WorldWideScience

Sample records for alteration comportement geochimique

  1. Geochemical behaviour of uranium in the cycle of alteration; Comportement geochimique de l'uranium dans le cycle d'alteration

    Energy Technology Data Exchange (ETDEWEB)

    Chervet, J.; Coulomb, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Soudan, P. [Centre d' Etude de Lalumine, Compagnie Pechiney (France)

    1958-07-01

    les circulations d'eaux sur les massifs granitiques et examinons l'influence de la presence de gisements d'uranium sur la composition de ces eaux. d) Nous observons l'amplitude des phenomenes qui limitent les dispersions: fixations, precipitations, etc., et le comportement de la vegetation dans les zones uraniferes. e) Enfin, l'antagonisme: alteration chimique - equilibre radioactif provoque un profond desequilibre dans les materiaux alteres. Nous essayons d'utiliser la mesure de ce desequilibre pour l'explication de mecanismes geochimiques. (auteur)

  2. Sciences du comportement et de la communication: comportement du pharmacien en officine et comportement des usagers

    OpenAIRE

    Roosen, Marie

    1993-01-01

    Le comportement du pharmacien indique-t-il à l'usager ses rôles potentiels en éducation pour la santé dans un espace de santé ou traduit-il surtout un rôle d'opérateur commercial dans un espace de vente ?

  3. Experiments on geochemical prospecting for uranium in arid country; Essais de prospection geochimique de l'uranium en pays aride

    Energy Technology Data Exchange (ETDEWEB)

    Grimbert, A.; Obellianne, J.M. [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (France)

    1962-07-01

    The necessity for preliminary inquiries before applying routine geochemical prospecting techniques to the exploration of a new region is shown. Under conditions presumed to be unfavorable for geochemical prospecting as found in Nigeria along the banks of the Air, a preliminary examination showed that sampling of the stabilized superficial deposits at a depth of 15 cm made it possible to detect the presence of U-containing mineralizations hidden under about 20 meters of sterile sandy deposits. To confirm this result, a boring located on a U-containing geochemical anomaly in a paleosol, encountered a mineralized formation at a depth of 28 meters. (authors) [French] Les auteurs montrent la necessite des enquetes preliminaires avant toute application en routine des techniques geochimiques de prospection, lorsque l'on aborde une region nouvelle. Dans les conditions, a priori defavorables pour la prospection geochimique, que l'on trouve au Niger, en bordure de l'Air, une enquete preliminaire a etabli que l'echantillonnage des depots superficiels stabilises, a 15 centimetres de profondeur, permettait de deceler la presence de mineralisations uraniferes cachees sous une vingtaine de metres de sediments greseux steriles. Pour verifier ce resultat, un sondage implante sur une anomalie geochimique uranifere au sein d'un paleosol, a rencontre une formation mineralisee a 28 metres de profondeur. (auteurs)

  4. Alteration and long-term behaviour of different types of innovative materials for long-lived radionuclides confinement; Alteration et comportement a long terme de differentes classes de materiaux innovants pour le confinement des radionucleides a vie longue

    Energy Technology Data Exchange (ETDEWEB)

    Leturcq, G

    1998-09-29

    The present work is an experimental study on alteration mechanisms of synthetic and natural materials: aluminosilicate glasses, glass ceramics and Ti, Zr or P based ceramics. It is a part of CEA's study program on the immobilization of long- lived radionuclides and deals with chemical processes which control dissolution of amorphous and crystallized solids. The different aluminosilicate glasses studied are altered according to a process of hydrolysis of the bonds between the glass network formers; the activation energy of this reaction is about 60 kJ/mol. Alteration rates of all the glasses decrease by four orders of magnitude when the reaction progress increases. Kinetic laws based on the deviation from the thermodynamic equilibrium between leachate and the fresh solid cannot explain these great decreases. Alteration layers in the reactional interface seem to control the alteration kinetics by providing a passivation process. The chemical durability of the glass ceramics (zirconolite and titanite) improves by a factor of ten in regard to the primary glasses which were obtained by thermal treatment. Zirconium-titanate ceramics are altered only slightly by water. The altered mass corresponds to a few atomic layers only. Steady stases are quickly observed. On the basis of thermodynamic calculations, they are not correlated with saturation between the leachate and primary zirconium-titanate phases. Alteration here also ceases due to the development of a passivating layer. Models aiming at studying the chemical durability of zirconium-titanate ceramics under conditions more representative of a clayey site of geological storage were carried out. The results of the interactions of these ceramics with clays, at 708 deg.C, show clearly that there is no modification of the process of alteration, compared to the simpler pure water systems. Thus, perovskite and zirconolite do not deteriorate under these conditions. (author)

  5. Enlargement of the iliopsoas comportment

    International Nuclear Information System (INIS)

    The iliopsoas or iliopectineal comportment is a normal structure that occasionally communicates with the synovial cavity of the hip. Rarely, in association with certain pathologies that raise the intraarticular pressure, it becomes enlarged, producing an inguinal or pelvic mass, also referred to as iliopsas bursitis. We present five cases of this pathology detected over the past year in our hospitals. Three of the patients had undergone previous vascular punctures in the hip involved, one presented brucellosis-related arthropathy and the fifth had generative joint abnormalities. The plain radiography, arthrography, ultrasound, CT,CT-guided arthrography and MR images are provided and discussed. We present an etiological factor of this process (previous vascular puncture) that has not been previously reported in the literature. 13 refs

  6. Perspectives psychologiques sur le changement d' attidudes et de comportement du conducteur. (Psychological perspectives on changing driver attitude and behaviour.)

    OpenAIRE

    Goldenbeld, C. Levelt, P.B.M. & Heidstra, J.

    2000-01-01

    D' un point de vue psychologique, plusieurs techniques de changement du comportement peuvent etre utilisees pour modifier les comportements a risque du conducteur, telles que l' information, la recompense, la punition. La motivation qui sous-tend les comportements de conduite determine dans une large mesure la reussite des strategies de changement du comportement. L' article distingue trois grandes classes de comportements du conducteur : le comportement raisonne ou planifie, le comportement ...

  7. Comportement en situation d'urgence

    OpenAIRE

    Perrin, C.; Canu, B.; Magnin, J.; Roynard, M.

    2009-01-01

    Étude du comportement du couple conducteur / deux roues motorisé en situation d'urgence. Matériel : les Études Détaillées d'Accidents (EDA). Méthode utilisée pour l'analyse des cas d'accidents : Le modèle séquentiel de l'Inrets ; Reconstruction d'accident impliquant un Deux Roues Motorisé (DRM) ; Analyse spécifique. Résultats : Les accidents de type perte de contrôle ; Les accidents avec interaction multi usagers.

  8. The viewing room: A lens for developing ethical comportment.

    Science.gov (United States)

    McAllister, Margaret; Levett-Jones, Tracy; Petrini, Marcia A; Lasater, Kathie

    2016-01-01

    Healthcare is dynamic and complex, and against this background, nursing students must negotiate the transition from lay person to healthcare professional. Diverse life experiences and learning styles can further complicate this journey of transformation. The contemporary role of the nurse includes caring for and making clinical decisions about patients based on ethical principles. Learning about and integrating ethical comportment as part of the transformative journey requires nurse educators to create and implement learning experiences that challenge nursing students to think deeply and broadly about the experiences they encounter, to question their previous assumptions and prejudices, to consider the world of healthcare through a new lens, and to reflect on and learn from the process. The judicious use of film has the potential to assist students to recognize and develop ethical comportment as they prepare for real-world clinical practice experiences. In this paper, we present three film exemplars and related teaching strategies designed to facilitate transformative learning and development of ethical comportment. PMID:26520212

  9. Modélisation Elasto-Viscoplastique du Comportement des Aciers

    OpenAIRE

    PIPARD, Jean-Marc; ABED-MERAIM, Farid; BALAN, Tudor; Berveiller, Marcel; Bouaziz, Olivier; LEMOINE, Xavier

    2007-01-01

    Dans cet article, une modélisation des différentes phases (ferrite, perlite etc.…) d’un acier multiphasé est proposée moyennant une loi phénoménologique à base physique. La description unifiée du comportement viscoplastique peut être décrite à partir de lois de type sinus hyperbolique. Dans cette optique, une loi en sinus hyperbolique est utilisée afin de décrire de façon physiquement acceptable l’ensemble des comportements asymptotiques du comportement viscoplastique. L’écrouissage de chacun...

  10. Comportement quantique des appareils de mesure : illustrations en optique quantique

    OpenAIRE

    Amri, Taoufik

    2011-01-01

    Cette thèse explore le comportement quantique des appareils de mesure avec des illustrations en optique quantique. Il s'agit de la première étude des propriétés quantiques de mesures effectuées par n'importe quel type d'appareil de mesure. Nous montrons que les propriétés quantiques d'une mesure, comme son caractère projectif ou non-classique, ne peuvent être révélées que par les états quantiques d'une approche inhabituelle de la physique quantique : l'approche rétrodictive. Cette approche co...

  11. Identification du comportement de composites en fatigue bi-axiale

    OpenAIRE

    Busca, Damien

    2014-01-01

    La connaissance du comportement de composites sous un état de contraintes multi-axial reste un enjeu majeur pour l’optimisation du dimensionnement des structures. La machine de fatigue bi-axiale présente au LGP permet de générer un état de contrainte bi-axial par l’utilisation d’éprouvettes cruciformes. La conception des éprouvettes reste un enjeu majeur pour les chercheurs pour répondre aux problèmes spécifiques liés aux matériaux composites. Un nouveau type d’éprouvette cruciforme en compos...

  12. Comment encourager les comportements prosociaux ou citoyens au travail : le rôle des inducteurs organisationnels et individuels

    OpenAIRE

    Boundenghan, Méthode Claudien

    2014-01-01

    Depuis les années 1980, les investigations des chercheurs sur les comportements des individus en milieu de travail sont de plus en plus tournées vers les comportements plus spontanés et volontaires qui ont pour conséquence, l'amélioration du fonctionnement organisationnel. Connus sous plusieurs vocables tels que les comportements de citoyenneté organisationnelle (Organ, 1988 ; Paillé, 2006), comportements organisationnels prosociaux (Brief & Motowidlo, 1986 ; Desrumaux, Léoni, Bernaud, & Defr...

  13. Sexualité des jeunes et comportements sexuels à risque à Kinshasa (R.D. Congo)

    OpenAIRE

    Kalambayi Banza, Barthélémy

    2007-01-01

    La sexualité, pourtant base de la reproduction humaine, n'a intéressé les démographes que comme facteur ou déterminant indirect de la fécondité (principalement en Afrique Centrale). L'intérêt des chercheurs en sciences sociales pour des études sur la sexualité est né avec l'émergence du SIDA dans la perspective des comportements sexuels à risque d'IST/VIH/SIDA. Or, cette perspective restreint le champ d'investigation et limite la connaissance, car la sexualité va au-delà des comportements...

  14. Le prix du transport : quels impacts sur le comportement des utilisateurs ?

    OpenAIRE

    MADRE,JL

    2004-01-01

    Cet article évoque les problèmes soulevés par l'augmentation du prix du carburant et des transports en commun. Quel est l'impact de ces évolutions sur le budget et les comportements des usagers ? Et comment les maitriser ?

  15. Origin and geochemical behavior of uranium in marine sediments. Utilization of the {sup 234}U/{sup 238}U ratio in marine geochemistry; Origine et comportement geochimique de l`uranium dans les sediments marins. Utilisation du rapport ({sup 234}U/{sup 238}U) en geochimie marine

    Energy Technology Data Exchange (ETDEWEB)

    Organo, Catherine [Paris-11 Univ., 91 - Orsay (France)

    1997-01-20

    The first part of this thesis presents the current situation of knowledge of uranium in marine environment. The second part describes the methods of analysis as well as the material support of the study, i.e., the sediments and marine deposits investigated. The third part is dedicated to the study of uranium mobility in marine sediments characterized by detrital terrigenous composition (pelagic clays). This approach allowed quantifying the entering and leaving flux of uranium after the sediment settling and, to discuss, on this basis, the consequences on the uranium oceanic balance. In the third part the origin and behavior of uranium in zones of high surface productivity is studied. The uranium enrichments observed in the hemi-pelagic sediments of the EUMELI (J.G.O.F.S.-France) programme will constitute a material of study adequate for measuring the variations in the {sup 234}U/2{sup 38U} ratio in solid phase, in response to the oxido-reducing characteristics of the sediment. Thus establishing the origin of the trapped uranium has been possible. Also, the nature of the sedimentary phases related to uranium in bio-genetic sediments in the Austral Ocean was determined. Thus a relationship between the variations in the {sup 234}U/{sup 238} and the diagenetic transformations was possible to establish. Finally in the fifth part a study of the behavior of uranium in a polymetallic shell characteristic for deposits of hydrogenized origin 146 refs., 57 figs., 23 tabs.

  16. La formation du comportement de plainte chez le consommateur: recherche exploratoire chez des usagers de restaurants

    OpenAIRE

    Moliner Velázquez, Beatriz; Berenguer Contrí, Gloria; Gil Saura, Irene

    2011-01-01

    Cette recherche aborde le processus de formation du comportement de plainte chez le consommateur. L´objectif général est d´approfondir sur la nature de ce type de réponse à l´insatisfaction, en décrivant sa formation à partir des apports d´un ensemble de variables puisées dans la littérature. En partant du fait que le comportement de plainte englobe trois types de réponses (de plainte, vis à vis des tiers, et privé), nous analysons l´effet provoqué par le niveau d´insatisfaction, la probabili...

  17. Modélisation du comportement dynamique des rotors d’hélicoptères

    OpenAIRE

    Velkova, Cvetelina Vladimirova

    2013-01-01

    Modélisation du comportement dynamique des rotors d'hélicoptèresL'objectif de la thèse est l'étude et la modélisation du comportement dynamique et aérodynamique du rotor de l'hélicoptère en considérant à la fois les forces d'inertie et les forces aérodynamiques et en tenant compte des déformations élastiques des pales. L'algorithme de couplage proposé permet d'effectuer le calcul transitoire avec échange de données entre les solveurs fluide et structure à chaque pas de temps.La particularité ...

  18. Geochemical controls of the oils acidity in petroleum reservoirs; Controles geochimiques de l'acidite des huiles dans les reservoirs petroliers

    Energy Technology Data Exchange (ETDEWEB)

    Rouquette, N.

    2004-12-01

    Within the framework of this thesis, we were interested in the study of acid oils. Thus, after having developed an analytical method to separate acids from crude oils, this one was applied to the analysis of several series of acid oils presenting various degrees of biodegradation. In the first chapter devoted to their molecular study, it was shown that the alteration of the organic matter proceeds according to a quasi-stepwise order and that the major part of the carboxylic acids appeared as an Unresolved Complex Mixture. The only identified resolved compounds were apparently not formed by biodegradation of the oil in place but rather seem either to have been incorporated during oil migration, or to correspond to compounds initially present in the reservoir rock. Among those, we isolated and identified by NMR a new higher plant tri-terpenic derivative, the 24-nor,28-lupanoic acid. In the second chapter, a new method to evaluate acidity, applicable to small quantities of oil, was developed. This one is based on the methylation of the acid species by iodo-methane marked with carbon 13. In the case of a series from the Gulf of Guinea tested initially, the enrichment after labelling presents a perfect correlation with the values of acidity measured by the TAN method (for 'Total Acid Number'). The isotopic labelling method was applied later to a broader range of oil samples. As a whole, a linear correlation seems to exist between {sup 13}C labelling and TAN index, which lets consider that this method could represent an interesting alternative to the measurement of the TAN index in oil exploration. (author)

  19. Les patrons culturels du comportement reproductif et sexuel dans les Andes Boliviennes

    OpenAIRE

    Rozée, Virginie

    2007-01-01

    Les représentations et pratiques culturelles existantes autour de la reproduction et de la sexualité sont des éléments clés pour appréhender la santé reproductive et sexuelle et les droits afférents en Bolivie. De part l’importante diversité culturelle du pays, il n’existe pas un mais divers patrons du comportement reproductif et sexuel. Les aymaras considèrent par exemple que l’accouchement et la menstruation nettoient et purifient le corps, que la femme est fertile lors des menstruations, q...

  20. Effets d'irradiation et comportement des produits de fission dans la zircone et le spinelle

    OpenAIRE

    Gentils, Aurélie

    2003-01-01

    Certains oxydes sous forme cristalline, plus particulièrement la zircone (ZrO2) et le spinelle (MgAl2O4), sont des matrices potentielles pour la transmutation du plutonium et des actinides mineurs. Ce travail concerne l'étude des propriétés physico-chimiques de ces matrices, avec un accent particulier sur leur comportement vis-à-vis de l'irradiation et leur capacité à confiner les produits de fission. Les irradiations à basse énergie et l'incorporation d'analogues stables de produits de fissi...

  1. Le bio à la cantine. Impact sur les attitudes et comportements des parents d'élèves

    OpenAIRE

    Jean-Louis PERNIN

    2014-01-01

    L’objectif de cette recherche est d’examiner l’impact que l’introduction de produits biologiques au sein des cantines scolaires peut avoir sur les croyances et les comportements des parents d’élèves. Au niveau théorique, cette introduction correspond à la création ou au renforcement de normes sociales, normes injonctives et/ou descriptives, qui, selon la théorie du comportement planifié, sont des antécédents de l’intention comportementale. Les résultats montrent, d’une part, un impact signifi...

  2. Perception et anticipation du comportement d’autrui en situation simulée de conduite automobile

    OpenAIRE

    Munduteguy, Christophe; DARSES, Françoise

    2007-01-01

    L’anticipation du comportement d’autrui est un mécanisme central dans la gestion des interactions. L’activité de conduite automobile a la particularité de maintenir les interactants à distance les uns des autres, les obligeant à gérer leur interdépendance à l’aide de ressources limitées pour communiquer. Sur la base d’entretiens recueillis en simulation de conduite, on montre que le pronostic du comportement d’autrui se construit sur des indices issus de re...

  3. Comportement alimentaire, quantités ingérées et performances des bovins conduits en groupe

    OpenAIRE

    Ingrand, Stéphane

    2000-01-01

    La hiérarchie sociale et les effets d’entraînement sont deux composantes importantes du comportement social qui influencent fortement le niveau d’ingestion et le comportement alimentaire des bovins conduits en groupe. Cet effet se traduit pour des animaux à besoins nutritionnels élevés (animaux laitiers ou en croissance) par des niveaux d’ingestion supérieurs et une moindre efficacité alimentaire par rapport à des situations où les animaux sont alimentés individuellement (à l’attache ou en bo...

  4. Analyse du comportement thermodynamique pour deux systèmes de chauffage solaire – murs échangeurs de chaleur

    OpenAIRE

    Grigoraş, Cătălin; Mateescu, Theodor; Cherecheş, Nelu-Cristian

    2011-01-01

    Le but de ce travail est d’effectuer une nouvelle recherche dans le domaine du chauffage solaire passif et actif an étudiant le comportement thermodynamique de deux types de murs capteurs solaires et en même temps d’essayer d’encourager l’étude et la construction de maisons qui utilisent l’énergie solaire.

  5. Évaluation de la qualité des comportements des agents en simulation : application à un simulateur de conduite en environnement virtuel

    OpenAIRE

    DARTY, Kevin

    2015-01-01

    Cette thèse se situe dans le contexte de la Simulation Multi-Agents et s'intéresse à l'évaluation de la capacité des agents à reproduire individuellement des comportements humains. Les comportements que nous considérons sont dits 'de haut niveau', par opposition aux comportements moteurs ou réflexes. Cette problématique se retrouve dans de nombreux domaines avec la Réalité Virtuelle, les Agents Conversationnels Animés, les agents d'un simulateur immersif, les jeux. L'approche dominante pour é...

  6. Évaluation de la qualité des comportements des agents en simulation : application à un simulateur de conduite en environnement virtuel

    OpenAIRE

    Darty, Kévin

    2015-01-01

    Cette thèse se situe dans le contexte de la Simulation Multi-Agent et s'intéresse à l'évaluation de la capacité des agents à reproduire individuellement des comportements humains. Les comportements que nous considérons sont dits "de haut niveau", par opposition aux comportements moteurs ou réflexes. Cette problématique se retrouve dans de nombreux domaines avec la Réalité Virtuelle, les Agents Conversationnels Animés, les agents d'un simulateur immersif, les jeux. L'approche dominante pour év...

  7. Comportement en flexion des bétons fibrés sous chargement cyclique

    OpenAIRE

    Boulekbache Bensaid; Hamrat Mostefa; Chemrouk Mohamed; Amziane Sofiane

    2014-01-01

    Ce papier présente les résultats d’une étude expérimentale sur le comportement en flexion des bétons de fibres métalliques. On étudie l’effet de la rhéologie du béton sur l’orientation des fibres et l’influence de l’orientation sur les propriétés mécaniques. La rigidité de l’ancrage des fibres étudiée par les essais cycliques est liée aux caractéristiques rhéologiques et mécaniques de la matrice. Les résultats montrent que la fluidité des bétons est un paramètre essentiel de l’orientation des...

  8. Comportement cyclique du loess non saturé du Nord de France

    OpenAIRE

    KARAM, JP; CUI, YJ; TERPEREAU, JM; MARCHADIER, G

    2006-01-01

    Pour mieux comprendre le comportement de certains horizons de loess rencontrés sur la ligne du TGV Nord entre Paris et Lille, des essais de chargement cycliques à hautes fréquences ont été réalisés sur le loess prélevé à côté de la ligne du TGV. L'accent a été mis sur l'effet de la teneur en eau et de la fréquence. La modification de la microstructure a été étudié après le chargement à l'aide de la technique de porosimétrie au mercure.

  9. Etude de l'influence des granulats recyclés sur le comportement des MBE

    OpenAIRE

    TAHAR, Zine el abidine; KADRI, El-Hadj; NGO, Tien-Tung; BOUVET, Adrien; KACI, Abdelhak; Aggoun, Salima

    2015-01-01

    International audience L'élargissement de l'utilisation des matériaux cimentaires comportant des granulats recyclés, dont les propriétés physico-chimiques sont différentes de ceux à base de granulats naturels, est inévitablement cautionné par une maitrise accrue, d'une part, de leurs propriétés mécaniques, d'autre part, de leur mise en œuvre. Afin d'optimiser ces derniers, l'étude menée porte principalement sur l'impact de la nature et du dosage en granulats recyclés sur la mise en œuvre e...

  10. Analyse par le calcul des structures du comportement cyclique à long terme des infrastructures de transport

    OpenAIRE

    Abdelkrim, Malek

    2004-01-01

    Dans le contexte de l'ingénierie du transport, ce travail est consacré à l'étude du comportement cyclique à long terme des infrastructures (voie ferrée, chaussées routières, ...). Ces dernières sont sujettes à des chargements de trafic qui provoquent des dégradations importantes (défauts de voies ferrées et orniérage des chaussées) ayant pour conséquence des problèmes d'exploitation, de confort et de sécurité des usagers. Les campagnes de maintenance étant coûteuses, il en résulte la nécessit...

  11. Analyse et validation d'un modèle de comportement directionnel des outils de forage monobloc pdc

    OpenAIRE

    Menand, Stéphane

    2001-01-01

    La prédiction du comportement directionnel d'un système de forage nécessite d'établir un modèle de comportement directionnel de l'outil de forage. Par une approche cinématique et sur la base d'une simplification de la structure de coupe de l'outil, le modèle élaboré aboutit à une loi reliant les efforts moyens exercés sur l'outil au déplacement de ce dernier. Chaque partie de l'outil, à savoir, la structure de coupe, la garde active et la garde passive, a une influence distincte sur le compor...

  12. Espace de comportement et espace microgéographique: le jeu de la «Révolution Verte»

    Directory of Open Access Journals (Sweden)

    Peter GOULD

    1987-03-01

    Full Text Available Les relations bidimensionnelles sont examinées entre les joueurs dans l'espace microgéographique de la salle de jeu et dans l'espace de comportement engendré par les interactions qu'ils perçoivent. Les asymétries sont interprétées comme étant des «vents de pauvreté» et des effets de comportement antisocial. L'analyse cartographique combinée à la multidimensionnalité et à la régression euclidienne crée des intuitions sur de simples relations structurelles qui restent à examiner.

  13. Comportement des articulations costo-vertébrales lors du chargement frontal quasi-statique de la cage thoracique

    OpenAIRE

    Eckert, Martine

    2001-01-01

    Afin d'améliorer le réalisme d'un modèle mathématique destine à simuler le comportement au choc du thorax humain, l'objectif de ce travail était de caractériser expérimentalement le comportement cinématique des articulations costo-vertébrales lorsque la cage thoracique dans son ensemble est soumise a des compressions au niveau du sternum. Des essais de compression quasi-statique ont été réalises sur cages thoraciques éviscérées de sujets d'anatomie. L'axe de rotation des cotes 3, 5 et 7 par r...

  14. LES COMPORTEMENTS DE NUPTIALITÉ DE L'ÎLE-DE-FRANCE ANTICIPENT-ILS CEUX DE LA FRANCE ?

    OpenAIRE

    Dumont, Gérard-François

    1993-01-01

    L'étude des comportements de nuptialité dans la région française la plus urbaine – l'Ile-de-France – et dans la France dans son ensemble met en évidence des différences notables. Cependant, lorsqu'on analyse cinq facteurs, ces différences paraissent correspondre plus à des décalages temporels qu'à des diversités réelles.

  15. Comportement en flexion des bétons fibrés sous chargement cyclique

    Directory of Open Access Journals (Sweden)

    Boulekbache Bensaid

    2014-04-01

    Full Text Available Ce papier présente les résultats d’une étude expérimentale sur le comportement en flexion des bétons de fibres métalliques. On étudie l’effet de la rhéologie du béton sur l’orientation des fibres et l’influence de l’orientation sur les propriétés mécaniques. La rigidité de l’ancrage des fibres étudiée par les essais cycliques est liée aux caractéristiques rhéologiques et mécaniques de la matrice. Les résultats montrent que la fluidité des bétons est un paramètre essentiel de l’orientation des fibres. Dès lors que l’on obtient une orientation dans le sens de l’efficacité mécanique, la résistance à la flexion est nettement améliorée.

  16. Etude du processus de changement vecu par des familles ayant decide d'adopter volontairement des comportements d'attenuation des changements climatiques

    Science.gov (United States)

    Leger, Michel T.

    Les activites humaines energivores telles l'utilisation intensive de l'automobile, la surconsommation de biens et l'usage excessif d'electricite contribuent aux changements climatiques et autres problemes environnementaux. Bien que plusieurs recherches rapportent que l'etre humain est de plus en plus conscient de ses impacts sur le climat de la planete, ces memes recherches indiquent qu'en general, les gens continuent a se comporter de facon non ecologique. Que ce soit a l'ecole ou dans la communaute, plusieurs chercheurs en education relative a l'environnement estiment qu'une personne bien intentionnee est capable d'adopter des comportements plus respectueux de l'environnement. Le but de cette these etait de comprendre le processus d'integration de comportements d'attenuation des changements climatiques dans des familles. A cette fin, nous nous sommes fixe deux objectifs : 1) decrire les competences et les procedes qui favorisent l'adoption de comportements d'attenuation des changements climatiques dans des familles et 2) decrire les facteurs et les dynamiques familiales qui facilitent et limitent l'adoption de comportements d'attenuation des changements climatiques dans des familles. Des familles ont ete invitees a essayer des comportements personnels et collectifs d'attenuation des changements climatiques de sorte a integrer des modes de vie plus ecologiques. Sur une periode de huit mois, nous avons suivi leur experience de changement afin de mieux comprendre comment se produit le processus de changement dans des familles qui decident volontairement d'adopter des comportements d'attenuation des changements climatiques. Apres leur avoir fourni quelques connaissances de base sur les changements climatiques, nous avons observe le vecu de changement des familles durant huit mois d'essais a l'aide de journaux reflexifs, d'entretiens d'explicitation et du journal du chercheur. La these comporte trois articles scientifiques. Dans le premier article, nous presentons une

  17. Caractérisation et comportement sous irradiation de phases powellites dopées terres rares – Application au comportement à long terme des matrices de confinement des déchets nucléaires.

    OpenAIRE

    Mendoza, Clément

    2010-01-01

    Ce travail porte sur le comportement sous irradiation d'une vitrocéramique élaborée par traitement thermique d'une version riche en molybdène du verre de confinent de déchets nucléaires R7/T7 et plus particulièrement de la phase cristalline. Des terres rares (Nd3+ et Eu3+) sont utilisées à la fois comme simulants des produits de fission et des actinides mineurs et comme sondes structurales luminescentes. La phase cristalline présente dans ce type de vitrocéramique est un molybdate de calcium ...

  18. Caractérisation et comportement sous irradiation de phases powellites dopées terres rares : applications au comportement à long terme de matrices de confinement de déchets nucléaires

    OpenAIRE

    Mendoza, Clément

    2010-01-01

    Ce travail porte sur le comportement sous irradiation d'une vitrocéramique élaborée par traitement thermique d'une version riche en molybdène du verre de confinement de déchets nucléaires R7/T7 et plus particulièrement de la phase cristalline. Des terres rares (Nd3+ et Eu3+) sont utilisées à la fois comme simulants des produits de fission et des actinides mineurs et comme sondes structurales luminescentes. La phase cristalline présente dans ce type de vitrocéramique est un molybdate de calciu...

  19. Mesures thermiques des flux de seve et comportement hydrique des arbres. II. Evolution dans le temps des flux de seve et comportement hydrique des arbres en presence ou non d'une irrigation localisee

    OpenAIRE

    Cabibel, B; Do, F

    1991-01-01

    La mesure thermique des flux de sève dans les troncs et les racines de pommiers est utilisée pour caractériser les comportements relatifs d’arbres soumis ou non à une irrigation localisée. On estime leurs transpirations horaires et journalières et appréhende le fonctionnement hydrique des diverses composantes de leur systèmes racinaires. L’étude des cinétiques des flux, mesurées dans les troncs, permet de mettre en évidence l’apparition, dans le temps, d’un stress hydrique dans les arbres...

  20. Modélisation robuste du comportement dynamique d'un système non linéaire frottant

    OpenAIRE

    Ragot, Pascal; Berger, Sébastien; Aubry, Evelyne

    2010-01-01

    Ce travail présente l'étude du comportement dynamique d'un système soumis à des instabilités de type Sprag-Slip générées par du frottement. La mise en équation de ce système conduit à un système d'équations différentielles non linéaire. Dans un premier temps, une approche déterministe du comportement est réalisée : la résolution classique de ces équations différentielles permet de déterminer le comportement dynamique du système étudié, ainsi que sa sensibilité aux différents paramètres. Dans ...

  1. Traitement des ambiances lumineuses, sensibilité perceptive et incidences sur le comportement dans un espace social

    OpenAIRE

    Bernstein, Daniel

    2005-01-01

    Un aspect original réside dans la connexion des domaines de la psychologie cognitive, de la psychologie de l'environnement et de l'éclairage autour de la question: le comportement dans un espace social, est-il affecté (et comment) par les ambiances lumineuses et par la sensibilité perceptive des usagers ? Actuellement, dans la grande majorité des cas, les travaux existants, dans le domaine des ambiances des bâtiments, considèrent le sujet comme un personnage moyen. D'autre part, les travaux d...

  2. Formalisation et gestion des connaissances dans la modélisation du comportement des incendies de forêt

    OpenAIRE

    Napoli, Aldo

    2001-01-01

    Nous proposons de traiter dans cette thèse, une partie du vaste domaine de la recherche dans le domaine des incendies de forêt. Nous nous intéressons plus particulièrement à la formalisation des connaissances (structuration des connaissances et de leurs interrelations) pour l'analyse du comportement des feux de forêt et plus précisément pour la modélisation de la vitesse de propagation d'un front de flammes. Le système incendie de forêt, de par sa complexité, doit être appréhendé par une déma...

  3. Interaction dynamique sol-structure : influence de non linéarités de comportement du sol

    OpenAIRE

    Gandomzadeh, Ali

    2011-01-01

    L'interaction dynamique sol-structure a été largement explorée en supposant le comportement linéaire du sol. Néanmoins, pour des séismes d'intensité modérée à forte, la contrainte de cisaillement maximale peut facilement atteindre la limite élastique du sol. Du point de vue de l'interaction sol-structure, les effets non linéaires peuvent modifier la rigidité du sol à la base de la structure ainsi que la quantité d'énergie dissipée dans le sol. En conséquence, ignorer les caractéristiques non ...

  4. Caractérisation et effet de l'anisotropie sur le comportement de sols reconstitués

    OpenAIRE

    NGUYEN THANH, Loc; Szymkiewicz, Fabien; Reiffsteck, Philippe; Bourgeois, Emmanuel; Mestat, Philippe

    2011-01-01

    L'anisotropie du comportement des sols peut être déterminante pour prévoir la réponse d'un massif de sol en interaction avec un ouvrage de génie civil. Une démarche d'observation et de mise en évidence de l'anisotropie a été mise en oeuvre afin de cerner l'influence de ce phénomène. Deux types principaux d'anisotropie des sols ont été étudiés : l'anisotropie induite, qui est celle des sols initialement homogènes et isotropes ayant subi des surcharges historiques, et l'anisotropie inhérente, q...

  5. Comportement du sol au labour : évolution de l’état structural au cours du labour

    OpenAIRE

    Coulomb, I; Caneill, J.; Manichon, H

    1993-01-01

    Le rôle de l’état initial du sol vis-à-vis des processus de fragmentation par la charrue à socs est étudié expérimentalement en sol limono-argileux à comportement fragile. À cet effet, on compare les évolutions de trois états structuraux initiaux différents au cours du labour. Après discussion de la compatibilité des volumes de sol caractérisés avant et après labour, qui doivent être représentatifs du volume de sol réellement travaillé par la charrue, l’évolution de l’état structural du sol e...

  6. Étude du comportement thermique et sous irradiation du xénon dans l'oxycarbure de zirconium

    OpenAIRE

    Gutierrez, Gaëlle

    2011-01-01

    Les réacteurs GEN IV (GFR) nécessitent l'emploi de matériaux d'enrobage ayant une bonne transparence aux neutrons, une conductivité thermique élevée et agissant comme barrière de diffusion pour les produits de fission. Le but de cette étude est de déterminer le rôle de la température et de l'irradiation sur le comportement du xénon implanté dans l'oxycarbure de zirconium (ZrCxOy). A cet effet, des poudres de deux stoechiométries ZrC0,95O0,05 et ZrC0,8O0,2 ont été synthétisées puis frittées pa...

  7. Comportement thermo-hydro-mécanique et microstructure de l'argilite du Callovo-Oxfordien

    OpenAIRE

    Menaceur, Hamza

    2014-01-01

    Le développement de l'énergie nucléaire durant les dernières années nécessite de trouver des solutions pour le stockage et le confinement des déchets radioactifs. Une solution envisagée est l'enfouissement dans les formations argileuses peu perméables comme les argilites. Dans cette perspective, l'Andra a mis l'accent sur l'étude du comportement à court et à long terme de l'argilite du Callovo-Oxfordien (COx), considérée comme une roche hôte potentielle en France. Dans le cadre de ce projet, ...

  8. Evaluation environnementale du comportement d'un laitier LD utilisé en infrastructure routière

    OpenAIRE

    Legret, Michel

    2011-01-01

    Ce rapport présente les principaux résultats obtenus dans le cadre du projet ECLAIR, coordonné par le LCPC et financé par le programme « Écotechnologies et Développement Durable - PRECODD » de l'ANR. Ces recherches ont été dédiées au comportement environnemental d'un laitier d'aciérie de conversion valorisé dans un scénario de sous-couche routière grâce à une approche intégrée. L'étude a principalement concerné les éléments traces métalliques contenus dans les phases minérales des la...

  9. Evaluation environnementale du comportement d'un laitier LD utilisé en infrastucture routière

    OpenAIRE

    Legret, Michel; INSTITUT FRANCAIS DES SCIENCES ET TECHNOLOGIES DES TRANSPORTS, DE L'AMENAGEMENT ET DES RESEAUX - IFSTTAR

    2011-01-01

    Ce rapport présente les principaux résultats obtenus dans le cadre du projet ECLAIR, coordonné par le LCPC et financé par le programme «Ecotechnologies et Développement Durable -PRECODD» de l'ANR. Ces recherches ont été dédiées au comportement environnemental d'un laitier d'aciérie de conversion valorisé dans un scénario de sous-couche routière grâce à une approche intégrée. L'étude a principalement concerné les éléments traces métalliques contenus dans les phases minérales des laitiers et le...

  10. Modélisation des organisations sociales : analyse structurelle, régulation des comportements et évolution

    OpenAIRE

    Chapron, Paul

    2012-01-01

    Le travail présenté dans ce mémoire s'inscrit dans le cadre du projet SocLab, qui propose une formalisation de la sociologie de l'action organisée (SAO). Cette formalisation repose sur un méta-modèle de la structure des organisations sociales, à partir duquel il est possible de développer une étude analytique des propriétés d'une organisation et de simuler les comportements que les acteurs sont susceptibles d'adopter. On est alors en mesure de réaliser un diagnostique organisationnel qui, s'i...

  11. Smectite alteration

    International Nuclear Information System (INIS)

    This report contains the proceedings of a second workshop in Washington DC December 8-9, 1983 on the alteration of smectites intended for use as buffer materials in the long-term containment of nuclear wastes. It includes extended summaries of all presentations and a transcript of the detailed scientific discussion. The discussions centered on three main questions: What is the prerequisite for and what is the precise mechanism by which smectite clays may be altered to illite. What are likly sources of potassium with respect to the KBS project. Is it likely that the conversion of smectite to illite will be of importance in the 10 5 to the 10 6 year time frame. The workshop was convened to review considerations and conclusions in connection to these questions and also to broaden the discussion to consider the use of smectite clays as buffer materials for similar applications in different geographical and geological settings. SKBF/KBS technical report 83-03 contains the proceedings from the first workshop on these matters that was held at the State University of New York, Buffalo May 26-27, 1982. (Author)

  12. La force de l'attitude : quelle modération de la relation entre attitude, intention d'achat et comportement ?

    OpenAIRE

    Bressoud, Etienne

    2008-01-01

    La force de l'attitude est définie comme une dimension non évaluative de l'attitude qui modère le lien direct entre attitude et comportement. Son rôle modérateur est étudié dans cette recherche qui retient un cadre conceptuel qui lie attitude et comportement par l'intermédiaire de l'intention d'achat. Une synthèse des travaux relatifs à la force de l'attitude permet la clarification d'un construit aux multiples opérationnalisations et justifie une conceptualisation fondée sur l'expérience dir...

  13. Inégalités sociales des comportements de santé : l'herbe est-elle plus verte ailleurs ?

    OpenAIRE

    Devaux, Marion

    2014-01-01

    Cette thèse traite des inégalités sociales en matière de comportements de santé tels que les modes de vie liés à la santé (spécifiquement, l’obésité et la consommation d’alcool) et l’utilisation des services de santé, dans plusieurs pays de l’OCDE. Ce travail repose sur une approche micro-Économétrique et utilise un grand nombre de bases de données nationales. Les objectifs de cette thèse sont de: (1) comparer les inégalités sociales de comportements de santé entre des pays ayant des caractér...

  14. Identification d'un modèle de comportement thermique de bâtiment à partir de sa courbe de charge

    OpenAIRE

    Zayane, Chadia

    2011-01-01

    Dans un contexte de préoccupation accrue d'économie d'énergie, l'intérêt que présente le développement de stratégies visant à minimiser la consommation d'un bâtiment n'est plus à démontrer. Que ces stratégies consistent à recommander l'isolation des parois, à améliorer la gestion du chauffage ou à préconiser certains comportements de l'usager, une démarche préalable d'identification du comportement thermique de bâtiment s'avère inévitable.Contrairement aux études existantes, la démarche menée...

  15. De l'intention d'achat au comportement : essais de modélisations incluant variables attitudinales, intra-personnelles et situationnelles

    OpenAIRE

    Bressoud, Etienne

    2001-01-01

    Les recherches en psychologie étudient le lien entre l'attitude et le comportement. Parallèlement, les chercheurs en marketing s'intéressent à cette même relation dans un contexte d'achat, en introduisant l'intention en tant que variable médiatrice. Une réelle distinction entre intention et comportement reste pourtant rare, d'où l'objet de cette recherche qui réside dans la volonté de mettre au jour les conditions de validité du lien entre ces deux concepts.Cet objectif amène à prendre en com...

  16. Étude du comportement interne de l’abdomen lors d’un impact : observations par échographie ultrarapide

    OpenAIRE

    HELFENSTEIN, Clémentine

    2013-01-01

    À cause de difficultés d’observations, les recherches passées en biomécanique de l’abdomen soumis aux chocs se sont essentiellement limitées à la description de comportements externes. Cette étude s’intéresse au comportement interne d’organes abdominaux à l’aide de techniques récentes : l’échographie ultrarapide et l’élastographie par ondes de cisaillement. Tout d’abord, l’effet de conditions de perfusion sur la géométrie et le module de cisaillement interne de reins de porc ex vivo a été éva...

  17. Behaviour of an irradiated photomultiplier; Etude du comportement d'un photomultiplicateur sous rayonnements nucleaires

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-04-15

    transitoires, le controle ou la s ete d'un reacteur nucleaire ou d'un assemblage critique, nous avons etudie le comportement de 8 photomultiplicateurs Radiotechnique 51 AVP et UVP et EMI 9 524 B dans le flux gamma d'un puits de stockage de 1 a 10{sup 3} Rh{sup -1} et dans un canal de pile a EL 2 ou le domaine d'exposition variait de 1 a 2. 10{sup 3} Rh{sup -1} et 6. 10{sup 5} a 5. 10{sup 7} n.cm{sup -2}.s{sup -1}. Des impulsions parasites a l'anode du photomultiplicateur sont produites par ces rayonnements. En comparant les amplitudes de ces impulsions a celles delivrees par un scintillateur NaI, on a constate que leur niveau maximal etait d'une centaine de keV a 10{sup 3} Rh{sup -1} dans le flux gamma du puits de stockage, et de 200 a 400 keV a 10{sup 3} Rh{sup -1} et 10{sup 7} n.cm{sup -2}.s{sup -1} dans le canal de pile. D'autre part, la detection d'une impulsion lumineuse de reference, correspondant a 200 keV (NaI) n'est perturbee qu'au dela de quelques centaines de Rh{sup -1} par le rayonnement {gamma} seul, et de 5. 10{sup 6} n.cm{sup -2} s{sup -1} et {approx}500 Rh{sup -1} dans le canal de pile. La dispersion de ces resultats est de l'ordre de 2 pour les 8 tubes eprouves. Nous attribuons a l'effet Cerenkov dans la fenetre du photomultiplicateur, la part principale des effets du rayonnement {gamma}. La discrimination des effets respectifs des neutrons et du rayonnement {gamma} est abordee. Nous n'avons pas constate d'evolution sensible des parametres des photomultiplicateurs etudies, pendant les expositions. Leurs caracteristiques n'ont pas ete modifiees par les doses recues dont le maximum etait de 4.10{sup 12} neutrons.cm{sup 2} et {approx_equal} 3. 10{sup 4} roentgens. L'interet de l'emploi de photomultiplicateurs et circuits rapides, pour reculer les limites d'emploi des photomultiplicateurs sous rayonnements est souligne. (auteur)

  18. Time-scales of erosion and weathering processes in the Himalayan river system: Element and isotope approach using the U-series; Constantes de temps des processus d'erosion et d'alteration dans le systeme himalayen: approche geochimique elementaire et isotopique par les series de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Granet, M

    2007-06-15

    The time-scales of erosion and weathering processes are key parameters which need to be determined to understand the response of the reliefs to external forcing like tectonics, climate and human activities. They were recovered by using U-series nuclides analyzed in sediments and suspended materials carried by the Himalayan rivers of the Ganges and Brahmaputra basins. In the Ganges basin, the time-scales of weathering determined from the study of coarse sediments carried by the Kali Gandaki range from several ky, where the uplift is located, to 350 ky. Such values indicate that the bed-rocks are in situ weathered for a long period before the weathering residual products get transported in the rivers as coarse sediments. At the outlet of the high range, these sediments are carried by the tributaries of the Ganges, the Gandak and Ghaghara, during a transfer period of about 100 ka. The study of the sediments at the outlet of the Brahmaputra tributaries allows to propose time-scales of weathering ranging from 110 to 270 ky. Such long periods confirm that during their transfer in the plains, the sediments are temporarily trapped at several places in the basins. In the Ganges and Brahmaputra rivers, the time-scales of sedimentary transfer are 575 and 160 ky, respectively. These values, which are of the same order as their response times, are much longer than the timescales of the Quaternary climate oscillations. It confirms the buffering action of the asiatic alluvial plains for the high-frequency sediment flux variations in response to external forcing in the chain. The study of suspended materials suggests that their chemical compositions result from the mixing of coarse river sediments with fine particles from various locations in the basin which are affected by vegetation recycling. By contrast to coarse sediments, the time-scales of transfer for the suspended materials are fast, e.g. a few ky, pointing the potential of U-series nuclides to assess particle transport laws as a function of their size. (author)

  19. Simulation multi-échelle du skin-pass des aciers IF : Prédiction de la texture de déformation et du comportement mécanique

    OpenAIRE

    SOHO, Komi; LEMOINE, Xavier; Abed-Meraim, Farid; ZAHROUNI, Hamid

    2015-01-01

    L’objectif principal de cette étude est de prédire la texture la texture de déformation et le comportement mécanique des aciers IF au cours du procédé de laminage des produits plats à faible taux de réduction. Un modèle basé sur l’homogénéisation autocohérente du comportement élastoplastique du monocristal est adopté pour modéliser le comportement de l’acier. Afin de réduire les temps de calcul dans la simulation multi-échelle, une procédure simplifiée est adoptée pour coupler le code de simu...

  20. Analyse expérimentale du comportement au cisaillement des murs en maçonnerie de pierre renforcés par matériaux composites TRC & NSM FRP

    OpenAIRE

    GHARIB, Turath; Gabor, Aron; FERRIER, Emmanuel

    2015-01-01

    International audience Cette étude concerne l'étude du renforcement de structure en pierre par matériaux composites. Une première phase concerne la caractérisation des matériaux et l'analyse des comportements mécanique de petits éléments de maçonnerie. Les comportements en compression, sont déterminés pour des éprouvettes de maçonnerie soumis en compression uni-axiale perpendiculaires aux joints horizontaux. Les comportements de cisaillement de maçonnerie ont été étudiés sur des éprouvette...

  1. Détermination des paramètres non linéaires constitutifs de lois de comportement viscoélastique par mesures de champ dans des écoulements complexes

    OpenAIRE

    Boukellal, Ghalia

    2010-01-01

    Les modèles de comportement issus des théories "moléculaires" permettent de faire le lien entre structure moléculaire et comportement dans des écoulements rhéométriques. Cependant, ces modèles peuvent être mis en défaut dès que l'écoulement est complexe ou fortement non-linéaire. Dans cette thèse, nous avons présenté des résultats expérimentaux permettant d'identifier les paramètres non linéaires constitutifs de ces lois de comportement viscoélastique pour les polymères fondus, en utilisant d...

  2. Comportement du sol au labour : methode d'analyse et evaluation des consequences de l'etat initial du sol sur l'etat transforme par le labour

    OpenAIRE

    Coulomb, I.; Caneill, J; Manichon, H

    1993-01-01

    Nous étudions expérimentalement l’effet de l’état structural de la couche labourée avant labour sur son état après labour, en sol limono-argileux dans le domaine hydrique de comportement fragile du sol. Nous comparons deux traitements caractérisés par des états avant labour continus et compacts induits par compactage ou fragmentaires. On distingue deux types d’états compactés en fonction de la date de tassement (1 semaine avant labour, 1 mois avant labour). Trois classes de vitesses de labour...

  3. 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...

  4. Influence des conditions de soudage sur le comportement en fatigue d'un acier THR Dual Phase soudé par point

    OpenAIRE

    Rossillon, Frédérique

    2007-01-01

    Les principaux modèles de comportement en fatigue des assemblages soudés par point ne prennent en compte que des paramètres géométriques. Or, les contraintes résiduelles, la microstructure de la Zone Affectée Thermiquement et la forme du fond d'entaille sont, a priori, autant de facteurs d'influence supplémentaires. L'objectif de ce travail est la compréhension des facteurs prédominants de la tenue en fatigue des assemblages soudés par point en acier THR, afin de proposer des conditions de so...

  5. Une méthode d'identification en dynamique des structures basée sur le filtre de Kalman et l'erreur en relation de comportement

    OpenAIRE

    Alarcon, Albert; Bodel, Charles; Bonnet, Marc

    2011-01-01

    National audience Ce travail est issu de la problématique industrielle d'EDF autour du comportement dynamique des structures en présence de méconnaissances de modèle. On propose une méthode basée sur l'utilisation conjointe du filtre de Kalman Unscented et de l'erreur en relation de comportement pour localiser et identifier les paramètres structuraux permettant de mieux représenter des mesures physiques. Un exemple numérique d'une poutre en béton contenant à la fois de l'endomma...

  6. Croyances et comportements de sécurité des usagers et agents du trafic routier : une étude des perceptions et de l'explication naïve des accidents de la route au Cameroun.

    OpenAIRE

    Ngueutsa, Robert,

    2012-01-01

    La présente thèse envisage de cerner les comportements des Camerounais sur les routes.En l’occurrence, nous voulons savoir comment les croyances fatalistes, les croyances decontrôle, les croyances au contrôle divin, les croyances et valeurs culturelles, l’explicationnaïve des accidents et la perception du risque peuvent affecter les comportements des usagerset agents du trafic routier au Cameroun. Cinq études sont réalisées dans le cadre de notrethèse. La première étude examine 522 procès-ver...

  7. Comportement mécanique des cavités dans le sel. Etat actuel de nos connaissances Mechanical Behaviour of Salt Cavities. Present State of Our Knowledge

    Directory of Open Access Journals (Sweden)

    Boucly P.

    2006-11-01

    Full Text Available L'utilisation depuis dix ans des premières cavités salines créées sur le site de Tersanne s'est accompagnée d'une réduction de leur volume relativement importante. Cette observation a conduit le Gaz de France à développer d'importantes études sur le comportement rhéologique du sel dans lequel sont creusées les cavités. Ces études, effectuées en collaboration avec des laboratoires universitaires, ont consisté en de nombreux essais en laboratoire (essais de longue durée à la température des terrains visant à déterminer les lois de comportement du matériau. Parallèlement, des modèles de calcul de divers degrés de complexité ont été élaborés afin de prendre en compte ces lois dans l'estimation de la stabilité et de la tenue à long terme de la cavité. Ces études ont abouti récemment à la mise au point d'un premier modèle de comportement du sel qui rend compte de l'ensemble des observations effectuées à ce jour sur les cavités. Grâce à ce modèle, il est maintenant possible d'étudier quelle influence a sur leur volume un type d'utilisation donné des cavités. The exploitation over the last ten years of the first salt cavities created in the Tersanne area has resulted in a relatively large decrease in their volume. This observation led Gaz de France to do extensive research on the rheological behavior of the salt into which cavities are leached. This research, performed in cooperation with university laboratories, consisted of numerous laboratory tests (long-duration tests at formation temperatures to determine the behavior laws of the material. At the same time, models for computing different degrees of complexity were developed to take these laws into account in evaluating the stability and long-term resistance of the cavity. This research has recently resulted in the development of an initial salt-behavior model involving all the observations made concerning these cavities to date. This model can now be

  8. Le rôle du comportement des banques dans la libéralisation financière : le cas du Malawi, 1987-1999

    OpenAIRE

    Mlachila, Montfort

    2013-01-01

    Notre étude a été inspirée par l’observation que malgré les efforts considérables en matière de la libéralisation financière au Malawi à partir de la fin des années 1980, les résultats apparents étaient plutôt médiocres, notamment en ce qui concerne la persistance de marges d’intermédiation (spreads) élevés. L’objectif central de notre travail est d’essayer d’élucider pourquoi. Notre hypothèse centrale est que si l’on ne tient pas compte du comportement des banques en matière de leurs réactio...

  9. Rapport d'évaluation : Compte rendu sur le comportement du procédé ECOMIX, pour le comité IVOR

    OpenAIRE

    Brosseaud, Yves; LABORATOIRE CENTRAL DES PONTS ET CHAUSSEES - LCPC

    2005-01-01

    Le comité IVOR a confié au LCPC la mission d'évaluer les capacités du procédé ECOMIX à répondre aux exigences d'une application en couche de roulement sur chaussée à trafic moyen ou modéré, selon les mêmes attentes que celles plus traditionnelles des enrobés à chaud. Ce compte-rendu constitue la synthèse des évaluations réalisées. Il doit permettre au comité de porter un jugement sur le produit en prenant en compte les considérations techniques et avis sur le comportement du procédé. COMP...

  10. Analyse expérimentale du comportement biomécanique de deux types d'implants d'ostéosynthèse

    OpenAIRE

    Gómez Clemente, Raquel

    2010-01-01

    Ce projet s´inscrit dans une étude sur l´analyse du comportement biomécanique de deux types d´implants d´ostéosynthèse des fractures condyliennes latérales du coude chez le chien. Il est en relation avec l´entreprise SYNTHES qui fabrique les vis qui vont être utilisées dans l´étude, et des vétérinaires. Ces deux types d´implants sont deux vis différentes, une pleine et une cannulée. Dans ce projet la problématique de l´étude, et la recherche bibliographique faite pour étudier des angles, posi...

  11. Premiers resultats experimentaux sur le comportement de Tabebuia heterophylla (DC) Britton et de Hymenaea courbaril L. vis-a vis de la secheresse

    OpenAIRE

    Huc, Roland

    1985-01-01

    Deux espèces de la forêt de basse altitude d’Amérique tropicale (Antilles), Tabebebuia heterophylla (poirier-pays) et Hymenaea courbaril (courbaril), se révèlent intéressantes pour le reboisement des régions les moins arrosées. Le comportement de ces espèces vis-à-vis de la sécheresse est étudié grâce à un traitement sous forme d’arrosage différencié appliqué à des jeunes plants âgés de 1 an, en pépinière. L'évolution de l’état hydrique des plants est suivie au cours de 6 mois d’expéri...

  12. Comportement en fatigue d'un BTHP dans des poutres mixtes préfléchies innovantes pour des ponts-rails

    OpenAIRE

    TOUTLEMONDE, F; STAQUET, S

    2007-01-01

    La validation expérimentale d'une extension possible de la technique des poutres mixtes préfléchies, développée en Belgique sous le nom de "Preflex", a été réalisée. Du béton à très hautes performances (C80/95) a été utilisé pour ses avantages potentiels de faibles effets différés et de résistance à la traction élevée. Il s'agissait notamment de valider le maintien du comportement de la section mixte des poutres même après un grand nombre de cycles de chargement représentatif des charges appl...

  13. Influence de la répartition granulométrique sur le comportement mécanique d'un sol

    OpenAIRE

    Reiffsteck, P.; NGUYEN PHAM, PT; ARBAUT, J

    2007-01-01

    La compréhension du comportement des sols hétérogènes impose de connaître l'influence de la distribution granulométrique sur les paramètres mécaniques. Les résultats d'essais effectués sur un sable et des billes de verre de quatre diamètres, mélangés en différentes proportions de manière à recréer une courbe granulométrique, sont présentés. Des mélanges de kaolinite et de sable de Fontainebleau ont été également étudiés afin d'évaluer l'influence des proportions en particules fines et grossiè...

  14. Etude du comportement d'agrégation des larves nécrophages de Diptères :de l'individuel au collectif

    OpenAIRE

    Boulay, Julien

    2015-01-01

    Le comportement d’agrégation est considéré comme le premier pas vers des niveaux de socialité supérieurs. La compréhension des facteurs clés permettant l’émergence des décisions collectives chez les groupes composés d’individus simples (ayant une connaissance limitée de leur environnement) est donc fondamentale pour étudier l’évolution de la socialité. A l’heure actuelle, la majorité des études se sont focalisées sur les espèces les plus sociales, et notamment celles formant des groupes monos...

  15. L’analyse par intervalles pour une prévision fiable du comportement des bâtiments : cas d’une paroi multicouche

    OpenAIRE

    Merheb, Rania; Mora, Laurent; PALOMO, Elena

    2012-01-01

    Ce papier vise à démontrer l’intérêt d’employer des méthodes basées sur l’analyse par intervalles pour étudier l’effet des incertitudes, liées aux paramètres d’entrée, sur le comportement des bâtiments. Le cas d’une paroi multicouche est étudié et 2 méthodes sont employées pour borner la fluctuation des températures et des flux internes. Une analyse des résultats nous mène à confirmer notre proposition. Nous obtenons des enveloppes peu pessimistes et de haut niveau de fiabilité avec cette ...

  16. Comportement thermique du xénon dans le nitrure de titane fritté matrice inerte d'intérêt des RNR-G

    OpenAIRE

    Bes, René

    2010-01-01

    Ce travail se place dans le cadre des réacteurs nucléaires de 4ème génération tels que les réacteurs à neutrons rapides et caloporteur gaz (RNR-G), pour lesquels des matériaux réfractaires comme le nitrure de titane (TiN) enroberont le combustible afin de permettre la rétention des produits de fission. Cette étude a porté sur le comportement thermique intragranulaire du xénon dans des échantillons de TiN obtenus par frittage à chaud sous charge. Le rôle de la microstructure sur le comportemen...

  17. Modèle numérique micro-mécanique d'agrégat polycristallin pour le comportement des combustibles oxydes

    OpenAIRE

    Pacull, Julien

    2011-01-01

    Dans les réacteurs nucléaires à eau sous-pression (REP), le combustible est constitué de pastilles d'oxyde d'uranium (UO2) empilées dans des tubes métalliques, l'ensemble constituant un crayon combustible. La simulation du comportement des crayons combustibles en situation nominale ou incidentelle nécessite d'avoir recours à une modélisation multi-échelle et multi-physique, les phénomènes modélisés étant regroupés en deux catégories : la thermo-mécanique et la physico-chimie relative au compo...

  18. Comportement thermique des défauts lacunaires induits par l’hélium et les gaz de fission dans le dioxyde d’uranium

    OpenAIRE

    Belhabib, Tayeb

    2012-01-01

    Dans les nouvelles centrales nucléaires dites 4ème génération, comme d’ailleurs les anciennes, le dioxyde d’uranium devra opérer dans des milieux hostiles de températures et d’irradiation avec la présence des produits de fission (PF) et des particules alpha (α). Le fonctionnement dans ces conditions extrêmes induira des déplacements d’atomes et dégradera les propriétés thermiques et mécaniques du combustible UO2. La compréhension du comportement des défauts lacunaires, des PF et de l’hélium e...

  19. Prévision du comportement des terrains sous l'influence des failles par méthodes numériques et microsismiques

    OpenAIRE

    Sylla, Mamoudou; Senfaute, Gloria; AL HEIB, Marwan; Derrien, Yves; Josien, Jean-Pierre

    1999-01-01

    Les exploitations souterraines provoquent un déséquilibre du massif rocheux suite aux vides créés par l'extraction du minerai. Les modifications du comportement du massif dépendent des contraintes naturelles, de la présence de failles et des conditions d'exploitation, en particulier de la géométrie des chantiers et de la méthode d'exploitation utilisée. Ainsi, les perturbations provoquées par l'exploitation vont entraîner un réajustement du milieu vers un autre régime d'équilibre. Ce nouveau ...

  20. Les comportements face au VIH/sida des hommes qui ont des relations sexuelles avec des hommes: résultats de Gaysurvey 2009

    OpenAIRE

    Lociciro Stéphanie; Jeannin André; Dubois-Arber Françoise

    2010-01-01

    Gaysurvey est une enquête menée périodiquement en Suisse parmi les hommes qui ont des relations sexuelles avec des hommes (HSH). Elle s'inscrit dans le dispositif de surveillance du VIH, établi par l'Office fédéral de la santé publique, en tant qu'instrument de suivi des comportements face au VIH/sida dans ce groupe-cible. Elle a déjà été réalisée à huit reprises. [Auteurs, p. 5] [Table des matières] 1. Résumé. 2. Zusammenfassung. 3. Introduction. 4. Méthodologie. 5. Résultats : Participation...

