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Sample records for aux oxyanions selenite

  1. Study of the Cupriavidus metallidurans CH34 resistance of selenite and selenate oxy-anions: accumulation, localisation and transformation of selenium; Etude de la resistance de Cupriavidus metallidurans CH34 aux oxyanions selenite et seleniate: accumulation, localisation et transformation du selenium

    Energy Technology Data Exchange (ETDEWEB)

    Avoscan, L

    2007-06-15

    Selenium is an essential trace element for the living organisms but it is very toxic at high concentration. Selenite and selenate oxides, soluble forms, highly toxic and bio-assimilable, are the most prevalent forms in the environment. Some soil micro-organisms play a dominant role and contribute to the natural cycle of selenium. Our study model, Cupriavidus (formerly Ralstonia) metallidurans CH34, a telluric bacterium characteristic of metal-contaminated biotopes, is known to resist selenite by reducing it into elemental selenium, an insoluble and less toxic form of selenium. In order to better understand the mechanisms of selenium reduction in the bacteria, three methods of speciation were combined (XAS (XANES and EXAFS), HPLC-ICP-MS and SDS-PAGEPIXE). They were completed by the direct quantification of selenium accumulated in the bacteria. Speciation analyses highlighted the existence of two mechanisms of reduction of selenium oxides in C. metallidurans CH34. Assimilation transforms selenite and selenate into organic selenium, identified as seleno-methionine and leads to its non-specific incorporation into bacterial proteins (presence of selenious proteins). Detoxication precipitates selenite in nano-particles of elemental selenium. This way of detoxication is not set up after an exposure to selenate although it is nevertheless possible to detect elemental selenium but in very small amount compared to the exposure of selenite. Seleno-diglutathion is detected in bacteria stressed by an exposure to selenate in medium limited in sulphate. Bacteria exposed to selenite accumulate 25 times more selenium than when they are exposed to selenate. The study of mutants resistant to selenite, which do not express the membrane protein DedA, showed that the accumulation of selenium after exposure to selenite is decreased compared with the wild strain meaning probable link between the transport of selenite and the DedA protein. Finally, selenate would use the sulphate permease

  2. Study of the Cupriavidus metallidurans CH34 resistance of selenite and selenate oxy-anions: accumulation, localisation and transformation of selenium

    International Nuclear Information System (INIS)

    Selenium is an essential trace element for the living organisms but it is very toxic at high concentration. Selenite and selenate oxides, soluble forms, highly toxic and bio-assimilable, are the most prevalent forms in the environment. Some soil micro-organisms play a dominant role and contribute to the natural cycle of selenium. Our study model, Cupriavidus (formerly Ralstonia) metallidurans CH34, a telluric bacterium characteristic of metal-contaminated biotopes, is known to resist selenite by reducing it into elemental selenium, an insoluble and less toxic form of selenium. In order to better understand the mechanisms of selenium reduction in the bacteria, three methods of speciation were combined (XAS (XANES and EXAFS), HPLC-ICP-MS and SDS-PAGEPIXE). They were completed by the direct quantification of selenium accumulated in the bacteria. Speciation analyses highlighted the existence of two mechanisms of reduction of selenium oxides in C. metallidurans CH34. Assimilation transforms selenite and selenate into organic selenium, identified as seleno-methionine and leads to its non-specific incorporation into bacterial proteins (presence of selenious proteins). Detoxication precipitates selenite in nano-particles of elemental selenium. This way of detoxication is not set up after an exposure to selenate although it is nevertheless possible to detect elemental selenium but in very small amount compared to the exposure of selenite. Seleno-diglutathion is detected in bacteria stressed by an exposure to selenate in medium limited in sulphate. Bacteria exposed to selenite accumulate 25 times more selenium than when they are exposed to selenate. The study of mutants resistant to selenite, which do not express the membrane protein DedA, showed that the accumulation of selenium after exposure to selenite is decreased compared with the wild strain meaning probable link between the transport of selenite and the DedA protein. Finally, selenate would use the sulphate permease

  3. Etude de la résistance de Cupriavidus metallidurans CH34 aux oxyanions sélénite et séléniate : accumulation, localisation et transformation du sélénium.

    OpenAIRE

    Avoscan, Laure

    2007-01-01

    Le sélénium est un élément trace essentiel pour les organismes vivants mais à forte concentration, il est très toxique. Les oxyanions sélénite et séléniate sont les formes les plus toxiques et prédominantes dans l'environnement. Certains micro-organismes jouent un rôle prépondérant en contribuant au cycle naturel du sélénium. Notre modèle d'étude Cupriavidus (anciennement Ralstonia) metallidurans CH34, bactérie tellurique issue de biotopes contaminés en métaux, est connu pour résister au sélé...

  4. Effects of selenium oxyanions on the white-rot fungus Phanerochaete chrysosporium

    KAUST Repository

    Espinosa-Ortiz, Erika J.

    2014-10-24

    The ability of Phanerochaete chrysosporium to reduce the oxidized forms of selenium, selenate and selenite, and their effects on the growth, substrate consumption rate, and pellet morphology of the fungus were assessed. The effect of different operational parameters (pH, glucose, and selenium concentration) on the response of P. chrysosporium to selenium oxyanions was explored as well. This fungal species showed a high sensitivity to selenium, particularly selenite, which inhibited the fungal growth and substrate consumption when supplied at 10 mg L−1 in the growth medium, whereas selenate did not have such a strong influence on the fungus. Biological removal of selenite was achieved under semi-acidic conditions (pH 4.5) with about 40 % removal efficiency, whereas less than 10 % selenium removal was achieved for incubations with selenate. P. chrysosporium was found to be a selenium-reducing organism, capable of synthesizing elemental selenium from selenite but not from selenate. Analysis with transmission electron microscopy, electron energy loss spectroscopy, and a 3D reconstruction showed that elemental selenium was produced intracellularly as nanoparticles in the range of 30–400 nm. Furthermore, selenite influenced the pellet morphology of P. chrysosporium by reducing the size of the fungal pellets and inducing their compaction and smoothness.

  5. Electron-Exchange Reactions Mediated by Oxyanions

    International Nuclear Information System (INIS)

    Although a considerable amount of information is available on the rates of electron transfer from one metal ion to another through organic ligands (such as carboxylic acids), little has been obtained for ligands not containing carbon-carbon bonds: the one notable exception is the series of halogeno bridges. We have measured electron exchange rates between CoIII and CrII , VII, and EuII using oxyanions as bridging groups. The measurements have been carried out spectrophotometrically, using pentaamminecobalt (III) complexes in perchlorate and sulfate media. Bridging groups include metaborate, carbonate, nitrate, nitrite (both as the nitro and the nitrito ligands), sulfite, sulfate, thiosulfate, selenite, selenate, and tellurate. Specific rates increase along a series such as -OBO, -OCO-2, -ONO2, and down a series such as -OSO-3 , -OSeO-3 (k = 23 M-1sec-1 for the CrII reduction of the sulfato complex, 360 M-1 sec-1 for that of the selenato). In general, rates are more rapid with CrII as the reducing agent. Some experiments with TiIII show it to be the slowest. It appears possible to correlate changes in kbi with (i) the central atom of the ligand and (ii) the number of oxygen atoms present in the ligand but not bound to the cobalt center (that is, with the number of attack sites available to the reductant). For example, at 25°C, the specific rate for the CrH reduction of the sulfito complex is 18 M-1sec-1 and that for the sulfato is 20±2 M-1 sec1: both ligands possess three oxygens not bound to the cobalt; for the bonding in the sulfito complex is Co-S, while that in the sulfato is Co-O-S. The activation parameters for the two reactions are almost identical. Another striking example is found in the tetraammine series: the specific rate for the reaction of the chelated sulfate is 35 M-1 sec-1, while that for the chelated sulfite, is 17 M-1 sec-1. The sulfato complex possesses two oxygens free, the sulfito only one. The complexes offer the opportunity of studying

  6. Nanocrystalline hydroxyapatite doped with selenium oxyanions: A new material for potential biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Kolmas, Joanna, E-mail: joanna.kolmas@wum.edu.pl [Medical University of Warsaw, Faculty of Pharmacy, Department of Inorganic and Analytical Chemistry, ul. Banacha 1, 02-097 Warsaw (Poland); Oledzka, Ewa; Sobczak, Marcin [Medical University of Warsaw, Faculty of Pharmacy, Department of Inorganic and Analytical Chemistry, ul. Banacha 1, 02-097 Warsaw (Poland); Nałęcz-Jawecki, Grzegorz [Medical University of Warsaw, Faculty of Pharmacy, Department of Environmental Health Sciences, ul. Banacha 1, 02-097 Warsaw (Poland)

    2014-06-01

    Selenium-substituted hydroxyapatites containing selenate SeO{sub 4}{sup 2−} or selenite SeO{sub 3}{sup 2−} ions were synthesized using a wet precipitation method. The selenium content was determined by atomic absorbance spectrometry. The raw, unsintered powders were also characterized using powder X-ray diffraction, middle-range FT-IR spectroscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopic microanalysis. The synthesized apatites were found to be pure and nanocrystalline with a crystal size similar to that in bone mineral. The incorporation of selenium oxyanions into the crystal lattice was confirmed. The toxicity of hydroxyapatites containing selenite or selenate ions was evaluated with a protozoan assay and bacterial luminescence test. - Highlights: • We synthesized and analyzed hydroxyapatites doped with selenium oxyanions. • We used various analytical methods, i.e. XRD, TEM, AAS and FT-IR. • We confirmed incorporation of SeO{sub 3}{sup 2−} and SeO{sub 4}{sup 2−} into the crystal lattice. • The toxicity of the materials was studied.

  7. Nanocrystalline hydroxyapatite doped with selenium oxyanions: A new material for potential biomedical applications

    International Nuclear Information System (INIS)

    Selenium-substituted hydroxyapatites containing selenate SeO42− or selenite SeO32− ions were synthesized using a wet precipitation method. The selenium content was determined by atomic absorbance spectrometry. The raw, unsintered powders were also characterized using powder X-ray diffraction, middle-range FT-IR spectroscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopic microanalysis. The synthesized apatites were found to be pure and nanocrystalline with a crystal size similar to that in bone mineral. The incorporation of selenium oxyanions into the crystal lattice was confirmed. The toxicity of hydroxyapatites containing selenite or selenate ions was evaluated with a protozoan assay and bacterial luminescence test. - Highlights: • We synthesized and analyzed hydroxyapatites doped with selenium oxyanions. • We used various analytical methods, i.e. XRD, TEM, AAS and FT-IR. • We confirmed incorporation of SeO32− and SeO42− into the crystal lattice. • The toxicity of the materials was studied

  8. Nanomembrane Canister Architectures for the Visualization and Filtration of Oxyanion Toxins with One-Step Processing.

    Science.gov (United States)

    Aboelmagd, Ahmed; El-Safty, Sherif A; Shenashen, Mohamed A; Elshehy, Emad A; Khairy, Mohamed; Sakaic, Masaru; Yamaguchi, Hitoshi

    2015-11-01

    Nanomembrane canister-like architectures were fabricated by using hexagonal mesocylinder-shaped aluminosilica nanotubes (MNTs)-porous anodic alumina (PAA) hybrid nanochannels. The engineering pattern of the MNTs inside a 60 μm-long membrane channel enabled the creation of unique canister-like channel necks and cavities. The open-tubular canister architecture design provides controllable, reproducible, and one-step processing patterns of visual detection and rejection/permeation of oxyanion toxins such as selenite (SeO3(2-)) in aquatic environments (i.e., in ground and river water sources) in the Ibaraki Prefecture of Japan. The decoration of organic ligand moieties such as omega chrome black blue (OCG) into inorganic Al2O3@tubular SiO2/Al2O3 canister membrane channel cavities led to the fabrication of an optical nanomembrane sensor (ONS). The OCG ligand was not leached from the canister as observed in washing, sensing, and recovery assays of selenite anions in solution, which enabled its multiple reuse. The ONS makes a variety of alternate processing analyses of selective quantification, visual detection, rejection/permeation, and recovery of toxic selenite quick and simple without using complex instrumentation. Under optimal conditions, the ONS canister exhibited a high selectivity toward selenite anions relative to other ions and a low-level detection limit of 0.0093 μM. Real analytical data showed that approximately 96% of SeO3(2-) anions can be recovered from aquatic and wastewater samples. The ONS canister holds potential for field recovery applications of toxic selenite anions from water. PMID:26178184

  9. Immobilized poly-L-histidine for chelation of metal cations and metal oxyanions

    International Nuclear Information System (INIS)

    The biohomopolymer poly-L-histidine (PLHis) was immobilized onto controlled pore glass (CPG) and its metal binding capabilities evaluated through the use of a flow injection-flame atomic absorption system. The metal binding capability of PLHis-CPG was determined through the analysis of the generated breakthrough curves. The polymer likely coordinates cationic metals through the imidazole side chain (pKa∼6) present on each histidine residue with both strong and weak binding sites for Cu2+, Cd2+, Co2+, and Ni2+. Weak to minimal binding was observed for Mn2+, Ca2+, Mg2+, Na+, and Cr3+. The bound metals are quantitatively released from the column with an acid strip. It has also been shown that the protonated imidazole side chain present in acidic solutions is capable of binding metal oxyanions such as chromates, arsenates, and selenites; although oxyanion binding currently exhibits interferences from competing anions in solution, such as sulfate and nitrate. The interference in oxyanion binding is less severe in the presence of chloride, phosphate, and acetate. PLHis-CPG exhibits a capacity of ∼30 μmol Cu2+/g CPG in neutral to basic conditions, and a capacity of ∼70 μmol Cr(VI)/g CPG, ∼4 μmol As(V)/g CPG, and ∼4 μmol Se(IV)/g CPG in acidic conditions

  10. Reduction of chromate and carotene-synthesizing activity of selenite-resistant mutants of the yeast Xanthophyllomyces dendrorhous (Phaffia rhodozyma

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    Grzàdka M.

    2009-08-01

    Full Text Available Aim. The yeast P. rhodozyma is a perspective microbial producer of carotenoid pigment astaxanthin with a high antioxidant power. The aim of the work was to study the ability of the selenite-resistant strains of this yeast to reduce chrome(VI compounds, as well as to analyze the relations between synthesis of carotenoids, resistance to selenite and chromate-reducing activity of P. rhodozyma. Methods. The yeast cells were grown at standard conditions for this species. The residual chromate content in cultural liquid was determined colorimetrically using diphenylcarbazide. The carotenoid content was determined after extraction of the pigments from the previously permeabilized cells by organic solvents. Results. The selected selenite-resistant mutants of the yeast P. rhodozyma revealed the different combinations of the phenotypes related with tolerance/sensitivity to chromate and selenite, as well as ability to reduce chromate. Conclusions. The obtained results give reasons for suggesting that pathways of detoxification of chromate and selenite by the yeast P. rhodozyma are different, although run through a common reductive type. The isolated mutant strains would be served as the useful models to study relations between homeostasis of Se and Cr oxyanions and biosynthesis of carotenes.

  11. Saffron administration prevents selenite-induced cataractogenesis

    OpenAIRE

    Olga E. Makri; Ferlemi, Anastasia-Varvara; Lamari, Fotini N.; Georgakopoulos, Constantine D.

    2013-01-01

    Purpose The present study sought to investigate whether Crocus sativus stigmas (saffron) extract prevents selenium-induced cataractogenesis in vivo, and to study its possible protective mechanism. Methods Wistar rat pups were randomized into three groups. Group I (control) received subcutaneous injection of normal saline on postnatal day 10. Groups II (selenite-treated) and III (selenite+saffron-treated) received subcutaneous injection of sodium selenite (20 µmol/kg body weight) on postnatal ...

  12. Antitumour Acitivty of Chitosan Hydrogen Selenites

    Institute of Scientific and Technical Information of China (English)

    CaiQinQIN; XiaoHaiGAO; 等

    2002-01-01

    Chitosans reacted with selenious acid to prepare chitosan hydrogen selenites, which were found to be growth-inhibitory against sarcoma 180 solid tumor. The results indicated that the activity also depended on the molecular weight of chitosan supports.

  13. Antitumour Activity of Chitosan Hydrogen Selenites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Chitosans reacted with selenious acid to prepare chitosan hydrogen selenites, which were found to be growth-inhibitory against sarcoma 180 solid tumor. The results indicated that the activity also depended on the molecular weight of chitosan supports.

  14. Preparation and characterization of selenite substituted hydroxyapatite

    International Nuclear Information System (INIS)

    Selenite-substituted hydroxyapatite (Se-HA) with different Se/P ratios was synthesized by a co-precipitation method, using sodium selenite (Na2SeO3) as a Se source. Selenium has been incorporated into the hydroxyapatite lattice by partially replacing phosphate (PO43−) groups with selenite (SeO32−) groups. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) techniques reveal that substitutions of phosphate groups by selenite groups cause lower carbonate groups occupying at phosphate sites and change the lattice parameters of hydroxyapatite. The powders obtained are nano-crystalline hydroxyapatite when the Se/P ratios are not more than 0.1. The particle shape of Se-HA has not been altered compared with selenite-free hydroxyapatite but Se-incorporation reduces the crystallite size. The crystallinity was reduced as the Se/P ratios increased until amorphous phase (Se/P = 0.3) appeared in the Se-HA powder obtained, and then another crystal phase presented as calcium selenite hydrate (Se/P = 10). In addition, the sintering tests show that the Se-HA powders with the Se/P ratio of 0.1 have thermal stability at 900 °C for 2 h; hence they have great potential in the fabrication of bone repair scaffolds. - Highlights: ► We investigate the Se/P ratio for the synthesis of selenium substituted HA. ► Nano-crystalline HA structure is remained when Se/P ratio is below 0.1. ► Calcium selenite hydrate forms when Se/P ratio is beyond 10. ► Selenite substituted HA powders (Se/P < 0.1) are stable at 900 °C for 2 h.

  15. Toxicity and accumulation of selenite in four microalgae

    Science.gov (United States)

    Wang, Dazhi; Cheng, Zhaodi; Li, Shaojing; Gao, Yahui

    2003-09-01

    The toxicity and bioaccumulation of selenite in four microalgae, Spirulina platensis, Dunaliella salina, Dunaliella bardawill and Phaeodactylum tricornutum cultured in the presence of selenite were investigated. Lower concentrations of selenite were generally nontoxic and frequently stimulated algal growth, while higher concentrations of selenite inhibited algal growth. Selenite was more toxic to D. salina and D. bardawill than to S. platensis and P. Tricornutum. All algae cultured in selenite were able to incorporate Se to different degrees, which depended on algal species. The distributions of selenite among intracellular macromolecular compounds were different among algal species: most of the selenite was associated with proteins in S. platensis, D. salina and D. bardawill, while most of the selenite was associated with lipids in P. tricornutum, which reflected the physiological differences among the algae. These observations suggest that algae are able to accumulate selenite and bind it with intracellular macromolecular compounds when exposed to high concentration of selenite. This may represent a form of storage or detoxification of selenite by the algae.

  16. Toxicity and Accumulation of Selenite in Four Microalgae

    Institute of Scientific and Technical Information of China (English)

    王大志; 程兆第; 李少菁; 高亚辉

    2003-01-01

    The toxicity and bioaccumlation of selenite in four microalgae, Spirulina platensis,Dunaliella salina, Dunaliella bardawill and Phaeodactylum tricornutum cultured in the presence of selenite were investigated. Lower concentrations of selenite were generally nontoxic and frequently stimulated algal growth, while higher concentrations of selenite inhibited algal growth. Selenite was more toxic to D. salina and D. bardawill than to S. platensis and P. tricornutum. All algae cultured in selenite were able to incorporate Se to different degrees, which depended on algal species. The distributions of selenite among intracellular macromolecular compounds were different among algal species: most of the selenite was associated with proteins in S. platensis, D. salina and D. bardawill, while most of the selenite was associated with lipids in P. tricornutum, which reflected the physiological differences among the algae. These observations suggest that algae are able to accumulate selenite and bind it with intracellular macromolecular compounds when exposed to high concentration of selenite. This may represent a form of storage or detoxification of selenite by the algae.

  17. Surface structural ion adsorption modeling of competitive binding of oxyanions by metal (hydr)oxides

    Energy Technology Data Exchange (ETDEWEB)

    Hiemstra, T.; Riemsdijk, W.H. van [Wageningen Univ. and Research Centre (Netherlands)

    1999-02-01

    An important challenge in surface complexation models (SCM) is to connect the molecular microscopic reality to macroscopic adsorption phenomena. This study elucidates the primary factor controlling the adsorption process by analyzing the adsorption and competition of PO{sub 4}, AsO{sub 4}, and SeO{sub 3}. The authors show that the structure of the surface-complex acting in the dominant electrostatic field can be ascertained as the primary controlling adsorption factor. The surface species of arsenate are identical with those of phosphate and the adsorption behavior is very similar. On the basis of the selenite adsorption, The authors show that the commonly used 1pK models are incapable to incorporate in the adsorption modeling the correct bidentate binding mechanism found by spectroscopy. The use of the bidentate mechanism leads to a proton-oxyanion ratio and corresponding pH dependence that are too large. The inappropriate intrinsic charge attribution to the primary surface groups and the condensation of the inner sphere surface complex to a point charge are responsible for this behavior of commonly used 2pK models. Both key factors are differently defined in the charge distributed multi-site complexation (CD-MUSIC) model and are based in this model on a surface structural approach. The CD-MUSIC model can successfully describe the macroscopic adsorption phenomena using the surface speciation and binding mechanisms as found by spectroscopy. The model is also able to predict the anion competition well. The charge distribution in the interface is in agreement with the observed structure of surface complexes.

  18. OXYANION SORPTION TO HIGH SURFACE AREA IRON AND ALUMINUM OXIDES

    Science.gov (United States)

    Sorption of selected oxyanions (Mo, As, and P) to high surface area iron and aluminum oxides was investigated using in situ Raman and ATR-FTIR spectroscopy, batch sorption methods, electrophoretic mobility measurements, and surface complexation modeling. In situ ATR-FTIR and Raman spectra were coup...

  19. Microbial manufacture of chalcogenide-based nanoparticles via the reduction of selenite using Veillonella atypica: an in situ EXAFS study

    Science.gov (United States)

    Pearce, Carolyn I.; Coker, Victoria S.; Charnock, John M.; Pattrick, Richard A. D.; Mosselmans, J. Frederick W.; Law, Nicholas; Beveridge, Terry J.; Lloyd, Jonathan R.

    2008-04-01

    The ability of metal-reducing bacteria to produce nanoparticles, and their precursors, can be harnessed for the biological manufacture of fluorescent, semiconducting nanomaterials. The anaerobic bacterium Veillonella atypica can reduce selenium oxyanions to form nanospheres of elemental selenium. These selenium nanospheres are then further reduced by the bacterium to form reactive selenide which could be precipitated with a suitable metal cation to produce nanoscale chalcogenide precipitates, such as zinc selenide, with optical and semiconducting properties. The whole cells used hydrogen as the electron donor for selenite reduction and an enhancement of the reduction rate was observed with the addition of a redox mediator (anthraquinone disulfonic acid). A novel synchrotron-based in situ time-resolved x-ray absorption spectroscopy technique was used, in conjunction with ion chromatography and inductively coupled plasma-atomic emission spectroscopy, to study the mechanisms and kinetics of the microbial reduction of selenite to selenide. The products of this biotransformation were also assessed using electron microscopy, energy-dispersive spectroscopy, x-ray diffraction and fluorescence spectroscopy. This process offers the potential to prepare chalcogenide-based nanocrystals, for application in optoelectronic devices and biological labelling, from more environmentally benign precursors than those used in conventional organometallic synthesis.

  20. Microbial manufacture of chalcogenide-based nanoparticles via the reduction of selenite using Veillonella atypica: an in situ EXAFS study

    International Nuclear Information System (INIS)

    The ability of metal-reducing bacteria to produce nanoparticles, and their precursors, can be harnessed for the biological manufacture of fluorescent, semiconducting nanomaterials. The anaerobic bacterium Veillonella atypica can reduce selenium oxyanions to form nanospheres of elemental selenium. These selenium nanospheres are then further reduced by the bacterium to form reactive selenide which could be precipitated with a suitable metal cation to produce nanoscale chalcogenide precipitates, such as zinc selenide, with optical and semiconducting properties. The whole cells used hydrogen as the electron donor for selenite reduction and an enhancement of the reduction rate was observed with the addition of a redox mediator (anthraquinone disulfonic acid). A novel synchrotron-based in situ time-resolved x-ray absorption spectroscopy technique was used, in conjunction with ion chromatography and inductively coupled plasma-atomic emission spectroscopy, to study the mechanisms and kinetics of the microbial reduction of selenite to selenide. The products of this biotransformation were also assessed using electron microscopy, energy-dispersive spectroscopy, x-ray diffraction and fluorescence spectroscopy. This process offers the potential to prepare chalcogenide-based nanocrystals, for application in optoelectronic devices and biological labelling, from more environmentally benign precursors than those used in conventional organometallic synthesis

  1. Sodium selenite as a new rodenticide

    Directory of Open Access Journals (Sweden)

    Goran Jokić

    2014-09-01

    Full Text Available Rodents are the most destructive group of small mammalian pests considering the overall damage that they cause by feeding and other activities, or as vectors of many disease agents. In practice, chemical rodenticides have been the most widespread and most effective method of control of commensal (Mus musculus, Rattus norvegicus and R. rattus and most harmful field rodent pests (Apodemus sylvaticus, A. agrarius and Microtus arvalis. After anticoagulant and vitamin D3 rodenticides, which were introduced worldwide in the 1980s, no other chemical compound has had a comparable role as a rodenticide in practice. In the past decade, commercial baits containing 0.1% sodium selenite have also been registered in Serbia in various formulations both for controlling rodents indoors and in the field. Data on sodium selenite as a rodenticide have been scarce. The present paper surveys research data reported so far, analyzing and drawing conclusions regarding the validity and feasibility of sodium selenite as a method of rodent control with reference to the available ecotoxicological data.

  2. Analyses of Oxyanion Materials by Prompt Gamma Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Firestone, Richard B; Perry, D.L.; English, G.A.; Firestone, R.B.; Leung, K.-N.; Garabedian, G.; Molnar, G.L.; Revay, Zs.

    2008-03-24

    Prompt gamma activation analysis (PGAA) has been used to analyze metal ion oxyanion materials that have multiple applications, including medicine, materials, catalysts, and electronics. The significance for the need for accurate, highly sensitive analyses for the materials is discussed in the context of quality control of end products containing the parent element in each material. Applications of the analytical data for input to models and theoretical calculations related to the electronic and other properties of the materials are discussed.

  3. Influence of the oxyanion nature of the electrolyte on the corrosion/passivation behaviour of nickel

    OpenAIRE

    Trompette, Jean-Luc; Massot, Laurent; Vergnes, Hugues

    2013-01-01

    The electrochemical behaviour of nickel in the presence of various electrolyte solutions at 0.1 mol/L concentration exhibits a distinction according to the oxyanion nature of the investigated anions. Passivity is achieved with oxyanions whereas it fails with anions not containing oxygen. SIMS and XPS measurements performed from isotopic and non isotopic KNO₃ electrolytes indicate that the oxygen and nitrogen atoms from nitrate oxyanions are incorporated into the passive film during anodic pol...

  4. Nano-sized Minerals of Elemental Selenium and Tellurium Formed by Bacterial Dissimilatory Reduction of Se- and Te-Oxyanions.

    Science.gov (United States)

    Oremland, R. S.

    2007-12-01

    Selenium and tellurium are both Group 16 elements that have curious opto-electrical properties making them of potential interest for photovoltaic applications. The process of dissimilatory reduction of selenate and selenite by 3 diverse species of anaerobes, Bacillus selenitireducens, Sulfurospirillum barnesii, and Selenihalanaerobacter shriftii resulted in the accumulation of many uniformly-sized nanospheres (diameter = approx. 300 nm) that aggregated on the outside of their cell envelopes (Oremland et al., 2004). Despite their uniformity of shape, purified Se-nanospheres from the 3 different species displayed significantly different spectral properties (UV- visible light and Raman) indicating differing internal arrangements of their Se atoms. Se-nanospheres from all 3 species also had lower bandgap energies than that of elemental selenium formed by chemical means. We subsequently determined that S. barnesii and B. selenitireducens could grow by dissimilatory reduction of Te- oxyanions, although progress was hampered by the fact that Te concentrations above 0.6 mM proved toxic to cells (Baesman et al., 2007). Unlike the case for Se-nanospheres, the Te-nanoparticles formed by the two microbes were entirely different. S. barnesii formed small, irregularly shaped spheroids (smaller than 50 nm diameter) that coalesced into larger aggregates. In contrast, B. selenitreducens formed nano-rods (10 nm diameter x 200 nm length) that coalesced into larger shards which formed even larger rosette-shaped aggregates once they sloughed off the cells. Spectroscopy of purified Te-rosettes indicated an internal trigonally-shaped array of Te atoms. Future research on Te(0) nano-materials formed by anaerobic bacteria would be aided by isolation of novel species adapted to growth at high batch culture concentrations of Te-oxyanions (approx. 10 mM). Furthermore, the ability of microbes like B. selenitreducens to form selenide by reduction of Se(0) suggests an application in the

  5. 40 CFR 721.4668 - Hydrated alkaline earth metal salts of metalloid oxyanions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hydrated alkaline earth metal salts of... Specific Chemical Substances § 721.4668 Hydrated alkaline earth metal salts of metalloid oxyanions. (a... hydrated alkaline earth metal salts of metalloid oxyanions (PMN P-94-1557) is subject to reporting...

  6. Selenite Reduction by Anaerobic Microbial Aggregates: Microbial Community Structure, and Proteins Associated to the Produced Selenium Spheres

    KAUST Repository

    Gonzalez-Gil, Graciela

    2016-04-26

    Certain types of anaerobic granular sludge, which consists of microbial aggregates, can reduce selenium oxyanions. To envisage strategies for removing those oxyanions from wastewater and recovering the produced elemental selenium (Se0), insights into the microbial community structure and synthesis of Se0 within these microbial aggregates are required. High-throughput sequencing showed that Veillonellaceae (c.a. 20%) and Pseudomonadaceae (c.a.10%) were the most abundant microbial phylotypes in selenite reducing microbial aggregates. The majority of the Pseudomonadaceae sequences were affiliated to the genus Pseudomonas. A distinct outer layer (∼200 μm) of selenium deposits indicated that bioreduction occurred in the outer zone of the microbial aggregates. In that outer layer, SEM analysis showed abundant intracellular and extracellular Se0 (nano)spheres, with some cells having high numbers of intracellular Se0 spheres. Electron tomography showed that microbial cells can harbor a single large intracellular sphere that stretches the cell body. The Se0 spheres produced by the microorganisms were capped with organic material. X-ray photoelectron spectroscopy (XPS) analysis of extracted Se0 spheres, combined with a mathematical approach to analyzing XPS spectra from biological origin, indicated that proteins and lipids were components of the capping material associated to the Se0 spheres. The most abundant proteins associated to the spheres were identified by proteomic analysis. Most of the proteins or peptide sequences capping the Se0 spheres were identified as periplasmic outer membrane porins and as the cytoplasmic elongation factor Tu protein, suggesting an intracellular formation of the Se0 spheres. In view of these and previous findings, a schematic model for the synthesis of Se0 spheres by the microorganisms inhabiting the granular sludge is proposed.

  7. Selenite Reduction by Anaerobic Microbial Aggregates: Microbial Community Structure, and Proteins Associated to the Produced Selenium Spheres

    Science.gov (United States)

    Gonzalez-Gil, Graciela; Lens, Piet N. L.; Saikaly, Pascal E.

    2016-01-01

    Certain types of anaerobic granular sludge, which consists of microbial aggregates, can reduce selenium oxyanions. To envisage strategies for removing those oxyanions from wastewater and recovering the produced elemental selenium (Se0), insights into the microbial community structure and synthesis of Se0 within these microbial aggregates are required. High-throughput sequencing showed that Veillonellaceae (c.a. 20%) and Pseudomonadaceae (c.a.10%) were the most abundant microbial phylotypes in selenite reducing microbial aggregates. The majority of the Pseudomonadaceae sequences were affiliated to the genus Pseudomonas. A distinct outer layer (∼200 μm) of selenium deposits indicated that bioreduction occurred in the outer zone of the microbial aggregates. In that outer layer, SEM analysis showed abundant intracellular and extracellular Se0 (nano)spheres, with some cells having high numbers of intracellular Se0 spheres. Electron tomography showed that microbial cells can harbor a single large intracellular sphere that stretches the cell body. The Se0 spheres produced by the microorganisms were capped with organic material. X-ray photoelectron spectroscopy (XPS) analysis of extracted Se0 spheres, combined with a mathematical approach to analyzing XPS spectra from biological origin, indicated that proteins and lipids were components of the capping material associated to the Se0 spheres. The most abundant proteins associated to the spheres were identified by proteomic analysis. Most of the proteins or peptide sequences capping the Se0 spheres were identified as periplasmic outer membrane porins and as the cytoplasmic elongation factor Tu protein, suggesting an intracellular formation of the Se0 spheres. In view of these and previous findings, a schematic model for the synthesis of Se0 spheres by the microorganisms inhabiting the granular sludge is proposed. PMID:27199909

  8. Effect of selenite on 86Rb uptake by rat lens

    International Nuclear Information System (INIS)

    The effect was observed in vitro of selenite on the uptake of 86Rb by the lens in two weeks old and adult rats. Also measured was the uptake of 86Rb by the lens in vitro in 30-days old rats with cataracts induced by the administration of selenite at day 14 after birth and in control animals of the same age. Selenite in a concentration of 0.4 mM and more caused an insignificant decrease in 86Rb uptake by the lens in adult rats while in the lens of young rats the uptake decreased significantly already at concentrations lower by two orders. Lenses with cataracts took up significantly less 86Rb than transparent lenses; body weight, the weight of the fresh lens and its dry mass decreased while the water content in the lens was higher as compared with control groups. (author). 2 tabs., 26 refs

  9. Sodium selenite and cancer related lymphedema: Biological and pharmacological effects.

    Science.gov (United States)

    Pfister, Christina; Dawzcynski, Horst; Schingale, Franz-Josef

    2016-09-01

    A significant percentage of cancer patients develop secondary lymphedema after surgery or radiotherapy. The preferred treatment of secondary lymphedema is complex physical therapy. Pharmacotherapy, for example with diuretics, has received little attention, because they were not effective and only offered short-term solutions. Sodium selenite showed promise as a cost-effective, nontoxic anti-inflammatory agent. Treatment with sodium selenite lowers reactive oxygen species (ROS) production, causes a spontaneous reduction in lymphedema volume, increases the efficacy of physical therapy for lymphedema, and reduces the incidence of erysipelas infections in patients with chronic lymphedema. Besides biological effects in reducing excessive production of ROS, sodium selenite also displays various pharmacological effects. So far the exact mechanisms of these pharmacological effects are mostly unknown, but probably include inhibition of adhesion protein expression. PMID:27267968

  10. Selenite cataract and its attenuation by vitamin E in wistar rats.

    Directory of Open Access Journals (Sweden)

    Mathew Joe

    2003-01-01

    Full Text Available Purpose: To study the role of vitamin E in preventing cataract formation in experimental animals. Methods: An experimental model (selenite cataract was selected for this study. Selenite cataract was produced in rats by subcutaneous administration of sodium selenite. Biochemical and histological changes following induction of selenite cataract in weanling wistar rats were studied vis-à-vis the role of vitamin E in attenuating or preventing cataractogenesis. Results: Vitamin E was capable of preventing selenite cataractogenesis. Selenite cataract did not develop in 91.6% (11 of 12 and 76.7% (8 of 12 vitamin E treated rats, when administered on the 12th and 10th post partum day respectively. Conclusion: The study confirmed that selenite induced cataract in wistar rats is attenuated by vitamin E.

  11. Aux origines du monde

    CERN Multimedia

    2004-01-01

    "C'est l'histoire d'une aventure humaine, scientifique, international qui a vu le jour il y a cinquante ans, aux confins de la Suisse et du département de l'Ain. Le plus grand laboratoire de physique des particules du monde, le Cern, a été fondé en 1954. Les festivités organisées à l occasion de cet anniversaire connaîtront leur point d'orgue le 16 octobre prochain, avec portes-ouvertes, accueil de personallités et inauguration d'un monumnet spécifique, le Globe de l'innovation" (2 pages)

  12. Aeration conditions modify the immobilization of Se (selenite) and Tc (pertechnetate) on various soils

    International Nuclear Information System (INIS)

    Full text: Isotopes of both selenium and technetium are important components of radioactive waste destined for long-term storage and so it is important to understand their behaviour in the environment. In addition, selenium is an essential micro-nutrient, deficient in some soils but potentially toxic at only slightly larger concentrations found naturally or as a result of human activity. Both elements are redox sensitive, having oxidation states from +7 to 0 for Tc and from +6 to -2 for Se. They are often considered to behave very similarly in the environment, with the oxy-anions dominating in well-aerated soils. We have studied the sorption of both elements in contrasting soils and compared the consequences of prolonged incubation under well-aerated, water-saturated, or strictly anaerobic conditions. We used sequential or parallel chemical extractions to assess the chemical nature of the immobilized fractions. Pertechnetate remained easily water-extractable throughout prolonged incubation of the soils under aerated conditions. However flooded, hence reducing conditions decreased the water-extractability of Tc. There was no difference between the fraction extracted by water or by simple salt solution (exchangeable fraction). However, as Tc became progressively immobilized, 1M NaOH (to solubilize humic substances) or H2O2 (to solubilize soil organic matter and reoxidize reduced forms of Tc) increased more Tc, indicating the strong association of Tc with organic matter and differing extents of chemical reduction. Selenite sorbed to differing extents on the various soils studied however the fraction extracted by water was systematically very low. There was a large difference between the water-extractable and the exchangeable fractions. Incubation of the soils under well aerated conditions led to different changes in Se extractability. Freshly added Se was more easily extracted than native Se. Addition of fresh organic matter or strictly anaerobic conditions enhanced

  13. HEPATOPROTECTIVE ROLE OF SODIUM SELENITE AGAINST OXIDATIVE DAMAGE INDUCED BY MERCURIC CHLORIDE IN RAT ALBINOS WISTAR

    OpenAIRE

    Youcef Necib; Ahlem Bahi; Sakina Zerizer; Cherif Abdennour; Mohamed Salah Boulakoud

    2013-01-01

    Background: The present study was undertaken, to evaluate the protective effect of sodium selenite against mercuric chloride induced oxidative stress in experimental rats. Female Albinos Wistar rats randomly divided into four groups, were the first was served as a control, whereas the remaining groups respectively treated with: sodium selenite (1mg/ kg b.w; ip), mercuric chloride (1 mg/kg body weight i.p) and combination of sodium selenite and HgCl2. Change in liver enzyme activities, thiobar...

  14. The response of three aquatic plants to different concentration od selenite in media

    OpenAIRE

    Mohorko, Evelina

    2013-01-01

    The response of three aquatic plants (Myriophyllum spicatum, Ceratophyllum demersum and Potamogeton perfoliatus) to the change in selenite content in their environment was studied. All chosen aquatic plants were at first exposed to the medium with 10 mg/L of added selenite for various days of exposure (1 to 15 days). After the treatments the plants were transplanted to medium without added selenite for 5 days. After each treatment the photochemical efficiency of photosystem II (PS II), electr...

  15. Carboxymethylcellulose improves the antimutagenic activity of sodium selenite against maleic hydrazide in vicia faba seedlings

    International Nuclear Information System (INIS)

    In this study the genotoxic effects induced by a treatment with different doses of sodium selenite in Vicia faba seedlings were evaluated with or without the addition of carboxy methyl cellulose. A further objective of this study was to verify whether the adduct selenite-carboxymethylcellulose was also able to reduce the genotoxic damages induced by the herbicide maleic hydrazide, a strong mutagenic agent in plants, at a higher extent than selenite alone. The results obtained showed a genotoxic activity of sodium selenite at concentrations up to 8.6 mg L-1. In the treatments with selenite-carboxymethylcellulose, the genotoxicity induced by the complex was significantly lower in comparison to how much was observed in the treatment with selenite only. When sodium selenite's protective activity against the genotoxic effects induced by the herbicide maleic hydrazide was tested, a reduction of mutagenic damages was observed at the highest application doses of selenite (from 86 mg L-1). The treatments with selenite-carboxymethyl cellulose resulted in a further increase of selenium protective activity, which was observable for all doses used. These findings suggest a possible role played by carboxymethylcellulose in the regulation of the genotoxic activity of selenium

  16. Carmustine enhances the anticancer activity of selenite in androgen-independent prostate cancer cells

    International Nuclear Information System (INIS)

    Apoptosis is one of the major mechanisms targeted in the development of therapies against various cancers, including prostate cancer. Resistance to chemotherapy poses a significant problem for the effective treatment of androgen-independent (hormone-refractory) prostate cancer. Although high concentrations of sodium selenite exert strong anticarcinogenic effects in several cell culture systems and animal models, the therapeutic potential of selenite in patients with advanced or metastatic prostate cancer is extremely limited by the genotoxicity of high-dose selenite. We examined the ability of nontoxic concentrations of selenite to promote apoptosis and inhibit proliferation in carmustine-sensitized androgen-independent human prostate cancer cells. Androgen-dependent LNCaP cells exhibited a significant decrease in cell viability when exposed to nontoxic concentrations of selenite, whereas androgen-independent PC-3 and DU145 cells showed a significant decrease in cell viability only at higher concentrations. Treatment of PC-3 cells with a combination of nontoxic selenite and carmustine resulted in greater increases in cytotoxicity, reactive oxygen species generation, growth inhibition, apoptosis, and DNA double-strand breaks, with concomitant decreases in DNA synthesis, glutathione, glutathione reductase, and antiapoptotic proteins. Combination treatment with carmustine and selenite triggered caspase-dependent apoptosis in PC-3 cells, which was not apparent when these cells were treated with selenite or carmustine alone. Genotoxicity in normal prostate epithelial cells was completely absent in the combination treatment of carmustine and selenite. In addition, carmustine decreased the induction of DNA double strand breaks by high-dose selenite in normal prostate epithelial cells. This is the first study to demonstrate that a nontoxic dose of selenite, in combination with carmustine, significantly induces apoptosis and growth inhibition in androgen

  17. Modeling selenite adsorption envelopes on oxides, clay minerals, and soils using the triple layer model

    Science.gov (United States)

    Selenite adsorption behavior was investigated on amorphous aluminum and iron oxides, clay minerals: kaolinite, montmorillonite, and illite, and 45 surface and subsurface soil samples from the Southwestern and Midwestern regions of the USA as a function of solution pH. Selenite adsorption decreased ...

  18. Selenium uptake, tolerance and reduction in Flammulina velutipes supplied with selenite.

    Science.gov (United States)

    Wang, Jipeng; Wang, Bo; Zhang, Dan; Wu, Yanhong

    2016-01-01

    Recently, selenium (Se) enriched mushrooms have been exploited as dietary Se supplements, but our knowledge of the metabolic process during the Se enrichment process is far from complete. In this study, the uptake, tolerance and reduction of selenite in a widely cultivated mushroom, Flammulina velutipes, was investigated. The results showed that pH variation (from 5.5-7.5), metabolic inhibitor (0.1 mM 2,4-DNP) and P or S starvation led to 11-26% decreases in the selenite uptake rate of F. velutipes. This indicates that a minor portion of the selenite uptake was metabolism dependent, whereas a carrier-facilitated passive transport may be crucial. Growth inhibition of F. velutipes initiated at 0.1 mM selenite (11% decrease in the growth rate) and complete growth inhibition occurred at 3 mM selenite. A selenite concentration of 0.03-0.1 mM was recommended to maintain the balance between mycelium production and Se enrichment. F. velutipes was capable of reducing selenite to elemental Se [Se(0)] including Se(0) nanoparticles, possibly as a detoxification mechanism. This process depended on both selenite concentration and metabolism activity. Overall, the data obtained provided some basic information for the cultivation of the selenized F. velutipes, and highlighted the opportunity of using mushrooms for the production of Se(0) nanoparticles. PMID:27547513

  19. The Sorption of Selenate and Selenite onto Magnetite in the Carbonate Solution

    International Nuclear Information System (INIS)

    While metal selenide and elemental and elemental selenium have a very low solubility, selenite and selenite and selenate are soluble and mobile. The metal canister containing high-level wastes or spent fuels would be disposed in a borehole or tunnel located a deep underground according to a Korean concept. In this geological condition, the iron canister will be corroded into magnetite. Since studies on selenium sorption have indicated that it can be strongly adsorbed by iron oxyhydroxide and oxides, retention of selenite and selenate on the magnetite could that be possible due to immobilization process. However several anions in groundwater, especially carbonate with high concentration in KAERI Underground Research Tunnel groundwater, can compete with selenium oxides for the sorption onto iron corrosion products. In this work, the sorption of selenate and selenite onto magnetite was studied in various ph solutions with and without carbonate ion. Then the results were applied for surface complexation modeling. The sorption reaction of both selenate and selenite onto magnetite at room temperature was reached to equilibrium within 3 days. Sorption of selenite onto magnetite was decreased with increasing ph since the ration of hydrated selenite selenate was found at ph 7 ∼ 11 because of the existence of free SeO42- as only predominant species in the ph range. Carbonate ion in the solution affected the selenite adsorption onto magnetite

  20. The Sorption of Selenate and Selenite onto Magnetite in the Carbonate Solution

    International Nuclear Information System (INIS)

    Naturally selenium exists as four different oxidation states with different chemical behaviors: selenide, elemental selenium, selenite and selenate. While metal selenide and elemental and elemental selenium have a very low solubility, selenite and selenite and selenate are soluble and mobile. In this geological condition, the iron canister will be corroded into magnetite. Since studies on selenium sorption have indicated that it can be strongly adsorbed by iron oxyhydroxides and oxides, retention of selenite and selenate on the magnetite could that be possible due to immobilization process. However several anions in groundwater, especially carbonate with high concentration in KAERI Underground Research Tunnel groundwater, can compete with selenium oxides for the sorption onto iron corrosion products. In this work, the sorption of selenate and selenite onto magnetite was studied in various pH solutions with and without carbonate ion. Then the results were applied for surface complexation modeling. The sorption reaction of both selenate and selenite onto magnetite at room temperature was reached to equilibrium within 3 days. Sorption of selenite onto magnetite was decreased with increasing pH since the ration of hydrated selenite selenate was found at pH 7 ∼ 11 because of the existence of free SeO42- as only predominant species in the pH range

  1. Contribution of cutinase serine 42 side chain to the stabilization of the oxyanion transition state.

    Science.gov (United States)

    Nicolas, A; Egmond, M; Verrips, C T; de Vlieg, J; Longhi, S; Cambillau, C; Martinez, C

    1996-01-16

    Cutinase from the fungus Fusarium solani pisi is a lipolytic enzyme able to hydrolyze both aggregated and soluble substrates. It therefore provides a powerful tool for probing the mechanisms underlying lipid hydrolysis. Lipolytic enzymes have a catalytic machinery similar to those present in serine proteinases. It is characterized by the triad Ser, His, and Asp (Glu) residues, by an oxyanion binding site that stabilizes the transition state via hydrogen bonds with two main chain amide groups, and possibly by other determinants. It has been suggested on the basis of a covalently bond inhibitor that the cutinase oxyanion hole may consist not only of two main chain amide groups but also of the Ser42 O gamma side chain. Among the esterases and the serine and the cysteine proteases, only Streptomyces scabies esterase, subtilisin, and papain, respectively, have a side chain residue which is involved in the oxyanion hole formation. The position of the cutinase Ser42 side chain is structurally conserved in Rhizomucor miehei lipase with Ser82 O gamma, in Rhizopus delemar lipase with Thr83 O gamma 1, and in Candida antartica B lipase with Thr40 O gamma 1. To evaluate the increase in the tetrahedral intermediate stability provided by Ser42 O gamma, we mutated Ser42 into Ala. Furthermore, since the proper orientation of Ser42 O gamma is directed by Asn84, we mutated Asn84 into Ala, Leu, Asp, and Trp, respectively, to investigate the contribution of this indirect interaction to the stabilization of the oxyanion hole. The S42A mutation resulted in a drastic decrease in the activity (450-fold) without significantly perturbing the three-dimensional structure. The N84A and N84L mutations had milder kinetic effects and did not disrupt the structure of the active site, whereas the N84W and N84D mutations abolished the enzymatic activity due to drastic steric and electrostatic effects, respectively. PMID:8555209

  2. Structural and kinetic contributions of the oxyanion binding site to the catalytic activity of acylaminoacyl peptidase.

    Science.gov (United States)

    Kiss, András L; Palló, Anna; Náray-Szabó, Gábor; Harmat, Veronika; Polgár, László

    2008-05-01

    It is widely accepted that the catalytic activity of serine proteases depends primarily on the Asp-His-Ser catalytic triad and other residues within the vicinity of this motif. Some of these residues form the oxyanion binding site that stabilizes the tetrahedral intermediate by hydrogen bonding to the negatively charged oxyanion. In acylaminoacyl peptidase from the thermophile Aeropyrum pernix, the main chain NH group of Gly369 is one of the hydrogen bond donors forming the oxyanion binding site. The side chain of His367, a conserved residue in acylaminoacyl peptidases across all species, fastens the loop holding Gly369. Determination of the crystal structure of the H367A mutant revealed that this loop, including Gly369, moves away considerably, accounting for the observed three orders of magnitude decrease in the specificity rate constant. For the wild-type enzyme ln(k(cat)/K(m)) vs. 1/T deviates from linearity indicating greater rate enhancement with increasing temperature for the dissociation of the enzyme-substrate complex compared with its decomposition to product. In contrast, the H367A variant provided a linear Arrhenius plot, and its reaction was associated with unfavourable entropy of activation. These results show that a residue relatively distant from the active site can significantly affect the catalytic activity of acylaminoacyl peptidase without changing the overall structure of the enzyme. PMID:18325786

  3. Recovery of Elemental Tellurium Nanoparticles by the Reduction of Tellurium Oxyanions in a Methanogenic Microbial Consortium

    Science.gov (United States)

    Ramos-Ruiz, Adriana; Field, Jim A.; Wilkening, Jean V.; Sierra-Alvarez, Reyes

    2016-01-01

    This research focuses on the microbial recovery of elemental tellurium (Te0) from aqueous streams containing soluble tellurium oxyanions, tellurate (TeVI) and tellurite (TeIV). An anaerobic mixed microbial culture occurring in methanogenic granular sludge was able to biocatalyze the reduction of both Te oxyanions to produce Te0 nanoparticles (NPs) in sulfur-free medium. TeIV reduction was 7-fold faster than that of TeVI, such that TeIV did not accumulate to a great extent during TeVI reduction. Endogenous substrates in the granular sludge provided the electron equivalents required to reduce Te oxyanions; however, the reduction rates were modestly increased with an exogenous electron donor such as H2. The effect of four redox mediators (anthraquinone-2,6-disulfonate, hydroxocobalamin, riboflavin, and lawsone) was also tested. Riboflavin increased the rate of TeIV reduction by 11-fold and also enhanced the fraction Te recovered as extracellular Te0 NPs from 21% to 64%. Lawsone increased the rate of TeVI reduction by 5-fold and the fraction of Te recovered as extracellular material increased from 49% to 83%. The redox mediators and electron donors also impacted the morphologies and localization of Te0 NPs, suggesting that NP production can be tailored for a particular application. PMID:26735010

  4. The Comparative Studies of Binding Activity of Curcumin and Didemethylated Curcumin with Selenite: Hydrogen Bonding vs Acid-Base Interactions

    Science.gov (United States)

    Liao, Jiahn-Haur; Wu, Tzu-Hua; Chen, Ming-Yi; Chen, Wei-Ting; Lu, Shou-Yun; Wang, Yi-Hsuan; Wang, Shao-Pin; Hsu, Yen-Min; Huang, Yi-Shiang; Huang, Zih-You; Lin, Yu-Ching; Chang, Ching-Ming; Huang, Fu-Yung; Wu, Shih-Hsiung

    2015-12-01

    In this report, the in vitro relative capabilities of curcumin (CCM) and didemethylated curcumin (DCCM) in preventing the selenite-induced crystallin aggregation were investigated by turbidity tests and isothermal titration calorimetry (ITC). DCCM showed better activity than CCM. The conformers of CCM/SeO32- and DCCM/SeO32- complexes were optimized by molecular orbital calculations. Results reveal that the selenite anion surrounded by CCM through the H-bonding between CCM and selenite, which is also observed via IR and NMR studied. For DCCM, the primary driving force is the formation of an acid-base adduct with selenite showing that the phenolic OH group of DCCM was responsible for forming major conformer of DCCM. The formation mechanisms of selenite complexes with CCM or DCCM explain why DCCM has greater activity than CCM in extenuating the toxicity of selenite as to prevent selenite-induced lens protein aggregation.

  5. The Comparative Studies of Binding Activity of Curcumin and Didemethylated Curcumin with Selenite: Hydrogen Bonding vs Acid-Base Interactions

    Science.gov (United States)

    Liao, Jiahn-Haur; Wu, Tzu-Hua; Chen, Ming-Yi; Chen, Wei-Ting; Lu, Shou-Yun; Wang, Yi-Hsuan; Wang, Shao-Pin; Hsu, Yen-Min; Huang, Yi-Shiang; Huang, Zih-You; Lin, Yu-Ching; Chang, Ching-Ming; Huang, Fu-Yung; Wu, Shih-Hsiung

    2015-01-01

    In this report, the in vitro relative capabilities of curcumin (CCM) and didemethylated curcumin (DCCM) in preventing the selenite-induced crystallin aggregation were investigated by turbidity tests and isothermal titration calorimetry (ITC). DCCM showed better activity than CCM. The conformers of CCM/SeO32− and DCCM/SeO32− complexes were optimized by molecular orbital calculations. Results reveal that the selenite anion surrounded by CCM through the H-bonding between CCM and selenite, which is also observed via IR and NMR studied. For DCCM, the primary driving force is the formation of an acid-base adduct with selenite showing that the phenolic OH group of DCCM was responsible for forming major conformer of DCCM. The formation mechanisms of selenite complexes with CCM or DCCM explain why DCCM has greater activity than CCM in extenuating the toxicity of selenite as to prevent selenite-induced lens protein aggregation. PMID:26635113

  6. Preventive effect of onion juice on selenite-induced experimental cataract

    OpenAIRE

    Javadzadeh Alireza; Ghorbanihaghjo Amir; Bonyadi Somayeh; Rashidi Mohammad; Mesgari Mehran; Rashtchizadeh Nadereh; Argani Hassan

    2009-01-01

    Purpose: To evaluate the effects of onion juice on sodium-selenite induced cataract formation. Materials and Methods: Thirty-two 10-day-old Wistar-albino rat pups were divided into four equal groups. Group 1 received only subcutaneous saline injection. In Group 2, sodium-selenite (30 nmol / g body weight) was injected subcutaneously. In Group 3, subcutaneous sodium-selenite was injected and one drop 50% diluted fresh juice of crude onion was instilled every 8 h into the ...

  7. Microbial respiration with chlorine oxyanions: diversity and physiological and biochemical properties of chlorate- and perchlorate-reducing microorganisms.

    Science.gov (United States)

    Liebensteiner, Martin G; Oosterkamp, Margreet J; Stams, Alfons J M

    2016-02-01

    Chlorine oxyanions are valuable electron acceptors for microorganisms. Recent findings have shed light on the natural formation of chlorine oxyanions in the environment. These suggest a permanent introduction of respective compounds on Earth, long before their anthropogenic manufacture. Microorganisms that are able to grow by the reduction of chlorate and perchlorate are affiliated with phylogenetically diverse lineages, spanning from the Proteobacteria to the Firmicutes and archaeal microorganisms. Microbial reduction of chlorine oxyanions can be found in diverse environments and different environmental conditions (temperature, salinities, pH). It commonly involves the enzymes perchlorate reductase (Pcr) or chlorate reductase (Clr) and chlorite dismutase (Cld). Horizontal gene transfer seems to play an important role for the acquisition of functional genes. Novel and efficient Clds were isolated from microorganisms incapable of growing on chlorine oxyanions. Archaea seem to use a periplasmic Nar-type reductase (pNar) for perchlorate reduction and lack a functional Cld. Chlorite is possibly eliminated by alternative (abiotic) reactions. This was already demonstrated for Archaeoglobus fulgidus, which uses reduced sulfur compounds to detoxify chlorite. A broad biochemical diversity of the trait, its environmental dispersal, and the occurrence of relevant enzymes in diverse lineages may indicate early adaptations of life toward chlorine oxyanions on Earth. PMID:26104311

  8. The effect of cysteine and sodium selenite on the toxicity of cadmium in staphylococcus aureus

    International Nuclear Information System (INIS)

    Cysteine was shown to have a protective effect on the killing rate caused by cadmium (Cd) but no effect on the uptake of Cd in S. aureus 3719-. The addition of 254x10-3 mmol/l of sodium selenite or more into the liquid growth medium increased the lag phase of growth of S. aureus 3719-. Sodium selenite had no protective effect on the toxicity of Cd in S.aureus 3719- as evaluated by the length of the lag phase of growth in the presence of Cd and varying amounts of sodium selenite. 534 x 10-6 mmol/l of sodium selenite in the growth medium had no effect on the uptake of Cd in S. aureus. (author)

  9. Selenite transiently represses transcription of photosynthesis-related genes in potato leaves.

    Science.gov (United States)

    Poggi, Valeria; Del Vescovo, Valerio; Di Sanza, Claudio; Negri, Rodolfo; Hochkoeppler, Alejandro

    2008-01-01

    A striking response of potato leaves to aspersion with selenite was observed at the transcriptional level by means of cDNA microarrays analysis. This response is characterized by a general transient repression of genes coding for components of photosynthetic systems and of other light-regulated genes. In particular, maximal repression was observed 8 h after selenite aspersion, while 24 h after the treatment a complete recovery of normal transcriptional levels was detected. Another general feature of the transcriptional response to selenite is represented by the transcriptional induction of genes related to amino acid metabolism, and to stress defense; interestingly, two genes coding for glutathione S-transferases were found early-induced upon selenite treatment. PMID:17846914

  10. Recycling of spent adsorbents for oxyanions and heavy metal ions in the production of ceramics.

    Science.gov (United States)

    Verbinnen, Bram; Block, Chantal; Van Caneghem, Jo; Vandecasteele, Carlo

    2015-11-01

    Spent adsorbents for oxyanion forming elements and heavy metals are classified as hazardous materials and they are typically treated by stabilization/solidification before landfilling. The use of lime or cement for stabilization/solidification entails a high environmental impact and landfilling costs are high. This paper shows that mixing spent adsorbents in the raw material for the production of ceramic materials is a valuable alternative to stabilize oxyanion forming elements and heavy metals. The produced ceramics can be used as construction material, avoiding the high economic and environmental impact of stabilization/solidification followed by landfilling. To study the stabilization of oxyanion forming elements and heavy metals during the production process, two series of experiments were performed. In the first series of experiments, the main pollutant, Mo was adsorbed onto iron-based adsorbents, which were then mixed with industrial sludge (3 w/w%) and heated at 1100°C for 30 min. Mo was chosen, as this element is easily adsorbed onto iron-based adsorbents and it is the element that is the most difficult to stabilize (i.e. the highest temperatures need to be reached before the concentrations in the leachate are reduced). Leaching concentration from the 97/3 sludge/adsorbent mixture before heating ranged between 85 and 154 mg/kg; after the heating process they were reduced to 0.42-1.48 mg/kg. Mo was actually stabilized, as the total Mo concentration after addition was not affected by the heat treatment. In the second series of experiments, the sludge was spiked with other heavy metals and oxyanion forming elements (Cr, Ni, Cu, Zn, As, Cd and Pb) in concentrations 5 times higher than the initial concentrations; after heat treatment the leachate concentrations were below the regulatory limit values. The incorporation of spent adsorbents in ceramic materials is a valuable and sustainable alternative to the existing treatment methods, saving raw materials in the

  11. Evaluation of sorption capacity of modified wood biomass for arsenic five-valent oxyanions

    International Nuclear Information System (INIS)

    In the present work is assessed bio-sorption of arsenic oxyanions, which represent one of two most common special arsenic occurring in contaminated waters. A wood biomass was used as sorbent, which was modified by amorphous oxohydroxides of iron to increase sorption capacity, to whom arsenic has high affinity. The work estimated sorption capacity of wood biomass adjusted by oxohydroxides of iron. The Langmuir model as well as the Freundlich model were suitable for evaluation of experimental results. Maximal sorption capacity of investigated sorbent was 9.259 mg/g, what is comparable with values published by other authors.

  12. Study of the selenite reduction in Rhodobacter sphaeroides f. sp. denitrificans

    International Nuclear Information System (INIS)

    Selenium is an essential element for all living organisms at the low level; however it becomes toxic and mutagenic at higher concentrations. The predominant forms of selenium in natural environments are selenate and selenite which are toxic. Bacteria can use several mechanisms of detoxification such as methylation in volatile compounds or reduction in elemental selenium. In this way, our model, Rhodobacter sphaeroides f. sp. denitrificans, is able to reduce selenite into selenium. We have combined biochemical and molecular approaches to better characterize the mechanism and protagonists of this reduction. After studying the physiological response of the bacterium in the presence of selenite, we screened a transposon library in order to isolate mutants with a weakened reduction ability. Two of these selected mutants are affected in genes involved in the molybdenum cofactor synthesis, moaA and mogA. Several reductases, the molybdo enzymes, required this cofactor. Furthermore the addition of tungsten, a competitor for the molybdenum, in the culture medium, dramatically reduces the rate of selenite reduction. These results strongly suggest that a molybdo enzyme is involved in one of the selenite reduction pathways. The potential role of different proteins has been investigated, especially for the nitrate reductase, the DMSO reductase and the biotin sulfoxide reductase. We have also selected a mutant affected in the smoM gene which encodes a peri-plasmic component of a TRAP transporter. The phenotype of this mutant suggests the involvement of this transporter in the selenite import. (author)

  13. Microbial selenite reduction with organic carbon and electrode as sole electron donor by a bacterium isolated from domestic wastewater.

    Science.gov (United States)

    Nguyen, Van Khanh; Park, Younghyun; Yu, Jaecheul; Lee, Taeho

    2016-07-01

    Selenium is said to be multifaceted element because it is essential at a low concentration but very toxic at an elevated level. For the purpose of screening a potential microorganism for selenite bioremediation, we isolated a bacterium, named strain THL1, which could perform both heterotrophic selenite reduction, using organic carbons such as acetate, lactate, propionate, and butyrate as electron donors under microaerobic condition, and electrotrophic selenite reduction, using an electrode polarized at -0.3V (vs. standard hydrogen electrode) as the sole electron donor under anaerobic condition. This bacterium determined to be a new strain of the genus Cronobacter, could remove selenite with an efficiency of up to 100%. This study is the first demonstration on a pure culture could take up electrons from an electrode to perform selenite reduction. The selenium nanoparticles produced by microbial selenite reduction might be considered for recovery and use in the nanotechnology industry. PMID:27099943

  14. Inhibitory Effect of Sodium Selenite on Microsatellite Instability of RER+ Colorectal Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective Investigation of the effects of sodium selenite on genetic instability of human tumor cells via its role in alteration of microsatellite sequence(MS) of RER+ (replication error) colon cancer cell line. Methods RER+ and RER- human colon cancer cell lines, RKO or SW480, were used as hosts for lipofection with pcmv-car in which a foreign(CA)14 repeat was inserted in the coding sequence of LacZ reporter gene, resulting in misreading LacZ frame. Any mutation which makes the base number of (CA)14 tract to be 3-fold will resume the normal reading frame of the reporter gene, and thus lead to expression and production of bioactive β-galactosidase. To test the effect of selenite on MI(microsatellite instability) of tumor cells, a series of concentrations of selenite were administered in cell culture in vitro. Variable expression of bioactive β-galactosidase of transfectant cells resulted from selenite administration was measured by A reading at λ410 after X-gal staining; Results Mutations of the exogenous(CA)14 developed and maintained in pcmv-car transfectant RKO cells but not in SW480 cells. It was found that blue cell frequency of RKO transfectant cells was markedly reduced after incubation of cells with 5 μmol/L of selenite for 5 days, at which concentration it was not toxic to cell growth. However, selenite at lower concentration of 1μmol/L didn′t exhibit suppression of blue cell rate until cell′s exposure to it for a longer period up to 5 weeks or more. Conclusion Our data showed that selenite displayed inhibitory effect on MI of human cancer cells and thus demonstrated its beneficial role in stabilization of human genomic DNA.

  15. Hepatoprotective Role of Sodium Selenite Against Oxidative Damage Induced by Mercuric Chloride in Rat Albinos Wistar

    Directory of Open Access Journals (Sweden)

    Youcef Necib

    2013-11-01

    Full Text Available Background: The present study was undertaken, to evaluate the protective effect of sodium selenite against mercuric chloride induced oxidative stress in experimental rats. Female Albinos Wistar rats randomly divided into four groups, were the first was served as a control, whereas the remaining groups respectively treated with: sodium selenite (1mg/ kg b.w; ip, mercuric chloride (1 mg/kg body weight i.p and combination of sodium selenite and HgCl2. Change in liver enzyme activities, thiobarbituric acid reactive substances (TBARS level, antioxidants and reduced glutathione (GSH contents were determined after 10 days experimental period. Results: Exposure of rats to mercuric chloride caused a significant increase the lipid peroxidation level along with corresponding decrease in the reduced glutathione and various antioxidant enzymes in liver. And increase in serum: glucose level, APL and transaminases activities and decreased in total protein and albumin levels. Furthermore, treatment with mercuric chloride caused a marked elevation of liver weight and decreased body weight. Supplementation of sodium selenite resulted in decreased of lipid peroxidation level and in the serum: AST, ALT and APL activities were decreased along with increase in total protein, albumin and liver GSH levels. The activities of antioxidants enzymes: glutathione peroxidase (GSH -Px and glutathione –S-transferase (GST were also concomitantly restored to near normal level by sodium selenite supplementation to mercuric chloride intoxicated rats. Liver histological studies have confirmed the changes observed in biochemical parameters and proved the beneficial role of sodium selenite. Conclusion: The results clearly demonstrate that sodium selenite treatment augments the antioxidants defense mechanism in mercuric chloride induced toxicity and provides evidence that it may have a therapeutic role in free radical mediated diseases.

  16. Protective Role of Sodium Selenite on Mercuric Chloride Induced Oxidative and Renal Stress in Rats

    Directory of Open Access Journals (Sweden)

    Necib, Youcef

    2013-04-01

    Full Text Available Backgroud: Reactive oxygen species are known to play a major role in mercuric chloride induced oxidative and renal stress. Sodium selenite as an exogenous source of selenium is used for endogenous selenoprotein synthesis to scavenge the free radicals. The study was designed to investigate the possible protective role of sodium selenite in mercuric chloride induced renal stress, by using biochemical approaches. Adult male Albinos Wistar rats were randomly divided into four groups. The first group was served as the control, the second group was given sodium selenite (0.25 mg/kg b.w, while the third group was given mercuric chloride (0.25 mg/kg, finally, the fourth group was given combined treatment of sodium selenite and mercuric chloride for 3 weeks.Results: The effects of sodium selenite on mercuric chloride induced oxidative and renal stress were evaluated by serum creatinine, urea, uric acid, billirubin levels and LDH activity, kidney tissue lipid peroxidation, GSH levels, GSH-Px, GST and catalase activities and hematological parameters. Administration of mercuric chloride induced significant increase in serum: creatinine, urea, uric acid and billirubin concentration showing renal stress. Mercuric chloride also induced oxidative stress, as indicate by decreased kidney tissue of GSH level, GSH-Px, GST, and catalase activities along with increase the level of lipid peroxidation. Furthermore, treatment with mercuric chloride caused a marked elevation of kidney weight and decreased body weight and erythrocytes, hemoglobin, hematocrit levels. Sodium selenite treatment markedly reduced elevated serum: creatinine, urea, uric acid and billirubin levels, and LDH activity and conteracted the deterious effects of mercuric chloride on oxidative stress markers and hematological parameters and atteneuated histopathological changes caused by HgCl2 in kidney.Conclusion: Our results indicate that sodium selenite could have a beneficial role against mercuric

  17. Adsorption of Oxy-Anions in the Teaching Laboratory: An Experiment to Study a Fundamental Environmental Engineering Problem

    Science.gov (United States)

    D'Arcy, Mitch; Bullough, Florence; Moffat, Chris; Borgomeo, Edoardo; Teh, Micheal; Vilar, Ramon; Weiss, Dominik J.

