Littérature scientifique sur le sujet « Latex naturel »
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Articles de revues sur le sujet "Latex naturel"
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Chabane, Habib, Nouara Tahi et Francisque Leynadier. « Comparaison de l'efficacité d'extraits de latex ammoniaqué et non ammoniaqué pour le diagnostic de l'allergie immédiate aux protéines de latex naturel ». Revue Française d'Allergologie et d'Immunologie Clinique 41, no 1 (janvier 2001) : 132. http://dx.doi.org/10.1016/s0335-7457(01)80080-0.
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Van Gasse, A. L., M. A. Faber, V. Sabato, C. H. Bridts, A. Nayak, D. H. Beezhold et D. G. Ebo. « Pertinence clinique de l’Hev b 12, la protéine de transfert lipidique (LTP) du latex naturel (Hevea brasiliensis) ». Revue Française d'Allergologie 55, no 3 (avril 2015) : 222. http://dx.doi.org/10.1016/j.reval.2015.02.030.
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Barbara, J., M. C. Santais, D. A. Lévy, F. Ruff et F. Leynadier. « Prévention de la sensibilisation par inhalation de protéines de latex naturel chez le cobaye grâce à un filtre utilisé en anesthésie ». Revue Française d'Allergologie et d'Immunologie Clinique 44, no 5 (septembre 2004) : 488–90. http://dx.doi.org/10.1016/j.allerg.2004.05.004.
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Jarjoura, S., B. Picard, R. Calloens, D. Delaunois, Y. Mercier et V. Banse. « Exploration in vitro de la sensibilisation simultanée au latex naturel, aux fruits, aux aliments d'origine végétale et aux profilines par dosage des IgE spécifiques et par immunoblot ». Immuno-analyse & ; Biologie Spécialisée 15, no 6 (novembre 2000) : 421–26. http://dx.doi.org/10.1016/s0923-2532(00)80041-1.
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Perez, Jean. « Natural Latex ». Clinical Reviews in Allergy 11, no 3 (septembre 1993) : 355–61. http://dx.doi.org/10.1007/bf02914417.
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Yunginger, John W. « NATURAL RUBBER LATEX ». Immunology and Allergy Clinics of North America 15, no 3 (août 1995) : 583–95. http://dx.doi.org/10.1016/s0889-8561(22)00764-0.
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Metier, J. M. « Natural latex 1991 ». Clinical Reviews in Allergy 11, no 3 (septembre 1993) : 299–307. http://dx.doi.org/10.1007/bf02914413.
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Page, Elena H., Eric J. Esswein, Martin R. Petersen, Daniel M. Lewis et Toni A. Bledsoe. « Natural Rubber Latex : ». Journal of Occupational and Environmental Medicine 42, no 6 (juin 2000) : 613–20. http://dx.doi.org/10.1097/00043764-200006000-00010.
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Hamann, Curtis P., Pamela A. Rogers et Kim M. Sullivan. « NATURAL RUBBER LATEX ». Journal of the American Dental Association 130, no 1 (janvier 1999) : 18–19. http://dx.doi.org/10.14219/jada.archive.1999.0010.
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Brown, Robert H., Robert G. Hamilton, Margaret Mintz, Anne E. Jedlicka, Alan L. Scott et Steven R. Kleeberger. « Genetic Predisposition to Latex Allergy ». Anesthesiology 102, no 3 (1 mars 2005) : 496–502. http://dx.doi.org/10.1097/00000542-200503000-00004.
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Background Occupational exposure of healthcare workers to natural rubber latex has led to sensitization and potentially life-threatening anaphylaxis. Although environmental exposure to natural rubber latex products is necessary for sensitization, it is not sufficient. A number of genetic factors also seem to contribute to the latex sensitization; however, the multigenic nature of the allergic phenotype has made the identification of susceptibility genes difficult. The current study tests the hypothesis that known functional polymorphisms in genes encoding interleukin 4, interleukin 13, and interleukin 18 occur in a higher frequency in healthcare workers with natural rubber latex allergy. Methods Four hundred thirty-two healthcare workers with occupational exposure to natural rubber latex were screened using a clinical history questionnaire and latex-specific immunoglobulin E serology. Genomic DNA was extracted from peripheral blood lymphocytes and analyzed for single-nucleotide polymorphisms in candidate genes of interest. Data from cases and controls were analyzed by nominal logistic regression, with P < 0.05 considered significant. Results The latex allergy phenotype was significantly associated with promoter polymorphisms in IL13 -1055 (P = 0.02), IL18 -607 (P = 0.02), and IL18 -656 (P = 0.02) compared with nonatopic controls. Conclusions The significant association of IL13 and IL18 promoter polymorphisms with latex allergy suggests a potential location for genetic control in the induction of latex allergy in individuals and extends the understanding of the genetic basis for the induction of immediate-type hypersensitivity in healthcare workers occupationally exposed to natural rubber latex.
Thèses sur le sujet "Latex naturel"
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Gay, Gérard. « L'allergie immediate au latex naturel ». Angers, 1990. http://www.theses.fr/1990ANGE1042.
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Wisunthorn, Pansook Suwaluk. « Etude de l'élaboration par séchage et des propriétés fonctionnelles de films à base de latex naturel d'Hevea brasiliensis ». Montpellier 2, 2006. http://www.theses.fr/2006MON20051.
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Alousque, Fanny. « Etude de la stabilité colloïdale du latex de caoutchouc naturel ». Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066648.
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Cette thèse, menée en collaboration avec Michelin dans le cadre de la fabrication de matériaux composites, porte sur la stabilité colloïdale du latex de caoutchouc naturel (NR). Ce latex est une dispersion colloïdale polydisperse d'un polymère naturel dans un sérum aqueux. Les particules sont stabilisées par une couche complexe de phospholipides et de protéines. Cette dispersion peut être coagulée de façon irréversible par voie physique (sous cisaillement) ou par voie physico-chimique (ajout de cations divalents ou de particules hydrophobes). Dans ce travail, nous avons étudié la coagulation du latex par les cations divalents. Pour cela nous avons utilisé des outils physico-chimiques : diagrammes de stabilité en présence de divers cations, suivi cinétique de l'agrégation des particules et mesures rhéologiques. Ensuite, nous avons sondé la surface de particules de NR, par électrophorèse, en présence de tensioactifs et aussi selon la taille des particules. Pour expliquer la coagulation, nous suggérons que l'augmentation de la force ionique écrante les interactions répulsives et que les cations forment des ponts ioniques entre les particules. Ces ponts les maintiennent au contact et l'irréversibilité du phénomène est assurée par l'adhésion entre les chaines de polymères proches de la surface. L'adsorption des tensioactifs modifie la surface des particules et la coagulation du latex. Une légère différence de charge de surface a été observée entre les particules de NR selon leur taille. Enfin, un phénomène de coagulation similaire a été obtenu avec un latex synthétique, ce qui ouvre la voie à l'exploitation industrielle de ce phénomène de coagulationThis work, in collaboration with Michelin for the fabrication of composite materials, deals with the colloidal stability of the latex of natural rubber (NR). The NR latex is a polydisperse colloidal dispersion of a bio-polymer in an aqueous serum. The particles are stabilized by a complex layer of phospholipids and proteins. This dispersion can be coagulated by a physical way (under shearing), or by a physical-chemical way (addition of divalent cations or hydrophobic particles). In this thesis, we studied the coagulation of the NR latex by divalent cations with physical-chemical tools (stability diagrams with different cations, aggregation kinetic of particles, rheological measuremments). Then, the surface of NR particles has been characterized by electrophoresis, firstly in the presence surfactants and secondly depending on the particles size. From the results of the first part we suggest that the coagulation with divalent cations is due to a screening effect because of the increase of ionic strength and that divalent cations can bridge the particles together. This allows keeping them in contact. Adhesion between polymer chains near the surface ensures the irrversible cohesion. In a second time, we saw that the adsorption of surfactants changes the particles surface and the coagulation of NR latex with cations. A small difference of surface charge is observed between the biggest and the smallest NR particles. Finally, a similar behavior has been obtained with a synthetic latex in presence of divalent cations. Our results could be used to develop an industrial process based on this coagulation phenomenon
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GIBAUD, BERTRAND. « Le latex de caoutchouc naturel et sa biocompatbilite (en particulier avec le tissu osseux) ». Nantes, 1990. http://www.theses.fr/1990NANT038M.
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Rubio, Alexandre. « Dépollution d'un effluent industriel complexe par filtration membranaire : propriétés du latex naturel de skim concentré ». Electronic Thesis or Diss., Montpellier, SupAgro, 2016. http://www.theses.fr/2016NSAM0013.
