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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

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    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. Modelling of adsorption of redox sensitive oxyanions on gibbsite

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    Miedaner, M.M.; Weerasooriya, R.; Tobschall, H.J. [Inst. fuer Geologie und Mineralogie, Friedrich Alexander Univ. Erlangen-Nuernberg, Erlangen (Germany)

    2004-06-01

    The adsorptive behaviour of minerals in natural soils has been the focus of many scientific investigations for a long time. Besides mineralogical studies, geochemists are also trying to determine the filter capacity with respect to waste-waters and to understand the buffering capacity for oxyanions (As, Se, Mo, P) in soils. The present work is part of an on-going project on developing a thermodynamically consistent database for the adsorption of oxyanions onto different Al-derived oxides / hydrooxides that are ubiquitous in nature. The experimental data are quantified by both 1-pK and 2-pK surface complexation models using charge distribution multi site ion complexation- (CD-MUSIC), double layer- (DLM) and triple layer- (TLM) mechanistic models explicitly accounting for the finite size of oxyanions. With this objective the adsorption of redox-sensitive oxyanions, e.g. As and Se on gibbsite was investigated as a function of solution pH, redox state e.g. arsenite and arsenate; selenate and selenite, and adsorbate loading. All experiments were carried out in batch systems to determine adsorption edges, isotherms and proton exchange ratios (r{sub anion/OH-}) upon oxyanions adsorption. Initial concentration of the adsorbates and the pH were ranged 1.34 - 13.4 {mu}mol/L and 4 - 9.2 respectively. Possible surface configurations were examined using both vibration spectroscopy and molecular modelling methods. (orig.)

  4. Selenite Protection of Tellurite Toxicity towards Escherichia coli

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    Helen A. Vrionis

    2015-12-01

    Full Text Available In this work the influence of selenite on metal resistance in Escherichia coli was examined. Both synergistic and antagonistic resistance and toxicities were found upon co exposure with selenite. In wild type cells co-exposure to selenite had little effect on arsenic resistance, decreased resistance to cadmium and mercury but led to a dramatic increased resistance to tellurite of 32 fold. Due to the potential importance of thiol chemistry in metal biochemistry, deletion strains in γ-glutamylcysteine synthetase (key step in glutathione biosynthesis, encoded by gshA, thioredoxin (trxA, glutaredoxin (grxA, glutathione oxidoreductase (gor, and the periplasmic glutathione transporter (cydD were also evaluated for resistance to various metals in the presence of selenite. The protective effect of selenite on tellurite toxicity was seen in several of the mutants and was pronounced in the gshA mutant were resistance to tellurite was increased up to 1000 fold relative to growth in the absence of selenite. Thiol oxidation studies revealed a faster rate of loss of reduced thiol content in the cell with selenite than with tellurite, indicating differential thiol reactivity. Selenite addition resulted in reactive oxygen species (ROS production equivalent to levels associated with H2O2 addition. Tellurite addition resulted in considerably lower ROS generation while vanadate and chromate treatment did not increase ROS production above that of background. This work shows increased resistance towards most oxyanions in mutants of thiol redox suggesting that metalloid reaction with thiol components such as glutathione actually enhances toxicity of some metalloids.

  5. 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.

  6. 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

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

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    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.

  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. Macroscopic and spectroscopic characterization of selenate, selenite, and chromate adsorption at the solid-water interface of gamma-Al(2)O(3).

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    Elzinga, Evert J; Tang, Yuanzhi; McDonald, Jason; DeSisto, Stephanie; Reeder, Richard J

    2009-12-15

    The interaction of selenate, selenite, and chromate with the hydrated surface of gamma-Al(2)O(3) was studied using a combination of macroscopic pH edge data, electrophoretic mobility measurements, and X-ray absorption spectroscopic analyses. The pH edge data show generally increased oxyanion adsorption with decreasing pH, and indicate ionic strength-(in)dependent adsorption of chromate and selenate across the pH range 4-9, and ionic strength-(in)dependent adsorption of selenite in this pH range. The adsorption of chromate peaks at pH 5.0, whereas for selenate and selenite no pH adsorption maxima are observed. Electrophoretic mobility measurements show that all three oxyanions decrease the zeta potential of gamma-Al(2)O(3) upon adsorption; however, only selenite decreased the pH(PZC) of the gamma-Al(2)O(3) sorbent. EXAFS data indicate that selenite ions are coordinated in a bridging bidentate fashion to surface AlO(6) octahedra, whereas no second-neighbor Al scattering was observed for adsorbed selenate ions. Combined, the results presented here show that pH is a major factor in determining the extent of adsorption of selenate, selenite, and chromate on hydrated gamma-Al(2)O(3). The results point to substantial differences between these anions as to the mode of adsorption at the hydrated gamma-Al(2)O(3) surface, with selenate adsorbing as nonprotonated outer-sphere complexes, chromate forming a mixture of monoprotonated and nonprotonated outer-sphere adsorption complexes, and selenite coordinating as inner-sphere surface complexes in bridging configuration.

  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. Selenium isotope ratios as indicators of selenium sources and oxyanion reduction

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    Johnson, T.M.; Herbel, M.J.; Bullen, T.D.; Zawislanski, P.T.

    1999-01-01

    Selenium stable isotope ratio measurements should serve as indicators of sources and biogeochemical transformations of Se. We report measurements of Se isotope fractionation during selenate reduction, selenite sorption, oxidation of reduced Se in soils, and Se volatilization by algae and soil samples. These results, combined with previous work with Se isotopes, indicate that reduction of soluble oxyanions is the dominant cause of Se isotope fractionation. Accordingly, Se isotope ratios should be useful as indicators of oxyanion reduction, which can transform mobile species to forms that are less mobile and less bioavailable. Additional investigations of Se isotope fractionation are needed to confirm this preliminary assessment. We have developed a new method for measurement of natural Se isotope ratio variation which requires less than 500 ng Se per analysis and yields ??0.2??? precision on 80Se/76Se. A double isotope spike technique corrects for isotopic fractionation during sample preparation and mass spectrometry. The small minimum sample size is important, as Se concentrations are often below 1 ppm in solids and 1 ??g/L in fluids. The Se purification process is rapid and compatible with various sample matrices, including acidic rock or sediment digests.

  12. 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 ...

  13. Nanoparticles Formed from Bacterial Oxyanion Reduction of Toxic Group 15 and Group 16 Metalloids

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    Pearce, Carolyn I.; Baesman, Shaun M.; Switzer Blum, Jodi; Fellowes, Jonathan W.; Oremland, Ronald S.

    2012-03-01

    Environmental Significance of Group 15 and 16 Toxic Metalloids Selenium, tellurium, and arsenic are present naturally in aquatic and terrestrial environments and share many similar biogeochemical characteristics. These elements are released into the environment through the weathering and decomposition of minerals contained within a variety of lithologies, with slow release rates resulting in low environmental concentrations. Selenium, tellurium, and arsenic occur in several oxidation states as oxyanions (e.g., selenate [SeO4 2], selenite [SeO3 2], tellurate [TeO4 2], tellurite [TeO3 2], arsenate [HAsO4 2], and arsenite [HAsO3 2]) in their native elemental states [e.g., Se(0), Te(0)] or in their most reduced states as selenide (-II) and telluride (-II) or arsenide/arsines (-III). These elements can be methylated through microbial activity to form compounds such as dimethylselenide (Ehrlich, 2002; Masscheleyn, et al., 1990), dimethyltelluride (Basnayake, et al., 2001; Fleming and Alexander, 1972), and methylarsonous acid (Dopp, et al., 2004) as well as a variety of toxic methylated arsine gases (Yuan, et al., 2008). These elements are also found as analogues of sulfurous proteins such as selenocysteine and selenomethionine (Bock, et al., 1991; Jones, et al., 1979; Stolz, et al., 2006; Zannoni, et al., 2008), tellurocysteine, telluromethionine (Zannoni, et al., 2008), and the arsenic-containing amino acid, arsenomethionine (Dembitsky and Levitsky, 2004).

  14. 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.

  15. 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.

  16. Selenite and tellurite form mixed seleno- and tellurotrisulfides with CstR from Staphylococcus aureus.

    Science.gov (United States)

    Luebke, Justin L; Arnold, Randy J; Giedroc, David P

    2013-04-01

    Staphylococcus aureus CstR (CsoR-like sulfur transferase repressor) is a member of the CsoR family of transition metal sensing metalloregulatory proteins. Unlike CsoR, CstR does not form a stable complex with transition metals but instead reacts with sulfite to form a mixture of di- and trisulfide species, CstR2(RS-SR') and CstR2(RS-S-SR')n)n=1 or 2, respectively. Here, we investigate if CstR performs similar chemistry with related chalcogen oxyanions selenite and tellurite. In this work we show by high resolution tandem mass spectrometry that CstR is readily modified by selenite (SeO3(2-)) or tellurite (TeO3(2-)) to form a mixture of intersubunit disulfides and selenotrisulfides or tellurotrisulfides, respectively, between Cys31 and Cys60'. Analogous studies with S. aureus CsoR reveals no reaction with selenite and minimal reaction with tellurite. All cross-linked forms of CstR exhibit reduced DNA binding affinity. We show that Cys31 initiates the reaction with sulfite through the formation of S-sulfocysteine (RS-SO3(2-)) and Cys60 is required to fully derivatize CstR to CstR2(RS-SR') and CstR2(RS-S-SR'). The modification of Cys31 also drives an allosteric switch that negatively regulates DNA binding while derivatization of Cys60 alone has no effect on DNA binding. These results highlight the differences between CstRs and CsoRs in chemical reactivity and metal ion selectivity and establish Cys31 as the functionally important cysteine residue in CstRs.

  17. 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.

  18. Selenite bioremediation potential of indigenous microorganisms from industrial activated sludge.

    Science.gov (United States)

    Garbisu, C; Alkorta, I; Carlson, D E; Leighton, T; Buchanan, B B

    1997-12-01

    Ten bacterial strains were isolated from the activated sludge waste treatment system (BIOX) at the Exxon refinery in Benicia, California. Half of these isolates could be grown in minimal medium. When tested for selenite detoxification capability, these five isolates (members of the genera Bacillus, Pseudomonas, Enterobacter and Aeromonas), were capable of detoxifying selenite with kinetics similar to those of a well characterized Bacillus subtilis strain (168 Trp+) studied previously. The selenite detoxification phenotype of the Exxon isolates was stable to repeated transfer on culture media which did not contain selenium. Microorganisms isolated from the Exxon BIOX reactor were capable of detoxifying selenite. Treatability studies using the whole BIOX microbial community were also carried out to evaluate substrates for their ability to support growth and selenite bioremediation. Under the appropriate conditions, indigenous microbial communities are capable of remediating selenite in situ.

  19. Rodenticide efficacy of sodium selenite baits in laboratory conditions

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    Jokić G.

    2014-01-01

    Full Text Available We examined the acceptance and palatability of baits containing different contents of sodium selenite as a rodenticide, in Swiss mice under laboratory conditions. In a no-choice and choice feeding test, the animals were exposed to baits containing 0.1, 0.05, 0.025 and 0.0125% of sodium selenite. The total bait consumption by Swiss mice in the no-choice feeding test was highly negatively correlated, while total sodium selenite intake was medium-positively correlated to the sodium selenite content in the bait. In the same test, daily intakes significantly depended on the content of sodium selenite in the bait, while the exposure and associated interactions of contents of sodium selenite and exposure had no statistically significant impact. Baits with sodium selenite contents of 0.05 and 0.1% had the most lethal effects. The negative impact of the sodium selenite content on bait acceptance and palatability was confirmed in choice feeding tests. Baits containing 0.05 and 0.1% of sodium selenite displayed the biological potential to be used as a rodenticide. It is necessary to improve its insufficient acceptability and palatability by adding adequate additives to the bait. The results of this study should be verified in experiments with wild rodents. [Projekat Ministarstva nauke Republike Srbije, br. III 46008 i br. OI 173039

  20. Sodium selenite as a new rodenticide

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    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.

  1. Retention of inorganic oxyanions by organo-kaolinite.

    Science.gov (United States)

    Li, Z; Bowman, R S

    2001-11-01

    A natural kaolinite (KGa-1b) was treated with the surfactant hexadecyltrimethylammonium bromide (HDTMA-Br) to a level twice that of the cation exchange capacity (CEC). Sorption of nitrate, arsenate, and chromate by the resultant organo-kaolinite was then quantified. Sorption of each oxyanion was well-described by the Langmuir isotherm. Sorption of nitrate was the greatest, with a Langmuir sorption maximum of 24 mmol/kg, although chromate showed the highest sorption affinity of 20 L/kg. Sorption of nitrate, arsenate, and chromate on organo-kaolinite was at least two orders of magnitude greater than their sorption on unmodified kaolinite. Desorption of the bromide counterion indicated that each of the oxyanions was retained by ion exchange on an HDTMA bilayer formed on the organo-kaolinite. Chromate sorption on the organo-kaolinite was unaffected by solution pH in the range 5-9, but decreased at pH 11 due to competition of OH- for anion exchange sites. Similarly, chromate exchange by organo-kaolinite was reduced in the presence of high background levels of chloride. Chromate was effectively retained when flowing through a packed bed of organo-kaolinite: after an input of more than 40 pore volumes, the effluent concentration of chromate was less than 10% of the input concentration, and 90% of the original HDTMA remained on the organo-kaolinite. The results demonstrate that properly prepared organoclays can remove oxyanions, as well as nonpolar organics, from contaminated waters. PMID:12230158

  2. Towards a selective adsorbent for arsenate and selenite in the presence of phosphate: Assessment of adsorption efficiency, mechanism, and binary separation factors of the chitosan-copper complex.

    Science.gov (United States)

    Yamani, Jamila S; Lounsbury, Amanda W; Zimmerman, Julie B

    2016-01-01

    The potential for a chitosan-copper polymer complex to select for the target contaminants in the presence of their respective competitive ions was evaluated by synthesizing chitosan-copper beads (CCB) for the treatment of (arsenate:phosphate), (selenite:phosphate), and (selenate:sulfate). Based on work by Rhazi et al., copper (II) binds to the amine moiety on the chitosan backbone as a monodentate complex (Type I) and as a bidentate complex crosslinking two polymer chains (Type II), depending on pH and copper loading. In general, the Type I complex exists alone; however, beyond threshold conditions of pH 5.5 during synthesis and a copper loading of 0.25 mol Cu(II)/mol chitosan monomer, the Type I and Type II complexes coexist. Subsequent chelation of this chitosan-copper ligand to oxyanions results in enhanced and selective adsorption of the target contaminants in complex matrices with high background ion concentrations. With differing affinities for arsenate, selenite, and phosphate, the Type I complex favors phosphate chelation while the Type II complex favors arsenate chelation due to electrostatic considerations and selenite chelation due to steric effects. No trend was exhibited for the selenate:sulfate system possibly due to the high Ksp of the corresponding copper salts. Binary separation factors, α12, were calculated for the arsenate-phosphate and selenite-phosphate systems, supporting the mechanistic hypothesis. While, further research is needed to develop a synthesis method for the independent formation of the Type II complexes to select for target contaminants in complex matrices, this work can provide initial steps in the development of a selective adsorbent.

  3. 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...

  4. 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.

  5. Alabaster and Selenite Gypsum:I-Dehydration-Rehydration Comparison Studies

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Two types of gypsum raw materials, selenite and alabaster, were used to prepare dental stone (α-hemihydrate).Gypsum lumps (0.8~2.5 cm) were hydrothermally treated at 135, 160 and 180°C for 6, 2 and 1 h respectively.The physicochemical properties and composition characteristics of the α-hemihydrates prepared from selenite and alabaster raw gypsum were determined. The results indicated that both the selenite and alabaster raw gypsum show the same chemical and mineralogical composition of calcium sulphate dihydrate. They differs only in their microstructure, selenite raw gypsum exhibits perfect regular crystals while alabaster gypsum, on the other hand,exhibits irregular, large size and interlocked crystals. Selenite is more accessible to dehydration than alabaster raw gypsum. The α-hemihydrate samples prepared from alabaster raw gypsum showed a very short setting time and a lower compressive strength values in relation to that prepared from selenite gypsum. The compressive strength values of the all prepared samples were higher than that specified by A.D.A specification for dental use. To optimize the setting time of both products further studies are needed.

  6. Selenium uptake, translocation and speciation in wheat supplied with selenate or selenite.

    Science.gov (United States)

    Li, Hua-Fen; McGrath, Steve P; Zhao, Fang-Jie

    2008-01-01

    Selenite can be a dominant form of selenium (Se) in aerobic soils; however, unlike selenate, the mechanism of selenite uptake by plants remains unclear. Uptake, translocation and Se speciation in wheat (Triticum aestivum) supplied with selenate or selenite, or both, were investigated in hydroponic experiments. The kinetics of selenite influx was determined in short-term (30 min) experiments. Selenium speciation in the water-extractable fraction of roots and shoots was determined by HPLC-ICPMS. Plants absorbed similar amounts of Se within 1 d when supplied with selenite or selenate. Selenate and selenite uptake were enhanced in sulphur-starved and phosphorus-starved plants, respectively. Phosphate markedly increased K(m) of the selenite influx. Selenate and selenite uptake were both metabolically dependent. Selenite was rapidly converted to organic forms in roots, with limited translocation to shoots. Selenomethionine, selenomethionine Se-oxide, Se-methyl-selenocysteine and several other unidentified Se species were detected in the root extracts and xylem sap from selenite-treated plants. Selenate was highly mobile in xylem transport, but little was assimilated to organic forms in 1 d. The presence of selenite decreased selenate uptake and xylem transport. Selenite uptake is an active process likely mediated, at least partly, by phosphate transporters. Selenite and selenate differ greatly in the ease of assimilation and xylem transport.

  7. Selenite benefits embryonic stem cells therapy in Parkinson's disease.

    Science.gov (United States)

    Tian, L-P; Zhang, S; Xu, L; Li, W; Wang, Y; Chen, S-D; Ding, J-Q

    2012-09-01

    Embryonic stem cells (ESC) transplantation is a potential therapeutic approach for Parkinson's disease (PD). However, one of the main challenges to this therapy is the post-transplantation survival of dopaminergic (DA) neurons. In this study, mouse ESC were differentiated into DA neurons by a modified serum free protocol. These ESC-derived neurons were then transplanted into striatum of 6-OHDA lesioned rat. The viability of grafted DA neurons was decreased, accompanied by activated microglia and high levels of proinflammatory factors, such as TNF-α and iNOS, in the graft niche. This suggested that the local neuroinflammation might be involved in the reduced cells viability. Selenite, the source of essential micronutrient selenium, could inhibit NF-κB p65 nuclear translocation and subsequently reduce iNOS, COX-2 and TNF-α expression in LPS-treated BV2 cells in a dose dependant manner. Before the transplantation of ESC-derived DA neurons, 6-OHDA lesioned rats were intraperitoneally injected with selenite. The expression levels of TNF-α and iNOS were decreased by 30% and 50%, respectively, in selenite treated group. The survival of implanted DA neurons and the rotational behavior of transplanted rats were also remarkably improved by selenite treatment. To sum up, selenite might benefit ESCs transplantation therapy in PD through anti-inflammation effects.

  8. 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

  9. 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

  10. 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...

  11. 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...

  12. Adsorption of Oxyanions from Industrial Wastewater using Perlite-Supported Magnetite.

    Science.gov (United States)

    Verbinnen, Bram; Block, Chantal; Vandecasteele, Carlo

    2016-05-01

    Most studies on oxyanion adsorption focus on their removal from synthetic solutions. It is often claimed that the considered adsorbents can be used to treat real (industrial) wastewaters, but this is seldom tested. Perlite-supported magnetite was characterized first by determining its specific surface area, magnetite content and by examining the coating. Tests on a synthetic solution showed that at the ideal pH values (pH 3 to 5), the order of adsorption is Mo(VI) > As(V) > Sb(V) > Cr(VI) > Se(VI). Most oxyanions can be removed for more than 75% with an adsorbent dosage of 1 g/l. Furthermore, perlite-supported magnetite has a higher removal efficiency for oxyanions than commercially available adsorbents and comparable adsorbents described in literature. Perlite-supported magnetite is suitable for treating real wastewaters: it can remove several oxyanions simultaneously from the considered industrial wastewater, but the adsorption order changes due to the presence of interfering anions.

  13. On the mechanical properties of selenite glass nanocomposites

    Science.gov (United States)

    Bar, Arun Kr.; Kundu, Ranadip; Roy, Debasish; Bhattacharya, Sanjib

    2016-05-01

    In this paper the room temperature micro-hardness of selenite glass-nanocomposites has been measured using a Vickers and Knoop micro hardness tester where the applied load varies from 0.01N to 0.98 N. A significant indentation size effect was observed for each sample at relatively low indentation test loads. The classical Meyer's law and the proportional specimen resistance model were used to analyze the micro-hardness behavior. It was found that the selenite glass-nanocomposite becomes harder with increasing CuI composition and the work hardening coefficient and mechanical properties like Young modulus, E, were also calculated. Our results open the way for the preparation, application and investigation of significant mechanical properties of new type of glass-nanocomposites.

  14. 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

  15. 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 ...

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. XAS Studies of Se Speciation in Selenite-Fed Rats

    Science.gov (United States)

    Weekley, Claire M.; Aitken, Jade B.; Witting, Paul K.; Harris, Hugh H.

    2014-01-01

    The biological activity of selenium is dependent on its chemical form. Therefore, knowledge of Se chemistry in vivo is required for efficacious use of selenium compounds in disease prevention and treatment. Using X-ray absorption spectroscopy, Se speciation in the kidney, liver, heart, spleen, testis and red blood cells of rats fed control (~0.3 ppm Se) or selenite-supplemented (1 ppm or 5 ppm Se) diets for 3 or 6 weeks, was investigated. X-ray absorption spectroscopy revealed the presence of Se–Se and Se–C species in the kidney and liver, and Se–S species in the kidney, but not the liver. X-ray absorption near edge structure (XANES) spectra showed that there was variation in speciation in the liver and kidneys, but Se speciation was much more uniform in the remaining organs. Using principal component analysis (PCA) to interpret the Se K-edge X-ray absorption spectra, we were able to directly compare the speciation of Se in two different models of selenite metabolism – human lung cancer cells and rat tissues. The effects of Se dose, tissue type and duration of diet on selenium speciation in rat tissues were investigated, and a relationship between the duration of the diet (3 weeks versus 6 weeks) and selenium speciation was observed. PMID:25363824

  1. 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 ...

  2. Abiotic Reduction of Selenite and Antimonate Under Controlled Oxygen Conditions

    Science.gov (United States)

    Belzile, N.; Truong, H. T.; Polack, R.; Chen, Y.

    2008-12-01

    Laboratory and field studies have reported the oxidation of elemental Se to selenite or selenate or that of antimonite to antimonate but the reduction studies of the two elements, especially in absence of bacteria are more scarce. We have performed experiments on the abiotic reduction of Se(IV) and Sb(V) under controlled oxygen conditions in presence of naturally-encountered reducing agents such as Fe(II) and dissolved sulfide. In the case of selenite, the reduction by ferrous iron is barely detectable at very low concentrations of oxygen. However, at concentrations of 200 ± 50 ppmv in the controlled atmosphere glove box, more iron oxide particles were formed at a higher initial Fe(II) concentration in the system and with time. In the pellets collected after filtration, a significant amount of Se(0) was found. Our field geochemical studies on Se also showed the same phenomenon, i.e. a higher level of Se(0) in lake sediments was accompanied by a higher presence of iron oxides. In the case of antimony, the reduction of Sb(V) by dissolved sulfide was extensive and far more rapid at more acidic pH values. Half lives for Sb(V) in the presence of excess dissolved sulfide at pH values of 5 to 7 were calculated and the reaction was found to be first order with respect to all three of [Sb(V)], [dissolved sulfide] and [H+]. Metastibnite precipitated after reduction of Sb(V) in working experimental samples at buffered pH of 5 and 6. The oxidation product of dissolved sulfide was identified as elemental sulfur. This study has demonstrated the ability of dissolved sulfide to reduce Sb(V) under a variety of environmentally relevant concentrations and conditions.

  3. 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

  4. 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

  5. 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)

  6. 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

  7. 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.

  8. Mineral systems and the thermodynamics of selenites and selenates in the oxidation zone of sulfide ores - a review

    Science.gov (United States)

    Charykova, Marina V.; Krivovichev, Vladimir G.

    2016-08-01

    Contemporary mineralogy and geochemistry are concerned with understanding and deciphering processes that occur near the surface of the Earth. These processes are especially important for resolving ecological challenges and developing principles of good environmental management. Selenium oxysalts, selenites and selenates, are relatively rare as minerals; there are presently only 34 known mineral species. Thirty-one "pure" selenites, which contain only selenite anionic groups, are known to occur naturally. The other three minerals each contain two anionic groups: selenate and selenite (schmiederite), selenate and sulphate (olsacherite), and selenate and iodate (carlosruizite). This work is intended to provide a classification of natural selenium oxysalts based on their chemical composition. Selenites belong to a particular mineral system, whose components are chemical elements required to construct the crystal structure of a mineral (species-defining constituents). The number of components represents the minimum number of independent elements necessary to define the composition of the system. All selenites and selenates are divided into two groups: anhydrous selenites (I) and hydrous selenites and selenates (II). The paper also presents systematized data published on the thermodynamics of selenites, which are formed in the weathering zone of sulfide and selenide ores, and determines approaches to the quantitative physicochemical modeling of formation conditions. The Eh-pH diagrams of the Me-Se-H2O systems (Me = Cu, Co, Ni, Fe, Zn, Ca, Al) were calculated and plotted for the average contents of these elements in aqueous weathering solutions in sulfide deposit oxidation zones.

  9. 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.

  10. Phenotype-dependent apoptosis signalling in mesothelioma cells after selenite exposure

    Directory of Open Access Journals (Sweden)

    Rundlöf Anna-Klara

    2009-06-01

    Full Text Available Abstract Background Selenite is a promising anticancer agent which has been shown to induce apoptosis in malignant mesothelioma cells in a phenotype-dependent manner, where cells of the chemoresistant sarcomatoid phenotype are more sensitive. Methods In this paper, we investigate the apoptosis signalling mechanisms in sarcomatoid and epithelioid mesothelioma cells after selenite treatment. Apoptosis was measured with the Annexin-PI assay. The mitochondrial membrane potential, the expression of Bax, Bcl-XL, and the activation of caspase-3 were assayed with flow cytometry and a cytokeratin 18 cleavage assay. Signalling through JNK, p38, p53, and cathepsins B, D, and E was investigated with chemical inhibitors. Furthermore, the expression, nuclear translocation and DNA-binding activity of p53 was investigated using ICC, EMSA and the monitoring of p21 expression as a downstream event. Levels of thioredoxin (Trx were measured by ELISA. Results In both cell lines, 10 μM selenite caused apoptosis and a marked loss of mitochondrial membrane potential. Bax was up-regulated only in the sarcomatoid cell line, while the epithelioid cell line down-regulated Bcl-XL and showed greater caspase-3 activation. Nuclear translocation of p53 was seen in both cell lines, but very little p21 expression was induced. Chemical inhibition of p53 did not protect the cells from apoptosis. p53 lost its DNA binding ability after selenite treatment and was enriched in an inactive form. Levels of thioredoxin decreased after selenite treatment. Chemical inhibition of MAP kinases and cathepsins showed that p38 and cathepsin B had some mediatory effect while JNK had an anti-apoptotic role. Conclusion We delineate pathways of apoptosis signalling in response to selenite, showing differences between epithelioid and sarcomatoid mesothelioma cells. These differences may partly explain why sarcomatoid cells are more sensitive to selenite.

  11. 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.

  12. 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

  13. 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…

  14. 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

  15. Reduced swim performance and aerobic capacity in adult zebrafish exposed to waterborne selenite.

    Science.gov (United States)

    Massé, Anita J; Thomas, Jith K; Janz, David M

    2013-04-01

    Although dietary exposure of adult fish to organoselenium in contaminated aquatic ecosystems has been reported to bioaccumulate and cause larval deformities in offspring, subtle physiological effects produced through low level waterborne selenium exposure in fish such as swim performance and aerobic capacity have not been investigated. To evaluate potential effects of selenite on these responses, adult zebrafish (Danio rerio) were exposed to nominal aqueous concentrations of 0, 10 or 100 μg/L sodium selenite for 14 days. Upon completion of the exposure period, fish underwent two successive swim trials in a swim tunnel respirometer to determine critical swim speed (Ucrit), oxygen consumption (MO2), standard and active metabolic rates, aerobic scope (AS) and cost of transport (COT) followed by analysis of whole body triglyceride and glycogen concentrations. Selenite exposure had a significant negative effect on Ucrit and aerobic capacity. Active metabolic rates and AS significantly decreased in both selenite exposure groups after the second swim trial. No significant effect was observed in MO2, standard metabolic rate, COT, triglyceride and glycogen levels, or condition factor between groups. These results suggest that aqueous selenite exposure at environmentally relevant concentrations produces adverse effects on aerobic capacity that can diminish endurance and maximum swim speeds, which may lower fish survivability.

  16. 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)

  17. 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 so...... that selenite is a better source than selenate when the Se concentration in the plants has to be raised to a level sufficient for livestock nutrition.......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...

  18. 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

  19. 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

  20. 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.

  1. 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)

  2. 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...

  3. Evaluating the potential for halogen bonding in ketosteroid isomerase’s oxyanion hole using unnatural amino acid mutagenesis

    Science.gov (United States)

    Kraut, Daniel A; Churchil, Michael J; Dawson, Phillip E

    2009-01-01

    There has recently been an increasing interest in controlling macromolecular conformations and interactions through halogen bonding. Halogen bonds are favorable electrostatic interactions between polarized, electropositive chlorine, bromine or iodine atoms and electronegative atoms such as oxygen or nitrogen. These interactions have been likened to hydrogen bonds both in terms of their favored acceptor molecules, their geometries, and their energetics. We asked whether a halogen bond could replace a hydrogen bond in the oxyanion hole of ketosteroid isomerase, using semi-synthetic enzyme containing para-halogenated phenylalanine derivatives to replace the tyrosine hydrogen bond donor. Formation of a halogen bond to the oxyanion in the transition state would be expected to rescue the effects of mutation to phenylalanine, but all of the halogenated enzymes were comparable in activity to the phenylalanine mutant. We conclude that, at least in this active site, a halogen bond cannot functionally replace a hydrogen bond. PMID:19260691

  4. Combining material characterization with single and multi-oxyanion adsorption for mechanistic study of chromate removal by cationic hydrogel

    Institute of Scientific and Technical Information of China (English)

    Irene M. C. Lo; Ke Yin; Samuel C. N. Tang

    2011-01-01

    Cationic hydrogel with magnetic property was synthesized via radical polymerization and its removal capacity of chromate from contaminated water was found to be 200 mg/g.Using Fourier transform infrared spectroscopy (FT-IR) study, the mechanism of chromate removal by hydrogel was found to be non-specific adsorption, mainly due to ion exchange, as evidenced by the positively charged functional group, trimethyl ammonium -N+(CH3)3.in the monomer.Verifications were accordingly determined by testing different oxyanion adsorption onto the hydrogel.The results of the chromate adsorption experiments illustrated that the amount of chromate adsorbed was nearly equal to that of the chloride released from the hydrogel, which is part of the evidence for ion exchange.Single and multi-oxyanion adsorption experiments were also performed, and it was demonstrated that ion removal was species independent, but charge dependent, another characteristic of the ion exchange process.It was found that the same Langmuir model can be applied to best fit the findings of single and multi-oxyanion adsorption, which further indicates the mechanism of chromate removal is attributed to ion exchange.In view of the above, the background anions compete for adsorption sites with chromate,evidenced by inhibitive chromate removal in the presence of background electrolytes in the batch studies, further echoing the ion exchange mechanism.

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. Experimental study and modelling of selenite sorption onto illite and smectite clays.

    Science.gov (United States)

    Missana, T; Alonso, U; García-Gutiérrez, M

    2009-06-15

    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 (from 1x10(-10) to 1x10(-3) M); and independent of ionic strength. Selenite sorption was also analysed in the illite/smectite system with the clays mixed in two different proportions, as follows: (a) 30% illite-70% smectite and (b) 43% illite-57% smectite. 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, separately obtained in the single mineral systems, 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. Although the use of a two-site model slightly improved the fit of data at a pH below 4, the simpler one-site model reproduced satisfactorily all the sorption data from pH 3 to 8. 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 model's predictions were consistent with the experimental adsorption data. PMID:19403144

  10. 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...

  11. 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)

  12. Adsorption behavior of antimony(III) oxyanions on magnetite surface in aqueous organic acid environment

    Science.gov (United States)

    Mittal, Vinit K.; Bera, Santanu; Narasimhan, S. V.; Velmurugan, S.

    2013-02-01

    Antimony(III) adsorption is observed on magnetite (Fe3O4) surface under acidic and reducing condition through surface hydroxyl (SOH) groups bonding on Fe3O4 surface. Desorption of adsorbed Sb(III) is observed from Fe3O4 surface along with iron release in organic acid at 85 °C after 5 h of experiment. Tartaric acid (TA) shows minimum Sb(III) adsorption on Fe3O4 among the organic acid studied. The reason is TA having two sets of adjacent functional groups viz. Odbnd Csbnd OH and Csbnd OH which are responsible for the formation of five-membered bidendate chelate with Sb(III). Other oxyanions, cations or complexing agents along with TA influences the Sb(III) adsorption on Fe3O4. The surface of magnetite is modified by the addition of fatty acids viz. Lauric acid, benzoic acid to bind the Ssbnd OH groups present on the surface. This results in delaying the process of adsorption without changing the quantity of saturation adsorption of Sb(III) on Fe3O4 surface.

  13. Germinating Peanut (Arachis hypogaea L.) Seedlings Attenuated Selenite-Induced Toxicity by Activating the Antioxidant Enzymes and Mediating the Ascorbate-Glutathione Cycle.