    2014-01-01

    Synthesizing and testing bicomposite adsorbents for the removal of environmentally problematic oxy-anions is high on the agenda of research-led universities. Here we present a laboratory module successfully developed at Imperial College London that introduces the advanced undergraduate student in engineering (chemical, civil, earth) and science…

  18. Selenite biotransformation during brewing. Evaluation by HPLC-ICP-MS.

    Science.gov (United States)

    Sánchez-Martínez, Maria; da Silva, Erik Galvão P; Pérez-Corona, Teresa; Cámara, Carmen; Ferreira, Sergio L C; Madrid, Yolanda

    2012-01-15

    Yeast (Saccharomyces cerevisiae) and lactic bacteria have shown their ability to accumulate and transform inorganic selenium into organo Se compounds. The objective of this work was to evaluate selenium biotransformation during brewing by using S. cerevisiae and Saccharomyces uvarum for Ale and Lager fermentation, respectively. Se-enriched beer was produced by the addition of sodium selenite (0, 0.2, 1.0, 2.0, 10.0, 20.0 μg Se mL(-1), respectively) to the fermentation media composed of yeast, malt extract and water. The alcoholic fermentation process was not affected by the presence of selenium regardless of the type of Saccharomyces being used. The percentage of selenium incorporated into beer, added between 1.0 and 10 μg mL(-1) was 55-60% of the selenium initially present. Se-compounds in post-fermentation (beer and yeast) products were investigated by using an analytical methodology based on HPLC-ICP-MS. For this purpose, several sample treatments, including ultrasonic-assisted enzymatic hydrolysis, in conjunction with different separation mechanisms like dialysis and anion exchange HPLC chromatography were applied for unambiguously identifying Se-species that produce during brewing. Selenomethionine was the main selenium compound identified in beer and yeast, being this species in the only case of the former not associated to peptides or proteins. PMID:22265498

  19. Metabolism of [75Se]selenite by rhesus monkeys

    International Nuclear Information System (INIS)

    The metabolism of [75Se]selenite was studied in rhesus monkeys. In blood samples taken various times after injection, Sephadex G-150 gel filtration revealed that the majority of the 75Se was associated with hemoglobin and low-molecular-weight compounds in erythrocytes up to 24 hours after selenium injection. Subsequently a gradual increase of 75Se occurred in glutathione peroxidase (GSH-Px) with a concurrent decrease of label with hemoglobin. In contrast to the erythrocytes, over 80% of the labeled selenium in plasma was associated with one peak 3 hours and later after injection. This major protein eluted at a position similar to GSH-Px on gel filtration, but subsequent chromatography on diethylaminoethyl (DEAE)-Sephacel separated the radiolabeled protein from GSH-Px. Gel filtration of heart, muscle, brain and pancreas cytosol revealed two major selenium-containing proteins, whereas one was predominant in liver and kidney. The major selenium peak was associated with GSH-Px in liver but not in the kidney. GSH-Px activity with either organic or inorganic peroxides as substrates and glutathione transferase activity were higher in liver than kidney

  20. Metabolism of (75Se)selenite by rhesus monkeys

    Energy Technology Data Exchange (ETDEWEB)

    Beilstein, M.A.; Butler, J.A.; Whanger, P.D.

    1984-08-01

    The metabolism of (75Se)selenite was studied in rhesus monkeys. In blood samples taken various times after injection, Sephadex G-150 gel filtration revealed that the majority of the 75Se was associated with hemoglobin and low-molecular-weight compounds in erythrocytes up to 24 hours after selenium injection. Subsequently a gradual increase of 75Se occurred in glutathione peroxidase (GSH-Px) with a concurrent decrease of label with hemoglobin. In contrast to the erythrocytes, over 80% of the labeled selenium in plasma was associated with one peak 3 hours and later after injection. This major protein eluted at a position similar to GSH-Px on gel filtration, but subsequent chromatography on diethylaminoethyl (DEAE)-Sephacel separated the radiolabeled protein from GSH-Px. Gel filtration of heart, muscle, brain and pancreas cytosol revealed two major selenium-containing proteins, whereas one was predominant in liver and kidney. The major selenium peak was associated with GSH-Px in liver but not in the kidney. GSH-Px activity with either organic or inorganic peroxides as substrates and glutathione transferase activity were higher in liver than kidney.

  1. Evaluation of Selenite Effects on Selenoproteins and Cytokinome in Human Hepatoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Susan Costantini

    2013-02-01

    Full Text Available The need to explore new alternative therapeutic strategies and chemoprevention methods for hepatocellular carcinoma is growing significantly. Selenium is a trace element that plays a critical role in physiological processes, and is used in cancer chemoprevention. The aim of this work was to test in vitro the effect of sodium selenite on the human hepatoma cell lines, HepG2 and Huh7, to assess its effect on the expression of GPX1, SELK and SELENBP1 and also to evaluate its action on inflammation determinants such as cytokines. Our results show that: (i the increase observed for the GPX1 and SELK expression is correlated with an increase in the sodium selenite concentration, also evidencing an inverse association between the levels of these two proteins and SELENBP1; (ii the selenium concentrations evaluated in protein extracts increase in proportional way with the selenite concentrations used in the treatment, suggesting that other selenoproteins can also be modulated and should be evaluated in further studies, and (iii some cytokines, VEGF and three pro-inflammatory cytokines, i.e., IL-6, IL-8, and IL-17, decreased with an increasing selenite concentration. Finally, interactomic studies show that GPX1 and SELK, and the four pro-inflammatory cytokines are functionally correlated evidencing a putative anti-inflammatory role for the selenite.

  2. Uptake and Distribution of Added Selenite and Selenate by Barley and Red Clover as Influenced by Sulphur

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel

    1973-01-01

    The uptake of added Se from selenite and selenate by barley and red clover was investigated in a pot experiment. Much more of selenate than of selenite was taken up but the Se concentrations in the plants declined more with time when selenate was the source. Increasing sulphate addition to the soil...

  3. In situ time-resolved X-ray near-edge absorption spectroscopy of selenite reduction by siderite

    International Nuclear Information System (INIS)

    The reduction oxidation-reaction between aqueous selenite (SeO32-) and siderite (FeCO3(s)) was monitored by in situ, time-resolved X-ray absorption near-edge structure (XANES) spectroscopy at the selenium K edge in a controlled electrochemical environment. Spectral evolutions showed that more than 60% of selenite was reduced at the siderite surface after 20 h of experiment, at which time the reaction was still incomplete. Fitting of XANES spectra by linear combination of reference spectra showed that selenite reaction with siderite is essentially a two-step process, selenite ions being immobilized on siderite surface prior to their reduction. A kinetic model of the reduction step is proposed, allowing to identify the specific contribution of surface reduction. These results have strong implications for the retention of selenite by corrosion products in nuclear waste repositories and in a larger extent for the fate of selenium in the environment. (authors)

  4. Aux marges du monde arabe

    Directory of Open Access Journals (Sweden)

    Hélène Thiollet

    2004-09-01

    Full Text Available L’étude des migrations contemporaines des Érythréens vers le Yémen au tournant des années quatre-vingt-dix permet d’observer les transformations des dynamiques régionales à l’œuvre dans le monde arabe. Les migrations sont un phénomène sensible aux différents aspects (politiques, économiques, culturels, géographiques de l’intégration régionale. Celle si est envisagée dans cet article à travers une approche doublement marginale : -la marginalité géographique de l’Érythrée arabo-africaine et du Yémen, économi­quement isolé dans la péninsule Arabique, -l’étude des migrations formelles et informelles, élément souvent marginal dans l’étude des institutions et des échanges qui constituent un système régional intégré. Cette étude est fondée sur une série d’entretiens menés au Yémen entre février et avril 2002 auprès des administrations yéménites et de la population érythréenne.

  5. The microbial impact on the sorption behaviour of selenite in an acidic, nutrient-poor boreal bog

    International Nuclear Information System (INIS)

    79Se is among the most important long lived radionuclides in spent nuclear fuel and selenite, SeO32−, is its typical form in intermediate redox potential. The sorption behaviour of selenite and the bacterial impact on the selenite sorption in a 7-m-deep profile of a nutrient-poor boreal bog was studied using batch sorption experiments. The batch distribution coefficient (Kd) values of selenite decreased as a function of sampling depth and highest Kd values, 6600 L/kg dry weight (DW), were observed in the surface moss and the lowest in the bottom clay at 1700 L/kg DW. The overall maximum sorption was observed at pH between 3 and 4 and the Kd values were significantly higher in unsterilized compared to sterilized samples. The removal of selenite from solution by Pseudomonas sp., Burkholderia sp., Rhodococcus sp. and Paenibacillus sp. strains isolated from the bog was affected by incubation temperature and time. In addition, the incubation of sterilized surface moss, subsurface peat and gyttja samples with added bacteria effectively removed selenite from the solution and on average 65% of selenite was removed when Pseudomonas sp. or Burkholderia sp. strains were used. Our results demonstrate the important role of bacteria for the removal of selenite from the solution phase in the bog environment, having a high organic matter content and a low pH. - Highlights: • Sterilization of bog samples inhibited the SeO32− removal from simulated bog water. • Bacteria isolated from the bog samples removed selenite from the solution. • Bacteria affect the removal of SeO32− from the solution in a nutrient-poor bog. • Selenite is reduced by the bacteria present in the bog both under oxic and anoxic conditions within the different microniches therein. • That is a prerequisite to read the record of the deformational history in metamorphic rocks

  6. Chemical forms of selenium in rat tissues after administration of selenite or selenomethionine

    Energy Technology Data Exchange (ETDEWEB)

    Beilstein, M.A.; Whanger, P.D.

    1986-09-01

    The chemical forms of selenium (Se) were determined in erythrocyte and liver proteins after injection of /sup 75/Se as either sodium selenite or selenomethionine (Se-Met) in male weanling rats. Gel-filtration chromatography (Sephadex G-150) of erythrocyte lysate revealed labeling of four fractions corresponding to void volume proteins, glutathione peroxidase (GPx), hemoglobin (Hb) and low-molecular-weight materials. Acid hydrolysates of erythrocyte protein fractions and whole liver were analyzed by ion-exchange chromatography (Dionex DC6A). Void volume proteins contained principally selenocysteine (/sup 75/Se-Cys) in (/sup 75/Se)selenite-injected animals. This material contained both /sup 75/Se-Met and /sup 75/Se-Cys 1 d postinjection in /sup 75/Se-Met-injected animals, but primarily /sup 75/Se-Cys at 20 d afterwards. GPx contained /sup 75/Se as /sup 75/Se-Cys regardless of the selenium compound injected. Hb of /sup 75/Se-Met-injected animals contained principally /sup 75/Se-Met at both 1 and 20 d postinjection. In (/sup 75/Se)selenite-injected animals, /sup 75/Se was present in hemoglobin as two unidentified forms. In acid hydrolysates of whole liver /sup 75/Se was recovered principally as /sup 75/Se-Cys from animals injected with (/sup 75/Se)selenite. For animals injected with /sup 75/Se-Met, liver /sup 75/Se was present initially as /sup 75/Se-Met, but after 5 d the majority of liver /sup 75/Se was as Se-Cys. No differences were found in deposition of /sup 75/Se in liver, kidney, testes, erythrocytes or plasma in rats injected with labeled selenite or Se-Met, but a significantly greater retention was found in muscle of Se-Met-injected rats as compared to those given selenite.

  7. Chemical forms of selenium in rat tissues after administration of selenite or selenomethionine

    International Nuclear Information System (INIS)

    The chemical forms of selenium (Se) were determined in erythrocyte and liver proteins after injection of 75Se as either sodium selenite or selenomethionine (Se-Met) in male weanling rats. Gel-filtration chromatography (Sephadex G-150) of erythrocyte lysate revealed labeling of four fractions corresponding to void volume proteins, glutathione peroxidase (GPx), hemoglobin (Hb) and low-molecular-weight materials. Acid hydrolysates of erythrocyte protein fractions and whole liver were analyzed by ion-exchange chromatography (Dionex DC6A). Void volume proteins contained principally selenocysteine (75Se-Cys) in [75Se]selenite-injected animals. This material contained both 75Se-Met and 75Se-Cys 1 d postinjection in 75Se-Met-injected animals, but primarily 75Se-Cys at 20 d afterwards. GPx contained 75Se as 75Se-Cys regardless of the selenium compound injected. Hb of 75Se-Met-injected animals contained principally 75Se-Met at both 1 and 20 d postinjection. In [75Se]selenite-injected animals, 75Se was present in hemoglobin as two unidentified forms. In acid hydrolysates of whole liver 75Se was recovered principally as 75Se-Cys from animals injected with [75Se]selenite. For animals injected with 75Se-Met, liver 75Se was present initially as 75Se-Met, but after 5 d the majority of liver 75Se was as Se-Cys. No differences were found in deposition of 75Se in liver, kidney, testes, erythrocytes or plasma in rats injected with labeled selenite or Se-Met, but a significantly greater retention was found in muscle of Se-Met-injected rats as compared to those given selenite

  8. Polarographic behaviour and determination of selenite and tellurite in simple solutions or in a binary mixture

    International Nuclear Information System (INIS)

    The polarographic behaviour of simple solutions of selenite and tellurite in 1 M ammonium salts of formate, acetate, tartrate, oxalate, and benzoate solutions in absence and in presence of Triton X-100 as a maximum suppressor and a temperature of 25OC has been investigated. Schemes for the mechanism of reductions occuring at the DME have been deduced. A method for analytical determination of selenite and tellurite in simple solutions as well as in a binary mixture in the presence of 4-14.10-3% Triton X-100 is reported. (author)

  9. In Vitro Antibacterial Spectrum of Sodium Selenite against Selected Human Pathogenic Bacterial Strains

    Directory of Open Access Journals (Sweden)

    Mohammad Firoz Alam

    2016-01-01

    Full Text Available The objective of this investigation was to predict the antibacterial properties of sodium selenite against selected human pathogens. A group of six human bacterial pathogens including Staphylococcus aureus, Streptococcus pyogenes, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella planticola were utilized for screening. The spectrum of activity was qualified based on zone of inhibition. Our study demonstrated that sodium selenite exhibits a strong spectrum of activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Klebsiella planticola. The spectrum of activity was compared with standard ciprofloxacin disc (5 μg/disc and observed to have satisfactory effect.

  10. Sorption of selenite onto chlorite considering mineral dissolution

    International Nuclear Information System (INIS)

    In this study we investigated the sorption of selenite (SeO32-) onto chlorite as a function of Se(IV) concentration, pH, and ionic strength. The sorption isotherm of Se(IV) onto chlorite was successfully presented by both the Langmuir isotherm and Tempkin equation although the Langmuir isotherm is somewhat better than the Tempkin equation. The sorption of Se(IV) onto chlorite was maintained to be constant at an acidic pH region, while the sorption decreased with an increasing pH at neutral and alkaline pH regions. However, the Se(IV) sorption onto chlorite was independent of the ionic strength of NaClO4 solution. The amount of Se(IV) sorbed onto chlorite was significantly low compared to those of iron oxides such as apatite, goethite, hematite, and magnetite because of the lower content of Fe. We also investigated the effect of Fe(II) ions dissolved from chlorite on the Se(IV) sorption as a function of contact time. The chemical oxidation states of selenium sorbed onto chlorite surface were identified using X-ray absorption near edge structure (XANES) at the Pohang synchrotron light source. The amount of Fe(II) dissolved was increased by the contact time of 28 days but decreased after 28-56 days although the amount of dissolved Fe(II) ions was significantly small. This decrease of the dissolved Fe(II) may be due to the formation of Fe-oxyhydroxides such as ferrihydrite. The results of XANES measurements also showed that the Se(IV) sorbed onto chlorite was not reduced into Se(0) or Se(-II) even in the presence of Fe(II) ions in the solution because of the low Fe content of the chlorite although the mechanism was not clearly understood. (author)

  11. Response of duckweed to various concentrations of selenite.

    Science.gov (United States)

    Mechora, Špela; Stibilj, Vekoslava; Germ, Mateja

    2015-02-01

    The uptake of Se(IV) and its effects on the physiological and biochemical characteristics of duckweed (Lemna minor L.) have been studied. Duckweed plants were cultivated in controlled conditions for 7 weeks in different concentrations of Na selenite: 0.5, 1, 2, 5 (exposed 42 days) and 10 mg Se L(-1) (survived 7-21 days). The addition of 1 mg Se L(-1) did not negatively affect photochemical efficiency whilst respiratory potential increased in weeks 2-4 compared to control. The addition of 1 mg Se(IV) L(-1) increased the amount of chlorophyll a in weeks 3 and 4 and the amount of carotenoids in weeks 1, 3 and 5. Concentrations of 2 and 5 mg Se L(-1) negatively affected photochemical efficiency in weeks 3 and 4, and increased respiratory potential in comparison to the control in weeks 1-4, whilst beyond week 4, the respiratory potential decreased. Plants exposed to the highest concentration of Se(IV) had to be replaced twice during the experiment because they were dying. That was reflected in photochemical efficiency as well as in respiratory potential, which decreased in time. The content of Se in duckweed increased with the increasing concentration of Se: plants growing in 0.5 mg Se L(-1) contained 0.9 mg Se g(-1) DM and plants exposed to 5 mg Se L(-1) contained 5.8 mg Se g(-1) DM. The group of plants exposed to 10 mg Se L(-1) for 21 days contained 19.5 mg Se g(-1) DM. Our study revealed that duckweed absorbed high amount of Se(IV) from the water. PMID:25028325

  12. Lead Nitrate Induced Toxic Effects on Small Intestine Tissues of Rats in Diabetic and Non-Diabetic Rats: Role of Sodium Selenite

    OpenAIRE

    Adıgüzel, Çağlar; KALENDER, Yusuf

    2015-01-01

    In this study, diabetic and non-diabetic male rats were given to sodium selenite, lead nitrate(LN) and sodium selenite plus lead nitrate through gavage. LN led to histopathological changes in small intestine tissue of non-diabetic LN and non-diabetic sodium selenite+LN groups. We observed that supplementation of sodium selenite has protective role on histopathological changes in small intestine tissue when the non-diabetic sodium selenite+LN group compared with non-diabetic LN group. In diabe...

  13. Study of retention mechanism of selenite on Ca/Mg bentonite

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Compacted bentonite is assumed to be the main engineered barrier in the concept of high level radioactive waste repository (HLWR) in granite host rock due to its favourable physical and chemical properties preventing migration of radionuclides released potentially from the solid waste matrix. Of primary concern of HLWR performance assessment are the anionic long lived radionuclides that can migrate almost without retardation through the barriers to the biosphere. Isotope 79Se belongs to this type of radionuclides due to its long half-time and limited sorption of its anionic forms. Selenium is redox sensitive element that may exist in four oxidation states. Its mobility strongly depends on in situ speciation affected by pH and redox potential of the geological environment, chemical and mineralogical composition of buffer/backfill materials and host rock. This study is an extension of our previous research on sorption and diffusion behaviour of selenite and selenate onto Ca/Mg bentonite B75 which has been selected as one of the candidates of buffer/backfill material for HLWR in the Czech Republic. Significant sorption of selenite at alkaline pH was observed which contradicts the standard model of non-specific sorption of anions on functional surface SOH groups. These groups are at high pH largely deprotonated and hence prevent the sorption of anions. The selenite sorption onto used bentonite was also supported by increasing ionic strength of liquid phase. This effect was not observed and was not taken into account in modelling of selenite sorption on similar clay materials. Our experimental results support assumption that selenite sorption at pH above 7 may be caused by formation of ternary surface complexes involving Ca and Mg or by precipitation of Ca/Mg selenites. This study focuses on clarification of complicated retention mechanism of selenite onto bentonite B75 at alkaline pH using batch experiments with

  14. Differential Acute Effects of Selenomethionine and Sodium Selenite on the Severity of Colitis

    Directory of Open Access Journals (Sweden)

    Franziska Hiller

    2015-04-01

    Full Text Available The European population is only suboptimally supplied with the essential trace element selenium. Such a selenium status is supposed to worsen colitis while colitis-suppressive effects were observed with adequate or supplemented amounts of both organic selenomethionine (SeMet and inorganic sodium selenite. In order to better understand the effect of these selenocompounds on colitis development we examined colonic phenotypes of mice fed supplemented diets before the onset of colitis or during the acute phase. Colitis was induced by treating mice with 1% dextran sulfate sodium (DSS for seven days. The selenium-enriched diets were either provided directly after weaning (long-term or were given to mice with a suboptimal selenium status after DSS withdrawal (short-term. While long-term selenium supplementation had no effect on colitis development, short-term selenite supplementation, however, resulted in a more severe colitis. Colonic selenoprotein expression was maximized in all selenium-supplemented groups independent of the selenocompound or intervention time. This indicates that the short-term selenite effect appears to be independent from colonic selenoprotein expression. In conclusion, a selenite supplementation during acute colitis has no health benefits but may even aggravate the course of disease.

  15. Differential acute effects of selenomethionine and sodium selenite on the severity of colitis.

    Science.gov (United States)

    Hiller, Franziska; Oldorff, Lisa; Besselt, Karolin; Kipp, Anna Patricia

    2015-04-01

    The European population is only suboptimally supplied with the essential trace element selenium. Such a selenium status is supposed to worsen colitis while colitis-suppressive effects were observed with adequate or supplemented amounts of both organic selenomethionine (SeMet) and inorganic sodium selenite. In order to better understand the effect of these selenocompounds on colitis development we examined colonic phenotypes of mice fed supplemented diets before the onset of colitis or during the acute phase. Colitis was induced by treating mice with 1% dextran sulfate sodium (DSS) for seven days. The selenium-enriched diets were either provided directly after weaning (long-term) or were given to mice with a suboptimal selenium status after DSS withdrawal (short-term). While long-term selenium supplementation had no effect on colitis development, short-term selenite supplementation, however, resulted in a more severe colitis. Colonic selenoprotein expression was maximized in all selenium-supplemented groups independent of the selenocompound or intervention time. This indicates that the short-term selenite effect appears to be independent from colonic selenoprotein expression. In conclusion, a selenite supplementation during acute colitis has no health benefits but may even aggravate the course of disease. PMID:25867950

  16. Deletion of thioredoxin reductase and effects of selenite and selenate toxicity in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Christopher J Boehler

    Full Text Available Thioredoxin reductase-1 (TRXR-1 is the sole selenoprotein in C. elegans, and selenite is a substrate for thioredoxin reductase, so TRXR-1 may play a role in metabolism of selenium (Se to toxic forms. To study the role of TRXR in Se toxicity, we cultured C. elegans with deletions of trxr-1, trxr-2, and both in axenic media with increasing concentrations of inorganic Se. Wild-type C. elegans cultured for 12 days in Se-deficient axenic media grow and reproduce equivalent to Se-supplemented media. Supplementation with 0-2 mM Se as selenite results in inverse, sigmoidal response curves with an LC50 of 0.20 mM Se, due to impaired growth rather than reproduction. Deletion of trxr-1, trxr-2 or both does not modulate growth or Se toxicity in C. elegans grown axenically, and (75Se labeling showed that TRXR-1 arises from the trxr-1 gene and not from bacterial genes. Se response curves for selenide (LC50 0.23 mM Se were identical to selenite, but selenate was 1/4(th as toxic (LC50 0.95 mM Se as selenite and not modulated by TRXR deletion. These nutritional and genetic studies in axenic media show that Se and TRXR are not essential for C. elegans, and that TRXR alone is not essential for metabolism of inorganic Se to toxic species.

  17. Experimental Study and modelling of the Sorption of Selenite and Europium Onto Smectite and Illite Clays

    International Nuclear Information System (INIS)

    This study provides a large set of experimental selenite sorption data for pure smectite and illite. Similar sorption behavior existed in both clays: linear within a large range of the Se concentrations investigated and independent of ionic strength. Selenite sorption was also analysed in the illite/smectite system with the clays mixed in two different proportions. The objective of the study was to provide the simplest model possible to fit the experimental data, a model also capable of describing selenite sorption in binary illite/smectite clay systems. Selenite sorption data were modeled using both a one-and a two-site non-electrostatic model that took into account the formation of two complexes at the edge sites of the clay. The complexation constants obtained by fitting sorption data of the individual minerals were incorporated into a model to predict the adsorption of selenium in the illite/ smectite mixtures; the models predictions were consistent with the experimental adsorption data. (Author) 42 refs

  18. Selenium homeostasis and induction of thioredoxin reductase during long term selenite supplementation in the rat

    DEFF Research Database (Denmark)

    Erkhembayar, Suvd; Mollbrink, Annelie; Eriksson, Malin;

    2011-01-01

    Selenium is a candidate treatment for liver tumour prevention in chronic liver disease. In this study, we have studied selenium uptake, distribution and accumulation in rats provided with water containing tumour-preventive doses of sodium selenite for 10weeks. Male Fischer 344 rats were given dri...

  19. Reduction of selenite by Azospirillum brasilense with the formation of selenium nanoparticles.

    Science.gov (United States)

    Tugarova, Anna V; Vetchinkina, Elena P; Loshchinina, Ekaterina A; Burov, Andrei M; Nikitina, Valentina E; Kamnev, Alexander A

    2014-10-01

    The ability to reduce selenite (SeO(3)(2-)) ions with the formation of selenium nanoparticles was demonstrated in Azospirillum brasilense for the first time. The influence of selenite ions on the growth of A. brasilense Sp7 and Sp245, two widely studied wild-type strains, was investigated. Growth of cultures on both liquid and solid (2 % agar) media in the presence of SeO(3)(2-) was found to be accompanied by the appearance of the typical red colouration. By means of transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS) and X-ray fluorescence analysis (XFA), intracellular accumulation of elementary selenium in the form of nanoparticles (50 to 400 nm in diameter) was demonstrated for both strains. The proposed mechanism of selenite-to-selenium (0) reduction could involve SeO(3)(2-) in the denitrification process, which has been well studied in azospirilla, rather than a selenite detoxification strategy. The results obtained point to the possibility of using Azospirillum strains as endophytic or rhizospheric bacteria to assist phytoremediation of, and cereal cultivation on, selenium-contaminated soils. The ability of A. brasilense to synthesise selenium nanoparticles may be of interest to nanobiotechnology for "green synthesis" of bioavailable amorphous red selenium nanostructures. PMID:24863127

  20. Experimental Study and modelling of the Sorption of Selenite and Europium Onto Smectite and Illite Clays

    Energy Technology Data Exchange (ETDEWEB)

    Missana, T.; Alonso, U.; Garcia-Gutierrez, M.

    2009-10-12

    This study provides a large set of experimental selenite sorption data for pure smectite and illite. Similar sorption behavior existed in both clays: linear within a large range of the Se concentrations investigated and independent of ionic strength. Selenite sorption was also analysed in the illite/smectite system with the clays mixed in two different proportions. The objective of the study was to provide the simplest model possible to fit the experimental data, a model also capable of describing selenite sorption in binary illite/smectite clay systems. Selenite sorption data were modeled using both a one-and a two-site non-electrostatic model that took into account the formation of two complexes at the edge sites of the clay. The complexation constants obtained by fitting sorption data of the individual minerals were incorporated into a model to predict the adsorption of selenium in the illite/ smectite mixtures; the models predictions were consistent with the experimental adsorption data. (Author) 42 refs.

  1. Pseudomonas seleniipraecipitatus sp. nov.: A selenite reducing -proteobacteria isolated from soil

    Science.gov (United States)

    Abstract: A Gram-negative, yellow pigmented bacterium designated strain CA5 that reduced selenite to elemental red selenium (Se0) was isolated from soil. 16S rRNA gene sequence alignment identified the isolate as a novel Pseudomonas sp. with P. argentinensis, P. flavescens and P. straminea as its c...

  2. Effect of sodium selenite on bone repair in tibiae of irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Anna Silvia Setti da [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR, (Brazil). Dept. of Physics; Ramos-Perez, Flavia Maria de Moraes; Boscolo, Frab Norberto; Almeida, Solange Maria [Universidade Estadual de Campinas (UNICAMP), Piracicaba, SP (Brazil). Piracicaba Dental School. Dept. of Oral Diagnosis], e-mail: flaviamaria@fop.unicamp.br; Manzi, Flavio Ricardo [Pontifical Catholic University of Minas Gerais (PUC-MG), Belo Horizonte, MG (Brazil). Dept. of Stomatology; Chicareli, Mariliani [State Univ. of Maringa, PR (Brazil). Dept. of Oral Diagnosis

    2009-07-01

    This study evaluated the radioprotective effect of sodium selenite on the bone repair process in tibiae of female rats. For such purpose, 100 female Wistar rats (Rattus norvegicus, albinus) were randomly assigned to 4 groups (n=25), according to the treatment received: administration of distilled water (control); administration of sodium selenite; gamma radiation; and administration of sodium selenite plus gamma radiation. A bone defect was prepared on both tibiae of all animals. Three days after surgery, the gamma radiation and selenium/ gamma radiation groups received 8 Gy gamma rays on the lower limbs. Five animals per group were sacrificed 7, 14, 21, 28 days after surgery for evaluation of the repair process by bone volumetric density analysis. The 5 animals remaining in each group were sacrificed 45 days postoperatively for examination of the mature bone by scanning electron microscopy. Based on all analyzed parameters, the results of the present study suggest that sodium selenite exerted a radioprotective effect in the bone repair of tibia of irradiated rats. (author)

  3. Reduction of Selenite to Elemental Red Selenium by Rhizobium sp. strain B1

    Science.gov (United States)

    bacterium that reduces the soluble and toxic selenite anion to insoluble elemental red selenium (Se0) was isolated from a laboratory bioreactor. Biochemical, morphological, and 16S rRNA gene sequence alignment identify the isolate as a Rhizobium sp. that is related to but is genetically divergent ...

  4. Rhizobium selenitireducens proteins involved in the reduction of selenite to elemental selenium

    Science.gov (United States)

    Microbial based bioremediation barriers can remove the metalloid selenite (SeO3–2) from flowing groundwater. The organisms associated with the process include microorganisms from within the bacterial and archaeal domains that can reduce soluble SeO3–2 to the insoluble and reddish-colored elemental ...

  5. Relationship between reactive oxygen species and sodium-selenite-induced DNA damage in HepG2 cells

    Institute of Scientific and Technical Information of China (English)

    ZOU Yunfeng; NIU Piye; GONG Zhiyong; YANG Jin; YUAN Jing; WU Tangchun; CHEN Xuemin

    2007-01-01

    Selenium compounds,as an effective chemopreventive agent,can induce apoptosis in tumor cells.Reactive oxygen species(ROS)are important mediators in apoptosis induced by various stimuli,which include chemopreventive agents.In this study,we investigated the relationship between ROS and the levels of DNA damage induced by selenite in HepG2 cells.After HepG2 cells were treated with selenite,there was a dose-dependent decrease in cell viability.The levels of ROS induced by selenite were measured by 2',7'-dichlorofluorescein diacetate(DCFH-DA)fluorescence,which shows a dose-and time-dependent increase in HepG2 cells.The levels of DNA damage in HepG2 increased in all cells treated with an increasing dose of selenite at 0,2.5,5,10,and 20 μmol/L.N-acetylcysteine(NAC),a known antioxidant,increased cell viability and decreased ROS generation.Moreover,NAC effectively blocked DNA damage induced by selenite.These results revealed that ROS might play an important role in selenite-induced DNA damage that can be reduced by NAC treatment.

  6. DFT and experimental study on the IR spectra and structure of 2-hydroxy-3-methoxybenzaldehyde ( o-vanillin) and its oxyanion

    Science.gov (United States)

    Velcheva, Evelina A.; Stamboliyska, Bistra A.; Boyadjieva, Pavlina J.

    2010-01-01

    The structure of o-vanillin molecule and its oxyanion have been studied by density functional theory (DFT), employing the B3LYP functional and 6-311++G** basis set. All conformational isomers of o-vanillin and of its anion have been located and their relative energies have been determined. The IR spectral changes, caused by the conversion of the molecule into the corresponding oxyanion have been studied. In a general agreement between theory and experiment, the conversion causes a frequency decrease of the carbonyl stretching band ν(C dbnd O) and essential intensity increases of the aromatic skeletal bands as well as methyl stretching band ν(CH 3). According to the NBO electric charge analysis, the oxyanionic center bears 60% of the whole anionic net charge.

  7. Sorption mechanisms of selenium species (selenite and selenate) on copper-based minerals

    International Nuclear Information System (INIS)

    The sorption of radionuclides on the surface of minerals represents a process capable to delay the migration of the elements from a spent fuel deep repository towards the biosphere. In the framework of a deep underground repository, an engineered clay barrier has a high trapping capacity for cationic radio-elements, in particular because of the negative charge of clay surfaces. However, anionic radioelements like selenium species, would be only weakly retained by chemical processes. In order to optimize the trapping capacity of a clay barrier with respect to anionic species, prospective studies are carried out in order to find and evaluate some minerals with specific chemical trapping functions. Among radionuclides, the case of selenium has to be considered because its isotope 79Se is present in radioactive wastes and has a half life time of 6.5 104 years. It is also judicious to find a mineral capable of trapping simultaneously several anionic radio-elements. Copper oxides and sulfides (Cu2O, CuO, Cu2S, CuS, CuFeS2 and Cu5FeS4) are good adsorbents with respect to selenium species (selenite and selenate). These minerals, with their selenium retention properties, could be used also for the decontamination of soils and waters or to process industrial effluents. The sorption mechanisms have been studied in details for copper oxides (Cu2O and CuO) with respect to selenite and selenate. Chalcomenite precipitates in acid pH conditions when selenite is added to a Cu2O and CuO suspension. Selenate, in contact with cuprite (Cu2O) leads also to a selenium-based precipitate in acid pH environment. For higher pH values, selenite and selenate are adsorbed on copper oxides (Cu2O and CuO) and lead to internal and external sphere complexes, respectively. In the case of a selenite/cuprite mixture in basic pH environment and at the equilibrium, a chemical reaction occurs between the oxidation product of cuprite, Cu(OH)2 and HSeO3. A preliminary study of selenite accumulation on

  8. Photoinduced Bioorthogonal 1,3-Dipolar Poly-cycloaddition Promoted by Oxyanionic Substrates for Spatiotemporal Operation of Molecular Glues.

    Science.gov (United States)

    Hatano, Junichi; Okuro, Kou; Aida, Takuzo

    2016-01-01

    PGlue(PZ), a pyrazoline (PZ)-based fluorescent adhesive which can be generated spatiotemporally in living systems, was developed. Since PGlue(PZ) carries many guanidinium ion (Gu(+)) pendants, it strongly adheres to various oxyanionic substrates through a multivalent salt-bridge interaction. PGlue(PZ) is given by bioorthogonal photopolymerization of a Gu(+)-appended monomer (Glue(TZ)), bearing tetrazole (TZ) and olefinic termini. Upon exposure to UV light, Glue(TZ) transforms into a nitrileimine (NI) intermediate (Glue(NI)), which is eligible for 1,3-dipolar polycycloaddition. However, Glue(NI) in aqueous media can concomitantly be deactivated into Glue(WA) by the addition of water, and the polymerization hardly occurs unless Glue(NI) is concentrated. We found that, even under high dilution, Glue(NI) is concentrated on oxyanionic substrates to a sufficient level for the polymerization, so that their surfaces can be point-specifically functionalized with PGlue(PZ) by the use of a focused beam of UV light. PMID:26530322

  9. Ionic flotation of complexing oxyanions. Thermodynamics of uranyl complexation in a sulfuric medium. Definition of selectivity conditions of the process

    International Nuclear Information System (INIS)

    Oxyanion ionic flotation process with dodecylamine hydrochloride as collector is studied by investigation of flotation and filtration recovery curves, suspension turbidity, conductimetric measurements, and solubility of ionic species. The process is controlled by chemical reactions of precipitation and by adsorption of surfactant confering hydrophobic or hydrophilic surface properties to the solid phase respectively when one or two monolayers of surfactant are successively adsorbed. Equilibrium constants (in terms of activity) of the uranium (VI) complexation with sulphate oxyanions are calculated through Raman spectroscopic study of uranyl sulphate aqueous solutions. The complexation results in a shift of the symmetrical stretching vibration band of U02 to low wavenumbers and an increase of their cross section. The solubility curves of ionic species in the precipitation of uranyl -sulphate complexes by dodecylamine hydrochloride are modelled. The knowledge of solubility products, activity coefficients of the species and critical micellar concentration of the surfactant allow the modelling of flotation recovery curves. Temperature and collector structure modifications are studied in terms of optimization parameters and uranium extraction of mine drainage water is processed. Residual concentration of surfactant is considerably lowered by adsorption on montmorillonite

  10. Effect of electroacupuncture to prevent selenite-induced cataract in Wistar rats Efeito da eletro-acupuntura na prevenção da catarata induzida por selenito de sódio em ratos Wistar

    OpenAIRE

    Angelino Julio Cariello; Fábio Henrique Casanova; Acácio Alves de Souza Lima Filho; Yara Juliano; Angela Tabosa

    2006-01-01

    PURPOSE: To investigate whether electroacupuncture can prevent selenite-induced cataract in an experimental model. METHODS: Fifty Wistar rat pups were randomized into 5 groups of 10 animals: Group 1 (control), no procedure was performed; Group 2 (selenite), sodium selenite (30 micromoles/kg body weight) was injected subcutaneously between postpartum days 10 to 12; Group 3 (anesthesia) received the same dose of selenite and underwent ether inhalation anesthesia during 10 minutes daily for one ...

  11. Notes de voyage aux Iles Baleares

    Directory of Open Access Journals (Sweden)

    Maurice LOUIS

    2009-10-01

    Full Text Available Les excursions du 1Vº Cours de Préhistoire et d'Archéologie, organisé en 1950 par l'Université de Barcelone en collaboratión avec l'Institut de Prehistoire méditerranéenne du Consejo Superior de Investigaciones Científicas d'Espagne, on conduit les participants aux Iles Baléares afin d'étudier sur place la civilisation dite "des talayots" de Majorque et de Minorque.

  12. Elucidation of the mechanism of reaction between S2O8(2-), Selenite and Mn2+ in aqueous solution and limestone-gypsum FGD liquor.

    Science.gov (United States)

    Akiho, Hiroyuki; Ito, Shigeo; Matsuda, Hiromitsu; Yoshioka, Toshiaki

    2013-10-01

    The mechanism of reaction between peroxodisulfate ion (S2O8(2-)), selenite (Se(IV)O3(2-)) and Mn(2+) as an inhibitor of selenite oxidation was studied using aqueous solutions composed of commercial reagents, as well as limestone-gypsum flue gas desulfurization (FGD) liquors sampled from coal fired power plants. The oxidation of selenite to selenate (Se(VI)O4(2-)) is promoted by the sulfate ion radical (SO4(-)) which results from decomposition of S2O8(2-). In the presence of Mn(2+), selenite oxidation was prevented due to the difference in rates of reaction with SO4(-). The ratio of the oxidation rate constants of selenite and Mn(2+) with SO4(-) was determined over a temperature range of 40-60 °C, and was found to be little influenced by the various coexisting components in FGD liquors. PMID:24015970

  13. Sorption kinetic study of selenite and selenate onto a high and low pressure aged iron oxide nanomaterial

    International Nuclear Information System (INIS)

    Highlights: ► Fe3O4 nanomaterials can be used to remove selenium from contaminated waters. ► Synthetic techniques used in this study require less steps and faster procedures than in previous techniques. ► Fe3O4 nanomaterials require less time and remove more selenium than previous materials tested. ► Fe3O4 nanomaterials would experience limitations for selenium binding in the presence of some competitive anions. - Abstract: The sorption of selenite (SeO32−) and selenate (SeO42−) onto Fe3O4 nanomaterials produced by non microwave-assisted or microwave-assisted synthetic techniques was investigated through use of the batch technique. The phase of both synthetic nanomaterials was determined to be magnetite by X-ray diffraction. The average grain sizes of non microwave-assisted and microwave-assisted synthetic Fe3O4 were determined to be 27 and 25 nm, respectively through use of the Scherrer's equation. Sorption of selenite was pH independent in the pH range of 2–6, while sorption of selenate decreased at pH 5 and 6. The addition of Cl− had no significant effect on selenite or selenate binding, while the addition of NO3− only affected selenate binding to the microwave assisted Fe3O4. A decrease of selenate binding to both synthetic particles was observed after the addition of SO42− while selenite binding was not affected. The addition of PO43− beginning at concentrations of 0.1 ppm had the most prominent effect on the binding of both selenite and selenate. The capacities of binding, determined through the use of Langmuir isotherm, were found to be 1923 and 1428 mg Se/kg of non microwave-assisted Fe3O4 and 2380 and 2369 mg Se/kg of microwave-assisted Fe3O4 for selenite and selenate, respectively.

  14. Explorations of New SHG Materials in the Alkali-Metal-Nb(5+)-Selenite System.

    Science.gov (United States)

    Cao, Xue-Li; Hu, Chun-Li; Kong, Fang; Mao, Jiang-Gao

    2015-11-16

    Standard high-temperature solid-state reactions of NaCl, Nb2O5, and SeO2 resulted in two new sodium selenites containing a second-order Jahn-Teller (SOJT) distorted Nb(5+) cation, namely, Na2Nb4O7(SeO3)4 (P1̅; 1) and NaNbO(SeO3)2 (Cmc21; 2). Compound 1 exhibits an unusual 3D [Nb4O7(SeO3)4](2-) anionic network composed of 2D [Nb4O11(SeO3)2](6-) layers which are further bridged by additional SeO3(2-) anions via corner sharing; the 2D [Nb4O11(SeO3)2](6-) layer is formed by unusual quadruple [Nb4O17](14-) niobium oxide chains of corner-sharing NbO6 octahedra being further interconnected by selenite anions via Nb-O-Se bridges. The polar compound 2 features a 1D [NbO(SeO3)2](-) anionic chain in which two neighboring Nb(5+) cations are bridged by one oxo and two selenite anions. The alignments of the polarizations from the NbO6 octahedra in 2 led to a strong SHG response of ∼7.8 × KDP (∼360 × α-SiO2), which is the largest among all phases found in metal-Nb(5+)-Se(4+)/metal-Nb(5+)-Te(4+)-O systems. Furthermore, the material is also type I phase matchable. The above experimental results are consistent with those based on DFT theoretical calculations. Thermal stabilities and optical properties for both compounds are also reported. PMID:26513233

  15. Sorption of selenite in a multi-component system using the “dialysis membrane” method

    International Nuclear Information System (INIS)

    79Se is a potentially mobile long-lived fission product, which may make a dominant contribution to the long-term radiation exposure resulting from deep geological disposal of radioactive waste. Its mobility is affected by sorption on minerals. Selenium sorption processes have been studied mainly by considering interaction with a single mineral surface. In the case of multi-component systems (e.g. soils), it is difficult to predict the radioelement behaviour only from the mineral constituents. This study contributes to the understanding of multi-component controls of Se concentrations towards predicting Se behaviour in soils after migration from a disposal site. This goal was approached by measuring selenite sorption on mono and multi-phase systems physically separated by dialysis membranes. To the best of the authors’ knowledge, very few studies have used dialysis membranes to study the sorption competition of selenite between several mineral phases. Other workers have used this method to study the sorption of pesticides on montmorillonite in the presence of dissolved organic matter. Indeed, this method allows measurement of individual Kd in a system composed of several mineral phases. Dialysis membranes allowed (i) determination of the competition of two mineral phases for selenite sorption (ii) and determination of the role of humic acids (HAs) on selenite sorption in oxidising conditions. Experimental results at pH 7.0 show an average Se(IV) sorption distribution coefficient (Kd) of approximately 125 and 9410 L kg−1 for bentonite and goethite, respectively. The average Kd for goethite decreases to 613 L kg−1 or 3215 L kg−1 in the presence of bentonite or HA, respectively. For bentonite, the average Kd decreases slightly in the presence of goethite (60 L kg−1) and remains unchanged in the presence of HA. The experimental data were successfully modelled with a surface complexation model using the PHREEQC geochemical code. The drastic decrease in Se

  16. Influence of selenite and selenate supplementation on the chromium uptake and translocation in Allium cepa

    International Nuclear Information System (INIS)

    Pot experiments were conducted on onion plant to study the effects of selenite and selenate treatments (0.5-6.0) μg ml-1 on the uptake and translocation of root absorbed chromium irrigated with 2 and 5 μg ml-1 of chromium in sand and soil. Both the form of selenium (SeO32-, and SeO42-) were found equally effective in reducing the chromium burden of the plant. No significant difference (p>0.05) in dry matter yields among various selenium treatments exist suggesting no salt injury occurred in the plants under prevailing conditions. (author). 10 refs., 1 tab

  17. Protective Roles of Sodium Selenite against Aflatoxin B1-Induced Apoptosis of Jejunum in Broilers

    OpenAIRE

    Xi Peng; Shengqiang Zhang; Jing Fang; Hengmin Cui; Zhicai Zuo; Junliang Deng

    2014-01-01

    The effects of aflatoxin B1 (AFB1) exposure and sodium selenite supplementation on cell apoptosis of jejunum in broilers were studied. A total of 240 one-day-old male AA broilers were randomly assigned four dietary treatments containing 0 mg/kg of AFB1 (control), 0.3 mg/kg AFB1 (AFB1), 0.4 mg/kg supplement Se (+ Se) and 0.3 mg/kg AFB1 + 0.4 mg/kg supplement Se (AFB1 + Se), respectively. Compared with the control broilers, the number of apoptotic cells, the expression of Bax and Caspase-3 mRN...

  18. Determination of selenite and selenate in human urine by ion chromatography and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Jons, O.

    2000-01-01

    The selenium species selenite, selenate and selenomethionine were separated in aqueous solution by ion chromatography. The separation was performed on an IonPac AG11 in series with an AS11 anion exchange column by elution with 25 mM sodium hydroxide in 2% methanol. The Se-78 and Se-82 isotopes were...... monitored in the inductively coupled plasma mass spectrometry (ICP-MS) detector. When the chromatographic system was applied to analysis of urine samples diluted 1 + 1, the selenomethionine signal appeared in the front together with other unresolved selenium species, while the selenite and selenate signals...

  19. Thermally-Induced Chemistry and the Jovian Icy Satellites: A Laboratory Study of the Formation of Sulfur Oxyanions

    Science.gov (United States)

    Loeffler, Mark J.; Hudson, Reggie L.

    2011-01-01

    Laboratory experiments have demonstrated that magnetospheric radiation in the Jovian system drives reaction chemistry in ices at temperatures relevant to Europa and other icy satellites. Here we present new results on thermally-induced reactions at 50-100 K in solid H2O-SO2 mixtures, reactions that take place without the need for a high-radiation environment. We find that H2O and SO2 react to produce sulfur Oxyanions, such as bisulfite, that as much as 30% of the SO2 can be consumed through this reaction, and that the products remain in the ice when the temperature is lowered, indicating that these reactions are irreversible. Our results suggest that thermally-induced reactions can alter the chemistry at temperatures relevant to the icy satellites in the Jovian system.

  20. Separation of Selenite from Inorganic Selenium Ions using TiO2 Magnetic Nanoparticles

    International Nuclear Information System (INIS)

    A simple and quick separation technique for selenite in natural water was developed using TiO2 SiO2/Fe3O4 nanoparticles. For the synthesis of nanoparticles, a polymer-assisted sol-gel method using hydroxypropyl cellulose (HPC) was developed to control particle dispersion in the synthetic procedure. In addition, titanium butoxide (TBT) precursor, instead of the typical titanium tetra isopropoxide, was used for the formation of the TiO2 shell. The synthesized nanoparticles were used to separate selenite (Se4+) in the presence of Se6+ or selenium anions for the photocatalytic reduction to Se0 atom on the TiO2 shell, followed by magnetic separation using Fe3O4 nanoparticles. The reduction efficiency of the photocatalytic reaction was 81.4% at a UV power of 6W for 3 h with a dark adsorption of 17.5% to the nanoparticles, as determined by inductively coupled plasma-mass spectrometry (ICP-MS). The developed separation method can be used for the speciation and preconcentration of selenium cations in environmental and biological analysis

  1. Loss of cytoskeletal proteins and lens cell opacification in the selenite cataract model.

    Science.gov (United States)

    Matsushima, H; David, L L; Hiraoka, T; Clark, J I

    1997-03-01

    This study of lens protein composition found that some cytoskeletal proteins were degraded during the earliest stages of cataract formation. Cataract was induced in 13-14 day old rats by a single subcutaneous injection of sodium selenite (19 mumol kg-1). By 24 hr after the injection of selenite, the ratio of insoluble to soluble protein increased as lens opacification began. The increase in insoluble protein aggregates was correlated with an accelerated loss of proteins having molecular weights of 42, 55/57 and 235 kDa which reacted with antibodies to the cytoskeletal proteins actin, tubulin/vimentin and spectrin, respectively. We observed the loss of 49, 60 and 90 kDa proteins which were not identified. In the lenses of animals protected from protein aggregation and opacification by administration of 1.5 mmol kg-1 pantethine, the pattern of proteins in SDS-PAGE gels resembled the pattern for proteins from transparent lenses of normal untreated animals and loss of cytoskeletal proteins was prevented. PMID:9196390

  2. Introduction aux études historiques

    OpenAIRE

    Langlois, Charles-Victor; Seignobos, Charles; Noiriel, Gérard

    2014-01-01

    L’Introduction aux études historiques constitue le texte de référence de ce qu’on a appelé « l’école méthodique historique » française. Ce manuel cherche à définir les règles de la méthode historique afin de contribuer à asseoir la scientificité d’une discipline, l’histoire, dans le contexte de sa professionnalisation universitaire. Le texte affirme le primat des archives comme preuves et sources du récit historique, et revient sur les différentes étapes du travail sur archives, de la localis...

  3. Relationship of membrane-bound sulfhydryl groups to vitamin D-stimulated uptake of [75Se]Selenite by the brush border membrane vesicles from chick duodenum

    International Nuclear Information System (INIS)

    The uptake of selenite by purified brush border membrane vesicles isolated from duodena of rachitic or vitamin D-treated chicks was studied by using radioactive selenite and a rapid filtration technique. Cholecalciferol treatment (500 IU at 72 h) significantly enhanced selenite uptake, a response that decreased when the vesicles were stored at room temperature for 2.5 h prior to the uptake measurement. Preincubation of the vesicles in 1.0 mmol/L H2O2 reduced [75Se]selenite uptake, indicating the involvement of oxidizable groups in the uptake reaction. Iodoacetic acid (IAA), a sulfhydryl-blocking reagent, at 1-2 mmol/L concentration eliminated the difference in selenite uptake due to cholecalciferol and had no effect on vesicles from rachitic animals. A higher concentration of IAA (10 mmol/L) enhanced selenite uptake manyfold and increased the absolute difference due to cholecalciferol treatment. Single intravenous doses of 100 IU cholecalciferol, 100 IU ergocalciferol, or 0.1 micrograms 1,25-dihydroxycholecalciferol also stimulated selenite uptake, suggesting a general response to vitamin D compounds. Normal animals given a single dose of 1,25-dihydroxycholecalciferol 12 h prior to killing also responded. Treatments that enhanced the uptake of [75Se]selenite also increased the amount of membrane-bound sulfhydryl groups, suggesting the involvement of membrane-bound sulfhydryl groups in the vitamin D response. A significant increase in selenite uptake by intravenous 1,25-dihydroxycholecalciferol occurred within 10 min. This rapid effect provides a new tool to probe early biochemical effects of vitamin D on intestinal epithelium

  4. Bi6(SeO3)3O5Br2: A new bismuth oxo-selenite bromide

    International Nuclear Information System (INIS)

    A new bismuth oxo-selenite bromide Bi6(SeO3)3O5Br2 was synthesized and structurally characterized. The crystal structure belongs to the triclinic system (space group P1-bar , Z=2, a=7.1253(7) Å, b=10.972(1) Å, c=12.117(1) Å, α=67.765(7)°, β=82.188(8)°, γ=78.445(7)°) and is unrelated to those of other known oxo-selenite halides. It can be considered as an open framework composed of BiOx or BiOyBrz polyhedrons forming channels running along [1 0 0] direction which contain the selenium atoms in pyramidal shape oxygen coordination (SeO3E). The spectroscopic properties and thermal stability were studied. The new compound is stable up to 400 °C. - graphical abstract: New bismuth oxo-selenite bromide with new open framework structure. Highlights: ► New bismuth oxo-selenite bromide was found and structurally characterized. ► Bi6(SeO3)3O5Br2 exhibit a new open framework structure type. ► BiOx or BiOyBrz polyhedrons form channels in the structure which are decorated by [SeO3E] groups.

  5. Selenium balance in the adult cat in relation to intake of dietary sodium selenite and organically bound selenium

    NARCIS (Netherlands)

    Todd, S.E.; Thomas, D.G.; Hendriks, W.H.

    2012-01-01

    The response of cats to dietary sodium selenite (Na2SeO3) and organically bound selenium was studied in two separate studies with four cats per treatment and three levels of selenium supplementation (targets 1.0, 1.5 and 2.0 µg/g DM) for each Se source. Whole blood and plasma selenium concentrations

  6. Foliar application of selenite and selenate to potato (Solanum tuberosum): effect of a ligand agent on selenium content of tubers.

    Science.gov (United States)

    Poggi, V; Arcioni, A; Filippini, P; Pifferi, P G

    2000-10-01

    The effect of a foliar spray of selenium on potatoes was investigated for 2 years. Amounts of 0, 50, and 150 g of Se ha(-)(1) were applied both as sodium selenate and as sodium selenite in water, either pure or with the addition of 0.15% of soluble leonardite as a source of humic acids (pH 7). Tuber selenium concentration increased with the application levels, both with sodium selenate and with sodium selenite, when only aqueous solutions were used. When humic acids were added, the tuber selenium level rose more markedly after the application of sodium selenate as compared to the case of the aqueous solutions; however, in the case of sodium selenite, the level showed a large increase only after the application of 50 g of Se ha(-)(1). Kinetics showed that humic acids raised the selenate availability, but no differences were found in the distribution of selenium in the tuber fractions. Foliar application of selenium with humic acids was proven to be a good way to increase the selenium content of potatoes, but the assimilation process of selenium was simpler with selenate than with selenite. PMID:11052729

  7. Effect of sulfide, selenite and mercuric mercury on the growth and methylation capacity of the sulfate reducing bacterium Desulfovibrio desulfuricans

    International Nuclear Information System (INIS)

    Cultures of the sulfate reducing bacteria Desulfovibrio desulfuricans were grown under anoxic conditions to study the effect of added sulfide, selenite and mercuric ions. A chemical trap consisting in a CuSO4 solution was used to control the poisoning effect induced by the bacterial production of hydrogen sulfide via the precipitation of CuS. Following the addition of Hg2+, the formation of methylmercury (MeHg) was correlated to bacterial proliferation with most of MeHg found in the culture medium. A large fraction (50–80%) of added Hg2+ to a culture ended up in a solid phase (Hg0 and likely HgS) limiting its bioavailability to cells with elemental Hg representing ∼ 40% of the solid. Following the addition of selenite, a small fraction was converted into Se(0) inside the cells and, even though the conversion to this selenium species increased with the increase of added selenite, it never reached more than 49% of the added amount. The formation of volatile dimethylselenide is suggested as another detoxification mechanism. In cultures containing both added selenite and mercuric ions, elemental forms of the two compounds were still produced and the increase of selenium in the residual fraction of the culture suggests the formation of mercuric selenite limiting the bioavailability of both elements to cells. - Highlights: ► Detoxification mechanisms of D. desulfuricans were studied in presence of added sulfide, selenite and mercuric ions. ► The poisoning effect of H2S added to or generated by cultures of D. desulfuricans can be controlled with a chemical trap. ► The addition of selenite to cultures triggered the formation of elemental Se and other forms of volatile and non-volatile Se. ► The addition of mercuric ions to cultures led to the production of methylmercury, volatile Hg and solid mercuric sulfide. ► With both Se and Hg added to cultures, fractionation of species in solid and liquid phases suggests the formation of HgSe

  8. Pharmacokinetics and Toxicity of Sodium Selenite in the Treatment of Patients with Carcinoma in a Phase I Clinical Trial: The SECAR Study

    DEFF Research Database (Denmark)

    Brodin, Ola; Eksborg, Staffan; Wallenberg, Marita;

    2015-01-01

    trial. Patients received first line of chemotherapy following selenite treatment to investigate altered sensitivity to these drugs and preliminary assessment of any clinical benefits. Materials and Methods: Thirty-four patients with different therapy resistant tumors received iv sodium selenite daily...... nonlinear pattern. The most common adverse events were fatigue, nausea, and cramps in fingers and legs. DLTs were acute, of short duration and reversible. Biomarkers for organ functions indicated no major systemic toxicity. In conclusion, sodium selenite is safe and tolerable when administered up to 10.2 mg...

  9. Extracellular thiol-assisted selenium uptake dependent on the x(c)(-) cystine transporter explains the cancer-specific cytotoxicity of selenite

    DEFF Research Database (Denmark)

    Olm, E.; Fernandes, A. P.; Hebert, C.;

    2009-01-01

    The selenium salt selenite (SeO32-) is cytotoxic in low to moderate concentrations, with a remarkable specificity for cancer cells resistant to conventional chemotherapy. Our data show that selenium uptake and accumulation, rather than intracellular events, are crucial to the specific selenite...... cytotoxicity observed in resistant cancer cells. We show that selenium uptake depends on extracellular reduction, and that the extracellular environment is a key factor specific to selenite cytotoxicity. The extracellular reduction is mediated by cysteine, and the efficacy is determined by the uptake...

  10. Explorations of new selenites of the group IIIA and IVA metals

    International Nuclear Information System (INIS)

    Systematic explorations of new phases in the GaIII/InIII/GeIV–SeIV–O systems by hydrothermal syntheses or solid-state reactions at high-temperature led to six new ternary compounds, namely, M2Se2O7 (M=Ga 1, In 2), M(OH)(SeO3) (M=Ga 3, In 4), α-Ge(SeO3)25 and β-Ge(SeO3)26. Ga2Se2O71 displays a 3D open framework composed of 2D gallium oxide layers being further bridged and capped by SeO3 groups. In2Se2O72 features a 3D indium oxide framework formed by corner- and edge- sharing InO6 octahedra with SeO3 groups attached on the cavities and the 8-member ring tunnels of the structure. The isostructural of M(OH)(SeO3) (M=Ga 3, In 4) exhibit a 2D metal selenite layer composed of 1D edge-sharing MO6 octahedral chains that are interconnected by SeO3 groups. α-Ge(SeO3)2 (P21/n) 5 displays a 3D open framework with 1D 8-member ring tunnels along the a-axis while β-Ge(SeO3)2 (Pa-3) 6 exhibits a condensed 3D network. - Graphical abstract: Highlights: ► Up to now, selenites of the group IIIA and IVA metals are still rare. ► Hydrothermal or solid state reactions yielded six new compounds in this system. ► They are M2Se2O7 (M=Ga, In), M(OH)(SeO3) (M=Ga, In), α-Ge(SeO3)2 and β-Ge(SeO3)2. ► They exhibit four different 3D and one 2D structural types. ► α-Ge(SeO3)2 and β-Ge(SeO3)2 represent the first examples of germanium selenites.

  11. The oxyanion hole of Pseudomonas fluorescens mannitol 2-dehydrogenase: a novel structural motif for electrostatic stabilisation in alcohol dehydrogenase active sites

    OpenAIRE

    Klimacek, Mario; Nidetzky, B

    2009-01-01

    Abstract The side chains of Asn-191 and Asn-300 constitute a characteristic structural motif of the active site of Pseudomonas fluorescens mannitol 2-dehydrogenase that lacks precedent in known alcohol dehydrogenases and resembles the canonical oxyanion binding pocket of serine proteases. We have used steady-state and transient kinetic studies of the effects of varied pH and deuterium isotopic substitutions in substrates and solvent on the enzymatic rates to delineate catalytic con...

  12. Influence of dietary sodium selenite on tissue selenium levels of growing pigs

    International Nuclear Information System (INIS)

    Twenty Norwegian Landrace pigs were divided into 5 groups and fed a basal diet consisting of a mixture of dried skim milk and whey powder together with ground barley. The diet was supplemented with 0, 0.2, 0.8, 1.2, and 2.2 μg/g selenium as sodium selenite and was fed for 12 weeks. The muscle selenium level was increased by a factor of about 4 and the liver selenium by a factor of about 12 when the dietary selenium supplement was increased from zero to 2.2μg/g. There was a significant linear correlation between dietary selenium and selenium concentrations in tissues. Possible benefit for humans consuming meat from animals having received the selenium doses used in this experiment are discussed. (author)

  13. New indium selenite-oxalate and indium oxalate with two- and three-dimensional structures

    International Nuclear Information System (INIS)

    Two new indium(III) compounds with extended structures, [In2(SeO3)2(C2O4)(H2O)2].2H2O (I) and [NH3(CH2)2NH3][In(C2O4)2]2.5H2O (II), have been prepared under mild hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. Compound I crystallizes in the triclinic system, space group P-1, with a=5.2596(11) A, b=6.8649(14) A, c=9.3289(19) A, α=101.78(3)o, β=102.03(3)o, γ=104.52(3)o, while compound II crystallizes in the orthorhombic system, space group Fdd2, with a=15.856(3) A, b=31.183(6) A, c=8.6688(17) A. In compound I, indium-selenite chains are bridged by oxalate units to form two-dimensional (2D) In2(SeO3)2C2O4 layers, separated by non-coordinating water molecules. In compound II, the indium atoms are connected through the oxalate units to generate a 3D open framework containing cross-linked 12- and 8-membered channels. - Graphical abstract: Two new indium(III) compounds have been hydrothermally synthesized and structurally characterized. In I, the indium-selenite chains are bridged by oxalate units to form 2D In2(SeO3)2C2O4 layers. In II, the indium atoms are connected through the oxalate units to generate a 3D open framework containing cross-linked 12- and 8-membered ring channels

  14. Protective Roles of Sodium Selenite against Aflatoxin B1-Induced Apoptosis of Jejunum in Broilers

    Directory of Open Access Journals (Sweden)

    Xi Peng

    2014-12-01

    Full Text Available The effects of aflatoxin B1 (AFB1 exposure and sodium selenite supplementation on cell apoptosis of jejunum in broilers were studied. A total of 240 one-day-old male AA broilers were randomly assigned four dietary treatments containing 0 mg/kg of AFB1 (control, 0.3 mg/kg AFB1 (AFB1, 0.4 mg/kg supplement Se (+ Se and 0.3 mg/kg AFB1 + 0.4 mg/kg supplement Se (AFB1 + Se, respectively. Compared with the control broilers, the number of apoptotic cells, the expression of Bax and Caspase-3 mRNA were significantly increased, while the expression of Bcl-2 mRNA and the Bcl-2/Bax ratio were significantly decreased in AFB1 broilers. The number of apoptotic cells and the expression of Caspase-3 mRNA in AFB1 + Se broilers were significantly higher than those in the control broilers, but significantly lower than those in AFB1 broilers. There were no significant changes in the expression of Bax mRNA between AFB1 + Se and control broilers; the expression of Bcl-2 mRNA and the Bcl-2/Bax ratio in AFB1 + Se broilers were significantly lower than those in the control broilers, but significantly higher than those in AFB1 broilers. In conclusion, 0.3 mg/kg AFB1 in the diet can increase cell apoptosis, decrease Bcl-2 mRNA expression, and increase of Bax and Caspase-3 mRNA expression in broiler’s jejunum. However, supplementation of dietary sodium selenite at the concentration of 0.4 mg/kg Se may ameliorate AFB1-induced apoptosis by increasing Bcl-2 mRNA expression, and decreasing Bax and Caspase-3 mRNA expression.

  15. Pharmacokinetics and Toxicity of Sodium Selenite in the Treatment of Patients with Carcinoma in a Phase I Clinical Trial: The SECAR Study

    Directory of Open Access Journals (Sweden)

    Ola Brodin

    2015-06-01

    Full Text Available Background: Sodium selenite at high dose exerts antitumor effects and increases efficacy of cytostatic drugs in multiple preclinical malignancy models. We assessed the safety and efficacy of intravenous administered sodium selenite in cancer patients’ refractory to cytostatic drugs in a phase I trial. Patients received first line of chemotherapy following selenite treatment to investigate altered sensitivity to these drugs and preliminary assessment of any clinical benefits. Materials and Methods: Thirty-four patients with different therapy resistant tumors received iv sodium selenite daily for consecutive five days either for two weeks or four weeks. Each cohort consisted of at least three patients who received the same daily dose of selenite throughout the whole treatment. If 0/3 patients had dose-limiting toxicities (DLTs, the study proceeded to the next dose-level. If 2/3 had DLT, the dose was considered too high and if 1/3 had DLT, three more patients were included. Dose-escalation continued until the maximum tolerated dose (MTD was reached. MTD was defined as the highest dose-level on which 0/3 or 1/6 patients experienced DLT. The primary endpoint was safety, dose-limiting toxic effects and the MTD of sodium selenite. The secondary endpoint was primary response evaluation. Results and Conclusion: MTD was defined as 10.2 mg/m2, with a calculated median plasma half-life of 18.25 h. The maximum plasma concentration of selenium from a single dose of selenite increased in a nonlinear pattern. The most common adverse events were fatigue, nausea, and cramps in fingers and legs. DLTs were acute, of short duration and reversible. Biomarkers for organ functions indicated no major systemic toxicity. In conclusion, sodium selenite is safe and tolerable when administered up to 10.2 mg/m2 under current protocol. Further development of the study is underway to determine if prolonged infusions might be a more effective treatment strategy.

  16. Sorption kinetic study of selenite and selenate onto a high and low pressure aged iron oxide nanomaterial

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Christina M.; Hernandez, Jeffrey; Peralta-Videa, Jose R. [Department of Chemistry, The University of Texas at El Paso, 500 W University Ave., El Paso, TX 79968 (United States); Botez, Cristian E. [Department of Physics, The University of Texas at El Paso, 500 W University Ave., El Paso, TX 79968 (United States); Parsons, Jason G. [Department of Chemistry, The University of Texas-Pan American 1201 W University Drive, Edinburg, TX 78534 (United States); Gardea-Torresdey, Jorge L., E-mail: jgardea@utep.edu [Department of Chemistry, The University of Texas at El Paso, 500 W University Ave., El Paso, TX 79968 (United States); Environmental Science and Engineering PhD program, The University of Texas at El Paso, 500 W University Ave., El Paso, TX 79968 (United States)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Fe{sub 3}O{sub 4} nanomaterials can be used to remove selenium from contaminated waters. Black-Right-Pointing-Pointer Synthetic techniques used in this study require less steps and faster procedures than in previous techniques. Black-Right-Pointing-Pointer Fe{sub 3}O{sub 4} nanomaterials require less time and remove more selenium than previous materials tested. Black-Right-Pointing-Pointer Fe{sub 3}O{sub 4} nanomaterials would experience limitations for selenium binding in the presence of some competitive anions. - Abstract: The sorption of selenite (SeO{sub 3}{sup 2-}) and selenate (SeO{sub 4}{sup 2-}) onto Fe{sub 3}O{sub 4} nanomaterials produced by non microwave-assisted or microwave-assisted synthetic techniques was investigated through use of the batch technique. The phase of both synthetic nanomaterials was determined to be magnetite by X-ray diffraction. The average grain sizes of non microwave-assisted and microwave-assisted synthetic Fe{sub 3}O{sub 4} were determined to be 27 and 25 nm, respectively through use of the Scherrer's equation. Sorption of selenite was pH independent in the pH range of 2-6, while sorption of selenate decreased at pH 5 and 6. The addition of Cl{sup -} had no significant effect on selenite or selenate binding, while the addition of NO{sub 3}{sup -} only affected selenate binding to the microwave assisted Fe{sub 3}O{sub 4}. A decrease of selenate binding to both synthetic particles was observed after the addition of SO{sub 4}{sup 2-} while selenite binding was not affected. The addition of PO{sub 4}{sup 3-} beginning at concentrations of 0.1 ppm had the most prominent effect on the binding of both selenite and selenate. The capacities of binding, determined through the use of Langmuir isotherm, were found to be 1923 and 1428 mg Se/kg of non microwave-assisted Fe{sub 3}O{sub 4} and 2380 and 2369 mg Se/kg of microwave-assisted Fe{sub 3}O{sub 4} for selenite and selenate, respectively.

