999 resultados para PLATE FORMATION


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Il existe quatre filières de formation pour les psychologues conseillères et conseillers en orientation scolaire et professionnelle en Suisse. Une d'entre elles est de niveau universitaire et les trois autres sont de niveau post-grade (deuxième ou troisième cycle). Une des filières post-grade est proposée par une Université de sciences appliquées. Tout en étant spécifiques aux régions linguistiques, ces formations rendent compte d'un profil de compétences défini au niveau national. Le modèle théorique qui fonde généralement ces formations est éclectique. L'apprentissage social et la problématique de l'ajustement au contexte sont également des aspects qui constituent cette approche intégrative.

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The Cerro Quema district, located on the Azuero Peninsula, Panama, is part of a large regional hydrothermal system controlled by regional faults striking broadly E-W, developed within the Río Quema Formation. This formation is composed of volcanic, sedimentary and volcano-sedimentary rocks indicating a submarine depositional environment, corresponding to the fore-arc basin of a CretaceousPaleogene volcanic arc. The structures observed in the area and their tectono-stratigraphic relationship with the surrounding formations suggest a compressive and/or transpressive tectonic regime, at least during Late CretaceousOligocene times. The igneous rocks of the Río Quema Formation plot within the calc-alkaline field with trace and rare earth element (REE) patterns of volcanic arc affinity. This volcanic arc developed on the Caribbean large igneous province during subduction of the Farallon Plate. Mineralization consists of disseminations of pyrite and enargite as well as a stockwork of pyrite and barite with minor sphalerite, galena and chalcopyrite, hosted by a subaqueous dacitic lava dome of the Río Quema Formation. Gold is present as submicroscopic grains and associated with pyrite as invisible gold. A hydrothermal alteration pattern with a core of advanced argillic alteration (vuggy silica with alunite, dickite, pyrite and enargite) and an outer zone of argillic alteration (kaolinite, smectite and illite) has been observed. Supergene oxidation overprinted the hydrothermal alteration resulting in a thick cap of residual silica and iron oxides. The ore minerals, the alteration pattern and the tectono-volcanic environment of Cerro Quema are consistent with a high sulfidation epithermal system developed in the Azuero peninsula during pre-Oligocene times.

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While genetic mutation is a hallmark of cancer, many cancers also acquire epigenetic alterations during tumorigenesis including aberrant DNA hypermethylation of tumor suppressors, as well as changes in chromatin modifications as caused by genetic mutations of the chromatin-modifying machinery. However, the extent of epigenetic alterations in cancer cells has not been fully characterized. Here, we describe complete methylome maps at single nucleotide resolution of a low-passage breast cancer cell line and primary human mammary epithelial cells. We find widespread DNA hypomethylation in the cancer cell, primarily at partially methylated domains (PMDs) in normal breast cells. Unexpectedly, genes within these regions are largely silenced in cancer cells. The loss of DNA methylation in these regions is accompanied by formation of repressive chromatin, with a significant fraction displaying allelic DNA methylation where one allele is DNA methylated while the other allele is occupied by histone modifications H3K9me3 or H3K27me3. Our results show a mutually exclusive relationship between DNA methylation and H3K9me3 or H3K27me3. These results suggest that global DNA hypomethylation in breast cancer is tightly linked to the formation of repressive chromatin domains and gene silencing, thus identifying a potential epigenetic pathway for gene regulation in cancer cells.

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Single-stranded DNA (ssDNA) plays a major role in several biological processes. It is therefore of fundamental interest to understand how the elastic response and the formation of secondary structures are modulated by the interplay between base pairing and electrostatic interactions. Here we measure force-extension curves (FECs) of ssDNA molecules in optical tweezers set up over two orders of magnitude of monovalent and divalent salt conditions, and obtain its elastic parameters by fitting the FECs to semiflexible models of polymers. For both monovalent and divalent salts, we find that the electrostatic contribution to the persistence length is proportional to the Debye screening length, varying as the inverse of the square root of cation concentration. The intrinsic persistence length is equal to 0.7 nm for both types of salts, and the effectivity of divalent cations in screening electrostatic interactions appears to be 100-fold as compared with monovalent salt, in line with what has been recently reported for single-stranded RNA. Finally, we propose an analysis of the FECs using a model that accounts for the effective thickness of the filament at low salt condition and a simple phenomenological description that quantifies the formation of non-specific secondary structure at low forces.

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[Introduction (extrait)] Il existe de nombreuses formations destinées à prévenir la maltraitance envers les personnes âgées. A ce jour, leur efficacité n'est cependant pas prouvée, faute d'évaluation de leur impact sur les pratiques professionnelles. La formation PREMALPA, qui existe depuis 2003, a fait l'objet d'une évaluation en 2013.

