813 research outputs found
Le partenariat orthophoniste â psychologue dans la prise en charge dâun dĂ©ficit dâexpression
Parfois la prise en charge orthophonique rencontre une limite qui est lâaspect psychologique de la problĂ©matique. Le travail en collaboration avec un psychologue peut sâavĂ©rer nĂ©cessaire mais rencontre un certain nombre de contraintes qui rendent impossible cette participation.
Cet article prĂ©sente un outil qui encourage lâexpression dâune problĂ©matique psychologique et Ă©ventuellement des rĂ©ajustements internes Ă la personne sans intervention extĂ©rieure. Pour ce
faire, lâEpreuve des Trois Arbres utilise la mĂ©diation de lâarbre, favorise le discours subjectif en Ă©cartant tout jugement. Lâarbre a Ă©tĂ© choisi en raison des nombreuses analogies que lâesprit Ă©tablit spontanĂ©ment entre un ĂȘtre humain et un arbre.
Suite Ă un accompagnement orthophonique, lâĂ©tude de cas prĂ©sentĂ©e retrace une pratique qui comprend une phase test avec lâEpreuve des Trois Arbres, un accompagnement personnalisĂ© basĂ© sur la production de saynĂštes centrĂ©es sur le thĂšme de lâarbre et une phase retest.
Lâapproche phĂ©nomĂ©nologique qui vise lâexpression dâun discours subjectif, a permis une Ă©volution considĂ©rable du cas prĂ©sentĂ© en rĂ©installant des voies de sens depuis le point de vue du sujet. LâEpreuve des Trois Arbres constitue un outil pour dĂ©passer des limitations disciplinaires au service
de la personne
La relaxation contre lâĂ©puisement des soignants en maison de retraite
Cette recherche avec des professionnels en maison de retraite étudie l\u27effet d\u27un programme de relaxation sur le burn-out. Il s\u27agit de mesurer l\u27impact de la relaxation sur la pratique des soignants. AprÚs un entrainement à la relaxation (Jacobson, 1938 ; Schultz, 1958), une évaluation du degré de tension ressentie par les soignants et des symptÎmes psychologiques et comportementaux présentés par les personnes dépendantes lors de la toilette est réalisée avec des questionnaires (Dovero, 1998 ; MBI, 1981 ; NPI-ES, 2000) remplis par les soignants avant et aprÚs l\u27entraßnement. Cette recherche montre que l\u27entraßnement et la pratique réguliÚre de la relaxation diminuent les tensions ressenties par les soignants et l\u27appréhension suscitée par certains soins comme la toilette. De plus, elle ouvre des perspectives concernant l\u27influence de l\u27état interne du soignant sur l\u27évaluation des troubles du comportement présents chez les personnes dépendantes lors de situations de soin
Positron lifetime measurements on neutronâirradiated InP crystals
Neutronâirradiated InP single crystals have been investigated by positronâlifetime measurements. The samples were irradiated with thermal neutrons at different fluences yielding concentrations for Snâtransmuted atoms between 2Ă1015 and 2Ă1018 cmâ3. The lifetime spectra have been analyzed into one exponential decay component. The mean lifetimes show a monotonous increase with the irradiation dose from 246 to 282 ps. The increase in the lifetime has been associated to a defect containing an Indium vacancy. Thermal annealing at 550â°C reduces the lifetime until values closed to those obtained for the asâgrown and conventionally doped InP [email protected] ; [email protected]
Fe/Co Alloys for the Catalytic Chemical Vapor Deposition Synthesis of Single- and Double-Walled Carbon Nanotubes (CNTs). 1. The CNTâFe/CoâMgO System
Mg0.90FexCoyO (x + y ) 0.1) solid solutions were synthesized by the ureic combustion route. Upon reduction at 1000 °C in H2-CH4 of these powders, Fe/Co alloy nanoparticles are formed, which are involved in the formation of carbon nanotubes, which are mostly single and double walled, with an average diameter close to 2.5 nm. Characterizations of the materials are performed using 57Fe Mošssbauer spectroscopy and electron microscopy, and a well-established macroscopic method, based on specific-surface-area measurements, was applied to quantify the carbon quality and the nanotubes quantity. A detailed investigation of the Fe/Co alloysâ formation and composition is reported. An increasing fraction of Co2+ ions hinders the dissolution of iron in the MgO lattice and favors the formation of MgFe2O4-like particles in the oxide powders. Upon reduction, these particles form R-Fe/Co particles with a size and composition (close to Fe0.50Co0.50) adequate for the increased production of carbon nanotubes. However, larger particles are also produced resulting in the formation of undesirable carbon species. The highest CNT quantity and carbon quality are eventually obtained upon reduction of the iron-free Mg0.90Co0.10O solid solution, in the absence of clusters of metal ions in the starting material. Introduction Catalyti
Carbon Nanotubes by a CVD Method. Part II: Formation of Nanotubes from (Mg, Fe)O Catalysts