    Science.gov (United States)

    Wang, Guang; Zhang, Hong; Lai, Furao; Wu, Hui

    2016-02-17

    Selenite can enhance the selenium nutrition level of crops, but excessive selenite may be toxic to plant growth. To elucidate the mechanisms underlying the role of selenite in production and detoxification of oxidative toxicity, peanut seedlings were developed with sodium selenite (0, 3, and 6 mg/L). The effects of selenite on antioxidant capacity, transcript levels of antioxidant enzyme genes, and enzyme activities in hypocotyl were investigated. The CuZn-SOD, GSH-Px, GST, and APX gene expression levels and their enzyme activities in selenite treatments were 1.0-3.6-fold of the control. Selenite also significantly increased the glutathione and ascorbate concentrations by mediating the ascorbate-glutathione cycle, and the selenite-induced hydrogen peroxide may act as a second messenger in the signaling pathways. This work has revealed a complex antioxidative response to selenite in peanut seedling. Understanding these mechanisms may help future research in increasing selenite tolerance and selenium accumulation in peanut and other crops.

  14. Substrate-dependent Aux cluster: A new insight into Aux/CeO2

    Science.gov (United States)

    Zhu, Kong-Jie; Yang, Yan-Ju; Lang, Jia-Jian; Teng, Bo-Tao; Wu, Feng-Min; Du, Shi-Yu; Wen, Xiao-Dong

    2016-11-01

    To theoretically study the structures of metal clusters on oxides is very important and becomes one of the most challenging works in computational heterogeneous catalysis since many factors affect their structures and lead to various possibilities. In this work, it is very interesting to find that the stable structures and stability evolution of Aux clusters on ceria are varied with different index surfaces of CeO2. The corresponding reasons in chemical, geometric and electronic properties are systematically explored. Aux (x = 1-4) clusters prefer to separately disperse at the O-O bridge sites on CeO2(100) due to the low coordination number of surface O; while aggregate due to the strong Au-Au attractions when x is larger than 4. Owing to the uniform distribution of O-O bridge sites on CeO2(111) and (100), the most stable configurations of Aux are 3D structures with bottom atoms more than top ones when x is larger than 4. However, 2D configurations of Aux/CeO2(110) (x < 10) are more stable than the corresponding 3D structures due to the particular O-O arrangement on CeO2(110). 3D Aux clusters across O-O-Y lines are suggested as the most stable configurations for Aux/CeO2(110) (x ≥ 10). The present work gives a detailed example for the theoretical study of metal clusters on oxide, and will shed light into the design for controllable synthesis of ceria-based catalysts with metal nanoparticles supported on CeO2.

  15. 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.

  16. 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.

  17. Assistance et discipline, introduction aux articles

    Directory of Open Access Journals (Sweden)

    Jean-Claude Vimont

    2012-07-01

    Full Text Available Quand Michel Foucault publie Surveiller et punir en 1975, aux lendemains de trois années de mutineries dans l'univers carcéral, il ne se contente pas d'offrir une généalogie de la prison moderne, mais analyse les systèmes disciplinaires à l'oeuvre dans d'autres institutions. Les études que nous reproduisons dans cette rubrique incitent à une réflexion sur la dimension coercitive de certains dispositifs d'assistance et de soins. Non de manière statique, car les oeuvres, les institutions évolue...

  18. [Uptake and translocation of selenate or selenite by wheat and rice seedlings].

    Science.gov (United States)

    Chen, Si-Yang; Jiang, Rong-Feng; Li, Hua-Fen

    2011-01-01

    Solution culture experiments were carried out to study the uptake and translocation of selenate (Na2SeO4) or selenite (Na2SeO3) by wheat and rice seedlings. When supplied with Na2SeO4 in nutrient solution, the concentrations of selenium (Se) in normal shoots and roots of rice were 30.3 mg x kg(-1) and 39.0 mg x kg(-1) respectively, and the absorbed Se was quickly translocated to shoots accounting for 80% of the total uptake. Se concentrations in wheat shoots and roots were 1.76 mg x kg(-1) and 6.99 mg x kg(-1) respectively, accounting for 62% in shoots. However, when supplied with Na2SeO3, Se concentrations in shoots and roots of rice were 4.40 mg x kg(-1) and 230 mg x kg(-1) respectively, 1.24 mg x kg(-1) and 88.3 mg x kg(-1) in shoots and roots of wheat respectively, and only 8.2% was transferred to shoots. The influence of phosphorus (P) starvation on Se uptake was different for rice and wheat seedlings. Comparing to normal plants, the Se concentrations in the shoots and roots of rice under P starvation condition were decreased, however increased for wheat. In Na2SeO3 uptake kinetics, K(m) of wheat seedlings was 8.7 folds of that of rice, and the affinity of wheat root to selenite was much weaker than that of rice. The Se uptake rate of wheat (V(max)) was 14% lower than that of rice. The uptake and translocation mechanisms of selenate and selenite by rice and wheat seedlings were revealed. And the results demonstrate that the absorbed selenate is quickly translocated to shoot and selenite is mainly accumulated in root. These results provide basic information for biofortification of crops with Se.

  19. 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.

  20. 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

  1. 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...

  2. 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

  3. Redifferentiation of Human Gastric Cancer Cells Induced by Ascorbic Acid and Sodium Selenite

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective To explore the effects and mechanisms of ascorbic acid (AA) and sodium selenite (SS) on growth inhibition and redifferentiation in human gastric cancer cells. Methods In the present study, trypan blue dye exclusion method was used to determine the cell growth curve and mitotic index, cell electrophoresis and colonogenic potential were used as the indexes of redifferentiation. In order to find out the mechanisms of redifferentiation, the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were assayed, the content of malondialdehyde (MDA), reduced glutathione (GSH) and H2O2 were evaluated. Results After treatment with AA 3 mol/L + SS 2μmol/L, the growth rate and mitotic index of human gastric cancer cells (MGc-803) decreased remarkably. The indexes related with cell malignancy were alleviated. For example, cell surface charge was obviously decreased, the electrophoresis rate was dropped from 2.21 to 1.15μm@s-1@V-1@cm-1. The indexes related with cell redifferentiation were promoted. For example, the colonogenic potential was decreased to 93.5%. These results indicated that redifferentiation of human gastric cancer cells was successfully induced by AA + SS. The activities of SOD and GPX were significantly higher, while the activity of CAT was slower in treated group than that in the control. The content of MDA was slightly decreased, GSH was sharply decreased, and H2O2 content was dramatically increased. Conclusion These results indicated that combination of ascorbic acid and sodium selenite may induce the redifferentiation of human gastric cancer cells and inhibit cell growth by virtue of enhancing the activities of antioxidative enzymes and inducing the formation of H2O2, and altering the cell redox status. Combination of ascorbic acid and sodium selenite may be a potent anticancer agent for human gastric cancer.

  4. Ion-beam-induced modifications in the structural and electrical properties of copper oxide selenite nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Rana, Pallavi, E-mail: prana.phy@gmail.com; Chauhan, R.P.

    2015-04-15

    Highlights: •Nanowires were synthesized via template-assisted electrodeposition method. •Copper oxide selenite nanowires were irradiated with 160 MeV, Ni{sup +12} ion beam. •XRD confirmed no change in phase of irradiated nanowires. •Electrical resistivity of nanowires was found to decrease with the ion fluence. -- Abstract: Irradiation with swift heavy ions (SHIs) with energy in the MeV range is a unique tool for engineering the properties of materials. In this context, the objective of the present work is to study the conduction of charge carriers in pre- and post-ion-irradiated semiconducting nanowires. Copper oxide selenite nanowires were synthesized using a template-assisted electrodeposition technique from an aqueous solution of 0.8 M CuSO{sub 4}·5H{sub 2}O and 8 mM SeO{sub 2}. The synthesized nanowires were observed to have a monoclinic structure with linear I–V characteristics (IVC). The effect of irradiation with 160 MeV Ni{sup +12} ions on the properties of the copper oxide selenite nanowires was investigated for fluences varying from 10{sup 11} to 10{sup 13} ions/cm{sup 2}. XRD spectra confirmed no change in the phase of the swift-heavy-ion-irradiated nanowires, but a modification in the orientation of the planes was observed that depended on the ion fluence. The electrical resistivity of the semiconducting nanowires also varied with the ion fluence. Simultaneous irradiation-induced modifications to the electro-chemical potential gradient and the granular properties of the material may have been the origin of the alteration in the structural and electrical properties of the nanowires.

  5. Sodium Selenite Acts as an Otoprotectant against Neomycin-Induced Hair Cell Damage in a Zebrafish Model.

    Science.gov (United States)

    Chang, Jiwon; Choi, June; Rah, Yoon Chan; Yoo, Myung Hoon; Oh, Kyoung Ho; Im, Gi Jung; Lee, Seung Hoon; Kwon, Soon Young; Park, Hae-Chul; Chae, Sung Won; Jung, Hak Hyun

    2016-01-01

    Sodium selenite is a trace element essential for many physiological functions in the body. It is involved in various biological processes; it acts as a cofactor for antioxidant enzymes that protect against free radicals and is reported to limit metal-mediated oxidative DNA damage. In the present study, we investigated the effect of sodium selenite on neomycin ototoxicity in wild-type and transgenic zebrafish (Brn3C: EGFP). Five or six days post-fertilization, zebrafish larvae were co-exposed to 125 μM neomycin and various concentrations (10 μM, 100 μM, 250 μM, and 500 μM) of sodium selenite for 1 h. Hair cells within neuromasts of the supraorbital (SO1 and SO2), otic (O1), and occipital (OC1) lateral lines were analyzed by fluorescence microscopy (n = 10 fish per treatment). Hair cell survival was estimated as the ratio of the hair cell numbers in each group compared to those of the control group that were not exposed to neomycin. Apoptosis and hair cell damage of neuromasts were evaluated using the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) assay and 2-[4-(dimethylamino) styryl]-N-ethylpyridinium iodide (DASPEI) assay, respectively. Ultrastructural changes were evaluated using scanning electron microscopy and transmission electron microscopy. Neuromast hair cells were preserved in zebrafish exposed to 125 μM neomycin and 500 μM sodium selenite for 1 h. Sodium selenite protected against neomycin-induced hair cell loss of neuromasts, reduced apoptosis, and prevented zebrafish ultrastructural changes. We propose that sodium selenite protects against neomycin-induced hair cell damage by inhibiting apoptosis, decreasing the disarray of stereocilia, and preventing ultrastructural changes in the neuromast hair cells of the zebrafish.

  6. 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

  7. Exchange Reaction Between Selenite and Hydroxyl Ion of Variable Charge Soil Surfaces: Ⅱ. Kinetics of Hydroxyl Release

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shi-Wei; ZHANG Gang-Ya; ZHANG Xiao-Nian

    2003-01-01

    A self-made constant pH automated titration instrument was used to study the kinetics of hydroxyl release during selenite reacting with variable charge soils. The rate of hydroxyl release was very rapid at the first several minutes, then gradually slowed down, and at last did not change any more. The experimental data was well fitted by the Langmuir kinetic equation, and with increasing selenite concentration or decreasing solution pH, the reaction lasted longer, the maximum of hydroxyl release (xm) increased, and the binding constant (k) decreased. The time of hydroxyl release with Xuwen latosol was much longer than that with Jinxian red soil.

  8. 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.

  9. Selenium intoxication with selenite broth resulting in acute renal failure and severe gastritis

    Directory of Open Access Journals (Sweden)

    Kamble P

    2009-01-01

    Full Text Available Selenium (Se is an essential trace element in human and animal nutrition. It is also widely utilized in industrial processes. Reports of acute selenium toxicity in humans are rare. We report a case of a 23-year-old female who consumed about 100 mL of liquid selenite broth and presented with severe nausea, vomiting, abdominal pain, hematemesis and acute renal failure (ARF. The serum selenium level was significantly increased. Gastro-duodenoscopy revealed severe corrosive gastritis. Renal biopsy showed features of acute tubular necrosis (ATN, affecting primarily the proximal tubules. The patient was managed with gastric lavage, blood transfusions, infusion of fresh frozen plasma (FFP and platelet concentrates and hemo-dialysis. The patient was discharged five weeks after admission and her renal functions reco-vered completely by eight weeks after admission. She continues to be on regular follow-up for any possible sequelae of mucosal corrosive damage. This case highlights a case of selenium intoxication from selenite broth resulting in ARF and corrosive gastritis. The recovery was complete.

  10. 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

  11. 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...

  12. 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

  13. 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

  14. 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, ...

  15. Effects of sulfate and selenite on mercury methylation in a mercury-contaminated rice paddy soil under anoxic conditions.

    Science.gov (United States)

    Wang, Yongjie; Dang, Fei; Zhong, Huan; Wei, Zhongbo; Li, Ping

    2016-03-01

    Biogeochemical cycling of sulfur and selenium (Se) could play an important role in methylmercury (MeHg) dynamics in soil, while their potential effects on MeHg production in rice paddy soil are less understood. The main objective of this study was to explore the effects of sulfate and selenite on net MeHg production in contaminated rice paddy soil, characterized with massive MeHg production and thus MeHg accumulation in rice. A series of microcosm incubation experiments were conducted using a contaminated paddy soil amended with sulfate and/or selenite, in which sulfate-reducing bacteria were mainly responsible for MeHg production. Our results demonstrated that sulfate addition reduced solid and dissolved MeHg levels in soils by ≤18 and ≤25 %, respectively. Compared to sulfate, selenite was more effective in inhibiting net MeHg production, and the inhibitory effect depended largely on amended selenite doses. Moreover, sulfate input played a dual role in affecting Hg-Se interactions in soil, which could be explained by the dynamics of sulfate under anoxic conditions. Therefore, the effects of sulfate and selenium input should be carefully considered when assessing risk of Hg in anoxic environments (e.g., rice paddy field and wetland).

  16. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Truong, Hoang-Yen T. [Department of Biology, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Chen, Yu-Wei [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Belzile, Nelson, E-mail: nbelzile@laurentian.ca [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada); Cooperative Freshwater Ecology Unit, Laurentian University, Sudbury, Ontario, Canada P3E 2C6 (Canada)

    2013-04-01

    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 CuSO{sub 4} 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 Hg{sup 2+}, 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 Hg{sup 2+} to a culture ended up in a solid phase (Hg{sup 0} 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 H{sub 2}S 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.

  18. 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

  19. 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

    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......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...

  20. 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...

  1. 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...

  2. 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)

  3. 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.

  4. 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

  5. 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.

  6. Arsenic and other oxyanion-forming trace elements in an alluvial basin aquifer: Evaluating sources and mobilization by isotopic tracers (Sr, B, S, O, H, Ra)

    Energy Technology Data Exchange (ETDEWEB)

    Vinson, David S., E-mail: dsv3@duke.edu [Duke University, Division of Earth and Ocean Sciences, Box 90227, Durham, NC 27708 (United States); McIntosh, Jennifer C. [University of Arizona, Department of Hydrology and Water Resources, 1133 E. James E. Rogers Way, Tucson, AZ 85721 (United States); Dwyer, Gary S.; Vengosh, Avner [Duke University, Division of Earth and Ocean Sciences, Box 90227, Durham, NC 27708 (United States)

    2011-08-15

    Highlights: > Elevated natural As and F occur in the Willcox Basin aquifer of Arizona. > Oxyanion-forming elements are derived from volcanic-source aquifer sediments. > Sr isotopes trace sediment sources linked to oxyanion-forming trace elements. > {sup 87}Sr/{sup 86}Sr > 0.720 indicates Proterozoic crystalline-source sediment contributing low As. > Both sediment source and hydrogeochemical evolution (Ca/Na) affect As levels. - Abstract: The Willcox Basin is a hydrologically closed basin in semi-arid southeastern Arizona (USA) and, like many other alluvial basins in the southwestern USA, is characterized by oxic, near-neutral to slightly basic groundwater containing naturally elevated levels of oxyanion-forming trace elements such as As. This study evaluates the sources and mobilization of these oxyanionic trace elements of health significance by using several isotopic tracers of water-rock interaction and groundwater sources ({sup 87}Sr/{sup 86}Sr, {delta}{sup 34}S{sub SO4}, {delta}{sup 11}B, {delta}{sup 2}H, {delta}{sup 18}O, {sup 3}H). Values of {delta}{sup 2}H (-85 per mille to -64 per mille) and {delta}{sup 18}O (-11.8 per mille to -8.6 per mille) are consistent with precipitation and groundwater in adjacent alluvial basins, and low to non-detectable {sup 3}H activities further imply that modern recharge is slow in this semi-arid environment. Large variations in {sup 87}Sr/{sup 86}Sr ratios imply that groundwater has interacted with multiple sediment sources that constitute the basin-fill aquifer, including Tertiary felsic volcanic rocks, Paleozoic sedimentary rocks, and Proterozoic crystalline rocks. In general, low concentrations of oxyanion-forming trace elements and F{sup -} are associated with a group of waters exhibiting highly radiogenic values of {sup 87}Sr/{sup 86}Sr (0.72064-0.73336) consistent with waters in Proterozoic crystalline rocks in the mountain blocks (0.73247-0.75010). Generally higher As concentrations (2-29 {mu}g L{sup -1}), other

  7. 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.

  8. 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

  9. 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

  10. 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

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

    Directory of Open Access Journals (Sweden)

    Bahaa A. Abdul-Hussein

    2015-08-01

    Full Text Available 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 intravitreal injection of 0.1ml sodium selenite 0.01 wv in the right eye. Results Heparin sodium was effective in prevention of cataract and the mean score of opacity was 0.170.01 at the end of trial period in stead of the expected score 4 0.00 which observed in DW group and there was non significant difference comparing to pre induction p0.05. Conclusions Heparin sodium eye drops exerted a detectable preventive effect against sodium selenite - induced cataract in rabbits also it was found to be apparently safe and tolerable along the trial period.

  12. 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 < 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. Copyright ?? 2007, American Society for Microbiology. All Rights Reserved.

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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

  18. 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)

  19. Investigating different mechanisms for biogenic selenite transformations: Geobacter sulfurreducens, Shewanella oneidensis and Veillonella atypica

    Science.gov (United States)

    Pearce, C.I.; Pattrick, R.A.D.; Law, N.; Charnock, J.M.; Coker, V.S.; Fellowes, J.W.; Oremland, R.S.; Lloyd, J.R.

    2009-01-01

    The metal-reducing bacteria Geobacter sulfurreducens, Shewanella oneidensis and Veillonella atypica, use different mechanisms to transform toxic, bioavailable sodium selenite to less toxic, non-mobile elemental selenium and then to selenide in anaerobic environments, offering the potential for in situ and ex situ bioremediation of contaminated soils, sediments, industrial effluents, and agricultural drainage waters. The products of these reductive transformations depend on both the organism involved and the reduction conditions employed, in terms of electron donor and exogenous extracellular redox mediator. The intermediary phase involves the precipitation of elemental selenium nanospheres and the potential role of proteins in the formation of these structures is discussed. The bionanomineral phases produced during these transformations, including both elemental selenium nanospheres and metal selenide nanoparticles, have catalytic, semiconducting and light-emitting properties, which may have unique applications in the realm of nanophotonics. This research offers the potential to combine remediation of contaminants with the development of environmentally friendly manufacturing pathways for novel bionanominerals. ?? 2009 Taylor & Francis.

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

    Science.gov (United States)

    Kong, Fang; Li, Pei-Xin; Zhang, Su-Yun; Mao, Jiang-Gao

    2012-06-01

    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.

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

    Directory of Open Access Journals (Sweden)

    El Okda, E. A.

    2016-04-01

    Full Text Available 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 (NaSeO bodyweight, except the control groups NC (negative control, did not receive NaSeO 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-Ae, 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.

  2. 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...

  3. Mechanism(s of Toxic Action of Zn2+ and Selenite: A Study on AS-30D Hepatoma Cells and Isolated Mitochondria

    Directory of Open Access Journals (Sweden)

    Elena A. Belyaeva

    2011-01-01

    Full Text Available Mitochondria of AS-30D rat ascites hepatoma cells are found to be the main target for Zn2+ and sodium selenite (Na2SeO3. High [mu]M concentrations of Zn2+ or selenite were strongly cytotoxic, killing the AS-30D cells by both apoptotic and necrotic ways. Both Zn2+ and selenite produced strong changes in intracellular generation of reactive oxygen species (ROS and the mitochondrial dysfunction via the mitochondrial electron transport chain (mtETC disturbance, the membrane potential dissipation, and the mitochondrial permeability transition pore opening. The significant distinctions in toxic action of Zn2+ and selenite on AS-30D cells were found. Selenite induced a much higher intracellular ROS level (the early event compared to Zn2+ but a lower membrane potential loss and a lower decrease of the uncoupled respiration rate of the cells, whereas the mtETC disturbance was the early and critical event in the mechanism of Zn2+ cytotoxicity. Sequences of events manifested in the mitochondrial dysfunction produced by the metal/metalloid under test are compared with those obtained earlier for Cd2+, Hg2+, and Cu2+ on the same model system.

  4. Atomic resolution structure of a lysine-specific endoproteinase from Lysobacter enzymogenes suggests a hydroxyl group bound to the oxyanion hole.

    Science.gov (United States)

    Asztalos, Peter; Müller, Astrid; Hölke, Werner; Sobek, Harald; Rudolph, Markus G

    2014-07-01

    Lysobacter enzymogenes lysyl endoproteinase (LysC) is a trypsin-type serine protease with a high pH optimum that hydrolyses all Lys-Xaa peptide bonds. The high specificity of LysC renders it useful for biotechnological purposes. The K30R variant of a related lysyl endoproteinase from Achromobacter lyticus has favourable enzymatic properties that might be transferrable to LysC. To visualize structural differences in the substrate-binding sites, the crystal structures of wild-type and the K30R variant of LysC were determined. The mutation is located at a distance of 12 Å from the catalytic triad and subtly changes the surface properties of the substrate-binding site. The high pH optimum of LysC can be attributed to electrostatic effects of an aromatic Tyr/His stack on the catalytic aspartate and is a general feature of this enzyme subfamily. LysC crystals in complex with the covalent inhibitor N(α)-p-tosyl-lysyl chloromethylketone yielded data to 1.1 and 0.9 Å resolution, resulting in unprecedented precision of the active and substrate-binding sites for this enzyme subfamily. Error estimates on bond lengths and difference electron density indicate that instead of the expected oxyanion a hydroxyl group binds to the partially solvent-exposed oxyanion hole. Protonation of the alkoxide catalytic intermediate might be a recurring feature during serine protease catalysis.

  5. Lupeol, a pentacyclic triterpenoid isolated from Vernonia cinerea attenuate selenite induced cataract formation in Sprague Dawley rat pups.

    Science.gov (United States)

    Asha, Radha; Gayathri Devi, V; Abraham, Annie

    2016-02-01

    This study investigated the inhibitory effects of active component isolated from flavonoid fraction of Vernonia cinerea (FVC), lupeol on selenite induced cataract formation. Previous reports suggest that phytochemicals or natural plant products retard the process of cataractogenesis by scavenging free oxygen radicals. Hence, the present study sought to assess the potential of lupeol on in vivo selenite induced cataract models. Lupeol, a pentacyclic triterpenoid, was isolated from the ethyl acetate fraction of methanolic extract of Vernonia cinerea, follows standard chromatographic techniques. Structural elucidation of the compound was carried out using (1)H NMR, (13)C NMR, Mass spectrometry together with other complementary techniques (UV and IR). From these, the isolated compound was identified as Lupeol (3'-hydroxylup-20(29)-ene). The antioxidant activity was comparatively studied using DPPH radical scavenging and FRAP assay. Lupeol exhibited higher DPPH radical scavenging activity as well as reducing power assay. In this study, cataract was induced by a single subcutaneous injection of sodium selenite (4 μg/g body weight) on rat pups. Lupeol was administered orally from 8th day upto 21st day at a concentration 25 μg/g body weight. Cataract was visualized on 16th day with the help of an ophthalmoscope and later on with the naked eye. On the 30th day, rats were euthanized by sodium pentothal injection, lenses were excised and the biochemical parameters such as activity of superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx), Glutathione reductase (GR), Glutathione-S-transferase (GST), Ca(2+) ATPase, glutathione content (GSH), reactive oxygen species (ROS), lipid peroxidation products (malondialdehyde) were estimated and found effective in the treatment of cataract by lupeol.

  6. Selenite reduction in boom clay: effect of FeS{sub 2}, clay minerals and dissolved organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Bruggeman, C.; Maes, A.; Vancluysen, J. [Katholieke Universiteit Leuven, Lab. for Colloid Chemistry, Leuven (Belgium)

    2005-07-01

    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. {sup 79}Se is thought to occur in, and be released from the solid waste matrix in a variety of redox states, including Se oxyanions such as SeO{sub 3}{sup 2-} or SeO{sub 4}{sup 2-}. 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 SeO{sub 3}{sup 2-} in over-saturation with respect to the proclaimed thermodynamical solubility of reduced Se solid phases (SeO, FeSe, FeSe{sub 2}), 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)

  7. 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.

  8. 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)

  9. Field study of time-dependent selenium partitioning in soils using isotopically enriched stable selenite tracer.

    Science.gov (United States)

    Di Tullo, Pamela; Pannier, Florence; Thiry, Yves; Le Hécho, Isabelle; Bueno, Maïté

    2016-08-15

    A better understanding of selenium fate in soils at both short and long time scales is mandatory to consolidate risk assessment models relevant for managing both contamination and soil fertilization issues. The purpose of this study was thus to investigate Se retention processes and their kinetics by monitoring time-dependent distribution/speciation changes of both ambient and freshly added Se, in the form of stable enriched selenite-77, over a 2-years field experiment. This study clearly illustrates the complex reactivity of selenium in soil considering three methodologically defined fractions (i.e. soluble, exchangeable, organic). Time-dependent redistribution of Se-77 within solid-phases having different reactivity could be described as a combination of chemical and diffusion controlled processes leading to its stronger retention. Experimental data and their kinetic modeling evidenced that transfer towards less labile bearing phases are controlled by slow processes limiting the overall sorption of Se in soils. These results were used to estimate time needed for (77)Se to reach the distribution of naturally present selenium which may extend up to several decades. Ambient Se speciation accounted for 60% to 100% of unidentified species as function of soil type whereas (77)Se(IV) remained the more abundant species after 2-years field experiment. Modeling Se in the long-term without taking account these slow sorption kinetics would thus result in underestimation of Se retention. When using models based on Kd distribution coefficient, they should be at least reliant on ambient Se which is supposed to be at equilibrium. PMID:27100008

  10. 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....

  11. 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...

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

    OpenAIRE

    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 usin...

  13. 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...

  14. The Combination of α-Tocopheryl Succinate and Sodium Selenite on Breast Cancer: A Merit or a Demerit?

    Directory of Open Access Journals (Sweden)

    Doaa M. Badr

    2016-01-01

    Full Text Available α-Tocopheryl succinate (α-TOS, a mitochondria-targeting agent, induces apoptosis in malignant cells in vitro and in vivo. Selenite is a nutritional supplement that has been shown to stimulate apoptosis in cancer cells. This study was designed to investigate the cytotoxic effect of combined treatment of α-TOS and sodium selenite (SSe in vitro and in vivo and to explore their effect on apoptosis and autophagy in breast cancer. The type of interaction between α-TOS and SSe was evaluated and levels of oxidative stress and apoptotic and autophagic markers were determined. SSe alone showed varying degrees of cytotoxicity on all the tested cell lines. Its combination with α-TOS was antagonistic in vitro in MCF7 and in vivo in mice bearing Ehrlich tumor compared to α-TOS-treated one. Combination of TOS with 2 μM of SSe increased the level of glutathione without changes in antiapoptotic markers Bcl-2 and Mcl-1 at 16 and 48 hrs. SSe decreased caspase 3 activity and protein level of caspases 7 and 9, while it increased autophagic markers beclin-1 and LC3B protein levels of MCF7 cells treated with α-TOS. In conclusion, SSe antagonizes α-TOS-induced apoptosis via inhibition of oxidative stress and promoting prosurvival machinery of autophagy.

  15. Molecular Structures of Al/Si and Fe/Si Coprecipitates and the Implication for Selenite Removal.

    Science.gov (United States)

    Chan, Ya-Ting; Kuan, Wen-Hui; Tzou, Yu-Min; Chen, Tsan-Yao; Liu, Yu-Ting; Wang, Ming-Kuang; Teah, Heng-Yi

    2016-04-20

    Aluminum and iron oxides have been often used in the coagulation processes during water purification due to their unique surface properties toward anions. In the presence of silica, the coprecipitation of Al/Si or Fe/Si might decrease the efficiency of wastewater purification and reuse. In this study, surface properties and molecular structures of Al/Si and Fe/Si coprecipitates were characterized using spectroscopic techniques. Also, the selenite removal efficiency of Al/Si and Fe/Si coprecipitates in relation to their surface and structural properties was investigated. While dissolved silicate increased with increasing pH from Fe/Si coprecipitates, less than 7% of silicate was discernible from Al/Si samples over the range from acidic to alkaline conditions. Our spectroscopic results showed that the associations between Al and Si were relatively stronger than that between Fe and Si in coprecipitates. In Al/Si coprecipitates, core-shell structures were developed with AlO6/AlO4 domains as the shells and Si frameworks polymerized from the SiO2 as the cores. However, Si framework remained relatively unchanged upon coprecipitation with Fe hydroxides in Fe/Si samples. The Si core with Al shell structure of Al/Si coprecipitates shielded the negative charges from SiO2 and thereby resulted in a higher adsorption capacity of selenite than Fe/Si coprecipitates.

  16. Molecular Structures of Al/Si and Fe/Si Coprecipitates and the Implication for Selenite Removal

    Science.gov (United States)

    Chan, Ya-Ting; Kuan, Wen-Hui; Tzou, Yu-Min; Chen, Tsan-Yao; Liu, Yu-Ting; Wang, Ming-Kuang; Teah, Heng-Yi

    2016-04-01

    Aluminum and iron oxides have been often used in the coagulation processes during water purification due to their unique surface properties toward anions. In the presence of silica, the coprecipitation of Al/Si or Fe/Si might decrease the efficiency of wastewater purification and reuse. In this study, surface properties and molecular structures of Al/Si and Fe/Si coprecipitates were characterized using spectroscopic techniques. Also, the selenite removal efficiency of Al/Si and Fe/Si coprecipitates in relation to their surface and structural properties was investigated. While dissolved silicate increased with increasing pH from Fe/Si coprecipitates, less than 7% of silicate was discernible from Al/Si samples over the range from acidic to alkaline conditions. Our spectroscopic results showed that the associations between Al and Si were relatively stronger than that between Fe and Si in coprecipitates. In Al/Si coprecipitates, core-shell structures were developed with AlO6/AlO4 domains as the shells and Si frameworks polymerized from the SiO2 as the cores. However, Si framework remained relatively unchanged upon coprecipitation with Fe hydroxides in Fe/Si samples. The Si core with Al shell structure of Al/Si coprecipitates shielded the negative charges from SiO2 and thereby resulted in a higher adsorption capacity of selenite than Fe/Si coprecipitates.

  17. XAS and XFM studies of selenium and copper speciation and distribution in the kidneys of selenite-supplemented rats.

    Science.gov (United States)

    Weekley, Claire M; Shanu, Anu; Aitken, Jade B; Vogt, Stefan; Witting, Paul K; Harris, Hugh H

    2014-09-01

    Dietary selenium has been implicated in the prevention of cancer and other diseases, but its safety and efficacy is dependent on the supplemented form and its metabolites. In this study, X-ray absorption spectroscopy (XAS) and X-ray fluorescence microscopy (XFM) have been used to investigate the speciation and distribution of Se and Cu in vivo. In kidneys isolated from rats fed a diet containing 5 ppm Se as selenite for 3 weeks, Se levels increased 5-fold. XFM revealed a strong correlation between the distribution of Se and the distribution of Cu in the kidney, a phenomenon that has previously been observed in cell culture (Weekley et al., JBIC, J. Biol. Inorg. Chem., 2014, DOI: 10.1007/s00775-014-1113-x). However, X-ray absorption spectra suggest that most of the Se in the kidney is found as Se-Se species, rather than Cu-bound, and that most of the Cu is bound to S and N, presumably to amino acid residues in proteins. Furthermore, SOD1 expression did not change in response to the high Se diet. We cannot rule out the possibility of some Cu-Se bonding in the tissues, but our results suggest mechanisms other than the formation of Cu-Se species and SOD1 upregulation are responsible for the highly correlated distributions of Se and Cu in the kidneys of rats fed high selenite diets.

  18. 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.

  19. 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...

  20. 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

  1. 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.

  2. 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...

  3. 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

    2016-03-17

    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.

  4. 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.; 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

  5. 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.

  6. SYNTHESIS OF pH-RESPONSIVE AMPHIPHILIC DIBLOCK COPOLYMERS CONTAINING POLYISOBUTYLENE via OXYANION-INITIATED POLYMERIZATION AND THEIR MULTIPLE SELF-ASSEMBLY MORPHOLOGIES

    Institute of Scientific and Technical Information of China (English)

    Huai-chao Wang; Ming-zu Zhang; Pei-hong Ni; Jin-lin He; Ying Hao; Yi-xian Wu

    2013-01-01

    Two pH-responsive amphiphilic diblock copolymers,namely polyisobutylene-block-poly[2-(N,N-dimethylamino)ethyl methacrylate] (PIB-b-PDMAEMA) and polyisobutylene-block-poly(metharylic acid) (PIB-b-PMAA),were synthesized via oxyanion-initiated polymerization,and their multiple self-assembly behaviors have been studied.An exo-o1efin-terminated highly reactive polyisobutylene (HRPIB) was first changed to hydroxyl-terminated PIB (PIB-OH) via hydroboration-oxidation of C=C double bond in the chain end,and then reacted with KH to yield a potassium alcoholate of PIB (PIB-O-K+).PIB-O-K+ was immediately used as a macroinitiator to polymerize DMAEMA monomer,resulting in a cationic diblock copolymer PIB-b-PDMAEMA.With the similar synthesis procedure,the anionic diblock copolymer PIB-b-PMAA could be prepared via a combination of oxyanion-initiated polymerization of tert-butyl methacrylate (tBMA) and subsequent hydrolysis of tert-butyl ester groups in PtBMA block.The functional PIB and block copolymers have been fully characterized by 1H-NMR,FT-IR spectroscopy,and gel permeation chromatography (GPC).These samples allowed us to systematically investigate the effects of block composition on the pH responsivity and various self-assembled morphologies of the copolymers in THF/water mixed solvent.Transmission electron microscopy (TEM) images revealed that these diblock copolymers containing small amount of original PIB without exo-olefin-terminated group are able to self-assemble into micelles,vesicles with different particle sizes and cylindrical aggregates,depending on various factors including block copolymer composition,solvent polarity and pH value.