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Le latex naturel d’hévéa (LCN) est une dispersion colloïdale aqueuse de caoutchouc naturel de polyisoprène (PI). Après concentration, le LCN (1,2 Mt/an) a de nombreuses applications (gants chirurgicaux, préservatifs) grâce aux propriétés de son composant principal, le PI. La centrifugation, méthode de concentration généralement utilisée, donne un co-produit (skim) pauvre en particules de caoutchouc (5 % massique) mais riche en composés non caoutchouc. Sa récupération actuelle (coagulation par H2SO4) conduit à un caoutchouc de basse qualité et l’effluent final est polluant pour les rivières (H2S). Des essais antérieurs de filtration avaient montré la faisabilité du concept, mais présentaient une faible productivité, des problèmes de coagulation, de colmatage.La thèse vise un procédé de concentration du skim par ultrafiltration (UF), récupérant le PI de qualité et réduisant la charge de l’effluent, destiné à l’application industrielle, dans le cadre du projet Filtexcol (ADEME). L’optimisation du procédé a inclus la caractérisation chimique et physicochimique des skims au-delà des seuls paramètres hydrodynamiques en unité pilote. La composition chimique (espèces non caoutchouc) des skims étudiés est variable (taux de lipides, protéines, tensioactifs (TA) anioniques, non ioniques). Leur stabilité au cisaillement est mesurée via un test rapide mis au point pour être utilisable en usine, adapté à la faible charge du milieu (PI ~3-5 %, non-PI ~2 %). L’aptitude d’un skim à l’UF peut être estimée via sa stabilité sous forte contrainte de cisaillement, paramètre principal limitant.La stabilité augmente avec le taux de protéines extractibles et de TA non ioniques. Elle est améliorée par des additifs à des taux précis sous peine d’obtenir l’effet inverse. Par contre, la stabilité n’est pas liée au potentiel Zêta. L’effet des TA non ioniques (mono-, diacylglycérols) formés par hydrolyse des lipides indique une stabilisation par répulsion stérique, mais la corrélation observée aussi avec les protéines, combinée aux TA anioniques (savons) en forte concentration et au pH optimal supérieur à 9,5, peut impliquer aussi la répulsion électrostatique. Nos résultats montrent une structure complexe différente de celle du LCN concentré. Ces résultats relatifs à la physicochimie contrôlant la stabilité du skim, combinés à la granulométrie, ont permis de choisir en pilote 10 L le type de pompe (équipement critique en raison du risque de fort cisaillement) et de membrane (ZrO2), de réaliser un pilote de 100L équipé d’un module membranaire multicanal pour l’industrie, de déterminer le domaine critique d’UF (pression transmembranaire, vitesse tangentielle, taux de retour rétentat) vis-à-vis du flux de perméat J (flux critique, flux limite) et les conditions partiellement optimisées via un plan d’expérience combiné à la simulation par réseau de neurones artificiels. Le contrôle du pH durant le nettoyage et le conditionnement de la membrane assure un J élevé dès le début de l’UF. Mais même hors du domaine critique, J initial est très inférieur J-eau (1/20), l’interaction rapide skim-membrane introduit la principale résistance hydraulique puis J reste stable, témoignant de l’absence d’interactions ultérieures. Le fait de concentrer le PI (rétentat) augmente proportionnellement la résistance jusqu’au facteur de concentration volumique ~3, au-delà elle évolue peu. J se stabilise à 20 L/h.m² après 20 h d’UF. Le régime de filtration recherché via la loi des puissances est de type SBM : faible colmatage de la membrane durant la concentration (bouchage partiel à l’intérieur de pores). La totalité du PI et les non-PI (protéines et lipides) associés aux particules sont retenus et concentrés en pilote 100 L jusqu’à ~40 % de matière sèche ; la demande chimique en oxygène du nouvel effluent (perméat) est divisée par 4. Ces performances ouvrent la voie à des essais à plus grande échelle et à des applications prometteusesNatural rubber latex (LCN) is an aqueous colloidal dispersion of polyisoprene (PI) natural rubber. After concentration, LCN (1,2 Mt/an) has many applications (surgical gloves, condoms) thanks to the properties of its main component, PI. Centrifugation concentration is mainly performed, producing a co-product (skim) with low rubber particle content (5% weight) but rich in non-rubber compounds. Its current recovery (H2SO4 coagulation) leads to low-quality rubber and the final effluent is hazardous for rivers (H2S). Previous filtration tests have proven the feasibility of the concept, but showed low productivity, coagulation problems and clogging.The thesis aims for a skim concentration process by ultrafiltration (UF), recovering the valuable PI and reducing the load of the effluent - for industrial application – within the Filtexcol project (ADEME). The process optimization included chemical and physicochemical characterization beyond only hydrodynamic parameters with a pilot plant. The chemical composition (non-rubber compounds) of the studied skims varies (lipid content, protein, anionic and nonionic surfactants (TA)). Their shear stability is measured with a rapid test developed to be factory use compatible, adapted to low load medium (PI ~3-5% ; non-PI ~2%). The UF suitability of the skim can be estimated via its high shear stability, the main limiting factor. The stability increases with the extractible protein and the non-ionic TA content. It is improved by precise additive amounts otherwise leading to the opposite effect. However stability is not related to the Zeta potential. The effect of nonionic TA (mono and diacylglycerol) formed by lipid hydrolysis indicates stabilization by steric repulsion, but the correlation also observed with proteins combined to anionic TA (soaps) in high concentration and optimal pH above 9,5 can also involve electrostatic repulsion.Our results show a complex structure different from the concentrated LCN’s. These results related to physcochemistry controlling the stability of the skim, combined with granulometry, allowed to choose through a 10L pilot the pump type (critical equipment due to the risk of high shear) and the membrane (ZrO2), to build a 100L pilot with a multicanal industrial membrane module, to determine a critical UF area (transmembrane pressure, tangential speed, retentate return rate) regarding the permeate flux J (critical flux, limit flux) and the partially optimized conditions via an experimental plan combined with artificial neural network simulation.PH control during cleaning and membrane conditioning ensures high J since early UF operation. But even outside of the critical area, initial J is very inferior to J-water (1/20), the rapid skim-membrane interaction introduces the main hydraulic resistance then J remains stable, reflecting the absence of subsequent interactions. Concentrating PI (retentate) increases proportionally the resistance to the volume concentration factor ~3 after which it decreases only slightly.J stabilizes at 20 L/h.m² after 20h of UF. The filtration state searched by the power law is SBM : low membrane fouling during concentration (partial blockage inside the pores). The entire PI and the particle-associated non-PIs (proteins and lipids) are retained and concentrated into the 100L pilot until ~40% dry matter; the chemical oxygen demand of the new effluent is divided by 4. These performance open the way to larger-scale trials and promising applications
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Bellacicco, Sophie. « Etude de l’impact de l’origine clonale du latex d’Hevea brasiliensis sur la composition biochimique du latex et la mésostructure du caoutchouc naturel ». Thesis, Montpellier, SupAgro, 2014. http://www.theses.fr/2014NSAM0003.
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Le caoutchouc naturel produit du latex d'Hevea brasiliensis a des propriétés remarquables qui n'ont jamais été égalées par ses homologues synthétiques. Toutefois, ce matériau d'origine naturel présente un désavantage : la variabilité non négligeable de ses propriétés. Cette dernière est partiellement attribuée aux 3 à 5 % de composés non isoprènes (lipides, protéines, sucres et minéraux) présents dans le caoutchouc naturel. Parmi les facteurs pouvant être tenus comme responsables de cette variabilité, l'origine clonale semble prépondérante. L'objectif principal de cette étude était d'évaluer l'impact de l'origine clonale sur la variabilité en composition biochimique du latex (lipides, protéines, sucres et éléments minéraux) et sur les caractéristiques mésostructurales du caoutchouc naturel; puis d'étudier les relations pouvant exister entre le génotype, la composition biochimique du latex et la mésostructure du caoutchouc. Cette étude a été conduite sur 5 clones d'Hevea brasiliensis : GT1, RRIM600, PB235, PB217 et PB260. Des études préalables à la caractérisation clonale ont permis de déterminer les conditions d'échantillonnage à mettre en œuvre pour pratiquer des prélèvements de latex clonaux les plus représentatifs possible des clones. Le latex étant un matériau instable, il été choisi de travailler sur du latex lyophilisé pour l'analyse de tous les composés biochimiques du latex (autres que les lipides) et pour l'étude de la mésostructure du caoutchouc naturel. Des protocoles d'extractions des protéines et des sucres sur lyophilisat de latex ont été développés en se basant sur les propriétés de solubilisation du caoutchouc naturel en milieu organique. L'extraction des lipides a été réalisée en suivant le protocole mis au point sur plantation sur latex frais par Liengrayoon (Liengprayoon, 2008). Les différents résultats obtenus au niveau de la composition biochimique du latex et de la mésostructure du caoutchouc ont permis de mettre en évidence l'importante de l'origine clonale des latex. L'étude des relations entre le génotype et la composition biochimique du latex (ACP) a clairement montré que l'origine clonale jouait un rôle important dans la variabilité totale des données biochimiques du latex. Les analyses des relations entre la biochimie du latex et la mésostructure du caoutchouc naturel ont permis de mettre en évidence des corrélations intéressantes des lipides et des protéines avec la mésostructure (essentiellement Mn et I). Cette analyse biochimique clonale des latex s'est révélée pertinente pour étudier la diversité clonale et ses répercutions sur la mésostructure du caoutchouc naturel. Cette approche de la diversité clonale d'Hevea brasiliensis, ainsi que les connaissances acquises lors de cette étude constituent une base de données solide à compléter par des études futures sur des plantations différentes, des clones différents et des analyses biochimiques et structurales plus pousséesNatural rubber produced from Hevea brasiliensis latex possesses remarkable properties which have not been matched by its synthetic counterparts. However, this natural origin material presents a disadvantage: the significant variability of its properties. This variability has been partly ascribed to the 3 to 5% non isoprene components (lipids, proteins, sugars and minerals) present in the natural rubber. Among the factors that could be held responsible for this variability, clonal origin seems to be decisive.The main aim of this study was to evaluate the impact of clonal origin on the biochemical latex composition and on natural rubber mésostructural characteristics and also to study relationships between genotype, latex biochemical composition and rubber mesostructure. This study was conducted with five Hevea brasiliensis clones: GT1, RRIM600, PB235, PB217 and PB260. Before clonal characterization, preliminary studies were performed to determine the suitable sampling conditions in order to get the latex samples that represented as much as possible the clones. Fresh latex is an unstable material. It was decided to work on freeze-dried latex for the biochemical components analysis (except lipids) and for the natural rubber mesostructure study. Protocols for proteins and sugars' extractions on freeze-dried latex have been developed on the natural rubber solubilizing properties in organic media. Lipids extractions was performed according to the protocol developed by Liengrayoon (Liengprayoon , 2008) on fresh latex.The different results obtained on the latex biochemical composition and the natural rubber mesostructure allowed to clearly observe the clonal origin importance. Study of relationships between genotype and latex biochemical composition (PCA) has clearly shown that the clonal origin played an important role in the total variability of latex biochemical data. Analysis of relationships between latex biochemistry and natural rubber mesostructure helped highlight interesting correlations of lipids and proteins with mesostructure (mainly Mn and I).This biochemical analysis of clonal latex has proved to be appropriate for studying the clonal diversity and its repercussions on the natural rubber mesostructure. This approach of Hevea brasiliensis clonal diversity, and the knowledge gained from this study, provides a solid basis to be completed by further studies on different plantations, different clones and further biochemical and structural analyses
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Musigamart, Natedao. « Study of the role of lipids from maturated coagula from Hevea brasiliensis latex on natural rubber behavior in oxidative conditions ». Thesis, Montpellier, SupAgro, 2015. http://www.theses.fr/2015NSAM0004/document.