  1. Cuivre nanostructuré et nanopoudres de cuivre dope avec de l'argent pour l'étude du comportement thermo-mécanique

    OpenAIRE

    Duhamel, Cecilie

    2005-01-01

    A température ambiante, le cuivre métallique massif nanostructuré présente un comportement de type élasto-plastique quasi-parfait. Afin d'approfondir les connaissances sur la déformation plastique de ce matériau, nous en avons étudié les propriétés thermo-mécaniques par des essais de compression avec sauts de vitesse en température et des essais de relaxation à température ambiante. Deux paramètres sont mesurés à partir de ces essais : une sensibilité à la vitesse maximale élevée (m = 0,17), ...

  2. La qualité de l'eau de boisson à Richard-Toll : influence du comportement de l'utilisateur

    OpenAIRE

    Robidoux, L.; Ghedin, E.; Handschumacher, Pascal; Hébrard, Georges; Schmit, J.P.

    1998-01-01

    La ville de Richard-Toll offre sept types de points d'eau à sa population, allant du site ouvert non aménagé (fleuve) aux bornes offrant de l'eau canalisée. Les usagers y gèrent eux-mêmes leur réserve d'eau quotidienne. Pour évaluer l'effet du site d'approvisionnement et du comportement de l'usager sur la qualité de l'eau consommée, l'eau de 14 sites, représentant les sept types de points d'eau présents dans la ville, a été échantillonnée. De plus, quatre usagers ont été associés à chaque poi...

  3. Étude du comportement interne de l’abdomen lors d’un impact : observations par échographie ultrarapide

    OpenAIRE

    HELFENSTEIN, Clémentine

    2013-01-01

    La protection des usagers et la prévention des risques sont des enjeux majeurs de la sécurité routière. La conception des véhicules inclut un grand nombre d’éléments de sécurité passive qui ont pour rôle de minimiser les séquelles corporelles des usagers si l’impact se produit. L’objectif global de cette thèse est donc de mettre en place des protocoles d’essais et d’observer ces comportements internes grâce à une technique d’imagerie récente : l’échog...

  4. Étude du comportement interne de l’abdomen lors d’un impact : observations par échographie ultrarapide

    OpenAIRE

    HELFENSTEIN, Clémentine

    2013-01-01

    La protection des usagers et la prévention des risques sont des enjeux majeurs de la sécurité routière. La conception des véhicules inclut un grand nombre d’éléments de sécurité passive qui ont pour rôle de minimiser les séquelles corporelles des usagers si l’impact se produit. L’objectif global de cette thèse est donc de mettre en place des protocoles d’essais et d’observer ces comportements internes grâce à une technique d’imagerie récente : l’échographie ultrarapide. Une attention particul...

  5. Comportement biomécanique de la paroi abdominale et de ses composants musculaires : du specimen isolé au patient

    OpenAIRE

    TRAN, Doris

    2013-01-01

    Dans le but d’améliorer le traitement des éventrations, cette thèse porte sur la biomécanique de la paroi abdominale. Plusieurs aspects de son comportement ont été étudiés: de la paroi globale aux constituants, de la paroi passive ex vivo sous chargement contrôlé à la paroi active in vivo sous chargement physiologique et enfin de la paroi saine des volontaires non-malades à la paroi lésée des patients en pré-opératoire. Un protocole a été développé pour évaluer la contribution des compo...

  6. Comportement biomécanique de la paroi abdominale et de ses composants musculaires : du spécimen isolé au patient

    OpenAIRE

    TRAN, Doris

    2013-01-01

    Dans le but d’améliorer le traitement des éventrations, cette thèse porte sur la biomécanique de la paroi abdominale. Plusieurs aspects de son comportement ont été étudiés: de la paroi globale aux constituants, de la paroi passive ex vivo sous chargement contrôlé à la paroi active in vivo sous chargement physiologique et enfin de la paroi saine des volontaires non-malades à la paroi lésée des patients en pré-opératoire. Un protocole a été développé pour évaluer la contribution des composants ...

  7. Etude expérimentale et modélisation du comportement en fatigue multiaxiale d'un polymère renforcé pour application automobile

    OpenAIRE

    Klimkeit, Bert

    2009-01-01

    Cette thèse contribue à la compréhension du comportement en fatigue des thermoplastiques renforcés par des fibres de verre courtes. Deux différents matériaux sont étudiés : Un mélange de polybutylène téréphtalate et polyéthylène téréphtalate (PBT+PET GF30) et un polyamide 66 (PA66 GF35). Les enjeux scientifiques de la thèse concernent les chargements multiaxiaux, l'influence de la contrainte moyenne et l'orientation de fibres sur la tenue en fatigue. En outre, les mécanismes de rupture sont a...

  8. Modèle probabiliste de comportement et algorithme d'apprentissage par imitation pour les personnages crédibles dans les jeux vidéo

    OpenAIRE

    Tencé, Fabien

    2011-01-01

    Ce manuscrit cherche à concevoir un modèle de comportement pour le contrôle de personnages crédibles dans les jeux vidéo. Nous définissons un personnage crédible comme un programme informatique capable de contrôler une représentation virtuelle de façon à ce que des observateurs dans l'environnement virtuel pensent que la représentation est contrôlée par un humain. Nous établissons 10 critères plus précis pour établir notre thèse. Pour répondre à ces 10 critères nous avons étudié des modèles d...

  9. Etude du complexe épaule / membre supérieur. Lois de comportement en butées et modélisation cinématique

    OpenAIRE

    Malak, A.

    2003-01-01

    Dans le cadre de la protection des automobilistes, le but de la simulation est d'aboutir à un modèle prédictif des lésions de l'être humain quelle que soit la direction de la sollicitation. La modélisation se heurte à un certain nombre de difficultés liées à un manque de données biomécaniques concernant le complexe épaule / membre supérieur. L'objectif de ce travail était de déterminer des lois de comportement (efforts / déplacements) en butées et de proposer un modèle cinématique pour le com...

  10. Apprentissage de modèles de comportement pour le contrôle d'exécution et la planification robotique

    OpenAIRE

    Infantes, Guillaume

    2006-01-01

    Les systèmes robotiques autonomes évoluent dans des environnements fortement imprévisibles, et sont sujets à des très grandes imprécisions des capteurs et de leur connaissance en général. De fait, ils sont construits dans l'objectif de robustesse et non pas de fournir des modèles de leur comportement, qui sont nécessaires à la prise de décision de plus haut niveau, type planification ou contrôle d'exécution. Dans les applications actuelles, ils sont souvent très abstraits et simplifiés par ra...

  11. Mafia et comportements mafieux

    OpenAIRE

    Ghiloni, Jacques

    2011-01-01

    Dans le film Gomorra , consa-cré à la mafia napolitaine, on pouvait voir les rites initiatiques, la structuration hiérarchique et familiale du sous-prolétariat mafieux. On découvrait également les rapports d'intérêts qui reliaient la Camorra et l'économie capita-liste, au travers de l'enfouissement illégal des déchets industriels européens. Nous retrouvons dans ce numéro de la revue Illusio ces rites initiatiques, cette logique de domination, cette structuration familiale. Mais de manière plu...

  12. Les comportements alimentaires

    Directory of Open Access Journals (Sweden)

    Sabbagh Claire

    2012-09-01

    Full Text Available Although public policies have for many years spearheaded information campaigns about how eating affects health, rising obesity rates show that the expected effects have yet to be achieved. Why consumers do not practically comply with nutritional recommendations? This question lead the ministry in charge of Agriculture, Food and Fisheries to require in 2010 an updated state of knowledge for peer-reviewed literature and to commission INRA to undertake a collective scientific expertise on dietary behaviours. The aim was to investigate the multiple determinants of behaviours and how behaviours form and change in individuals according to social class and age, but also collectively over a long period of time. The expertise reports that the consumer is subjected to different environmental stimuli which can bias opinion and that dietary behavior can be affected by information strategies combining different tools and targeting individuals or specific groups. This article sets out the conclusions of the expertise report which draws on nearly 1,600 scientific articles from around the world and was prepared by some twenty experts from fields as diverse as epidemiology, nutrition, sociology and economics.

  13. Le comportement mécanique des risers. Influence des principaux paramètres Mechanical Behaviour of Marine Risers Mode of Influence of Principal Parameters

    Directory of Open Access Journals (Sweden)

    Sparks C.

    2006-11-01

    Full Text Available Cet article a pour but de déterminer les principaux paramètres qui gouvernent le comportement mécanique des risers de forage et de production, et d'expliquer pourquoi et comment ils interviennent. Une compréhension claire de ces influences permet d'optimiser rapidement un riser donné sans avoir recours à un grand nombre d'analyses par ordinateur. Celui qui conçoit un riser est principalement préoccupé par les points suivants : - niveaux de contraintes dans la partie courante du riser ; - mouvements angulaires à la base du riser (ou moments, dans le cas d'une liaison rigide ; - mouvements relatifs au niveau de la liaison plate-forme/riser. La méthode utilisée dans cet article consiste à établir des expressions analytiques valables pour des risers simplifiés. Les conclusions tirées de ces expressions ont ensuite été verifiéés à l'aide d'un programme de calcul capable de simuler le comportement dynamique d'un riser dans des configurations variées. This paper attempts to identify the principal parameters, that influence the behavior of drilling and production risers and to explain how and why they do so. Clear understanding of these influences enable particular risers to be optimised rapidly without recourse to an inordinate number of computer analyses. The points of greatest concern, to the riser designer, are: a Stress levels in the main length of riser. (b Angular movement at sea bed (or moment, if the connection is rigid. (c Relative movement at riser/platform connection. The approach, used in the paper, has been ta derive analytical expressions, for simplified riser cases. Conclusions drawn from these expressions have then been checked for validity, by using a dynamic analysis computer program to simulate a wide range of cases.

  14. Sur la modélisation du comportement thermomécanique et métallurgique des aciers. Application au procédé de soudage et de traitements thermiques

    OpenAIRE

    Trinh, Ngoc Thuy

    2008-01-01

    Le travail de la thèse porte sur la modélisation fine des lois de comportement thermomécaniques et métallurgiques des aciers afin de déterminer l'état mécanique résiduel des structures lors d'une opération de soudage. Il s'agit de définir les cinétiques de transformation de phases à l'état solide ainsi que le comportement mécanique du matériau multiphasé. Dans un cadre théorique original-les matériaux standards généralisés avec des liaisons internes-nous avons proposé des modèles de comportem...

  15. Modélisation thermodynamique du comportement cyclique d'alliages à mémoire de forme TiNi et CuZnAl sollicités en traction ondulée

    OpenAIRE

    Bourbon, G.; Lexcellent, C.

    1994-01-01

    L'extension au cas cyclique, d'un modèle de comportement pseudoélastique d'alliages à mémoire de forme (A.M.F.), mis au point par Raniecki, Lexcellent et Tanaka, ne pose pas de problème. La forme des boucles d'hystérésis permet une identification plus fiable des paramètres thermodynamiques pour le Ti Ni que pour le Cu Zn Al.

  16. Wie benutzerfreundlich ist der OPAC RERO ?: qualitative Analyse im Rahmen des Forschungsprojektes ACUEIL (Analyse du comportement des utilisateurs en recherche bibliographique - Extraction et interprétation des fichiers Log)

    OpenAIRE

    Küffer, Sabina; Stettler, Andrea,; Schneider, René

    2008-01-01

    Durch die Entwicklung in der Informationsgesellschaft stehen auch bibliothekarische Suchmaschinen (OPAC) vor neuen Herausforderungen. Der optimale OPAC sollte fä-hig sein, die zwei grössten Hindernisse zu bewältigen: • Beziehung Mensch – Maschine • Beziehung Suchmaschine – Datenbank Im Rahmen des Forschungsprojektes ACUEIL (Analyse du Comportement des Utili-sateurs en recherche bibliographique – Extraction et Interprétation des fichiers Log) wird die erste dieser Beziehungen genauer unter die...

  17. Comportement des poteaux composites en profils creux en acier remplis de béton Behavior of composite columns in hollow steel section filled with concrete

    Directory of Open Access Journals (Sweden)

    Othmani N.

    2012-09-01

    Full Text Available Le but de cet article, est la determination des rigidites flexionnelles EIx et EIy d’fune section mixte acier beton et plus precisement d’fun poteau en tube d’facier de section rectangulaire, remplie de beton, sollicitee a la flexion bi-axiale (N, Mx et My. L’festimation des rigidites sera faite a partir d’fune approche theorique par une analyse du poteau en elements finis (element barre a 4 degres de liberte, basee sur les conditions d’fequilibres a mi-portee en utilisant la relation moment-courbure (M–Φ de l’felement deforme par application de l’fequation suivante: EI=M/Φ. Le comportement des materiaux est celui comme adopte par les reglements Eurocode 2 et 3, respectivement pour le beton et l’facier. Afin de valider l’fapproche theorique utilisee dans cette etude, deux comparaisons ont ete faites : une premiere permettant de comparer les resultats des rigidites determinees par les relations moments courbures et celles calculees par l’fEurocode 4 et une deuxieme comparaison entre les charges de ruines de deux poteaux de grandeurs natures avec ceux testes au laboratoire [2]. Au vu des resultats obtenus, nous pouvons conclure que l’approche théorique utilisée dans cette étude ainsi que les modèles de comportement des matériaux sont adéquats pour ce genre de problèmes. The purpose of this paper is the determination of flexural stiffness EIx and EIy of a concrete filled rectangular cross section of a composite steel column, under biaxial bending (N, Mx and My. The rigidities will be estimated from a theoretical approach using a finite element analysis (element bar with 4 degrees of freedom, based on the equilibrium conditions at mid-span using the moment-curvature relationships (M–Φ of the deformed element by applying the following equation: EI=M/Φ. The material behavior is the one adopted by Eurocode 2 and 3, respectively, for concrete and steel. To validate the theoretical approach used, two comparisons

  18. Attention Alters Perceived Attractiveness.

    Science.gov (United States)

    Störmer, Viola S; Alvarez, George A

    2016-04-01

    Can attention alter the impression of a face? Previous studies showed that attention modulates the appearance of lower-level visual features. For instance, attention can make a simple stimulus appear to have higher contrast than it actually does. We tested whether attention can also alter the perception of a higher-order property-namely, facial attractiveness. We asked participants to judge the relative attractiveness of two faces after summoning their attention to one of the faces using a briefly presented visual cue. Across trials, participants judged the attended face to be more attractive than the same face when it was unattended. This effect was not due to decision or response biases, but rather was due to changes in perceptual processing of the faces. These results show that attention alters perceived facial attractiveness, and broadly demonstrate that attention can influence higher-level perception and may affect people's initial impressions of one another. PMID:26966228

  19. Illustration de systèmes de surveillance de deuxième génération du VIH et IST à travers une étude de comportement et une étude de séroprévalence dans les Territoires français du Pacifique Sud

    OpenAIRE

    Laroche Sophie

    2007-01-01

    Ce mémoire se penche sur la prévalence du VIH/SIDA et d'autres IST [infections sexuellement transmissibles] parmi les jeunes dans les Territoires français du Pacifique Sud. Le présent rapport expose les principes des SDG [systèmes de surveillance de deuxième génération], illustrés par deux types d'enquêtes : une enquête de comportements et une enquête de séroprévalence. [...] L'enquête de comportements intitulée: "Enquête sur les attitudes, comportements et croyance du VIH/SIDA parmi les jeun...

  20. Influence des paramètres matériaux sur le comportement des élastomères Influence of the material parameters on the mechanical properties of rubbers

    Directory of Open Access Journals (Sweden)

    Merckel Yannick

    2013-11-01

    Full Text Available Le comportement sous sollicitations cycliques des matériaux élastomères induit un adoucissement, une déformation rémanente et une anisotropie. Le travail présenté portera sur la caractérisation de ces phénomènes d'endommagements afin d'établir des liens avec les propriétés matériaux. The behavior of rubber-like materials under cyclic loading induces softening, permanent stretch and anisotropy. The aim of the presented work is to characterize such damage in order to introduced relation to material properties.

  1. La conception incrémentale de jeux sérieux musicaux pour la santé : théorie et application au traitement des troubles du comportement et de la maladie d'Alzheimer

    OpenAIRE

    Benveniste, Samuel

    2010-01-01

    Le jeu sérieux pour la santé (ludicament) est un domaine en pleine expansion dont les acteurs se proposent de rendre la prise en charge médicale plus motivante en y introduisant du "fun". De même, la musicothérapie encourage la recherche du "fun" musical et est de plus en plus plébiscitée par soignants et patients, notamment dans le cadre du traitement des troubles du comportement (Autisme, troubles limites...) et des maladies neuro-dégénératives (Alzheimer, Parkinson...). Pour profiter des s...

  2. Caractérisation et compréhension du comportement en corrosion de structures en alliage d'aluminium-cuivre-lithium 2050 assemblées par Friction Stir Welding (FSW)

    OpenAIRE

    Proton, Vincent

    2012-01-01

    A l'heure où les matériaux composites prennent une part toujours plus importante dans les structures aéronautiques, l'utilisation de l'alliage d'aluminium-lithium 2050 assemblé par Friction Stir Welding (FSW) est envisagé pour remplacer les structures rivetées en alliages d'aluminium traditionnels. L'objectif global de ce travail de thèse était d'étudier le comportement en corrosion et en corrosion sous contrainte de joints soudés FSW de l'alliage d'aluminium-lithium 2050 mais aussi l'influen...

  3. Influence des actionnaires institutionnels et dominants sur le comportement des dirigeants en matière de choix d'investissement : Une étude dans le contexte français de 1994 à 1998

    OpenAIRE

    Olivero, Bernard; JARBOUI Anis

    2006-01-01

    International audience Cet article examine l'hypothèse selon laquelle la présence d'actionnaires dominants ou d'investisseurs institutionnels dans le capital ou le conseil d'administration influence le comportement des dirigeants en matière d'horizon temporel et de risque des investissements (DRHTI) Les indicateurs retenus pour le DRHTI sont la volatilité de la rentabilité, le , le ratio R&D/Actif et le ratio Placement LT/CT. L'étude empirique se base sur des données françaises dans la pér...

  4. Étude du comportement des PME/PMI suisses en matière d’adoption de système de gestion intégré : entre méconnaissance et satisfaction: Cahier de recherche

    OpenAIRE

    Equey Balzli, Catherine

    2007-01-01

    Dans un environnement de mondialisation, de nombreux auteurs affirment que les outils de gestion intégrés (ERP) sont indispensables aux PME/PMI. Quelle est la situation des PME/PMI en Suisse en matière d’adoption d’ERP et comment se comportent-elles? Quel est le profil de la PME/PMI suisse qui utilise un ERP ? Notre recherche est basée sur une approche empirique. L’analyse statistique des réponses de près de sept cents PME/PMI des secteurs secondaire et tertiaire de toute la Suisse dévoile de...

  5. Modélisation multi-échelle du couplage physico-chimie - mécanique du comportement du combustible à haute température des réacteurs à eau sous pression

    OpenAIRE

    Julien, Jérôme

    2008-01-01

    Dans le cadre de la problématique de l'Interaction entre la Pastille et la Gaine (IPG) d'un crayon combustible, il est nécessaire d'avoir une bonne description du comportement thermomécanique du combustible. Lorsque le combustible est soumis à de fortes variations de puissance, une des principales sollicitations provient du phénomène de gonflement gazeux induit par l'irradiation. En effet, le combustible est un milieu poreux contenant différents types de cavités et l'accumulation de produits ...

  6. Influence de la temperature et de l'humidite sur le comportement dans le sol de trois especes ou varietes de Fusarium responsables de la pourriture seche des tubercules de pomme de terre

    OpenAIRE

    Tivoli, Bernard; Corbiere, Roselyne; Jouan, B.

    1983-01-01

    En France, 3 espèces ou variétés de Fusarium sont principalement responsables de la pourriture sèche des tubercules de pomme de terre en conservation : F. solani var. coeruleum (Sacc) Booth, F. roseum var. sambucinum (Fuck) Sn. et H., et F. roseum var. arthrosporioides (Sherb.) Messiaen et Cassini. Ces parasites peuvent être hébergés dans le sol qui constitue alors le support de l’inoculum primaire véhiculé, après la récolte, par les tubercules. Leur comportement dans le sol est étudié, p...

  7. Analyse des comportements et expérience des utilisateurs d'une plateforme de visioconférence pour l'enseignement des langues Le cas de la phase 1.0 de VISU

    OpenAIRE

    Codreanu, Tatiana

    2014-01-01

    Cette recherche a pour objet l’étude des comportements des utilisateurs d’une plateformede visioconférence poste à poste. Les utilisateurs de la plateforme sont deux groupes de tuteurset leurs étudiantes ; le groupe de tuteurs est constitué de tuteurs en formation (de futursenseignants en formation universitaire professionnalisante) et d’enseignants de FLE utilisant lesoutils du web 2.0. Cette recherche a pour cadre l’enseignement du FLE à destination d’ungroupe d'étudiantes américaines de l’...

  8. De la médiation documentaire à la navigation numérique : vers une modélisation du comportement informationnel des médecins en contexte hospitalier

    OpenAIRE

    TIETSE, Samuel

    2013-01-01

    Cette étude fait suite aux travaux en sciences de l’information qui visent à intégrer les aspects techniques, cognitifs et organisationnels dans l’analyse des pratiques informationnelles. Elle se base à la fois sur une approche holistique du comportement des usagers en contexte professionnel, et sur un nouveau cadre conceptuel pour tenter d’expliquer les pratiques d’accès à l’information pour l’action. Ce courant de recherche a évolué, avec l’émergence du web, au gré de multiples paradigmes d...

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

    OpenAIRE

    CARVALHO, Tania; Jeanguenat, Michel

    2012-01-01

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

  10. Progettazione dello spazio urbano e comportamenti criminosi / Planification de l’espace urbain et comportements criminels / Urban space planning and crime

    Directory of Open Access Journals (Sweden)

    Sicurella Sandra

    2012-04-01

    Full Text Available Crime is a common phenomenon in urban spaces. There is a relationship between crime, urban environment and the perception of security. For this reason, it is important to plan safe public spaces from an architectural point of view because it may help to reduce number of crimes and citizens’ feelings of insecurity. It is thus necessary to study the problem of urban crime from different perspectives: in this sense, architecture, town planning, law, sociology and criminology may help actively to solve the problems connected to crime in our cities.L’espace urbain est l’un des principaux lieux des phénomènes criminels. C’est en effet dans les villes que se développent des phénomènes indicatifs de la genèse, de l’explication des comportements criminels et du contrôle social. Dans la relation entre criminalité, environnement physique et perception de la sécurité, une importance considérable est accordée à la planification des espaces urbains car une organisation soignée du point de vue architectural et urbanistique peut affecter positivement l’atténuation du sentiment de vulnérabilité et contribuer à la réduction de la criminalité. Afin de limiter les possibilités de commission des crimes et de réduire le sentiment d’insécurité ressenti par les citoyens, il est donc nécessaire d’utiliser une approche multidisciplinaire pour aborder les problématiques de nos villes : architectes, urbanistes, juristes, sociologues et criminologues peuvent, tous ensemble, devenir les acteurs de la concertation urbaine pour intervenir efficacement dans nos villes.

  11. Concerning the study of the irreversible magnetic behaviour of superconductivity; Contribution a l'etude du comportement magnetique irreversible des supraconducteurs

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-03-01

    The influence of the presence of extended lattice defects on the magnetic behaviour has been studied for the case of type I superconductors, such as Re and Ta, and in a more quantitative manner for the type II superconductor niobium. In this case, measurements of the thermal conductivity have given an estimate of the relative concentration of lattice defects in each specimen. These measurements show that the larger the number of lattice defects, the more irreversible becomes the magnetization curve, and the larger becomes the values of the critical current, which is related by a simple model to the magnetization values. Finally, a study by transmission electron microscopy has confirmed on the one hand the diversity of the extended lattice defects and on the other hand has allowed the formulation of several hypothesis on their respective influence. [French] L'influence de la presence de defauts etendus sur le comportement magnetique a ete etudie pour des supraconducteurs de premiere espece, tels que le rhenium et le tantale, et plus quantitativement pour un supraconducteur de deuxieme espece, le niobium. Dans ce cas, des mesures de conductibilite thermique ont permis d'estimer la concentration relative des defauts du reseau dans chaque echantillon. Ces mesures montrent que plus les defauts du reseau sont nombreux, plus la courbe d'aimantation est irreversible, et plus les valeurs du courant critique, reliees par un modele simple aux valeurs de l'aimantation, sont elevees. Enfin une etude par microscopie electronique en transmission - a permis d'une part de constater la diversite des defauts etendus et d'autre part de formuler quelques hypotheses sur leurs influences respectives.

  12. Étude expérimentale et modélisation du comportement en compression des structures nid d'abeille

    Science.gov (United States)

    Aminanda, Y.; Castanié, B.; Barrau, J. J.; Thévenet, P.; Guedra-Degeorges, D.

    2002-12-01

    Dans le domaine aéronautique les impacts, même de faible énergie, sur des structures sandwichs à âme nid d'abeille posent des problèmes majeurs en terme de résistance résiduelle. La modélisation de l'endom magement dû à l'impact nécessite la connaissance préliminaire du comportement du nid d'abeille en compression. Des essais réalisés en compression quasi-statique uniforme sur des pains de nids d'abeille en différents matériaux (Nomex, Aluminium et Canson) permettent de décomposer la séquence de formation du pli et les facteurs influents. Ces essais tendent à montrer que la force de compression transite essentiellement par les arêtes verticales du nida. Des essais complémentaires sur un motif d'arête confirme cette analyse. La modélisation issue de cette analyse propose, pour connaître la réponse d'une structure nid d'abeille en compression ou indentation, de déterminer la réponse individuelle d'une arête verticale par un essai de compression uniforme. A partir de la loi expérimentale obtenue, la réponse à l'indentation de la structure sandwich est la superposition de la réponse des arêtes pour la forme d'indenteur et la profondeur d'indentation considérée. Une bonne corrélation essais/calcul est obtenue lors d'essais de validation sur nida Nomex avec diverses formes d'indenteurs. La méthode proposée est générale et peut être étendue à divers matériaux cellulaires.

  13. Stimuli de l'environnement, organes des sens et comportement des Monogènes juvéniles et adultes

    Directory of Open Access Journals (Sweden)

    KEARN G. C.

    1993-01-01

    Full Text Available Lorsque les larves de Monogènes (oncomiracidiums établissent leur premier contact avec l'hôte, cela correspond à un changement fondamental dans leur mode de vie. La disparition de quelques structures sensorielles et l'acquisition de nouvelles en témoignent ; mais il existe certainement d'autres types de changements encore inconnus au niveau du système nerveux. Le développement larvaire lui-même, à ce moment là, est initié par des facteurs eux aussi inconnus. Nos connaissances du rôle des facteurs de l'environnement sur la vie des stades parasites juvéniles et adultes sont très limitées. Chez Entobdella soleae, parasite cutané de la Sole, il existe une réponse comportementale au changement de concentration d'oxygène ; chez l'adulte d'Encotyllabe caballeroi, chez qui des yeux se développent chez les post-larves, une réponse nette à la lumière existe. Les yeux persistants que l'on trouve chez d'autres Monogènes adultes, doivent avoir un rôle plus subtil dans le comportement. Le courant d'eau peut influencer le choix du site de fixation ou le développement dissymétrique du hapteur chez les Polyopisthocotylea, mais chez Entobdella soleae, parasite cutané, c'est le premier contact, et non une réponse au courant d'eau qui est déterminant dans l'orientation, la locomotion et éventuellement la migration. Ce contact est aussi certainement important dans la locomotion de certains parasites branchiaux comme Tetraonchus monenteron. L'attraction par des phéromones n'a pas été démontrée chez les Monogènes et l'environnement turbulent de la plupart d'entre eux rend ce mode de communication peu adapté. Cependant, les relations particulières entre E. soleae et son hôte poisson plat procurent une situation où ce phénomène serait possible et avantageux. Bien que les hormones des hôtes apparaissent jouer un rôle dans la biologie de la reproduction des hématophages comme les Polystomes, la démonstration exp

  14. Altered fingerprints: analysis and detection.

    Science.gov (United States)

    Yoon, Soweon; Feng, Jianjiang; Jain, Anil K

    2012-03-01

    The widespread deployment of Automated Fingerprint Identification Systems (AFIS) in law enforcement and border control applications has heightened the need for ensuring that these systems are not compromised. While several issues related to fingerprint system security have been investigated, including the use of fake fingerprints for masquerading identity, the problem of fingerprint alteration or obfuscation has received very little attention. Fingerprint obfuscation refers to the deliberate alteration of the fingerprint pattern by an individual for the purpose of masking his identity. Several cases of fingerprint obfuscation have been reported in the press. Fingerprint image quality assessment software (e.g., NFIQ) cannot always detect altered fingerprints since the implicit image quality due to alteration may not change significantly. The main contributions of this paper are: 1) compiling case studies of incidents where individuals were found to have altered their fingerprints for circumventing AFIS, 2) investigating the impact of fingerprint alteration on the accuracy of a commercial fingerprint matcher, 3) classifying the alterations into three major categories and suggesting possible countermeasures, 4) developing a technique to automatically detect altered fingerprints based on analyzing orientation field and minutiae distribution, and 5) evaluating the proposed technique and the NFIQ algorithm on a large database of altered fingerprints provided by a law enforcement agency. Experimental results show the feasibility of the proposed approach in detecting altered fingerprints and highlight the need to further pursue this problem. PMID:21808092

  15. Comportement multifonctionnel des composites comportant des nano/micro renforts

    OpenAIRE

    Zhao, Hang

    2015-01-01

    Due to the outstanding mechanical electrical and thermal properties, carbon nanotubes (CNTs) received worldwide attentions and intensive investigations in last decades. CNTs are greatly potential in applications such as energy storage and microelectronics. The one dimensional structure, high aspect ratio and low density, promote CNTs serving as the excellent fillers in composites field. However, due to the strong interactions, CNTs are usually difficult to be dispersed and aligned in a polyme...

  16. Music alters visual perception.

    Directory of Open Access Journals (Sweden)

    Jacob Jolij

    Full Text Available BACKGROUND: Visual perception is not a passive process: in order to efficiently process visual input, the brain actively uses previous knowledge (e.g., memory and expectations about what the world should look like. However, perception is not only influenced by previous knowledge. Especially the perception of emotional stimuli is influenced by the emotional state of the observer. In other words, how we perceive the world does not only depend on what we know of the world, but also by how we feel. In this study, we further investigated the relation between mood and perception. METHODS AND FINDINGS: We let observers do a difficult stimulus detection task, in which they had to detect schematic happy and sad faces embedded in noise. Mood was manipulated by means of music. We found that observers were more accurate in detecting faces congruent with their mood, corroborating earlier research. However, in trials in which no actual face was presented, observers made a significant number of false alarms. The content of these false alarms, or illusory percepts, was strongly influenced by the observers' mood. CONCLUSIONS: As illusory percepts are believed to reflect the content of internal representations that are employed by the brain during top-down processing of visual input, we conclude that top-down modulation of visual processing is not purely predictive in nature: mood, in this case manipulated by music, may also directly alter the way we perceive the world.

  17. Genetic Alterations in Glioma

    International Nuclear Information System (INIS)

    Gliomas are the most common type of primary brain tumor and have a dismal prognosis. Understanding the genetic alterations that drive glioma formation and progression may help improve patient prognosis by identification of novel treatment targets. Recently, two major studies have performed in-depth mutation analysis of glioblastomas (the most common and aggressive subtype of glioma). This systematic approach revealed three major pathways that are affected in glioblastomas: The receptor tyrosine kinase signaling pathway, the TP53 pathway and the pRB pathway. Apart from frequent mutations in the IDH1/2 gene, much less is known about the causal genetic changes of grade II and III (anaplastic) gliomas. Exceptions include TP53 mutations and fusion genes involving the BRAF gene in astrocytic and pilocytic glioma subtypes, respectively. In this review, we provide an update on all common events involved in the initiation and/or progression across the different subtypes of glioma and provide future directions for research into the genetic changes

  18. Comportement des éléments traces au cours des processus de dégazage. Etude des volcans Piton de la Fournaise (Réunion) et Lascar (Chili)

    OpenAIRE

    Menard, Gabrielle

    2014-01-01

    Dans le cadre de cette thèse, nous avons cherché à mieux comprendre le comportement des éléments traces – et notamment des éléments légers Li et B – lors des processus de dégazage magmatique par une approche géochimique, basée sur l'analyse de produits volcaniques naturels (laves, gaz, aérosols volcaniques) de deux volcans aux styles éruptifs très contrastés, le Piton de la Fournaise (Réunion) et le Lascar (Chili). Dans un premier temps, cette étude s'est intéressée au rôle des transferts de ...

  19. Comportement électrochimique d'un acier inoxydable sous rayonnement et en milieu représentatif des réacteurs à eau pressurisée (REPs).

    OpenAIRE

    Wang, Mi

    2013-01-01

    Cette thèse est dédiée à l'étude du comportement des aciers inoxydables sous irradiation exposés en condition primaire des réacteurs à eau pressurisée (REP). Le potentiel électrochimique de l'acier inoxydable austénitique 316L et les paramètres environnementaux comme la teneur en hydrogène, ont été mesurés de façon continue à haute température (HT) et haute pression (HT) grâce à un dispositif expérimental unique, la cellule HTHP. Deux sources d'irradiation ont été utilisées: les protons et le...

  20. Etude de l'influence du platine sur le comportement en oxydation d'un système barrière thermique comprenant une sous-couche NiCoCrAlYTa

    OpenAIRE

    Vande Put, Aurélie

    2009-01-01

    La résistance à l'écaillage d'un système barrière thermique est fonction de la composition et microstructure des matériaux constituant le système, ainsi que des procédés utilisés pour son élaboration. Cette thèse s'intéresse à l'influence d'une couche de platine déposée à la surface du dépôt NiCoCrAlYTa (sous-couche) sur le comportement en oxydation du système barrière thermique. Une étude approfondie est d'abord menée afin d'identifier les atouts et points faibles en oxydation cyclique d'un ...

  1. Comportement mécanique et acoustique d'un bio-composite 100% végétal à base de chènevotte et d'amidon

    OpenAIRE

    Le, Anh Tuan; Gacoin, A; Li, A; El Walkil, N

    2015-01-01

    Le bio-composite chanvre-amidon est un nouveau matériau 100% végétal constitué d'amidon de blé et de chènevotte. C'est un matériau durable pour la construction et le bâtiment. Dans ce travail, une étude sur le comportement mécanique et acoustique a été réalisée. Deux paramètres prépondérants sont étudiés : le rapport chanvre sur amidon (en anglais hemp/starch) et la taille des fibres. Le rapport chanvre/amidon H/S est fixé à 6, 8 ou 10 et 2 tailles de fibres de chènevotte 0-15 mm et 0-20 mm s...

  2. Comportement en corrosion d'un alliage d'aluminium cuivre-lithium AW2050 : couplage environnement, microstructure, et état de contrainte du matériau

    OpenAIRE

    Guérin, Mathilde

    2014-01-01

    Les problématiques de corrosion restent un sujet d'étude majeur lorsqu'il s'agit d'améliorer les propriétés des alliages pour structures aéronautiques. Dans le cadre de ce travail, le comportement en corrosion d'un alliage AW2050 de type Al-Cu-Li-X est étudié. L'analyse du couplage entre les microstructures caractéristiques de cet alliage et l'environnement agressif constitue un point central de l'étude. Le travail réalisé a permis d'identifier les facteurs de premier ordre parmi les paramètr...

  3. Assemblage mécanique : stratégies d'optimisation des procédés et d'identification des comportements mécaniques des matériaux

    OpenAIRE

    Roux, Émile

    2011-01-01

    Ce travail de thèse porte sur la mise en place d'une méthodologie d'optimisation des procédés d'assemblage, ainsi que sur l'identification de paramètres de lois de comportement et d'endommagement pour la modélisation des assemblages par déformation plastique. La première partie du travail est axée sur la création d'une plateforme d'optimisation et d'analyse inverse permettant d'exploiter des calculs par éléments finis. Dans le cadre du développement de cette plateforme, un algorithme d'optimi...

  4. Transfert de charges et d'énergie dans différents systèmes moléculaires excités comportant un métal de transition d6

    OpenAIRE

    Freys, Jonathan

    2010-01-01

    Ces dernières années dans le domaine de la chimie, une des recherches les plus en vogue est le développement de systèmes moléculaires simples pouvant mimer les propriétés existant dans les systèmes naturels, comme par exemple les propriétés de transferts de charges du photosystème II, lors de la photosynthèse des plantes. Dans ce travail de thèse, il a été entrepris la synthèse et l'étude de nouveaux systèmes comportant un métal de transition d6 pouvant entraîner un transfert photo-induit de ...

  5. Référentiel de tests pour la vérification de la programmation des lois de comportement dans les logiciels d'éléments finis

    OpenAIRE

    MESTAT, P; Humbert, P.

    2001-01-01

    Le développement et la diffusion de logiciels de calcul par éléments finis soulèvent trois problèmes importants : la vérification des procédures de calcul, la validation des modèles de comportement et, enfin, l'utilisation correcte de ces logiciels pour la modélisation des ouvrages (maîtrise et justification des hypothèses de calcul). Les aspects liés à la validation des modèles et aux recommandations pour la maîtrise des logiciels ont déjà fait l'objet de nombreuses publications. En revanche...

  6. 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...

  7. Un modèle de structure par terme des prix des matières premières avec comportement asymétrique du rendement d'opportunité

    OpenAIRE

    Galli, Alain; Lautier, Delphine

    2001-01-01

    Cet article propose un nouveau modèle de structure par terme des prix des matières premières, dans lequel le rendement d’opportunité présente un comportement asymétrique. Un tel modèle permet de valoriser des transactions avec livraison différée sur le marché physique et de couvrir le produit de ces transactions contre les fluctuations des prix des matières premières (section 1). L’étude de la théorie du stockage conduit à formuler l’hypothèse d’asymétrie du rendement d’opportunité et met en ...

  8. Texture et Anisotropie du comportement mécanique après laminage à chaud d'un alliage léger Aluminium Cuivre Lithium (2050) pour l'aéronautique

    OpenAIRE

    Contrepois, Quentin

    2010-01-01

    Ce travail vise à comprendre l’évolution de la texture cristallographique et l’anisotropie du comportement mécanique après laminage à chaud et traitements thermiques d’un Al-Cu-Li 2050 et d’un Al-Zn-Mg-Cu 7050, et expliquer leurs différences. La texture est analysée par EBSD et RX après des essais de compression plane à chaud et après des laminages à chaud industriels. L’anisotropie est étudiée sur des tôles fortes industrielles après différents détensionnements et dans différents états micro...

  9. Simulation du comportement thermique en régime permanent d'un moteur asynchrone à refroidissement extérieur. Etude par éléments finis

    OpenAIRE

    Glises, R.; Hostache, G.; Kauffmann, J.

    1994-01-01

    On réalise l'étude du comportement thermique en régime permanent d'un moteur asynchrone de 4 kW. Le logiciel de calculs magnétiques par éléments finis flux2D est converti en un outil de résolution de l'équation de la chaleur. Cette dernière équation sert à simuler les transferts thermiques tant dans les domaines fluides que solides. Une pseudo-étude tridimensionnelle est réalisée par le biais de deux études bidimensionnelles : la première effectuée suivant un plan radial (plan perpendiculaire...

  10. Approche multi-agent pour la multi-modélisation et le couplage de simulations. Application à l'étude des influences entre le fonctionnement des réseaux ambiants et le comportement de leurs utilisateurs.

    OpenAIRE

    Siebert, Julien

    2011-01-01

    Ce travail de thèse, mené sur deux thématiques : les réseaux ambiants et la simulation multi-agent, a pour contexte l'étude des interactions entre le fonctionnement des réseaux ambiants (réseaux pair-à-pair et réseaux mobiles ad hoc networks) et les comportements de leurs usagers (mobilité, partage d'un service, etc.). Pour étudier ces phénomènes, nous avons mis en lumière le besoin de réutiliser, de coupler et de faire interagir des outils de modélisation et de simulation provenant de domain...

  11. Méta-modèles réduits et séparés du comportement de balayage d'un moteur Diesel 2-temps pour l'exploration évolutionnaire des espaces de solutions

    OpenAIRE

    Cagin, Stéphanie

    2015-01-01

    L’utilisation de techniques numériques lors de la conception d’un produit s’est largement généralisée au cours des 30 dernières années. Pourtant, la lenteur des calculs et la spécialisation des modèles numériques restent problématiques.Nous avons donc choisi de développer des modèles réduits du comportement de balayage sur un moteur Diesel 2-temps à lumières. Ces modèles sont analytiques, génériques, rapides d’utilisation et permettent d’éliminer les problématiques de traitement numérique. Il...

  12. COMPORTEMENT HYDRO-MECANIQUE DE ROCHES RESERVOIR SOUS CONTRAINTES :
    Relations entre évolution de perméabilité et échelles des mécanismes d'endommagement

    OpenAIRE

    Dautriat, Jérémie

    2009-01-01

    La compréhension et la prévention des mécanismes d'endommagement ayant un impact sur les cinétiques de production et les taux de récupération reste un problème ouvert en ingénierie de réservoir. L'objectif de cette étude repose sur la caractérisation du comportement hydromécanique de roches gréseuses et carbonatés en 'condition de réservoir' et l'identification des mécanismes locaux responsables des évolutions de perméabilité mesurables macroscopiquement. L'essentiel du travail expérimental s...

  13. Étude du comportement sous pression mécanique uniaxiale de la cellulose et de l’amidon (natif et amorphe) : influence de la température et du taux d’hydratation

    OpenAIRE

    Jallabert, Bastien

    2014-01-01

    Le projet HYPMOBB vise à évaluer un procédé de mise en œuvre de matière végétale par thermo-compression. Dans le cadre de ce projet, les travaux présentés ont pour objectif d’étudier le comportement des polysaccharides sous haute contrainte mécanique (0-300 MPa) et thermique (25-200°C). Trois variétés de biopolymères ont été choisies : la cellulose, l’amidon natif de pomme de terre et ce même amidon après gélatinisation. Elles représentent trois modèles différents d’organisation: hautement cr...

  14. Modélisation thermomécanique visco-hyperélastique du comportement d'un polymère semi-cristallin : application au cas d'une matrice polyamide 6.6

    OpenAIRE

    Baquet, Erwan

    2011-01-01

    Cette étude doctorale porte sur une matrice polyamide 6.6, utilisé dans les matériaux renforcé fibre de verre courtes, et consiste en la mise en place d'une modélisation thermomécanique, autour de la transition mécanique α du polymère. Une première partie consiste en la mise en évidence expérimentale du comportement thermomécanique du matériau de l'étude. Une campagne d'essais mécanique en traction et cisaillement a été menée, où un effort important sur le protocole expérimental a été mené. L...

  15. Long-term behavior of glass-ceramic zirconolite; Etude du comportement a long terme des vitrocristallins a base de zirconolite

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Ch

    2003-07-01

    This work is a part of the investigation of new containment matrices considered for specific conditioning of radionuclides after separation. The aim was to demonstrate the long-term aqueous corrosion resistance of the glass-ceramic zirconolite considered for the conditioning of plutonium and the minor actinides. This material is composed of crystals of zirconolite (CaZrTi{sub 2}O{sub 7}) dispersed in a residual vitreous phase. It appears that glass-ceramic zirconolite presents a better kinetic behavior than the nuclear glass R 7T7. This is mainly due to a more important rate decrease that occurs more rapidly, that induces a quantity of glass altered at least 10 times as small as for R 7T7 glass. This high slowdown of the alteration rate is attributed to the formation of an alteration film that has been the subject of a specific study. We have demonstrated that the rate decrease was controlled as for the R7T7 glass by the amorphous phase of the alteration film forming a diffusion barrier for reactive species. It seems that the porosity is not the single parameter that explains the protective effect of the gel. The main differences compared with R7T7 glass are that silicon does not control the alteration of the material and that the gel is composed of two distinct phases. We have in particular identified a dense phase enriched in titanium and neodymium that probably influences deeply the kinetics. (author)

  16. Epigenetic alterations in gastric carcinogenesis

    Institute of Scientific and Technical Information of China (English)

    In-Seon CHOI; Tsung-Teh WU

    2005-01-01

    Gastric cancer is believed to result in part from the accumulation of multiple genetic alterations leading to oncogene overexpression and tumor suppressor loss. Epigenetic alterations as a distinct and crucial mechanism to silence a variety of methylated tissue-specific and imprinted genes, have been extensively studied in gastric carcinoma and play important roles in gastric carcinogenesis. This review will briefly discuss the basic aspects of DNA methylation and CpG island methylation, in particular the epigenetic alterations of certain critical genes implicated in gastric carcinogenesis and its relevance of clinical implications.

  17. Pulmonary alterations in Behcet's disease

    International Nuclear Information System (INIS)

    Purpose: This study aims to demonstrate pulmonary alterations (PA) in patients with Behcet's disease by using CT. Materials and methods: CTs of 50 patients with Behcet's disease and 20 others in a control group have been evaluated retrospectively for PA (septal, reticular, nodular, atelectatic opacities). Results: Eight out of 50 patients (16%) with Behcet's disease showed PA. Three out of 20 (15%) in the control group showed PA. No differences were observed between Behcet's disease patients and the control group regarding pulmonary alterations (p = 0.917). No differences were observed in the disease duration, ages and sex in either group in those with and without PA. Conclusion: Pulmonary alterations can be seen in patients with Behcet's disease, but these alterations are not significant.

  18. La cohérence des comportements professionnels et privés chez les viticulteurs biologiques alsaciens The Coherence of Professional and Private Behaviours among Alsatian Organic Winegrowers

    Directory of Open Access Journals (Sweden)

    Jean Nizet

    2011-02-01

    Full Text Available Cette contribution s’interroge sur la forte cohérence observée au niveau des comportements professionnels et privés d’un petit échantillon de viticulteurs alsaciens que nous avons interviewés longuement. On s’attache d’abord à décrire ces comportements et à identifier les principes à partir desquels les acteurs les justifient. On propose ensuite deux hypothèses susceptibles de rendre compte de la cohérence constatée. La première suggère que cette cohé­rence est en partie construite par le discours des interviewés. La seconde s’interroge sur les mécanismes de socialisation. Trois mécanismes sont iden­tifiés : les tensions identitaires que les personnes ressentent lorsqu’elles s’écar­tent des principes évoqués ; les contrôles, formels et surtout informels, qu’elles exercent les unes sur les autres ; la hiérarchie qui s’instaure dans le champ de la viticulture biologique, en raison précisément de la plus ou moins forte cohé­rence des comportements. On montre que ces mécanismes combinent leurs effets pour produire une socialisation puissante et uniforme, qui fait des viti­culteurs biologiques interviewés des individus beaucoup plus intégrés que ce que prédisent des théories sociologiques qui mettent en avant la diversité, ou encore l’éclatement de l’expérience de l’individu contemporain.This contribution looks at the strong level of coherence observed in the behaviours, both professional and private, of a small sample of Alsatian winegrowers whom we interviewed at length. First there is an attempt at describing these behaviours and identifying the principles by which the actors justify them. We then propose two hypotheses liable to account for the coherence observed. The first suggests that this coherence is in part constructed out of the speech of the interviewees. The second asks about the socialization mechanisms. Three mechanisms are identified : the identitary tensions these

  19. Art as Alterity in Education

    Science.gov (United States)

    Zhao, Guoping

    2014-01-01

    In education, art has often been perceived as entertainment and decoration and is the first subject to go when there are budget cuts or test-score pressures. Drawing on Emmanuel Lévinas's idea of the primacy of radical alterity that breaks the totality of our being, enables self-transformation and ethics, and ensures community as a totality…

  20. Élaboration et validation d'un modèle numérique reflétant le comportement mécanique du fémur sous chargement statique de compression

    Science.gov (United States)

    Jacquet, E.; Garbuio, P.; Pernin, J. N.

    2002-12-01

    Pour tenter d'améliorer les techniques d'ostéosynthèse, afin de réduire les fractures du fémur, apparaît la nécessité de développer un modèle géométrique et numérique capable de caractériser le comportement mécanique du fémur humain. La présente étude propose des résultats expérimentaux issus de tests de compression sur fémurs frais équipés de jauges d'extensomètre. Le modèle géométrique est introduit dans un code de calculs par éléments finis pour représenter le champ des déformations à la surface de l'os. On montre la cohérence du modèle au plan qualitatif et des améliorations pouvant être apportées à ce modèle sont discutées.

  1. Chemosensory alterations and cancer therapies

    International Nuclear Information System (INIS)

    Taste and olfaction provide sensory information and sensory pleasure. Cancer therapies affect both. Chemotherapy has not been shown to produce dramatic losses of taste or smell, but systematic studies on various chemotherapeutic agents and types of cancer are lacking. Radiation therapy does produce clear losses of both taste and smell. Both chemotherapy and radiation therapy alter the pleasure produced by taste and smell through the formation of conditioned aversions. That is, foods consumed in proximity with the nausea of therapy come to be unpleasant. The impact of conditioned aversions can be diminished by providing a scapegoat food just before therapy. Alterations in foods may be beneficial to the cancer patient. Increasing the concentrations of flavor ingredients can compensate for sensory losses, and providing pureed foods that retain the cognitive integrity of a meal can benefit the patient who has chewing or swallowing problems

  2. Altered states: psychedelics and anesthetics.

    Science.gov (United States)

    Icaza, Eduardo E; Mashour, George A

    2013-12-01

    The psychedelic experience has been reported since antiquity, but there is relatively little known about the underlying neural mechanisms. A recent neuroimaging study on psilocybin revealed a pattern of decreased cerebral blood flow and functional disconnections that is surprisingly similar to that caused by various anesthetics. In this article, the authors review historical examples of psychedelic experiences induced by general anesthetics and then contrast the mechanisms by which these two drug classes generate altered states of consciousness. PMID:24061599

  3. Buccal alterations in diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Negrato Carlos

    2010-01-01

    Full Text Available Abstract Long standing hyperglycaemia besides damaging the kidneys, eyes, nerves, blood vessels, heart, can also impair the function of the salivary glands leading to a reduction in the salivary flow. When salivary flow decreases, as a consequence of an acute hyperglycaemia, many buccal or oral alterations can occur such as: a increased concentration of mucin and glucose; b impaired production and/or action of many antimicrobial factors; c absence of a metalloprotein called gustin, that contains zinc and is responsible for the constant maturation of taste papillae; d bad taste; e oral candidiasis f increased cells exfoliation after contact, because of poor lubrication; g increased proliferation of pathogenic microorganisms; h coated tongue; i halitosis; and many others may occur as a consequence of chronic hyperglycaemia: a tongue alterations, generally a burning mouth; b periodontal disease; c white spots due to demineralization in the teeth; d caries; e delayed healing of wounds; f greater tendency to infections; g lichen planus; h mucosa ulcerations. Buccal alterations found in diabetic patients, although not specific of this disease, have its incidence and progression increased when an inadequate glycaemic control is present.

  4. Multiple scenarios of bentonite alteration

    International Nuclear Information System (INIS)

    Performance assessment for TRU waste repositories has shown that soluble and poorly sorbing nuclides such as I-129 and C-14 dominate the dose. These nuclides are expected to migrate with groundwater flow, hence hydraulic conditions and their evolution with time in the repository are key issues for repository safety. Cementitious material will be used for waste packaging, backfilling and structural material in a TRU waste repository. Bentonite is also expected to be used for some TRU wastes to provide the function of a hydraulic barrier in the disposal system. There is concern that the coexistence of cementitious material and bentonite cause the alteration of smectite due to interaction with hyperalkaline leachates and consequent deleterious perturbation of the function of bentonite as a hydraulic barrier. Many research studies have been performed to identify possible mechanisms of cement-bentonite interaction. However, uncertainties still exist in our understanding of the precise chemical scheme of bentonite alteration in highly alkaline conditions, especially the space and time variation of secondary mineral occurrences. In order to reflect this uncertainty, multiple scenarios of bentonite alteration were developed based on the possible mineralogical changes derived from knowledge of both experiments and observation of natural systems. It was focused that the mineral reaction involving hyperalkaline fluids would thermodynamically depend on the variable chemical condition in bentonite buffer and that kinetics would be important as well as thermodynamic stability in controlling their occurrence, i.e., the kinetic controls may operate to remain metastable minerals over the long term. The mineralogical consequences of the interaction between clays and alkaline fluids are summarized as follows. Clay → C-S-H gel and other solids which can rapidly precipitate. Clay and gel → illite. Clay and gel → metastable zeolite. Clay and gel → metastable zeolite → stable

  5. Acid Sulfate Alteration on Mars

    Science.gov (United States)

    Ming, D. W.; Morris, R. V.

    2016-01-01

    A variety of mineralogical and geochemical indicators for aqueous alteration on Mars have been identified by a combination of surface and orbital robotic missions, telescopic observations, characterization of Martian meteorites, and laboratory and terrestrial analog studies. Acid sulfate alteration has been identified at all three landing sites visited by NASA rover missions (Spirit, Opportunity, and Curiosity). Spirit landed in Gusev crater in 2004 and discovered Fe-sulfates and materials that have been extensively leached by acid sulfate solutions. Opportunity landing on the plains of Meridiani Planum also in 2004 where the rover encountered large abundances of jarosite and hematite in sedimentary rocks. Curiosity landed in Gale crater in 2012 and has characterized fluvial, deltaic, and lacustrine sediments. Jarosite and hematite were discovered in some of the lacustrine sediments. The high elemental abundance of sulfur in surface materials is obvious evidence that sulfate has played a major role in aqueous processes at all landing sites on Mars. The sulfate-rich outcrop at Meridiani Planum has an SO3 content of up to 25 wt.%. The interiors of rocks and outcrops on the Columbia Hills within Gusev crater have up to 8 wt.% SO3. Soils at both sites generally have between 5 to 14 wt.% SO3, and several soils in Gusev crater contain around 30 wt.% SO3. After normalization of major element compositions to a SO3-free basis, the bulk compositions of these materials are basaltic, with a few exceptions in Gusev crater and in lacustrine mudstones in Gale crater. These observations suggest that materials encountered by the rovers were derived from basaltic precursors by acid sulfate alteration under nearly isochemical conditions (i.e., minimal leaching). There are several cases, however, where acid sulfate alteration minerals (jarosite and hematite) formed in open hydrologic systems, e.g., in Gale crater lacustrine mudstones. Several hypotheses have been suggested for the

  6. Early prevention of the antisocial behaviour of youth: situation in Latvia/La prévention précoce du comportement antisocial chez les jeunes : la situation en Lettonie

    Directory of Open Access Journals (Sweden)

    Kronberga Ilona

    2015-09-01

    Full Text Available Public opinion on prevention is often very narrow and stigmatised: the concept of prevention is more often related to a crime than to antisocial behaviour. Often such approach limits not only the understanding of the usability and content of prevention methods but also the age of children at which a successful use of these methods is acceptable. Due to the aforementioned, it is possible to put forward a hypothesis: successful prevention of antisocial behaviour in the work with children at a young age decreases the necessity of crime prevention in later years of children and youth development. Therefore, this publication will focus on the use and practice of prevention methods in the early period of child development – pre-school and primary school. L’opinion publique sur la prevention est souvent perçue à travers des termes trops restrictifs et stigmatizés : le concept de prévention est le plus souvent lié à la criminalité qu’au comportement antisocial. Bien souvent, de tels propos limitent non seulement la compréhension de la possibilité d’utilisation des méthodes de prévention, mais aussi l’âge auquel ces méthodes peuvent être utilisées avec succès. C’est dans ce sens qu’il est possible d’avancer une hypothèse : la prévention réussie du comportement antisocial dans le cadre de l’intervention pour les enfants en bas âge réduit la nécéssité de son maintien après. Par conséquent, cet article va examiner l’utilisation et la pratique des méthodes de prévention précoce dès l’école maternelle et primaire. L’opinione comune sulla prevenzione è spesso molto limitata e stigmatizzata: il concetto di prevenzione è più frequentemente collegato al crimine piuttosto che al comportamento antisociale. Di frequente tale approccio limita non soltanto l’ambito dell’utilizzabilità e del contenuto dei metodi di prevenzione, ma anche l’età dei bambini per i quali si possono utilizzare in maniera

  7. Inorganic Species Behaviour in Thermochemical Processes for Energy Biomass Valorisation Comportement des espèces inorganiques dans les procédés thermochimiques de valorisation énergétique de la biomasse

    Directory of Open Access Journals (Sweden)

    Froment K.

    2013-09-01

    ériaux de lits (en réacteurs à lits fluidisés, les canalisations et l’aval du procédé ne sont pas toujours bien connues. Ces sujets concernant le comportement des espèces inorganiques et les conséquences technologiques et économiques vont probablement prendre de l’importance dans un futur proche en raison de : la tension sur le marché du bois qui augmente ainsi que les prix : une solution est de remplacer cette ressource « noble et propre » qu’est le bois par une ressource plus riche en cendres, comme la paille, les cultures énergétiques dédiées, ou les déchets agricoles voire ménagers. La production de biogaz depuis des décharges de déchets est une bonne illustration de la valorisation de déchets. Aller plus loin dans l’utilisation de ces ressources (conversion thermochimique riches en cendres augmentera leur potentielle réutilisation mais également les difficultés techniques de manière importante! l’enrichissement des sols pour l’agriculture dépend aujourd’hui de la possibilité de réemploi des cendres de biomasse, auxquelles il faut ajouter des fertilisants artificiels. La question de comment réutiliser la matière inorganique de la biomasse après conversion thermochimique devient un sujet important. L’objectif est de présenter une synthèse des difficultés technologiques liées à la présence de ces espèces inorganiques (corrosion, bouchages, etc. : un résumé détaillé du comportement des espèces inorganiques de la biomasse dans les procédés thermiques sera donné, allant des espèces relâchées pendant le traitement de la biomasse jusqu’à la prévention et les solutions quand c’est possible. Les sujets suivants seront développés : inventaires des espèces inorganiques de différentes ressources ; synthèse de la spéciation des espèces inorganiques dans les divers procédés de conversion thermiques ; barrières technologiques à franchir pour des raisons économiques et améliorations technologiques des

  8. Correlated alteration effects in CM carbonaceous chondrites

    Science.gov (United States)

    Browning, Lauren B.; McSween, Harry Y., Jr.; Zolensky, Michael E.

    1996-07-01

    Three parameters are proposed to determine the relative extent of alteration in CM chondrites. The mineralogic alteration index monitors the relative progress of coupled substitutions in the progressive alteration of cronstedtite to Mg-serpentine and increases with increasing alteration. To calculate values of this index, an algorithm has been developed to estimate the average matrix phyllosilicate composition in individual CM chondrites. The second parameter is the volume percent of isolated matrix silicates, which decreases with progressive alteration due to mineral hydration. Finally, the volume percent of chondrule alteration monitors the extent of chondrule phyllosilicate production and increases as alteration proceeds. These parameters define the first CM alteration scale that relies on multiple indicators of progressive alteration. The following relative order of increasing alteration is established by this model: Murchison ≤ Bells Cochabamba and Boriskino experienced is less precisely constrained, although both fall near the middle of this sequence. A comparison between the mineralogic alteration index and literature values for the whole-rock chemistry of CM chondrites reveals several correlations. A positive, nearly linear correlation between bulk H content and progressive CM alteration suggests an approximately constant production rate of new phyllosilicates relative to the mineralogical transition from cronstedtite to Mg-serpentine. The abundance of trapped planetary 36Ar decreases systematically in progressively altered CM chondrites, suggesting the wholesale destruction of primary noble gas carrier phase (s) by aqueous reactions. Because low temperature fluid-rock reactions are generally associated with large isotopic mass fractionation factors, we also compared our model predictions with δ18O values for bulk CM samples. Although some of these data are poorly resolved, the order of increasing δ18O values approximates the order of increasing

  9. TWO STAGE FRAMEWORK FOR ALTERED FINGERPRINT MATCHING

    OpenAIRE

    T. R. Anoop; M.G. Mini

    2015-01-01

    Fingerprint alteration is the process of masking one’s identity from personal identification systems especially in boarder control security systems. Failure of matching the altered fingerprint of the criminals against the watch list of fingerprints can help them to break the security system. This fact leads to the need of a method for altered fingerprint matching. This paper presents a two stage method for altered fingerprint matching. In first stage, approximated global ridge orientation fie...