  7. 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.

  8. OVER- EXPRESSION OF AN AUX1 HOMOLOG TRIGGERS OVARY INITIATION IN VITRO OF POPULUS TOMENTOSA CARR.

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    PtAUX1, an ortholog of Arabidopsis AtAUX1 ( encoding auxin influx carrier protein), has been cloned from Populus tomentosa. PtAUX1 protein is similar to Arabidopsis AtAUX1 in structure, but PtAUX1 contains an additional cAMP/cGMP - dependent protein kinase phosphorylation site. Its overexpression lines driven by 35S promoter exhibits a novel phenotype related flower development which has not been revealed in AtAUX1 mutants. Ovary - like structures each with 1 ~ 2 styles, but without a cup - like disc and a bract, can initial from regenerated transgenic bud in cluster,resembling an inflorescence. The histological dissections illuminate that the ovary - like structures have womb and transmitting tissue inner its styles, but no ovules. PtAUX1 expression pattern are ubiquitous and various in different organs,which is coincident with its candidate auxin influx, functioning in distributing auxin thorough a plant body. These results suggest that PtAUX1 or polar auxin transport has a substantial function in floral organ initiation.

  9. 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

  10. 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...

  11. Feticismo e desiderio in Poulet aux prunes di Marjane Satrapi

    Directory of Open Access Journals (Sweden)

    Stefania Rimini

    2013-05-01

    Full Text Available Il saggio si propone di individuare e descrivere le sfumature erotiche e sentimentali del film Poulet aux prunes di Marjane Satrapi, felice adattamento dell’omonima graphic novel. Il racconto procede per scarti, ellissi, anticipazioni e flasback, dando luogo a una narrazione labirintica dalla singolare trama arabescante. Le sottili dinamiche seduttive messe in campo dal complesso stile di regia di Satrapi-Paronnaud vengono analizzate alla luce delle categorie feticistiche individuate da Massimo Fusillo, che offrono interessanti modelli di interazione fra desiderio e creatività. L’esito di tale indagine consente di ampliare il dibattito relativo al rapporto di scambio e interferenza fra oggetti, pulsioni e sguardi nel cinema contemporaneo.

  12. 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 ...

  13. 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...

  14. 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.

  15. 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.

  16. 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.

  17. OsAUX1 controls lateral root initiation in rice (Oryza sativa L.).

    Science.gov (United States)

    Zhao, Heming; Ma, Tengfei; Wang, Xin; Deng, Yingtian; Ma, Haoli; Zhang, Rongsheng; Zhao, Jie

    2015-11-01

    Polar auxin transport, mediated by influx and efflux transporters, controls many aspects of plant growth and development. The auxin influx carriers in Arabidopsis have been shown to control lateral root development and gravitropism, but little is known about these proteins in rice. This paper reports on the functional characterization of OsAUX1. Three OsAUX1 T-DNA insertion mutants and RNAi knockdown transgenic plants reduced lateral root initiation compared with wild-type (WT) plants. OsAUX1 overexpression plants exhibited increased lateral root initiation and OsAUX1 was highly expressed in lateral roots and lateral root primordia. Similarly, the auxin reporter, DR5-GUS, was expressed at lower levels in osaux1 than in the WT plants, which indicated that the auxin levels in the mutant roots had decreased. Exogenous 1-naphthylacetic acid (NAA) treatment rescued the defective phenotype in osaux1-1 plants, whereas indole-3-acetic acid (IAA) and 2,4-D could not, which suggested that OsAUX1 was a putative auxin influx carrier. The transcript levels of several auxin signalling genes and cell cycle genes significantly declined in osaux1, hinting that the regulatory role of OsAUX1 may be mediated by auxin signalling and cell cycle genes. Overall, our results indicated that OsAUX1 was involved in polar auxin transport and functioned to control auxin-mediated lateral root initiation in rice.

  18. 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

  19. 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

  20. 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...

  1. 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.

  2. 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...

  3. 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.

  4. 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

  5. Combination of Oxyanion Gln114 Mutation and Medium Engineering to Influence the Enantioselectivity of Thermophilic Lipase from Geobacillus zalihae

    Directory of Open Access Journals (Sweden)

    Thean Chor Leow

    2012-09-01

    Full Text Available The substitution of the oxyanion Q114 with Met and Leu was carried out to investigate the role of Q114 in imparting enantioselectivity on T1 lipase. The mutation improved enantioselectivity in Q114M over the wild-type, while enantioselectivity in Q114L was reduced. The enantioselectivity of the thermophilic lipases, T1, Q114L and Q114M correlated better with log p as compared to the dielectric constant and dipole moment of the solvents. Enzyme activity was good in solvents with log p < 3.5, with the exception of hexane which deviated substantially. Isooctane was found to be the best solvent for the esterification of (R,S-ibuprofen with oleyl alcohol for lipases Q114M and Q114L, to afford E values of 53.7 and 12.2, respectively. Selectivity of T1 was highest in tetradecane with E value 49.2. Solvents with low log p reduced overall lipase activity and dimethyl sulfoxide (DMSO completely inhibited the lipases. Ester conversions, however, were still low. Molecular sieves employed as desiccant were found to adversely affect catalysis in the lipase variants, particularly in Q114M. The higher desiccant loading also increased viscosity in the reaction and further reduced the efficiency of the lipase-catalyzed esterifications.

  6. 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.

  7. 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

  8. Exchange Reaction Between Selenite and Hydroxyl Ion of Variable Charge Soil Surfaces:I.Electrolyte Species and pH Effects

    Institute of Scientific and Technical Information of China (English)

    ZHOU SHIWEI; ZHANG GANGYA; ZHANG XIAONIAN

    2003-01-01

    Hydroxyl release of red soil and latosol surfaces was quantitatively measured using a self-made constantpH automated titration instrument, to study the changes of hydroxyl release with different added seleniteamounts and pH levels, and to study the effects of electrolytes on hydroxyl release. Hydroxyl release increasedwith the selenite concentration, with a rapid increase at a low selenite concentration while slowing down ata high concentration. The pH where maximum of hydroxyl release appeared was not constant, shifting toa lower valus with increasing selenite concentration. Hydroxyl release decreased with increasing electrolyteconcentration, and the decrease was very rapid at a low electrolyte concentration but slow at a high electrolyteconcentration. For NaC1O4, NaC1 and Na2SO4, hydroxyl release was in the order of NaClO4 > NaCl >Na2SO4, and the difference was very significant. But for NaCl, KCl and CaCl2, the order of hydroxyl releasewas NaCl > KCl > CaCl2, and the difference was smaller. The amount of hydroxyl release from Xuwenlatosol was greater than that from Jinxian red soil. Hydroxyl release existed in a wider range of pH withXuwen latosol than with Jinxian red soil, due to their difference in soil properties. However, both soils hadsimilar curves of hydroxyl release, indicating the common characteristics of variable charge soils.

  9. 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...

  10. 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

  11. Puzzolanic cements of greater resistance at the attack of selenitic waters than the high sulfate resistance portland cements, and viceverse

    Directory of Open Access Journals (Sweden)

    Talero, Rafael

    1987-09-01

    Full Text Available This work confirms the certainty of the predictions of useful service given by Kaluosek and al. for the sulphate resistant portland cements (type V, USA, subject to severe selenitic attack. Two sulphate resistant portland cements, were tested by means of the Le Chatelier Anstett method. The tarts were destroyed at ages of three years, having detected in them the presence of thaumasite by XRD. Even so, the impossibility and possibility thaumasite formation was confirmed in pozzolanic cements tarts, which either had or did not have adequate amount of pozzolana (diatomite for such purpose.

    Este trabajo confirman las predicciones de vida útil dadas por Kalousek y colaboradores, para los cementos portland de elevada resistencia al ataque de los iones sulfato (tipo V, USA, sometidos a un severo ataque selenitoso. Se ensayaron dos cementos portland de elevada resistencia al ataque del yeso, mediante el ensayo de Le Chatelier-Anstett. Sus tortas correspondientes se destruyeron a la edad de tres años, habiéndose detectado en las mismas la presencia de thaumasita por DRX. Asimismo se confirmó la imposibilidad y posibilidad de formación de thaumasita en tortas de cementos puzolánicos, los cuales tenían, o no, respectivamente, una adecuada cantidad de puzolana (diatomita para tales fines.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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.).

  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. 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

  19. 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...

  20. 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.)

  1. 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.

  2. The carrier AUXIN RESISTANT (AUX1) dominates auxin flux into Arabidopsis protoplasts.

    Science.gov (United States)

    Rutschow, Heidi L; Baskin, Tobias I; Kramer, Eric M

    2014-11-01

    The ability of the plant hormone auxin to enter a cell is critical to auxin transport and signaling. Auxin can cross the cell membrane by diffusion or via auxin-specific influx carriers. There is little knowledge of the magnitudes of these fluxes in plants. Radiolabeled auxin uptake was measured in protoplasts isolated from roots of Arabidopsis thaliana. This was done for the wild-type, under treatments with additional unlabeled auxin to saturate the influx carriers, and for the influx carrier mutant auxin resistant 1 (aux1). We also used flow cytometry to quantify the relative abundance of cells expressing AUX1-YFP in the assayed population. At pH 5.7, the majority of auxin influx into protoplasts - 75% - was mediated by the influx carrier AUX1. An additional 20% was mediated by other saturable carriers. The diffusive influx of auxin was essentially negligible at pH 5.7. The influx of auxin mediated by AUX1, expressed as a membrane permeability, was 1.5 ± 0.3 μm s(-1) . This value is comparable in magnitude to estimates of efflux permeability. Thus, auxin-transporting tissues can sustain relatively high auxin efflux and yet not become depleted of auxin.

  3. Oligomerization of SCFTIR1 Is Essential for Aux/IAA Degradation and Auxin Signaling in Arabidopsis.

    Science.gov (United States)

    Dezfulian, Mohammad H; Jalili, Espanta; Roberto, Don Karl A; Moss, Britney L; Khoo, Kerry; Nemhauser, Jennifer L; Crosby, William L

    2016-09-01

    The phytohormone auxin is a key regulator of plant growth and development. Molecular studies in Arabidopsis have shown that auxin perception and signaling is mediated via TIR1/AFB-Aux/IAA co-receptors that assemble as part of the SCFTIR1/AFB E3 ubiquitin-ligase complex and direct the auxin-regulated degradation of Aux/IAA transcriptional repressors. Despite the importance of auxin signaling, little is known about the functional regulation of the TIR1/AFB receptor family. Here we show that TIR1 can oligomerize in planta via a set of spatially clustered amino acid residues. While none of the residues identified reside in the interaction interface of the TIR1-Aux/IAA degron, they nonetheless regulate the binding of TIR1 to Aux/IAA substrate proteins and their subsequent degradation in vivo as an essential aspect of auxin signaling. We propose oligomerization of TIR1 as a novel regulatory mechanism in the regulation of auxin-mediated plant patterning and development. PMID:27618443

  4. Oligomerization of SCFTIR1 Is Essential for Aux/IAA Degradation and Auxin Signaling in Arabidopsis.

    Science.gov (United States)

    Dezfulian, Mohammad H; Jalili, Espanta; Roberto, Don Karl A; Moss, Britney L; Khoo, Kerry; Nemhauser, Jennifer L; Crosby, William L

    2016-09-01

    The phytohormone auxin is a key regulator of plant growth and development. Molecular studies in Arabidopsis have shown that auxin perception and signaling is mediated via TIR1/AFB-Aux/IAA co-receptors that assemble as part of the SCFTIR1/AFB E3 ubiquitin-ligase complex and direct the auxin-regulated degradation of Aux/IAA transcriptional repressors. Despite the importance of auxin signaling, little is known about the functional regulation of the TIR1/AFB receptor family. Here we show that TIR1 can oligomerize in planta via a set of spatially clustered amino acid residues. While none of the residues identified reside in the interaction interface of the TIR1-Aux/IAA degron, they nonetheless regulate the binding of TIR1 to Aux/IAA substrate proteins and their subsequent degradation in vivo as an essential aspect of auxin signaling. We propose oligomerization of TIR1 as a novel regulatory mechanism in the regulation of auxin-mediated plant patterning and development.

  5. 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

  6. 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.

  7. 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.

  8. Application of real-time RT-PCR quantification to evaluate differential expres sion of Arabidopsis Aux/IAAgenes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The molecular techniques including Northern blot, dot blot, in situ hybridization, etc. have been success fully used to estimate semi-quantitatively mRNA levels in plant samples. In this study, we employed a real-time reverse transcription-PCR (RT-PCR) assay using SYBR Green Ifluorescence methodology to evaluate accurate quant itation and sequence specific detection of Aux/IAA mRNA levels in Arabidopsis. Results obtained indicate a linear dynamic range of 102-106 Aux/IAA mRNA copies with standard de viations of generally less than 15%. As a model experiment,the outcome of analysis of expression patterns of five Aux/IAA genes in Arabidopsis under various chemical and temperature treatments is presented. The method presented here provides a sensitive and rapid technique to evaluate plant Aux/IAA mRNA expression levels in nanogram order.

  9. 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...

  10. 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.

  11. 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.)

  12. 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.

  13. Optimization of an anion-exchange high performance liquid chromatography-inductively coupled plasma-mass spectrometric method for the speciation analysis of oxyanion-forming metals and metalloids in leachates from cement-based materials.

    Science.gov (United States)

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

    2010-10-01

    A method was developed for the speciation analysis of the oxyanions of As(III), As(V), Cr(VI), Mo(VI), Sb(III), Sb(V), Se(IV), Se(VI) and V(V) in leachates from cement-based materials, based on anion-exchange HPLC coupled with ICP-MS. The method was optimized in a two-step multivariate approach: the effect of sample pH and mobile phase composition on resolution, peak symmetry and analysis time was studied. Optimum conditions were then identified for the significant experimental factors by studying their interdependence. A mobile phase composition of 20 mM ammonium nitrate, 50 mM ammonium tartrate and pH 9.5 was found to be a compromise optimum for the separation of the target analytes using isocratic elution. The optimum condition provided separation of the analytes in less than 6 min, at a mobile phase flow rate of 1.0 mL/min. The signal intensities of the analytes were improved by adding 1% methanol to the mobile phase. The limit of detection of the method was in the range 0.2-2.2 μg/L for the various species. The effect of sample constituents was studied using spiked concrete leachates. The method was used to determine the target oxyanionic species in leachates generated from a concrete material in the pH range 3.5-12.4; CrO(4)(2-), MoO(4)(2-) and VO(4)(3-) were detected in most of the leachates.

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

    DEFF Research Database (Denmark)

    Cao, Zhen; Wu, Lin-Ping; Li, Yun-Xia;

    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. (1)H-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 (1)H-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...

  15. Selenite Effect on the Content of Mercury in Chicken Blood and Tissue%硒对雏鸡血液及组织汞含量的影响

    Institute of Scientific and Technical Information of China (English)

    武瑞; 仝宗喜; 杨爽; 王伟; 康世良

    2001-01-01

    选用雏鸡作实验动物,采用分组对比的方法,通过测定血液、羽毛、粪便和组织中汞、硒含量,研究硒对雏鸡血液及组织汞含量的影响,进而探讨硒与汞的拮抗机理。实验结果表明:汞在鸡体内的分布具有较强的选择性,主要蓄积于肝脏和肾脏,其含量分布为肾脏>肝脏>大脑>心脏>肌肉>全血。血液和组织中汞含量相关回归分析表明,血汞不能反映体内汞负荷,但可粗略地反映近期汞摄入水平;肝脏和肾脏汞含量及其动态变化可较好地反映体内的汞负荷;毛汞可反映动物生长期体内吸收的汞量;粪汞含量升高可诊断为汞吸收;这对汞中毒的诊断及环境生物学的监测有一定的意义。硒与汞之间存在拮抗作用,汞可以影响硒的吸收、分布、利用,硒也可以改变汞的积累部位和积累方式。%In the study we selected the chickens as laboratory animal, derided groups for comparison, determiated the content of selenite and mercury in the chickan blood, feather, excrements and tissue for studing the selenie effect on the content of mercury, for the more to reveal the antagonistic mechanism between selenite and mercury. The results were shown that: 1. Mercury was selectively distributed to different organs.It mainly stored up in liver and kidey. Its content were in kidney, liver, brain, chest muscle and blood in order. The mercury content in the hlood did not reflect the mercury content in the body, but it could show rcent intake of mercury;The experiment showed the mercury content in liver and kindey and its dynamic change could perfectly reflect the mercury content in the body;The mercury content in the feather could show absorb of mercury content during grow; The mercury content in the excrements could diagnosis absorb of mercury content. All there were significent in diagnoaing mercury poisoning and envirimeatal biology monitoring. 2. It exist that the

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. DES ACCENTS ÉTRANGERS AUX ABORDS DE L’UTOPIE BROSSARDIENNE

    Directory of Open Access Journals (Sweden)

    Ghislaine Boulanger

    2011-12-01

    Full Text Available Cet article analyse l’analogie entre une langue sexiste et une langue étrangère, et démontre comment cette comparaison met en jeu des dimensions identitaires qui seront progressivement refoulées aux frontières de l’utopie féministe imaginée par Nicole Brossard. Cette étude met en relief certains problèmes d’exclusion reliés à la disparition symbolique de l’accent, tels que l’effacement de l’identité juive dans le roman Picture theory.

  2. 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.

  3. 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...

  4. 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...

  5. 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.  

  6. 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

  7. 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)....

  8. 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.)

  9. 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

  10. 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...

  11. 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

  12. 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.

  13. 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

  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 sa...

  15. 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...

  16. Effect of sodium selenite on some enzymes of coelomic fluid to the immune response of holothurian Apostichopus japonicus%亚硒酸钠对刺参免疫反应中体腔液酶活力的影响

    Institute of Scientific and Technical Information of China (English)

    刘洪展; 郑风荣; 孙修勤; 唐学玺

    2012-01-01

    The aquaculture of the sea cucumber Apostichopus jp0nicus(Echinodermata,Holothuroidea)has been growing rapidly over recent years in China in response to increasing consumer demand. Indeed, it has become an important sector of the marine industry in Northern China. However,with rapid growth and the use of non-standard practices and culture techniques,epidemic diseases of A. Japonicus now pose increasing problems to the industry. Therefore, the healthy aquaculture of A. Japonicus is important. For a reasonable evaluation of selenium effect on sea cucumber aquaculture, using laboratory tests to simulate the sodium selenite treatment and virus infection conditions, the detection and observation of the sea cucumber body cavity fluid immune enzyme changes, pathological changes and the relative rate of protection were made. The results showed that: the change of immune enzymes in coelomic fluid of sea cucumbers under simulated sodium selenite treatments and bacteria infected conditions was tested in order to reasonably evaluate the influence of selenium on aquaculture diseases. Results indicated that the activities of superoxide dismutase (SOD), glutathione peroxidase ( GPx), lysozyme ( LYZ), phenoloxidase ( PO) and alkaline phosphatase (ALP)in coelomic fluid rose after sodium selenite treatments were enhanced. However,SOD,GPX and LYZ activities first ascended and then declined, and PO and ALP activities showed continued rise under additional pathogen injection into sea cucumbers, but the increasing extent of ALP activity was reduced along with increased sodium selenite concentration, and total diseased incidence rose and relative percent survival decreased under the severe sodium selenite treatment. This suggested that applying sodium selenite with moderate concentration could enhance immunity of sea cucumber to bacterial infection, but infecting also aggravated immune damage of sea cucumber by sodium selenite stress. Therefore, the diseases of cultured sea cucumber can

  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. Isolation of tellurite- and selenite-resistant bacteria from hydrothermal vents of the Juan de Fuca Ridge in the Pacific Ocean.

    Science.gov (United States)

    Rathgeber, Christopher; Yurkova, Natalia; Stackebrandt, Erko; Beatty, J Thomas; Yurkov, Vladimir

    2002-09-01

    Deep-ocean hydrothermal-vent environments are rich in heavy metals and metalloids and present excellent sites for the isolation of metal-resistant microorganisms. Both metalloid-oxide-resistant and metalloid-oxide-reducing bacteria were found. Tellurite- and selenite-reducing strains were isolated in high numbers from ocean water near hydrothermal vents, bacterial films, and sulfide-rich rocks. Growth of these isolates in media containing K(2)TeO(3) or Na(2)SeO(3) resulted in the accumulation of metallic tellurium or selenium. The MIC of K(2)TeO(3) ranged from 1,500 to greater than 2,500 micro g/ml, and the MIC of Na(2)SeO(3) ranged from 6,000 to greater than 7,000 micro g/ml for 10 strains. Phylogenetic analysis of 4 of these 10 strains revealed that they form a branch closely related to members of the genus Pseudoalteromonas, within the gamma-3 subclass of the Proteobacteria. All 10 strains were found to be salt tolerant, pH tolerant, and thermotolerant. The metalloid resistance and morphological, physiological, and phylogenetic characteristics of newly isolated strains are described.

  20. 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.

  1. 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

  2. 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.

  3. 亚硒酸盐在不同理化性质土壤中运移规律研究%Selenite transport in soils with various physico-chemical properties

    Institute of Scientific and Technical Information of China (English)

    刘冠男; 薛薇; 孙春美; 李德先; 刘新会

    2016-01-01

    The transport of heavy metals in soil determines their risks to underground water and human health. However, such transport is controlled by soil properties. Here we studied the adsorption, desorption and transport of selenite in different soils:FC1(0~10 cm surface soil from Fengcheng, Jiangxi), FC2(10~20 cm subsurface soil from Fengcheng, Jiangxi), DC(surface soil in Dexing, Jiangxi)and BD(sur-face soil in Baoding, Hebei), to uncover the effects of soil physico-chemical properties on selenite transport in soils. Results showed that FC1 and FC2 soils, having higher amorphous iron oxide and organic matter(OM)and lower soil pH than others, had greater selenite adsorp-tion, with the maximum adsorption capacities of 621.50 mg·kg-1 and 592.20 mg·kg-1, respectively. The maximum selenite adsorption was 219.29 mg·kg-1 for DC and 163.51 mg·kg-1 for BD. However, BD soil had the highest selenite desorption rate and amount. In packed soil column experiment, selenite transported faster in BD soil than in other soils, suggesting that the transport of selenite in soil column was in-fluenced by the adsorption and desorption abilities of selenite in soils. In intact soil column, selenite transported quicker than in the packed soil columns. The breakthrough curve of selenite in intact soil column fitted DTSMZ(Dual-porosity with Two-Site Sorption in the Mobile Zone)model well by HYDRUS-1D software. Our results indicate the possibility of selenium pollution in groundwater due to the presence of macropore and preferential flow in the field conditions.%通过亚硒酸盐在江西丰城稻田表层0~10 cm土壤(FC1)、次表层10~20 cm土壤(FC2)、江西德兴菜地表层土壤(DC)、河北保定旱地表层土壤(BD)等几种土壤中的吸附解吸及土柱运移实验,研究了亚硒酸盐在土壤中的运移行为,探讨了亚硒酸盐在不同理化性质土壤中的运移规律。结果表明:具有较高含量活性Fe及有机

  4. 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...

  5. 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...

  6. 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...

  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. Des furoncles résistants aux antibiotiques: penser à la myiase !!

    Science.gov (United States)

    Ajili, Faida; Abid, Rim; Bousseta, Najeh; Mrabet, Ali; Karoui, Ghazi; Louzir, Bassem; Battikh, Riadh; Othmani, Salah

    2013-01-01

    Les myiases sont des infections parasitaires par des larves de mouches. La localisation cutanée doit être évoquée de retour d'un pays tropical devant une évolution inhabituelle de lésions cutanées. Nous rapportons une observation d'un militaire tunisien, ayant séjourné en République Démocratique du Congo. Il était atteint de myiase cutanée simulatrice d'une furonculose résistante aux antibiotiques. L'intérêt de cette observation est de souligner l'importance d’évoquer la myiase dont le traitement est simple et rapide chez un patient de retour de zone d'endémie. PMID:24106569

  9. 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...

  10. 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.

  11. 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...

  12. 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

  13. 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...

  14. 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 ...

  15. 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...

  16. 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...

  17. 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 ...

  18. 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.

  19. 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

  20. 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.

  1. A serpin-induced extensive proteolytic susceptibility of urokinase-type plasminogen activator implicates distortion of the proteinase substrate-binding pocket and oxyanion hole in the serpin inhibitory mechanism.

    Science.gov (United States)

    Egelund, R; Petersen, T E; Andreasen, P A

    2001-02-01

    The formation of stable complexes between serpins and their target serine proteinases indicates formation of an ester bond between the proteinase active-site serine and the serpin P1 residue [Egelund, R., Rodenburg, K.W., Andreasen, P.A., Rasmussen, M.S., Guldberg, R.E. & Petersen, T.E. (1998) Biochemistry 37, 6375-6379]. An important question concerning serpin inhibition is the contrast between the stability of the ester bond in the complex and the rapid hydrolysis of the acyl-enzyme intermediate in general serine proteinase-catalysed peptide bond hydrolysis. To answer this question, we used limited proteolysis to detect conformational differences between free urokinase-type plasminogen activator (uPA) and uPA in complex with plasminogen activator inhibitor-1 (PAI-1). Whereas the catalytic domain of free uPA, pro-uPA, uPA in complex with non-serpin inhibitors and anhydro-uPA in a non-covalent complex with PAI-1 was resistant to proteolysis, the catalytic domain of PAI-1-complexed uPA was susceptible to proteolysis. The cleavage sites for four different proteinases were localized in specific areas of the C-terminal beta-barrel of the catalytic domain of uPA, providing evidence that the serpin inhibitory mechanism involves a serpin-induced massive rearrangement of the proteinase active site, including the specificity pocket, the oxyanion hole, and main-chain binding area, rendering the proteinase unable to complete the normal hydrolysis of the acyl-enzyme intermediate. The distorted region includes the so-called activation domain, also known to change conformation on zymogen activation.

  2. Etude sur les tendons en materiaux composites et leur application aux ancrages postcontraints

    Science.gov (United States)

    Chennouf, Adil

    L'objectif general de la presente these est d'evaluer le comportement a l'arrachement et au fluage d'ancrages injectes constitues de tendons en materiaux composites afin d'etablir des recommandations plus appropriees et realistes pour le dimensionnement et la conception. Quatre types de tendons en materiaux composites, deux a base de fibres d'aramide et deux a base de fibres de carbone, ont ete utilises dans l'etude. Les travaux de recherche de cette these ont porte notamment sur: (I) Une caracterisation physique et mecanique des tendons en materiaux composites utilises dans l'etude. (II) Une etude en laboratoire sur les coulis de scellement. La premiere etape de cette etude a concerne le developpement d'un coulis de scellement performant adapte aux tendons en materiaux composites et a differentes situations d'injection. La seconde etape a traite des essais de caracterisations physique et mecanique du coulis de scellement developpe comparativement a trois coulis de scellement usuels d'un meme rapport E/L de 0,4. (III) Une etude sur des modeles reduits d'ancrages injectes. (IV) Une etude sur des modeles d'ancrages a grande echelle. La synthese de ces etudes a permis d'enoncer les principales conclusions suivantes: (1) Les valeurs moyennes des charges de rupture des tendons en materiaux composites ont ete de 1% a 29% superieures a celles specifiees par les manufacturiers. (2) L'etude sur les coulis de scellement a permis le developpement de coulis de ciment repondant aux criteres fixes, soient une grande stabilite, une bonne fluidite, une legere expansion et de bonnes caracteristiques mecaniques. (3) Les tendons en materiaux composites ont montre des contraintes d'adherence maximum superieures a celles des tendons en acier. (4) Le type de fibre, la configuration et le fini de surface des tendons en materiaux composites gouvernent leur resistance a l'adherence. (5) L'introduction de sable et d'autres ajouts comme les fines de silice et la poudre d'aluminium au coulis

  3. 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

  4. 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

  5. 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...

  6. 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 ...

  7. 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

  8. 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...

  9. 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.

  10. 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

  11. 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.

  12. La politique européenne d’aide à la mise aux normes de qualité

    Directory of Open Access Journals (Sweden)

    Vialatte Philippe

    2001-05-01

    Full Text Available La Commission européenne peut aider les pays en développement à financer des programmes de mise aux normes de qualité pour contribuer à la lutte contre la pauvreté, améliorer les conditions de vie des populations locales et leur permettre de bénéficier encore plus largement des opportunités offertes par le marché européen.

  13. Comparison of VITEK 2 YST Card and API 20C AUX system in identification of non- albicans Candida species

    Directory of Open Access Journals (Sweden)

    Süleyman Durmaz

    2012-03-01

    Full Text Available Objectives: In the present study, it was aimed to compare results obtained by using VITEK 2 YST Card (bioMérieux, France with those obtained by using API 20C AUX (bioMérieux, France for identification of non- albicans Candida species, which was isolated from various clinical samples, at level of species.Materials and methods: Forty-one non-albicans Candida isolates, which were isolated from 28 urine, 10 blood and 3 vaginal swab specimens, and found to be negative by germ tube test, were identified by using VITEK 2 YST Card (bioMérieux, France. In addition, microscopic morphology was assessed in corn-meal Tween 80 agar, while carbohydrate assimilation was assessed by using commercially available API 20C AUX kit (bioMérieux, France.Results: Thirty-four isolates (82.9% were identified as identical species by these 2 systems, while different results were obtained in 7 isolates (17.1%. 5 isolates, identified as Candida glabrata by API 20C AUX system, were identified as Candida tropicalis (n=2, Candida krusei, Candida lipolitica and Candida kefyr by VITEK 2 YST Card. One other isolate, identified as C.tropicalis, was identified as Candida parapsilosis; and additional one isolate, identified as C.parapsilosis, was identified as C.tropicalis.Conclusion: It was concluded that one should be cautious in the identification of C.glabrata, in particular, C.tropicalis and C.parapsilosis, although between VITEK 2 YST Card and API 20C AUX system results was found largely similarity in identification of non-albicans Candida spp.

  14. The tomato Aux/IAA transcription factor IAA9 is involved in fruit development and leaf morphogenesis.

    Science.gov (United States)

    Wang, Hua; Jones, Brian; Li, Zhengguo; Frasse, Pierre; Delalande, Corinne; Regad, Farid; Chaabouni, Salma; Latché, Alain; Pech, Jean-Claude; Bouzayen, Mondher

    2005-10-01

    Auxin/indole-3-acetic acid (Aux/IAA) proteins are transcriptional regulators that mediate many aspects of plant responses to auxin. While functions of most Aux/IAAs have been defined mainly by gain-of-function mutant alleles in Arabidopsis thaliana, phenotypes associated with loss-of-function mutations have been scarce and subtle. We report here that the downregulation of IAA9, a tomato (Solanum lycopersicum) gene from a distinct subfamily of Aux/IAA genes, results in a pleiotropic phenotype, consistent with its ubiquitous expression pattern. IAA9-inhibited lines have simple leaves instead of wild-type compound leaves, and fruit development is triggered before fertilization, giving rise to parthenocarpy. This indicates that IAA9 is a key mediator of leaf morphogenesis and fruit set. In addition, antisense plants displayed auxin-related growth alterations, including enhanced hypocotyl/stem elongation, increased leaf vascularization, and reduced apical dominance. Auxin dose-response assays revealed that IAA9 downregulated lines were hypersensitive to auxin, although the only early auxin-responsive gene that was found to be upregulated in the antisense lines was IAA3. The activity of the IAA3 promoter was stimulated in the IAA9 antisense genetic background, indicating that IAA9 acts in planta as a transcriptional repressor of auxin signaling. While no mutation in any member of subfamily IV has been reported to date, the phenotypes associated with the downregulation of IAA9 reveal distinct and novel roles for members of the Aux/IAA gene family. PMID:16126837

  15. SIDARI : un système intelligent distribué appliqué aux réseaux informatiques

    OpenAIRE

    Oumtanaga, S.

    1996-01-01

    Cet article présente le projet SIDARI, un système intelligent distribué appliqué aux réseaux informatiques. Après avoir exposé les besoins et les contraintes en formation des réseaux informatiques, nous proposons une solution issue des techniques de l'intelligence artificielle, de l'approche orientée objets, et des tuteurs intelligents. (Résumé d'auteur)

  16. 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.

  17. 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

  18. Proposition d'attribution de deux contrats pour la fourniture de fils supraconducteurs destines aux aimants de correction du LHC

    CERN Document Server

    1999-01-01

    Le présent document concerne l'attribution de deux contrats pour la fourniture de fils supraconducteurs émaillés de quatre types différents (fil 1, fil 2, fil 3 et fil 4) destinés aux aimants de correction du LHC. Un appel d'offres (IT-2649/LHC/LHC) a été adressé le 13 juillet 1999 à quatre entreprises dans quatre Etats membres, trois entreprises au Japon et trois entreprises aux Etats-Unis. A la date de clôture, le CERN avait reçu cinq offres. Il est demandé au Comité des finances d'approuver la négociation de deux contrats: 1. d'une part avec IGC (USA) pour la fourniture de fils supraconducteurs 1 et 2 destinés aux aimants de correction du LHC pour un prix total net de 996 074 dollars des Etats-Unis, non révisable, avec une option pour la fourniture de fils 1 et 2 supplémentaires représentant 20% de la quantité initiale pour un prix total net de 199 215 dollars des Etats-Unis, révisable, ce qui porte le montant total à 1 195 289 dollars US, révisable pour l'option. Au taux de change in...

  19. 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.

  20. 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&...