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Le caoutchouc naturel (CN), un produit dérivé du latex d'Hevea brasiliensis, est connu pour ses propriétés mécaniques supérieures pour certaines à celles de ses concurrents synthétiques. Néanmoins, le haut degré d'insaturation du poly(cis-1,4-isoprene) le rend susceptible à la thermo-oxydation. Heureusement, le CN est doté de composés non-isoprènes dont certains ont des propriétés antioxydantes. Les lipides sont les plus importants non-isoprènes retenus dans le caoutchouc et contiennent des molécules à activité antioxydante en particulier les tocotriènols. Il est connu que durant la maturation de coagula de latex, la composition chimique et les propriétés du caoutchouc obtenu sont altérées, mais les mécanismes complexes de cette altération ne sont pas encore complètement élucidés. Dans cette étude, l'évolution de certaines molécules antioxydantes natives pendant la maturation a été suivie en relation avec certaines propriétés physiques du caoutchouc. Deux expérimentations de maturation ont été mises en œuvre. La première mettait en jeu des conditions non contrôlées de maturation suivies d'un procédé de confection du caoutchouc basé sur celui des feuilles fumées (RSS) ou non (USS). La seconde a été conduite dans un dispositif expérimental dédié permettant le contrôle des facteurs de l'environnement tels que l'humidité relative, la température et la concentration en oxygène. Le procédé de confection du caoutchouc était dans ce cas basé sur celui des caoutchoucs spécifiés techniquement (TSR). L'évolution des échantillons pendant la maturation a été étudiée à différentes échelles : propriétés en masse (P0, P30 et PRI), mésostructure (% gel, Mw and Mn) et composition biochimique (lipides). En parallèle, l'activité antioxydante in vitro des extraits lipidiques correspondants a été mesurée en utilisant une méthode DPPH optimisée. La quantité et la qualité des lipides extraits évoluent pendant la maturation, en particulier en aérobiose. La quantité totale de lipides décroit, avec, en début de maturation, une libération d'acides gras dont la quantité diminue ensuite, avec une disparation des espèces insaturées en premier. La quantité de γ-tocotrienol libres extraits change peu au cours de la maturation alors que sa forme estérifiée montre un enrichissement en acides gras saturés. L'activité antioxydante de l'extrait lipidique mesurée in vitro est corrélée avec la concentration de γ-tocotrienol libre mais pas avec les valeurs de P30 et PRI qui estiment la résistance du caoutchouc à la thermo-oxydation. Cette absence de corrélation pourrait être due à la différence des conditions de mesure in-vitro de celles existantes au sein du matériau caoutchouc. La localisation des antioxydants dans le caoutchouc et en particulier leur possibilité physique d'interagir avec les doubles liaisons du poly(cis-1,4-isoprene) ou avec des espèces oxydantes reste à étudier afin de comprendre ce qui régit la chute de P30 au cours de la maturation. Des lipides non extractibles ou des molécules non-isoprènes plus polaires (protéines, polyphénols, …) pourraient également influencer la résistance du caoutchouc à la thermo-oxydationNatural rubber (NR), a derived product from H. brasiliensis latex, is known for its high mechanical properties that are, for some, superior to those of its synthetic counterparts. However, the high degree of unsaturation of poly(cis-1,4-isoprene) makes it susceptible to thermo-oxidation. Fortunately, NR is endowed with non-isoprene components of which some have antioxidant properties. Especially, lipids, the main non-isoprene component retained in NR, have been reported to contain antioxidant substances, especially tocotrienols. It is well known that during the maturation of latex coagula, both NR physical properties and chemical composition are altered, but the complex mechanisms of this alteration are still to be elucidated. In the present work, the evolution of some native antioxidant molecules during maturation was followed in relation with some physical properties. Two experimental conditions of maturation were chosen. The first experiment involved uncontrolled conditions based on traditional unsmoked (USS) or ribbed smoked sheet (RSS) processing, while the second was performed in a dedicated maturation device with full control of environmental factors (relative humidity, temperature and oxygen content) followed by a processing based on that of Technically Specified Rubber (TSR). The evolution of samples during maturation was studied at different scales: bulk properties (P0, P30 and PRI), mesostructure (% gel content, Mw and Mn) and biochemical composition (lipids components). In parallel, in vitro antioxidant activity of NR lipid extracts was also investigated using an optimized DPPH method. Lipid quantity and quality evolved during maturation, especially under aerobic conditions. The total amount of lipid extract decreased, with a release of free fatty acids at early stage of maturation followed by a later decrease, unsaturated fatty acids being the first to disappear. The amount of extractable free γ-tocotrienol did not change much during maturation, while its esterified form was enriched in saturated fatty acids. The antioxidant activity measured in vitro correlated well with free γ-tocotrienol concentration but not with the resistance of rubber to thermo-oxidation assessed by P30 or PRI. Indeed, the in vitro conditions of measurement were far from those occurring inside rubber material. The localization of antioxidants in rubber and especially their physical possibility to interact with the double bonds of poly(cis-1,4-isoprene) or with oxidant species should be further investigated to understand what drives the drop of P30 along maturation time. Non extractable lipids or more polar non-isoprene molecular species (proteins, polyphenols, etc…) could also influence the resistance to thermo-oxidation
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Salomez, Mélanie. « Etude du rôle des microorganismes dans les modifications biochimiques intervenant lors de la maturation des coagulums de latex d’Hevea brasiliensis : impact sur les propriétés du caoutchouc naturel sec ». Thesis, Montpellier, SupAgro, 2014. http://www.theses.fr/2014NSAM0002.
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L'objectif général de cette thèse était d'étudier les mécanismes microbiens intervenant dans l'évolution de la structure et des propriétés du caoutchouc naturel produit à partir du latex d'Hevea brasiliensis lors de la maturation du latex et des coagula de tasse. Pour cela, trois niveaux d'analyses ont été réalisés sur des expériences de maturation en conditions contrôlées : analyse de la structure et des propriétés du caoutchouc sec, analyse des flores microbiennes et analyses biochimiques. Après une phase de mises au point méthodologiques permettant notamment d'optimiser les conditions de maturation en chambre contrôlée et de définir une méthode d'extraction d'ADN adaptée au latex et au sérum de coagulum, des échantillons de caoutchouc sec et de sérum ont été produits à différents temps de maturation et selon différents traitements faisant varier trois paramètres : la présence de microorganismes, la présence d'oxygène, et le mode de coagulation du latex. Les analyses sur caoutchouc sec se sont portées sur la macrostructure (P0, P30 et PRI) et sur la mésostructure (Mw, Mn et gel total). L'analyse des flores microbiennes s'est appuyée sur plusieurs méthodologies complémentaires : comptages sur boîtes, dosage de l'ADN total, clonage/séquençage et pyroséquençage 454. L'objectif était d'évaluer la diversité des flores sur plantation et dans le latex ainsi que de suivre la dynamique de leur évolution au cours de la maturation en milieu contrôlé. Diverses analyses biochimiques ont réalisées sur latex, sérum et caoutchouc sec (taux d'azote, protéines, lipides, sucres, québrachitol, acides organiques). Les résultats obtenus ont ensuite été analysés en vue d'établir des corrélations et de proposer des mécanismes reliant l'évolution des propriétés du caoutchouc sec à celle de la biochimie du latex et des coagula et de leur évolution sous l'action des microorganismes et des enzymes, et de proposer quelques pistes en vue de l'amélioration des itinéraires techniques dans la filièreThe overall objective of this thesis was to study the microbial mechanisms involved in the evolution of the structure and the properties of the natural rubber from Hevea brasiliensis during the maturation of latex and cup-coagula. For this, three levels of analyses were performed on maturation experiments under controlled conditions: dry rubber structure and properties, biochemistry and microbial flora. After a methodology development phase aiming at (i) optimizing maturation conditions in a controlled chamber and (ii) defining suitable DNA extraction methods, samples of serum and dry rubber coagulum were produced at different times and under different maturation treatments varying three parameters: the presence of microorganisms, the presence of oxygen, and the latex coagulation method. Dry rubber analyses concerned macrostructure (P0, P30 and PRI) and mesostructure (Mw, Mn and total gel). The microbial flora was analyzed using several complementary methods: plate-counts, total DNA determination, cloning / sequencing and 454 pyrosequencing. The objective was to assess microbial diversity on field and in latex, and to follow the dynamics of their evolution during maturation in a controlled environment. Various biochemical investigations were performed on latex, serum and dry rubber (nitrogen content, proteins, lipids, sugars, quebrachitol, organic acids). The results were then analyzed for correlations to propose mechanisms linking changes in dry rubber properties, latex and coagula biochemistry, and their evolution under the action of microorganisms and enzymes. Some ideas for improving technical routes in the process are also proposed
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Schneider, Michael. « Renforcement de polymeres avec des particules composites de latex a base de caoutchouc naturel ». Université Louis Pasteur (Strasbourg) (1971-2008), 1995. http://www.theses.fr/1995STR13216.
