Impact de la crise de 2009 sur les élevages laitiers dans le Vakinankaratra, Madagascar

Dans un contexte d'utilisation de l'approche " exploitation " par le principal projet de développement local (BVPI-SEHP) et la nécessité de comprendre des systèmes de production diversifiés, le CIRAD, à travers le projet CORUS a proposé une modélisation des exploitations agricoles laitières et l'identification d'une typologie des élevages laitiers dans le Vakinankaratra. La récente crise politique et économique de janvier 2009 a eu des répercussions importantes sur la filière lait. La diversification des activités , l'intensification des cultures et la durabilité des systèmes de culture sont des priorités pour l'agriculture des hautes terres, L'agriculture de conservation a été une des possibilités d'introduire de la durabilité dans les systèmes de production. En 2010, les systèmes de culture de type semis direct sous couverture végétale ( SCV) ne sont pas diffusés sur les hautes terres du fait de deux contraintes majeures : i) la compétition pour la biomasse entre alimentation animale/production de fumier et le mulch en systèmes SCV ii) il n'existe pas de plante de couverture adaptée au froid à l'exception de l'avoine qui seule peut pousser si l'eau est disponible en saison sèche ce qui limite considérablement son emploi. Cette communication est centrée sur l'analyse des stratégies d'adaptation des éleveurs laitiers pour maintenir le revenu de l'exploitation face à la crise politique de janvier 2009 qui a débouché sur une crise économique majeure. Elle est basée sur des données d'enquêtes débutées en 2007 et mises à jour en 2010. L'objectif de l'étude est la compréhension globale du fonctionnement des pratiques des exploitants laitiers et la modélisation des revenus. L'analyse est faite sur 3 zones qui représentent la diversité du triangle laitier, principale région productrice de lait du pays. Des scénarios prospectifs, rendant compte de l'efficience et des risques des choix techniques qui peuvent être adoptés par les exploitants permettent d'explorer l'évolution de la situation avant et après crise (depuis 2008)

Generating and Adding Flows on Locally Complete Metric Spaces

As a generalization of a vector field on a manifold, the notion of an arc field on a locally complete metric space was introduced in \cite{BC}. In that paper, the authors proved an analogue of the Cauchy-Lipschitz Theorem i.e they showed the existence and uniqueness of solution curves for a time independent arc field. In this paper, we extend the result to the time dependent case, namely we show the existence and uniqueness of solution curves for a time dependent arc field. We also introduce the notion of the sum of two time dependent arc fields and show existence and uniqueness of solution curves for this sum.Comment: 29 pages,6 figure

Calculus of Tangent Sets and Derivatives of Set Valued Maps under Metric Subregularity Conditions

In this paper we intend to give some calculus rules for tangent sets in the sense of Bouligand and Ursescu, as well as for corresponding derivatives of set-valued maps. Both first and second order objects are envisaged and the assumptions we impose in order to get the calculus are in terms of metric subregularity of the assembly of the initial data. This approach is different from those used in alternative recent papers in literature and allows us to avoid compactness conditions. A special attention is paid for the case of perturbation set-valued maps which appear naturally in optimization problems.Comment: 17 page

Evaluation of hydrological models on small mountainous catchments: impact of the meteorological forcings

Hydrological modelling of small mountainous catchments is particularly challenging because of the high spatio-temporal resolution required for the meteorological forcings. In situ measurements of precipitation are typically scarce in these remote areas, particularly at high elevations. Precipitation reanalyses propose different alternative forcings for the simulation of streamflow using hydrological models. In this paper, we evaluate the performances of two hydrological models representing some of the key processes for small mountainous catchments (&lt; 300 km2), using different meteorological products with a fine spatial and temporal resolution. The evaluation is performed on 55 small catchments of the northern French Alps. While the simulated streamflows are adequately reproduced for most of the configurations, these evaluations emphasize the added value of radar measurements, in particular for the reproduction of flood events. However, these better performances are only obtained because the hydrological models correct the underestimations of accumulated amounts (e.g. annual) from the radar data in high-elevation areas.</p

The opposite of Dante's hell? The transfer of ideas for social housing at international congresses in the 1850s–1860s

With the advent of industrialization, the question of developing adequate housing for the emergent working classes became more pressing than before. Moreover, the problem of unhygienic houses in industrial cities did not stop at the borders of a particular nation-state; sometimes literally as pandemic diseases spread out 'transnationally'. It is not a coincidence that in the nineteenth century the number of international congresses on hygiene and social topics expanded substantially. However, the historiography about social policy in general and social housing in particular, has often focused on individual cases because of the different pace of industrial and urban development and is thus dominated by national perspectives. In this paper, I elaborate on transnational exchange processes and local adaptations and transformations. I focus on the transfer of the housing model of SOMCO in Mulhouse, (a French house building association) during social international congresses. I examine whether cross-national networking enabled and facilitated the implementation of ideas on the local scale. I will elaborate on the transmission and the local adaptation of the Mulhouse-model in Belgium. Convergences, divergences, and different factors that influenced the local transformations (personal choice, political situation, socioeconomic circumstances) will be taken into accoun

The Regulation of MS-KIF18A Expression and Cross Talk with Estrogen Receptor

This study provides a novel view on the interactions between the MS-KIF18A, a kinesin protein, and estrogen receptor alpha (ERα) which were studied in vivo and in vitro. Additionally, the regulation of MS-KIF18A expression by estrogen was investigated at the gene and protein levels. An association between recombinant proteins; ERα and MS-KIF18A was demonstrated in vitro in a pull down assay. Such interactions were proven also for endogenous proteins in MBA-15 cells were detected prominently in the cytoplasm and are up-regulated by estrogen. Additionally, an association between these proteins and the transcription factor NF-κB was identified. MS-KIF18A mRNA expression was measured in vivo in relation to age and estrogen level in mice and rats models. A decrease in MS-KIF18A mRNA level was measured in old and in OVX-estrogen depleted rats as compared to young animals. The low MS-KIF18A mRNA expression in OVX rats was restored by estrogen treatment. We studied the regulation of MS-KIF18A transcription by estrogen using the luciferase reporter gene and chromatin immuno-percipitation (ChIP) assays. The luciferase reporter gene assay demonstrated an increase in MS-KIF18A promoter activity in response to 10−8 M estrogen and 10−7M ICI-182,780. Complimentary, the ChIP assay quantified the binding of ERα and pcJun to the MS-KIF18A promoter that was enhanced in cells treated by estrogen and ICI-182,780. In addition, cells treated by estrogen expressed higher levels of MS-KIF18A mRNA and protein and the protein turnover in MBA-15 cells was accelerated. Presented data demonstrated that ERα is a defined cargo of MS-KIF18A and added novel insight on the role of estrogen in regulation of MS-KIF18A expression both in vivo and in vitro