  1. 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)

  2. 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

  3. Contribution aux Methodes Analytiques des Substances a L'aide de Faisceaux de Particules Chargees

    Science.gov (United States)

    Saidi, Abdelmajid

    Nous avons vu les possibilites d'analyse par particules chargees des aerosols recueillis sur des filtres de type MILLIPORE. La meme technique a ete utilisee pour des filtres ayant servi a la filtration de l'eau du fleuve Saint-laurent. Deux techniques ont ete utilisees: (1) FAST (Forward Alpha Scattering Technique): pour analyser l'hydrogene, le carbone, l'oxygene et puis l'azote. Des alpha de 12 MeV ont ete utilises. (2) PIXE (Particle Induced X-ray Emission): pour analyser les elements moyens et lourds, dans ce cas des protons de 3 MeV ainsi que des ions d'argon de 1 et 1.6 MeV ont ete utilises. Les etudes ont montre que sous vide, la majorite des problemes proviennent des dommages causes par l'echauffement du a l'impact du faisceau sur le filtre. L'analyse quantitative par l'intermediaire du faisceau extrait peut presenter des difficultes en ce qui concerne les elements legers pour lesquels l'absorption des rayonnements caracteristiques dans l'atmosphere externe est importante. Les ions lourds se pretent mal aux analyses des aerosols du fait de leur limite de sensibilite. L'analyse directe de liquides par des protons est particulierement interessante puisqu'elle ne necessite aucune preparation prealable des echantillons. A cet effet, un programme de calcul de concentration des elements dans la solution a analyser a ete mis au point. Nous avons determine la limite de sensibilite de la methode PIXE pour les cibles minces (filtre) et pour le cas ou la matrice est de l'eau. Enfin, la technique FAST peut etre un complement de la technique PIXE.

  4. 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...

  5. 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.

  6. 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.)

  7. 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...

  8. Interactions entre les bacteries et les algues dans une culture continue de phytoplancton naturel soumise aux conditions exterieures

    OpenAIRE

    Gauthier, M; Martin, Y; Lelong, P; Breittmayer, V

    1984-01-01

    Au cours d'une expérience de culture continue de phytoplancton marin en grand volume soumise aux conditions extérieures, des tests microbiologiques et biochimiques ont été effectués pour mettre en évidence la production de substances antibactériennes et antialgales par les algues unicellulaires. De nombreux paramètres ont été mesurés pour caractériser la croissance de ces algues (qualitativement et quantitativement) et des bassin expérimental et dans la biomasse à différents stades de la cult...

  9. Mobilisations urbaines et espaces de résistance aux Jeux Olympiques de Londres et de Vancouver

    OpenAIRE

    Nativel, Corinne

    2012-01-01

    En juillet 2012, Londres accueillera les Jeux Olympiques et Paralympiques d’été. Partant du constat que l’organisation et la tenue de grands évènements sportifs suscitent d’importantes controverses et que les mouvements d’opposition aux JO restent encore méconnus, cet article propose d’identifier et d’analyser les mobilisations et espaces de résistance dans la capitale britannique. Il présente quelques éléments théoriques ainsi que la genèse et les principaux marqueurs contextuels des JO lond...

  10. 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.

  11. Les références aux documents en ligne dans les textes scientifiques

    Directory of Open Access Journals (Sweden)

    Marc Couture

    2010-01-01

    Full Text Available [Français] Avec le développement de la diffusion en ligne de documents scientifiques, la primauté reconnue traditionnellement à l’imprimé devient de moins en moins pertinente ; les références à des ressources et documents en ligne forment ainsi une proportion significative des références dans certaines revues scientifiques, notamment celles qui, comme la RITPU, s’intéressent à l’information et à la communication. Dans cet article, on passe d’abord en revue les divers rôles des références répertoriés dans la littérature. On décrit ensuite les caractéristiques et les conditions permettant aux documents en ligne de jouer pleinement ces rôles. On montre enfin comment, dans l’adaptation française des normes de l’APA adoptée par la RITPU, certains choix touchant le format des notices des documents en ligne facilitent la tâche des évaluateurs et des lecteurs des articles. Par la même occasion, les auteurs y trouveront conseils et consignes visant à rendre plus pertinente et efficace cette dimension souvent négligée de la communication scientifique. [English] With the increase of online scientific publications, the traditional primacy of print documents has become less and less relevant. In some scientific journals, notably in the field of information technology and its applications (like IJTHE, a significant part of the citations now refer to online documents. This paper first reviews the various roles played by citations in scientific texts according to the literature. It then describes the characteristics and conditions which must be met if citations to online documents are to fully play these roles. Finally, it shows how, in the French-language adaptation of the APA reference formats which was adopted by IJTHE, a few choices have been made regarding online references in order to ease the task of both referees and readers. By the same token, authors will find guidelines and suggestions which should improve

  12. 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....

  13. 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...

  14. 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...

  15. Le secteur bovin (viande et lait): quel avenir face aux évolutions des marchés et de la PAC ?

    OpenAIRE

    Chatellier, Vincent

    2010-01-01

    Cette communication propose une synthèse des principales évolutions économiques de la filière bovine. Elle présente, dans un premier temps, l’évolution de la production, de la consommation et des échanges de viande bovine aux échelles internationales, communautaires et françaises. Dans une même logique, elle s’intéresse ensuite au secteur laitier. Dans une dernière partie, une réflexion est proposée quant aux évolutions pressenties de la PAC pour ces deux productions agricoles....

  16. 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 ...

  17. 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

  18. Effects of Sodium Selenite and Selenium Yeast on Dynamic Change of Egg Selenium Content in Laying Hens%酵母硒和亚硒酸钠对蛋鸡蛋硒含量动态变化的影响

    Institute of Scientific and Technical Information of China (English)

    卢建; 王克华; 曲亮; 童海兵; 沈曼曼; 李尚民; 窦套存; 胡玉萍

    2014-01-01

    This experiment was conducted to compare the effects of sodium selenite and selenium yeast on dy-namic change of egg selenium content in laying hens. Two hundred and sixteen 30-week-old healthy Hy-Line Brown laying hens with a similar laying rate were randomly assigned to 3 groups with 6 replicates in each group and 12 laying hens per replicate. The laying hens in control group were fed a basal diet without adding seleni-um, while those in experimental groups were fed the basal diet supplemented with 0. 30 mg/kg selenium in forms of sodium selenite and selenium yeast, respectively. Preliminary trail period was 14 days and experimen-tal period was 56 days. The results showed as follows:1) there were no significantly differences in the laying rate, average egg weight, average daily egg weight, average daily feed intake, the ratio of feed to egg, mor-tality, and egg quality on day 56 of the experiment among the 3 groups ( P>0.05) . 2) The egg selenium con-tent in the group supplemented with selenium yeast was significantly higher than that in the group supplemented with sodium selenite and in the control group on day 3 of the experiment (P0.05)。2)正试期第56天,试验组常规蛋品质与对照组相比较差异不显著( P>0.05)。3)正试期第3天,酵母硒组蛋硒含量显著高于对照组和亚硒酸钠组( P<0.05);14 d后,亚硒酸钠组蛋硒含量显著高于对照组( P<0.05);正试期第3、5、7、14、21、28和56天,酵母硒组蛋硒含量比亚硒酸钠组分别显著高出了28.18%、34.98%、45.35%、47.39%、67.53%、63.35%和65.71%( P<0.05)。4)随着试验天数的增加,对照组蛋鸡蛋硒含量显著降低( P<0.05),亚硒酸钠组蛋鸡蛋硒含量呈现先降低后增加的趋势(P<0.05),酵母硒组蛋鸡蛋硒含量显著增加(P<0.05)。由此可见,33~40周龄,蛋鸡饲粮中不额外添加硒以及添加0.30 mg/kg硒的酵母硒和亚硒酸钠对生产性能和蛋品质无不良影响;相对于亚硒酸钠,酵母硒中硒向

  19. Une méthode de production de truites fario destinées aux repeuplements de restauration

    Directory of Open Access Journals (Sweden)

    MAISSE G.

    1981-01-01

    Full Text Available Une méthode de production de populations de truites fario présentant une forte variabilité génétique est proposée pour les repeuplements de restauration. Du sperme de géniteurs sauvage est conservé à des températures voisines de 0° C et à l'obscurité, pendant la durée du transport entre le cours d'eau d'origine et la pisciculture, où l'on procède à l'insémination d'ovules de truites fario d'élevage en utilisant le dilueur de sperme 532. La descendance est destinée de préférence aux déversements au stade oeuf dans le milieu préalablement restauré.

  20. 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...

  1. 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...

  2. 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.

  3. 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...

  4. 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 ...

  5. Dépouillement de l'essai aux barres de Hopkinson par une technique de calcul inverse

    OpenAIRE

    Gary, G.; Zhao, H

    1994-01-01

    Le dépouillement classique des essais aux barres d'Hopkinson ne permet pas la mesure directe d'une relation précise "contrainte-déformation" à vitesse de déformation constante en raison du non équilibre des forces et de la variation importante de vitesse de déformation au cours de l'essai, en particulier dans la zone des faibles déformations. Nous proposons ici une méthode de dépouillement basée sur une technique du calcul inverse permettant de passer outre ces limitations, et d'améliorer ain...

  6. 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...

  7. 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.

  8. Décentraliser la gestion de réseaux grâce aux agents mobiles

    OpenAIRE

    Galtier, Virginie

    1998-01-01

    Stage de DEA. Rapport de stage.; Dans un contexte où les réseaux informatiques et de télécommunications prennent une importance toujours plus critique, la gestion de réseaux devient une activité cruciale. Mais les systèmes inspirés du modèle centralisé de l'OSI et largement utilisés s'adaptent mal aux nouvelles caractéristiques des réseaux actuels (de plus en plus évolutifs). Utiliser les agents mobiles pour décentraliser cette gestion permettrait de gagner en efficacité en distribuant la tâc...

  9. 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.

  10. 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

  11. The auxin transporter, OsAUX1, is involved in primary root and root hair elongation and in Cd stress responses in rice (Oryza sativa L.).

    Science.gov (United States)

    Yu, ChenLiang; Sun, ChenDong; Shen, Chenjia; Wang, Suikang; Liu, Fang; Liu, Yan; Chen, YunLong; Li, Chuanyou; Qian, Qian; Aryal, Bibek; Geisler, Markus; Jiang, De An; Qi, YanHua

    2015-09-01

    Auxin and cadmium (Cd) stress play critical roles during root development. There are only a few reports on the mechanisms by which Cd stress influences auxin homeostasis and affects primary root (PR) and lateral root (LR) development, and almost nothing is known about how auxin and Cd interfere with root hair (RH) development. Here, we characterize rice osaux1 mutants that have a longer PR and shorter RHs in hydroponic culture, and that are more sensitive to Cd stress compared to wild-type (Dongjin). OsAUX1 expression in root hair cells is different from that of its paralogous gene, AtAUX1, which is expressed in non-hair cells. However, OsAUX1, like AtAUX1, localizes at the plasma membrane and appears to function as an auxin tranporter. Decreased auxin distribution and contents in the osaux1 mutant result in reduction of OsCyCB1;1 expression and shortened PRs, LRs and RHs under Cd stress, but may be rescued by treatment with the membrane-permeable auxin 1-naphthalene acetic acid. Treatment with the auxin transport inhibitors 1-naphthoxyacetic acid and N-1-naphthylphthalamic acid increased the Cd sensitivity of WT rice. Cd contents in the osaux1 mutant were not altered, but reactive oxygen species-mediated damage was enhanced, further increasing the sensitivity of the osaux1 mutant to Cd stress. Taken together, our results indicate that OsAUX1 plays an important role in root development and in responses to Cd stress.

  12. 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...

  13. 磷与四价硒的共存对小白菜磷、硒吸收及转运的影响%Combined effects of phosphate and selenite on the uptake and translocation of phosphorus and selenium in pakchoi

    Institute of Scientific and Technical Information of China (English)

    赵文龙; 胡斌; 王嘉薇; 肖然; 梁东丽

    2013-01-01

    Pot experiments combined with chemical analysis were carried out to study the combined effects of phosphate and selenite on the growth,absorption and translocation of phosphorus and selenium in pakchoi with the aim to providing theoretical basis for safe selenium supplement and phytoremediation in selenium-contaminated soils.The results showed that under the selenium concentration (5.0 mg·kg-1) used in the present study,phosphate can promote the growth of pakchoi significantly and result in the increase of shoot and root biomass (p < 0.01).When selenite and phosphate co-exist,selenite can suppress the uptake of phosphate and the growth of root.The promotion and suppression are coexistent in the effect of phosphate on the uptake of selenite.At a high amount of selenite (>2.5 mg· kg-1),phosphate can promote the uptake of selenite compared with the no phosphate treatment,but the high mount of phosphate can reduce the root concentration of selenium in pakchoi significantly.Pakchoi has a greater preference for phosphate than selenite,and phosphate can suppress the transfer of selenium from the root to shoot.Our findings suggest that reasonable phosphate application may be an important strategy for avoiding the effect of phosphate to the uptake and translocation by plants.Appropriate phosphate application may be an important strategy for avoiding the effect of phosphate on the uptake and translocation by plants during selenium supplement or selenium contaminated soil remediation.%采用土培盆栽试验和化学分析相结合的方法,研究了不同浓度磷酸盐与四价硒共存对小白菜生长、磷和硒吸收及转运的影响,旨在为安全有效地进行补硒和硒污染土壤的植物修复提供理论依据.结果表明,在供试硒浓度范围内(≤5.0 mg·kg-1),施磷均显著促进了小白菜的生长,表现为地上、地下部生物量的增大(p<0.01).与单施磷相比,硒与磷共存能抑制小白菜根系生长,且抑制其对磷的

  14. 苗期小麦和水稻对硒酸盐/亚硒酸盐的吸收及转运机制%Uptake and Translocation of Selenate or Selenite by Wheat and Rice Seedlings

    Institute of Scientific and Technical Information of China (English)

    陈思杨; 江荣风; 李花粉

    2011-01-01

    Solution culture experiments were carried out to study the uptake and translocation of selenate ( Na2SeO4 ) or selenite (Na2SeO3) by wheat and rice seedlings. When supplied with Na2SeO4 in nutrient solution, the concentrations of selenium (Se) in normal shoots and roots of rice were 30. 3 mg· kg - 1 and 39.0 mg· kg - 1 respectively, and the absorbed Se was quickly translocated to shoots accounting for 80% of the total uptake. Se concentrations in wheat shoots and roots were 1.76 mg·kg-1 and 6. 99 mg·kg-1 respectively, accounting for 62% in shoots. However, when supplied with Na2SeO3 , Se concentrations in shoots and roots of rice were 4.40 mg· kg - 1 and 230 mg· kg- 1 respectively, 1.24 mg· kg- 1 and 88.3 mg· kg-1 in shoots and roots of wheat respectively, and only 8. 2% was transferred to shoots. The influence of phosphorus (P) starvation on Se uptake was different for rice and wheat seedlings.Comparing to normal plants, the Se concentrations in the shoots and roots of rice under P starvation condition were decreased, however increased for wheat. In Na2SeO3 uptake kinetics, Km of wheat seedlings was 8. 7 folds of that of rice, and the affinity of wheat root to selenite was much weaker than that of rice. The Se uptake rate of wheat (Vmax) was 14% lower than that of rice. The uptake and translocation mechanisms of selenate and selenite by rice and wheat seedlings were revealed. And the results demonstrate that the absorbed selenate is quickly translocated to shoot and selenite is mainly accumulated in root. These results provide basic information for biofortification of crops with Se.%采用营养液培养方法研究了苗期小麦和水稻对硒酸盐(Na2SeO4)和亚硒酸盐(Na2SeO3)的吸收及转运机制.营养液中供给Na2SeO4时,正常培养的水稻地上部和根中硒的含量分别30.3 mg·kg-1和39.0 mg·kg-1,水稻吸收的硒有80%从根转移到了地上部;小麦地上部和根中硒的含量分别为1.76 mg·kg-1和6.99 mg·kg-1

  15. 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.

  16. Clinical and economic evaluation of BBL CHROMagar Salmonella (CHROMSal) versus subculture after selenite broth enrichment to CHROMSal and Hektoen enteric agars to detect enteric Salmonella in a large regional microbiology laboratory.

    Science.gov (United States)

    Church, Deirdre L; Emshey, Diana; Lloyd, Tracie; Pitout, Johann

    2010-09-01

    Stool culture for enteric pathogens is one of the most labor-intensive clinical microbiology procedures. Direct plating of stool to BBL CHROMagar Salmonella (CHROMSal) (BD Diagnostics, Sparks, MD) versus subculture after selenite broth enrichment (Sel) to CHROMSal (Sel-CHROMSal) and Hektoen enteric agar (Sel-Hek) (PML Microbiologicals, Eugene, OR) to detect Salmonella were compared. The number of colony picks and biochemical/serotyping tests per plate was recorded. A cost comparison was done. Fifty-one of 2999 (1.7%) stools yielded Salmonella sp., and 80% of isolates grew on CHROMSal by 24 h. CHROMSal demonstrated much less false-positive growth compared to Sel-Hek (P < 0.0001), which reduced biochemical and serotyping tests by 85% and 20%, respectively. Sel-CHROMSal and CHROMSal versus Sel-Hek improved enteric Salmonella detection when compared to a true positive "gold standard" (i.e., recovery by any culture method) with a sensitivity, specificity, positive predictive value, and negative predictive value of 100% and 94.12%, 100% and 99.97%, 100% and 97.96%, and 100% and 99.90%, respectively. CHROMSal use would result in substantial cost and labor savings.

  17. 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 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

  18. Du sport aux activités physiques de loisir : des formes culturelles et sociales bigarrées

    Directory of Open Access Journals (Sweden)

    Éric Dugas

    2007-07-01

    Full Text Available L'espace ludique des formes sociales des pratiques physiques accepte maintes variations. Du jeu informel et libre aux activités physiques institutionnelles (les sports, plusieurs catégories de situations motrices, distinctes des unes des autres, jalonnent l'espace des jeux sportifs. Après avoir défini et délimité, dans un premier temps, les contours et la richesse de l'univers des pratiques physiques ludiques, nous essayons, dans un second temps de mettre au jour le type de pratiques qui coïncident le mieux aux aspirations des pratiquants du xxie siècle. On s'aperçoit actuellement que malgré l'hégémonie du sport au sein de l'espace médiatique et économique, il se dessine néanmoins une tendance forte : la prédominance d’activités physiques ludiques de plus en plus autocontrôlées qui laissent l'initiative aux pratiquants et dans lesquelles les institutions sportives ne sont plus totalement ou pas du tout maître du jeu.From sport to leisure physical activities: mixed cultural and social formsThe game space of physical activities' social forms accepts many variations. From informal and free games to institutional physical activities (sports, several motor situation categories, distinct from each other, punctuate the space of physical games. After having specified and delimited the contours and richness of the world of playful physical activities, we will try to bring to light the kind of practices which coincide best with the 21st century's players or sports (women. Currently, we can see that in spite of sport's hegemony within the media and the economic spheres, a strong tendency is becoming apparent: the predominance of more and more self-controlled playful physical activities, which leave the initiative to players and in which governing bodies are not totally or not at all in command any more.Del deporte a las actividades de ocio: una mezcolanza en las formas culturales y socialesEl espacio lúdico de las formas sociales de

  19. 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

  20. The French Tsunami warning center for the Mediterranean and North-East Atlantic (CENtre d'ALerte aux Tsunamis, CENALT)

    Science.gov (United States)

    Schindelé, F.; Bossu, R.; Alabrune, N.; Arnoul, P.; Duperray, P.; Gailler, A.; Guilbert, J.; Hébert, H.; Hernandez, B.; Loevenbruck, A.; Roudil, P.

    2012-04-01

    The CENALT (CENtre d'Alerte aux Tsunamis) is responsible for the French NTWC (National Tsunami Warning Center). This center was established through a project that was requested by the French Ministry of Interior and the Ministry of Sustainable Development. It is implemented by the Commissariat à l'énergie atomique et aux énergies alternatives (CEA), the French Hydrographic and Oceanographic Service (SHOM) and the Centre National de la Recherche Scientifique (CNRS), and is based in Bruyères-le-Châtel (30 km from Paris). This center is based on three main components: seismic network data, sea level network data, dissemination system and processing and analyzing softwares and is operating on a 24/7 basis. The CENALT has established scientific cooperation with 8 institutions and implemented and funded private leased lines to exchange data with institutions from 5 different European countries (Germany, Italy, Portugal, Spain, Tunisia). The seismic data are processed with the Seiscomp 3 software. SHOM is working on making all French tide-gauge stations operated and available in real-time in 2012, and they installed 5 new tide gage stations. The tide gage data will be processed with a customized version of the Guitar (Gempa) software allowing the detection of tsunami signals, complemented by other softwares developed by the CEA. Historical tsunami databases (sources and observations) and earthquake databases, mostly based on available international databases, have been synthetized by CEA to produce information maps in real time, used to guide operators of permanence. Precomputed tsunami scenarios are implemented to build in real time maps of the highest tsunami impact expected in deep water. Along with an optimized tsunami modeling tool, these softwares help to define the areas where the tsunami may be observed and cause damage. The CENALT has been operating since early January 2012 as a pre-operational service and will be fully operational in July 2012. It is also

  1. 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...

  2. 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 ...

  3. 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...

  4. 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.

  5. 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...

  6. INAVEM : un parcours professionnel d’écoute et d’aide aux victimes / INAVEM: a professional way of listening to and helping victims of crime

    Directory of Open Access Journals (Sweden)

    Bellucci Sabrina

    2012-08-01

    Full Text Available It is only in the last 20 years that support for victims of crime has received attention. The French history of associations dedicated to victims of crime is based on INAVEM (Institut National d’Aide aux Victimes et de Médiation – National Institute for Victims of Crime and Mediation: indeed, an associative network and its federation devoted to a mission of general interest and public service, constitute a French specificity. In France, the enforcement of the public policy to help and support victims of crime relies on associations, the most of which joined the INAVEM. L’aide aux victimes a longtemps été méconnue, elle s’est construite progressivement et a connu un essor considérable au cours de ces vingt dernières années. L’histoire associative française au service de la cause des victimes se fonde sur l’INAVEM (Institut National d’Aide aux Victimes et de Médiation : en effet, un réseau associatif et sa fédération en charge d’une mission d’intérêt général, de service public, constitue une spécificité française. La mise en œuvre de la politique publique d’aide aux victimes repose en France sur des structures associatives, la plupart adhérentes à l’INAVEM.

  7. 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.

  8. Modernité, corps et transformation de soi: Les salons de coiffure aux îles Tonga (Polynésie occidentale)

    NARCIS (Netherlands)

    N. Besnier

    2013-01-01

    Aux îles Tonga, la fin des années 2000 fut marquée par une véritable explosion des salons de coiffure dans la petite capitale, Nuku’alofa. Ce phénomène reflète de nouvelles manières de concevoir le corps, par lesquelles les Tongiennes cherchent à se distancier de la vie traditionnelle sans néanmoins

  9. Mutation in domain II of IAA1 confers diverse auxin-related phenotypes and represses auxin-activated expression of Aux/IAA genes in steroid regulator-inducible system.

    Science.gov (United States)

    Park, Jin-Young; Kim, Hye-Joung; Kim, Jungmook

    2002-12-01

    Most of Aux/IAA genes are rapidly induced by auxin. The Aux/IAA proteins are short-lived nuclear proteins sharing the four conserved domains. Domain II is critical for rapid degradation of Aux/IAA proteins. Among these gene family members, IAA1 is one of the earliest auxin-inducible genes. We used a steroid hormone-inducible system to reveal putative roles and downstream signaling of IAA1 in auxin response. Arabidopsis transgenic plants were generated expressing fusion protein of IAA1 (IAA1-GR) or IAA1 with a mutation in domain II (iaa1-GR) and the glucocorticoid hormone-binding domain (GR). IAA1-GR transgenic plants did not exhibit any discernable phenotypic differences by DEX treatment that allows nuclear translocation of the fusion protein. In contrast, diverse auxin-related physiological processes including gravitropism and phototropism were impaired by DEX treatment in roots, hypocotyls, stems, and leaves in iaa1-GR transgenic plants. Auxin induction of seven Aux/IAA mRNAs including IAA1 itself was repressed by DEX treatment, suggesting that IAA1 functions in the nucleus by mediating auxin response and might act as a negative feedback regulator for the expression of Aux/IAA genes including IAA1 itself. Auxin induction of Aux/IAA genes in the presence of cycloheximide can be repressed by DEX treatment, showing that the repression of transcription of the Aux/IAAs by the iaa1 mutant protein is primary. Wild-type IAA1-GR could not suppress auxin induction of IAA1 and IAA2. These results indicate that inhibition of auxin-activated transcription of Aux/IAA genes by the iaa1 mutant protein might be responsible for alteration of various auxin responses.

  10. 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

  11. TIR1/AFB-Aux/IAA auxin perception mediates rapid cell wall acidification and growth of Arabidopsis hypocotyls

    Science.gov (United States)

    Fendrych, Matyáš; Leung, Jeffrey; Friml, Jiří

    2016-01-01

    Despite being composed of immobile cells, plants reorient along directional stimuli. The hormone auxin is redistributed in stimulated organs leading to differential growth and bending. Auxin application triggers rapid cell wall acidification and elongation of aerial organs of plants, but the molecular players mediating these effects are still controversial. Here we use genetically-encoded pH and auxin signaling sensors, pharmacological and genetic manipulations available for Arabidopsis etiolated hypocotyls to clarify how auxin is perceived and the downstream growth executed. We show that auxin-induced acidification occurs by local activation of H+-ATPases, which in the context of gravity response is restricted to the lower organ side. This auxin-stimulated acidification and growth require TIR1/AFB-Aux/IAA nuclear auxin perception. In addition, auxin-induced gene transcription and specifically SAUR proteins are crucial downstream mediators of this growth. Our study provides strong experimental support for the acid growth theory and clarified the contribution of the upstream auxin perception mechanisms. DOI: http://dx.doi.org/10.7554/eLife.19048.001 PMID:27627746

  12. Flora Tristan: De la nécessité de faire bon accueil aux femmes étrangères

    Directory of Open Access Journals (Sweden)

    Martine Reid

    2014-10-01

    Full Text Available Dans son traité De la nécessité de faire bon accueil aux femmes étrangères (1835, Flora Tristan (1803-1844, l’écrivaine française qui adopte l’état psychologique d’une étrangère dans son propre pays, traite de la situation des femmes “étrangères” qui voyagent seules en France et/ou commencent une nouvelle vie dans le pays, en particulier à Paris. Politiquement engagée auprès des plus défavorisés à partir du socialisme, Tristan propose la création d’une association pour ces femmes. En assimilant les deux groupes d'"étrangères” (nationales et non nationales, car elle pense que le même type d’accueil doit être fourni à toutes, Tristan préconise l’aide à la voisine nécessiteuse, voisine qui est à la fois un sujet national ou un sujet en transit, une femme sans-papiers ou une réfugiée.

  13. Influência do auxílio mecânico na colheita de tomates Influence of the harvesting aid equipment in tomato harvest

    Directory of Open Access Journals (Sweden)

    Augusto C. Sanchez

    2006-12-01

    Full Text Available O objetivo deste trabalho foi avaliar parâmetros que influenciam na colheita auxiliada e comparar a colheita tradicionalmente realizada para tomate de mesa em propriedades agrícolas, no Estado de São Paulo. Para tanto, foi desenvolvido um dispositivo de auxílio à colheita, de estrutura metálica, dotado de rodas e com assentos acoplados para um ou dois colhedores, avaliado em quatro modalidades de colheita: testemunha (colheita-padrão utilizada na Fazenda Santa Luzia, Brotas-SP, colhedor a pé com auxílio, colhedor sentado com auxílio e composição dos dois sistemas, com dois colhedores sentados e um a pé, em diferentes velocidades de deslocamento. Os resultados demonstraram que os tipos de colheita com auxílio mecânico se apresentaram mais eficientes do que a testemunha em relação à produtividade horária média por colhedor. O sistema de colheita auxiliada com três colhedores apresentou aumento de 290% na produtividade média horária por colhedor, para a faixa de 0,5 a 1,0 fruto por planta, seguido dos sistemas de colheita auxiliada com colhedor a pé, com aumento de aproximadamente 41%, e colheita auxiliada com colhedor sentado, com aumento de aproximadamente 35%. Esses resultados comprovam a importância do uso do dispositivo de auxílio mecânico.Fresh tomato harvest is traditionally made without harvesting aids. The main goal of this research was to evaluate performance parameters of fresh tomato harvesting aid equipment and compare it to traditional harvest, in the state of São Paulo. Therefore, an equipment was developed and the harvest process was evaluated in four different ways: traditional system (harvest system used in Santa Luzia farm, Brotas, SP, Brazil, picker walking with a harvesting aid equipment, picker seated in a harvesting aid equipment and a composition of both systems: two pickers seated and one picker walking in two different velocities ranges. The different systems using harvesting aid showed an

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. A velocity map imaging study of gold-rare gas complexes: Au-Ar, Au-Kr, and Au-Xe

    Science.gov (United States)

    Hopkins, W. Scott; Woodham, Alex P.; Plowright, Richard J.; Wright, Timothy G.; Mackenzie, Stuart R.

    2010-06-01

    The ultraviolet photodissociation dynamics of the gold-rare gas atom van der Waals complexes (Au-RG, RG=Ar, Kr, and Xe) have been studied by velocity map imaging. Photofragmentation of Au-Ar and Au-Kr at several wavelengths permits extrapolation to zero of the total kinetic energy release (TKER) spectra as monitored in the Au(P23/2∘[5d106p]) fragment channel, facilitating the determination of ground state dissociation energies of D0″(Au-Ar)=149±13 cm-1 and D0″(Au-Kr)=240±19 cm-1, respectively. In the same spectral region, transitions to vibrational levels of an Ω'=1/2 state of the Au-Xe complex result in predissociation to the lower Au(P21/2∘[5d106p])+Xe(S10[5p6]) fragment channel for which TKER extrapolation yields a value of D0″(Au-Xe)=636±27 cm-1. Asymmetric line shapes for transitions to the v'=14 level of this state indicate coupling to the Au(P23/2∘[5d106p])+Xe(S10[5p6]) continuum, which allows us to refine this value to D0″(Au-Xe)=607±5 cm-1. The dissociation dynamics of this vibrational level have been studied at the level of individual isotopologues by fitting the observed excitation spectra to Fano profiles. These fits reveal a remarkable variation in the predissociation dynamics for different Au-Xe isotopologues. For Au-Ar and Au-Xe, the determined ground state dissociation energies are in good agreement with recent theoretical calculations; the agreement of the Au-Kr value with theory is less satisfactory.

  19. 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.

  20. 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

  1. Exposition aux endotoxines aéroportées et allergènes dans les animaleries et risques pour la santé

    OpenAIRE

    SCHWERY M.

    2014-01-01

    L'exposition aux endotoxines peut présenter des effets bénéfiques sur la santé. En effet, plusieurs études démontrent leur importance dans la théorie hygiéniste ainsi que leur effet négatif sur la croissance de certaines tumeurs. Toutefois, dans divers secteurs professionnels, l'environnement de travail favorise la présence d'endotoxines aéroportées et peut exposer le personnel à des risques sanitaires. C'est le cas...

  2. 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...

  3. 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 ...

  4. Cartographie de la vulnérabilité globale d'une population citadine face aux risques naturels: le cas de Manizales

    Directory of Open Access Journals (Sweden)

    Anne-Catherine CHARDON

    1994-12-01

    Full Text Available Cette méthode cartographique sert à évaluer la vulnérabilité de la population d’une grande ville andine (Manizales, Colombie, exposée aux séismes et à de fréquents glissements de terrain. Sept facteurs naturels et huit facteurs socio-économiques, mesurés à l’échelle du quartier, sont intégrés, avec d’autre facteurs géographiques, dans une carte de vulnérabilité globale.

  5. 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.

  6. 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

  7. 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.

  8. La défense face aux défis du dérèglement climatique

    Directory of Open Access Journals (Sweden)

    Bastien Alex

    2015-01-01

    Full Text Available Dans un rapport rédigé il y a plus de dix ans, le Pentagone établissait un lien entre sécurité et changement climatique. Depuis lors, l’étude du potentiel crisogène du phénomène s’est approfondie. Du fait de sa propension à renforcer le pouvoir de nuisance des aléas naturels et à, indirectement, produire de nouveaux risques, il est désormais considéré comme un « multiplicateur de menace » (Center for Naval Analyses 2007. Le changement climatique est ainsi un enjeu de premier plan pour les acteurs de la défense, institutionnels, militaires et industriels, et soulève plusieurs problématiques. Dans un premier temps se pose évidemment la question des risques et menaces sécuritaires découlant des manifestations des changements climatiques (modification du régime des précipitations, hausse du niveau des mers et océans, multiplication des phénomènes climatiques exceptionnels et l’étude de leur propension à générer de l’insécurité. Dans un deuxième temps se pose celle des réponses à y apporter en matière doctrinale (réflexion stratégique, opérationnelle (gestion de crise mais aussi en termes capacitaires (impacts sur l’outil militaire. Enfin, il convient d’étudier dans un troisième temps, et c’est là un paradoxe, les conséquences sur la sécurité internationale des politiques et stratégies d’adaptation qui seront développées par les Etats ou d’autres acteurs pour faire face aux défis posés par le dérèglement climatique.

  9. Élaboration de couches minces de carbone par ablation laser femtoseconde pour application aux biomatériaux implantables

    Science.gov (United States)

    Loir, A.-S.; Garrelie, F.; Donnet, C.; Subtil, J.-L.; Belin, M.; Forest, B.; Rogemond, F.; Laporte, P.