Texte intégralRésumé :
L'evolution de nos travaux s'est deroulee selon une chronologie allant de la synthese en emulsion de particules composites a base de caoutchouc naturel et d'acrylate de butyle jusqu'a la mise au point de melanges binaires (polymere thermoplastique + particules) et ternaires (un polymere thermoplastique majoritaire + un second polymere thermoplastique minoritaire + particules). Cette etude avait pour objectif principal de definir les parametres qui gouvernent l'amelioration de la resistance aux chocs d'un melange modele dont on maitrise parfaitement la composition, la nature et l'interface de la phase dispersee. Les techniques de microscopie electronique a balayage et a transmission ont permis de correler la morphologie des particules renforcantes avec le mode de deformation des differentes matrices thermoplastiques utilisees
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CHALLIOUI, GILLET CAROLE. « Degradation du caoutchouc naturel en phase latex par oxydation controlee. Action du couple phenylhydrazine/oxygene sur un modele des structures polyisopreniques ». Le Mans, 1994. http://www.theses.fr/1994LEMA1024.
Texte intégralRésumé :
Ce memoire traite de l'etude de la degradation controlee du caoutchouc naturel en phase latex sous l'action du couple redox phenylhydrazine/oxygene. En se basant sur les resultats des travaux anterieurs et possedant a present, des methodes d'analyses plus performantes (rmn #1h 400mhz et cg/sm), notre travail a consiste a identifier de maniere plus sure et plus complete les fonctions d'extremites de chaine apres degradation. Pour cela, nous avons cherche dans un premier temps a alimenter notre reflexion en completant nos connaissances des processus d'oxydation et de degradation du polyisoprene par une etude bibliographique de l'autoxydation des acides gras insatures (chapitre i). Nous avons ensuite consacre le deuxieme chapitre a la modelisation de la procedure de degradation du caoutchouc naturel en phase latex par une reaction de degradation d'une molecule modele, le 4,8-dimethyldodeca-4,8-diene, en emulsion. La synthese de molecules modeles supposees se former et l'analyse des melanges de degradation ont permis de preciser (chapitre iii): 1) la nature des extremites de chaine apres scission ; 2) les differents modes de fragmentation ; 3) les phenomenes de modification chimique sans rupture de chaines. En etudiant l'evolution en fonction du temps des produits de degradation (chapitre iv), les etapes successives de la reaction ont pu etre reconstituees: 1) fragmentation des chaines et formation d'extremites carbonyle ; 2) reaction d'une partie de ces fonctions carbonyle avec la phenylhydrazine residuelle pour donner des phenylhydrazones tres reactives avec l'oxygene. Les structures d'oxydation alors formees sont susceptibles de se decomposer plus ou moins rapidement ; 3) degradation par recurrence des extremites carbonyle (aldehydes et cetones). Des hypotheses de mecanismes sont proposees pour l'ensemble de ces degradations
Livres sur le sujet "Latex naturel"
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Grant, Edward. The nature of natural philosophy in the late Middle Ages. Washington, D.C : Catholic University of America Press, 2010.
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The nature of natural philosophy in the late Middle Ages. Washington, D.C : Catholic University of America Press, 2010.
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Grant, Edward. The nature of natural philosophy in the late Middle Ages. Washington, D.C : Catholic University of America Press, 2010.
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Preventing allergic reactions to natural rubber latex in the workplace. Cincinnati, Ohio?] : U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 1997.
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Field, E. Anne. Guidance for the management of natural rubber latex allergy in dental patients and dental healthcare workers. London) : Faculty of General Dental Practitioners (UK, The Royal College of Surgeons of England, 2004.
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William, Marlin, dir. Nature near : Late essays of Richard Neutra. Santa Barbara, Calif : Capra Press, 1989.
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1956-, Herbert Lynn M., Volk Gregory, Paine Roxy 1966-, Contemporary Arts Museum et Rose Art Museum, dir. Roxy Paine : Second nature. Houston : Contemporary Arts Museum, 2002.
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Chene, Dennis Des. Physiologia : Natural philosophy in late Aristotelian and Cartesian thought. Ithaca : Cornell University Press, 1996.
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Hilary, Tovey, et Blanc Michel 1945-, dir. Food, nature and society : Rural life in late modernity. Aldershot, Hampshire, England : Ashgate, 2001.
Trouver le texte intégralChapitres de livres sur le sujet "Latex naturel"
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Steiner, G., et C. Zimmerer. « Natural Rubber (Latex) ». Dans Polymer Solids and Polymer Melts – Definitions and Physical Properties I, 583–89. Berlin, Heidelberg : Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-32072-9_58.
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Shepelev, O., N. Meiry et M. Shepelev. « Concerning the Nature of Heat Sensitivity of Natural Latex ». Dans Surfactants in Solution, 1599–606. Boston, MA : Springer US, 1986. http://dx.doi.org/10.1007/978-1-4613-1833-0_37.
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Turjanmaa, K., H. Alenius, S. Mäkinen-Kiljunen, T. Reunala et T. Palosuo. « Natural-Rubber-Latex Allergy ». Dans Handbook of Occupational Dermatology, 719–29. Berlin, Heidelberg : Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-662-07677-4_88.
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Urs, Amog P., V. N. Manjuprasanna, G. V. Rudresha, M. Yariswamy et B. S. Vishwanath. « Plant Latex Proteases : Natural Wound Healers ». Dans Proteases in Physiology and Pathology, 297–323. Singapore : Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-2513-6_14.
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Allmers, Henning. « Occupational Allergy to Natural Rubber Latex (NRL) ». Dans Kanerva’s Occupational Dermatology, 1–13. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-40221-5_67-2.
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Allmers, Henning. « Occupational Allergy to Natural Rubber Latex (NRL) ». Dans Kanerva's Occupational Dermatology, 755–67. Berlin, Heidelberg : Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-02035-3_67.
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Ruëff, Franziska. « Sensitization and Allergy to Natural Rubber Latex ». Dans Encyclopedia of Medical Immunology, 615–19. New York, NY : Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4614-9194-1_468.
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Allmers, Henning. « Occupational Allergy to Natural Rubber Latex (NRL) ». Dans Kanerva’s Occupational Dermatology, 1015–27. Cham : Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-68617-2_67.
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Zuhainis, Saad Wan, Aziana Abu Hassan, Manroshan Singh et Rosfarizan Mohamad. « Microbial Surfactant for Preservation of Natural Rubber Latex ». Dans Beneficial Microorganisms in Agriculture, Aquaculture and Other Areas, 101–28. Cham : Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-23183-9_6.
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bin W. Zin, Wan Manshol. « Radiation Vulcanisation Natural Rubber Latex and its Properties ». Dans Polymers and Other Advanced Materials, 701–8. Boston, MA : Springer US, 1995. http://dx.doi.org/10.1007/978-1-4899-0502-4_72.
Texte intégralActes de conférences sur le sujet "Latex naturel"
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Ramesh, Aparna. « Le Corbusier in Chandigarh : A Search for the Natural Order ». Dans LC2015 - Le Corbusier, 50 years later. Valencia : Universitat Politècnica València, 2015. http://dx.doi.org/10.4995/lc2015.2015.784.