  10. Genetic alterations in pancreatic carcinoma

    Directory of Open Access Journals (Sweden)

    Schmid Roland M

    2003-01-01

    Full Text Available Abstract Cancer of the exocrine pancreas represents the fifth leading cause of cancer death in the Western population with an average survival after diagnosis of 3 to 6 months and a five-year survival rate under 5%. Our understanding of the molecular carcinogenesis has improved in the last few years due to the development of novel molecular biological techniques. Pancreatic cancer is a multi-stage process resulting from the accumulation of genetic changes in the somatic DNA of normal cells. In this article we describe major genetic alterations of pancreatic cancer, mutations in the proto-oncogene K-RAS and the tumor suppressors INK4A, TP53 and DPC4/SMAD4. The accumulation of these genetic changes leads to a profound disturbance in cell cycle regulation and continuous growth. The knowledge of the underlying molecular mechanisms will offer new therapeutic and diagnostic options and hopefully improve the outcome of this aggressive disease.

  11. Genetic alterations in pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Muhammad Wasif Saif; Lena Karapanagiotou; Kostas Syrigos

    2007-01-01

    The diagnosis of pancreatic cancer is devastating for patients and their relatives as the incidence rate is approximately the same as mortality rate. Only a small percentage, which ranges from 0.4% to 4% of patients who have been given this diagnosis, will be alive at five years. At the time of diagnosis, 80% of pancreatic cancer patients have unresectable or metastatic disease.Moreover, the therapeutic alternatives offered by chemotherapy or radiotherapy are few, if not zero. For all these reasons, there is an imperative need of analyzing and understanding the primitive lesions that lead to invasive pancreatic adenocarcinoma. Molecular pathology of these lesions is the key of our understanding of the mechanisms underlying the development of this cancer and will probably help us in earlier diagnosis and better therapeutic results. This review focuses on medical research on pancreatic cancer models and the underlying genetic alterations.

  12. Epigenetic alterations underlying autoimmune diseases.

    Science.gov (United States)

    Aslani, Saeed; Mahmoudi, Mahdi; Karami, Jafar; Jamshidi, Ahmad Reza; Malekshahi, Zahra; Nicknam, Mohammad Hossein

    2016-03-01

    Recent breakthroughs in genetic explorations have extended our understanding through discovery of genetic patterns subjected to autoimmune diseases (AID). Genetics, on the contrary, has not answered all the conundrums to describe a comprehensive explanation of causal mechanisms of disease etiopathology with regard to the function of environment, sex, or aging. The other side of the coin, epigenetics which is defined by gene manifestation modification without DNA sequence alteration, reportedly has come in to provide new insights towards disease apprehension through bridging the genetics and environmental factors. New investigations in genetic and environmental contributing factors for autoimmunity provide new explanation whereby the interactions between genetic elements and epigenetic modifications signed by environmental agents may be responsible for autoimmune disease initiation and perpetuation. It is aimed through this article to review recent progress attempting to reveal how epigenetics associates with the pathogenesis of autoimmune diseases. PMID:26761426

  13. Hindlimb unloading alters ligament healing

    Science.gov (United States)

    Provenzano, Paolo P.; Martinez, Daniel A.; Grindeland, Richard E.; Dwyer, Kelley W.; Turner, Joanne; Vailas, Arthur C.; Vanderby, Ray Jr

    2003-01-01

    We investigated the hypothesis that hindlimb unloading inhibits healing in fibrous connective tissue such as ligament. Male rats were assigned to 3- and 7-wk treatment groups with three subgroups each: sham control, ambulatory healing, and hindlimb-suspended healing. Ambulatory and suspended animals underwent surgical rupture of their medial collateral ligaments, whereas sham surgeries were performed on control animals. After 3 or 7 wk, mechanical and/or morphological properties were measured in ligament, muscle, and bone. During mechanical testing, most suspended ligaments failed in the scar region, indicating the greatest impairment was to ligament and not to bone-ligament insertion. Ligament testing revealed significant reductions in maximum force, ultimate stress, elastic modulus, and low-load properties in suspended animals. In addition, femoral mineral density, femoral strength, gastrocnemius mass, and tibialis anterior mass were significantly reduced. Microscopy revealed abnormal scar formation and cell distribution in suspended ligaments with extracellular matrix discontinuities and voids between misaligned, but well-formed, collagen fiber bundles. Hence, stress levels from ambulation appear unnecessary for formation of fiber bundles yet required for collagen to form structurally competent continuous fibers. Results support our hypothesis that hindlimb unloading impairs healing of fibrous connective tissue. In addition, this study provides compelling morphological evidence explaining the altered structure-function relationship in load-deprived healing connective tissue.

  14. Dolichol alters brain membrane functions

    International Nuclear Information System (INIS)

    It has been well demonstrated that there is a direct correlation between increase in dolichol level in brain and aging. An abnormally high level of dolichol was found in brain tissue of patients with pathological aging disorders. The aim of this study is to examine the physiological significance of dolichol affecting membrane transport activity and phospholipid acyl group turnover. Dolichol added to synaptic plasma membranes resulted in a biphasic effect on (Na+, K+)-ATPase, i.e., an enhancement of activity at low concentrations (5 μg/125 mg protein) and an inhibition of activity at high concentrations (40-100 μg). To probe the membrane acyl group turnover, the incorporation of [14C]-arachidonate into plasma membrane phospholipids was examined in the presence and absence of dolichol. Dolichol elicited an increase in the incorporation of label into phospholipids. However, the effects varied depending on whether BSA is present. In the absence of BSA, the increase in labeling of phosphatidylinositols is higher than that of phosphatidylcholines. These results suggest that dolichols, when inserted into membranes, may alter membrane functions

  15. Dolichol alters brain membrane functions

    Energy Technology Data Exchange (ETDEWEB)

    Sun, G.Y.; Sun, A.Y.; Schroeder, F.; Wood, G.; Strong, R.

    1986-03-05

    It has been well demonstrated that there is a direct correlation between increase in dolichol level in brain and aging. An abnormally high level of dolichol was found in brain tissue of patients with pathological aging disorders. The aim of this study is to examine the physiological significance of dolichol affecting membrane transport activity and phospholipid acyl group turnover. Dolichol added to synaptic plasma membranes resulted in a biphasic effect on (Na/sup +/, K/sup +/)-ATPase, i.e., an enhancement of activity at low concentrations (5 ..mu..g/125 mg protein) and an inhibition of activity at high concentrations (40-100 ..mu..g). To probe the membrane acyl group turnover, the incorporation of (/sup 14/C)-arachidonate into plasma membrane phospholipids was examined in the presence and absence of dolichol. Dolichol elicited an increase in the incorporation of label into phospholipids. However, the effects varied depending on whether BSA is present. In the absence of BSA, the increase in labeling of phosphatidylinositols is higher than that of phosphatidylcholines. These results suggest that dolichols, when inserted into membranes, may alter membrane functions.

  16. Protamine alterations in human spermatozoa.

    Science.gov (United States)

    Jodar, Meritxell; Oliva, Rafael

    2014-01-01

    Protamines are the major nuclear proteins in sperm cells, having a crucial role in the correct packaging of the paternal DNA. The fact that protamine haploinsufficiency in mice resulted in abnormal chromatin packaging and male infertility suggested that the protamines could also be important candidates in explaining some of the idiopathic male infertility cases in humans. The first clinical studies focused on analyzing protamines at the protein level. Various studies have found the presence of an altered amount of protamines in some infertile patients, in contrast to the normal situation in fertile individuals where the two protamines, protamine 1 and protamine 2, are both present in approximately equal quantities. Subsequently, the protamine genes were the subject of various mutational genetic screening studies in search of variants that could be associated with deregulation in the protamine expression observed. The results of these protamine mutational studies showed that the presence of high penetrant mutations is a very rare cause of male infertility. However, some variants and some haplotypes described may behave as risk factors for male infertility. More recently, the presence of RNA in the mature sperm cell has also been investigated. The present chapter will introduce the basic aspects of protamine evolution and function and review the various articles published to date on the relationship between the protamines studied at the DNA, RNA, and protein levels and male infertility. PMID:23955674

  17. Hyperglycaemia Alters Thymic Epithelial Cell Function

    Directory of Open Access Journals (Sweden)

    Vera Alexandrovna Abramova

    2013-07-01

    Full Text Available Insulin-dependent diabetes mellitus (IDDM is considered to be a consequence of unchecked auto-immune processes. Alterations in immune system responses are thought to be the cause of the disease, but the possibility that altered metabolite levels (glucose can establish the disease by specifically acting on and altering thymus stroma functions has not been investigated. Therefore, the direct effect of hyperglycaemia (HG on central tolerance mechanisms as a causative agent needs to be investigated.

  18. Comportement des fondations et des ancrages de structures marines sous l'effet de sollicitations cycliques Behavior of Foundations and Anchors for Marine Structures under the Effect of Cyclic Stresses

    Directory of Open Access Journals (Sweden)

    Le Tirant P.

    2006-11-01

    Full Text Available L'exploration et l'exploitation des hydrocarbures en haute mer conduisent à la mise en place d'ouvrages fixes ou flottants de dimensions de plus en plus colos sales, par des profondeurs d'eau sans cesse croissantes, atteignant actuellement 200 à 300 mètres en production, un millier de mètres en exploration. Les fondations des ouvrages pétroliers de production comprennent essentiel-lement- les pieux ou groupes de pieux, battus ou forés; - les fondations superficielles à embase poids. Le comportement des fondations ou ancrages de structures sous l'action des sollicitations cycliques est étudié, en fonction de la nature des terrains, à partir - de mesures et d'observations sur des structures réelles; d'expérimentations sur des modèles en semi-grandeur ou de simulations sur modèles réduits. Les exemples donnés situent la diversité des problèmes rencontrés pour l'instal-lation des ouvrages en haute mer et! l'ampleur des travaux nécessaires pour décrire plus correctement les phénomènes d'intéraction sols-structures mannes sous l'effet des chargements cycliques et transitoires et, par suite, mieux optimiser le dimensionnement des fondations et des ancrages. Exploration and production of hydrocarbons in the high seas lead ta the installation of fixed or floating structures having more and more colossal sizes at constantly increasing water depths which now attain 200 ta 300 meters for production and 1000 meters for exploration. The foundations of ail production structures mainly consist of - pilings or groups of pilings, either driven or drilled; superficial gravity foundations the behovior of foundations or anchors for such structures under the effect of cyclic stresses is examined as a function of the nature of formations, on the basis of - measurements and observations on actual structures, experiments with semi-full-sized models or by simulations with scale models. The examples given illustrate the diversity of the problems

  19. Comportement mécanique des tuyaux. Influence de la traction, de la pression et du poids linéique. Application aux risers Mechanical Behavior of Pipes and Risers. Influence of Tension, Pressure and Weight

    Directory of Open Access Journals (Sweden)

    Sparks C.

    2006-11-01

    Full Text Available L'influence de la traction, de la pression et du poids linéique sur le comportement d'un tuyau (ou d'un riser a déjà été traitée dans de nombreux articles. Malgré cela, elle est fréquemment mal comprise, ce qui a parfois de; conséquences sérieuses. Par souci de clarté, l'approche de cet article est délibérément très élémentaire. Les problèmes principaux de la flexion, du flambage, de l'allongement et de la contrainte limite, qui sont souvent traités dans des articles différents, sont ici étudiés ensemble d'une façon homogène. On présente des interprétation: physiques, faciles à visualiser, des deux concepts de tension effective et de contrainte effective, dont l'utilisation est très répandue, ainsi que leur rapport avec des notions analogues dans d'autres domaines de l'art de l'ingénieur. La puissance de ces deux concepts est démontrée à la fin de l'article où ils sont utilisés pour résoudre huit problèmes divers. The influence of tension, pressure, and weight on different aspects of pipe and riser behavior has already been the subject of many articles (see references. In spite of this it has frequently been misunderstood, sometimes with serious consequences. The object of this payer is to explain the subject clearly and the approach is therefore deliberately very elementary. The principal problems of bending, buckling, yielding and strains, usually treated in separated papers, are here treated homogeneously. The widely used concepts of effective tension and effective stress are given interpretations, easy to visualise, which are related to analogous concepts in other engineering fields. Finally, eight diverse particular examples of the influence of tension, pressure and weight on pipe and riser behavior, are discussed.

  20. Simulation du comportement thermique en régime permanent d'un moteur asynchrone à refroidissement extérieur. Etude par éléments finis

    Science.gov (United States)

    Glises, R.; Hostache, G.; Kauffmann, J. M.

    1994-09-01

    The steady state thermal modelling of an 4kW asynchronous motor is realized. A design has been made thanks to the Flux2D finite element magnetic calculus software converted into a resolution tool of the heat equation. This last is used to simulate the heat flux in fluid and solid areas. A 3D study is effected thanks to two 2D studies. The first concerns a radial view (perpendicular to the mechanical axis) whereas the second is effected for an axial view (parallel to the mechanical axis). Thermal conductivities of the materials and thermal contact resistances of the motor are determined through two different tests creating different overheatings. The first is made with a sinewave supply and pre-determine the thermophysical parameters. The second effected with direct current supplies at the rotor and the stator is used to validate these last parameters. On réalise l'étude du comportement thermique en régime permanent d'un moteur asynchrone de 4kW. Le logiciel de calculs magnétiques par éléments finis flux2D est converti en un outil de résolution de l'équation de la chaleur. Cette dernière équation sert à simuler les transferts thermiques tant dans les domaines fluides que solides. Une pseudo-étude tridimensionnelle est réalisée par le biais de deux études bidimensionnelles : la première effectuée suivant un plan radial (plan perpendiculaire à l'axe du moteur) et la seconde suivant un plan axial (plan parallèle à l'axe). Les conductivités des matériaux et des résistances thermiques de contact composant le moteur sont déterminées à l'aide de deux types d'essais qui induisent des échauffements différents. Le premier est réalisé avec une alimentation sinusoïdale et sert à prédéterminer les paramètres thermophysiques. Le second est effectué avec des alimentations à courant continu tant au stator qu'au rotor et a pour rôle la validation de ces paramètres.

  1. Dolomite effect on borosilicate glass alteration

    International Nuclear Information System (INIS)

    Highlights: ► Dolomite is a common mineral of clayey formations considered for radioactive waste disposals. ► Borosilicate glass/dolomite interaction have been studied by batch tests and solid analysis. ► Mg provided by dolomite combines with Si from glass to yield secondary Mg–silicates. ► This precipitation increases glass alteration, though in a moderate manner. ► Geochemical modeling allows to quantify the alteration mechanisms involved. - Abstract: Dolomite (CaMg(CO3)2) is one of the common rock-forming minerals in many geological media, in particular in clayey layers that are currently considered as potential host formations for a deep radioactive waste disposal facility. Magnesium in solution is one of the elements known to potentially enhance the alteration of nuclear glasses. The alteration of borosilicate glasses with dolomite as a Mg-bearing mineral source was investigated for 8 months in batch tests at 90 °C. Glass composition effects were investigated through two compositions (SiBNaAlCaZrO and SiBNaAlZrO) differing in their Ca content. The Ca-rich glass alteration is slightly enhanced in the presence of dolomite compared to the alteration observed in pure water. This greater alteration is explained by the precipitation of Mg silicate phases on the dolomite and glass surfaces. In contrast, the Ca-free glass alteration decreases in the presence of dolomite compared to the alteration observed in pure water. This behavior is explained by Ca incorporation in the amorphous layer (formed during glass alteration) coming from dolomite dissolution. Calcium acts as a layer reorganizer and limits glass alteration by reducing the diffusion of reactive species through the altered layer. Modeling was performed using the GRAAL model implemented within the CHESS/HYTEC geochemical code to discriminate and interpret the mechanisms involved in glass/dolomite interactions. Magnesium released by dolomite dissolution reacts with silica provided by glass

  2. Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior; Apports des analogues naturels vitreux a la validation des codes de prediction du comportement a long terme des verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Techer, I

    1999-07-01

    This study assesses the extend of the analogy between the alteration behavior in water and in a moist clay environment of aluminosilicate volcanic glass and alumino-borosilicate nuclear containment glass. Basaltic glass alteration in water initially occurs by hydrolysis processes with an activation energy on the order of 73 kJ.mol{sup -1}. As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r{sub 0}, The alteration kinetics are not governed by the alteration solution chemistry alone, the glass alteration film appears to have a major role as a diffusion barrier limiting the transfer of reaction species and products. All these aspects highlight the behavioral analogy between basaltic glass and nuclear borosilicate glass in aqueous media. Conversely, the alteration reaction of obsidian-type volcanic glass involves other mechanisms than those governing the dissolution of borosilicate glass. Basaltic glass alteration is also examined in the presence of a clay environmental material, in a study of the natural basaltic glass and argillaceous pelites system of the Salagou basin in southern France, in an approach combining mineralogical, chemical and isotopic data to assess the interactions between a basaltic glass and the argillaceous pelites. Laboratory leach test results with basaltic glass and measured data for the Salagou glass in its natural environment are modeled using a code implementing a kinetic law coupling diffusive transfer of dissolved silica with a reaction affinity law. (author)

  3. A kernel version of multivariate alteration detection

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Vestergaard, Jacob Schack

    2013-01-01

    Based on the established methods kernel canonical correlation analysis and multivariate alteration detection we introduce a kernel version of multivariate alteration detection. A case study with SPOT HRV data shows that the kMAD variates focus on extreme change observations....

  4. Altered States of Consciousness and Alcohol.

    Science.gov (United States)

    Jones, Ben Morgan; And Others

    This document contains the reports of research at a symposium on "Altered States of Consciousness and Alcohol." The participants primarily agreed that alcohol induces an altered state of consciousness similar to other drugs, but that this phenomenon has not been explicitly stated due to the current interest in newer and more novel drugs. The…

  5. Elaboration of an Elasto-Plastic Model for High Porosity Chalks. Application to the Compaction of Petroleum Reservoirs Elaboration d'un modèle de comportement élasto-plastique pour les craies très poreuses. Application à la compaction des réservoirs pétroliers

    Directory of Open Access Journals (Sweden)

    Shahrour I.

    2006-11-01

    Full Text Available This paper presents a study of the compaction of petroleum reservoirs applied to very porous carbonate rocks such as chalk. In production estimates made in reservoir engineering, the processing of the mechanical problem is often greatly simplified. Good modelling of how materials behave gives special consideration to the influence of mechanical deformations on fluid recovery. After an analysis of the mechanical behaviour of very porous chalks, an elastoplastic behaviour model is derived so as to reproduce the principal experimental observations. This behaviour model can then be used to perform local simulations of the mechanical behaviour of a reservoir under- going depletion and thus to demonstrate the importance of the stress path and the initial stress state on the deformation of materials and hence on the recovery rate. Dans les applications pétrolières, les études de la compaction des roches réservoirs interviennent dans l'estimation des quantités de fluide récupérables et de la subsidence induite par la déplétion du champ de production. Dans la première partie du travail, nous montrons qu'à partir de l'équation linéarisée de la conservation de la masse de fluide, il est possible d'exprimer un taux de récupération distinguant les contributions respectives du fluide et de la roche. En ingénierie de réservoirs, l'hypothèse d'un chemin de contrainte prépondérant dans le milieu de production permet d'exprimer la contribution de la déformation de la roche au moyen de la compressibilité volumique des pores selon ce chemin. Le taux de récupération obtenu est alors dépendant du chemin de contrainte. Lorsque le chemin de contrainte dans le réservoir n'est pas homogène, il est alors nécessaire de connaître la loi de comportement mécanique du matériau étudié. Dans le cas des carbonates très poreux, nous désirons montrer l'influence liée au choix du chemin de contrainte sur les estimations obtenues par une m

  6. Long-term alteration of cementitious materials

    International Nuclear Information System (INIS)

    Long-term alteration of cementitious materials in the geological condition has been discussed for the safety assessment of radioactive waste disposal. This paper describes the status of understanding long-term chemical alteration of cement, by reviewing some of our investigations on this issue in which we developed a thermodynamic incongruent C-S-H dissolution/precipitation model and a reactive transport calculation code. Alteration of C-S-H gel in a saline groundwater and the change of chemical barrier performance of cementitious materials due to the alteration are also discussed. Some key issues to be discussed further are given and suggested for the future studies on the long-term alteration of cementitious materials in the repository environment. (author)

  7. Aqueous Alteration on Mars. Chapter 23

    Science.gov (United States)

    Ming, Douglas W.; Morris, Richard V.; Clark, Benton C.

    2007-01-01

    Aqueous alteration is the change in composition of a rock, produced in response to interactions with H2O-bearing ices, liquids, and vapors by chemical weathering. A variety of mineralogical and geochemical indicators for aqueous alteration on Mars have been identified by a combination of surface and orbital robotic missions, telescopic observations, characterization of Martian meteorites, and laboratory and terrestrial analog studies. Mineralogical indicators for aqueous alteration include goethite (lander), jarosite (lander), kieserite (orbiter), gypsum (orbiter) and other Fe-, Mg-, and Ca-sulfates (landers), halides (meteorites, lander), phyllosilicates (orbiter, meteorites), hematite and nanophase iron oxides (telescopic, orbiter, lander), and Fe-, Mg-, and Ca-carbonates (meteorites). Geochemical indicators (landers only) for aqueous alteration include Mg-, Ca-, and Fe-sulfates, halides, and secondary aluminosilicates such as smectite. Based upon these indicators, several styles of aqueous alteration have been suggested on Mars. Acid-sulfate weathering (e.g., formation of jarosite, gypsum, hematite, and goethite), may occur during (1) the oxidative weathering of ultramafic igneous rocks containing sulfides, (2) sulfuric acid weathering of basaltic materials, and (3) acid fog (i.e., vapors rich in H2SO4) weathering of basaltic or basaltic-derived materials. Near-neutral or alkaline alteration occurs when solutions with pH near or above 7 move through basaltic materials and form phases such as phyllosilicates and carbonates. Very low water:rock ratios appear to have been prominent at most of the sites visited by landed missions because there is very little alteration (leaching) of the original basaltic composition (i.e., the alteration is isochemical or in a closed hydrologic system). Most of the aqueous alteration appears to have occurred early in the history of the planet (3 to 4.5 billion years ago); however, minor aqueous alteration may be occurring at the

  8. Influence of clay environment and of corroding canister on the long-term behaviour of nuclear glasses; Influence des materiaux argileux et des produits de corrosion du conteneur metallique sur le comportement a long terme des verres nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    GIn, St. [CEA Valrho, Dir. de l' Energie Nucleaire, DEN, 30 - Marcoule (France)

    1997-07-01

    This article reviews the current state of knowledge of R77 glass alteration mechanisms in the presence of the clay materials under consideration for use in an engineered barrier, and in the presence of metal canister corrosion products. These issues are addressed by a phenomenological approach and by modeling. In most cases, the codes are unable to account for the glass alteration data obtained in clay media. The main reason for this discrepancy lies in the glass alteration kinetics (a first-order law based exclusively on silicon) that do not take into account other elements including aluminum, zirconium or the rare earths, which are strongly mobilized in clay media. (author)

  9. Étude et modélisation du comportement d'un écoulement annulaire dispersé : application à la mesure de débit de gaz humide à l'aide d'un débitmètre à Venturi

    OpenAIRE

    Lupeau, Alexandre

    2005-01-01

    Le travail proposé a pour but d'apporter des éléments de compréhension sur le comportement d’un débitmètre gaz sec de type Venturi en configuration d'écoulement annulaire dispersé (gaz humide). Ce type d'écoulement se présente sous la forme d’un mélange gaz/liquide avec des fractions volumiques de gaz supérieures à 99%. Le liquide se répartit à l'intérieur des conduites sous forme de gouttes et d'un film ruisselant sur les parois. Ce sont les interactions entre le gaz et ces différents constitu...

  10. Étude de l'influence des défauts de soudage sur le comportement plastique et la durée de vie en fatigue de soudures par friction-malaxage d'un alliage Al-Cu-Li

    OpenAIRE

    Le Jolu, Thomas

    2011-01-01

    Dans un but de réduction de poids des avions, un alliage Al-Cu-Li (2198-T8) assemblé par friction-malaxage est envisagé par les avionneurs pour des applications de type fuselage et intrados de l'aile. L'objectif de cette étude est de déterminer le comportement en fatigue des soudures par friction-malaxage et l'influence de certains défauts de soudage pour une durée de vie de l'ordre de 105 cycles. Pour cela le matériau de base, des soudures réalisées pleine tôle (sans défaut), des soudures co...

  11. Effet du stress hydrique sur le comportement écophysiologique et la maturité phénolique de la vigne Vitis vinifera L. : étude de cinq cépages autochtones de Midi-Pyrénées

    OpenAIRE

    ATTIA, Faouzi

    2007-01-01

    Eu égard aux changements climatiques, la vigne est de plus en plus soumise à des conditions de sècheresse estivale prononcée, provoquant un stress hydrique important. Cette étude a porté sur les cinq principaux cépages du vignoble midi pyrénéen : Cot, Négrette, Tannat, Fer Servadou et Duras en situation de stress hydrique. Les études ont été réalisées en culture hydroponique sous serre en conditions contrôlées. Dans un premier temps, nous avons caractérisé l’état hydrique et le comportement é...

  12. Etude expérimentale du comportement magnétique du (La0,8Ca 0,2)MnO3 préparé par la méthode de co-précipitation

    OpenAIRE

    Tanaka, J.; Nozaki, H.; Horiuchi, S.; Tsukioka, M.

    1983-01-01

    La phase monoclinique de l'oxyde de manganèse complexe (La0,8Ca 0,2)MnO3 préparé par la méthode de co-précipitation présente un comportement magnétique particulier : l'aimantation diminue très rapidement à une température de 30 °C inférieure au point de transition ferromagnétique, où la résistivité électrique change. Cette diminution très rapide de l'aimantation peut être attribuée à une localisation soudaine du porteur. Un modèle possible de l'état du porteur localisé est proposé....

  13. Etude en laboratoire de l’effet du rapport de surconsolidation sur le comportement non drainé des sols. Laboratory study of overconsolidated ratio of the undrained soil behavior.

    Directory of Open Access Journals (Sweden)

    Khelafi H.

    2012-09-01

    Full Text Available Dans cet article, on présente une étude en laboratoire de l’influence du rapport de surconsolidation sur le comportement non drainé d’un sable limoneux. L’étude est basée sur des essais triaxiaux non drainés qui ont été réalisés pour des rapports de surconsolidation (OCR = 1, 2, 4 et 8 , à des fractions de fines particules du mélange variant entre 0% et 40% .Les essais ont été effectués sur des échantillons ayant une densité initiale Dr =50 %. L’article est scindé en deux parties principales. La première partie présente les sols étudiés ; la seconde partie donne une analyse des essais réalisés et discute de l’influence du rapport de surconsolidation sur la résistance du sol. Les essais montrent que l’augmentation du rapport de surconsolidation (OCR fait croître d’une manière considérable la résistance du sol se traduisant par une augmentation de la dilatance. L’augmentation de la fraction des fines ( Fc de 0 à 40 % augmente la phase de la contractance et par consequent reduit la phase de dilatance du sol étudié. Une décroissance de l’angle de frottement φ° est due a une forte teneur en fine (Fc =40% et à OCR = 1 ( sol normalement consolidé. In this paper, we present a laboratory study of the influence of overconsolidation ratio on the undrained behavior of silty sand. This study is based on the undrained triaxial tests which were performed for the overconsolidation ratio at OCR = 1, 2, 4 and 8, with fractions of fines of mixture varying between 0 % and 40 %. Tests were carried out on samples with an relative density Dr= 50% and confinement pressure σ’c = 100 kPa . The article is divided into two main parts. The first one presents the soils studied and the second one gives an analysis of the results and discusses the influence of overconsolidation ratio on the shear strength of the soil. The tests show that the shear strength of the soil increases with increasing overconsolidation ratio

  14. Comportement mécanique de la glace. Mécanismes de l'interaction glace/ouvrages en mer Mechanical Behavior of Ice. Interaction Mechanisms Between Ice and Offshore Structures

    Directory of Open Access Journals (Sweden)

    Putot C.

    2006-11-01

    Full Text Available Un bon dimensionnement des ouvrages en mer Arctique nécessite un calcul assez précis des forces exercées par les glaces dérivantes. En conditions hivernales, pour lesquelles, en mer de Beaufort notamment, la glace se déplace généralement lentement, les déformations sont dues au fluage et se caractérisent par des modifications graduelles : la glace contourne l'obstacle à la manière d'un écoulement visqueux. Ce type de comportement est bien connu de nos jours, de sorte que les efforts correspondants peuvent être prédits avec une certaine sûreté. Les difficultés surgissent aux vitesses élevées : ces dernières conditions sont celles de l'impact de glaces dérivantes en été. Les déformations par fluage sont impuissantes à redistribuer les efforts et ceux-ci s'accroissent donc jusqu'à la rupture brutale. C'est donc sur un scénario de fracturation par blocs que doit désormais porter l'attention, pour une meilleure appréciation des efforts qui autrement seraient fortement surestimés, lors de l'interaction aux vitesses élevées. En particulier, l'étude de l'amorçage et de la propagation des fissures par foisonnement des défauts inévitablement présents dans la glace, constitue une orientation capitale pour une meilleure compréhension des mécanismes d'endommagement précédant la formation de glace pilée, un des schémas de ruine classiques. The proper sizing of offshore arctic structures requires the quite accurate computing of the forces exerted by drifting ice. Under winterlike conditions, for which ice generally moves slowly, particularly in the Beaufort Sea, deformations are due to creep and are characterized by gradual modifications. The ice flows around the obstacle like viscous flow. This type of behavior is well known today, so that the corresponding stresses can be predicted with some reliability. However, difficulties occur with higher speeds, such as the impact of drifting ice in summer. Creep deformations

  15. Progrès récents de la connaissance du comportement mécanique des cavités salines Recent Progress in Understanding the Mechanical Behavior of Salt Cavities

    Directory of Open Access Journals (Sweden)

    Fauveau M.

    2006-11-01

    Full Text Available La diminution de volume des cavités salines exploitées à Tersanne depuis quinze ans a conduit le Gaz de France à développer des études sur la rhéologie du sel en collaboration avec des laboratoires universitaires. Ces études ont abouti à la mise au point d'un modèle rhéologique rendant compte des observations effectuées in situ. Simultanément ont été développés, en collaboration avec l'École Nationale Supérieure des Mines de Paris, des modèles numériques qui permettent d'effectuer des simulations du comportement mécanique des cavités. Le plus performant de ces modèles est le code VIPLEF. Validé par une confrontation avec des solutions analytiques et la simulation d'un cas réel (cavité TE O2 de Tersanne, ce programme a permis d'étudier l'influence de la forme d'une cavité sur sa perte de volume et d'ébaucher un critère de choix de forme optimale . Les récentes études ont également permis de mettre en évidence les paramètres qui concourent à la remontée du fond des cavités (gravité, gradient géothermique, stratigraphie, forme de la cavité, etc. , grâce à l'utilisation de ce modèle. De nombreuses intuitions de physiciens ont pu être ainsi confirmées et approfondies par le calcul numérique. The reduction in the geometric volume of the salt cavities used for gas storage at Tersanne, France, for 15 years led Gaz de France to undertake research on the rheology of salt in cooperation with university laboratories. This research led to the development of a rheological model describing in situ observations. At the same time, in collaboration with the Ecole Nationale Supérieure des Mines in Paris, numerical models were developed for simulating the mechanical behavior of cavities. The most effective such model is the VIPLEF code. Checked by comparison with analytical solutions and by simulation of an actual case (TE O2 cavity at Tersanne, this program was used to study the influence of the shape of a cavity on

  16. Comportment of the world photovoltaic market

    International Nuclear Information System (INIS)

    In this paper, we purpose to determine the world production of photovoltaic modules over the last decade. From 1987 to 1988, we note an increase of 23% and the world production reaches 35.2 M W p, it was the first real progress since 1983. This increase is due to a renewed on the renewable energies, caused by environment problems. Then, in view of the study of the development of photovoltaic in the world and of the behaviour of the most important countries, we realised analysis of the production. Using the time state of the market and perspectives study, we give some forecast for the next decade. (author)

  17. Comportement des pesticides ionisables dans les sols

    OpenAIRE

    Kah, Mélanie; Brown, Colin D.

    2007-01-01

    Ionisable pesticides can be partially ionised within the range of natural soil pH and this strongly influences their reactivity in soils. This group includes important, worldwide contaminants of groundwater and surface waters. It is essential that their specific behaviour is recognised within risk assessment procedures. Experiments were carried out with ten pesticides (six acids and four bases) and nine arable soils (range in pH, texture and organic matter content) to advance the understandin...

  18. Simulation Du Comportement Dynamique Du Voilier

    CERN Document Server

    Roncin, Kostia

    2010-01-01

    A simulator of two sailing boats in interaction is being made in order to provide sportsmen with a reliable analytical tool. We presently describe different models we used. Stationary hydrodynamics efforts have been specially evaluated. Experiences plan method has been implemented to exploit the towing tank tests made in the Fluids Mechanic Laboratory of Ecole Centrale de Nantes. Here are set out partial results of the model we achieved. At last, a simulator example illustrates the possibilities provided.

  19. Altering Flashlamp Output for Realistic Solar Simulation

    Science.gov (United States)

    Mueller, R. L.; Seaman, C. H.

    1985-01-01

    Commercial glass optical filter corrects spectrum of xenon flashtubes used to test photovoltaic solar cells. Filter withstands thousands of flashes without perceptible alteration of passband characteristics. With filter, calibration errors reduced to less than 1 percent.

  20. Borosilicate glass alteration driven by magnesium carbonates

    International Nuclear Information System (INIS)

    Highlights: ► We studied borosilicate glass/hydromagnesite interaction. ► Magnesium silicate precipitation increases glass alteration. ► Geochemical modeling allows to quantify the alteration mechanisms involved. - Abstract: The alteration of simplified synthetic glass, representative of the French reference nuclear glass R7T7, in presence of hydromagnesite has been experimentally investigated and modeled. Magnesium in solution is known to potentially enhance glass alteration; nuclear glass clayed host rocks contain magnesium and can dissolve to maintain the concentration of magnesium in solution. For modeling purposes, it was suitable to study a simple system. Hydromagnesite was therefore chosen as a simple model mineral in order to check the influence of an Mg-rich mineral on glass alteration. Since the models use thermodynamic and kinetic parameters measured in pure water and pH-buffered solutions, changing the solution composition or adding minerals is a key step towards the validation of the modeling assumptions before using the model for predictive purposes. Experiments revealed that glass alteration is enhanced in presence of hydromagnesite. Modeling was performed using the GRAAL model implemented within the CHESS/HYTEC reactive transport code. Modeling proved useful both for explaining the mechanisms involved and quantifying the impact on glass alteration: Mg coming from hydromagnesite dissolution reacts with Si provided by the glass in order to form magnesium silicates. This reaction decreases the pH down to neutral conditions where magnesium silicates are more soluble than at the natural alkali pH imposed by glass or hydromagnesite dissolution. The driving force of the magnesium silicate precipitation is eventually the interdiffusion of alkali within the altered amorphous glass layer as this mechanism consumes protons. The model’s ability to describe the concentrations of elements in solution and formed solids whatever the glass

  1. Diabetes and mitochondrial bioenergetics: Alterations with age

    OpenAIRE

    Ferreira, Fernanda M.; Palmeira, Carlos M.; Seiça, Raquel; Moreno, António J.; Santos, Maria S.

    2003-01-01

    Several studies have been carried out to evaluate the alterations in mitochondrial functions of diabetic rats. However, some of the results reported are controversial, since experimental conditions, such as aging, and/or strain of animals used were different. The purpose of this study was to evaluate the metabolic changes in liver mitochondria, both in the presence of severe hyperglycaemia (STZ-treated rats) and mild hyperglycaemia (Goto-Kakizaki (GK) rats). Moreover, metabolic alterations we...

  2. Sleep Deprivation Alters Choice Strategy Without Altering Uncertainty or Loss Aversion Preferences

    Directory of Open Access Journals (Sweden)

    O'Dhaniel A Mullette-Gillman

    2015-10-01

    Full Text Available Sleep deprivation alters decision making; however, it is unclear what specific cognitive processes are modified to drive altered choices. In this manuscript, we examined how one night of total sleep deprivation (TSD alters economic decision making. We specifically examined changes in uncertainty preferences dissociably from changes in the strategy with which participants engage with presented choice information. With high test-retest reliability, we show that TSD does not alter uncertainty preferences or loss aversion. Rather, TSD alters the information the participants rely upon to make their choices. Utilizing a choice strategy metric which contrasts the influence of maximizing and satisficing information on choice behavior, we find that TSD alters the relative reliance on maximizing information and satisficing information, in the gains domain. This alteration is the result of participants both decreasing their reliance on cognitively-complex maximizing information and a concomitant increase in the use of readily-available satisficing information. TSD did not result in a decrease in overall information use in either domain. These results show that sleep deprivation alters decision making by altering the informational strategies that participants employ, without altering their preferences.

  3. Alteration features in natural zirconolite from carbonatites

    International Nuclear Information System (INIS)

    In nature, zirconolite occurs as an accessory mineral in many different rock types, but the majority of reported occurrences are from carbonatites (magmatic carbonates) of geological age varying from a few million years to 2 billion years old. Within these 19 carbonatite occurrences, of which 15 have been studied in some detail, zirconolite displays varying degrees of alteration in six samples. This alteration ranges from incipient minor effects to major corrosion, recrystallization and complete replacement by secondary phases. The degree of alteration broadly correlates with either the age, or actinide content of the zirconolite (or both), and thus the extent and degree of metamictization. Changes in zirconolite composition with alteration include an increase in hydration (H2O), Si, Ba and Pb (possibly radiogenic in origin), and a decrease primarily in Ca and Fe. Th can be remobilized, and of the rare earth elements (REE), there is evidence that the heavy-REE are mobilized more readily than the light-REE. Using backscattered electron images and electron microprobe analyses, this study documents and illustrates the range of alteration features observed in zirconolite from several carbonatites, in terms of both compositional and textural changes, and provides some physico-chemical information on the fluids responsible for the alteration. Copyright (2001) Material Research Society

  4. Chronic hyperammonemia, glutamatergic neurotransmission and neurological alterations.

    Science.gov (United States)

    Llansola, Marta; Montoliu, Carmina; Cauli, Omar; Hernández-Rabaza, Vicente; Agustí, Ana; Cabrera-Pastor, Andrea; Giménez-Garzó, Carla; González-Usano, Alba; Felipo, Vicente

    2013-06-01

    This mini-review focus on our studies on alterations in glutamatergic neurotransmission and their role in neurological alterations in rat models of chronic hyperammonemia and hepatic encephalopathy (HE). Hyperammonemia impairs the glutamate-nitric oxide (NO)-cGMP pathway in cerebellum, which is responsible for reduced learning ability. We studied the underlying mechanisms and designed treatments to restore the pathway and learning. This was achieved by treatment with: phosphodiesterase 5 inhibitors, cGMP, anti-inflammatories (ibuprofen), p38 inhibitors or GABAA receptor antagonists (bicuculline). Hyperammonemia alters signal transduction associated to metabotropic glutamate receptors (mGluRs). Hypokinesia in hyperammonemia and HE is due to increased extracellular glutamate and mGluR1 activation in substantia nigra; blocking this receptor restores motor activity. The motor responses to mGluRs activation in nucleus accumbens (NAcc) are altered in hyperammonemia and HE, with reduced dopamine and increased glutamate release. This leads to activation of different neuronal circuits and enhanced motor responses. These studies show that altered responses to activation of NMDA receptors and mGluRs play essential roles in cognitive and motor alterations in hyperammonemia and HE and provide new treatments restoring cognitive and motor function. PMID:23010935

  5. Models for the Behavior of Offshore Structure Foundations. Part One: Methodologies and Rheological Models for Soils Modèles pour le comportement des fondations d'ouvrages types marins. Première partie : Méthodologies et modèles rhéologiques de sols

    Directory of Open Access Journals (Sweden)

    Meimon Y.

    2006-11-01

    structure. Prospects opened up by the research are discussed. La conception des fondations de grands ouvrages est une tâche complexe qui requiert à la fois l'expérience de l'expert et l'utilisation de modèles numériques adéquats pour assurer la sécurité et optimiser les coûts de dimensionnement. En fait, prévoir le comportement d'une fondation nécessite de bien évaluer les effets combinés de la technique de mise en place, de la variabilité spatiale des propriétés mécaniques, de l'incertitude sur les chargements et des techniques de modélisation du comportement mécanique des géomatériaux. Ceci est particulièrement vrai pour les plates-formes marines, qu'elles soient destinées à l'exploration ou à la production du pétrole, dans la mesure où les chargements non-monotones dus à l'environnement marin, souvent très sévère, peuvent avoir des effets très néfastes sur le comportement de ces structures. On présente, en deux parties, la synthèse d'une dizaine d'années d'activités de recherche, menées par une équipe de l'Institut Français du Pétrole (IFP, en collaboration avec plusieurs équipes universitaires et des centres techniques et industriels, pour la mise au point de méthodologies et d'outils adaptés au calcul du comportement des fondations d'ouvrages types marins durant toute la durée de vie de la plate-forme. Cet article concerne la première partie qui est dévolue à l'exposé des démarches développées et à la modélisation de l'état local des géomatériaux par des modèles rhéologiques. Démarches de modélisation du comportement des fondations d'ouvrages marins : On analyse d'abord la spécificité des fondations de plates-formes marines en insistant sur les différences avec les ouvrages à terre : dimension inusitée, chargement aléatoire par les éléments marins. On peut alors dégager plusieurs types de fondation (fig. 2. 1 et 2. 2 et les classes de problèmes qu'il est important d'étudier, qui recouvrent aussi

  6. Cerebrospinal fluid space alterations in melancholic depression.

    Directory of Open Access Journals (Sweden)

    Esther Via

    Full Text Available Melancholic depression is a biologically homogeneous clinical entity in which structural brain alterations have been described. Interestingly, reports of structural alterations in melancholia include volume increases in Cerebro-Spinal Fluid (CSF spaces. However, there are no previous reports of CSF volume alterations using automated whole-brain voxel-wise approaches, as tissue classification algorithms have been traditionally regarded as less reliable for CSF segmentation. Here we aimed to assess CSF volumetric alterations in melancholic depression and their clinical correlates by means of a novel segmentation algorithm ('new segment', as implemented in the software Statistical Parametric Mapping-SPM8, incorporating specific features that may improve CSF segmentation. A three-dimensional Magnetic Resonance Image (MRI was obtained from seventy patients with melancholic depression and forty healthy control subjects. Although imaging data were pre-processed with the 'new segment' algorithm, in order to obtain a comparison with previous segmentation approaches, tissue segmentation was also performed with the 'unified segmentation' approach. Melancholic patients showed a CSF volume increase in the region of the left Sylvian fissure, and a CSF volume decrease in the subarachnoid spaces surrounding medial and lateral parietal cortices. Furthermore, CSF increases in the left Sylvian fissure were negatively correlated with the reduction percentage of depressive symptoms at discharge. None of these results were replicated with the 'unified segmentation' approach. By contrast, between-group differences in the left Sylvian fissure were replicated with a non-automated quantification of the CSF content of this region. Left Sylvian fissure alterations reported here are in agreement with previous findings from non-automated CSF assessments, and also with other reports of gray and white matter insular alterations in depressive samples using automated approaches

  7. Alter(n – ein vielschichtiger Begriff

    Directory of Open Access Journals (Sweden)

    Nicole Maly-Lukas

    2005-07-01

    Full Text Available Diese Veröffentlichung, die aus einer Vortragsreihe an der katholischen Fachhochschule Freiburg entstanden ist, führt die Leserinnen und Leser in die verschiedenen Sichtweisen des Alter(ns in der modernen Gesellschaft ein. Es handelt sich um eine gelungene Zusammenstellung von Beiträgen aus unterschiedlichen Disziplinen, die sich alle aus ihrer Sicht dem Thema Alter(n widmen. Die einzelnen Artikel sind zwischen 8 und 38 Seiten lang und recht schnell und einfach zu lesen. Je nach Hintergrund und Interessen werden die einzelnen Leserinnen und Leser dabei sicher unterschiedliche Beiträge favorisieren. Schade ist nur, dass durch die ungleichen Längen der Beiträge bestimmte thematische Schwerpunkte – ob gewollt oder nicht – gesetzt werden. Dies sollte die Leserinnen und Leser, die offen für unterschiedlichste Sichtweisen des Alter(ns sind, jedoch nicht davon abhalten, dieses Buch zu lesen.

  8. Public health implications of altered puberty timing

    DEFF Research Database (Denmark)

    Golub, Mari S; Collman, Gwen W; Foster, Paul M D;

    2008-01-01

    sexual debut, potential sexual abuse, and psychosocial difficulties. Altered puberty timing is also of concern for the development of reproductive tract cancers later in life. For example, an early age of menarche is a risk factor for breast cancer. A low age at male puberty is associated....... Altered timing of puberty also has implications for behavioral disorders. For example, an early maturation is associated with a greater incidence of conduct and behavior disorders during adolescence. Finally, altered puberty timing is considered an adverse effect in reproductive toxicity risk assessment...... for chemicals. Recent US legislation has mandated improved chemical testing approaches for protecting children's health and screening for endocrine-disrupting agents, which has led to changes in the US Environmental Protection Agency's risk assessment and toxicity testing guidelines to include puberty...

  9. Bone alterations by stress in athletes

    International Nuclear Information System (INIS)

    This report describes our experiences with the bone imaging in athletes. We studied 10 athletes and 10 other patients with spondylolisthesis of the lumbar spine and 16 athletes with suspicion of alterations of extremities. An increased uptake of this radiopharmaceutical was detected in six of 10 athletes with spondylolisthesis caused probably by stress fracture. Bone scans were negative in seven of 16 athletes with suspicion of lesion of extremities. In the remaining 9 patients scans were abnormal and showed periosteal injuries, epiphyseal alteration, joint abnormalities, tibial stress fractures and couvert fracture. It was also abnormal in bone injuries not evident in radiography. (orig.)

  10. Public health implications of altered puberty timing

    DEFF Research Database (Denmark)

    Golub, M.S.; Collman, G.W.; Foster, P.M.;

    2008-01-01

    . Altered timing of puberty also has implications for behavioral disorders. For example, an early maturation is associated with a greater incidence of conduct and behavior disorders during adolescence. Finally, altered puberty timing is considered an adverse effect in reproductive toxicity risk assessment...... for chemicals. Recent US legislation has mandated improved chemical testing approaches for protecting children's health and screening for endocrine-disrupting agents, which has led to changes in the US Environmental Protection Agency's risk assessment and toxicity testing guidelines to include puberty......-related assessments and to the validation of pubertal male and female rat assays for endocrine screening Udgivelsesdato: 2008/2...

  11. Questions Regarding Alterity in Social Collaborative Networks

    Directory of Open Access Journals (Sweden)

    Florinela Floria

    2010-01-01

    Full Text Available The idea of alterity has become important in the last decades, when talking about the Information Age, which provides acknowledgement to the software development specialists about the importance of understanding the other’s behavior, needs, objectives and beliefs.
    Our main purpose is to bring to attention the question of social representation related to the images of individuals as different entities that are integrated in virtual teams, virtual projects and e-activities. Regarding the consciousness about the other’s alterity, we assert that it opens a dialogical perspective about the Information Society, where it is essential to share and communicate knowledge to the others.

  12. Portrét-Alter ego

    OpenAIRE

    BUČKOVÁ, Michaela

    2013-01-01

    The bachelor work is focused in the topic of alter ego in art, mainly in portrait and self- portrait. This work is diveded in two parts-theory and practical part. In the first part I´m interested in ?alter ego?- where it comes form, history (shamanism), these days ( body modification). In the sekond part I´m interested in person (as a whole unit), psychology and psychoanalysis. In the end of the theory I remember (notice) an author, who works with simile topics. In the practical part I descri...

  13. Gait Retraining: Altering the Fingerprint of Gait.

    Science.gov (United States)

    Davis, Irene S; Futrell, Erin

    2016-02-01

    In terms of running, there is evidence that links mechanics with injury. This evidence provides the justification for altering these mechanics. Increased hip adduction and vertical impact loading have been most commonly associated with injury. More work is needed in order to understand the optimal way to retrain gait patterns in runners. The human body has a considerable ability to adapt. To provide individuals with the ability to alter faulty movement patterns in ways that can reduce injury risk is a powerful tool. PMID:26616188

  14. Experimental Analysis of Impact Glass Alteration

    Science.gov (United States)

    Kalleson, E.; Dypvik, H.; Hellevang, H.

    2011-12-01

    Phyllosilicates have been suggested to commonly appear on the surface of Mars, mainly associated with Noachian successions. The formation of these aqueous minerals, indicate the presence of liquid water on an early Noachian Mars. In the present project we seek to better understand the alteration process of melt rocks, impact melt in particular. On the Earth large amounts of phyllosilicates have been detected in relation with impact craters and impact glass / melt. In the studies we use impact melt and glasses from different impact structures as starting materials for alteration experiments and modeling of mineral alteration / transformation products. The studied samples vary in age and lithology (glass, suevite and melt), with mineralogical composition partly reflecting the target lithologies at sites of impact. During impact some of the target rocks are melted by the intense heat. Some melt are ejected out of the crater, whereas about half of the melt remains within the impact structure. If water is present, hydrothermal systems may be established within the crater and exist for thousands of years after impact. In the experimental study we aim at representing possible alteration conditions of melt bearing rocks the first few thousand years after an impact. The samples are put into a saline solution containing 30 mg/l NaCl in Parr stirred titanium batch reactors at a temperature of 200 to 230 °C and 15 bar pressure for 3 weeks. The geochemistry / mineralogy of samples and reaction products are studied before and after the alteration experiments (dissolution and precipitation). The experimental results are compared to results of geochemical modeling (PHREEQC) in order to increase our understanding of the chemical reactions during alteration. The alterations products reflect the composition of both the source material and the percolation water. The first results (artificial melt and Chesapeake Bay impact melt) show the formation of smectite, chlinochlore, Fe

  15. Behaviour of a pre-stressed concrete pressure-vessel subjected to a high temperature gradient; Comportement d'un caisson en beton precontraint soumis a un gradient de temperature eleve

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Bonvalet, Ch.; Dawance, G.; Marechal, J.C. [Centre Experimental de Recherches et d' Etudes du Batiment et des Travaux Publics (CEBTP), 76 - Harfleur (France)

    1965-07-01

    results obtained make it possible both to draw up a programme for future tests and to propose a calculation model for pre-stressed concrete pressure-vessels. (authors) [French] Apres avoir rappele les problemes poses par les caissons pour les reacteurs atomiques (formes des caissons, pressions, ouvertures, fondations, etc.), on expose l'interet presente par les caissons en beton precontraint, par rapport aux caissons en acier. Toutefois, l'utilisation des caissons en beton precontraint souleve de nombreuses difficultes liees aux proprietes des betons. Ainsi, faute de connaissances approfondies du materiau, il est necessaire de placer une peau d'etancheite en acier contre le beton, d'avoir un isolant thermique ou un circuit de refroidissement pour limiter les deformations et les contraintes, etc. Par suite, l'etude du comportement du beton precontraint et du caisson soumis a un gradient eleve de temperature peut apporter des informations utiles. Une maquette au l/10eme d'un caisson cylindrique en beton precontraint sans fond ni ouverture laterale, a ete realisee. Avant de decrire les essais effectues, quelques considerations theoriques sont developpees concernant les conditions de similitude 'modele reduit - ouvrage reel' et le calcul des sollicitations thermiques et mecaniques. La maquette de caisson en beton precontraint etait chauffee interieurement par un element de pyrotenax et refroidie exterieurement par un violent courant d'air. Le beton etait precontraint par des cables horizontaux et verticaux a 80 kg/cm{sup 2}; le gradient thermique atteignait 160 deg. C, Les deformations globales et locales, la variation de la teneur en eau, le module d'elasticite, la tension et le fluage des cables, la profondeur des fissures ont ete mesures au cours des differents essais. Les deformations globales observees sont compatibles avec les theories des deformations thermiques et le fluage des cables a atteint 20 a 30 pour cent

  16. Connective tissue alteration in abdominal wall hernia

    DEFF Research Database (Denmark)

    Henriksen, N A; Yadete, D H; Sørensen, Lars Tue; Ågren, Sven Per Magnus; Jørgensen, Lars Nannestad

    2011-01-01

    The aetiology and pathogenesis of abdominal wall hernia formation is complex. Optimal treatment of hernias depends on a full understanding of the pathophysiological mechanisms involved in their formation. The aim of this study was to review the literature on specific collagen alterations in abdom...

  17. Acting: An Altered State of Consciousness.

    Science.gov (United States)

    Scheiffele, Eberhard

    2001-01-01

    Uses notions from the field Psychology of Consciousness, including an explanation of how psychologists define and investigate Altered States of Consciousness (ASCs). Argues that actors routinely enter an ASC. Establishes acting as a way to enter an ASC and discusses why theater artists, educators, and advocates need to be aware of both the dangers…

  18. Reorientation from Altered States: Please, More Carefully.

    Science.gov (United States)

    Heikkinen, Charles A.

    1989-01-01

    Claims counselors too often appear to forget to reorient clients from altered states of consciousness used in counseling and that failure to reorient can result in unnecessary discomfort for clients. Provides suggestions for when and how to reorient to avoid unwanted, lingering aftereffects. (Author/ABL)

  19. Direct alteration of a traumatic nightmare.

    Science.gov (United States)

    Halliday, G

    1982-04-01

    A brief case history of a young male farm worker who suffered recurrent nightmares subsequent to being run over by a tractor is given. A method for reducing the nightmares, by encouraging the patient to alter a small, emotionally nonsignificant detail of the dream, is then described. PMID:7079069

  20. Psychobiology of Altered States of Consciousness

    Science.gov (United States)

    Vaitl, Dieter; Birbaumer, Niels; Gruzelier, John; Jamieson, Graham A.; Kotchoubey, Boris; Kubler, Andrea; Lehmann, Dietrich; Miltner, Wolfgang H. R.; Ott, Ulrich; Sammer, Gebhard; Strauch, Inge; Strehl, Ute; Wackermann, Jiri; Weiss, Thomas

    2005-01-01

    The article reviews the current knowledge regarding altered states of consciousness (ASC) (a) occurring spontaneously, (b) evoked by physical and physiological stimulation, (c) induced by psychological means, and (d) caused by diseases. The emphasis is laid on psychological and neurobiological approaches. The phenomenological analysis of the…

  1. SEDAH. Data Server for hydrologic alteration evaluation

    International Nuclear Information System (INIS)

    Several tasks and studies have been developed from 2008 till 2010 all around the country in order to evaluate the hydrologic alteration of water bodies. In most cases this alteraction has been evaluated through IAHRIS (Martinez and Fernandez, 2006). The necessity of creating a new toll that allowed a better performance of the National Flow-Stage Stations Network data was showed up by developing these works. The output data series should match IAHRIS and IHA. SEDAH (Data Server for Evaluating Hydrologic Alteration) Helps to solve some of these problems by supplying an easy way to select flow stations, dates, flow series typology, etc. Moreover, other useful utilities are: a preliminary appraisement of quality data, calssification of altered or reference flow series and exportation of data in different file formats. The web application works with different data bases, daily, monthly and annual series belonging to, wither actual series from flow station data or completed series by statistical procedures. Through SEDAH the user has easy access to all this huge information ready for being applied in hydrologic alteration assessment, environmental fows regime, river restoration projects, etc. Furthermore, this first phase of the application constitute the basis for future powerful functionalities related to the natural flow series obtaining. (Author) 5 refs.

  2. Hemostasis alterations in metabolic syndrome (review).

    Science.gov (United States)

    Palomo, Iván; Alarcón, Marcelo; Moore-Carrasco, Rodrigo; Argilés, Josep M

    2006-11-01

    Metabolic syndrome (MS) is characterized by the presence of at least three of the following alterations: enlargement of the waist diameter, higher levels of arterial pressure, low density lipoprotein cholesterol and glycemia, and reduction of high density lipoprotein cholesterol. The prevalence of MS reaches 23% in young adults, a percentage that increases with age. People with MS have a greater risk of suffering from cardiovascular disease (CVD). The physiopathologic alterations now found to exist in MS are diverse; among them is endothelial dysfunction, which triggers atherogenic lesions and hypercoagulability characterized by alterations of the coagulation factors and the regulatory proteins of fibrinolysis such as the plasminogen activator inhibitor (PAI-1). The increase in oxidative stress and/or the reactive oxygen species in patients with MS is partially related to the oxidation state of the lipoproteins, especially of the low density lipoproteins. This fact favors atherogenesis. Moreover, the oxidative stress produces alterations in the production of adipokines, cytokines secreted by the adipose tissues. The abnormality in the transport of lipoprotein diminishes the catabolism of the very low density lipoprotein (VLDL) and increases the catabolism of the high density lipoprotein (HDL), which creates insulin resistance. This process is associated with a lower concentration of adiponectin that in turn regulates the catabolism of VLDL and HDL; consequently increasing the flow of fatty acids from the adipose tissue to the liver and muscles. The proinflammatory cytokines, among them tumor necrosis factor alpha (TNF-alpha), are of great importance in MS regulating different processes and molecules such as PAI-1. PAI-1 is controlled by the group of transcription factors peroxisome proliferator-activated receptor (PPAR), especially by PPAR gamma and alpha ligands. In summary, MS includes multiple alterations related to insulin resistance at several levels: hepatic

  3. Epigenetic alteration of sedimentary rocks at hydrogenic uranium deposit

    International Nuclear Information System (INIS)

    The author introduces the concept, the recognition criteria, the genesis and classification of the epigenetic alteration of sedimentary rocks in brief, and expounds the mineral-geochemical indications and characteristics of oxidation and reduction alterations in different geochemical zones in detail, and proposes the two models of ore-controlling zonation of epigenetic alteration. The authors finally introduce research methods of epigenetic alteration

  4. 28 CFR 36.403 - Alterations: Path of travel.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Alterations: Path of travel. 36.403... Alterations: Path of travel. (a) General. An alteration that affects or could affect the usability of or... the maximum extent feasible, the path of travel to the altered area and the restrooms, telephones,...

  5. Behaviour and passage of European silver eels (Anguilla anguilla at a small hydropower plant during their downstream migration Comportement et passage de l’anguille argentée (Anguilla anguilla au niveau d’une petite centrale hydroélectrique lors de sa migration de dévalaison

    Directory of Open Access Journals (Sweden)

    De-Oliveira E.