  17. Formation of tellurium nanocrystals during anaerobic growth of bacteria that use Te oxyanions as respiratory electron acceptors

    Science.gov (United States)

    Baesman, S.M.; Bullen, T.D.; Dewald, J.; Zhang, Dongxiao; Curran, S.; Islam, F.S.; Beveridge, T.J.; Oremland, R.S.

    2007-01-01

    Certain toxic elements support the metabolism of diverse prokaryotes by serving as respiratory electron acceptors for growth. Here, we demonstrate that two anaerobes previously shown to be capable of respiring oxyanions of selenium also achieve growth by reduction of either tellurate [Te(VI)] or tellurite [Te(IV)] to elemental tellurium [Te(0)]. This reduction achieves a sizeable stable-Te-isotopic fractionation (isotopic enrichment factor [??] = -0.4 to -1.0 per ml per atomic mass unit) and results in the formation of unique crystalline Te(0) nanoarchitectures as end products. The Te(0) crystals occur internally within but mainly externally from the cells, and each microorganism forms a distinctly different structure. Those formed by Bacillus selenitireducens initially are nanorods (???10-nm diameter by 200-nm length), which cluster together, forming larger (???1,000-nm) rosettes composed of numerous individual shards (???100-nm width by 1,000-nm length). In contrast, Sulfurospirillium barnesii forms extremely small, irregularly shaped nanospheres (diameter electron diffraction indicate that both biominerals are composed entirely of Te and are crystalline, while Raman spectroscopy confirms that they are in the elemental state. These Te biominerals have specific spectral signatures (UV-visible light, Raman) that also provide clues to their internal structures. The use of microorganisms to generate Te nanomaterials may be an alternative for bench-scale syntheses. Additionally, they may also generate products with unique properties unattainable by conventional physical/chemical methods. Copyright ?? 2007, American Society for Microbiology. All Rights Reserved.

  18. Unusual carboxylesterase bearing a GGG(A)X-type oxyanion hole discovered in Paenibacillus barcinonensis BP-23.

    Science.gov (United States)

    Infanzón, Belén; Valenzuela, Susana V; Fillat, Amanda; Pastor, F I Javier; Diaz, Pilar

    2014-09-01

    Strain Paenibacillus barcinonensis BP-23, previously isolated from Ebro's river delta (Spain), bears a complex hydrolytic system showing the presence of at least two enzymes with activity on lipidic substrates. EstA, a cell-bound B-type carboxylesterase from the strain was previously isolated and characterized. The gene coding for a second putative lipase, located upstream cellulase Cel5A, was obtained using a genome walking strategy and cloned in Escherichia coli for further characterization. The recombinant clone obtained displayed high activity on medium/short-chain fatty acid-derivative substrates. The enzyme, named Est23, was purified and characterized, showing maximum activity on pNP-caprylate (C8:0) or MUF-heptanoate (C7:0) under conditions of moderate temperature and pH. Although Est23 displays a GGG(A)X-type oxyanion hole, described as an important motif for tertiary alcohol ester resolution, neither conversion nor enantiomeric resolution of tertiary alcohols could be detected. Amino acid sequence alignment of Est23 with those of known bacterial lipase families and with closely related proteins suggests that the cloned enzyme does not belong to any of the described bacterial lipase families. A phylogenetic tree including Est23 and similar amino acid sequences showed that the enzyme belongs to a differentiated sequence cluster which probably constitutes a new family of bacterial lipolytic enzymes. PMID:24929101

  19. Uptake of /sup 75/Se-selenite by brush border membrane vesicles from chick duodenum stimulated by vitamin D

    Energy Technology Data Exchange (ETDEWEB)

    Mykkanen, H.M.; Wasserman, R.H.

    1989-02-01

    Brush border membrane vesicles were isolated from mucosal homogenates of duodena from normal, rachitic and vitamin D-treated rachitic chicks using a discontinuous sucrose gradient, and further purified by glycerol gradient centrifugation. In vitro uptake of 75Se-selenite by purified brush border membrane vesicles was studied using a rapid filtration technique. The time course of 75Se uptake was non-linear; rapid initial binding was followed by a gradual decrease in the rate of uptake until an equilibrium value was reached at 60-120 min. The initial binding at 36 s was not affected by selenite concentration in the incubation buffer, while the fractional rate of uptake between the 36 s and 2 min time periods was clearly lower with 1 mM Se than with 4-100 microM Se. 75Se uptake did not show any dependency on the external Na-gradient, nor could it be inhibited by other anions (arsenate, phosphate). Treatment of rachitic chicks either with cholecalciferol (500 Iu, 72 h) or with 1,25(OH)2-cholecalciferol (0.5 microgram given 16 h prior to isolation of the vesicles) significantly enhanced 75Se uptake. A threefold excess of mannitol in the outside buffer reduced 75Se uptake by vesicles from vitamin D-deficient and D-treated chicks 60% and 35% respectively, but had no effect on vesicles from vitamin D-treated chicks preloaded with 75Se. Neither saponin treatment nor excess cold selenite could release the label from the vesicles preloaded with 75Se. These data are compatible with the hypothesis that selenite easily crosses the brush border membrane into the intravesicular space and, once inside, is tightly bound by the membrane.

  20. Tellurite-, tellurate-, and selenite-based anaerobic respiration by strain CM-3 isolated from gold mine tailings.

    Science.gov (United States)

    Maltman, Chris; Piercey-Normore, Michele D; Yurkov, Vladimir

    2015-09-01

    The newly discovered strain CM-3, a Gram-negative, rod-shaped bacterium from gold mine tailings of the Central Mine in Nopiming Provincial Park, Canada, is capable of dissimilatory anaerobic reduction of tellurite, tellurate, and selenite. CM-3 possesses very high level resistance to these oxides, both aerobically and anaerobically. During aerobic growth, tellurite and tellurate resistance was up to 1500 and 1000 µg/ml, respectively. In the presence of selenite, growth occurred at the highest concentration tested, 7000 µg/ml. Under anaerobic conditions, resistance was decreased to 800 µg/ml for the Te oxides; however, much like under aerobic conditions, growth with selenite still took place at 7000 µg/ml. In the absence of oxygen, CM-3 couples oxide reduction to an increase in biomass. Following an initial drop in viable cells, due to switching from aerobic to anaerobic conditions, there was an increase in CFU/ml greater than one order of magnitude in the presence of tellurite (6.6 × 10(3)-8.6 × 10(4) CFU/ml), tellurate (4.6 × 10(3)-1.4 × 10(5) CFU/ml), and selenite (2.7 × 10(5)-5.6 × 10(6) CFU/ml). A control culture without metalloid oxides showed a steady decrease in CFU/ml with no recovery. ATP production was also increased in the presence of each oxide, further indicating anaerobic respiration. Partial 16S rRNA gene sequencing revealed a 99.0 % similarity of CM-3 to Pseudomonas reactans. PMID:26254805

  1. Uptake of 75Se-selenite by brush border membrane vesicles from chick duodenum stimulated by vitamin D

    International Nuclear Information System (INIS)

    Brush border membrane vesicles were isolated from mucosal homogenates of duodena from normal, rachitic and vitamin D-treated rachitic chicks using a discontinuous sucrose gradient, and further purified by glycerol gradient centrifugation. In vitro uptake of 75Se-selenite by purified brush border membrane vesicles was studied using a rapid filtration technique. The time course of 75Se uptake was non-linear; rapid initial binding was followed by a gradual decrease in the rate of uptake until an equilibrium value was reached at 60-120 min. The initial binding at 36 s was not affected by selenite concentration in the incubation buffer, while the fractional rate of uptake between the 36 s and 2 min time periods was clearly lower with 1 mM Se than with 4-100 microM Se. 75Se uptake did not show any dependency on the external Na-gradient, nor could it be inhibited by other anions (arsenate, phosphate). Treatment of rachitic chicks either with cholecalciferol (500 Iu, 72 h) or with 1,25(OH)2-cholecalciferol (0.5 microgram given 16 h prior to isolation of the vesicles) significantly enhanced 75Se uptake. A threefold excess of mannitol in the outside buffer reduced 75Se uptake by vesicles from vitamin D-deficient and D-treated chicks 60% and 35% respectively, but had no effect on vesicles from vitamin D-treated chicks preloaded with 75Se. Neither saponin treatment nor excess cold selenite could release the label from the vesicles preloaded with 75Se. These data are compatible with the hypothesis that selenite easily crosses the brush border membrane into the intravesicular space and, once inside, is tightly bound by the membrane

  2. Effect Of Heparin Sodium In Protection Of The Lens Against Cataract Induced With Intravitreal Injection Of Sodium Selenite- In Rabbits

    OpenAIRE

    Bahaa A. Abdul-Hussein

    2015-01-01

    Abstract Objective To evaluate the possible protective role of heparin sodium eye drops against sodium selenite induced cataract in rabbits.Materials and Methods A group of 18 adult rabbits Oryctologus cuniculus were divided into 3 groups each one of 6 rabbits normal group without treatment and induction control group received DW pre and post induction of cataract and heparin sodium group received heparin sodium eye drops pre and post induction of cataract. The cataract had been induced by i...

  3. Detoxification of selenite and mercury by reduction and mutual protection in the assimilation of both elements by Pseudomonas fluorescens

    International Nuclear Information System (INIS)

    A study on the assimilation and detoxification of selenium and mercury and on the interaction between these two elements was conducted on Pseudomonas fluorescens. P. fluorescens was able to convert separately both elements to their elemental forms, which are less toxic and biologically less available. To study the converting mechanism of selenite to elemental Se, cells were grown in the presence of various selenite concentrations and several parameters such as extracellular protein concentrations, pH, carbohydrate concentrations, isocitrate dehydrogenase (ICDH) and malic enzyme were monitored. Transmission electron microscopy (TEM) and various analytical methods were applied to confirm the interaction between selenium and cell. The former appeared as a red precipitate localized predominantly in the consumed culture medium. P. fluorescens also resisted to the toxic effect of mercury by converting Hg2+ to the volatile and less toxic form Hg . Mercury reductase was likely responsible for the conversion of Hg2+ to Hg . More importantly, the interaction between mercury and selenium was also studied. The presence of selenite significantly reduced the accumulation of mercury in P. fluorescens. It was also interesting to note that mercury appeared to behave as a protecting agent against selenium intoxication as the bioaccumulation of Se was also inhibited by this metal. The formation of Se-Hg complexes could explain this mutual protective effect. No precipitate of elemental Se could be detected when Hg was present in the cultures

  4. Simultaneous tracing of 76Se-selenite and 77Se-selenomethionine by absolute labeling and speciation

    International Nuclear Information System (INIS)

    Nutritional selenocompounds are transformed into the assumed common intermediate selenide, which is utilized for the synthesis of selenoenzymes or transformed into methylated metabolites for excretion. Hence, selenocompound metabolites can be traced only with labeled selenium. Here we applied a new tracer method for the metallomics of biometals using simultaneous speciation of each metallome labeled with different homo-elemental isotopes to metabolism and availability of selenium. Rats were depleted of endogenous natural abundance selenium by feeding a single selenium stable isotope (82Se-selenite) and then administered 76Se-selenite and 77Se-selenomethionine (77Se-SeMet)simultaneously. Biological samples were subjected to quantification and speciation analysis by HPLC-ICPMS. Metabolites of the labeled 76Se and 77Se and interaction with endogenous selenium were traced and examined without interference from the corresponding endogenous natural abundance isotopes. Differences in the distribution and metabolism among organs and between the two nutritional selenocompounds were compared under exactly identical biological and analytical conditions: (1) selenite was distributed more efficiently than SeMet in organs and body fluids except the pancreas. (2) SeMet was taken up by organs in its intact form. (3) Selenium of SeMet origin was distributed selectively in the pancreas and mostly bound to a protein together with intact SeMet. (4) Selenosugars A and B but not trimethylselenonium (TMSe) were detected in the liver. (5) Selenosugar B and TMSe were detected in the kidneys

  5. Sorption mechanisms of selenium species (selenite and selenate) on copper-based minerals; Mecanismes de sorption des especes du selenium (selenite et seleniate) sur des mineraux a base de cuivre

    Energy Technology Data Exchange (ETDEWEB)

    Devoy, J

    2001-09-01

    The sorption of radionuclides on the surface of minerals represents a process capable to delay the migration of the elements from a spent fuel deep repository towards the biosphere. In the framework of a deep underground repository, an engineered clay barrier has a high trapping capacity for cationic radio-elements, in particular because of the negative charge of clay surfaces. However, anionic radioelements like selenium species, would be only weakly retained by chemical processes. In order to optimize the trapping capacity of a clay barrier with respect to anionic species, prospective studies are carried out in order to find and evaluate some minerals with specific chemical trapping functions. Among radionuclides, the case of selenium has to be considered because its isotope {sup 79}Se is present in radioactive wastes and has a half life time of 6.5 10{sup 4} years. It is also judicious to find a mineral capable of trapping simultaneously several anionic radio-elements. Copper oxides and sulfides (Cu{sub 2}O, CuO, Cu{sub 2}S, CuS, CuFeS{sub 2} and Cu{sub 5}FeS{sub 4}) are good adsorbents with respect to selenium species (selenite and selenate). These minerals, with their selenium retention properties, could be used also for the decontamination of soils and waters or to process industrial effluents. The sorption mechanisms have been studied in details for copper oxides (Cu{sub 2}O and CuO) with respect to selenite and selenate. Chalcomenite precipitates in acid pH conditions when selenite is added to a Cu{sub 2}O and CuO suspension. Selenate, in contact with cuprite (Cu{sub 2}O) leads also to a selenium-based precipitate in acid pH environment. For higher pH values, selenite and selenate are adsorbed on copper oxides (Cu{sub 2}O and CuO) and lead to internal and external sphere complexes, respectively. In the case of a selenite/cuprite mixture in basic pH environment and at the equilibrium, a chemical reaction occurs between the oxidation product of cuprite, Cu

  6. Structural Insights into an Oxalate-producing Serine Hydrolase with an Unusual Oxyanion Hole and Additional Lyase Activity.

    Science.gov (United States)

    Oh, Juntaek; Hwang, Ingyu; Rhee, Sangkee

    2016-07-15

    In Burkholderia species, the production of oxalate, an acidic molecule, is a key event for bacterial growth in the stationary phase. Oxalate plays a central role in maintaining environmental pH, which counteracts inevitable population-collapsing alkaline toxicity in amino acid-based culture medium. In the phytopathogen Burkholderia glumae, two enzymes are responsible for oxalate production. First, the enzyme oxalate biosynthetic component A (ObcA) catalyzes the formation of a tetrahedral C6-CoA adduct from the substrates acetyl-CoA and oxaloacetate. Then the ObcB enzyme liberates three products from the C6-CoA adduct: oxalate, acetoacetate, and CoA. Interestingly, these two stepwise reactions are catalyzed by a single bifunctional enzyme, Obc1, from Burkholderia thailandensis and Burkholderia pseudomallei Obc1 has an ObcA-like N-terminal domain and shows ObcB activity in its C-terminal domain despite no sequence homology with ObcB. We report the crystal structure of Obc1 in its apo and glycerol-bound form at 2.5 Å and 2.8 Å resolution, respectively. The Obc1 N-terminal domain is essentially identical both in structure and function to that of ObcA. Its C-terminal domain has an α/β hydrolase fold that has a catalytic triad for oxalate production and a novel oxyanion hole distinct from the canonical HGGG motif in other α/β hydrolases. Functional analyses through mutagenesis studies suggested that His-934 is an additional catalytic acid/base for its lyase activity and liberates two additional products, acetoacetate and CoA. These results provide structural and functional insights into bacterial oxalogenesis and an example of divergent evolution of the α/β hydrolase fold, which has both hydrolase and lyase activity. PMID:27226606

  7. Formation of tellurium nanocrystals during anaerobic growth of bacteria that use Te oxyanions as respiratory electron acceptors.

    Science.gov (United States)

    Baesman, Shaun M; Bullen, Thomas D; Dewald, James; Zhang, Donghui; Curran, Seamus; Islam, Farhana S; Beveridge, Terry J; Oremland, Ronald S

    2007-04-01

    Certain toxic elements support the metabolism of diverse prokaryotes by serving as respiratory electron acceptors for growth. Here, we demonstrate that two anaerobes previously shown to be capable of respiring oxyanions of selenium also achieve growth by reduction of either tellurate [Te(VI)] or tellurite [Te(IV)] to elemental tellurium [Te(0)]. This reduction achieves a sizeable stable-Te-isotopic fractionation (isotopic enrichment factor [epsilon] = -0.4 to -1.0 per ml per atomic mass unit) and results in the formation of unique crystalline Te(0) nanoarchitectures as end products. The Te(0) crystals occur internally within but mainly externally from the cells, and each microorganism forms a distinctly different structure. Those formed by Bacillus selenitireducens initially are nanorods ( approximately 10-nm diameter by 200-nm length), which cluster together, forming larger ( approximately 1,000-nm) rosettes composed of numerous individual shards ( approximately 100-nm width by 1,000-nm length). In contrast, Sulfurospirillum barnesii forms extremely small, irregularly shaped nanospheres (diameter < 50 nm) that coalesce into larger composite aggregates. Energy-dispersive X-ray spectroscopy and selected area electron diffraction indicate that both biominerals are composed entirely of Te and are crystalline, while Raman spectroscopy confirms that they are in the elemental state. These Te biominerals have specific spectral signatures (UV-visible light, Raman) that also provide clues to their internal structures. The use of microorganisms to generate Te nanomaterials may be an alternative for bench-scale syntheses. Additionally, they may also generate products with unique properties unattainable by conventional physical/chemical methods. PMID:17277198

  8. Comparative effects of selenite and selenate on nitrate assimilation in barley seedlings

    Science.gov (United States)

    Aslam, M.; Harbit, K. B.; Huffaker, R. C.

    1990-01-01

    The effect of SeO3= and SeO4= on NO3- assimilation in 8-d-old barley (Hordeum vulgare L.) seedlings was studied over a 24-h period. Selenite at 0.1 mol m-3 in the uptake solutions severely inhibited the induction of NO3- uptake and active nitrate reductases. Selenate, at 1.0 mol m-3 in the nutrient solution, had little effect on induction of activities of these systems until after 12 h; however, when the seedlings were pretreated with 1.0 mol m-3 SeO4= for 24 h, subsequent NO3- uptake from SeO4(=) -free solutions was inhibited about 60%. Sulphate partially alleviated the inhibitory effect of SeO3= when supplied together in the ambient solutions, but had no effect in seedlings pretreated with SeO3=. By contrast, SO4= partially alleviated the inhibitory effect of SeO4= even in seedlings pretreated with SeO4=. Since uptake of NO3- by intact seedlings was also inhibited by SO3=, the percentage of the absorbed NO3- that was reduced was not affected. By contrast, SeO4=, which affected NO3- uptake much less, inhibited the percentage reduced of that absorbed. However, when supplied to detached leaves, both SeO3= and SeO4= inhibited the in vivo reduction of NO3- as well as induction of nitrate reductase and nitrite reductase activities. Selenite was more inhibitory than SeO4= ; approximately a five to 10 times higher concentration of SeO4= than SeO3= was required to achieve similar inhibition. In detached leaves, the inhibitory effect of both SeO3= and SeO4= on in vivo NO3- reduction as well as on the induction of nitrate reductase activity was partially alleviated by SO4=. The inhibitory effects of Se salts on the induction of the nitrite reductase were, however, completely alleviated by SO4=. The results show that in barley seedlings SeO3= is more toxic than SeO4=. The reduction of SeO4= to SeO3= may be a rate limiting step in causing Se toxicity.

  9. Interaction of selenite with reduced Fe and/or S species: An XRD and XAS study

    Science.gov (United States)

    Finck, Nicolas; Dardenne, Kathy

    2016-05-01

    In this study, we investigated the interaction between selenite and either Fe(II)aq or S(- II)aq in solution, and the results were used to investigate the interaction between Se(IV)aq and FeS in suspension. The reaction products were characterized by a combination of methods (SEM, XRD and XAS) and the reaction mechanisms were identified. In a first experiment, Se(IV)aq was reduced to Se(0) by interaction with Fe(II)aq which was oxidized to Fe(III), but the reaction was only partial. Subsequently, some Fe(III) produced akaganeite (β-FeOOH) and the release of proton during that reaction decreased the pH. The pH decrease changed the Se speciation in solution which hindered further Se(IV) reduction by Fe(II)aq. In a second experiment, Se(IV)aq was quantitatively reduced to Se(0) by S(- II)aq and the reaction was fast. Two sulfide species were needed to reduce one Se(IV), and the observed pH increase was due to a proton consumption. For both experiments, experimental results are consistent with expectations based on the oxidation reduction potential of the various species. Upon interaction with FeS, Se(IV)aq was reduced to Se(0) and minute amounts of pyrite were detected, a consequence of partial mackinawite oxidation at surface sulfur sites. These results are of prime importance with respect to safe deep disposal of nuclear waste which contains the long-lived radionuclide 79Se. This study shows that after release of 79Se(IV) upon nuclear waste matrix corrosion, selenite can be reduced in the near field to low soluble Se(0) by interaction with Fe(II)aq and/or S(- II)aq species. Because the solubility of Se(0) species is significantly lower than that of Se(IV), selenium will become much less (bio)available and its migration out of deep HLW repositories may be drastically hindered.

  10. Selenite -Se(4)- uptake mechanisms in the unicellular green alga Chlamydomonas reinhardtii: bioaccumulation and effects induced on growth and ultrastructure

    International Nuclear Information System (INIS)

    Selenium is an essential element, but becomes very toxic at higher concentrations. It occurs in the environment at concentrations ranging from nM to μM and selenium pollution is a worldwide phenomenon. This works aims at improving the knowledge on the interactions between selenite - Se(IV) - and a freshwater phyto-planktonic organism: the unicellular green algae Chlamydomonas reinhardtii. The aim of the performed experiments were: i) to investigate selenite -Se(IV)- uptake mechanisms in C. reinhardtii, using Se75 as a tracer in short term exposures (-2.nM-1.h-1. The uptake was proportional to ambient levels in a broad range of intermediate concentrations (from nM to μM). However, fluxes were higher at very low concentrations ( μM), suggesting that a high affinity but rapidly saturated transport mechanism could be used at low concentrations, in parallel with a low affinity mechanism that would only saturate at high concentrations (∼mM). The latter could involve transporters used by sulphate and nitrates, as suggested by the inhibition of selenite uptake by those element. Se(IV) speciation changes with pH did not induce significant effect on bioavailability. On the basis of the relationship between Se concentration and maximal cell density achieved, an EC50 of 80 μM ([64; 98]) was derived. No adaptation mechanism were observed as the same the same toxicity was quantified for Se-pre-exposed algae. Observations by TEM suggested chloroplasts as the first target of selenite cytotoxicity, with effects on the stroma, thylakoids and pyrenoids. At higher concentrations, we could observe an increase in the number and volume of starch grains. For the cell collected at 96 h, electron-dense granules were observed. Energy-dispersive X-ray microanalysis revealed that they contained selenium and were also rich in calcium and phosphorus. Finally, growth inhibition was highly correlated to the bioaccumulation of selenite. The latter was inhibited by increasing concentrations of

  11. Interaction of selenite with iron sulphide minerals: implications for the geochemical fate of Se in Boom Clay

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. The geochemistry of selenium, exhibiting valence states from +VI to -II, is of key importance due to its role as a highly toxic essential micro-nutrient and as a significant component of high level radioactive waste (HLRW). XAS studies conducted at circum-neutral pH have shown that pyrite (FeS2), the most relevant redox-active mineral in Boom clay, reduces selenite to a solid-state Se(0) phase. This observation raises several questions. First, why does an Fe-free Se(0) phase in form presence of pyrite, while selenite is reduced to FeSex by troilite and mackinawite (FeS)? What is the exact identity of this elemental Se phase, which has been observed by several authors? Why is a dissolved, low oxidation-state selenium species encountered in association with the Se(0) phase; and what is its identity? Correlating selenium redox chemistry with sulphide mineral oxidation pathways allowed to link these observations to the different oxidation behaviour of acid-soluble and acid-insoluble metal sulphides. The end products of Se(IV) reduction by acid-soluble iron sulphur minerals are fairly well known, but the solid and liquid phase species present during interaction of SeO32- with pyrite are poorly characterized. The solid phase reaction product could not yet be assigned as a specific phase, but clearly identified as a Se0 compound. Trigonal (grey) selenium could be excluded as a candidate. Acid insoluble metal sulphides such as pyrite, molybdenite or tungstenite exhibit oxidative dissolution only. Upon six consequent one-electron oxidation steps, a thiosulphate anion is liberated (thiosulphate pathway). In contrast, acid soluble metal sulphides (troilite, mackinawite, sphalerite, etc.) exhibit also non-oxidative dissolution thereby liberating sulphide species (H2S, HS-,S2-). Under oxidative dissolution in presence of Fe-III, they release sulphide cations (e.g. H2S+). The latter can spontaneously dimerize into disulphide

  12. Switching to instant black coffee modulates sodium selenite-induced cataract in rats

    Science.gov (United States)

    El Okda, E. A.; Mohamed, M. M.; Shaheed, E. B.; Abdel-Moemin, A. R.

    2016-01-01

    The influence of daily consumption of some common beverages on the development of cataract in rats was investigated. Total phenol content was determined in the beverages and an oral standardized dose of total phenols from each beverage was given to the treated rats. Weaned male albino rats were used and divided into five groups (n=7). Rats were fed Ain 93G and administered the standardized dose of instant coffee, black tea and hibiscus beverages for 30 days. On day 14 all rats were injected with a single dose of sodium selenite (Na2SeO3) 15 µmol/kg bodyweight, except the control groups NC (negative control, did not receive Na2SeO3) and PC (positive control, was already injected on day 1 of the study). The rats were continued on Ain 93G and the standardized dose for another 16 days. Positive control rats were used. Total phenols were 210, 40, and 44 mg/g dry weight gallic acid equivalent in black coffee, black tea, and hibiscus, respectively. Decreased levels (statistically significant P<0.05) of malondialdehyde, total nitric oxide, Ca-ATPase, tumor necrosis factor-α, interleukin-1β, superoxide dismutase, and conversely, increased levels (statistically significant P<0.05) of total protein, reduced glutathione, catalase were found in the lenses of the coffee group compared to PC. There are co-phenol substances in the instant black coffee that promoted coffee to be the most effective beverage. PMID:27158251

  13. Radioprotective effect of sodium selenite on bone repair in the tibia of ovariectomized rats

    International Nuclear Information System (INIS)

    This study evaluated protection by selenium (Se) in the bone repair process in ovariectomized rats after irradiation. For such purpose, 80 ovariectomized female Wistar rats were randomly divided into 4 experimental groups: ovariectomized (Ov), Ov/Se, Ov/irradiated (Irr) and Ov/ Se/Irr. A bone defect was created on the tibia of all animals 40 days after ovariectomy. Two days after surgery, only the Ov/Se and Ov/Se/Irr rats received 0.8 mg Se/kg. Three days after surgery, only the Ov/Irr and Ov/Se/Irr rats received 10 Gy of x-rays on the lower limb region. The animals were euthanized at 7, 14, 21 and 28 days after surgery to assess the repair process, which was evaluated by analysis of trabecular bone number (Masson Trichrome) and birefringence analysis (Picrosirius). It was possible to observe a delay in the bone repair process in the ovariectomized/irradiated group and similarity between the ovariectomized, Ov/Se and Ov/Se/Irr groups. In conclusion, sodium selenite exerted a radioprotective effect in the bone repair of tibia of ovariectomized rats without toxicity. (author)

  14. Radioprotective effect of sodium selenite on bone repair in the tibia of ovariectomized rats

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Deborah Queiroz de; Neves, Ellen Gaby; Boscolo, Frab Norberto; Almeida, Solange Maria de [University of Campinas (UNICAMP), Piracicaba, SP (Brazil). Piracicaba Dental School. Department of Oral Diagnosis. Oral Radiology Area; Ramos-Perez, Flavia Maria de Moraes [Federal University of Pernambuco, Recife, PE (Brazil). Department of Clinical and Preventive Dentistry; Marques, Marcelo Rocha [University of Campinas (UNICAMP), Piracicaba, SP (Brazil). Piracicaba Dental School. Division of Histology. Department of Morphology

    2012-07-01

    This study evaluated protection by selenium (Se) in the bone repair process in ovariectomized rats after irradiation. For such purpose, 80 ovariectomized female Wistar rats were randomly divided into 4 experimental groups: ovariectomized (Ov), Ov/Se, Ov/irradiated (Irr) and Ov/ Se/Irr. A bone defect was created on the tibia of all animals 40 days after ovariectomy. Two days after surgery, only the Ov/Se and Ov/Se/Irr rats received 0.8 mg Se/kg. Three days after surgery, only the Ov/Irr and Ov/Se/Irr rats received 10 Gy of x-rays on the lower limb region. The animals were euthanized at 7, 14, 21 and 28 days after surgery to assess the repair process, which was evaluated by analysis of trabecular bone number (Masson Trichrome) and birefringence analysis (Picrosirius). It was possible to observe a delay in the bone repair process in the ovariectomized/irradiated group and similarity between the ovariectomized, Ov/Se and Ov/Se/Irr groups. In conclusion, sodium selenite exerted a radioprotective effect in the bone repair of tibia of ovariectomized rats without toxicity. (author)

  15. Effect of selenite on the morphology and respiratory activity of Phanerochaete chrysosporium biofilms.

    Science.gov (United States)

    Espinosa-Ortiz, Erika J; Pechaud, Yoan; Lauchnor, Ellen; Rene, Eldon R; Gerlach, Robin; Peyton, Brent M; van Hullebusch, Eric D; Lens, Piet N L

    2016-06-01

    The temporal and spatial effects of selenite (SeO3(2-)) on the physical properties and respiratory activity of Phanerochaete chrysosporium biofilms, grown in flow-cell reactors, were investigated using oxygen microsensors and confocal laser scanning microscopy (CLSM) imaging. Exposure of the biofilm to a SeO3(2-) load of 1.67mgSeL(-1)h(-1) (10mgSeL(-1) influent concentration), for 24h, resulted in a 20% reduction of the O2 flux, followed by a ∼10% decrease in the glucose consumption rate. Long-term exposure (4days) to SeO3(2-) influenced the architecture of the biofilm by creating a more compact and dense hyphal arrangement resulting in a decrease of biofilm thickness compared to fungal biofilms grown without SeO3(2-). To the best of our knowledge, this is the first time that the effect of SeO3(2-) on the aerobic respiratory activity on fungal biofilms is described. PMID:26935326

  16. Sodium selenite-induced hypothermia in mice: indirect evidence for a neural effect.

    Science.gov (United States)

    Watanabe, C; Suzuki, T

    1986-12-01

    The effect of sodium selenite (SS) on the body temperature of adult male ICR mice was examined. SS (10-60 mumol/kg) administered subcutaneously resulted in a transient and dose-dependent hypothermia at ambient temperatures (Ta) of 20 and 30 degrees C. Reduced oxygen consumption accompanied the changes in body temperature. In addition, SS-treated mice exhibited transient cold-seeking behavior in the thermogradient. This SS-induced hypothermia was very similar to those induced by ethanol, tetrahydrocannabinol, triethyltin, sulfolane, and chlordimeform in that these all were transient, dependent on Ta, and not counteracted by behavioral thermoregulation. From these results, involvement of neural afferent or integral pathways is suggested. Further, acute mortality of SS-injected mice was enhanced with the elevation of Ta, as in the case of the chemicals mentioned above. Considering the diverse chemical and pharmacological properties of these chemicals, these results may suggest a possible interrelation between the hypothermic response and the modification of toxicity. PMID:3787631

  17. Effect of dietary fat on plasma glutathione peroxidase levels and intestinal absorption of 75Se-labeled sodium selenite in chicks

    International Nuclear Information System (INIS)

    The effect of dietary fat on the availability of selenium was investigated in chicks fed either 4 or 20% butter, olive oil, rape oil, corn oil or sunflower oil in the diet for 3 weeks after hatching. Plasma glutathione peroxidase (GSH-Px) activity was used as an indicator of the body selenium status. In addition, the intestinal absorption of sodium selenite (75Se-labeled) was determined by using both the in vivo ligated loop procedure and oral administration of the isotope. The plasma GSH-Px levels increased with increasing proportion of the polyunsaturated fatty acids in the diet. Increasing the amount of fat from 4 to 20% significantly enhanced the GSH-Px activity in the groups receiving butter or olive oil, but had no effect in animals fed the unsaturated fats. The absorption of [75Se]selenite from the ligated duodenal loops tended to be reduced in chicks fed corn oil or sunflower oil as compared to the animals receiving butter in their diet. On the other hand, the type of dietary fat did not appear to affect the absorption of the orally administered selenite. The present study demonstrates that the type of dietary fat can affect the plasma GSH-Px levels in chicks without altering the intestinal absorption of selenite. However, the results on the absorption of the intraduodenally injected sodium selenite suggest that dietary fat plays some role in the intestinal transport of selenium

  18. Magnetotransport in CeCu6-xAux

    International Nuclear Information System (INIS)

    We report on a comparative study of the low-temperature magnetoresistance ρxx(B) and Hall resistance ρxy(B) of CeCu6-xAux for 0=xx(B), and of the anomalous Hall effect and bandstructure effects of the heavy-quasiparticle bands affecting ρxy(B)

  19. A classical force field for tetrahedral oxyanions developed using hydration properties: The examples of pertechnetate (TcO4-) and sulfate (SO42-)

    Science.gov (United States)

    Williams, Christopher D.; Carbone, Paola

    2015-11-01

    Radioactive pertechnetate, 99TcO4-, is one of the most problematic ionic species in the context of the clean up and storage of nuclear waste. Molecular simulations can be used to understand the behavior of TcO4- in dilute aqueous solutions, providing reliable potentials are available. This work outlines the development of a new potential model for TcO 4- and competing SO42-, optimized using their hydration properties, such as the Gibbs hydration free energy (calculated using Bennett's acceptance ratio method). The findings show that the TcO4- oxyanion has a very low hydration free energy (-202 kJ mol-1) compared to other anions (Cl-, I-, SO42-) leading to fast water exchange dynamics and explaining its observed high mobility in the aqueous environment. Its hydrated structure, investigated using ion-water radial distribution functions, shows that it is unique amongst the other anions in that it does not possess well-defined hydration shells. Since contaminants and ubiquitous species in the aqueous environment are often present as tetrahedral oxyanions, it is proposed that the approach could easily be extended to a whole host of other species.

  20. A classical force field for tetrahedral oxyanions developed using hydration properties: The examples of pertechnetate (TcO4(-)) and sulfate (SO4(2-)).

    Science.gov (United States)

    Williams, Christopher D; Carbone, Paola

    2015-11-01

    Radioactive pertechnetate, (99)TcO4(-), is one of the most problematic ionic species in the context of the clean up and storage of nuclear waste. Molecular simulations can be used to understand the behavior of TcO4(-) in dilute aqueous solutions, providing reliable potentials are available. This work outlines the development of a new potential model for TcO4(-) and competing SO4(2-), optimized using their hydration properties, such as the Gibbs hydration free energy (calculated using Bennett's acceptance ratio method). The findings show that the TcO4(-) oxyanion has a very low hydration free energy (-202 kJ mol(-1)) compared to other anions (Cl(-), I(-), SO4(2-)) leading to fast water exchange dynamics and explaining its observed high mobility in the aqueous environment. Its hydrated structure, investigated using ion-water radial distribution functions, shows that it is unique amongst the other anions in that it does not possess well-defined hydration shells. Since contaminants and ubiquitous species in the aqueous environment are often present as tetrahedral oxyanions, it is proposed that the approach could easily be extended to a whole host of other species. PMID:26547171

  1. Adsorption of arsenite and selenite using an inorganic ion exchanger based on Fe–Mn hydrous oxide

    KAUST Repository

    Szlachta, Małgorzata

    2012-01-01

    The adsorption behaviour and mechanism of As(III) and Se(IV) oxyanion uptake using a mixed inorganic adsorbent were studied. The novel adsorbent, based on Fe(III)-Mn(III) hydrous oxides and manganese(II) carbonate, was synthesised using a hydrothermal precipitation approach in the presence of urea. The inorganic ion exchanger exhibited a high selectivity and adsorptive capacity towards As(III) (up to 47.6mg/g) and Se(IV) (up to 29.0mg/g), even at low equilibrium concentration. Although pH effects were typical for anionic species (i.e., the adsorption decreased upon pH increase), Se(IV) was more sensitive to pH changes than As(III). The rates of adsorption of both oxyanions were high. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) studies showed that the ion exchange adsorption of both anions took place via OH - groups, mainly from Fe(III) but also Mn(III) hydrous oxides. MnCO 3 did not contribute directly to As(III) and Se(IV) removal. A higher adsorptive capacity of the developed material towards As(III) was partly due to partial As(III) oxidation during adsorption. © 2011 Elsevier Inc.

  2. Selenite reduction in boom clay: effect of FeS2, clay minerals and dissolved organic matter

    International Nuclear Information System (INIS)

    In Belgium, the Boom clay layer is considered as the candidate host rock for the disposal of high-level radioactive waste (HLRW). For this disposal, Selenium 79 is considered to be a critical radionuclide and responsible for the highest dose to man over a period of tens of thousands of years. The behaviour and reactivity of Se thereby depend on its speciation and on its complex biogeochemical transformations. 79Se is thought to occur in, and be released from the solid waste matrix in a variety of redox states, including Se oxyanions such as SeO32- or SeO42-. The composition of the solid and liquid phases of Boom clay was published before. In this paper, the reduction of Se oxyanions was investigated by adding appropriate amounts of SeO32- in over-saturation with respect to the proclaimed thermodynamical solubility of reduced Se solid phases (SeO, FeSe, FeSe2), to a number of systems which represent Boom clay geochemical conditions. The range of systems is chosen in order to incorporate in an increasing way the different Se competing organic and inorganic phases present in the Boom clay matrix. (authors)

  3. Change of selenium in plasma of dairy cows receiving two levels of sodium-selenite during the transition period

    OpenAIRE

    A. Giubbiotti; A. Bakudila Mbuta; E. Trevisi; F. Piccioli Cappelli

    2010-01-01

    With the aim to study the plasma Se content during transition period, 2 groups of 12 dairy cows were monitored the month before and after calving. In stall 1 (S1) cows were tied and individually fed, in stall2 (S2) cows were free and fed TMR. In both stalls cows were supplied with Se as Na-selenite. In S1 3 mg/d of Se were fed mixed with corn silage while, in S2, Se was offered with TMR, in dry period 2 mg/d were added with a mineral-vitamin supplement, in lactation 2.6 mg/d (when DMI was 22....

  4. Influence of long-term cadmium and selenite exposure on resistance to Listeria monocytogenes during acute and chronic infection in mice

    OpenAIRE

    Šimonytė, Sandrita; Plančiūnienė, Rita; Cherkashin, Gennadij; žekonis, Gediminas

    2006-01-01

    The aim of the present study was to evaluate the effect of long-term exposure to cadmium and selenite ions on the BALB/c mice resistance to experimental Listeria monocytogenes infection. A low-dose six-week exposure to cadmium ions (10 mg/ l in drinking water) decreased the clearance of listeria from mice liver and spleen at 24 h in the early phase of infection. Long-term treatment of mouse with selenite ions (0.15 mg/l) did not activate the elimination of bacteria from the organs. Eight week...

  5. Sorption of selenite ions on solid soil components using dialysis membranes

    International Nuclear Information System (INIS)

    Selenium-79 is a radionuclide that is produced in nuclear reactors with a yield of about 0.04%. According to the French concept of deep geological high-level waste disposal selenium can have a significant effect on the cumulative radioactive dose if it is transported through the geosphere without retardation. Once in the biosphere, selenium may be retarded via sorption onto soil components including clays, calcite and Fe-oxides. The aim of this work is to develop a new method, an alternative of batch experiments, to determine the influence of chemical interactions on selenium sorption onto solid phases commonly present in soils. A method using a dialysis membrane was used. Five milliliters of a solid/synthesized water suspension in a dialysis bag was placed in 100 mL of synthesized water containing selenium in known concentration. We first studied the effect of the dialysis membrane on the equilibrium time for each soil components. The sorption of selenite ions onto bentonite, goethite and calcite was characterized by sorption kinetics. Also, the effects of pH and selenium concentration in solution on the sorption were investigated. To establish the contribution of the different solids to the sorption, experiments with one component (bentonite, calcite, goethite) were carried out and a value of Kd was calculated. The preliminary experimental Kd obtained were between 0-58 L.kg-1 for calcite and between 0-70 L.kg-1 for bentonite. Preliminary results with two solid phases at pH 7 (bentonite + calcite and goethite + calcite) show that the Kd of bentonite and goethite decrease in comparison with the single system. The retention behaviour of calcite remains the same one in a system with one component and in a system with two components at pH 7. (authors)

  6. Soja MON 87701 Résistant Aux Insectes

    OpenAIRE

    Canada, Publié par la Direction des aliments de Santé

    2014-01-01

    Santé Canada a avisé Monsanto Canada Inc. qu’il ne s’oppose pas à l’utilisation alimentaire du soja MON 87701 résistant aux insectes. Le Ministère a réalisé une évaluation approfondie de cette lignée de soja conformément aux Lignes directrices sur l’évaluation de l’innocuité des aliments nouveaux. Ces lignes directrices sont fondées sur les principes admis internationalement de l’établissement de l’innocuité d’aliments comportant des caractères nouveaux. Le texte qu...

  7. Des arbres et des herbes aux marges du Sahara

    OpenAIRE

    Bernus, Edmond

    1992-01-01

    Le Sahara possède une végétation qui est d'autant plus précieuse pour ses habitants qu'elle est rare. Les herbes, prairies d'"éphémères" dans les zones aux pluies les plus aléatoires, ou vivaces et annuelles plus régulières, fournissent un fourrage très recherché. Dans les marges méridionales des herbes permettent des ramassages de graines qui donnent aux nomades des nourritures appréciées. Mil, sorgho et riz poussent à l'état spontané : les deux premiers ont été domestiqués dans cette région...

  8. Sensibilisation aux gestes et postures de travail - French version only

    CERN Multimedia

    2004-01-01

    Nous vous proposons un nouveau cours de sécurité lié aux manutentions manuelles (durée 1 jour) : Sensibilisation aux gestes et postures de travail. Si vous êtes amené à manipuler régulièrement des charges lourdes ou volumineuses, cette formation peut vous aider à prévenir les lésions musculaires ou dorsales. A l'issue de cette formation, vous serez capable d'adopter et d'appliquer les principes de base de sécurité physique et d'économie d'efforts dans les manipulations d'objets. Les cours sont pris en charge par la Commission de Sécurité. L'inscription EDH est obligatoire. Pour plus d'information, veuillez consulter les pages Formation & Développement (Groupe Sécurité)

  9. Absorption, distribution, metabolism and excretion of selenium following oral administration of elemental selenium nanoparticles or selenite in rats

    DEFF Research Database (Denmark)

    Löschner, Katrin; Hadrup, Niels; Hansen, Marianne;

    2014-01-01

    A suspension of nanoparticles of BSA-stabilized red amorphous elemental selenium (Se) or an aqueous solution of sodium selenite was repeatedly administered by oral gavage for 28 days at 0.05 mg/kg bw/day (low dose) or at 0.5 mg/kg bw/day (high dose) as Se to female rats. Prior to administration......, the size distribution of the Se nanoparticles was characterized by dynamic light scattering and transmission electron microscopy, which showed that the particles’ mean diameter was 19 nm and ranged in size from 10-80 nm. Following administration of the high dose of Se nanoparticles or selenite the...... concentration of Se was determined by ICP-MS in liver, kidney, urine, feces, stomach, lungs, plasma at µg/g level and in brain and muscle tissue at sub-µg/g level. In order to test if any elemental Se was present in liver, kidney or feces, an in situ derivatization selective to elemental Se was made by...

  10. Thermodynamics of arsenates, selenites, and sulfates in the oxidation zone of sulfide ores: I. Thermodynamic constants at ambient conditions

    Science.gov (United States)

    Charykova, M. V.; Krivovichev, V. G.; Depmeir, W.

    2010-12-01

    Understanding and deciphering processes proceeding near the surface are among the urgent tasks of contemporary mineralogy and geochemistry, which are especially important for resolving ecological challenges and developing principles of rational environmental management. The paper presents systematized data published on thermodynamics of minerals (arsenates, sulfates, selenites, and selenates), which are formed in the weathering zone of sulfide ores, and determines approaches to quantitative physicochemical modeling of their formation conditions. Diagrams of phase and chemical equilibria (Eh-pH, diagrams of solubility) of the subsystems of the model system Fe-Cu-Zn-Pb-Co-Ni-As-Se-S-H2O (Fe2+, Fe3+, Cu2+, Zn2+, Pb2+, Ni2+, Co2+, H+//SeO{3/2-}, SeO{4/2-}, AsO{4/3-}, SO{4/2-}, OH--H2O) are used as a thermodynamic basis for modeling mineral-forming processes in the weathering zone of ore deposits. Seventy-two arsenates, about 70 sulfates, and 7 selenites and selenates have been identified in the framework of this system. The available published values of standard thermodynamic functions of the formation of minerals and chemical compounds are given, as well as the Pitzer equation parameters to describe the sulfate systems, which are substantially specific due to the high solubility of their components.

  11. Prevention effect in selenite-induced cataract in vivo and antioxidative effects in vitro of Crataegus pinnatifida leaves.

    Science.gov (United States)

    Wang, Tao; Zhang, Peng; Zhao, Chunfeng; Zhang, Yi; Liu, Hong; Hu, Limin; Gao, Xiumei; Zhang, Deqin

    2011-07-01

    Cataract is the leading cause of blindness worldwide. It is a multifactorial disease primarily associated with oxidative stress produced by free radicals. The present study was undertaken to evaluate the anticataract potential of Crataegus pinnatifida (hawthorn tree) leaves extract in selenite-induced cataract in vivo and antioxidant effects in vitro. In vitro antioxidant assay of C. pinnatifida leaves extract on NO production inhibition, aldose reductase inhibition, and O(2)(-) radical scavenging activities gave the IC(50) of 98.3, 89.7, and 5.98 μg/mL, respectively. To characterize some major compounds in C. pinnatifida leaves extract, nine flavonoids were identified via LC-MS/MS qualitative analysis. Based on in vitro screening results, C. pinnatifida leaves extract eye drops in 0.1% hydroxypropyl methyl cellulose solution were prepared to evaluate the anticataract potential in vivo. Administration of C. pinnatifida leaves extract eye drops alternately three times a day in rat pups with selenite-induced oxidative stress significantly increased serum SOD and CAT activities, and tended to reduce MDA level compared with control group. The antioxidant enzyme SOD, CAT, and GSH activities in lens showed a significant increase. These results may be applied in the future for the prevention and treatment of cataracts. PMID:20596791

  12. Sensitivities of selenite, selenate, selenomethionine and trimethylselenonium ion in aqueous solution and in blood plasma - ETAAS compared with ICP-MS

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Larsen, E.H.

    1998-01-01

    Aqueous solutions and blood plasma spiked with selenite (Se(IV)), selenate (Se(VI)), selenomethionine (SeMet) or trimethylselenonium (TMSe) iodide were analyzed by Zeeman-corrected electrothermal atomic absorption spectrometry (ETAAS) using palladium as a chemical modifier, and by inductively cou...

  13. Draft Genome Sequence of "Halomonas chromatireducens" Strain AGD 8-3, a Haloalkaliphilic Chromate- and Selenite-Reducing Gammaproteobacterium.

    Science.gov (United States)

    Sharko, Fedor S; Shapovalova, Anna A; Tsygankova, Svetlana V; Komova, Anastasia V; Boulygina, Eugenia S; Teslyuk, Anton B; Gotovtsev, Pavel M; Namsaraev, Zorigto B; Khijniak, Tatiana V; Nedoluzhko, Artem V; Vasilov, Raif G

    2016-01-01

    Here, we report the complete genome sequence (3.97 Mb) of "Halomonas chromatireducens" AGD 8-3, a denitrifying bacterium capable of chromate and selenite reduction under extreme haloalkaline conditions. This strain was isolated from soda solonchak soils of the Kulunda steppe, Russian Federation. PMID:26988058

  14. Draft Genome Sequence of “Halomonas chromatireducens” Strain AGD 8-3, a Haloalkaliphilic Chromate- and Selenite-Reducing Gammaproteobacterium

    OpenAIRE

    Sharko, Fedor S.; Shapovalova, Anna A.; Svetlana V. Tsygankova; Komova, Anastasia V.; Boulygina, Eugenia S; Teslyuk, Anton B.; Gotovtsev, Pavel M.; Namsaraev, Zorigto B.; Khijniak, Tatiana V.; Nedoluzhko, Artem V; Vasilov, Raif G.

    2016-01-01

    Here, we report the complete genome sequence (3.97 Mb) of “Halomonas chromatireducens” AGD 8-3, a denitrifying bacterium capable of chromate and selenite reduction under extreme haloalkaline conditions. This strain was isolated from soda solonchak soils of the Kulunda steppe, Russian Federation.

  15. Effect of dietary sodium selenite, Se-enriched yeast and Se-enriched Chlorella on egg Se concentration, physical parameters of eggs and laying hen production

    Czech Academy of Sciences Publication Activity Database

    Skřivan, M.; Šimáně, J.; Dlouhá, G.; Doucha, Jiří

    2006-01-01

    Roč. 51, č. 4 (2006), s. 163-167. ISSN 1212-1819 Institutional research plan: CEZ:AV0Z50200510 Keywords : sodium selenite * se-yeast * se-chlorella Subject RIV: EE - Microbiology, Virology Impact factor: 0.421, year: 2006

  16. Seleno-l-Methionine Is the Predominant Organic Form of Selenium in Cupriavidus metallidurans CH34 Exposed to Selenite or Selenate†

    OpenAIRE

    Avoscan, Laure; Collins, Richard; Carriere, Marie; Gouget, Barbara; Covès, Jacques

    2006-01-01

    The accumulated organic form of selenium previously detected by X-ray absorption near-edge structure (XANES) analyses in Cupriavidus metallidurans CH34 exposed to selenite or selenate was identified as seleno-l-methionine by coupling high-performance liquid chromatography to inductively coupled plasma-mass spectrometry.

  17. GC-ICP-MS determination of dimethylselenide in human breath after ingestion of (77)Se-enriched selenite: monitoring of in-vivo methylation of selenium.

    Science.gov (United States)

    Kremer, Daniel; Ilgen, Gunter; Feldmann, Jörg

    2005-10-01

    The amount of volatile dimethylselenide (DMSe) in breath has been monitored after ingestion of sub-toxic amounts of selenium (300 microg (77)Se, as selenite) by a healthy male volunteer. The breath samples were collected in Tedlar bags every hour in the first 12 h and then at longer intervals for the next 10 days. The samples were subjected to speciation analysis for volatile selenium compounds by use of cryotrapping-cryofocussing-GC-ICP-MS. Simultaneously, all urine was collected and subjected to total selenium determination by use of ICP-MS. By monitoring m/z 82 and 77, background or dietary selenium and selenium from the administered selenite were simultaneously determined in the urine and in the breath-dietary selenium only was measured by monitoring m/z 82 whereas the amount of spiked (77)Se (99.1% [enriched spike]) and naturally occurring selenium (7.6% [natural abundance]) were measured by monitoring m/z 77. Quantification of DMSe was performed by using DMSe gas samples prepared in Tedlar bags (linear range 10-300 pg, R (2)=0.996, detection limit of Se as DMSe was 10 pg Se, or 0.02 ng L(-1), when 0.5 L gas was collected). Dimethylselenide was the only selenium species detected in breath samples before and after the ingestion of (77)Se-enriched selenite. Additional DM(77)Se was identified as early as 15 min after ingestion of the isotopically-labelled selenite. Although the maximum concentration of (77)Se in DMSe was recorded 90 min after ingestion, the natural isotope ratio for selenium in DMSe (77/82) was not reached after 20 days. The concentration of DMSe correlated with the total Se concentration in the urine during the experiment (R (2)=0.80). Furthermore, the sub-toxic dose of 300 microg selenium led to a significant increase of DMSe and renal excretion of background selenium, confirming that selenium ingested as selenite is homeostatically controlled by excretion. The maximum concentration of DMSe resulting from the spiked selenite was 1.4 ng Se L(-1

  18. GC-ICP-MS determination of dimethylselenide in human breath after ingestion of {sup 77}Se-enriched selenite: monitoring of in-vivo methylation of selenium

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, Daniel [University of Aberdeen, Department of Chemistry, College of Physical Sciences, Aberdeen, Scotland (United Kingdom); Johannes Gutenberg University Mainz, Environmental Geochemistry, Mainz (Germany); Ilgen, Gunter [University of Bayreuth, Central Analytics, Bayreuth Center for Ecology and Environmental Research (BayCEER), Bayreuth (Germany); Feldmann, Joerg [University of Aberdeen, Department of Chemistry, College of Physical Sciences, Aberdeen, Scotland (United Kingdom)

    2005-10-01

    The amount of volatile dimethylselenide (DMSe) in breath has been monitored after ingestion of sub-toxic amounts of selenium (300 {mu}g {sup 77}Se, as selenite) by a healthy male volunteer. The breath samples were collected in Tedlar bags every hour in the first 12 h and then at longer intervals for the next 10 days. The samples were subjected to speciation analysis for volatile selenium compounds by use of cryotrapping-cryofocussing-GC-ICP-MS. Simultaneously, all urine was collected and subjected to total selenium determination by use of ICP-MS. By monitoring m/z 82 and 77, background or dietary selenium and selenium from the administered selenite were simultaneously determined in the urine and in the breath - dietary selenium only was measured by monitoring m/z 82 whereas the amount of spiked {sup 77}Se (99.1% [enriched spike]) and naturally occurring selenium (7.6% [natural abundance]) were measured by monitoring m/z 77. Quantification of DMSe was performed by using DMSe gas samples prepared in Tedlar bags (linear range 10-300 pg, R {sup 2}=0.996, detection limit of Se as DMSe was 10 pg Se, or 0.02 ng L{sup -1}, when 0.5 L gas was collected). Dimethylselenide was the only selenium species detected in breath samples before and after the ingestion of {sup 77}Se-enriched selenite. Additional DM{sup 77}Se was identified as early as 15 min after ingestion of the isotopically-labelled selenite. Although the maximum concentration of {sup 77}Se in DMSe was recorded 90 min after ingestion, the natural isotope ratio for selenium in DMSe (77/82) was not reached after 20 days. The concentration of DMSe correlated with the total Se concentration in the urine during the experiment (R {sup 2}=0.80). Furthermore, the sub-toxic dose of 300 {mu}g selenium led to a significant increase of DMSe and renal excretion of background selenium, confirming that selenium ingested as selenite is homeostatically controlled by excretion. The maximum concentration of DMSe resulting from the

  19. Palladium nanoparticles encapsulated in core-shell silica: A structured hydrogenation catalyst with enhanced activity for reduction of oxyanion water pollutants

    KAUST Repository

    Wang, Yin

    2014-10-03

    Noble metal nanoparticles have been applied to mediate catalytic removal of toxic oxyanions and halogenated hydrocarbons in contaminated water using H2 as a clean and sustainable reductant. However, activity loss by nanoparticle aggregation and difficulty of nanoparticle recovery are two major challenges to widespread technology adoption. Herein, we report the synthesis of a core-shell-structured catalyst with encapsulated Pd nanoparticles and its enhanced catalytic activity in reduction of bromate (BrO3-), a regulated carcinogenic oxyanion produced during drinking water disinfection process, using 1 atm H2 at room temperature. The catalyst material consists of a nonporous silica core decorated with preformed octahedral Pd nanoparticles that were further encapsulated within an ordered mesoporous silica shell (i.e., SiO2@Pd@mSiO2). Well-defined mesopores (2.3 nm) provide a physical barrier to prevent Pd nanoparticle (6 nm) movement, aggregation, and detachment from the support into water. Compared to freely suspended Pd nanoparticles and SiO2@Pd, encapsulation in the mesoporous silica shell significantly enhanced Pd catalytic activity (by a factor of 10) under circumneutral pH conditions that are most relevant to water purification applications. Mechanistic investigation of material surface properties combined with Langmuir-Hinshelwood modeling of kinetic data suggest that mesoporous silica shell enhances activity by promoting BrO3- adsorption near the Pd active sites. The dual function of the mesoporous shell, enhancing Pd catalyst activity and preventing aggregation of active nanoparticles, suggests a promising general strategy of using metal nanoparticle catalysts for water purification and related aqueous-phase applications.

  20. Selenite -Se(4)- uptake mechanisms in the unicellular green alga Chlamydomonas reinhardtii: bioaccumulation and effects induced on growth and ultrastructure; Mecanismes de prise en charge du selenite - Se(4)-chez l'algue verte unicellulaire Chlamydomonas reinhardtii. Bioaccumulation et effets induits sur la croissance et l'ultrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Morlon, H

    2005-03-15

    Selenium is an essential element, but becomes very toxic at higher concentrations. It occurs in the environment at concentrations ranging from nM to {mu}M and selenium pollution is a worldwide phenomenon. This works aims at improving the knowledge on the interactions between selenite - Se(IV) - and a freshwater phyto-planktonic organism: the unicellular green algae Chlamydomonas reinhardtii. The aim of the performed experiments were: i) to investigate selenite -Se(IV)- uptake mechanisms in C. reinhardtii, using Se{sup 75} as a tracer in short term exposures (<1 h); ii) to assess selenite toxicity as measured with growth impairment and ultrastructural damage (with EDAX-TEM analysis), using long term exposures (96 h) to stable selenite; iii) to evaluate the bioaccumulation capacity of selenite and its potential links with toxicity. Short-term experiments revealed a negligible adsorption and a time-dependent linear absorption with an estimated absorbed flux of about 0.2 nmol.m{sup -2}.nM{sup -1}.h{sup -1}. The uptake was proportional to ambient levels in a broad range of intermediate concentrations (from nM to {mu}M). However, fluxes were higher at very low concentrations (< nM), and decrease with increasing high concentrations ( > {mu}M), suggesting that a high affinity but rapidly saturated transport mechanism could be used at low concentrations, in parallel with a low affinity mechanism that would only saturate at high concentrations ({approx}mM). The latter could involve transporters used by sulphate and nitrates, as suggested by the inhibition of selenite uptake by those element. Se(IV) speciation changes with pH did not induce significant effect on bioavailability. On the basis of the relationship between Se concentration and maximal cell density achieved, an EC50 of 80 {mu}M ([64; 98]) was derived. No adaptation mechanism were observed as the same the same toxicity was quantified for Se-pre-exposed algae. Observations by TEM suggested chloroplasts as the first

  1. Sexe et pouvoir aux États-Unis

    OpenAIRE

    Mokhtar BEN BARKA

    2012-01-01

    Les adversaires politiques de Bill Clinton aiment à dire que l’Histoire se souviendra de lui plus à cause de ses mensonges et de sa sexualité débordante qu’en raison de son bilan. En vérité, les frasques sexuelles du président Clinton ne sont que la perpétuation d’une tradition qui remonte aux origines de la nation américaine. “Long before there was a United States of America”, écrit Shelley Ross, “there was sex, scandal, and corruption in American politics. In fact, some of the most notoriou...

  2. Broadband conductivity spectra of fast-ion-conducting silver selenite glasses: Dependence on power law and scaling

    Science.gov (United States)

    Deb, B.; Bhattacharya, S.; Ghosh, A.

    2011-11-01

    In this letter we have studied broadband conductivity spectra (10 Hz-3 GHz) of fast-ion-conducting silver selenite glasses of compositions xAgI-(1-x)(yAg2O-(1-y)SeO2). We have observed that the conductivity spectra below 10 MHz are characterized by a power law with exponent less than unity, while the conductivity spectra in the high-frequency range (above 10 MHz) have been adequately explained in the framework of the unified site relaxation model with exponent greater than unity. The scaling of the conductivity spectra indicates that the time-temperature superposition principle is valid in the low-frequency regime, but not in the high-frequency regime.

  3. Pigments content in Сhlorella vulgaris under the influence of the sodium selenite and the ions of metals

    Directory of Open Access Journals (Sweden)

    O. I. Bodnar

    2016-01-01

    Full Text Available We investigated the content of pigments in Chlorella vulgaris Beij. (Chlorophyta under the influence of sodium selenite in concentrations based on Se4+ 0.5, 5.0, 10.0 and 20.0 mg/dm3 during one, three and seven days and under the influence of the simultaneous action of selenite in concentrations 10 mg Se4+/dm3 and ions of Zn2+, Mn2+, Co2+,Cu2+, Fe3+ in concentrations 5.00, 0.25, 0.05, 0.008 and 0.002 mg/dm3over seven days. This research was carried out to establish the conditions for obtaining algal lipidis substance enriched with selenium and biogenic metals in the aquaculture. The content of pigments was determined spectrophotometrically, the cellular walls were separatedby centrifuge in the percoll gradient and investigated microscopically. The pigments content in the Ch. vulgaris increased by 1.5–2.5 times in comparison with the control sample under the influence of 10 mg Se4+/dm3 with and without metal ions, in all variants of experimental influence due to binding of SeО32– with proteins and lipids. We found that selenium was included in all lipid fractions (triacylglycerols, dyacylglycerols, phospholipids, nonetherified fatty acids; the maximum amount of selenium-containing lipids wasrecorded in chloroplasts. The increase in the contents of carotenoids caused by the actions of experimental factors played an exceptional role in the mechanism of antioxidant protection that prevents destruction of chlorophyll and, accordingly, increases its amount in cells. Changes in the functioning of the photosynthetic apparatus of Ch. vulgaris affect the whole complex of metabolic transformation. Thus, the successful cultivation of chlorella, enriched with selenium and biogenic metals, is possible within seven days under the influence of 10 mg Se4+/dm3 and the above-mentioned concentration of metal ions.

  4. Toxicity of selenite in the unicellular green alga Chlamydomonas reinhardtii: Comparison between effects at the population and sub-cellular level

    International Nuclear Information System (INIS)

    The toxicity of selenium in aquatic ecosystems is mainly linked to its uptake and biotransformation by micro-organisms, and its subsequent transfer upwards into the food chain. Thus, organisms at low trophic level, such as algae, play a crucial role. The aim of our study was to investigate the biological effects of selenite on Chlamydomonas reinhardtii, both at the sub-cellular level (effect on ultrastructure) and at the population level (effect on growth). The cells were grown under batch culture conditions in well-defined media and exposed to waterborne selenite at concentrations up to 500 μM; i.e. up to lethal conditions. Based on the relationship between Se concentration and cell density achieved after a 96 h exposure period, an EC50 of 80 μM with a 95% confidence interval ranging between 64 and 98 μM was derived. No adaptation mechanisms were observed: the same toxicity was quantified for algae pre-contaminated with Se. The inhibition of growth was linked to impairments observed at the sub-cellular level. The intensity of the ultrastructural damages caused by selenite exposure depended on the level and duration of exposure. Observations by TEM suggested chloroplasts as the first target of selenite cytotoxicity, with effects on the stroma, thylakoids and pyrenoids. At higher concentrations, we could observe an increase in the number and volume of starch grains. For cells collected at 96 h, electron-dense granules were observed. Energy-dispersive X-ray microanalysis revealed that these granules contained selenium and were also rich in calcium and phosphorus. This study confirms that the direct toxicity of selenite on the phytoplankton biomass is not likely to take place at concentrations found in the environment. At higher concentrations, the link between effects at the sub-cellular and population levels, the over-accumulation of starch, and the formation of dense granules containing selenium are reported for the first time in the literature for a

  5. ZnVSe2O7 and Cd6V2Se5O21: new d10 transition-metal selenites with V(IV) or V(V) cations.

    Science.gov (United States)

    Jiang, Hai-Long; Kong, Fang; Fan, Yang; Mao, Jiang-Gao

    2008-08-18

    Two new metal selenites with a combination of vanadium(IV) or vanadium(V) cations, namely, ZnVSe 2O 7 and Cd 6V 2Se 5O 21, have been synthesized by hydrothermal and high-temperature solid-state reactions, respectively. The structure of ZnVSe 2O 7 features a 3D network of vanadium(IV) selenite with 1D tunnels occupied by zinc(II) ions. The 3D network of vanadium(IV) selenite is formed by corner-sharing V (IV)O 6 octahedral chains bridged by selenite groups. In Cd 6V 2Se 5O 21, the interconnection of cadmium(II) ions by bridging and chelating selenite groups led to a 3D framework with large tunnels along the b axis, and the 1D chains of corner-sharing V (V)O 4 tetrahedra are inserted in the above large tunnels and are bonded to the cadmium selenite framework via Cd-O-V bridges. Both compounds exhibit broad emission bands in the blue-light region. Results of magnetic property measurements show there is significant antiferromagnetic interaction between V (4+) centers in ZnVSe 2O 7. The electronic structure calculations for both compounds have been also performed. PMID:18576595

  6. Safety Training: Sensibilisation aux gestes et postures de travail

    CERN Multimedia

    Laetitia Laddada

    2004-01-01

    Nous vous proposons un nouveau cours de sécurité lié aux manutentions manuelles (durée 1 jour) : Sensibilisation aux gestes et postures de travail. Si vous êtes amené à manipuler régulièrement des charges lourdes ou volumineuses, cette formation peut vous aider à prévenir les lésions musculaires ou dorsales. A l'issue de cette formation, vous serez capable d'adopter et d'appliquer les principes de base de sécurité physique et d'économie d'efforts dans les manipulations d'objets. Les cours sont pris en charge par la Commission de Sécurité. L'inscription EDH est obligatoire. Pour plus d'information, veuillez consulter les pages Formation & Développement (Groupe Sécurité). FORMATION EN SECURITE SAFETY TRAINING Laetitia Laddada 73811 - 79236 safety.training@cern.ch

  7. Safety Training: Sensibilisation aux gestes et postures de travail

    CERN Multimedia

    Laetitia Laddada

    2004-01-01

    If you wish to participate in one of the following courses, please discuss with your supervisor and apply electronically directly from the course description pages that can be found on the Web at: http://www.cern.ch/Training/ or fill in an 'application for training' form available from your Divisional Secretariat or from your DTO (Divisional Training Officer). Applications will be accepted in the order of their receipt.Nous vous proposons un nouveau cours de sécurité lié aux manutentions manuelles (durée 1 jour) : Sensibilisation aux gestes et postures de travail. Si vous êtes amené à manipuler régulièrement des charges lourdes ou volumineuses, cette formation peut vous aider à prévenir les lésions musculaires ou dorsales. A l'issue de cette formation, vous serez capable d'adopter et d'appliquer les principes de base de sécurité physique et d'&e...

  8. Separation and identification of selenotrisulfides in epithelial cell homogenates by LC-ICP-MS and LC-ESI-MS after incubation with selenite

    DEFF Research Database (Denmark)

    Gabel-Jensen, Charlotte; Gammelgaard, Bente; Bendahl, Lars; Stürup, Stefan; Jøns, Ole

    2006-01-01

    To elucidate how selenite is metabolised in the intestine after oral intake, it was incubated with homogenized epithelial cells from pigs. When the metabolites were analysed by LC-ICP-MS, two major selenium metabolites were separated in the supernatant from the homogenate. These metabolites were...... formed instantly but disappeared within 15 min. No other selenium-containing compounds appeared during this time. Hence, the secondary reaction products were either volatilised or precipitated. To verify the identity of the compounds, a larger amount of selenite was incubated with epithelial cells. The...... selenodiglutathione (GS-Se-SG). The two transient selenium compounds in the epithelial cell incubation mixture co-eluted with the synthesized Cys-Se-SG and GS-Se-SG, respectively. The identities of these compounds were verified by LC-ESI-MS. Hence, these selenium metabolites have now been identified by ESI-MS after...