Texte intégralRésumé :
Abstract: This paper is an attempt to analyse and decode Le Corbusier’s application of his exceptionally singular and complex understanding of the order of the natural world in his urban masterpiece- Chandigarh City. It was Le Corbusier’s strong belief that architecture was a personal search for truth, a truth that was contained in the organic harmony of nature. He was convinced that with the advent of the machine in the 19th century, ties between man and nature had been severed. For the sake of the citizen’s physiological and psychological health, he felt it was essential that future cities focus on reconnecting man to nature through large green parks open to the sky, unpolluted by the machine. His own formative years in the lush forests of the Swiss countryside, sketching and abstracting natural forms helped him observe and internalise the inherent logic in their geometry. Over the years, a deeper study of mathematical proportions of the human body led Le Corbusier to propose the Modulor as a standard for the human scale in architecture. This only further cemented his belief that there was no separate natural order and man-made order; man was a part of nature and therefore a part of the natural order as well. However, it was the spiritual aspect of city planning that fascinated Le Corbusier the most. After a life long study of natural forms, he was fully convinced that this Spirit was hidden in the geometries of nature. To him, it was essential that the twentieth century city employ this spiritual order as a means restore harmony between man, nature and the cosmos. Resumen: Este trabajo conforma un intento para analizar y decodificar la aplicación de Le Corbusier en su comprensión excepcionalmente singular y compleja del orden del mundo natural en su obra maestra urbana - La Ciudad de Chandigarh. La firme creencia de Le Corbusier era que la arquitectura constituía una búsqueda personal de la verdad, una verdad establecida en la armonía orgánica de la naturaleza. Estaba convencido de que con el surgimiento de las máquinas en el siglo XIX, los lazos entre el hombre y la naturaleza se habían roto. Por el bien de la salud fisiológica y sicológica de los ciudadanos, sentía que era fundamental que las ciudades futuras se enfocaran en reconectar al hombre con la naturaleza a través de grandes parques verdes abiertos al cielo, sin ser contaminados por máquinas. Sus propios años de formación en los frondosos bosques del campo Suizo, esbozando y captando formas naturales lo ayudaron a observar e internalizar la lógica inherente en su geometría. Con el transcurso de los años, un estudio más profundo de proporciones matemáticas del cuerpo humano, llevaron a que Le Corbusier propusiera el Modulor como un estándar para la escala humana en arquitectura. Esto sólo consiguió consolidar aun más su creencia de que no había una separación entre el orden natural y el hecho por el hombre; el hombre era parte de la naturaleza y por lo tanto parte del orden natural también. Sin embargo, fue el aspecto espiritual de la planificación de la ciudad lo que más fascinó a Le Corbusier. Luego de un estudio de formas naturales a lo largo de la vida, se convenció por completo acerca de que este Espíritu estaba escondido en las geometrías de la naturaleza. Para él era primordial que la ciudad del siglo veinte empleara este orden espiritual como un medio para restaurar la armonía entre el hombre, la naturaleza y el cosmos. Keywords: Chandigarh; City Planning; Capitol Complex; Modulor Man; Open Hand; Natural Order. Palabras clave: Chandigarh; Planificación de la ciudad ; Capitol Complex; Modulor Man; Open Hand; Orden del Mundo Natural. DOI: http://dx.doi.org/10.4995/LC2015.2015.784
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Como, Alessandra, Luisa Smeragliuolo Perrotta et Isotta Forni. « Le Corbusier Roof-Spaces ». Dans LC2015 - Le Corbusier, 50 years later. Valencia : Universitat Politècnica València, 2015. http://dx.doi.org/10.4995/lc2015.2015.960.
Texte intégralRésumé :
Abstract: From technical solution, the roof-garden became a key spatial theme within Le Corbusier’s work and creativity, evolving to become a fundamental component of his vision for the contemporary city. The roof garden is an open space in which to cultivate both the mind and body, and to experience a direct relationship with nature; through plants, the sky, and the sun, the urban and the natural world are combined together in the surroundings. This article follows the principal steps of Le Corbusier’s research, starting with his initial experimentation in his own apartment studio in rue Nungesser-et-Coli, through to the complex development at the Unité. It follows how the roof garden becomes an optical device toward the horizon and a strong evocative instrument. The relationship with the nature and the horizon are the key of readings of several selected design projects which demonstrate at the same time the continuity of the research and the richness of the variations on the theme itself. The roof garden is one of the most fertile topics of Le Corbusier’s legacy, evident in contemporary architectural developments. Resumen: A partir de una solución técnica, el roof-garden se convierte en el tema central del trabajo y de la poética de Le Corbusier, evolucionando para convertirse en un componente fundamental de su visión de la ciudad contemporánea. El roofgarden es un espacio abierto en el que el hombre puede cultivar la mente y el cuerpo, donde se puede experimentar una relación directa con la naturaleza -la vegetación, a través de las plantas, el cielo, el sol, el urbano -y el mundo natural se combinan juntos en los alrededores. Este texto sigue los pasos principales de la investigación de Le Corbusier , partiendo de las experimentaciones iniciales -en su apartamento-estudio en la rue Nungesser-et-Coli- hasta el complejo desarrollado en la Unité. El texto sigue como el roof garden se convierte en un dispositivo óptico hacia el horizonte y en un gran instrumento evocativo. La relación con la naturaleza y el horizonte son las claves de lectura de varios proyectos seleccionados que muestran a la vez la continuidad de la investigación y la riqueza de las variaciones sobre el tema. El roof garden es uno de los temas más vivos del legado de Le Corbusier, también de gran importancia hoy en la arquitectura contemporánea. Keywords: Roof-garden; Nature; View; Horizon; Landscape. Palabras clave: Roof-garden; Naturaleza; Vista; Horizonte; Paisaje. DOI: http://dx.doi.org/10.4995/LC2015.2015.960
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Huang, Zuohua, Seiichi Shiga, Takamasa Ueda, Nobuhisa Jingu, Hisao Nakamura, Tusneaki Ishima, Tomio Obokata, Mitsuhiro Tsue et Michikata Kono. « Effect of Fuel Injection Timing Relative to Ignition Timing on the Natural-Gas Direct-Injection Combustion ». Dans ASME 2001 Internal Combustion Engine Division Spring Technical Conference. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/ices2001-107.
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Abstract Effect of fuel injection timing relative to ignition timing on natural gas direct-injection combustion was studied by using a rapid compression machine. The ignition timing was fixed at 80 ms from the compression start. When the injection timing was relatively earlier (injection start at 60 ms), the heat release pattern showed slower burn in the initial stage and faster burn in the late stage, which is similar to that of flame propagation of a premixed gas. In contrast to this, when the injection timing was relatively later (injection start at 75 ms), the heat release rate showed faster burn in the initial stage and slower burn in the late stage, which is similar to that of diesel combustion. The shortest duration was realized at the injection end timing of 80 ms (the same timing as the ignition timing) over the wide range of equivalence ratio. The degree of charge stratification and the intensity of turbulence generated by the fuel jet is considered to cause these behaviors. Earlier injection leads to longer duration of the initial combustion, whereas the later injection does longer duration of the late combustion. Earlier injection showed relatively lower CO emission while later injection produces relatively lower NOx emission. It was suggested that earlier injection leads to lower mixture stratification combustion and later injection leads to higher mixture stratification combustion. Combustion efficiency maintained high value over the wide range of equivalence ratio.
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Itham Mahajan, Rajini. « THE INEVITABLE ORDER : Revisiting the Calibrated Biomimetics of Le Corbusier’s Modulor ». Dans LC2015 - Le Corbusier, 50 years later. Valencia : Universitat Politècnica València, 2015. http://dx.doi.org/10.4995/lc2015.2015.895.
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Abstract: Biomimetics is a philosophy in Architecture that addresses issues not through mimicry but by understanding the rules governing natural forms. Biomimetics has gained popularity in the past few decades but it would be more apposite to state that this philosophy may have had its origins many years previously in the conceptualization of the Modulor, as Le Corbusier strived to unite Mathematics, Physiology & Design. Common knowledge shows that disturbed by application of generic Imperial and Standard systems of measurements, the Modulor was ideated to help perceive the built environment as a physical extension of the human body. Le Corbusier’s attempt to develop a harmonious scale towards the measurement of the absolute has been criticized for adopting industrial efficiency; though alienating human emotion was farthest from Corbusier’s thought. What then is the architectural paradox in comprehending The Modulor as the universal proportioning system- racial differences in anthropometry, mechanizing architectural built forms within and without or simply an apprehension of losing mannerisms in architecture? Trying to unravel the mysteries of nature through analytics of the numbering system, Corbusier was consumed by the all-pervasive need to find answers to eternal questions in scientific spirituality. This paper explores the inevitable order of Le Corbusier’s universe, revisiting the conceptualization of the Modulor, its relevance to architectural philosophies in general and Biomimetics in particular and the universal application of the same as a governing factor in Design methodologies. Keywords: Le Corbusier, Biomimetic, Modulor, Universal Application, Design. DOI: http://dx.doi.org/10.4995/LC2015.2015.895
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Gorgeri, Fabiola. « Memory and change through Le Corbusier. Fragments of urban views ». Dans LC2015 - Le Corbusier, 50 years later. Valencia : Universitat Politècnica València, 2015. http://dx.doi.org/10.4995/lc2015.2015.927.
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Abstract: In the urban project of Le Corbusier the relationship between new and existing is opportunity of poetic composition. The real traces of the past of one place are transformative tools by which the new project is developed. The projects after World War II, like reconstruction project of Saint-Dié, are occasions to reflect about the new urban developments, rapid and extensive, and the relation of them with the landscape in a new territorial vision. The fragments of past and the new buildings are seen like belonging to a same context of reference and the entire urban composition forming part of a landscape on more large scale. Therefore, the urban project is an ensemble of architectural objects and nature that are held together by calculated visual relation. It is a kind of montage of urban views related to the dimension and measure of the human subject, like visual points or pedestrian paths. Memory and change are linked together by the natural history process and commensurate also to the human measure by a three dimension urbanism where the architecture can anew make the city. Resumen: En el proyecto urbanístico de Le Corbusier la relación entre la nueva y la existente es la oportunidad de la composición poética. Las huellas reales del pasado de un lugar son herramientas de transformación por el que se desarrolla el nuevo proyecto. Los proyectos después de la Segunda Guerra Mundial, como el proyecto de reconstrucción de Saint-Dié, son ocasiones para reflexionar acerca de los nuevos desarrollos urbanos, rápidas y amplias, y la relación de ellos con el paisaje en una nueva visión territorial. Los fragmentos del pasado y los nuevos edificios son vistos como pertenecientes a un mismo contexto de referencia y toda la composición que forma parte urbana de un paisaje de más gran escala. Por lo tanto, el proyecto urbano es un conjunto de objetos arquitectónicos y la naturaleza que se mantienen unidas por la relación visual calculada. Es una especie de montaje de vistas urbanas relacionadas con la dimensión y la medida del ser humano, al igual que los puntos visuales o caminos peatonales. La memoria y el cambio están unidos entre sí por el proceso de la historia natural y acorde también a la medida humana por un tres dimensiones urbanismo donde la arquitectura de nuevo puede hacer de la ciudad. Keywords: urban project; landscape; memory; Saint-Dié. Palabras clave: proyecto urbano; paisaje; memoria; Saint-Dié. DOI: http://dx.doi.org/10.4995/LC2015.2015.927
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« Natural Rubber Latex as Admixture for Polymer Concrete ». Dans "SP-330 : Recent Advances in Concrete Technology and Sustainability Issues Proceedings Fourteenth International Conference Beijing, China". American Concrete Institute, 2018. http://dx.doi.org/10.14359/51711238.