    2005-06-01

    Des films de tetrahedral amorphous-Carbon (ta-C) ont été déposés, sous vide poussé, par ablation d'une cible de graphite avec un laser Ti : saphir (durée d'impulsion 170 fs, fréquence de répétition 1 kHz, énergie maximale par impulsion 1,5 mJ, longueur d'onde 800 nm) sur substrats standard et sur biomatériaux (acier AISI 316L, polyéthylène à très haut poids moléculaire). Les propriétés de ces couches (structure, propriétés nanomécaniques et tribologiques) ont été caractérisées, en fonction des conditions d'élaboration, en examinant l'intérêt de l'utilisation d'un laser femtoseconde et leur capacité à satisfaire aux exigences spécifiques du domaine biomédical. Les propriétés d'adhérence des films ont été considérablement améliorées lors du dépôt sur des substrats en acier inoxydable préalablement préparés par décapage ionique in situ sous atmosphère d'argon. La surface hémisphérique d'une tête fémorale, en acier inoxydable, de prothèse de hanche de diamètre 22,2 mm a été revêtue d'un film de DLC adhérent et homogène en épaisseur. La résistance à l'usure de ce revêtement sera quantifiée à l'aide d'un simulateur de marche durant un million de cycles (correspondant à une année d'activité physique d'un être humain).

  10. 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)

  11. 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...

  12. 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...

  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

    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...

  14. 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...

  15. Endosidin1 defines a compartment involved in endocytosis of the brassinosteroid receptor BRI1 and the auxin transporters PIN2 and AUX1.

    Science.gov (United States)

    Robert, Stéphanie; Chary, S Narasimha; Drakakaki, Georgia; Li, Shundai; Yang, Zhenbiao; Raikhel, Natasha V; Hicks, Glenn R

    2008-06-17

    Although it is known that proteins are delivered to and recycled from the plasma membrane (PM) via endosomes, the nature of the compartments and pathways responsible for cargo and vesicle sorting and cellular signaling is poorly understood. To define and dissect specific recycling pathways, chemical effectors of proteins involved in vesicle trafficking, especially through endosomes, would be invaluable. Thus, we identified chemicals affecting essential steps in PM/endosome trafficking, using the intensely localized PM transport at the tips of germinating pollen tubes. The basic mechanisms of this localized growth are likely similar to those of non-tip growing cells in seedlings. The compound endosidin 1 (ES1) interfered selectively with endocytosis in seedlings, providing a unique tool to dissect recycling pathways. ES1 treatment induced the rapid agglomeration of the auxin translocators PIN2 and AUX1 and the brassinosteroid receptor BRI1 into distinct endomembrane compartments termed "endosidin bodies"; however, the markers PIN1, PIN7, and other PM proteins were unaffected. Endosidin bodies were defined by the syntaxin SYP61 and the V-ATPase subunit VHA-a1, two trans-Golgi network (TGN)/endosomal proteins. Interestingly, brassinosteroid (BR)-induced gene expression was inhibited by ES1 and treated seedlings displayed a brassinolide (BL)-insensitive phenotype similar to a bri1 loss-of-function mutant. No effect was detected in auxin signaling. Thus, PIN2, AUX1, and BRI1 use interactive pathways involving an early SYP61/VHA-a1 endosomal compartment.

  16. 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

  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. 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

  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. 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

  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. Effect of glutathione and sodium selenite on the metabolism of arsenic in mice exposed to arsenic through drinking water%谷胱甘肽与亚硒酸钠对饮水砷暴露小鼠体内砷代谢的影响

    Institute of Scientific and Technical Information of China (English)

    于霄云; 钟媛; 牛玉红; 曲春清; 李革新; 吕秀强; 孙贵范; 金亚平

    2008-01-01

    Objective To explore the effect of glutathione(GSH)and sodium selenite on the metabolism of arsenic in the liver,kidney and blood of mice exposed to iAsⅢ through drinking water.Methods The mice were randomly divided into control,arsenic,GSH and sodium selenite group,respectively.And each group had eight mice and the mice were exposed to 50 mg/L arsenite by drinking water for 4 weeks.Mice were intraperitoneally injected with GSH(600 mg/kg)and sodium selenite (1 mg/kg)for seven days from the beginning of the fourth week.At the end of the fourth week,liver,kidney and blood were samplod to assess the concentrations of inorganic arsenic(iAs),monomethylarsenic acid(MMA),dimethylarsenic acid(DMA)by hydride generation trapping by ultra-hypothermia coupled with atomic absorption spectrometry.Results The liver DMA(233.76±60.63 ng/g)concentration in GSH group was significantly higher than the arsenic group(218.36±42.71 ng/g).The concentration of DMA (88.52±30.86 ng/g)and total arenic(Tas)(162.32±49.45 ng/g)in blood of GSH group was significantly higher than those[(45.32±12.19 ng/g),(108.51±18.00 ng/g),respectively]of arsenic groups(q values were 3.06,6.40,10.72 respectively,P<0.05).The primary methylated index(PMI)(0.65±0.050)and secondary methyhted index(SMI)(0.55±0.050)in liver sample of GSH group were significantly higher than those(0.58±0.056,0.44±0.093)in arsenic group.In blood samples,the PMI (0.85±0.066)in GSH group was significantly higher than that(0.54±0.113)in arsenic group(q values were 3.75,5.26,4.21 respectively,P<0.05).However,no significant difference was identified between sodium selenite and arsenic groups in liver,kidney or blood samples.And no significant difference was detected in kidney samples among all arsenic exposing groups.Conclusion Exogenous GSH could promote the methylated metabolism of iAsⅢ,but sodium selenite showed no significant effects.%目的 探讨给予外源性谷胱甘肽(GSH)和亚硒酸钠(sodium selenite)对饮

  6. 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...

  7. 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...

  8. Fouille de données complexes : des relevés terrain aux données satellitaires pour la cartographie de paysages agricoles

    OpenAIRE

    Badra, F.; Vintrou, E; Bégué, A.; Teisseire, M.

    2010-01-01

    National audience; Dans cet article, nous présentons une approche préliminaire de caractérisation des paysages ruraux et de leurs systèmes de culture à partir de techniques de fouille de données (recherche d'itemsets fréquents). Cette méthode permet de coupler des données de relevé terrain aux indicateurs de texture extraits des images satellites. Sa mise en œuvre sur des données associées au Mali pose les premières bases d'une méthode originale d'extraction de motifs séquentiels à partir de ...

  9. Gestion de l’eau en Crau : comment s’adapter aux tensions sur la ressource en eau à l’échelle des exploitations agricoles

    Directory of Open Access Journals (Sweden)

    MÉROT, Anne ; BERGEZ, Jacques-Eric ; WALLACH, Daniel ; DURU, Michel ; CHARRON, François ; CAPILLON, Alain ; WERY, Jacques ; ISBERIE, Carole ; MAILHOL, Jean-Claude

    2011-10-01

    Full Text Available Dans le contexte actuel d'augmentation de la pression sur la ressource en eau, quels sont les moyens pour économiser de l'eau en améliorant l'efficience d'irrigation d'une culture tout en préservant la production ? Le travail agronomique présenté ici combine expérimentation, enquête et modélisation pour évaluer l'efficience du mode d'irrigation gravitaire des prairies de la plaine de Crau et proposer de nouveaux scénarios de gestion adaptés aux différents usages et usagers de la ressource en eau.

  10. Nicole Fouché. Benjamin Franklin et Thomas Jefferson : Aux sources de l’amitié franco-américaine 1776-1808.

    Directory of Open Access Journals (Sweden)

    Nathalie Caron

    2006-04-01

    Full Text Available Spécialiste des relations franco-américaines, Nicole Fouché propose une comparaison presque terme à terme entre deux Pères fondateurs de renom, Benjamin Franklin et Thomas Jefferson. Ce choix, comme la brièveté de l’ouvrage, le nombre limité de notes, la présence d’une courte bibliographie et l’absence d’index, répond aux exigences de la collection « Biographies américaines », dirigée par Annick Foucrier, dont l’objectif est de « présenter l’histoire des Etats-Unis à travers les vies de deux ...

  11. 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...

  12. 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...

  13. 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

  14. 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...

  15. 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...

  16. 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...

  17. "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...

  18. 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...

  19. Profils de virulence et de résistance aux B-lactamines de souches cliniques de Klebsiellapneumoniae isolées de sondes endotrachéales

    OpenAIRE

    BELAID, KHADIDJA

    2015-01-01

    La présence étude visait à détecter les facteurs de virulence et de résistance aux B-lactamines des souches cliniques de Kiebsiella pneumoniae isolées des prélèvements à partir des sondes d'aspiration trachéale. Au totale, 10 souches de K. pneumoniae ont été isolées, identifiées, et - testés leurs résistances vis-à-vis de 7 antibiotiques (B-Iactamine). Les antibiotiques qui présentent le plus d'efficacité sont: Imipenème et Cefoxitine. La résistance a l'Ampiciline et Ticarcilli...

  20. Adaptation aux impacts du changement climatique sur les écosystèmes aquatiques continentaux, conclusion de l'ARP ADAGE

    OpenAIRE

    Gerdeaux, Daniel

    2010-01-01

    Les écosystèmes d’eau douce sont d’importants réservoirs de biodiversité très sensibles au changement global. Outre leur intérêt propre, les enjeux qui s’y rattachent sont multiples : importance pour le maintien de la biodiversité terrestre, services écologiques (régulation et épuration de l’eau et énergie renouvelable) et engagements réglementaires. Aux conventions internationales et directives européennes protégeant certains types d’espèces et d’habitats, s’ajoute la DCE qui demande le reto...

  1. 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,...

  2. 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

  3. « 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.

  4. 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.

  5. 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.

  6. Sorption and diffusion of selenium oxyanions in granitic rock

    Science.gov (United States)

    Ikonen, Jussi; Voutilainen, Mikko; Söderlund, Mervi; Jokelainen, Lalli; Siitari-Kauppi, Marja; Martin, Andrew

    2016-09-01

    The processes controlling diffusion and sorption of radionuclides have been studied extensively in the laboratory, whereas, only a few in-situ experiments have been carried out in order to study in-situ diffusion over the long-term (several years). This is largely due to the fact that in-situ experiments are typically time consuming and cost intensive, and it is commonly accepted that laboratory scale tests are well-established approaches to characterizing the properties of geological media. In order to assess the relevance of laboratory experiments, the Swiss National Cooperative for Disposal of Radioactive Waste (Nagra) have been conducting extensive experiments in the Underground Rock Laboratory (URL) at the Grimsel Test Site (GTS) in order to study radionuclide transport and retention in-situ. One of the elements used in these experiments is non-radioactive selenium, as an analog for the radiotoxic isotope Se-79, which is present in radioactive waste. In this work, two laboratory through-diffusion experiments using selenium as a tracer were carried out in block (decimeter) scale rock specimens to support one of the ongoing radionuclide transport and retention in-situ experiment at the GTS mentioned above. The though-diffusion tests of selenium were performed under atmospheric conditions in both Kuru grey granite (KGG) and Grimsel granodiorite (GG). The decrease of selenium concentration in an inlet hole drilled into each of the rock samples and the breakthrough of selenium into sampling holes drilled around the inlet were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The effective diffusion (De) and distribution coefficients (Kd) of selenium were then determined from the changes of selenium concentration in the inlet and sampling holes using a Time-Domain Diffusion (TDD) simulations. In addition, Kd of selenium was measured by batch sorption experiments as a function of pH and Se concentration in atmospheric conditions and nitrogen atmosphere. The speciation of selenium was studied by HPLC-ICP-MS in simulated ground waters of each of the rock types. The Kd of selenium was found to be in the range of (6.2-7.0 ± 2.0) × 10- 3 m3/kg in crushed rock whereas the Kd obtained from block scale through diffusion experiment varied between (1.5 ± 0.3) × 10- 3 m3/kg and (1.0 ± 0.6) × 10- 4 m3/kg. The De of selenium was significantly higher for GG; De = (2.5 ± 1.5) × 10- 12 m2/s than for KGG; De = (7 ± 2) × 10- 13 m2/s due to the higher permeability of GG compared with KGG.

  7. 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...

  8. 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...

  9. 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.

  10. Cohabitation sociale et ordre public aux Champs-Élysées :Gestion et appropriation du carré des jeux (1700-1830

    Directory of Open Access Journals (Sweden)

    Véronique Laporte

    2011-08-01

    Full Text Available Au 18e siècle et au début du 19e siècle, les Champs-Élysées sont ouverts à tous et attirent une clientèle diversifiée. Des joueurs issus d’horizons très différents s’y retrouvent pour pratiquer différentes activités, telles que la longue paume, les boules ou les barres. Afin que les promeneurs ne soient pas importunés par les jeux, ces derniers sont confinés dans une vaste clairière servant également lors des revues militaires et des fêtes publiques. Les autorités ont une volonté réelle d’offrir aux visiteurs des espaces de jeux, mais elles craignent aussi les débordements susceptibles d’être créés par les amusements. En effet, qu’importe si les joueurs sont nobles ou écoliers, la même crainte transparaît. Il s’agit de la peur des attroupements. C’est pourquoi les autorités tentent de diminuer l’affluence aux Champs-Élysées en contrôlant le nombre et la nature des jeux pratiqués dans cet espace public.At the end of the 18th century and the beginning of the 19th century, the Champs-Élysées were open to people of all extractions and attracted indeed a diversified public. Players of different social origins gathered for various collective games such as the longue paume, bowls, or "les barres". In order not to disturb the strollers, the games were confined in a clearing also used for military reviews and public celebrations. Authorities had a will to offer playing spaces to visitors, but were at the same time concerned by the possibility of public overflowings. Whether they be aristocrats or schoolboys, the same apprehension comes out: the fear of gatherings. This is the why the authorities attempted to reduce the crowds on the Champs-Élysées by controlling the number and the nature of the games practiced in that public place.

  11. The Study of Over-expression of the Auxin Influx Carrier Gene PtAUX1 in Populus tomentosa Carr.%毛白杨生长素载体蛋白基因PtAUX1超表达的研究

    Institute of Scientific and Technical Information of China (English)

    于淑惠; 闫辉; 左曼曼; 郎庆雯; 樊金会

    2012-01-01

    The aim was to study the action of genes encoding auxin signaling components in plants development. P. tomentosa and Arabidopsis were chosen as the research object in the paper. PtAUXl complied with the role of auxin characteristics and influenced organ morphology through the regulation of auxin polar transport in the distribution of the plants. By using expression vector of P. tomentosa PtAUXl constructed by our laboratory, the auxin influx import carrier PtA UX1 was transformed into Arabidopsis and Poplar. PtA UX1 transgenic plants were detected by PCR, and the phenotypes of transgenic plants and morphologic characters cultured in vivo were analyzed. The experiments showed that the over-expression of PtAUXl influenced many organs of the morphological development. Transgenic plant of Poplar had vigorous growth and spire. Transgenic plant of Arabidopsis had grown in groveling, not altered root geotropism, trichome number increased on the stem, and abnormal floral organs. The results indicated that PtAUXl promoted cells and tissues to absorb endogenesis IAA by auxin polar transport, and then participated in organ polarity establishment, and influenced morphology and development of the organs.q%以毛白杨和拟南芥为研究对象,研究生长素信号转导因子基因在植物发育过程中的作用.利用构建好的tAUX1的表达载体,转化拟南芥和毛白杨,获得转基因植株,通过PCR技术检测转化植株,分析植株表型并观察植株离体条件下的形态变化.结果显示PtAUX1影响植株各器官的形态发育,毛白杨长势旺盛、外植体有莲座状幼叶产生,拟南芥出现了匍匐生长、不改变根的向地性、茎上的表皮毛增多、花器官畸形等现象.以上结果表明PtAUX1基因通过生长素极性运输,促进各细胞、组织对内源生长素IAA的吸收,进而参与器官极性的建立,影响各器官的形态和发育过程.

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  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. 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 : ...

  19. Les Méduses dans la Marée de l’Histoire: L’Anse aux Meadows, Nan Sdins and Cultural Heritage Agendas

    Directory of Open Access Journals (Sweden)

    Philip Hayward

    2008-11-01

    Full Text Available This paper reflects upon the relation of island communities to global cultural heritage agendas through discussion of two particular examples, the first two island locations successfully nominated by the Canadian government for UNESCO World Heritage listing: L’Anse aux Meadows, on Newfoundland, and Nan Sdins (Ninstints on SGang Gwaii . This reflection involves discussion of the motives and discourses that led to their formal establishment as cultural heritage sites and those that have come into play in subsequent social inscriptions and interpretations. This line of inquiry intersects with – and is illuminated by - a consideration of the spatial contexts of the island networks that have facilitated particular moments upon which their heritage status is based. In particular, I refer to their relation to sea-lanes and coastal/inter-island lines of contact that are, in turn, predicated on particular moments of climatic, navigational and socio-economic history. The paper concludes by offering a point of mediation between traditional concepts of heritage agendas and socio-cultural development in island communities pertinent to the development of Island Studies as an activist enterprise.

  20. 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.

  1. 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.

  2. 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.

  3. La femme écrivain hébraïque narre aux enfants Israeli Women Writing for Children: Devora Omer an Author of Young Literature ספרות נוער כתובה על ידי נשים : דבורה עומר

    Directory of Open Access Journals (Sweden)

    Dorit Shilo

    2011-11-01

    Full Text Available Les auteurs de la littérature israélienne pour enfants. Dans la première partie de l'article, j'explore les premiers jours de la littérature hébraïque pour enfants (XIXe siècle. Je tiens à souligner que ce sont les auteurs masculins qui ont régné sur ce genre littéraire et qu’à travers le XXe siècle un phénomène intriguant apparaît: les femmes commencent à écrire des oeuvres littéraires pour les enfants, et deviennent professionnelles dans ce domaine.La deuxième partie de l'article est dédiée à Devora Omer (né en 1932 qui est l'une des romancières les plus populaires et appréciées chez les enfants dans la littérature israélienne contemporaine. En particulier, j'examine le protagoniste féminin, Zohara, dans son œuvre Le’eov ad mavet (Aimer jusqu'à la mort, 1980, par rapport à la représentation de son apparence physique et à son monologue intérieur. Je suggère que même si elle est intégrée dans l'armée et donc « égale » aux hommes, le personnage principal du roman entretient la conception de l'auteur de la féminité, c'est-à-dire être physiquement attractive, même dans la bataille, pendant qu’elle est obligée d'accomplir les tâches ménagères, traditionnellement considérées comme le travail des femmes. En conclusion, la représentation de Zohara renvoie aux conflits entre les sexes dans la société israélienne contemporaine.In the first part of the article, I explore the early days of Hebrew children’s literature (19th century. I emphasize that it was male authors who ruled this literary genre and throughout the 20th century an intriguing phenomenon appears: women start writing literary works for children, becoming professionals in the domain. The second part of the article is dedicated to Devora Omer (born 1932 who is one of the most popular and well-appreciated children’s novelists in contemporary Israeli literature. In particular, I examine the female protagonist, Zohara, in

  4. 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

  5. Des psy aux rabbins – pour une pensée de la Shoah From Psychologists to Rabbis – rethinking the Holocaust

    Directory of Open Access Journals (Sweden)

    Nathalie Zajde

    2010-03-01

    Full Text Available Le monde juif traditionnel contemporain, c’est-à-dire celui qui recourt aux concepts de la Thora pour se penser et penser les événements, ne s’est que fort peu intéressé à la Shoah. Les quelques interprétations proposées sont souvent anciennes – bon nombre datent de l’époque de la Shoah – et ne donnent pas lieu à des innovations ; elles n’intéressent que peu les penseurs de la tradition juive contemporaine au regard de leur foisonnante production. De leur côté, la psychiatrie, la psychologie et même la psychanalyse s’intéressent depuis fort longtemps à la Shoah et aux internés en camp de concentration – le point le plus marquant étant la création du Syndrome du survivant des camps de concentration à la fin des années 1950. Mais ni le fameux syndrome, ni pratiquement aucun des textes, des manuels, des articles traitant des survivants de la Shoah, ne mentionnent l’identité juive des patients de manière scientifiquement pertinente. Pourquoi chercher à combler ces lacunes de part et d’autre ? Pourquoi a-t-on besoin de faire se rencontrer la discipline « psy » et l’univers de la pensée juive ? L’auteur, responsable, au Centre Georges Devereux à l’Université de Paris 8, de dispositifs cliniques de recherche en psychothérapie des survivants et descendants de survivants de la Shoah, expose les raisons de cette réflexion et soumet des propositions.The contemporary Jewish world, namely the one which bases itself on concepts from the Torah in order to comprehend itself and events, has taken a minimal interest in the Holocaust. The few interpretations it has put forward are often old – many dating from the period of the Holocaust, with few innovations – and they have little interest for contemporary Jewish scholars, if one looks at the latter’s abundant output. On their side, psychiatry, psychology and even psycho-analysis have, for a long time, taken an interest in the Holocaust and

  6. From Psychologists to Rabbis – rethinking the Holocaust Des psy aux rabbins – pour une pensée de la Shoah

    Directory of Open Access Journals (Sweden)

    Nathalie Zajde

    2010-03-01

    Full Text Available The contemporary Jewish world, namely the one which bases itself on concepts from the Torah in order to comprehend itself and events, has taken a minimal interest in the Holocaust. The few interpretations it has put forward are often old – many dating from the period of the Holocaust, with few innovations – and they have little interest for contemporary Jewish scholars, if one looks at the latter’s abundant output. On their side, psychiatry, psychology and even psycho-analysis have, for a long time, taken an interest in the Holocaust and in the internees of concentration camps – the most famous achievement being the identification of the concentration camp survivor syndrome at the end of the 1950s. But neither this famous syndrome, nor practically any other books, manuals, or articles dealing with Holocaust survivors mention the Jewish identity of the patients in a pertinent scientific manner. Why seek to fill these gaps on either side? Why deem it necessary to connect the psychological disciplines with the world of Jewish thought? The author, in charge, at the Centre Georges Devereux at the University of Paris 8, of clinical research psychotherapy tools for Holocaust survivors and descendants of survivors, analyzes the reasons behind these issues and puts forward suggestions.Le monde juif traditionnel contemporain, c’est-à-dire celui qui recourt aux concepts de la Thora pour se penser et penser les événements, ne s’est que fort peu intéressé à la Shoah. Les quelques interprétations proposées sont souvent anciennes – bon nombre datent de l’époque de la Shoah – et ne donnent pas lieu à des innovations ; elles n’intéressent que peu les penseurs de la tradition juive contemporaine au regard de leur foisonnante production. De leur côté, la psychiatrie, la psychologie et même la psychanalyse s’intéressent depuis fort longtemps à la Shoah et aux internés en camp de concentration — le point le plus

  7. The Aux/IAA gene rum1 involved in seminal and lateral root formation controls vascular patterning in maize (Zea mays L.) primary roots.

    Science.gov (United States)

    Zhang, Yanxiang; Paschold, Anja; Marcon, Caroline; Liu, Sanzhen; Tai, Huanhuan; Nestler, Josefine; Yeh, Cheng-Ting; Opitz, Nina; Lanz, Christa; Schnable, Patrick S; Hochholdinger, Frank

    2014-09-01

    The maize (Zea mays L.) Aux/IAA protein RUM1 (ROOTLESS WITH UNDETECTABLE MERISTEMS 1) controls seminal and lateral root initiation. To identify RUM1-dependent gene expression patterns, RNA-Seq of the differentiation zone of primary roots of rum1 mutants and the wild type was performed in four biological replicates. In total, 2 801 high-confidence maize genes displayed differential gene expression with Fc ≥2 and FDR ≤1%. The auxin signalling-related genes rum1, like-auxin1 (lax1), lax2, (nam ataf cuc 1 nac1), the plethora genes plt1 (plethora 1), bbm1 (baby boom 1), and hscf1 (heat shock complementing factor 1) and the auxin response factors arf8 and arf37 were down-regulated in the mutant rum1. All of these genes except nac1 were auxin-inducible. The maize arf8 and arf37 genes are orthologues of Arabidopsis MP/ARF5 (MONOPTEROS/ARF5), which controls the differentiation of vascular cells. Histological analyses of mutant rum1 roots revealed defects in xylem organization and the differentiation of pith cells around the xylem. Moreover, histochemical staining of enlarged pith cells surrounding late metaxylem elements demonstrated that their thickened cell walls displayed excessive lignin deposition. In line with this phenotype, rum1-dependent mis-expression of several lignin biosynthesis genes was observed. In summary, RNA-Seq of RUM1-dependent gene expression in maize primary roots, in combination with histological and histochemical analyses, revealed the specific regulation of auxin signal transduction components by RUM1 and novel functions of RUM1 in vascular development.

  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. Le traducteur aux frontières des discours: le "monologue narrativisé" dans les deux traductions slovènes de Madame Bovary

    Directory of Open Access Journals (Sweden)

    Florence Gacoin-Marks

    2013-12-01

    Full Text Available Forme de discours souvent ambiguë et polyphonique dont Flaubert a généralisé lʼemploi dans son écriture romanesque, en particulier dans Madame Bovary, le "monologue narrativisé", plus connu sous le nom de "discours indirect libre", passionne encore aujourdʼhui tant les linguistes que les narratologues et pose aux traducteurs étrangers des difficultés parfois insurmontables. Les différences entre les codes linguistiques français et slovène, notamment lʼabsence en slovène de la concordance des temps dans les propositions complétives, ont pour effet que, dans cette langue, le monologue narrativisé, appelé "discours semidirect", est beaucoup plus nettement détaché des autres formes du discours coexistant dans les textes littéraires. Par ailleurs, contrairement au discours indirect libre français, il se rapporte à une instance énonciative clairement identifiée et est, de ce fait, pratiquement monophonique. En traduisant la prose française, notamment les oeuvres de Flaubert, le traducteur slovène sera donc toujours contraint de prendre parti, de poser des frontières entre les différents types de discours et de transformer le discours indirect libre français polyphonique soit en discours narratif, soit en discours semi-direct slovène monophonique. Dʼautre part, il sera contraint dʼinterpréter les formes verbales ambiguës au sein même du discours indirect libre français, en particulier le conditionnel qui, généralement strictement temporel, peut toutefois également exprimer lʼhypothèse ou lʼaltérité énonciative.

  10. Économiste et développement durable : de la professionnalité aux métiers

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    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. 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

  12. L’expertise médico-légale face aux perversions : instrument ou argument de la justice ? The Medico-Legal Expert on Perversion: Instrument or Argument?

    Directory of Open Access Journals (Sweden)

    Gilles Trimaille

    2011-03-01

    Full Text Available L’expertise médico-légale n’est pas une création du XIXe siècle mais l’application du Code pénal napoléonien de 1810 va profondément modifier la place des experts dans le débat judiciaire. Face à certains comportements étranges, les juges seront amenés à solliciter de plus en plus fréquemment les experts psychiatres afin de déterminer le niveau de responsabilité imputable aux auteurs de crimes ou délits. Dans le domaine spécifique des infractions sexuelles, il reviendra aux psychiatres de déterminer la limite entre la perversité et la perversion, le partage entre la sanction et le soin. Malgré un souci croissant de scientificité présent dans les études médicales consacrées aux perversions sexuelles, les experts psychiatres du XIXe siècle n’arriveront pas toujours à se déprendre des valeurs politiques et morales dominantes de leur temps.Medico-legal expertise was not a creation of the 19th century but application of the Napoleonic Criminal Code of 1810 profoundly changed the role of experts in judicial proceedings. Faced with certain strange behaviors, judges were increasingly led to solicit psychiatric experts so as to determine the level of responsibility attributable to those accused of crimes or misdemeanors. In the specific domain of sexual offenses, it fell to psychiatrists to determine the border between perversity and perversion, and the distinction between sanction and care.  In spite of growing concern with the scientific character of medical studies devoted to sexual perversions, psychiatric experts of the 19th century did not always succeed in separating themselves from the dominant political and moral values of their times.

  13. 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 ?...

  14. 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.

  15. 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

  16. 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”.

  17. 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

  18. 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

  19. 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.

  20. Protective Effects of Sodium Selenite against Cadmium Chloride-Induced Injury on Kidney and Liver Cells of Rat%亚硒酸钠拮抗氯化镉染毒大鼠肝、肾细胞损伤的研究

    Institute of Scientific and Technical Information of China (English)

    欧阳彩群; 叶卓明; 曾艳飞

    2012-01-01

    目的 观察亚硒酸钠处理对亚慢性氯化镉中毒大鼠肝、肾结构的影响,为氯化镉慢性中毒的防治和亚硒酸钠蓄积性毒性研究提供依据.方法 雄性SD大鼠54只,随机分成3组.对照组大鼠饮用蒸馏水;其余两组大鼠饮用含30 mg/L 氯化镉蒸馏水;硒干预组大鼠给予5 μmol/kg 亚硒酸钠溶液灌胃.结果 与对照组比较,氯化镉组大鼠组织中GSH-Px及SOD活性降低、MDA含量增加;硒干预组大鼠组织GSH-Px及SOD活性显著升高、MDA含量降低.组织病理切片观察结果,单纯给氯化镉组大鼠肾小球肿胀或固缩,肾小囊囊腔增大,肾小管上皮细胞变性坏死并脱落等病理损伤.硒干预组大鼠肝、肾脏组织结构未见明显损伤.结论 饮用含氯化镉的水源可致肾脏组织明显损伤,低剂量亚硒酸钠可拮抗氯化镉对肾组织的损伤作用,对氯化镉所致组织氧化损伤有一定的修复作用.%Objective To study the - induced injury on kidney and liver cells of rat and the protective effects of sodium selenite. Methods 54 healthy SPF male SD rats were divided randomly into three groups. Croup Ⅰ : rats drinking distilled water as control; Croup Ⅱ:rats drinking water containing 30mg/L CdCl, distilled water; Croup Ⅲ: rats drinking water containing 30mg/L CdCl, distilled water, while giving 5 μnol/kg Na2SeO3 solution gavage, 5 days a week, once a day. Rats were killed on the 2nd, 4th and 8th week after initiation of the experiment. Blood were collected, kidneys and livers were removed immediately, ? xed in 10% methanal ? xative, routinely processed and stained with hematoxylin and eosin. Results In Se - administered rat homogenates, the contents of MDA were lowei ,and the activity of CSH - Px and SOD were significantly higher than those of control. In Cd - treated rats, we noticed histopathological changes in kidneys and livers, while no obvious changes were found in Se - administered rats. Conclusion The sodium selenite

  1. Le statut juridique en droit interne des espèces animales liées aux milieux aquatiques continentaux métropolitains

    Directory of Open Access Journals (Sweden)

    BENTATA V.

    1997-01-01

    poissons et les agnathes, font l'objet de listes diverses : espèces représentées dans les eaux douces soumises à la législation sur la pêche ; espèces susceptibles de provoquer des déséquilibres biologiques ; espèces citées au 3° de l'article L.232-10 du code rural ; espèces non représentées, mais figurant sur la liste ministérielle de celles dont l'introduction peut être autorisée en vertu d'un arrêté préfectoral pris au titre de l'article R.*232-8 du code rural ; autres espèces non représentées, mais d'introduction autorisée en vertu d'une décision ministérielle prise au titre de l'article R.*232-9 du code rural. Les classifications agricoles interviennent aussi, dans la mesure où l'article 342 du code rural prévoit l'établissement d'une liste d'«organismes nuisibles» aux végétaux ou aux produits végétaux, différente de celle - évoquée plus haut - qui concerne exclusivement certaines espèces de gibiers. Il est également utile d'examiner quelques catégories remarquables d'espèces qui ne figurent pas sur ces listes. Ainsi : les espèces visées par des listes négatives ; certaines espèces omises sur des listes positives ; différents cas particuliers de mammifères ; certaines espèces d'animaux d'ornement ou d'aquariophilie... On conclut par l'examen des possibilités d'appartenance d'une même espèce à différentes catégories juridiques, et par l'examen du poids relatif que prennent respectivement espèces indigènes et espèces introduites dans ces catégories.

  2. 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

  3. 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

  4. 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

  5. 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)

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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...

  11. 8ème édition de l'atelier "Fouille de données complexes" : complexité liée aux données multiples

    OpenAIRE

    Cleuziou, Guillaume; De Runz, Cyril; Lebbah, Mustapha; Wemmert, Cédric

    2011-01-01

    Actes du 8ème atelier Fouille de données complexes - complexité liée aux données multiples - dans le cadre de la conférence EGC'2011.; L'atelier sur la fouille de données complexes est proposé à l'instigation du groupe de travail EGC "Fouille de données complexes". Chaque année les organisateurs proposent une thématique de recherche qui suscite l'intérêt des chercheurs et des industriels. La précédente édition de l'atelier ayant permis de fédérer avec succès des recherches portant sur la prob...

  12. 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...

  13. Commande multi-modèles tolérante aux défauts : Application au contrôle de la dynamique d'un véhicule automobile.

    OpenAIRE

    Oudghiri, Mohammed

    2008-01-01

    Cette thèse traite la synthèse de lois de commande tolérantes aux défauts (FTC) pour le contrôle de la dynamique du châssis du véhicule automobile. L'étude est basée sur l'approche multimodèle avec la formulation et la résolution des problèmes de synthèse de lois de commande en utilisant les techniques LMI (Inégalités Matricielles Linéaires).La première partie consacrée à la FTC passive comporte trois chapitres. La première concerne la synthèse d'une loi de commande multimodèle par retour d'é...

  14. Introduction aux religions préislamiques d’Arabie du Nord. Recherches sur les divinités du paganisme arabe, à travers l’épigraphie et l’iconographie

    OpenAIRE

    Roche, Marie-Jeanne

    2009-01-01

    Le semestre de l’année 2011-2012 est consacré à l’examen de documents attestant de visites de fidèles dans des sanctuaires de divinités d’origine étrangère, dans le nord de l’Arabie antique, sans qu’il y ait nécessairement des pélerinages organisés pour un grand nombre de pélerins et à dates fixes […]. Le semestre de l’année 2009-2010 est consacré aux différentes notions de Destin et de Fortune, à travers des exemples de documents mentionnant ou figurant Manāt, Gad, Tychè et Némésis. On menti...

  15. Latte-Abdallah Stéphanie, Images aux frontières, Représentations et constructions sociales et politiques, Palestine, Jordanie 1948-2000, Publications de l’IFPO, 2005, 369 p.

    Directory of Open Access Journals (Sweden)

    Véronique Bontemps

    2008-01-01

    Full Text Available Le traitement médiatique du 11 septembre 2001, et les images, diffusées en boucle sur les chaînes de télévision, des avions s’écrasant sur les Twin Towers ont tragiquement confirmé l’immense pouvoir des images sur notre appréhension de la réalité sociale. L’ouvrage Images aux frontières s’inscrit dans cette interrogation. Il regroupe des articles de sociologues, anthropologues, historiens et politologues autour de la notion « d’image » dans la construction des identités collectives en Palesti...