  9. Peculiarities of antithyroid autoimmunity indicators in type 2 diabetic patients depending on leptin level in blood serum and their dynamics as a result of sodium selenite treatment

    OpenAIRE

    ABRAMOVA N.O.; PASHKOVSKA N.V.; BEREZOVA M.S.

    2015-01-01

    There were studied 46 patients with diabetes mellitus type 2 in order to identify the autoimmune processes directed against thyroid tissue and dependence of those changes on the level of leptin in blood serum. It was established that in patients with high leptin serum level antithyroid antibody titer increased. In order to adjust the levels of antithyroid antibodies sodium selenite was prescribed against the background of standard therapy. Statistically significant reduction in antibodies exp...

  10. Mechanism of Selenite Removal by a Mixed Adsorbent Based on Fe–Mn Hydrous Oxides Studied Using X-ray Absorption Spectroscopy

    KAUST Repository

    Chubar, Natalia

    2014-11-18

    © 2014 American Chemical Society. Selenium cycling in the environment is greatly controlled by various minerals, including Mn and Fe hydrous oxides. At the same time, such hydrous oxides are the main inorganic ion exchangers suitable (on the basis of their chemical nature) to sorb (toxic) anions, separating them from water solutions. The mechanism of selenite adsorption by the new mixed adsorbent composed of a few (amorphous and crystalline) phases [maghemite, MnCO3, and X-ray amorphous Fe(III) and Mn(III) hydrous oxides] was studied by extended X-ray absorption fine structure (EXAFS) spectroscopy [supported by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) data]. The complexity of the porous adsorbent, especially the presence of the amorphous phases of Fe(III) and Mn(III) hydrous oxides, is the main reason for its high selenite removal performance demonstrated by batch and column adsorption studies shown in the previous work. Selenite was bound to the material via inner-sphere complexation (via oxygen) to the adsorption sites of the amorphous Fe(III) and Mn(III) oxides. This anion was attracted via bidentate binuclear corner-sharing coordination between SeO3 2- trigonal pyramids and both FeO6 and MnO6 octahedra; however, the adsorption sites of Fe(III) hydrous oxides played a leading role in selenite removal. The contribution of the adsorption sites of Mn(III) oxide increased as the pH decreased from 8 to 6. Because most minerals have a complex structure (they are seldom based on individual substances) of various crystallinity, this work is equally relevant to environmental science and environmental technology because it shows how various solid phases control cycling of chemical elements in the environment.

  11. Supplementation with Sodium Selenite and Selenium-Enriched Microalgae Biomass Show Varying Effects on Blood Enzymes Activities, Antioxidant Response, and Accumulation in Common Barbel (Barbus barbus)

    Czech Academy of Sciences Publication Activity Database

    Kouba, A.; Velíšek, J.; Stará, A.; Masojídek, Jiří; Kozák, P.

    2014-01-01

    Roč. 2014, Article ID 408270 (2014). ISSN 2314-6141 R&D Projects: GA ČR GA521/09/0656; GA MŠk ED2.1.00/03.0110; GA MŠk LO1205; GA MŠk ED2.1.00/01.0024 Grant ostatní: GA JU(CZ) 087/2013/Z Institutional support: RVO:61388971 Keywords : selenite * selenium * antioxidant response Subject RIV: EE - Microbiology, Virology

  12. Effects of selenium supplementation as sodium selenite or selenized yeast and different amounts of vitamin E on selenium and vitamin E status of broilers

    Directory of Open Access Journals (Sweden)

    Marković Radmila

    2008-01-01

    Full Text Available The aim of this experiment was to determine the effects of broiler meal supplementation with different forms of selenium (as Na-selenite or selenized yeast and different amounts of vitamin E on selenium and vitamin E status in broiler tissues. A total number of 240 broilers (Cobb 500 were divided in four experimental groups supplemented with Se and vitamin E for a period of 42 days: group SS+E20 - 0.3 mg/kg sodium selenite and 20 IU of vitamin E; group SY+E20 - 0.3 mg/kg selenized yeast and 20 IU of vitamin E; group SS+E100 - 0.3 mg/kg sodium selenite and 100 IU of vitamin E; group SY+E100 - 0.3 mg/kg selenized yeast and 100 IU of vitamin E. Blood plasma Se and MDA concetrations and Se dependent GSH-Px were determined on days 1, 21 and 42, where's content of Se and vitamin E in breast muscle and liver were measured on days 21 and 42 of the experiment. Highest blood plasma glutathione peroxidase (GSH-Px activities were detected in groups SS+E20 and SS+E100. Supplementation with selenium enriched yeast did not result in a significant increase in plasma GSH-Px activity. Selenium and vitamin E concentrations in breast meat and liver were significantly higher in groups supplemented selenized yeast compared to those receiving Na-selenite. Selenium and vitamin E supplementation did not alter plasma MDA concentrations, but in tissues, selenized yeast provided a consistent, although not significant, reduction in MDA content. The increased dose of vitamin E supplemented in broiler meal was not justifiable on the basis of vitamin E tissue content and antioxidative effect.

  13. Variation in drug sensitivity of malignant mesothelioma cell lines with substantial effects of selenite and bortezomib, highlights need for individualized therapy.

    Directory of Open Access Journals (Sweden)

    Adam Szulkin

    Full Text Available BACKGROUND: Malignant mesothelioma cells have an epithelioid or sarcomatoid morphology, both of which may be present in the same tumor. The sarcomatoid phenotype is associated with worse prognosis and heterogeneity of mesothelioma cells may contribute to therapy resistance, which is often seen in mesothelioma. This study aimed to investigate differences in sensitivity between mesothelioma cell lines to anti-cancer drugs. We studied two novel drugs, selenite and bortezomib and compared their effect to four conventional drugs. We also investigated the immunoreactivity of potential predictive markers for drug sensitivity; Pgp, MRP-1, ERCC1, RRM1, TS, xCT and proteasome 20S subunit. MATERIALS AND METHODS: We treated six mesothelioma cell lines with selenite, bortezomib, carboplatin, pemetrexed, doxorubicin or gemcitabine as single agents and in combinations. Viability was measured after 24 and 48 hours. Immunocytochemistry was used to detect predictive markers. RESULTS: As a single agent, selenite was effective on four out of six cell lines, and in combination with bortezomib yielded the greatest response in the studied mesothelioma cell lines. Cells with an epithelioid phenotype were generally more sensitive to the different drugs than the sarcomatoid cells. Extensive S-phase arrest was seen in pemetrexed-sensitive cell lines. MRP-1 predicted sensitivity of cell lines to treatment with carboplatin and xCT predicted pemetrexed effect. CONCLUSIONS: The observed heterogeneity in sensitivity of mesothelioma cell lines with different morphology highlights the need for more individualized therapy, requiring development of methods to predict drug sensitivity of individual tumors. Selenite and bortezomib showed a superior effect compared to conventional drugs, motivating clinical testing of these agents as future treatment regime components for patients with malignant mesothelioma.

  14. Maturation arrest of neutrophils-a possible reason for the leucopenia in sodium selenite induced sub-chronic selenosis in cow calves.

    Science.gov (United States)

    Rampal, Satyavan; Kumar, Rakesh; Randhawa, Charanjit S; Sood, Naresh

    2008-01-01

    The effect of long-term administration of sodium selenite on leucocyte indices of peripheral blood of calves was determined. Nine calves, 9-12 months old, with an average body weight of 104kg were divided into three groups. Calves of groups 2 and 3 were administered with sodium selenite at 0.1 and 0.25mg/kg body weight for 98 consecutive days. The clinical signs characteristic of selenosis viz. alopecia, cracking of hooves, intradigital lesions and discoloration of hard palate, started appearing from 45 to 60 days onwards with high dose, whereas only subtle indications of toxicosis were observed in the low-dose group. The prolonged administration of sodium selenite produced a progressive and dose-dependent decline in the circulating leucocyte count with concomitant decline in the circulating neutrophil count. There was a high negative correlation (0.94) between blood selenium levels and neutrophils. Granulocyte/agranulocyte ratio was also significantly reduced in the treated animals. Evaluation of bone marrow smears revealed a decline in the myeloid to erythroid ratio. In addition, there was also maturation arrest of neutrophils at promyelocyte or myelocyte level as shown by differential granulocyte count in the bone marrow. The results indicated that host's immune response may be adversely affected. PMID:21783834

  15. Sexe et pouvoir aux États-Unis

    Directory of Open Access Journals (Sweden)

    Mokhtar BEN BARKA

    2003-06-01

    Full Text Available Les adversaires politiques de Bill Clinton aiment à dire que l’Histoire se souviendra de lui plus à cause de ses mensonges et de sa sexualité débordante qu’en raison de son bilan. En vérité, les frasques sexuelles du président Clinton ne sont que la perpétuation d’une tradition qui remonte aux origines de la nation américaine. “Long before there was a United States of America”, écrit Shelley Ross, “there was sex, scandal, and corruption in American politics. In fact, some of the most notoriou...

  16. Le date rape aux États-Unis

    OpenAIRE

    Fassin, Éric

    2013-01-01

    Pour appréhender une culture, on peut partir, non des représentations partagées, mais des polémiques qui la déchirent. Ainsi du date rape aux États-Unis, invention du féminisme universitaire et médiatique des années 1980 : en posant la question de la violence au cœur des rapports amoureux, le féminisme impose moins une orthodoxie qu’il ne propose une interprétation, doublement contestée durant les années quatre-vingt-dix par les intellectuels conservateurs et les essayistes « post-féministes ...

  17. Les TIC, un prétexte aux relations internationales

    OpenAIRE

    Rozzonelli, Carole

    2014-01-01

    La plupart de nos étudiants ne pouvant pas se permettre de passer quelques mois à l’étranger avant leur troisième année à l’université, nous avons développé une démarche pédagogique utilisant les nouvelles technologies. Il s’agit d’une expérience d’apprentissage originale : en nous référant fréquemment à la transmission en temps réel et aux nombreux services interactifs que l’Internet peut nous offrir de nos jours. Nos étudiants se servent de ressources en ligne pour l’apprentissage de l’angl...

  18. Shakespeare Cliff, rempart symbolique aux portes du royaume

    Directory of Open Access Journals (Sweden)

    Jeremy Price

    2006-02-01

    Full Text Available Figure 1 : Clarkson STANFIELD, Shakespeare Cliff, Dover, 1849, 1862« Il est une falaise, dont le front haut et courbeRegarde avec effroi dans l’abîme qu’elle enserre :Conduis-moi jusqu’à son bordEt je remédierai à la misère que tu souffresPar quelque riche objet ; de cet endroitJe n’aurai point besoin de guide. »Les lignes ci-dessus, tirées de l’Acte IV, Scène I du Roi Lear, font allusion aux falaises de Douvres, plus particulièrement à leur point culminant, un grand bloc de calcaire et de cr...

  19. Two novel calixarene functionalized iron oxide magnetite nanoparticles as a platform for magnetic separation in the liquid–liquid/solid–liquid extraction of oxyanions

    International Nuclear Information System (INIS)

    This article focuses on the syntheses of 25,27-bis[3-(N-ethylsulfonic acid)aminopropxy]-26,28-dihydroxy-5,11,17,23-tetra-tert-butyl-calix[4]arene (3) and 25,27-bis[3-(N-ethyl-dihydrogen phosphate)aminopropxy]-26,28-dihydroxy-5,11,17,23-tetra-tert-butyl-calix[4] arene (4) as well as their immobilization onto [3-(2,3-epoxypropoxy)-propyl]-trimethoxysilane-modified Fe3O4 magnetite nanoparticles, and the extraction abilities of four new extractants which were characterized by a combination of FTIR, 1H NMR, elemental analyses, transmission electron microscopy (TEM) and thermogravimetric analyses (TGA) involving electrostatic and hydrogen bonding interactions between the calixarene and oxide anions such as arsenate and dichromate anions. The extraction results indicate that these new calixarene derivatives having high extraction capabilities would be used as effective extractants for the removal of the dichromate/arsenate ions from water. - Highlights: ► Two novel calix[4]arene appended magnetic nanoparticles have been synthesized. ► Calixarene-grafted magnetic nanoparticles are becoming a hot topic. ► Long-term exposure to As(V)/Cr(VI) contaminated water causes various types of cancers. ► Clx-MNs have been effectively used for the extraction of toxic oxyanions. ► Two novel calix[4]arene appended magnetic nanoparticles have been synthesized

  20. A novel familial mutation in the PCSK1 gene that alters the oxyanion hole residue of proprotein convertase 1/3 and impairs its enzymatic activity.

    Directory of Open Access Journals (Sweden)

    Michael Wilschanski

    Full Text Available Four siblings presented with congenital diarrhea and various endocrinopathies. Exome sequencing and homozygosity mapping identified five regions, comprising 337 protein-coding genes that were shared by three affected siblings. Exome sequencing identified a novel homozygous N309K mutation in the proprotein convertase subtilisin/kexin type 1 (PCSK1 gene, encoding the neuroendocrine convertase 1 precursor (PC1/3 which was recently reported as a cause of Congenital Diarrhea Disorder (CDD. The PCSK1 mutation affected the oxyanion hole transition state-stabilizing amino acid within the active site, which is critical for appropriate proprotein maturation and enzyme activity. Unexpectedly, the N309K mutant protein exhibited normal, though slowed, prodomain removal and was secreted from both HEK293 and Neuro2A cells. However, the secreted enzyme showed no catalytic activity, and was not processed into the 66 kDa form. We conclude that the N309K enzyme is able to cleave its own propeptide but is catalytically inert against in trans substrates, and that this variant accounts for the enteric and systemic endocrinopathies seen in this large consanguineous kindred.

  1. High-resolution multinuclear magnetic resonance of inorganic solids. Oxygen-17 nuclear magnetic resonance studies of inorganic oxides, oxyanions, and silicates

    International Nuclear Information System (INIS)

    High resolution (8.45 and 11.7 Tesla) oxygen-17 NMR spectra have been obtained for a variety of oxides, oxyanions, carbonyls and for crystals and glasses in the system CaO-MgO-SiO2 using magic-angle sample spinning (MASS) and variable-angle sample spinning (VASS) techniques. The results indicate that a very wide range of oxygen-17 quadrupole coupling constants and linewidths are to be anticipated in solid state oxygen-17 NMR studies. The linewidth of solid Mg17O (0.3 ppm) is narrower than that of liquid water, due to the high symmetry of the oxygen site. In the SiO42- unit of forsterite, each nonequivalent oxygen is partially resolved, and split by a large second-order quadrupole interaction, permitting determination of the isotropic chemical shifts, quadrupole coupling constants, and electric field gradient tensor asymmetry parameters for each of the three types of oxygen present. The oxygen-17 spectra of many glasses contain multiple peaks due to non-bridging oxygens, bridging oxygens coordinated to non-Q4 silicons, and bridging oxygens coordinated to Q4 silicons. The oxygen-17 quadrupole coupling constant decreases as the percent ionic character of the cation oxygen bond increases. For metasilicate crystals and glasses, the oxygen-17 chemical shift of the non-bridging oxygen becomes progressively deshielded as the ionic potential of the cation present increases

  2. Application de la combustion catalytique aux turbines à gaz

    Science.gov (United States)

    Lebas, E.; Martin, G. H.

    2002-04-01

    La réduction des émissions d'oxydes d'azote sur turbines à gaz est obtenue par diminution de la température au sein de la chambre de combustion. Les techniques possibles comprennent l'injection d'eau ou de vapeur, la combustion pauvre et l'oxydation catalytique. Parmi celles-ci, la dernière est la plus prometteuse en terme de coûts et de performances, avec des émissions de NOx ramenées à un seul chiffre (typiquement inférieures à 3 ppm). L'IFP travaille depuis maintenant 10 ans sur l'adaptation de la combustion catalytique aux turbines à gaz. Les études ont été conduites au travers de projets européen tels que AGATA (Advance Gas Turbine for Automotive Application) et ULECAT (Ultra Low CATalytic combustor for dual fuel gas turbine). Le premier projet était destiné au développement de véhicules hybrides et le second à la combustion stationnaire de biogaz et de combustible Diesel. Les études en cours dans ce domaine portent sur le développement d'une unité de cogénération intégrant une microturbine à combustion catalytique. Les travaux menés à l'IFP concernent la mise au point de catalyseurs répondant aux exigences de la combustion catalytique en turbine à gaz et le développement de chambres de combustion permettant la mise en oeuvre de ces catalyseurs.

  3. Constitutive auxin response in Physcomitrella reveals complex interactions between Aux/IAA and ARF proteins.

    Science.gov (United States)

    Lavy, Meirav; Prigge, Michael J; Tao, Sibo; Shain, Stephanie; Kuo, April; Kirchsteiger, Kerstin; Estelle, Mark

    2016-01-01

    The coordinated action of the auxin-sensitive Aux/IAA transcriptional repressors and ARF transcription factors produces complex gene-regulatory networks in plants. Despite their importance, our knowledge of these two protein families is largely based on analysis of stabilized forms of the Aux/IAAs, and studies of a subgroup of ARFs that function as transcriptional activators. To understand how auxin regulates gene expression we generated a Physcomitrella patens line that completely lacks Aux/IAAs. Loss of the repressors causes massive changes in transcription with misregulation of over a third of the annotated genes. Further, we find that the aux/iaa mutant is blind to auxin indicating that auxin regulation of transcription occurs exclusively through Aux/IAA function. We used the aux/iaa mutant as a simplified platform for studies of ARF function and demonstrate that repressing ARFs regulate auxin-induced genes and fine-tune their expression. Further the repressing ARFs coordinate gene induction jointly with activating ARFs and the Aux/IAAs. PMID:27247276

  4. Constitutive auxin response in Physcomitrella reveals complex interactions between Aux/IAA and ARF proteins

    Science.gov (United States)

    Lavy, Meirav; Prigge, Michael J; Tao, Sibo; Shain, Stephanie; Kuo, April; Kirchsteiger, Kerstin; Estelle, Mark

    2016-01-01

    The coordinated action of the auxin-sensitive Aux/IAA transcriptional repressors and ARF transcription factors produces complex gene-regulatory networks in plants. Despite their importance, our knowledge of these two protein families is largely based on analysis of stabilized forms of the Aux/IAAs, and studies of a subgroup of ARFs that function as transcriptional activators. To understand how auxin regulates gene expression we generated a Physcomitrella patens line that completely lacks Aux/IAAs. Loss of the repressors causes massive changes in transcription with misregulation of over a third of the annotated genes. Further, we find that the aux/iaa mutant is blind to auxin indicating that auxin regulation of transcription occurs exclusively through Aux/IAA function. We used the aux/iaa mutant as a simplified platform for studies of ARF function and demonstrate that repressing ARFs regulate auxin-induced genes and fine-tune their expression. Further the repressing ARFs coordinate gene induction jointly with activating ARFs and the Aux/IAAs. DOI: http://dx.doi.org/10.7554/eLife.13325.001 PMID:27247276

  5. Increasing Selenium and Yellow Pigment Concentrations in Foxtail Millet (Setaria italica L.) Grain with Foliar Application of Selenite.

    Science.gov (United States)

    Ning, Na; Yuan, Xiang-Yang; Dong, Shu-Qi; Wen, Yin-Yuan; Gao, Zhen-Pan; Guo, Mei-Jun; Guo, Ping-Yi

    2016-03-01

    Although addition of selenium (Se) is known to increase Se in crops, it is unclear whether exogenous Se is linked to nutritional and functional components in foxtail millet (Setaria italica L.). In this study, we examined the potential of increasing Se and yellow pigment (YP) in foxtail millet grain by foliar application of Se. Field experiments were conducted during the growing season of foxtail millet in 2013 and 2014 to assess the effects of foliar spray of sodium selenite (10-210 g Se ha(-1)) on the yield, Se uptake and accumulation, total YP, and microminerals in the grain. Average grain yields with Se application were 5.60 and 4.53 t ha(-1) in the 2 years, showing no significant differences from the unfertilized control. However, grain Se concentration increased linearly with Se application rate, by 8.92 and 6.09 μg kg(-1) in the 2 years with application of 1 g Se ha(-1) (maximum grain recovery rates of Se fertilizer, 52 and 28 %). Likewise, total grain YP concentration markedly increased by 0.038 and 0.031 mg kg(-1) in the 2 years with application of 1 g Se ha(-1). Grain Mn, Cu, Fe, and Zn concentrations were not significantly affected by Se application. This study indicated that foliar application of Se effectively and reliably increased the concentrations of Se and YP in foxtail millet grain without affecting the yield or mineral micronutrient concentrations. Thus, foliar-applied selenite has a significant potential to increase the concentrations of selenium and YP (putative lutein (Shen, J Cereal Sci 61:86-93, 2015; Abdel-Aal, Cereal Chem 79:455-457, 2002; Abdel-Aal, J Agric Food Chem 55:787-794, 2007)) of foxtail millet and, thus, the health benefits of this crop. PMID:26201681

  6. Effects of systemic or topical administration of sodium selenite on early radiation effects in mouse oral mucosa

    Energy Technology Data Exchange (ETDEWEB)

    Gehrisch, A. [Dept. of Radiotherapy and Radiooncology, Medical Faculty Carl Gustav Carus, Technical Univ. of Dresden (Germany); Doerr, W. [Dept. of Radiotherapy and Radiooncology, Medical Faculty Carl Gustav Carus, Technical Univ. of Dresden (Germany); Experimental Center, Medical Faculty Carl Gustav Carus, Technical Univ. of Dresden (Germany)

    2007-01-15

    Purpose: to quantify the effect of sodium selenite (selenium) on radiation-induced oral mucositis (mouse) after subcutaneous or topical administration. Material and methods: mucosal ulceration of the lower epithelium of mouse tongue was analyzed. Selenium (5 {mu}g) was applied subcutaneously (s.c.) or locally, 60 min or 30 min prior to irradiation, respectively. In combination with single-dose irradiation, a single selenium application was given. With daily fractionated irradiation (3 Gy/fraction) for 1 week (days 0-4), selenium was administered at all 5 days of irradiation. With ten fractions over 2 weeks, selenium was applied in week 1, week 2, or both. All fractionation protocols were terminated by graded test doses to generate full dose-effect curves. Results: in a single-dose control experiment, the ED{sub 50} (dose after which ulcer induction is expected in 50% of the mice) was 12.9 {+-} 1.6 Gy. Selenium increased the ED{sub 50} to 17.7 {+-} 2.6 Gy (s.c.; p = 0.0003) and 16.3 {+-} 3.0 Gy (local; p = 0.0104). The ED{sub 50} for test irradiation after 5 x 3 Gy was 7.4 {+-} 2.2 Gy. Subcutaneous administration of selenium resulted in an ED{sub 50} of 11.5 {+-} 2.0 Gy (p = 0.0015), local application yielded an ED{sub 50} of 10.0 {+-} 2.1 Gy (p = 0.0284). The ED{sub 50} for test irradiation after 10 x 3 Gy/2 weeks was 8.0 {+-} 1.7 Gy. Subcutaneous or local administration of selenium in week 1 yielded a significant increase in ED{sub 50} to 10.5 {+-} 1.0 Gy (p = 0.0069) and 10.7 {+-} 1.0 Gy (p = 0.0039), respectively. By clear contrast, selenium administration in week 2 had no significant effect. Administration in both weeks resulted in an ED{sub 50} of 9.1 {+-} 2.0 Gy (s.c.; p = 0.2747) and 9.7 {+-} 1.4 Gy (local; p = 0.0541). Conclusion: administration of sodium selenite during clinically relevant fractionated irradiation protocols has a significant effect during the initial treatment phase, i.e., week 1 in the mouse. Therefore, in clinical radiotherapy, the

  7. The anticancer effects of sodium selenite and selenomethionine on human colorectal carcinoma cell lines in nude mice.

    Science.gov (United States)

    Yang, Yang; Huang, Fang; Ren, Yun; Xing, Lu; Wu, Ying; Li, Zhushi; Pan, Huazhen; Xu, Caimin

    2009-01-01

    The studies were carried out on nude mice bearing human colorectal carcinoma SW480 cell line xenografts to evaluate the chemotherapeutic potential of selenium containing compounds such as sodium selenite (SSe) and selenomethionine (SeMet). Three doses of anticancer drugs were used, including 0.1 mg/kg/day SSe (LSSe), 2 mg/kg/day SSe (HSSe), and 2 mg/kg/day SeMet. We explored the anticancer effect of SSe and SeMet administered by IP injection for 21 days. We observed the pathologic changes and the cell apoptosis in tumor tissue by HE staining and TUNNEL assay after HSSe and SeMet treatment. GSH level and antioxidant enzyme GPX activity in tumor tissues were assessed. In addition, Western blotting was used to detect the expression of apoptosis-related proteins. The results suggested that HSSe and SeMet had significantly inhibited tumor growth in vivo. We also observed the pathologic changes and cell apoptosis in tumor tissues after HSSe and SeMet treatment. GSH level was a bit increased but the GPX activity was reduced. Moreover, SSe and SeMet treatment downregulated the expression of the protein Bcl-xL, increased the expression of Bax, Bad, and Bim, and activated caspase-9. SSe and SeMet may be the selective, low-toxic anticancer agents to treat human colorectal carcinoma cancer. PMID:19911698

  8. Selenite reduction in Boom clay: Effect of FeS2, clay minerals and dissolved organic matter

    International Nuclear Information System (INIS)

    Several experiments were set up to study Se speciation and solubility in the reducing Boom clay environment, starting from oxidized Se species which were added in oversaturation with respect to the thermodynamic solubility of reduced Se solid phases. Upon introduction of SeO32- to FeS2-containing samples, adsorption of SeO32- occurred at the FeS2 surface, and led to a reduction and precipitation of a Se0 solid phase with a solubility of 3x10-9 M (after 60 days). In the presence of humic substances, an association of Se with these humic substances was observed and the 3x10-9 M solubility limit was not reached in the same time delay. Upon introduction of SeO32- to Boom clay suspensions (equilibration up to 9 months), the initial adsorption of SeO32- on the solid phase was increased with respect to systems containing only FeS2, due to the presence of (illite) clay minerals. This competing adsorption process, and the presence of humic substances, again decreased the kinetics of reduction with respect to FeS2 samples. Also, an association of Se with Boom clay humic substances was observed, and amounted up to ∼10-7 M in some samples after 9 months equilibration. - Selenite reduction by FeS2 is kinetically controlled, with clay minerals and organic matter playing an important role

  9. RELATIVE CHLOROPHYLL CONTENT CHANGES DURING UPTAKING OF SELENITE AND SELENATE BY MAIZE PLANTS GROWN IN NUTRIENT SOLUTION

    Directory of Open Access Journals (Sweden)

    Farzaneh Garousi

    2015-02-01

    Full Text Available Chlorophyll content (chl, one of the most important physiological parameters related to plant photosynthesis, is usually used to predict plant potential and portable, non-destructive chlorophyll meters could be a valuable and effective tool for estimating Relative Chlorophyll Content (RCC in leaves. In this study, two species of soluble inorganic Selenium forms, selenite (SeIV and selenate (SeVI at different concentrations were investigated on maize plants that were growing in nutrient solutions during 2 weeks and changes of RCC within this time was monitored. It means chlorophyll content of three leaves of maize when everyone grew completely was measured according to Special Products Analysis Division (SPAD value and the results revealed that high concentrations of SeIV (10, 30 and 90 mg.kg-1 were toxic for maize even lower amounts (1 and 3 mg.kg-1 had effects of damage on it while this state wasn’t adjusted for lower concentrations of SeVI (1 and 3 mg.kg-1 and treated samples didn’t have significant differences with controls although in higher amounts (10 and 30 mg.kg-1 toxic effects were seen in them, too.

  10. Les représentations sociales du travail dans des parcours de retour aux études aux niveaux collégial et universitaire

    OpenAIRE

    Claude Julie Bourque; Pierre Doray

    2009-01-01

    Cet article porte sur le volet éducatif de la production et de la reproduction de la main-d’œuvre hautement qualifiée par l’examen des processus en jeu au moment des retours aux études dans des programmes de formation technique et de génie. Nous nous intéressons en particulier à une situation emblématique des référentiels politiques récents en matière d’éducation, soit les retours aux études. Nous cherchons à mieux comprendre comment le retour aux études se réalise, comment les représentation...

  11. The Reaction Specificity of Nanoparticles in Solution: Application to the Reaction of Nanoparticulate Iron and Iron-Bimetallic Compounds with Chlorinated Hydrocarbons and Oxyanions

    International Nuclear Information System (INIS)

    The prospect for better remediation technologies using nanoparticles of iron, iron oxides, and iron with catalytic metals (i.e., bimetallics) has potentially transformative implications for environmental management of DOE sites across the country. Of particular interest is the potential to avoid undesirable products from the degradation of chlorinated solvents by taking advantage of the potential selectivity of nanoparticles to produce environmentally benign products from CCl4. Chlorinated solvents are the most frequently reported subsurface contaminants across the whole DOE complex, and carbon tetrachloride (CCl4) is the chlorinated solvent that is of greatest concern at Hanford (U. S. Department Energy 2001). In evaluating technologies that might be used at the site, a critical concern will be that CCl4 reduction usually occurs predominantly by hydrogenolysis to chloroform (CHCl3) and methylene chloride (CH2Cl2), both of which are nearly as problematic as CCl4 (National Research Council, 1978). Competing reaction pathways produce the more desirable products carbon monoxide (CO) and/or formate (HCOO-), and possibly CO2, but the proportion of reaction that occurs by these pathways is highly variable. Iron-based metallic and oxide nanoparticles have been shown to have enhanced reactivity towards a variety of chemical species, including chlorinated hydrocarbons and reducible oxyanions. Possibly of greater importance is the ability of nanoparticles to select for specific reaction products, potentially facilitating the formation of more environmentally acceptable products. The purpose of this study is to develop a fundamental understanding of the mechanism responsible for the overall particle reactivity and reaction selectivity of reactive metal and oxide nanoparticles. To achieve this objective the project involves the synthesis (using solution and vacuum synthesis methods) and characterization of well-defined nanoparticles, measurements of particle reactivity in

  12. Introduction aux études sur le genre. - 2e éd. revue et augm.

    NARCIS (Netherlands)

    L. Bereni; S. Chauvin; A. Jaunait; A. Revillard

    2012-01-01

    Pourquoi offre-t-on des poupées aux filles et des voitures aux garçons ? Pourquoi les femmes gagnent-elles moins que les hommes ? Comment expliquer qu’elles effectuent les deux tiers du travail domestique ? Pourquoi est-ce si mal vu pour un homme d’être efféminé ? Le pouvoir est-il intrinsèquement m

  13. Aux limites de la physique les paradoxes quantiques

    CERN Document Server

    Rothen, François

    2012-01-01

    Dans l’esprit des pères fondateurs de la science moderne, les phénomènes matériels se déroulent selon un schéma unique. La cause précède nécessairement l’effet, et la connaissance de l’effet permet de remonter à la cause. Sur la scène de la nature, le hasard n’occupe qu’une place congrue. On ne fait appel à lui que pour pallier notre ignorance. Dans les années 1920, la révolution quantique bouleverse ce cadre rigide. Elle accorde une place de choix au hasard, si malmené jusqu’alors, puis elle met en scène une constellation de phénomènes inexplicables aux yeux de la science dite classique. Après une courte introduction historique, l’auteur met ses lecteurs au contact de certains de ces phénomènes si contraires à l’intuition. Refusant l’aide du langage mathématique, il les convie à pénétrer dans un monde quantique qui déconcerte le novice avant de l’éblouir par sa nouveauté et sa cohérence. Un accent particulier est mis sur une application nouvelle de la physiqu...

  14. Structures of zinc selenite and copper selenite

    International Nuclear Information System (INIS)

    ZnSeO3, Mr=192.3, orthorhombic, Pcab, a=6.233(1), b=7.200(2), c=11.987(3)A, V=537.9(3) A3, Z=8, Dx=4.75 g cm-3, λ(MoKα)=0.71073 A, μ=236.7 cm-1, F(000)=704, T=297 K, R=0.035 for 608 observed reflections. CuSeO3, Mr=190.5, orthorhombic, Pcab, a=5.954(1), b=7.006(1), c=12.232(2) A, V=510.2(1) A3, Z=8, Dx=4.96 g cm-3, λ(MoKα)=0.71073 A, μ=239.4 cm-1, F(000)=696, T=297 K, R=0.037 for 675 observed reflections. The cation coordinations are trigonal bipyramidal and trigonal pyramidal for (Zn, Cu) and Se, respectively. The trigonal bipyramids share edges and corners to form a sheet parallel to (011). These sheets are linked along χ by the SeO3 groups that share corners with adjacent sheets to form an open framework. (orig.)

  15. Protective effect of sodium selenite and zinc sulfate on intensive swimming-induced testicular gamatogenic and steroidogenic disorders in mature male rats.

    Science.gov (United States)

    Jana, Kuladip; Samanta, Pravat K; Manna, Indranil; Ghosh, Prasanta; Singh, Narendra; Khetan, Ramawatar P; Ray, Binoy R

    2008-10-01

    To investigate the ameliorative potential of sodium selenite and zinc sulfate on intensive-swimming-induced testicular disorders, 48 Wistar male rats (age, 4 months; mass, 146.2 +/- 3.6 g) were randomly divided into 4 groups: the unexercised-control group (n = 12); the exercised group (n = 12); the control supplemented group (n = 12); and the exercised supplemented group (n = 12). For 10 weeks, the exercised rats underwent a protocol that consisted of 4 h.d-1 swimming, for 6 d.week-1; the control rats did not exercise. For 10 weeks, both the supplemented groups received an oral daily dose of a combination of sodium selenite and zinc sulfate (6 and 3 mg.kg body mass-1, respectively). After 10 weeks, a significant reduction (p rats in the exercised group, compared with rats in both control groups, in paired testicular masses; in epididymal sperm count; in testicular Delta5, 3beta-hydroxysteroid dehydrogenase (HSD) and 17beta-HSD; in plasma levels of testosterone, luteinizing hormone, follicle-stimulating hormone, and prolactin; in the numbers of preleptotine spermatocytes, midpachytene spermatocytes, and stage 7 spermatids of the stage VII seminiferous epithelium cycle; and in fertility performance. As well, a significant increase (p exercised group, compared with both control groups, in plasma corticosterone levels and in testicular content of malondialdehyde and catalase activity. At the same time, there was a significant reduction (p exercised group, compared with both control groups, in plasma concentrations of zinc and selenium; in the testicular content of glutathione (GSH), the glutathione and glutathione disulphide (GSSG) ratio, ascorbic acid, and alpha-tocopherol; and in testicular activities of superoxide dismutase, glutathione-peroxidase, and glutathione-S-transferase in the testes. No significant changes were seen in the number of spermatogonia-A from the stage VII seminiferous epithelium cycle or the testicular content of GSSG among the groups. Sodium

  16. Quality of meat and selenium content in tissues of rabbits fed diets supplemented with sodium selenite, selenized yeast and selenized algae

    OpenAIRE

    Marounek, M; Dokoupilová, A.; Volek, Z.; Hoza, I.

    2009-01-01

    Forty rabbits weaned at 35 d of age were randomly assigned to 4 groups of 10 rabbits each. The rabbits were fed a basal granulated diet containing 0.08 mg Se/kg, or diets obtained from basal diet, supplemented with sodium selenite, selenized yeast (Se-yeast) or selenized algae Chlorella (Se-algae) to increase the Se concentration to 0.40 mg/kg. After 6 weeks rabbits were slaughtered at 77 d of age. Samples of meat, liver and hair were analyzed. The Se supplements did not influence rabbit grow...

  17. Sensitivities of selenite, selenate, selenomethionine and trimethylselenonium ion in aqueous solution and in blood plasma - ETAAS compared with ICP-MS

    DEFF Research Database (Denmark)

    Gammelgaard, B.; Larsen, Erik Huusfeldt

    1998-01-01

    Aqueous solutions and blood plasma spiked with selenite (Se(IV)), selenate (Se(VI)), selenomethionine (SeMet) or trimethylselenonium (TMSe) iodide were analyzed by Zeeman-corrected electrothermal atomic absorption spectrometry (ETAAS) using palladium as a chemical modifier, and by inductively...... coupled plasma mass spectrometry (ICP-MS). Using ETAAS, the sensitivities for Se(IV), SeMet and TMSe in aqueous solution were similar, whereas the sensitivity of Se(VI) was 63% of that value. In blood plasma, the ETAAS sensitivities of Se(IV) and Se(VI) were equal, whereas the sensitivities of SeMet and...

  18. Lead (II) selenite halides Pb3(SeO3)2X2 (X = Br, I): Synthesis and crystal structure

    International Nuclear Information System (INIS)

    Two lead selenite halides, Pb3(SeO3)2Br2 and Pb3(SeO3)2I2, have been prepared by solid-phase synthesis and structurally characterized. These compounds are isotypic and can be considered 3D with a microporous framework composed of lead polyhedra (distorted Archimedean antiprisms formed by oxygen and halogen atoms). The framework contains channels oriented in the [010] direction. These channels contain selenium atoms, which are bound with framework oxygen atoms belonging to different lead polyhedra.

  19. Structural basis for the auxin-induced transcriptional regulation by Aux/IAA17.

    Science.gov (United States)

    Han, Mookyoung; Park, Yangshin; Kim, Iktae; Kim, Eun-Hee; Yu, Tae-Kyung; Rhee, Sangkee; Suh, Jeong-Yong

    2014-12-30

    Auxin is the central hormone that regulates plant growth and organ development. Transcriptional regulation by auxin is mediated by the auxin response factor (ARF) and the repressor, AUX/IAA. Aux/IAA associates with ARF via domain III-IV for transcriptional repression that is reversed by auxin-induced Aux/IAA degradation. It has been known that Aux/IAA and ARF form homo- and hetero-oligomers for the transcriptional regulation, but what determines their association states is poorly understood. Here we report, to our knowledge, the first solution structure of domain III-IV of Aux/IAA17 (IAA17), and characterize molecular interactions underlying the homotypic and heterotypic oligomerization. The structure exhibits a compact β-grasp fold with a highly dynamic insert helix that is unique in Aux/IAA family proteins. IAA17 associates to form a heterogeneous ensemble of front-to-back oligomers in a concentration-dependent manner. IAA17 and ARF5 associate to form homo- or hetero-oligomers using a common scaffold and binding interfaces, but their affinities vary significantly. The equilibrium dissociation constants (KD) for homo-oligomerization are 6.6 μM and 0.87 μM for IAA17 and ARF5, respectively, whereas hetero-oligomerization reveals a ∼ 10- to ∼ 100-fold greater affinity (KD = 73 nM). Thus, individual homo-oligomers of IAA17 and ARF5 spontaneously exchange their subunits to form alternating hetero-oligomers for transcriptional repression. Oligomerization is mainly driven by electrostatic interactions, so that charge complementarity at the interface determines the binding affinity. Variable binding affinity by surface charge modulation may effectively regulate the complex interaction network between Aux/IAA and ARF family proteins required for the transcriptional control of auxin-response genes. PMID:25512488

  20. A group of new selenite-chlorides of strontium and d-metals (Co,Ni): Synthesis, thermal behavior and crystal chemistry

    International Nuclear Information System (INIS)

    The new selenite-chlorides with composition Sr3(SeO3)2Cl2 (I) and Sr2M(SeO3)2Cl2 (M=Co, Ni (II and III)) were obtained. They crystallize in monoclinic system I: space group C2/m, a=13.203(2) A, b=5.5355(8) A, c=6.6170(10) A, β=95.89(1)o, Z=2; II Space group P21/n, a=5.3400(10) A, b =6.4279(6) A, c=12.322(1) A, β=92.44(1)o, Z=2; III: space group P21/n, a=5.3254(11) A, b=6.4363(13) A, c=12.197(2), β=92.53(3)o, Z=2. All three compounds are constructed in the same manner. Sr polyhedra form infinite layers, which are interconnected into a 3D framework by means of Sr polyhedra in the case of I or Co and Ni polyhedra in the case of II and III. Se atoms are situated inside the channels of the 3D framework. The topological analysis of ELF for I confirmed that the lone electron pairs of SeO3 groups are located inside these channels. - Graphical abstract: Three new selenite-chlorides Sr3(SeO3)2Cl2 and Sr2M(SeO3)2Cl2 (M= Co,Ni)

  1. Precise AuxPt1-x Alloy Nanoparticle Array of Tunable Composition for Catalytic Applications

    Science.gov (United States)

    Jahn, Sarah; Lechner, Sebastian J.; Freichels, Helene; Möller, Martin; Spatz, Joachim P.

    2016-02-01

    A 3-dimensional Block Copolymer Micellar nanoLithography (BCML) process was used to prepare AuxPt1-x alloy nanoparticles (NPs) monodisperse in size and composition, strongly anchored onto SiO2-particles (0.2 wt.% AuxPt1-x/SiO2). The particles possess a face-centered cubic (fcc) crystal structure and their size could be varied from 3-12 nm. We demonstrate the uniformity of the Au/Pt composition by analyzing individual NPs by energy-dispersive X-ray spectroscopy. The strongly bound AuxPt1-x NPs catalyzed the oxidation of CO with high activity. Thermal ageing experiments in pure CO2 as well as in ambient atmosphere demonstrated stability of the size distribution for times as long as 22 h.

  2. Dietary sodium selenite affects host intestinal and systemic immune response and disease susceptibility to necrotic enteritis in commercial broilers.

    Science.gov (United States)

    Xu, S Z; Lee, S H; Lillehoj, H S; Bravo, D

    2015-01-01

    1. This study was to evaluate the effects of supplementary dietary selenium (Se) given as sodium selenite on host immune response against necrotic enteritis (NE) in commercial broiler chickens. 2. Chicks were fed from hatching on a non-supplemented diet or diets supplemented with different levels of Se (0.25, 0.50, and 1.00 Se mg/kg). To induce NE, broiler chickens were orally infected with Eimeria maxima at 14 d of age and then with Clostridium perfringens 4 d later using our previously established NE disease model. 3. NE-associated clinical signs and host protective immunity were determined by body weight changes, intestinal lesion scores, and serum antibodies against α-toxin and necrotic enteritis B (NetB) toxin. The effects of dietary Se on the gene expression of pro-inflammatory cytokines e.g., interleukin (IL)-1β, IL-6, IL-8LITAF (lipopolysaccharide-induced TNFα-factor), tumour necrosis factor (TNF) SF15, and inducible nitric oxide synthase (iNOS), glutathione peroxidase 7 (GPx7), and avian β-defensins (AvBD) 6, 8, and 13 (following NE infection) were analysed in the intestine and spleen. 4. The results showed that dietary supplementation of newly hatched broiler chicks with 0.25 Se mg/kg from hatch significantly reduced NE-induced gut lesions compared with infected birds given a non-supplemented diet. The levels of serum antibody against the NetB toxin in the chicks fed with 0.25 and 0.50 mg/kg Se were significantly higher than the non-supplemented control group. The transcripts for IL-1β, IL-6, IL-8, iNOS, LITAF, and GPx7, as well as AvBD6, 8, and 13 were increased in the intestine and spleen of Se-supplemented groups, whereas transcript for TNFSF15 was decreased in the intestine. 5. It was concluded that dietary supplementation with optimum levels of Se exerted beneficial effects on host immune response to NE and reduced negative consequence of NE-induced immunopathology. PMID:25387235

  3. Change of selenium in plasma of dairy cows receiving two levels of sodium-selenite during the transition period

    Directory of Open Access Journals (Sweden)

    A. Giubbiotti

    2010-04-01

    Full Text Available With the aim to study the plasma Se content during transition period, 2 groups of 12 dairy cows were monitored the month before and after calving. In stall 1 (S1 cows were tied and individually fed, in stall2 (S2 cows were free and fed TMR. In both stalls cows were supplied with Se as Na-selenite. In S1 3 mg/d of Se were fed mixed with corn silage while, in S2, Se was offered with TMR, in dry period 2 mg/d were added with a mineral-vitamin supplement, in lactation 2.6 mg/d (when DMI was 22.2 kg/d with the concentrate. Forages, the same for both stalls, and concentrates were sampled for chemical composition and Se determination. Cows were checked for milk yield and its content of somatic cells (SCC, health problems, and bled for Se determination in plasma. Average Se intake was higher in S1, in both dry (4.08 vs 2.76 mg/d and lactating (5.80 vs 2.11 mg/d period. Besides the supplementation, differences depended on high Se intake in S1 with the concentrate (increased after calving to 11.5 kg/DM on d 30 and containing 0.24 mg/kg DM of Se. According to the intake, plasma Se content resulted higher in S1 in dry (1.20 vs 0.74 μmol/L and lactating (1.47 vs 0.62 μmol/L cows. In close-up plasma Se decreased in both groups, in first days of lactation increased in S1, while decreased in S2 to level indicating a deficient intake (0.50 μmol/L. These results confirm the link between Se intake and its plasma level. Finally, Se plasma content did not seem related to cow health status during transition period.

  4. Genome-Wide Analysis and Characterization of Aux/IAA Family Genes in Brassica rapa.

    Directory of Open Access Journals (Sweden)

    Parameswari Paul

    Full Text Available Auxins are the key players in plant growth development involving leaf formation, phototropism, root, fruit and embryo development. Auxin/Indole-3-Acetic Acid (Aux/IAA are early auxin response genes noted as transcriptional repressors in plant auxin signaling. However, many studies focus on Aux/ARF gene families and much less is known about the Aux/IAA gene family in Brassica rapa (B. rapa. Here we performed a comprehensive genome-wide analysis and identified 55 Aux/IAA genes in B. rapa using four conserved motifs of Aux/IAA family (PF02309. Chromosomal mapping of the B. rapa Aux/IAA (BrIAA genes facilitated understanding cluster rearrangement of the crucifer building blocks in the genome. Phylogenetic analysis of BrIAA with Arabidopsis thaliana, Oryza sativa and Zea mays identified 51 sister pairs including 15 same species (BrIAA-BrIAA and 36 cross species (BrIAA-AtIAA IAA genes. Among the 55 BrIAA genes, expression of 43 and 45 genes were verified using Genebank B. rapa ESTs and in home developed microarray data from mature leaves of Chiifu and RcBr lines. Despite their huge morphological difference, tissue specific expression analysis of BrIAA genes between the parental lines Chiifu and RcBr showed that the genes followed a similar pattern of expression during leaf development and a different pattern during bud, flower and siliqua development stages. The response of the BrIAA genes to abiotic and auxin stress at different time intervals revealed their involvement in stress response. Single Nucleotide Polymorphisms between IAA genes of reference genome Chiifu and RcBr were focused and identified. Our study examines the scope of conservation and divergence of Aux/IAA genes and their structures in B. rapa. Analyzing the expression and structural variation between two parental lines will significantly contribute to functional genomics of Brassica crops and we belive our study would provide a foundation in understanding the Aux/IAA genes in B. rapa.

  5. Genome-Wide Analysis and Characterization of Aux/IAA Family Genes in Brassica rapa.

    Science.gov (United States)

    Paul, Parameswari; Dhandapani, Vignesh; Rameneni, Jana Jeevan; Li, Xiaonan; Sivanandhan, Ganesan; Choi, Su Ryun; Pang, Wenxing; Im, Subin; Lim, Yong Pyo

    2016-01-01

    Auxins are the key players in plant growth development involving leaf formation, phototropism, root, fruit and embryo development. Auxin/Indole-3-Acetic Acid (Aux/IAA) are early auxin response genes noted as transcriptional repressors in plant auxin signaling. However, many studies focus on Aux/ARF gene families and much less is known about the Aux/IAA gene family in Brassica rapa (B. rapa). Here we performed a comprehensive genome-wide analysis and identified 55 Aux/IAA genes in B. rapa using four conserved motifs of Aux/IAA family (PF02309). Chromosomal mapping of the B. rapa Aux/IAA (BrIAA) genes facilitated understanding cluster rearrangement of the crucifer building blocks in the genome. Phylogenetic analysis of BrIAA with Arabidopsis thaliana, Oryza sativa and Zea mays identified 51 sister pairs including 15 same species (BrIAA-BrIAA) and 36 cross species (BrIAA-AtIAA) IAA genes. Among the 55 BrIAA genes, expression of 43 and 45 genes were verified using Genebank B. rapa ESTs and in home developed microarray data from mature leaves of Chiifu and RcBr lines. Despite their huge morphological difference, tissue specific expression analysis of BrIAA genes between the parental lines Chiifu and RcBr showed that the genes followed a similar pattern of expression during leaf development and a different pattern during bud, flower and siliqua development stages. The response of the BrIAA genes to abiotic and auxin stress at different time intervals revealed their involvement in stress response. Single Nucleotide Polymorphisms between IAA genes of reference genome Chiifu and RcBr were focused and identified. Our study examines the scope of conservation and divergence of Aux/IAA genes and their structures in B. rapa. Analyzing the expression and structural variation between two parental lines will significantly contribute to functional genomics of Brassica crops and we belive our study would provide a foundation in understanding the Aux/IAA genes in B. rapa. PMID

  6. Ti1-xAux Alloys: Hard Biocompatible Metals and Their Possible Applications

    Science.gov (United States)

    Svanidze, Eteri; Besara, Tiglet; Ozaydin, M. Fevzi; Xin, Yan; Han, Ke; Liang, Hong; Siegrist, Theo; Morosan, Emilia

    2015-03-01

    The search for new hard materials is often challenging from both theoretical and experimental points of view. Furthermore, using materials for biomedical applications calls for alloys with high biocompatibility which are even more sparse. The Ti1-xAux (0 . 22 dental, and prosthetic applications, where they could be used as both permanent and temporary components. Additionally, the ability of Ti1-xAux alloys to adhere to ceramic parts could reduce the weight and cost of these components. The work at Rice was supported by NSF DMR 0847681 (E.M. and E.S.).

  7. Les raisons d'être de la franchise dans les transactions de services aux entreprises

    OpenAIRE

    Allam, Délila

    2008-01-01

    La franchise, comme forme hybride de coordination procède à une allocation asymétrique des droits juridiques et économiques entre les parties. Elle constitue une forme de coordination particulièrement performante en parvenant à équilibrer incitation et contrôle. Pourtant, les prestations de services aux entreprises représentent moins de 7% des réseaux de franchise recensés en France. Nous montrons pourquoi les marchés des services aux entreprises pourraient devenir de "nouvelles terres de con...

  8. Report of transparency and nuclear safety 2007 CEA Fontenay aux Roses; Rapport transparence et securite nucleaire 2007 CEA Fontenay aux Roses

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This report presents the activities of the CEA Center of Fontenay aux roses for the year 2007. After many years of decommissioning and dismantling of nuclear installations, the Center is now devoted (since 2005) to the development of research programmes on biology and biomedical technologies. The actions concerning the safety, the radiation protection, the significant events, the release control and the environmental impacts and the wastes stored on the center are discussed. (A.L.B.)

  9. Effect of supplementation of different levels of selenium as nanoparticles/sodium selenite on blood biochemical profile and humoral immunity in male Wistar rats

    Directory of Open Access Journals (Sweden)

    S. J. Bunglavan

    2014-12-01

    Full Text Available Aim: To study the effect of supplementation of different levels of selenium as nanoparticles/sodium selenite on blood biochemical profile and humoral immunity in male Wistar rats. Materials and Methods: The experimental research was conducted at Division of Animal Nutrition, Indian Veterinary Research Institute, Izatnagar. 63 male Wistar rats were divided into 9 equal groups on the basis of their mean body weight (BW (124.3±3.1 g BW following completely randomized design. Experimental feeding was similar in all the groups except for the source and level of selenium (Se in the diet. While Group 1 (control was fed a basal diet with no Se supplementation, in Groups 2 and 3, 150 ppb Se was supplemented either as sodium selenite or Se nanoparticles, respectively. In Groups 4, 5, 6 and 7, Se was supplemented as its nanoparticles at 50%, 25%, 12.5% and 6.25% levels respectively i.e. at 75 ppb, 37.5 ppb, 18.75 ppb and 9.375 ppb levels respectively. In Groups 8 and 9, 300 ppb Se was supplemented either as Se nanoparticles or sodium selenite, respectively. Experimental feeding was conducted for a period of 91 days. At the end of the experimental trial, blood samples were collected to analyze the blood serum biochemical profile (serum glucose, serum total protein (TP, serum albumin, serum globulin, serum albumin: globulin ratio [A:G ratio], serum total cholesterol and humoral immunity. Results: The levels of serum glucose, serum TP and serum albumin were comparable (p>0.05 among the nine groups of male Wistar rats. The mean serum total cholesterol was significantly (p<0.001 lowered in all the Se supplemented Wistar rats compared to the control group. The mean serum globulin level was significantly (p<0.05 higher and A:G ratio was significantly (p<0.05 lowered in Group 3 (supplemented with 150 ppb selenium nanoparticles followed by Groups 2, 4, 5, 6, 8, and 9 as compared to the control group. The mean serum antibody titer was significantly (p<0.001 higher

  10. Monitoring the performance of Aux. Feedwater Pump using Smart Sensing Model

    Energy Technology Data Exchange (ETDEWEB)

    No, Young Gyu; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2015-10-15

    Many artificial intelligence (AI) techniques equipped with learning systems have recently been proposed to monitor sensors and components in NPPs. Therefore, the objective of this study is the development of an integrity evaluation method for safety critical components such as Aux. feedwater pump, high pressure safety injection (HPSI) pump, etc. using smart sensing models based on AI techniques. In this work, the smart sensing model is developed at first to predict the performance of Aux. feedwater pump by estimating flowrate using group method of data handing (GMDH) method. If the performance prediction is achieved by this feasibility study, the smart sensing model will be applied to development of the integrity evaluation method for safety critical components. Also, the proposed algorithm for the performance prediction is verified by comparison with the simulation data of the MARS code for station blackout (SBO) events. In this study, the smart sensing model for the prediction performance of Aux. feedwater pump has been developed. In order to develop the smart sensing model, the GMDH algorithm is employed. The GMDH algorithm is the way to find a function that can well express a dependent variable from independent variables. This method uses a data structure similar to that of multiple regression models. The proposed GMDH model can accurately predict the performance of Aux.

  11. Hydrothermal synthesis and crystal structure of a three-dimensional metal selenite containing double helical chains: Fe3(H2O)(SeO3)3

    International Nuclear Information System (INIS)

    A novel three-dimensional (3D) transition metal selenite Fe3(H2O)(SeO3)3 (1) has been hydrothermally synthesized and characterized by the elemental analyses, IR spectrum, TG analysis and the single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic system, space group P1-bar, with a=8.0916(16) A, b=8.2089(16) A, c=8.5679(17) A, α=69.21(3) deg., β=62.74(3) deg., γ=67.16(3) deg., Z=2, and R1[I>2σ(I)]=0.0379. Compound 1 exhibits an interesting 3D framework formed by {FeO6} octahedra and {SeO3} trigonal pyramids via the corner- and/or edge-sharing mode. Furthermore, compound 1 consists of left-handed and right-handed helical chains, which are further entangled to form the double helical chains

  12. Selenite reduction by the obligate aerobic bacterium Comamonas testosteroni S44 isolated from a metal-contaminated soil

    DEFF Research Database (Denmark)

    Zheng, Shixue; Su, Jing; Wang, Liang;

    2014-01-01

    Background: Selenium (Se) is an essential trace element in most organisms but has to be carefully handled since there is a thin line between beneficial and toxic concentrations. Many bacteria have the ability to reduce selenite (Se(IV)) and (or) selenate (Se(VI)) to red elemental selenium...... that is less toxic. Results: A strictly aerobic bacterium, Comamonas testosteroni S44, previously isolated from metal(loid)-contaminated soil in southern China, reduced Se(IV) to red selenium nanoparticles (SeNPs) with sizes ranging from 100 to 200 nm. Both energy dispersive X-ray Spectroscopy (EDX or EDS......) and EDS Elemental Mapping showed no element Se and SeNPs were produced inside cells whereas Se(IV) was reduced to red-colored selenium in the cytoplasmic fraction in presence of NADPH. Tungstate inhibited Se(VI) but not Se(IV) reduction, indicating the Se(IV)-reducing determinant does not contain...

  13. THE EFFECTS OF SODIUM SELENITE AND SELENIZED YEAST SUPPLEMENTATION INTO DIET FOR LAYING HENS ON SELECTED QUALITATIVE PARAMETERS OF TABLE EGGS

    Directory of Open Access Journals (Sweden)

    HENRIETA ARPÁŠOVÁ

    2013-07-01

    Full Text Available In this experiment the effects of supplementation of the diet for laying hens with sodium selenite (SS or selenized yeast (SY on whole egg and egg shell quality of layers were studied. The chickens of Shaver Starcross 288 strain were randomly divided at the day of hatching into 4 groups (n=12; in each. The birds were fed from Day 1 of life to 9 months of age with diets differing in amounts and/or forms of selenium. Control group received basal diet (BD containing selenium naturally occurring in feeds (0.1 mg Se/kg of dry matter (DM. First and second experimental group of chickens were fed with a same BD enriched with equivalent dose of Se 0.4 mg/kg DM in form of sodium selenite or selenized yeast, respectively. The feed for third experimental group of birds consisted of BD supplemented with selenized yeast to the final amount of selenium 1.0 mg/kg DM. The egg weight was significantly higher in the groups with SY supplementation only. On the contrary the egg shell ratio was significantly lower in the groups with SY supplementation in both amounts. The width of egg was significantly increased in the groups with selenium supplementation in both forms. The value of egg shell strength was significantly decreased in group with SY in the highest amount 0.9 mg/kg DM The average egg shell thickness was the highest in the experimental group with Se-yeast in amount 0.9 mg/kg DM, however different was not significant compared with control group. The results showed that the most of selected parameters of egg quality appeared to be significantly influenced by selenium supplementation into laying hen’s basal diet.

  14. Penser aux/les limites de nos limites

    Directory of Open Access Journals (Sweden)

    Jacques Lévy

    2010-12-01

    Full Text Available Le mot « frontière » a beaucoup de succès, dans son sens propre mais plus encore comme métaphore d’une multitude de réalités qui ont à voir avec les limites, c’est-à-dire avec notre propension à découper le monde en objets séparables. Mais on constate une grande indétermination entre concept et métaphore et un usage trop facile de mélanges entre ceux-ci. Il faut donc d’abord admettre que la matérialité n’est qu’une des composantes de notre monde, mais que l’immatériel n’est pas l’irréel, le simulé ou le métaphorique. Après un détour par une théorie des limites et ses limites et une distinction entre le topographique (continu et le topologique (discontinu appliquée à l’intérieur et aux limites d’une aire, deux exemples sont développés qui visent à montrer que, si l’on trouve des frontières, ce n’est pas forcément là où on les attend et que l’appréciation juste de la place des frontières suppose la prise en compte de bien d’autres considérations que la seule limitation volontaire et brutale du franchissement d’une ligne imaginaire tracée au sol.Think about limits and the limits of our limitsThe word “boundary” has been very successful in its literal sense but even more so as a metaphor of a multitude of realities involving limits, that is, with regards to our tendency to divide the world into separable objects. However, one can observe a considerable uncertainty between the concept and the metaphor and an utilisation too easy of various mixtures of them. It becomes necessary therefore to first admit that materiality is only one of the components of our world whilst the immaterial is not unreal, simulated or metaphoric. After a detour consisting of examining a theory of limits and its limits and making the distinction between the topographic (continuous and the topologic (discontinuous applied to the interior and the limits of an area, two examples are developed which aim to

  15. Thermodynamic modeling of iodine and selenium retention in solutions with high salinity; Rueckhaltung und thermodynamische Modellierung von Iod und Selen in hochsalinaren Loesungen. Gewinnung von Daten fuer Selenit, Selenat und Iodid fuer Belange der Langzeitsicherheitsanalyse des Nahfelds eines Endlagers fuer gefaehrliche Abfaelle

    Energy Technology Data Exchange (ETDEWEB)

    Hagemann, Sven; Moog, Helge C.; Herbert, Horst-Juergen; Erich, Agathe

    2012-04-15

    The report on iodine and selenium retention in saline solutions includes the following chapters: (1) Introduction and scope of the work. (2) Actual status of knowledge. (3) Experimental and numerical models. (4) Thermodynamic properties of selenite and hydrogen selenite in solutions of oceanic salts. (5) Thermodynamic properties of selenate in solutions of oceanic salts. (6) Thermodynamic properties of iodide in solutions of oceanic salts. (7) Experimental studies on the retention of iodine and selenium in selected sorbents. (8) Summary and conclusions.

  16. La résistance des insectes aux insecticides : problématique et enjeux en Afrique centrale

    OpenAIRE

    Brévault, Thierry; Beyo, Jacques; Nibouche, Samuel; Vaissayre, Maurice

    2003-01-01

    Les observations indiquent que des cas de résistance aux insecticides sont apparus dans la zone des savanes d'Afrique centrale chez plusieurs espèces de ravageurs des cultures cotonnière et maraîchères. La résistance aux insecticides de la famille des pyréthrinoïdes mise en évidence chez la noctuelle, Helicoverpa armigera (Hübner), en Afrique de l'ouest semble désormais concerner l'Afrique centrale. Au Cameroun, les résultats obtenus au laboratoire confirment l'apparition d'une résistance aux...

  17. Combination of carmustine and selenite effectively inhibits tumor growth by targeting androgen receptor, androgen receptor-variants, and Akt in preclinical models: New hope for patients with castration resistant prostate cancer.

    Science.gov (United States)

    Thamilselvan, Vijayalakshmi; Menon, Mani; Thamilselvan, Sivagnanam

    2016-10-01

    Despite established androgen receptor (AR) antagonists, AR/AR-variants signaling remain a major obstacle for the successful treatment of castration resistant prostate cancer (CRPC). In addition, CRPC cells adapt to survive via AR-independent pathways to escape next generation therapies. Therefore, there is an urgent need for drugs that can target these signaling pathways in CRPC. In this study, we sought to determine whether carmustine and selenite in combination could induce apoptosis and inhibit growth of CRPC in-vitro and in-vivo. CRPC (22Rv1, VCaP, and PC-3) cell lines in culture and xenograft mouse were used. Combination of carmustine and selenite treatment significantly increased reactive oxygen species, apoptosis and growth inhibition in CRPC cells with down regulation of anti-apoptotic (Bcl-2 and Mcl-1) and proliferative proteins (c-Myc and cyclin-D1). This effect was associated with complete reduction of AR/AR-variants, AR-V7, PSA and significant induction of p27Kip1. Combination treatment substantially abolished phospho-Akt, phospho-GSK-3β, and anchorage-independent growth in AR-positive and AR-negative cells. Consistent with in-vitro results, combination treatment effectively induced apoptosis and completely inhibited xenograft tumor growth and markedly reduced AR/AR-variants, AR-V7, PSA, and Bcl-2 in xenograft tumors without causing genotoxicity in host mice. Individual agent treatment showed only partial effect. The combination treatment showed a significant synergistic effect. The present study is the first to demonstrate that the combination of carmustine and selenite treatment completely suppressed CRPC tumor growth by reducing AR/AR-variants and Akt signaling. Our findings suggest that the combination of carmustine and selenite could constitute a promising next-generation therapy for successful treatment of patients with CRPC. PMID:27198552

  18. Toibibou, Ali Mohamed. — La transmission de l’Islam aux Comores

    OpenAIRE

    Hecquet, Vincent

    2012-01-01

    Ce livre décrit les institutions musulmanes aux Comores à partir d’une étude centrée sur la ville de Mbéni, qui est l’un des principaux centres religieux de l’archipel. Aux Comores, la quasi-totalité des 706 000 habitants partage la foi musulmane depuis que celle-ci y a été propagée entre le XIe et le XVIe siècles. Située sur la côte nord-est de la Grande-Comore, Mbéni est une ville de 6 500 habitants à environ soixante-quinze kilomètres de Moroni. Au XIXe siècle, deux étudiants originaires d...

  19. Le Carnaval de Schignano : un dernier salut aux émigrants

    Directory of Open Access Journals (Sweden)

    Cristina Del Biaggio

    2011-05-01

    Full Text Available Pour arriver à Schignano, il faut passer par una cürva al giazz e una cürva al suu [Un virage dans la glace et un virage au soleil], comme disent les mots en dialecte d’une récente chanson écrite par Davide Van De Sfroos, compositeur-interprète de la région. C’est dans ce petit hameau de la Vallée d’Intelvi, au-dessus du Lac de Côme, que, tous les ans, le carnaval anime le village. Une fête populaire spontanée, sans règles écrites, ni lois, qui survit grâce aux habitants qui l’animent, aux ar...

  20. Résistance génétique des petits ruminants aux helminthes en Afrique

    OpenAIRE

    Baker, R.L.

    1997-01-01

    Certaines races locales de ruminants présentent des aptitudes génétiques particulières à résister et/ou à tolérer les parasites internes. Cet article passe en revue les données encore éparses existant sur les variabilité intra et inter-races de la résistance aux helminthes des bovins, ovins et caprins, et décrit plus précisément les projets de recherches de l’International Livestock Research Institute (ILRI) en matière de résistance génétique aux nématodes gastro-intestinaux des petits rumina...

  1. T0002 / MilliNewton / Erreurs dues à l'orientation et aux forces latérales

    OpenAIRE

    Maeder, Thomas

    2004-01-01

    Le capteur de force MilliNewton est sensible aux forces latérales, dans le sens longitudinal à la poutre. Le degré de sensibilité du capteur à ces forces dépend essentiellement de la taille de la bille et de la longueur de la poutre. En revanche, la sensibilité aux forces latérales perpendiculaires à la poutre est très faible.

  2. Report of transparency and nuclear safety 2007 CEA Fontenay aux Roses

    International Nuclear Information System (INIS)

    This report presents the activities of the CEA Center of Fontenay aux roses for the year 2007. After many years of decommissioning and dismantling of nuclear installations, the Center is now devoted (since 2005) to the development of research programmes on biology and biomedical technologies. The actions concerning the safety, the radiation protection, the significant events, the release control and the environmental impacts and the wastes stored on the center are discussed. (A.L.B.)

  3. Disruptions in AUX1-Dependent Auxin Influx Alter Hypocotyl Phototropism in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Bethany B.Stone; Emily L.Stowe-Evans; Reneé M.Harper; R.Brandon Celaya; Karin Ljung; G(o)ran Sandberg; Emmanuel Liscum

    2008-01-01

    Phototropism represents a differential growth response by which plant organs can respond adaptively to changes in the direction of incident light to optimize leaf/stem positioning for photosynthetic light capture and root growth orientation for water/nutrient acquisition. Studies over the past few years have identified a number of components in the signaling pathway(s) leading to development of phototropic curvatures in hypocotyls. These include the phototropin photoreceptors (phot1 and phot2) that perceive directional blue-light (BL) cues and then stimulate signaling,leading to relocalization of the plant hormone auxin, as well as the auxin response factor NPH4/ARF7 that responds to changes in local auxin concentrations to directly mediate expression of genes likely encoding proteins necessary for development of phototropic curvatures. While null mutations in NPH4/ARF7 condition an aphototropic response to unidirectional BL, seedlings carrying the same mutations recover BL-dependent phototropic responsiveness if coirradiated with red light (RL) or pre-treated with either ethylene. In the present study, we identify second-site enhancer mutations in the nph4 background that abrogate these recovery responses. One of these mutations-map1 ((m)odifier of (a)rf7 (p)henotypes (1))-was found to represent a missense allele of AUX1-a gene encoding a high-affinity auxin influx carrier previously associated with a number of root responses. Pharmocological studies and analyses of additional aux1 mutants confirmed that AUX1 functions as a modulator of hypocotyl phototropism. Moreover, we have found that the strength of dependence of hypocotyl phototropism on AUX1-mediated auxin influx is directly related to the auxin responsiveness of the seedling in question.

  4. Développement d'immunoessais associés aux électrodes sérigraphiées: des particules superparamagnétiques aux nanobodies

    OpenAIRE

    Patris, Stéphanie

    2014-01-01

    Cette thèse a pour vocation de contribuer au développement de différents immunocapteurs ampérométriques associés aux électrodes sérigraphiées (SPE). Les immunocapteurs sont des dispositifs simples associant un anticorps ou un antigène qui assurent la sélectivité à un transducteur (ici une SPE) ;ce dernier transforme la liaison anticorps/antigène en un signal mesurable (ici ampérométrique).Le travail est divisé en deux volets principaux.Le premier est consacré à la mise en œuvre de différents ...

