvement, celui amorcé en 1927, date de la fondation de Niamey, celui vécu aujourd'hui, d'une manière parfois très aiguë par la majeure partie de la population, celui de l'avenir qui résulte de la prise de conscience actuelle et de la volonté d'apporter des solutions durables. […]

[France's margins and the necessary territorial attractiveness].

International audience

[The France of margins: a very small population or significance?]

International audience

Occupational contact urticaria: lessons from the French National Network for Occupational Disease Vigilance and Prevention (RNV3P)

International audience

Kinetics of tidal resuspension of microbiota: Testing the effects of sediment cohesiveness and bioturbation using flume experiments

Resuspension of the top few sediment layers of tidal mud flats is known to enhance planktonic biomass of microbiota (benthic diatoms and bacteria). This process is mainly controlled by tidal shear stress and cohesiveness of mud, and is also influenced by bioturbation activities. Laboratory experiments in a race track flume were performed to test the interactive effects of these factors on both the critical entrainment and resuspension kinetics of microbiota from silt-clay sediments from the Marennes-Oleron Bay, France. The marine snail Hydrobia ulvae was used to mimic surface bioturbation activities. As expected, the kinetics of microbial resuspension versus shear stress were largely controlled by the cohesiveness of silt-clay sediments. However, our results indicate that the effect of surface tracking by H. ulvae on microbial resuspension was clearly dependent on the interaction between sediment cohesiveness and shear velocity. Evidence was also found that microphytobenthos and bacteria are not simultaneously resuspended from silt-clay bioturbated sediments. This supports the theory that diatoms within the easily eroded mucus matrix behave actively and bacteria adhering to fine silt particles eroded at higher critical shear velocities behave passively.

Job satisfaction among primary school personnel in Madagascar

This article analyzes the job satisfaction of primary school teachers in Madagascar. Based on the estimation of multilevel models, low wages and problems getting paid, job insecurity, lack of in-service training, high pupil-teacher ratios, and lack of basic infrastructure and teaching materials are identified as the main reasons for dissatisfaction. Principals’ control of teachers’ activities also adversely affects satisfaction, suggesting that, in Malagasy schools, neither school directors nor teachers have succeeded in adopting organizational cultures based on cooperation among their members. These results are likely to stimulate debates on educational policy, both in Madagascar and in many other developing countries.

Work engagement among school directors and teachers' behavior at work

Using data from a representative sample of public primary schools in Madagascar, this paper analyzes engagement at work among school directors and investigates the impact of school heads' supervisory roles on teachers' behavior at work. The results show clear signs of weak management within public primary schools. We find that school heads' engagement at work is positively associated with their employment conditions, job satisfaction, and overall working environment. The results also indicate that principals' management styles have a positive effect on teachers’ commitment at work, but no significant impact on absenteeism.

Antiplasmodial activity of iron(II) and ruthenium(II) organometallic complexes against Plasmodium falciparum blood parasites

This work reports the in vitro activity against Plasmodium falciparum blood forms (W2 clone, chloroquine-resistant) of tamoxifen-based compounds and their ferrocenyl (ferrocifens) and ruthenocenyl (ruthenocifens) derivatives, as well as their cytotoxicity against HepG2 human hepatoma cells. Surprisingly with these series, results indicate that the biological activity of ruthenocifens is better than that of ferrocifens and other tamoxifen-like compounds. The synthesis of a new metal-based compound is also described. It was shown, for the first time, that ruthenocifens are good antiplasmodial prototypes. Further studies will be conducted aiming at a better understanding of their mechanism of action and at obtaining new compounds with better therapeutic profile.

A avaliação de competências: da arqueologia do bom à edificação do impossível

A participação, como avaliador externo, em processos de Reconhecimento, Validação e Certificação de Competências, desde o aparecimento, em Portugal, dos Centros RVCC, tem proporcionado o contacto com pessoas envolvidas em poderosos processos de mudança pessoal, associados à construção de novas representações de si mesmas. Estas autênticas metamorfoses pessoais, com importantes ecos ao nível familiar, profissional e comunitário, apresentam a extraordinária capacidade de reinterpretar o passado e reconstruir os projetos de futuro, num movimento pessoal que altera, profundamente, o presente de cada indivíduo que participa nestes processos. Nesta comunicação pretendem-se apresentar os principais vértices do processo de avaliação de competências que se protagonizou e se refletiu acerca do momento deste autêntico corredor oficial, através do qual milhares de portugueses têm vindo a trazer, para o campo formal, um importante conjunto de aprendizagens que concretizaram nos ambientes não formais.