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Alison, Aurosa. « Les « Unités » Modulor dans la Philosophie de l’Espace de Gaston Bachelard ». Dans LC2015 - Le Corbusier, 50 years later. Valencia : Universitat Politècnica València, 2015. http://dx.doi.org/10.4995/lc2015.2015.1045.
Texte intégralRésumé :
Résumé: Celui du Modulor est le premier exemple de la mesure humaine utilisée dans l’architecture. L’architecture de la moitié du vingtième siècle a été influencée par les projets de Le Corbusier. En même temps, la pensée de Gaston Bachelard s’évolue contextuellement au Mouvement Moderne et en 1957 le philosophe publie le célèbre ouvrage « La Poétique de l’espace ». Une bonne partie de sa pensée a été influencée par l’étude des quatre éléments naturels, par une conception de l’espace intime et par les différents développements de l’image de la maison. La description de la maison, dans les mots de Bachelard, correspond aux thèses principales de Carl Gustav Jung sur les différentes étapes de l’âme. Dans cette étude nous analysons les liaisons entre une conception intime de l’espace vécu et la pensée progressive de l’architecture moderne. A travers les exemples suggérés par l’Unité d’Habitation et par le Cabanon de Le Corbusier, nous voulons illustrer les dynamiques d’une philosophie de l’espace, émotionnelle, intime et secret. Abstract: The Modulor is the first example of the human measure. The architecture of the second part of the twenty century was influenced by Le Corbusier works. The development of the thought of Gaston Bachelard is contextualized in the second half of the twentieth century too, he writhed the Poetic of the Space on 1957. His philosophy was influenced based on the study of the four natural elements, up to the conception of intimate space, namely that of the house. The Bachelard house description corresponds to the Carl Gustav Jung’s theses about the soul life and the soul stadium. In this paper we analyse the correspondences between an intimate conception of the lived space and an architectural progressive thought. Throw the examples of Le Corbusier’s Unité d’Habitation and of Le Corbusier’s Cabanon we try to explain the emotional, intimate and secret dynamic of a current Space Philosophy. Mots clés: Unités, Modulor, Architecture, Mouvement Moderne, Gaston Bachelard, Poétique de l’espace, Espace intime. Keywords: Unités, Modulor, Architecture, Gaston Bachelard, Space Philosophy, Intimate Space. DOI: http://dx.doi.org/10.4995/LC2015.2015.1045
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Serra, Juan, Jorge Llopis, Ana Torres et Manuel Giménez. « Criterios de combinación de colores para la arquitectura en Salubra I : estudio de tonos ». Dans LC2015 - Le Corbusier, 50 years later. Valencia : Universitat Politècnica València, 2015. http://dx.doi.org/10.4995/lc2015.2015.570.
Texte intégralRésumé :
Resumen: Realizamos un nuevo estudio de las combinaciones de colores seleccionados por Le Corbusier en los ‘claviers’ para la empresa de papeles pintados Salubra en 1931, mediante su análisis en el espacio de color Natural Color System NCS, que permite comprender las variables perceptivas de los colores (tono, negrura y cromaticidad) y sus criterios de armonía. En este artículo discutimos las gamas tonales seleccionadas y aquellas que están ausentes., e intentamos desentrañar el orden subyacente en las combinaciones de colores mediante el estudio de las similitudes y contrastes de sus tonalidades en NCS. De manera gráfica, se demuestran algunos principios de armonía como el recurso habitual de contrastar tonos fríos con cálidos, algo que difiere ligeramente del tradicional contraste de complementariedad. El trabajo completo ha sido publicado en Color Research and Application © Wiley Periodicals. Color combination criteria in Le Corbusier's Purist architecture based on Salubra claviers from 1931. DOI: 10.1002/col.21940. Abstract: We have carried out a new study of the color combinations selected by Le Corbusier in the ‘claviers’ for the Salubra wallpaper company in 1931, by analyzing them in the Natural Color System NCS, which allows us to understand the perceptive variables of colors (hue, blackness and chromaticness) as well as their combination criteria. In this paper, the selected hue ranges are discussed, and those absent ones. We aim to find out the underlying order in the color combinations by studying the similarities and contrasts of their hues in NCS. We demonstrate graphically some principles in Le Corbusier’s color preferences, such as the usual resource of contrasting cool with warm colors, something slightly different to the traditional contrast of complementary colors. The complete work has been published in Color Research and Application © Wiley Periodicals. Color combination criteria in Le Corbusier's Purist architecture based on Salubra claviers from 1931. DOI: 10.1002/col.21940. Palabras clave: color, armonía; Le Corbusier; Salubra; arquitectura; Natural Color System. Keywords: color; harmony; Le Corbusier; Salubra; architecture; Natural Color System. DOI: http://dx.doi.org/10.4995/LC2015.2015.570
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Siti Nor Qamarina, M., M. R. Fatimah Rubaizah, A. Nurul Suhaira et M. Y. Norhanifah. « Exploiting epoxidized natural rubber latex (ENRL) as a starting raw material for latex-based products ». Dans ADVANCED MATERIALS FOR SUSTAINABILITY AND GROWTH : Proceedings of the 3rd Advanced Materials Conference 2016 (3rd AMC 2016). Author(s), 2017. http://dx.doi.org/10.1063/1.5010566.
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Ribeiro, J. A., S. S. Rodrigues et L. M. Brasil. « Occlusion child derived from natural latex for amblyopia treatment ». Dans 2013 Pan American Health Care Exchanges (PAHCE). IEEE, 2013. http://dx.doi.org/10.1109/pahce.2013.6568293.
Texte intégralRapports d'organisations sur le sujet "Latex naturel"
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Vessel, E. M. Investigation of natural latex rubber gloves. Office of Scientific and Technical Information (OSTI), mars 1993. http://dx.doi.org/10.2172/10188886.
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Hudgens, Bian, Jene Michaud, Megan Ross, Pamela Scheffler, Anne Brasher, Megan Donahue, Alan Friedlander et al. Natural resource condition assessment : Puʻuhonua o Hōnaunau National Historical Park. National Park Service, septembre 2022. http://dx.doi.org/10.36967/2293943.
Texte intégralRésumé :
Natural Resource Condition Assessments (NRCAs) evaluate current conditions of natural resources and resource indicators in national park units (parks). NRCAs are meant to complement—not replace—traditional issue- and threat-based resource assessments. NRCAs employ a multi-disciplinary, hierarchical framework within which reference conditions for natural resource indicators are developed for comparison against current conditions. NRCAs do not set management targets for study indicators, and reference conditions are not necessarily ideal or target conditions. The goal of a NRCA is to deliver science-based information that will assist park managers in their efforts to describe and quantify a park’s desired resource conditions and management targets, and inform management practices related to natural resource stewardship. The resources and indicators emphasized in a given NRCA depend on the park’s resource setting, status of resource stewardship planning and science in identifying high-priority indicators, and availability of data and expertise to assess current conditions for a variety of potential study resources and indicators. Puʻuhonua o Hōnaunau National Historical Park (hereafter Puʻuhonua o Hōnaunau NHP) encompasses 1.7 km2 (0.7 mi2) at the base of the Mauna Loa Volcano on the Kona coast of the island of Hawaiʻi. The Kona coast of Hawaiʻi Island is characterized by calm winds that increase in the late morning to evening hours, especially in the summer when there is also a high frequency of late afternoon or early evening showers. The climate is mild, with mean high temperature of 26.2° C (79.2° F) and a mean low temperature of 16.6° C (61.9° F) and receiving on average 66 cm (26 in) of rainfall per year. The Kona coast is the only region in Hawaiʻi where more precipitation falls in the summer than in the winter. There is limited surface water runoff or stream development at Puʻuhonua o Hōnaunau NHP due to the relatively recent lava flows (less than 1,500 years old) overlaying much of the park. Kiʻilae Stream is the only watercourse within the park. Kiʻilae Stream is ephemeral, with occasional flows and a poorly characterized channel within the park. A stream gauge was located uphill from the park, but no measurements have been taken since 1982. Floods in Kiʻilae Stream do occur, resulting in transport of fluvial sediment to the ocean, but there are no data documenting this phenomenon. There are a small number of naturally occurring anchialine pools occupying cracks and small depressions in the lava flows, including the Royal Fishponds; an anchialine pool modified for the purpose of holding fish. Although the park’s legal boundaries end at the high tide mark, the sense of place, story, and visitor experience would be completely different without the marine waters adjacent to the park. Six resource elements were chosen for evaluation: air and night sky, water-related processes, terrestrial vegetation, vertebrates, anchialine pools, and marine resources. Resource conditions were determined through reviewing existing literature, meta-analysis, and where appropriate, analysis of unpublished short- and long-term datasets. However, in a number of cases, data were unavailable or insufficient to either establish a quantitative reference condition or conduct a formal statistical comparison of the status of a resource within the park to a quantitative reference condition. In those cases, data gaps are noted, and comparisons were made based on qualitative descriptions. Overall, the condition of natural resources within Puʻuhonua o Hōnaunau NHP reflects the surrounding landscape. The coastal lands immediately surrounding Puʻuhonua o Hōnaunau NHP are zoned for conservation, while adjacent lands away from the coast are agricultural. The condition of most natural resources at Puʻuhonua o Hōnaunau NHP reflect the overall condition of ecological communities on the west Hawai‘i coast. Although little of the park’s vegetation...