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A conditional heat-sensitive mutation in the cdc14 gene of the fission yeast Schizosaccharomyces pombe results in failure to form a septum. Cells become highly elongated and multinucleate as growth and nuclear division continue in the absence of cell division. This article describes the cloning of the cdc14 gene and the identification of its product, a protein of 240 amino acids, p28cdc14. A null allele of the cdc14 gene shows that the gene is essential for septum formation and completion of the cell-division cycle. Overexpression of the gene product, p28cdc14, causes cell-cycle arrest in late G2 before mitosis. Cells leaking past the block activate p34cdc2 kinase and show condensed chromosomes, but the normal rearrangements of the microtubules and microfilaments that are associated with the transition from interphase to mitosis do not occur. Overexpression of p28cdc14 in mutants, in which the timing of mitosis is altered, suggests that these effects may be mediated upstream of the mitotic inhibitor wee1. These data are consistent with the idea that p28cdc14 may play a role in both the initiation of mitosis and septum formation and, by doing so, be part of the mechanism that coordinates these two cell-cycle events.

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Much of the analytical modeling of morphogen profiles is based on simplistic scenarios, where the source is abstracted to be point-like and fixed in time, and where only the steady state solution of the morphogen gradient in one dimension is considered. Here we develop a general formalism allowing to model diffusive gradient formation from an arbitrary source. This mathematical framework, based on the Green's function method, applies to various diffusion problems. In this paper, we illustrate our theory with the explicit example of the Bicoid gradient establishment in Drosophila embryos. The gradient formation arises by protein translation from a mRNA distribution followed by morphogen diffusion with linear degradation. We investigate quantitatively the influence of spatial extension and time evolution of the source on the morphogen profile. For different biologically meaningful cases, we obtain explicit analytical expressions for both the steady state and time-dependent 1D problems. We show that extended sources, whether of finite size or normally distributed, give rise to more realistic gradients compared to a single point-source at the origin. Furthermore, the steady state solutions are fully compatible with a decreasing exponential behavior of the profile. We also consider the case of a dynamic source (e.g. bicoid mRNA diffusion) for which a protein profile similar to the ones obtained from static sources can be achieved.

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OBJECTIVE: To determine whether infusion line compliance contributes to irregular drug delivery during vertical displacement of syringe pumps. DESIGN: Five different commercially available infusion lines were studied at infusion rates of 0.5, 1.0, and 1.5 ml/h. Zero drug delivery time was measured after acute line loop formation (70 cm) using an electronic balance. Compliance of each infusion line was calculated using a pressure transducer and measurement of the occlusion release bolus at 300 mmHg occlusion pressure. Finally, the influence of infusion line compliance on drug delivery during acute lowering of the syringe pump was studied using low- and high-compliance infusion lines. RESULTS: Acute line loop formation resulted in zero drug delivery time from 5.1 +/- 1.5 to 44.0 +/- 6.8 s at flow rates of 0.5 ml/h. Increased flow rates significantly reduced loop-induced flow variability. A close correlation was found between zero drug delivery time and calculated infusion line compliance at 0.5 ml/h (linear regression R2 = 0.79). Lowering of the syringe pump 50 cm prolonged zero drug delivery time from 295.8 +/- 20.7 s with the low-compliance tube to 463.3 +/- 24.0 s with the high-compliance infusion line. CONCLUSIONS: Infusion line compliance contributes to irregular drug delivery associated with vertical displacement of syringe pumps. Siphoning of the infusion line during patient care should be avoided, and flow rates of 1 ml/h or higher are recommended. Low-compliance infusion lines are indicated whenever highly short-acting vasoactive drugs at low delivery rates are administered.

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PIDD (p53-induced protein with a death domain [DD]), together with the bipartite adapter protein RAIDD (receptor-interacting protein-associated ICH-1/CED-3 homologous protein with a DD), is implicated in the activation of pro-caspase-2 in a high molecular weight complex called the PIDDosome during apoptosis induction after DNA damage. To investigate the role of PIDD in cell death initiation, we generated PIDD-deficient mice. Processing of caspase-2 is readily detected in the absence of PIDDosome formation in primary lymphocytes. Although caspase-2 processing is delayed in simian virus 40-immortalized pidd(-/-) mouse embryonic fibroblasts, it still depends on loss of mitochondrial integrity and effector caspase activation. Consistently, apoptosis occurs normally in all cell types analyzed, suggesting alternative biological roles for caspase-2 after DNA damage. Because loss of either PIDD or its adapter molecule RAIDD did not affect subcellular localization, nuclear translocation, or caspase-2 activation in high molecular weight complexes, we suggest that at least one alternative PIDDosome-independent mechanism of caspase-2 activation exists in mammals in response to DNA damage.