  16. Contribution à la compréhension des mécanismes moléculaires de résistance de mycobacterium tuberculosis aux agents anti-tuberculeux

    OpenAIRE

    Mathys, Vanessa

    2009-01-01

    Malgré la disponibilité d’un traitement curatif et un vaccin largement utilisé, l’OMS estime qu’approximativement un tiers de la population mondiale est infectée par Mycobacterium tuberculosis, l’agent étiologique de la tuberculose, et qu’environ 2 millions de personnes en meurent chaque année. La compréhension de l’épidémiologie de la tuberculose et les actions de contrôle de la maladie ont été, récemment, compliquées par l’émergence de bacilles tuberculeux résistants aux antibiotiques et pa...

  17. L’accès des femmes aux emplois supérieurs de la fonction publique : une construction au croisement des itinéraires professionnels et familiaux

    OpenAIRE

    Douarin, Laurence Le; Doniol-Shaw, Ghislaine

    2011-01-01

    À l’initiative de la direction des ressources humaines du ministère de l’équipement, une enquête a été menée auprès des femmes occupant les postes les plus élevés en vue de comprendre le cheminement qui leur a permis d’y parvenir. Cet article s’interroge sur l’accès des femmes aux emplois supérieurs de la fonction publique, en repérant les freins mais aussi les ressources dans lesquelles elles puisent pour surmonter les épreuves rencontrées lors de leur ascension. Il porte une attention parti...

  18. Arnaud de Lajartre, Vincent Gaboriau (dir., 2004, Les Collectivités Territoriales face aux risques physiques, Paris, L’Harmattan, collection « Logiques juridiques », 261 p.

    Directory of Open Access Journals (Sweden)

    Stéphane Callens

    2005-02-01

    Full Text Available Cet ouvrage réunit les contributions d’un colloque qui s’est tenu à Angers en mars 2002, sur le thème « Les Collectivités Territoriales face aux risques physiques ». Il faut entendre par « risques physiques », l’ensemble des risques non directement financiers, qu’ils soient « majeurs » (catastrophes naturelles ou technologiques, ou « mineurs » (accidents. Les treize contributions sont toutes intéressantes en elles-mêmes. On peut regretter toutefois que les éditeurs n’aient pas fait un effor...

  19. Quelles traces de développement professionnel dans le domaine de l’éducation aux médias et à l’information à l’issue de la formation initiale des professeurs-documentalistes ?

    OpenAIRE

    Kerneis, Jacques

    2015-01-01

    Dans cette communication, nous situerons la place d'une unité d'enseignement (UE) nommée « Education aux médias » dans le cursus de la formation actuelle des professeurs-documentalistes à l'ESPE de Bretagne. Nous verrons comment elle s'articule avec les autres UE présentes dans la maquette de la formation et en particulier avec une UE « Cultures numériques » en Master 1 et « pédagogie et numérique » en Master 2. Nous nous centrerons ensuite sur les compétences travaillées dans ces différentes...

  20. Enjeux politiques de l’adaptation aux changements climatiques dans les projets de gestion intégrée des zones côtières à Madagascar 

    OpenAIRE

    Andriamasinoro, Jessica Onitsoa; Sarrasin, Bruno

    2016-01-01

    Pour faire face aux changements climatiques, les pays économiquement pauvres comme Madagascar ont été invités par les Nations-Unies à soumettre un Programme d’actions nationales d’adaptation (PANA) qui identifie les projets jugés prioritaires en matière d’adaptation. On trouve parmi ces derniers la gestion intégrée des zones côtières (GIZC). Celle-ci résulte aussi d’une mise à jour du Livre blanc de la politique de développement durable des zones côtières et marines ayant mené à l’élaboration...

  1. Julie Bouchard, Comment le retard vient aux Français. Analyse d’un discours sur la recherche, l’innovation et la compétitivité (1940-1970)

    OpenAIRE

    Lamy, Jérôme

    2009-01-01

    L’ouvrage de Julie Bouchard met en lumière le lien entre deux discours dominants dans les années d’après Deuxième guerre mondiale, celui d’un retard français en matière de sciences et de techniques et celui relatif au projet de modernisation de la société française figurant dans les rapports des Commissions du Plan et de la Délégation générale à la recherche scientifique et technique (DGRST). L’analyse confronte les enjeux économiques, politiques, sociaux et communicationnels liés aux science...

  2. Règlement de sécurité contre l'incendie relatif aux établissements recevant du public dispositions générales et commentaires de la commission centrale de sécurité

    CERN Document Server

    2015-01-01

    L’ouvrage comporte : les dispositions des Codes de la construction et de l'habitation, et l'urbanisme relatives à la protection contre l'incendie ; les articles : GN, GE, CO, AM, DF, CH, GZ, EL, EC, AS, GC et MS ; les instructions techniques ; les textes relatifs aux commissions de sécurité ; les textes concernant l’accessibilité des personnes handicapées ; les textes intéressant les qualifications des personnels des services de sécurité des ERP (SSIAP) ; la jurisprudence sur les ERP avec des arrêts du Conseil d'État et des arrêts des cours administratives d'appel.

  3. La compréhension des violences faites aux femmes comme problème public dans un contexte post-dictatorial : étude comparée des cas espagnol et chilien

    OpenAIRE

    Miranda-Pérez, Fabiola; Sanz-Gavillon, Anne-Claire

    2016-01-01

    Depuis la fin des dictatures, en Espagne et au Chili, une importance croissante a été accordée aux politiques d’égalité, notamment à la faveur de l’action des mouvements féminins et féministes qui ont apporté de nouveaux outils permettant d’analyser la réalité sociale. Dans ce contexte, les violences envers les femmes ont pu être conceptualisées comme un problème public et la lutte contre ce phénomène s’est peu à peu convertie en un des axes principaux de l’action publique en matière d’égalit...

  4. Interpolation de niveaux d'exposition aux émissions radioélectriques in situ à l'aide de méthodes géostatistiques

    OpenAIRE

    Ould Isselmou, Yahya

    2007-01-01

    Les réglementations et normes radioélectriques précisent différentes valeurs limites d'exposition radioélectrique à ne pas dépasser. Les niveaux d'expositions constatés autour des antennes de radio et de télécommunications sont très en dessous des limites d'exposition recommandées par la commission de protection contre les rayonnements non-ionisants. Aujourd'hui, les personnes se trouvant à proximité des émetteurs radio ne cherchent plus simplement à vérifier la conformité aux normes. La dema...

  5. Perception et comportement de recours aux soins de santé dans les pays en voie de développement. Le cas de la République Démocratique du Congo

    OpenAIRE

    Manzambi Kuwekita, Joseph; Reginster, Jean-Yves

    2013-01-01

    L’objectif principal de cet ouvrage consistait à identifier les facteurs du comportement de recours aux soins de santé dans la ville de Kinshasa. Neuf facteurs historiques (1909-1960) ont été dégagés comme facteurs influant sur l’offre et l’utilisation actuelles des soins de santé à Kinshasa : (i) gratuité des soins, (ii) présence du médecin, (iii) implication des religieuses dans l’offre des soins, (iv) convention d’agrément par l’État d’hôpitaux et de dispensaires fondés par les missions re...

  6. Vegetation mapping for tropical marine/coastal zone applications = Cartographie de la végétation, applications aux zones côtières et marines tropicales

    OpenAIRE

    Morgan, G A

    1992-01-01

    L'image multispectrale satellitaire appliquée aux zones tropicales, a été analysée afin de permettre une représentation pointue de la végétation par carte thématique jusqu'au 1/100 000 provenant d'une seule scène satellitaire. La clé du succès est dans le soin apporté au choix de la scène initiale et l'adoption d'une méthodologie basée sur une vérité terrain-botanique rigoureuse et fiable. Cette méthodologie utilisera un nombre adéquat de "caractérisations de parcelles" selon une surface cart...

  7. Nouveau rôle de l'Etat dans la gestion des périmètres publics irrigués : soutien aux associations d'irrigants exemple du delta de la Medjerda, Tunisie

    OpenAIRE

    Rahmoune Baudu, Leïla

    2001-01-01

    International audience Dans le secteur agricole tunisien, l'application de la politique de décentralisation et de désengagement de l'Etat depuis 1989 a entraîné la fusion de tous les offices régionaux dont l'Office de mise en valeur de la vallée de la Medjerda (Omvvm). L'abandon de certaines fonctions de l'Omvvm, et notamment celles concernant de la prise en charge des irrigants, s'est accompagné d'une politique de création d'associations des usagers de l'eau. Cet article s'intéresse aux a...

  8. Modélisation du procédé de soudage hybride Arc / Laser par une approche level set application aux toles d'aciers de fortes épaisseurs

    OpenAIRE

    Desmaison, Olivier; Bellet, Michel; Guillemot, Gildas

    2013-01-01

    Le procédé de soudage hybride Arc/Laser est une solution aux assemblages difficiles de tôles de fortes épaisseurs. Ce procédé innovant associe deux sources de chaleur : un arc électrique produit par une torche MIG et une source laser placée en amont. Ce couplage améliore le rendement du procédé, la qualité du cordon et les déformations finales. La modélisation de ce procédé par une approche Level Set permet une prédiction du développement du cordon et du champ de température associé. La simul...

  9. Élaboration automatique d’une stratégie de tolérance aux fautes de services web basée sur la diversité

    OpenAIRE

    BOUAKKAZ, khadidja; BELHARIZI, Asmaa

    2015-01-01

    La capacité d’une application à continuer l’exécution en présence de fautes de composants réfère à la Tolérance aux fautes (TF). La TF qui est une des méthodes de sûreté de fonctionnement vise à accepter la faute avec une certaine déviation, mais elle ne permet pas de tolérer les défaillances causées par cette faute. Cette dernière repose sur des stratégies principales afin de garantir la fiabilité de ces composants, dans notre cas des services Web. Les services Web similaires ...

  10. Imagerie par résonance magnétique appliquée aux matériaux du génie civil Magnetic Resonance Imaging Applied to Civil Engineering Materials

    OpenAIRE

    Coussot P.

    2006-01-01

    Un imageur par résonance magnétique dédié aux matériaux du génie civil et de la construction est actuellement en cours d'acquisition par le LCPC (Laboratoire Central des Ponts et Chaussées). Il sera géré par le LMSGC à Champs-sur-Marne et installé dans les locaux de l'IFI (Institut francilien d'Ingénierie). De nombreuses collaborations avec des laboratoires et des entreprises sont envisagées et certaines déjà mises en place. D'un point de vue général, les recherches concerneront les transfert...

  11. Control of Urea SCR Systems for US Diesel Applications Commande des systèmes de RCS à l’urée destinés aux applications Diesel US

    Directory of Open Access Journals (Sweden)

    van Nieuwstadt M.

    2011-09-01

    Full Text Available This paper sets out to qualify challenges in the control of urea selective catalytic reduction systems for NOx conversion in Diesel powertrains. We show the importance of ammonia storage control, and the difficulties in estimating it in the face of system uncertainties. The slow storage dynamics of the SCR catalyst are shown to be a major limiting factor on the performance of SCR systems in transient operation. Lastly we show the effect of sensor uncertainty on system performance and how NOx sensors can be used in conjunction with input correlation to distinguish NOx slip from ammonia slip. Cet article a pour objet de qualifier les défis en matière de commande des systèmes de réduction catalytique sélective (RCS dans une solution à base d’urée, pour la conversion des NOx au sein de groupes motopropulseurs Diesel. Nous montrons l’importance de la maîtrise du stockage d’ammoniac ainsi que les difficultés à l’estimer face aux incertitudes du système. Les dynamiques de stockage lentes du catalyseur de RCS s’avèrent constituer un facteur de limitation majeur quant aux performances des systèmes de RCS au cours d’un fonctionnement transitoire. Enfin, nous montrons l’effet de l’incertitude des capteurs sur les performances du système et comment les capteurs de NOx peuvent être utilisés en association avec une corrélation d’entrée pour distinguer une déviation de NOx d’un glissement d’ammoniac.

  12. Les règles de mélange appliquées aux équations d'état Mixing Rules Applied to Equations of State

    Directory of Open Access Journals (Sweden)

    Lermite C.

    2006-11-01

    Full Text Available Sous haute pression, les propriétés thermodynamiques et les équilibres de phase sont généralement évalués en appliquant la même équation d'état aux phases en présence. Les règles de mélange déterminent la variation des paramètres avec la composition. L'extension de ces méthodes à des systèmes polaires exige une révision de ces règles. Une seconde difficulté se présente si on applique une équation d'état contenant plus de deux paramètres. Les relations existant entre les grandeurs d'excès et les règles de mélange apportent une solution aux problèmes ainsi définis. Les exemples proposés portent sur la prédiction des équilibres de phase de systèmes ternaires, l'application du concept de contributions de groupes et l'utilisation d'une équation d'état contenant quatre paramètres. Under high pressure, thermodynamic properties and phase equilibria are generally evaluated by applying the same equation of state to the phases present. Mixing rules determine how parameters vary with the composition. The extension of such methods to polar systems requires these rules to be revised. A second difficulty arises if an equation of state containing more than two parameters is used. The relations existing between excess functions and mixing rules provide a solution to the problems thus defined. The examples proposed concern the predicting of phase equilibria for ternary systems, the application of the concept of group contributions and the use of an equation of state containing four parameters.

  13. Developpement d'une plateforme de calcul d'equilibres chimiques complexes et adaptation aux problemes electrochimiques et d'equilibres contraints

    Science.gov (United States)

    Neron, Alex

    Avec l'arrivée de l'environnement comme enjeu mondial, le secteur de l'efficacité énergétique prend une place de plus en plus importante pour les entreprises autant au niveau économique que pour l'image de la compagnie. Par le fait même, le domaine des technologies de l'énergie est un créneau de recherche dont les projets en cours se multiplient. D'ailleurs, un des problèmes qui peut survenir fréquemment dans certaines entreprises est d'aller mesurer la composition des matériaux dans des conditions difficiles d'accès. C'est le cas par exemple de l'électrolyse de l'aluminium qui se réalise à des températures très élevées. Pour pallier à ce problème, il faut créer et valider des modèles mathématiques qui vont calculer la composition et les propriétés à l'équilibre du système chimique. Ainsi, l'objectif global du projet de recherche est de développer un outil de calcul d'équilibres chimiques complexes (plusieurs réactions et plusieurs phases) et l'adapter aux problèmes électrochimiques et d'équilibres contraints. Plus spécifiquement, la plateforme de calcul doit tenir compte de la variation de température due à un gain ou une perte en énergie du système. Elle doit aussi considérer la limitation de l'équilibre due à un taux de réaction et enfin, résoudre les problèmes d'équilibres électrochimiques. Pour y parvenir, les propriétés thermodynamiques telles que l'énergie libre de Gibbs, la fugacité et l'activité sont tout d'abord étudiées pour mieux comprendre les interactions moléculaires qui régissent les équilibres chimiques. Ensuite, un bilan énergétique est inséré à la plateforme de calcul, ce qui permet de calculer la température à laquelle le système est le plus stable en fonction d'une température initiale et d'une quantité d'énergie échangée. Puis, une contrainte cinétique est ajoutée au système afin de calculer les équilibres pseudo-stationnaires en évolution dans le temps. De plus, la

  14. Compatibility problems of canning materials with carbon dioxide at high temperatures; Problemes de comptabilite des materiaux de gainage avec le gaz carbonique aux temperatures elevees

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R.; Loriers, H. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    comparativement les moins oxydables. Au dessus de 600 C, les nuances stabilisees au niobium, sans addition de molybdene, s'averent les plus recommandables. A partir de 700 C, la nuance 20 Cr - 25 Ni + Nb semble meme s'imposer par rapport a la nuance classique 18 Cr - 10 Ni + Nb, surtout en raison d'une tendance moins accentuee aux penetrations locales d'oxyde. Par ailleurs, l'alliage fer-aluminium a 25 pour cent d'aluminium en poids, presente une resistance a l'oxydation remarquable, tout en permettant une economie appreciable de neutrons, mais sa mise en oeuvre technologique reste delicate. Enfin, des etudes recentes ont permis d'etablir que certains alliages a base de zirconium, renfermant 1 a 4 pour cent de cuivre en poids, pourraient constituer une solution valable jusqu'a des temperatures de l'ordre de 600 C. Ces alliages s'oxydent en effet beaucoup moins rapidement que le zirconium non allie et d'autres alliages classiques, qui avaient ete elimines precedemment pour cette raison. Finalement, parmi les materiaux capables de supporter les conditions physicochimiques auxquelles seraient soumises les gaines d'elements combustibles dans les reacteurs a moyenne temperature, les plus susceptibles d'application immediate seraient les aciers inoxydables austenitiques et les alliages zirconium-cuivre, dont la metallurgie est relativement bien connue. Dans le futur, l'interet pratique des alliages de beryllium et des alliages fer-aluminium devrait croitre, compte tenu des etudes poursuivies en vue de l'amelioration de leurs proprietes mecaniques et de leur mise en oeuvre. (auteurs)

  15. Metabolism of selenite to selenosugar and trimethylselenonium in vivo

    DEFF Research Database (Denmark)

    Jackson, Matthew I; Lunøe, Kristoffer; Gabel-Jensen, Charlotte;

    2013-01-01

    Impaired S-adenosylmethionine (SAM)-dependent transmethylation and methylation capacity feature in diseases related to obesity or aging, and selenium (Se) metabolism is altered in these states. We tested the hypothesis that SAM metabolism is required for methylation and excretion of Se in a rat...

  16. Reduction of selenite on iron surfaces: Amicro-spectroscopic study

    Science.gov (United States)

    Scheidegger, A. M.; Grolimund, D.; Cui, D.; Devoy, J.; Spahiu, K.; Wersin, P.; Bonhoure, I.; Janousch, M.

    2003-03-01

    Under anoxie conditions zero-valent iron can react with water to produce hydrogen gas and magnetite or green rust, a highly reactive mineral phase that can induce reduction processes and thus control the speciation, the solubility, toxicity and the mobility of redox sensitive elements in (nuclear) waste repositories. In this study micro X-ray fluorescence (micro-XRF) and micro X-ray absorption spectroscopy (micro-XAS) were used to investigate the speciation of selenium that immobilized in the presence of Fe(0) and an anoxie synthetic groundwater solution. The selenium immobilization was accompanied by the formation of a green rust corrosion layer. Micro-XRF revealed that a Se-rich layer is present along the iron surfaces that were exposed to the Se(IV) solution. Micro-XAS experiments at the Se K-edge showed that Se(IV) was reduced to elemental Se(0). Thus, the reactivity of zero-valent and green rust should to be considered in assessing the long-term fate of selenium in nuclear waste repositories.

  17. Selenium enrichment and anti-oxidant status in baker’s yeast, Saccharomyces cerevisiae at different sodium selenite concentrations Enriquecimiento con selenio y estado anti-oxidante de la levadura de harinas Saccharomyces Cerevisiae con diferentes concentraciones de selenito sódico

    Directory of Open Access Journals (Sweden)

    T. Kaur

    2006-12-01

    Full Text Available The use of selenized yeast as enriched selenium supplements in human nutrition has become a topic of increasing interest over the last decade. The present study was designed with the aim to achieve a balance between selenium (Se incorporation and optimal growth of yeast cells along with effect of Se enrichment on antioxidant defense status of yeast cells. Since oxidative stress has been known to play a role in the life span of all types of cells, so in the present studies anti-oxidant defense status was evaluated in the Se- enriched baker’s yeast cell culture model. Upon Se supplementation as sodium selenite at various concentrations in the growth medium, a continuous increase in glutathione peroxidase (GSH-Px activity and Se content was observed. In case of reduced glutathione (GSH decreasing trend were observed with increasing Se concentrations An increasing trend in total glutathione as well as glutathione-s-transferase activity was observed at increasing Se concentrations. Thus, Se supplementation significantly enhanced GSH-Px levels along with alterations in other anti-oxidant enzymes, suggesting the role of Se in the enzyme defense system of yeast against oxidative damage. Further, as Se exerts growth inhibitory effect on cells, the growth inhibition study was carried out and decrease in biomass was observed with increasing concentrations of Se. Due to nutritional benefits, Se-enriched yeast may be considered a safe source of Se supplementation.El uso de levaduras "selenizadas" como suplementos enriquecidos con selenio en nutrición humana se ha convertido en un tema de interés creciente en la última década. Este estudio se diseño con el objetivo de conseguir un equilibrio entre la incorporación de selenio (Se y el crecimiento óptimo de las células levaduriformes, junto con el efecto del enriquecimiento de Se sobre el estado de defensa anti-oxidante de las levaduras. Puesto que se sabe que el estrés oxidativo desempeña una funci

  18. Analyse d’un genre de discours spécialisé : les lettres annuelles de Warren Buffett aux actionnaires de Berkshire Hathaway et leur spécificité

    Directory of Open Access Journals (Sweden)

    Catherine RESCHE

    2010-09-01

    Full Text Available 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 adoptée nous a également donné l’occasion de mesurer l’évolution interne de ces documents sur une période de 32 ans. Les résultats de l’étude font ressortir une très grande présence de l’auteur dans son discours et la nature dialogique de ce discours. La « marqueterie discursive » atypique qui caractérise le style Buffett conduit également à envisager ses lettres comme des macro-actes de langage. Néanmoins, elles se rattachent sans ambiguïté au genre « lettre aux actionnaires » par la situation dans laquelle elles sont produites, le but qu’elles poursuivent et la fonction sociale qu’elles remplissent. Ce sont ces mêmes éléments qui permettent de les considérer comme un échantillon de discours spécialisé, même si leur syntaxe n’est pas spécifique et si le discours n’est pas particulièrement technique.The paper focuses on a particular genre which is characteristic of the corporate world. Warren Buffett’s letters to the shareholders seem to arouse unprecedented interest among readers who greatly outnumber his shareholders. The letters’ form and content were analyzed quantitatively and qualitatively and compared to a sample corpus of other letters to the shareholders in order to determine their specificity. The diachronic approach that was chosen was an opportunity to observe how Buffett’s letters have evolved over a period of 32 years. The findings of this analysis seem to indicate that the

  19. Use of optical aids by visually impaired students: social and cultural factors Uso de auxílios ópticos por escolares com deficiência visual: fatores socioculturais

    Directory of Open Access Journals (Sweden)

    Gelse Beatriz Martins Monteiro

    2006-08-01

    Full Text Available PURPOSE: To identify conceptions, social and cultural factors regarding the use of optical aids by visually impaired students and to present information to health and educational professionals. METHODS: Qualitative research using spontaneous theater (interactive theater modality based on improvisation as research instrument. To analyze data, an adapted form of the collective subject discourse technique - procedures for organization of verbal data - was applied. Scenes, gestures, expressions, silences and behaviors were added to the original proposal. The study population included all visually impaired students from elementary public schools, aged 10 to 14 years who attended a resource room in a São Paulo state city. The students were examined at a university low vision service. RESULTS: Little knowledge about the impairment and difficult adaptation to use of optical aids were identified. The students' behavior showed denial of own problems, discomfort on public use of aids and lack of participation in own health decisions. CONCLUSION: Analysis through spontaneous theater session allows the professional to gather information which is not possible to acquire in the health assistance atmosphere. Needs, difficulties and barriers the users found before the prescribed treatment were identified.OBJETIVO: Identificar concepções e verificar aspectos socioculturais a respeito do uso de auxílios ópticos por escolares deficientes visuais e oferecer informações a profissionais das áreas de saúde e educacional. MÉTODOS: Utilizou-se pesquisa qualitativa mediante aplicação da técnica do teatro espontâneo - modalidade de teatro interativo, de improviso, construído a partir de histórias contadas pelos participantes. Para análise das informações colhidas, foi adaptada a técnica de análise do discurso do sujeito coletivo, conjunto de procedimentos de organização de dados discursivos de natureza verbal. Por se tratar de técnica psicodram

  20. Entre Africanité et Afro-Américanité. Divinités « akan » et culte des ancêtres aux États-Unis

    Directory of Open Access Journals (Sweden)

    Pauline Guedj

    2007-07-01

    Full Text Available En 1967, naquit aux États-Unis la première maison de culte « akan » qui, s’inspirant des pratiques d’un sanctuaire de religion dite « traditionnelle » à Larteh Kubease au Ghana, rassemblait en son sein des adeptes afro-américains de ce culte fraîchement importé. En revenant sur l’histoire du mouvement « akan » aux États-Unis, sur ses réalités actuelles et sur les rituels sur lesquels il repose, l’auteur se propose d’analyser la manière dont le culte des ancêtres constitue aujourd’hui pour les fidèles une nouvelle stratégie, leur permettant de mêler leurs propres expériences afro-américaines à une tentative jusqu’auboutiste de retour à l’identité africaine ancestrale et immuable qu’ils espèrent recouvrer.The first « Akan » shrine house based on the practices of the Akonedi Shrine in Larteh Kubease, Ghana, was born in New York in 1967. It assembled many African American practitioners who used « Akan » religion to search for their roots. Analyzing the history of the « Akan » movement in America, dealing with its current reality as well as describing some of its rituals, this paper will study the way in which ancestors worship constitute today a new step in the reafricanization process in North America. Worshipping their African American ancestors along with their African gods, the practitioners of the « Akan » religion have managed to include their own experience in their effort to go back to their ancestral roots.La primera casa-templo « akan » surgió en los Estados Unidos en el año 1967, agrupando adeptos afro-americanos que se inspiraban de las prácticas de un santuario de religión « tradicional » en Larteh Kubease (Ghana. Retomando la historia del movimiento « akan » en Estados Unidos, así como la descripción de sus realidades actuales y de los rituales que lo conforman, la autora propone analizar en que medida el culto a los ancestros constituye hoy en día una nueva

  1. Radiographie par rayons X à haute résolution de défauts topologiques en volume de structures modulées comparée aux neutrons en faisceau blanc

    Science.gov (United States)

    Fernandez Palacio, J.; Hamelin, B.; Marmeggi, J. C.

    2004-11-01

    Une émission de rayons X par un générateur à haute tension (plage : 50 - 410 kV) a été développée pour être utilisée avec un diffractomètre à rayons X durs et caractériser en volume des monocristaux. Le fort flux issu d'une installation de radiologie à foyer fin avec un grand pouvoir de pénétration en profondeur autorise l'étude d'échantillons très absorbants. Quelques exemples de l'utilisation de ces propriétés pour des échantillons épais et très absorbants sont présentés ; principalement l'analyse de contraintes et la topographie X projetée 2D dans des matériaux en comparaison avec l'information par la diffraction des neutrons. La diffraction à haute énergie apparaît dans la direction transmise, les angles de Bragg sont petits et ainsi les différentes lignes de réflexions sont réparties autour du faisceau principal. La presse uni-axiale utilisée pour les expériences est optimisée effectivement avec l'absence d'un bruit de fond dû à l'usage de fentes. L'optique des rayons X durs et neutrons appliquée aux échantillons épais donne une information complémentaire dans les expériences sur l'analyse de la densité volumétrique par la diffusion des rayons X et neutrons. On l'applique à des problèmes concernant des cristaux aux structures modulées étudiées sous des charges mécaniques et thermiques.

  2. Des « mouvements pacifistes » aux « mouvements anti-occupation » israéliens

    Directory of Open Access Journals (Sweden)

    Karine Lamarche

    2008-08-01

    que le produit d’un rapport de force sur le terrain de plus en plus difficile avec les représentants de l’ordre, contribuant à rendre les répertoires d’actions d’autant plus transgressifs.Cet article présentera divers groupes et organisations qui ont contribué à écrire l’histoire du mouvement pacifiste israélien, de manière non-exhaustive et suivant un développement chronologique. La première partie sera consacrée aux années succédant la conquête des territoires palestiniens, caractérisées par des mobilisations pacifistes à caractère sécuritaire (« le Mouvement pour la paix et la sécurité », Oz Ve’Shalom, « la Paix Maintenant », etc. mais aussi par la première initiative de protestation israélo-palestinienne conjointe (le « Comité de solidarité avec l’Université Bir Zeit ». Dans un second temps, nous examinerons la période des années 80 marquée par la guerre du Liban puis par la première Intifada, et qui vit l’émergence d’un mouvement pacifiste de masse. Celui-ci se caractérisa notamment par l’apparition de nombreuses organisations créées dans le but de défendre les droits de l’homme (HaMoked, les « Rabbins pour les droits de l’homme », ICAHD, B’Tselem, etc., mais aussi de groupes dénonçant, de manière plus ou moins subversive, l’occupation et ses conséquences sur la société israélienne (Daï La’Kibush, The 21st Year, les « Femmes en Noir », etc.. Oslo constitue évidemment un moment charnière pour le camp de la paix israélien puisque le projet pour lequel celui-ci s’était mobilisé sembla sur le point d’aboutir pour finalement échouer radicalement. Suite à l’espoir suscité par les négociations entre le gouvernement israélien et l’OLP, la dégradation très rapide de la situation sur le terrain (assassinat d’Yitzhak Rabin, massacre commis par Baruch Goldstein à Hébron, intensification de la colonisation, bouclages répétés en Cisjordanie, reprise des

  3. A importância do treinamento da criança com baixa visão, com emprego dos auxílios ópticos, para capacitação educacional: relato de caso The value of optical aids' training for low vision child education: case report

    OpenAIRE

    Eduardo Toshio Sato; Celina Tamaki-Castro; Danilo Dimas Monteiro de Castro

    2010-01-01

    O aprendizado do correto manuseio do auxílio óptico foi treinado: localização, focalização e seguimento com o telescópio de 8x de magnificação. Após essa etapa iniciou-se o aprendizado de cópia da lousa com o auxílio adaptado. Totalizaram-se 17 sessões para a criança receber a prescrição final devido às grandes dificuldades apresentadas pela baixa acentuada das funções visuais.Training of the proper handling of optical devices was performed: location, targeting and tracking with the 8x magnif...

  4. "Quelque part {u00E1 un tournant du destin..." ; "Ciel vide, bőte aux lettres vide, chemin vide..." ; "Singe indécis..." ; Ithaque / Tõnu Õnnepalu ; trad. par Antoine Chalvin avec le concours de l'auteur

    Index Scriptorium Estoniae

    Õnnepalu, Tõnu

    1992-01-01

    Orig.: "Kusagil saatuse käänakul..." ; "Tühi taevas, tühi postkast, tühi kruusatee..." ; "Otsustusvõimetu ahv..." ; Ithaka. Sisu: "Quelque part {u00E1 un tournant du destin..." ; "Ciel vide, bőte aux lettres vide, chemin vide..." ; "Singe indécis..." ; Ithaque. T. Õnnepalust lk. 93. Kadriann Soosaare illustratsioon lk. 97

  5. Potentialités et intérêts de l'élevage larvaire de la crevette d'eau douce indigène Macrobrachium carcinus (L. (Palaemonidae aux Antilles françaises

    Directory of Open Access Journals (Sweden)

    HERMAN F.

    1999-01-01

    Full Text Available De précédents travaux, réalisés en laboratoire, ont montré que le développement larvaire de Macrobrachium carcinus nécessitait un environnement salin. Le nombre de larves mises en élevage lors de ces essais était cependant trop faible pour envisager une production de masse de l'espèce. Lors de l'expérience ici présentée, 46.900 larves au stade I ont été mises en élevage à une température oscillant entre 28 et 30°C. Il a été montré qu'en faisant varier la salinité, la production de masse de post-larves était possible en 45 jours, avec un taux de survie finale de 14,3 % et un taux de métamorphose de 10,6 %. Ces résultats sont nettement inférieurs à ceux obtenus en routine avec l'espèce indonésienne Macrobrachium rosenbergii, mais attestent des possibilités d'élevage de M. carcinus aux Antilles françaises et ailleurs.

  6. La phonétique dans l'enseignement de l'anglais aux spécialistes d’autres disciplines : enjeux et priorités Teaching English phonetics to ESP students: issues and priorities

    Directory of Open Access Journals (Sweden)

    Alain Diana

    2011-03-01

    Full Text Available La phonétique est rarement enseignée à des spécialistes d’autres disciplines, car son utilité n'est pas toujours reconnue. Nous passerons en revue les arguments en faveur d'un tel enseignement, et nous discuterons de la nécessité ou non d'adopter un modèle anglophone. Puis nous chercherons quelles sont les priorités à établir dans un tel cadre, au niveau suprasegmental (intonation, accent, rythme comme au niveau segmental (voyelles et consonnes. L'idée d'un amalgame de diverses prononciations sera approfondie pour tenter de déboucher sur l'ébauche d'un programme spécifique s'adressant aux spécialistes d’autres disciplines.Phonetics is hardly ever taught to ESP students, because it is rarely considered as a priority. We shall first focus on the arguments in favour of such an approach, and the need to adopt a native English model will be discussed. We shall then consider the priorities that need to be addressed in such a framework, whether at segmental (vowels and consonants or suprasegmental level (intonation, stress and rhythm. The idea of creating an amalgam of various pronunciations is considered and will lead to a tentative syllabus aimed at ESP students.