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Haggart, J. W., L. T. Dafoe, K. M. Bell, G L Williams, E. T. Burden, L. D. Currie, R. A. Fensome et A. R. Sweet. Historical development of a litho- and biostratigraphic framework for onshore Cretaceous-Paleocene deposits along western Baffin Bay. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/321828.
Texte intégralRésumé :
Cretaceous-Paleogene strata along the eastern coast of Baffin Island, on Bylot Island, and on associated islands north of Cape Dyer, have been known since the early days of exploration of Baffin Bay in the mid-nineteenth century. Studies of these strata in the 1970s-1990s established their clastic nature and revealed details of their stratigraphy, ages, and depositional settings. Onshore strata in the Cape Dyer area accumulated in close association with volcanic deposits related to late-stage rifting in the Late Cretaceous to Early Paleocene that eventually formed Baffin Bay. In contrast, deposits in more northerly areas, such as the Eclipse and North Bylot troughs on Bylot Island, exhibit similar clastic rocks, but lack conspicuous volcanic strata, and have been associated with either the Sverdrup Basin or the Baffin Bay rift. The litho- and biostratigraphy of these deposits are summarized and discussed in terms of differing and contrasting stratigraphic interpretations, age assignments, and depositional environments.
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Raymond, Kara, Laura Palacios et Evan Gwilliam. Status of climate and water resources at Big Bend National Park : Water year 2019. Sous la direction de Tani Hubbard. National Park Service, septembre 2022. http://dx.doi.org/10.36967/2294267.
Texte intégralRésumé :
Climate and hydrology are major drivers of ecosystem structure and function, particularly in arid and semi-arid ecosystems. Understanding changes in climate, groundwater, streamflow, and water quality is central to assessing the condition of park resources. This report combines data collected on climate, groundwater, and springs at Big Bend National Park (NP) to provide an integrated look at climate and water conditions during water year (WY) 2019 (October 2018–September 2019). However, this report does not address the Rio Grande or its tributaries. Annual precipitation was higher than normal (1981–2010) for Big Bend NP at four of the five National Oceanic and Atmospheric Administration Cooperative Observer Program weather stations: 111% of normal for Chisos Basin, 122% of normal for Panther Junction, 155% of normal for Persimmon Gap, and 124% of normal for Rio Grande Village. Castolon had 88% of normal annual precipitation. All five stations had higher than normal rainfall in October and December, while rainfall totals were substantially below normal at all stations in November, February, and March. Monthly precipitation totals for April through September were more variable from station to station. Mean monthly maximum air temperatures were below normal in the fall months, with Panther Junction as much as 7.5°F below normal in October. Monthly temperatures from January through July were more variable. Temperatures in August and September were warmer than normal at every station, up to +9.4°F at Rio Grande Village and +8.7°F at Chisos Basin in July. The reconnaissance drought index values indicate generally wetter conditions (based on precipitation and evaporative demand) at Chisos Basin since WY2016 and at Panther Junction and Persimmon Gap since WY2015, except for WY2017. This report presents the manual and automatic groundwater monitoring results at nine wells. Five wells had their highest water level in or just before WY2019: Panther Junction #10 peaked at 99.94 ft below ground surface (bgs) in September 2018, Contractor’s Well peaked at 31.43 ft bgs in November 2018, T-3 peaked at 65.39 ft bgs in December 2018, K-Bar #6 Observation Well peaked at 77.78 ft bgs in February 2019, and K-Bar #7 Observation Well peaked at 43.18 ft bgs in February 2019. This was likely in response to above normal rainfall in the later summer and fall 2018. The other monitoring wells did not directly track within-season precipitation. The last measurement at Gallery Well in WY2019 was 18.60 ft bgs. Gallery Well is located 120 feet from the river and closely tracked the Rio Grande stage, generally increasing in late summer or early fall following higher flow events. Water levels in Gambusia Well were consistently very shallow, though the manual well measurement collected in April was 4.25 ft bgs—relatively high for the monitoring record—and occurred outside the normal peak period of later summer and early fall. The last manual measurement taken at TH-10 in WY2019 was 34.80 ft bgs, only 0.45 ft higher than the earliest measurement in 1967, consistent with the lack of directional change in groundwater at this location, and apparently decoupled from within-season precipitation patterns. The last water level reading in WY2019 at Oak Springs #1 was 59.91 ft bgs, indicating an overall decrease of 26.08 ft since the well was dug in 1989. The Southwest Network Collaboration (SWNC) collects data on sentinel springs annually in the late winter and early spring following the network springs monitoring protocol. In WY2019, 18 sentinel site springs were visited at Big Bend NP (February 21, 2019–March 09, 2019). Most springs had relatively few indications of natural and anthropogenic disturbances. Natural disturbances included recent flooding, drying, and wildlife use. Anthropogenic disturbances included flow modifications (e.g., springboxes), hiking trails, and contemporary human use. Crews observed one to seven facultative/obligate wetland plant...
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DeVivo, Joseph C. Inventories 2.0 : A plan for the next generation of NPS natural resource inventories. National Park Service, 2019. http://dx.doi.org/10.36967/2266646.
Texte intégralRésumé :
This Inventory 2.0 plan identifies IMD’s planned role in each of the ten inventories, and lays out a framework for ensuring the inventories led by IMD result in scientifically credible information for parks resource management, planning, and operations; and also identifies the means by which studies to collect new inventory data will be identified, prioritized, and implemented. Highlights include: IMD plans to lead three of the ten inventories (Species, Vegetation Community Mapping, and Surficial Geology/Soils Mapping), and contribute to the others in partnership with other programs. For the three IMD-led inventories, IMD will develop (or work with the Geologic Resources Division to develop) peer-reviewed inventory science plans that will lay out inventory objectives; and methods for data management, analysis, and integration to ensure that credible and useful inventory data are provided to parks in a timely manner. IMD will phase in implementation of IMD-led inventories during the first five years of program implementation. This will allow IMD to focus near-term efforts on meeting needs identified by the greatest number of parks (Species) while conducting necessary scoping to further refine needs for Vegetation Community Mapping and Surficial Geology/Soils Mapping inventories. During the next two years, IMD inventory efforts will be focused on implementing the Species Inventory, beginning with foundational work in advance of field data collection efforts to be funded in 2020. Additional scoping to identify suitable methods and minimum product specifications for Vegetation Community and Surficial Geology/Soils Mapping will be conducted in 2019-2020. These two new inventories will be phased in based on findings from scoping and progress toward closing out existing (1.0) inventory efforts. All I&M parks will be eligible for IMD funding to support inventories (see Appendix A). Non-I&M parks established before 2000 may be eligible for studies and activities to collect new inventory data pending approval of the project by the IMD Leadership Team. Inventories 2.0 funding cannot be spent to collect new data in parks established in 2000 or later, that are not currently served by an I&M network. Existing data from other sources may still be synthesized and delivered to these parks, however. Inventories 2.0 funding will not be used to fund programs or initiatives already funded or implemented by other programs or agencies. We will endeavor to partner with these entities when possible and appropriate to meet inventory needs identified in this plan, and to ensure IMD-created inventory (and monitoring) data are available to support other programs. Data and other information products resulting from new IMD-funded inventory studies will be managed by IMD rather than third-party repositories. This does not preclude sharing data with third parties or use of third-party tools or data distribution systems. At a minimum IMD commits to make inventory data available to others via the NPS Data Store (https://irma.nps.gov/DataStore/) as well as data and/or map services. To the extent possible, IMD management of inventory data will use the data management infrastructure used for managing monitoring data. This includes a commitment to leverage data, tools, systems, and expertise where it already exists. Because of IMD’s explicit mandate to integrate I&M data with planning, wherever practicable, IMD commits to work with NPS Planning to ensure map and data services are integrated into NPS Atlas projects for each park or other planning tools as they are developed over time.
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Liseroudi, M. H., O. H. Ardakani, P. K. Pedersen, R. A. Stern, J M Wood et H. Sanei. Diagenetic and geochemical controls on H2S distribution in the Montney Formation, Peace River region, western Canada. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329785.