The aim of this paper is to study the formation of carbon nanotubes (CNTs) from different Fe/MgO oxide powders that were prepared by combustion synthesis and characterized in detail in a companion paper. Depending on the synthesis conditions, several iron species are present in the starting oxides including Fe2+ ions, octahedral Fe3+ ions, Fe3+ clusters, and MgFe2O4-like nanoparticles. Upon reduction during heating at 5 °C/min up to 1000 °C in H2/CH4 of the oxide powders, the octahedral Fe3+ ions tend to form Fe2+ ions, which are not likely to be reduced to metallic iron whereas the MgFe2O4-like particles are directly reduced to metallic iron. The reduced phases are R-Fe, Fe3C, and ç-Fe-C. Fe3C appears as the postreaction phase involved in the formation of carbon filaments (CNTs and thick carbon nanofibers). Thick carbon nanofibers are formed from catalyst particles originating from poorly dispersed species (Fe3+ clusters and MgFe2O4-like particles). The nanofiber outer diameter is determined by the particle size. The reduction of the iron ions and clusters that are well dispersed in the MgO lattice leads to small catalytic particles (<5 nm), which tend to form SWNTS and DWNTs with an inner diameter close to 2 nm. Well-dispersed MgFe2O4-like particles can also be reduced to small metal particles with a narrow size distribution, producing SWNTs and DWNTs. The present results will help in tailoring oxide precursors for the controlled formation of CNTs
Water Chemisorption and Reconstruction of the MgO Surface
The observed reactivity of MgO with water is in apparent conflict with
theoretical calculations which show that molecular dissociation does not occur
on a perfect (001) surface. We have performed ab-initio total energy
calculations which show that a chemisorption reaction involving a
reconstruction to form a (111) hydroxyl surface is strongly preferred with
Delta E = -90.2kJ/mol. We conclude that protonation stabilizes the otherwise
unstable (111) surface and that this, not the bare (001), is the most stable
surface of MgO under ambient conditions.Comment: RevTeX, 4 pages, 1 Encapsulated Postscript Figur
Carbon Nanotubes by a CVD Method. Part I: Synthesis and Characterization of the (Mg, Fe)O Catalysts
The controlled synthesis of carbon nanotubes by chemical vapor deposition requires tailored and wellcharacterized catalyst materials. We attempted to synthesize Mg1-xFexO oxide solid solutions by the combustion route, with the aim of performing a detailed investigation of the influence of the synthesis conditions (nitrate/urea ratio and the iron content) on the valency and distribution of the iron ions and phases. Notably, characterization of the catalyst materials is performed using 57Fe Mošssbauer spectroscopy, X-ray diffraction, and electron microscopy. Several iron species are detected including Fe2+ ions substituting for Mg2+ in the MgO lattice, Fe3+ ions dispersed in the octahedral sites of MgO, different clusters of Fe3+ ions, and MgFe2O4-like nanoparticles. The dispersion of these species and the microstructure of the oxides are discussed. Powders markedly different from one another that may serve as model systems for further study are identified. The formation of carbon nanotubes upon reduction in a H2/CH4 gas atmosphere of the selected powders is reported in a companion paper
Pepper pectin methylesterase inhibitor protein CaPMEI1 is required for antifungal activity, basal disease resistance and abiotic stress tolerance
Pectin is one of the main components of the plant cell wall that functions as the primary barrier against pathogens. Among the extracellular pectinolytic enzymes, pectin methylesterase (PME) demethylesterifies pectin, which is secreted into the cell wall in a highly methylesterified form. Here, we isolated and functionally characterized the pepper (Capsicum annuum L.) gene CaPMEI1, which encodes a pectin methylesterase inhibitor protein (PMEI), in pepper leaves infected by Xanthomonascampestris pv. vesicatoria (Xcv). CaPMEI1 transcripts are localized in the xylem of vascular bundles in leaf tissues, and pathogens and abiotic stresses can induce differential expression of this gene. Purified recombinant CaPMEI1 protein not only inhibits PME, but also exhibits antifungal activity against some plant pathogenic fungi. Virus-induced gene silencing of CaPMEI1 in pepper confers enhanced susceptibility to Xcv, accompanied by suppressed expression of some defense-related genes. Transgenic ArabidopsisCaPMEI1-overexpression lines exhibit enhanced resistance to Pseudomonas syringae pv. tomato, mannitol and methyl viologen, but not to the biotrophic pathogen Hyaloperonospora parasitica. Together, these results suggest that CaPMEI1, an antifungal protein, may be involved in basal disease resistance, as well as in drought and oxidative stress tolerance in plants
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