  7. Saqayti: For greater rationalization of tapstand water supplies Une meilleure rationalisation de la distribution d’eau grâce aux Saqaytis Saqayti para racionalizar la utilización de los puntos de abastecimiento de agua

    Directory of Open Access Journals (Sweden)

    T. Hascoet

    2011-04-01

    foyers, en particulier dans les zones urbaines et péri-urbaines, ne peuvent actuellement toujours pas bénéficier d’un raccordement individuel au réseau d’eau potable pour des raisons structurelles et/ou financières. Afin de leur garantir toutefois un accès à ce service essentiel, les autorités locales ont mis en place des points d’eau communaux collectifs -les bornes fontaines- où L’eau, financée par les communes, est desservie gratuitement et sans restriction d’accès. Mais si ces bornes fontaines constituent une solution à court terme, elles ne permettent ni d’assurer une gestion rationnelle de la ressource, ni de la partager équitablement. En effet, cet accès libre et gratuit entraîne surconsommations, gaspillages et utilisation de l’eau par des consommateurs qui n’étaient pas initialement ciblés par cette aide. Ceci a engendre de fait des charges élevées pour les municipalités concernées, qui menacent la durabilité du service dans son ensemble. Partant de ce constat, et conformément aux recommandations de la communauté internationale et de la société civile, un nouveau type de point d’eau, la borne fontaine « Saqayti », a été développé pour distribuer de l’eau prépayée à des usagers dans les villes de Rabat, Tanger et Tétouan. L’accès y est contingenté aux seuls porteurs d’une clé à puce électronique, préalablement choisis au cas par cas par l'autorité municipale. Ce système permet ainsi de limiter la distribution de l’eau aux seules populations visées qui peuvent accéder librement au point d’eau jusqu’à un seuil mensuel, prépayé par les communes, équivalent à leurs besoins essentiels. Cet article se propose de montrer que Saqayti se conçoit comme une solution de complément innovante au raccordement individuel au réseau, assurant aux populations les plus pauvres un accès au service d’eau et d’assainissement, répondant  aux standards de qualité internationaux, tout en

  8. Chemical, spectroscopic, and ab initio modelling approach to interfacial reactivity applied to anion retention by siderite

    International Nuclear Information System (INIS)

    Among the many radionuclides contained in high-level nuclear waste, 79Se was identified as a potential threat to the safety of long term underground storage. However, siderite (FeCO3) is known to form upon corrosion of the waste container, and the impact of this mineral on the fate of selenium was not accounted for. In this work, the interactions between selenium oxyanions - selenate and selenite - and siderite were investigated. To this end, both experimental characterizations (solution chemistry, X-ray Absorption Spectroscopy - XAS) and theoretical studies (ab initio modelling using Density Functional Theory - DFT ) were performed. Selenite and selenate (≤ 103 M) retention experiments by siderite suspensions (75 g/L ) at neutral pH in reducing glovebox (5 % H2) showed that selenite is quantitatively immobilized by siderite after 48 h of reaction time, when selenate is only partly immobilized after 10 days. In the selenite case, XAS showed that immobilized selenium is initially present as Se(IV) probably sorbed on siderite surface. After 10 days of reaction, selenite ions are quantitatively reduced and form poorly crystalline elementary selenium. Selenite retention and reduction kinetics are therefore distinct. On the other hand, the fraction of immobilized selenate retained in the solid fraction does not appear to be significantly reduced over the probed timescale (10 days). For a better understanding of the reduction mechanism of selenite ions by siderite, the properties of bulk and perfect surfaces of siderite were modelled using DFT. We suggest that the properties of the valence electrons can be correctly described only if the symmetry of the fundamental state electronic density is lower than the experimental crystallographic symmetry. We then show that the retention of simple molecules as O2 or H2O on siderite and magnesite (10-14) perfect surfaces (perfect cleavage plane, whose surface energy is the lowest according to DFT) can be modelled with good

  9. Chemical, spectroscopic, and ab initio modelling approach to interfacial reactivity applied to anion retention by siderite; Approche couplee chimique, spectroscopique et de modelisation ab initio a la reactivite de surface: application a la retention des anions par la siderite

    Energy Technology Data Exchange (ETDEWEB)

    Badaut, V.

    2010-07-15

    Among the many radionuclides contained in high-level nuclear waste, {sup 79}Se was identified as a potential threat to the safety of long term underground storage. However, siderite (FeCO{sub 3}) is known to form upon corrosion of the waste container, and the impact of this mineral on the fate of selenium was not accounted for. In this work, the interactions between selenium oxyanions - selenate and selenite - and siderite were investigated. To this end, both experimental characterizations (solution chemistry, X-ray Absorption Spectroscopy - XAS) and theoretical studies (ab initio modelling using Density Functional Theory - DFT) were performed. Selenite and selenate ({<=} 10{sup 3} M) retention experiments by siderite suspensions (75 g/L) at neutral pH in reducing glovebox (5 % H{sub 2}) showed that selenite is quantitatively immobilized by siderite after 48 h of reaction time, when selenate is only partly immobilized after 10 days. In the selenite case, XAS showed that immobilized selenium is initially present as Se(IV) probably sorbed on siderite surface. After 10 days of reaction, selenite ions are quantitatively reduced and form poorly crystalline elementary selenium. Selenite retention and reduction kinetics are therefore distinct. On the other hand, the fraction of immobilized selenate retained in the solid fraction does not appear to be significantly reduced over the probed timescale (10 days). For a better understanding of the reduction mechanism of selenite ions by siderite, the properties of bulk and perfect surfaces of siderite were modelled using DFT. We suggest that the properties of the valence electrons can be correctly described only if the symmetry of the fundamental state electronic density is lower than the experimental crystallographic symmetry. We then show that the retention of simple molecules as O{sub 2} or H{sub 2}O on siderite and magnesite (10{sup -14}) perfect surfaces (perfect cleavage plane, whose surface energy is the lowest according

  10. L’accès du plus grand nombre aux services essentiels ne se fera pas sans une implication du secteur privé et sans une tarification adéquate de ces services

    Directory of Open Access Journals (Sweden)

    Luc Rigouzzo

    2012-01-01

    Full Text Available La couverture, via le secteur privé, des besoins en services de base (eau, énergie, services financiers, logement,.. des populations des pays en développement est une nécessité si l’on veut essayer de faire reculer la pauvreté.  Toutefois les financements privés « classiques » ne s’orientent pas spontanément vers ces secteurs notamment en raison du refus de faire  « payer » un service essentiel à des populations pauvres, sujet qui a fait souvent l’objet de campagnes de rejets de la part d’acteurs de la société civile. De très nombreux exemples montrent pourtant que, compte tenu de l’impact de ces services sur leur qualité de vie, les consommateurs  de ces pays, notamment du « bas de la pyramide » sont disposés à les payer pourvus qu’ils aient accès à un service de qualité. Dans ces secteurs, le coût nominal du service  importe beaucoup moins que son coût d’opportunité et l’impact qu’aura ce service sur la vie des bénéficiaires.  Bien souvent ce service peut même être  payé ex ante ce qui peut permettre aux familles de mieux contrôler les dépenses qu’elles peuvent y consacrer. Il faut toutefois distinguer la fourniture de services essentiels de celles de bien de consommation courante et bien entendu éviter les dérives. En tout état de cause la possibilité de construire des modèles équilibrés financièrement conditionne  la mobilisation de financement en quantité suffisante de la part des  acteurs financiers locaux et internationaux. Dans ce domaine comme dans d’autres, la voie est donc probablement la voie du juste milieu,  en évitant les excès d’une sur-tarification, mais en acceptant de conserver des modèles économiques rentables. Ceux-ci doivent  permettre aux investisseurs d’avoir des résultats qui les conduisent à accroitre et poursuivre leurs investissements, et  d’augmenter le plus rapidement possible le nombre de bénéficiaires. Prétendre construire

  11. Oh, Canada ! La baisse de la criminalité au Canada et aux Etats-Unis entre 1991 et 2002  Explaining the American and Canadian Crime Drop in the 1990’s

    Directory of Open Access Journals (Sweden)

    Marc Ouimet.

    2009-11-01

    Full Text Available Après des décennies d’augmentation constante de leur criminalité, le Canada et les États-Unis connaissent des baisses importantes depuis le début des années 1990. Plusieurs explications ont récemment fait surface aux États-Unis sur les facteurs pouvant rendre compte de cette baisse, dont une augmentation du nombre de policiers, l’application par les forces de l’ordre de méthodes plus répressives et l’augmentation importante du taux d’incarcération. Notre analyse des tendances de la criminalité entre 1991 et 2001 pour quatre types d’infractions indique que des baisses comparables de la criminalité sont observables au Canada sans que des changements notables en termes de répression policière ou d’incarcération soient notables. Ainsi, les explications démographiques, économiques et culturelles semblent plus aptes à rendre compte des baisses de la criminalité en Amérique du Nord.After decades of continuously increasing crime rates, Canada and the United States have now experienced their first prolonged period of decline in crime rates. Criminologists are just starting to look at the reasons that may explain such a reversal. In the U.S., many factors have been invoked to explain the trend, including increases in the number of police officers, more aggressive policing, and an increased use of incarceration. Although Canada’s crime trends are similar to those found in the U.S., there has been little or no change in policing practices or incarceration trends. This paper suggests that the causes of the decline in crime rates lie elsewhere, namely, in demographic shifts, improved employment opportunities and changes in collective values. Full Text

  12. L’assistance juridique japonaise aux pays dits « émergents » d’Asie Japanese Legal Technical Assistance to Emerging Countries in Asia. A Contribution to the Pluralistic Approach to the Circulation of Law

    Directory of Open Access Journals (Sweden)

    Isabelle Giraudou

    2011-03-01

    Full Text Available Fort d’un système normatif à la croisée de plusieurs traditions juridiques, le Japon entend participer plus résolument au développement actuel des modes de circulation du droit via notamment sa poli­tique de coopération internationale en matière d’assistance juridique et judiciaire aux pays émergents d’Asie. Cet article examine les particularités de la politique japonaise d’assistance en prenant appui sur des réflexions plus larges concernant les modalités contemporaines d’interaction des normes et le renouvellement des processus d’élaboration du droit. Cela permet de cerner les contradictions d’une assistance juridique conçue à la fois comme outil d’uniformisation du droit et instrument de coordination normative, au service d’une approche pluraliste de la circulation des normes.On the strength of a legal system stemming from various traditions of law, Japan is trying to participate more actively in the current development of the circulation of law, especially through its policy of international cooperation in the field of legal technical assistance and judicial assistance to emerging countries in Asia. This paper scrutinizes the specificities of the Japanese policy in the field drawing on broader analyses about contemporary means of interaction between norms and the reshaping of the processes by which law is elaborated. This may help shed some light on the contradictions of a form legal technical assistance that is conceived both as a tool for the standardization of law and a device that facilitates the coordination of laws at the service of an approach of legal pluralism.

  13. Harmonization of welding qualification provisions in RCC-M and European standards; Rapprochement des regles relatives aux qualifications de soudage dans les normes europeennes et le RCC-M

    Energy Technology Data Exchange (ETDEWEB)

    Lemoine, M. [Areva-NP, Tour AREVA, 92084 - Paris La Defense cedex (France); Lainez, B. [Areva-NP, usine de Chalon sur Saone 71380 Saint Marcel (France); Anastassiades, P. [EDF/Ceidre - 2 rue Ampere - 93206 SAINT-DENIS Cedex (France)

    2007-07-01

    Since a long time, numerous precautions for welding have been integrated in the nuclear codes, in particular in the RCC-M applicable to pressurized water reactors, in order to guarantee a high quality level of permanent assemblies. In parallel, European and ISO standardization works have led to a harmonisation of practices on qualification of welding processes, welders and operators. In the context of the regulatory evolutions presented during this conference, it was judged appropriate to bring closer the RCC-M practices and those of EN and ISO standards, while taking the precaution of specifying, if necessary, the complementary provisions allowing maintaining guarantees of quality consistent with the prior experience feedback. This paper presents the amendments brought to the RCC-M Code by the 2005 and 2007 addenda, in order to respond to this objective, and develops their motivations. (authors) [French] De nombreuses precautions ont ete integrees de longue date dans les codes nucleaires, et en particulier dans le RCC-M applicable aux reacteurs a eau sous pression, en matiere de soudage afin de garantir un haut niveau de qualite de ces assemblages permanents. Par ailleurs, des travaux europeens, puis ISO, ont conduit a une harmonisation des pratiques en matiere de qualification des modes operatoires de soudage et des soudeurs et operateurs. Dans le contexte des evolutions reglementaires presentees par ailleurs au cours de cette conference, il a ete juge opportun de rapprocher les pratiques du RCC-M et celles des normes EN et ISO, en prenant la precaution de specifier au besoin les dispositions complementaires permettant de maintenir des garanties de qualite coherentes avec le retour d'experience anterieur. La communication presente les amenagements apportees au code RCC-M par les modificatifs 2005 et 2007, afin de repondre a cet objectif, et en developpe les motivations. (auteurs)

  14. Apoios de decisão: instrumento de auxílio à medicina baseada em preferências. Uma revisão conceitual Decision aids: an instrument to eliciting patient preference. Current concepts

    Directory of Open Access Journals (Sweden)

    Mirhelen Mendes de Abreu

    2006-08-01

    Full Text Available A necessidade da incorporação das preferências dos pacientes nas tomadas de decisão é uma realidade da assistência médica contemporânea, que caracteriza a medicina baseada em preferências. Os apoios de decisão são instrumentos que surgem como mecanismos de auxílio ao médico a expor riscos e benefícios de uma determinada tomada de decisão, sendo um mecanismo facilitador para a decisão compartilhada. Na literatura médica, particularmente em reumatologia, nota-se um emergente interesse pelo estudo das preferências dos pacientes nos ensaios clínicos. Este artigo de revisão tem por objetivo conceituar e caracterizar os apoios de decisão e suas implicações na pesquisa e prática clínicas, bem como ressaltar os princípios metodológicos necessários para a sua utilização e desenvolvimento.Patient preferences in decision making is one reality of the medical assistance, which characterizes the value based medicine. The decision aids are instruments that appear as support mechanisms for the doctor to exercise this model of decision making. In medical literature, particularly in rheumatology, an emergent interest on patient's preference study is noticed in clinical trials. The aim of this article is to appraise and to characterize the decision aids and its implications in the practical research and clinics, as well as standing out the necessary methodology principles for its use and development.

  15. Reconstruction of Petroleum Feedstocks by Entropy Maximization. Application to FCC Gasolines Reconstruction de coupes pétrolières par maximisation d’entropie. Application aux essences de FCC

    Directory of Open Access Journals (Sweden)

    Hudebine D.

    2011-06-01

    pétrolier, les coupes sont généralement des mélanges complexes de plusieurs centaines à plusieurs millions d’espèces chimiques différentes. De ce fait, les outils analytiques, même les plus performants, ne permettent pas de séparer et d’identifier l’ensemble des composés présents. Les fractions pétrolières sont donc actuellement caractérisées soit via des descripteurs macroscopiques moyens (densité, analyse élémentaire, résonance magnétique nucléaire, etc., soit à l’aide de techniques séparatives (distillation, chromatographie gaz ou liquide, spectrométrie de masse, etc. qui ne quantifient cependant que quelques grandes familles de molécules. Les méthodes de reconstruction de coupes pétrolières sont des approches informatiques qui permettent d’évoluer vers un détail plus moléculaire en se basant sur le principe suivant : définir des mélanges simplifiés mais cohérents de composés chimiques à partir de données analytiques parcellaires et de connaissances expertes du procédé étudié. Ainsi, la méthode de reconstruction par maximisation d’entropie, proposée dans cet article, est une technique récente et puissante permettant de déterminer les fractions molaires d’un mélange préétabli de composés chimiques en maximisant un critère entropique et en respectant les contraintes analytiques fixées par le modélisateur. L’utilisation de cette méthodologie permet de réduire le nombre de degrés de liberté du système de quelques milliers (correspondant aux fractions molaires des composés à quelques dizaines (correspondant aux paramètres de Lagrange associés aux contraintes analytiques et ainsi de diminuer fortement le temps de calcul nécessaire à la résolution du problème. Cette approche a été appliquée avec succès à la reconstruction d’essences de FCC en prédisant précisément la composition moléculaire de ce type de coupes pétrolières à partir d’une distillation simulée et d

  16. Femicidio: la forma più estrema di violenza contro le donne / Fémicide : la forme la plus extrême de violence faite aux femmes / Femicide: the most extreme form of violence against women

    Directory of Open Access Journals (Sweden)

    Karadole Cristina

    2012-04-01

    the victims and, especially, the clear links between this crime and violence against women. Le fémicide, comme forme extrême de violence faite aux femmes, est un phénomène encore méconnu car il existe encore peu d’études sur le sujet en Italie. À l’issue d’une revue de la littérature criminologique et féministe internationale, cet article vise à définir le concept de « fémicide » et ses différentes déclinaisons dans la recherche scientifique et dans la lutte politique féministe. Le texte met en évidence la particularité de ce délit, qui doit être considéré différemment par rapport aux autres formes d’homicides. En effet, il s’agit d’un crime qui découle de la relation de pouvoir entre les hommes et les femmes ; le fémicide est l'acte final du cycle de la violence masculine contre les femmes, dont il représente le point culminant. Contrairement au sens commun et à la représentation médiatique et comme cet essai tente de le démontrer, le fémicide n’existe pas dans les cultures autres qu’occidentales, pas plus qu’il n’est particulièrement rattaché aux situations de difficulté sociale ou de marginalité culturelle, mais il s'inscrit, en tant que violence à l’égard des femmes, dans des rapports « normaux » et dans le conflit homme/femme. Cela signifie que des situations considérées comme « sûres » peuvent pourtant comporter des facteurs de risque d’être victimes de fémicide pour les femmes concernées. En effet, les fémicides peuvent intervenir chez soi ou au domicile de la famille, dans une relation conjugale comme pour des couples non mariés.Ensuite, l’auteur analyse aussi bien les premières études sociologiques et criminologiques italiennes que des données sur le phénomène. La seconde partie de ce texte est dédiée à la lecture des informations tirées d’une étude sur les articles de presse menée par le Groupe d'études sur le fémicide de l'association bolognaise contre la violence

  17. L’évolution de l’affirmative action aux États-Unis sous la présidence de George W. Bush Evolution of Affirmative Action in the United States during the Presidency of George W. Bush

    Directory of Open Access Journals (Sweden)

    Marie-Christine Pauwels

    2010-03-01

    Full Text Available L’offensive contre l’affirmative action engagée depuis les années 1980 s’est accrue pendant les deux mandats de la présidence Bush, et l’opinion publique s’est radicalisée, percevant désormais de plus en plus fréquemment ces programmes comme une série d’avantages indûment octroyés à un certain nombre de « privilégiés ». Tout programme d’affirmative action doit désormais être étayé par des disparity studies démontrant la réalité de la discrimination, et seules des mesures très ciblées (narrowly tailored sont autorisées pour y remédier. La charge de la preuve a été en quelque sorte inversée. Mais contrairement aux idées reçues, l’affirmative action n’est pas sur le point de disparaître aux États-Unis et malgré son hostilité de principe, le gouvernement Bush n’a pris aucune mesure concrète pour démanteler ces programmes. L’affirmative action connaît aujourd’hui plusieurs transformations majeures, l’évolution la plus marquante étant l’effacement du critère ethno-racial au profit de critères plus neutres et moins idéologiquement polarisants, essentiellement d’ordre géographique et territorial. Dans l’enseignement supérieur par exemple, des procédures d’admission codées ont vu le jour pour favoriser l’accès des minorités ethniques sous-représentées aux campus d’élite, et diverses stratégies de contournement ont été mises en place dans l’adjudication des marchés publics. Ces transformations sont également intéressantes à analyser d’un point de vue transnational, puisque l’on observe une convergence croissante avec le modèle français de discrimination positive, lui aussi fondé sur le camouflage et l’euphémisation de l’identité ethno-raciale et sur une logique de territoire.This article examines the fate of affirmative action in the United States during the eight years of the Bush administration. After a brief reminder of the major landmarks

  18. Spontaneous and reversible interaction of vanadium(V) oxyanions with amine derivatives

    International Nuclear Information System (INIS)

    The interaction between vanadate and tri- or tetradentate ethanolamine derivatives has been studied by using 51V NMR spectroscopy. The reactions occur spontaneously in aqueous solutions, at ambient temperatures and in the physiological pH range. In addition to one amine group and one hydroxyl group, the ethanolamine derivative should contain a third and/or fourth functionality that is an alcohol, a carboxylic acid, a phosphonium acid, or an amine. The reactions are highly dependent on pH, concentrations of monomeric vanadate, amine. The stability constants for the complexes are minimum orders of magnitude greater than those found for vanadate derivatives of corresponding ether derivatives, and the high stability is associated with the central nitrogen. Only one vanadium complex is formed in substantial amounts in the reaction of ethanolamine derivatives with vanadate, and that complex is mononuclear in vanadium. Several of the ethanolamine derivatives that form complexes are commonly used buffers in biological and biomedical studies in vitro. 22 refs., 10 figs., 7 tabs

  19. Optical Basicity: A Practical Acid-Base Theory for Oxides and Oxyanions

    Science.gov (United States)

    Duffy, J. A.

    1996-12-01

    The optical basicity concept relies on the Lewis approach to acids and bases and was developed for dealing with chemical problems in non-aqueous, non-protonic media such as silicates, phosphates and borates which are important in glass making and (as slags) for refining steel. Basic oxides such as Na2O or CaO are ionic while SO3, P4O10 or SiO2 are covalent, and it is the magnitude of negative charge borne by the oxygen atoms or ions which governs the degree of acidity or basicity. The oxygen atoms of sulfates, phosphates or network systems such as silicates bear charges which are between those of their parent oxides. In principle, the negative charge can be estimated using the optical (ultraviolet) spectra of certain probe ions and is represented by the optical basicity value, Lambda. Optical basicity values, available for 16 oxides, increase from the acidic SO3 to the very basic Cs2O in a way which conforms with electronegativity and polarizability. The optical basicity concept also extends to fluorides and sulfides.

  20. Electron Spin Resonance of Tetrahedral Transition Metal Oxyanions (MO4n-) in Solids.

    Science.gov (United States)

    Greenblatt, M.

    1980-01-01

    Outlines general principles in observing sharp electron spin resonance (ESR) lines in the solid state by incorporating the transition metal ion of interest into an isostructural diamagnetic host material in small concentration. Examples of some recent studies are described. (CS)

  1. Métodos de auxílio multicritério à decisão aplicados a problemas de PCP: mapeamento da produção em periódicos publicados no Brasil Multicriteria decision aid methods applied to PPC problems: a mapping of papers published in Brazilian journals

    OpenAIRE

    Dey Salvador Sanchez Rodriguez; Helder Gomes Costa; Luiz Felipe Roris Rodriguez Scavarda do Carmo

    2013-01-01

    O presente trabalho tem por objetivo estabelecer um mapeamento da produção científica divulgada em importantes periódicos publicados no Brasil sobre a aplicação de Métodos de Auxílio Multicritério à Decisão (AMD) à modelagem de problemas de Planejamento e Controle da Produção. O mapeamento contemplou 32 artigos, que foram selecionados criteriosamente, tendo como base a lista de periódicos científicos oferecida no Scielo e em importantes sociedades científicas brasileiras no âmbito da Engenhar...

  2. Application de la métabolomique à l’étude du lien entre les expositions environnementales aux pesticides pendant la grossesse et le développement de l’enfant : approches épidémiologique et toxicologique

    OpenAIRE

    Bonvallot, Nathalie

    2014-01-01

    Les expositions environnementales aux pesticides chez la femme enceinte sont une préoccupation de santé publique. L’association d’analyses métabolomiques par RMN chez l’Homme et l’animal a permis de tester l’utilité de cet outil dans l’étude des mélanges complexes. Les empreintes métaboliques proviennent des urines et du sang de cordon de plus de 300 femmes de la cohorte PELAGIE (Bretagne) et des urines, sang, foie et cerveaux de rates et de leurs fœtus exposés par voie orale durant la gestat...

  3. L'enquêteur face à la protection sociale ou la protection sociale face à l'enquêteur : le travail sociologique dans un milieu contrôlé. Le cas des réformes en matière de protection sociale aux Philippines

    OpenAIRE

    Diaz, Pablo

    2015-01-01

    Cette contribution propose une réflexion sur les bienfaits de l'objectivation des négociations d'accès aux organisations bureaucratiques. Revenant sur une expérience d'enquête au sein de l'administration philippine dans le cadre d'une recherche portant sur la mise en place d'un programme de conditional cash transfer (CCT), il met en avant les enjeux méthodologiques et heuristiques soulevés par la confrontation du chercheur à un important dispositif de gatekeeping. Plus précisément, à travers ...

  4. Localization of the Dissimilatory Arsenate Reductase in Sulfurospirillum Barnesi Strain SeS-3

    Directory of Open Access Journals (Sweden)

    Eman Afkar

    2012-01-01

    Full Text Available Problem statement: Sulfurospirillim barnesii strain SeS-3 is one of the recently known bacterial isolates that can obtain energy to support growth by respiring the toxic oxyanions of arsenic and selenium under anaerobic conditions. Approach: The ultimate goal of this investigation is to localize the active sites for the reduction of arsenate arsenite as well as selenate selenite in S. barnesii strain SeS-3. Results: The ability of the type strain Sulfurospirillium barnesii strain SES-3 (ATCC 700032 to reduce selenate and arsenate were tested using cell grown anaerobically with 20 mM lactate as the carbon source and either 10 mM selenate or 5 mM arsenate as the terminal electron acceptors were harvested after the turbidity reached 0.3, 0.4 absorption units at 600 nm, cell density 4gm wet cells. The results of this study showed that the mobilization of the toxic oxyanions of arsenic and selenium by Sulfurospirillum barnesii strain SES-3 is linked to the membrane. The enzyme is specific for the reduction of arsenate, selenate, selenite, nitrite, thiosulfate and phosphate. Whereas, no specificity was detected for arsenite nitrate, fumarate, when they served as the final electron acceptor. Conclusion/Recommendations: This study concluded that the mechanism of arsenate reduction by S.barnesii strain SeS-3 is connected into the membrane. The environmental significance of this bacterium and its impact to the bioremediation potential in the underground water and sedimentary environment is also discussed.

  5. Potentiel et limites d'utilisation, aux températures élevées, des lubrifiants liquides dans les moteurs Potential and Limitations of Use of Liquid Lubricants in Engines At High Temperatures

    Directory of Open Access Journals (Sweden)

    Toulhoat H.

    2006-11-01

    Full Text Available Cet article examine les possibilités de réponse de la formulation des lubrifiants à une élévation des températures dans les moteurs automobiles de la prochaine décennie; l'accroissement des puissances spécifiques des moteurs, et la réduction de leurs dimensions et de leur poids, la pénétration des turbo-compresseurs et des pots catalytiques, et dans une certaine mesure la tendance à réduire les rejets thermiques à l'échappement, sont des forces motrices pour cette évolution. Une augmentation de la température moyenne à la rampe d'environ 15 à 20°C est attendue pour la plupart des moteurs courants, à essence ou Diesel. Les températures en fond de gorge de segment de feu resteront très probablement dans l'intervalle actuel 250-260°C grâce aux systèmes de refroidissement des pistons. L'évolution des moteurs Diesel de camions dans les cinq dernières années est significative de cette tendance. Une telle évolution n'induira pas de bouleversements majeurs dans la formulation des lubrifiants pour automobiles. Cependant, elle déterminera une demande en VI significativement accrue de façon à maintenir les conditions de la lubrification hydrodynamique aux paliers, aussi bien que le comportement au démarrage à froid. Ceci sera obtenu par une meilleure combinaison des bases, avec une mise en oeuvre accrue des bases hydrotraitées et synthétiques, et un renforcement de l'additivation en épaississants ( règle du pouce: 0. 25 % par incrément de 1°C de température moyenne. Une alternative pourrait provenir de progrès réalisés sur le comportement visco-élastique et la stabilité sous cisaillement de ces polymères additifs de viscosité. Une autre exigence sur les propriétés des lubrifiants afin de faire face à cet accroissement apparemment marginal de température de fonctionnement, sera une meilleure résistance à l'oxydation, et dans cette optique, le recours aux bases non conventionnelles sera à nouveau

  6. La compréhension en lecture aux deuxième et troisième cycles du primaire: regard sur les pratiques déclarées d’enseignement

    Directory of Open Access Journals (Sweden)

    Virgine Martel

    2010-06-01

    Full Text Available RésuméAfin de dresser le portrait actuel des pratiques enseignantes en matière de compréhension en lecture aux deuxième et troisième cycles du primaire, la présente recherche a identifié, par le biais d'un questionnaire, les pratiques pédagogiques de 413 enseignants de différentes régions du Québec. Alors que les études réalisées au tournant des années 2000 laissaient penser que les enseignants se conformaient à un enseignement relativement traditionnel et peu tourné vers l'enseignement de stratégies de compréhension, les résultats de la présente recherche démontrent que les enseignants déclarent équiper leurs élèves de stratégies en vue de développer leur compétence à comprendre le discours écrit. Toutefois, il semble évident que certaines pratiques, notamment celles liées à l'enseignement de stratégies métacognitives et à l'enseignement réciproque sont délaissées par plus de la moitié des enseignants. Ainsi, des améliorations sont souhaitables, voire fondamentales afin d'améliorer la compétence des élèves.AbstractThis article presents the results of a survey completed by 413 elementary school teachers across Quebec. The study aimed to document current teaching practices relating to reading comprehension. While studies completed at the beginning of this century suggested that teachers tend to resort to relatively traditional teaching that does not focus explicitly on teaching comprehension strategies, the results of this study show that teachers claim that they equip their students with strategies that enhance their reading comprehension skills. However, some practices, and in particular those linked to metacognitive strategies and reciprocal teaching, appear to be neglected by more than half of the participants in this study. Implications for improving reading instruction are offered.

  7. Software Educativo como auxílio na aprendizagem da matemática: uma experiência utilizando as quatro operações com alunos do 4º Ano do Ensino Fundamental I

    Directory of Open Access Journals (Sweden)

    Marcílio Farias da Silva

    2013-01-01

    Full Text Available As dificuldades de aprendizagem decorrentes do modelo de ensino encontrado nas escolas e os avanços dos recursos tecnológicos são fatores que influenciam a educação matemática. Os alunos apresentam um grau de dificuldade relevante com relação ao ensino-aprendizagem, causado pela falta de motivação, de aulas monótonas e sem relação com o cotidiano. Ao mesmo tempo, os recursos tecnológicos vêm sendo inseridos na educação de forma crescente, trazendo resultados positivos para o ensino. Considerando tais fatores, este trabalho analisou o uso de software educativo como auxílio na aprendizagem de matemática, apresentando-o como uma possibilidade de tornar as aulas mais motivadoras aos alunos. Para verificar se essa utilização traz resultados positivos para o ensino-aprendizagem, buscou-se tal comprovação por meio de estudo de caso de natureza exploratória realizado com alunos do 4º ano do ensino fundamental I, utilizando como ferramenta o software educativo Tux of Math Command. Realizou-se uma análise comportamental dos alunos na realização de operações matemáticas em diferentes situações: resolvendo as operações em sala de aula, e utilizando o jogo no laboratório de informática. Na utilização do software, verificou-se uma atitude mais instigante dos alunos do que na resolução das operações em sala de aula. Esse interesse foi decorrente da associação do jogo feita pelos alunos, não como problema a ser resolvido e sim como algo prazeroso e significativo, em oposição ao ocorrido em sala de aula, momento em que prevaleceu a insegurança e a necessidade de apresentar soluções. A pesquisa possibilitou afirmação do questionamento apresentado neste trabalho, confirmando que a utilização do software educativo auxilia o processo de ensino-aprendizagem de matemática.

  8. Histoire de l’hôpital. L’éclairage des salles d’opération aux XIXe et XXe siècles : l’apparition du scialytique

    Directory of Open Access Journals (Sweden)

    Francis Dreyer

    2009-05-01

    Full Text Available L’éclairage des salles d’opération dans les hôpitaux et plus particulièrement celui des zones opératoires était l’un des problèmes récurrents qui entravaient le déroulement de certaines interventions. Les ombres, la focalisation et la chaleur de la source gênaient les chirurgiens. Plus que cela, la promiscuité entre les praticiens et leurs patients, la tradition des cours magistraux et les usages multiples de la salle de travail entraînaient la prolifération de maladies nosocomiales mortelles. Au début du XXe siècle, la venue d’une nouvelle source lumineuse, le scialytique BBT, qui projette un faisceau lumineux sans ombre portée, permit enfin de répondre aux besoins des médecins. Plus que la simple amélioration d’un confort visuel, le scialytique participa à la transformation de l’ancienne salle d’opération en un élément unique : le bloc opératoire. Cet espace hautement spécialisé et confiné put dès lors être placé stratégiquement, suivant les besoins, à l’intérieur de « l’hôpital bloc » moderne.The lighting of operating rooms in hospitals, and, more especially the lighting of operating zones, was a persistent problem which could interfere with certain surgical operations. Shadows, focussing and the heat from the light source were nuisance for the surgeons. The promiscuity between surgeons and patients, the tradition of holding courses during operations and the fact that operating rooms could be used for other purposes led to an increase in often fatal nosocomial infections. At the beginning of the twentieth century, the appearance of a new type of operating lamp, the scialytique BBT, which could light without casting shadows, at last brought a solution to the problem. But this new type of lighting not only increased the visual comfort of surgeons at work, it also had an impact in transforming the operating room into a dedicated space, the modern operating theatre. This highly specialised

  9. Imagerie par résonance magnétique appliquée aux matériaux du génie civil Magnetic Resonance Imaging Applied to Civil Engineering Materials

    Directory of Open Access Journals (Sweden)

    Coussot P.

    2006-12-01

    Full Text Available Un imageur par résonance magnétique dédié aux matériaux du génie civil et de la construction est actuellement en cours d'acquisition par le LCPC (Laboratoire Central des Ponts et Chaussées. Il sera géré par le LMSGC à Champs-sur-Marne et installé dans les locaux de l'IFI (Institut francilien d'Ingénierie. De nombreuses collaborations avec des laboratoires et des entreprises sont envisagées et certaines déjà mises en place. D'un point de vue général, les recherches concerneront les transferts et changements de phase dans les milieux granulaires et poreux. Une série de dispositifs de recherche complémentaire est à l'étude. Ceux-ci permettront de solliciter les échantillons (chauffage, refroidissement, écoulement, transfert, fissuration tout en réalisant des images de la structure interne. Ceci nous permettra de mettre en relation les propriétés macroscopiques des matériaux et leurs évolutions au niveau mésoscopique. A magnetic resonance imager for use with civil engineering and construction materials is being acquired by the LCPC (Laboratoire Central des Ponts et Chaussées. It will be managed by the LMSGC at Champs-sur-Marne and will be installed on the premises of the IFI (Institut francilien d'Ingénierie. Numerous joint projects between laboratories and industry are contemplated and some are already under way. The general outlook for these research projects is to study transfers and phase changes in granular porous media. A number of supplementary research devices are being studied. These devices will make it possible to submit samples to heating, cooling, flow, transfer and fissuring while recording images of their internal structure. This will allow us to discover the relationship between the macroscopic properties of materials and mesoscopic changes.

