L'infiltration des eaux pluviales en milieu urbain : conséquences sur l'écosystème aquatique souterrain

International audienceL'urbanisation induit une imperméabilisation des sols et une augmentation du ruissellement, réduisant ainsi la recharge de la nappe souterraine. La gestion des eaux de pluie consiste à les collecter et les infiltrer vers la nappe qui est protégée de la pollution par des processus auto-épurateurs localisés dans le sol et la zone insaturée. Les dynamiques de la matière organique et des micro-organismes ont été suivies dans les eaux de surface et les eaux souterraines en amont et en aval des trois systèmes d'infiltration (SI). Les teneurs en Carbone Organique dissous (COD) biodégradable et réfractaire ont été mesurées sur l'eau et la croissance des biofilms a été suivie à l'aide des substrats artificiels incubés dans le milieu. Le COD diminue fortement au cours de l'infiltration, mais sa fraction biodégradable demeure plus forte en aval de SI, tout comme les biofilms qui sont stimulés par les infiltrations en biomasse et en diversité. ABSTRACT Urbanization increases impervious surfaces and stormwater runoff reducing groundwater recharge. Stormwater management mainly consists in the collection of rain water and its infiltration to the aquifer, which is protected by the self-purification capacity of the soil and the unsaturated zone. The dynamics of organic matter and microorganisms were studied in surface water and in groundwater upstream and downstream of three stormwater infiltration systems (SIS). Dissolved Organic Carbon (DOC) concentrations were measured in surface and in ground waters, while biofilm dynamics were studied using artificial substrates incubated in the waters. DOC sharply decrease from surface water to the groundwater, but the biodegradable fraction of DOC was higher downstream than upstream of the SIS and the biofilms were stimulated by the infiltration for both biomass and bacterial diversity

An essential function of the mitogen‐activated protein kinase Erk2 in mouse trophoblast development

The closely related mitogen-activated protein kinase isoforms extracellular signal-regulated kinase 1 (ERK1) and ERK2 have been implicated in the control of cell proliferation, differentiation and survival. However, the specific in vivo functions of the two ERK isoforms remain to be analysed. Here, we show that disruption of the Erk2 locus leads to embryonic lethality early in mouse development after the implantation stage. Erk2 mutant embryos fail to form the ectoplacental cone and extra-embryonic ectoderm, which give rise to mature trophoblast derivatives in the fetus. Analysis of chimeric embryos showed that Erk2 functions in a cell-autonomous manner during the development of extra-embryonic cell lineages. We also found that both Erk2 and Erk1 are widely expressed throughout early-stage embryos. The inability of Erk1 to compensate for Erk2 function suggests a specific function for Erk2 in normal trophoblast development in the mouse, probably in regulating the proliferation of polar trophectoderm cells

Activation of MEK1 or MEK2 isoform is sufficient to fully transform intestinal epithelial cells and induce the formation of metastatic tumors

<p>Abstract</p> <p>Background</p> <p>The Ras-dependent ERK1/2 MAP kinase signaling pathway plays a central role in cell proliferation control and is frequently activated in human colorectal cancer. Small-molecule inhibitors of MEK1/MEK2 are therefore viewed as attractive drug candidates for the targeted therapy of this malignancy. However, the exact contribution of MEK1 and MEK2 to the pathogenesis of colorectal cancer remains to be established.</p> <p>Methods</p> <p>Wild type and constitutively active forms of MEK1 and MEK2 were ectopically expressed by retroviral gene transfer in the normal intestinal epithelial cell line IEC-6. We studied the impact of MEK1 and MEK2 activation on cellular morphology, cell proliferation, survival, migration, invasiveness, and tumorigenesis in mice. RNA interference was used to test the requirement for MEK1 and MEK2 function in maintaining the proliferation of human colorectal cancer cells.</p> <p>Results</p> <p>We found that expression of activated MEK1 or MEK2 is sufficient to morphologically transform intestinal epithelial cells, dysregulate cell proliferation and induce the formation of high-grade adenocarcinomas after orthotopic transplantation in mice. A large proportion of these intestinal tumors metastasize to the liver and lung. Mechanistically, activation of MEK1 or MEK2 up-regulates the expression of matrix metalloproteinases, promotes invasiveness and protects cells from undergoing anoikis. Importantly, we show that silencing of MEK2 expression completely suppresses the proliferation of human colon carcinoma cell lines, whereas inactivation of MEK1 has a much weaker effect.</p> <p>Conclusion</p> <p>MEK1 and MEK2 isoforms have similar transforming properties and are able to induce the formation of metastatic intestinal tumors in mice. Our results suggest that MEK2 plays a more important role than MEK1 in sustaining the proliferation of human colorectal cancer cells.</p

Validation de nettoyage en production industrielle (stratégie de management de la qualité)

LIMOGES-BU Médecine pharmacie (870852108) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

Prescriptions médicamenteuses chez les enfants de moins de deux ans en Aquitaine (étude à partir des données de remboursement de l'assurance maladie)

BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

Conception et synthèse de nouveaux ligands des récepteurs alpha7 nicotiniques de structure pyridinique

CAEN-BU Médecine pharmacie (141182102) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

TRIFOCAL INTRAOCULAR LENS WITH EXTENDED RANGE OF VISION AND CORRECTION OF LONGITUDINAL CHROMATIC ABERRATION

publication date: 2017-02-15; filing date: 2015-08-12The present invention relates to an intraocular lens, and in particular to an intraocular lens with three focal points and a diffractive profile on an anterior or posterior face. This lens provides extended range of vision (EROV) from far to near distance and reduces linear chromatic aberration (LCA)

A sustained rat model for studing the long-lasting catabolic state of sepsis

Most animal models of sepsis induced high mortality or early recovery and do not mimic the long-lasting catabolic state observed in patients. The purpose of this study is to develop a model of sepsis which reproduces these disorders, especially the long-lasting muscle wasting. This report summarizes our observations in a series of seven experiments using this model with rats to study the route of live Escherichia coli administration, dose of bacteria, reproducibility of the model, bacterial count in tissues, comparison of injection of live or dead bacteria, metabolic perturbations linked to infection, and potential role of tumor necrosis factor alpha (TNF-alpha) in muscle wasting. After intravenous infection, animals were anorexic and the catabolic state was long-lasting: body weight loss for 2 to 3 days followed by a chronic wasting state for several days. Liver, spleen, lung protein content, and plasma concentration of alpha(2)-macroglobulin were increased 2 and 6 days after infection. At 6 days, muscle protein content was substantially (-40%) reduced. The plasma TNF-alpha level measured 1.5 h after infection correlated with body weight loss observed 9 days later. The inhibition of TNF-alpha secretion by administration of pentoxifyilline 1 h before infection reduced muscle wasting and activation of proteolysis at day 2 and abolished them at day 6, This septic model mimics in rats the prolonged protein metabolism alterations and muscle atrophy characteristics of infected patients and thus is useful for studying the impact of nutritional support on outcome

Adaptable Translator of B Specifications to Embedded C Programs

This paper presents the results of the RNTL BOM project, which aimed to develop an approach to generate efficient code from B formal developments. The target domain is smart card applications, in which memory and code size is an important factor. The results detailed in this paper are a new architecture of the translation process, a way to adapt the B0 language in order to include types of the target language and a set of validated optimizations. An assessment of the proposed approach is given through a case study, relative to the development of a Java Card Virtual Machine environment