    2010-09-01

    Full Text Available Between 2004 and 2007, 116 downstream migrant silver eels (Anguilla anguilla were monitored at a hydropower plant on the Gave de Pau river in South-West France using radio and PIT telemetry. The objectives of the study were: (i to determine the environmental conditions when eels arrived and passed the facility; (ii to determine the rate of eel escapement (passage other than via the turbines; (iii to describe the behaviour of eels faced with the intake structure and the permeability of the intake trashracks for the different sizes of eel; and (iv to determine whether surface bypasses originally designed for salmon could be effective for eels. Five types of behaviour of silver eels in the forebay and at the plant intakes were identified. The study showed the key factor influencing both eel behaviour and the route taken through the plant was variation in river discharge. Escapement rate was related to eel length and the spill flow to river flow ratio, which could be described by a logistic regression model. The surface bypasses originally designed for salmon were found to aid downstream eel migration significantly. At velocities < 0.40 m·s−1, no eels, even the largest, for which the racks are a physical barrier, were found impinged on the trashracks. De 2004 à 2007, une étude sur la migration de dévalaison de l’anguille argentée européenne (Anguilla anguilla a été menée sur la centrale hydroélectrique de Baigts sur le Gave de Pau dans le Sud-Ouest de la France. Cette étude, au cours de laquelle 116 individus ont été suivis par télémétrie PIT et radio, avait pour objectifs : (i de déterminer les conditions de milieu propices à l’arrivée sur site et au franchissement de l’aménagement; (ii de déterminer les taux d’échappement (passages par des voies autres que les turbines; (iii d’analyser le comportement des anguilles devant les ouvrages et la perméabilité des grilles de la prise d’eau en fonction de la taille

  6. Microbial colonization and alteration of basaltic glass

    Directory of Open Access Journals (Sweden)

    J. Einen

    2006-03-01

    Full Text Available Microorganisms have been reported to be associated with the alteration of the glassy margin of seafloor pillow basalts (Thorseth et al., 2001, 2003; Lysnes et al., 2004. The amount of iron and other biological important elements present in basalts and the vast abundance of basaltic glass in the earth's crust, make glass alteration an important process in global element cycling. To gain further insight into microbial communities associated with glass alteration, five microcosm experiments mimicking seafloor conditions were inoculated with seafloor basalt and incubated for one year. Mineral precipitations, microbial attachment to the glass and glass alteration were visualized by scanning electron microscopy (SEM, and the bacterial community composition was fingerprinted by PCR and denaturing gradient gel electrophoresis (DGGE in combination with sequencing. SEM analysis revealed a microbial community with low morphological diversity of mainly biofilm associated and prosthecate microorganisms. Approximately 30 nm thick alteration rims developed on the glass in all microcosms after one year of incubation; this however was also seen in non inoculated controls. Calcium carbonate precipitates showed parallel, columnar and filamentous crystallization habits in the microcosms as well as in the sterile controls. DGGE analysis showed an alteration in bacterial community profiles in the five different microcosms, as a response to the different energy and redox regimes and time. In all microcosms a reduction in number of DGGE bands, in combination with an increase in cell abundance were recorded during the experiment. Sequence analysis showed that the microcosms were dominated by four groups of organisms with phylogenetic affiliation to four taxa: The Rhodospirillaceae, a family containing phototrophic marine organisms, in which some members are capable of heterotrophic growth in darkness and N2 fixation; the family Hyphomicrobiaceae, a group

  7. Hypergravity-induced altered behavior in Drosophila

    Science.gov (United States)

    Hosamani, Ravikumar; Wan, Judy; Marcu, Oana; Bhattacharya, Sharmila

    2012-07-01

    Microgravity and mechanical stress are important factors of the spaceflight environment, and affect astronaut health and behavior. Structural, functional, and behavioral mechanisms of all cells and organisms are adapted to Earth's gravitational force, 1G, while altered gravity can pose challenges to their adaptability to this new environment. On ground, hypergravity paradigms have been used to predict and complement studies on microgravity. Even small changes that take place at a molecular and genetic level during altered gravity may result in changes in phenotypic behavior. Drosophila provides a robust and simple, yet very reliable model system to understand the complexity of hypergravity-induced altered behavior, due to availability of a plethora of genetic tools. Locomotor behavior is a sensitive parameter that reflects the array of molecular adaptive mechanisms recruited during exposure to altered gravity. Thus, understanding the genetic basis of this behavior in a hypergravity environment could potentially extend our understanding of mechanisms of adaptation in microgravity. In our laboratory we are trying to dissect out the cellular and molecular mechanisms underlying hypergravity-induced oxidative stress, and its potential consequences on behavioral alterations by using Drosophila as a model system. In the present study, we employed pan-neuronal and mushroom body specific knock-down adult flies by using Gal4/UAS system to express inverted repeat transgenes (RNAi) to monitor and quantify the hypergravity-induced behavior in Drosophila. We established that acute hypergravity (3G for 60 min) causes a significant and robust decrease in the locomotor behavior in adult Drosophila, and that this change is dependent on genes related to Parkinson's disease, such as DJ-1α , DJ-1β , and parkin. In addition, we also showed that anatomically the control of this behavior is significantly processed in the mushroom body region of the fly brain. This work links a molecular

  8. Microbial colonization and alteration of basaltic glass

    Science.gov (United States)

    Einen, J.; Kruber, C.; Øvreås, L.; Thorseth, I. H.; Torsvik, T.

    2006-03-01

    Microorganisms have been reported to be associated with the alteration of the glassy margin of seafloor pillow basalts (Thorseth et al., 2001, 2003; Lysnes et al., 2004). The amount of iron and other biological important elements present in basalts and the vast abundance of basaltic glass in the earth's crust, make glass alteration an important process in global element cycling. To gain further insight into microbial communities associated with glass alteration, five microcosm experiments mimicking seafloor conditions were inoculated with seafloor basalt and incubated for one year. Mineral precipitations, microbial attachment to the glass and glass alteration were visualized by scanning electron microscopy (SEM), and the bacterial community composition was fingerprinted by PCR and denaturing gradient gel electrophoresis (DGGE) in combination with sequencing. SEM analysis revealed a microbial community with low morphological diversity of mainly biofilm associated and prosthecate microorganisms. Approximately 30 nm thick alteration rims developed on the glass in all microcosms after one year of incubation; this however was also seen in non inoculated controls. Calcium carbonate precipitates showed parallel, columnar and filamentous crystallization habits in the microcosms as well as in the sterile controls. DGGE analysis showed an alteration in bacterial community profiles in the five different microcosms, as a response to the different energy and redox regimes and time. In all microcosms a reduction in number of DGGE bands, in combination with an increase in cell abundance were recorded during the experiment. Sequence analysis showed that the microcosms were dominated by four groups of organisms with phylogenetic affiliation to four taxa: The Rhodospirillaceae, a family containing phototrophic marine organisms, in which some members are capable of heterotrophic growth in darkness and N2 fixation; the family Hyphomicrobiaceae, a group of prosthecate oligotrophic

  9. Experimental alteration of basalt glass applied to the alteration of nuclear waste glass

    International Nuclear Information System (INIS)

    The main objective of the experiments was to produce in the laboratory an altered basalt glass similar to basalt glass altered in a natural environment. This objective has been accomplished with a very good correlation between the observed alteration of basalt glass in a natural environment with that in the laboratory. The formation of the amorphous hydration layer, smectite, analcime, calcium carbonate, and thomsonite all have been observed in natural glass samples that have undergone palagonitization. The SRL 165 glass reacts to a greater extent than the synthetic basalt glass under the same conditions. The alteration of SRL 165 glass produced a smectite clay, analcime, and gyrolite similar to that produced by the synthetic basalt glass

  10. Postural Stability is Altered by Blood Shift

    Science.gov (United States)

    Marais, M.; Denise, P.; Guincetre, J. Y.; Normand, H.

    2008-06-01

    Non-vestibular influences as shift in blood volume changed perception of body posture. Then, factors affecting blood shift may alter postural control. The purpose of our study was to investigate the effects of leg venous contention on postural stability. Twelve subjects were studied on a balance plate for 5 minutes with the eyes closed, in 3 conditions: with no leg venous contention or grade 1 and 3 support stockings. Standard deviation of x and y position was calculated before and after the closure of the eyes. Strong venous contention altered postural stability, after the eyes were closed, during the first 10 s of standing. As support stockings prevent blood shift induced by upright posture, this result is in line with the hypothesis that blood shifts influence the perception of body orientation and postural control among others factors as vision, vestibular inputs... This strong venous contention could induce an increase of fall.

  11. Epigenetic alterations of sedimentary rocks at deposits

    International Nuclear Information System (INIS)

    Notions are explained, and technique for studying epigenetic alterations of sedimentary rocks at uranium deposits is described. Main types of epigenetic transformations and their mineralogic-geochemical characteristics are considered. Rock alterations, accompanying uranium mineralization, can be related to 2 types: oxidation and reduction. The main mineralogic-geochemical property of oxidation transformations is epigenetic limonitization. Stratal limonitization in primary grey-coloured terrigenic rocks and in epigenetically reduced (pyritized) rocks, as well as in rock, subjected to epigenetic gleying, are characterized. Reduction type of epigenetic transformations is subdivided into sulphidic and non-sulphidic (gley) subtypes. Sulphidic transformations in grey-coloured terrigenic rocks with organic substance of carbonic row, in rocks, containing organic substance of oil row, sulphide transformations of sedimentary rocks, as well as gley transformations, are considered

  12. White matter microstructure alterations in bipolar disorder

    Science.gov (United States)

    Bellani, Marcella; Perlini, Cinzia; Ferro, Adele; Cerruti, Stefania; Rambaldelli, Gianluca; Isola, Miriam; Cerini, Roberto; Dusi, Nicola; Andreone, Nicola; Balestrieri, Matteo; Mucelli, Roberto Pozzi; Tansella, Michele; Brambilla, Paolo

    2012-01-01

    Summary Genetic, neuropathological and magnetic resonance imaging findings support the presence of diffuse white matter cytoarchitectural disruption in bipolar disorder. In this study, diffusion-weighted imaging (DWI) was applied to study cortical white matter microstructure organisation in 24 patients with DSM-IV bipolar disorder and 35 matched normal controls. DWI images were obtained using a 1.5 Tesla scanner and apparent diffusion coefficient (ADC) values were determined over regions of interest placed, bilaterally, in the frontal, temporal, parietal, and occipital white matter. Significantly increased ADC values were found in bipolar patients with respect to normal controls in the right temporal lobe, left parietal lobe and bilateral occipital lobes. ADC values did not associate significantly with age or with clinical variables (p>0.05). Diffuse cortical white matter alterations on DWI in bipolar disorder denote widespread disruption of white matter integrity and may be due to altered myelination and/or axonal integrity. PMID:22687164

  13. Alteration of diaspore by thermal treatment

    Institute of Scientific and Technical Information of China (English)

    杨华明; 胡岳华; 杨武国; 敖伟琴; 邱冠周

    2004-01-01

    Diaspore (α-AlOOH) was heated at various temperatures from 300 to 1000 ℃ for 2 h. The alteration of diaspore by thermal treatment was investigated by differential thermal analysis, thermogravimetric analysis and X-ray diffraction. The mechanism of thermal decomposition of diaspore was discussed according to the Coats-Redfern equation. It is found that after thermal treatment at 500 ℃, diaspore is transformed entirely to corundum (α-Al2O3). Combined with the mass loss ratio obtained from the thermogravimetric analysis data, the activation energies for the thermal treatment of diaspore are calculated as Ea=10.4 kJ/mol below 400 ℃ and Eb=47.5 kJ/mol above 400 ℃, respectively, which is directly related to the structural alteration of diaspore during the thermal treatment. The results indicate that the thermal decomposition of diaspore is conducted primarily by means of an interfacial reaction.

  14. Altered Sensory Feedbacks in Pianist's Dystonia: the altered auditory feedback paradigm and the glove effect

    Directory of Open Access Journals (Sweden)

    Felicia Pei-Hsin Cheng

    2013-12-01

    Full Text Available Background: This study investigates the effect of altered auditory feedback (AAF in musician's dystonia (MD and discusses whether altered auditory feedback can be considered as a sensory trick in MD. Furthermore, the effect of AAF is compared with altered tactile feedback, which can serve as a sensory trick in several other forms of focal dystonia. Methods: The method is based on scale analysis (Jabusch et al. 2004. Experiment 1 employs synchronization paradigm: 12 MD patients and 25 healthy pianists had to repeatedly play C-major scales in synchrony with a metronome on a MIDI-piano with 3 auditory feedback conditions: 1. normal feedback; 2. no feedback; 3. constant delayed feedback. Experiment 2 employs synchronization-continuation paradigm: 12 MD patients and 12 healthy pianists had to repeatedly play C-major scales in two phases: first in synchrony with a metronome, secondly continue the established tempo without the metronome. There are 4 experimental conditions, among them 3 are the same altered auditory feedback as in Experiment 1 and 1 is related to altered tactile sensory input. The coefficient of variation of inter-onset intervals of the key depressions was calculated to evaluate fine motor control. Results: In both experiments, the healthy controls and the patients behaved very similarly. There is no difference in the regularity of playing between the two groups under any condition, and neither did AAF nor did altered tactile feedback have a beneficial effect on patients’ fine motor control. Conclusions: The results of the two experiments suggest that in the context of our experimental designs, AAF and altered tactile feedback play a minor role in motor coordination in patients with musicians' dystonia. We propose that altered auditory and tactile feedback do not serve as effective sensory tricks and may not temporarily reduce the symptoms of patients suffering from MD in this experimental context.

  15. Alterations of lipid metabolism in Wilson disease

    OpenAIRE

    Stremmel Wolfgang; Eckert Nicola; Pfeiffenberger Jan; Gotthardt Daniel; Gohdes Annina; Seessle Jessica; Reuner Ulrike; Weiss Karl

    2011-01-01

    Abstract Introduction Wilson disease (WD) is an inherited disorder of human copper metabolism, characterised by accumulation of copper predominantly in the liver and brain, leading to severe hepatic and neurological disease. Interesting findings in animal models of WD (Atp7b-/- and LEC rats) showed altered lipid metabolism with a decrease in the amount of triglycerides and cholesterol in the serum. However, serum lipid profile has not been investigated in large human WD patient cohorts to dat...

  16. Inflammation and Immune System Alterations in Frailty

    OpenAIRE

    Yao, Xu; Li, Huifen; Leng, Sean X.

    2011-01-01

    Frailty is an important geriatric syndrome characterized by multi-system dysregulation. Substantial evidence suggests heightened inflammatory state and significant immune system alterations in frailty. A heightened inflammatory state is marked by increases in levels of inflammatory molecules (IL-6 and CRP) and counts of white blood cell and its subpopulations, which may play an important role in the pathogenesis of frailty, directly or through its detrimental influence to other physiologic sy...

  17. Postoperative Alterations in Taste and Smell

    OpenAIRE

    Elterman, Kelly Galina; Mallampati, Seshagiri Rao; Kaye, Alan David; Urman, Richard Dennis

    2014-01-01

    Context: Alterations in taste and smell, including but not limited to anosmia, ageusia, hypogeusia, and dysgeusia, have been described in association with various medications, including anesthetic agents. Frequently, these symptoms occur 1-2 weeks after medication administration and last several months. While such a phenomenon is a rare occurrence, it nonetheless can significantly impact patients’ satisfaction and quality of life. Evidence Acquisition: The methodology consisted of a thorough ...

  18. Questions Regarding Alterity in Social Collaborative Networks

    OpenAIRE

    Florinela Floria; Cosmin Ion Tomozei

    2010-01-01

    The idea of alterity has become important in the last decades, when talking about the Information Age, which provides acknowledgement to the software development specialists about the importance of understanding the other’s behavior, needs, objectives and beliefs.
    Our main purpose is to bring to attention the question of social representation related to the images of individuals as different entities that are integrated in virtual teams, virtual projects and e-activities....

  19. Altered Levels of Acetylcholinesterase in Alzheimer Plasma

    OpenAIRE

    García Ayllón, María Salud; Riba Llena, Iolanda; Serra Basante, Carol; Alom, Jordi; Boopathy, Rathnam; Sáez-Valero, Javier

    2010-01-01

    Background Many studies have been conducted in an extensive effort to identify alterations in blood cholinesterase levels as a consequence of disease, including the analysis of acetylcholinesterase (AChE) in plasma. Conventional assays using selective cholinesterase inhibitors have not been particularly successful as excess amounts of butyrylcholinesterase (BuChE) pose a major problem. Principal Findings Here we have estimated the levels of AChE activity in human plasma by first imm...

  20. Alteration of pulmonary function in diabetic nephropathy

    OpenAIRE

    Shafiee, Gita; Khamseh, Mohammad E.; Rezaei, Nader; Aghili, Rokhsareh; MALEK, Mojtaba

    2013-01-01

    Background Type 2 diabetes mellitus is increasing worldwide with an alarming rate. It is associated with the development of various chronic complications. The aim of this study was to explore the alteration of pulmonary function, and its association with renal complications in people with type 2 diabetes mellitus. Methods This cross-sectional study was conducted on three groups; 40 diabetic subjects without nephropathy (urinary albumin300 mg/day) .Diabetic subjects were matched to the control...

  1. Saccadic Alterations in Severe Developmental Dyslexia

    OpenAIRE

    Stefano Pensiero; Paolo Brambilla; Agostino Accardo; Paola Michieletto

    2013-01-01

    It is not sure if persons with dyslexia have ocular motor deficits in addition to their deficits in rapid visual information processing. A 15-year-old boy afflicted by severe dyslexia was submitted to saccadic eye movement recording. Neurological and ophthalmic examinations were normal apart from the presence of an esophoria for near and slightly longer latencies of pattern visual evoked potentials. Subclinical saccadic alterations were present, which could be at the basis of the reading path...

  2. Altered Gait Termination Strategies Following a Concussion

    OpenAIRE

    Buckley, Thomas A.; Munkasy, Barry A.; Tapia-Lovler, Tiffen G.; Wikstrom, Erik A.

    2013-01-01

    The purpose was to determine if planned gait termination can identify acute and lingering motor control strategy alterations in post-concussion individuals. Controls completed 2 standard gait and 5 planned gait termination trials once while concussed individuals were tested on Day-1 and Day-10 post-concussion. Dependent variables included gait velocity and normalized, relative to standard gait, peak propulsive and braking forces. Control and only Day-1 post-concussion gait velocity differed. ...

  3. Glaucoma Alters the Circadian Timing System

    OpenAIRE

    Drouyer, Elise; Dkhissi-Benyahya, Ouria; Chiquet, Christophe; WoldeMussie, Elizabeth; Ruiz, Guadalupe; Wheeler, Larry A.; Denis, Philippe; Cooper, Howard M.

    2008-01-01

    Glaucoma is a widespread ocular disease and major cause of blindness characterized by progressive, irreversible damage of the optic nerve. Although the degenerative loss of retinal ganglion cells (RGC) and visual deficits associated with glaucoma have been extensively studied, we hypothesize that glaucoma will also lead to alteration of the circadian timing system. Circadian and non-visual responses to light are mediated by a specialized subset of melanopsin expressing RGCs that provide photi...

  4. Adaptive optics without altering visual perception

    OpenAIRE

    Koenig,, I.; NW, Hart; HJ, Hofer

    2014-01-01

    Adaptive optics combined with visual psychophysics creates the potential to study the relationship between visual function and the retina at the cellular scale. This potential is hampered, however, by visual interference from the wavefront-sensing beacon used during correction. For example, we have previously shown that even a dim, visible beacon can alter stimulus perception (Hofer, H. J., Blaschke, J., Patolia, J., & Koenig, D. E. (2012). Fixation light hue bias revisited: Implications for ...

  5. Ocean acidification alters fish-jellyfish symbiosis.

    Science.gov (United States)

    Nagelkerken, Ivan; Pitt, Kylie A; Rutte, Melchior D; Geertsma, Robbert C

    2016-06-29

    Symbiotic relationships are common in nature, and are important for individual fitness and sustaining species populations. Global change is rapidly altering environmental conditions, but, with the exception of coral-microalgae interactions, we know little of how this will affect symbiotic relationships. We here test how the effects of ocean acidification, from rising anthropogenic CO2 emissions, may alter symbiotic interactions between juvenile fish and their jellyfish hosts. Fishes treated with elevated seawater CO2 concentrations, as forecast for the end of the century on a business-as-usual greenhouse gas emission scenario, were negatively affected in their behaviour. The total time that fish (yellowtail scad) spent close to their jellyfish host in a choice arena where they could see and smell their host was approximately three times shorter under future compared with ambient CO2 conditions. Likewise, the mean number of attempts to associate with jellyfish was almost three times lower in CO2-treated compared with control fish, while only 63% (high CO2) versus 86% (control) of all individuals tested initiated an association at all. By contrast, none of three fish species tested were attracted solely to jellyfish olfactory cues under present-day CO2 conditions, suggesting that the altered fish-jellyfish association is not driven by negative effects of ocean acidification on olfaction. Because shelter is not widely available in the open water column and larvae of many (and often commercially important) pelagic species associate with jellyfish for protection against predators, modification of the fish-jellyfish symbiosis might lead to higher mortality and alter species population dynamics, and potentially have flow-on effects for their fisheries. PMID:27358374

  6. Chromite alteration processes within Vourinos ophiolite

    Science.gov (United States)

    Grieco, Giovanni; Merlini, Anna

    2012-09-01

    The renewed interest in chromite ore deposits is directly related to the increase in Cr price ruled by international market trends. Chromite, an accessory mineral in peridotites, is considered to be a petrogenetic indicator because its composition reflects the degree of partial melting that the mantle experienced while producing the chromium spinel-bearing rock (Burkhard in Geochim Cosmochim Acta 57:1297-1306, 1993). However, the understanding of chromite alteration and metamorphic modification is still controversial (e.g. Evans and Frost in Geochim Cosmochim Acta 39:959-972, 1975; Burkhard in Geochim Cosmochim Acta 57:1297-1306, 1993; Oze et al. in Am J Sci 304:67-101, 2004). Metamorphic alteration leads to major changes in chromite chemistry and to the growth of secondary phases such as ferritchromite and chlorite. In this study, we investigate the Vourinos complex chromitites (from the mines of Rizo, Aetoraches, Xerolivado and Potamia) with respect to textural and chemical analyses in order to highlight the most important trend of alteration related to chromite transformation. The present study has been partially funded by the Aliakmon project in collaboration between the Public Power Corporation of Greece and Institute of Geology and Mineral Exploration of Kozani.

  7. Altered DNA methylation in PAH deficient phenylketonuria.

    Science.gov (United States)

    Dobrowolski, Steven F; Lyons-Weiler, James; Spridik, Kayla; Biery, Amy; Breck, Jane; Vockley, Jerry; Yatsenko, Svetlana; Sultana, Tamanna

    2015-01-01

    While phenylalanine (PHE) is the toxic insult in phenylketonuria (PKU), mechanisms underlying PHE toxicity remain ill-defined. Altered DNA methylation in response to toxic exposures is well-recognized. DNA methylation patterns were assessed in blood and brain from PKU patients to determine if PHE toxicity impacts methylation. Methylome assessment, utilizing methylated DNA immunoprecipitation and paired-end sequencing, was performed in DNA obtained from brain tissue of classical PKU patients, leukocytes from poorly controlled PKU patients, leukocytes from well controlled PKU patients, and appropriate control tissues. In PKU brain tissue, expression analysis determined the impact of methylation on gene function. Differential methylation was observed in brain tissue of PKU patients and expression studies identified downstream impact on gene expression. Altered patterns of methylation were observed in leukocytes of well controlled and poorly controlled patients with more extensive methylation in patients with high PHE exposure. Differential methylation of noncoding RNA genes was extensive in patients with high PHE exposure but minimal in well controlled patients. Methylome repatterning leading to altered gene expression was present in brain tissue of PKU patients, suggesting a role in neuropathology. Aberrant methylation is observed in leukocytes of PKU patients and is influenced by PHE exposure. DNA methylation may provide a biomarker relating to historic PHE exposure. PMID:25990862

  8. Alterations of lipid metabolism in Wilson disease

    Directory of Open Access Journals (Sweden)

    Stremmel Wolfgang

    2011-05-01

    Full Text Available Abstract Introduction Wilson disease (WD is an inherited disorder of human copper metabolism, characterised by accumulation of copper predominantly in the liver and brain, leading to severe hepatic and neurological disease. Interesting findings in animal models of WD (Atp7b-/- and LEC rats showed altered lipid metabolism with a decrease in the amount of triglycerides and cholesterol in the serum. However, serum lipid profile has not been investigated in large human WD patient cohorts to date. Patients and Methods This cohort study involved 251 patients examined at the Heidelberg and Dresden (Germany University Hospitals. Patients were analysed on routine follow-up examinations for serum lipid profile, including triglycerides, cholesterol, high density lipoprotein (HDL and low density lipoprotein (LDL. Data on these parameters at time of diagnosis were retrieved by chart review where available. For statistical testing, patients were subgrouped by sex, manifestation (hepatic, neurological, mixed and asymptomatic and treatment (D-penicillamine, trientine, zinc or combination. Results A significant difference in total serum cholesterol was found in patients with hepatic symptoms, which diminished under therapy. No alterations were observed for HDL, LDL and triglycerides. Conclusion Contradictory to previous reports using WD animal models (Atp7b-/- and LEC rats, the most obvious alteration in our cohort was a lower serum cholesterol level in hepatic-affected patients, which might be related to liver injury. Our data suggested unimpaired cholesterol metabolism in Wilson disease under therapy, independent of the applied medical treatment.

  9. Graviresponses of osteocytes under altered gravity

    Science.gov (United States)

    Di, S. M.; Qian, A. R.; Qu, L. N.; Zhang, W.; Wang, Z.; Ding, C.; Li, Y. H.; Ren, H. G.; Shang, P.

    2011-09-01

    Single cell was capable of sensing and responding to alterations of gravity. Osteocytes, as the most abundant cells of the bone tissue playing an important role in the bone mechanotransduction, are very sensitive to mechanical stimuli. However, the effect of altered gravity on osteocytes so far is less known according to the public papers. Further study on this issue will help to verify and develop the theory of how cells perceive and respond to gravity. It also brings new ideas to the study of space bone loss. In our study, Osteocyte-like MLO-Y4 cells were exposed to 30 parabolic flights three times on ZERO-G airbus A300 to investigate the comprehensive effect on osteocytes stimulated by hyper- and hypo-gravity forces. It showed that the cell morphology, as well as cell area and height, was not changed significantly by hyper-gravity and hypo-gravity. However, the cytoskeleton was reorganized. In flight cells, F-actin polymerization was enhanced at the cell periphery and microtubule organizing center disappeared, but no apoptotic feathers were detected. The results of western blot showed that connexin 43 (Cx43) expression was down-regulated, indicating an decrease of gap-junction. In conclusion, hyper- and hypo-gravity stimulation altered the cytoskeleton architecture and suppressed gap-junction of osteocyte-like MLO-Y4 cells.

  10. Is Obesity Associated with Altered Energy Expenditure?

    Science.gov (United States)

    Carneiro, Isabella P; Elliott, Sarah A; Siervo, Mario; Padwal, Raj; Bertoli, Simona; Battezzati, Alberto; Prado, Carla M

    2016-05-01

    Historically, obese individuals were believed to have lower energy expenditure (EE) rates than nonobese individuals (normal and overweight), which, in the long term, would contribute to a positive energy balance and subsequent weight gain. The aim of this review was to critically appraise studies that compared measures of EE and its components, resting EE (REE), activity EE (AEE), and diet-induced thermogenesis (DIT), in obese and nonobese adults to elucidate whether obesity is associated with altered EE. Contrary to popular belief, research has shown that obese individuals have higher absolute REE and total EE. When body composition (namely the metabolically active component, fat-free mass) is taken into account, these differences between obese and nonobese individuals disappear, suggesting that EE in obese individuals is not altered. However, an important question is whether AEE is lower in obese individuals because of a decrease in overall physical activity or because of less energy expended while performing physical activity. AEE and DIT could be reduced in obese individuals, mostly because of unhealthy behavior (low physical activity, higher intake of fat). However, the current evidence does not support the hypothesis that obesity is sustained by lower daily EE or REE. Future studies, comparing EE between obese and nonobese and assessing potential physiologic abnormalities in obese individuals, should be able to better answer the question of whether these individuals have altered energy metabolism. PMID:27184275

  11. Experimental study of kinetic and mechanism of dissolution of apatite structured minerals. Application to the prediction of the long term behavior of an actinides storage host matrix; Etude experimentale de la cinetique et des mecanismes d'alteration de mineraux apatitiques. Application au comportement d'une ceramique de confinement d'actinides mineurs

    Energy Technology Data Exchange (ETDEWEB)

    Chairat, C

    2005-11-15

    The motivation for this study is to assess the potential of using apatite structured ceramics as long-lived actinide storage hosts. To assess their ability to resist aqueous corrosion, the dissolution of natural fluoro-apatite and synthetic Nd-britholite (neodymium is a proxy for the trivalent actinides) was studied. Mineral surfaces were characterized using a combined spectrometric, electrokinetic and potentiometric approach and dissolution rates were measured in closed and open system reactors as a function of solution composition. Experimental results suggest apatitic minerals dissolve via distinct step sequence: 1) fluoride release, 2) release of the calcium situated in the M1, and 3) the simultaneous removal of phosphate and calcium II via the breaking of only Ca-O bonds. TST based rate equations based in this mechanism accurately describe fluoro-apatite and synthetic britholite dissolution rates as a function of solution composition. Nd release rates are limited by precipitation of Nd-rhabdophane. (author)

  12. Iceland as a Model for Chemical Alteration on Mars

    Science.gov (United States)

    Bishop, Janice L.; Schiffman, P.; Murad, E.; Southard, R.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    Subglacial volcanic activity on Iceland has led to the formation of a variety of silicate and iron oxide-rich alteration products that may serve as a model for chemical alteration on Mars. Multiple palagonitic tuffs, altered pillow lavas, hydrothermal springs and alteration at glacial run-off streams were observed during a recent field trip in Iceland. Formation of alteration products and ferrihydrite in similar environments on Mars may have contributed to the ferric oxide-rich surface material there. The spectral and chemical properties of Icelandic alteration products and ferrihydrites are presented here.

  13. I comportamenti violenti nel sonno REM: aspetti clinici, criminologici e medico-legali / Les comportements violents pendant le sommeil MOR : aspects cliniques, criminologiques et médico-légaux / The Violent Behaviour in REM Sleep-related: Clinical, Criminological and Forensic Aspects

    Directory of Open Access Journals (Sweden)

    Cimino Luca

    2011-04-01

    Full Text Available The violent behaviour of sleep represents a new frontier of forensic interest. After examining the clinical aspects of a particular form of parasomnia related to REM stage of sleep, called REM Behavior Disorder-RBD, the author highlights the criminological and forensic implications emphasizing the distinctive features in terms of responsibility and imputability.Les comportements violents pendant le sommeil MOR représentent une nouvelle “frontière” d’intérêt de la psychologie médico-légale. Après avoir examiné les aspects cliniques d’une forme particulière de parasomnie liée à la phase MOR du sommeil (denominata REM Behaviour Disorders-RBD, l’auteur de l’article met en évidence ses implications criminologiques et médico-légales; en outre, il souligne les aspects particuliers de cette parasomnie en matière de responsabilité et d’imputabilité.I comportamenti violenti del sonno rappresentano una nuova “frontiera” di interesse forense. L’autore, dopo aver esaminato gli aspetti clinici di una particolare forma di parasonnia legata alla fase REM del sonno, denominata REM Behaviour Disorders-RBD, ne sottolinea le implicazioni criminologiche e medico-legali sottolineandone gli aspetti peculiari in tema di colpa ed imputabilità.

  14. Enamel alteration following tooth bleaching and remineralization.

    Science.gov (United States)

    Coceska, Emilija; Gjorgievska, Elizabeta; Coleman, Nichola J; Gabric, Dragana; Slipper, Ian J; Stevanovic, Marija; Nicholson, John W

    2016-06-01

    The purpose of this study was to compare the effects of professional tooth whitening agents containing highly concentrated hydrogen peroxide (with and without laser activation), on the enamel surface; and the potential of four different toothpastes to remineralize any alterations. The study was performed on 50 human molars, divided in two groups: treated with Opalescence(®) Boost and Mirawhite(®) Laser Bleaching. Furthermore, each group was divided into five subgroups, a control one and 4 subgroups remineralized with: Mirasensitive(®) hap+, Mirawhite(®) Gelleѐ, GC Tooth Mousse™ and Mirafluor(®) C. The samples were analysed by SEM/3D-SEM-micrographs, SEM/EDX-qualitative analysis and SEM/EDX-semiquantitative analysis. The microphotographs show that both types of bleaching cause alterations: emphasized perikymata, erosions, loss of interprizmatic substance; the laser treatment is more aggressive and loss of integrity of the enamel is determined by shearing off the enamel rods. In all samples undergoing remineralization deposits were observed, those of toothpastes based on calcium phosphate technologies seem to merge with each other and cover almost the entire surface of the enamel. Loss of integrity and minerals were detected only in the line-scans of the sample remineralized with GC Tooth Mousse™. The semiquantitative EDX analysis of individual elements in the surface layer of the enamel indicates that during tooth-bleaching with HP statistically significant loss of Na and Mg occurs, whereas the bleaching in combination with a laser leads to statistically significant loss of Ca and P. The results undoubtedly confirm that teeth whitening procedures lead to enamel alterations. In this context, it must be noted that laser bleaching is more aggressive for dental substances. However, these changes are reversible and can be repaired by application of remineralization toothpastes. PMID:27197087

  15. Alterations of 5-Hydroxymethylcytosine in Human Cancers

    Directory of Open Access Journals (Sweden)

    Ali Yesilkanal

    2013-06-01

    Full Text Available Prior to 2009, 5-methylcytosine (5-mC was thought to be the only biologically significant cytosine modification in mammalian DNA. With the discovery of the TET enzymes, which convert 5-methylcytosine (5-mC to 5-hydroxymethylcytosine (5-hmC, however, intense interest has emerged in determining the biological function of 5-hmC. Here, we review the techniques used to study 5-hmC and evidence that alterations to 5-hmC physiology play a functional role in the molecular pathogenesis of human cancers.

  16. Metabolic alterations during ascosporogenesis of Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Sporulation of S. cerevisiae has been shown to alter the profiles of enzymes involved in gluconeogenesis and glycolysis. The enhancement in the levels of total cellular carbohydrates could be correlated with the enhancement in fructose 1,6-diphosphatase and trehalose-phosphate synthetase. The latter activity could account for the 15-fold increase in trehalose levels in sporulating cells. Glucose-6-phosphatase, pyruvate kinase and phosphofructokinase showed continuous decline during ascosporogenesis. The relative incorporation of radioactivity from possible precursors of gluconeogenesis indicated that acetate-2-14C alone could contribute to carbohydrate synthesis. (author)

  17. Genitourinary echography alterations in the pseudoxanthoma elasticum

    International Nuclear Information System (INIS)

    This is the case of a black male sex patient aged 13 diagnosed with elastic. Renal and testicular ultrasonographic study showed echo-refractive images in testes and kidneys without neither acoustic shadow nor alterations of renal function or of the urinary sediment. There was not a family history of cutaneous lesions related with this entity. These renal and testicular findings have been documented in the medical literature, thus, authors recommended that its popularization is interesting since it has been proposed that they are part of the disease phenotype

  18. SON68 glass alteration enhanced by magnetite

    International Nuclear Information System (INIS)

    This paper reports experimental and modeling results of SON68 glass / magnetite interactions while in contact with synthetic groundwater from a clay environment. It is shown that magnetite enhances glass alteration, first by the sorption of Si released from the glass onto magnetite surfaces, then by a second process that could be the precipitation of an iron silicate mineral or the transformation of magnetite into a more reactive phase like hematite or goethite. This study globally suggests a detrimental effect of magnetite on the long-term durability of nuclear glass in geological disposal conditions. (authors)

  19. 28 CFR 36.404 - Alterations: Elevator exemption.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Alterations: Elevator exemption. 36.404... Alterations: Elevator exemption. (a) This section does not require the installation of an elevator in an... facility has an elevator....

  20. Time is the key Music and Altered States of Consciusness

    OpenAIRE

    Fachner, Jörg

    2011-01-01

    Introduction: In this chapter, I will summarize the literature on how music and altered states of consciousness (ASC) are connected. Essential aspects include induction and expression of emotions and rhythmic body movements to music and how an altered experience of music is connected to states of altered temporality. Winkelman (2000) stressed the human capacity for experiencing ASC as a fundamental biological function. Studies on brain functions of altered music experience a...

  1. Female genital alteration: a compromise solution.

    Science.gov (United States)

    Arora, Kavita Shah; Jacobs, Allan J

    2016-03-01

    Despite 30 years of advocacy, the prevalence of non-therapeutic female genital alteration (FGA) in minors is stable in many countries. Educational efforts have minimally changed the prevalence of this procedure in regions where it has been widely practiced. In order to better protect female children from the serious and long-term harms of some types of non-therapeutic FGA, we must adopt a more nuanced position that acknowledges a wide spectrum of procedures that alter female genitalia. We offer a revised categorisation for non-therapeutic FGA that groups procedures by effect and not by process. Acceptance of de minimis procedures that generally do not carry long-term medical risks is culturally sensitive, does not discriminate on the basis of gender, and does not violate human rights. More morbid procedures should not be performed. However, accepting de minimis non-therapeutic f FGA procedures enhances the effort of compassionate practitioners searching for a compromise position that respects cultural differences but protects the health of their patients. PMID:26902479

  2. Nucleolar proteins change in altered gravity

    Science.gov (United States)

    Sobol, M. A.; Kordyum, E. L.; Gonzalez-Camacho, F.; Medina, F. J.

    Discovery of gravisensitivity of cells no specified to gravity perception focused continuous attention on an elucidation of mechanisms involved in altered gravity effects at the different levels of cellular organization A nucleolus is the nuclear domain in which the major portion of ribosome biogenesis takes place This is a basic process for cell vitality beginning with the transcription of rDNA followed by processing newly synthesized pre-rRNA molecules A wide range of nucleolar proteins plays a highly significant role in all stages of biosynthesis of ribosomes Different steps of ribosome biogenesis should respond to various external factors affecting generally the cell metabolism Nevertheless a nucleolus remains not enough studied under the influence of altered environmental conditions For this reason we studied root apices from 2-day old Lepidium sativum seedlings germinated and grown under slow horizontal clinorotation and stationary conditions in darkness The extraction of cell nuclei followed by sequential fractionation of nuclear proteins according to their solubility in buffers of increasing ionic strength was carried out This procedure gave rise to 5 distinct fractions We analyzed nuclear subproteomes of the most soluble fraction called S2 It is actually a functionally significant fraction consisting of ribonucleoproteins actively engaged in pre-rRNA synthesis and processing 2D-electrophoresis of S2 fraction proteins was carried out The gels were silver stained and stained gels were scanned and analyzed

  3. Origins of altered reinforcement effects in ADHD

    Directory of Open Access Journals (Sweden)

    Tripp Gail

    2009-02-01

    Full Text Available Abstract Attention-deficit/hyperactivity disorder (ADHD, characterized by hyperactivity, impulsiveness and deficient sustained attention, is one of the most common and persistent behavioral disorders of childhood. ADHD is associated with catecholamine dysfunction. The catecholamines are important for response selection and memory formation, and dopamine in particular is important for reinforcement of successful behavior. The convergence of dopaminergic mesolimbic and glutamatergic corticostriatal synapses upon individual neostriatal neurons provides a favorable substrate for a three-factor synaptic modification rule underlying acquisition of associations between stimuli in a particular context, responses, and reinforcers. The change in associative strength as a function of delay between key stimuli or responses, and reinforcement, is known as the delay of reinforcement gradient. The gradient is altered by vicissitudes of attention, intrusions of irrelevant events, lapses of memory, and fluctuations in dopamine function. Theoretical and experimental analyses of these moderating factors will help to determine just how reinforcement processes are altered in ADHD. Such analyses can only help to improve treatment strategies for ADHD.

  4. Aqueous Alteration Mineralogy in CM Carbonaceous Chondrites

    Science.gov (United States)

    Chokai, J.; Zolensky, M.; Le, L.; Nakamura, K.; Mikouchi, T.; Monkawa, A.; Koizumi, E.; Miyamoto, M.

    2004-01-01

    Iron-nickel sulfides are found in most or all solar system environments, and are probably the only minerals found in all extraterrestrial materials on hand. Despite the ubiquity, they have not received the attention they deserve. The most common Fe-Ni sulfides in chondrites are troilite (FeS), pyrrhotite (Fe1- XS) and pentlandite (Fe,Ni)9S8. Troilite is believed to have resulted from sulfidation of metal (Fe-Ni) grains in an H2Scontaining environment. Pyrrhotite is produced when friable troilite grains, which are exfoliated from the metal nucleus, are submitted to continued sulfidation [1]. Some asteroids are known to have experienced aqueous alteration, forming products including new generations of sulfides (pyrrhotite and pentlandite). Pentlandite in particular is known to form during such alteration [1]. However, experimental work by Lauretta has indicated that pentlandite may also have been formed during the initial sulfidation process [2], due to the faster diffusion rate of nickel into the forming sulfide, as compared to iron. Finally, there is considerable evidence [1,3&4] for a family of phases intermediate between pyrrhotite and pentlandite, following the trend of the high temperature monosulfide solid solution [5], something not encountered in terrestrial rocks.

  5. Origins of altered reinforcement effects in ADHD.

    Science.gov (United States)

    Johansen, Espen Borgå; Killeen, Peter R; Russell, Vivienne A; Tripp, Gail; Wickens, Jeff R; Tannock, Rosemary; Williams, Jonathan; Sagvolden, Terje

    2009-01-01

    Attention-deficit/hyperactivity disorder (ADHD), characterized by hyperactivity, impulsiveness and deficient sustained attention, is one of the most common and persistent behavioral disorders of childhood. ADHD is associated with catecholamine dysfunction. The catecholamines are important for response selection and memory formation, and dopamine in particular is important for reinforcement of successful behavior. The convergence of dopaminergic mesolimbic and glutamatergic corticostriatal synapses upon individual neostriatal neurons provides a favorable substrate for a three-factor synaptic modification rule underlying acquisition of associations between stimuli in a particular context, responses, and reinforcers. The change in associative strength as a function of delay between key stimuli or responses, and reinforcement, is known as the delay of reinforcement gradient. The gradient is altered by vicissitudes of attention, intrusions of irrelevant events, lapses of memory, and fluctuations in dopamine function. Theoretical and experimental analyses of these moderating factors will help to determine just how reinforcement processes are altered in ADHD. Such analyses can only help to improve treatment strategies for ADHD. PMID:19226460

  6. Obesity Promotes Alterations in Iron Recycling

    Directory of Open Access Journals (Sweden)

    Marta Citelli

    2015-01-01

    Full Text Available Hepcidin is a key hormone that induces the degradation of ferroportin (FPN, a protein that exports iron from reticuloendothelial macrophages and enterocytes. The aim of the present study was to experimentally evaluate if the obesity induced by a high-fat diet (HFD modifies the expression of FPN in macrophages and enterocytes, thus altering the iron bioavailability. In order to directly examine changes associated with iron metabolism in vivo, C57BL/6J mice were fed either a control or a HFD. Serum leptin levels were evaluated. The hepcidin, divalent metal transporter-1 (DMT1, FPN and ferritin genes were analyzed by real-time polymerase chain reaction. The amount of iron present in both the liver and spleen was determined by flame atomic absorption spectrometry. Ferroportin localization within reticuloendothelial macrophages was observed by immunofluorescence microscopy. Obese animals were found to exhibit increased hepcidin gene expression, while iron accumulated in the spleen and liver. They also exhibited changes in the sublocation of splenic cellular FPN and a reduction in the FPN expression in the liver and the spleen, while no changes were observed in enterocytes. Possible explanations for the increased hepcidin expression observed in HFD animals may include: increased leptin levels, the liver iron accumulation or endoplasmic reticulum (ER stress. Together, the results indicated that obesity promotes changes in iron bioavailability, since it altered the iron recycling function.

  7. Neurobiological alterations in alcohol addiction: a review.

    Science.gov (United States)

    Erdozain, Amaia M; Callado, Luis F

    2014-01-01

    The exact mechanism by which ethanol exerts its effects on the brain is still unknown. However, nowadays it is well known that ethanol interacts with specific neuronal membrane proteins involved in signal transmission, resulting in changes in neural activity. In this review different neurochemical alterations produced by ethanol are described. Primarily, ethanol interacts with two membrane receptors: GABAA and NMDA ion channel receptors. Ethanol enhances the GABA action and antagonizes glutamate action, therefore acting as a CNS depressant. In addition, ethanol affects most other neurochemical and endocrine systems. In regard to the brain reward system, both dopaminergic and opioid system are affected by this drug. Furthermore, the serotonergic, noradrenergic, corticotropin-releasing factor and cannabinoid systems seem to play an important role in the neurobiology of alcoholism. At last but not least, ethanol can also modulate cytoplasmic components, including the second messengers. We also review briefly the different actual and putative pharmacological treatments for alcoholism, based on the alterations produced by this drug. PMID:25578004

  8. Morphology of altered layers of glasses

    International Nuclear Information System (INIS)

    The alteration of the french nuclear waste glass R7T7 has been studied through chemical analysis, thermo-poro-metry and X-ray scattering. Pseudo-dynamic leaching was used, with daily renewal of the leaching solution. The behavior of the R77 glass has been compared to cesium borosilicate glasses with small amounts of Ca and Zr added. As compared to these simplified compositions, the R7T7 glass has a quasi-congruent leaching of Na, B and Si and strongly retains Ca and Zr. The altered layers are very porous (porosity > 40% ). The pore size increases with time to reach a constant value that is independent of the nature of the glass but that strongly depends on the method used for leaching. The pore radii are about 4 nm in pseudo-dynamic mode and 2 nm in static conditions. X-ray scattering indicate that the pores are compact with a sharp interface. Their origin is related to the quasi-equilibrium reaction of hydrolysis redeposition of silica. (authors)

  9. Proteomic alterations in root tips of Arabidopsis thaliana seedlings under altered gravity conditions

    Science.gov (United States)

    Zheng, H. Q.; Wang, H.

    Gravity has a profound influence on plant growth and development Removed the influence of gravitational acceleration by spaceflight caused a wide range of cellular changes in plant Whole seedling that germinated and grown on clinostats showed the absent of gravitropism At the cellular level clinostat treatment has specific effects on plant cells such as induce alterations in cell wall composition increase production of heat-soluble proteins impact on the cellular energy metabolism facilitate a uniform distribution of plastids amyloplasts and increase number and volume of nucleoli A number of recent studies have shown that the exposure of Arabidopsis seedlings and callus cells to gravity stimulation hyper g-forces or clinostat rotation induces alterations in gene expression In our previous study the proteome of the Arabidopsis thaliana callus cells were separated by high resolution two-dimensional electrophoresis 2-DE Image analysis revealed that 80 protein spots showed quantitative and qualitative variations after exposure to clinostat rotation treatment We report here a systematic proteomic approach to investigate the altered gravity responsive proteins in root tip of Arabidopsis thaliana cv Landsberg erecta Three-day-old seedlings were exposed for 12h to a horizontal clinostat rotation H simulated weightlessness altered g-forces by centrifugation 7g hypergravity a vertical clinostat rotation V clinostat control or a stationary control grown conditions Total proteins of roots were extracted

  10. An Alterities Required for Living Together

    Directory of Open Access Journals (Sweden)

    Wellington Amancio Da Silva

    2015-05-01

    Full Text Available This article outlines some existential concepts and socio-affective self, of others and nature on the altered perspective of Hannah Arendt (2010a, 2010b, 1997 and Leonardo Boff (1991, 1999, 2000 in their usual representations in everyday life. From the point of view of the analysis of the Cartesian world view, the self that is considering in the foreground in the face of the other and the world, representations and set up all show that there is always from the perspective of the self, the ego cogitans, egocentrism. This article urges readers to invite everyone to rethink this rather artificial logic governing human relations from Western, especially the Middle Ages, and it has shown injustices from that imbalance of meanings and judgments in the face of otherness, which bring in ourselves.

  11. Immune system alterations in amyotrophic lateral sclerosis

    DEFF Research Database (Denmark)

    Hovden, H; Frederiksen, J L; Pedersen, S W

    2013-01-01

    Amyotrophic lateral sclerosis is a disease of which the underlying cause and pathogenesis are unknown. Cumulatative data clearly indicates an active participation by the immune system in the disease. An increasingly recognized theory suggests a non-cell autonomous mechanism, meaning that multiple...... cells working together are necessary for the pathogenesis of the disease. Observed immune system alterations could indicate an active participation in this mechanism. Damaged motor neurons are able to activate microglia, astrocytes and the complement system, which further can influence each other and...... contribute to neurodegeneration. Infiltrating peripheral immune cells appears to correlate with disease progression, but their significance and composition is unclear. The deleterious effects of this collaborating system of cells appear to outweigh the protective aspects, and revealing this interplay might...

  12. Hydraulic characterization of hydrothermally altered Nopal tuff

    International Nuclear Information System (INIS)

    Understanding the mechanics of variably saturated flow in fractured-porous media is of fundamental importance to evaluating the isolation performance of the proposed high-level radioactive waste repository for the Yucca Mountain site. Developing that understanding must be founded on the analysis and interpretation of laboratory and field data. This report presents an analysis of the unsaturated hydraulic properties of tuff cores from the Pena Blanca natural analog site in Mexico. The basic intent of the analysis was to examine possible trends and relationships between the hydraulic properties and the degree of hydrothermal alteration exhibited by the tuff samples. These data were used in flow simulations to evaluate the significance of a particular conceptual (composite) model and of distinct hydraulic properties on the rate and nature of water flow

  13. Functional alterations in macrophages after hypoxia selection.

    Science.gov (United States)

    Degrossoli, Adriana; Giorgio, Selma

    2007-01-01

    Regions of low oxygen tension are common features of inflamed and infected tissues and provide physiologic selective pressure for the expansion of cells with enhanced hypoxia tolerance. The aim of this study was to investigate whether macrophages resistant to death induced by hypoxia were accompanied by functional alterations. A mouse macrophage cell line (J774 cells) was used to obtain subpopulations of death-resistant macrophages induced by long-term exposure to severe hypoxia (J774 macrophages to periods of severe hypoxia results in the selection of cells with phenotypes associated with the modulation of heat-shock protein 70 kDa (HSP70) expression, tumor necrosis factor-alpha (TNF-alpha), and nitric oxide (NO) production and reduced susceptibility to parasite Leishmania infection. Thus, we suggest that hypoxia-selected macrophages may influence the outcome of inflammation and infection. PMID:17202589

  14. [Molecular alterations in melanoma and targeted therapies].

    Science.gov (United States)

    Mourah, Samia; Lebbé, Céleste

    2014-12-01

    Melanoma is a skin cancer whose incidence is increasing steadily. The recent discovery of frequent and recurrent genetic alterations in cutaneous melanoma allowed a molecular classification of tumors into distinct subgroups, and paved the way for targeted therapy. Several signaling pathways are involved in the progression of this disease with oncogenic mutations affecting signaling pathways: MAPK, PI3K, cAMP and cyclin D1/CDK4. In each of these pathways, several potential therapeutic targets have been identified and specific inhibitors have already been developed and have shown clinical efficacy. The use of these inhibitors is often conditioned by tumors genotyping. In France, melanomas genotyping is supported by the platforms of the National Cancer Institute (INCA), which implemented a national program ensuring access to innovation for personalized medicine. The identification of new targets in melanoma supplies a very active dynamic development of innovative molecules contributing to changing the therapeutic landscape of this pathology. PMID:25776766

  15. Epigenetic alterations associated with cholangiocarcinoma (review).

    Science.gov (United States)

    Isomoto, Hajime

    2009-08-01

    Cholangiocarcinoma (CCA) is a highly lethal malignant tumor arising from the biliary tract epithelium. Chronic inflammatory conditions, including primary sclerosing cholangitis, liver fluke infestation, and hepatolithiasis, are considered risk factors, but the cause is still unknown in most cases. Recent advances in molecular pathogenesis have highlighted the importance of epigenetic alterations, including promoter hypermethylation and histone deacetylation, in the process of cholangiocarcinogenesis. More recently, research interest has been focusing on microRNA (mir), a major subtype of non-coding RNA. Mir is highly conserved among species and regulates the expression of specific target genes by binding to the 3'-untranslated regions of messenger RNA. The number of studies on a possible link between mir and various cancers is growing. This review provides a comprehensive overview of the genes currently known to be hypermethylated in CCA and their putative roles in cholangiocarcinogenesis. The epigenetic role of mir in the pathogenesis of CCA is also discussed. PMID:19578760

  16. Saccadic Alterations in Severe Developmental Dyslexia

    Directory of Open Access Journals (Sweden)

    Stefano Pensiero

    2013-01-01

    Full Text Available It is not sure if persons with dyslexia have ocular motor deficits in addition to their deficits in rapid visual information processing. A 15-year-old boy afflicted by severe dyslexia was submitted to saccadic eye movement recording. Neurological and ophthalmic examinations were normal apart from the presence of an esophoria for near and slightly longer latencies of pattern visual evoked potentials. Subclinical saccadic alterations were present, which could be at the basis of the reading pathology: (1 low velocities (and larger durations of the adducting saccades of the left eye with undershooting and long-lasting postsaccadic onward drift, typical of the internuclear ophthalmoplegia; (2 saccades interrupted in mid-flight and fixation instability, which are present in cases of brainstem premotor disturbances.

  17. Molecular Alterations Associated with Osteosarcoma Development

    Directory of Open Access Journals (Sweden)

    Kosei Ando

    2012-01-01

    Full Text Available Osteosarcoma is the most frequent malignant primary bone tumor characterized by a high potency to form lung metastases which is the main cause of death. Unfortunately, the conventional chemotherapy is not fully effective on osteosarcoma metastases. The progression of a primary tumor to metastasis requires multiple processes, which are neovascularization, proliferation, invasion, survival in the bloodstream, apoptosis resistance, arrest at a distant organ, and outgrowth in secondary sites. Consequently, recent studies have revealed new insights into the molecular mechanisms of metastasis development. The understanding of the mechanism of molecular alterations can provide the identification of novel therapeutic targets and/or prognostic markers for osteosarcoma treatment to improve the clinical outcome.

  18. Riparian invasive alters stream nitrogen dynamics.

    Science.gov (United States)

    Mineau, M.; Baxter, C.; Marcarelli, A.; Minshall, G.

    2008-12-01

    Invasive species may be most likely to have strong effects on the ecosystem they invade when they contribute a new function such as nitrogen (N) fixation. Russian olive (Eleagnus angustifolia) is a non-native invasive tree which is rapidly spreading along riparian corridors in the American West. Russian olive is a nitrogen fixing plant due to a symbiotic relationship with Actinomycetes and is invading systems that frequently lack a strong native N fixer. The contribution of reactive N by these invasive riparian plants to soils may also be altering N cycling and processing in the adjacent streams. We measured nutrient limitation via periphyton growth on nutrient diffusing substrates and nitrate uptake using short term nitrate additions in Deep Creek, ID. Measurements were made in three reaches along a Russian olive invasion gradient, with an upstream reference reach that has no Russian olive and two downstream invaded reaches, one with moderate density and one with high density. Periphyton growth in Deep Creek was significantly N limited in the reference reach while the moderately invaded reach showed no significant limitation and the highly invaded reach was significantly P limited. The nitrate uptake velocity (Vf) for both of the invaded reaches was an order of magnitude less than the reference reach, implying that biological demand for nitrate is significantly less in the invaded reaches than the reference. Considering the current extent of Russian olive invasion and its continued rapid spread, possible alteration of N cycling in waterways may have important implications for the management of both this invasive species and management of nutrient pollution in waters of the western U.S.

  19. Glaucoma alters the circadian timing system.

    Science.gov (United States)

    Drouyer, Elise; Dkhissi-Benyahya, Ouria; Chiquet, Christophe; WoldeMussie, Elizabeth; Ruiz, Guadalupe; Wheeler, Larry A; Denis, Philippe; Cooper, Howard M

    2008-01-01

    Glaucoma is a widespread ocular disease and major cause of blindness characterized by progressive, irreversible damage of the optic nerve. Although the degenerative loss of retinal ganglion cells (RGC) and visual deficits associated with glaucoma have been extensively studied, we hypothesize that glaucoma will also lead to alteration of the circadian timing system. Circadian and non-visual responses to light are mediated by a specialized subset of melanopsin expressing RGCs that provide photic input to mammalian endogenous clock in the suprachiasmatic nucleus (SCN). In order to explore the molecular, anatomical and functional consequences of glaucoma we used a rodent model of chronic ocular hypertension, a primary causal factor of the pathology. Quantitative analysis of retinal projections using sensitive anterograde tracing demonstrates a significant reduction (approximately 50-70%) of RGC axon terminals in all visual and non-visual structures and notably in the SCN. The capacity of glaucomatous rats to entrain to light was challenged by exposure to successive shifts of the light dark (LD) cycle associated with step-wise decreases in light intensity. Although glaucomatous rats are able to entrain their locomotor activity to the LD cycle at all light levels, they require more time to re-adjust to a shifted LD cycle and show significantly greater variability in activity onsets in comparison with normal rats. Quantitative PCR reveals the novel finding that melanopsin as well as rod and cone opsin mRNAs are significantly reduced in glaucomatous retinas. Our findings demonstrate that glaucoma impacts on all these aspects of the circadian timing system. In light of these results, the classical view of glaucoma as pathology unique to the visual system should be extended to include anatomical and functional alterations of the circadian timing system. PMID:19079596

  20. Glaucoma Alters the Circadian Timing System

    Science.gov (United States)

    Drouyer, Elise; Dkhissi-Benyahya, Ouria; Chiquet, Christophe; WoldeMussie, Elizabeth; Ruiz, Guadalupe; Wheeler, Larry A.; Denis, Philippe; Cooper, Howard M.

    2008-01-01

    Glaucoma is a widespread ocular disease and major cause of blindness characterized by progressive, irreversible damage of the optic nerve. Although the degenerative loss of retinal ganglion cells (RGC) and visual deficits associated with glaucoma have been extensively studied, we hypothesize that glaucoma will also lead to alteration of the circadian timing system. Circadian and non-visual responses to light are mediated by a specialized subset of melanopsin expressing RGCs that provide photic input to mammalian endogenous clock in the suprachiasmatic nucleus (SCN). In order to explore the molecular, anatomical and functional consequences of glaucoma we used a rodent model of chronic ocular hypertension, a primary causal factor of the pathology. Quantitative analysis of retinal projections using sensitive anterograde tracing demonstrates a significant reduction (∼50–70%) of RGC axon terminals in all visual and non-visual structures and notably in the SCN. The capacity of glaucomatous rats to entrain to light was challenged by exposure to successive shifts of the light dark (LD) cycle associated with step-wise decreases in light intensity. Although glaucomatous rats are able to entrain their locomotor activity to the LD cycle at all light levels, they require more time to re-adjust to a shifted LD cycle and show significantly greater variability in activity onsets in comparison with normal rats. Quantitative PCR reveals the novel finding that melanopsin as well as rod and cone opsin mRNAs are significantly reduced in glaucomatous retinas. Our findings demonstrate that glaucoma impacts on all these aspects of the circadian timing system. In light of these results, the classical view of glaucoma as pathology unique to the visual system should be extended to include anatomical and functional alterations of the circadian timing system. PMID:19079596

  1. Wound trauma alters ionizing radiation dose assessment

    Directory of Open Access Journals (Sweden)

    Kiang Juliann G

    2012-06-01

    Full Text Available Abstract Background Wounding following whole-body γ-irradiation (radiation combined injury, RCI increases mortality. Wounding-induced increases in radiation mortality are triggered by sustained activation of inducible nitric oxide synthase pathways, persistent alteration of cytokine homeostasis, and increased susceptibility to bacterial infection. Among these factors, cytokines along with other biomarkers have been adopted for biodosimetric evaluation and assessment of radiation dose and injury. Therefore, wounding could complicate biodosimetric assessments. Results In this report, such confounding effects were addressed. Mice were given 60Co γ-photon radiation followed by skin wounding. Wound trauma exacerbated radiation-induced mortality, body-weight loss, and wound healing. Analyses of DNA damage in bone-marrow cells and peripheral blood mononuclear cells (PBMCs, changes in hematology and cytokine profiles, and fundamental clinical signs were evaluated. Early biomarkers (1 d after RCI vs. irradiation alone included significant decreases in survivin expression in bone marrow cells, enhanced increases in γ-H2AX formation in Lin+ bone marrow cells, enhanced increases in IL-1β, IL-6, IL-8, and G-CSF concentrations in blood, and concomitant decreases in γ-H2AX formation in PBMCs and decreases in numbers of splenocytes, lymphocytes, and neutrophils. Intermediate biomarkers (7 – 10 d after RCI included continuously decreased γ-H2AX formation in PBMC and enhanced increases in IL-1β, IL-6, IL-8, and G-CSF concentrations in blood. The clinical signs evaluated after RCI were increased water consumption, decreased body weight, and decreased wound healing rate and survival rate. Late clinical signs (30 d after RCI included poor survival and wound healing. Conclusion Results suggest that confounding factors such as wounding alters ionizing radiation dose assessment and agents inhibiting these responses may prove therapeutic for radiation combined

  2. Near-field/altered-zone models report

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, E. L., LLNL

    1998-03-01

    nonlithophysal and lower lithophysal units. These units are made up of moderately to densely welded, devitrified, fractured tuff. The rock's chemical composition is comparable to that of typical granite, but has textural features and mineralogical characteristics of large-scale, silicic volcanism. Because the repository horizon will be approximately 300 m below the ground surface and 200 m above the water table, the repository will be partially saturated. The welded tuff matrix in the host units is highly impermeable, but water and gas flow readily through fractures. The degree of fracturing in these units is highly variable, and the hydrologic significance of fracturing is an important aspect of site investigation. This report describes the characterization and modeling of a region around the potential repository--the altered zone--a region in which the temperature will be increased significantly by waste-generated heat. Numerical simulation has shown that, depending on the boundary conditions, rock properties, and repository design features incorporated in the models, the altered zone (AZ) may extend from the water table to the ground surface. This report also describes models of the near field, the region comprising the repository emplacement drifts and the surrounding rock, which are critical to the performance of engineered components. Investigations of near-field and altered-zone (NF/AZ) processes support the design of underground repository facilities and engineered barriers and also provide constraint data for probabilistic calculations of waste-isolation performance (i.e., performance assessment). The approach to investigation, which is an iterative process involving hypothesis testing and experimentation, has relied on conceptualizing engineered barriers and on performance analysis. This report is a collection, emphasizing conceptual and numerical models, of the recent results contributed from studies of NF/AZ processes and of quantitative measures of NF

  3. Near-field/altered-zone models report

    International Nuclear Information System (INIS)

    lithophysal units. These units are made up of moderately to densely welded, devitrified, fractured tuff. The rock's chemical composition is comparable to that of typical granite, but has textural features and mineralogical characteristics of large-scale, silicic volcanism. Because the repository horizon will be approximately 300 m below the ground surface and 200 m above the water table, the repository will be partially saturated. The welded tuff matrix in the host units is highly impermeable, but water and gas flow readily through fractures. The degree of fracturing in these units is highly variable, and the hydrologic significance of fracturing is an important aspect of site investigation. This report describes the characterization and modeling of a region around the potential repository--the altered zone--a region in which the temperature will be increased significantly by waste-generated heat. Numerical simulation has shown that, depending on the boundary conditions, rock properties, and repository design features incorporated in the models, the altered zone (AZ) may extend from the water table to the ground surface. This report also describes models of the near field, the region comprising the repository emplacement drifts and the surrounding rock, which are critical to the performance of engineered components. Investigations of near-field and altered-zone (NF/AZ) processes support the design of underground repository facilities and engineered barriers and also provide constraint data for probabilistic calculations of waste-isolation performance (i.e., performance assessment). The approach to investigation, which is an iterative process involving hypothesis testing and experimentation, has relied on conceptualizing engineered barriers and on performance analysis. This report is a collection, emphasizing conceptual and numerical models, of the recent results contributed from studies of NF/AZ processes and of quantitative measures of NF/AZ performance. The selection and

  4. Genetic alterations and epigenetic changes in hepatocarcinogenesis

    Directory of Open Access Journals (Sweden)

    Luz Stella Hoyos Giraldo

    2007-02-01

    Full Text Available

    Hepatocarcinogenesis as hepatocellular carcinoma (HCC is associated with background of chronic liver disease usually in association with cirrhosis, marked hepatic fibrosis, hepatitis B virus (HBV and/or hepatitis virus (HCV infection, chronic inflammation, Aflatoxin B1(AFB1 exposure, chronic alcoholism, metabolic disorder of the liver and necroinflamatory liver disease. Hepatocarcinogenesis involve two mechanisms, genetic alterations (with changes in the cell's DNA sequence and epigenetic changes (without changes in the cell's DNA sequence, but changes in the pattern of gene expression that can persist through one or more generations (somatic sense. Hepatocarcinogenesis is associated with activation of oncogenes and decreased expression of tumor suppressor genes (TSG; include those involved in cell cycle control, apoptosis, DNA repair, immortalization and angiogenesis. AFB1 is metabolized in the liver into a potent carcinogen, aflatoxin 8, 9-epoxide, which is detoxified by epoxide hydrolase (EPHX and glutathione S-transferase M1 (GSTM1.