  5. Développement d'immunoessais associés aux électrodes sérigraphies: des particules superparamagnétiques aux nanobodies

    OpenAIRE

    Patris, Stéphanie

    2014-01-01

    Cette thèse a pour vocation de contribuer au développement de différents immunocapteurs ampérométriques associés aux électrodes sérigraphiées (SPE). Les immunocapteurs sont des dispositifs simples associant un anticorps ou un antigène qui assurent la sélectivité à un transducteur (ici une SPE) ;ce dernier transforme la liaison anticorps/antigène en un signal mesurable (ici ampérométrique). Le travail est divisé en deux volets principaux. Le premier est consacré à la mise en œuvre de dif...

  6. Les monuments commémoratifs dédiés aux universitaires et aux savants : Entre espace communautaire et espace public

    OpenAIRE

    Hottin, Christian

    1999-01-01

    Tout autant que les hommes politiques ou les gens de lettres, les universitaires et les savants ont été statufiés depuis le XIXe siècle : la première période de la troisième République marque l'apogée de ce phénomène. Lorsqu'elles étaient en bronze, ces œuvres, comme les autres, n'ont pas échappé aux sélections opérées pendant l'Occupation. Enfin, de nouvelles effigies d'hommes de science ont été exécutées après 1945 et, bien que ralenti, ce mouvement de commémoration se poursuit de nos jours...

  7. The ARF, AUX/IAA and GH3 gene families in citrus: genome-wide identification and expression analysis during fruitlet drop from abscission zone A.

    Science.gov (United States)

    Xie, Rangjin; Pang, Shaoping; Ma, Yanyan; Deng, Lie; He, Shaolan; Yi, Shilai; Lv, Qiang; Zheng, Yongqiang

    2015-12-01

    Completion of the whole genome sequencing of citrus enabled us to perform genome-wide identification and functional analysis of the gene families involved in agronomic traits and morphological diversity of citrus. In this study, 22 CitARF, 11 CitGH3 and 26 CitAUX/IAA genes were identified in citrus, respectively. Phylogenetic analysis revealed that all the genes of each gene family could be subdivided into three groups and showed strong evolutionary conservation. The GH3 and AUX/IAA gene families shrank and ARF gene family was highly conserved in the citrus genome after speciation from Arabidopsis thaliana. Tissue-specific expression profiles revealed that 54 genes were expressed in at least one tissue while just 5 genes including CitARF07, CitARF20, CitGH3.04, CitAUX/IAA25 and CitAUX/IAA26 with very low expression level in all tissues tested, suggesting that the CitARF, CitGH3 and CitAUX/IAA gene families played important roles in the development of citrus organs. In addition, our data found that the expression of 2 CitARF, 4 CitGH3 and 4 AUX/IAA genes was affected by IAA treatment, and 7 genes including, CitGH3.04, CitGH3.07, CitAUX/IAA03, CitAUX/IAA04, CitAUX/IAA18, CitAUX/IAA19 and CitAUX/IAA23 were related to fruitlet abscission. This study provides a foundation for future studies on elucidating the precise role of citrus ARF, GH3 and AUX/IAA genes in early steps of auxin signal transduction and open up a new opportunity to uncover the molecular mechanism underlying citrus fruitlet abscission. PMID:25982744

  8. Optical absorption of selenite single crystals subjected to high electric fields and irradiated with X-rays or γ-rays

    International Nuclear Information System (INIS)

    Measurements of the optical absorption coefficient of selenite single crystals show two peaks at 236 and 400 nm when plotted as a function of wavelength. These peaks decrease with increasing irradiation time for both γ and X-rays. Subsequent thermal bleaching increases the absorption coefficient at all wavelengths and flattens out the peaks at 1400C and 3300C respectively. The imposition of an a.c. or d.c. field prior to irradiation preserves the thermal bleaching characteristics with an overall increase in absorption coefficient. These effects are attributed to two different types of bond formed by water of crystallization giving rise to the two absorption peaks. Irradiation may destroy some of the bands of loosely bound water molecules near defect regions leading to a decrease in absorption. Thermal bleaching removes water molecules reducing the transparency of the samples, the more strongly bound molecules being removed at the higher temperature. Irradiation after a.c. or d.c. field treatment may introduce more defect regions enabling the removal of more water molecules by bleaching and hence increasing the absorption. (U.K.)

  9. Modulation of Framework and Centricity: Cation Size Effect in New Quaternary Selenites, ASc(SeO3)2 (A = Na, K, Rb, and Cs).

    Science.gov (United States)

    Song, Seung Yoon; Ok, Kang Min

    2015-05-18

    Four new stoichiometrically equivalent quaternary scandium selenites, ASc(SeO3)2 (A = Na, K, Rb, and Cs) have been hydrothermally synthesized using A2CO3, Sc(NO3)3·xH2O (or ScO3), and SeO2 as starting materials. All four materials share similar bond networks that are composed of corner-shared distorted ScO6 octahedra and SeO3 trigonal pyramids. However, each material reveals different frameworks and centricities. Detailed structural analysis suggests that the structural variation is attributed to the difference in size and subsequent coordination number for the alkali metal cations. Powder second-harmonic generation (SHG) measurements on noncentrosymmetric (NCS) RbSc(SeO3)2 show that the compound has an SHG efficiency similar to that of (NH4)H2PO4. The observed SHG efficiency is due to the remaining net polarization after cancellation of oppositely aligned moments for SeO3 and ScO6 groups. Thorough characterizations such as spectroscopic, thermal, and elemental analyses for the new materials are presented as are dipole moment and out-of-center distortion calculations. PMID:25915517

  10. New inorganic (an)ion exchangers with a higher affinity for arsenate and a competitive removal capacity towards fluoride, bromate, bromide, selenate, selenite, arsenite and borate

    KAUST Repository

    Chubar, Natalia

    2011-12-01

    Highly selective materials and effective technologies are needed to meet the increasingly stronger drinking water standards for targeted ionic species. Inorganic ion exchangers based on individual and mixed-metal hydrous oxides (or mixed adsorbents that contain inorganic ion exchangers in their composition) are adsorptive materials that are capable of lowering the concentrations of anionic contaminants, such as H 2AsO 4 -, H 3AsO 3, F -, Br -, BrO 3 -, HSeO 4 -, HSeO 3 - and H 3BO 3, to 10 μg/L or less. To achieve a higher selectivity towards arsenate, a new ion exchanger based on Mg-Al hydrous oxides was developed by a novel, cost-effective and environmentally friendly synthesis method via a non-traditional (alkoxide-free) sol-gel approach. The exceptional adsorptive capacity of the Mg-Al hydrous oxides towards H 2AsO 4 - (up to 200 mg[As]/gdw) is due to the high affinity of this sorbent towards arsenate (steep equilibrium isotherms) and its fast adsorption kinetics. Because of the mesoporous (as determined by N 2 adsorption and SEM) and layered (as determined by XRD and FTIR) structure of the ion-exchange material as well as the abundance of anion exchange sites (as determined by XPS and potentiometric titration) on its surface the material demonstrated very competitive (or very high) removal capacity towards other targeted anions, including fluoride, bromide, bromate, selenate, selenite, and borate. © 2011 IWA Publishing.

  11. Exposition aux dispositifs d'éclairage scénique : risque pour la santé des professionnels du spectacle vivant ou enregistré

    OpenAIRE

    Salsi, Serge; Barlier-Salsi, Annick

    2013-01-01

    La directive européenne 2006/25/CE, relative à l'exposition des travailleurs aux rayonnements optiques, prévoit l'évaluation des risques des situations de travail. Elle est particulièrement importante dans l'industrie des arts du spectacle où des expositions intentionnelles à des projecteurs peuvent être exigées pendant des périodes de l'ordre de 8 heures par jour. L'objectif de la présente étude était de fournir aux éclairagistes des informations, relatives aux risques associés aux projecteu...

  12. Charge-based fractionation of oxyanion-forming metals and metalloids leached from recycled concrete aggregates of different degrees of carbonation: a comparison of laboratory and field leaching tests.

    Science.gov (United States)

    Mulugeta, Mesay; Engelsen, Christian J; Wibetoe, Grethe; Lund, Walter

    2011-02-01

    The release and charge-based fractionation of As, Cr, Mo, Sb, Se and V were evaluated in leachates generated from recycled concrete aggregates (RCA) in a laboratory and at a field site. The leachates, covering the pH range 8.4-12.6, were generated from non-carbonated, and artificially and naturally carbonated crushed concrete samples. Comparison between the release of the elements from the non-carbonated and carbonated samples indicated higher solubility of the elements from the latter. The laboratory leaching tests also revealed that the solubility of the elements is low at the "natural pH" of the non-carbonated materials and show enhancement when the pH is decreased. The charge-based fractionation of the elements was determined by ion-exchange solid phase extraction (SPE); it was found that all the target elements predominantly existed as anions in both the laboratory and field leachates. The high fraction of the anionic species of the elements in the leachates from the carbonated RCA materials verified the enhanced solubility of the oxyanionic species of the elements as a result of carbonation. The concentrations of the elements in the leachates and SPE effluents were determined by inductively coupled plasma mass spectrometry (ICP-MS). PMID:20542679

  13. Chemical composition and geologic history of saline waters in Aux Vases and Cypress Formations, Illinois Basin

    Science.gov (United States)

    Demir, I.; Seyler, B.

    1999-01-01

    Seventy-six samples of formation waters were collected from oil wells producing from the Aux Vases or Cypress Formations in the Illinois Basin. Forty core samples of the reservoir rocks were also collected from the two formations. Analyses of the samples indicated that the total dissolved solids content (TDS) of the waters ranged from 43,300 to 151,400 mg/L, far exceeding the 35,400 mg/mL of TDS found in typical seawater. Cl-Br relations suggested that high salinities in the Aux Vases and Cypress formation waters resulted from the evaporation of original seawater and subsequent mixing of the evaporated seawater with concentrated halite solutions. Mixing with the halite solutions increased Na and Cl concentrations and diluted the concentration of other ions in the formation waters. The elemental concentrations were influenced further by diagenetic reactions with silicate and carbonate minerals. Diagenetic signatures revealed by fluid chemistry and rock mineralogy delineated the water-rock interactions that took place in the Aux Vases and Cypress sandstones. Dissolution of K-feldspar released K into the solution, leading to the formation of authigenic illite and mixed-layered illite/smectite. Some Mg was removed from the solution by the formation of authigenic chlorite and dolomite. Dolomitization, calcite recrystallization, and contribution from clay minerals raised Sr levels significantly in the formation waters. The trend of increasing TDS of the saline formation waters with depth can be explained with density stratification. But, it is difficult to explain the combination of the increasing TDS and increasing Ca/Na ratio with depth without invoking the controversial 'ion filtration' mechanism.

  14. Conference - Découvrez notre région - Aux bornes de Genève

    CERN Multimedia

    Staff Association

    2016-01-01

      Les premières bornes-frontière sont posées en 1816 aux confins du royaume de Sardaigne, d’autres feront leur apparition dès 1818 du côté du royaume de France. Deux cents ans plus tard, on retrouve toujours ces pierres, témoins de la naissance du canton et patrimoine partagé des communes genevoises, gessiennes et savoisiennes qui font notre région.  

  15. La conquête de l’Algérie racontée aux enfants

    OpenAIRE

    Guillemette Tison

    2012-01-01

    L’histoire de la conquête de l’Algérie est racontée aux enfants aussi bien dans les manuels que dans les romans. Cet article propose d’examiner comment les années 1827 à 1847 sont restituées dans les ouvrages scolaires et non scolaires, par l’utilisation d’anecdotes récurrentes, par la mise en scène de figures de héros ou de collectivités.

  16. Douleur aux urgences: rôle infirmier et recommandations de bonne pratique

    OpenAIRE

    Buletti, Martina; Vacherand, Virginie; Borloz, Corinne

    2015-01-01

    Dans le contexte des urgences, la douleur représente une problématique de santé importante puisque près de 80% des patients consultent pour cette raison. Depuis de nombreuses années, des études montrent que la prise en charge de la douleur aux urgences est sous-optimale et que la majorité des patients continue à ressentir de la douleur à sa sortie de l’hôpital. L’infirmier ayant un rôle important à jouer dans la prise en charge de la douleur des patients, en particulier dans ce contexte, nous...

  17. Au delà du DSM : les ontologies comme aide aux classifications descriptives psychiatriques ?

    OpenAIRE

    Richard, Marion; Aimé, Xavier; Krebs, Marie-Odile; Charlet, Jean

    2013-01-01

    La caractérisation des pathologies en psychiatrie pose généralement plus de difficultés que dans les autres domaines de la médecine. Les consensus au sujet des critères définissant les pathologies mentales restent minimaux. Dans ce contexte, notre but est de construire une ressource terminologique et ontologique permettant de caractériser les patients résistant aux traitements en particulier dans le contexte de la schizophrénie. Pour cela, nous utiliserons une méthodologie maintenant éprouvée...

  18. Dialogisme et interdiscours : des discours coloniaux aux discours du développement

    OpenAIRE

    Dufour, Françoise

    2007-01-01

    Cet article explore l’articulation des notions de dialogisme et d’interdiscours à partir de l’analyse des reformulations repérables dans le passage des discours coloniaux aux discours du développement. L’analyse d’un corpus authentique de la formation discursive du développement permet de mettre en évidence différents niveaux de négociation avec l’hétérogénéité discursive auxquels l’énonciateur est soumis dans les nominations de l’autre. Les discours du développement interagissent dialogiquem...

  19. François-Ronan DUBOIS (2014), Introduction aux Porn Studies

    OpenAIRE

    Loubradou, Esther

    2015-01-01

    « La pornographie est un exemple typique de ces objets culturels dont le discours public s’empare volontiers sans jamais en produire une connaissance un tant soit peu détaillée » (p. 7). Cette connaissance partielle est pourtant regrettable et par rapport aux débats virulents entre discours anti-pornographiques et discours pro-sexe, la nécessité d’une posture compétente et objective sans perspective de condamnation ou de défense sur la pornographie se fait sentir. François-Ronan Dubois propos...

  20. Fertilisation et sensibilité des cultures de laitue et de tomate aux bioagresseurs

    OpenAIRE

    Julhia, L.; Nicot, Philippe C.

    2014-01-01

    Les producteurs de légumes sont confrontés à de nouveaux défis avec la réduction de l’usage des produits phytosanitaires. Limiter le recours aux moyens de lutte chimique conduit à revisiter les pratiques et à mettre en oeuvre des stratégies globales à moindre risque phytosanitaire. La fertilisation est examinée dans son action sur la santé des plantes et comme levier dans la gestion des bioagresseurs. L’étude porte sur deux cultures légumières majeures en France, en termes de surfaces, la lai...

  1. Le capital-risque aux Etats-Unis dans les technologies de l'information

    OpenAIRE

    Patrice Boivin

    1999-01-01

    Aux États-Unis, les années 1990 consacrent la montée en puissance des fonds de capital-risque comme sources de financement pour les entreprises spécialisées dans les technologies de l'information. Plus précisément, les secteurs des logiciels et des communications reçoivent les montants les plus importants, en raison de leur potentiel de croissance lié au développement exponentiel d'Internet (accroissement des besoins de communication des entreprises et développement du commerce électronique)....

  2. Evaluation of the radiology state at the CEA/Fontenay-aux-Roses and its environment

    International Nuclear Information System (INIS)

    Since 1946 the nuclear installations followed one other at the CEA of Fontenay-aux-Roses still their gradual stop the last ten years, except two installations INB34 and INB73, necessary for the wastes management. Today these installations form the subject of a drainage program. The public opinion is regularly informed on this program since 1999. This document presents the stock of the actions realized since this date: the track keeping of the sites activities impacts on the environment and the actions realized since 1999. (A.L.B.)

  3. Protection sociale et démocratie aux États-Unis

    OpenAIRE

    Ndiaye, Pap

    2000-01-01

    L'assurance et l'assistance sociale firent longtemps l'objet d'un consensus large dans la classe politique et la population américaines, particulièrement notable entre la fin de la Seconde Guerre mondiale et le début des années 1970, en apparaissant comme des piliers d'une démocratie moderne, capable de répondre aux défis posés par l'essor du grand capitalisme industriel. [Premier paragraphe de l'article

  4. L'hostilité aux OGM survit-elle à des produits attractifs ?

    OpenAIRE

    Kassardjian, Elsa; Robin, Stéphane; Ruffieux, Bernard

    2011-01-01

    Nous testons ici les dispositions à payer des consommateurs pour des aliments transgéniques de seconde génération, c'est-à-dire ayant des caractéristiques innovantes attractives pour le consommateur par rapport au produit conventionnel. Nous testons également les dispositions à payer de tels produits lorsqu'ils sont obtenus avec des technologies alternatives aux biotechnologies transgéniques. Les résultats indiquent que la disposition à payer positive pour une caractéristique désirable obtenu...

  5. Étude de la chasse aux sorcières dans les bailliages alsaciens du comté de Hanau-Lichtenberg aux XVIe et XVIIe siècles

    OpenAIRE

    Doré, Stéphanie

    2011-01-01

    Nombre d’explications concernant la chasse aux sorcières ont été avancées sans toutefois que l’une d’entre elles ait parue suffisante pour embrasser l’ensemble de ce phénomène aux multiples facettes. La chasse aux sorcières a été abordée dans cette étude à mi-chemin entre la macro – et la micro – histoire, dans une aire géographique limitée à l’Alsace – excluant de ce fait les bailliages de Lemberg, Willstätt et Lichtenau – afin d’appréhender de façon plus approfondie les relations sociales d...

  6. Est-on aux pizzas comme on est aux casseroles ? Sur les emplois métonymiques des syntagmes prépositionnels en à avec un nom d’objet

    Directory of Open Access Journals (Sweden)

    Hernandez Patricia

    2012-07-01

    Full Text Available Ce travail aborde les emplois spatiaux du type être à + article défini + nom d’objet (par exemple, être aux surgelés, aux casseroles, aux costumes, aux pizzas. De tels emplois sont compris, dans les ouvrages de spécialité comme des relations de localisation interprétables selon les connaissances partagées aussi bien sur le contexte d’énonciation que sur l’univers environnant. Sur la base de ce savoir lié aux routines établies, le repérage induit par la préposition à déclenche des inférences sur les interactions entre l’entité à situer et l’objet de référence. Notre parcours des descriptions existantes (Vandeloise 1988, Borillo 2001, Aurnague 2009, Corblin 2010 est suivi d’une réflexion, inspirée des principes de base de la sémantique cognitive (Langacker 1987, sur la nature de ces connexions. Ainsi, notre analyse prend en compte la corrélation entre objets et actions dans les rapports expérientiels entre l’être humain et son environnement : les lexèmes renvoyant aux entités dénotées offrent des clés d’accès à des routines et des synthèses d’expérience (Janet 1935, Brown 1965, Cadiot et Nemo 1997b. Ces scénarios, organisés en cadres d’interactions typiques (Fillmore 1982, fournissent un fond de connaissances permettant des connexions métonymiques par proximité conceptuelle selon des Modèles Cognitifs Idéalisés (Lakoff 1987, Radden & Kövecses 1999. Notre réflexion théorique est étayée par des occurrences attestées qui permettent de mieux saisir le rôle du contexte et des critères pragmatiques dans l’interprétation des formulations. En effet, sur la base d’une analyse contextuelle d’usages effectifs sur support électronique (Google France octobre 2011, nous présentons une ébauche de classement de ces emplois particuliers. La taxinomie proposée, qui ne se veut nullement définitive, conçoit les formulations en à avec des noms d’objet comme donnant un accès mental

  7. Etude du rôle du facteur de transcription MtATB2 dans l’adaptation des légumineuses aux stress abiotiques et aux carences nutritives de fin de cycle

    OpenAIRE

    Leclercq, Pierre; Rossin, Nadia; Le Signor, Christine; Sanchez, Myriam; Verdier, Jérôme; Wen, Jiangqi; Mysore, Kirankumar; Gallardo Guerrero, Karine; Thompson, Richard; Ochatt, Sergio; Vernoud, Vanessa

    2013-01-01

    Dans un contexte climatique global d’augmentation des températures et de baisses dans les régimes hydriques, et dans la perspective de développer une agriculture plus respectueuse de l’environnement, l’étude de la réponse des plantes aux stress abiotiques (thermiques et hydriques) et aux carences nutritives (bas niveau d’intrants) est cruciale. Nous nous intéressons en particulier à l’impact de ces stress sur le développement des légumineuses en fin de cycle (pois et Medicago truncatula), inc...

  8. La sensibilisation aux valeurs liées à l’eau et à la bonne gouvernance

    OpenAIRE

    Smets, Henri

    2008-01-01

    Pour les économistes ‘traditionnels”, l’eau est une matière première indispensable à la vie humaine de la même manière que l’essence est indispensable aux moteurs des voitures et l’électricité aux ordinateurs. Aussi conviendrait-il, selon eux de traiter l’eau comme les autres marchandises et de la soumettre aux lois du marché afin d’en optimiser la gestion. Les difficultés concernant son approvisionnement et sa répartition entre les usagers seront automatiquement résolues par le mécanisme des...

  9. Les représentations sociales du travail dans des parcours de retour aux études aux niveaux collégial et universitaire

    Directory of Open Access Journals (Sweden)

    Claude Julie Bourque

    2009-10-01

    Full Text Available Cet article porte sur le volet éducatif de la production et de la reproduction de la main-d’œuvre hautement qualifiée par l’examen des processus en jeu au moment des retours aux études dans des programmes de formation technique et de génie. Nous nous intéressons en particulier à une situation emblématique des référentiels politiques récents en matière d’éducation, soit les retours aux études. Nous cherchons à mieux comprendre comment le retour aux études se réalise, comment les représentations professionnelles agissent sur ce dernier et comment l’expérience scolaire influence les projets des individus. Notre analyse met l’accent sur les ressorts sociaux et culturels des décisions relatives au choix de programmes et à l’orientation professionnelle d’étudiants qui ont interrompu leurs études et qui y retournent. Nous explorons le discours d’étudiants et d’étudiantes qui ont choisi de profiter de la souplesse du système d’éducation québécois pour compléter ou bonifier leur formation initiale ou encore pour tenter une réorientation professionnelle. En particulier, nous désirons savoir comment les différentes formes d’articulation entre éducation et travail influencent les représentations sociales des étudiants au sujet des titres scolaires, de l’évolution de leur carrière scolaire et de leur projet professionnel personnel.This paper deals with the educational aspect of the production and reproduction of highly qualified manpower through examining the processes at play when people return to school by enrolling in technical or engineering training programs. Our interest is focussed specifically on returning to school as an emblematic situation in recent educational policy frameworks. We are trying to better understand how school return is done, how professional representations act upon it and how previous school experience influences individual projects. Our analysis focuses on the

  10. Identification and expression analysis of primary auxin-responsive Aux/IAA gene family in cucumber (Cucumis sativus)

    Indian Academy of Sciences (India)

    Defang Gan; Dan Zhuang; Fei Ding; Zhenzhou Yu; Yang Zhao

    2013-12-01

    Aux/IAA is an important gene family involved in many aspects of growth and development. Aux/IAA proteins are short-lived nuclear proteins that are induced primarily by various phytohormones. In this study, 29 Aux/IAA family genes (CsIAA01–CsIAA29) were identified and characterized in cucumber, including gene structures, phylogenetic relationships, conserved protein motifs and chromosomal locations. These genes show distinct organizational patterns of their putative motifs. The distributions of the genes vary: except for five CsIAA genes in cucumber that were not located, seven CsIAA genes were found on scaffold, while the other 17 CsIAA genes were distributed on seven other chromosomes. Based on a phylogenetic analysis of the Aux/IAA protein sequences from cucumber, Arabidopsis and other plants, the Aux/IAA genes in cucumber were categorized into seven subfamilies. To investigate whether the expression of CsIAA genes is associated with auxin induction, their transcript levels were monitored in seedlings treated with IAA (indole-3-acetic acid), and their expression patterns were analysed by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). The results showed that 11/29 CsIAA genes were expressed in leaves whether treated with IAA or not and the time course of processing and compared with the control, five CsIAA genes showed low expression only after 60 min treatment with IAA, while 11 genes showed no expression. These results provide useful information for further functional analysis of Aux/IAA gene family in cucumber.

  11. Edgar Morin, aux risques d'une pensée libre

    CERN Document Server

    Pena Vega, Alfredo

    2011-01-01

    8 juillet 2011 ; Edgar Morin fête ses 90 ans et 60 ans passés au sein du CNRS. Une occasion unique pour l'équipe d'Hermès et Dominique Wolton, d'analyser et de critiquer la pensée de ce grand intellectuel. Aspiration à la liberté, attention à la complexité du monde et une profonde originalité épistémologique, Edgar Morin a bouleversé aussi bien la philosophie, la politique que la physique ou les mathématiques. Avec un souci constant : faire communiquer et interagir toutes les sciences pour relever le défi de la compréhension. Plus qu'un simple hommage, ce numéro questionne l'œuvre d'Edgar Morin au filtre de la communication, dévoilant les mécaniques de cette vision du monde profondément originale, échappant aux cloisonnements et aux certitudes académiques, portée par un projet central, celui d'une réforme des connaissances. Suivant les cheminements intellectuels et politiques de ce chercheur itinérant et passionné à travers l'Europe, l'Est, l'Amérique latine ou les États-Unis, ce...

  12. Safety Training: Sensibilisation aux gestes et postures de travail

    CERN Multimedia

    Laetitia Laddada

    2004-01-01

    Nous vous proposons un nouveau cours de sécurité lié aux manutentions manuelles (durée 1 jour) : Sensibilisation aux gestes et postures de travail. Si vous êtes amené à manipuler régulièrement des charges lourdes ou volumineuses, cette formation peut vous aider à prévenir les lésions musculaires ou dorsales. A l'issue de cette formation, vous serez capable d'adopter et d'appliquer les principes de base de sécurité physique et d'économie d'efforts dans les manipulations d'objets. Les cours sont pris en charge par la Commission de Sécurité. L'inscription EDH est obligatoire. Pour plus d'information, veuillez consulter les pages Formation & Développement (Groupe Sécurité). Formation & Développement (Groupe Sécurité) FORMATION EN SECURITE SAFETY TRAINING Laetitia Laddada 73811 - 79236 sa...

  13. Safety Training: Sensibilisation aux gestes et postures de travail

    CERN Multimedia

    Laetitia Laddada

    2004-01-01

    If you wish to participate in one of the following courses, please discuss with your supervisor and apply electronically directly from the course description pages that can be found on the Web at: http://www.cern.ch/Training/ or fill in an 'application for training' form available from your Divisional Secretariat or from your DTO (Divisional Training Officer). Applications will be accepted in the order of their receipt. Nous vous proposons un nouveau cours de sécurité lié aux manutentions manuelles (durée 1 jour) : Sensibilisation aux gestes et postures de travail. Si vous êtes amené à manipuler régulièrement des charges lourdes ou volumineuses, cette formation peut vous aider à prévenir les lésions musculaires ou dorsales. A l'issue de cette formation, vous serez capable d'adopter et d'appliquer les principes de base de sécurité physique et d'économie d'efforts dans les manipulations...

  14. Safety Training: Sensibilisation aux gestes et postures de travail

    CERN Multimedia

    Laetitia Laddada

    2004-01-01

    >Nous vous proposons un nouveau cours de sécurité lié aux manutentions manuelles (durée 1 jour) : Sensibilisation aux gestes et postures de travail. Si vous êtes amené à manipuler régulièrement des charges lourdes ou volumineuses, cette formation peut vous aider à prévenir les lésions musculaires ou dorsales. A l'issue de cette formation, vous serez capable d'adopter et d'appliquer les principes de base de sécurité physique et d'économie d'efforts dans les manipulations d'objets. Les cours sont pris en charge par la Commission de Sécurité. L'inscription EDH est obligatoire. Pour plus d'information, veuillez consulter les pages Formation & Développement (Groupe Sécurité). Formation & Développement (Groupe Sécurité) FORMATION EN SECURITE SAFETY TRAINING Laetitia Laddada 73811 - 79236 s...

  15. Safety Training: Sensibilisation aux gestes et postures de travail

    CERN Multimedia

    Laetitia Laddada

    2004-01-01

    Nous vous proposons un nouveau cours de sécurité lié aux manutentions manuelles (durée 1 jour) : Sensibilisation aux gestes et postures de travail. Si vous êtes amené à manipuler régulièrement des charges lourdes ou volumineuses, cette formation peut vous aider à prévenir les lésions musculaires ou dorsales. A l'issue de cette formation, vous serez capable d'adopter et d'appliquer les principes de base de sécurité physique et d'économie d'efforts dans les manipulations d'objets. Les cours sont pris en charge par la Commission de Sécurité. L'inscription EDH est obligatoire. Pour plus d'information, veuillez consulter les pages Formation & Développement (Groupe Sécurité). Formation & Développement (Groupe Sécurité) FORMATION EN SECURITE SAFETY TRAINING Laetitia Laddada 73811 - 79236 safety.training@cern.ch

  16. EXAFS and FTIR studies of selenite and selenate sorption by alkoxide-free sol–gel generated Mg–Al–CO 3 layered double hydroxide with very labile interlayer anions

    KAUST Repository

    Chubar, Natalia

    2014-08-08

    © the Partner Organisations 2014. Current research on Layered Double Hydroxides (LDHs, also known as hydrotalcites, HTs) is predominantly focused on their intercalations, but the industrial application of LDHs for anion exchange adsorption has not yet been achieved. It was recently recognized that, to develop LDH applications, these materials should be produced using methods other than direct co-precipitation. Mg-Al-CO3LDH produced using an alkoxide-free sol-gel synthesis showed exceptional removal properties for aqueous selenium species. Se K-edge EXAFS/XANES and FTIR studies (supporting the data by XRD patterns) were performed to explain the unusual adsorptive performance of Mg-Al LDH by revealing the molecular-level mechanism of HSeO3 -, SeO4 2-and {HSeO3 -+ SeO4 2-} uptake at pH 5, 7 and 8.5. The role of inner-sphere complexation (exhibited by inorganic adsorbents with good performance) in adsorption of both selenium aqueous species was not confirmed. However, Mg-Al LDH fully met the other expectations regarding the involvement of the interlayer anions. The interlayer carbonate (due to its favorable speciation and generous HT hydration) gave a "second breath" to selenite sorption and was the only mechanism that controlled the removal of Se(vi). Because inner sphere complexation was the leading mechanism for selenite removal, ion exchange via surface OH-and interlayer CO3 2-species was the only mechanism for selenate removal; both of these species were easily bound to Mg-Al LDH (on its surface and gently parked into the interlayer forming a multilayer without violation of the structure of Mg-Al-CO3LDH). This work provides the first theoretical explanation of why it is more difficult to sorb selenate than selenite and which material should be used for this purpose. This journal is

  17. ETUDE DE LA STABILITE AUX PETITES PERTURBATIONS DANS LES GRANDS RESEAUX ELECTRIQUES : OPTIMISATION DE LA REGULATION PAR UNE METHODE METAHEURISTIQUE

    OpenAIRE

    Alkhatib, Hasan

    2008-01-01

    Depuis une vingtaine d'années, les grands réseaux électriques se trouvent obligés de fonctionner à pleine puissance et souvent aux limites de la stabilité. L'amélioration de la stabilité aux petites perturbations, en particulier l'amortissement des oscillations interrégionales, est donc devenue un objectif prioritaire. Les interactions entre les générateurs de différentes régions et les régulateurs utilisés nécessitent une optimisation globale de leurs performances : c'est le meilleur moyen p...

  18. Transition des soins curatifs aux soins palliatifs dans un contexte de soins intensifs dans le cadre des soins infirmiers

    OpenAIRE

    Grzywack, Maurine; Meyer, Margaux; Ventimiglia, Valérie; Charmillot, Pierre-Alain

    2016-01-01

    Buts : Le travail de Bachelor, comprenant une revue de littérature et d’articles probants, comporte les objectifs suivants : 1) Mettre en évidence les différentes perceptions infirmières liées à la mort dans le contexte de soins intensifs par rapport aux soins palliatifs. 2) Relever les difficultés, obstacles, rencontrés par les professionnels de la discipline infirmière dans un milieu très aigu concernant la transition des soins curatifs aux soins palliatifs. 3) Mettre en lumière les interve...

  19. Change of choline compounds in sodium selenite-induced apoptosis of rats used as quantitative analysis by in vitro 9.4T MR spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Zhen Cao; Lin-Ping Wu; Yun-Xia U; Yu-Bo Guo; Yao-Wen Chen; Ren-Hua Wu

    2008-01-01

    AIM: To study liver cell apoptosis caused by the toxicity of selenium and observe the alteration of choline compounds using in vitro 9.4T high resolution magnetic resonance spectroscopy.METHODS: Twenty male Wistar rats were randomly divided into two groups.The rats in the treatment group were intraperitoneally injected with sodium selenite and the control group with distilled water.All rats were sacrificed and the livers were dissected.1H-MRS data were collected using in vitro 9.4T high resolution magnetic resonance spectrometer.Spectra were processed using XWINNMR and MestRe-c 4.3.HE and TUNEL staining was employed to detect and confirm the change of liver cells.RESULTS: Good 1H-MR spectra of perchloric acid extract from liver tissue of rats were obtained.The conventional metabolites were detected and assigned.Concentrations of different ingredient choline compounds in treatment group vs control group were as follows: total choline compounds,5.08±0.97 mmol/L vs 3.81±1.16 mmol/L (P = 0.05); and free choline,1.07±0.23 mmol/L vs 0.65±0.20 mmol/L (P = 0.00).However,there was no statistical significance between the two groups.The hepatic sinus and cellular structure of hepatic cells in treatment group were abnormal.Apoptosis of hepatic cells was confirmed by TUNEL assay.CONCLUSION: High dose selenium compounds can cause the rat liver lesion and induce cell apoptosis in vivo.High resolution 1H-MRS in vitro can detect diversified metabolism.The changing trend for different ingredient of choline compounds is not completely the same at early period of apoptosis.

  20. Réguler pour contrôler le développement de la résistance aux pesticides (La durabilité de la sensibilité des bioagresseurs aux pesticides et aux variétés résistantes)

    OpenAIRE

    Stefan Ambec; Marion Desquilbet

    2011-01-01

    L’utilisation de pesticides et l’introduction de variétés résistantes à certains bioagresseurs (insectes, champignons, virus, bactéries) en agriculture exercent une pression de sélection sur ces populations de bioagresseurs. Au cours du temps, l’efficacité de ces technologies peut diminuer si des résistances (aux pesticides ou aux variétés résistantes) se développent. La durabilité des pesticides et des variétés résistantes est donc en grande partie tributaire de leur utilisation. Plus une te...

  1. Répondre aux suds : imaginaires et défis géopolitiques aux frontières du nord : cas du maroc et du mexique.

    Directory of Open Access Journals (Sweden)

    Philippe Sierra

    2010-11-01

    Full Text Available Maroc et Mexique sont deux Etats qui ont construit depuis une quinzaine d’années un nouveau discours et de nouvelles politiques pour valoriser leur proximité au « Nord ». Alena et Mexamérique d’un côté, quasi intégration au marché européen et péninsule tingitane de l’autre, sont devenues des lignes majeures des discours gouvernementaux. Cette valorisation des nords a provoqué une nouvelle vision des territoires nationaux, dans laquelle il faut répondre aux inquiétudes des suds, éloignés et sources de problèmes géopolitique tant au Mexique (la rébellion néo-zapatiste au Chiapas qu’au Maroc (le Sahara occidental. Cet article tente de montrer comment à travers les nouveaux plans de développement mis en place par les Etats pour répondre différemment à leurs inquiétudes, de nouvelles représentations géopolitiques révélatrices des « imaginaires du sud » se mettent en place auxquelles répondent des populations en soif d’identité.

  2. Planification successorale : les avancées du Règlement européen relatif aux successions

    OpenAIRE

    Wautelet, Patrick

    2012-01-01

    Cette présentation a pour objectif de mettre en exergue les grands principes retenus par le Règlement européen relatif aux successions. Pour ce faire, les règles européennes sont contrastées avec le cadre juridique actuel.

  3. Hydrothermal synthesis and structural analysis of new mixed oxyanion borates: Ba11B26O44(PO4)2(OH)6, Li9BaB15O27(CO3) and Ba3Si2B6O16

    International Nuclear Information System (INIS)

    Several new borate compounds, Ba11B26O44(PO4)2(OH)6 (1), Li9BaB15O27(CO3) (2), and Ba3Si2B6O16 (3) were synthesized containing other hetero-oxyanion building blocks in addition to the borate frameworks. They were all prepared under hydrothermal conditions and characterized by single crystal and powder X-ray diffraction, and IR spectroscopy. Crystal data: For 1; space group P21/c, a=6.8909 (14) Å, b=13.629 (3) Å, c=25.851 (5) Å, β=90.04 (3)°; For 2; space group P-31c, a=8.8599 (13) Å, c=15.148 (3) Å; For 3; space group P-1, a=5.0414 (10) Å, b=7.5602 (15) Å, c=8.5374 (17) Å, α=77.15 (3)°, β=77.84 (3)°, γ=87.41 (3)° for 3. Compounds 1 and 2 contain isolated oxyanions [PO4]3− and [CO3]2− respectively, sitting in channels created by the borate framework, while structure 3 has the [SiO4]4− groups directly bonded to the borate groups creating a B–O–Si framework. - Highlights: • Hydrothermal syntheses of three new mixed oxyanion borates are presented. • Ba11B26O44(PO4)2(OH)6 contains isolated [PO4]3− in voids of the borate framework. • Li9BaB15O27(CO3) contains isolated [CO3]2− in channels created by the framework. • Ba3Si2B6O16 has direct bonding of [SiO4]4− and borates creating a B–O–Si framework

  4. Chapitre 4. La Russie face aux révoltes libyenne et syrienne

    OpenAIRE

    De Tinguy, Anne

    2014-01-01

    Résumé : Face aux soulèvements dans le monde arabe, la Russie a glissé d’une attitude de compréhension à une prise de distance avec les stratégies adoptées par la majorité des États occidentaux et arabes, d’abord dans le cas libyen mais surtout dans le dossier syrien. Dans ses choix, la diplomatie russe est aussi bien guidée par des considérations stratégiques régionales (appui à un partenaire de longue date, ventes d’armes, facilités navales à Tartous, peur d’avoir à ses frontières un « seco...

  5. Goa aux portes des métropoles. Communautés transnationales et musique techno

    OpenAIRE

    Boutouyrie, Eric

    2011-01-01

    Il s’agit dans cette contribution de montrer et de comprendre comment Goa fut le lieu d’une double invention au milieu des années 1980 : celle d’un courant musical de la mouvance techno (la « Psychedelic Trance » ou « Goatrance ») et celle de manifestations spatiales inédites (les « parties trance ») reproduites de nos jours aux quatre coins du globe. Dans un contexte postcolonial caractérisé, entre autres, par un métissage des sonorités, l’émergence d’une culture mondiale et un repli identit...

  6. Report on nuclear safety and transparency 2011 - Fontenay-aux-Roses CEA centre

    International Nuclear Information System (INIS)

    After a brief presentation of the Fontenay-aux-Roses CEA centre, this report indicates the different safety measures in the different nuclear base installations (INB) of this site (measures related to different risks, to emergency situations, to inspections and audits). It describes measures related to radiation protection: organisation, dosimetry results. It presents the different significant events which occurred in 2011 and were declared to the ASN. It discusses the results of measurements of liquid, gaseous and chemical releases from the installations and their impact on the environment. It addresses the radioactive waste management (measures to limit their volume and to limit their impact on health and on the environment, notably on water and soils, type and quantities of wastes stored in INBs). It presents the different measures and actions related to information transparency

  7. La lettre aux Colossiens: une théologie de la mémoire

    OpenAIRE

    Dettwiler, Andréas

    2013-01-01

    La lettre aux Colossiens - très probablement un document deutéropaulinien - peut être vue avant tout comme un remarquable effort théologique de mémoire. Si son auteur n'a pas l'ambition de dire quelque chose de réellement inédit, il y propose une relecture très originale de la tradition religieuse communément partagée entre lui et la communauté destinataire, pour offrir à celle-ci une interprétation qui donne sens à ce qu'elle vit dans une situation devenue de plus en plus opaque et conflictu...

  8. Décompositions parcimonieuses et persistantes de signaux multicanaux. Applications aux signaux MEEG.

    OpenAIRE

    Kowalski, Matthieu; Torrésani, Bruno

    2009-01-01

    On considère le problème de la régression parcimonieuse de signaux multicanaux sur des repères temps-fréquences. Les signaux multicanaux sont décomposés sur un unique repère en utilisant des coefficients vectoriels (i.e. multi-canal). La parcimonie apparaît habituellement grâce à des approches type “basis pursuit denoising” : la régression s'effectue en minimisant une fonctionnel qui fait intervenir un terme d'attache aux données 2 , et une pénalité 1 sur les coefficients. Dans cette contribu...

  9. Le passage aux urgences : lieu des ruptures de prise en charge ?

    OpenAIRE

    Thomas, Jérôme

    2014-01-01

    Cette communication s'interroge sur l'impact de l'usage des systèmes d'information médicale sur la clinique menée dans le cadre de l'intervention de psychiatrie aux urgences. Elle montre que ces systèmes d'information sont ambivalents dans leurs effets puisqu'ils se substituent parfois à la clinique, en la contraignant selon des normes gestionnaires, mais qu'ils sont aussi des lieux d'inscription de la mémoire de l'institution et du récit de la rencontre avec les patients en crise. Ces récits...

  10. Emission de bandes larges dans ZnSe : cathodoluminescence, thermoluminescence, transitions dues aux centres profonds

    OpenAIRE

    Hitier, G.; Curie, D.; Visocekas, R.

    1981-01-01

    Dans cet article nous étudions le comportement thermique des émissions de bandes larges sur des cristaux de ZnSe cubique dopés et self-activés. La bande rouge du cuivre (1,96 eV) s'élargit principalement du côté des basses énergies quand la température croît et la bande verte (2,33 eV) disparaît aux environs de la température ordinaire. Nous obtenons les énergies d'activation thermique. Nous étudions aussi les profondeurs des pièges par différentes techniques de thermoluminescence ainsi que l...

  11. Nanocristaux d'amidon: Preparation et Application aux emballages flexibles et barrières

    OpenAIRE

    Le Corre, Déborah

    2011-01-01

    Ce travail examine la potentielle mise à l'échelle industrielle des procédés de préparation des nanocristaux d'amidon (SNCs). Une caractérisation approfondie (morphologie, viscosité, stabilité thermique et propriétés en nanocomposites) de 5 SNCs différents montre une faible influence de la source botanique, contrairement aux nanocristaux de cellulose. L'analyse du procédé de préparation actuel des SNCs a conduit à 3 nouvelles stratégies d'optimisation et à la définition d'une nouvelle générat...

  12. La panique pédophile aux États-Unis et en France

    OpenAIRE

    Kristen Zgoba; Mélanie-Angela Neuilly

    2005-01-01

    Durant la première moitié des années 1990, les États-Unis traversèrent ce qui peut être appelé une crise liée aux crimes sexuels. Ceci entraîna le passage de législations spécifiques destinées à adresser ce qui était perçu par le public comme un problème social de grande envergure. Durant la seconde moitié des années 1990, l’Europe (principalement l’Angleterre, la Belgique, les Pays-Bas, la France, et l’Allemagne) se trouva dans la même situation que les États-Unis. Là aussi des législations ...

  13. Former des enseignants pour faire apprendre aux élèves

    OpenAIRE

    Galand, Benoît; Entretiens Jacques Cartier, « Le déploiement à large échelle des meilleures pratiques pour soutenir la persévérance scolaire : un défi collectif. »

    2013-01-01

    Si le décrochage scolaire est clairement un phénomène multifactoriel, les recherches convergent pour mettre en avant le rôle proximal que joue l'expérience scolaire des élèves dans le processus d'abandon de l'école. Réfléchir aux pistes de prévention du décrochage en partant de ce constat amène à une série de défis imbriqués. Le premier de ces défis est d'identifier ce qui affecte l'expérience scolaire des élèves, pour la rendre plus positive. Il s'agit notamment de repérer les pratiques péda...

  14. Introduction aux modèles espace état et au filtre de Kalman

    OpenAIRE

    Lemoine, Matthieu; Pelgrin, Florian

    2003-01-01

    Nous détaillons ici les principaux concepts et problèmes liés aux modèles espace-état, ainsi que leurs applications. Nous présentons d'abord ces modèles dans leur généralité. Ensuite, nous explicitons les algorithmes utilisés afin de procéder à l'estimation par le maximum de vraisemblance, c'est-à-dire fondamentalement le filtre de Kalman et l'algorithme EM. Nous considérons enfin quatre applications : les décompositions tendance-cycle, l'extraction d'indicateurs coïncidents d'activité, l'est...

  15. Compartimentation microscopique: depuis les microchambres femtolitriques jusqu'aux particules pseudo-virales

    OpenAIRE

    Tresset, Guillaume

    2013-01-01

    Avec l'avènement de la microélectronique et des techniques de miniaturisation, de nouveaux domaines transdisciplinaires sont nés au confluent des sciences de l'ingénieur, de la matière et du vivant. La technologie a désormais investi l'échelle du nanomètre ; elle parvient à sonder, mais aussi surtout à façonner les constituants élémentaires de la matière synthétique et organique, depuis les atomes jusqu'aux complexes macromoléculaires. La nécessité d'isoler des molécules et des assemblages su...

  16. L'Ecole aux prises avec les idéologues de l'informatisation sociale

    OpenAIRE

    Thellen, Stéphane

    2002-01-01

    Cette communication s'inscrit dans une perspective sociologique de l'informatisation du champ éducatif. L'arrimage École / Société par le biais des nouvelles technologies de l'information et de la communication (NTIC) interpelle le sociologue, celui-ci s'étant toujours intéressé au procès de socialisation dans laquelle fut engagée l'École publique moderne. Or en ce début de 21ème siècle, le discours dominant sur l'informatisation des activités scolaires semble univoque : on prétend qu'aux pro...

  17. Observation spatiale et SIG: des outils pour cartographier les zones sensibles aux mouvements de terrain

    Directory of Open Access Journals (Sweden)

    Jean-Yves SCANVIC

    1994-12-01

    Full Text Available Les niveaux de sensibilité des sols aux mouvements de terrain ont été cartographiés dans différents bassins de risques en Bolivie, en Colombie et à Taïwan, selon une méthodologie développée au BRGM et fondée en partie sur l’extraction visuelle et numérique d’informations contenues dans les données de télédétection spatiale stéréoscopiques et leur gestion-valorisation dans un SIG. Ces cartes font apparaître l’intérêt de l’imagerie Spot pour la gestion du risque naturel.

  18. Kirchner (Klaus) et Hugel (André), Staline parle aux Alsaciens en Russie

    OpenAIRE

    Muller, Claude

    2012-01-01

    Ecrit à deux mains et en deux langues, l’ouvrage commun de l’Allemand Klaus Kirchner et du Français André Hugel est aussi à deux entrées. Dans une première partie, Klaus Kirchner présente des tracts de guerre soviétiques balancés sur le front russe, destinés aux Alsaciens incorporés de force dans l’armée allemande. Si l’essentiel de la documentation provient des recherches de Klaus Kirchner, certains tracts font partie de la collection personnelle d’André Hugel. Dans la seconde partie, André ...

  19. Aux vrais beaux biens : souvenirs autour de Max Ophuls

    OpenAIRE

    Müller, Martina

    2007-01-01

    En 1989 j’ai interrogé des collaborateurs de Max Ophuls qui avaient travaillé avec lui au théâtre, à la radio et au cinéma. Ces entretiens ont été enregistrés pour mon documentaire de quatre-vingt dix minutes : Max Ophuls. Aux vrais beaux biens, produit par la Westdeutscher Rundfunk, télévision allemande de Cologne. Cette émission – diffusée en 1990 et jamais présenté en France – est composée d’interviews et de commentaires de séquences. En outre on y entend la voix de Max Ophuls et on le voi...

  20. Alternatives aux traitements anthelminthiques en élevage biologique des ruminants

    OpenAIRE

    Hoste, Hervé; Cabaret, Jacques; Grosmond, G.; Guitard, J.-P.

    2009-01-01

    En termes de gestion sanitaire des troupeaux, les recommandations du règlement de la commission européenne du 5 septembre 2008 (CE 889/2008), remplaçant le REPAB, visent à restreindre le recours aux traitements chimiques pour gérer les pathologies. Elles privilégient en contre-partie les règles d’hygiène et le développement de la réponse immune de l’animal. Ces principes généraux se retrouvent et sont illustrés dans la gestion du parasitisme helminthique par les strongles gastro-intestinaux q...

  1. Jean-Philippe BELLEAU, Le mouvement indien au Brésil. Du village aux organisations

    OpenAIRE

    Fichet, Pascaline

    2015-01-01

    « Le mouvement indien au Brésil est un miracle », annonce l'accroche de la quatrième de couverture du dernier ouvrage de Jean-Philippe Belleau, Le mouvement indien au Brésil, Du village aux organisations. Depuis 1974, année de la première assemblée indigène brésilienne, les indiens du Brésil se sont progressivement constitués en acteurs modernes et éminents de l'espace politico-social national, à travers ce que l'auteur qualifiera de « mouvement indien » brésilien. Comment ces individus issus...

  2. Charles-Victor Langlois et Charles Seignobos, Introduction aux études historiques

    OpenAIRE

    Castellesi, Romain

    2014-01-01

    Positivistes, scientistes, fétichistes du document, généralistes : autant de qualificatifs utilisés par l’école des Annales, incarnées par un Lucien Febvre revanchard, et largement repris tout au long du XXe siècle pour critiquer les auteurs de L’Introduction aux études historiques, parue en 1898. L’intérêt nouveau suscité par l’ouvrage de Charles Seignobos et Charles-Victor Langlois signe t-il leur retour en grâce ? Dans sa préface inédite à cette nouvelle édition de l’ouvrage dans la toute ...

  3. Dreamlands : des parcs d’attractions aux cités du futur

    OpenAIRE

    Didelon, Valéry

    2012-01-01

    Comme l’exposition éponyme qui s’est tenue au Centre Pompidou au printemps et à l’été 2010, le catalogue Dreamlands entend nous éclairer sur ce qu’ont en commun les premières expositions universelles, Disneyland, Las Vegas et Dubaï. L’hypothèse est ainsi posée : depuis la fin du XIXe siècle, le parc d’attractions serait devenu aux yeux des artistes, des architectes et des urbanistes un modèle pour imaginer et construire la ville de demain. Comme le champ de foire avant lui, il est de facto un...

  4. Safety Training: Ergonomie - Sensibilisation aux gestes et postures de travail

    CERN Multimedia

    Laetitia Laddada

    2004-01-01

    Nous vous proposons un nouveau cours d'ergonomie (durée : 1 jour) Sensibilisation aux gestes et postures de travail. A l'issue de cette formation, vous serez capable d'adopter et d'appliquer les principes de base de sécurité physique et d'économie d'efforts dans les manipulations d'objets. Les cours sont pris en charge par la Commission de Sécurité. L'inscription EDH est obligatoire. Pour plus d'information, veuillez consulter les pages Formation & Développement (Groupe Sécurité). FORMATION EN SECURITE SAFETY TRAINING Laetitia Laddada 73811 - 79236 safety.training@cern.ch

  5. La présence perturbatrice du Front national aux élections municipales

    OpenAIRE

    Perrineau, Pascal

    2014-01-01

    Depuis sa percée électorale aux élections européennes de 1984, le Front national a toujours atteint ses meilleurs niveaux lors des élections nationales et particulièrement lors de l'élection-reine qu'est l'élection présidentielle. Dans les cinq élections présidentielles qui se sont tenues depuis lors, il rassemble en moyenne presque 15% des suffrages exprimés (tableau 1). Les deux autres séries d'élections dans lesquelles il dépasse la barre des 10% des suffrages exprimés (s.e.) sont les élec...

  6. Adenosine Diphosphate Ribosylation Factor-GTPaseActivating Protein Stimulates the Transport of AUX1Endosome, Which Relies on Actin Cytoskeletal Organization in Rice Root DevelopmentF

    Institute of Scientific and Technical Information of China (English)

    Cheng Du; Yunyuan XU; Yingdian Wang; Kang Chong

    2011-01-01

    Polar auxin transport,which depends on polarized subcellular distribution of AUXIN RESISTANT 1/LIKE AUX1 (AUX1/LAX) influx carriers and PIN-FORMED (PIN) efflux carriers,mediates various processes of plant growth and development.Endosomal recycling of PIN1 is mediated by an adenosine diphosphate (ADP)ribosylation factor (ARF)-GTPase exchange factor protein,GNOM.However,the mediation of auxin influx carrier recycling is poorly understood.Here,we report that overexpression of OsAGAP,an ARF-GTPase-activating protein in rice,stimulates vesicle transport from the plasma membrane to the Golgi apparatus in protoplasts and transgenic plants and induces the accumulation of early endosomes and AUX1.AUX1 endosomes could partially colocalize with FM4-64 labeled early endosome after actin disruption.Furthermore,OsAGAP is involved in actin cytoskeletal organization,and its overexpression tends to reduce the thickness and bundling of actin filaments.Fluorescence recovery after photobleaching analysis revealed exocytosis of the AUX1 recycling endosome was not affected in the OsAGAP overexpression cells,and was only slightly promoted when the actin filaments were completely disrupted by Lat B.Thus,we propose that AUX1 accumulation in the OsAGAP overexpression and actin disrupted cells may be due to the fact that endocytosis of the auxin influx carrier AUX1 early endosome was greatly promoted by actin cytoskeleton disruption.

  7. Selenite supplementation reduces arsenate uptake greater than phosphate but compromises the phosphate level and physiological performance in hydroponically grown Oryza sativa L.

    Science.gov (United States)

    Kumar, Navin; Dubey, Arvind Kumar; Jaiswal, Praveen Kumar; Sahu, Nayan; Behera, Soumit Kumar; Tripathi, Rudra Deo; Mallick, Shekhar

    2016-01-01

    The present study evaluates the reduction of arsenate (As[V]) uptake in rice seedlings through individual and combined supplementation of phosphate (PO4(3-)) and selenite (Se[IV]) in a hydroponic condition. The toxic response in seedlings receiving As(V) manifested as inhibition in physiological parameters such as water use efficiency, stomatal conductance, photosynthetic assimilation rate, transpiration rate, photochemical quenching, and electron transport rate, along with growth. Arsenic accumulation significantly decreased with Se(IV) treatment (0.5 μg mL(-1), 1 μg mL(-1), and 2 μg mL(-1)) in a dose-dependent manner (20%, 35%, and 53%, respectively); however, it compromised the PO4(3-) level and physiological performance. The lower level of Se(IV), (0.5 μg mL(-1)), was relatively beneficial in terms of reduction in As accumulation than the higher level of Se(IV), (2 μg mL(-1)), which was rather toxic. Further, decrease in As uptake, replenished the level of PO4(3-) and physiological performance in seedlings treated with As+Se+P compared with those treated with As+Se. However, supplementation with only PO4(3-) (10 μg mL(-1) and 20 μg mL(-1)) along with As(V) was less effective in reducing As accumulation compared with As+Se. Seedlings receiving As+Se+P also exhibited lower thiobarbituric acid-reactive substances (TBARS) and electrical conductivity levels compared with both As+Se and As+P. Among all the treatments, the activity of antioxidant enzymes was highest in plants treated with As+Se+P. Hence, the higher antioxidant enzyme activity in As+Se+P along with lower levels of TBARS, H2 O2 , and As accumulation are attributed to the competitive reduction in As uptake in the presence of Se(IV) and PO4(3-). PMID:26189439

  8. Utilisation de la chimie chromatogénique pour la conception et la réalisation de matériaux cellulosiques barrières à l'eau, aux graisses et aux gaz.

    OpenAIRE

    Stinga, Nicoleta Camelia

    2008-01-01

    La chimie chromatogénique est un nouveau procédé de chimie propre qui permet le greffage moléculaire de matériaux hydroxylés avec des acides gras à longue chaîne. Dans cette étude, elle a été appliquée à la conception et à la réalisation de matériaux cellulosiques présentant les propriétés barrière requises pour l'emballage alimentaire (barrière à l'eau, aux graisses, aux gaz ...). Dans un premier temps, nous avons voulu approfondir notre connaissance du mécanisme de la réaction de greffage d...

  9. Modelisation de la diffusion sur les surfaces metalliques: De l'adatome aux processus de croissance

    Science.gov (United States)

    Boisvert, Ghyslain

    Cette these est consacree a l'etude des processus de diffusion en surface dans le but ultime de comprendre, et de modeliser, la croissance d'une couche mince. L'importance de bien mai triser la croissance est primordiale compte tenu de son role dans la miniaturisation des circuits electroniques. Nous etudions ici les surface des metaux nobles et de ceux de la fin de la serie de transition. Dans un premier temps, nous nous interessons a la diffusion d'un simple adatome sur une surface metallique. Nous avons, entre autres, mis en evidence l'apparition d'une correlation entre evenements successifs lorsque la temperature est comparable a la barriere de diffusion, i.e., la diffusion ne peut pas etre associee a une marche aleatoire. Nous proposons un modele phenomenologique simple qui reproduit bien les resultats des simulations. Ces calculs nous ont aussi permis de montrer que la diffusion obeit a la loi de Meyer-Neldel. Cette loi stipule que, pour un processus active, le prefacteur augmente exponentiellement avec la barriere. En plus, ce travail permet de clarifier l'origine physique de cette loi. En comparant les resultats dynamiques aux resultats statiques, on se rend compte que la barriere extraite des calculs dynamiques est essentiellement la meme que celle obtenue par une approche statique, beaucoup plus simple. On peut donc obtenir cette barriere a l'aide de methodes plus precises, i.e., ab initio, comme la theorie de la fonctionnelle de la densite, qui sont aussi malheureusement beaucoup plus lourdes. C'est ce que nous avons fait pour plusieurs systemes metalliques. Nos resultats avec cette derniere approche se comparent tres bien aux resultats experimentaux. Nous nous sommes attardes plus longuement a la surface (111) du platine. Cette surface regorge de particularites interessantes, comme la forme d'equilibre non-hexagonale des i lots et deux sites d'adsorption differents pour l'adatome. De plus, des calculs ab initio precedents n'ont pas reussi a confirmer la

  10. Solid-state synthesis, structure and properties of a novel open-framework cadmium selenite bromide: [Cd10(SeO3)8Br4]·HBr·H2O

    International Nuclear Information System (INIS)

    A novel open-framework cadmium selenite bromide, [Cd10(SeO3)8Br4]·HBr·H2O (1), has been obtained by a solid-state reaction at 450 °C, and the structure has been determined by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in Pbcm of the orthorhombic system: a=10.882(3), b=16.275(5), c=18.728(6) Å, V=3317(2) Å3, R1/wR2=0.0411/0.0659. Compound 1 is characteristic of a novel 3-D open-framework structure, composing ∞2[CdSeO3] layers and the pillars of edge-shared CdO3Br2 square pyramids. The lattice water molecules and the HBr molecules locate in the voids of the framework. Optical absorption spectrum of 1 reveals the presence of an optical gap of 1.65 eV. Solid-state photoluminescent study indicates that compound 1 exhibits strong violet emission. TG–DSC measurement shows that compound 1 is thermally stable up to 200 °C. - Graphical abstract: A metal selenite halide has been synthesized and features a 3-D open-framework structure, composing edge-shared CdO8 decahedra and pillars of edge-sharing pentahedra. UV–vis, TG–DSC and luminescent measurements are also reported. Highlights: • This paper reports a novel cadmium selenite bromide obtained by an intermediate-temperature solid-state reaction. • The title compound is characteristic of a novel 3-D open-framework structure, composing ∞2[CdSeO3] layers and the pillars of edge-shared CdO3Br2 square pyramids. • The title compound is thermally stable up to 200 °C. • The title compound has an optical gap of 1.65 eV and exhibits strong violet emission

  11. Order of 30 March 1988 on licensing of gaseous radioactive effluent releases by the Fontenay-aux-Roses Nuclear Research Centre

    International Nuclear Information System (INIS)

    This Decree prescribes the documents and information the Fontenay-aux-Roses Nuclear Research Centre must provide to the Central Service for Protection against Ionizing Radiation (SCPRI) and lays down the permissible effluent release limits for the Centre

  12. Inégalités sociales dans le renoncement aux soins de santé et dans leur utilisation

    OpenAIRE

    Tchicaya, Anastase; Lorentz, Nathalie

    2011-01-01

    Cette recherche se focalise sur l’analyse des inégalités sociales associées à l’accès et à l’utilisation des services de soins médicaux et hospitaliers au Luxembourg. Les données utilisées proviennent des enquêtes PSELL3/EU-SILC réalisées chaque année sur un échantillon représentatif de la population luxembourgeoise vivant en ménage privé. Des indicateurs d’accès aux soins (ou de renoncement aux soins) et d’utilisation des services de santé sont définis et les principales mesures d’inégalité ...

  13. Annliese Nef, Conquérir et gouverner la Sicile islamique aux XIe et XIIe siècles

    OpenAIRE

    Lejbowicz, Max

    2012-01-01

    625 pages de texte abondamment annotées, 106 d’annexes de nature diverse (iconographique, tabulaire, lexicographique, onomastique), 57 consacrées aux Sources et bibliographie, 13 à quatre Index, 5 aux abréviations, sans compter, intégrés au texte, sept figures (en fait des cartes et des plans) et dix-huit tableaux : l’ouvrage sous examen a l’épaisseur et le sérieux d’une thèse. Plus précisément : il est « la version profondément remaniée d’une thèse de doctorat soutenue en 2001 » (p. 9). Rapp...

  14. Periodicity, Electronic Structures, and Bonding of Gold Tetrahalides [AuX4](-) (X = F, CI, Br, I, At, Uus)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wan-Lu; Li, Yong; Xu, Congqiao; Wang, Xue B.; Vorpagel, Erich R.; Li, Jun

    2015-12-07

    Systematic theoretical and experimental investigations have been performed to understand the periodicity and electronic structures of trivalent-gold halides using gold tetrahalides [AuX4]⁻ anions (X = F, Cl, Br, I, At, Uus). The [AuX4]⁻ (X = Cl, Br, I) anions were produced in gas phase and their negative-ion photoelectron spectra were obtained, which exhibited rich and well-resolved spectral peaks. We calculated the adiabatic as well as vertical electron detachment energies using density functional methods with scalar and spin-orbit coupling relativistic effects. The simulated photoelectron spectra based on these calculations are in good agreement with the experimental spectra. Our results show that the trivalent Au(III) oxidation state becomes progressively less stable while Au(I) is preferred when the halides become heavier along the Period Table. This trend reveals that the oxidation state of metals in complexes can be manipulated through ligand design

  15. L’utilisation du vaccin contre l’influenza chez les enfants allergiques aux œufs

    OpenAIRE

    Hui, Charles PS; MacDonald, Noni E

    2011-01-01

    Les enfants sont plus vulnérables à la morbidité attribuable à l’influenza. Les vaccins contre l’influenza sont cultivés sur des œufs et pour cette raison, une infime quantité de protéines d’œuf persiste dans leur composition. De récentes recherches et de nouveaux paramètres de pratique suscités par la pandémie mondiale d’influenza de 2009 ont remis en question la décision de ne pas administrer le vaccin contre l’influenza aux patients allergiques aux œufs. Selon les données disponibles, l’an...

  16. Retention mechanisms of oxyanions in cementitious materials

    OpenAIRE

    Mota Gassó, Berta

    2011-01-01

    Increasing global cement production faces challenges such as cost increases in energy supply, requirements to reduce CO2 emissions, and the supply of raw materials in sufficient quality and amounts. Worldwide cement manufacturing represents 5% of man-made CO2 emissions, from which 50% is related to chemical process of clinker production, 40% to burning fuel and 10% is split between electricity use and transportation. To conserve natural non-renewable resources and preventing unnecessary landf...

  17. La douleur aux urgences: quelles interventions permettent à l'infirmière d'optimiser la prise en charge ?

    OpenAIRE

    Badan, Aurélie; Bouchard, Sara; Borloz, Corinne

    2015-01-01

    La douleur est le principal motif d'admission aux urgences. Les spécificités de ce domaine font que les soignants rencontrent certains obstacles qui limitent la qualité de la prise en charge. L'infirmière joue un rôle déterminant dans le soulagement de la douleur et possède de nombreuses responsabilités quant à la qualité de la prise en charge.

  18. Distribution et extension de la résistance chloroplatique aux atrazines chez les adventices annuelles en France

    OpenAIRE

    GASQUEZ, Jacques; BARRALIS, Gilbert; Aigle, N.

    1982-01-01

    La résistance chloroplastique aux triazines a été observée en France chez 13 espèces, dont les auteurs précisent l’importance agronomique et la distribution géographique ; les 3 espèces qui présentent la plus grande dispersion sont Amaranthus retroflexus L., Chenopodium album L. et Solanum nigrum L.

  19. Second meeting of the Atomic and Molecular Data Centre network. Fontenay aux Roses, 23-24 May 1980

    International Nuclear Information System (INIS)

    Summary report of the Second A+M Data Centre Network (DCN) meeting convened by the IAEA Nuclear Data Section at the CEA Laboratory at Fontenay-aux-Roses, France, 23-24 May 1980. The meeting was attended by 20 representatives from centres and groups from six Member States concerned with the coordinated international management of atomic and molecular data pertinent to controlled fusion research and technology

  20. Phloem-specific expression of a melon Aux/IAA in tomato plants alters auxin sensitivity and plant development

    Directory of Open Access Journals (Sweden)

    Guy eGolan

    2013-08-01

    Full Text Available Phloem sap contains a large repertoire of macromolecules in addition to sugars, amino acids, growth substances and ions. The transcription profile of melon phloem sap contains over 1,000 mRNA molecules, most of them associated with signal transduction, transcriptional control, and stress and defense responses. Heterografting experiments have established the long-distance trafficking of numerous mRNA molecules. Interestingly, several trafficking transcripts are involved in the auxin response, including two molecules coding for auxin/indole acetic acid (Aux/IAA. To further explore the biological role of the melon Aux/IAA transcript CmF-308 in the vascular tissue, a cassette containing the coding sequence of this gene under a phloem-specific promoter was introduced into tomato plants. The number of lateral roots was significantly higher in transgenic plants expressing CmF-308 under the AtSUC2 promoter than in controls. A similar effect on root development was obtained after transient expression of CmF-308 in source leaves of N. benthamiana plants. An auxin-response assay showed that CmF-308-transgenic roots are more sensitive to auxin than control roots. In addition to the altered root development, phloem-specific expression of CmF-308 resulted in shorter plants, a higher number of lateral shoots and delayed flowering, a phenotype resembling reduced apical dominance. In contrast to the root response, cotyledons of the transgenic plants were less sensitive to auxin than control cotyledons. The reduced auxin sensitivity in the shoot tissue was confirmed by lower relative expression of several Aux/IAA genes in leaves and an increase in the relative expression of a cytokinin-response regulator, TRR8/9b. The accumulated data suggest that expression of Aux/IAA in the phloem modifies auxin sensitivity in a tissue-specific manner, thereby altering plant development.