Análisis narratológico y traducción de la prosa liteararia de M. Eminescu

La tesis tiene como objetivo principal el análisis narratológico de la prosa literaria de Mihail Eminescu. La metodología utilizada es descriptiva. En el primer capítulo, se describe el contexto histórico, social y literario del autor rumano. Es decir, se ha intentado acercar a Eminescu al lector hispánico. A continuación, en el segundo capítulo, se realiza el estudio específico del corpus textual. Para el estudio de su prosa, por tanto, se adopta una visión diacrónica. La dedicación de Eminescu a la narrativa preexiste, y subyace en el tiempo respecto a su creación poética. Se han utilizado las ediciones críticas de Perpessicius y de Rusu. En el tercer capítulo, se desarrolla el análisis de los textos a partir de los postulados de la narratología. Se ofrece una visión conjunta de toda esta producción con una metodología abierta, pero basada sobre todo en los postulados teóricos de Gérard Genette y la narratología, de los que tomamos el planteamiento analítico general, con la división en historia y discurso, junto con bastantes acercamientos particulares. En este tercer capítulo, también se presentan algunas cuestiones intertextuales en una doble vertiente, en las conexiones con otras obras y autores, y en las conexiones con las novelas del propio Eminescu. A lo largo de toda la tesis, se facilita bibliografía pormenorizada de las tres grandes secciones del trabajo: biografía y contexto histórico-social del autor; el corpus textual y la crítica literaria. Los índices finales pretenden facilitar la lectura de la tesis a lectores que desconocen la lengua rumana. El anexo ofrece, como resultado del análisis narratológico, la primera traducción en español de la prosa literaria de M. Eminescu. Se ha intentado crear una traducción que sea lo suficientemente atractiva y placentera para un lector hispánico y lo suficientemente honesta para con Eminescu. Como principal conclusión se propone a M. Eminescu, el “último gran poeta romántico de Europa”, como una figura narrativa olvidada de la literatura rumana y europea del siglo XIX. Se ha destacado también la influencia de la filosofía, de las culturas orientales, clásicas y contemporáneas, como las del romanticismo. El análisis estilístico de la escritura de Eminescu revela una prosa romántica, con una marcada tendencia hacia la expresión poética en el plano formal, y caracterizada, en el plano del contenido, por una gran riqueza cultural, filosófica, pictórica e histórica.

Developpement et industralisation de l'economie portugaise dans le contexte de la division internationale du travail.

Doutoramento em Economia.

La politique economique portugaise dans le periode de la dictature (1926-1974). Analyse de trois stratégies de l'État.

Doutoramento em Economia.

Le fait littéraire au temps du numérique. Pour une ontologie de l’imaginaire

Souvent conçues comme le vecteur de changements majeurs, les pratiques numériques constituent une occasion de mieux comprendre le fait littéraire en faisant apparaître de manière plus explicite que jamais des aspects ontologiques qui, en tant que tels, ont une valeur atemporelle. En particulier, et c’est l’objet de cet article, le fait numérique donne l’occasion de réinvestir une problématique qui parcourt l’ensemble de la réflexion sur le statut de la littérature depuis Platon et Aristote : celle du rapport entre littérature et réalité, dont Sartre et Derrida avaient déjà œuvré à déconstruire l’opposition au XXe siècle. Selon nous, le numérique souligne l’absence de séparation entre symbolique et non-symbolique, nous empêchant de penser une rupture entre imaginaire et réel. Pour rendre compte de cette structure, nous nous appuierons sur le concept d’éditorialisation, qui vient désigner l’ensemble des dispositifs permettant la production de contenus dans l’espace numérique en tenant compte de la fusion entre espace numérique et espace non numérique. À travers des exemples littéraires – Traque Traces de Cécile Portier et Laisse venir d’Anne Savelli et Pierre Ménard – nous démontrerons comment la littérature participe aujourd’hui à l’éditorialisation du monde, enterrant ainsi définitivement le dualisme imaginaire-réel pour lui préférer une structure anamorphique.

L'homme de l'ombre. Raimundo Saporta

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