    A failure of detoxification processes can allow to mutagenic metabolite to bind to DNA and inducing P53 mutation. Genetic polymorphism of EPHX and GSTM1 can make individuals more susceptible to AFB1. Epigenetic inactivation of GSTP1 by promoter hypermethylation plays a role in the development of HCC because, it leads that electrophilic metabolite increase DNA damage and mutations. HBV DNA integration into the host chromosomal DNA of hepatocytes has been detected in HBV-related HCC.

    DNA tumor viruses cause cancer mainly by interfering with cell cycle controls, and activating the cell's replication machinery by blocking the action of key TSG. HBx protein is a

  5. Effect of Added Surfactants on the Dynamic Interfacial Tension Behaviour of Alkaline/Diluted Heavy Crude Oil System Effet de l’ajout de tensioactifs sur le comportement dynamique de la tension interfaciale du système solution alcaline/brut dilué

    Directory of Open Access Journals (Sweden)

    Trabelsi S.

    2013-02-01

    Full Text Available This study has been undertaken to get a better understanding of the interactions between Enhanced Oil Recovery (EOR surfactants used in chemical flooding and in situ surfactants present in an heavy oil. We report an experimental study of dynamic Interfacial Tension (IFT behaviour of diluted heavy oil/surfactant enhanced-alkaline systems. The dynamic IFT was measured using pendant drop and spinning drop tensiometers. The dynamic IFT between diluted heavy oil and alkaline solution (pH 11 with no added surfactant increased sharply with time, which was attributed to the transfer of the in situ surfactant (produced by saponification of the acids groups present in the crude oil across the oil/water interface. The addition of Sodium Dodecyl Benzene Sulfonate (SDBS above the Critical Micellar Concentration (CMC ~ 0.002%, changed completely the dynamic IFT behaviour of the diluted heavy oil as the IFT strongly decreased and finally reached a plateau, of about 1.5 × 10-3 mN/m at a concentration of only 0.02%. We attributed the efficiency of SDBS to a synergistic effect between the in situ surfactant and the added surfactant that form a mixed interfacial monolayer, which is very efficient in decreasing the IFT to ultra low values and in resisting mass transfer across the oil/water interface. Cette étude a été réalisée pour mieux comprendre les interactions entre les tensioactifs utilisés pour la récupération assistée de pétrole et les tensioactifs in situ présents dans le brut. Nous expérimentons le comportement dynamique des tensions interfaciales (mesurées par les méthodes de goutte pendante et goutte tournante entre le brut lourd dilué et les solutions alcalines avec ajout de tensioactif. La tension interfaciale dynamique entre le brut dilué et une solution alcaline (pH 11 sans ajout de tensioactif croît fortement au cours du temps, cette augmentation est attribuée au transfert des tensioactifs in situ (produits par saponification des

  6. Pyrogenic organic matter can alter microbial communication

    Science.gov (United States)

    Masiello, Caroline; Gao, Xiaodong; Cheng, Hsiao-Ying; Silberg, Jonathan

    2016-04-01

    Soil microbes communicate with each other to manage a large range of processes that occur more efficiently when microbes are able to act simultaneously. This coordination occurs through the continuous production of signaling compounds that are easily diffused into and out of cells. As the number of microbes in a localized environment increases, the internal cellular concentration of these signaling compounds increases, and when a threshold concentration is reached, gene expression shifts, leading to altered (and coordinated) microbial behaviors. Many of these coordinated behaviors have biogeochemically important outcomes. For example, methanogenesis, denitrification, biofilm formation, and the development of plant-rhizobial symbioses are all regulated by a simple class of cell-cell signaling molecules known as acyl homoserine lactones (AHLs). Pyrogenic organic matter in soils can act to disrupt microbial communication through multiple pathways. In the case of AHLs, charcoal's very high surface area can sorb these signaling compounds, preventing microbes from detecting each others' presence (Masiello et al., 2014). In addition, the lactone ring in AHLs is vulnerable to pH increases accompanying PyOM inputs, with soil pH values higher than 7-8 leading to ring opening and compound destabilization. Different microbes use different classes of signaling compounds, and not all microbial signaling compounds are pH-vulnerable. This implies that PyOM-driven pH increases may trigger differential outcomes for Gram negative bacteria vs fungi, for example. A charcoal-driven reduction in microbes' ability to detect cell-cell communication compounds may lead to a shift in the ability of microbes to participate in key steps of C and N cycling. For example, an increase in an archaeon-specific AHL has been shown to lead to a cascade of metabolic processes that eventually results in the upregulation of CH4 production (Zhang et al., 2012). Alterations in similar AHL compounds leads to

  7. The geology of uranium in the Saint-Sylvestre granite district (Limousin, Massif Central, France); La geologie de l'uranium dans le massif granitique de Saint-Sylvestre (Limousin - Massif Central Francais)

    Energy Technology Data Exchange (ETDEWEB)

    Marquaire, C.; Moreau, M.; Barbier, J.; Ranchin, G.; Carrat, H.G.; Coppens, R.; Senecal, J.; Koszotolanyi, C.; Dottin, H

    1969-07-01

    This report concerns the geology of uranium in Limousin, more particularly in the St-Sylvestre massif, and the related phenomena: regional geology, petrographic and geochemical zonal distribution observed in various granite massifs, uranium movement in connection with surface alteration, geochronology of uranium ore. The work is made up of six articles covering the various scientific aspects listed above. Each article is headed with an abstract. The paper comprises the following chapters: Foreword by Marcel ROUBAULT. 1. Ch. MARQUAIRE, M. MOREAU Outline of geological conditions in Northern Limousin and distribution of uraniferous occurrences. 2. J. BARBIER, G. RANCHIN, H. G. CARRAT and R. COPPENS Geology of the St-Sylvestre Massif and uranium geochemistry - Introduction to laboratory studies - Problems of methodology. 3. J. BARBIER and G. RANCHIN Petrographical and geochemical zones in the St-Sylvestre granite massif (Limousin - French 'Massif Central'). 4. J. BARBIER and G. RANCHIN Uranium geochemistry in the St-Sylvestre Massif (Limousin - French 'Massif Central') - Occurrences of primary geochemical uranium and replacement processes. 5. J. SENEGAL Monograph of the Brugeaud orebody. 6. R. COPPENS, Ch. KOSZTOLANYI and H. DOTTIN Geochronological study of the Brugeaud mine. 1969. (authors) [French] Ce memoire est consacre a la geologie de l'uranium dans le Limousin, plus specialement dans le massif de St-Sylvestre, et aux phenomenes qui s'y rattachent: geologie regionale, phenomenes de zonalite petrographique et geochimique dans certains massifs granitiques, mouvements de l'uranium lies a l'alteration superficielle, geochronologie du minerai d'uranium. L'ouvrage comprend six articles qui recouvrent les differents aspects scientifiques enumeres. Chacun de ces six articles est precede d'un resume. La composition du memoire st la suivante: Marcel ROUBAULT, Preface. 1. Ch. MARQUAIRE, M. MOREAU Esquisse geologique du

  8. Identification et étude du comportement de quelques additifs des huiles moteurs à base minérale par spectrophotométries IR intégrale et différentielle Identification and Study of the Behavior of Several Additives for Mineral-Bass Motor Oils by Differential and Integral Ir Spectrophotometry

    Directory of Open Access Journals (Sweden)

    Subran C.

    2006-11-01

    Full Text Available L'utilisation d'additifs dans les huiles moteurs est un facteur déterminant pour la longévité et les performances des moteurs. On présente dans cet article quelques procédés d'identification de certains additifs (améliorant d'indice de viscosité, antioxydants, détergents, antimousse, abaisseur du point de congélation en utilisant les méthodes de la spectroscopie IR différentielle et intégrale, l'étude de leur comportement durant l'altération des huiles, le contrôle des dosages dans les huiles neuves. La technique est caractérisée par sa rapidité, par les faibles quantités d'huile prélevées (millilitres, par la possibilité d'un contrôle permanent et d'un diagnostique possible de l'ensemble huile-moteur. The addition of additives to motor oils is one of the main factors in determining the optimum duration of the use of an oil as well as the lifetime and efficiency of an automotive engine. This article describes several processes used for identifying various additives (VI improvers, antioxidant, detergent, antifoaming, pour-point depressant involving differential and integral IR spectroscopy methods. Additive behavior during use is discussed along with how to control dosages in new oils. The technique proposed is characterized by its rapidity, by the small quantities of samples used (milliliters by the possibility of permanent control, and by being able to make a general diagnosis of the oil/engine system.

  9. Utilisation de modèles mathématiques de simulation pour la prévision et le contrôle du comportement des stockages souterrains en nappe aquifère Simulation by Mathematical Models At Forecast and Control the Behaviour of Underground Storage Facilities in Aquifer Layers

    Directory of Open Access Journals (Sweden)

    Dussaud M.

    2006-11-01

    Full Text Available Depuis de nombreuses années, des modèles analytiques de prévision de pression des stockages de gaz en nappe aquifère permettent de simuler de façon satisfaisante le comportement en pression des réservoirs souterrains. De puissants outils de calcul, les modèles maillés, ont été acquis et développés par Gaz de France, permettant d'étudier, outre le régime de pression, des problèmes plus fins (effets des hétérogénéités, de la répartition et du fonctionnement des puits, prise en compte du déplacernent diphasique, etc. . Après une description rapide des modèles disponibles, quelques exemples ainsi que quelques considérations sur leur utilisation sont développés. For many years analytical models for pressure forecasting in underground gas storage facilities in aquifer layers have been used for satisfactorily simulating pressure behavior in underground reservoirs. Powerful computing tools in the form of network models have been acquired and developed by Gaz de France for investigating, in addition to pressure conditions, more delicate problems such as the effects of heterogeneities and of well distribution and operating, while taking two-phase displacements into consideration, etc. After a brief description of the models now available, several examples as well as some considerations of their use are discussed.

  10. Study of high density polyethylene under UV irradiation or mechanical stress by fluorescence spectroscopy; Etude du comportement du polyethylene haute densite sous irradiation ultraviolette ou sollicitation mecanique par spectroscopie de fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Douminge, L.

    2010-05-15

    Due to their diversity and their wide range of applications, polymers have emerged in our environment. For technical applications, these materials can be exposed to aggressive environment leading to an alteration of their properties. The effects of this degradation are linked to the concept of life duration, corresponding to the time required for a property to reach a threshold below which the material becomes unusable. Monitoring the ageing of polymer materials constitute a major challenge. Fluorescence spectroscopy is a technique able to provide accurate information concerning this issue. In this study, emphasis was placed on the use of fluorescence spectroscopy to study the phenomena involved in either the UV radiation or mechanical stresses of a polymer. In the case of high density polyethylene, the lack of intrinsic fluorescent signal leads to the use of a dye. This dye gives a fluorescent response depending on its microenvironment. All modifications in the macromolecular chain generate a shift of the fluorescent peak. This work can be dissociated in two major parts, on one hand the influence of UV aging on the fluorescent response and in another hand the influence of mechanical stresses. In the first part, complementary analyses like FTIR or DSC are used to correlate fluorescent results with known photo degradation mechanisms. The results show the great sensibility of the technique to the microstructural rearrangement in the polymer. In the second part, the dependence between the stress and the fluorescence emission gives opportunity to evaluate internal stresses in the material during cyclic solicitations. (author)

  11. Basaltic glass: alteration mechanisms and analogy with nuclear waste glasses

    International Nuclear Information System (INIS)

    A synthetic basaltic glass was dissolved experimentally at 90 deg. C under static conditions in initially pure water. The basaltic glass dissolution rates measured near and far from equilibrium were compared with those of SON 68 nuclear waste glass. Experimental and literature data notably suggested that the alteration mechanisms for the two glasses are initially similar. Under steady-state concentration conditions, the alteration rate decreased of four orders of magnitude below the initial rate (r0). The same alteration rate decrease was observed for basaltic and nuclear glass. These findings tend to corroborate the analogy of the two glasses alteration kinetics. The effect of dissolved silica in solution, observed through dynamic leach tests with silicon-rich solutions, cannot account for the significant drop in the basaltic glass kinetics. Hence, a protective effect of the glass alteration film was assumed and experimentally investigated. Moreover, modeling with LIXIVER argue for a significant effect of diffusion in the alteration gel

  12. Brain alterations in paedophilia: a critical review.

    Science.gov (United States)

    Mohnke, Sebastian; Müller, Sabine; Amelung, Till; Krüger, Tillmann H C; Ponseti, Jorge; Schiffer, Boris; Walter, Martin; Beier, Klaus M; Walter, Henrik

    2014-11-01

    Psychosocial and biological factors have been implicated in paedophilia, such as alterations in brain structure and function. The purpose of this paper is to review the expanding body of literature on this topic including brain abnormality case reports, as well as structural and functional neuroimaging studies. Case studies of men who have committed sexual offences against children implicate frontal and temporal abnormalities that may be associated with impaired impulse inhibition. Structural neuroimaging investigations show volume reductions in paedophilic men. Although the findings have been heterogeneous, smaller amygdala volume has been replicated repeatedly. Functional neuroimaging investigations demonstrate an overlap between paedophiles and teleiophiles during sexual arousal processing. While it is controversial among studies regarding group differences, reliable discrimination between paedophilic and teleiophilic men may be achieved using functional activation patterns. Nevertheless, the heterogeneous findings published so far suggest further research is necessary to disentangle the neurobiological mechanisms of paedophilic preference. A number of methodological confounds have been identified, which may account for the inconsistent results that could prove to be beneficial for future investigations. PMID:25116710

  13. Plant growth conditions alter phytolith carbon

    Directory of Open Access Journals (Sweden)

    Kimberley L Gallagher

    2015-09-01

    Full Text Available Many plants, including grasses and some important human food sources, accumulate and precipitate silica in their cells to form opaline phytoliths. These phytoliths contain small amounts of organic matter (OM that are trapped during the process of silicification. Previous work has suggested that plant silica is associated with compounds such as proteins, lipids, lignin and carbohydrate complexes. It is not known whether these compounds are cellular components passively encapsulated as the cell silicifies, polymers actively involved in the precipitation process or random compounds assimilated by the plant and discarded into a glass wastebasket. Here, we used Raman spectroscopy to map the distribution of OM in phytoliths, and to analyze individual phytoliths isolated from Sorghum bicolor plants grown under different laboratory treatments. Using mapping, we showed that OM in phytoliths is distributed throughout the silica and is not related to dark spots visible in light microscopy, previously assumed to be the repository for phytolith OM. The Raman spectra exhibited common bands indicative of C-H stretching modes of general OM, and further more diagnostic bands consistent with carbohydrates, lignins and other OM. These Raman spectra exhibited variability of spectral signatures and of relative intensities between sample treatments indicating that differing growth conditions altered the phytolith carbon. This may have strong implications for understanding the mechanism of phytolith formation, and for use of phytolith carbon isotope values in dating or paleoclimate reconstruction.

  14. Genomic and epigenomic alterations in prostate cancer

    Directory of Open Access Journals (Sweden)

    Anna Maria eAschelter

    2012-11-01

    Full Text Available Prostate cancer (PC is the second most frequently diagnosed cancer and the second leading cause of cancer deaths in man. The treatment of localized PC includes surgery or radiation therapy. In case of relapse after a definitive treatment or in patients with locally advanced or metastatic disease, the standard treatment includes the androgen-deprivation therapy (ADT. By reducing the levels of Testosterone and dihydrotestosterone (DHT under the castration threshold, the ADT acts on the androgen receptor (AR, even if indirectly. The effects of the ADT are usually temporary and nearly all patients, initially sensitive to the androgen ablation therapy, have a disease progression after a 18-24 months medium term. This is probably due to the selection of the cancer cell clones and to their acquisition of critical somatic genome and epigenomic changes. This review aims to provide an overview about the genetic and epigenetic alterations having a crucial role in the carcinogenesis and in the disease progression toward the castration resistant prostate cancer (CRPC. We focused on the role of the androgen receptor, on its signaling cascade and on the clinical implications that the knowledge of these aspects would have on hormonal therapy, on its failure and its toxicity.

  15. Ictal alterations of consciousness during ecstatic seizures.

    Science.gov (United States)

    Picard, Fabienne; Kurth, Florian

    2014-01-01

    Patients with ecstatic epileptic seizures report an altered consciousness, which they describe as a sense of heightened perception of themselves – they “feel very present” – and an increased vividness of sensory perceptions. Recently, the anterior insula has been proposed as the region where these seizures originate, based on the results of ictal nuclear imaging in three patients, the first induction of ecstatic auras by electrical stimulation, and the functional characteristics of the anterior insula in neuroimaging literature. Specifically, the anterior insula is thought to play a key role in integrating information from within the body, the external world, as well as the emotional states. In addition, the anterior insula is thought to convert this integrated information into successive global emotional moments, thus enabling both the construct of a sentient self as well as a mechanism for predictive coding. As part of the salience network, this region is also involved in switching from mind wandering toward attentional and executive processing. In this review, we will summarize previous patient reports and recap how insular functioning may be involved in the phenomenon of ecstatic seizures. Furthermore, we will relate these hypotheses to the results from research on meditation and effects of drug abuse. PMID:24436968

  16. Altering Emulsion Stability with Heterogeneous Surface Wettability

    Science.gov (United States)

    Meng, Qiang; Zhang, Yali; Li, Jiang; Lammertink, Rob G. H.; Chen, Haosheng; Tsai, Peichun Amy

    2016-06-01

    Emulsions–liquid droplets dispersed in another immiscible liquid–are widely used in a broad spectrum of applications, including food, personal care, agrochemical, and pharmaceutical products. Emulsions are also commonly present in natural crude oil, hampering the production and quality of petroleum fuels. The stability of emulsions plays a crucial role in their applications, but controlling the stability without external driving forces has been proven to be difficult. Here we show how heterogeneous surface wettability can alter the stability and dynamics of oil-in-water emulsions, generated by a co-flow microfluidic device. We designed a useful methodology that can modify a micro-capillary of desired heterogeneous wettability (e.g., alternating hydrophilic and hydrophobic regions) without changing the hydraulic diameter. We subsequently investigated the effects of flow rates and heterogeneous wettability on the emulsion morphology and motion. The experimental data revealed a universal critical timescale of advective emulsions, above which the microfluidic emulsions remain stable and intact, whereas below they become adhesive or inverse. A simple theoretical model based on a force balance can be used to explain this critical transition of emulsion dynamics, depending on the droplet size and the Capillary number–the ratio of viscous to surface effects. These results give insight into how to control the stability and dynamics of emulsions in microfluidics with flow velocity and different wettability.

  17. Radiofrequency treatment alters cancer cell phenotype

    Science.gov (United States)

    Ware, Matthew J.; Tinger, Sophia; Colbert, Kevin L.; Corr, Stuart J.; Rees, Paul; Koshkina, Nadezhda; Curley, Steven; Summers, H. D.; Godin, Biana

    2015-07-01

    The importance of evaluating physical cues in cancer research is gradually being realized. Assessment of cancer cell physical appearance, or phenotype, may provide information on changes in cellular behavior, including migratory or communicative changes. These characteristics are intrinsically different between malignant and non-malignant cells and change in response to therapy or in the progression of the disease. Here, we report that pancreatic cancer cell phenotype was altered in response to a physical method for cancer therapy, a non-invasive radiofrequency (RF) treatment, which is currently being developed for human trials. We provide a battery of tests to explore these phenotype characteristics. Our data show that cell topography, morphology, motility, adhesion and division change as a result of the treatment. These may have consequences for tissue architecture, for diffusion of anti-cancer therapeutics and cancer cell susceptibility within the tumor. Clear phenotypical differences were observed between cancerous and normal cells in both their untreated states and in their response to RF therapy. We also report, for the first time, a transfer of microsized particles through tunneling nanotubes, which were produced by cancer cells in response to RF therapy. Additionally, we provide evidence that various sub-populations of cancer cells heterogeneously respond to RF treatment.

  18. Foveal Thickness Alterations in Patients with Migraine

    Science.gov (United States)

    Cankaya, Cem; Tecellioglu, Mehmet

    2016-01-01

    Aim: To investigate the alterations in foveal retinal thickness (FT) values in patients with migraine and to reveal the correlations between FT and clinical characteristics of migraine disease. Methods: This study included sixty-eight eyes of 34 migraine patients [twenty-eight eyes of 14 patients with aura (group 1), and forty eyes of 20 patients without aura (group 2)] and forty eyes of 20 healthy volunteer who served as the control group (group 3). FT values were measured by optical coherence tomography (OCT) in each group. Results: Mean age of patients in group 1, 2, and 3 was 34.0± 6.82, 35.2±10.12, and 35.1± 6.85 years, respectively (p=0.84). Mean FT was 211.07±7.36, 220.0±12.01, and 221.85±12.27 in groups 1, 2, and 3, respectively. There was statistically significance among the group 1-2 and 1-3 (p=0.002 and pmigraine with aura may lead to a reduction in FT values. This finding can be explained by the blood flow decrease theory in migraine; however larger studies seem mandatory. PMID:27147787

  19. Pathogenic alteration in severe burn wounds.

    Science.gov (United States)

    Fu, Yang; Xie, Bing; Ben, DaoFeng; Lv, KaiYang; Zhu, ShiHui; Lu, Wei; Tang, HongTai; Cheng, DaSheng; Ma, Bing; Wang, GuangYi; Xiao, ShiChu; Wang, GuangQing; Xia, ZhaoFan

    2012-02-01

    The present study aims to define the trend of time related changes with local bacterial alteration of bacterial resistance in severe burns in our burn center during a 12-year period. Retrospective analysis of microbiological results on severely burned wounds between 1998 and 2009 was carried out. A study of 3615 microbial isolates was performed. Staphylococcus aureus was the most commonly isolated pathogen (38.2%) followed by A. baumannii (16.2%), Streptococcus viridans (11.4%), Pseudomonas aeruginosa (10.4%), coagulase-negative staphylococci (CNS, 9.2%). The species ratios of S. aureus and A. baumannii increased significantly from 1st to 8th week of hospitalization, while those of Streptococcus viridans, P. aeruginosa and coagulase-negative staphylococci decreased during the same period. Bacterial resistance rates were compared between the periods 1998-2003 and 2004-2009. Vancomycin remained as the most sensitive antibiotic in S. aureus including methicillin-resistant S. aureus (MRSA). It was very likely that the majority of infections caused by Streptococcus viridans, P. aeruginosa and coagulase-negative staphylococci occurred in the early stage of burn course and the majority of infections caused by A. baumannii occurred 4 weeks after admission. The use of different antibiotics was probably the major contributor to these trends. PMID:22100426

  20. Shadows alter facial expressions of Noh masks.

    Directory of Open Access Journals (Sweden)

    Nobuyuki Kawai

    Full Text Available BACKGROUND: A Noh mask, worn by expert actors during performance on the Japanese traditional Noh drama, conveys various emotional expressions despite its fixed physical properties. How does the mask change its expressions? Shadows change subtly during the actual Noh drama, which plays a key role in creating elusive artistic enchantment. We here describe evidence from two experiments regarding how attached shadows of the Noh masks influence the observers' recognition of the emotional expressions. METHODOLOGY/PRINCIPAL FINDINGS: In Experiment 1, neutral-faced Noh masks having the attached shadows of the happy/sad masks were recognized as bearing happy/sad expressions, respectively. This was true for all four types of masks each of which represented a character differing in sex and age, even though the original characteristics of the masks also greatly influenced the evaluation of emotions. Experiment 2 further revealed that frontal Noh mask images having shadows of upward/downward tilted masks were evaluated as sad/happy, respectively. This was consistent with outcomes from preceding studies using actually tilted Noh mask images. CONCLUSIONS/SIGNIFICANCE: Results from the two experiments concur that purely manipulating attached shadows of the different types of Noh masks significantly alters the emotion recognition. These findings go in line with the mysterious facial expressions observed in Western paintings, such as the elusive qualities of Mona Lisa's smile. They also agree with the aesthetic principle of Japanese traditional art "yugen (profound grace and subtlety", which highly appreciates subtle emotional expressions in the darkness.

  1. Gestational dexamethasone alters fetal neuroendocrine axis.

    Science.gov (United States)

    Ahmed, R G

    2016-09-01

    This study tested whether the maternal transport of dexamethasone (DEXA) may affect the development of the neuroendocrine system. DEXA (0.2mg/kg b.w., subcutaneous injection) was administered to pregnant rats from gestation day (GD) 1-20. In the DEXA-treated group, a decrease in maternal serum thyroxine (T4), triiodothyronine (T3), and increase in thyrotropin (TSH) levels (hypothyroid status) were observed at GDs 15 & 20 with respect to control group. The reverse pattern (hyperthyroid status) was observed in their fetuses at embryonic days (EDs) 15 & 20. Although the maternal body weight was diminished, the weight of the thyroid gland was increased at studied GDs as compared to the control group. The fetal growth retardation, hyperleptinemia, hyperinsulinism, and cytokines distortions (transforming growth factor-beta; TGF-β, tumor necrosis factor-alpha; TNF-α, and interferon-γ; IFN-γ) were noticed at examined EDs if compared to the control group. Alternatively, the maternofetal thyroid dysfunctions due to the maternal DEXA administration attenuated the levels of fetal cerebral norepinephrine (NE) and epinephrine (E), and elevated the levels of dopamine (DA) and 5-hydroxytryptamine (5-HT) at considered days. These alterations were age-dependent and might damage the nerve transmission. Finally, maternal DEXA might act as neuroendocrine disruptor causing dyshormonogenesis and fetal cerebral dysfunction. PMID:27220267

  2. Microgravity alters cancer growth and progression.

    Science.gov (United States)

    Jhala, Dhwani V; Kale, Raosaheb K; Singh, Rana P

    2014-01-01

    Study of the process of cancer initiation, growth and progression in altered gravity is of utmost importance considering the health status of researchers visiting in space and future scope of space tourism. Microgravity affects various cells in the body differently; however, the mechanisms of such effects are not understood completely. Therefore, it is imperative to explore various physiological and biochemical processes, particularly those which can influence the process of carcinogenesis. If the changes in physiological or biochemical processes do not revert back to normalcy even after returning from the space to earth, it may lead to various aberrations and morphological changes during the life span. Such changes could lead to pathological conditions including cancer. For example, microgravity is observed to suppress the activity of immune cells, which itself increases the risk of cancer development. It is little known how the microgravity affects cellular and molecular events that determine physiological and biological responses. There is also a possibility of changes in epigenetic signatures during microgravity exposure which remains unexplored. Herein, we have reviewed the effect of microgravity on relevant molecular and biological processes, and how it could influence the course of cancer development. In this regard, we have also highlighted the areas of research that require more attention to bridge the gap of understanding for such biological processes. PMID:24720362

  3. Alterated integrin expression in lichen planopilaris

    Directory of Open Access Journals (Sweden)

    Erriquez Roberta

    2007-02-01

    Full Text Available Abstract Background Lichen planopilaris (LPP is an inflammatory disease characterized by a lymphomononuclear infiltrate surrounding the isthmus and infundibulum of the hair follicle of the scalp, that evolves into atrophic/scarring alopecia. In the active phase of the disease hairs are easily plucked with anagen-like hair-roots. In this study we focused on the expression of integrins and basement membrane components of the hair follicle in active LPP lesions. Methods Scalp biopsies were taken in 10 patients with LPP and in 5 normal controls. Using monoclonal antibodies against α3β1 and α6β4 integrins we showed the expression of these integrins and of the basement membrane components of the hair follicle in active LPP lesions and in healthy scalp skin. Results In the LPP involved areas, α3β1 was distributed in a pericellular pattern, the α6 subunit was present with a basolateral distribution while the β4 subunit showed discontinuous expression at the basal pole and occasionally, basolateral staining of the hair follicle. Conclusion: An altered distribution of the integrins in active LPP lesions can explain the phenomenon of easy pulling-out of the hair with a "gelatinous" root-sheath.

  4. Origin and significance of chromosomal alterations

    International Nuclear Information System (INIS)

    The spontaneous frequency of chromsomal changes (structural and numerical aberations) in humans is in the order of 6 in 1,000 newborn. Chromosomal analysis of spontaneous abortuses indicate that about 50% of all spontaneous abortions are chromsomally abnormal. Populations exposed to ionizing radiations (atom bomb survivors) or chemical mutagens (e.g., workers occupational.y exposed to vinyl chloride or benzene) show increased frequencies of chromosomal aberrations in their peripheral blood lymphocytes. Many types of human cancer are associated with specific or non-specific chromosomal aberrations. Several human recessive diseases, such as ataxia telangiectasia (A-T), Faconi's anemia (FA) and Bloom's syndrome (BS) are associated with increased frequencies of chromosomal aberrations. However, no detectable increase in the frequency of spontaneous point mutations in human populations exposed to ionizing radiations or chemical mutagens has been demonstrated so far. These observations point to the importance of understanding the mechanism involved in the origin of chromosomal alterations and their significance, which the author discusses in this paper

  5. Serum Protein Profile Alterations in Hemodialysis Patients

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, G A; Davies, R W; Choi, M W; Perkins, J; Turteltaub, K W; McCutchen-Maloney, S L; Langlois, R G; Curzi, M P; Trebes, J E; Fitch, J P; Dalmasso, E A; Colston, B W; Ying, Y; Chromy, B A

    2003-11-18

    Background: Serum protein profiling patterns can reflect the pathological state of a patient and therefore may be useful for clinical diagnostics. Here, we present results from a pilot study of proteomic expression patterns in hemodialysis patients designed to evaluate the range of serum proteomic alterations in this population. Methods: Surface-Enhanced Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (SELDI-TOFMS) was used to analyze serum obtained from patients on periodic hemodialysis treatment and healthy controls. Serum samples from patients and controls were first fractionated into six eluants on a strong anion exchange column, followed by application to four array chemistries representing cation exchange, anion exchange, metal affinity and hydrophobic surfaces. A total of 144 SELDI-TOF-MS spectra were obtained from each serum sample. Results: The overall profiles of the patient and control samples were consistent and reproducible. However, 30 well-defined protein differences were observed; 15 proteins were elevated and 15 were decreased in patients compared to controls. Serum from one patient exhibited novel protein peaks suggesting possible additional changes due to a secondary disease process. Conclusion: SELDI-TOF-MS demonstrated dramatic serum protein profile differences between patients and controls. Similarity in protein profiles among dialysis patients suggests that patient physiological responses to end-stage renal disease and/or dialysis therapy have a major effect on serum protein profiles.

  6. Altered myoelectric activity in the experimental blind loop syndrome.

    OpenAIRE

    Justus, P G; Fernandez, A; Martin, J.L.; King, C E; Toskes, P P; Mathias, J R

    1983-01-01

    Nutrient malabsorption and diarrhea are characteristic of the blind loop syndrome. Alterations in motility have been implicated as a cause of bacterial overgrowth, but the possibility that altered motility may result from alterations in the flora has not been explored. The purpose of this study was to characterize the myoelectric activity of the small intestine in the blind loop rat model. Eight groups of rats were studied: rats with self-filling blind loops, which develop bacterial overgrowt...

  7. Altered States of Consciousness during an Extreme Ritual

    OpenAIRE

    Lee, Ellen M.; Klement, Kathryn R.; Ambler, James K.; Loewald, Tonio; Comber, Evelyn M.; Hanson, Sarah A.; Pruitt, Bria; Sagarin, Brad J.

    2016-01-01

    Extreme rituals (body-piercing, fire-walking, etc.) are anecdotally associated with altered states of consciousness—subjective alterations of ordinary mental functioning (Ward, 1984)—but empirical evidence of altered states using both direct and indirect measures during extreme rituals in naturalistic settings is limited. Participants in the “Dance of Souls”, a 3.5-hour event during which participants received temporary piercings with hooks or weights attached to the piercings and danced to m...

  8. Neuroinflammation and neurological alterations in chronic liver diseases

    OpenAIRE

    Carmina Montoliu; Marta Llansola; Vicente Felipo

    2015-01-01

    Several million people with chronic liver diseases (cirrhosis, hepatitis) show neurological alterations, named hepatic encephalopathy (HE) with cognitive and motor alterations that impair quality of life and reduces life span. Inflammation acts synergistically with hyperammonemia to induce cognitive and motor alterations in patients with chronic liver disease and minimal hepatic encephalopathy (MHE). Previous studies in animal models have suggested that neuroinflammation is a major player in ...

  9. Determining the relative extent of alteration in CM chondrites

    Science.gov (United States)

    Browning, Lauren B.; McSween, Harry Y., Jr.; Zolensky, Michael

    1993-03-01

    The aqueous alteration of CM chondrites provides a record of the processes attending the earliest stages of parent body evolution. However, resolving the alteration pathways of chondritic evolution requires a means for distinguishing the relative extent of alteration that individual samples have experienced. Three new indices for gauging the relative degree of alteration in CM chondrites based on modal and compositional analyses of 7 CM falls were proposed. The proposed alteration parameters are consistent with the basic tenets of several previous models and correlate with additional indices to produce an integrated method for determining the relative extent of alteration. The model predicts the following order of progressive alteration: Murchison (MC) is less than or equal to Bells (BL) is less than Murray (MY) is less than Cochabamba (CC) is less than Mighei (MI) is less than Nogoya (NG) is less than or equal to Cold Bokkeveld (CB). The broad range of CM phyllosilicate compositions observed within individual meteorites is fundamental to the characterization of the aqueous alteration process. Chemical analyses of CM phyllosilicates suggest that these phases became systematically enriched in Mg and depleted in Fe with increasing alteration.

  10. Alteration kinetics of the glass-ceramic zirconolite and role of the alteration film Comparison with the SON68 glass

    Science.gov (United States)

    Martin, C.; Ribet, I.; Frugier, P.; Gin, S.

    2007-06-01

    The glass-ceramic zirconolite is being considered for specific conditioning of plutonium or the minor actinides. The actinides are distributed throughout the zirconolite crystals and the residual glass phase. Since zirconolite alteration is extremely limited, actinide release from the glass-ceramic material is mainly attributable to alteration of the residual glass. Specimens corresponding to the residual glass phase alone were therefore altered under different conditions to compare their kinetics with the one of the SON68 glass (inactive R7T7 type glass). Glass-ceramic zirconolite presents a more important rate decrease occuring more rapidly and that induces a quantity of glass altered at least 10 times as small as for SON68 glass. This slowdown of the alteration rate is attributed to the formation of an alteration film that has been the subject of a specific study. We have in particular identified a dense phase enriched in titanium and neodymium that probably influences deeply the kinetics.

  11. Optical tweezers reveal how proteins alter replication

    Science.gov (United States)

    Chaurasiya, Kathy

    Single molecule force spectroscopy is a powerful method that explores the DNA interaction properties of proteins involved in a wide range of fundamental biological processes such as DNA replication, transcription, and repair. We use optical tweezers to capture and stretch a single DNA molecule in the presence of proteins that bind DNA and alter its mechanical properties. We quantitatively characterize the DNA binding mechanisms of proteins in order to provide a detailed understanding of their function. In this work, we focus on proteins involved in replication of Escherichia coli (E. coli ), endogenous eukaryotic retrotransposons Ty3 and LINE-1, and human immunodeficiency virus (HIV). DNA polymerases replicate the entire genome of the cell, and bind both double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) during DNA replication. The replicative DNA polymerase in the widely-studied model system E. coli is the DNA polymerase III subunit alpha (DNA pol III alpha). We use optical tweezers to determine that UmuD, a protein that regulates bacterial mutagenesis through its interactions with DNA polymerases, specifically disrupts alpha binding to ssDNA. This suggests that UmuD removes alpha from its ssDNA template to allow DNA repair proteins access to the damaged DNA, and to facilitate exchange of the replicative polymerase for an error-prone translesion synthesis (TLS) polymerase that inserts nucleotides opposite the lesions, so that bacterial DNA replication may proceed. This work demonstrates a biophysical mechanism by which E. coli cells tolerate DNA damage. Retroviruses and retrotransposons reproduce by copying their RNA genome into the nuclear DNA of their eukaryotic hosts. Retroelements encode proteins called nucleic acid chaperones, which rearrange nucleic acid secondary structure and are therefore required for successful replication. The chaperone activity of these proteins requires strong binding affinity for both single- and double-stranded nucleic

  12. Altering petrology through microbial dissimilatory phosphite oxidation

    Science.gov (United States)

    Zhu, H.; Figueroa, I.; Coates, J. D.

    2013-12-01

    Microbial enhanced oil recovery (MEOR) takes advantage of various microbial metabolisms to increase hydrocarbon and energy yield by improving oil flow and flood water sweep in a reservoir during tertiary recovery. Wormholing at the injection well is believed to be the result of the large drop in pressure when water exits the injection well and enters the unconsolidated reservoir matrix. One possible means of prevent this event is to consolidate the rock matrix immediately around the injection well to create a permeable zone of stable petrology. Many microbial processes are known to result in the precipitation of ionic components into their environment creating solid-phase minerals. Such processes could be judiciously applied to bind unconsolidated matrices in order to form a permeable concreted rock matrix, which would minimize wormholing events and thus improve floodwater sweep. However, to date, apart from the application of urea oxidation creating calcium carbonate precipitation, there has been little investigation of the applicability of these precipitated bioconcretions to MEOR strategies and none to control wormholing events. Here we present a novel approach to altering rock petrology to concrete unconsolidated matrices in the near well environment by the biogenesis of authigenic minerals through microbial dissimilatory phosphite oxidation. Desulfotignum phosphitoxidans, strain FiPS-3 is currently the only isolated organism capable of using phosphite (HPO32-) as an electron donor for growth. This process, known as dissimilatory phosphite oxidation (DPO), can be coupled to either sulfate reduction or homoacetogenesis and leads to the accumulation of inorganic phosphate in the medium. The resulting insoluble mineral phases can coat the rock environment resulting in a concretion binding the unconsolidated matrix particles into a single phase. In this study we demonstrate that DPO can effectively produce calcium or magnesium phosphate minerals in packed glass

  13. STRUCTURAL ALTERATIONS OF SKELETAL MUSCLE IN COPD

    Directory of Open Access Journals (Sweden)

    Sunita eMathur

    2014-03-01

    Full Text Available Background: Chronic obstructive pulmonary disease (COPD is a respiratory disease associated with a systemic inflammatory response. Peripheral muscle dysfunction has been well characterized in individuals with COPD and results from a complex interaction between systemic and local factors. Objective: In this narrative review, we will describe muscle wasting in people with COPD, the associated structural changes, muscle regenerative capacity and possible mechanisms for muscle wasting. We will also discuss how structural changes relate to impaired muscle function and mobility in people with COPD. Key Observations: Approximately 30-40% of individuals with COPD experience muscle mass depletion. Furthermore, muscle atrophy is a predictor of physical function and mortality in this population. Associated structural changes include a decreased proportion and size of type-I fibers, reduced oxidative capacity and mitochondrial density mainly in the quadriceps. Observations related to impaired muscle regenerative capacity in individuals with COPD include a lower proportion of central nuclei in the presence or absence of muscle atrophy and decreased maximal telomere length, which has been correlated with reduced muscle cross-sectional area. Potential mechanisms for muscle wasting in COPD may include excessive production of reactive oxygen species, altered amino acid metabolism and lower expression of peroxisome proliferator-activated receptors-gamma-coactivator 1-alpha mRNA. Despite a moderate relationship between muscle atrophy and function, impairments in oxidative metabolism only seems weakly related to muscle function. Conclusion: This review article demonstrates the cellular modifications in the peripheral muscle of people with COPD and describes the evidence of its relationship to muscle function. Future research will focus on rehabilitation strategies to improve muscle wasting and maximize function.

  14. Altered thalamic functional connectivity in multiple sclerosis

    International Nuclear Information System (INIS)

    Highlights: •We demonstrated decreased connectivity between thalamus and cortical regions in MS. •Increased intra- and inter-thalamic connectivity was also observed in MS. •The increased functional connectivity is attenuated by increasing disease duration. -- Abstract: Objective: To compare thalamic functional connectivity (FC) in patients with multiple sclerosis (MS) and healthy controls (HC), and correlate these connectivity measures with other MRI and clinical variables. Methods: We employed resting-state functional MRI (fMRI) to examine changes in thalamic connectivity by comparing thirty-five patients with MS and 35 age- and sex-matched HC. Thalamic FC was investigated by correlating low frequency fMRI signal fluctuations in thalamic voxels with voxels in all other brain regions. Additionally thalamic volume fraction (TF), T2 lesion volume (T2LV), EDSS and disease duration were recorded and correlated with the FC changes. Results: MS patients were found to have a significantly lower TF than HC in bilateral thalami. Compared to HC, the MS group showed significantly decreased FC between thalamus and several brain regions including right middle frontal and parahippocampal gyri, and the left inferior parietal lobule. Increased intra- and inter-thalamic FC was observed in the MS group compared to HC. These FC alterations were not correlated with T2LV, thalamic volume or lesions. In the MS group, however, there was a negative correlation between disease duration and inter-thalamic connectivity (r = −0.59, p < 0.001). Conclusion: We demonstrated decreased FC between thalamus and several cortical regions, while increased intra- and inter-thalamic connectivity in MS patients. These complex functional changes reflect impairments and/or adaptations that are independent of T2LV, thalamic volume or presence of thalamic lesions. The negative correlation between disease duration and inter-thalamic connectivity could indicate an adaptive role of thalamus that is

  15. Altered levels of acetylcholinesterase in Alzheimer plasma.

    Directory of Open Access Journals (Sweden)

    María-Salud García-Ayllón

    Full Text Available BACKGROUND: Many studies have been conducted in an extensive effort to identify alterations in blood cholinesterase levels as a consequence of disease, including the analysis of acetylcholinesterase (AChE in plasma. Conventional assays using selective cholinesterase inhibitors have not been particularly successful as excess amounts of butyrylcholinesterase (BuChE pose a major problem. PRINCIPAL FINDINGS: Here we have estimated the levels of AChE activity in human plasma by first immunoprecipitating BuChE and measuring AChE activity in the immunodepleted plasma. Human plasma AChE activity levels were approximately 20 nmol/min/mL, about 160 times lower than BuChE. The majority of AChE species are the light G(1+G(2 forms and not G(4 tetramers. The levels and pattern of the molecular forms are similar to that observed in individuals with silent BuChE. We have also compared plasma AChE with the enzyme pattern obtained from human liver, red blood cells, cerebrospinal fluid (CSF and brain, by sedimentation analysis, Western blotting and lectin-binding analysis. Finally, a selective increase of AChE activity was detected in plasma from Alzheimer's disease (AD patients compared to age and gender-matched controls. This increase correlates with an increase in the G(1+G(2 forms, the subset of AChE species which are increased in Alzheimer's brain. Western blot analysis demonstrated that a 78 kDa immunoreactive AChE protein band was also increased in Alzheimer's plasma, attributed in part to AChE-T subunits common in brain and CSF. CONCLUSION: Plasma AChE might have potential as an indicator of disease progress and prognosis in AD and warrants further investigation.

  16. Polarization Altering Devices in Guided Wave Optics

    Science.gov (United States)

    Sletten, Mark Arthur

    In this thesis, four guided wave optical devices are investigated, each of which alters the state of polarization of the lightwave which passes through it. Chapter 1 contains general information on the operation of these devices and on the systems in which they are typically used, and the subsequent chapters discuss each device in detail. Chapter 2 presents a quasi-optic analysis of a thin film polarization converter formed by a thin, isotropic film on an anisotropic, electrooptic substrate. In Chapter 3, a singular perturbation technique with multiple scales is used to analyze a thick metal surface polariton polarizer for a planar optical waveguide. This analysis is extended in Chapter 4 to a similar device in which the metal is assumed to have a finite thickness. The analysis indicates two regions of operation for this device and also indicates the importance of phase matching the surface polariton to the transverse magnetic mode guided by the dielectric waveguide. An experimental investigation of a surface polariton polarizer fabricated with optical fiber and silicon v-grooves is reported in Chapter 5. The fabrication process for these devices is described, and the results of investigations into the dependence of the extinction ratio on the device length and fiber core to metal spacing are presented. Chapter 6 outlines a singular perturbation analysis of a polarization splitting directional coupler. Like the polarizers discussed in Chapters 3, 4 and 5, the coupler owes its polarization selecting capability to interactions with surface polaritons. The final chapter contains suggestions for future research related to the polarizer analysis and experiments.

  17. Deforestation alters rainfall: a myth or reality

    Science.gov (United States)

    Hanif, M. F.; Mustafa, M. R.; Hashim, A. M.; Yusof, K. W.

    2016-06-01

    To cope with the issue of food safety and human shelter, natural landscape has gone through a number of alterations. In the coming future, the expansion of urban land and agricultural farms will likely disrupt the natural environment. Researchers have claimed that land use change may become the most serious issue of the current century. Thus, it is necessary to understand the consequences of land use change on the climatic variables, e.g., rainfall. This study investigated the impact of deforestation on local rainfall. An integrated methodology was adopted to achieve the objectives. Above ground biomass was considered as the indicator of forest areas. Time series data of a Moderate Resolution Imaging Spectroradiometer (MODIS) sensor were obtained for the year of 2000, 2005, and 2010. Rainfall data were collected from the Department of Irrigation and Drainage, Malaysia. The MODIS time series data were classified and four major classes were developed based on the Normalised Difference Vegetation Index (NDVI) ranges. The results of the classification showed that water, and urban and agricultural lands have increased in their area by 2, 3, and 6%, respectively. On the other hand, the area of forest has decreased 10% collectively from 2000 to 2010. The results of NDVI and rainfall data were analysed by using a linear regression analysis. The results showed a significant relationship at a 90% confidence interval between rainfall and deforestation (t = 1.92, p = 0.06). The results of this study may provide information about the consequences of land use on the climate on the local scale.

  18. Altered thalamic functional connectivity in multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yaou; Liang, Peipeng; Duan, Yunyun; Huang, Jing; Ren, Zhuoqiong; Jia, Xiuqin [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Dong, Huiqing; Ye, Jing [Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Shi, Fu-Dong [Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052 (China); Butzkueven, Helmut [Department of Medicine, University of Melbourne, Parkville 3010 (Australia); Li, Kuncheng, E-mail: kunchengli55@gmail.com [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China)

    2015-04-15

    Highlights: •We demonstrated decreased connectivity between thalamus and cortical regions in MS. •Increased intra- and inter-thalamic connectivity was also observed in MS. •The increased functional connectivity is attenuated by increasing disease duration. -- Abstract: Objective: To compare thalamic functional connectivity (FC) in patients with multiple sclerosis (MS) and healthy controls (HC), and correlate these connectivity measures with other MRI and clinical variables. Methods: We employed resting-state functional MRI (fMRI) to examine changes in thalamic connectivity by comparing thirty-five patients with MS and 35 age- and sex-matched HC. Thalamic FC was investigated by correlating low frequency fMRI signal fluctuations in thalamic voxels with voxels in all other brain regions. Additionally thalamic volume fraction (TF), T2 lesion volume (T2LV), EDSS and disease duration were recorded and correlated with the FC changes. Results: MS patients were found to have a significantly lower TF than HC in bilateral thalami. Compared to HC, the MS group showed significantly decreased FC between thalamus and several brain regions including right middle frontal and parahippocampal gyri, and the left inferior parietal lobule. Increased intra- and inter-thalamic FC was observed in the MS group compared to HC. These FC alterations were not correlated with T2LV, thalamic volume or lesions. In the MS group, however, there was a negative correlation between disease duration and inter-thalamic connectivity (r = −0.59, p < 0.001). Conclusion: We demonstrated decreased FC between thalamus and several cortical regions, while increased intra- and inter-thalamic connectivity in MS patients. These complex functional changes reflect impairments and/or adaptations that are independent of T2LV, thalamic volume or presence of thalamic lesions. The negative correlation between disease duration and inter-thalamic connectivity could indicate an adaptive role of thalamus that is

  19. Algal toxins alter copepod feeding behavior.

    Directory of Open Access Journals (Sweden)

    Jiarong Hong

    Full Text Available Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod's feeding appendages-a "sampling beating" that has short durations (<100 ms and involves little fluid entrainment and a longer duration "grazing beating" that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. tonsa demonstrates aversion to both toxic algal species. In mixtures of S. major and the neurotoxin producing K. brevis, sampling and grazing diminish rapidly, presumably due to neurological effects of consuming brevetoxins while trying to feed on S. major. In contrast, on mixtures of cytotoxin producing K. veneficum, both behavioral modes persist, indicating that intake of karlotoxins does not immediately inhibit the copepod's grazing behavior. These findings add critical insight into how these algal toxins may influence the copepod's feeding behavior, and suggest how some harmful algal species may alter top-down control exerted by grazers like copepods.

  20. Algal toxins alter copepod feeding behavior.

    Science.gov (United States)

    Hong, Jiarong; Talapatra, Siddharth; Katz, Joseph; Tester, Patricia A; Waggett, Rebecca J; Place, Allen R

    2012-01-01

    Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major) to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod's feeding appendages-a "sampling beating" that has short durations (<100 ms) and involves little fluid entrainment and a longer duration "grazing beating" that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. tonsa demonstrates aversion to both toxic algal species. In mixtures of S. major and the neurotoxin producing K. brevis, sampling and grazing diminish rapidly, presumably due to neurological effects of consuming brevetoxins while trying to feed on S. major. In contrast, on mixtures of cytotoxin producing K. veneficum, both behavioral modes persist, indicating that intake of karlotoxins does not immediately inhibit the copepod's grazing behavior. These findings add critical insight into how these algal toxins may influence the copepod's feeding behavior, and suggest how some harmful algal species may alter top-down control exerted by grazers like copepods. PMID:22629336

  1. Borosilicate nuclear waste glass alteration kinetics theoretical basis for the kinetic law of nuclear glass alteration

    International Nuclear Information System (INIS)

    Work carried out since the early 1980's to predict the long-term behavior of nuclear containment glasses has revealed the inadequacy of existing models, notably in accounting for the fundamental mechanisms involved in some complex systems (e.g. glass-water-clay), inciting us to examine and discuss the theoretical basis for the hypotheses generally assumed in our models. This paper discusses the theoretical basis for the Aagaard-Helgeson law and its application to nuclear glasses. The contribution of other types of kinetic laws is also considered to describe the alteration kinetics of nuclear glasses. (authors)

  2. Physiological alterations in UV-irradiated cells: liquid holding recovery

    International Nuclear Information System (INIS)

    The biochemical and physiological alterations that occur in ultraviolet irradiated cells, during liquid holding have been studied. Incubation in buffer acts not to interfer directly with the mechanic repairs but by promoting metabolic alterations that would block some irreversible and lethal physiological responses. (L.M.J.)

  3. Elk herbivory alters small mammal assemblages in high elevation drainages

    Science.gov (United States)

    Parsons, Elliott W.R.; Maron, John L.; Martin, Thomas E.

    2012-01-01

    Heavy herbivory by ungulates can substantially alter habitat, but the indirect consequences of habitat modification for animal assemblages that rely on that habitat are not well studied. This is a particularly important topic given that climate change can alter plant–herbivore interactions.

  4. 9 CFR 151.5 - Alteration of pedigree certificate.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Alteration of pedigree certificate. 151.5 Section 151.5 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT... Certification of Purebred Animals § 151.5 Alteration of pedigree certificate. No pedigree certificate which...

  5. 24 CFR 8.23 - Alterations of existing housing facilities.

    Science.gov (United States)

    2010-04-01

    ... (including a public housing project as required by § 8.25(a)(2)) that has 15 or more units and the cost of the alterations is 75 percent or more of the replacement cost of the completed facility, then the... under this paragraph. Alterations to common areas or parts of facilities that affect accessibility...

  6. 14 CFR 21.289 - Major repairs, rebuilding and alteration.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Major repairs, rebuilding and alteration. 21.289 Section 21.289 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... authorization, a manufacturer may— (a) After finding that a major repair or major alteration meets...

  7. MICROSATELLITE ALTERATION AND ITS CHARACTERISTICS IN COLORECTAL CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To determine the role of microsatellite alterations incarcinogenesis of colorectal carcinoma (CRC). Methods: Alterations of 10 microsatellite loci from 5 different chromosomes were detected in 92 colorectal cancers and their paired normal mucosa by PCR, denatured polyacrylamide gel electrophoresis and silver staining. Associations of microsatellite alterations with clinopathologic parameters were statistically clarified.Results: Alterations of microsatellite were classified into microsatellite instability type I, type II and loss of heterozygosity (LOH). The carcinoma with ≥30% loci microsatellite alterations was defined as replication error(RER) positive tumors. Of 92 cases, 14 were RER+. Microsatellite alterations of P53(1) and D18S363 loci (64.29% ) was most commonly identified in the RER+ tumors. RER+ were more commonly seen in poorly differentiated carcinomas and tended to occur in mucoid carcinomas. The type of microsatellite alterations varied in different histological types of CRC. Conclusions: Microsatellite alteration is a common molecular event in CRC. Different microsatellite loci showed various biologic significance. P53(1) and D18S363 should be essentially detected loci that can show the RER status of tumors.

  8. Biogeochemistry of hydrothermally and adjacent non-altered soils

    Science.gov (United States)

    As a field/lab project, students in the Soil Biogeochemistry class of the University of Nevada, Reno described and characterized seven pedons, developed in hydrothermally and adjacent non-hydrothermally altered andesitic parent material near Reno, NV. Hydrothermally altered soils had considerably lo...

  9. Genetic alterations and markers of melanoma

    Directory of Open Access Journals (Sweden)

    N. N. Mazurenko

    2014-01-01

    Full Text Available Melanoma remains the most deadly form of malignant skin disease with high risk of metastases. Metastatic melanoma is prognostic highly unfavorable and resistant to traditional chemotherapy and biologic treatment. There is a great progress in understanding of the molecular mechanisms underlying melanoma initiation and progression. The external (ultraviolet irradiation and internal (genetic factors are involved in melanoma genesis. 5–14 % of melanoma cases occur in familial context due to genetic predisposition risk factors. Among them rare germinal mutations in the cell cycle genes regulators CDKN2A and CDK4 and in the master gene of melanocyte homeostasis MITF, as well as single nucleotide polymorphisms of several low-penetrated genes, namely MC1R, have been identified. The main cell signaling pathways and oncogene driver mutations are involved in melanoma pathogenesis. RAS / RAF / MEK / ERK cascade is hyperactivated in 75 % of cutaneous melanoma cases. Activation of PI3K / AKT / mTOR signaling pathway is important for melanoma progression. Recent studies revealed that melanomas are genetically and phenotypically heterogeneous tumors. Spectrum of chromosomal alterations and activating mutations corresponding to tumor molecular portraits varies in melanomas of different location. Most of cutaneous melanomas contain BRAF (50 % or NRAS (20 % mutations, and NRAS mutations occur on chronically sun-exposed skin. Activating KIT mutations have been reported in approximately 20–30 % of certain subtypes of melanoma, including acral and mucosal, and melanoma that develop on photodamaged skin. Cutaneous metastatic melanoma derive from preexisting nevi in 25 % of cases, molecular mechanisms of nevi malignization are discussed. Deepsequencing approaches of melanoma samples of different melanoma types highlighted new melanoma driver genes, that are damaged due to tumorigenic effects of ultraviolet: PPP6C, RAC1, SNX31, TACC1 and STK19. The

  10. Rare earth impact on glass structure and alteration kinetics

    International Nuclear Information System (INIS)

    This work is related to the question of the geological deep repository of high-level waste glass. These wastes include fission products and minor actinides, elements which can be simulated by rare earths. As new glass compositions could enable increased rare earth concentrations, it is crucial to know and understand rare earth impact on glass structure on the one hand, and on glass alteration kinetics or their incorporation into an altered layer. This work studied simplified borosilicate glasses in order to limit synergetic effects between rare earths and other elements. Various complementary techniques were used to characterize pristine and altered glasses (solid-high resolution NMR, Raman spectroscopy, fluorescence, SIMS, SAXS). Firstly, the structural role of a rare earth is discussed and is compared to a calcium cation. The local environment of rare earths is also probed. Secondly, rare earth (nature and concentration) impact on several alteration regimes was studied (initial rate, rate drop). Then, after alteration, rare earth elements being retained within the altered layer, the structural impact of rare earth elements (and their local environment) in this alteration layer was also investigated. (author)

  11. Geothermal alteration of clay minerals and shales: diagenesis

    International Nuclear Information System (INIS)

    The objective of this report is to perform a critical review of the data on the mineral and chemical alterations that occur during diagenesis and low-grade metamorphism of shale and other clay-rich rocks - conditions similar to those expected from emplacement of heat-producing radioactive waste in a geologic repository. The conclusions drawn in this document are that the following type of alterations could occur: smectite alteration, ion mobilization, illitic shales, kaolinite reactions, chlorite reactions, organic reactions, paleotemperatures, low temperature shales, high temperature shales, and phase equilibrium changes

  12. Genomic alterations in pancreatic cancer and their relevance to therapy

    Institute of Scientific and Technical Information of China (English)

    Erina; Takai; Shinichi; Yachida

    2015-01-01

    Pancreatic cancer is a highly lethal cancer type, for which there are few viable therapeutic options. But, with the advance of sequencing technologies for global genomic analysis, the landscape of genomic alterations in pancreatic cancer is becoming increasingly well understood. In this review, we summarize current knowledge of genomic alterations in 12 core signaling pathways or cellular processes in pancreatic ductal adenocarcinoma, which is the most common type of malignancy in the pancreas, including four commonly mutated genes and many other genes that are mutated at low frequencies. We also describe the potential implications of these genomic alterations for development of novel therapeutic approaches in the context of personalized medicine.