  1. Shoot-supplied ammonium targets the root auxin influx carrier AUX1 and inhibits lateral root emergence in Arabidopsis

    KAUST Repository

    Li, Baohai

    2011-03-24

    Deposition of ammonium (NH4 +) from the atmosphere is a substantial environmental problem. While toxicity resulting from root exposure to NH4 + is well studied, little is known about how shoot-supplied ammonium (SSA) affects root growth. In this study, we show that SSA significantly affects lateral root (LR) development. We show that SSA inhibits lateral root primordium (LRP) emergence, but not LRP initiation, resulting in significantly impaired LR number. We show that the inhibition is independent of abscisic acid (ABA) signalling and sucrose uptake in shoots but relates to the auxin response in roots. Expression analyses of an auxin-responsive reporter, DR5:GUS, and direct assays of auxin transport demonstrated that SSA inhibits root acropetal (rootward) auxin transport while not affecting basipetal (shootward) transport or auxin sensitivity of root cells. Mutant analyses indicated that the auxin influx carrier AUX1, but not the auxin efflux carriers PIN-FORMED (PIN)1 or PIN2, is required for this inhibition of LRP emergence and the observed auxin response. We found that AUX1 expression was modulated by SSA in vascular tissues rather than LR cap cells in roots. Taken together, our results suggest that SSA inhibits LRP emergence in Arabidopsis by interfering with AUX1-dependent auxin transport from shoot to root. © 2011 Blackwell Publishing Ltd.

  2. Periodicity, Electronic Structures, and Bonding of Gold Tetrahalides [AuX4]- (X = F, Cl, Br, I, At, Uus).

    Science.gov (United States)

    Li, Wan-Lu; Li, Yong; Xu, Cong-Qiao; Wang, Xue-Bin; Vorpagel, Erich; Li, Jun

    2015-12-01

    Systematic theoretical and experimental investigations have been performed to understand the periodicity, electronic structures, and bonding of gold halides using tetrahalide [AuX4](-) anions (X = F, Cl, Br, I, At, Uus). The [AuX4](-) (X = Cl, Br, I) anions were experimentally produced in the gas phase, and their negative-ion photoelectron spectra were obtained, exhibiting rich and well-resolved spectral peaks. As expected, Au-X bonds in such series contain generally increasing covalency when halogen ligands become heavier. We calculated the adiabatic electron detachment energies as well as vertical electron detachment energies using density functional theory methods with scalar relativistic and spin-orbit coupling effects. The computationally simulated photoelectron spectra are in good agreement with the experimental ones. Our results show that the trivalent Au(III) oxidation state becomes progressively less stable while Au(I) tends to be preferred when the halides become heavier along the Periodic Table. This series of molecules provides an example for manipulating the oxidation state of metals in complexes through ligand design. PMID:26550845

  3. Report on transparency and nuclear safety - Fontenay-aux-Roses CEA centre - 2012

    International Nuclear Information System (INIS)

    This report presents the different nuclear base installations (INB) of the Fontenay-aux-Roses CEA centre, gives an overview of measures regarding safety within these installations (organisation, general arrangements, arrangements related to different risks, defence in-depth, management of emergency situations, inspections, audits and second-level controls, arrangements and main events specific to the different installations and buildings, issues related to transports, soil radiological assessment) and measures related to radiation protection (organisation and results). It reports the significant events related to safety and radiation protection which occurred in 2012 and were declared to the ASN, and discusses how the return-on-experience has been used. It reports and comments the results of measurements of radiological and chemical gaseous and liquid effluents, of surveys of the environment. It also evokes important events related to these measurement and survey processes, presents the environmental management approach. The next part addresses the management of radioactive wastes: arrangements aimed at limiting the volume of warehoused wastes, and at limiting their impact on health and on the environment, nature and quantities of warehoused wastes. The different arrangements regarding transparency and information are reviewed (TSN report, newsletter, and so on)

  4. Cours Sécurité : Sensibilisation aux gestes et postures de travail

    CERN Multimedia

    DGS Unit

    2010-01-01

    Prochaine session le 21 octobre 2010. 12 places disponibles. Ce cours concerne toutes les personnes appelées à réaliser des manutentions manuelles dans le cadre de leurs activités. Contenu du cours : Théorie - Présentation des objectifs du programme ; - L'accident du travail (définition, coûts) ; - Statistiques CNAM ; - Notion d'anatomie (mécanique humaine) ; - Les différentes pathologies (lumbago, sciatique, hernie discale) ; - Discussion sur les problèmes particuliers rencontrés dans la vie courante. Pratique - Les efforts mécaniques sur la colonne dus aux mauvaises postures ; - Les principes de base de l'utilisation de la mécanique humaine ; - Exercices pratiques d'application (sur objets divers standards) ; - Prises de vues au caméscope des positions de chacun. Pour vous inscrire : https://edh.cern.ch/Document/Personnel/TRN?new=YES&...

  5. Desenvolvimento de ferramenta computacional para auxílio ao projeto de gemas lapidadas

    Directory of Open Access Journals (Sweden)

    Luiz S Martins-Filho

    2005-12-01

    Full Text Available Esse trabalho apresenta um estudo sobre ferramenta computacional para auxílio ao projeto de lapidação de gemas. O material escolhido para o estudo é o quartzo hialino. São apresentados aspectos de desenvolvimento histórico do processamento de gemas e também os diagramas de lapidação e seus principais parâmetros. Para a determinação do grau de eficiência de um modelo de lapidação, são propostos dois critérios: a brilhância e o aproveitamento em peso. A ferramenta computacional, a ser utilizada na estimação desses resultados de um determinado projeto, baseia-se nas redes neurais artificiais. A validação da ferramenta proposta utiliza testes sobre dados de 62 diferentes projetos de lapidação.This paper presents a study on a Computer-aided-design (CAD tool for lapidary design. The material chosen is rock crystal quartz. Aspects of historical development of gemstone lapidary, faceting diagrams and faceting parameters are presented. Two criteria are proposed to assess the efficiency of a given lapidary design: brilliance and yield. To estimate these two results, the tool developed is based on artificial neural networks. Tests with 62 different lapidary designs were used to validate the proposed CAD tool.

  6. A Quantum Multicritical point in CeCu6-xAux

    International Nuclear Information System (INIS)

    Full text: CeCu6-xAux is a well-known heavy-fermion system in which the ground state is antiferromagnetically ordered for x > 0.1 and temperatures below 1K. Non-Fermi-liquid behaviour occurs around this critical concentration. The parent compound, CeCu6, exhibits a structural phase transition near 230K, where it changes from the Pnma orthorhombic room-temperature structure to the P21/c monoclinic structure. The monoclinicity increases as temperature falls, with β reaching 91.44 degrees at 10K. In the work presented here, powder neutron diffraction is used to explore the monoclinicity at 10K as a function of composition for 0.0 2, suggests that the distortion vanishes by x = 0.14. A reanalysis of single-crystal diffraction data on the magnetically ordered side of the phase diagram indicate that long-range order disappears at the same critical concentration. At a minimum, the structural distortion and antiferromagnetism seem to be competing with each other, and this raises the intriguing possibility that lattice degrees of freedom are important in the non-Fermi-liquid regime. (authors)

  7. Field-induced quantum criticality in CeCu6-xAux

    International Nuclear Information System (INIS)

    The heavy-fermion system CeCu6-xAux is an archetype for pressure-induced quantum criticality at the onset of antiferromagnetic order. Up to now, investigations focused mainly on the behavior close to the critical concentration xc∼0.1. The antiferromagnetic order of samples with higher Au content can, however, be also suppressed by magnetic fields. We studied the field-induced quantum critical behavior of samples with Au contents x=0.3, 0.5 and 1.0 in fields applied along the magnetic easy axis by using thermal expansion and magnetostriction measurements. Due to their high sensitivities these measurements are especially suited to expose deviations from Fermi-liquid behavior. The measurements have been performed for temperatures ranging between 20 mK and 10 K, and in magnetic fields up to 14 T. With increasing Au content and critical field Bc they show strongly varying critical behavior. We discuss our results taking into account the field-dependent Zeeman splitting of the CEF ground-state doublet, which manifests itself as a Schottky-like anomaly at low temperatures and fields larger than Bc.

  8. Phloem-Mobile Aux/IAA Transcripts Target to the Root Tip and Modify Root Architecture

    Institute of Scientific and Technical Information of China (English)

    Michitaka Notaguchi; Shmuel Wolf; William J. Lucas

    2012-01-01

    In plants,the phloem is the component of the vascular system that delivers nutrients and transmits signals from mature leaves to developing sink tissues.Recent studies have identified proteins,mRNA,and small RNA within the phloem sap of several plant species.It is now of considerable interest to elucidate the biological functions of these potential long-distance signal agents,to further our understanding of how plants coordinate their developmental programs at the whole-plant level.In this study,we developed a strategy for the functional analysis of phloem-mobile mRNA by focusing on IAA transcripts,whose mobility has previously been reported in melon (Cucumis melo cv.Hale's Best Jumbo).Indoleacetic acid (IAA) proteins are key transcriptional regulators of auxin signaling,and are involved in a broad range of developmental processes including root development.We used a combination of vasculature-enriched sampling and hetero-grafting techniques to identify IAA18 and IAA28 as phloemmobile transcripts in the model plant Arabidopsis thaliana.Micro-grafting experiments were used to confirm that these IAA transcripts,which are generated in vascular tissues of mature leaves,are then transported into the root system where they negatively regulate lateral root formation.Based on these findings,we present a model in which auxin distribution,in combination with phloem-mobile AuxIIAA transcripts,can determine the sites of auxin action.

  9. Application of solar chargers to prospection instruments; Application des chargeurs solaires aux appareils de prospection

    Energy Technology Data Exchange (ETDEWEB)

    Caille, G. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The use of conventional batteries has certain disadvantages, and for this reason high-voltage batteries have been gradually replaced in all prospection instruments by transistor supply systems, using less cumbersome sources of energy. All the same low voltages are still necessary, and in hot or damp countries the use of these batteries leads to consumptions out of all proportion to the services rendered. This is why the use of solar energy possesses real advantages. After a brief review of the basic ideas on semiconductors, this article describes a selenium solar battery which was developed by the Westinghouse brakes and signals society. (author) [French] L'utilisation de piles classiques presente certains inconvenients. C'est pourquoi, dans tous les appareils de prospection, les piles fournissant des tensions elevees ont ete remplacees au fur et a mesure par des alimentations a base de transistors, utilisant des sources d'energie moins encombrantes. Toutefois, il faut tout de meme avoir des tensions faibles et l'utilisation de ces piles entraine dans les pays chauds ou humides une consommation disproportionnee par rapport aux services rendus. C'est pourquoi l'emploi de l'energie solaire presente de reels avantages. Cet expose decrit, apres un rappel de notion de base sur les semi-conducteurs, une batterie solaire a base de selenium qui a ete realisee par la Societe des freins et signaux Westinghouse. (auteur)

  10. Nd3(SeO3)4OH: the first rare earth hydroxide selenite with the Gd3(SeO3)4F-type structure

    International Nuclear Information System (INIS)

    Monocrystals of a new neodymium hydroxide selenite Nd3(SeO3)4OH are prepared by hydrothermal synthesis and studied by X-ray diffraction. The compound is found to crystallize in space group P63mc with the unit cell parameters: a = 10.547(1) A, c = 7.134(1) A, Z = 2. The Nd3(SeO3)4OH structure contains a three-dimensional framework of chains consisting of NdO9 polyhedra. Selenium(IV) atoms, whose environment includes three oxygen atoms each, are arranged along voids of the framework. The Nd3(SeO3)4OH structure is isotypical to Gd3(SeO3)4F. The hydroxide oxygen atom in the new structure plays the role of the F atom in Gd3(SeO3)4F

  11. Synthesis, structure, and characterization of two new bismuth(III) selenite/tellurite nitrates: [(Bi3O2)(SeO3)2](NO3) and [Bi(TeO3)](NO3)

    Science.gov (United States)

    Meng, Chang-Yu; Wei, Ming-Fang; Geng, Lei; Hu, Pei-Qing; Yu, Meng-Xia; Cheng, Wen-Dan

    2016-07-01

    Two new bismuth(III) selenite/tellurite nitrates, [(Bi3O2)(SeO3)2](NO3) and [Bi(TeO3)](NO3), have been synthesized by conventional facile hydrothermal method at middle temperature 200 °C and characterized by single-crystal X-ray diffraction, powder diffraction, UV-vis-NIR optical absorption spectrum, infrared spectrum and thermal analylsis. Both [(Bi3O2)(SeO3)2](NO3) and [Bi(TeO3)](NO3) crystallize in the monoclinic centronsymmetric space group P21/c with a=9.9403(4) Å, b=9.6857(4) Å, c=10.6864(5) Å, β=93.1150(10)° for [(Bi3O2)(SeO3)2](NO3) and a=8.1489(3) Å, b=9.0663(4) Å, c=7.4729(3) Å, β=114.899(2)° for Bi(TeO3)(NO3), respectively. The two compounds, whose structures are composed of three different asymmetric building units, exhibit two different types of structures. The structure of [(Bi3O2)(SeO3)2](NO3) features a three-dimensional (3D) bismuth(III) selenite cationic tunnel structure [(Bi3O2)(SeO3)2] 3∞ with NO3- anion group filling in the 1D tunnel along b axis. The structure of [Bi(TeO3)](NO3) features 2D bismuth(III) tellurite [Bi(TeO3)2]2∞ layers separated by NO3- anion groups. The results of optical diffuse-reflectance spectrum measurements and electronic structure calculations based on density functional theory methods show that the two compounds are wide band-gap semiconductors.

  12. Tectonic conditions of hydrothermal polymetallic vein-type mineralization, Sainte Marie-aux-Mines, France

    Science.gov (United States)

    Hafeznia, Y.; Bourlange, S.; Ohnenstetter, M.

    2012-04-01

    The Sainte-Marie-aux-Mines (SMM) mines host one of the most famous and oldest silver deposits in Europe. The SMM district is located in the central part of the Vosges mountains, France, within gneiss and granites of the Moldanubian zone. The SMM district includes the Neuenberg E-W vein-type Cu-Ag-As/Pb-Zn deposit and the Altenberg N-S vein-type Pb-Zn-Ag deposit. Deposition of the SMM hydrothermal mineralization occurred under a brittle tectonic regime that might be connected to neo-Variscan and/or post-Variscan tectonics, in a similar way as the polymetallic vein deposits of the Black Forest, Germany. A structural study was done in the Neuenberg area, in the vicinity of the Saint-Jacques vein, and within the Gabe Gottes mine, considering the orientation, extent, chronology and density of faults as well as the nature of the infilling minerals. In the Gabe-Gottes mine, the Saint-Jacques vein comprises multiple successive, sub-parallel subvertical veinlets with gangue minerals, mostly carbonates and quartz, and metal-bearing phases, sulfides and sulfosalts. The veinlets are 2 to 50 cm thick and strike N80° to N110°, the earlier veins slightly dipping towards the north, and the latest one, to the south. Seven systems of faults were identified, which may be classified into three major groups formed respectively before, during and after the main stage of ore deposition: a) Pre-mineralization faults - These consist of sinistral NE-SW strike-slip faults, and NW-SE and NE-SW steeply dipping normal faults. These could be related to Carboniferous events considering their relationships with the granitoid intrusives present in the mine area (Brézouard leucogranite ~329 Ma), and the extensional tectonics developed during exhumation processes. b) Faults associated with the main ore-deposition - These faults could be related to late-Hercynian processes from compressional to extensional tectonic regimes. Mineralization controlling faults consist of dextral and sinistral E

  13. Expression of wild-type PtrIAA14.1, a poplar Aux/IAA gene causes morphological changes in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Shanda eLiu

    2015-06-01

    Full Text Available Aux/IAA proteins are transcriptional repressors that control auxin signaling by interacting with Auxin Response Factors (ARFs. So far all of the identified Aux/IAA mutants with auxin-related phenotypes in Arabidopsis and rice (Oryza sativa are dominant gain-of-function mutants, with mutantions in Domain II that affected stability of the corresponding Aux/IAA proteins. On the other hand, morphological changes were observed in knock-down mutants of Aux/IAA genes in tomato (Solanum lycopersicum, suggesting that functions of Aux/IAA proteins may be specific for certain plant species. We report here the characterization of PtrIAA14.1, a poplar (Populus trichocarpa homologue of IAA7. Bioinformatics analysis showed that PtrIAA14.1 is a classic Aux/IAA protein. It contains four conserved domains with the repressor motif in Domain I, the degron in Domain II, and the conserved amino acid signatures for protein-protein interactions in Domain III and Domain IV. Protoplast transfection assays showed that PtrIAA14.1 is localized in nucleus. It is unable in the presence of auxin, and it represses auxin response reporter gene expression. Expression of wild type PtrIAA14.1 in Arabidopsis resulted in auxin-related phenotypes including down-curling leaves, semi-draft with increased number of branches, and greatly reduced fertility, but expression of the Arabidopsis Aux/IAA genes tested remain largely unchanged in the transgenic plants. Protein-protein interaction assays in yeast and protoplasts showed that PtrIAA14.1 interacted with ARF5, but not other ARFs. Consistent with this observation, vascular patterning was altered in the transgenic plants, and the expression of AtHB8 (Arabidopsis thaliana Homeobox Gene 8 was reduced in transgenic plants.

  14. La formation des enseignants aux TIC : allier pédagogie et innovation

    Directory of Open Access Journals (Sweden)

    Marcel Lebrun

    2004-05-01

    Full Text Available [Français] Relativement au champ des technologies éducatives, nous souhaitons étayer l’hypothèse suivante : si généralement on attribue le fait d’apprendre aux étudiants, il est aussi vrai que les enseignants apprennent, que les sociétés apprennent. La cohérence et la préoccupation de ces différents niveaux (étudiants, enseignants, institutions autour de la question de l’apprentissage peuvent, selon nous, être considérées comme un guide et comme un signe d’une éducation de qualité. Dans ce cas, les modèles généraux de l’apprentissage et du développement de dispositifs pédagogiques peuvent être interrogés afin d’élaborer de nouveaux usages et de nouvelles méthodes d’enseignement et de formation des enseignants, pour promouvoir l’innovation technologique dans les institutions et pour en valider la qualité. [English] In this paper, we will try to elaborate, in the field of educational technology, the following hypothesis : students learn, teachers learn too and furthermore institutions learn. The coherence and the awareness of these various levels (students, teachers, institutions around learning may be considered as a guide and an indicator of the quality of education. In this context, the general models for learning and for teaching may be used to develop new teaching or staff training methods, to promote technology innovation in institutions along with the assessment of these initiatives.

  15. Evaluation of the radiology state at the CEA/Fontenay-aux-Roses and its environment; Point sur l'etat radiologique du CEA/Fontenay-aux-Roses et de son environnement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-10-01

    Since 1946 the nuclear installations followed one other at the CEA of Fontenay-aux-Roses still their gradual stop the last ten years, except two installations INB34 and INB73, necessary for the wastes management. Today these installations form the subject of a drainage program. The public opinion is regularly informed on this program since 1999. This document presents the stock of the actions realized since this date: the track keeping of the sites activities impacts on the environment and the actions realized since 1999. (A.L.B.)

  16. RELIGION ET IMMIGRATION AUX ÉTATS-UNIS [Religion and immigration in the United States of America

    OpenAIRE

    Dumont, Gérard-François

    2012-01-01

    International audience In any country, the number of religions evolve according to the number of people who identify with the various religions and the number of people who deviate. In the United States, this type of evolution is particularly dependent on immigration resulting in significant changes in the religious distribution of the population. Aux États-Unis, l'évolution des effectifs des religions est tout particulièrement dépendant de l'immigration qui engendre des changements imp...

  17. Contribution to the study of several chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses

    International Nuclear Information System (INIS)

    From the checking of 2750 index cards of hazards, the study relates the distribution of the chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses. Those concerning the greatest number of agents in the Centre are classified according to the categories corresponding to the different conditions of working. Thus, the most important are put forward. Then, the authors rapidly make a review of hazards which may have some special interest because they appear more specific of the nuclear energy or because they are the most frequently noted on the index cards of hazards. The case of the tributylphosphate is studied more precisely. (authors)

  18. Comportements des marchés et perception de la faillite de Lehman Brothers aux États-Unis

    OpenAIRE

    Dumontaux, Nicolas; Pop, Adrian

    2010-01-01

    La faillite spectaculaire de la banque d'investissement Lehman Brothers a été perçue par de nombreux analystes comme un véritable point de retournement dans la crise financière actuelle. Le spectre du risque systémique a semé la panique parmi les investisseurs, non seulement aux États-Unis, mais aussi sur les marchés financiers internationaux. À l'aide de séries boursières sur le cours des actions des établissements financiers, nous analysons la perception de la faillite de Lehman Brothers au...

  19. Aspectos clínico-patológicos da intoxicação experimental por selenito de sódio em eqüinos Clinical and pathological aspects of experimental poisoning by sodium selenite in horses

    Directory of Open Access Journals (Sweden)

    Pedro Brandini Néspoli

    2001-09-01

    Full Text Available Dadas as controvérsias sobre a intoxicação por selênio, foram realizados nove experimentos com a administração de selenito de sódio, por via intramuscular, em eqüinos, com o intuito de estudar e melhor fundamentar os aspectos clínico-patológicos e toxicológicos sobre esse tema. Conseguiram-se produzir quadros com evoluções superaguda, aguda, subaguda e crônica; alguns sinais clínicos de origem nervosa observados nos quadros agudos foram similares aos descritos para "blind staggers"; a despeito disto, o carácter conflitante e duvidoso das descrições sobre essa pretensa entidade historicamente descrita, não permite uma comparação mais exata. O quadro crônico, por outro lado, configurou claramente a primeira reprodução de "alkali disease", por via parenteral, em eqüinos. Estabeleceu-se 1,49 mg/kg de selenito de sódio como a dose única letal para essa espécie. Descrevem-se diversos achados clínico-patológicos relativos aos sistemas cardiovascular e nervoso, antes não mencionados na literatura relativa aos eqüinos intoxicados por selênio. Entre eles, destacam-se, clinicamente, sopro e arritmia cardíacos, desdobramento de bulhas e convulsão. À necropsia, um animal apresentou nítido achatamento das circunvoluções cerebrais e, em relação à histopatologia, lise e necrose de neurônios do córtex, edema de astrócitos, bem como ativação endotelial e gliose. Em relação à patogênese, postula-se que as alterações degenerativo-necróticas observadas no sistema nervoso central, devam-se ao edema, por sua vez conseqüente ao aumento da permeabilidade vascular, determinada pelo selenito de sódio.Due to the numerous contradictions on selenium poisoining, and in order to improve knowledge about the clinical, pathological and toxicological aspects, experiments were performed with intramuscular injections of sodium selenite in 9 horses. Peracute, acute, subacute and chronic poisoning was reproduced; some nervous

  20. L’accès aux ressources d’une formation guidé par des ontologies

    Directory of Open Access Journals (Sweden)

    Marie-Hélène Abel

    2006-01-01

    Full Text Available [Français] Beaucoup de ressources sont mises à contribution pour supporter une formation de type e-learning. L’un des objectifs du projet MEMORAe est de rendre ces ressources plus accessibles aux apprenants. Ce projet propose une approche fondée sur une mémoire organisationnelle de l’ensemble des notions et des ressources de la formation. Un principe est d’indexer ces ressources sur les concepts d’ontologie. Nous décrivons les moyens déployés à cette fin. Nous présentons les scénarios par lesquels les apprenants accèdent aux connaissances en parcourant ces ontologies. Enfin, nous illustrons notre propos à l’aide de deux applications actuellement mises en place en université. [English] Many resources are now available in order to support e-learning. One objective of the MEMORAe project is to make these resources more accessible to the students. This project proposes an approach based on an organizational memory of the notions and resources of the formation. A principle is to index these resources on the concepts of some ontologies. We describe the means implemented in this aim. We present the manner in which the students reach the knowledge, by moving in these ontologies. At last, we illustrate our presentation by means of two applications recently set up in some universities.

  1. Les ecarts de financement en matiere d'adaptation aux changements climatiques - avec la perspective des CPDN

    DEFF Research Database (Denmark)

    Olhoff, Anne; Bee, Skylar; Puig, Daniel

    rapport sur les écarts financiers et les options permettant de les combler. Le rapport sera publié au printemps 2016. Cette mise à jour doit contribuer aux débats lors de la 21ème session de la Conférence des Parties (COP 21) à la Convention-Cadre des Nations Unies sur les Changements Climatiques (CCNUCC......). Elle comprend les principales conclusions concernant les coûts et les financements de l’adaptation aux changements climatiques du rapport AGR 2014 du PNUE ainsi que les conclusions préliminaires de l’évaluation de 2016. De plus, elle s’appuie sur les réflexions concernant les coûts de l’adaptation et...... les besoins de financement présentes dans les composantes adaptation des Contributions Prévues Déterminées au niveau National (CPDN) (INDC) – soit les engagements post 2020 que les pays se proposent mettre en oeuvre dans le cadre d’un nouvel accord mondial sur les changements climatiques....

  2. INFLUENCE DE LA STRUCTURE ET DE LA SEGREGATION AUX JOINTS DE GRAINS SUR LES PROPRIETES ELECTRIQUES ET LE RENDEMENT PHOTOVOLTAIQUE DU SILICIUM POLYCRISTALLIN

    OpenAIRE

    Maurice, J.; Laval, J

    1982-01-01

    On relie les propriétés électriques et structurales des joints de grains dans le cas du silicium polycristallin produit par la méthode Bridgman (C.G.E.), en comparant les mesures macroscopiques de réponse photovoltaïque (LBIC) et de chute de potentiel aux joints, aux analyses cristallographiques et chimiques effectuées en microscopie électronique (STEM, EDS, EELS). On peut distinguer trois types de joints : 1) les joints plans -cohérents- qui n'influent pas sur le photocourant, à moins d'être...

  3. Dans un service d’urgences, comment les infirmières peuvent-elles apporter un soin relationnel aidant aux femmes victimes d’abus sexuel ?

    OpenAIRE

    Décosterd, Joanna; Stam, Jessica; Berset, Christine

    2013-01-01

    Une personne victime d’abus sexuel se présente aux urgences d’un hôpital et doit attendre de nombreuses heures sans recevoir de soins et d’attention de la part des professionnels. En prenant connaissance de la thématique de l’abus sexuel, nous constatons que les femmes sont les plus touchées, que l’abus peut être de différente nature et que les conséquences physiques, psychiques et sociales sont importantes. Du point de vue des infirmières travaillant aux urgences, il ressort que leurs princi...

  4. Homosexualité/hétérosexualité : les enquêtes sur les comportements sexuels en France et aux USA

    OpenAIRE

    Lhomond, Brigitte; Michaels, Stuart

    2009-01-01

    Cet article propose une analyse des résultats concernant l’attirance et les pratiques homosexuelles dans les deux enquêtes nationales récentes sur les comportements sexuels en France et aux USA. On observe des attitudes sociales différentes vis‑à‑vis de l’homosexualité dans les deux pays avec une beaucoup plus grande acceptation en France, une affirmation plus nette de l’attirance homosexuelle aux Etats‑Unis, surtout chez les hommes et une structuration socio-démographique assez similaire des...

  5. Tolérance aux fautes dans les applications J2EE: Une solution scalable et générique

    OpenAIRE

    Bouchenak, Sara; Krakowiak, Sacha; De Plama, Noël

    2005-01-01

    La plate-forme J2EE définit un modèle pour développer des applications réparties dans une architecture multi-tiers, telles que les applications Web de commerce électronique. Avec la multiplication des couches logicielles et intergicielles, les applications Internet sont encore plus sujettes aux défaillances ; ces défaillances étant, pour la majorité, causées par des fautes logicielles ou des fautes de l'opérateur. Dans cet article, nous proposons un système de tolérance aux fautes qui traite ...

  6. La panique pédophile aux États-Unis et en France

    Directory of Open Access Journals (Sweden)

    Kristen Zgoba

    2005-09-01

    Full Text Available Durant la première moitié des années 1990, les États-Unis traversèrent ce qui peut être appelé une crise liée aux crimes sexuels. Ceci entraîna le passage de législations spécifiques destinées à adresser ce qui était perçu par le public comme un problème social de grande envergure. Durant la seconde moitié des années 1990, l’Europe (principalement l’Angleterre, la Belgique, les Pays-Bas, la France, et l’Allemagne se trouva dans la même situation que les États-Unis. Là aussi des législations étaient promulguées, de nature variée, afin de procurer des réponses à la panique du public. Selon une approche sociologique constructionniste, une panique morale prend place lorsque certains types de comportements ou d’individus apparaissent comme posant un extrême danger pour le tissu social. Étant donné que la pédophilie représente symboliquement l’ultime horreur dans la catégorie des crimes sexuels en ce que des enfants en sont les victimes, la présente contribution propose une grille d’analyse constructionniste afin d’estimer l’existence potentielle d’une crise morale liée à ce crime. Cet article pose les bases d’une démarche continue d’analyse du phénomène pédophile selon la grille théorique des paniques morales.The Pedophilia Panic in France and in the United States - In the early and mid-1990s, the United States experienced what could be called a sex crime crisis. This led to the passing of specific legislations aimed at addressing what was perceived by the public at large as a major social problem. In the mid- and late-1990s, Europe (mainly Britain, Belgium, the Netherlands, France, and Germany found itself in the same predicament as the US. There too, legislations were passed, varying in their nature, in order to provide the public with answers to its panic. According to a social constructionist approach, a moral panic occurs when certain types of behaviors or individuals are thought to

  7. Synthesis, structure and properties of (CN{sub 3}H{sub 6}){sub 4}Zn{sub 3}(SeO{sub 3}){sub 5}, the first organically-templated selenite

    Energy Technology Data Exchange (ETDEWEB)

    HARRISON,W.T.A.; PHILLIPS,MARK L.F.; STANCHFIELD,JESSE L.; NENOFF,TINA M.

    2000-05-22

    An astonishing variety of inorganic networks templated by organic species have been reported over the last 10 years. A great deal of attention has been paid to the structure-directing role of the organic species, and the structural effect of variously coordinated cations, for example distorted octahedral vanadium and pyramidal tin. Less exploratory work has been carried out on the anionic part of the inorganic network, and most groups reported so far (phosphate, germanate, etc.) invariably adopt tetrahedral coordination. The possibilities of incorporating the pyramidal [HP0{sub 3}]{sup 2{minus}} hydrogen phosphite group into extended structures templated by inorganic, alkaline earth cations was explored a few years ago. In this paper the authors report the synthesis, crystal structure, and some properties of (CN{sub 3}H{sub 6}){sub 4}{center_dot}Zn{sub 3}(SeO{sub 3}){sub 5}, the first organically-templated phase to contain the pyramidal selenite [SeO{sub 3}]{sup 2{minus}} anion.

  8. Interventions et attitudes envers les patientes victimes de violences domestiques aux urgences: une revue de la littérature étoffée

    OpenAIRE

    Suchet, Amandine; Gasser, Catherine

    2013-01-01

    But: déterminer les interventions, les attitudes infirmières et les obstacles se présentant lors d’un dépistage de violences domestiques aux urgences, afin d’améliorer et d’avoir une meilleure prise en charge des femmes victimes d’abus.

  9. Les images de l’Arabie Saoudite aux États-Unis - De 1973 au 11 septembre 2001

    OpenAIRE

    Raymond Vidén, Anna

    2011-01-01

    Cette étude avance l’idée que la relation américano-saoudienne « spéciale » fait partie intégrante d’un récit sur la relation entre les États-Unis et l’Arabie Saoudite, créé par la compagnie pétrolière ARAMCO et entretenu par Washington au travers de déclarations, doctrines politiques et voyages officiels en Arabie Saoudite. L’Arabie Saoudite elle-même entretient ce récit avec sa diplomatie publique et l’influence exercée par le « lobby saoudien » aux États-Unis. Ce récit souligne l’importanc...

  10. The Politics of Religion in the United States Manifestations politiques de la religion aux États-Unis

    Directory of Open Access Journals (Sweden)

    Josef Braml

    2011-04-01

    Full Text Available Aux États-Unis, les attitudes religieuses ont plus d’influence sur les choix politiques que dans n’importe quelle autre démocratie occidentale. L’engagement religieux/moral de la droite chrétienne polarise les États-Unis, ce qui a des conséquences sur le plan électoral mais aussi sur les choix politiques réels. L’importance de la droite chrétienne dans la coalition électorale du Parti républicain oblige celui-ci à mettre l’accent sur les questions liées à la sécurité nationale, en particulier la lutte anti-terroriste, afin de mieux souder une coalition électorale hétérogène.

  11. Environnements stellaire : des étoiles lambda Boötis aux disques protoplanétaires

    OpenAIRE

    Gonzalez, Jean-François

    2005-01-01

    J'ai effectué une étude des éléments C, N, et O dans les atmosphères d'étoiles chimiquement particulières de la séquence principale, où ils sont sous-abondants et répartis de manière inhomogène. J'ai recensé les processus physiques qu'il faut inclure dans les calculs d'accélération radiative et montré leur importance relative. Des améliorations majeures par rapport aux approximations usuelles ont été obtenues grâce à l'utilisation systématique des données atomiques du projet OPACITY. Elles pe...

  12. Le système opioïde endogène et l’addiction aux drogues1

    OpenAIRE

    Maldonado, Rafael

    2010-01-01

    L’addiction aux drogues est une maladie psychiatrique chronique qui conduit à d’importantes altérations adaptatives dans les circuits de récompense du cerveau. Plusieurs systèmes de neurotransmission sont impliqués dans ces modifications. Cependant, un des systèmes neurochimiques qui joue un rôle essentiel dans l’addiction est le système opioïde endogène. Les récepteurs opioïdes et les peptides opioïdes endogènes sont très largement présents dans les structures cérébrales qui contrôlent les p...

  13. Vieillir et faire face au cancer : des ressources objectives aux ressources sélectives

    OpenAIRE

    Marche, Hélène; Pian, Anaïk

    2014-01-01

    Dans le prolongement de travaux considérant le vieillissement comme processus et contexte à part entière, l’article s’intéresse aux ressources mobilisées par les individus âgés pour contrôler leur trajectoire du cancer. À travers la mise en perspective de deux études de cas concernant des individus âgés occupant des positions contrastées voire opposées dans l’espace social, trois dimensions sont plus particulièrement explorées : les rapports au monde médical, le contrôle de l’information sur ...

  14. Le registre aux notices de Dinant : le nombre d'affaires d'avortement transmises à la justice

    OpenAIRE

    Villers, Stéphanie

    2013-01-01

    L’analyse des articles du Code pénal sanctionnant l’avortement a prouvé combien il était malaisé de rassembler et de démontrer les quatre éléments constitutifs de l’avortement. Dans l’impasse face à cette infraction d’un autre genre, la justice n’a souvent d’autre choix que d’abandonner les poursuites. L’orientation dominante des affaires d’avortement est donc le sans suite ou le non-lieu. Comment les connaître et les quantifier ? À cet égard, le registre aux notices, témoin de l’activité du ...

  15. Le "non-recours" aux soins des populations précaires. Constructions et réceptions des normes.

    OpenAIRE

    Rode, Antoine

    2010-01-01

    Les populations précaires sont celles pour qui persistent les difficultés dans l'accès et l'utilisation des soins, alors que leur état de santé est plus dégradé que pour le reste de la population. Ces constats communs à plusieurs études viennent pleinement réinterroger l'effectivité des dispositifs – protection et services de soins – mis en place en France depuis les années 1990 pour favoriser l'accès aux soins de tous. Dans ce contexte, la question du « non-recours » dans le domaine des soin...

  16. ALDUY Cécile, WAHNICH Stéphane, 2015, Marine Le Pen prise aux mots

    OpenAIRE

    Née, Émilie

    2016-01-01

    Alors que le discours politique est l’objet privilégié, l’objet « noble », presque naturel de l’analyse de discours française (du côté de la lexicologie comme de la rhétorique), peu de chercheurs se sont penchés sur les discours des dirigeants du Front national. Et pourtant, comme l’indique Cécile Alduy en ouverture de Marine Le Pen prise aux mots, l’histoire du Front national « c’est aussi, fondamentalement, une histoire de mots » (p. 14). Ce paradoxe s’explique si l’on considère le discours...

  17. Modification chimique des bitumes : Une nouvelle alternative aux bitumes modifiés polymères

    OpenAIRE

    Orange, G; MARTIN, JV; SUCH, C

    2004-01-01

    Cet article présente une alternative à la modification des bitumes par des polymères basée sur l'utilisation de nouveaux additifs issus de la chimie des phosphates (gamme InnovaltTM). Une augmentation de un à deux grades (grade Pene) peut être très facilement obtenue selon la nature du bitume par ajout de seulement 0,5 à 1,5 % poids d'InnovaltTM N sans aucun autre additif. De plus, cette nouvelle technologie peut être utilisée dans le cas des bitumes modifiés aux polymères : l'utilisation d'I...

  18. Marketers as Innovators: how ethnic marketing revisits ethnicity Marketing ethnique et innovation aux États-Unis

    Directory of Open Access Journals (Sweden)

    Marie-Christine Pauwels

    2009-10-01

    Full Text Available L’innovation aux États-Unis est ici vue sous un angle social et culturel. Il ne s’agit plus d’étudier l’innovation technologique, mais l’innovation en matière de produit. L’article aborde la création de valeur à travers la variable ethnique dans le domaine de la vente, du marketing et de la publicité. Les nouvelles tendances en matière d’ethno-marketing sont analysées, en particulier la manière dont les professionnels utilisent la notion d’ethnicité pour vendre des produits de consommation courante à un marché de consommateurs de plus en plus exigeants, soit en ayant recours à une segmentation de ces consommateurs en micro-marchés toujours plus étroits, soit en privilégiant un marketing multi- ou trans-culturel.

  19. Le souffle du changement ou le retour aux habitudes ? Le cas de la tempête de 2009

    OpenAIRE

    Deuffic, P.

    2015-01-01

    / Face aux risques subis ou redoutés comme les tempêtes et incendies, une étude montre que les forestiers landais ont finalement peu modifier peu leurs comportements. Après les phases de stupéfaction, de gestion de l’urgence, d’abattement, est venue une période de réflexions et de propositions mais qui n'a guère fait évoluer les pratiques à court terme. Cette étude montre que le changement a besoin d’être accompagné, anticipé, conforté par différents canaux d’informati...

  20. Commande tolérante aux défauts : une approche basée sur la platitude

    OpenAIRE

    Martínez Torres, César

    2014-01-01

    L’objectif de ce manuscrit est de fournir une technique de commande tolérante aux défauts basée sur la platitude différentielle. Pour ce type de systèmes, il est possible de trouver un ensemble de variables, nommées sorties plates, tel que, les états et les entrées de commande du système puissent s’exprimer en fonction de ces sorties et d’un nombre fini de ses dérivées temporelles. Le bloc de détection et d’isolation doit assurer la détection du défaut le plus rapidement possible. Cette actio...

  1. Contribution à l'étude des addictions: La Cotinine, du tabagisme aux gènes

    OpenAIRE

    Riah, Victor Omar

    2003-01-01

    Le tabagisme est reconnu comme une dépendance comparable aux autres dépendances : alcool, opiacées et autres psycho-stimulants. Les mécanismes responsables de l'initiation et du maintien de l'addiction sont également impliqués dans les déviations comportementales en général, comme les déviations nutritionnelles, les compulsions.... La nicotine de la feuille de tabac est très toxique, dès son absorption, elle atteint le cerveau et tout l'organisme, active ses récepteurs et produit des effets t...

  2. Magnetic and thermodynamic properties of CeCu6-xAux for 0≤x≤2

    International Nuclear Information System (INIS)

    The Neel temperature TN(x) of the heavy-fermion alloys CeCu6-xAux exhibits a sharp maximum, TN=2.2 K for x=1, coinciding with a change of the lattice constant b(x) from a slight contraction for x1. The samples remain single-phase orthorhombic (at room temperature) up to x=1.4 after annealing at 700 C and up to x=2 directly after preparation. Measurements of the specific heat indicate that C/T at low T shows a nonmonotonic behavior with a maximum at x∼0.25 and a minimum at x=1. These extrema can be qualitatively understood by considering the contributions from Kondo quasiparticle and magnetic excitations. ((orig.))

  3. Health physics around a controlled fusion research device: the Tokamak at Fontenay-aux-Roses (T.F.R.)

    International Nuclear Information System (INIS)

    The X and neutron dosimetry measurement near the magnetic confinement device for hot plasma, called T.F.R. (Tokamak, Fontenay-aux-Roses) are presented. The biological shielding consists of an ordinary concrete wall 30 cm thick; the dose rate is thus limited at 10-1 mrem per discharge (corresponding to 10 mrem per day) in the whole area frequented by people during T.F.R. operation. A numerical calculation, taking into account the true geometry and X ray reflexion by the walls and roof, and normalized to the measurements, gives some indications on the electron beam which produces X rays. The photoneutron source (up to 1010 neutrons per dischage) and the activation of the vacuum vessel result from high energy electrons (>= 10 MeV) supporting a 10 to 1,000 A current

  4. Probing the structures of gold-aluminum alloy clusters AuxAly(-): a joint experimental and theoretical study.

    Science.gov (United States)

    Khetrapal, Navneet Singh; Jian, Tian; Pal, Rhitankar; Lopez, Gary V; Pande, Seema; Wang, Lai-Sheng; Zeng, Xiao Cheng

    2016-05-01

    Besides the size and structure, compositions can also dramatically affect the properties of alloy nanoclusters. Due to the added degrees of freedom, determination of the global minimum structures for multi-component nanoclusters poses even greater challenges, both experimentally and theoretically. Here we report a systematic and joint experimental/theoretical study of a series of gold-aluminum alloy clusters, AuxAly(-) (x + y = 7,8), with various compositions (x = 1-3; y = 4-7). Well-resolved photoelectron spectra have been obtained for these clusters at different photon energies. Basin-hopping global searches, coupled with density functional theory calculations, are used to identify low-lying structures of the bimetallic clusters. By comparing computed electronic densities of states of the low-lying isomers with the experimental photoelectron spectra, the global minima are determined. It is found that for y ≥ 6 there is a strong tendency to form the magic-number square bi-pyramid motif of Al6(-) in the AuxAly(-) clusters, suggesting that the Al-Al interaction dominates the Au-Au interaction in the mixed clusters. A closely related trend is that for x > 1, the gold atoms tend to be separated by Al atoms unless only the magic-number Al6(-) square bi-pyramid motif is present, suggesting that in the small-sized mixed clusters, Al and Au components do not completely mix with one another. Overall, the Al component appears to play a more dominant role due to the high robustness of the magic-number Al6(-) square bi-pyramid motif, whereas the Au component tends to be either "adsorbed" onto the Al6(-) square bi-pyramid motif if y ≥ 6, or stays away from one another if x < y < 6. PMID:27119726

  5. Diversification and expression of the PIN, AUX/LAX and ABCB families of putative auxin transporters in Populus

    Directory of Open Access Journals (Sweden)

    Nicola eCarraro

    2012-02-01

    Full Text Available Intercellular transport of the plant hormone auxin is mediated by three families of membrane-bound protein carriers, with the PIN and ABCB families coding primarily for efflux proteins and the AUX/LAX family coding for influx proteins. In the last decade our understanding of gene and protein function for these transporters in Arabidopsis has expanded rapidly but very little is known about their role in woody plant development. Here we present a comprehensive account of all three families in the model woody species Populus, including chromosome distribution, protein structure, quantitative gene expression, and evolutionary relationships. The PIN and AUX/LAX gene families in Populus comprise 16 and 8 members respectively, and show evidence for the retention of paralogs following a relatively recent whole genome duplication. There is also evidence for differential expression across tissues within many gene pairs. The ABCB family is previously undescribed in Populus and includes 20 members, showing a much deeper evolutionary history including both tandem and whole genome duplication as well as probable loss. A striking number of these transporters are expressed in developing Populus stems and we suggest that evolutionary and structural relationships with known auxin transporters in Arabidopsis can point toward candidate genes for further study in Populus. This is especially important for the ABCBs, which is a large family and includes members in Arabidopsis that are able to transport other substrates in addition to auxin. Protein modeling, sequence alignment and expression data all point to ABCB1.1 as a likely auxin transport protein in Populus. Given that basipetal auxin flow through the cambial zone shapes the development of woody stems, it is important that we identify the full complement of proteins involved in this process. This work should lay the foundation for studies targeting specific proteins for functional characterization and in situ

  6. L’institutionnalisme de John Commons et les origines de l’État providence aux États-Unis

    Directory of Open Access Journals (Sweden)

    Isabel da Costa

    2010-12-01

    Full Text Available La politique officielle des États-Unis, soutenue par la pensée économique et juridique, était à l’origine le « laissez-faire » sur le marché et dans les relations de travail. Cet article analyse la construction d’un rôle légitime pour l’État dans la régulation sociale du marché du travail à travers l’ébauche de réglementations du travail et l’émergence de dispositifs de protection sociale aux États-Unis. Nous analyserons tout d’abord comment le mouvement progressiste a impulsé certaines réformes sociales établissant les prémisses d’une législation sociale ; nous nous attacherons ensuite à démontrer la contribution majeure de l’institutionnalisme de John Commons et de ses disciples de l’université du Wisconsin à la conception et au développement de l’État providence aux États-Unis.The official policy of the United States, backed by economic and legal thought, was originally “laissez-faire” on the market and in labor relations. This article analyzes the development of a legitimate role for the state in the social regulation of the labor market through the emergence of the early labor regulations and social protection schemes in the United States. We first analyze how the progressive movement brought about certain social reforms establishing the beginnings of social legislation; we will then focus on the major contribution of the institutionalism of John Commons and his followers from the University of Wisconsin to the design and the development of the welfare state in the United States.

  7. Politiques et idéaux éducatifs de l'Ecole québécoise et française (1963-2004). Évolutions et enjeux des discours relatifs aux valeurs et aux finalités de l'éducation scolaire du rapport Parent au rapport Thélot.

    OpenAIRE

    GIOL, Franck

    2013-01-01

    Les mutations qui affectent l’éducation scolaire des sociétés occidentales de l’après Deuxième Guerre mondiale peuvent être lues comme la marque d’une décomposition de la modernité, décomposition considérée par certains auteurs comme l’un des traits les plus saillants de la postmodernité. A ce titre, elles ne peuvent manquer d’affecter les idéaux éducatifs, et plus particulièrement les valeurs et les finalités dont l’Ecole contemporaine se trouve investie.La fin du récit de l’émancipation par...

  8. Les adolescents aux urgences: quels sont les moyens ou les mesures envisagées par les infirmières pour identifier les comportements à risque chez des adolescents admis aux urgences afin de diminuer les récidives ?

    OpenAIRE

    CARVALHO, Tania; Jeanguenat, Michel

    2012-01-01

    Ce travail de Bachelor repose sur la problématique des adolescents aux comportements à risques se retrouvant aux urgences et dont le risque de récidive est présent. Mon questionnement se pose au niveau des infirmières des urgences et sur les moyens ou les mesures qu’elles ont afin d’identifier ces adolescents dont les comportements à risques répétitifs sont souvent une forme d’exprimer leur souffrance. Ma question de recherche est formulée de la manière suivante : Quels sont les moyens ou les...

  9. Synthesis of [(77)Se]-methylselenocysteine when preparing sauerkraut in the presence of [(77)Se]-selenite. Metabolic transformation of [ (77)Se]-methylselenocysteine in Wistar rats determined by LC-IDA-ICP-MS.

    Science.gov (United States)

    Sánchez-Martínez, María; Pérez-Corona, Teresa; Martínez-Villaluenga, Cristina; Frías, Juana; Peñas, Elena; Porres, Jesús M; Urbano, Gloria; Cámara, Carmen; Madrid, Yolanda

    2014-12-01

    The use of enriched Se isotopes as tracers has provided important information on Se metabolism. However, selenium isotopes are expensive and difficult to obtain. A simple and cheap strategy based on the production of [(77)Se]-methylselenocysteine ([(77)Se]-MeSeCys) when preparing sauerkraut in the presence of [(77)Se]-selenite was developed. The resulting [(77)Se]-MeSeCys was used for evaluating the metabolic transformation of MeSeCys in Wistar rats, by feeding them with an AIN-93 M diet containing 20 % sauerkraut enriched in [(77)Se]-MeSeCys. Organs (liver, kidney, brain, testicles, and heart) were obtained after seven days of treatment and subjected to total selenium and selenium-speciation analysis by high-performance liquid chromatography coupled with isotope-dilution-analysis inductively-coupled-plasma mass spectrometry (HPLC-IDA-ICP-MS). Analysis of (77)Se-labeled organs revealed a prominent increase (more than 100 % Se-level enhancement) of selenium in the kidney and heart, whereas in the liver selenium concentration only increased by up to 20 % and it remained constant in the brain and testicles. (77)Se-enriched-sauerkraut supplementation does not alter the concentration of other essential elements in comparison to controls except for in the heart and kidney, in which selenium was positively correlated with Mg, Zn, Cu, and Mo. HPLC-ICP-MS analysis of hydrolyzed extracts after carbamidomethylation of the (77)Se-labeled organs revealed the presence of [(77)Se]-SeCys and an unknown Se-containing peak, the identity of which could not be verified by electrospray-ionization (ESI)-MS-MS. Low amounts of [(77)Se]-MeSeCys were found in (77)Se-labeled liver and kidney extracts, suggesting the incorporation of this selenium species in its intact form. PMID:25311192

  10. Probing the structures of gold-aluminum alloy clusters AuxAly-: a joint experimental and theoretical study

    Science.gov (United States)

    Khetrapal, Navneet Singh; Jian, Tian; Pal, Rhitankar; Lopez, Gary V.; Pande, Seema; Wang, Lai-Sheng; Zeng, Xiao Cheng

    2016-05-01

    Besides the size and structure, compositions can also dramatically affect the properties of alloy nanoclusters. Due to the added degrees of freedom, determination of the global minimum structures for multi-component nanoclusters poses even greater challenges, both experimentally and theoretically. Here we report a systematic and joint experimental/theoretical study of a series of gold-aluminum alloy clusters, AuxAly- (x + y = 7,8), with various compositions (x = 1-3 y = 4-7). Well-resolved photoelectron spectra have been obtained for these clusters at different photon energies. Basin-hopping global searches, coupled with density functional theory calculations, are used to identify low-lying structures of the bimetallic clusters. By comparing computed electronic densities of states of the low-lying isomers with the experimental photoelectron spectra, the global minima are determined. It is found that for y >= 6 there is a strong tendency to form the magic-number square bi-pyramid motif of Al6- in the AuxAly- clusters, suggesting that the Al-Al interaction dominates the Au-Au interaction in the mixed clusters. A closely related trend is that for x > 1, the gold atoms tend to be separated by Al atoms unless only the magic-number Al6- square bi-pyramid motif is present, suggesting that in the small-sized mixed clusters, Al and Au components do not completely mix with one another. Overall, the Al component appears to play a more dominant role due to the high robustness of the magic-number Al6- square bi-pyramid motif, whereas the Au component tends to be either ``adsorbed'' onto the Al6- square bi-pyramid motif if y >= 6, or stays away from one another if x = 6 there is a strong tendency to form the magic-number square bi-pyramid motif of Al6- in the AuxAly- clusters, suggesting that the Al-Al interaction dominates the Au-Au interaction in the mixed clusters. A closely related trend is that for x > 1, the gold atoms tend to be separated by Al atoms unless only the magic

  11. Le rôle politique des revues conservatrices aux Etats-Unis depuis les années 1980

    Directory of Open Access Journals (Sweden)

    Marie-Cécile Naves

    2004-09-01

    Full Text Available L’article vise à étudier, à travers l’exemple de la théorie de la « Fin de l’Histoire » de Fukuyama, en quoi la revue américaine The National Interest est, à l’instar d’autres revues conservatrices, un instrument médiatique crucial pour la diffusion de certains idéaux du Parti Républicain aux Etats-Unis depuis le milieu des années 1980. Il s’agit par là même de réfléchir aux conditions de production et de diffusion de cette théorie, dans un contexte géopolitique et intellectuel exceptionnel, celui de la fin de la guerre froide. L’évolution des liens entre intellectuels et pouvoir politique américains, avec pour enjeu, depuis le début des années 1980, la politique étrangère, sont au cœur de cette réflexion.El artículo intenta estudiar a través del ejemplo de la teoría del « Fin de la Historia » de Fukuyama, hasta que punto la revista americana The National Interest es, a semejanza de otras revistas conservadoras, un instrumento crucial para la difusión de algunos ideales del partido republicano en los estados Unidos desde mediados de los años ochenta. Se trata de reflexionar sobre las condiciones de producción y de difusión de esta teoría, en un contexto geopolítico e intelectual excepcional, el del final de la guerra fría. El centro de esta reflexión es la evolución de las relaciones entre los intelectuales y el poder político americano, teniendo como telón de fondo, la política exterior.The article aims at studying, through the example of Fukuyama’s theory of the « End of History », how the American journal The National Interest, as other conservative journals, has, since the mid 1980s, been a crucial media instrument for the dissemination of some ideals of the Republican Party. We have thus to think about the conditions of production and dissemination of this theory in an exceptional geopolitical and intellectual context – the end of the cold war. The changing links between

  12. La comorbidité entre dépendance aux opiacés et dépression : mécanismes sérotoninergiques dans un modèle murin

    OpenAIRE

    Lutz, Pierre-Eric

    2012-01-01

    L’addiction ou dépendance aux substances psychoactives est une affection chronique, fréquente et grave, émaillée de rechutes et de périodes d’abstinence. Les études épidémiologiques montrent que l’abstinence aux opiacés est fortement associée à une prévalence accrue de la dépression. Nous résumons ici les principaux aspects cliniques de la dépendance aux opiacés et de la dépression, en détaillant leurs mécanismes physiopathologiques. Puis, nous présentons notre modèle d’abstinence aux opiacés...

  13. Mémoire de guerre et nouvelles pratiques culturelles sous la IIIe République : l’exemple du monument aux morts de 1870 à Marseille

    OpenAIRE

    Dalisson, Rémi

    2013-01-01

    La gestion de la mémoire de la guerre de 1870/1871 fut un enjeu capital pour la Troisième République. Comme les autres fêtes, elle devait la légitimer. Les érections et les inaugurations de monuments aux morts aux combattants « morts pour la patrie » est emblématique de cette politique culturelle de masse. L’exemple de Marseille, qui inaugura son monument en 1894, à un moment charnière de l’histoire nationale, illustre les ambiguïtés de la politique de la mémoire de guerre républicaine. Il mo...

  14. Le culte lua’ aux esprits des princes (Thaïlande). La construction d’une légitimité

    OpenAIRE

    Guégan, Emma

    2012-01-01

    Parmi les Lua’, groupe de langue austro-asiatique de la province de Nan en Thaïlande, une communauté se targue d’être garante de la prospérité de l’ensemble des habitants, très majoritairement taï, du territoire de l’ancienne principauté de Pua. Ils affirment être les seuls capables d’effectuer le culte aux « esprits des princes », pourtant autrefois exclusivement réalisé par des princes taï. En examinant les discours et pratiques liés à ces anciens princes et aux rites qui leur sont adressés...

  15. Un cadre conceptuel pour explorer localement les facteurs de vulnérabilité et les options d’adaptation aux changements climatiques

    OpenAIRE

    Beaulieu, Nathalie; Santos Silva, Julia; Plante, Steve

    2016-01-01

    Cet article décrit un cadre conceptuel pour explorer les facteurs affectant la vulnérabilité aux aléas reliés au climat ainsi que des options d’adaptation aux changements climatiques. Ce cadre permet de guider des réflexions dans un langage simple et non technique, tout en étant compatible avec différentes conceptualisations de la vulnérabilité. Il a été développé à travers l’élaboration d’un plan d’action pour l’adaptation avec l’administration municipale de Rivière-au-Tonnerre sur la Côte-N...

  16. Field and concentration dependent scaling behavior of the thermal expansion near the quantum critical point of CeCu6-xAux

    International Nuclear Information System (INIS)

    The heavy-fermion system CeCu6-xAux exhibits long-range antiferromagnetic order at x>0.1. The order can be suppressed by hydrostatic or chemical pressure, through the variation of the Au content, as well as by the application of a magnetic field. The quantum critical point at the onset of antiferromagnetism leads to non-Fermi liquid behavior visible in thermodynamic and transport properties. Among these, the thermal expansion offers a particularly sensitive probe to study the quantum critical scaling behavior due to the strong pressure dependence of the Kondo effect in heavy-fermion materials. To shed light on the difference between the two control parameters, pressure and magnetic field, we studied the scaling behavior of the thermal expansion on CeCu6-xAux single crystals with varying Au content as a function of the magnetic field in the temperature range between 40 mK and 10 K.

  17. Observation et diagnostic de processus industriels à modèle non linéaire : application aux machines électriques

    OpenAIRE

    Mahamoud, Ayan

    2010-01-01

    Cette thèse porte sur la définition d'une stratégie robuste pour le diagnostic des processus industriels à modèle non linéaire. La stratégie définie repose sur l'utilisation d'observateurs non linéaires non seulement pour le diagnostic mais aussi pour la commande de ces systèmes. L'objectif est triple. L'observateur synthétisé devra reconstruire les variables d'état, être sensible aux défauts pour le diagnostic tout en étant robuste aux perturbations et autres incertitudes paramétriques pour ...

  18. Les trajectoires de conversion écologique face aux enjeux économiques et sociaux du « logement durable » en France

    OpenAIRE

    Hamman, Philippe; Frank, Cécile; Mangold, Marie

    2014-01-01

    Cet article interroge les trajectoires de conversion écologique des modes de vie à travers un questionnement du logement en développement durable en France, et retient deux groupes cibles : les jeunes primo-accédants et les séniors, dans trois régions différentes. Par rapport aux programmes immobiliers axés sur le « durable » qui se développent à l’heure actuelle, et mettent fréquemment l’accent sur une dimension technique liée aux économies d’énergie, la recherche révèle la pluralité des dyn...

  19. Comportements par rapport au VIH/sida et aux autres infections sexuellement transmissibles dans l'univers de la prostitution féminine

    OpenAIRE

    Meystre-Agustoni Giovanna; Voellinger Rachel; Balthasar Hugues; Dubois-Arber Françoise

    2008-01-01

    L'étude actuelle vise à décrire la situation face au VIH/sida et aux autres IST des prostituées (femmes, transgenres) exerçant dans la rue, dans les salons, dans les cabarets et autres bars en Suisse. [...] L'étude a pour objectifs d'apporter des éléments de réponse aux questions suivantes : Importance numérique, évolution et modalités d'exercice de la prostitution féminine. - "Profil" (nationalité, etc.) des prostituées selon le lieu d'exercice. - Profil des prostituées sous l'angle de la lo...

  20. Gestion bancaire du risque de non-remboursement des crédits aux entreprises : une revue de la littérature

    OpenAIRE

    Rougès, Véronique

    2003-01-01

    Les banquiers subissent un risque de non-remboursement des crédits aux entreprises. Ce risque peut être réduit lors des deux phases du crédit : lors de l'octroi, par une analyse du risque de défaillance et la rédaction de contrats incitatifs, et en cours de vie, par un suivi actif du crédit.

  1. A TILLING allele of the tomato Aux/IAA9 gene offers new insights into fruit set mechanisms and perspectives for breeding seedless tomatoes

    OpenAIRE

    Mazzucato, Andrea; Cellini, Francesco; Bouzayen, Mondher; Zouine, Mohamed; Mila, Isabelle; Minoia, Silvia; Petrozza, Angelo; Picarella, Maurizio E.; Ruiu, Fabrizio; Carriero, Filomena

    2015-01-01

    Parthenocarpy is a desired trait in fruit crops; it enables fruit set under environmental conditions suboptimal for pollination, and seedless fruits represent a valuable consumer product. We employed TILLING-based screening of a mutant tomato population to find genetic lesions in Aux/IAA9, a negative regulator of the auxin response involved in the control of fruit set. We identified three mutations located in the coding region of this gene, including two singlebase substitutions and one singl...

  2. Syntheses, crystal structures, and properties of three new metal selenites Na2Co2(SeO3)3, Na2Co1.67Ni0.33(SeO3)3, and Na2Ni2(SeO3)3

    International Nuclear Information System (INIS)

    Three new sodium cobalt (nickel) selenite compounds, namely, Na2Co2(SeO3)3, Na2Co1.67Ni0.33(SeO3)3, and Na2Ni2(SeO3)3 have been hydro-/solvothermally synthesized in the mixed solvents of acetonitrile and water. Single-crystal X-ray diffraction analyses reveal that these isostructural compounds belong to the orthorhombic Cmcm space group and their structures feature three-dimensional open frameworks constructed by the two-dimensional layers of [MSeO3] pillared by the [SeO3]2- groups. The two different types of Na+ ions reside in the intersecting two-dimensional channels parallel to the a- and c-axes, respectively. Their thermal properties have been investigated via TGA-DSC. The magnetic measurements indicate the existence of the antiferromagnetic interactions in these compounds. - Graphical abstract: Three new isostructural metal selenites, Na2Co2(SeO3)3, Na2Co1.67Ni0.33(SeO3)3, and Na2Ni2(SeO3)3 have been hydro-/solvothermally synthesized and characterized. Their structures feature three-dimensional open frameworks with Na+-occupied channels.

  3. Annual progress report of the Fontenay-aux-Roses Research Group, January 1 to December 31 1974

    International Nuclear Information System (INIS)

    The salient events of 1974 were the full-time working of TFR at Fontenay-aux-Roses and the building of Petula and Wega at Grenoble. The remounting of TFR after reinforcement of the vacuum chamber was followed by an increase in the small plasma radius by elimination of the copper shell to prolong the present program. In agreement with the Culham laboratory a common program to develop the injection of neutral particles up to the performance needed for the JET has begun. At Grenoble the mounting of Petula was finished and the technological problems of the vacuum chamber (metallic joints for the alumina-metal joints) have been solved. The mounting of Wega was pursued simultaneously with that of Petula within the European context of a collaboration with Garching and the Royal Military School. In the ''Ionized Gas Theory Section'' work was centered on: M.H.D. equilibrium and stability, plasma development in Tokamaks, waves, transport and convection, spectroscopy, micro-instabilities and turbulence. Fundamental physics covers the subjects: EQUATOR, EOS-POP and ODE experiments, HCN laser and atomic collisions. The activity in open configuration concerned the experiment Bille-en-Tete MB

  4. Carbachol阻断亚硒酸钠对离体皮质神经元的致凋亡作用%Carbachol blocks apoptosis induced by sodium selenite in cultured cortical neurons

    Institute of Scientific and Technical Information of China (English)

    肖荣; 闫秀珍; 王瑞; 乔中东; 乔健天

    2001-01-01

    在早期工作发现小剂量亚硒酸钠(Sodium selenite)对离体皮质神经元的致凋亡作用的基础上,观察了在亚硒酸钠致凋亡模型中加入M型胆碱能受体激动剂Carbachol(Carb)能否阻止凋亡过程和相伴随的有关基因表达的改变.结果显示:①用不同剂量(0.004,0.02,0.1,0.5,2.5和12.5 mmol/L)的Carb和0.5μmol/L亚硒酸钠共同处理培养的新生小鼠皮质神经元时,用琼脂糖凝胶电泳DNA梯形检测和流式细胞仪亚二倍体峰检测,都证明Carb表现出对亚硒酸钠致凋亡作用的剂量依赖性保护效应;②用RT-PCR技术证明,在与Carb共同孵育的实验中,不再出现或减弱了亚硒酸钠单独处理时出现的bcl-2基因表达的下调和bax,p53,c-fos以及AChE基因表达的上调.上述结果表明,亚硒酸钠对皮质神经元的致凋亡作用和与之相伴随的基因表达的改变,可被一定浓度的Carb所阻断,提示亚硒酸钠致凋亡作用可能同本室发现的β-淀粉样蛋白的C末端5肽片段的致凋亡作用具有类似的途径,以类似的基因表达改变为基础,并对Carb的抗凋亡机制进行了讨论.

  5. Le projet Petits Films : du retour aux participants à la valorisation des données

    Directory of Open Access Journals (Sweden)

    Piccoli Vanessa

    2015-01-01

    Full Text Available En 2014, au sein du laboratoire ICAR (équipe InSitu / Cellule Corpus Complexe un projet appelé “Petits Films” a été conduit avec une double finalité : confectionner des petits films à partir de trois différents corpus et parallèlement mener une réflexion sur les modalités de réalisation, les finalités et les contraintes de ce type de réalisation. On considère que dans le domaine de l’analyse conversationnelle, dans lequel les chercheurs recourent de plus en plus à des corpus de données vidéo, la réalisation d’un petit film peut représenter non seulement un retour pour les participants, mais aussi un moyen de valorisation du corpus, d’un type d’approche en linguistique et plus largement de l’activité du laboratoire de recherche. Grâce à leur forme agréable et à leur courte durée, les petits films sont conçus pour la diffusion et la valorisation des méthodologies et des recherches, ils sont accessibles pour un large public, même de non-experts. Cependant, il est nécessaire de réfléchir aux questions juridiques et déontologiques que soulève cette opération.

  6. Les stratégies des investisseurs : des bords de ville aux bords de mer

    Directory of Open Access Journals (Sweden)

    Sophie Cueille

    2004-03-01

    Full Text Available L’architecture de la villégiature a un prix. Construire des villes nouvelles, qu’elles soient balnéaires, thermales ou périurbaines, induit la mise en place de réseaux ferroviaires et viaires, d’édifices dévolus à la détente, les soins ou les jeux, d’hôtels et de maisons. Quels sont les investisseurs qui engagent d’importants financements en ces lieux ? Personnages de la vie politique, industrielle et bancaire, le plus souvent parisiens, tous se saisissent des besoins de la nouvelle société bourgeoise montante, consommatrice de loisirs dès le milieu du XIXe siècle. Si certains projets peuvent être initialement teintés d’une certaine forme de philanthropie, toutes les opérations deviennent très vite de véritables entreprises lucratives. Sociétés civiles en tous genres, concessions et affermages, les formules d’investissement s’adaptent au produit où souvent se mêlent intérêts publics et privés. La réussite de tels projets suscite également le financement de campagnes publicitaires importantes : journaux, affiches et guides sont publiés pour faire accourir la clientèle visée et ainsi rapporter aux investisseurs les profits escomptés.

  7. Aux Débuts de la syntaxe structural: Tesnière et la construction d’une syntaxe

    Directory of Open Access Journals (Sweden)

    Pierre Swiggers

    1994-12-01

    Full Text Available “…il est parfaitement possible de constituer une syntaxe sur des données purement syntaxiques et en dehors de toute morphologie. Certes, le système proposé (... est loin d'être parfait. Mais on ne saurait le taxer d'arbitraire, prétendre qu'il dépasse la réalité des données, et n'y voir qu'une vue personnelle et subjective de son auteur (... Pour être plus abstraits et plus difficiles à saisir que Jes faits morphologiques, Jes faits syntaxiques n'en ont pas moins une réalité objective. Et ceux qui voudront Jes étudier pour édifier la syntaxe qui nous manque encore peuvent être en tout cas assurés de construire sur un terrain solide" (Lucien Tesniere, "Comment construire une syntaxe''., p. 229. Le projet tesniérien d'une syntaxe structurale - aboutissant aux Élements de syntaxe structurale (1959, deuxieme ed. 1966, ouvrage posthume - a sa propre histoire. Une histoire qui la rattache d'ailleurs à un courant de pensee international, qui se manifeste dans l'reuvre de Bally,2 Jespersen,3 Sapir,4 Brunot,5 Brøndal 6 et Hjelmslev,7 et qui s'articule autour de la problématique des classes de mots. En fait, ce courant de pensée se présente en premier lieu comme une critique du système des parties du discours: celles-ci ne sont guère des composantes du discours, au sens où elles constitueraient les bases constructives du discours, mais elles sont en fait des parties du système de la langue. Il importe done de franchir le pas, à partir d'elles, vers l'organisation de la phrase.

  8. ETUDES ANALYTIQUES : Détection des OGM : du libre choix des consommateurs aux études de biovigilance

    Directory of Open Access Journals (Sweden)

    Bertheau Yves

    2000-07-01

    Full Text Available Les récentes affaires de semences conventionnelles de colza et de maïs contaminées par des traces d’OGM ont à nouveau, s’il en était besoin, rappelé à notre bon souvenir les besoins en méthodes de détection et d’identification des OGM fiables et sensibles. Les développements se poursuivent, certes bien plus lentement qu’initialement espéré du fait du nombre important de facteurs à maîtriser et du caractère relativement inédit de ce travail. Concernant des matrices alimentaires variées, cette détection se heurte au manque de recul dans plusieurs domaines tels que celui de l’extraction et la purification d’acides nucléiques en quantité et en qualité. Bien que développées pour satisfaire aux besoins réglementaires européens concernant l’alimentation humaine, ces méthodes devraient être aisément applicables dans d’autres domaines concernés par les OGM (étude des transferts de gènes par flux pollinique, éventuels transferts horizontaux, suivi des acides nucléiques lors de l’ingestion.... Au-delà des OGM, les méthodes mises en œuvre devraient présenter un intérêt dans d’autres domaines comme la microbiologie, l’épidémiologie ou l’authentification des composants biologiques d’un produit.