  10. La diaspora portoricaine aux Etats-Unis

    OpenAIRE

    Auberte Pallud

    2012-01-01

    En retraçant brièvement l’histoire des Portoricains résidents sur l’ile et sur les Etats-Unis continentaux, cette étude se réfère à des penseurs tels que  Bouilla, Deleuze et Gattari ainsi que Scheffer,  pour offrir un nouveau cadre théorique et une nouvelle conceptualisation de l’identité et de la diaspora.Brushing an overview of Puertoricans’ history, those living on the Island and those living on the continent, the present study refers to thinkers such as Bonilla’s, Deleuze, and Gattari’s,...

  11. Les politiques alimentaires face aux enjeux nutritionnels

    Directory of Open Access Journals (Sweden)

    Martin Ambroise

    2008-03-01

    Full Text Available Food policies can use of two intervention strategies. The first is changing consumer behaviour through information and education. The second is to act on the characteristics of the food supply, on the nutritonal composition of products in the same time on the prices. All require collaboration between governments and enterprises.

  12. Hypertranscendance et Groupes de Galois aux differences

    OpenAIRE

    Hardouin, Charlotte

    2006-01-01

    This paper deals with criteria of algebraic independence for the derivatives of solutions of rank one difference equations. The key idea consists in deriving from the commutativity of the differentiation and difference operators a sequence of iterated extensions of the original difference module, thereby setting the problem in the framework of difference Galois theory and finally reducing it to an exercise in linear algebra. The involved tannakian categories are neutral over non necessarily a...

  13. La défunte aux entraves

    OpenAIRE

    Duval, Sandrine

    2009-01-01

    Une sépulture d’esclave, datée entre le début du IIe s. av. J.-C. et le changement d’ère, a été mise au jour dans un vallon de garrigue, sur la commune de Martigues (Bouches-du-Rhône). Cette inhumation isolée illustre un contexte funéraire singulier, lié au caractère intrinsèque de l’objet sépulcral associé : si les entraves portées par l’individu de son vivant signifiaient un bannissement social, elles témoignent cependant du statut de cette défunte au sein de la collectivité. Cette sépultur...

  14. The axion hunting; La chasse aux axions

    Energy Technology Data Exchange (ETDEWEB)

    Robillard, C. [Laboratoire Collisions, Agregats, Reactivite (CNRS / Universite Toulouse 3), 31 (France)

    2009-05-15

    The axion is a neutral, light and very weakly interacting particle that was imagined in the seventies to unify some aspects of the basic interactions. Another important feature of axions is their capacity to transform themselves into photons when crossing a magnetic field, the probability of this conversion is very low, proportional to the intensity of the magnetic field and all the less low as the mass of the axion is tiny. Axions are perfect candidates to dark matter and could also explain why the solar corona is so hot. The magnetic fields inside the sun are so intense that they could enable axions to mutate into photons leading to an excess of energy and light in the out layers of the sun. Till now, no experiment has led to the detection of axions despite the announcement made in march 2006 of their discovery by an Italian team, these experimental results were unanimously acknowledged as biased. The ADMX program (Axion Dark Matter eXperiment) launched in the nineties, has led to constrains on the mass of the axions: the 1.9 - 3.3 eV range for the mass has been experimentally barred. Other experiments like CAST (CERN Axion Solar Telescope) have led to complementary constrains on the mass or to new constrains on the axion-photon coupling. (A.C.)

  15. Aux origines de la civilisation orientale

    Directory of Open Access Journals (Sweden)

    Jean Perrot

    2007-09-01

    Full Text Available Entre le 10e et le 3e millénaire av. l’ère chrétienne, l’Asie du Sud-Ouest a été le théâtre d’événements annonciateurs d’une inflexion décisive du destin de l’humanité. Ces événements signalent un changement radical dans le rapport des hommes avec le milieu naturel. Mettant à profit une amélioration générale des conditions climatiques, amélioration qui s’accentue à partir de 10 000 avant l’ère chrétienne, des bandes qui vivaient de la chasse, de la pêche et de la cueillette dans les régions l...

  16. Accessibilite des batiments publics aux personnes handicapees

    CERN Document Server

    Colloca, C

    2003-01-01

    Selon les législations suisse et franèaise, les lieux de travail ainsi que les bâtiments recevant du public, doivent être aménagés en tenant compte de la présence de travailleurs et de public handicapés et de manière à favoriser leur autonomie. Les dispositions adoptées pour les accès, les portes, les dégagements et les ascenseurs desservant les postes de travail ou à vocation conviviale, et les locaux annexes tels que locaux sanitaires, locaux de restauration, parcs de stationnement, doivent permettre l'accès et l'évacuation des personnes handicapées, notamment celles circulant en fauteuil roulant.

  17. Building integrated photovoltaic; Photovaltaique integre aux batiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-01-01

    Durable, modular and flexible in use, as demonstrated by the different case studies in this publication, photovoltaic can replace diverse building elements, from glass facades to weather proof roofs. This leaflet towards architects describes aesthetic, technical, economic and environmental interest of building integrated photovoltaic. (author)

  18. Cryptographie appliqué aux textes arabe

    OpenAIRE

    AHMED BELHADJ, Souhila

    2011-01-01

    L’objectif principal de notre projet est d’étudier les différents algorithmes de cryptage utilisés pour le chiffrement et la protection des données circulée dans les réseaux informatique. La cryptographie moderne se décomposés en deux classes : La cryptographie symétrique qui utilise la même clé pour chiffrer et déchiffrer des messages et qui a l’avantage d’être rapide. Le cryptage asymétrique nécessitant des notions essentiel en mathématiques et qui utilise une clé publique pour chi...

  19. Optique quantique multimode : des images aux impulsions

    OpenAIRE

    Chalopin, Benoît

    2009-01-01

    This thesis is devoted to the theoretical and experimental study of multimode optical parametric oscillators (OPO) in the transverse and longitudinal domains. We first recall the common tools used to operate non-classical states of light, with a special emphasis on the concept of mode in the quantum description of the electromagnetic field. We recall the techhniques used to describe and manipulate experimentally the transverse (images) and longitudinal (pulses) modes, and compare the two case...

  20. Du monde universitaire aux acteurs culturels

    OpenAIRE

    Gonçalves, Stéphanie; Gouy, Audrey; Heiter, Gerrit Berenike; Paillet, Camille

    2015-01-01

    Les journées d’études « Danse(s) et Politique(s), enjeux et pratiques de l’interaction entre danse et politique » ont été organisées à Bruxelles les 25 et 26 avril 2013. Une partie des communications viennent enrichir et compléter ce numéro thématique de Recherches en danse qui approfondit les réflexions alors entamées. Le choix de cette thématique est le résultat d’une collaboration fructueuse née dès 2010 entre le Département Recherche du Centre national de la danse (CND) à Pantin et l’Atel...

  1. How Molecular Evolution Technologies can Provide Bespoke Industrial Enzymes: Application to Biofuels Comment les technologies d’évolution moléculaire peuvent fournir des enzymes industrielles sur mesure : application aux biocarburants

    Directory of Open Access Journals (Sweden)

    Fourage L.

    2013-08-01

    est l’un des principaux goulets d’étranglement dans le développement de la conversion biologique de la biomasse lignocellulosique en biocarburants. L’un des organismes les plus efficaces pour la production d’enzymes cellulolytiques est le champignon Trichoderma reesei, principalement grâce à sa capacité importante de sécrétion. La conversion de la cellulose en glucose implique trois types de cellulases travaillant en synergie : les endoglucanases (EC 3.2.1.4 clivant de façon aléatoire les liaisons glycosidiques en (3-1,4, les cellobiohydrolases (EC 3.2.1.91 attaquant la chaîne de cellulose aux deux extrémités afin de produire le cellobiose, dimère qui sera converti en glucose par l’action des (3-glucosidases (EC 3.2.1.21. De façon inattendue, la quantité de 3-glucosidase (BGL1 sécrétée par les souches de T. reesei représente un très faible pourcentage de la quantité totale des protéines sécrétées qui en fait donc une activité limitante du cocktail. Cette faible activité limite d’autant plus les performances du cocktail que le cellobiose représente le principal inhibiteur de la réaction cellulolyse par les cellobiohydrolases. Ce goulot d’étranglement peut être atténué soit par une surexpression de la (3-glucosidase chez T. reesei, soit par une amélioration de son activité spécifique. Après un bref aperçu des principales technologies existantes, cet exemple sera utilisé dans cette revue pour illustrer le potentiel des technologies d’évolution dirigée pour développer des enzymes répondant aux besoins de l’industrie des biotechnologies. Nous décrivons comment la mise en oeuvre d’une stratégie d’évolution dirigée par le L-ShufflingTM avec trois gènes parentaux provenant de la biodiversité microbienne permet d’obtenir des activités (3-glucosidases très améliorées par rapport à la Cel3a (3-glucosidase de T. reesei (activité spécifique 242 fois plus élevée pour le substrat pNPGIc. Cette am

  2. Quantification de la Charge Virale et tests de résistance du VIH-1 aux ARV à partir d’échantillons DBS (Dried Blood Spots chez des patients Guinéens sous traitement antirétroviral

    Directory of Open Access Journals (Sweden)

    Nestor Bangoura

    2015-05-01

    Full Text Available Problématique: Comme dans plusieurs pays du Sud, le suivi virologique des patients sous traitement antirétroviral (TARV en Guinée est timide voire inexistant dans certaines localités. Le but de cette étude était d’évaluer la faisabilité technique et logistique de l’utilisation des DBS dans les tests de charge virale (CV et de génotypage.Méthode: De septembre à octobre 2010, les DBS ont été préparés à partir de prélèvements sanguins de patients adultes sous TARV. Le délai d’envoi des échantillons au laboratoire de référence était de 30 jours maximum après le prélèvement et se faisait à température ambiante. La CV a été quantifiée et les échantillons de patients en échec virologique (CV ≥ 3 log10 copies/mL ont été génotypés selon le protocole de l’ANRS. L’algorithme de Stanford version 6.0.8 a été utilisé pour l’analyse et l’interprétation des mutations de résistance.Résultats: Parmi les 136 patients inclus, 129 et 7 étaient respectivement sous première et deuxième ligne de traitement avec une médiane de suivi de 35 mois [IQR: 6-108]. L’échec virologique a été noté chez 33 patients. Parmi eux, 84.8% (n = 28/33 ont bénéficié d’ungénotypage. Le taux de résistance global était de 14% (n = 19/136. Le CRF02_AG était le sous type viral le plus prévalent (82%; n = 23.Conclusion: En plus de montrer la faisabilité technique et logistique des tests de CV et de génotypage à partir des DBS, ces résultats montrent l’intérêt de leurs utilisations dans le suivi virologique des patients sous TARV. Cette étude a permis également de documenter l’échec virologique, la résistance aux ARV et la diversité génétique du VIH-1 en Guinée.Mots clés: VIH-1, Résistance aux ARV, DBS (Dried Blood Spots, Guinée Conakry, Génotypage,Charge Virale. Quantification of Viral load and resistance tests of HIV-1 to ARVs from dried blood spotssamples in Guinean patients undergoing

  3. Analyse de la sensibilité aux paramètres gazoles d'un moteur diesel d'automobile à injection directe Small Direct Injection Diesel Engine Sensitivity to the Diesel Fuel Characteristics

    Directory of Open Access Journals (Sweden)

    Montagne X.

    2006-12-01

    Full Text Available L'étude présentée a été réalisée dans le cadre du GMCL (Groupement Moteur Carburant Lubrifiant, organisme qui réunit des constructeurs d'automobiles, des raffineurs et des additiveurs, avec l'objectif d'examiner la sensibilité d'un moteur Diesel à injection directe d'automobile aux paramètres du gazole. Les partenaires de cette étude sont Elf, IFP, Octel, PSA, Renault et Total. Parmi les solutions technologiques permettant de disposer de convertisseurs d'énergie assurant de faibles niveaux d'émissions de polluants et de consommation, le moteur Diesel se place naturellement en bonne position. Dans ce contexte, on enregistre aujourd'hui l'émergence du moteur Diesel à injection directe pour les véhicules légers en raison de ses performances, notamment en regard de la consommation. Toutefois, cette technologie nécessite une technique d'injection performante, associée à la gestion électronique, demande de l'EGR et un catalyseur d'oxydation afin de régler les problèmes d'émissions polluantes et sonores. Il est donc de première importance de cerner avec précision la sensibilité du moteur Diesel à injection directe aux paramètres carburants afin de tirer le meilleur profit de cette technologie. À partir d'un ensemble de gazoles formulés pour faire varier la composition chimique, l'indice de cétane et la densité, un moteur Audi à injection directe de type 1Z a été testé au banc, dans des conditions standard de réglage (avance à l'injection et taux de gaz recyclés. Cet ensemble de résultats a ainsi permis de démontrer que l'accroissement de l'indice de cétane, la réduction de la densité et de la teneur en polyaromatiques ont une influence positive sensible sur les émissions de CO, d'hydrocarbures imbrûlés, des VOF. En ce qui concerne les émissions de particules, l'indice de cétane semble avoir une influence négative sur la fraction sèche dans certaines conditions. De plus, il apparaît que les

  4. A importância do treinamento da criança com baixa visão, com emprego dos auxílios ópticos, para capacitação educacional: relato de caso The value of optical aids' training for low vision child education: case report

    Directory of Open Access Journals (Sweden)

    Eduardo Toshio Sato

    2010-06-01

    Full Text Available O aprendizado do correto manuseio do auxílio óptico foi treinado: localização, focalização e seguimento com o telescópio de 8x de magnificação. Após essa etapa iniciou-se o aprendizado de cópia da lousa com o auxílio adaptado. Totalizaram-se 17 sessões para a criança receber a prescrição final devido às grandes dificuldades apresentadas pela baixa acentuada das funções visuais.Training of the proper handling of optical devices was performed: location, targeting and tracking with the 8x magnification telescope. After this step, learning to a copy from a blackboard with the adapted optical aid was initiated. Seventeen sessions were required for the child's final prescription due to severe low vision and loss of visual functions.

  5. 金融危机下的民营企业转型——基于奥克斯集团的案例分析%Transformation of Private Enterprise in Financial Crisis——Case Study of AUX Group

    Institute of Scientific and Technical Information of China (English)

    陈颖

    2011-01-01

    世界金融危机袭来,奥克斯集团采取了保持信心、现金为王、自主创新、精益管理、建设学习型企业、文化转型等措施应对挑战。在后危机时代,奥克斯集团将从思想认识和当前工作上突出三个"更加注重",从战略高度确定做强制造业、适度多元化的发展方向,从管理角度突出人才的重要性和快速高效的执行力,开展创新转型。%With the international financial crisis coming,Ningbo AUX Group adopted the approaches of holding confidence,controlling cash flow,independent innovation,lean management,building learning organization,and culture transformation to address challenges.During the periods of post financial crisis,AUX Group needs to emphasize three " more importance " on thoughts,insist on the development orientation of manufacturing industry and moderate diversification,manage talents and executing ability in order to carry out innovative transformation.

  6. La symétrie « dissimulée » dans l’ordonnance des illustrations aux strophes de la deuxième moitié de L’Hymne Acathiste peintes sur la façade méridionale de l’église de la Décollation de Saint-Jean le Précurseur du village d’Arbore

    Directory of Open Access Journals (Sweden)

    Constantin I. Ciobanu

    2011-01-01

    Full Text Available Cette note a comme but l’explication de l’ordonnance insolite des illustrations aux strophes de la deuxième moitié de l’Hymne Acathiste peintes sur la façade méridionale de l’église de La décollation de Saint Jean le Précurseur du village d’Arbore. D’une manière à peu près mathématique, en partant de l’ordonnance consacrée des illustrations aux strophes de l’hymne, l’auteur essaye de démontrer comment, grâce à l’utilisation itérative du même cliché sur les parties recto et verso des décalques, peut-on obtenir le groupement des illustrations de l’église d’Arbore.

  7. Nova proposta de treinamento e avaliação do uso de auxílios ópticos em portadores de visão subnormal New proposal for training and evaluation of the use of optical aids in low vision patients

    Directory of Open Access Journals (Sweden)

    Silvana Terezinha Figueiredo Moya

    2002-01-01

    Full Text Available Objetivo: Elaboração de uma nova seqüência de treinamento e avaliação no uso do auxílio óptico para portadores de baixa visão. Métodos: Construção de tabelas obedecendo a uma seqüência de complexidade lingüística, iniciando com palavras, seguindo com expressões, períodos e culminando com textos. Utilização do novo material em 32 portadores de retinose pigmentária, com acuidade visual entre 0,5 e 1,3 LogMAR (20/63 e 20/400, registrando as velocidades de leitura com e sem auxílio óptico. Resultados: Tabelas de palavras, expressões, períodos e textos de tamanhos variados, com impressão de letras pretas em fundo branco e letras brancas em fundo preto. Apresentação dos dados referentes à idade, sexo, acuidade visual, auxílio óptico empregado, tamanho da impressão lida, velocidades de leitura sem e com auxílio e número de sessões de treinamento. Conclusões: A leitura de textos constitui o melhor instrumento de avaliação qualitativa e quantitativa no uso dos auxílios ópticos. As tabelas propostas baseiam-se em uma complexidade lingüística crescente, tentando minimizar ao máximo os fatores não relacionados à visão. Constitui valioso instrumento na prática da visão subnormal, entretanto, o desempenho de leitura depende de fatores relacionados a cada paciente.Purpose: The design and use of new near-vision charts for training and evaluation of the use of optical aids in low vision patients. Methods: Construction of new charts obeying a linguistic complexity, starting with words, followed by expressions and sentences and ending with texts. The new material was used in thirty-two patients with retinitis pigmentosa, with a corrected visual acuity from 0.5 to 1.3 LogMAR. Reading speeds were recorded with and without optical aids. Results: Word-reading, expression-reading, sentence-reading and text-reading charts in different sizes, with black print on a white background and white print on a black background. The

  8. Le moment terroriste de la chouannerie : des atteintes à l’ordre public aux attentats contre le Premier Consul The terrorist moment of Chouannerie: from threats to public order to political attacks against the First Consul

    Directory of Open Access Journals (Sweden)

    Aurélien Lignereux

    2012-03-01

    Full Text Available En mettant fin aux opérations militaires, la pacification de l’hiver 1800 disqualifie par le fait même en actes de brigandage les violences commises par les chouans insoumis. Lecture sommaire et tendancieuse sans doute mais qui a été avalisée par la configuration historiographique : les spécialistes de la police napoléonienne prennent alors le relais des historiens de la guerre civile. Un tel compartimentage, redoublé par la scission opérée entre Paris et l’Ouest, altère la compréhension de la chouannerie en créant un hiatus dans ses modes d’action. C’est en effet masquer une continuité réelle entre les attentats contre Bonaparte et l’usage délibéré de la terreur dans les départements de l’Ouest par des bandes s’employant à déstabiliser l’ordre républicain et à saboter le processus de réconciliation au moyen d’assassinats publics et d’enlèvements spectaculaires lors des périodes dites d’entre-chouannage ou de chouannerie à volonté. Mettre en évidence cette stratégie d’intimidation éclaire d’un jour nouveau l’affaire de la Machine infernale, rue Nicaise le 3 Nivôse an 9, et la conspiration de l’an 12 : pour s’en convaincre, il n’est qu’à envisager l’itinéraire de leurs auteurs, qui sauront toutefois emprunter in fine le mode opératoire projeté par les jacobins.By ending the military operations, the pacification of the winter 1800 disqualifies in acts of robbery the violence committed by the rebellious Chouans. Not doubt it is a ummary and biased reading but it was endorsed by the historiographical configuration: specialists of the Napoleonic police relaying historians of the civil war. Such a compartmentalization, doubled by the split operated between Paris and the West, alters the understanding of the revolt of the Chouans by creating a hiatus in its modes of action. It is indeed to mask a real continuity between attempts against Bonaparte and the deliberated use of

  9. Concession of sickness benefit to social security beneficiaries due to mental disorders Chance de deferimento de requerimentos de auxílio-doença a segurados do Instituto Nacional do Seguro Social com transtornos mentais

    Directory of Open Access Journals (Sweden)

    Adriana Kelmer Siano

    2011-01-01

    Full Text Available OBJECTIVE: Assess the odds of having an initial claim for statutory sickness benefit awarded (ascribed to mental disorder as the main registered diagnosis, in relation to institutional, clinical, sociodemographic and welfare factors in Juiz de Fora-MG, Brazil. METHOD: Two models of logistic regression, taking into account the categories of the medical examiners, were built with the aim of characterizing the relative weight of several variables affecting the medical conclusion. RESULTS: The factors more strongly related to an award of benefit were a claimant assessed by a physician without a specialization in psychiatry; with a diagnosis of psychosis; up to 29 years of age; with other non-psychiatric (musculoskeletal and cardiovascular co-morbidities; registered with the national insurance system as employed; and male. DISCUSSION: In both models, examiners with a specialization in psychiatry were associated with a lower likelihood of award of benefit. This suggests that examinations undertaken by doctors having a specialty related to the diagnosis supporting the sickness benefit claim are stricter than those undertaken by non-specialists. CONCLUSION: The results suggest that benefit award odds were associated with the specialty of the examiner, medical diagnosis, age, gender and claimant category.OBJETIVO: Avaliar a chance de deferimento em relação a fatores institucionais, clínicos, sociodemográficos e previdenciários em exames periciais iniciais de requerentes de auxílio-doença com registro de algum transtorno mental como diagnóstico principal em Juiz de Fora-MG. MÉTODO: Considerando as categorias de peritos médicos avaliadores, foram construídos dois modelos de regressão logística buscando caracterizar o peso relativo de diversas variáveis sobre a conclusão médico-pericial. RESULTADOS: Os fatores que se mostraram fortemente associados a maior chance de deferimento foram: segurado avaliado por perito médico sem especialidade em

  10. Impacts des TIC sur l’enseignement et l’apprentissage des conceptions relatives au champ électrostatique en classes préparatoires aux grandes écoles d’ingénieurs (CPGE

    Directory of Open Access Journals (Sweden)

    Abdelaziz Bouchaib

    2011-01-01

    Full Text Available [Français] Cet article décrit une séquence d’enseignement au cours de laquelle nous avons expérimenté les ressources numériques du site Université en Ligne (UeL, relatives au module d’électrostatique, avec des étudiants de la première année des classes préparatoires aux grandes écoles d’ingénieurs. Nous rappelons brièvement les difficultés conceptuelles rencontrées chez les étudiants de premier cycle universitaire dans le domaine de l’électrostatique. La description de la séquence, expérimentée durant trois années consécutives en deux versions, est suivie d’une analyse des perceptions des étudiants à propos du site UeL. Cette analyse montre que les étudiants sont largement satisfaits du contenu, de la clarté et de la motivation que le site procure dans l’apprentissage. Nous étudions ensuite l’apport de l’UeL sur les conceptions des étudiants participant à l’expérimentation à propos du champ électrostatique créé par une charge ponctuelle et du principe de superposition des champs créés par deux charges ponctuelles. Les résultats montrent que, lorsque les ressources de l’UeL sont intégrées en situation d’auto-apprentissage accompagné par un enseignant tuteur, elles permettent une bonne appropriation de ces concepts et une meilleure interprétation des situations utilisées comme instrument d’évaluation. [English] This article describes a teaching sequence in which we have experimented digital resources of “online university (UeL” site related to Electrostatics module with students of the first year of preparatory classes for engineering schools. We briefly remind the conceptual difficulties faced by the first cycle university students in the domain of Electrostatics. The sequence description experienced during three consecutive years in two versions is followed by an analysis of students’ perception of UeL site. This analysis shows that students are widely satisfied of the

  11. Les recommandations de prise en charge des complications métaboliques associées aux antipsychotiques de deuxième génération chez les enfants et les adolescents

    Science.gov (United States)

    Ho, Josephine; Panagiotopoulos, Constadina; McCrindle, Brian; Grisaru, Silviu; Pringsheim, Tamara

    2012-01-01

    HISTORIQUE : Les antipsychotiques de deuxième génération s’associent souvent à des complications métaboliques. Ces médicaments sont utilisés plus souvent pour le traitement des troubles de santé mentale chez les enfants, ce qui a requis l’élaboration de lignes directrices officielles sur la surveillance de leur innocuité et de leur efficacité. Des lignes directrices ont déjà été élaborées pour surveiller les complications métaboliques et neurologiques. Afin d’aider les praticiens qui effectuent ces interventions de surveillance, une série de recommandations thérapeutiques complémentaires a été élaborée pour les cas où l’on observe des mesures ou des résultats anormaux. OBJECTIF : Créer des recommandations probantes afin de contribuer à la prise en charge des complications métaboliques chez les enfants traités au moyen d’antipsychotiques de deuxième génération. MÉTHODOLOGIE : Les auteurs ont procédé à une analyse systématique des publications sur les complications métaboliques des antipsychotiques de deuxième génération chez les enfants. Les membres du groupe consensuel ont évalué l’information recueillie grâce à l’analyse bibliographique systématique et ont fait appel à un processus de groupe nominal pour parvenir à un consensus à l’égard de recommandations thérapeutiques. Dans la mesure du possible, ils se sont reportés aux lignes directrices existantes sur l’évaluation et le traitement des anomalies métaboliques chez les enfants. RÉSULTATS : Des recommandations probantes sont présentées pour contribuer à la prise en charge des complications métaboliques, y compris la prise de poids, l’augmentation du tour de taille, l’élévation des taux de prolactine, de cholestérol, de triglycérides et de glucose, les épreuves de fonction hépatique anormales et les études thyroïdiennes anormales. CONCLUSION : Il faut recourir à des mesures de surveillance convenables lorsqu’on prescrit

  12. Formation of Se (0 Nanoparticles by Duganella sp. andAgrobacterium sp. isolated from Se-laden soil of North-East Punjab, India

    Directory of Open Access Journals (Sweden)

    Bajaj Mini

    2012-07-01

    Full Text Available Abstract Background Selenium (Se is an essential trace element, but is toxic at high concentrations. Depending upon the geological background, the land use or on anthropogenic pollution, different amounts of Se may be present in soil. Its toxicity is related to the oxyanions selenate and selenite as they are water soluble and bioavailable. Microorganisms play an important role in Se transformations in soil and its cycling in the environment by transforming water-soluble oxyanions into water insoluble, non-toxic elemental Se (0. For this study, soil samples were collected from selenium-contaminated agricultural soils of Punjab/India to enrich and isolate microbes that interacted with the Se cycle. Results A mixed microbial culture enriched from the arable soil of Punjab could reduce 230 mg/l of water soluble selenite to spherical Se (0 nanoparticles during aerobic growth as confirmed by SEM-EDX. Four pure cultures (C 1, C 4, C 6, C 7 of Gram negative, oxidase and catalase positive, aerobic bacteria were isolated from this mixed microbial consortium and identified by 16 S rDNA gene sequence alignment as two strains of Duganella sp. (C 1, C 4 and two strains of Agrobacterium sp.(C 6, C 7. SEM/TEM-EDX analyses of the culture broth of the four strains revealed excretion of uniformly round sharply contoured Se (0 nanoparticles by all cultures. Their size ranged from 140–200 nm in cultures of strains C 1 and C 4, and from 185–190 nm in cultures of strains C 6 and C 7. Both Duganella sp. revealed better selenite reduction efficiencies than the two Agrobacterium sp. Conclusions This is the first study reporting the capability of newly isolated, aerobically growing Duganella sp. and Agrobacterium sp. from soils of Punjab/India to form spherical, regularly formed Se (0 nanoparticles from water soluble selenite. Among others, the four strains may significantly contribute to the biogeochemical cycling of Se in soil. Bioconversion of toxic

  13. Modélisation de l'interdiffusion et du comportement en oxydation cyclique de superalliages monocristallins à base de nickel revêtus d'une sous-couche γ-γ’ riche en platine. Extension aux systèmes barrière thermique

    OpenAIRE

    Audigié, Pauline

    2015-01-01

    Les systèmes barrière thermique actuels connaissent une importante dispersion de durées de vie liée principalement aux ondulations de surface du revêtement métallique β-(Ni,Pt)Al provoquant l’écaillage du dépôt céramique. Les revêtements γ-γ’ riches en platine sont étudiés en tant qu’alternative au système actuel. Ce travail de thèse s’est intéressé à l’élaboration des revêtements γ-γ’ riches en platine sur un superalliage à base de nickel, l’AM1 à partir de procédés conventionnels : dépôt él...

  14. Offrir une réponse aux besoins médicaux et psychosociaux des patients tuberculeux au Burkina Faso. Quelles stratégies adopter? / Responding to the medical and psychosocial needs of tuberculosis patients in Burkina Faso - What strategies to adopt?

    OpenAIRE

    Drabo, Koiné Maxime

    2008-01-01

    Résumé exécutif Introduction. La prise en charge (PEC) des malades de tuberculose a été confiée à des institutions spécialisées et réduite aux seuls aspects biomédicaux du problème. En associant une revue de littérature sur les dimensions du problème posé par la tuberculose et un état des lieux sur la prise de charge de la tuberculose, les besoins non couverts par les centres de diagnostic et de traitement (CDTs) ont été identifiés dans trois districts sanitaires (DS) ruraux du Burkina ...

  15. La fonction logistique, un outil performant d'analyse et de prévision à moyen terme. Application à la production de pétrole et de gaz aux Etats-Unis, en URSS et dans d'autres pays The Logistic Function, an Efficient Medium-Range Analysis and Forecasting Method

    OpenAIRE

    Seguret J.

    2006-01-01

    A partir de la similitude observée entre l'évolution de la production pétrolière d'un pays et celle de la pénétration d'un produit dans un marché (fonction logistique), l'auteur expose le principe d'une méthode originale qui permet, sous certaines conditions, de prévoir quelle sera la production annuelle probable d'un pays producteur à un horizon de 10 à 15 ans. La validité de cette méthode est d'abord démontrée sur l'exemple de la production pétrolière aux Etats-Unis. Elle est ensuite illust...

  16. Apport de l'analyse interactive d'images à l'étude de l'évolution structurale de zones déformées : application à une zone de cisaillement pan-africaine de l'Adrar des Iforas (Mali) et aux orthogneiss du massif du Grand Paradis (Alpes, Italie)

    OpenAIRE

    Champenois, Michel

    1989-01-01

    L'analyse quantitative de la déformation des roches apparaît indispensable si l'on veut pouvoir comprendre et discuter les mécanismes de la déformation à différentes échelles d'observation. Dans ce mémoire, l'étude de la déformation finie à l'échelle microscopique, a été réalisée à partir de la forme et de l'orientation de cristaux constituant les populations de marqueurs. A cette fin, nous avons développé un outil permettant d'avoir facilement accès, aux paramètres de forme et d'orientation,...

  17. Dépistage de la consommation d’alcool et intervention brève parmi des patients dépendants aux opiacés et à la cocaïne : étude contrôlée et randomisée

    OpenAIRE

    Feldman, Nelson

    2013-01-01

    Cette recherche clinique décrit la prévalence de la consommation d’alcool parmi des patients en traitement ambulatoire pour dépendance aux opiacés et à la cocaïne dans le Service d’Addictologie des HUG avec l’utilisation de l’AUDIT et évalue l’efficacité de l’Intervention Brève chez les buveurs excessifs et les patients alcoolo-dépendants. Les sujets inclus dans cette étude étaient 254 patients toxicodépendants entre 2003 et 2005. Cette étude a montré une prévalence élevée (44%) de la consomm...

  18. Caractérisation de l'effet de la vitesse du courant sur la croissance d'une population algale et évaluation du décrochement et de la biomasse en dérive. Application aux algues et macrophytes du canal de Gignac (34) : Mise en place de protocoles.

    OpenAIRE

    Suaire, M.

    2008-01-01

    / Les canaux d'irrigation, correspondant à des cours d'eau artificiels canalisés, sont utilisés pour répondre à des besoins multiples tels que l'irrigation des cultures, l'apport en eaux jusqu'aux stations de potabilisation etc. La gestion de ces canaux est fortement perturbée par des proliférations d'algues et plantes aquatiques, notamment durant la période estivale de mai à août. Le canal de Gignac, situé dans l'Hérault n'est pas épargné par ce phénomène d'accumulation d'algues qui conduit ...

  19. Modélisation du procédé de soudage hybride Arc / Laser par une approche level set application aux toles d'aciers de fortes épaisseurs A level-set approach for the modelling of hybrid arc/laser welding process application for high thickness steel sheets joining

    OpenAIRE

    Desmaison Olivier; Bellet Michel; Guillemot Gildas

    2013-01-01

    Le procédé de soudage hybride Arc/Laser est une solution aux assemblages difficiles de tôles de fortes épaisseurs. Ce procédé innovant associe deux sources de chaleur : un arc électrique produit par une torche MIG et une source laser placée en amont. Ce couplage améliore le rendement du procédé, la qualité du cordon et les déformations finales. La modélisation de ce procédé par une approche Level Set permet une prédiction du développement du cordon et du champ de température associé. La simul...

  20. Potentiel des moteurs à mélange pauvre face aux moteurs actuels à réglage stoechiométrique : consommation, émissions, exigence en octane The Challenge to Modern Stoichiometric Engines by the Potential Lean-Burn Engine: Consumption, Emissions, Fuel Requirements

    OpenAIRE

    Douaud A. M.; Ecomard A.; Guibet J. C.; Prigent M.

    2006-01-01

    Le moteur à allumage commandé pour application automobile aux États-Unis est généralement dépollué par catalyse trifonctionnelle qui impose un contrôle stoechiométrique du mélange air-carburant. Le contexte européen de 1990 pour la qualité de l'air stimule l'industrie automobile dans ses recherches de solutions techniques performantes. Le moteur à mélange pauvre, performant en consommation, est une solution potentielle si l'émission de NOx peut être maîtrisée par la combustion. Cet objectif n...