  13. Cocaine triggers epigenetic alterations in the corticostriatal circuit.

    Science.gov (United States)

    Sadri-Vakili, Ghazaleh

    2015-12-01

    Acute and repeated exposure to cocaine induces long-lasting alterations in neural networks that underlie compulsive drug seeking and taking. Cocaine exposure triggers complex adaptations in the brain that are mediated by dynamic patterns of gene expression that are translated into enduring changes. Recently, epigenetic modifications have been unveiled as critical mechanisms underlying addiction that contribute to drug-induced plasticity by regulating gene expression. These alterations are also now linked to the heritability of cocaine-induced phenotypes. This review focuses on how changes in the epigenome, such as altered DNA methylation, histone modifications, and microRNAs, regulate transcription of specific genes that contribute to cocaine addiction. PMID:25301690

  14. ORIENTATION FIELD RECONSTRUCTION OF ALTERED FINGERPRINT USING ORTHOGONAL WAVELETS

    Directory of Open Access Journals (Sweden)

    Mini M.G.

    2016-11-01

    Full Text Available Ridge orientation field is an important feature for fingerprint matching and fingerprint reconstruction. Matching of the altered fingerprint against its unaltered mates can be done by extracting the available features in the altered fingerprint and using it along with approximated ridge orientation. This paper presents a method for approximating ridge orientation field of altered fingerprints. In the proposed method, sine and cosine of doubled orientation of the fingerprint is decomposed using orthogonal wavelets and reconstructed back using only the approximation coefficients. No prior information about the singular points is needed for orientation approximation. The method is found suitable for orientation estimation of low quality fingerprint images also.

  15. White matter alterations in neurodegenerative and vascular dementia

    International Nuclear Information System (INIS)

    Due to a significant overlap of the two syndromes, differentiation of degenerative dementia of the Alzheimer-type from vascular dementia may be difficult even when imaging studies are available. White matter changes occur in many patients suffering from Alzheimer's disease. Little is known about the impact of white matter changes on the course and clinical presentation of Alzheimer's disease. High sensitivity of MRI in the detection of white matter alterations may account for over-diagnosing vascular dementia. The clinical significance of white matter alterations in dementia is still a matter of debate. The article reviews current concepts about the role of white matter alterations in dementia. (orig.)

  16. Soudage par explosion thermique sous charge de cermets poreux à base de TiC-Ni sur substrat en acier-comportement tribologique Welding of porous TiC–Ni based cermets on substrate steel by thermal explosion under load-tribological behaviour

    Directory of Open Access Journals (Sweden)

    Lemboub Samia

    2013-11-01

    Full Text Available Dans ce travail, nous nous intéressons à l'élaboration de cermets à base de TiC-Ni par dispersion de particules de carbures, oxydes ou borures dans une matrice de nickel, grâce à la technique de l'explosion thermique sous une charge de 20 MPa. La combustion de mélanges actifs (Ti-C-Ni-An où An = Al2O3, MgO, SiC, TiB2, WC, basée sur la réaction de synthèse de TiC (ΔHf298K = −184 kJ/mole, génère des cermets complexes. Un court maintien sous charge du cermet à 1373 K, après l'explosion thermique, permet son soudage sur un substrat en acier XC55. Les cermets obtenus dans ces conditions demeurent poreux et conservent une porosité de l'ordre de 25–35 %. La densité relative du cermet, sa dureté et son comportement tribologique, dépendront de la nature de l'addition dans les mélanges de départ. Porous TiC-Ni based cermets were obtained by dispersion of carbides, oxides or borides particles in a nickel matrix thanks to the thermal explosion technique realized under a load of 20 MPa. The combustion of active mixtures (Ti-C-Ni-An where An = Al2O3, MgO, SiC, TiB2 or WC based on the titanium carbide reaction synthesis (ΔHf = −184 kJ/mol, generates porous complex cermets. After the thermal explosion, a short maintenance under load at 1373 K of the combustion product, allows at the same time the cermets welding on a carbon steel substrate. The obtained cermets under these conditions preserve a porosity of about 25–35%. The relative density, hardness and tribological behaviour of the complex cermets depend on the additions nature (An in the starting mixtures.

  17. « Comment se comporter avec un roi chrétien » : l’ouvrage perdu d’Abū l-Ḥasan ʿAlī Ibn al-Qaṭṭān et les enjeux du cérémonial almohade

    Directory of Open Access Journals (Sweden)

    Mehdi Ghouirgate

    2014-05-01

    Full Text Available Cet article propose de revenir sur un document aussi exceptionnel que méconnu. Il s’agit du résumé d’un ouvrage (maqāla, aujourd’hui perdu, intitulé « Comment se comporter avec un roi chrétien », et que l’on trouve dans le dictionnaire bio-bibliographique d’Ibn ʿAbd al-Malik. Cette maqāla fut rédigée, par un homme de lettres au service des Almohades, Abū l-Ḥasan ʿAlī Ibn al-Qaṭṭān (m. 1231. C’est la seule source qui ait consigné des indications sur la conduite que devait adopter le souverain lors d’une cérémonie, en présence d’un prince étranger. À ce titre, on y trouve des renseignements essentiels sur le cérémonial almohade ainsi que sur les dilemmes que devaient résoudre le calife : d’un point de vue idéologique, il ne pouvait souffrir aucun autre pouvoir, mais l’impossibilité de mener des opérations d’envergure sur deux fronts à la fois l’amena à composer avec le roi du León. De même, c’est le seul document à avoir fait état d’une divergence de point de vue entre le calife et les intellectuels organiques du système, les Ṭalaba. Ce différend met en lumière des tensions latentes au sommet entre divers serviteurs de l’État, qui n’avaient pas la même forme de légitimité, ni tout à fait les mêmes intérêts.

  18. Low Temperature Rheological Behavior of Umbarka Waxy Crude and Influence of Flow Improver Etude du comportement rhéologique du brut paraffinique d'Umbarka à basse température et de l'influence d'un additif pour l'amélioration des caractéristiques d'écoulement

    Directory of Open Access Journals (Sweden)

    El-Gamal I. M.

    2006-12-01

    Full Text Available The low temperature flow properties; pour point and rheological parameters; have been determined for untreated and additive treated Umbarka waxy crude. The rheological characteristics of the crude showed non-Newtonian yield pseudoplastic flow behavior and pronounced thixotropic effect. Viscometric data are fitted to Bingham, Casson and Herschel-Bulkley plastic flow models using linear and non-linear computer regression analysis. Herschel parameters showed inconsistent results whereas Casson equation fitted the data reasonably well. Treatment of the crude with flow improver ameliorated both rheological properties and pour point but in a different manner. The influence of the additive on the rheology of the crude is greatly affected by shear rate. The thixotropic phenomenon of the crude is likely to be temperature-dependent in addition to the other controlling factors. L'objet de cette étude est de déterminer les caractéristiques du brut paraffinique d'Umbarka, avec et sans additif pour l'amélioration de l'écoulement, à savoir, l'écoulement à basse température, le point d'écoulement, et les données rhéologiques. Les caractéristiques rhéologiques du brut font apparaître un comportement d'écoulement pseudoplastique avec une limite élastique non newtonienne ainsi qu'un effet thixotropique accusé. Une corrélation a été établie entre les données viscométriques et les modèles d'écoulement plastique de Bingham, Casson et Herschel-Bulkley en utilisant une analyse de régression informatique linéaire et non linéaire. Si les paramètres de Herschel conduisent à des résultats incohérents, l'équation de Casson, en revanche, permet d'établir une corrélation raisonnablement satisfaisante des données. Le traitement du brut à l'aide d'un additif d'amélioration de l'écoulement a des répercussions positives, quoique différentes, sur les propriétés rhéologiques et le point d'écoulement. Les effets de l'additif sur la rh

  19. Influence of natural organic matter on the speciation of radionuclides in a geochemistry context; Influence de la matiere organique naturelle sur la speciation des radionucleides en contexte geochimique

    Energy Technology Data Exchange (ETDEWEB)

    Marang, L

    2007-09-15

    The principal aim of this work is the study of the influence of natural organic matter, in particularly humic substances (HS), on the speciation of radionuclides (RN). The studied radionuclides are cobalt (II), europium (III) and uranium (VI). It has been shown that mobility and bioavailability of a metal are related to its speciation. The NICA-Donnan model describes metal ion binding to NOM: it accounts for NOM chemical heterogeneity, competition during binding and ionic strength effects. However the model has been calibrated with a limited number of experimental data for the RN. Indeed there is only a few speciation technique available for the study of the interactions RN-HS. Within the framework of this study, we have developed and optimised speciation technique (Flux Donnan Membrane Technique and the use of an un-solubilized humic acid) in order to acquire new experimental data, we have also studied the effect of the competition on RN speciation and finally we have tested the model capacity to predict the RN behavior in laboratory or in situ. (author)

  20. Studying uranium migration in natural environment: experimental approach and geochemical modeling; Etude de la migration de l'uranium en milieu naturel: approche experimentale et modelisation geochimique

    Energy Technology Data Exchange (ETDEWEB)

    Phrommavanh, V.

    2008-10-15

    The present study deals with characterizing uranium migration in a limited zone of Le Bouchet site, a former uranium ore treatment facility, which is dismantled and the rehabilitation of which is under process. Some wastes are packed in a rehabilitated disposal nearby, called the Itteville site. In the framework of the monitoring of the deposit environment (air, water, sediment) set by prefectorial decrees, a piezometer (PZPK) located downstream to the latter, has shown total dissolved uranium peaks each winter since the 1990's. PZPK collects both the interstitial water of a calcareous peat formation, between the surface and 3 m, and an alluvial aquifer near 6 m of depth. Firstly, a hydrogeochemical characterization of the site has evidenced the uranium source term, which is present in the peat soil near 0.8 m, hence excluding any leaching from the waste disposal. Actually, a few microparticles of uranium oxide and mixed uranium-thorium oxide have been detected, but they do not represent the major part of the source term. Secondly, water chemistry of the peat soil water and PZPK has been monitored every two months from 2004 to 2007 in order to understand the reasons of the seasonal fluctuations of [U]tot.diss.. Completed with geochemical modeling and a bacterial identification by 16S rDNA sequence analysis, water chemistry data showed an important sulfate-reducing bacterial activity in summertime, leading to reducing conditions and therefore, a total dissolved uranium content limited by the low solubility of uraninite U{sup IV}O{sub 2}(s). In wintertime, the latter bacterial activity being minimal and the effective pluviometry more important, conditions are more oxidant, which favors U(VI), more soluble, notably as the Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) complex, evidenced by TRLFS. Finally, bacterial activity has been reproduced in laboratory in order to better characterize its impact on uranium solubility in the peat soil. Various parameters were tested (C sources, temperature, nutrients) to recreate conditions close and also different to those in situ. 16S rDNA sequence bacterial identifications, throughout the incubation time, have confirmed an increase of sulfate-reducing bacteria proportion. At the same time, water chemistry, as well as geochemical calculations and SEM observations and XANES analyses, have evidenced an decrease of [U]tot.diss., owing to its reduction as UO{sub 2}(s) (certainly as nano-particles). Even though the reaction mechanism could not be determined, that is to say biotic (direct uranium reduction by bacteria) or abiotic (indirect reduction), these experiments have showed that sulfate-reducing bacteria can prevail among a varied indigenous population in conditions close to those in situ. Moreover, the studied calcareous peat contains a significant amount of weddellite (CaC{sub 2}O{sub 4}.2H{sub 2}O(s)), accounting for a permanent input of oxalate ions C{sub 2}O{sub 4}{sup 2-} which can be used as C source in the course of sulfate and/or uranium reduction in the summer. (author)

  1. Alterations in polyadenylation and its implications for endocrine disease

    Directory of Open Access Journals (Sweden)

    LennartFriis-Hansen

    2013-05-01

    This review gives a detailed description of alterations in polyadenylation in endocrine disease, an overview of the current literature on polyadenylation and summarizes the clinical implications of the current state of research in this field.

  2. Penis Reconstructions 'Life-Altering' for Men, Studies Show

    Science.gov (United States)

    ... nlm.nih.gov/medlineplus/news/fullstory_158725.html Penis Reconstructions 'Life-Altering' for Men, Studies Show Both ... Men who undergo surgery to create a new penis seem to fare well in the long term, ...

  3. The alteration of the BPM, burden neutrality and autonomous greening

    International Nuclear Information System (INIS)

    The foundation of the purchase tax on passenger cars (BPM) in the Netherlands is gradually altered from catalogue value to CO2 emission per kilometer of the new car. The tariffs have been established in such a way that they meet the precondition of burden neutrality of the BPM alteration. There is some discussion about this and the first part of this publication will address this issue. The issue of burden neutrality is part of a study by DHV Investment Services (DHV). The first main conclusion of the DHV study is that the alteration is not budget neutral. The study entails an applied welfare analysis of the alteration of the BPM foundation. Some comments on the welfare analysis are provided in the second part of this memo. Another issue that is addressed involves the question if and how the autonomous decrease in CO2 emission of newly sold cars can be established in practice.

  4. Smoking During Pregnancy Seems to Alter Fetal DNA, Study Finds

    Science.gov (United States)

    ... nlm.nih.gov/medlineplus/news/fullstory_158077.html Smoking During Pregnancy Seems to Alter Fetal DNA, Study ... that were affected by a mother-to-be's smoking. The findings may help improve understanding about the ...

  5. Characterizing genomic alterations in cancer by complementary functional associations.

    Science.gov (United States)

    Kim, Jong Wook; Botvinnik, Olga B; Abudayyeh, Omar; Birger, Chet; Rosenbluh, Joseph; Shrestha, Yashaswi; Abazeed, Mohamed E; Hammerman, Peter S; DiCara, Daniel; Konieczkowski, David J; Johannessen, Cory M; Liberzon, Arthur; Alizad-Rahvar, Amir Reza; Alexe, Gabriela; Aguirre, Andrew; Ghandi, Mahmoud; Greulich, Heidi; Vazquez, Francisca; Weir, Barbara A; Van Allen, Eliezer M; Tsherniak, Aviad; Shao, Diane D; Zack, Travis I; Noble, Michael; Getz, Gad; Beroukhim, Rameen; Garraway, Levi A; Ardakani, Masoud; Romualdi, Chiara; Sales, Gabriele; Barbie, David A; Boehm, Jesse S; Hahn, William C; Mesirov, Jill P; Tamayo, Pablo

    2016-05-01

    Systematic efforts to sequence the cancer genome have identified large numbers of mutations and copy number alterations in human cancers. However, elucidating the functional consequences of these variants, and their interactions to drive or maintain oncogenic states, remains a challenge in cancer research. We developed REVEALER, a computational method that identifies combinations of mutually exclusive genomic alterations correlated with functional phenotypes, such as the activation or gene dependency of oncogenic pathways or sensitivity to a drug treatment. We used REVEALER to uncover complementary genomic alterations associated with the transcriptional activation of β-catenin and NRF2, MEK-inhibitor sensitivity, and KRAS dependency. REVEALER successfully identified both known and new associations, demonstrating the power of combining functional profiles with extensive characterization of genomic alterations in cancer genomes. PMID:27088724

  6. Alteration of basaltic glasses from the Central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.

    Textural, mineralogical and compositional characteristics of basaltic glasses from the Central Indian Ocean show them to be altered to varying extents through their interaction with the seawater, resulting in the formation of palagonite. The major...

  7. Violent Video Games Alter Brain Function in Young Men

    Science.gov (United States)

    ... Updates News from the RSNA Annual Meeting Violent Video Games Alter Brain Function in Young Men At A ... functional MRI, researchers have found that playing violent video games for one week causes changes in brain function. ...

  8. Tumor microenvironmental genomic alterations in juvenile nasopharyngeal angiofibroma

    DEFF Research Database (Denmark)

    Silveira, Sara Martoreli; Custódio Domingues, Maria Aparecida; Butugan, Ossamu;

    2012-01-01

    BACKGROUND: To better characterize the pathophysiology of juvenile nasopharyngeal angiofibroma (JNA), endothelial and stromal cells were evaluated by genomic imbalances in association with transcript expression levels of genes mapped on these altered regions. METHODS: High-resolution comparative...

  9. Contribution to uranium geochemistry in intrusive granites; Contribution a la geochimie de l'uranium dans les granites intrusifs

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-01-15

    , un certain nombre de massifs granitiques francais: - 3 massifs hercyniens francais, en Vendee, en Bretagne et dans le Morvan, - 1 massif africain, probablement precambrien, du Hoggar. Dans chaque massif, nous determinons en premier lieu le cadre petrochimique et evaluons le degre d'homogeneite chimique des roches. Dans les familles petrochimiques ainsi determinees, nous etudions le comportement geochimique de l'uranium. Du point de vue de la geochimie des granites etudies, le comparaison des lois de repartition des elements majeurs fait apparaitre dans les 4 massifs une convergence de composition moyenne que ne laissaient pas prevoir la geologie et la petrographie. Nous etablissons les lois de repartition statistiques et geographiques de l'uranium total en fonction des variations petrochimiques. L'etude des formes de l'uranium a l'interieur des roches a attire notre attention sur l'importance qualitative et quantitative de la fraction de cet uranium soluble dans les acides dilues. Nous reprenons donc, d'un cote les lois de repartition de l'uranium insoluble qui represente pratiquement l'uranium inclus dans les structures cristallines (zircon, allanite...) et justifions d'un autre cote l'interet presente par l'uranium soluble qui, malgre un caractere plus complexe, permet par son unite geochimique dans les phenomenes postmagmatiques, de trouver une liaison genetique entre les gisements uraniferes et les massifs intrusifs. Nous presentons enfin, un schema du cycle geochimique de l'uranium dans lequel nous esperons avoir pu apporter quelques precisions sur la phase ignee. (auteur)

  10. Alterations in serum lipid profile patterns in oral cancer

    OpenAIRE

    Singh, Simranjit; Ramesh, Venkatapathy; Premalatha, Balakrishnan; Prashad, Karthikshree Vishnu; Ramadoss, Koliyan

    2013-01-01

    Background: Alterations in serum lipids have long been associated with cancer as lipids play an important role in maintenance of cell integrity. Aims: To evaluate alterations in plasma lipid profile in oral cancer patients, to compare and correlate the serum lipid profile in different grades of carcinoma and to evaluate the correlation of serum lipid profile between the tobacco habituates and non-habituates. Materials and Methods: Among 75 study subjects, 50 individuals were oral carcinoma pa...

  11. Lymph nodes cytology in HIV seropositive cases with haematological alterations

    OpenAIRE

    Neelima Tirumalasetti; Prema Latha, P.

    2014-01-01

    Background & objectives: Lymphadenopathy and haematological alterations are the earliest manifestations with other associated opportunistic infections and malignancies. Hence, there is a need for simple investigations like fine needle aspiration cytology (FNAC) for evaluation of HIV lymphadenopathy and a haemogram to interpret the haematological alterations. This study was undertaken to analyze the cytological patterns of lymph node lesions in HIV/AIDS patients, to compare with available clin...

  12. Human alteration of natural light cycles: causes and ecological consequences

    OpenAIRE

    Gaston, Kevin J; Duffy, James P.; Gaston, Sian; Bennie, Jonathan; Davies, Thomas W

    2014-01-01

    Artificial light at night is profoundly altering natural light cycles, particularly as perceived by many organisms, over extensive areas of the globe. This alteration comprises the introduction of light at night at places and times at which it has not previously occurred, and with different spectral signatures. Given the long geological periods for which light cycles have previously been consistent, this constitutes a novel environmental pressure, and one for which there is evidence for biolo...

  13. VIDEOFLUOROSCOPIC SWALLOWING STUDY: esophageal alterations in patients with dysphagia

    OpenAIRE

    2014-01-01

    Context Videofluoroscopic swallowing study is a dynamic exam and allows the evaluation of the complete swallowing process. However, most published studies have only reported alterations in the oropharynx and pharyngoesophageal transition, leaving the analysis of the esophagus as a secondary goal. Objectives The goal of this study was to investigate the prevalence of alterations in the esophageal phase thorough videofluoroscopic swallowing study in patients with dysphagia. Methods Consecut...

  14. ALTERED STATES OF LITERATURE: SHAMANIC ASSIMILATION AND ROMANTIC INSPIRATION

    OpenAIRE

    Marcel de Lima Santos

    2012-01-01

    This article deals with the connections between the assimilation of certain shamanic practices related to Romantic inspiration in English literature. The interest in the world of altered states of consciousness as a manifestation of the sacred is typical among Romantic writers in nineteenth-century England. These writers in fact sought the manifestation of the world of dreams by means of ingesting substances that alter consciousness, thus assimilating a practice that is likewise and primarily...

  15. Modeling human perception of orientation in altered gravity

    OpenAIRE

    Clark, Torin K.; Newman, Michael C.; Oman, Charles M.; Merfeld, Daniel M.; Young, Laurence R.

    2015-01-01

    Altered gravity environments, such as those experienced by astronauts, impact spatial orientation perception, and can lead to spatial disorientation and sensorimotor impairment. To more fully understand and quantify the impact of altered gravity on orientation perception, several mathematical models have been proposed. The utricular shear, tangent, and the idiotropic vector models aim to predict static perception of tilt in hyper-gravity. Predictions from these prior models are compared to th...

  16. AM symbiosis alters phenolic acid content in tomato roots

    OpenAIRE

    López-Ráez, Juan A.; Flors, Victor; García, Juan M.; Pozo, Maria J.

    2010-01-01

    Arbuscular mycorrhizal (AM) fungi colonize the roots of most plants to establish a mutualistic symbiosis leading to important benefits for plant health. We have recently shown that AM symbiosis alters both transcriptional and hormonal profiles in tomato roots, many of these changes related to plant defense. Here, we analytically demonstrate that the levels of other important defense-related compounds as phenolic acids are also altered in the symbiosis. Both caffeic and chlorogenic acid levels...

  17. Altered mitochondrial regulation in quadriceps muscles of patients with COPD

    DEFF Research Database (Denmark)

    Naimi, Ashley I; Bourbeau, Jean; Perrault, Helene;

    2011-01-01

    Evidence exists for locomotor muscle impairment in patients with chronic obstructive pulmonary disease (COPD), including fiber type alterations and reduced mitochondrial oxidative capacity. In this study high-resolution respirometry was used to quantify oxygen flux in permeabilized fibres from...... only ~50% that of control subjects. These results indicate that quadriceps muscle mitochondrial function is altered in patients with COPD. The regulatory mechanisms underlying these functional abnormalities remain to be uncovered....

  18. Heavy metals and epigenetic alterations in brain tumors.

    Science.gov (United States)

    Caffo, Maria; Caruso, Gerardo; Fata, Giuseppe La; Barresi, Valeria; Visalli, Maria; Venza, Mario; Venza, Isabella

    2014-12-01

    Heavy metals and their derivatives can cause various diseases. Numerous studies have evaluated the possible link between exposure to heavy metals and various cancers. Recent data show a correlation between heavy metals and aberration of genetic and epigenetic patterns. From a literature search we noticed few experimental and epidemiological studies that evaluate a possible correlation between heavy metals and brain tumors. Gliomas arise due to genetic and epigenetic alterations of glial cells. Changes in gene expression result in the alteration of the cellular division process. Epigenetic alterations in brain tumors include the hypermethylation of CpG group, hypomethylation of specific genes, aberrant activation of genes, and changes in the position of various histones. Heavy metals are capable of generating reactive oxygen assumes that key functions in various pathological mechanisms. Alteration of homeostasis of metals could cause the overproduction of reactive oxygen species and induce DNA damage, lipid peroxidation, and alteration of proteins. In this study we summarize the possible correlation between heavy metals, epigenetic alterations and brain tumors. We report, moreover, the review of relevant literature. PMID:25646073

  19. Antagonist effects of calcium on borosilicate glass alteration

    Energy Technology Data Exchange (ETDEWEB)

    Mercado-Depierre, S. [CEA Marcoule, DTCD SPDE LCLT, 30207 Bagnols sur Cèze (France); Angeli, F., E-mail: frederic.angeli@cea.fr [CEA Marcoule, DTCD SPDE LCLT, 30207 Bagnols sur Cèze (France); Frizon, F. [CEA Marcoule, DTCD SECM LP2C, 30207 Bagnols sur Cèze (France); Gin, S. [CEA Marcoule, DTCD SPDE LCLT, 30207 Bagnols sur Cèze (France)

    2013-10-15

    Graphical abstract: Display Omitted -- Highlights: •Kinetic study of glass alteration is investigated in calcium-enriched solutions. •New insights into silicon–calcium interactions in glass/cement systems are proposed. •Glass alteration is controlled by pH, Ca concentration and reaction progress. •Evidence of antagonist effects according to the importance of these parameters. -- Abstract: Numerous studies have been conducted on glass and cement durability in contact with water, but very little work to date has focused directly on interactions between the two materials. These interactions are mostly controlled by silicon–calcium reactivity. However, the physical and chemical processes involved remain insufficiently understood to predict the evolution of coupled glass–cement systems used in several industrial applications. Results are reported from borosilicate glass alteration in calcium-rich solutions. Our data show that four distinct behaviors can be expected according to the relative importance of three key parameters: the pH, the reaction progress (short- or long-term alteration) and the calcium concentration. Glass alteration is thus controlled by specific mechanisms depending on the solution chemistry: calcium complexation at the glass surface, precipitation of calcium silicate hydrates (C–S–H) or calcium incorporation in the altered layer. These findings highlight the impact of silicon–calcium interactions on glass durability and open the way for a better understanding of glass–cement mixing in civil engineering applications as well as in nuclear waste storage.

  20. Persistent Memory Effects and the Mid- and Post-Brick Dynamic Behaviour of Three-Way Automotive Catalysts Effets mémoires persistants et comportement dynamique des briques médiane et postérieure de catalyseurs automobiles à trois voies

    Directory of Open Access Journals (Sweden)

    Peyton Jones J.C.

    2011-09-01

    Full Text Available This paper presents the results of an experimental study into the dynamic behaviour of a three-way automotive catalyst and its associated exhaust gas oxygen sensors. Motivated by issues of feedback sensor location, the study seeks to overlay the results of repeat experiments, with sensors and fast-response gas analyzers positioned at different locations, in order to obtain a detailed picture of system dynamics at different points within the catalyst. Initial results demonstrated that the dynamic response of the catalyst can be significantly affected by a persistent memory effect in addition to reversible deactivation dynamics and the familiar oxygen storage/release dynamics of the system. In particular, the effects of prior rich or stoichiometric operation are shown to persist even after extended periods of lean operation. This memory effect is important, not only because of its potential impact on conversion efficiency, but also because of its impact on the repeatability of experiments carried out under what would appear to be near-identical operating conditions. By pre-conditioning under rich conditions highly repeatable experiments were achieved. The results were combined to give a detailed picture of catalyst dynamics at pre-, mid- and post-catalyst locations, and provide insight into catalyst and (non-ideal exhaust gas oxygen sensor behavior. Cet article présente les résultats d’une étude expérimentale en matière de comportement dynamique d’un catalyseur automobile à trois voies et de ses capteurs d’oxygène de gaz d’échappement associés. Motivée par les problèmes de localisation des capteurs de retour d’information, l’étude cherche à corréler les résultats d’expériences répétées, capteurs et analyseurs de gaz à réponse rapide étant disposés en des emplacements différents afin d’obtenir une image détaillée des dynamiques de système en différents points à l’intérieur du catalyseur. Les r

  1. Alteration mapping at Goldfield, Nevada, by cluster and discriminant analysis of Landsat digital data. [mapping of hydrothermally altered volcanic rocks

    Science.gov (United States)

    Ballew, G.

    1977-01-01

    The ability of Landsat multispectral digital data to differentiate among 62 combinations of rock and alteration types at the Goldfield mining district of Western Nevada was investigated by using statistical techniques of cluster and discriminant analysis. Multivariate discriminant analysis was not effective in classifying each of the 62 groups, with classification results essentially the same whether data of four channels alone or combined with six ratios of channels were used. Bivariate plots of group means revealed a cluster of three groups including mill tailings, basalt and all other rock and alteration types. Automatic hierarchical clustering based on the fourth dimensional Mahalanobis distance between group means of 30 groups having five or more samples was performed using Johnson's HICLUS program. The results of the cluster analysis revealed hierarchies of mill tailings vs. natural materials, basalt vs. non-basalt, highly reflectant rocks vs. other rocks and exclusively unaltered rocks vs. predominantly altered rocks. The hierarchies were used to determine the order in which sets of multiple discriminant analyses were to be performed and the resulting discriminant functions were used to produce a map of geology and alteration which has an overall accuracy of 70 percent for discriminating exclusively altered rocks from predominantly altered rocks.

  2. Valuing hydrological alteration in multi-objective water resources management

    Science.gov (United States)

    Bizzi, Simone; Pianosi, Francesca; Soncini-Sessa, Rodolfo

    2012-11-01

    SummaryThe management of water through the impoundment of rivers by dams and reservoirs is necessary to support key human activities such as hydropower production, agriculture and flood risk mitigation. Advances in multi-objective optimization techniques and ever growing computing power make it possible to design reservoir operating policies that represent Pareto-optimal tradeoffs between multiple interests. On the one hand, such optimization methods can enhance performances of commonly targeted objectives (such as hydropower production or water supply), on the other hand they risk strongly penalizing all the interests not directly (i.e. mathematically) included in the optimization algorithm. The alteration of the downstream hydrological regime is a well established cause of ecological degradation and its evaluation and rehabilitation is commonly required by recent legislation (as the Water Framework Directive in Europe). However, it is rarely embedded in reservoir optimization routines and, even when explicitly considered, the criteria adopted for its evaluation are doubted and not commonly trusted, undermining the possibility of real implementation of environmentally friendly policies. The main challenges in defining and assessing hydrological alterations are: how to define a reference state (referencing); how to define criteria upon which to build mathematical indicators of alteration (measuring); and finally how to aggregate the indicators in a single evaluation index (valuing) that can serve as objective function in the optimization problem. This paper aims to address these issues by: (i) discussing the benefits and constrains of different approaches to referencing, measuring and valuing hydrological alteration; (ii) testing two alternative indices of hydrological alteration, one based on the established framework of Indicators of Hydrological Alteration (Richter et al., 1996), and one satisfying the mathematical properties required by widely used optimization

  3. Resumption of nuclear glass alteration: State of the art

    International Nuclear Information System (INIS)

    Studies of nuclear glass alteration kinetics have shown that after the beginning of a rate drop due to the approach of silica saturation of the solution and the formation of a passivating layer, a resumption of alteration is possible. This phenomenon corresponding to an acceleration of the glass dissolution rate is systematically associated with the precipitation of zeolites and, to a lesser extent, calcium silicate hydrates. Secondary phases which precipitate from the major glass network-forming elements (Si, Al) strongly impact the dissolution kinetics. The literature data are generally consistent and the results are reproducible, showing that the resumption of alteration is observed at high pH, temperature, and S/V ratio during laboratory experiments. The studies also show that the resumption of alteration is strongly dependent on the composition of the glass and the leaching solutions. The wide range of glass compositions studied (about 60 glasses in the articles reviewed) and the variable test conditions (temperature, pH, and solution composition) make it extremely difficult to compare and compile the data, or to decorrelate the effects of the composition on the time before the resumption of alteration and on its magnitude. The observations to date have led to a proposed macroscopic mechanism based on the loss of the passivating properties of the alteration layer after consumption of a fraction of the network-forming elements by precipitation of zeolites. No multiscale mechanistic approach exists, however, to account for the nucleation and growth of zeolites at the expense of the glass. For example, the effect of aluminum in the gel or in solution on the glass alteration kinetics is not sufficiently understood today. Although thermodynamic models have been proposed to delimit the ranges of glass compositions subject to a resumption of alteration, their development is hampered by inadequate knowledge of the newly formed phases and their nucleation

  4. Altered States of Consciousness during an Extreme Ritual

    Science.gov (United States)

    Loewald, Tonio; Comber, Evelyn M.; Hanson, Sarah A.; Pruitt, Bria

    2016-01-01

    Extreme rituals (body-piercing, fire-walking, etc.) are anecdotally associated with altered states of consciousness—subjective alterations of ordinary mental functioning (Ward, 1984)—but empirical evidence of altered states using both direct and indirect measures during extreme rituals in naturalistic settings is limited. Participants in the “Dance of Souls”, a 3.5-hour event during which participants received temporary piercings with hooks or weights attached to the piercings and danced to music provided by drummers, responded to measures of two altered states of consciousness. Participants also completed measures of positive and negative affect, salivary cortisol (a hormone associated with stress), self-reported stress, sexual arousal, and intimacy. Both pierced participants (pierced dancers) and non-pierced participants (piercers, piercing assistants, observers, drummers, and event leaders) showed evidence of altered states aligned with transient hypofrontality (Dietrich, 2003; measured with a Stroop test) and flow (Csikszentmihalyi, 1990; Csikszentmihalyi & Csikszentmihalyi, 1990; measured with the Flow State Scale). Both pierced and non-pierced participants also reported decreases in negative affect and psychological stress and increases in intimacy from before to after the ritual. Pierced and non-pierced participants showed different physiological reactions, however, with pierced participants showing increases in cortisol and non-pierced participants showing decreases from before to during the ritual. Overall, the ritual appeared to induce different physiological effects but similar psychological effects in focal ritual participants (i.e., pierced dancers) and in participants adopting other roles. PMID:27175897

  5. Are histological alterations observed in the gallbladder precancerous lesions?

    Directory of Open Access Journals (Sweden)

    Adriana Lúcia Agnelli Meirelles-Costa

    2010-01-01

    Full Text Available INTRODUCTION: Gallbladder cancer, which is characterized by rapid progression and a poor prognosis, is a complex disease to treat. Unfortunately, little is known currently about its etiology or pathogenesis. A better understanding of its carcinogenesis and determining risk factors that lead to its development could help improve the available treatment options. METHOD: Based on this better understanding, the histological alterations (such as acute cholecystitis, adenomyomatosis, xanthogranulomatous cholecystitis, polyps, pyloric metaplasia, intestinal metaplasia, dysplasia, cancer and others in gallbladders from 1,689 patients who underwent laparoscopic cholecystectomy for cholecystolithiasis were analyzed. The association of these gallbladder histological alterations with clinical data was studied. RESULTS: Gender analysis revealed a greater incidence of inflammatory changes in males, while dysplasia and cancer were only found in women. The incidence of cholesterolosis was greater in the patients 60 years of age and under, and the incidence of adenomyomatosis and gangrene was greater in the elderly patients. A progressive increase in the average age was observed as alterations progressed through pyloric metaplasia, intestinal metaplasia, dysplasia and then cancer, suggesting that the metaplasia-dysplasia-carcinoma sequence may occur in gallbladder cancer. Gallbladder histological alterations were also observed in asymptomatic patients. CONCLUSION: The results of this study suggest that there could be an association between some histological alterations of gallbladder and cancer, and they also suggest that the metaplasia-dysplasia-carcinoma sequence could in fact be true in the case of gallbladder cancer. Nevertheless, further studies directed towards a perfect understanding of gallbladder carcinogenesis are required.

  6. Hydrothermal surface alteration in the Copahue Geothermal Field (Argentina)

    Energy Technology Data Exchange (ETDEWEB)

    Mas, Graciela R.; Mas, Luis C.; Bengochea, Leandro

    1996-01-24

    In the area of the Copahue Geothermal Field, there are five active geothermal manifestations, which mainly consist of fumaroles, hot springs and mud pots. Four of these manifestations are located in Argentina: Las Máquinas, Termas de Copahue, Las Maquinitas and El Anfiteatro, and the fifth on the Chilean side: Chancho Co. All of them present a strong acid sulfate country rock alteration, characterized by the assemblage alunite + kaolinite + quartz + cristobalite + pyrite + sulfur + jarosite, as the result of the base leaching by fluids concentrated in H2SO4 by atmospheric oxidation at the water table in a steam heated environment of H2S released by deeper boiling fluids. Another alteration zone in this area, called COP-2, is a fossil geothermal manifestation which shows characteristics of neutral to alkaline alteration represented mainly by the siliceous sinter superimposed over the acid alteration. The mineralogy and zoning of these alteration zones, and their relation with the hidrothermal solutions and the major structures of the area are analized.

  7. The genetic alteration of retinoblastoma gene in esophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jae Il; Shim, Yung Mok; Kim, Chang Min [Korea Cancer Center Hospital of Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-12-01

    Retinoblastoma(RB) gene is the prototype of tumor suppressor gene and it`s alteration have been frequently observed in a large number of human tumors. To investigate the role of RB in esophageal cancer, we studied 36 esophageal cancer tissues with Southern blot analysis to detect gross LOH and PCR-SSCP method to find minute LOH and mutation, if any. In the cases with abnormalities, the nucleotide sequence analysis was performed. Allelic loss of chromosome 13q14 occurred in 20 out of 32 informative cases (62.5%) by Southern analysis. Furthermore, PCR-LOH added three positive cases. Mobility shift by PCR-SSCP was observed in one case at exon 22, which showed 1 bp deletion in codon 771 of RB gene resulting in frame shift mutation. Besides, nine PCR-band alteration in tumor tissue compared with normal tissue were observed in exon 14 and 22, but mutation was not found on sequencing analysis suggesting the epigenetic alteration in tumor tissue. Analysis of the clinical data did not show any difference depending upon RB alteration. However, the total incidence of RB gene may play an important role in the development of esophageal cancer. The main genetic alteration of RB gene was deletion detected by Southern blot and one bp deletion leading to frame shift was also observed. 8 figs, 5 tabs. (Author).

  8. Alteration of the Specificity of PstⅠRestriction Endonuclease

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The influence of factors on the substrate-specificity of Pst Ⅰ restriction endonuclease has been studied with the method of electrophoresis. The results show that, the specificity of Pst Ⅰ almost can not be influenced by the single alteration of the concentration of Tris*HCl, Mg2+ or Na+ in the reaction system, but it can be altered by the reduction of any two of them. The specificity can not be altered by the single alteration of pH or the replacement of Mg2+ with Mn2+. The addition of glycerol or dimethylsulphoxide (DMSO) to the reaction system results in the relaxation of the substrate-specificity of Pst Ⅰ , but dimethylmethylformide, glycol and ethyl alcohol can not bring about the alteration of Pst Ⅰ specificity. Through the method of cloning and sequencing, the nucleotides of No.1 and 6 in the recognition sequence of Pst Ⅰ have changed (1C→A or 6G→T). Used with the enzyme analysis of an artificially synthetic DNA segment containing a special sequence, the nucleotides of No.1 and 6 have both changed (1C→A and 6G→T). The recognition sequence of Pst Ⅰ is speculated to be changed from CTGCA↓G to TGCA↓.

  9. Mechanisms for altered carnitine content in hypertrophied rat hearts

    International Nuclear Information System (INIS)

    Carnitine levels are reduced in hypertrophied hearts of rats subjected to aortic constriction (banding) and evaluated in hypertrophied hearts of spontaneously hypertensive rats (SHR). In an attempt to determine the mechanisms for these alterations, L-[14C]carnitine transport was examined in isolated perfused hearts. Total carnitine uptake was significantly reduced by ∼20% in hypertrophied hearts of banded rats at all perfusate carnitine concentrations employed. The reduction in total uptake was due to a 40% reduction in carrier-mediated carnitine uptake with no difference in uptake by diffusion. In contrast, carnitine uptake was not altered in isolated hypertrophied hearts of SHR. However, serum carnitine levels were elevated in SHR, which could result in increased myocardial carnitine uptake in vivo. The data suggest that altered carnitine content in hypertrophied hearts of aortic-banded rats is due to an alteration in the carrier-mediated carnitine transport system in the myocardium. However, altered carnitine content in hypertrophied hearts of SHR is not due to a change in the carnitine transport system per se but may rather be due to a change in serum carnitine levels

  10. Altered States of Consciousness during an Extreme Ritual.

    Directory of Open Access Journals (Sweden)

    Ellen M Lee

    Full Text Available Extreme rituals (body-piercing, fire-walking, etc. are anecdotally associated with altered states of consciousness-subjective alterations of ordinary mental functioning (Ward, 1984-but empirical evidence of altered states using both direct and indirect measures during extreme rituals in naturalistic settings is limited. Participants in the "Dance of Souls", a 3.5-hour event during which participants received temporary piercings with hooks or weights attached to the piercings and danced to music provided by drummers, responded to measures of two altered states of consciousness. Participants also completed measures of positive and negative affect, salivary cortisol (a hormone associated with stress, self-reported stress, sexual arousal, and intimacy. Both pierced participants (pierced dancers and non-pierced participants (piercers, piercing assistants, observers, drummers, and event leaders showed evidence of altered states aligned with transient hypofrontality (Dietrich, 2003; measured with a Stroop test and flow (Csikszentmihalyi, 1990; Csikszentmihalyi & Csikszentmihalyi, 1990; measured with the Flow State Scale. Both pierced and non-pierced participants also reported decreases in negative affect and psychological stress and increases in intimacy from before to after the ritual. Pierced and non-pierced participants showed different physiological reactions, however, with pierced participants showing increases in cortisol and non-pierced participants showing decreases from before to during the ritual. Overall, the ritual appeared to induce different physiological effects but similar psychological effects in focal ritual participants (i.e., pierced dancers and in participants adopting other roles.

  11. Neuroinflammation and neurological alterations in chronic liver diseases

    Directory of Open Access Journals (Sweden)

    Carmina Montoliu

    2015-01-01

    Full Text Available Several million people with chronic liver diseases (cirrhosis, hepatitis show neurological alterations, named hepatic encephalopathy (HE with cognitive and motor alterations that impair quality of life and reduces life span. Inflammation acts synergistically with hyperammonemia to induce cognitive and motor alterations in patients with chronic liver disease and minimal hepatic encephalopathy (MHE. Previous studies in animal models have suggested that neuroinflammation is a major player in HE. This would also be the case in patients with liver cirrhosis or hepatitis C with HE. Rats with MHE show microglial activation and neuroinflammation that is associated with cognitive impairment and hypokinesia. The anti-inflammatory drug ibuprofen reduces microglial activation and neuroinflammation and restores cognitive and motor functions in rats with MHE. Chronic hyperammonemia per se induces neuroinflammation. Both peripheral inflammation and hyperammonemia would contribute to neuroinflammation in chronic liver failure. Therefore, neuroinflammation may be a key therapeutic target to improve the cognitive and motor alterations in MHE and overt HE. Identifying new targets to reduce neuroinflammation in MHE without inducing secondary effects would serve to develop new therapeutic tools to reverse the cognitive and motor alterations in patients with HE associated with chronic liver diseases.

  12. Altered States of Consciousness during an Extreme Ritual.

    Science.gov (United States)

    Lee, Ellen M; Klement, Kathryn R; Ambler, James K; Loewald, Tonio; Comber, Evelyn M; Hanson, Sarah A; Pruitt, Bria; Sagarin, Brad J

    2016-01-01

    Extreme rituals (body-piercing, fire-walking, etc.) are anecdotally associated with altered states of consciousness-subjective alterations of ordinary mental functioning (Ward, 1984)-but empirical evidence of altered states using both direct and indirect measures during extreme rituals in naturalistic settings is limited. Participants in the "Dance of Souls", a 3.5-hour event during which participants received temporary piercings with hooks or weights attached to the piercings and danced to music provided by drummers, responded to measures of two altered states of consciousness. Participants also completed measures of positive and negative affect, salivary cortisol (a hormone associated with stress), self-reported stress, sexual arousal, and intimacy. Both pierced participants (pierced dancers) and non-pierced participants (piercers, piercing assistants, observers, drummers, and event leaders) showed evidence of altered states aligned with transient hypofrontality (Dietrich, 2003; measured with a Stroop test) and flow (Csikszentmihalyi, 1990; Csikszentmihalyi & Csikszentmihalyi, 1990; measured with the Flow State Scale). Both pierced and non-pierced participants also reported decreases in negative affect and psychological stress and increases in intimacy from before to after the ritual. Pierced and non-pierced participants showed different physiological reactions, however, with pierced participants showing increases in cortisol and non-pierced participants showing decreases from before to during the ritual. Overall, the ritual appeared to induce different physiological effects but similar psychological effects in focal ritual participants (i.e., pierced dancers) and in participants adopting other roles. PMID:27175897

  13. Timescales and settings for alteration of chondritic meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Krot, A N; Hutcheon, I D; Brearley, A J; Pravdivtseva, O V; Petaev, M I; Hohenberg, C M

    2005-11-16

    Most groups of chondritic meteorites experienced diverse styles of secondary alteration to various degrees that resulted in formation of hydrous and anhydrous minerals (e.g., phyllosilicates, magnetite, carbonates, ferrous olivine, hedenbergite, wollastonite, grossular, andradite, nepheline, sodalite, Fe,Ni-carbides, pentlandite, pyrrhotite, Ni-rich metal). Mineralogical, petrographic, and isotopic observations suggest that the alteration occurred in the presence of aqueous solutions under variable conditions (temperature, water/rock ratio, redox conditions, and fluid compositions) in an asteroidal setting, and, in many cases, was multistage. Although some alteration predated agglomeration of the final chondrite asteroidal bodies (i.e. was pre-accretionary), it seems highly unlikely that the alteration occurred in the solar nebula, nor in planetesimals of earlier generations. Short-lived isotope chronologies ({sup 26}Al-{sup 26}Mg, {sup 53}Mn-{sup 53}Cr, {sup 129}I-{sup 129}Xe) of the secondary minerals indicate that the alteration started within 1-2 Ma after formation of the Ca,Al-rich inclusions and lasted up to 15 Ma. These observations suggest that chondrite parent bodies must have accreted within the first 1-2 Ma after collapse of the protosolar molecular cloud and provide strong evidence for an early onset of aqueous activity on these bodies.

  14. Ultrastructural alterations in adult Schistosoma mansoni caused by artemether

    Directory of Open Access Journals (Sweden)

    Shuhua Xiao

    2002-07-01

    Full Text Available Progress has been made over the last decade with the development and clinical use of artemether as an agent against major human schistosome parasites. The tegument has been identified as a key target of artemether, implying detailed studies on ultrastructural damage induced by this compound. We performed a temporal examination, employing a transmission electron microscope to assess the pattern and extent of ultrastructural alterations in adult Schistosoma mansoni harboured in mice treated with a single dose of 400 mg/kg artemether. Eight hours post-treatment, damage to the tegument and subtegumental structures was seen. Tegumental alterations reached a peak 3 days after treatment and were characterized by swelling, fusion of distal cytoplasma, focal lysis of the tegumental matrix and vacuolisation. Tubercles and sensory organelles frequently degenerated or collapsed. Typical features of subtegumental alterations, including muscle fibres, syncytium and parenchyma tissues, were focal or extensive lysis, vacuolisation and degeneration of mitochondria. Severe alterations were also observed in gut epithelial cells and vitelline cells of female worms. Our findings of artemether-induced ultrastructural alterations in adult S. mansoni confirm previous results obtained with juvenile S. mansoni and S. japonicum of different ages.

  15. You stole my food! Eating alterations in frontotemporal dementia.

    Science.gov (United States)

    Aiello, Marilena; Silani, Vincenzo; Rumiati, Raffaella I

    2016-08-01

    Patients with different types of dementia may exhibit pathological eating habits, including food fads, hyperphagia, or even ingestion of inanimate objects. Several findings reveal that such eating alterations are more common in patients with frontotemporal dementia (FTD) than other types of dementia. Moreover, eating alterations may differ between the two variants of the disease, namely the behavioral variant and semantic dementia (SD). In this review, we summarized evidences regarding four areas: eating and body weight alterations in FTD, the most common assessment methods, anatomical correlates of eating disorders, and finally, proposed underlying mechanisms. An increasing understanding of the factors that contribute to eating abnormalities may allow first, a better comprehension of the clinical features of the disease and second, shed light on the mechanism underlying eating behaviors in the normal population. PMID:27327171

  16. Nutrient loading alters the performance of key nutrient exchange mutualisms.

    Science.gov (United States)

    Shantz, Andrew A; Lemoine, Nathan P; Burkepile, Deron E

    2016-01-01

    Nutrient exchange mutualisms between phototrophs and heterotrophs, such as plants and mycorrhizal fungi or symbiotic algae and corals, underpin the functioning of many ecosystems. These relationships structure communities, promote biodiversity and help maintain food security. Nutrient loading may destabilise these mutualisms by altering the costs and benefits each partner incurs from interacting. Using meta-analyses, we show a near ubiquitous decoupling in mutualism performance across terrestrial and marine environments in which phototrophs benefit from enrichment at the expense of their heterotrophic partners. Importantly, heterotroph identity, their dependence on phototroph-derived C and the type of nutrient enrichment (e.g. nitrogen vs. phosphorus) mediated the responses of different mutualisms to enrichment. Nutrient-driven changes in mutualism performance may alter community organisation and ecosystem processes and increase costs of food production. Consequently, the decoupling of nutrient exchange mutualisms via alterations of the world's nitrogen and phosphorus cycles may represent an emerging threat of global change. PMID:26549314

  17. Altered cortical causality after remifentanil administration in healthy volunteers

    DEFF Research Database (Denmark)

    Khodayari-Rostamabad, Ahmad; Graversen, Carina; Olesen, Soren S;

    2014-01-01

    Alterations in cortical causality information flow induced by remifentanil infusion in healthy volunteers was investigated in a placebo-controlled double-blind cross-over study. For each of the 21 enrolled male subjects, 2.5 minutes of resting electroencephalography (EEG) data were collected before...... features being reproducible between the two baseline recordings, several PSI features were altered by remifentanil administration in comparison to placebo. Furthermore, several of the PSI features altered by remifentanil were correlated to changes in both CRT and pain scores. The results indicate that...... remifentanil administration influence the information flow between several brain areas. Hence, the EEG causality approach offers the potential to assist in deciphering the cortical effects of remifentanil administration....

  18. Review on environmental alterations propagating from aquatic to terrestrial ecosystems.

    Science.gov (United States)

    Schulz, Ralf; Bundschuh, Mirco; Gergs, René; Brühl, Carsten A; Diehl, Dörte; Entling, Martin H; Fahse, Lorenz; Frör, Oliver; Jungkunst, Hermann F; Lorke, Andreas; Schäfer, Ralf B; Schaumann, Gabriele E; Schwenk, Klaus

    2015-12-15

    Terrestrial inputs into freshwater ecosystems are a classical field of environmental science. Resource fluxes (subsidy) from aquatic to terrestrial systems have been less studied, although they are of high ecological relevance particularly for the receiving ecosystem. These fluxes may, however, be impacted by anthropogenically driven alterations modifying structure and functioning of aquatic ecosystems. In this context, we reviewed the peer-reviewed literature for studies addressing the subsidy of terrestrial by aquatic ecosystems with special emphasis on the role that anthropogenic alterations play in this water-land coupling. Our analysis revealed a continuously increasing interest in the coupling of aquatic to terrestrial ecosystems between 1990 and 2014 (total: 661 studies), while the research domains focusing on abiotic (502 studies) and biotic (159 studies) processes are strongly separated. Approximately 35% (abiotic) and 25% (biotic) of the studies focused on the propagation of anthropogenic alterations from the aquatic to the terrestrial system. Among these studies, hydromorphological and hydrological alterations were predominantly assessed, whereas water pollution and invasive species were less frequently investigated. Less than 5% of these studies considered indirect effects in the terrestrial system e.g. via food web responses, as a result of anthropogenic alterations in aquatic ecosystems. Nonetheless, these very few publications indicate far-reaching consequences in the receiving terrestrial ecosystem. For example, bottom-up mediated responses via soil quality can cascade over plant communities up to the level of herbivorous arthropods, while top-down mediated responses via predatory spiders can cascade down to herbivorous arthropods and even plants. Overall, the current state of knowledge calls for an integrated assessment on how these interactions within terrestrial ecosystems are affected by propagation of aquatic ecosystem alterations. To fill

  19. Negative Searches for Evidence of Aqueous Alteration on Asteroid Surfaces

    Science.gov (United States)

    Vilas, F.

    2005-01-01

    Small bodies in the Solar System preserve evidence of the processes occurring during early Solar System formation, unlike the larger planets that undergo continuous churning of their surfaces. We study these bodies to understand what processes affected different stages of Solar System formation. The action of aqueous alteration (the alteration of material by the interaction of that material with liquid formed by the melting of incorporated ice) of near-subsurface material has been inferred to occur on many asteroids based on the spectrophotometric evidence of phyllosilicates and iron alteration minerals. The definitive indication of aqueous alteration is the 3.0- micron absorption feature attributed to structural hydroxyl (OH) and interlayer and adsorbed water (H2O) in phyllosilicates (clays) (hereafter water of hydration). A weak absorption feature centered near 0.7 microns attributed to an Fe (2+) right arrow Fe (3+) charge transfer transition in oxidized iron in phyllosilicates has been observed in the reflectance spectra and photometry of approximately 50% of the main-belt C-class asteroids. An approximately 85% correlation between this 0.7- micron feature and the 3.0- micron water of hydration absorption feature was found among the low-albedo asteroids. The feature is usually centered near 0.68 microns in asteroid spectra, and ranges in wavelength from approximately 0.57 to 0.83 microns. Serendipitously, three of the Eight Color Asteroid Survey filters the v (0.550 microns), w (0.701 microns), and x (0.853 microns)-bracket this feature well, and can be used to determine the presence of this feature in the reflectance properties of an asteroid, and probe the aqueous alteration history of larger samples of asteroid data. Two efforts to search for evidence of aqueous alteration based on the presence of this 0.7- micron absorption feature are presented here.

  20. R7T7 glass alteration mechanism in an aqueous closed system: understanding and modelling the long term alteration kinetic

    International Nuclear Information System (INIS)

    The long term alteration rate of the French R7T7 nuclear glass has been investigated since many years because it will define the overall resistance of the radionuclide containment matrix. Recent studies have shown that the final rate remains constant or is slightly decreasing with time. It never reaches zero. Though this residual rate is very low, only 5 nm per year at 50 C, it would be the dominant alteration phenomenon in a geological repository. Two mechanisms are suggested for explaining such behaviour: diffusion in solution of elements from glass through an amorphous altered layer and precipitation of neo-formed phases. The diffusion processes are in agreement with a solid state diffusion mechanism and can lead to secondary phase precipitation due to solution concentration increases. Observed phases are mainly phyllosilicates and zeolites, in specific conditions. Phyllosilicates are expected to maintain the residual kinetic rate whereas alteration resumption could be observed in presence of zeolites at very high pH or temperature (10.5 at 90 C or temperature above 150 C). Both diffusion and neo-formed phase precipitation have been investigated in order to better understand their impact on the residual alteration rate and have then been modelled by a calculation code, coupling chemistry and transport, in order to be able to better anticipate the long term behaviour of the glass R7T7 in an aqueous closed system. (author)

  1. Valuing hydrological alteration in Multi-Objective reservoir management

    Science.gov (United States)

    Bizzi, S.; Pianosi, F.; Soncini-Sessa, R.

    2012-04-01

    Water management through dams and reservoirs is worldwide necessary to support key human-related activities ranging from hydropower production to water allocation for agricultural production, and flood risk mitigation. Advances in multi-objectives (MO) optimization techniques and ever growing computing power make it possible to design reservoir operating policies that represent Pareto-optimal tradeoffs between the multiple interests analysed. These progresses if on one hand are likely to enhance performances of commonly targeted objectives (such as hydropower production or water supply), on the other risk to strongly penalize all the interests not directly (i.e. mathematically) optimized within the MO algorithm. Alteration of hydrological regime, although is a well established cause of ecological degradation and its evaluation and rehabilitation are commonly required by recent legislation (as the Water Framework Directive in Europe), is rarely embedded as an objective in MO planning of optimal releases from reservoirs. Moreover, even when it is explicitly considered, the criteria adopted for its evaluation are doubted and not commonly trusted, undermining the possibility of real implementation of environmentally friendly policies. The main challenges in defining and assessing hydrological alterations are: how to define a reference state (referencing); how to define criteria upon which to build mathematical indicators of alteration (measuring); and finally how to aggregate the indicators in a single evaluation index that can be embedded in a MO optimization problem (valuing). This paper aims to address these issues by: i) discussing benefits and constrains of different approaches to referencing, measuring and valuing hydrological alteration; ii) testing two alternative indices of hydrological alteration in the context of MO problems, one based on the established framework of Indices of Hydrological Alteration (IHA, Richter et al., 1996), and a novel satisfying the

  2. Study on epigenetic alterations of ore-enclosing sedimentary rocks

    International Nuclear Information System (INIS)

    Epigenetic alterations of sedimentary rocks under effect of exogenous undeground waters of various types: near-surface, ground, stratum, and deep circulation waters, are considered. Association to postsedimentary tectonic structures, confinement of neogenesis to areas of high permeability (porous or crack one), geochemical contradictions between mineral neogenis and facial outlook of deposits, noncoincidence of variability gradient of authigenous mineral associations with variability of primary facial signs of deposits, regular position of mineral formations and ore concentrations in epigenetic mineralogo-geochemical zonation are referred to epigenetic criteria. The complex of epigenetic alterations accompanying mineralization is frequently used as a search sign of uranium deposit of a certain type

  3. Antibiotic use during pregnancy alters the commensal vaginal microbiota

    DEFF Research Database (Denmark)

    Stokholm, J.; Schjørring, S.; Eskildsen, Carl Emil Aae;

    2014-01-01

    Antibiotics may induce alterations in the commensal microbiota of the birth canal in pregnant women. Therefore, we studied the effect of antibiotic administration during pregnancy on commensal vaginal bacterial colonization at gestational week 36. Six hundred and sixty-eight pregnant women from the...... significant changes in vaginal Streptococcus agalactiae (group B streptoccocus) or Staphylococcus aureus colonization following antibiotic treatment in pregnancy. Antibiotic administration during pregnancy leads to alterations in the vaginal microbiological ecology prior to birth, with potential morbidity......, and long-term effects on the early microbial colonization of the neonate....

  4. Polarized Microscopy in Lesions With Altered Dermal Collagen.

    Science.gov (United States)

    Elbendary, Amira; Valdebran, Manuel; Parikh, Kruti; Elston, Dirk M

    2016-08-01

    Alterations in dermal collagen are noted in dermatofibroma, dermatofibrosarcoma protuberans, morphea, lichen sclerosus et atrophicus, hypertrophic scars, and keloids. The authors sought to determine whether variations in birefringence of collagen by polarized microscopy could be of help in diagnosing such conditions. Representative hematoxylin and eosin sections of 400 cases, including dermatofibroma, dermatofibrosarcoma protuberans, hypertrophic scars, keloid, morphea, and lichen sclerosus, were examined under polarized microscopy. Distinct patterns of birefringence of collagen for each disease were noted under polarized microscopy. This study highlights the use of polarized microscopy as adjunctive tool in differentiating different diseases with collagen alteration. PMID:26959692

  5. Altering contingencies to facilitate compliance with traffic light systems

    OpenAIRE

    Jason, Leonard A.; Neal, Angela M.; Marinakis, George

    1985-01-01

    The effects of altering light pattern sequences on driver compliance at a busy, urban intersection were explored. The baseline light timing sequences resulted in only 46.8% of drivers stopping at the yellow or red lights. Using an A-B-C design, we altered light pattern sequences that increased the probability of drivers stopping at the signals to 88.8% and 98.8%. These findings indicate that traffic light contingencies have potent effects in influencing driver behaviors at busy intersections....

  6. Biological Alteration of Basaltic Glass With Altered Composition and Oxidation States

    Science.gov (United States)

    Bailey, B. E.; Staudigel, H.; Templeton, A.; Tebo, B. M.; Ryerson, F.; Plank, T.; Schroder, C.; Klingelhoefer, G.