Texte intégralRésumé :
The Lower Triassic Montney Formation is a major siltstone dominated unconventional tight gas play in the Western Canadian Sedimentary Basin (WCSB). In the Peace River region, the Montney Formation contains a regionally variable amount of hydrogen sulfide (H2S) in gas-producing wells with western Alberta's wells having the highest concentrations. Previous studies on the source and distribution of H2S in the Montney Formation mainly focused on variations of H2S concentration and its relationship with other hydrocarbon and non-hydrocarbon gases, sulfur isotope composition of H2S, as well as organo-sulfur compounds in the Montney Formation natural gas. None of those studies, however, focused on the role of diagenetic and geochemical processes in the formation of dissolved sulfate, one of the two major ingredients of H2S formation mechanisms, and pyrite within the Montney Formation. According to the results of this study, the Montney Formation consists of two different early and late generations of sulfate minerals (anhydrite and barite), mainly formed by the Montney Formation pore water and incursion of structurally-controlled Devonian-sourced hydrothermal sulfate-rich fluids. In addition, pyrite the dominate sulfide mineral, occurred in two distinct forms as framboidal and crystalline that formed during early to late stages of diagenesis in western Alberta (WAB) and northeast British Columbia (NEBC). The concurrence of the late-stage anhydrite and barite and various types of diagenetic pyrite with high H2S concentrations, particularly in WAB, their abundance, and spatial distribution, imply a correlation between the presence of these sulfate and sulfide species and the diagenetic evolution of sulfur in the Montney Formation. The sulfur isotope composition of anhydrite/barite, H2S, and pyrite demonstrates both microbial and thermochemical sulfate reduction (MSR and TSR) controlled the diagenetic sulfur cycle of the Montney Formation. The relationship between the delta-34S values of the present-day produced gas H2S and other sulfur-bearing species from the Montney and other neighboring formations verifies a dual native and migrated TSR-derived origin for the H2S gas with substantial contributions of in situ H2S in the Montney reservoir.
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Kerr, D. E. Reconnaissance surficial geology, Brichta Lake, Nunavut, NTS 76-P. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329670.
Texte intégralRésumé :
Preliminary surficial geology studies, based on air photo interpretation and limited legacy field data in the Brichta Lake map area, provide an understanding of the distribution and nature of surficial materials, and regional glacial history. The terrain is characterized by extensive glacial and meltwater scouring that has affected bedrock outcrops, and eroded hummocky and streamlined till, till blankets, and till veneers in the southwest regions. Streamlined bedrock and till landforms indicate ice flow towards the northwest and north-northwest during the last glaciation. Subglacial meltwater corridors and broader erosional zones, trending north-northwest, consisting of eskers, washed till veneer, ridged till, and scoured bedrock, result from late-phase ablation of the ice sheet during deglaciation. Glaciomarine and postglacial marine sediments extend discontinuously inland from the Queen Maud Gulf to 200 m a.s.l. elevation, notably up Tingmeak and Ellice rivers and their tributaries. In some eastern parts of the map area below 160 m a.s.l. elevation, thick marine deposits form plains that blanket broad shallow valleys.
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van der Sloot, Bart. The Quality of Life : Protecting Non-personal Interests and Non-personal Data in the Age of Big Data. Universitätsbibliothek J. C. Senckenberg, Frankfurt am Main, 2021. http://dx.doi.org/10.21248/gups.64579.
Texte intégralRésumé :
Under the current legal paradigm, the rights to privacy and data protection provide natural persons with subjective rights to protect their private interests, such as related to human dignity, individual autonomy and personal freedom. In principle, when data processing is based on non-personal or aggregated data or when such data pro- cesses have an impact on societal, rather than individual interests, citizens cannot rely on these rights. Although this legal paradigm has worked well for decades, it is increasingly put under pressure because Big Data processes are typically based indis- criminate rather than targeted data collection, because the high volumes of data are processed on an aggregated rather than a personal level and because the policies and decisions based on the statistical correlations found through algorithmic analytics are mostly addressed at large groups or society as a whole rather than specific individuals. This means that large parts of the data-driven environment are currently left unregu- lated and that individuals are often unable to rely on their fundamental rights when addressing the more systemic effects of Big Data processes. This article will discuss how this tension might be relieved by turning to the notion ‘quality of life’, which has the potential of becoming the new standard for the European Court of Human Rights (ECtHR) when dealing with privacy related cases.
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Fields, Michael J., Mordechai Shemesh et Anna-Riitta Fuchs. Significance of Oxytocin and Oxytocin Receptors in Bovine Pregnancy. United States Department of Agriculture, août 1994. http://dx.doi.org/10.32747/1994.7568790.bard.
Texte intégralRésumé :
Oxytocin has multiple actions in bovine reproductive tract and it was our purpose to determine the nature of these actions and their significance for the physiology of bovine reproduction. The bovine oxytocin receptors (OTR) gene was cloned and its expression studied during the cycle and pregnancy. OTR mRNA changed in parallel with OTR with control occurring mainly at the transcriptional level. However, the endocrine regulation of OTR were found in endometrium and cervical mucosa at estrus and at parturition. In both tissues OTR were suppressed in the luteal phase and early pregnancy. Whereas cervical OTR remained suppressed throughout pregnancy, endometrial OTR began to increase soon after implantation and reached higher concentrations in midpregnancy than at estrus. OTR in caruncles did not increase until third trimester, and OTR in cervical mucosa, cotyledons and fetal membranes increased only at term. Myometrial OTR showed less variation and OTR were present throughout the cycle and pregnancy but increased significantly during mid- and late pregnancy. OTR were localized in endometrial epithelial cells and lumina epithelial cells of cervical mucosa as determined by immunohistochemistry. Endometrial OTR were functional throughout pregnancy and mediated PGF release from day 50 onwards in a receptor density related manner. OTR in cervical mucosa mediated PGE release both in vivo and in vitro, as shown in cyclic cows. The ontogeny of uterine OTR was studied from third trimester fetal stage until puberty. OTR were present in endometrium and cervical mucosa in high concentrations throughout this period; myometrial OTR began to increase somewhat later but also reached adult values by 6-mo of age. In the prepuberal heifers OT injections failed to initiate PGF2a, release. The influence of steroids on the effect of OT was examined. Ovariectomy and E2 were without effect, but P4 with or without E2 induced a massive PGF2a release in response to OT in spite of reduced OTR. Bovine cyclooxygenases (COX-1 and COX-2) were cloned and their expression studied in the endometrium of prepuberal heifers and pregnant cows. Untreated and E2 treated prepuberal heifers did not express COX-2 but P4 treated heifers did express the mRNA for COX-2, albeit weakly. During the second half of pregnancy COX-2 mRNA was strongly expressed in cotyledons and somewhat less in caruncles, whereas endometrium, myometrium and cervical mucosa showed only weak, if any, COX-2 mRNA under basal conditions. However, 2 h after OT injection significant increases in COX-2 mRNA were found in endometrial RNA. Thus OT is capable of inducing the expression of the inducible COX-2 gene, and hence the conversion of arachidonic acid to prostanoids. The results indicate that the functions of OT are numerous and probably essential for successful pregnancy and parturition.
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Czosnek, Henryk Hanokh, Dani Zamir, Robert L. Gilbertson et Lucas J. William. Resistance to Tomato Yellow Leaf Curl Virus by Combining Expression of a Natural Tolerance Gene and a Dysfunctional Movement Protein in a Single Cultivar. United States Department of Agriculture, juin 2000. http://dx.doi.org/10.32747/2000.7573079.bard.
Texte intégralRésumé :
Background The tomato yellow leaf curl disease (TYLCV) has been a major deterrent to tomato production in Israel for the last 20 years. This whitefly-transmitted viral disease has been found in the Caribbean Island in the early 1990s, probably as an import from the Middle East. In the late 1990s, the virus has spread to the US and is now conspicuous in Florida and Georgia. Objectives Because of the urgency facing the TYLCV epidemics, there was a compelling need to mobilize scientists to develop tomato variety resistant to TYLCV. The major goal was to identify the virus movement protein (MP) and to express a defective from of MP in a cultivar that contained the natural Ty-1 resistance gene. The research included 1. cloning of the TYLCV isolate from the Dominican Republic (DR) which is (or a close variant) also present in the continental USA; 2. ddefining the role of the MP; 3. mutating the putative MP gene; 4. introducing the modified gene into an advance Ty-1 line; 5. testing the transgenic plants in the field. The pressing threat to tomato production in the US resulted in an extension of the objectives: more emphasis was placed on characterization of TYLCV i the DR, on determination of the epidemiology of the virus in the DR, and on using new TYLCV resistance sources for tomato breeding. Achievements and signification 1. The characterization of TYLCV-DR allowed for more effective TYLCV management strategies that are now implemented in the DR. 2. The identification of the TYLCV MPs and, more importantly, insight into their function has provided a model for how these proteins function in TYLCV movement and support the targeting of one or more of these proteins in a dominant lethal strategy to engineer plants for TYLCV resistance. 3. The transgenic plants that are being generated with wild-type and mutated TYLCV MPs will serve to test the hypothesis that interference with one or more of the TYLCV movement proteins will be a strategy for generating TYLCV-resistant plants. 4. The fine mapping of the resistance Ty-1 gene allowed eliminating deleterious chromosome segments from the wild tomato genitor L. chilense. It may in a near future allow the cloning of the first geminivirus resistance gene. 5. Another resistance source from the wild tomato species L. hirsitum was introgressed into the domesticated tomato, resulting in the production of resistant breeding lines. Implications 1. The monitoring of TYLCV in whiteflies has been applied in the DR. These tools are presently being used to assist in the evaluation of the host-free period and to help select the appropriate locations for growing tomatoes in the DR. 2. An overall strategy to obtain resistance against TYLCV has been used. The expression of wild-type or mutated TYLCV MPs in transgenic tomato is another addition to the arsenal used to fight TYLCV, together with marker assisted breeding and mobilization of additional resistant genes from the wild.