  9. Determinants socio-économiques de l'automédication aux antimalariens à Kisangani/RD Congo

    Directory of Open Access Journals (Sweden)

    Tshomba Oloma Antoine

    2013-01-01

    Full Text Available RESUME Objectif de l’étude : Évaluer l’importance et les déterminants socio-économiques de l’automédication aux anti-malariens dans la commune de la Tshopo à KisanganiMatériel et méthodes: Nous avons réalisé une étude transversale utilisant un questionnaire d’enquête pour collecter les données. Par un échantillonnage systématique, 384 ménages au minimum ont été enquêtés. Résultats : Au total 386 responsables de ménage ont participé à l’enquête. 346 (89,6% de responsables avaient reconnu pratiquer l’automédication aux anti-malariens. Deux facteurs socio-économiques étaient significativement liés à l’automédication dans l’analyse classique : le revenu mensuel des responsables (p=0,0013 et la charge familiale en terme de nombre d’enfants (p=0,0034. L’âge, le sexe, l’occupation des responsables, le niveau d’instruction et la religion des responsables n’étaient pas associés à la pratique. A l’analyse multi variée, les deux facteurs sont restés significatifs : les revenus supérieurs à 100 dollars américains préviennent la pratique [ORaj=0,25 (0,11-0,58, p=0,001] et le nombre élevé d’enfants dans le ménage la favorise [ORaj=3,94(1,62-9,55, p=0,0024] entre 3-4 enfants et ORaj=3,34(1,067-10,46, p=0,038, à partir de 7 enfantsConclusion : La prévalence de l’automédication aux anti-malariens est alarmante dans la commune de la Tshopo à Kisangani. La menace de la résistance, la circulation possible de médicaments de qualité douteuse et le contexte local de contrôle de qualité fait de cette pratique un problème important de santé publique. Une évaluation sérieuse de cette pratique serait donc utile dans le futur. ABSTRACTObjective: To assess the importance and socioeconomic determinants of self-medication with anti-malarial in the city of Kisangani/TshopoMaterials and methods: We conducted a cross-sectional study using a questionnaire to collect data. By systematic

  10. Validation d’un dispositif en ligne d’aide à la persévérance aux études postsecondaires

    Directory of Open Access Journals (Sweden)

    Alan Wright

    2009-01-01

    Full Text Available [Français] De plus en plus d’universités mettent en place des dispositifs de soutien à la persévérance aux études universitaires. Ce texte fait état du contexte de recherche justifiant la mise en ligne d’un dispositif d’aide à la persévérance aux études. SAMI-Persévérance signifie : système d’aide multimédia interactif à la persévérance aux études postsecondaires. Les difficultés éprouvées par les étudiants universitaires auxquelles SAMI-Persévérance répond, la méthodologie pour valider le dispositif auprès de 103 étudiants et les résultats sur les plans de la convivialité, de la pertinence et de l’utilité du dispositif également présentés. [English] An increasing number of universities are creating instruments to support student perseverance. This paper describes the context which leads to the creation of an online system supporting student perseverance. SAMI-Perseverance is an interactive, multi-media system supporting student perseverance in post-secondary education. The results of an instrument validation study undertaken with a sample of 103 individuals from the target population are presented. This article describes the nature of the student difficulties addressed, as well as the methodology used in the validation study. The study’s findings with regard to measures of userfriendliness, relevance, and usefulness of the instrument are described.

  11. 外源四价硒条件下硫对小麦硒吸收的影响机制%Effects of Sulfur on Selenium Uptake in Wheat and Its Mechanism when Amended with Selenite

    Institute of Scientific and Technical Information of China (English)

    刘新伟; 段碧辉; 赵小虎; 郭再华; 胡承孝; 赵竹青

    2015-01-01

    22.4倍,而硫浓度为1 mmol·L-1时,其硒含量迅速降为四价硒处理的2.8倍和51.8%,表明硫可以显著缩小小麦对四价和六价硒的吸收能力差异。【结论】施用适量硫肥在改善小麦生长的同时,可以通过降低土壤 pH 和提高有机质含量,促使水溶态硒在土壤中向铁锰氧化物结合态、有机结合态及残渣态的钝化,并抑制交换态中四价硒向六价态的转化,从而降低小麦对硒的吸收。因此,可以通过在高硒缺硫地区增施硫肥以及缺硒高硫地区减施硫肥来有效调控作物体内的硒含量。%[Objective]This study was conducted to investigate the effects of sulfur (S) on the fractions and species of amended selenite in soil by applying S fertilizer, and explore the mechanism through which S controls the selenium (se) uptake of wheat.[Method]Wheat (Triticum aestivum L. cv. Zhengmai 9023) was chosen as the test material, and underwent seedling stage soil cultivation and solution cultivation. A potted soil experiment was performed on wheat and the application amounts of S were 0, 150, and 300 mg·kg-1, respectively, Sulfur was used as S source, Se source was selenite (Na2SeO3) and it was designated at 0 and 5 mg·kg-1. The wheat seedlings were harvested on the 70th day after sowing and soil samples were taken. The treatments started two weeks after the seedlings were planted in hydroponic experiment which the nutrient solution was made with 1/5 Hogland-Arnon formula. Different amounts of S were added in the experiment: 0, 0.1, and 2 mmol·L-1; Se was designed at 10 µmol·L-1. Se and S was supplied to plants in the form of sodium selenite (Na2SeO3), sodium selenate (Na2SeO4·10H2O) and magnesium sulfate (MgSO4·7H2O), respectively. Wheat was harvested after 24h. A fully interactional design was performed and each treatment was repeated four times in potted soil experiment and hydroponic experiment. The hydride generation atomic fluorescence

  12. Sinovite e tenossinovite no Brasil: uma análise dos benefícios auxílio-doença

    Directory of Open Access Journals (Sweden)

    Dilma Maria de Andrade

    2015-03-01

    Full Text Available OBJETIVO: Analisar os fatores pessoais associados à prevalência e duração dos benefícios auxílio-doença decorrentes de sinovite e tenossinovite (CID10 M65. MÉTODO: Estudo transversal referente aos benefícios auxílio-doença decorrentes de sinovite e tenossinovite concedidos pelo Instituto Nacional de Seguro Social aos empregados no Brasil em 2008. Dados sobre o ramo de atividade econômica (Classificação Nacional de Atividades Econômicas - CNAE divisão, classe, sexo, idade, espécie e duração dos benefícios foram coletados do Sistema Único de Benefícios. A população corresponde à média mensal dos vínculos empregatícios declarados ao Cadastro Nacional de Informações Sociais. RESULTADOS: Em 2008 foram concedidos 35.601 benefícios auxílio-doença decorrentes de sinovite e tenossinovite, com prevalência de 10,9/10.000 vínculos empregatícios. No conjunto dos benefícios auxílio-doença houve maior razão de prevalência (RP acidentária (RP 1,2, sendo esta maior em mulheres (RP 3,3, e em trabalhadores com idade acima de 39 anos (RP 1,4. As CNAE 37-Esgoto (55,4 e 60-Atividade de rádio e TV (47,1 apresentaram as maiores prevalências, no entanto, 64-Atividade de serviços financeiros e 6422-Bancos múltiplos caracterizaram mais acidentes de trabalho (RP 3,2 e 3,8, respectivamente e maior duração (70 e 73 dias, respectivamente. A maior duração de benefício ocorreu entre trabalhadores com idade superior a 39 anos. Tanto a CNAE-divisão 60-Atividade de rádio e TV, quanto a CNAE-classe 6010-Atividade de rádio apresentaram elevadas razões de feminilidade (RP 8,1 e 10,8, respectivamente. CONCLUSÃO: A incapacidade para o trabalho por sinovite e tenossinovite apresenta associação tanto da prevalência quanto da duração com o ramo de atividade, sexo, idade e espécie de benefício (previdenciário/acidentário.

  13. ESTIMATION DES PERTES FER DANS LES MACHINES ELECTRIQUES.
    MODELE D'HYSTERESIS LOSS SURFACE ET APPLICATION AUX MACHINES SYNCHRONES A AIMANTS.

    OpenAIRE

    Gautreau, Thierry

    2005-01-01

    Suite aux directives européennes incitant les constructeurs de moteurs électriques à supprimerde leur offre, les moteurs à faible rendement, une politique de conception de moteurs à hautrendement est engagée. Toutefois, l'évaluation préalable, en simulation, de ce paramètre, etnotamment des pertes fer de la machine reste aujourd'hui un problème difficile. Dans cetteoptique, depuis quelques années, un modèle, nommé « Loss Surface », de calcul a posteriorides pertes fer sous le logiciel élément...

  14. L'intervenant face aux objectifs de mission: entre tensions vécues et régulations tentées

    OpenAIRE

    Verstraeten, Michel

    2006-01-01

    Lorsqu’on s’intéresse aux récits de missions de conseil, on constate que les objectifs de mission qui sont proposés à l’intervenant suscitent souvent chez lui des questions délicates :faut-il poursuivre ce travail avec lequel je ne me sens pas en accord ?dans quelle voie faut-il s'engager face à une incompatibilité entre les souhaits du commanditaire et les objectifs contractualisés ?faut-il aller jusqu'au bout de la réalisation des objectifs contractualisés alors que le commanditaire semble ...

  15. Transhumance et gestion des ressources naturelles au Sahel : contraintes et perspectives face aux mutations des systèmes de productions pastorales

    OpenAIRE

    Kiema, André; Tontibomma, Ghislain Bambara; Zampaligré, Nouhoun

    2015-01-01

    En région sahélienne du Burkina Faso, l’élevage est de type extensif basé essentiellement sur l’exploitation des ressources naturelles. Les pratiques traditionnelles actuelles ne permettent plus de répondre efficacement aux problèmes d’alimentation et d’abreuvement des animaux. L’amplitude des mouvements des pasteurs, la transhumance, est devenue plus importante et les séjours dans les zones d’accueil deviennent de plus en plus longs. Ce travail fait une situation de référence de la pratique ...

  16. Le graphe et la graphie de la Terre. Un exercice formel pour commémorer le bicentennaire du Voyage aux Amériques équinoxales

    Directory of Open Access Journals (Sweden)

    Hervé Gazel

    1999-06-01

    Full Text Available Cette communication interroge la migration de connaissances géographiques vers un support numérique. Une telle migration peut se concevoir comme une hypertextualisation. Elle passe par l’examen de la relation entre le graphe et l’écriture géographique. L’exemple de la classification des climats qui renvoie aux travaux de Humboldt permet de montrer comment la mutation de connaissances géographiques est liée à l’analyse de la relation entre graphe et graphie de la terre.

  17. Electromigration : structure de zone frontière, application à la séparation d'espèces en solution et aux transferts interfaciaux

    OpenAIRE

    Londiche, Henry

    1982-01-01

    L'application d'un champ de forces externes à un milieu liquide contenant un ou plusieurs solutés permet d'agir sur sa composition en modifiant les conditions d'équilibre thermodynamique. En particulier surimposer un champ électrique aux transferts entre phases non miscibles conduit à rendre complètes l'extraction liquide liquide d'un soluté contenu dans une phase non polaire ou la dissolution d'un sel réputé insoluble. Le passage d'un courant électrique continu d'intensité. constante dans un...

  18. Le recours aux modeles dans l'enseignement de la biologie au secondaire : Conceptions d'enseignantes et d'enseignants et modes d'utilisation

    Science.gov (United States)

    Varlet, Madeleine

    Le recours aux modeles et a la modelisation est mentionne dans la documentation scientifique comme un moyen de favoriser la mise en oeuvre de pratiques d'enseignement-apprentissage constructivistes pour pallier les difficultes d'apprentissage en sciences. L'etude prealable du rapport des enseignantes et des enseignants aux modeles et a la modelisation est alors pertinente pour comprendre leurs pratiques d'enseignement et identifier des elements dont la prise en compte dans les formations initiale et disciplinaire peut contribuer au developpement d'un enseignement constructiviste des sciences. Plusieurs recherches ont porte sur ces conceptions sans faire de distinction selon les matieres enseignees, telles la physique, la chimie ou la biologie, alors que les modeles ne sont pas forcement utilises ou compris de la meme maniere dans ces differentes disciplines. Notre recherche s'est interessee aux conceptions d'enseignantes et d'enseignants de biologie au secondaire au sujet des modeles scientifiques, de quelques formes de representations de ces modeles ainsi que de leurs modes d'utilisation en classe. Les resultats, que nous avons obtenus au moyen d'une serie d'entrevues semi-dirigees, indiquent que globalement leurs conceptions au sujet des modeles sont compatibles avec celle scientifiquement admise, mais varient quant aux formes de representations des modeles. L'examen de ces conceptions temoigne d'une connaissance limitee des modeles et variable selon la matiere enseignee. Le niveau d'etudes, la formation prealable, l'experience en enseignement et un possible cloisonnement des matieres pourraient expliquer les differentes conceptions identifiees. En outre, des difficultes temporelles, conceptuelles et techniques peuvent freiner leurs tentatives de modelisation avec les eleves. Toutefois, nos resultats accreditent l'hypothese que les conceptions des enseignantes et des enseignants eux-memes au sujet des modeles, de leurs formes de representation et de leur approche

  19. La participation des personnes utilisatrices aux exercices de planification et d'organisation des services de santé mentale au Québec

    Directory of Open Access Journals (Sweden)

    Michèle Clément

    2013-10-01

    Full Text Available Cet article documente la manière dont s'est renouvelé et s'est transformé au fil du temps le projet de faire participer les usagers aux exercices de planification et d'organisation des services de santé mentale au Québec (Canada. Pour ce faire, les auteurs reviennent sur l'ensemble des documents ministériels qui ont traité de cette question et dégage, pour les principaux moment-clés, les principales modalités de participation des usagers.

  20. L’impact des attentats du 11 septembre 2001 sur le discours relatif aux immigrants dans la presse canadienne et australienne

    OpenAIRE

    Tolazzi, Sandrine; Maserati, Carole

    2009-01-01

    Les attentats du 11 septembre 2001 ont profondément bouleversé le champ des représentations, non seulement aux États-Unis mais également au sein de pays comme le Canada ou l’Australie qui ont offert leur soutien au gouvernement américain dans sa « guerre contre la terreur ». Ainsi, la figure de l’immigrant, par exemple, est très vite apparue comme une menace potentielle pour la sécurité des citoyens. Dans le but de creuser ce constat, cet article se penche sur les transformations du discours ...

  1. André Pavlovsky et les feux de Saint-Jean-de-Luz, la modernité aux accents néo-basques

    OpenAIRE

    Doulat, Fabienne

    2015-01-01

    En 1937, s’achèvent les travaux des feux verts de Saint-Jean-de-Luz réalisés d’après le projet de l’architecte André Pavlovsky (1891-1961). Cette collaboration exceptionnelle entre un architecte et le service des Phares et balises, ne se fait d’ailleurs pas sans quelques tensions. L’exhaussement de la tour existante du feu amont et la construction du nouveau feu aval adoptent une architecture originale non seulement par rapport aux phares traditionnellement construits mais aussi dans le paysa...

  2. Du « signifiant flottant » au « transmédia storytelling », ou le retour aux stratégies

    OpenAIRE

    Maigret, Éric

    2015-01-01

    Éric Maigret reprend le concept de braconnage emprunté par Henry Jenkins à Michel de Certeau pour voir si une compétence de braconnier textuel, dans une stratégie transmédia, ne se réduirait finalement pas à un traçage prédéterminé qui répondrait aux angoisses existentielles des industries par temps de reconfiguration médiatique et d'éparpillement des audiences.

  3. LES PYGMEES RIVERAINS DES AIRES PROTEGEES : DES PEUPLES SOUMIS AUX NOUVELLES FORMES D'ESCLAVAGE. CAS DU PARC NATIONAL DE KAHUZI-BIEGA EN REPUBLIQUE DEMOCRATIQUE CONGO

    OpenAIRE

    Kakule Lyamahesana, Jean-Claude

    2013-01-01

    Pour faire face aux catastrophes écologiques qui se présagent dans le futur proche, le monde entier est unanime qu'il faille protéger les ressources environnementales pour l'équilibre planétaire. La solution à ces problèmes menaçant l'humanité tout entière est la conservation des forêts dont la substance peut servir de régulateur climatique. Cette proposition est devenue un impératif mondial. Au niveau du continent africain, les efforts sont bien fournis dans ce sens. Pour rendre de plus en p...

  4. Profils de virulence et de résistance aux 13- lactamines de souches cliniques de Kiebsiella pneumoniae isolées de sondes urinaires

    OpenAIRE

    BERRIAH, Asma

    2015-01-01

    Kiebsiella pneumoniae représente une des principales germes pathogène qui rentre souvent dans le contexte de maladies graves et des infection nosocomiales, dont notre travail s'inscrit dans le cadre de recherche de profils de virulence et de résistance aux 3-lactamine de 10 souches de Kiebsiella pneumoniae pré-identifiées isolées à partir des sondes urinaires portées par le laboratoire du « LapSab». Elles ont été identifié présomptivement selon leur caractères biochimiques par ...

  5. Contribution to the study of several chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses; Contribution a l'etude de quelques nuisances chimiques au centre d'etudes nucleaires de Fontenay-aux-Roses

    Energy Technology Data Exchange (ETDEWEB)

    Megemont, C.; Grau, C. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-10-01

    From the checking of 2750 index cards of hazards, the study relates the distribution of the chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses. Those concerning the greatest number of agents in the Centre are classified according to the categories corresponding to the different conditions of working. Thus, the most important are put forward. Then, the authors rapidly make a review of hazards which may have some special interest because they appear more specific of the nuclear energy or because they are the most frequently noted on the index cards of hazards. The case of the tributylphosphate is studied more precisely. (authors) [French] A partir de l'examen de 2750 fiches de nuisances, l'etude porte sur la repartition des nuisances chimiques au Centre d'Etudes Nucleaires de Fontenay-aux-Roses. Celles qui concernent le plus grand nombre d'agents du Centre sont classees selon les categories correspondant aux differentes conditions de travail. Les plus importantes d'entre elles sont ainsi mises en evidence. | Les auteurs passent ensuite en revue, rapidement, les nuisances qui peuvent presenter un interet particulier soit parce qu'elles semblent plus specifiques de l'Energie Nucleaire, soit parce qu'on les rencontre le plus frequemment sur les fiches de nuisances. Le cas du tributylphosphate est envisage de facon plus detaillee. (auteurs)

  6. Avaliação do efeito radioprotetor do selenito de sódio no processo de reparação tecidual em ratos Evaluation of the radioprotective effect of sodium selenite in the tissue repair process in rats

    Directory of Open Access Journals (Sweden)

    Fabrício M. Tuji

    2005-09-01

    Full Text Available OBJETIVO: Avaliar a ação radioprotetora do selenito de sódio no processo de reparação tecidual. MATERIAIS E MÉTODOS: Ratos Wistar foram submetidos a procedimento cirúrgico para a realização de ferida na região dorsal. Os animais foram divididos em quatro grupos experimentais: controle, selênio, irradiado e selênio-irradiado. Os grupos selênio e selênio-irradiado receberam 2,0 mg/kg de selenito de sódio, 48 horas após a cirurgia. Os grupos irradiado e selênio-irradiado foram submetidos à irradiação em dose única de 6 Gy, administrada somente nas bordas das feridas. Após 4, 7, 13 e 21 dias do procedimento cirúrgico, os animais foram sacrificados e avaliados por meio de análise morfológica, histoquímica e birrefringência do tecido. RESULTADOS: O aspecto estrutural e morfológico, assim como a qualidade do tecido e sua maturação através da quantidade e disposição dos feixes de fibras colágenas, juntamente com o seu grau de orientação macromolecular, permitiu observar a presença de intenso retardo provocado pela irradiação, bem como o efeito radioprotetor do selenito de sódio no processo de reparação. CONCLUSÃO: Dentro das condições experimentais utilizadas, o selenito de sódio apresentou-se como radioprotetor eficaz, visto que o processo de reparação no grupo selênio-irradiado comportou-se, histologicamente, semelhante ao grupo controle.OBJECTIVE: To evaluate the radioprotective effect of sodium selenite in the tissue repair process. MATERIALS AND METHODS: Male Wistar rats submitted to a surgical procedure to produce a wound in the dorsal region. These animals were then divided in four experimental groups: control, selenium, irradiated and selenium-irradiated. The selenium and selenium-irradiated groups received sodium selenite (2.0 mg/kg, 48 hours after surgery. The irradiated and selenium-irradiated groups received a single dose of 6 Gy, administered only in the borders of the wound. The animals were

  7. Non-Fermi-liquid behaviour in the heavy-fermion system CeCu6-xAux

    International Nuclear Information System (INIS)

    In heavy-fermion systems with 4f or 5f atoms (such as Ce or U) the competition between the on-site moment compensation by the Kondo effect and the long-range RKKY interaction between localized magnetic moments leads to the possibility of either a non-magnetic or a magnetically ordered ground state. However, even in the case of no long-range magnetic order as exemplified by CeCu6, short-range dynamic intersite correlations are observed. Yet, the thermodynamic and transport properties of this alloy at very low temperatures T resemble those of a Fermi liquid (FL). Upon alloying with Au, long-range incommensurate antiferromagnetism is observed in CeCu6-xAux for x > 0.1. For x=0.1 where TN=0, the specific heat C depends on T as C/T ∼ -ln(T/To), the magnetic susceptibility as χ ∼ 1 -α√T, and the T-dependent part of the electrical resistivity as Δρ ∼ T. This is in marked contrast to the FL behaviour C/T ∼ χ ∼ constant: Δρ ∼ T2. It is suggested that low-energy spin excitations are at the origin of these non-Fermi-liquid (NFL) anomalies which occur at a zero-temperature quantum phase transition. Large magnetic fields B restore FL behaviour. The low-T range of FL behaviour in C and ρ extends towards higher T with increasing B, with the crossover temperature Tcr varying roughly linearly with B. Apart from changing the Au concentration x, the magnetic - non-magnetic transition can be tuned by applying pressure p to antiferromagnetic samples with x>0.1. For x=0.3, TN → 0 at pc approx. 8 kbar and NFL behaviour is observed in the specific heat for this critical pressure. For x=0.2, pc approx. 4 kbar where we likewise observe a logarithmic divergence of C/T and for p = 6.9 kbar we recover FL behaviour. Finally, we report on a remarkable 'universality' of C/T in the system CeCu6-xMx with M = Au, Pd, Pt: regardless of how TN=0 is reached in this system (alloying with different elements M, varying concentration, or applying pressure), the C/T versus ln T

  8. Dépendance économique aux produits forestiers non ligneux : cas des ménages riverains des forêts de Boulon et de Koflandé, au Sud-Ouest du Burkina Faso

    DEFF Research Database (Denmark)

    Ouédraogo, M; Ouédraogo, D; Thiombiano, T;

    2013-01-01

    forêts. Les résultats montrent que le revenu moyen annuel par ménage est de 846 800 F CFA avec une contribution de 60% du revenu des cultures et 12% du revenu d’élevage. Les PFNL procurent en moyenne 72 479 F CFA par ménage et par an à près de 93% des ménages enquêtés. La dépendance économique des...... ménages aux PFNL est estimée à 12%. Elle diminue avec le revenu, traduisant une plus grande dépendance des ménages pauvres aux PFNL. Par ailleurs, les hommes sont économiquement moins dépendants des PFNL que les femmes. Les autres déterminants de la dépendance aux PFNL sont le statut d’autochtone, la...

  9. Détermination de quelques paramètres hématologiques chez les agriculteurs exposés aux pesticides dans la région de Tlemcen

    OpenAIRE

    SAIDI, Fatima Zohra

    2015-01-01

    Résumé Les pesticides représentent une large gamme de produits utilisés de façon très variable. Les agriculteurs sont aujourd'hui le groupe le plus exposé aux risques de contact avec les pesticides. L'objectif de notre travail consiste à mettre en évidence les altérations hématologiques chez les hommes agriculteurs disposés aux pesticides comparés aux hommes témoins. Un prélèvement sanguin est réalisé afin de déterminer quelques paramètres hématologiques (FNS, numérations cellu...

  10. Des millets aux nations

    OpenAIRE

    Pitsos, Nicolas

    2012-01-01

    L’auteur de ce roman construit son intrigue sur l’histoire de plusieurs familles d’une part au moment de l’effondrement d’un monde, celui des millets de l’Empire ottoman fondé sur le principe de l’identification des individus en fonction de leurs croyances religieuses et, d’autre part, lors de la mise en place d’une nouvelle organisation politique, celle des États-nations obsédés par l’idée de la définition de l’individu sur la base de critères nationaux. L'exemple narratif dominant est celui...

  11. La chasse aux axions

    CERN Multimedia

    Robilliard, Cécile

    2009-01-01

    Since three years, physicists double efforts to catch an hypothetical particle that would not interact - or little - with the matter. Its detection would resolve a lot of problems in the filed of particle physics and cosmology. (4 pages)

  12. Onomastique basque aux Philippines

    OpenAIRE

    Morvan, Michel

    2010-01-01

    En l'an de grâce 1521, le 16 mars, le célèbre navigateur conquérant portugais au service de l'Espagne, Ferdinand Magellan, aborde par l'est cet ensemble d'îles innombrables (près de sept mille !) de l'Océan Pacifique qui prendra bientôt le nom de Philippines. L'ensemble en question était peuplé de Negritos de type mélanésien (sans aucun doute les plus anciennes ethnies) et de Philippins asiatiques proprement dits venus par la suite de Malaisie et d'Indonésie. Les Musulmans avaient déjà pris p...

  13. Des divisions aux alternances

    Directory of Open Access Journals (Sweden)

    Eric Clemens

    2012-12-01

    Full Text Available - From the divisions to the alternations - Society, action and common good give sense to democracy. Society is in fact a set of unmitigated divisions (horizontal and vertical, material and symbolic. Democratic action, since the discourse’s conflicts, doesn’t change the human beings, but things between they, in the alternation of power’s institutions for our only good in common: the body. With this aim, the Basic Income Earth Network is necessary.

  14. Redox Transformations of Arsenic Oxyanions in Periphyton Communities

    OpenAIRE

    Kulp, Thomas R.; Hoeft, Shelley E.; Oremland, Ronald S.

    2004-01-01

    Periphyton (Cladophora sp.) samples from a suburban stream lacking detectable dissolved As were able to reduce added As(V) to As(III) when incubated under anoxic conditions and, conversely, oxidized added As(III) to As(V) with aerobic incubation. Both types of activity were abolished in autoclaved controls, thereby demonstrating its biological nature. The reduction of As(V) was inhibited by chloramphenicol, indicating that it required the synthesis of new protein. Nitrate also inhibited As(V)...

  15. Transport of radioselenium oxyanions by diffusion in unsaturated soils

    International Nuclear Information System (INIS)

    There is a lack of data on the diffusion of long-lived radionuclides in soils, especially of those originated from the leaching of radioactive waste in waste disposal facilities. Here, the simultaneous diffusion of two radioselenium species, which were postulated to be radioselenite and radioselenate, was examined for the first time in four soils at laboratory level by applying the planar-source method. The Gaussian-shaped experimental diffusion profile was deconvoluted into two Gaussian functions, and then the apparent diffusion coefficients (Da) were quantified for each species. Radioselenate Da values ranged from 1.4 x 10-11 to 1.5 x 10-10 m2s-1, while those of radioselenite were two orders of magnitude lower (from 5.2 x 10-13 to 2.7 x 10-12 m2s-1) for all samples and conditions tested. The radioselenite distribution coefficient values derived from Da correlated to soil properties, such as pH and Al/Fe mineral content, and thus were consistent with the factors controlling the sorption of selenium species in soils.

  16. Transport of radioselenium oxyanions by diffusion in unsaturated soils

    Energy Technology Data Exchange (ETDEWEB)

    Aldaba, David; Rigol, Anna; Vidal, Miquel [Barcelona Univ. (Spain). Dept. de Quimica Analitica; Garcia-Gutierrez, Miguel [CIEMAT, Dept. de Medioambiente, Madrid (Spain); Abrao, Taufik [State University of Londrina (UEL) (Brazil). Dept. of Electrical Engineering (DEEL)

    2015-07-01

    There is a lack of data on the diffusion of long-lived radionuclides in soils, especially of those originated from the leaching of radioactive waste in waste disposal facilities. Here, the simultaneous diffusion of two radioselenium species, which were postulated to be radioselenite and radioselenate, was examined for the first time in four soils at laboratory level by applying the planar-source method. The Gaussian-shaped experimental diffusion profile was deconvoluted into two Gaussian functions, and then the apparent diffusion coefficients (D{sub a}) were quantified for each species. Radioselenate D{sub a} values ranged from 1.4 x 10{sup -11} to 1.5 x 10{sup -10} m{sup 2}s{sup -1}, while those of radioselenite were two orders of magnitude lower (from 5.2 x 10{sup -13} to 2.7 x 10{sup -12} m{sup 2}s{sup -1}) for all samples and conditions tested. The radioselenite distribution coefficient values derived from D{sub a} correlated to soil properties, such as pH and Al/Fe mineral content, and thus were consistent with the factors controlling the sorption of selenium species in soils.

  17. La « brutalisation » de la guerre. Des guerres d’Italie aux guerres de Religion

    Directory of Open Access Journals (Sweden)

    Jean-Louis Fournel

    2005-04-01

    avait fait ses premières armes sur les champs de bataille italiens et des réactions face aux atrocités de la guerre civile, permettrait peut-être tout à la fois d’inscrire la barbarie dans le présent des conflits, de permettre un nouveau discours pacifiste, de confier paradoxalement au souverain comme instance laïque, au-dessus des choix religieux personnels, le rôle d’arbitre et de régulateur des guerres (cf. les politiques, et, enfin, de relancer la question du jus in bello (le jus ad bellum n’étant plus vraiment opératoire, pas plus que le rôle d’arbitre du pape qui s’effondrera bientôt définitivement dans l’Europe née du traité de Westphalie.

  18. Du karma aux planètes From the Karma to the Planets: Arakanese Healers and their Heterogeneous Practices

    Directory of Open Access Journals (Sweden)

    Céline Coderey

    2012-10-01

    Full Text Available En Arakan, les conceptions de la maladie et les pratiques thérapeutiques relevant du bouddhisme theravāda, de l’astrologie, du culte des esprits, de la médecine et de bien d’autres domaines forment un ensemble signifiant et hiérarchisé. Ensemble signifiant parce que malades et thérapeutes considèrent ces conceptions et pratiques comme indissociables les unes des autres et devant donc être combinées afin de mener à bien le processus de guérison. Ensemble hiérarchisé car, à l’intérieur de celui-ci, le bouddhisme occupe une place hégémonique au niveau des valeurs. Néanmoins, dans le domaine thérapeutique, son apport est limité. Ce n’est que combinées aux pratiques astrologiques, médicales, etc. que les pratiques bouddhiques peuvent contribuer à la prévention et au soin des maladies. L’attention est ici portée sur la manière dont laquelle cette totalité signifiante et hiérarchisée s’exprime dans les pratiques des thérapeutes. Sur la base d’une étude de cas, l’article montre que souvent les thérapeutes cumulent plusieurs formations et pratiques plus ou moins hétérogènes afin de pouvoir intervenir sur le plus grand nombre possible de facteurs de la maladie : déséquilibre des éléments corporels, mauvais karma, influences planétaires néfastes, agressions par des puissances maléfiques.In Arakan, sickness-related conceptions and therapeutic practices issuing from Theravada Buddhism, astrology, spirits cult and medicine form a meaningful and hierarchical whole. This whole is meaningful because patients and healers consider that it is the combination of various conceptions and various practices which makes sense and which guarantees the succes of the healing treatement. The whole is hierarchical because conceptions and practices are organised into a hierarchy where Buddhism occupies an hegemonic position. Nevertheless, in the healing field its contribution is limited. Only if combined with

  19. Analyse des statistiques de pêche aux engins dans le bassin du Rhône. Deuxième partie : étude des captures

    Directory of Open Access Journals (Sweden)

    CHANGEUX T.

    1993-07-01

    Full Text Available En confrontant les captures déclarées et les autorisations délivrées sur le Rhône et la Saône en 1988 et 1989, on estime pour ces deux années les prélèvements de la pêche aux engins à 238 t/an et 273 t/an. Les captures sont essentiellement constituées de grands cyprinidés (Abramis brama, Blicca bjoerkna, Rutilus rutilus et Chondrostoma nasus et de poissons amphihalins comme les muges (Liza ramada en majorité ou l'anguille (Anguilla anguilla. La pêche professionnelle fluviale représente en moyenne 72 % des captures. Pour certaines espèces comme les aloses (Alosa fallax en majorité, le brochet (Esox lucius, le sandre (Stizostedion lucioperca et le poisson-chat (ictalurus mêlas, les pêcheurs amateurs aux engins et filets prélèvent des quantités comparables à celles des professionnels. De plus, les amateurs sont majoritaires dans les productions de la Saône amont. La biomasse totale des captures du Rhône deltaïque arrive en seconde position derrière celle de la Saône aval, située au centre du bassin. Ce secteur apparaît comme une zone de première importance pour la pratique de la pêche aux engins strictement fluviale en France. Les captures déclarées suivent un rythme saisonnier en relation avec le cycle de l'effort de pêche mis en évidence dans la première partie de l'article (CHANGEUX et ZYLBERBLAT, ce numéro. Les aloses sont capturées pendant la fermeture des autres pêches, au mois de mai. Les muges sont capturés pendant la saison "froide" et la friture de petits cyprinidés (Alburnus alburnus, en majorité pendant la "saison chaude". Dans la Saône aval, l'analyse des Captures par Unité d'Effort (CPUE valide la distinction des métiers définis dans la première partie de l'article. L'utilisation des CPUE est envisagée pour suivre les stocks des principales captures du secteur.

  20. Immigration(s et accès aux soins en Guyane Immigration(s and access to health care in French Guyana

    Directory of Open Access Journals (Sweden)

    Estelle Carde

    2012-11-01

    Full Text Available L’immigration en Guyane est plurielle. Aux migrants caribéens que la précarité et les violences politiques ont chassés de chez eux se mêlent des migrants partis de France métropolitaine pour goûter à l’exotisme de cette société française sise en Amérique du Sud. Cette pluralité se retrouve lorsque les premiers, usagers étrangers du système de soins, rencontrent des professionnels qui, bien que français, sont soit autochtones, soit eux-mêmes migrants. Ces usagers étrangers sont parfois victimes de discriminations opérées par des professionnels autochtones qui les suspectent de venir profiter indûment du système de soins local. Si ces discriminations ont également cours ailleurs en France, elles sont exacerbées en Guyane par l’importance des flux migratoires et des difficultés socio-économiques. Une autre figure de l’accès aux soins en contexte d’immigration, plus spécifique à la Guyane, est celle de professionnels migrants qui attribuent à certains de leurs usagers étrangers, au nom de leur identité ethnique, une autochtonie que ne leur reconnaît pas la loi. Enfin, les enjeux de l’accès aux soins en contexte d’immigration s’articulent à l’ensemble des rapports sociaux inégalitaires qui traversent la société guyanaise.Immigration in French Guyana is plural. Caribbean migrants, driven away by poverty and political violence, mix with migrants who left metropolitan France to taste the exotism of this French society in South America. This plurality shapes access to health care, since foreign users meet French professionals who are either native or migrants. These foreigners may be victims of discrimination on the part of native professionals who suspect them of taking advantage of the local health care system. Whereas such discrimination exists elsewhere in France, the situation seems exacerbated in French Guyana by the importance of the migratory flows and socioeconomic difficulties. Migrant

  1. Combining histology, stable isotope analysis and ZooMS collagen fingerprinting to investigate the taphonomic history and dietary behaviour of extinct giant tortoises from the Mare aux Songes deposit on Mauritius

    NARCIS (Netherlands)

    L.G. van der Sluis; H.I. Hollund; M. Buckley; P.G.B. de Louw; K.F. Rijsdijk; H. Kars

    2014-01-01

    Taphonomic research of bones can provide additional insight into a site's formation and development, the burial environment and ongoing post-mortem processes. A total of 30 tortoise (Cylindraspis) femur bone samples from the Mare aux Songes site (Mauritius) were studied histologically, assessing par

  2. Les enjeux économiques et industriels liés au recours aux partenariats public-privédans le domaine spatialUne application : le contrat de Private Finance Initiative britannique Skynet V

    OpenAIRE

    Frédéric Marty

    2008-01-01

    Analyse économique du contrat de partenariat public-privé relatif aux satellites de télécommunications de défense Skynet V.Etude de la construction contractuelle et de sa renégociation : impact sur l'équilibre économique du contrat

  3. Les enjeux économiques et industriels liés au recours aux partenariats public-privé
    dans le domaine spatial
    Une application : le contrat de Private Finance Initiative britannique Skynet V

    OpenAIRE

    Marty, Frédéric

    2008-01-01

    Analyse économique du contrat de partenariat public-privé relatif aux satellites de télécommunications de défense Skynet V.Etude de la construction contractuelle et de sa renégociation : impact sur l'équilibre économique du contrat

  4. Expression of PIN and AUX1 genes encoding putative carrier proteins for auxin polar transport in etiolated pea epicotyls [correction of epicotyles] under simulated microgravity conditions on a three-dimensional clinostat.

    Science.gov (United States)

    Hoshino, Tomoki; Hitotsubashi, Reiko; Miyamoto, Kensuke; Tanimoto, Eiichi; Ueda, Junichi

    2003-10-01

    Etiolated pea (Pisum sativum L. cv. Alaska) seedlings grown under simulated microgravity conditions on a 3-dimensional clinostat showed automorphosis-like growth and development similar to that observed in true microgravity conditions in space. Application of inhibitors of auxin polar transport phenocopied automorphosis-like growth on 1 g conditions, suggesting that automorophosis is closely related to auxin polar transport. Strenuous efforts to know the relationships between automorphosis and auxin polar transport in pea seedlings at molecular bases resulted in successful identification of PsPIN2 and PsAUX1 encoding putative auxin efflux and influx carrier protein, respectively. Significantly high levels in homology were found on nucleotide and deduced amino acid sequences among PsPIN2, PsPIN1 and AtPINs, and between PsAUX1 and AtAUX1. Expression of PsPIN1 and PsAUX1 genes in etiolated pea seedlings grown on the clinostat were substantially affected, but that of PsPIN2 was not. Roles of these genes in auxin polar transport and automorphosis of etiolated pea seedlings are also described. PMID:14676360

  5. Les évolutions du modèle énergétique britannique face aux enjeux géopolitiques internes

    OpenAIRE

    Bailoni, Mark

    2015-01-01

    Le Royaume-Uni doit réviser son modèle énergétique, pour se préparer à l’épuisement de ses ressources naturelles et pour répondre aux exigences environnementales. Depuis le début des années 2000, les gouvernements successifs ont entamé plusieurs stratégies : développement des énergies renouvelables, relance du nucléaire et volonté d’exploiter le gaz de schiste. Outre certaines contradictions et certains revirements dans l’approche politique, les évolutions du modèle énergétique britannique se...

  6. Brevets pharmaceutiques, génériques et santé publique. Le cas de l’accès aux traitements antirétroviraux

    OpenAIRE

    Coriat, Benjamin; Orsi, Fabienne

    2006-01-01

    En 1994, la signature des ADPIC a signifié l’entrée dans un monde régi par le type de droits de propriété intellectuelle qui s’était établi dans les pays les plus développés. Une série de problèmes nouveaux, notamment pour ce qui concerne l’accès aux soins des pays à bas revenus, ont alors surgi. En se basant sur le cas de la lutte contre l’épidémie du Sida, l’article explore les contradictions et les tensions qu’a fait naître la signature des ADPIC en matière de Santé publique....

  7. Analyse pharmacothérapeutique chez la personne âgée aux urgences et renforcement du lien ville-hôpital

    OpenAIRE

    Faure, Rémi; Moch, Céline; France, Mathilde; Castel-Kremer, Elisabeth; Favre, Muriel; Tazarourte, Karim; Paillet, Carole; Pivot, Christine

    2015-01-01

    Introduction : L’optimisation de la prise en charge médicamenteuse et la coopération ville-hôpital constituent un axe majeur d’amélioration de la qualité et de la sécurité des soins. L’objectif de cette étude était de mettre en place une nouvelle activité pharmaceutique aux urgences pour diminuer l’iatrogénie médicamenteuse chez la personne âgée (PA) et renforcer le lien ville-hôpital.Matériels et méthodes :Il s’agit d’une étude prospective, monocentrique. Les patients de plus de 75 ans admis...

  8. Aspects épidémiologiques des accidents vasculaires cérébraux (AVC) aux urgences de l'institut de cardiologie d'Abidjan (ICA)

    OpenAIRE

    N'goran, Yves N'da Kouakou; Traore, Fatou; Tano, Micesse; Kramoh, Kouadio Euloge; Kakou, Jean-Baptiste Anzouan; Konin, Christophe; Kakou, Maurice Guikahue

    2015-01-01

    Introduction L'objectif de notre étude était de décrire les caractéristiques sociodémographiques et les Facteurs de Risque cardio-Vasculaires (FRV) des patients admis pour accidents vasculaires cérébraux (AVC) dans un service autre que celui de la neurologie. Méthodes Étude transversale rétrospective sur une période de 2 ans (janv. 2010 et déc. 2011), réalisée aux urgences de l'institut de cardiologie d'Abidjan. Résultats Il s'agissait de 176 adultes avec un âge moyen de 60 ans, une prédomina...

  9. Etude, analyse et modélisation physique de la production de la parole avec applications aux troubles liés à une surdité profonde

    OpenAIRE

    Delebecque, Louis

    2015-01-01

    L’apprentissage du langage parlé nécessite un contrôle musculaire très précis des différents organes intervenant dans la production de la parole. La production de sons voisés, qui résulte de l’auto-oscillation des cordes vocales, est notamment influencée par l’ensemble du système phonatoire, du diaphragme jusqu’aux lèvres. Les travaux réalisés dans le cadre de cette thèse s’inscrivent dans un contexte de modélisation physique de la parole. Les objectifs s’articulent autour de la compréhension...

  10. Style ou pragmatisme ? Le débat sur l’architecture du xixe siècle aux Pays-Bas

    OpenAIRE

    van Leeuwen, Wilfred

    2013-01-01

    Aux Pays-Bas, sans doute plus qu’ailleurs, l’arrogance du modernisme éclipsa pendant longtemps la richesse et les qualités particulières de l’architecture du xixe siècle. La sobriété et l’austérité néerlandaise, que le modernisme incarnait avec tant d’enthousiasme, faisaient peu de cas du « siècle de l’ornement ». L’étude de cette période se montra donc hésitante : il fallut attendre les années 1990 pour disposer de travaux scientifiques d’une certaine envergure et de monographies d’architect...

  11. Vers un modèle d'indexation sémantique adapté aux dossiers médicaux de patients

    OpenAIRE

    Dinh, Duy; Tamine, Lynda

    2010-01-01

    Ce papier présente un modèle d'indexation sémantique adapté aux dossiers électroniques de patients. Ce modèle servira de support à des processus de recherche d'information médicale, permettant à terme de promouvoir l'expérience collective des médecins. Compte tenu de la spécificité de ce type de documents, le processus d'indexation est basé sur la succession d'étapes d'annotation sémantique fondée sur l'utilisation de MeSH (Medical Subject Headings), de désambiguïsation répondant au problème ...

  12. Loïc Artiaga, dir., Le roman populaire 1836-1960. Des premiers feuilletons aux adaptations télévisuelles

    OpenAIRE

    Hecquet, Vincent

    2012-01-01

    Regroupant les travaux de huit universitaires, cet ouvrage retrace l’histoire du roman populaire et en analyse les thèmes et la poétique. Le genre est étudié depuis son origine jusqu’aux années 60, période à partir de laquelle la télévision remplace l’édition comme principal vecteur de la culture de masse. Le roman populaire accompagne l’histoire de la presse et de l’édition depuis les années 1830.Sa diffusion est liée à l’élargissement du lectorat, à la constitution d’un capitalisme éditoria...

  13. Parler l’« interlangue » de mon siècle : la poesia visiva face aux mass media

    OpenAIRE

    Gaëlle Theval

    2011-01-01

    La poesia visiva se donne pour but de résister à la massification aliénante véhiculée par les médias, en développant une poésie visuelle qui se réapproprie le langage même des médias incriminés. L’adoption de cette « interlangue », qui repose sur l’association du mot et de l’image, a une fonction double : il s’agit à la fois de redonner une place à la poésie dans la société contemporaine dominée par l’image en empruntant aux médias leur efficacité pragmatique, et, dans le même temps, de conte...

  14. Détection de résistances aux inhibiteurs de l'ALS : des outils moléculaires pour un diagnostic rapide et fiable

    OpenAIRE

    Délye, Christophe; Boucansaud, Karelle; Pernin, Fanny; Couloume, B.

    2008-01-01

    Les inhibiteurs de l’acétolactate-synthase (ALS) sont une des classes d’herbicides les plus utilisées actuellement. Être capable de diagnostiquer rapidement la présence de plantes résistantes à ces substances contribue à maintenir leur efficacité. La plupart des cas de résistance aux inhibiteurs de l’ALS sont dus à des mutations dans le gène de l’ALS. Des tests moléculaires ont été développés chez les principales graminées adventices du blé, le Vulpin (Alopecurus myosuroides) et les Ivraies (...

  15. Détection et isolation de pannes basées sur la platitude différentielle. Application aux engins atmosphériques.

    OpenAIRE

    Zhang, Nan

    2010-01-01

    Ce travail de thèse aborde le problème de la détection et de l’isolation des pannes à base de modèle du système dynamique non linéaire. Les techniques de détection et d’identification de pannes sont déjà appliquées aux systèmes industriels et elles jouent un rôle important pour assurer les performances attendues des systèmes automatiques. Les différentes approches du diagnostic des systèmes dynamiques semblent être souvent le résultat de contextes différents notamment en ce qui concerne les a...

  16. Résistance des insectes aux toxines de Bacillus thuringiensis produites par les plantes génétiquement modifiées

    OpenAIRE

    Augustin, Sylvie; Bethenod, Marie-Thérèse; Bourguet, Denis; Chaufaux, Josette; Courtin, Claudine; FREROT, Brigitte; Genestier, Gilles; Genissel, Anne; Pelozuelo, Laurent; Rejasse, Agnes; Thomas, Yan

    2004-01-01

    Un des risques environnementaux le plus souvent évoqué lors de l'utilisation des plantes transgéniques exprimant une toxine de Bacillus thuringiensis est la sélection d'insectes ravageurs résistants à cette toxine. Dans le cadre de cette ACI, plusieurs paramètres permettant un meilleur ajustement des stratégies de gestion de ces résistances ont été estimés. Nous avons ainsi montré que les fréquences des allèles de résistance aux toxines produites par les maïs Bt dans les populations naturelle...

  17. Écologie de Pseudomonas syringae dans un bassin versant : vers un modèle de transfert : des habitats naturels aux agro-systèmes

    OpenAIRE

    Monteil, Caroline

    2011-01-01

    Caractériser la dissémination des bio-agresseurs est un enjeu majeur pour la gestion et la prédiction des maladies en santé des plantes. Face aux limites des approches usuelles en pathologie végétale, une nouvelle vision a été proposée abordant les paradigmes d'histoire de vie des agents phytopathogènes en dehors des limites du système hôte-pathogène. Parmi ces agents phytopathogènes, les études sur P.syringae sont celles qui ont contribuées le plus à ce nouveau courant de pensée et dont on c...

  18. La médiatisation des problématiques de la violence et de l'addiction aux jeux vidéo

    OpenAIRE

    Mauco, Olivier

    2012-01-01

    Les problématiques de la violence et de l’addiction des jeux vidéo sont des thématiques récurrentes dans les médias généralistes. En étudiant la genèse du traitement médiatique de ces notions, dans une approche comparative et internationale, cet article suggère que la récurrence de ces thèmes est liée à la question de la sélection des experts du jeu vidéo. Leurs modes de sélections endogènes afin de répondre aux impératifs d’explication, produit une surreprésentation des professionnels de la p...

  19. Modélisation de dommages consécutifs aux séismes. Extension à d'autres risques naturels

    OpenAIRE

    CHIROIU, Lucian

    2004-01-01

    Les sujets que nous présentons abordent la question de la modélisation de dommages consécutifs aux séismes, avant et après l'événement. Cette approche a un caractère pluridisciplinaire, se situant entre les techniques propres au génie civil, à travers le calcul des structures, à la géographie, à travers l'analyse spatiale et à la télédétection, à travers l'utilisation de l'imagerie satellitaire. Le premier chapitre présente d'une part les objectifs, le fonctionnement et les principaux paramèt...

  20. Les déterminants du coût du capital des petites capitalisations : application aux segments B et C de la Bourse de Paris

    OpenAIRE

    Marrot, Olivier

    2008-01-01

    La spécificité des petites capitalisations (l’effet taille), est au centre des recherches en finance depuis de nombreuses années. Peu de travaux se sont cependant concentrés sur ce compartiment. Notre recherche porte sur les sociétés des listes B et C d’Euronext Paris sur la période 1994-2004. Le modèle APT avec utilisation d’attributs spécifiques comme sensibilité aux risques affectant la rentabilité des titres, palie la faible significativité des bêtas. Conformément à la littérature sur les...

  1. Des monastères aux funérailles. La construction d’une relation ethnographique avec des chrétiennes de Damas (Syrie

    Directory of Open Access Journals (Sweden)

    Anna Poujeau

    2009-03-01

    Full Text Available Des monastères aux funérailles. La construction d’une relation ethnographique avec des chrétiennes de Damas (Syrie. En juillet 2004, j’ai assisté aux funérailles d’un jeune homme de la famille au sein de laquelle je vivais à Damas. À l’époque, l’intense émotion suscitée par cet événement empêcha que je m’y intéresse de plus près. Ce n’est que deux ans plus tard, en juillet 2006, que j’ai décidé d’enquêter sur l’un des aspects majeurs de la cérémonie : les lamentations funèbres féminines. Lors de ce dernier terrain, les femmes de la famille que j’interrogeais, que j’accompagnais aux funérailles et dont j’enregistrais les chants m’assignèrent alors une place tout à fait particulière. Puisque, moi aussi, « je m’habillais en noir et je venais aux funérailles », je ne pouvais plus être considérée comme une étrangère. Dès lors, elles firent de moi la fille d’une de leur sœur émigrée à Paris et mariée avec un Français. Ce statut me fut par ailleurs confirmé lorsqu’elles m’attribuèrent une place dans leurs plaisanteries entre sœurs, tantes et neveux matrilatéraux.Dans cet article, je souhaite engager une double réflexion : sur la position et l’implication de l’ethnologue sur un terrain où l’émotion est au premier plan, ainsi que sur la façon dont être assignée à une place dans la parenté de ses informateurs donne enfin toute liberté d’action à l’ethnologue sur son terrain.From monasteries to funerals. The construction of ethnographical relations with the Christians of Damascus (Syria. In July 2004, I attended the funeral of a young man from the family with whom I was staying in Damascus. At the time, the intense emotion provoked by that event prevented me from immediately examining it more closely. It was only two years later, in July 2006, that I decided to study one of the main features of the ceremony: the women’s lamentations. During this

  2. Le positionnement de l'Inde sur le changement climatique : Des négociations internationales aux politiques nationales : des relations ambivalentes

    OpenAIRE

    Mathy, Sandrine

    2013-01-01

    Ce texte vise à décrire le positionnement de l'Inde vis-à-vis du changement climatique dans le but de cerner les marges de manœuvres existantes dans la contribution de l'Inde à l'atteinte d'un accord international lors de la COP 21 à Paris en 2015. Les première et seconde parties montrent respectivement les défis d'une Inde à la fois fortement exposée aux impacts du changement climatique et dont le développement économique est rendu dépendant du développement résilient d'un secteur énergétiqu...

  3. Les projets de Jacques Gondoin : première réponse aux rêves versaillais de Napoléon

    OpenAIRE

    Biraud, Émilie

    2012-01-01

    Résultats de la première commande faite par Napoléon Ier pour le château de Versailles, les projets réalisés par l’architecte Jacques Gondoin furent les plus complets parmi tous ceux proposés à l’Empereur entre 1806 et 1811, puisqu’ils englobaient l’ensemble du domaine versaillais. Étudié précédemment aux côtés des propositions de Pierre-François-Léonard Fontaine et d’Alexandre Dufour, dans des publications consacrées au projet de Napoléon de faire du palais des rois de France sa propre résid...

  4. Pollution persistante des sols aux Antilles par des insecticides organochlorés : HCH et chlordécone encore pour des siècles ?

    OpenAIRE

    Cabidoche, Yves-Marie; Cattan, Philippe; Clermont-Dauphin, Claridge; Gaspard, Sarra; Lesueur-Jannoyer, Magalie; Loranger-Merciris, Gladys

    2009-01-01

    La lutte contre le charançon du bananier, Cosmopolites sordidus, s’est longuement appuyée sur des insecticides organochlorés aux Antilles françaises à la fin du siècle dernier : - l’hexachlorocyclohexane (HCH), dont seul l’isomère γ est insecticide, a été appliqué à des doses massives, jusqu’à plus de 300 kg/ha/an d’HCH « technique » (mélange de 5 isomères dont 20% de γ), dans les années 60 à 70 ; - la chlordécone (CLD), appliquée à 3 kg de matière active (MA)/ha/an, par les insecticides US «...

  5. « L'esthétique du chant dans la piété calviniste aux premiers temps de la Réforme (1536-1545) »

    OpenAIRE

    Grosse Christian

    2010-01-01

    Contrairement aux idées reçues, l'esthétique assume bien une fonction dans les formes rituelles adoptées par les Eglises issues de la Réforme calviniste. Mais il revient moins à l'image, considérée avant tout comme une source de distraction, qu'à la musique de porter cette dimension dans la piété réformée. Retraçant la formation de la pensée calvinienne sur la question des rapports entre culte et musique entre 1536 et 1543, cette étude montre comment le théologien en vient durant ces années à...

  6. Immigration(s) et accès aux soins en Guyane Immigration(s) and access to health care in French Guyana

    OpenAIRE

    Estelle Carde

    2012-01-01

    L’immigration en Guyane est plurielle. Aux migrants caribéens que la précarité et les violences politiques ont chassés de chez eux se mêlent des migrants partis de France métropolitaine pour goûter à l’exotisme de cette société française sise en Amérique du Sud. Cette pluralité se retrouve lorsque les premiers, usagers étrangers du système de soins, rencontrent des professionnels qui, bien que français, sont soit autochtones, soit eux-mêmes migrants. Ces usagers étrangers sont parfois victime...

  7. Contribution à la conception de circuits intégrés analogiques en technologie CMOS basse tension pour application aux instruments d'observation de la Terre

    OpenAIRE

    Standarovski, Denis

    2005-01-01

    Le présent mémoire de thèse s'inscrit dans la problématique d'intégration de chaînes pour traitement du signal vidéo issu d'un capteur CCD dédiées aux instruments d'observation de la Terre. La solution présentée à travers cette étude consiste à concevoir des circuits intégrés spécifiques (ASIC) analogiques avec des technologies CMOS sub-microniques basse-tension, principalement développées pour les circuits numériques complexes. Dans une première partie, nous présentons le contexte de l'étude...

  8. Les compétences en littératie médiatique. De la définition aux nouveaux enjeux éducatifs.

    OpenAIRE

    Pierre FASTREZ; De Smedt, Thierry

    2013-01-01

    La littératie médiatique peut être décrite comme l’ensemble des compétences permettant à l’individu d’évoluer de façon critique et créative, autonome et socialisée dans l’environnement médiatique contemporain. Cet article présente une définition de la littératie médiatique sous la forme d’un inventaire structuré de ces compétences liées aux usages médiatiques. Cette définition constitue un outil diagnostique permettant au monde scolaire (et, par extension associatif, professionnel et familial...

  9. Fédéralisme et droits des LGBT aux États-Unis et au Canada : analyse comparatives des politiques

    Directory of Open Access Journals (Sweden)

    Miriam Smith

    2014-12-01

    Full Text Available L’article examine le militantisme LGBT et les résultats des politiques en matière de droit pénal et du mariage entre personnes de même sexe de 1969 à aujourd’hui, dans le cadre d’une analyse comparée du fédéralisme aux États-Unis et au Canada. Nous soutiendrons que le fédéralisme a grandement façonné les politiques publiques relatives aux droits des LGBT. Dans le régime américain, le potentiel d’expansion du fédéralisme a favorisé les changements graduels de politiques dans les États et, parallèlement, les multiples points de véto créés par le système de séparation des pouvoirs conjugués aux compétences conférés aux États dans d’importants domaines de politiques ont entravé ces changements de politiques. Dans le régime canadien, la centralisation des mécanismes de protection des droits de la personne dans la Charte de même que la dynamique descendante de l’exercice du pouvoir dans le régime parlementaire de type Westminster ont facilité les changements de politiques. Le fédéralisme est souvent perçu comme un obstacle à l’adoption de politiques progressistes. La répartition des pouvoirs entrave l’élaboration de politiques cohérentes et prête le flanc à la prolifération de vétos dont peuvent se prévaloir des groupes influents pour freiner le changement. Les critiques de cette perspective arguent depuis longtemps que, même si le fédéralisme multiplie les points de véto, il présente aussi de nombreuses possibilités d’innovation. Ils font valoir que les groupes ont plus de poids dans les régimes fédéraux puisqu’ils peuvent exercer leur influence à deux paliers de gouvernement plutôt qu’à un. Ainsi, un groupe qui ne réussit pas à se faire entendre à l’un des paliers pourra tenter sa chance au second et pourra même dresser un palier contre l’autre pour atteindre ses objectifs stratégiques.

  10. Services globaux, géographies locales : les services aux entreprises dans les métropoles de Londres et Paris

    OpenAIRE

    Halbert, Ludovic; Pain, Kathy

    2010-01-01

    À la suite des travaux du GAWC (Globalization And World Cities), le programme de recherche Polynet a testé l’hypothèse selon laquelle les professionnels des services aux entreprises mis au cœur de la théorie de la ville globale selon S. Sassen participent à la formation de vastes régions métropolitaines dénommées Mega-Régions Urbaines (MRU). Cet article discute les hypothèses et la réalité de l’émergence des MRU à partir des cas de Londres et de Paris. En confrontant des entretiens réalisés a...

  11. UN CRITÈRE BASÉ SUR LA DISTANCE DE MAHALANOBIS POUR L'AFFECTATION D'OBJETS SUPPLÉMENTAIRES AUX CLASSES D'UNE CAH EUCLIDIENNE

    OpenAIRE

    Cassor, Frédérik; Le Roux, Brigitte

    2014-01-01

    Dans une classification ascendante hiérarchique euclidienne (méthode de Ward), la méthode usuelle d'affectation d'un individu supplémentaire à une classe est basée sur la distance géométrique du point-individu au centre de la classe. Cette méthode présente l'inconvénient de ne pas tenir compte de ce que les classes différent, quant aux poids, à leurs formes et à leurs dispersions ; elle ne tient pas compte également des dichotomies successives de la hiérarchie de parties issue de la classific...

  12. Rôles et actions des groupes dominants dans la ville : des outils aux processus historicisés. Introduction

    Directory of Open Access Journals (Sweden)

    Céline Tellier

    2009-05-01

    Full Text Available Fruit d’une journée d’étude organisée en mars 2008 par le programme de recherche ARC « Les élites dans la ville » de l’Université Libre de Bruxelles, ce numéro spécial regroupe une série d’articles qui s’intéressent aux modes opératoires de la « construction » de l’espace urbain par certains groupes sociaux, appelés ici « dominants ». Par « construction », nous n’entendons pas seulement les aspects matériels mais aussi, si pas davantage, les aspects sociaux et symboliques qui sont mis en œuvr...

  13. Etude de la qualité des captures de la pêcherie associée aux DCP ancrés. Projet MAGDELESA

    OpenAIRE

    Dromer, Clément; Eugene, Sonia; Régina, Françoise; Reynal, Lionel; Etienne, Monique; Mathieu, Heloïse; Pau, Cedric

    2015-01-01

    La qualité des produits est un élément du développement durable des pêcheries, car elle vise à garantir la fiabilité sanitaire des débarquements et leur valorisation optimale. Dans le cas de la pêche associée aux DCP ancrés, les embarcations non pontées utilisées pour la capture de grands poissons pélagiques ne sont pas de dimension suffisante pour être équipées de moyens de conservation adéquats (règlementaires) des prises. Cette étude permet, à partir d’embarquements en mer, de suivi des pr...

  14. Le commentaire d’Alcuin sur l’Épître aux Hébreux et le thème du sacrifice

    OpenAIRE

    Savigni, Raffaele

    2006-01-01

    Le premier commentaire latin sur l’épître aux Hébreux, incomplet et transmis anonyme ou sous le nom d’« Ambroise » (c’est à dire de l’Ambrosiaster), a été rédigé par Alcuin, qui souligne le rôle sacerdotal de Jésus, le nouvel Melchisédech ; et présente le prêtre comme un nouvel Aaron, qui doit calmer la colère de Dieu. Il spiritualise la notion de sacrifice, mais il entrevoit aussi une continuité typologique entre les temples et les sacrifices de l’Ancien Testament et les églises chrétiennes,...

  15. Comment évaluer l'exposition aux pesticides de l’air en population générale ? Enseignements d’une revue bibliographique

    OpenAIRE

    Aschan-Leygonie, Christina; Baudet-Michel, Sophie; Harpet, Cyrille; Augendre, Marie; Lavie, Émilie; Grésillon, Etienne; Hechinger, Morgane

    2015-01-01

    Cet article présente les méthodes mises en œuvre pour évaluer l’exposition aux pesticides de l’air en population générale. Il repose sur une revue bibliographique conduite à partir d’articles portant sur l’exposition environnementale en Amérique du Nord, Europe et Australie et parus dans des revues médicales et de sciences humaines. Dans un premier temps, les méthodes d’évaluation directe (présence des pesticides dans l'air, dans les poussières intérieures des résidences ou dans les matrices ...

  16. "Quels sont les facteurs qui peuvent donner aux élèves l'envie de pratiquer un sport en dehors du cadre scolaire ?"

    OpenAIRE

    Soos, Katia; Patelli, Gianpaolo

    2014-01-01

    Le sport est une activité physique qui apporte beaucoup aux élèves autant physiquement que mentalement. Il est recommandé de garder un certain équilibre grâce à une bonne hygiène de vie et par conséquent d’exercer une activité physique régulière. Aujourd’hui, les enfants sont sans cesse influencés ou attirés par des phénomènes nouveaux : internet, les jeux vidéos ou les séries télévisées. Ces distractions sont agréables, distrayantes et ne demandent pas beaucoup d’efforts physiques. C’e...

  17. Cinética e equilíbrio de adsorção dos oxiânions Cr (VI, Mo (VI e Se (VI pelo sal de amônio quaternário de quitosana Kinetics and equilibrium of adsorption of oxyanions Cr (VI, Mo (VI and Se (VI by quaternary ammonium chitosan salt

    Directory of Open Access Journals (Sweden)

    Viviane A. Spinelli

    2005-07-01

    one gram of cross-linked quaternary chitosan salt adsorbed 68.3 mg of chromium, 63.4 mg of molybdenum and 90.0 mg of selenium. The adsorption process followed a pseudo second-order kinetic rate equation and the equilibrium regarding the three ions was reached after 200 minutes. The studies from X-ray dispersive energy showed that the main adsorption mechanism is ionic exchange among Cl- groups on the polymer surface by oxyanions from solution and the anionic exchanger showed the following selectivity order: Cr (VI > Mo (VI > Se (VI.

  18. Bioinformatic cis-element analyses performed in Arabidopsis and rice disclose bZIP- and MYB-related binding sites as potential AuxRE-coupling elements in auxin-mediated transcription

    Directory of Open Access Journals (Sweden)

    Berendzen Kenneth W

    2012-08-01

    Full Text Available Abstract Background In higher plants, a diverse array of developmental and growth-related processes is regulated by the plant hormone auxin. Recent publications have proposed that besides the well-characterized Auxin Response Factors (ARFs that bind Auxin Response Elements (AuxREs, also members of the bZIP- and MYB-transcription factor (TF families participate in transcriptional control of auxin-regulated genes via bZIP Response Elements (ZREs or Myb Response Elements (MREs, respectively. Results Applying a novel bioinformatic algorithm, we demonstrate on a genome-wide scale that singular motifs or composite modules of AuxREs, ZREs, MREs but also of MYC2 related elements are significantly enriched in promoters of auxin-inducible genes. Despite considerable, species-specific differences in the genome structure in terms of the GC content, this enrichment is generally conserved in dicot (Arabidopsis thaliana and monocot (Oryza sativa model plants. Moreover, an enrichment of defined composite modules has been observed in selected auxin-related gene families. Consistently, a bipartite module, which encompasses a bZIP-associated G-box Related Element (GRE and an AuxRE motif, has been found to be highly enriched. Making use of transient reporter studies in protoplasts, these findings were experimentally confirmed, demonstrating that GREs functionally interact with AuxREs in regulating auxin-mediated transcription. Conclusions Using genome-wide bioinformatic analyses, evolutionary conserved motifs have been defined which potentially function as AuxRE-dependent coupling elements to establish auxin-specific expression patterns. Based on these findings, experimental approaches can be designed to broaden our understanding of combinatorial, auxin-controlled gene regulation.

  19. « Les citoyens ordinaires face aux discours de l'énergie : l'appropriation d'un problème public »

    Directory of Open Access Journals (Sweden)

    Bouillet Jérémy

    2014-07-01

    Full Text Available L'opinion publique sondée dans les grandes enquêtes témoigne de l'écart entre « pétitions de principe » et réalité au quotidien sur les questions d'énergie et d'environnement. Ce travail propose une explication de la manière dont les « citoyens ordinaires » intègrent des parties de discours sur les questions énergétiques, les ré-agencent et les prennent en compte ou non dans leur vie quotidienne, dans un jeu croisé de contraintes et de contradictions. Il exploite deux jeux de données liés à des forums en ligne organisés, l'un pendant la campagne présidentielle de 2012, moment politique par excellence, et l'autre au cours d'un moment de moindre politisation dans une région énergétiquement vulnérable : PACA. Un des intérêts de ces forums est de proposer aux enquêtés des scènes d'expression dont la publicité varie, faisant ainsi apparaître des écarts entre les principes défendus en « public » montrant ce que la norme doit être, et les pratiques routinières décrites en « privé »: de même ils permettent de faire apparaître des degrés de conflictualité liés aux divers aspects des enjeux énergétiques.

  20. Conserved and unique features of the homeologous maize Aux/IAA proteins ROOTLESS WITH UNDETECTABLE MERISTEM 1 and RUM1-like 1.

    Science.gov (United States)

    Zhang, Yanxiang; Marcon, Caroline; Tai, Huanhuan; von Behrens, Inga; Ludwig, Yvonne; Hey, Stefan; Berendzen, Kenneth W; Hochholdinger, Frank

    2016-02-01

    The maize (Zea mays L.) Aux/IAA protein RUM1 (ROOTLESS WITH UNDETECTABLE MERISTEM 1) is a key regulator of lateral and seminal root formation. An ancient maize genome duplication resulted in the emergence of its homeolog rum1-like1 (rul1), which displays 92% amino acid sequence identity with RUM1. Both, RUL1 and RUM1 exhibit the canonical four domain structure of Aux/IAA proteins. Moreover, both are localized to the nucleus, are instable and have similar short half-lives of ~23min. Moreover, RUL1 and RUM1 can be stabilized by specific mutations in the five amino acid degron sequence of domain II. In addition, proteins encoded by both genes interact in vivo with auxin response factors (ARFs) such as ZmARF25 and ZmARF34 in protoplasts. Although it was demonstrated that RUL1 and RUM1 can homo and heterodimerize in vivo, rul1 expression is independent of rum1. Moreover, on average rul1 expression is ~84-fold higher than rum1 in the 12 tested tissues and developmental stages, although the relative expression levels in different root tissues are very similar. While RUM1 and RUL1 display conserved biochemical properties, yeast-two-hybrid in combination with BiFC experiments identified a RUM1-associated protein 1 (RAP1) that specifically interacts with RUM1 but not with RUL1. This suggests that RUM1 and RUL1 are at least in part interwoven into different molecular networks. PMID:26672614

  1. Isolation, growth, and metabolism of an obligately anaerobic, selenate- respiring bacterium, strain SES-3

    Science.gov (United States)

    Oremland, R.S.; Blum, J.S.; Culbertson, C.W.; Visscher, P.T.; Miller, L.G.; Dowdle, P.; Strohmaier, F.E.