    2004-12-01

    The ocean crust is an extreme and oligotrophic environment and yet recent studies have shown that reactions between oceanic crust and seawater are capable of supporting microbial life. We are specifically targeting volcanic glass as a source of energy and nutrients necessary to support endolithic microbial communities. A significant amount of chemical energy is available from the process of iron oxidation and our goal is to determine the ability of microorganisms to use Fe(II) as an energy source as well as liberate other essential nutrients from the host rock. In addition, microbes may oxidize Mn or use phosphate from glass. To explore the dependency of microbial life on these nutrients and energy sources, we produce basaltic glasses with varying Fe oxidation states and relative abundance of iron, manganese and phosphate and introduce them to microbial isolates and consortia both in the laboratory and in deep-ocean environments. The natural exposure experiments occur in a variety of settings including hydrothermal vents and cold deep seawater (Loihi Seamount), brines (Mediterranean), and basaltic flows at spreading ridges (EPR), when possible on submarine lava flows of recent and known age. Upon collection of the exposure experiments, we compare basalt colonizing microbial communities on our synthetic glasses with the in situ glass communities through a large culturing effort and molecular (t-RFLP) studies. So far we have produced a number of enrichment cultures and isolated several iron-oxidizing and manganese-oxidizing bacteria that were used to inoculate glasses in the laboratory. Laboratory experiments concentrate on biofilm formation and dissolution of the colonized glasses. Continued collection of exposure experiments on a yearly time-scale provides valuable information regarding spatial and temporal variations in microbial community diversity and structure. We have also analyzed the authigenic reaction products of seafloor, microbially mediated alteration

  7. Comportement multiaxial des nids d'abeilles sous sollicitations dynamiques

    OpenAIRE

    Hou, Bing

    2011-01-01

    The study consists mainly of two parts. The first part is related to the dynamic strength enhancement of honeycombs under uniaxial compression. We firstly study numerically this particular phenomenon of thin-walled structure by using three micro-size FE models and this allows us to reveal the role played by lateral inertia in the dynamic enhancement. Further more, the dynamic enhancement of a series of honeycombs with different cell-size, cell-wall thickness and base material is studied exper...

  8. Evolution du comportement de manipulation chez les strepsirrhiniens

    OpenAIRE

    Peckre, Louise; Fabre, Anne‑Claire; Herrel, Anthony; Wall, Christine; Pouydebat, Emmanuelle

    2016-01-01

    Les capacités de préhension des catarrhiniens ont été largement étudiées dans le cadre de problématiques cognitives, fonctionnelles et évolutives. Une importante variabilité dans les types de saisies utilisés, incluant des stratégies longtemps décrites comme spécifiques des humains, a ainsi été mise en évidence. Cependant, bien que la préhension soit impliquée dans de nombreuses activités chez tous les primates, elle reste peu étudiée chez les platyrrhiniens et les strepsirrhiniens. Ces derni...

  9. Gouvernance environnementale locale et comportements économiques

    Directory of Open Access Journals (Sweden)

    Christophe Beaurain

    2004-02-01

    Full Text Available La notion de gouvernance est mobilisée de manière croissante aujourd’hui pour évoquer de nouvelles formes de coopérations entre acteurs de la vie économique et sociale. Appliquée aux questions environnementales, la gouvernance pose à la fois la question de la maîtrise du temps par les acteurs et celle du territoire d’application des décisions prises. On peut donc considérer qu’elle engage un renouvellement de l’articulation entre le temps et l’espace, que doit prendre en compte l’analyse des choix économiques dans ce domaine. L’exemple du bassin d’emploi dunkerquois montre que cette articulation est au cœur d’une participation des entreprises à la gouvernance environnementale.The concept of governance is more and more raised to conjure up new ways of cooperation between actors of the economic and social life. Applied to environmental matters, governance ask both the question of mastery of the time and the one of the territory’s application for taken decisions. We can consider that it engage a renewal of the joint between time and space, that the analysis of economic choices had to take into account. The example of “Dunkerque” show that this joint is the heart of firm’s collaboration in environmental governance.

  10. Comportement en fatigue des zones de reprises de plis

    OpenAIRE

    Weiss, Ambrosius

    2010-01-01

    Différentes configurations d’éprouvettes de zones de reprises de plis proches des applications industrielles en matériau carbone-époxy préimprégné unidirectionnel ont été étudiées sous chargement statique et de fatigue (R = -1). Après évaluation de l’influence de différents paramètres par un modèle éléments finis 2D, des configurations ont été définies et ont permis d’évaluer les paramètres suivants : positions des reprises de plis dans le stratifié, orientation des reprises de plis, et strat...

  11. COMPORTEMENT DE DEMANDE DE TIC : UNE COMPARAISON INTERNATIONALE

    OpenAIRE

    Cette, Gilbert; Lopez, Jimmy

    2009-01-01

    International audience Cette étude vise à apporter des éléments d'explication empiriques sur les écarts de diffusion des TIC entre pays industrialisés, en particulier des pays du continent européen vis-à-vis des États-Unis. Les données concernent onze pays de l'OCDE, sont macroéconomiques, annuelles et portent sur la période 1981-2005. Plusieurs résultats originaux ressortent de l'analyse : (i) l'infl uence du niveau d'éducation et des rigidités de marchés sur la diffusion des TIC se serai...

  12. Myelin alters the inflammatory phenotype of macrophages by activating PPARs

    OpenAIRE

    Bogie, Jeroen; Jorissen, Winde; Mailleux, Jo; Vanmierlo, Tim; van Horssen, Jack; Hellings, Niels; Stinissen, Piet; Hendriks, J. J. A.; Nijland, Philip G.; Zelcer, Noam

    2013-01-01

    Background Foamy macrophages, containing myelin degradation products, are abundantly found in active multiple sclerosis (MS) lesions. Recent studies have described an altered phenotype of macrophages after myelin internalization. However, mechanisms by which myelin affects the phenotype of macrophages and how this phenotype influences lesion progression remain unclear. Results We demonstrate that myelin as well as phosphatidylserine (PS), a phospholipid found in myelin, reduce nitri...

  13. Alteration of swelling clay minerals by acid activation

    NARCIS (Netherlands)

    Steudel, A.; Batenburg, L.F.; Fischer, H.R.; Weidler, P.G.; Emmerich, K.

    2009-01-01

    The bulk material of six dioctahedral and two trioctahedral swellable clay minerals was leached in H2SO4 and HCl at concentrations of 1.0, 5.0 and 10.0 M at 80 °C for several hours. Alteration of the clay mineral structures was dependent on the individual character of each mineral (chemical composit

  14. Reality Television: Altering Participants' Expectations of Adventure Programs

    Science.gov (United States)

    Lindner, Kevin

    2008-01-01

    In this article, the author shares his views on how reality television shows have altered participants' expectations of adventure programs and explores how such changes affect what leaders do with groups who sign on for an adventure education program. For some individuals, the chance to participate in an adventure program focused on group building…

  15. Efflux Pump Control Alters Synthetic Gene Circuit Function.

    Science.gov (United States)

    Diao, Junchen; Charlebois, Daniel A; Nevozhay, Dmitry; Bódi, Zoltán; Pál, Csaba; Balázsi, Gábor

    2016-07-15

    Synthetic biology aims to design new biological systems for predefined purposes, such as the controlled secretion of biofuels, pharmaceuticals, or other chemicals. Synthetic gene circuits regulating an efflux pump from the ATP-binding cassette (ABC) protein family could achieve this. However, ABC efflux pumps can also drive out intracellular inducer molecules that control the gene circuits. This will introduce an implicit feedback that could alter gene circuit function in ways that are poorly understood. Here, we used two synthetic gene circuits inducible by tetracycline family molecules to regulate the expression of a yeast ABC pump (Pdr5p) that pumps out the inducer. Pdr5p altered the dose-responses of the original gene circuits substantially in Saccharomyces cerevisiae. While one aspect of the change could be attributed to the efflux pumping function of Pdr5p, another aspect remained unexplained. Quantitative modeling indicated that reduced regulator gene expression in addition to efflux pump function could fully explain the altered dose-responses. These predictions were validated experimentally. Overall, we highlight how efflux pumps can alter gene circuit dynamics and demonstrate the utility of mathematical modeling in understanding synthetic gene circuit function in new circumstances. PMID:27111147

  16. 45 CFR 2400.64 - Alterations to Plan of Study.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Alterations to Plan of Study. 2400.64 Section 2400... Study. Although Junior Fellows are expected to pursue full-time study and Senior Fellows to pursue part-time study, the Foundation may permit Junior Fellows with an established need (such as the need...

  17. Altered autophagy in human adipose tissues in obesity

    Science.gov (United States)

    Context: Autophagy is a housekeeping mechanism, involved in metabolic regulation and stress response, shown recently to regulate lipid droplets biogenesis/breakdown and adipose tissue phenotype. Objective: We hypothesized that in human obesity autophagy may be altered in adipose tissue in a fat d...

  18. 31 CFR 306.42 - Alterations and erasures.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Alterations and erasures. 306.42 Section 306.42 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL... should be submitted for consideration....

  19. Tetracycline regulator expression alters the transcriptional program of mammalian cells

    OpenAIRE

    Hackl, Hubert; Rommer, Anna; Konrad, Torsten A; Nassimbeni, Christine; Wieser, Rotraud

    2010-01-01

    Tetracycline regulated ectopic gene expression is a widely used tool to study gene function. However, the tetracycline regulator (tetR) itself has been reported to cause certain phenotypic changes in mammalian cells. We, therefore, asked whether human myeloid U937 cells expressing the tetR in an autoregulated manner would exhibit alterations in gene expression upon removal of tetracycline.

  20. Study of altered platelet morphology with changes in glycaemic status

    Directory of Open Access Journals (Sweden)

    Mitakshara Sharma

    2016-03-01

    Conclusions: This study showed that platelet morphology is altered with increasing glycaemic levels. These changes can be known by measurements of PVI which is an important simple and effortless tool can be used more extensively to predict the acute vascular events and thereby help curb morbidity and mortality. [Int J Res Med Sci 2016; 4(3.000: 757-761

  1. Altered sense of agency in children with spastic cerebral palsy

    DEFF Research Database (Denmark)

    Ritterband-Rosenbaum, Anina; Christensen, Mark S; Kliim-Due, Mette;

    2011-01-01

    ABSTRACT: Background Children diagnosed with spastic Cerebral Palsy (CP) often show perceptual and cognitive problems, which may contribute to their functional deficit. Here we investigated if altered ability to determine whether an observed movement is performed by themselves (sense of agency...

  2. 14 CFR 77.13 - Construction or alteration requiring notice.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Construction or alteration requiring notice. 77.13 Section 77.13 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... or in either the Alaska or Pacific Airman's Guide and Chart Supplement. (ii) An airport...

  3. Chronic zinc deficiency alters chick gut microbiota composition and function

    Science.gov (United States)

    Zinc (Zn) deficiency is a prevalent micronutrient insufficiency. Although the gut is a vital organ for Zn utilization, and Zn deficiency is associated with impaired intestinal permeability and a global decrease in gastrointestinal health, alterations in the gut microbial ecology of the host under co...

  4. The Chutzpah Factor in Altered States of Consciousness

    Science.gov (United States)

    Pelletier, Kenneth; Peper, Erik

    1977-01-01

    Discusses the "chutzpah factor", the ability to transcend fear and enter into the unknown, in altered states of consciousness, especially in what are known as "adept" individuals. Examines the powerful effect a person's belief system has upon what he or she is able to do and endure. (Editor/RK)

  5. Reversible Altered Consciousness and Brain Atrophy Induced by Valproic Acid

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2003-08-01

    Full Text Available A 5-year-old female child with valproic acid (VPA-related alteration of consciousness and brain atrophy that progressed over a 3 day period and resolved within 12 hours of discontinuing VPA is reported from Dokkyo University School of Medicine and Shimotsuga General Hospital, Tochigi, Japan.

  6. Paroxysmal Perceptual Alteration: Drug-Induced Phenomenon or Schizophrenic Psychopathology?

    Science.gov (United States)

    Praharaj, Samir Kumar; Kongasseri, Sreejayan; Acharya, Mahima

    2016-01-01

    Brief and repetitive episodes of perceptual changes, termed paroxysmal perceptual alteration (PPA), have been described in association with antipsychotic treatment. We report a case of paranoid schizophrenia who had such perceptual changes akin to PPA for 15 years, which was not related to antipsychotic treatment. There was a rapid resolution of PPA after treatment with low-dose clonazepam. PMID:26954463

  7. Phytochemicals Perturb Membranes and Promiscuously Alter Protein Function

    NARCIS (Netherlands)

    Ingólfsson, Helgi I; Thakur, Pratima; Herold, Karl F; Hobart, E Ashley; Ramsey, Nicole B; Periole, Xavier; de Jong, Djurre H; Zwama, Martijn; Yilmaz, Duygu; Hall, Katherine; Maretzky, Thorsten; Hemmings, Hugh C; Blobel, Carl; Marrink, Siewert J; Kocer, Armagan; Sack, Jon T; Andersen, Olaf S

    2014-01-01

    A wide variety of phytochemicals are consumed for their perceived health benefits. Many of these phytochemicals have been found to alter numerous cell functions, but the mechanisms underlying their biological activity tend to be poorly understood. Phenolic phytochemicals are particularly promiscuous

  8. Clonal chromosomal alterations in fibroadenomas of the breast

    DEFF Research Database (Denmark)

    Cavalli, L R; Cornélio, D A; Wuicik, L; Bras, A T; Ribeiro, E M; Lima, R S; Urban, C A; Rogatto, S R; Cavalli, I J

    2001-01-01

    A cytogenetic study on short-term cell cultures from 10 fibroadenomas of the breast is reported. Clonal chromosomal alterations were observed in all cases analyzed, involving preferentially chromosomes X, 12, 14, 20, and 22. Normal karyotypes were found in 34.9% of the cells. The present findings...

  9. Alterations of the visual pathways in congenital blindness

    DEFF Research Database (Denmark)

    Ptito, Maurice; Schneider, Fabien C G; Paulson, Olaf B;

    2008-01-01

    18/19 and the middle temporal cortex (MT) showing volume reductions of up to 20%. Additional significant white matter alterations were observed in the inferior longitudinal tract and in the posterior part of the corpus callosum, which links the visual areas of both hemispheres. Our data indicate that...

  10. Revealing alteration of membrane structures during ischema using impedance spectroscopy

    Directory of Open Access Journals (Sweden)

    Mihaela Gheorghiu

    2002-11-01

    Full Text Available Alterations of membrane structure and function are essential characteristics of cells undergoing ischemia. Noninvasive monitoring of tissue alterations during ischemia and the estimation of the reversibility domain (corresponding to organ capability to fully recover its functions after shifting back to normal blood perfusion are important for biomedical applications allowing better time management during surgical interventions, especially in organ transplantation. Due to it’s capability to reveal inhomogeneities, as well as it’s noninvasive character, impedance spectroscopy was used for continuous monitoring of the progression of excised tissue samples during ischemia. We have developed a fast, noninvasive, automated method for quantitative analysis of impedance spectra of tissue samples, capable of revealing, through characteristic parameters (dispersion amplitudes, time constants and distribution parameters membrane based microscopic processes like the closure ofgap-junctions (a characteristic of the early alterations of ischemic tissues in the reversibility phase. Microscopic and equivalent circuit modeling was used to probe the effect of closure of cell connections and of changes in electrical properties of cell constituents on impedance spectra. We have developed a normalizing procedure emphasizing the pattern of ischemic alterations and enabling the comparison of different data sets.

  11. 27 CFR 5.23 - Alteration of class and type.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Alteration of class and type. 5.23 Section 5.23 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS LABELING AND ADVERTISING OF DISTILLED SPIRITS Standards of Identity...

  12. Altered cingulostriatal coupling in obsessive-compulsive disorder.

    Science.gov (United States)

    Beucke, Jan Carl; Kaufmann, Christian; Linnman, Clas; Gruetzmann, Rosa; Endrass, Tanja; Deckersbach, Thilo; Dougherty, Darin D; Kathmann, Norbert

    2012-01-01

    Neurobiological models of obsessive-compulsive disorder (OCD) assume abnormalities in corticostriatal networks involving cingulate and orbitofrontal cortices, but the connectivity within these systems is rarely addressed in experimental imaging studies in this patient group. Using an established monetary reinforcement paradigm known to involve the cingulate cortex and the ventral striatum, the present study sought to test for altered corticostriatal coupling in OCD patients anticipating potential punishment. The anterior midcingulate cortex (aMCC), a region integrating negative emotion, pain, and cognitive control, was chosen as a seed region due to its particular relevance in OCD, representing the neurosurgical target for cingulotomy, and showing increased responses to errors in OCD patients. Results from psychophysiological interaction analyses revealed that significantly altered, inverse coupling occurs between the aMCC and the ventral striatum when OCD patients anticipate potential punishment. This abnormality links the two major contemporary neurosurgical OCD target sites, and provides direct experimental evidence of altered corticostriatal connectivity in OCD. Noteworthy, an abnormal aMCC coupling with cortical areas outside of traditional corticostriatal circuitry was identified besides the alteration in the cingulostriatal pathway. In conclusion, these findings support the importance of applying connectivity methods to study corticostriatal networks in OCD, and favor the application of effective connectivity methods to study corticostriatal abnormalities in OCD patients performing tasks that involve symptom provocation and reinforcement learning. PMID:22823561

  13. Electromagnetic Evidence of Altered Visual Processing in Autism

    Science.gov (United States)

    Neumann, Nicola; Dubischar-Krivec, Anna M.; Poustka, Fritz; Birbaumer, Niels; Bolte, Sven; Braun, Christoph

    2011-01-01

    Individuals with autism spectrum disorder (ASD) demonstrate intact or superior local processing of visual-spatial tasks. We investigated the hypothesis that in a disembedding task, autistic individuals exhibit a more local processing style than controls, which is reflected by altered electromagnetic brain activity in response to embedded stimuli…

  14. Why climate change will invariably alter selection pressures on phenology

    NARCIS (Netherlands)

    Gienapp, Phillip; Reed, Thomas E.; Visser, Marcel E.

    2014-01-01

    The seasonal timing of lifecycle events is closely linked to individual fitness and hence, maladaptation in phenological traits may impact population dynamics. However, few studies have analysed whether and why climate change will alter selection pressures and hence possibly induce maladaptation in

  15. Altered Geometry: A New Angle on Teacher Technophobia

    Science.gov (United States)

    Lloyd, Margaret M.; Albion, Peter R.

    2009-01-01

    Teacher technophobia is analyzed using an activity systems framework and we contend that technophobic teachers make the mistake of confusing and collapsing the tool into the object thereby figuratively altering the geometry of the classic activity system triangle. Three case studies of technophobic teachers are reviewed and compared with…

  16. Study of glass alteration mechanisms in cement waters

    International Nuclear Information System (INIS)

    In the French deep geological repository concept, intermediate-level vitrified waste packages could be disposed of concrete medium. Chemical composition and pH of the interstitial leaching water are expected to influence the chemical durability of glass. Investigations have thus been carried out to study glass dissolution mechanisms and kinetics in contact with cement waters. Three cement pore waters were studied: the first two correspond to two stages of the Portland cement aging and the third corresponds to equilibrium with a low pH concrete. The S/V ratio (glass-surface-area-to-solution-volume ratio) and the chemistry of cement waters are the two main parameters that control glass alteration mechanisms. If the leaching flow from the glass allows a degree of supersaturation to be reached and maintained which leads to nucleation of secondary phases, then precipitation of these phases drives glass dissolution. At a very low S/V ratio, the calcium uptake into the alteration layer increases its passivating properties. Conversely, at a high S/V ratio, the calcium precipitates as cementitious phases consuming elements which form the alteration layer. The glass dissolution is maintained at a high rate. This study contributes to highlighting the beneficial role of low pH cement in glass alteration, and is a first step towards understanding the mechanisms between the glass and the cement medium. (author)

  17. Caterpillar feeding responses to sorghum leaves with altered lignin levels

    Science.gov (United States)

    Production of liquid fuels from biomass is impeded by the presence of lignin. Plants with lower or altered lignin are more amenable to lignocellulosic conversion to ethanol and other biofuels, but may be more susceptible to insect damage where lignin is an important resistance factor. Sorghum, Sorg...

  18. NEUTROPHIL MIGRATION UNDER AGAROSE IS ALTERED BY COPPER DEFICIENCY

    Science.gov (United States)

    Dietary copper deficiency alters neutrophil sequestration and margination within the pulmonary microcirculation in rats. In the current study, the role of copper in CD1 lb/CD18-dependent an -independent migration of neutrophils under agarose was studied. Male, weanling Sprague-Dawley rats were fed p...

  19. Functional and structural alterations induced by copper in xanthine oxidase

    Institute of Scientific and Technical Information of China (English)

    Mahnaz Hadizadeh; Ezzatollah Keyhani; Jacqueline Keyhani; Cyrus Khodadadi

    2009-01-01

    Xanthine oxidase (XO),a key enzyme in purine metab-olism,produces reactive oxygen species causing vascu-lar injuries and chronic heart failure.Here,copper's ability to alter XO activity and structure was investi-gated in vitro after pre-incubation of the enzyme with increasing Cu2+ concentrations for various periods of time.The enzymatic activity was measured by following XO-catalyzed xanthine oxidation to uric acid under steady-state kinetics conditions.Structural alterations were assessed by electronic absorption,fluorescence,and circular dichroism spectroscopy.Results showed that Cu2+ either stimulated or inhibited XO activity,depending on metal concentration and pre-incubation length,the latter also determining the inhibition type.Cu2+-XO complex formation was characterized by modifications in XO electronic absorption bands,intrinsic fluorescence,and α-helical and β-sheet content.Apparent dissociation constant values implied high- and low-affinity Cu2+ binding sites in the vicinity of the enzyme's reactive centers.Data indicated that Cu2+ binding to high-affinity sites caused alterations around XO molybdenum and flavin adenine dinucleo-tide centers,changes in secondary structure,and mod-erate activity inhibition;binding to low affinity sites caused alterations around all XO reactive centers including FeS,changes in tertiary structure as reflected by alterations in spectral properties,and drastic activity inhibition.Stimulation was attributed to transient stabilization of XO optimal conformation.Results also emphasized the potential role of copper in the regu-lation of XO activity stemming from its binding properties.

  20. Assessing hydrological alterations at multiple temporal scales: Adige River, Italy

    Science.gov (United States)

    Zolezzi, G.; Bellin, A.; Bruno, M. C.; Maiolini, B.; Siviglia, A.

    2009-12-01

    Hydrological alteration is one of the major threats to the integrity and functioning of riverine ecosystems. We propose to analyze such alterations by means of three approaches: the well-established range of variability approach (RVA), wavelet transform analysis (WT), and a combination of the two. This allows us to separate the most relevant scales of variability and to detect their alteration independently; such information cannot be provided by purely statistical methods like RVA. We show the advantages of this multiple approach through the analysis of two streamflow data sets of the Adige River at Trento, northeastern Italy: a daily streamflow record spanning from 1923 to 2006, and a record of instantaneous measurements with time step of 15 min from 2002 to 2006. Results suggest that starting from the 1960s, after the construction of the reservoirs currently in operation, a progressive flattening occurred in the hydrograph, which attenuated the amplitude of seasonal variations. This negative tendency worsened in the last few years, possibly as an effect of a reduction in winter snowfall. Wavelet analysis shows that hydroelectric production caused the high-frequency components of the signal to increase in amplitude and number, with fairly regular weekly and daily oscillations and sharp transitions. The whole spectrum of low flows is significantly altered. This alteration of the natural flow has adverse consequences on the ecological integrity of the ecosystem. Use of the range of variability approach, the wavelet transform analysis, and a new methodology which integrates both allows a better separation between natural and human-induced effects at ecologically relevant scales of variability, thereby identifying changes and trends due to hydropower management.

  1. 32 CFR Appendix B to Part 323 - Criteria for New and Altered Record Systems

    Science.gov (United States)

    2010-07-01

    ... alterations. b. Increases in numbers of individuals due to normal growth are not considered alterations unless... enlisted personnel to include all of DLA enlisted personnel would be considered an alteration). d. A... a new or altered system to DLA Support Services (DSS-CA) before collecting information and for...

  2. Contribution of altered signal transduction associated to glutamate receptors in brain to the neurological alterations of hepatic encephalopathy

    OpenAIRE

    Felipo, Vicente

    2006-01-01

    Patients with liver disease may present hepatic enceph-alopathy (HE), a complex neuropsychiatric syndrome covering a wide range of neurological alterations, including cognitive and motor disturbances. HE reduces the quality of life of the patients and is associated with poor prognosis. In the worse cases HE may lead to coma or death.

  3. Contribution to the modeling of elaborate cement barriers behaviour with respect to radioelements migration by the study of ancient analogue materials; Apport de l`etude de materiaux analogues anciens a la modelisation du comportement des barrieres ouvragees en ciment vis-a-vis de la migration des radioelements

    Energy Technology Data Exchange (ETDEWEB)

    Rougeau, P.

    1994-10-13

    The durability of cement matrices and their capacity of radioelements retention are determining factors for their use as elaborate barriers in radioactive waste disposal facilities. This study focusses on the observation of concretes in real situation of alteration or in contact with radioelements for predictive modelling. Two materials have been selected. One is a concrete from a gallery wall of the Margnac uranium mine (Cogema, France) submitted to uranium-rich infiltration waters. The alteration concentrates in two characteristic successive zones: the first is composed of calcium depleted and aluminum enriched calcite and calcium hydro-silicates and the second, between the first zone and the sound matrix, is characterized by a self-filling in process due to massive ettringite precipitation induced by sulfate ions transport. Uranium migration depends closely on the fissures and porosity of the cement matrix. The second series of samples correspond to 2000 years old archaeological cements from Pompei (Italy) made of volcanic ashes and carrying uranium traces. These samples were submitted to burying and alteration is characterized by a carbonation of the cement matrix. The mineralogy is closed to the one defined in the first alteration zone of the uranium mine concrete. Both studies demonstrate that the presence of carbonate ions in the percolation water plays a major role in the alteration process. Sulfate reactions must be considered too and tend to diminish the materials porosity and to increase the delay in radionuclides migration processes. (J.S.). 131 refs., 92 figs., 55 tabs., 51 photos., 15 appends.

  4. Hydrothermal alteration favoring phreatic eruption processes at Solfatara (Campi Flegrei)

    Science.gov (United States)

    Mayer, Klaus; Scheu, Bettina; Montanaro, Cristian; Aßbichler, Donjá; Isaia, Roberto; Dingwell, Donald B.

    2015-04-01

    Solfatara and Pisciarelli fumaroles are the main surface manifestations of the strong hydrothermal activity within the Campi Flegrei caldera system and pointing to a significant risk for phreatic eruptions in this densely populated area. Phreatic eruptions, triggered by various processes are hardly predictable in occurrence time and size. Despite their hazard potential, these eruptions, as well as the influence of hydrothermal alteration on their likelihood, magnitude and style, have so far been largely overlooked in experimental volcanology. The physical properties and the mechanical behavior of volcanic rocks are highly dependent on their original magmatic microstructure and on any eventual alteration of those microstructures due to hydrothermal reactions. We have therefore investigated the potential effects of hydrothermal alteration on rock microstructure and, as a consequence, on fragmentation dynamics. Rock samples from the vicinity of the Solfatara and Pisciarelli fumaroles have been characterized 1) geochemically (X-ray fluorescence, X-ray diffraction), 2) physically (density, porosity, permeability and elastic wave velocity) and 3) mechanically (uniaxial compressive strength, tensile strength). We furthermore have investigated the effects of hydrothermal alteration on fragmentation processes using a shock-tube apparatus, operating with Argon gas, water vapor and superheated water at temperatures up to 400°C and maximum pressures of 20 MPa. Fragmentation and ejection dynamics in the presence of three different energy sources within the pores have been investigated: overpressure by 1) Argon gas; or 2) water vapor and due to 3) steam flashing of superheated water. Fragmentation speed, fragmentation efficiency and fragmented particle ejection velocity were measured. Our results indicate on the one hand, that steam flashing provides the highest energy - resulting in increased fragmentation speed and particle ejection velocity and also a significant higher

  5. Preterm birth and structural brain alterations in early adulthood

    Directory of Open Access Journals (Sweden)

    Chiara Nosarti

    2014-01-01

    Full Text Available Alterations in cortical development and impaired neurodevelopmental outcomes have been described following very preterm (VPT birth in childhood and adolescence, but only a few studies to date have investigated grey matter (GM and white matter (WM maturation in VPT samples in early adult life. Using voxel-based morphometry (VBM we studied regional GM and WM volumes in 68 VPT-born individuals (mean gestational age 30 weeks and 43 term-born controls aged 19–20 years, and their association with cognitive outcomes (Hayling Sentence Completion Test, Controlled Oral Word Association Test, Visual Reproduction test of the Wechsler Memory Scale-Revised and gestational age. Structural MRI data were obtained with a 1.5 Tesla system and analysed using the VBM8 toolbox in SPM8 with a customized study-specific template. Similarly to results obtained at adolescent assessment, VPT young adults compared to controls demonstrated reduced GM volume in temporal, frontal, insular and occipital areas, thalamus, caudate nucleus and putamen. Increases in GM volume were noted in medial/anterior frontal gyrus. Smaller subcortical WM volume in the VPT group was observed in temporal, parietal and frontal regions, and in a cluster centred on posterior corpus callosum/thalamus/fornix. Larger subcortical WM volume was found predominantly in posterior brain regions, in areas beneath the parahippocampal and occipital gyri and in cerebellum. Gestational age was associated with GM and WM volumes in areas where VPT individuals demonstrated GM and WM volumetric alterations, especially in temporal, parietal and occipital regions. VPT participants scored lower than controls on measures of IQ, executive function and non-verbal memory. When investigating GM and WM alterations and cognitive outcome scores, subcortical WM volume in an area beneath the left inferior frontal gyrus accounted for 14% of the variance of full-scale IQ (F = 12.9, p < 0.0001. WM volume in posterior corpus

  6. Altered states of consciousness are related to higher sexual responsiveness.

    Science.gov (United States)

    Costa, Rui M; Pestana, José; Costa, David; Wittmann, Marc

    2016-05-01

    Altered states of consciousness lead to profound changes in the sense of self, time and space. We assessed how these changes were related to sexual responsiveness during sex. 116 subjects reported (a) intensity of awareness concerning body, space and time, and (b) satisfaction, desire, arousal, and orgasm occurrence. We differentiated vaginal intercourse orgasm from noncoital orgasm. Female vaginal intercourse orgasm was further differentiated as with or without concurrent clitoral masturbation. Overall, sexual responsiveness was related to greater body awareness and lesser time and space awareness. Satisfaction, desire, and arousal were especially associated with less time awareness in women. Female orgasms during vaginal intercourse were related to greater body awareness and lesser time awareness, but noncoital orgasms were unrelated. Our findings provide empirical support for the hypotheses that altered states of consciousness with attentional absorption are strongly related to sexual responsiveness in women, and to a lesser extent in men. PMID:27003264

  7. Alterations in HIV-1 LTR promoter activity during AIDS progression

    International Nuclear Information System (INIS)

    HIV-1 variants evolving in AIDS patients frequently show increased replicative capacity compared to those present during early asymptomatic infection. It is known that late stage HIV-1 variants often show an expanded coreceptor tropism and altered Nef function. In the present study we investigated whether enhanced HIV-1 LTR promoter activity might also evolve during disease progression. Our results demonstrate increased LTR promoter activity after AIDS progression in 3 of 12 HIV-1-infected individuals studied. Further analysis revealed that multiple alterations in the U3 core-enhancer and in the transactivation-response (TAR) region seem to be responsible for the enhanced functional activity. Our findings show that in a subset of HIV-1-infected individuals enhanced LTR transcription contributes to the increased replicative potential of late stage virus isolates and might accelerate disease progression

  8. Toxic Knowledge: Self-Alteration Through Child Abuse Work.

    Science.gov (United States)

    Sigad, Laura I; Davidov, Jonathan; Lev-Wiesel, Rachel; Eisikovits, Zvi

    2016-02-01

    The purpose of the present article is to examine the multiple ways in which the private lives of professionals are affected by involvement with child abuse intervention and prevention. Using a descriptive-phenomenological perspective and 40 in-depth interviews with professionals to present a model based on qualitative data, we studied the ways in which child abuse professionals conceptualize, understand, and integrate their experiences into their personal and family lives. We find that the process of internalizing child abuse knowledge occurs in two domains: One affirms or denies the existence of the phenomenon; the other concerns the strategies used to contend with the effects of working in abuse. Knowledge of child abuse is toxic, in the sense that it serves as a catalyst leading to the alteration of one's self-perception and parental identity. We present a typology of self-alteration resulting from child abuse knowledge and describe the mechanism of this change. PMID:25381277

  9. Metabolic alterations in cancer cells and therapeutic implications

    Institute of Scientific and Technical Information of China (English)

    Naima Hammoudi; Kausar Begam Riaz Ahmed; Celia Garcia-Prieto; Peng Huang

    2011-01-01

    Cancer metabolism has emerged as an important area of research in recent years. Elucidation of the metabolic differences between cancer and normal cells and the underlying mechanisms will not only advance our understanding of fundamental cancer cell biology but also provide an important basis for the development of new therapeutic strategies and novel compounds to selectively eliminate cancer cells by targeting their unique metabolism. This article reviews several important metabolic alterations in cancer cells, with an emphasis on increased aerobic glycolysis (the Warburg effect) and glutamine addiction, and discusses the mechanisms that may contribute to such metabolic changes. In addition, metabolic alterations in cancer stem cells, mitochondrial metabolism and its influence on drug sensitivity, and potential therapeutic strategies and agents that target cancer metabolism are also discussed.

  10. Alteration in cellular acetylcholine influences dauer formation in Caenorhabditis elegans.

    Science.gov (United States)

    Lee, Jeeyong; Kim, Kwang-Youl; Paik, Young-Ki

    2014-02-01

    Altered acetylcholine (Ach) homeostasis is associated with loss of viability in flies, developmental defects in mice, and cognitive deficits in human. Here, we assessed the importance of Ach in Caenorhabditis elegans development, focusing on the role of Ach during dauer formation. We found that dauer formation was disturbed in choline acetyltransferase (cha-1) and acetylcholinesterase (ace) mutants defective in Ach biosynthesis and degradation, respectively. When examined the potential role of G-proteins in dauer formation, goa-1 and egl-30 mutant worms, expressing mutated versions of mammalian G(o) and G(q) homolog, respectively, showed some abnormalities in dauer formation. Using quantitative mass spectrometry, we also found that dauer larvae had lower Ach content than did reproductively grown larvae. In addition, a proteomic analysis of acetylcholinesterase mutant worms, which have excessive levels of Ach, showed differential expression of metabolic genes. Collectively, these results indicate that alterations in Ach release may influence dauer formation in C. elegans. PMID:24219868

  11. Major depressive disorder alters perception of emotional body movements

    Directory of Open Access Journals (Sweden)

    Morten eKaletsch

    2014-01-01

    Full Text Available Much recent research has shown an association between mood disorders and an altered emotion perception. However, these studies were conducted mainly with stimuli such as faces. This is the first study to examine possible differences in how people with major depressive disorder (MDD and healthy controls perceive emotions expressed via body movements. 30 patients with MDD and 30 healthy controls observed video scenes of human interactions conveyed by point–light displays (PLDs. They rated the depicted emotions and judged their confidence in their rating. Results showed that patients with MDD rated the depicted interactions more negatively than healthy controls. They also rated interactions with negative emotionality as being more intense and were more confident in their ratings. It is concluded that patients with MDD exhibit an altered emotion perception compared to healthy controls when rating emotions expressed via body movements depicted in PLDs.

  12. ALTERED STATES OF LITERATURE: SHAMANIC ASSIMILATION AND ROMANTIC INSPIRATION

    Directory of Open Access Journals (Sweden)

    Marcel de Lima Santos

    2012-12-01

    Full Text Available This article deals with the connections between the assimilation of certain shamanic practices related to Romantic inspiration in English literature. The interest in the world of altered states of consciousness as a manifestation of the sacred is typical among Romantic writers in nineteenth-century England. These writers in fact sought the manifestation of the world of dreams by means of ingesting substances that alter consciousness, thus assimilating a practice that is likewise and primarily shamanic. This search is the object under investigation in this article, which aims at showing that, despite conspicuous cultural differences, there are indeed similarities that pervade shamanic practices and the Romantic ideal in their quests toward the sacred.

  13. ALTERATION OF U(VI)-PHASES UNDER OXIDIZING CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    A.P. Deditius; S. Utsunomiya; R.C. Ewing

    2006-02-21

    Uranium-(VI) phases are the primary alteration products of the UO{sub 2} in spent nuclear fuel and the UO{sub 2+x}, in natural uranium deposits. The U(VI)-phases generally form sheet structures of edge-sharing UO{sub 2}{sup 2+} polyhedra. The complexity of these structures offers numerous possibilities for coupled-substitutions of trace metals and radionuclides. The incorporation of radionuclides into U(VI)-structures provides a potential barrier to their release and transport in a geologic repository that experiences oxidizing conditions. In this study, we have used natural samples of UO{sub 2+x}, to study the U(VI)-phases that form during alteration and to determine the fate of the associated trace elements.

  14. Oral mucosal alterations among the institutionalized elderly in Brazil

    Directory of Open Access Journals (Sweden)

    Raquel Conceição Ferreira

    2010-09-01

    Full Text Available This study determined the prevalence of oral mucosal alterations and associated factors among the institutionalized elderly in Brazil. Data were collected through a structured questionnaire, a review of their medical records and an intra-oral examination. A sample of 335 individuals over 60 years of age was randomly selected. In total, 646 alterations were diagnosed; 59.1% were variations of the normal oral mucosa. The most frequent variation consisted of sublingual varicosities (51.6%. Denture stomatitis (15.2% and denture hyperplasia (12.8% were the most frequent lesions. Elderly patients who wore dentures had a significantly higher prevalence of oral mucosal lesions (p = 0.00 than those that didn't wear dentures. There was a high prevalence of variations of the normal oral mucosa and of mucosal lesions, especially denture-induced lesions, among the institutionalized elderly.

  15. Altered functional connectivity of prefrontal cortex in chronic heroin abusers

    Institute of Scientific and Technical Information of China (English)

    Yinbao Qi; Xianming Fu; Ruobing Qian; Chaoshi Niu; Xiangpin Wei

    2011-01-01

    In this study, we investigated alterations in the resting-state functional connectivity of the pre-frontal cortex in chronic heroin abusers using functional magnetic resonance imaging. We found that, compared with normal controls, in heroin abusers the left prefrontal cortex showed decreased functional connectivity with the left hippocampus, right anterior cingulate, left middle frontal gyrus, right middle frontal gyrus and right precuneus. However, the right prefrontal cortex showed decreased functional connectivity with the left orbital frontal cortex and the left middle frontal gyrus in chronic heroin abusers. These alterations of resting-state functional connectivity in the prefrontal cortices of heroin abusers suggest that their frontal executive neural network may be impaired, and that this may contribute to their continued heroin abuse and relapse after withdrawal.

  16. State-related alterations of gene expression in bipolar disorder

    DEFF Research Database (Denmark)

    Munkholm, Klaus; Vinberg, Maj; Berk, Michael;

    2012-01-01

    Munkholm K, Vinberg M, Berk M, Kessing LV. State-related alterations of gene expression in bipolar disorder: a systematic review. Bipolar Disord 2012: 14: 684-696. © 2012 The Authors. Journal compilation © 2012 John Wiley & Sons A/S. Objective:  Alterations in gene expression in bipolar disorder...... vulnerability pathways. This review therefore evaluated the evidence for whether gene expression in bipolar disorder is state or trait related. Methods:  A systematic review, using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guideline for reporting systematic reviews, based...... on comprehensive database searches for studies on gene expression in patients with bipolar disorder in specific mood states, was conducted. We searched Medline, Embase, PsycINFO, and The Cochrane Library, supplemented by manually searching reference lists from retrieved publications. Results:  A...

  17. Heart Alterations after Domoic Acid Administration in Rats

    Science.gov (United States)

    Vieira, Andres C.; Cifuentes, José Manuel; Bermúdez, Roberto; Ferreiro, Sara F.; Castro, Albina Román; Botana, Luis M.

    2016-01-01

    Domoic acid (DA) is one of the best known marine toxins, causative of important neurotoxic alterations. DA effects are documented both in wildlife and experimental assays, showing that this toxin causes severe injuries principally in the hippocampal area. In the present study we have addressed the long-term toxicological effects (30 days) of DA intraperitoneal administration in rats. Different histological techniques were employed in order to study DA toxicity in heart, an organ which has not been thoroughly studied after DA intoxication to date. The presence of DA was detected by immunohistochemical assays, and cellular alterations were observed both by optical and transmission electron microscopy. Although histological staining methods did not provide any observable tissue damage, transmission electron microscopy showed several injuries: a moderate lysis of myofibrils and loss of mitochondrial conformation. This is the first time the association between heart damage and the presence of the toxin has been observed. PMID:26978401

  18. Insulin resistance alters islet morphology in nondiabetic humans

    DEFF Research Database (Denmark)

    Mezza, Teresa; Muscogiuri, Giovanna; Sorice, Gian Pio;

    2014-01-01

    Type 2 diabetes is characterized by poor glucose uptake in metabolic tissues and manifests when insulin secretion fails to cope with worsening insulin resistance. In addition to its effects on skeletal muscle, liver, and adipose tissue metabolism, it is evident that insulin resistance also affects...... pancreatic β-cells. To directly examine the alterations that occur in islet morphology as part of an adaptive mechanism to insulin resistance, we evaluated pancreas samples obtained during pancreatoduodenectomy from nondiabetic subjects who were insulin-resistant or insulin-sensitive. We also compared...... insulin sensitivity, insulin secretion, and incretin levels between the two groups. We report an increased islet size and an elevated number of β- and α-cells that resulted in an altered β-cell-to-α-cell area in the insulin- resistant group. Our data in this series of studies suggest that neogenesis from...

  19. Blood coagulation and its alterations in hemorrhagic and thrombotic disorders.

    OpenAIRE

    Rapaport, S I

    1993-01-01

    Clinical observations have added to the understanding of basic mechanisms of blood coagulation and its alterations in certain hemorrhagic and thrombotic states. Much clinical evidence exists for concluding that the exposure of blood to tissue factor (thromboplastin) on tissue cells represents the key event initiating fibrin clot formation after tissue injury. This then results in the formation of activated factor VII (VIIa)-tissue factor complexes, which must activate both factor X and factor...

  20. How Do Thermal Recovery Methods Affect Wettability Alteration?

    OpenAIRE

    Abhishek Punase; Amy Zou; Riza Elputranto

    2014-01-01

    We will investigate the effect of temperature on wettability. First, we will list and summarize the different schools of thoughts from previous literature describing wettability changes for sandstone and carbonate reservoirs at elevated temperature. Next, we will describe the properties that affect wettability: how they alter wettability and how they are affected by temperature. After that, we will present indications of wettability changes and current wettability measurement techniques. Foll...

  1. Unusual Morphological Alteration in Sigmoid Notch: An Insight Through CBCT

    OpenAIRE

    Gupta, Anjali; Kant, Sanchita; Phulambrikar, Tushar; Kode, Manasi; Singh, Siddharth Kumar

    2015-01-01

    The Temporomandibular Joint (TMJ) is a ginglymo-diarthrodial joint known to be the most complex joint in human body. Growth disturbances, owing to genetic influences or trauma during the intrauterine life or during early developmental age may lead to morphological and functional variations in the mandible resulting in developmental anomaly. We report a rare case of altered sigmoid notch morphology on the right side and condylar hypoplasia on the left side, not related to any clear pathologica...

  2. Gravitropism of cucumber hypocotyls: biophysical mechanism of altered growth

    Science.gov (United States)

    Cosgrove, D. J.

    1990-01-01

    The biophysical basis for the changes in cell elongation rate during gravitropism was examined in aetiolated cucumber (Cucumis sativus L.) hypocotyls. Bulk osmotic pressures on the two sides of the stem and in the epidermal cells were not altered during the early time course of gravitropism. By the pressure-probe technique, a small increase in turgor (0.3 bar, 30 kPa) was detected on the upper (inhibited) side, whereas there was a negligible decrease in turgor on the lower (stimulated) side. These small changes in turgor and water potential appeared to be indirect, passive consequences of the altered growth and the small resistance for water movement from the xylem, and indicated that the change in growth was principally due to changes in wall properties. The results indicate that the hydraulic conductance of the water-transport pathway was large (.25 h-1 bar-1) and the water potential difference supporting cell expansion was no greater than 0.3 bar (30 kPa). From pressure-block experiments, it appeared that upon gravitropic stimulation (1) the yield threshold of the lower half of the stem did not decrease and (2) the wall on the upper side of the stem was not made more rigid by a cross-linking process. Mechanical measurements of the stress/strain properties of the walls showed that the initial development of gravitropism did not involve an alteration of the mechanical behaviour of the isolated walls. Thus, gravitropism in cucumber hypocotyls occurs principally by an alteration of the wall relaxation process, without a necessary change in wall mechanical properties.

  3. Gene Expression Profiling of Biological Pathway Alterations by Radiation Exposure

    OpenAIRE

    Lee, Kuei-Fang; Weng, Julia Tzu-Ya; Hsu, Paul Wei-Che; Chi, Yu-Hsiang; Chen, Ching-Kai; Liu, Ingrid Y.; CHEN, YI-CHENG; Wu, Lawrence Shih-Hsin

    2014-01-01

    Though damage caused by radiation has been the focus of rigorous research, the mechanisms through which radiation exerts harmful effects on cells are complex and not well-understood. In particular, the influence of low dose radiation exposure on the regulation of genes and pathways remains unclear. In an attempt to investigate the molecular alterations induced by varying doses of radiation, a genome-wide expression analysis was conducted. Peripheral blood mononuclear cells were collected from...

  4. Deciphering the role of interleukin-22 in metabolic alterations

    OpenAIRE

    Sabat, Robert; Wolk, Kerstin

    2015-01-01

    Inflammatory processes and metabolic alterations are supposed to substantially interact. Recently, cumulating reports describe a profound role of interleukin(IL)-22 in this relationship. IL-22 is a particular kind of immune mediator that is produced by certain lymphocyte populations and regulates the function of several tissue cells but not immune cells. So far, IL-22 was known to plays a fundamental role in the elimination of bacterial infections at border surfaces of the body and to protect...

  5. The Impact of Neuroimmune Alterations in Autism Spectrum Disorder

    OpenAIRE

    Gottfried, Carmem; Bambini-Junior, Victorio; Francis, Fiona; Riesgo, Rudimar; Savino, Wilson

    2015-01-01

    Autism spectrum disorder (ASD) involves a complex interplay of both genetic and environmental risk factors, with immune alterations and synaptic connection deficiency in early life. In the past decade, studies of ASD have substantially increased, in both humans and animal models. Immunological imbalance (including autoimmunity) has been proposed as a major etiological component in ASD, taking into account increased levels of pro-inflammatory cytokines observed in postmortem brain from patient...

  6. Radiodiagnosis of pulmonary alterations in systemic lupus erythematosus patients

    International Nuclear Information System (INIS)

    X-ray examination was carried out in 170 patients with systemic lupus erythematosus. Certain parameters of specific immunity were studied in 60 of them, while X-ray data were compared with morphological findings on autopsy in 20 cases. A tendency toward escalation of specific cell and humoral parameters was discovered in pulmonary lesion, predetermined by vasculitis and perivasculitis, as well as inflammatory and fibrotic alterations in the interstitial tissue

  7. Adaptive radiation-induced epigenetic alterations mitigated by antioxidants

    OpenAIRE

    Bernal, Autumn J.; Dolinoy, Dana C; Huang, Dale; Skaar, David A.; Weinhouse, Caren; Jirtle, Randy L

    2013-01-01

    Humans are exposed to low-dose ionizing radiation (LDIR) from a number of environmental and medical sources. In addition to inducing genetic mutations, there is concern that LDIR may also alter the epigenome. Such heritable effects early in life can either be positively adaptive or result in the enhanced formation of diseases, including cancer, diabetes, and obesity. Herein, we show that LDIR significantly increased DNA methylation at the viable yellow agouti (Avy) locus in a sex-specific man...

  8. Intensive reasoning training alters patterns of brain connectivity at rest

    OpenAIRE

    Mackey, AP; Singley, ATM; Bunge, SA

    2013-01-01

    Patterns of correlated activity among brain regions reflect functionally relevant networks that are widely assumed to be stable over time. We hypothesized that if these correlations reflect the prior history of coactivation of brain regions, then a marked shift in cognition could alter the strength of coupling between these regions. We sought to test whether intensive reasoning training in humans would result in tighter coupling among regions in the lateral frontoparietal network, as measured...

  9. Lipid-rhodopsin hydrophobic mismatch alters rhodopsin helical content

    OpenAIRE

    Soubias, Olivier; Niu, Shui-Lin; Mitchell, Drake C.; Gawrisch, Klaus

    2008-01-01

    The ability of photo-activated rhodopsin to achieve the enzymatically active metarhodopsin II conformation is exquisitely sensitive to bilayer hydrophobic thickness. The sensitivity of rhodopsin to the lipid matrix has been explained by the hydrophobic matching theory which predicts that lipid bilayers adjust elastically to the hydrophobic length of transmembrane helices. Here, we examined if bilayer thickness adjusts to the length of the protein or if the protein alters its conformation to a...

  10. Brain food: how nutrition alters our mood and behaviour

    OpenAIRE

    Banjari, Ines; Vukoje, Ivana; MANDIĆ, Milena L.

    2014-01-01

    Studies have been showing the food we eat affects chemical composition of our brain and alters our mood. Nutrition affects cognitive possibilities, including alertness and the production or release of neurotransmitters, the chemical messengers that carry information from one nerve cell to another. Foods are made up of more than one nutrient, and their interaction is going to affect the production and release of neurotransmitters. Neural impulses are largely resulting from sodium-potassium exc...

  11. Alteration of Energy Substrates and ROS Production in Diabetic Cardiomyopathy

    OpenAIRE

    O. Lorenzo; Ramírez, E.; Picatoste, B.; J. Egido; Tuñón, J.

    2013-01-01

    Diabetic cardiomyopathy is initiated by alterations in energy substrates. Despite excess of plasma glucose and lipids, the diabetic heart almost exclusively depends on fatty acid degradation. Glycolytic enzymes and transporters are impaired by fatty acid metabolism, leading to accumulation of glucose derivatives. However, fatty acid oxidation yields lower ATP production per mole of oxygen than glucose, causing mitochondrial uncoupling and decreased energy efficiency. In addition, the oxidatio...

  12. Safety assessment of genetically modified plants with deliberately altered composition

    OpenAIRE

    Halford, Nigel G.; Hudson, Elizabeth; Gimson, Amy; Weightman, Richard; Shewry, Peter R.; Tompkins, Steven

    2014-01-01

    The development and marketing of ‘novel’ genetically modified (GM) crops in which composition has been deliberately altered poses a challenge to the European Union (EU)'s risk assessment processes, which are based on the concept of substantial equivalence with a non-GM comparator. This article gives some examples of these novel GM crops and summarizes the conclusions of a report that was commissioned by the European Food Safety Authority on how the EU's risk assessment processes could be adap...

  13. Altered Brain Reward Circuits in Eating Disorders: Chicken or Egg?

    OpenAIRE

    Frank, Guido K.W.

    2013-01-01

    The eating disorders anorexia nervosa (AN) and bulimia nervosa (BN) are severe psychiatric disorders with high mortality. Our knowledge about the neurobiology of eating disorders is very limited, and the question remains whether alterations in brain structure or function in eating disorders are state related, remnants of the illness or premorbid traits. The brain reward system is a relatively well-characterized brain circuitry that plays a central role in the drive to eat and individuals with...

  14. Neuroinflammation alters voltage-dependent conductance in striatal astrocytes

    OpenAIRE

    Karpuk, Nikolay; Burkovetskaya, Maria; Kielian, Tammy

    2012-01-01

    Neuroinflammation has the capacity to alter normal central nervous system (CNS) homeostasis and function. The objective of the present study was to examine the effects of an inflammatory milieu on the electrophysiological properties of striatal astrocyte subpopulations with a mouse bacterial brain abscess model. Whole cell patch-clamp recordings were performed in striatal glial fibrillary acidic protein (GFAP)-green fluorescent protein (GFP)+ astrocytes neighboring abscesses at postinfection ...

  15. Fear and Reward Circuit Alterations in Pediatric CRPS.

    Science.gov (United States)

    Simons, Laura E; Erpelding, Nathalie; Hernandez, Jessica M; Serrano, Paul; Zhang, Kunyu; Lebel, Alyssa A; Sethna, Navil F; Berde, Charles B; Prabhu, Sanjay P; Becerra, Lino; Borsook, David

    2015-01-01

    In chronic pain, a number of brain regions involved in emotion (e.g., amygdala, hippocampus, nucleus accumbens, insula, anterior cingulate, and prefrontal cortex) show significant functional and morphometric changes. One phenotypic manifestation of these changes is pain-related fear (PRF). PRF is associated with profoundly altered behavioral adaptations to chronic pain. For example, patients with a neuropathic pain condition known as complex regional pain syndrome (CRPS) often avoid use of and may even neglect the affected body area(s), thus maintaining and likely enhancing PRF. These changes form part of an overall maladaptation to chronic pain. To examine fear-related brain circuit alterations in humans, 20 pediatric patients with CRPS and 20 sex- and age-matched healthy controls underwent functional magnetic resonance imaging (fMRI) in response to a well-established fearful faces paradigm. Despite no significant differences on self-reported emotional valence and arousal between the two groups, CRPS patients displayed a diminished response to fearful faces in regions associated with emotional processing compared to healthy controls. Additionally, increased PRF levels were associated with decreased activity in a number of brain regions including the right amygdala, insula, putamen, and caudate. Blunted activation in patients suggests that (a) individuals with chronic pain may have deficits in cognitive-affective brain circuits that may represent an underlying vulnerability or consequence to the chronic pain state; and (b) fear of pain may contribute and/or maintain these brain alterations. Our results shed new light on altered affective circuits in patients with chronic pain and identify PRF as a potentially important treatment target. PMID:26834606

  16. Alteration in cellular acetylcholine influences dauer formation in Caenorhabditis elegans

    OpenAIRE

    Lee, Jeeyong; Kim, Kwang-Youl; Paik, Young-Ki

    2014-01-01

    Altered acetylcholine (Ach) homeostasis is associated with loss of viability in flies, developmental defects in mice, and cognitive deficits in human. Here, we assessed the importance of Ach in Caenorhabditis elegans development, focusing on the role of Ach during dauer formation. We found that dauer formation was disturbed in choline acetyltransferase (cha-1) and acetylcholinesterase (ace) mutants defective in Ach biosynthesis and degradation, respectively. When examined the potential role o...

  17. Modeling Human Perception of Orientation in Altered Gravity

    Directory of Open Access Journals (Sweden)

    Torin K. Clark

    2015-05-01

    Full Text Available Altered gravity environments, such as those experienced by astronauts, impact spatial orientation perception and can lead to spatial disorientation and sensorimotor impairment. To more fully understand and quantify the impact of altered gravity on orientation perception, several mathematical models have been proposed. The utricular shear, tangent, and the idiotropic vector models aim to predict static perception of tilt in hyper-gravity. Predictions from these prior models are compared to the available data, but are found to systematically err from the perceptions experimentally observed. Alternatively, we propose a modified utricular shear model for static tilt perception in hyper-gravity. Previous dynamic models of vestibular function and orientation perception are limited to 1 G. Specifically, they fail to predict the characteristic overestimation of roll tilt observed in hyper-gravity environments. To address this, we have proposed a modification to a previous observer-type canal otolith interaction model based upon the hypothesis that the central nervous system treats otolith stimulation in the utricular plane differently than stimulation out of the utricular plane. Here we evaluate our modified utricular shear and modified observer models in four altered gravity motion paradigms: a static roll tilt in hyper-gravity, b static pitch tilt in hyper-gravity, c static roll tilt in hypo-gravity, and d static pitch tilt in hypo-gravity. The modified models match available data in each of the conditions considered. Our static modified utricular shear model and dynamic modified observer model may be used to help quantitatively predict astronaut perception of orientation in altered gravity environments.

  18. Age-dependent alterations of decorin glycosaminoglycans in human skin

    OpenAIRE

    Yong Li; Ying Liu; Wei Xia; Dan Lei; Voorhees, John J.; Fisher, Gary J.

    2013-01-01

    Proteoglycans, a family of glycosaminoglycan (GAG) conjugated proteins, are important constituents of human skin connective tissue (dermis) and are essential for maintaining mechanical strength of the skin. Age-related alterations of dermal proteoglycans have not been fully elucidated. We quantified transcripts of 20 known interstitial proteoglycans in human skin and found that decorin was the most highly expressed. Decorin was predominantly produced by dermal fibroblasts. Decorin was localiz...

  19. Alterations in the laryngeal mucosa after exposure to asbestos.

    OpenAIRE

    Kambic, V; Radsel, Z; Gale, N

    1989-01-01

    The laryngeal mucosa of 195 workers in an asbestos cement factory (Salonit Anhovo, Yugoslavia) and in a control group was examined. The factory manufactures asbestos cement products containing about 13% of asbestos (8% amosite, 12% crocidolite, and 80% chrysotile) of different provenance. Alterations in the laryngeal mucosa were more frequent in the factory workers than in the control group. The changes, mostly consistent with chronic laryngitis, were closely related to the degree of workplac...

  20. Cerebral Metabolic Alterations in Rats With Diabetic Ketoacidosis

    OpenAIRE

    Glaser, Nicole; Yuen, Natalie; Anderson, Steven E; Tancredi, Daniel J.; O'Donnell, Martha E.

    2009-01-01

    OBJECTIVE Cerebral edema is a life-threatening complication of diabetic ketoacidosis (DKA) in children. Recent data suggest that cerebral hypoperfusion and activation of cerebral ion transporters may be involved, but data describing cerebral metabolic alterations during DKA are lacking. RESEARCH DESIGN AND METHODS We evaluated 50 juvenile rats with DKA and 21 normal control rats using proton and phosphorus magnetic resonance spectroscopy (MRS). MRS measured cerebral intracellular pH and ratio...

  1. VIDEOFLUOROSCOPIC SWALLOWING STUDY: esophageal alterations in patients with dysphagia

    Directory of Open Access Journals (Sweden)

    Betina SCHEEREN

    2014-09-01

    Full Text Available Context Videofluoroscopic swallowing study is a dynamic exam and allows the evaluation of the complete swallowing process. However, most published studies have only reported alterations in the oropharynx and pharyngoesophageal transition, leaving the analysis of the esophagus as a secondary goal. Objectives The goal of this study was to investigate the prevalence of alterations in the esophageal phase thorough videofluoroscopic swallowing study in patients with dysphagia. Methods Consecutive patients with dysphagia who underwent videofluoroscopic swallowing study including esophageal analysis between May 2010 and May 2012 had their exams retrospectively reviewed. Patients were classified into two groups: Group I - without a pre-established etiological diagnosis and Group II - with neurological disease. During the exam, the patients ingested three different consistencies of food (liquid, pasty and solid contrasted with barium sulfate and 19 items were analyzed according to a protocol. The esophageal phase was considered abnormal when one of the evaluated items was compromised. Results Three hundred and thirty-three (n = 333 consecutive patients were studied - 213 (64% in Group I and 120 (36% in Group II. Esophageal alterations were found in 104 (31% patients, with a higher prevalence in Group I (36.2%, especially on the items esophageal clearance (16.9% and tertiary contractions (16.4%. It was observed that 12% of individuals in Group I only presented alterations on the esophageal phase. Conclusion Evaluation of the esophageal phase of swallowing during videofluoroscopic swallowing study detects abnormalities in patients with cervical dysphagia, especially in the group without pre-established etiological diagnosis.

  2. Catching Power: Race, Altered Solidarities, and Science in Trinidad

    OpenAIRE

    Crosson, J. Brent

    2014-01-01

    In Trinidad, "catching power" indexes the embodiment of other-than-human force, a cultivated practice that anthropologists have typically referred to as "spirit possession." This dissertation examines how "catching power" recursively transforms social scientific theories of power, and how practices codified as illicit superstition, but called science by practitioners, alter the limits of the authoritative categories of modern rationalization. For more than two centuries, colonial and postco...

  3. Diet rapidly and reproducibly alters the human gut microbiome

    OpenAIRE

    David, Lawrence A; Maurice, Corinne F; Carmody, Rachel N.; Gootenberg, David B.; Button, Julie E.; Wolfe, Benjamin E.; Ling, Alisha V.; Devlin, A. Sloan; Varma, Yug; Fischbach, Michael A.; Biddinger, Sudha B.; Dutton, Rachel J.; Turnbaugh, Peter J.

    2013-01-01

    Long-term diet influences the structure and activity of the trillions of microorganisms residing in the human gut 1–5 , but it remains unclear how rapidly and reproducibly the human gut microbiome responds to short-term macronutrient change. Here, we show that the short-term consumption of diets composed entirely of animal or plant products alters microbial community structure and overwhelms inter-individual differences in microbial gene expression. The animal-based diet increased the abundan...

  4. Alteration in global motor strategy following lateral ankle sprain

    OpenAIRE

    Bastien, Maude; Moffet, Hélène; Bouyer, Laurent J; Perron, Marc; Hébert, Luc J; Leblond, Jean

    2014-01-01

    Background Lateral ankle sprain (LAS) has often been considered an injury leading to localized joint impairments affecting the musculoskeletal system. Persistent chronic ankle instability and bilateral alterations in motor control after a first ankle sprain episode suggest that the origin of relapses might be a maladaptive reorganization of central motor commands. The objectives of this study were (1) to compare the quality of motor control through motor strategy variables of two groups (with...

  5. Effect of radiation on reconstitution of skin equivalent (dermal alterations)

    International Nuclear Information System (INIS)

    Dermal equivalents have been treated by single doses of gamma irradiation of 10, 20, 30 and 50 Gray. Numerations at different times show a dose and time dependant diminution of cellular population. This diminution is histologically observed in dermal part of reconstituted skin, in association with cellular and functional alterations of fibroblast cells. Modifications of epidermal epithelia are also noted in some reconstituted skin. This model would be useful to apprehend the effect of a dermal irradiation lesion on the later epidermization. (author)

  6. Stability of the gel formed during nuclear glass alteration

    International Nuclear Information System (INIS)

    This thesis is divided in two parts. The first part is dedicated to the study of the protective properties of the gels formed during the alteration of nuclear glass and the second part the stability of these gels after drying and the effect of the sulfate ions are studied. The protective properties of the gel of SON68 glass are assessed at different alteration progress and related to their morphology analyzed by X-ray reflectometry and gas adsorption. Initially a depleted glass layer is obtained, followed by the formation of a gel with an open porosity. Subsequently the gel densifies as the glass alteration rate decreases and finally the pore size increases upon the formation of a dense and thin zone within the film on the glass surface. The increase of the gradient density zone could explain the increase of the protective properties of the gel. A high reaction progress, when the thin and dense zone within the gel is formed, the protective properties are constant. Various simplified glasses are also studied. At high reaction progress there is a dense zone within the gel. The location of this zone depends on the glass composition which control the competition between the species diffusion in solution and their recondensation. The gel morphology, the protective properties, its stability and the glass composition are correlated. The drying induces some modifications of the morphology of the SON68 glass alteration layer (density, thickness and porosity) and of the mechanical properties (cracks, adhesion on glass). For protective gels these modifications are limited and don't raise the protective properties of the gel. The effect of the sulfate ions in a closed system is essentially to complex calcium. For sulfate ions concentrations in geological repository, the stability of the gel is not raised. (author)

  7. Vascular transcriptional alterations produced by juvenile obesity in Ossabaw swine

    OpenAIRE

    Padilla, Jaume; Jenkins, Nathan T.; Lee, Sewon; Zhang, Hanrui; Cui, Jian; Zuidema, Mozow Y.; Zhang, Cuihua; Hill, Michael A; Perfield, James W.; Jamal A. Ibdah; Booth, Frank W.; Davis, J Wade; Laughlin, M. Harold; Rector, R. Scott

    2013-01-01

    We adopted a transcriptome-wide microarray analysis approach to determine the extent to which vascular gene expression is altered as a result of juvenile obesity and identify obesity-responsive mRNAs. We examined transcriptional profiles in the left anterior descending coronary artery (LAD), perivascular fat adjacent to the LAD, and descending thoracic aorta between obese (n = 5) and lean (n = 6) juvenile Ossabaw pigs (age = 22 wk). Obesity was experimentally induced by feeding the animals a ...

  8. The nose and altered states of consciousness: Tascodrugites and Ezekiel

    OpenAIRE

    John J. Pilch

    2002-01-01

    The Church Father Epiphanius' description of the Tascodrugite practice of placing the forefinger on the nostril during prayer call be plausibly interpreted as a strategy for inducing an altered state of consciousness (ASC). Anthropological and neurophysiological research on how this human gesture achieves such an effect which is a pan-human potential suggests a similar plausible interpretation for Ezekiel 8:17 and the experience of Jesus in the Garden on the night of his arrest (Luke 22:43-44).

  9. Repeated Raking of Pine Plantations Alters Soil Arthropod Communities

    OpenAIRE

    Holly K. Ober; Lucas W. DeGroote

    2014-01-01

    Terrestrial arthropods in forests are engaged in vital ecosystem functions that ultimately help maintain soil productivity. Repeated disturbance can cause abrupt and irreversible changes in arthropod community composition and thereby alter trophic interactions among soil fauna. An increasingly popular means of generating income from pine plantations in the Southeastern U.S. is annual raking to collect pine litter. We raked litter once per year for three consecutive years in the pine plantatio...

  10. Ultrastructural alterations in skeletal muscle fibers of rats after exercise

    Science.gov (United States)

    Akuzawa, M.; Hataya, M.

    1982-01-01

    Ultrastructural alterations in skeletal muscle fibers were electron microscopically studied in rats forced to run on the treadmill until all-out. When they were mild and limited to relatively small areas, the reconstruction of filaments ensued within 10 days without infiltration of cells. When they were severe and extensive, phagocytes infiltrated in the lesions and removed degenerative sacroplasmic debris from muscle fibers. A little later, myoblasts appeared and regeneration was accomplished in 30 days in much the same manner as in myogenesis.

  11. Altered calcium metabolism in aging CA1 hippocampal pyramidal neurons

    OpenAIRE

    Oh, M. Matthew; Oliveira, Fernando A.; Waters, Jack; Disterhoft, John F.

    2013-01-01

    Altered neuronal calcium homeostasis is widely hypothesized to underlie cognitive deficits in normal aging subjects, but the mechanisms that underlie this change are unknown, possibly due to a paucity of direct measurements from aging neurons. Using CCD and two-photon calcium imaging techniques on CA1 pyramidal neurons from young and aged rats, we show that calcium influx across the plasma membrane increases with aging, and that this change is countered by increased intracellular calcium buff...

  12. Fish extinctions alter nutrient recycling in tropical freshwaters

    OpenAIRE

    McIntyre, Peter B; Jones, Laura E.; Flecker, Alexander S.; Vanni, Michael J.

    2007-01-01

    There is increasing evidence that species extinctions jeopardize the functioning of ecosystems. Overfishing and other human influences are reducing the diversity and abundance of fish worldwide, but the ecosystem-level consequences of these changes have not been assessed quantitatively. Recycling of nutrients is one important ecosystem process that is directly influenced by fish. Fish species vary widely in the rates at which they excrete nitrogen and phosphorus; thus, altering fish communiti...

  13. Computertomographische Darstellung der Prostata bei Rüden unterschiedlichen Alters

    OpenAIRE

    Schulze, Sabine

    2013-01-01

    In der Literatur ist in einigen Studien die computertomographischen Darstellung der caninen Prostata beschrieben, jedoch fehlen bis dato ausführliche Daten zur Auswertung dieser Untersuchungen. Mit Hilfe dieser Arbeit sollen in erster Linie methodische Fragestellungen der computertomographischen Darstellung der Prostata beantwortet werden. Es wurde bei insgesamt 50 unkastrierten Rüden mit einem Alter über zwei Jahren die Prostata computertomographisch untersucht. Zudem wurde bei allen Hun...

  14. Radiation-induced motility alterations in medulloblastoma cells

    OpenAIRE

    Rieken, Stefan; Rieber, Juliane; Brons, Stephan; Habermehl, Daniel; Rief, Harald; Orschiedt, Lena; Lindel, Katja; Klaus J. Weber; Debus, Jürgen; Combs, Stephanie E

    2015-01-01

    Photon irradiation has been repeatedly suspected of increasing tumor cell motility and promoting locoregional recurrence of disease. This study was set up to analyse possible mechanisms underlying the potentially radiation-altered motility in medulloblastoma cells. Medulloblastoma cell lines D425 and Med8A were analyzed in migration and adhesion experiments with and without photon and carbon ion irradiation. Expression of integrins was determined by quantitative FACS analysis. Matrix metallop...

  15. Ultrastructural alterations in adult Schistosoma mansoni caused by artemether

    OpenAIRE

    Xiao Shuhua; Shen Binggui; Utzinger Jürg; Chollet Jacques; Tanner Marcel

    2002-01-01

    Progress has been made over the last decade with the development and clinical use of artemether as an agent against major human schistosome parasites. The tegument has been identified as a key target of artemether, implying detailed studies on ultrastructural damage induced by this compound. We performed a temporal examination, employing a transmission electron microscope to assess the pattern and extent of ultrastructural alterations in adult Schistosoma mansoni harboured in mice treated wit...

  16. Metabolic Alterations Associated to Brain Dysfunction in Diabetes

    OpenAIRE

    João M N Duarte

    2015-01-01

    From epidemiological studies it is known that diabetes patients display increased risk of developing dementia. Moreover, cognitive impairment and Alzheimer’s disease (AD) are also accompanied by impaired glucose homeostasis and insulin signalling. Although there is plenty of evidence for a connection between insulin-resistant diabetes and AD, definitive linking mechanisms remain elusive. Cerebrovascular complications of diabetes, alterations in glucose homeostasis and insulin signalling, as w...

  17. A streptavidin mutant with altered ligand-binding specificity

    OpenAIRE

    Reznik, Gabriel O.; Vajda, Sandor; Sano, Takeshi; Cantor, Charles R.

    1998-01-01

    The biotin-binding site of streptavidin was modified to alter its ligand-binding specificity. In natural streptavidin, the side chains of N23 and S27 make two of the three hydrogen bonds with the ureido oxygen of biotin. These two residues were mutated to severely weaken biotin binding while attempting to maintain the affinity for two biotin analogs, 2-iminobiotin and diaminobiotin. Redesigning of the biotin-binding site used the difference in local electrostatic charge distribution between b...

  18. Biofilm growth alters regulation of conjugation by a bacterial pheromone

    OpenAIRE

    Cook, Laura; Barnes, Aaron; Dunny, Gary; Chatterjee, Anushree; Hu, Wei-Shou; Yarwood, Jeremy

    2011-01-01

    Conjugation is an important mode of horizontal gene transfer in bacteria, enhancing the spread of antibiotic resistance. In clinical settings, biofilms are likely locations for antibiotic resistance transfer events involving nosocomial pathogens such as Enterococcus faecalis. Here we demonstrate that growth in biofilms alters the induction of conjugation by a sex pheromone in E. faecalis. Mathematical modeling suggested that a higher plasmid copy number in biofilm cells would enhance a switch...

  19. Adolescent social defeat alters markers of adult dopaminergic function

    OpenAIRE

    Novick, Andrew M.; Forster, Gina L.; Tejani-Butt, Shanaz M.; Watt, Michael J.

    2011-01-01

    Stressful experiences during adolescence can alter the trajectory of neural development and contribute to psychiatric disorders in adulthood. We previously demonstrated that adolescent male rats exposed to repeated social defeat stress show changes in mesocorticolimbic dopamine content both at baseline and in response to amphetamine when tested in adulthood. In the present study we examined whether markers of adult dopamine function are also compromised by adolescent experience of social defe...

  20. Warming Can Boost Denitrification Disproportionately Due to Altered Oxygen Dynamics

    OpenAIRE

    2011-01-01

    Background Global warming and the alteration of the global nitrogen cycle are major anthropogenic threats to the environment. Denitrification, the biological conversion of nitrate to gaseous nitrogen, removes a substantial fraction of the nitrogen from aquatic ecosystems, and can therefore help to reduce eutrophication effects. However, potential responses of denitrification to warming are poorly understood. Although several studies have reported increased denitrification rates with rising te...

  1. Warming can boost denitrification disproportionately due to altered oxygen dynamics

    OpenAIRE

    Veraart, A.J.; Klein,, J.; M. Scheffer

    2011-01-01

    Background - Global warming and the alteration of the global nitrogen cycle are major anthropogenic threats to the environment. Denitrification, the biological conversion of nitrate to gaseous nitrogen, removes a substantial fraction of the nitrogen from aquatic ecosystems, and can therefore help to reduce eutrophication effects. However, potential responses of denitrification to warming are poorly understood. Although several studies have reported increased denitrification rates with rising ...

  2. Soil animals alter plant litter diversity effects on decomposition

    OpenAIRE

    Hättenschwiler, Stephan; Gasser, Patrick

    2005-01-01

    Most of the terrestrial net primary production enters the decomposer system as dead organic matter, and the subsequent recycling of C and nutrients are key processes for the functioning of ecosystems and the delivery of ecosystem goods and services. Although climatic and substrate quality controls are reasonably well understood, the functional role of biodiversity for biogeochemical cycles remains elusive. Here we ask how altering litter species diversity affects species-specific decompositio...

  3. Altered Endosome Biogenesis in Prostate Cancer has Biomarker Potential

    OpenAIRE

    Johnson, Ian R D; Parkinson-Lawrence, Emma J.; Shandala, Tetyana; Weigert, Roberto; Lisa M Butler; Brooks, Doug A.

    2014-01-01

    Prostate cancer is the second most common form of cancer in males, affecting one in eight men by the time they reach the age of 70. Current diagnostic tests for prostate cancer have significant problems with both false negatives and false positives, necessitating the search for new molecular markers. A recent investigation of endosomal and lysosomal proteins revealed that the critical process of endosomal biogenesis might be altered in prostate cancer. Here, a panel of endosomal markers was e...

  4. Conditions for Resilient Operations of Complex Systems Undergoing Technological Alterations

    OpenAIRE

    Tveiten, Camilla Knudsen

    2014-01-01

    Technological alterations are ongoing in many areas, also in high-risk industries. The petroleum production industry in Norway is going through a technologicallydriven transition period named “Integrated Operations” (IO). The transition includes changes in sensor technology that increase the amount of data provided for important decisions, information and communication technology that enable the remote operation of offshore fields and distributed organizations, and possibilities for operation...

  5. Germline CDKN2A/ARF alterations in human melanoma

    OpenAIRE

    Hashemi, Jamileh

    2002-01-01

    Approximately 10% of cases of human cutaneous malignant melanoma (CMM) have been estimated to occur in individuals with a familial predisposition, frequently in association with dysplastic nevus syndrome (DNS). The genetics of familial melanoma is complex and heterogeneous. To date only two melanoma predisposing genes have been identified. The CDKN2A/ARF locus on human chromosome 9p21 encodes two distinct cell cycle regulatory proteins, p16 and p14ARF. Germline alterations i...

  6. Prenatal corticosteroid exposure alters early developmental seizures and behavior

    OpenAIRE

    Velíšek, Libor

    2011-01-01

    In humans, corticosteroids are often administered prenatally to improve lung development in preterm neonates. Studies in exposed children as well as in children, whose mothers experienced significant stress during pregnancy indicate behavioral problems and possible increased occurrence of epileptic spasms. This study investigated whether prenatal corticosteroid exposure alters early postnatal seizure susceptibility and behaviors. On gestational day 15, pregnant rats were injected i.p. with hy...

  7. Chromatic alteration on marble surfaces analysed by molecular biology tools

    OpenAIRE

    Franco Palla; Elena Tartamella

    2007-01-01

    The patina represents a superficial natural alteration of the constituting matter of the work of art. It emerges from the natural and usual stabilization process that the materials of the surface undergo because of the interaction with outdoor agents characterizing the surrounding environment. Besides, it is not linked to an obvious phenomenon of degradation that can be noticed through the change in the original colour of the matter. This is what we intend when we talk about biological patina...

  8. Oral Dryness, Dietary Intake, and Alterations in Taste

    DEFF Research Database (Denmark)

    Dynesen, Anja Weirsøe

    2015-01-01

    Xerostomia and decreased salivary secretion may give rise to a number of oral complications. These include dry, atrophic and tender oral mucosa; impaired mastication, food bolus formation, and swallowing; altered sensation of taste; as well as increased risk of developing dental caries and erosion...... mouth patients should draw attention to the impact of an unbalanced diet on salivary secretion and emphasize that oral dryness may have a negative impact on food consumption....

  9. Altered Affective Response in Marijuana Smokers: An FMRI Study

    OpenAIRE

    Gruber, Staci A.; Rogowska, Jadwiga; Yurgelun-Todd, Deborah A

    2009-01-01

    More than 94 million Americans have tried marijuana, and it remains the most widely used illicit drug in the nation. Investigations of the cognitive effects of marijuana report alterations in brain function during tasks requiring executive control, including inhibition and decision-making. Endogenous cannabinoids regulate a variety of emotional responses, including anxiety, mood control, and aggression; nevertheless, little is known about smokers’ responses to affective stimuli. The anterior ...

  10. Contribution of altered signal transduction associated to glutamate receptors in brain to the neurological alterations of hepatic encephalopathy

    Institute of Scientific and Technical Information of China (English)

    Vicente Felipo

    2006-01-01

    Patients with liver disease may present hepatic encephalopathy (HE), a complex neuropsychiatric syndrome covering a wide range of neurological alterations,including cognitive and motor disturbances. HE reduces the quality of life of the patients and is associated with poor prognosis. In the worse cases HE may lead to coma or death.The mechanisms leading to HE which are not well known are being studied using animal models. The neurological alterations in HE are a consequence of impaired cerebral function mainly due to alterations in neurotransmission. We review here some studies indicating that alterations in neurotransmission associated to different types of glutamate receptors are responsible for some of the cognitive and motor alterations present in HE.These studies show that the function of the signal transduction pathway glutamate-nitric oxide-cGMP associated to the NMDA type of glutamate receptors is impaired in brain in vivo in HE animal models as well as in brain of patients died of HE. Activation of NMDA receptors in brain activates this pathway and increases cGMP. In animal models of HE this increase in cGMP induced by activation of NMDA receptors is reduced,which is responsible for the impairment in learning ability in these animal models. Increasing cGMP by pharmacological means restores learning ability in rats with HE and may be a new therapeutic approach to improve cognitive function in patients with HE.However, it is necessary to previously assess the possible secondary effects.Patients with HE may present psychomotor slowing,hypokinesia and bradykinesia. Animal models of HE also show hypolocomotion. It has been shown in rats with HE that hypolocomotion is due to excessive activation of metabotropic glutamate receptors (mGluRs) in substantia nigra pars reticulata. Blocking mGluR1 in this brain area normalizes motor activity in the rats, suggesting that a similar treatment for patients with HE could be useful to treat psychomotor slowing and

  11. Contribution of altered signal transduction associated to glutamate receptors in brain to the neurological alterations of hepatic encephalopathy

    Science.gov (United States)

    Felipo, Vicente

    2006-01-01

    Patients with liver disease may present hepatic enceph-alopathy (HE), a complex neuropsychiatric syndrome covering a wide range of neurological alterations, including cognitive and motor disturbances. HE reduces the quality of life of the patients and is associated with poor prognosis. In the worse cases HE may lead to coma or death. The mechanisms leading to HE which are not well known are being studied using animal models. The neurological alterations in HE are a consequence of impaired cerebral function mainly due to alterations in neurotransmission. We review here some studies indicating that alterations in neurotransmission associated to different types of glutamate receptors are responsible for some of the cognitive and motor alterations present in HE. These studies show that the function of the signal transduction pathway glutamate-nitric oxide-cGMP associated to the NMDA type of glutamate receptors is impaired in brain in vivo in HE animal models as well as in brain of patients died of HE. Activation of NMDA receptors in brain activates this pathway and increases cGMP. In animal models of HE this increase in cGMP induced by activation of NMDA receptors is reduced, which is responsible for the impairment in learning ability in these animal models. Increasing cGMP by pharmacological means restores learning ability in rats with HE and may be a new therapeutic approach to improve cognitive function in patients with HE. However, it is necessary to previously assess the possible secondary effects. Patients with HE may present psychomotor slowing, hypokinesia and bradykinesia. Animal models of HE also show hypolocomotion. It has been shown in rats with HE that hypolocomotion is due to excessive activation of metabotropic glutamate receptors (mGluRs) in substantia nigra pars reticulata. Blocking mGluR1 in this brain area normalizes motor activity in the rats, suggesting that a similar treatment for patients with HE could be useful to treat psychomotor slowing and

  12. Altered striatal intrinsic functional connectivity in pediatric anxiety.

    Science.gov (United States)

    Dorfman, Julia; Benson, Brenda; Farber, Madeline; Pine, Daniel; Ernst, Monique

    2016-05-01

    Anxiety disorders are among the most common psychiatric disorders of adolescence. Behavioral and task-based imaging studies implicate altered reward system function, including striatal dysfunction, in adolescent anxiety. However, no study has yet examined alterations of the striatal intrinsic functional connectivity in adolescent anxiety disorders. The current study examines striatal intrinsic functional connectivity (iFC), using six bilateral striatal seeds, among 35 adolescents with anxiety disorders and 36 healthy comparisons. Anxiety is associated with abnormally low iFC within the striatum (e.g., between nucleus accumbens and caudate nucleus), and between the striatum and prefrontal regions, including subgenual anterior cingulate cortex, posterior insula and supplementary motor area. The current findings extend prior behavioral and task-based imaging research, and provide novel data implicating decreased striatal iFC in adolescent anxiety. Alterations of striatal neurocircuitry identified in this study may contribute to the perturbations in the processing of motivational, emotional, interoceptive, and motor information seen in pediatric anxiety disorders. This pattern of the striatal iFC perturbations can guide future research on specific mechanisms underlying anxiety. PMID:27004799

  13. Low Reynolds Number Drag Alteration Inspired by Butterfly Scales

    Science.gov (United States)

    Laforte, Brent; Kronenberger, Courtney; Lang, Amy

    2012-11-01

    Biomimetics is the process of looking towards nature's adaptations for answers to today's engineering obstacles. An age-old engineering dilemma is trying to find new methods to reduce the amount of drag over a body. This research finds inspiration from butterfly scales which are hypothesized to alter surface friction over the wings. Drop testing was performed on axisymmetric, streamlined, teardrop models which were rapid-prototyped such that the surface was covered with either streamwise or transverse cavities modeled after the Monarch butterfly. The drop tank contained silicone oil with a viscosity two hundred times that of water insuring flow similarity between the model cavities (2.5 mm cavity depth) and the butterfly scale structures (about 30 microns cavity depth). A variation in Reynolds number was achieved by altering the model weight such that terminal speeds ranged from 5 to 70 cm/s. Results showed a reduction in surface friction for the transverse cavity configurations based on the roller-bearing effect. These findings suggest that the cavity shape and ratio is directly correlated to the amount of drag alteration. Funded by NSF REU grant 1062611.

  14. Tendon Extracellular Matrix Alterations in Ullrich Congenital Muscular Dystrophy

    Science.gov (United States)

    Sardone, Francesca; Traina, Francesco; Bondi, Alice; Merlini, Luciano; Santi, Spartaco; Maraldi, Nadir Mario; Faldini, Cesare; Sabatelli, Patrizia

    2016-01-01

    Collagen VI (COLVI) is a non-fibrillar collagen expressed in skeletal muscle and most connective tissues. Mutations in COLVI genes cause two major clinical forms, Bethlem myopathy and Ullrich congenital muscular dystrophy (UCMD). In addition to congenital muscle weakness, patients affected by COLVI myopathies show axial and proximal joint contractures and distal joint hypermobility, which suggest the involvement of the tendon function. We examined a peroneal tendon biopsy and tenocyte culture of a 15-year-old patient affected by UCMD with compound heterozygous COL6A2 mutations. In patient’s tendon biopsy, we found striking morphological alterations of tendon fibrils, consisting in irregular profiles and reduced mean diameter. The organization of the pericellular matrix of tenocytes, the primary site of collagen fibril assembly, was severely affected, as determined by immunoelectron microscopy, which showed an abnormal accumulation of COLVI and altered distribution of collagen I (COLI) and fibronectin (FBN). In patient’s tenocyte culture, COLVI web formation and cell surface association were severely impaired; large aggregates of COLVI, which matched with COLI labeling, were frequently detected in the extracellular matrix. In addition, metalloproteinase MMP-2, an extracellular matrix-regulating enzyme, was increased in the conditioned medium of patient’s tenocytes, as determined by gelatin zymography and western blot. Altogether, these data indicate that COLVI deficiency may influence the organization of UCMD tendon matrix, resulting in dysfunctional fibrillogenesis. The alterations of tendon matrix may contribute to the complex pathogenesis of COLVI related myopathies. PMID:27375477

  15. Limb neurovascular control during altered otolithic input in humans

    Science.gov (United States)

    Monahan, Kevin D.; Ray, Chester A.

    2002-01-01

    Head-down rotation (HDR), which activates the vestibulosympathetic reflex, increases leg muscle sympathetic nerve activity (MSNA) and produces calf vasoconstriction with no change in either cardiac output or arterial blood pressure. Based on animal studies, it was hypothesized that differential control of arm and leg MSNA explains why HDR does not alter arterial blood pressure. Fifteen healthy subjects were studied. Heart rate, arterial blood pressure, forearm and calf blood flow, and leg MSNA responses were measured during HDR in these subjects. Simultaneous recordings of arm and leg MSNA were obtained from five of the subjects. Forearm and calf blood flow, vascular conductances, and vascular resistances were similar before HDR, as were arm and leg MSNA. HDR elicited similar significant increases in leg (Delta 6 +/- 1 bursts min(-1); 59 +/- 16 % from baseline) and arm MSNA (Delta 5 +/- 1 bursts min(-1); 80 +/- 28 % from baseline). HDR significantly decreased calf (-19 +/- 2 %) and forearm vascular conductance (-12 +/- 2 %) and significantly increased calf (25 +/- 4 %) and forearm vascular resistance (15 +/- 2 %), with 60 % greater vasoconstriction in the calf than in the forearm. Arterial blood pressure and heart rate were not altered by HDR. These results indicate that there is no differential control of MSNA in the arm and leg during altered feedback from the otolith organs in humans, but that greater vasoconstriction occurs in the calf than in the forearm. These findings indicate that vasodilatation occurs in other vascular bed(s) to account for the lack of increase in arterial blood pressure during HDR.

  16. Chemical and Mechanical Alteration of Fractured Caprock Under Reactive Flow

    Science.gov (United States)

    Elkhoury, J. E.; Ameli, P.; Detwiler, R. L.

    2013-12-01

    Permeability evolution of fractures depends on chemical and mechanical processes. Stress perturbations lead to mechanical deformation and fracture propagation that can increase formation permeability. Chemical disequilibrium between fluids and resident minerals leads to dissolution and precipitation that further alter fracture porosity and permeability. The ability to predict whether these coupled chemical and mechanical processes will enhance or diminish fracture permeability remains elusive. Here, we present results from reactive-transport experiments in fractured anhydrite cores, with significant alteration of the rock matrix, where only the flow rate differed. For high flow rate, the transformation of anhydrite to gypsum occurred uniformly within the fracture leading to compaction and a two-order-of-magnitude decrease in permeability. For low flow rate, rock-fluid reactions proceeded to near equilibrium within the fracture with preferential flow paths persisting over the 6-month duration of the experiment and a negligible change in permeability. Anticipating such permeability evolution is critical for successful geologic CO2 sequestration and waste injection. Additionally, reactive alteration of the porous matrix bounding fractures will influence the strength of earthquake fault zones. Comparison of the aperture field before (a) and after (b) the reactive flow-through experiment at low flow rate. a) Aperture field from optical profilometry measurements of the fracture surfaces. b) Inferred aperture from x-ray computed tomography scans. Color scale I (blue) denotes mainly unaltered regions of the fracture and/or aperture 200 μm) leading to negligible change in permeability after a 6-month run.

  17. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

    1989-06-01

    The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of (/sup 3/H)Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in (14C)iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress (an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures), although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results.

  18. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

    International Nuclear Information System (INIS)

    The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of [3H]Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in [14C]iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress [an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures], although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results

  19. Altering the course of schizophrenia: progress and perspectives.

    Science.gov (United States)

    Millan, Mark J; Andrieux, Annie; Bartzokis, George; Cadenhead, Kristin; Dazzan, Paola; Fusar-Poli, Paolo; Gallinat, Jürgen; Giedd, Jay; Grayson, Dennis R; Heinrichs, Markus; Kahn, René; Krebs, Marie-Odile; Leboyer, Marion; Lewis, David; Marin, Oscar; Marin, Philippe; Meyer-Lindenberg, Andreas; McGorry, Patrick; McGuire, Philip; Owen, Michael J; Patterson, Paul; Sawa, Akira; Spedding, Michael; Uhlhaas, Peter; Vaccarino, Flora; Wahlestedt, Claes; Weinberger, Daniel

    2016-07-01

    Despite a lack of recent progress in the treatment of schizophrenia, our understanding of its genetic and environmental causes has considerably improved, and their relationship to aberrant patterns of neurodevelopment has become clearer. This raises the possibility that 'disease-modifying' strategies could alter the course to - and of - this debilitating disorder, rather than simply alleviating symptoms. A promising window for course-altering intervention is around the time of the first episode of psychosis, especially in young people at risk of transition to schizophrenia. Indeed, studies performed in both individuals at risk of developing schizophrenia and rodent models for schizophrenia suggest that pre-diagnostic pharmacotherapy and psychosocial or cognitive-behavioural interventions can delay or moderate the emergence of psychosis. Of particular interest are 'hybrid' strategies that both relieve presenting symptoms and reduce the risk of transition to schizophrenia or another psychiatric disorder. This Review aims to provide a broad-based consideration of the challenges and opportunities inherent in efforts to alter the course of schizophrenia. PMID:26939910

  20. Produced water exposure alters bacterial response to biocides.

    Science.gov (United States)

    Vikram, Amit; Lipus, Daniel; Bibby, Kyle

    2014-11-01

    Microbial activity during the holding and reuse of wastewater from hydraulic fracturing operations, termed produced water, may lead to issues with corrosion, sulfide release, and fouling. Biocides are applied to control biological activity, often with limited efficacy, which is typically attributed to chemical interactions with the produced water. However, it is unknown whether there is a biologically driven mechanism to biocide tolerance in produced water. Here, we demonstrate that produced water exposure results in an enhanced tolerance against the typically used biocide glutaraldehyde and increased susceptibility to the oxidative biocide hypochlorite in a native and a model bacteria and that this altered resistance is due to the salinity of the produced water. In addition, we elucidate the genetic response of the model organism Pseudomonas fluorescens to produced water exposure to provide a mechanistic interpretation of the altered biocide resistance. The RNA-seq data demonstrated the induction of genes involved in osmotic stress, energy production and conversion, membrane integrity, and protein transport following produced water exposure, which facilitates bacterial survival and alters biocide tolerance. Efforts to fundamentally understand biocide resistance mechanisms, which enable the optimization of biocide application, hold significant implications for greening of the fracturing process through encouraging produced water recycling. Specifically, these results suggest the necessity of optimizing biocide application at the level of individual shale plays, rather than historical experience, based upon produced water characteristics and salinity. PMID:25279933

  1. Making and monitoring errors based on altered auditory feedback

    Directory of Open Access Journals (Sweden)

    Peter ePfordresher

    2014-08-01

    Full Text Available Previous research has demonstrated that altered auditory feedback (AAF disrupts music performance and causes disruptions in both action planning and the perception of feedback events. It has been proposed that this disruption occurs because of interference within a shared representation for perception and action (Pfordresher, 2006. Studies reported here address this claim from the standpoint of error monitoring. In Experiment 1 participants performed short melodies on a keyboard while hearing no auditory feedback, normal auditory feedback, or alterations to feedback pitch on some subset of events. Participants overestimated error frequency when AAF was present but not for normal feedback. Experiment 2 introduced a concurrent load task to determine whether error monitoring requires executive resources. Although the concurrent task enhanced the effect of AAF, it did not alter participants’ tendency to overestimate errors when AAF was present. A third correlational study addressed whether effects of AAF are reduced for a subset of the population who may lack the kind of perception/action associations that lead to AAF disruption: poor-pitch singers. Effects of manipulations similar to those presented in Experiments 1 and 2 were reduced for these individuals. We propose that these results are consistent with the notion that AAF interference is based on associations between perception and action within a forward internal model of auditory-motor relationships.

  2. Hyperproliferative Hepatocellular Alterations after Intraportal Transplantation of Thyroid Follicles

    Science.gov (United States)

    Dombrowski, Frank; Klotz, Luisa; Hacker, Hans Jörg; Li, Yanhua; Klingmüller, Dietrich; Brix, Klaudia; Herzog, Volker; Bannasch, Peter

    2000-01-01

    The thyroid hormone 3,5,3′-triiodo-l-thyronine (T3) is a strong direct hepatocyte mitogen in vivo. The effects of T3 resemble those of peroxisome proliferators, which are known to induce hepatocellular tumors in rats. With the aim of studying long-term local effects of thyroid hormones on liver parenchyma, small pieces of thyroid tissue were transplanted via the portal veins into the livers of thyroidectomized male Lewis rats. At 1 week, 3 weeks, 3 months, and 18 months after transplantation, the transplants were found to proliferate, to synthesize thyroglobulin, and to release thyroxine and T3. At 3 and 18 months after transplantation, the hepatocytes of the liver acini downstream of the transplanted follicles showed an increase in cytoplasmic basophilia, a loss of glycogen, an enlargement and hyperchromasia of their nuclei, and a strong increase in cell turnover compared with unaltered liver acini. The altered hepatocytes exhibited an increase in the activities of glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, malic enzyme, mitochondrial glycerol-3-phosphate dehydrogenase, cytochrome-c-oxidase, and acid phosphatase; the activities of glycogen synthase and glycogen phosphorylase were strongly decreased. The hepatocytic alterations downstream of the transplanted follicles could be explained by effects of T3. On the other hand, they resembled alterations characteristic of amphophilic preneoplastic liver foci observed in different models of hepatocarcinogenesis. PMID:10623658

  3. Intrinsic Brain Activity in Altered States of Consciousness

    Science.gov (United States)

    Boly, M.; Phillips, C.; Tshibanda, L.; Vanhaudenhuyse, A.; Schabus, M.; Dang-Vu, T.T.; Moonen, G.; Hustinx, R.; Maquet, P.; Laureys, S.

    2010-01-01

    Spontaneous brain activity has recently received increasing interest in the neuroimaging community. However, the value of resting-state studies to a better understanding of brain–behavior relationships has been challenged. That altered states of consciousness are a privileged way to study the relationships between spontaneous brain activity and behavior is proposed, and common resting-state brain activity features observed in various states of altered consciousness are reviewed. Early positron emission tomography studies showed that states of extremely low or high brain activity are often associated with unconsciousness. However, this relationship is not absolute, and the precise link between global brain metabolism and awareness remains yet difficult to assert. In contrast, voxel-based analyses identified a systematic impairment of associative frontoparieto–cingulate areas in altered states of consciousness, such as sleep, anesthesia, coma, vegetative state, epileptic loss of consciousness, and somnambulism. In parallel, recent functional magnetic resonance imaging studies have identified structured patterns of slow neuronal oscillations in the resting human brain. Similar coherent blood oxygen level–dependent (BOLD) systemwide patterns can also be found, in particular in the default-mode network, in several states of unconsciousness, such as coma, anesthesia, and slow-wave sleep. The latter results suggest that slow coherent spontaneous BOLD fluctuations cannot be exclusively a reflection of conscious mental activity, but may reflect default brain connectivity shaping brain areas of most likely interactions in a way that transcends levels of consciousness, and whose functional significance remains largely in the dark. PMID:18591474

  4. Tendon Extracellular Matrix Alterations in Ullrich Congenital Muscular Dystrophy.

    Science.gov (United States)

    Sardone, Francesca; Traina, Francesco; Bondi, Alice; Merlini, Luciano; Santi, Spartaco; Maraldi, Nadir Mario; Faldini, Cesare; Sabatelli, Patrizia

    2016-01-01

    Collagen VI (COLVI) is a non-fibrillar collagen expressed in skeletal muscle and most connective tissues. Mutations in COLVI genes cause two major clinical forms, Bethlem myopathy and Ullrich congenital muscular dystrophy (UCMD). In addition to congenital muscle weakness, patients affected by COLVI myopathies show axial and proximal joint contractures and distal joint hypermobility, which suggest the involvement of the tendon function. We examined a peroneal tendon biopsy and tenocyte culture of a 15-year-old patient affected by UCMD with compound heterozygous COL6A2 mutations. In patient's tendon biopsy, we found striking morphological alterations of tendon fibrils, consisting in irregular profiles and reduced mean diameter. The organization of the pericellular matrix of tenocytes, the primary site of collagen fibril assembly, was severely affected, as determined by immunoelectron microscopy, which showed an abnormal accumulation of COLVI and altered distribution of collagen I (COLI) and fibronectin (FBN). In patient's tenocyte culture, COLVI web formation and cell surface association were severely impaired; large aggregates of COLVI, which matched with COLI labeling, were frequently detected in the extracellular matrix. In addition, metalloproteinase MMP-2, an extracellular matrix-regulating enzyme, was increased in the conditioned medium of patient's tenocytes, as determined by gelatin zymography and western blot. Altogether, these data indicate that COLVI deficiency may influence the organization of UCMD tendon matrix, resulting in dysfunctional fibrillogenesis. The alterations of tendon matrix may contribute to the complex pathogenesis of COLVI related myopathies. PMID:27375477

  5. Aqueous alteration of VHTR fuels particles under simulated geological conditions

    Science.gov (United States)

    Ait Chaou, Abdelouahed; Abdelouas, Abdesselam; Karakurt, Gökhan; Grambow, Bernd

    2014-05-01

    Very High Temperature Reactor (VHTR) fuels consist of the bistructural-isotropic (BISO) or tristructural-isotropic (TRISO)-coated particles embedded in a graphite matrix. Management of the spent fuel generated during VHTR operation would most likely be through deep geological disposal. In this framework we investigated the alteration of BISO (with pyrolytic carbon) and TRISO (with SiC) particles under geological conditions simulated by temperatures of 50 and 90 °C and in the presence of synthetic groundwater. Solid state (scanning electron microscopy (SEM), micro-Raman spectroscopy, electron probe microanalyses (EPMA) and X-ray photoelectron spectroscopy (XPS)) and solution analyses (ICP-MS, ionique chromatography (IC)) showed oxidation of both pyrolytic carbon and SiC at 90 °C. Under air this led to the formation of SiO2 and a clay-like Mg-silicate, while under reducing conditions (H2/N2 atmosphere) SiC and pyrolytic carbon were highly stable after a few months of alteration. At 50 °C, in the presence and absence of air, the alteration of the coatings was minor. In conclusion, due to their high stability in reducing conditions, HTR fuel disposal in reducing deep geological environments may constitute a viable solution for their long-term management.

  6. Ocean acidification causes ecosystem shifts via altered competitive interactions

    Science.gov (United States)

    Kroeker, Kristy J.; Micheli, Fiorenza; Gambi, Maria Cristina

    2013-02-01

    Ocean acidification represents a pervasive environmental change that is predicted to affect a wide range of species, yet our understanding of the emergent ecosystem impacts is very limited. Many studies report detrimental effects of acidification on single species in lab studies, especially those with calcareous shells or skeletons. Observational studies using naturally acidified ecosystems have shown profound shifts away from such calcareous species, and there has been an assumption that direct impacts of acidification on sensitive species drive most ecosystem responses. We tested an alternative hypothesis that species interactions attenuate or amplify the direct effects of acidification on individual species. Here, we show that altered competitive dynamics between calcareous species and fleshy seaweeds drive significant ecosystem shifts in acidified conditions. Although calcareous species recruited and grew at similar rates in ambient and low pH conditions during early successional stages, they were rapidly overgrown by fleshy seaweeds later in succession in low pH conditions. The altered competitive dynamics between calcareous species and fleshy seaweeds is probably the combined result of decreased growth rates of calcareous species, increased growth rates of fleshy seaweeds, and/or altered grazing rates. Phase shifts towards ecosystems dominated by fleshy seaweed are common in many marine ecosystems, and our results suggest that changes in the competitive balance between these groups represent a key leverage point through which the physiological responses of individual species to acidification could indirectly lead to profound ecosystem changes in an acidified ocean.

  7. Chromatic alteration on marble surfaces analysed by molecular biology tools

    Directory of Open Access Journals (Sweden)

    Franco Palla

    2007-07-01

    Full Text Available The patina represents a superficial natural alteration of the constituting matter of the work of art. It emerges from the natural and usual stabilization process that the materials of the surface undergo because of the interaction with outdoor agents characterizing the surrounding environment. Besides, it is not linked to an obvious phenomenon of degradation that can be noticed through the change in the original colour of the matter. This is what we intend when we talk about biological patina usually generated by macro and/or micro-organic colonization (fungi, bacteria, alga which contributes to surface bio-deterioration and thus lead to the formation of orange, red or even brown and dark pigmented areas. The presence of chromatic alterations (rose-coloured areas, as a consequence of bacterial colonization, was most particularly pointed out in different sites, such as in the marble slabs on the facades of both the Cathedral of Siena (Duomo di Siena and the Certosa of Pavia. The present study shows an example of chromatic alteration of the surface of marble works due to bacterial colonization.

  8. Alteration, fracture infills and weathering of the Strath Halladale granite

    International Nuclear Information System (INIS)

    The Strath Halladale Granite has undergone a complex history of faulting, alteration and weathering. The alteration varies from thin ramifying veins and irregular diffuse areas within fresh rock to alteration zones in which all the major phases have been partially or completely replaced. Initial reactions were associated with magmatic fluids which formed pegmatites and aplites within extensional fractures. Introduction of meteoric waters resulted in the formation of a convecting hydrothermal system driven by a magmatic heat energy source. The migrating fluids formed secondary dioctahedral micas and chlorite within the granite, and calcite, siderite, iron sulphide, iron oxides, smectites and quartz within the brittle fractures. Many fractures are shear zones which are infilled by granulated quartz, feldspar and mica. The presence of montmorillonite, the lowest temperature mineral phase, and a preliminary study of stable isotopes indicate temperatures in excess of 100 deg C for migrating alkali-rich fluids. In an assessment of the feasibility of the disposal of high level radioactive waste the ubiquitous presence of montmorillonite, which has a high sorption capacity, is important. (author)

  9. Human activities change marine ecosystems by altering predation risk.

    Science.gov (United States)

    Madin, Elizabeth M P; Dill, Lawrence M; Ridlon, April D; Heithaus, Michael R; Warner, Robert R

    2016-01-01

    In ocean ecosystems, many of the changes in predation risk - both increases and decreases - are human-induced. These changes are occurring at scales ranging from global to local and across variable temporal scales. Indirect, risk-based effects of human activity are known to be important in structuring some terrestrial ecosystems, but these impacts have largely been neglected in oceans. Here, we synthesize existing literature and data to explore multiple lines of evidence that collectively suggest diverse human activities are changing marine ecosystems, including carbon storage capacity, in myriad ways by altering predation risk. We provide novel, compelling evidence that at least one key human activity, overfishing, can lead to distinct, cascading risk effects in natural ecosystems whose magnitude exceeds that of presumed lethal effects and may account for previously unexplained findings. We further discuss the conservation implications of human-caused indirect risk effects. Finally, we provide a predictive framework for when human alterations of risk in oceans should lead to cascading effects and outline a prospectus for future research. Given the speed and extent with which human activities are altering marine risk landscapes, it is crucial that conservation and management policy considers the indirect effects of these activities in order to increase the likelihood of success and avoid unfortunate surprises. PMID:26448058

  10. Prenatal hyperandrogenism induces alterations that affect liver lipid metabolism.

    Science.gov (United States)

    Abruzzese, Giselle Adriana; Heber, Maria Florencia; Ferreira, Silvana Rocio; Velez, Leandro Martin; Reynoso, Roxana; Pignataro, Omar Pedro; Motta, Alicia Beatriz

    2016-07-01

    Prenatal hyperandrogenism is hypothesized as one of the main factors contributing to the development of polycystic ovary syndrome (PCOS). PCOS patients have high risk of developing fatty liver and steatosis. This study aimed to evaluate the role of prenatal hyperandrogenism in liver lipid metabolism and fatty liver development. Pregnant rats were hyperandrogenized with testosterone. At pubertal age, the prenatally hyperandrogenized (PH) female offspring displayed both ovulatory (PHov) and anovulatory (PHanov) phenotypes that mimic human PCOS features. We evaluated hepatic transferases, liver lipid content, the balance between lipogenesis and fatty acid oxidation pathway, oxidant/antioxidant balance and proinflammatory status. We also evaluated the general metabolic status through growth rate curve, basal glucose and insulin levels, glucose tolerance test, HOMA-IR index and serum lipid profile. Although neither PH group showed signs of liver lipid content, the lipogenesis and fatty oxidation pathways were altered. The PH groups also showed impaired oxidant/antioxidant balance, a decrease in the proinflammatory pathway (measured by prostaglandin E2 and cyclooxygenase-2 levels), decreased glucose tolerance, imbalance of circulating lipids and increased risk of metabolic syndrome. We conclude that prenatal hyperandrogenism generates both PHov and PHanov phenotypes with signs of liver alterations, imbalance in lipid metabolism and increased risk of developing metabolic syndrome. The anovulatory phenotype showed more alterations in liver lipogenesis and a more impaired balance of insulin and glucose metabolism, being more susceptible to the development of steatosis. PMID:27179108

  11. Epigenetic Alterations Associated with War Trauma and Childhood Maltreatment.

    Science.gov (United States)

    Ramo-Fernández, Laura; Schneider, Anna; Wilker, Sarah; Kolassa, Iris-Tatjana

    2015-10-01

    Survivors of war trauma or childhood maltreatment are at increased risk for trauma-spectrum disorders such as post-traumatic stress disorder (PTSD). In addition, traumatic stress has been associated with alterations in the neuroendocrine and the immune system, enhancing the risk for physical diseases. Traumatic experiences might even affect psychological as well as biological parameters in the next generation, i.e. traumatic stress might have transgenerational effects. This article outlines how epigenetic processes, which represent a pivotal biological mechanism for dynamic adaptation to environmental challenges, might contribute to the explanation of the long-lasting and transgenerational effects of trauma. In particular, epigenetic alterations in genes regulating the hypothalamus-pituitary-adrenal axis as well as the immune system have been observed in survivors of childhood and adult trauma. These changes could result in enduring alterations of the stress response as well as the physical health risk. Furthermore, the effects of parental trauma could be transmitted to the next generation by parental distress and the pre- and postnatal environment, as well as by epigenetic marks transmitted via the germline. While epigenetic research has a high potential of advancing our understanding of the consequences of trauma, the findings have to be interpreted with caution, as epigenetics only represent one piece of a complex puzzle of interacting biological and environmental factors. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26358541

  12. Limb immobilization alters functional electrophysiological parameters of sciatic nerve.

    Science.gov (United States)

    Alves, J S M; Leal-Cardoso, J H; Santos-Júnior, F F U; Carlos, P S; Silva, R C; Lucci, C M; Báo, S N; Ceccatto, V M; Barbosa, R

    2013-08-01

    Immobilization, used in clinical practice to treat traumatologic problems, causes changes in muscle, but it is not known whether changes also occur in nerves. We investigated the effects of immobilization on excitability and compound action potential (CAP) and the ultrastructure of the rat sciatic nerve. Fourteen days after immobilization of the right leg of adult male Wistar rats (n=34), animals were killed and the right sciatic nerve was dissected and mounted in a moist chamber. Nerves were stimulated at a baseline frequency of 0.2 Hz and tested for 2 min at 20, 50, and 100 Hz. Immobilization altered nerve excitability. Rheobase and chronaxy changed from 3.13 ± 0.05 V and 52.31 ± 1.95 µs (control group, n=13) to 2.84 ± 0.06 V and 59.71 ± 2.79 µs (immobilized group, n=15), respectively. Immobilization altered the amplitude of CAP waves and decreased the conduction velocity of the first CAP wave (from 93.63 ± 7.49 to 79.14 ± 5.59 m/s) but not of the second wave. Transmission electron microscopy showed fragmentation of the myelin sheath of the sciatic nerve of immobilized limbs and degeneration of the axon. In conclusion, we demonstrated that long-lasting leg immobilization can induce alterations in nerve function. PMID:23969978

  13. Limb immobilization alters functional electrophysiological parameters of sciatic nerve

    Directory of Open Access Journals (Sweden)

    J.S.M. Alves

    2013-08-01

    Full Text Available Immobilization, used in clinical practice to treat traumatologic problems, causes changes in muscle, but it is not known whether changes also occur in nerves. We investigated the effects of immobilization on excitability and compound action potential (CAP and the ultrastructure of the rat sciatic nerve. Fourteen days after immobilization of the right leg of adult male Wistar rats (n=34, animals were killed and the right sciatic nerve was dissected and mounted in a moist chamber. Nerves were stimulated at a baseline frequency of 0.2 Hz and tested for 2 min at 20, 50, and 100 Hz. Immobilization altered nerve excitability. Rheobase and chronaxy changed from 3.13±0.05 V and 52.31±1.95 µs (control group, n=13 to 2.84±0.06 V and 59.71±2.79 µs (immobilized group, n=15, respectively. Immobilization altered the amplitude of CAP waves and decreased the conduction velocity of the first CAP wave (from 93.63±7.49 to 79.14±5.59 m/s but not of the second wave. Transmission electron microscopy showed fragmentation of the myelin sheath of the sciatic nerve of immobilized limbs and degeneration of the axon. In conclusion, we demonstrated that long-lasting leg immobilization can induce alterations in nerve function.

  14. Data for mitochondrial proteomic alterations in the developing rat brain.

    Science.gov (United States)

    Villeneuve, Lance M; Stauch, Kelly L; Fox, Howard S

    2014-12-01

    Mitochondria are a critical organelle involved in many cellular processes, and due to the nature of the brain, neuronal cells are almost completely reliant on these organelles for energy generation. Due to the fact that biomedical research tends to investigate disease state pathogenesis, one area of mitochondrial research commonly overlooked is homeostatic responses to energy demands. Therefore, to elucidate mitochondrial alterations occurring during the developmentally important phase of E18 to P7 in the brain, we quantified the proteins in the mitochondrial proteome as well as proteins interacting with the mitochondria. We identified a large number of significantly altered proteins involved in a variety of pathways including glycolysis, mitochondrial trafficking, mitophagy, and the unfolded protein response. These results are important because we identified alterations thought to be homeostatic in nature occurring within mitochondria, and these results may be used to identify any abnormal deviations in the mitochondrial proteome occurring during this period of brain development. A more comprehensive analysis of this data may be obtained from the article "Proteomic analysis of mitochondria from embryonic and postnatal rat brains reveals response to developmental changes in energy demands" in the Journal of Proteomics. PMID:26217684

  15. Characterisation of thermally altered cement pastes. Influence on selenium sorption

    International Nuclear Information System (INIS)

    Full text of publication follows: In the French design of a deep geological radioactive waste repository, the temperature would eventually increase temporally from ambient to 70 deg. C, due to cement hydration exothermic reactions and to the heat generation of radioactive waste. The investigation of selenium sorption with thermally altered cementitious materials is of relevance for the understanding of sorption processes at the engineered cementitious barrier material. This work is the first study taking into account temperature as the main parameter in matrices preparation (cement cure, hydration, storage, alteration and individual phases syntheses) and batch sorption experiments. Cementitious materials (CEM I or OPC) and individual cement phases (mainly C-S-H and ettringite) have been synthesized with different temperature cycle conditions of curing, storage/hydration and alteration. C-S-H and ettringite were synthesized in order to compare to the sorption properties of thermally altered cementitious matrices. Equilibrium solutions and solid phases have been characterized in term of pH, Eh, [Ca], [Si], [Fe], [Al], by XRD (at 20 and 70 deg. C) and SEM techniques. The sorption of Se has been studied in a pH and Eh range, where Se(IV) is stable and precipitation is avoided. The operational solubility limit was determined in each equilibrium solutions at (21 ± 2) deg. C and (71 ± 2) deg. C. Sorption isotherms and sorption kinetics for selenite were determined, in the range of 5.5.10-8 to 1.3.10-3 mol/l of Se(IV). First results are i) storage temperature leads to significant changes in hydrated cement paste mineralogy ii) hydro-garnet and/or mono-sulfate (AFm) appears in spite of ettringite (AFt) with increasing temperature iii) C-S-H phases crystallinity increases with temperature. The Se sorption equilibrium was achieved within 10 days for C-S-H systems and within 20 days for the other systems. The Rd values for C-S-H phases increase with the CaO/SiO2 ratio, from

  16. Effect of composition variations on the long-term wasteform behavior of vitrified domestic waste incineration fly-ash purification residues; Influence des variations de composition des vitrifiats de refiom - residus d'epuration des fumees d'incineration d'ordures menageres - sur leur comportement a long terme

    Energy Technology Data Exchange (ETDEWEB)

    Frugier, P.

    2000-07-01

    The effect of variations in the composition of fly-ash purification residue from incinerated domestic waste on the quality of the containment achieved by vitrification was investigated. Three main factors determine the long-term containment quality: the production of a vitrified wasteform, the occurrence of possible crystallization, and the key parameters of long-term alteration in aqueous media. Each of these aspects is described within a composition range defined by variations in the three major elements. (silicon, calcium and aluminum) and two groups of constituents (alkali metals and toxic elements). The silicon fraction in the fly-ash residue was found to be decisive: it is impossible to obtain a satisfactory vitrified wasteform below a given silicon concentration. Compounds with the lowest silica content also exhibited the greatest tendency to crystallize under the cooling conditions prevailing in industrial processes (the dominant crystallized phase is a melilite that occupies a significant fraction of the material and considerably modifies the alteration mechanisms). The initial alteration rate in pure water and the altered glass thickness measured in a closed system at an advanced stage of the dissolution reaction are both inversely related to the silicon concentration in the glass. Several types of long-term behavior were identified according to the composition range, the process conditions and the vitrified waste disposal scenario. Four distinct 'classes' of vitrified wasteform were defined for direct application in industrial processes. (author)

  17. Uranium-induced sensory alterations in the zebrafish Danio rerio

    International Nuclear Information System (INIS)

    The effect of chronic exposure to uranium ions (UO22+) on sensory tissues including the olfactory and lateral line systems was investigated in zebrafish (Danio rerio) using scanning electron microscopy. The aim of this study was to determine whether exposure to uranium damaged sensory tissues in fish. The fish were exposed to uranium at the concentration of 250 μg l−1 for 10 days followed by a depuration period of 23 days. Measurements of uranium uptake in different fish organs: olfactory rosettes and bulbs, brain, skin, and muscles, were also determined by ICP-AES and ICP-MS during the entire experimental period. The results showed that uranium displayed a strong affinity for sensory structures in direct contact with the surrounding medium, such as the olfactory and lateral line systems distributed on the skin. A decreasing gradient of uranium concentration was found: olfactory rosettes > olfactory bulbs > skin > muscles > brain. At the end of the experiment, uranium was present in non-negligible quantities in sensory tissues. In parallel, fish exposed to uranium showed severe sensory tissue alterations at the level of the olfactory and lateral line systems. In both sensory systems, the gross morphology was altered and the sensory hair cells were significantly damaged very early after the initiation of exposure (from the 3rd day). At the end of the experiment, after 23 days of depuration, the lateral line system still displayed slight tissue alterations, but approximately 80% of the neuromasts in this system had regenerated. In contrast, the olfactory system took more time to recover, as more than half of the olfactory rosettes observed remained destroyed at the end of the experiment. This study showed, for the first time, that uranium is able to damage fish sensory tissues to such an extent that tissue regeneration is delayed.

  18. Alteration mechanisms of UOX spent fuel in aqueous media

    International Nuclear Information System (INIS)

    The mechanisms of underwater alteration of spent fuels need to be understood on the assumption of a direct disposal of the assemblies in a geological formation or for long duration storage in pool. This work is a contribution to the study of the effects of the alpha and/or beta/gamma radiolysis of water on the oxidation and the dissolution of the UO2 matrix of UOX spent fuel. The effects of the alpha radiolysis, predominant in geological disposal conditions, were quantified using samples of UO2 doped with plutonium. The leaching experiments highlighted two types of control for the matrix alteration according to the alpha activity. The first is based on the radiolytic oxidation of the surface and leads to a continuous release of uranium in solution whereas the second is based on a control by the solubility of uranium. An activity threshold, located between 18 MBq/g and 33 MBq/g, was defined in a carbonated water. The value of this threshold is dependent on the experimental conditions and the presence or not of electro-active species such as hydrogen in the system. The effects of the alpha/beta/gamma radiolysis in relation with the storage conditions were also quantified. The experimental data obtained on spent fuel indicate that the alteration rate of the matrix based on the behaviour of tracer elements (caesium and strontium) reached a maximum value of some mg.m-2.d-1, even under very oxidizing conditions. The solubility of uranium and the nature of the secondary phases depend however on the extent of the oxidizing conditions. (author)

  19. Alteration mechanisms of UOX spent fuel under water

    International Nuclear Information System (INIS)

    The mechanisms of spent fuel alteration in aqueous media need to be understood on the assumption of a direct disposal of the assemblies in a geological formation or for long duration storage in pool. This work is a contribution to the study of the effects of the alpha and/or beta/gamma radiolysis of water on the oxidation and the dissolution of the UO2 matrix of UOX spent fuel. The effects of the alpha radiolysis, predominant in geological disposal conditions, were quantified by using samples of UO2 doped with plutonium. The leaching experiments highlighted two types of control for the matrix alteration according to the alpha activity. The first is based on the radiolytic oxidation of the surface and leads to a continuous release of uranium in solution whereas the second is based on a control by the solubility of uranium. An activity threshold, between 18 MBq.g-1 and 33 MBq.g-1, was defined in a carbonated water. The value of this threshold is dependent on the experimental conditions and the presence or not of electro-active species such as hydrogen in the system. The effects of the alpha/beta/gamma radiolysis in relation with the storage conditions were also quantified. The experimental data obtained on spent fuel indicate that the alteration rate of the matrix based on the behaviour of tracer elements (caesium and strontium) reached a maximum value of some mg.m-2.d-1, even under very oxidizing conditions. The solubility of uranium and the nature of the secondary phases depend however on the extent of the oxidizing conditions. (author)

  20. Vascular transcriptional alterations produced by juvenile obesity in Ossabaw swine.

    Science.gov (United States)

    Padilla, Jaume; Jenkins, Nathan T; Lee, Sewon; Zhang, Hanrui; Cui, Jian; Zuidema, Mozow Y; Zhang, Cuihua; Hill, Michael A; Perfield, James W; Ibdah, Jamal A; Booth, Frank W; Davis, J Wade; Laughlin, M Harold; Rector, R Scott

    2013-06-01

    We adopted a transcriptome-wide microarray analysis approach to determine the extent to which vascular gene expression is altered as a result of juvenile obesity and identify obesity-responsive mRNAs. We examined transcriptional profiles in the left anterior descending coronary artery (LAD), perivascular fat adjacent to the LAD, and descending thoracic aorta between obese (n = 5) and lean (n = 6) juvenile Ossabaw pigs (age = 22 wk). Obesity was experimentally induced by feeding the animals a high-fat/high-fructose corn syrup/high-cholesterol diet for 16 wk. We found that expression of 189 vascular cell genes in the LAD and expression of 165 genes in the thoracic aorta were altered with juvenile obesity (false discovery rate ≤ 10%) with an overlap of only 28 genes between both arteries. Notably, a number of genes found to be markedly upregulated in the LAD of obese pigs are implicated in atherosclerosis, including ACP5, LYZ, CXCL14, APOE, PLA2G7, LGALS3, SPP1, ITGB2, CYBB, and P2RY12. Furthermore, pathway analysis revealed the induction of proinflammatory and pro-oxidant pathways with obesity primarily in the LAD. Gene expression in the LAD perivascular fat was minimally altered with juvenile obesity. Together, we provide new evidence that obesity produces artery-specific changes in pretranslational regulation with a clear upregulation of proatherogenic genes in the LAD. Our data may offer potential viable drug targets and mechanistic insights regarding the molecular precursors involved in the origins of overnutrition and obesity-associated vascular disease. In particular, our results suggest that the oxidized LDL/LOX-1/NF-κB signaling axis may be involved in the early initiation of a juvenile obesity-induced proatherogenic coronary artery phenotype. PMID:23592636