    1994-01-01

    A gram-negative, strictly anaerobic, motile vibrio was isolated from a selenate-respiring enrichment culture. The isolate, designated strain SES-3, grew by coupling the oxidation of lactate to acetate plus CO2 with the concomitant reduction of selenate to selenite or of nitrate to ammonium. No growth was observed on sulfate or selenite, but cell suspensions readily reduced selenite to elemental selenium (Se0). Hence, SES-3 can carry out a complete reduction of selenate to Se0. Washed cell suspensions of selenate- grown cells did not reduce nitrate, and nitrate-grown cells did not reduce selenate, indicating that these reductions are achieved by separate inducible enzyme systems. However, both nitrate-grown and selenate-grown cells have a constitutive ability to reduce selenite or nitrite. The oxidation of [14C]lactate to 14CO2 coupled to the reduction of selenate or nitrate by cell suspensions was inhibited by CCCP (carbonyl cyanide m- chlorophenylhydrazone), cyanide, and azide. High concentrations of selenite (5 mM) were readily reduced to Se0 by selenate-grown cells, but selenite appeared to block the synthesis of pyruvate dehydrogenase. Tracer experiments with [75Se]selenite indicated that cell suspensions could achieve a rapid and quantitative reduction of selenite to Se0. This reduction was totally inhibited by sulfite, partially inhibited by selenate or nitrite, but unaffected by sulfate or nitrate. Cell suspensions could reduce thiosulfate, but not sulfite, to sulfide. These results suggest that reduction of selenite to Se0 may proceed, in part, by some of the components of a dissimilatory system for sulfur oxyanions.

  2. Didier Combeau, Des Américains et des armes à feux. Violence et démocratie aux Etats-Unis. Saul Cornell, A Well-Regulated Militia : The Founding Fathers and the Origins of Gun Control in America.

    Directory of Open Access Journals (Sweden)

    Renaud Pacoud

    2008-07-01

    Full Text Available Deux ouvrages différents dans leur approche mais également passionnants permettent de saisir l’évolution du débat sur les armes à feu aux États-Unis. Des Américains et des armes à feux. Violence et démocratie aux Etats Unis de Didier Combeau rend compte de la relation complexe que les Américains entretiennent avec les armes à feu depuis la fondation de la nation et de la polémique contemporaine sur la question du droit aux armes. A Well-Regulated Militia : The Founding Fathers and the Origins...

  3. Didier Combeau, Des Américains et des armes à feux. Violence et démocratie aux Etats-Unis. Saul Cornell, A Well-Regulated Militia : The Founding Fathers and the Origins of Gun Control in America.

    OpenAIRE

    Renaud Pacoud

    2008-01-01

    Deux ouvrages différents dans leur approche mais également passionnants permettent de saisir l’évolution du débat sur les armes à feu aux États-Unis. Des Américains et des armes à feux. Violence et démocratie aux Etats Unis de Didier Combeau rend compte de la relation complexe que les Américains entretiennent avec les armes à feu depuis la fondation de la nation et de la polémique contemporaine sur la question du droit aux armes. A Well-Regulated Militia : The Founding Fathers and the Origins...

  4. Aspects épidémiologiques des accidents vasculaires cérébraux (AVC) aux urgences de l'institut de cardiologie d'Abidjan (ICA)

    Science.gov (United States)

    N'goran, Yves N'da Kouakou; Traore, Fatou; Tano, Micesse; Kramoh, Kouadio Euloge; Kakou, Jean-Baptiste Anzouan; Konin, Christophe; Kakou, Maurice Guikahue

    2015-01-01

    Introduction L'objectif de notre étude était de décrire les caractéristiques sociodémographiques et les Facteurs de Risque cardio-Vasculaires (FRV) des patients admis pour accidents vasculaires cérébraux (AVC) dans un service autre que celui de la neurologie. Méthodes Étude transversale rétrospective sur une période de 2 ans (janv. 2010 et déc. 2011), réalisée aux urgences de l'institut de cardiologie d'Abidjan. Résultats Il s'agissait de 176 adultes avec un âge moyen de 60 ans, une prédominance féminine. Les facteurs de risque majeurs retrouvés étaient l'hypertension artérielle dans 86,4% des cas, le diabète dans 11,4% des cas, le tabagisme dans 2,2% des cas. Les motifs de consultation étaient la perte de connaissance dans 36,4% des cas, l'hémiplégie dans 31,8% des cas, les céphalées dans 17,4% des cas, les vertiges dans 10,9% et les palpitations dans 2,2% des cas. La tension artérielle systolique moyenne était à 174 mmHg, la tension artérielle diastolique moyenne était à 105 mmHg et la pression pulsée moyenne était à 70 mmHg. Les AVC étaient associés à une arythmie complète par fibrillation auriculaire dans 11,4% des cas. Les AVC ischémiques représentaient 84,1%. L’évolution aux urgences a été marquée par un décès dans 17% (30) des cas. Conclusion Les AVC constituent un problème majeur de santé publique. Malgré sa prédominance féminine, ils (AVC) touchaient 44% des hommes dans notre étude lorsqu'on sait qu'en Afrique l'activité sociale repose sur les hommes. Ils restent une pathologie grave par la forte létalité. PMID:26327997

  5. Étude thermodynamique d'un procédé de captage du CO2 par formation d'hydrates appliqué aux fumées de postcombustion

    OpenAIRE

    Ben Attouche Sfaxi, Imen

    2011-01-01

    La sélectivité des hydrates vis-à-vis du CO2, fait à l'heure actuelle l'objet de travaux visant à mettre au point un procédé de captage du CO2 des fumées de combustion. Cette valorisation des hydrates fait partie des procédés de captage dits de "3ème génération", qui dans un contexte de transition énergétique, viennent apporter des solutions aux inconvénients associés aux procédés de 1ère génération (amines). L'objectif de ce travail de thèse est de proposer une étude des équilibres thermodyn...

  6. Quelle offre en soins infirmiers pour les patients se présentant aux urgences avec une douleur thoracique, pour un impact sur l'intensité de la douleur ?

    OpenAIRE

    Lambert, Jimmy; Stoll, Audrey; Viera, Salomé

    2014-01-01

    Introduction : L’évaluation et l’offre en soins de la douleur, et plus particulièrement la douleur thoracique aux urgences se révèle être un défi, par la complexité de son étiologie, et donc la difficulté de la mise en place d’un traitement. Objectif : Le but de cette recherche de revue littéraire est de mettre en évidence les différents outils et attitudes permettant une offre en soins optimale pour les patients se présentant aux urgences avec une douleur thoracique. Méthode : La stratégie d...

  7. Le culte lua’ aux esprits des princes (Thaïlande). La construction d’une légitimité The Lua’ Cult of the Princes’ Spirits : A Construction of Legitimity

    OpenAIRE

    Emma Guégan

    2012-01-01

    Parmi les Lua’, groupe de langue austro-asiatique de la province de Nan en Thaïlande, une communauté se targue d’être garante de la prospérité de l’ensemble des habitants, très majoritairement taï, du territoire de l’ancienne principauté de Pua. Ils affirment être les seuls capables d’effectuer le culte aux « esprits des princes », pourtant autrefois exclusivement réalisé par des princes taï. En examinant les discours et pratiques liés à ces anciens princes et aux rites qui leur sont adressés...

  8. Lutte contre la piraterie : faut-il faire appel aux sociétés de sécurité privées ?

    Directory of Open Access Journals (Sweden)

    2009-10-01

    Full Text Available Le point de vue d’un armateur françaisEric Frécon : Quel est l’environnement juridique dans lequel opèrent les armateurs soucieux de protéger leur navire avec des hommes en armes ?Sur un navire, dans les eaux nationales d’un pays, la protection armée s’effectue dans le cadre du droit maritime dudit pays. Ces eaux nationales s’entendent sans contestation aux douze nautiques mais dans certains cas, comme aux Etats-Unis, elles sont prolongées jusqu’à la limite de la ZEE soit 200 milles. Ainsi, d...

  9. Les effets de la livraison à domicile sur l’accès aux produits alimentaires : le cas des grandes surfaces alimentaires et des cybermarchés de l’aire urbaine dijonnaise

    OpenAIRE

    MOTTE BAUMVOL, Benjamin; BELTON CHEVALLIER, Leslie; SCHOELZEL, Miriam; CARROUET, Guillaume

    2012-01-01

    L’accessibilité des populations aux Grandes Surfaces Alimentaires (GSA) est différenciée selon les espaces. Si une très grande majorité de périurbains n’éprouvent pas de difficultés pour y accéder, certains y font face plus difficilement. Pour ces ménages en particulier, la livraison à domicile, constitue un moyen d’améliorer leur accès en supprimant les difficultés liées aux déplacements. A partir d’une recension de l’offre et d’une enquête par entretiens ...

  10. Équité socio-spatiale d’accès aux soins périnatals en milieu urbain : utilisation des techniques géographiques pour la planification sanitaire

    OpenAIRE

    Charreire, Hélène; Combier, Évelyne

    2009-01-01

    La ville, parce qu’elle concentre le potentiel humain et les services sur de faibles distances physiques, est souvent perçue comme le lieu où tout est accessible. Mais dans le domaine de la santé, proximité n’implique pas systématiquement accessibilité. D’autres formes de déterminants – sociaux, culturels– freinent le recours aux soins de la population. En santé périnatale, les difficultés d’accès aux soins peuvent se traduire par des retards de prise en charge de la grossesse (après le premi...

  11. Etude bioécologique du complexe des insectes liés aux cultures céréalières dans la region de Batna. (Algérie)

    OpenAIRE

    FRITAS, Saïd

    2012-01-01

    Dans le cadre de l'étude biocénotique des insectes liés aux liées aux cultures céréalières dans la région de Batna. Algérie, une connaissance aussi complète que possible de l'entomofaune fréquentant de blé dur s'avère indispensable. Les différentes méthodes de capture des insectes utilisées nous ont permis de récolter un nombre important des espèces, et un grand nombre reste encore inconnu. Ces espèces sont réparties entre 11 ordres systématiques dont les plus importants sont l...

  12. Stratégie d’implantation de Disneyland dans le monde. Innovation d’adaptation aux cultures nationales et régionale DISNEYLAND’S WORLDWIDE IMPLEMENTATION STRATEGY. INNOVATION OF ADAPTATION TO REGIONAL AND NATIONAL CONTEXT

    OpenAIRE

    Christopher HERBEZ

    2013-01-01

    Disney s’impose comme chef de file de l’oligopole du domaine des loisirs et du divertissement, grâce notamment à sa section Parcs et Loisirs. Ce statut n’est pas dû à son seul succès américain mais à une stratégie d’implantation mondiale. Ainsi, Disney impose son pouvoir aux quatre coins du globe en proposant un ensemble de parcs à l’image de la marque. Cette mondialisation est le résultat de multiples innovations d’adaptation aux cultures locales et régionales. Mais, qu’est-ce qu’une innovat...

  13. Analyse d’un genre de discours spécialisé : les lettres annuelles de Warren Buffett aux actionnaires de Berkshire Hathaway et leur spécificité

    OpenAIRE

    Resche, Catherine

    2011-01-01

    Cette étude a pour objet d’analyser un genre de discours spécialisé particulier au monde des entreprises. Les lettres aux actionnaires rédigées par Warren Buffett, dont la portée dépasse le cercle des actionnaires concernés, suscitent un intérêt hors du commun. Une analyse qualitative et quantitative portant sur le fond et la forme nous a permis de les comparer à un corpus témoin d’autres lettres aux actionnaires pour faire ressortir leur spécificité. La perspective diachronique qui a été ado...

  14. Jérôme Dubois J., 2009, Les politiques publiques territoriales. La gouvernance multi-niveaux face aux défis de l’aménagement. Presses Universitaires de Rennes, 216 p.

    OpenAIRE

    Gaudin, Jean-Pierre

    2009-01-01

    Voilà un ouvrage portant sur un sujet compliqué, qui rend très bien compte analytiquement de cette complication et qui aboutit à des conclusions qui ne sont dès lors pas simples … Jérôme Dubois s’intéresse ici aux défis les plus actuels que posent les politiques publiques dans leur « déclinaison » territoriale : arbitrages souvent opaques, territoires pas toujours pertinents, logiques de « chasseurs de primes » chez les élus locaux face aux guichets nationaux et européens, etc …Dans ces condi...

  15. Des langages de modélisation dédiés aux environnements de méta-modélisation dédiés

    OpenAIRE

    Temate Ngaffo, Suzy Hélène Germaine

    2012-01-01

    Les langages dédiés (DSL) sont de plus en plus utilisés parce qu’ils permettent aux utilisateurs qui ne sont pas des experts en programmation d’exprimer des solutions avec des langages simples qui capturent l’expertise de leur domaine. C’est encore plus vrai pour les langages dédiés graphiques (DSML) qui ont un niveau d’abstraction plus élevé que les langages dédiés de programmation. Implémenter un DSML revient généralement à fournir un éditeur dédié qui permette aux utilisateurs de manipuler...

  16. Handling Uncertainty in Accessing Petroleum Exploration Data Traitement de l'incertain dans l'accès aux données d'exploration pétrolière

    Directory of Open Access Journals (Sweden)

    Chung P. W. H.

    2006-11-01

    Full Text Available This paper discusses the role of uncertainty in accessing petroleum exploration databases. Two distinct forms of uncertainty are identified : the uncertainty in the user's requirements, and the uncertainty in the data held. A general mechanism is described which is applicable to both. Cet article traite du rôle de l'incertitude dans l'accès aux bases de données d'exploration pétrolière. Deux sortes distinctes d'incertitudes sont identifiées : l'incertitude au niveau des requêtes de l'utilisateur et l'incertitude attachée aux données stockées. Nous décrivons un mécanisme général qui s'applique à ces deux types d'incertitude.

  17. Intérêt de l'utilisation du questionnaire des problèmes associés aux jeux vidéo de Tejeiro (Problem Video game Playing: PVP) Étude exploratoire chez des enfants présentant un TDA/H

    OpenAIRE

    Bioulac, S.; Arfi, L.; Michel, G; Bouvard, M.-P.

    2010-01-01

    Resume Depuis ces dernieres annees, l?utilisation des jeux video apparait comme l?un des loisirs preferes des enfants et des adolescents. Cependant, les etudes portant sur l?addiction aux jeux video sont encore peu nombreuses. Afin d?evaluer les difficultes induites par une excessive des jeux video, l?equipe du Dr Tejeiro a developpe un autoquestionnaire : le questionnaire des problemes associes aux jeux video (Problem Video Game Playing Scale, Tejeiro, 2002). Nous...

  18. Uranium and selenium resistance in Cupriavidus metallidurans CH34

    Energy Technology Data Exchange (ETDEWEB)

    Avoscan, L.; Untereiner, G.; Carriere, M.; Gouget, B. [CEA Saclay, CNRS, UMR9956, Lab Pierre Sue, F-91191 Gif Sur Yvette, (France); Degrouard, J. [Univ Paris 11, Ctr Commun Microscopie Elect, CNRS, UMR8080, Orsay, (France)

    2007-07-01

    Cupriavidus metallidurans CH34, a soil bacterium, is known to resist a variety of heavy metals and metalloids. Its capacity to resist, accumulate and transform selenium (Se as selenite or selenate) and uranium (U as uranyl-carbonate and uranyl-citrate) was investigated. C. metallidurans CH34 resists to high U concentrations (up to 10 mM) whatever its speciation. However, no major accumulation could be measured: U-carbonate and U-citrate are not bio-available for the bacteria. The anaerobic response of C. metallidurans CH34 to U will be looked for. C. metallidurans CH34 resists to high Se concentrations (up to 4 mM of selenite and 8 mM of selenate). Bacteria exposed to 2 mM of selenite accumulate 25 times more Se than when they are exposed to same concentration of selenate. Se resistance is characterized by the reduction of oxy-anions in the bacteria. Selenite is reduced to elemental Se by an intracellular process, but the metabolic fate of selenate is unknown. By combining three methods of speciation (X-ray absorption spectroscopy (XANES and EXAFS), HPLC-ICP-MS and SDS-PAGE coupled with particle induced X-ray emission (PIXE)), we both identified and specified the chemical intermediates formed by this bacterium upon exposure to these oxy-anions. Two mechanisms of reduction of Se oxides in C. metallidurans CH34 were highlighted. Assimilation transforms selenite and selenate into organic Se, identified as seleno-methionine and leads to its non-specific incorporation into bacterial proteins (presence of selenious proteins). Detoxication precipitates selenite in nano-particles of elemental Se. (authors)

  19. Uranium and selenium resistance in Cupriavidus metallidurans CH34

    International Nuclear Information System (INIS)

    Cupriavidus metallidurans CH34, a soil bacterium, is known to resist a variety of heavy metals and metalloids. Its capacity to resist, accumulate and transform selenium (Se as selenite or selenate) and uranium (U as uranyl-carbonate and uranyl-citrate) was investigated. C. metallidurans CH34 resists to high U concentrations (up to 10 mM) whatever its speciation. However, no major accumulation could be measured: U-carbonate and U-citrate are not bio-available for the bacteria. The anaerobic response of C. metallidurans CH34 to U will be looked for. C. metallidurans CH34 resists to high Se concentrations (up to 4 mM of selenite and 8 mM of selenate). Bacteria exposed to 2 mM of selenite accumulate 25 times more Se than when they are exposed to same concentration of selenate. Se resistance is characterized by the reduction of oxy-anions in the bacteria. Selenite is reduced to elemental Se by an intracellular process, but the metabolic fate of selenate is unknown. By combining three methods of speciation (X-ray absorption spectroscopy (XANES and EXAFS), HPLC-ICP-MS and SDS-PAGE coupled with particle induced X-ray emission (PIXE)), we both identified and specified the chemical intermediates formed by this bacterium upon exposure to these oxy-anions. Two mechanisms of reduction of Se oxides in C. metallidurans CH34 were highlighted. Assimilation transforms selenite and selenate into organic Se, identified as seleno-methionine and leads to its non-specific incorporation into bacterial proteins (presence of selenious proteins). Detoxication precipitates selenite in nano-particles of elemental Se. (authors)

  20. Comptabilité environnementale et mondialisation. Quels défis ? Quels modèles pour y répondre ? Application d'un modèle Economie-Environnement-Impacts à l'évaluation des impacts environnementaux en Chine induits par l'Europe, et aux taxes carbone aux frontières de l'UE

    OpenAIRE

    Friot, Damien

    2009-01-01

    Cette thèse traite de l'intégration des contraintes liées à la mondialisation dans les méthodes de comptabilité environnementales. Nous proposons tout d'abord une analyse de la capacité des principales méthodes actuelles à répondre aux attentes sociétales et à relever les défis liés à la mondialisation. Nous développons à cette fin le premier cadre analytique spécifique à ces méthodes. Nous développons ensuite un modèle intégrant certaines des contraintes liées à la mondialisation. Ce modèle ...

  1. The treatment of irradiated uranium fuel. Results obtained while operating the pilot plant at Fontenay-aux-Roses; Le traitement de l'uranium irradie. Resultats d'exploitation de l'usine-pilote de Fontenay-aux-Roses

    Energy Technology Data Exchange (ETDEWEB)

    Regnaut, P.; Faugeras, P.; Brut, A.; Helou, R.; Redon, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    In this paper the results obtained from four years operation of the pilot plant when using bars of increasing activity, are summarised and compared with the results of parallel studies carried out in the laboratory. As a conclusion to the article, the optimum conditions for the different phases of a process based on solvent extraction are given. (author)Fren. [French] Cette conference resume les resultats obtenus durant quatre annees de fonctionnement de l'Usine-Pilote, avec des barreaux d'activite croissante et les compare aux resultats d'etudes conduites parallelement en laboratoire. En conclusion sont donnees les conditions optima pour les differentes phases d'un procede base sur l'extraction par solvant. (auteur)

  2. Phénomènes de mouillage aux petites échelles sur des substrats non structurés et structurés : films minces de cristaux liquides et propriétés de mouillage des liquides ioniques aux petites échelles

    OpenAIRE

    Richard, Céline J. E.

    2011-01-01

    A une époque où la miniaturisation est l'un des principaux défis de la science, la physique du mouillage aux petites échelles est loin d'être complètement comprise. Le rôle structurant des interfaces, les hétérogénéités du substrat ou l'occurrence d'effets dits de "ligne" commencent à se faire sentir. Le but de la présente thèse, expérimentale, est d'apporter de nouveaux indices permettant le développement des analyses théoriques. Deux systèmes à petite échelle et complexes ont été étudiés : ...

  3. Des lois de l'induction aux théorèmes de Thévenin et de Norton

    Directory of Open Access Journals (Sweden)

    Robbes Didier

    2011-10-01

    Full Text Available Les lois de Lenz et de l'auto-induction sont étudiées pour une boucle conductrice circulaire monotour, dans une gamme de fréquence de 1 Hz à 1 MHz. La fem en circuit ouvert et le courant de court circuit permettent au final d'obtenir les schémas équivalents de Thévenin et de Norton de la spire sous influence magnétique. La mesure de la tension en circuit ouvert met en oeuvre un amplificateur (de tension large bande à bas bruit. La mesure du courant de court circuit est réalisée d'une part avec un amplificateur à transimpédance lui aussi large bande et à bas bruit et d'autre part en mesurant l'induction magnétique locale au voisinage de la spire fermée sur elle même. Cette dernière est comparée aux calculs analytiques et numériques. La comparaison des deux mesures du courant de court circuit permet de remonter à l'impédance d'entrée de l'amplificateur à transimpédance. Cette méthode peut être utilement étendue pour des circuits couplés (transformateur élémentaire, transformateur de flux et pour l'étude de l'effet de peau.

  4. La science au(x miroir (s du prince. Savoir et pouvoir dans l'espace arabo-musulman d'hier et d'aujourd'hui

    Directory of Open Access Journals (Sweden)

    Abdel Wedoud Ould Cheikh

    2009-05-01

    Full Text Available Le sultan et le savant sont deux figures centrales de la « culture sultanienne » entendue comme un champ de normes et de valeurs présentant une certaine unité dans le monde arabo-musulman. Il y a entre ces deux figures une tension fondamentale, le clerc-savant étant seul autorisé à sermonner le détenteur du pouvoir au nom du savoir et de la justice. Dans la réalité actuelle des pays arabo-musulmans — illustrée ici par le cas de la Mauritanie —, la massification d'un enseignement fortement imprégné de tradition en même temps que socialement dévalué contribue sans doute à l'émergence d'une mouvance contestataire islamiste qui s'inscrit, sur un mode collectif, dans la continuité des admonestations du clerc censeur s'opposant aux dérives du sultan.

  5. Desenvolvimento de equipamento de auxílio à visão subnormal Development of a low vision aid device

    Directory of Open Access Journals (Sweden)

    Fernanda Alves da Silva Bonatti

    2006-04-01

    Full Text Available OBJETIVO: Design de equipamento de uso para perto para portador de visão subnormal. MÉTODOS: Verificar os principais produtos de auxílio à visão subnormal, identificando problemas que o usuário possa ter ao usá-los e por meio de possíveis intervenções do design fazer um projeto que possa contemplar suas necessidades. RESULTADOS: Foi desenvolvido um protótipo compreendido por prancha de leitura em que pode ser conectado o cabo de uma lupa, que se movimenta horizontal e verticalmente possibilitando o acompanhamento de uma linha do texto. CONCLUSÃO: O equipamento desenvolvido vem de encontro às necessidades visuais e de manuseio de portadores de visão subnormal para perto, incorporando facilidades para a leitura e escrita.PURPOSE: To develop the design of a near low vision aid that has esthetic and functional qualities intending to give its user a better life quality. METHODS: To verify low vision people's main needs concerning the current devices for near distance; to identify possible design interventions to make a project that fulfills their main needs. RESULTS: A prototype having a reading stand tied to the end of a magnifier that moves horizontally and vertically permitting the horizontal reading of a text line was developed. CONCLUSIONS: The developed device fulfills low vison people's visual and handling needs for near distance, contributing to the easiness to read and write.

  6. Contrôle d'accès aux expériences et au tunnel de l'accélérateur LHC

    CERN Document Server

    Cennini, E

    1998-01-01

    Le "LHC-Access and Interlock Working Group" réunit des représentants des divisions ST, SL, LHC et TIS. Il est chargé de définir une nouvelle philosophie pour les systèmes de Contrôle d'Accès et de Verrouillage des Faisceaux du LHC ainsi qu'obtenir l'approbation des comités LHC-TC, LHC-TCC et LEMIC. Cette philosophie constituera la base de la spécification technique de ces systèmes. Les sujets principaux traités sont la classification des zones d'accès en fonctions des risques, l'identification des emplacements des EIS-accès en fonction des contraintes de trafic, de sécurité et d'encombrement, ainsi que la définition du concept de patrouille de fermeture des zones radiations. La spécificité du LHC, quant aux risques qu'il présente, implique un changement considérable du point de vue du Contrôle d'Accès. Il est impératif de préparer les utilisateurs à un changement de comportement afin d'accroître la sécurité ainsi que de respecter les procédures et les règles d'accès.

  7. Les géographes - climatologues français et le changement climatique aux échelles régionales

    Directory of Open Access Journals (Sweden)

    Gérard Beltrando

    2010-04-01

    Full Text Available En France, sur le sujet du changement climatique et quel que soit son origine, les géographes - climatologues se sont majoritairement intéressés à la description et l’explication de la variabilité du climat à diverses échelles de temps et d’espace sur des périodes écoulées. Ils se sont moins investis sur les formes d’adaptations tenant compte des résultats des simulations du climat futur, tel qu’il est envisagé à partir des calculs obtenus par les modèles numériques du climat. Cette frilosité s’explique en partie par le manque de précision et de fiabilité accordé aux résultats produits par ces modèles, aux échelles des territoires occupés par les sociétés humaines, mais aussi parce que les travaux de géographes montrent depuis longtemps que les sociétés humaines - indépendamment du changement climatique sous l’effet des gaz à effet de serre additionnels - ont une part directe dans bien des catastrophes qui les affectent (construction dans des zones inondables, production agricole dans des régions où la pluviométrie peut être insuffisante certaines années…. Les géographes-climatologues, commencent à utiliser des nouvelles sorties de modèle à des échelles plus opérationnelles pour proposer des formes d’adaptations spécifiques à chaque territoire et à chaque secteur économique. Ces recherches prospectives sont réalisées en tenant compte à la fois de la part d’incertitude des résultats produits par des modèles numériques, mais aussi des particularités des groupes sociaux et des milieux physiques dans lesquels s’inscrivent ces changements. Cela est un préalable nécessaire à toutes formes de réflexion approfondies sur l'identification des facteurs d’adaptation.In France, on the topic of climate change, the geographer climatologists are focused on the description and explanation of climate variability at various temporal and spatial scales on last period. They are less

  8. Finance et risque aux Etats-Unis : vers une nouvelle frontière ? Finance and Risk in the USA: A New Frontier?

    Directory of Open Access Journals (Sweden)

    Christine Zumello

    2010-03-01

    Full Text Available Cet article aborde la question de l’évaluation et de l’anticipation du risque sur les marchés financiers aux États-Unis. Les différents types de risque sont analysés ainsi que les principales méthodes utilisées pour les évaluer. La crise des subprimes qui a marqué la fin du second mandat de G.W. Bush a semblé déboucher sur une crise systémique. Parmi les différentes strates de risque, le plus grave est celui qui porte le système financier et économique au naufrage. Les conditions de la remise en cause du système suite à des prises de risque ou une absence de contrôle rigoureux du risque posent la question de l’équilibre entre la sphère politique et la sphère financière.This article raises the question of the evaluation and anticipation of risk on financial markets in the United States. The various types of risk are analysed as well as the main methods used to measure risk. The subprime crisis which dominated the end of the second G.W. Bush presidential term seemed to bring the whole financial and economic system to the brink of collapse. The central notion of the measure and control of risk hinges on the role of the political sphere versus the financial sphere.

  9. L’enseignement supérieur aux Émirats Arabes Unis, entre émiratisation et contraintes du marché

    Directory of Open Access Journals (Sweden)

    William Gueraiche

    2012-07-01

    Full Text Available Depuis la création de la première université publique en 1977, le gouvernement fédéral émirien a fait de l’enseignement supérieur le principal outil de l’émiratisation (inclusion de cadres émiriens dans la fonction publique et le secteur privé. La multiplication des établissements d’enseignement supérieur privés depuis le milieu des années 1990 n’a pas changé cet objectif mais le ministère de l’enseignement supérieur est devenu progressivement une instance de régulation de l’offre universitaire par l’octroi d’accréditations. Quatre émirats (Abu Dhabi, Doubaï, Sharjah et Ras al Khaïmah se sont livrés une lutte féroce pour devenir le « hub » de l’enseignement supérieur aux E.A.U. et dans le Golfe. Ils ont essayé d’attirer des noms d’universités prestigieuses pour créer une dynamique. Cette compétition a tourné à l’avantage d’Abu Dhabi qui pourrait bien devenir le centre universitaire des Émirats voire de la région. Elle a aussi eu pour conséquence une redistribution des pouvoirs entre la fédération et les émirats locaux.

  10. Économiste et développement durable : de la professionnalité aux métiers

    Directory of Open Access Journals (Sweden)

    Catherine Figuière

    2010-12-01

    Full Text Available Les emplois intégrant certaines dimensions du développement durable (DD se développent, même si leur affichage n’est pas toujours limpide. Ce texte se propose de distinguer tout d’abord les nouveaux gisements d’emplois des nouvelles préoccupations intégrées à des pratiques existantes ; les postes proposés aux économistes se situant clairement dans cette seconde catégorie. Il vise ensuite, sur la base d’une expérimentation de formation universitaire menée à Grenoble, à mettre en évidence la nécessité d’une formation articulant  « une éducation à propos du développement durable » et la maîtrise d’outils transversaux de l’économie-gestion, tels que la conduite du changement. Cette maîtrise est en effet imposée par la grande variété de l’offre de situations professionnelles.Jobs requiring skills which integrate some dimensions of sustainable development are increasingly numerous, even if their description is not always clear. This paper proposes primarily to identify newly-created jobs from traditional jobs integrating new issues in their description. The jobs offered to economists clearly belong to the second category. Then, based on an experiment carried out at Grenoble University, this paper aims at stressing the need for training including on the one hand, courses “about sustainable development” and on the other, proficiency in using some transversal tools of economics and management, such as organisational change management. This proficiency is indeed imposed by the large variety of the professional positions on offer in this field.

  11. Light-dependent gravitropism and negative phototropism of inflorescence stems in a dominant Aux/IAA mutant of Arabidopsis thaliana, axr2.

    Science.gov (United States)

    Sato, Atsuko; Sasaki, Shu; Matsuzaki, Jun; Yamamoto, Kotaro T

    2014-09-01

    Gravitropism and phototropism of the primary inflorescence stems were examined in a dominant Aux/IAA mutant of Arabidopsis, axr2/iaa7, which did not display either tropism in hypocotyls. axr2-1 stems completely lacked gravitropism in the dark but slowly regained it in light condition. Though wild-type stems showed positive phototropism, axr2 stems displayed negative phototropism with essentially the same light fluence-response curve as the wild type (WT). Application of 1-naphthaleneacetic acid-containing lanolin to the stem tips enhanced the positive phototropism of WT, and reduced the negative phototropism of axr2. Decapitation of stems caused a small negative phototropism in WT, but did not affect the negative phototropism of axr2. p-glycoprotein 1 (pgp1) pgp19 double mutants showed no phototropism, while decapitated double mutants exhibited negative phototropism. Expression of auxin-responsive IAA14/SLR, IAA19/MSG2 and SAUR50 genes was reduced in axr2 and pgp1 pgp19 stems relative to that of WT. These suggest that the phototropic response of stem is proportional to the auxin supply from the shoot apex, and that negative phototropism may be a basal response to unilateral blue-light irradiation when the levels of auxin or auxin signaling are reduced to the minimal level in the primary stems. In contrast, all of these treatments reduced or did not affect gravitropism in wild-type or axr2 stems. Tropic responses of the transgenic lines that expressed axr2-1 protein by the endodermis-specific promoter suggest that AXR2-dependent auxin response in the endodermis plays a more crucial role in gravitropism than in phototropism in stems but no significant roles in either tropism in hypocotyls. PMID:24938853

  12. Influence du compartiment trophique dans les réponses des populations de poissons aux variations artificielles de débit

    Directory of Open Access Journals (Sweden)

    ORTH D. J.

    1995-04-01

    Full Text Available Les réponses des populations de poissons aux altérations de débit sont assez peu souvent correctement prédites à partir des simulations physiques d'habitat. Actuellement, les évaluations de débit réservé sont basées sur des analyses de l'habitat physique, qui sont supposées avoir une influence sur ces populations. Cela conduit au dilemme en matière de détermination de ces débits : combien d'espèces et de stades faut-il analyser et comment pondérer leur importance respective ? Dans certains cours d'eau, les simulations d'habitat physique issues de PHABSIM (Physical Habitat Simulation pour les poissons les plus courants montrent une surface pondérée utile insensible ou maximum à faible débit. Or, les débits moyens à forts débits sont indubitablement importants pour différentes raisons, telles que le recrutement des espèces inféodées à la plaine alluviale, le nettoyage du fond du lit, les entrées de matière organique et la production des invertébrés benthiques. La densité, la diversité et la production des insectes aquatiques dans différents types de cours d'eau montrent des variations spatiales et interannuelles considérables, souvent directement reliables aux débits. De même, la croissance et le succès de prise de nourriture des poissons varient en fonction de l'abondance des proies. Un modèle de chaîne trophique a été développé pour étudier l'influence de la nourriture de base (insectes aquatiques, proies constituées par les poissons de petite taille et écrevisses sur la production des poissons prédateurs clé (Black bass à petite bouche, Micropterus dolomieu, Rock bass, Ambloplites rupestris, et Poisson chat à tête plate, Pylodictis olivaris dans un grand cours d'eau à régime thermique chaud. L'analyse du modèle indique que la production des poissons est très dépendante de la disponibilité des proies, en particulier les insectes aquatiques et les écrevisses. A partir des analyses du mod

  13. Dépendance économique aux produits forestiers non ligneux : cas des ménages riverains des forêts de Boulon et de Koflandé au Sud-Ouest du Burkina Faso

    Directory of Open Access Journals (Sweden)

    Mathieu Ouédraogo

    2013-06-01

    Full Text Available Dépendance économique aux produits forestiers non ligneux : cas des ménages riverains des forêts de Boulon et de Koflandé au Sud-Ouest du Burkina Faso Résumé Cette étude a pour objectif d’évaluer la dépendance économique des ménages riverains des forêts de Boulon et de Koflandé aux produits forestiers non ligneux (PFNL et d’identifier les déterminants de cette dépendance. Des enquêtes ont été menées auprès de 583 ménages de 14 villages riverains de ces forêts. Les résultats montrent que le revenu moyen annuel par ménage est de 846 800 F CFA avec une contribution de 60% du revenu des cultures et 12% du revenu d’élevage. Les PFNL procurent en moyenne 72 479 F CFA par ménage et par an à près de 93% des ménages enquêtés. La dépendance économique des ménages aux PFNL est estimée à 12%. Elle diminue avec le revenu, traduisant une plus grande dépendance des ménages pauvres des PFNL. Par ailleurs, les hommes sont économiquement moins dépendants des PFNL que les femmes. Les principaux déterminants de la dépendance aux PFNL sont le statut d’autochtone, la taille du ménage, la superficie forestière et la densité de population du département qui affectent positivement la dépendance aux PFNL. Dans le cadre d’une politique de réduction de la pauvreté en milieu rural, il faut prendre des mesures qui favorisent l’accès durable des ménages les plus pauvres aux ressources forestières. Mots clés : Produits forestiers non ligneux, dépendance économique, modélisation économétrique, Burkina Faso.   Economic dependence on non-timber forest products: case of households living near the Forests of Boulon and Koflande, in the south-western of Burkina Faso Abstract This study aims at assessing the household economic dependence on non-timber forest products (NTFPs in Boulon and Koflande Forest area and the main determinants of that dependence. The data have been collected with a sample of 583

  14. Atlas de sensibilité du littoral aux pollutions marines. Création d’un site dédié Sextant. Atlas Polmar Réunion.

    OpenAIRE

    Vermenot, Coralie; Quimbert, Erwann; Satra Le Bris, Catherine; Ropert, Michel

    2013-01-01

    Dans le cadre de l’élaboration de l’Atlas de sensibilité du littoral aux pollutions marines, L’IFREMER a souhaité mettre à disposition des institutions un outil permettant d’accéder à l’ensemble des informations cartographiques ayant permis l’élaboration de cette annexe technique du dispositif spécifique POLMAR/TERRE. Le portail Sextant, infrastructure de données géoréférencées marines et littorales, permettant la mise en commun et le partage de l‘information géographique, permet de répon...

  15. Évaluation des risques écotoxicologiques liés aux rejets d'effluents hospitaliers dans les milieux aquatiques. Contribution à l'amélioration de la phase « caractérisation des effets ».

    OpenAIRE

    Boillot, Clotilde

    2008-01-01

    Ce mémoire de thèse s'inscrit dans la problématique de l'Evaluation Des Risques Ecotoxicologiques (EDREcotox) liés aux rejets d'effluents hospitaliers dans les milieux aquatiques. Le premier objectif vise à améliorer la connaissance des effets écotoxicologiques des effluents hospitaliers. Pour cela, nous avons étudié d'une part, les effets combinés des principaux polluants contenus dans ces effluents vis-à-vis de Daphnia magna et, d'autre part, les effluents provenant d'un hôpital d'une grand...

  16. Entre la veille stratégique et l'innovation, la démarche de veille créative : Ce que la veille créative emprunte aux wargames sur plateau

    OpenAIRE

    Goria, Stéphane

    2009-01-01

    De nombreuses formes de veilles ont déjà vu le jour. Chacune propose une facette qui lui est propre et permet soit de comprendre qui la réalise, sur quoi elle porte, ses objectifs ou comment elle est réalisée. Dans cet article, nous présentons une nouvelle forme de veille dite : veille créative. Elle se positionne, notamment, entre les veilles concurrentielle et prospective. Elle a pour objectif de donner de nouveaux moyens aux veilleurs pour identifier des menaces, des opportunités et des co...

  17. Modélisation et prévision des flux quotidiens des patients aux urgences hospitalières en utilisant l'analyse de séries chronologiques

    OpenAIRE

    Kadri, Farid; CHAABANE, Sondes; Harrou, Fouzi; Tahon, Christian

    2014-01-01

    La gestion efficace des flux de patients aux services d'urgence est devenue une question urgente pour la plupart des administrations hospitalières. Pour gérer cet afflux de patients, les services d'urgences nécessitent des ressources humaines et matérielles importantes, cependant, limitées. Dans ces conditions, le personnel médical se voit confronté très fréquemment à des situations de tension. Pour faire face à ces situations, les services d'urgences (SU) n'ont pas d'autre choix que de s'ada...

  18. Etude de quelques facteurs de pathogénicité liés aux infections fongiques hospitalières (production de biofiims et résistance)

    OpenAIRE

    SEDDIKI, Sidi Mohammed lahbib

    2014-01-01

    I 'J P - 0 ;; % 0 'L RESUME l andida albicans est une levure pathogène pour l'homme, elle est responsable de plus de 755'u de mycoses invasives ou systémiques. Actuellement, ces infections sont classées au quatrième rang, des infections nosocomiales. Ces dernières, sont liées essentiellement aux dispositiils médicaux tels que les cathéters et les sondes urinaire)qui favorisent la formation des biofilms. Dans ce contexte nous avons entrepris cette étude au niveau de ...

  19. Introduction aux journées d'études «Paroles à rire», suivie de considérations sur le recueil de paroles à rire chez les musiciens (Showbiz France)

    OpenAIRE

    Daphy, Eliane

    1996-01-01

    Introduction et communication aux Journées d'études « Paroles à rire », organisées par Eliane Daphy et Diana Rey-Hulman, Centre de recherche sur l'oralité, avec la collaboration du Laboratoire d'anthropologie urbaine, Salon de l'INALCO, Paris, 29 et 30 janvier 1996. Étudier le rire pose l'épineuse question de la désignation du phénomène. Quel champ recouvre-t-il : moquerie, rire, facétie, comique, farce, dérision, plaisanterie ? Quel terme pour les paroles qui ont en commun de faire rire ?...

  20. Les compétences infirmières mobilisées dans un service d'oncologie pédiatrique pour répondre aux besoins de l'enfant et sa famille: travail de Bachelor

    OpenAIRE

    Alemanno, Gaëtan; Lorency, Vincent; Morf, Benjamin; Delajoux, Annie

    2013-01-01

    Dans ce travail de bachelor, nous nous intéressons aux compétences infirmières en onco-hématologie pédiatrique. En faisant cette recherche, nous mettons en évidences le vécu des parents dont l’enfant est malade, ainsi que leurs différents besoins ressentis, que ce soit de l’enfant ou des proches aidants. Nous identifions ces compétences en comparant, les actions et pratiques infirmières, avec le modèle de Calgary.

  1. Constitution d’un Corpus de Français Langue Etrangère destiné aux Apprenants Allemands

    Directory of Open Access Journals (Sweden)

    Fauth Camille

    2014-07-01

    Nationale de la Recherche et Deutsche Forschungsgemeinschaft attribué à l’équipe Parole du LORIA UMR 7503, Nancy – France et à l’Equipe de Linguistique Computationnelle et de Phonétique FR 4.7 de l’Université de la Sarre Sarrebruck – Allemagne dans lequel le français et l’allemand sont des langues cibles. Pour la paire allemand-français, peu de corpus parallèles sont disponibles. Nous présentons ici l’élaboration d’un corpus de productions orales de locuteurs natifs et non natifs pour la paire allemand-français. Notre corpus entend mettre au jour les déviations phonétiques et phonologiques que les locuteurs allemands produisent lorsqu’ils apprennent le français. Ce travail s’insère dans un projet plus global, Ce projet entend étudier les difficultés que les locuteurs français rencontrent lorsqu’ils apprennent l’allemand, et réciproquement. Aussi, cinquante locuteurs allemands seront recrutés dans des milieux universitaires et scolaires (niveau lycée en Allemagne et cinquante locuteurs français dans les mêmes milieux en France. Il s’agit pour les deux populations de produire d’une part le corpus en langue étrangère (en langue française pour les locuteurs allemands et en langue allemande pour les locuteurs français mais également le corpus en langue maternelle (en allemand pour les allemands et en français pour les français. Les corpus ainsi obtenus devraient nous permettre d’identifier les difficultés que les locuteurs allemands ou français rencontrent lorsqu’ils apprennent le français ou l’allemand. Les données de contrôle sont doubles puisque l’on pourra à la fois se référer aux productions des apprenants dans leur langue maternelle (ici l’allemand, mais également à celles de locuteurs natifs (ici germanophones. Nous ne présenterons ici que la constitution du corpus en français.

  2. Le travail, marchandise fictive ? 100 ans de marchandisation de la main d’œuvre mexicaine aux États-Unis

    Directory of Open Access Journals (Sweden)

    Yves-Marie Abraham

    2008-12-01

    Full Text Available Pour Karl Polanyi, la société de marché est impossible, car elle suppose de traiter le travail, la terre et la monnaie comme des marchandises, ce qui ne peut qu’être destructeur de la société. A partir d’une analyse de l’utilisation de la main d’œuvre mexicaine par les employeurs américains depuis 100 ans, nous tentons de montrer que cette marchandisation est tout à fait possible en ce qui concerne le travail. Elle consiste, dans son principe, à réduire l’être humain à sa seule force de travail, tout en restant dans le cadre formel du salariat. Dans le cas des travailleurs mexicains, qu’il s’agisse d’ouvriers agricoles bénéficiant d’un contrat de travail temporaire sur le sol américain, d’employés de maquiladoras sur le sol mexicain ou de travailleurs sans-papiers vivant aux États-Unis, la frontière territoriale entre les deux pays apparaît comme un moyen particulièrement efficace pour accomplir cette réduction. C’est dire aussi que cette marchandisation du travail n’est pas forcément la conséquence de la mise en place de marchés autorégulateurs, contrairement à ce que soutient Polanyi.For Karl Polanyi, market society is impossible, since it supposes that work, land and money be treated as merchandise, which can only destroy society. On the basis of the analysis of the utilisation of Mexican labor by US firms over 100 years, this paper tries to show that merchandisation is quite possible as concerns work. It reduces the human being to his sole work force, while staying in the formal context of salaried work. In the case of Mexican workers, whether it be farm workers with temporary contracts in the US, or employees of maquiladoras on the Mexican soil, or illegal workers in the US, the territorial frontier between the two countries apears a particularly efficient way to accomplish this redcuction. The merchandisation of work is not necessarily the consequence of the establishment of autoregulating

  3. Preparatory operations before emptying of tank B located in the former Petrus tank room in Building 18 at the CEA site at Fontenay-aux-Roses

    Energy Technology Data Exchange (ETDEWEB)

    Toulemonde, V.; Jeanjacques, M.; Feaugas, P. [DRSN, CEA/DEN, CEA/Siege (Paris), 31-33, rue de la Federation, 75752 Paris cedex 15 (France); Idasiak, J.M.; Brenneis, C.; Laurent, F. [DDCO, CEA/DEN, CEA/Siege (Paris), 31-33, rue de la Federation, 75752 Paris cedex 15 (France); Bisel, I.; Pochon, P. [DRCP, CEA/DEN, CEA/Siege (Paris), 31-33, rue de la Federation, 75752 Paris cedex 15 (France)

    2003-07-01

    The Petrus line is installed in Hall 40, of Unit 4 of Building 18 at the CEA centre at Fontenay-aux-Roses. It was used for the production of transuranic elements between 1970 and July 1995, when operations in Building 18 ended. The Petrus cell, which was in place until 1965, was replaced by the shielded Petrus line at the late sixties. It was connected to two vulcathene effluent tanks (1 and 2), each with a capacity of 1 m{sup 3}, located on the second sub-level of the building in a room referred to as the 'former Petrus tank room'. These tanks were supplied by a main pipe shielded with 15 cm of lead located in the upstream adit. The content of these tanks was extracted via the intermediate tank to the Circe zone, held at a negative pressure differential and located in the downstream adit, at an intermediate level relative to level 0. From this tank, liquors were removed by suction with tank truck pumps. The Petrus line is also connected to three stainless steel tanks (A, B and C), with a capacity of 0.5 m{sup 3} each, located in the same room as the vulcathene tanks. The former tank room is entered via a lobby connected to the room by a lead plug door. The tank room is severely contaminated. Access to the room is therefore prevented due to the contamination and the high ambient dose rate. The stainless steel tanks that still contain liquors have been emptied using the existing piping, with the exception of tank B which still contains trilaurylamine (TLA) solution containing large amounts of actinides.The paper has the following contents: I. Introduction; II. The problem; III. Closed-circuit television investigation - connection to the PYRAMIDE software; IV. Taking of samples from tank; IV.I. General; IV.2. Phase 0: Preliminary work in Building 18; IV.3. Phase 1: Continuous scavenging of tank; IV.3. Phase 2: Making the borehole; IV.4. Phase 3: Installation of glovebox; IV.6. Phase 4: Cutting of the two pipes; IV.7. Stage 5. Fibro-scopic inspection; IV.8

  4. Preparatory operations before emptying of tank B located in the former Petrus tank room in Building 18 at the CEA site at Fontenay-aux-Roses

    International Nuclear Information System (INIS)

    The Petrus line is installed in Hall 40, of Unit 4 of Building 18 at the CEA centre at Fontenay-aux-Roses. It was used for the production of transuranic elements between 1970 and July 1995, when operations in Building 18 ended. The Petrus cell, which was in place until 1965, was replaced by the shielded Petrus line at the late sixties. It was connected to two vulcathene effluent tanks (1 and 2), each with a capacity of 1 m3, located on the second sub-level of the building in a room referred to as the 'former Petrus tank room'. These tanks were supplied by a main pipe shielded with 15 cm of lead located in the upstream adit. The content of these tanks was extracted via the intermediate tank to the Circe zone, held at a negative pressure differential and located in the downstream adit, at an intermediate level relative to level 0. From this tank, liquors were removed by suction with tank truck pumps. The Petrus line is also connected to three stainless steel tanks (A, B and C), with a capacity of 0.5 m3 each, located in the same room as the vulcathene tanks. The former tank room is entered via a lobby connected to the room by a lead plug door. The tank room is severely contaminated. Access to the room is therefore prevented due to the contamination and the high ambient dose rate. The stainless steel tanks that still contain liquors have been emptied using the existing piping, with the exception of tank B which still contains trilaurylamine (TLA) solution containing large amounts of actinides.The paper has the following contents: I. Introduction; II. The problem; III. Closed-circuit television investigation - connection to the PYRAMIDE software; IV. Taking of samples from tank; IV.I. General; IV.2. Phase 0: Preliminary work in Building 18; IV.3. Phase 1: Continuous scavenging of tank; IV.3. Phase 2: Making the borehole; IV.4. Phase 3: Installation of glovebox; IV.6. Phase 4: Cutting of the two pipes; IV.7. Stage 5. Fibro-scopic inspection; IV.8. Stage 6: Sample-taking

  5. L’enfant pauvre et la naissance de la photographie sociale aux États-Unis au XIXe siècle

    Directory of Open Access Journals (Sweden)

    Anne LESME

    2010-03-01

    Full Text Available À la fin du XIXe siècle, le journaliste et photographe Jacob Riis révèle les conditions de vie déplorables des familles d’immigrants à New York. C’est le début de la photographie sociale aux États-Unis où la représentation de l’enfant pauvre tiendra une place majeure. Ses photographies, projetées au cours de conférences faites par l’auteur et reproduites dans des publications, contribueront à un changement de mentalité. Si le regard de ce photographe reste celui d’un membre de la classe moyenne sur les enfants du Lower East Side, ses images apportent une nouvelle vision de la pauvreté, en phase avec un enfant désormais perçu comme innocent par la société. Par ailleurs, cet usage particulier du rôle probant de la photographie en soutien du texte inaugure un nouveau mode de communication dont les réformateurs useront afin d’émouvoir et de faire réagir le public des classes moyennes et aisées.At the end of the 19th century, Jacob Riis, journalist and photographer, brought to light the appalling conditions of the slums in New York; it was the beginning of the social documentary photography in the United States. The representation of destitute children was to become central in this genre. His photographs, used during stereopticon slides projections and published in books and articles, contributed to a change of mentality. However influenced by a middle-class vision of the Lower East Side’s children, Jacob Riis’s photographs contributed to bring a new perception of poverty in line with a child who was from that time perceived as innocent by a large part of society. This particular use of photography as a convincing and reliable medium added to the text initiated a new means of communication used by the reformers to move and provoke reactions from a middle and upper-class public.

  6. Parler l’« interlangue » de mon siècle : la poesia visiva face aux mass media

    Directory of Open Access Journals (Sweden)

    Gaëlle Theval

    2006-06-01

    Full Text Available La poesia visiva se donne pour but de résister à la massification aliénante véhiculée par les médias, en développant une poésie visuelle qui se réapproprie le langage même des médias incriminés. L’adoption de cette « interlangue », qui repose sur l’association du mot et de l’image, a une fonction double : il s’agit à la fois de redonner une place à la poésie dans la société contemporaine dominée par l’image en empruntant aux médias leur efficacité pragmatique, et, dans le même temps, de contester ce pragmatisme en usant du montage et du détournement, à des fins critiques. C’est la stratégie « cheval de Troie ».The aim of poesia visiva is to resist the alienating massification conveyed by the media, by developing a visual poetry which re-appropriates the language of the media in question. Adopting this “interlanguage”, which is based on the association of word and image, has a double function: it both restores a place for poetry in our contemporary society, which is dominated by images, by borrowing from the media their pragmatic efficiency, and, at the same time it questions this pragmatism by using photomontage and diversion in a critical way. This can be called a strategy of “the Trojan horse”.La poesia visiva tiene por objetivo resistir a la masificación enajenante vehiculada por los medios de comunicación, al desarrollar una poesía visual que se reapropia el lenguaje mismo de los medias en cuestión. La adopción de esta “intrelengua”, que tiene lugar por la asociación de la palabra y la imagen, tiene una doble función : por una parte, situar de nuevo la poesía en la sociedad contemporánea dominada por la imagen, al tomar la eficiencia pragmática de los medios, por otra, dudar de tal pragmatismo valiéndose del montaje y de la deformación con fines críticos. En otras palabras, la estrategia del “Caballo de Troya”.

  7. Copular and AUX-Constructions

    OpenAIRE

    Lang, Ewald

    2000-01-01

    Der vorliegende Band setzt im Anschluß an den Band ZAS Papers in Linguistics 14 (1999) die Vorpublikation von Arbeiten fort, die innerhalb oder im Umkreis des von der DFG geförderten Projekts "Schnittstellen der Semantik: Kopula-Prädikativ-Konstruktionen" am ZAS entstanden sind. Das Rahmenthema, wie es in ZASPiL 14 einleitend knapp umrissen wurde, wird derzeit im Projekt in drei Untersuchungssträngen bearbeitet. Sie beinhalten (1) die Klärung der in der Literatur auch weiterhin häufig bemü...

  8. The influence of Montreal's east-end industrial sector on the utilization of medical services for respiratory diagnoses in children from Point-aux-Trembles, Mercier-Est and Anjou (Montreal) : executive summary

    International Nuclear Information System (INIS)

    The main purpose of this report was to inform decision makers in Montreal's clinical and administrative health settings of the high utilization rate of medical service for diagnosing respiratory problems in children from Point-aux-Trembles, Mercier-Est and Anjou. From 1996 to 2005, the rate of hospitalization and emergency room use was 25 to 75 per cent higher in Montreal's east-end industrial sector than the rest of the city. The rate of mortality associated with respiratory problems was also 29 per cent higher in Pointe-aux-Trembles, with children under the age of 4 being the most affected. As such, Quebec's environmental public hearing board expressed concern regarding proposed plans for a new industrial plant in the area. A study was therefore conducted to determine the influence of industrial emissions on the occurrence of respiratory episodes in children living in Montreal's east-end industrial sector. Two approaches were used, notably case-crossover and case-only. The study included daily monitoring of winds, exhaust plumes from the industrial sector, and a comparison of sulfur dioxide emissions measured near households compared to those emitted by refineries. A link between hospital visits and medical consultations was then made. It was concluded that the number of medical consultations was not linked to the emission exposure levels. The emissions from Montreal's east-end industrial sector were found to be only weakly linked (3 per cent) to the high utilization rate of medical services for diagnosing respiratory problems. 2 figs

  9. Le raisonnement clinique de l'infirmier (ère) expert(e) lors de l'évaluation de la douleur chez les patients ventilés, sédatés et non communicants aux soins intensifs

    OpenAIRE

    Gerber A.

    2013-01-01

    Problématique : La douleur aux soins intensifs adultes est un problème majeur auquel l'équipe soignante est confrontée quotidiennement. Elle nécessite un traitement adéquat et, pour ce faire, une évaluation systématique et précise est requise. Les patients hospitalisés aux soins intensifs sont vulnérables de par leurs pathologies et les multiples stimulations douloureuses auxquelles ils sont exposés. L'évaluation de la douleur est rendue complexe par le fait qu'ils ne peuvent pas la communiqu...

  10. Attitudes des éleveurs et sensibilité des systèmes d'élevage face aux sécheresses dans les Alpes françaises

    Directory of Open Access Journals (Sweden)

    Laurent Dobremez

    2011-01-01

    Full Text Available Les systèmes d'élevage des Alpes françaises sont fortement exposés au changement climatique annoncé et la plupart subissent déjà des épisodes de sécheresse depuis le début des années 2000. Face à ces aléas, les éleveurs ont mis en œuvre un certain nombre de leviers et envisagent d'en activer d'autres à l'avenir. Des enquêtes en exploitation ont permis d’identifier ces leviers. Leur analyse permet de caractériser les attitudes des éleveurs face aux sécheresses et d’évaluer l’évolution de la sensibilité de leurs systèmes d’élevage. A l'exception des exploitations disposant de surfaces irriguées importantes, toutes les exploitations cherchent d'abord à contourner l’aléa. Elles ont recours aux achats de fourrage pour compenser la baisse des récoltes destinées aux stocks hivernaux, mais à des degrés divers selon la durée de l’hivernage. Pour les périodes de pâturage, les éleveurs de haute montagne et les systèmes laitiers des Alpes du nord jouent avant tout sur un système résistant grâce à l’agrandissement et au surdimensionnement des pâtures par rapport aux besoins du troupeau. Les exploitations pastorales des Alpes du sud misent aussi sur une diversité de surfaces et une certaine latitude dans la conduite technique pour s'adapter aux conditions de l'année. Une succession répétée d’années sèches pourrait se traduire par des ruptures plus radicales dans les systèmes d’élevage. Il faut aussi garder à l’esprit que le changement climatique n'est qu'un des facteurs influençant les modes de transformation des exploitations.Livestock farming systems in the French Alps are particularly exposed to the predicted climate change and most of them have already experienced periods of drought since the beginning of the 2000s. Faced with this risk, livestock farmers have put in place a certain number of measures and envisage introducing others in the future. For the present study, surveys were

  11. Application of Continuous Thermodynamics to Natural-Gas Mixtures Application de la thermodynamique continue aux mélanges de gaz naturel

    Directory of Open Access Journals (Sweden)

    Prausnitz J. M.

    2006-11-01

    Full Text Available This work reviews recent progress in the application of continuous thermodynamics towards calculation of phase equilibria in natural-gas mixtures. In such mixtures, there may be too many components to identify each component individually. Continuous thermodynamics provides a theoretical framework for representing the composition of a portion of the natural-gas mixture by a continuous distribution function. Advances in continuous thermodynamics are discussed in three areas :(1 Characterization and representation of composition in a many-component mixture(2 Development and application of molecular-thermodynamic models for continuous mixtures, and(3 Implementation of efficient numerical techniques for solving material-balance and phase-equilibrium equations. While continuous thermodynamics provides a useful tool for calculation of phase equilibria in natural-gas mixtures, successful implementation requires better chemical-analytical characterization methods. Further, improved semi-theoretical techniques must be developed to relate experimental characterization information to physically significant parameters in molecular-thermodynamic models. Ce travail examine les récents développements de l'application de la thermodynamique continue au calcul des équilibres de phases de mélanges de gaz naturel. Dans ces mélanges, les composants sont souvent en trop grand nombre pour qu'on puisse les identifier individuellement. La thermodynamique continue fournit un schéma théorique permettant de représenter la composition d'une partie de mélange de gaz naturel par une fonction de distribution continue. Les progrès de la thermodynamique continue sont examinés dans les trois domaines suivants : 1 caractérisation et représentation de la composition d'un mélange de plusieurs produits; 2 mise au point et application des modèles de thermodynamique moléculaire aux mélanges continus; 3 mise en oeuvre de techniques numériques efficaces pour r

  12. Des millets aux nations From millets to nations: the construction of national identities in the novel You too, are you Greek? by Vassilios Christopoulos

    Directory of Open Access Journals (Sweden)

    Nicolas Pitsos

    2012-05-01

    Full Text Available L’auteur de ce roman construit son intrigue sur l’histoire de plusieurs familles d’une part au moment de l’effondrement d’un monde, celui des millets de l’Empire ottoman fondé sur le principe de l’identification des individus en fonction de leurs croyances religieuses et, d’autre part, lors de la mise en place d’une nouvelle organisation politique, celle des États-nations obsédés par l’idée de la définition de l’individu sur la base de critères nationaux. L'exemple narratif dominant est celui du passage du millet des Roums à la nation des Grecs. Il s’agit d’un roman polyphonique quant à l’expression d’expériences traumatisantes issues de politiques de nettoyage ethnique et culturel, menées par les différentes parties impliquées dans les événements qui agitent l’Empire ottoman à la fin du XIXe et au début du XXe siècle. Dans ce sens, l’écriture de ce roman s’oppose aux lectures exclusivistes de l’événement historique, largement diffusées par les mythologies nationales balkaniques visant à exalter les souffrances de nos compatriotes et de nos coreligionnaires, tout en effaçant ou occultant les destins tragiques des Autres.The author of this novel puts in plot the history of various families, at the moment of the fall from one hand, of an entire world, this of ottoman empire’s millets, based on the principle of individual identification following their religious beliefs and during the establishment on the other hand, of a new political organization, this of State-Nations, obsessed by the idea of individual definition on the basis of national criteria. The predominant narrative paradigm is this of the Roum millet transition towards the Greeks' nation. It is about a polyphonic novel, regarding to the expression of traumatic experiences issued by the ethnic and cultural cleansing policies, conducted by the different actors implicated in the events which stirred up trouble in the ottoman

  13. The reactions of magnesium and its alloys with moist gases at high temperatures; Les reactions du magnesium et de ses alliages avec les gaz humides aux temperatures elevees

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-02-15

    presence sont moins oxydantes. De plus, un changement important d'energie d'activation du processus d'oxydation se produit systematiquement, mais aussi a une temperature variable suivant l'atmosphere consideree. Cependant, dans le cas des alliages, la cinetique d'oxydation lineaire classique est generalement precedee de courtes periodes d'induction, a caractere parabolique. On a ensuite mis en evidence et interprete deux possibilites d'inhibition de ia corrosion du magnesium par la vapeur d'eau: soit a la suite d'une fluoration superficielle partielle, soit lorsque le gaz porteur est l'anhydride carbonique. D'autre part, les conditions extremes de l'oxydation, c'est-a-dire les phenomenes d'inflammation qui surviennent a une temperature bien determinee dans chaque atmosphere, ont fait l'objet d'une etude particuliere. Enfin, on s'est efforce de degager la portee de l'ensemble de ces resultats aux deux points de vue fondamental et pratique. (auteur)

  14. Voyage aux Enfers ou rêve de jeune-fille ?Les révélations curieuses de la Fille dans le Gascon extravagant

    Directory of Open Access Journals (Sweden)

    Sophie Houdard

    2007-10-01

    Full Text Available 1637, la possession des ursulines de Loudun entre dans sa phase de publicité spectaculaire. Les jésuites exorcistes mettent tout en œuvre pour lutter contre les incrédulités. Jeanne des anges, la supérieure du couvent, délivrée du diable Béhémot censé avoir gravé des noms sur sa main devient un « miracle » ambulant. La même année, l’auteur anonyme du Gascon extravagant choisit de publier son « Histoire comique » : une Fille, prétendument possédée et un Ermite-exorciste deviennent, pour la première fois, les personnages centraux d’une fiction comique. Cette « invention » romanesque ne doit pas être prise à la légère : en « empruntant » à la possession ce couple, le Gascon extravagant « négocie » un espace critique avec la possession : la représentation dénonce, en l’installant dans l’espace fictionnel, la redoutable efficacité de la fable possessionniste. On verra comment la Fille et le récit de son Voyage aux enfers participent de cette représentation critique, en inventant une narration d’une rare ambiguïté.« A trip into Hell or a teen girl’s dream ? Young woman’s curious revelations in The Gascon extravagant »1637. The demonic possession of the Ursulines of Loudun enters its sensationalist stage. The Jesuit exorcists put their best efforts into fighting disbelief. Jeanne des Anges, the Mother Superior of the convent, who has been freed from Béhémot, a devil supposed to have engraved names on her hand, becomes a walking “miracle”. During the same year the anonymous author of Gascon extravagant decides to publish his « Histoire comique »: a supposedly possessed « Young woman » and an exorcist-« Hermit » become, for the first time, the main characters in a comic fiction. This romanesque « invention » ought not to be taken lightly: in « borrowing » this couple from the realm of demonic possession, The Gascon extravagant « negotiates » a critical

  15. L’art du vitrail en France au temps de la reconstruction et de la croissance. Note sur les fonds Hébert-Stevens - Bony conservés aux Archives nationales du monde du travail (Fonds n° 2002 001

    Directory of Open Access Journals (Sweden)

    Christian Hottin

    2009-11-01

    Full Text Available Cet article a pour objet de présenter brièvement le fonds de l’atelier Hébert-Stevens - Bony, entré aux Archives nationales (Archives nationales du monde du travail, Roubaix en 2002

  16. Descriptif et qualification d'un mode opératoire de soudage pour les matériaux métalliques - Épreuve de qualification d'un mode opératoire de soudage - Partie 6: Soudage à l'arc et aux gaz du cuivre et de ses alliages

    CERN Document Server

    2006-01-01

    Descriptif et qualification d'un mode opératoire de soudage pour les matériaux métalliques - Épreuve de qualification d'un mode opératoire de soudage - Partie 6: Soudage à l'arc et aux gaz du cuivre et de ses alliages

  17. Sensibilité aux mouvements de masse dans l'Apennin méridional (Campanie, Italie). Exemple des bassins versants de l'Ufita, du Miscano et du Calaggio

    OpenAIRE

    Sisto, Michele; Di Lisio, Antonio; Russo, Filippo

    2014-01-01

    Ce travail a pour objectif d'étudier les rapports entre la sensibilité des versants aux mouvements de masse et différents facteurs, dont le régime pluviométrique, dans une région de l'Apennin méridional caractérisée par sa grande complexité litho-structurale.Le régime des précipitations a été défini à partir de séries de données de longue durée, qui ont permis de calculer de nombreux indices climatiques. Parmi eux, sont présentés ici ceux qui ont une importance particulière en matière de décl...

  18. Epidémiologie de la résistance aux antibiotiques des entérobactéries au niveau du C.H.U de Sidi Bel Abbes

    OpenAIRE

    SOUNA, Djahida

    2014-01-01

    Les entérobactéries représentent une des principales familles de bacilles à Gram négatif responsables d’infections humaines graves. La surveillance de la sensibilité aux antibiotiques à l’hôpital est une étape essentielle; elle oriente le choix des traitements empiriques et permet de réduire la pression de sélection exercée par les antibiotiques. L’étude de 140 souches d’entérobactérie isolées en milieu hospitalier au niveau de différents services du CHU de Sidi Bel Abbes entre oc...

  19. Atlas de sensibilité du littoral aux pollutions marines, dispositif opérationnel ORSEC départemental de La Réunion. Annexe technique du dispositif spécifique Polmar-Terre.

    OpenAIRE

    Le Berre, Iwan; David, Laurence; Louze, Julien

    2012-01-01

    Cet atlas de sensibilité du littoral aux pollutions marines a été produit dans le cadre du projet "Elaboration des Atlas Polmar et DCE" confié par l'Etat (DEAL - La Réunion) au laboratoire universitaire LETG-Brest Géomer de Brest en lien avec la délégation IFREMER océan Indien. Le dispositif spécifique Polmar constitue un volet spécifique du dispositif opérationnel ORSEC départemental. Théoriquement révisé tous les cinq ans, il doit notamment fournir "un inventaire précis et hiérarchisé ...

  20. Émigrer con gusto  : les émigrés italiens et leur contribution à l’économie européenne aux xviie et

    OpenAIRE

    Riello, Giorgio

    2010-01-01

    Le rôle des migrants italiens dans la diffusion du « goût italien » est bien connu dans au XXe siècle : le design, la mode et le « made in Italy » sont aujourd’hui largement appréciés. Mais on sait moins que la relation entre esthétique et culture italienne est portée par une lingue histoire, depuis la Renaissance. Ce lien s’est maintenu aux XVIIe et XVIIIe siècles quand l’économie italienne décline et se marginalise. Les migrants jouent un rôle clé pour conforter le goût italien dans les art...