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The study area. located north of Konva (Central Turkey), is composed of Silurian to Cretaceous metamorphosed rocks. The lower unit of the oldest formation (Silurian-Early Permian) is mostly made up of Silurian-Early Carboniferous metacarbonates. These rocks pass laterally and vertically to Devonian-Early Permian series having continental margin, shallow water and pelagic characteristics. They are intruded or juxtaposed to different kinds of metamagmatic rocks. which show MORB. continental arc and within plate characteristics. The Palaeozoic units are covered unconformably by Triassic-Cretaceous metasedimentary units. All these rocks are overthrusted by Mesozoic ophiolites. The Palaeozoic sequence can be seen as a northern Palaeotethys passive, then active margin. The northward subduction of the Palaeotethys ocean during the Carboniferous-Triassic times, induced the development of a magmatic arc and fore-arc sequence (Carboniferous-Permian). Before the Early Triassic (?Late Permian) time. the fore-arc sequence was uplifted above sea level and eroded. The Triassic sequences are regarded as marking the onset of back-arc opening and detachment of the Anatolian Konya block from the active Eurasian margin. Finally. a suture zone formed during the Carman between the Konya region and the Menderes-Tauride Cimmerian block due to the closing of Palaeotethvs. This geodynamic evolution can be correlated with the evolution of the Karaburun sequence in western Turkey.

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The paper deals with the stratigraphic and structural setting of the sedimentary sequence cropping out in southeastern Zanskar and adjacent Lahul areas. The Tibetan Zone succession of southeastern Zanskar consists of about 6000 m of sediments, Late Precambrian~ ?Eocene in age, arranged in two superposed slabs (Pugh tal Unit, below, and Zangla Unit, above) tectonically resting upon the High Himalayan Crystalline. The Pughtal sequence, mostly terrigenous with carbonate units in the Cambrian, Silurian and Carboniferous, is about 2500 m thick. It was deposited from ?Late Precambrian to Carboniferous or ?Early Permian. The Permian Panjal Traps constitute the "sole" of the Zangla Unit, whose sedimentary sequence, about 3000 m thick, mainly carbonatic, spans from Late Permian (Kuling Formation) to Middle Jurassic (Kioto Limestone) in eastern Zanskar. In the Zangla area Late Jurassic/Cretaceous formations (Spiti Shales, Giumal Sandstone, Chikkim Limestone) are also present. Towards northwest, the sequence ranges up to Paleocene (Spanboth Formation) and ?Eocene (Chulung La Slates). Au nord de la Haute Chaine, dans la partie septentrionale de I'Himalaya, la marge continentale indienne a vu plus de 6000 m de sediments se deposer depuis I'Infracambrien jusqu'a I'Eocene. Lors de l'orogenese himalayenne, ces sediments ont ete decolles de leur substratum originel, dMormes et metamorphises de maniere differenciee suivant leur position. Ils reposent en contact tectonique sur la nappe cristalline du Haut-Himalaya. L'unite inferieure ou unite de Pughtal consiste, la ou elle est complete, en plus de 2500 m de sediments en partie detritiques terrigenes mais marque par l'edification de plates-formes carbonatees au Cambrien, Silurien et Carbonifere. Dans cette unite on releve deux grandes sequences sedimentaires separees par l'evenement epirogenique et magmatique tardi-Cambrien (500 rna), contrecoup de l'orogenese pan-africaine. Un niveau massif de vo1canites basaltiques permiennes ~ les Panjal Traps ~ forme la base ou sole de I'unite superieure (nappe de Zangla). Cette unite, plissee de maniere disharmonique, recouvre progressivement vers l'ouest des niveaux de plus en plus anciens de l'unite inferieure, niveaux eux-memes replisses en grands plis couches kilometriques a vergence nord. Dans la partie occidentale (Ringdom) l'unite superieure repose directement sur la nappe cristalline. Cette unite montre une serie sedimentaire avec des carbonates de plate-forme bien developpes au Trias superieur et au Lias puis des sediments surtout pelagiques et en partie detritiques terrigenes au Jurassique superieur et au Cretace. Des la fin du Cretace et jusqu'au Paleocene superieur s'edifie a nouveau une plate-forme peu profonde. La serie se termine par des couches continentales attribuees a l'Eocene. L'evolution geodynamique durant Ie Paleozoique et Ie Mesozoique est analysee. II en ressort que la sedimentation, a partir de I'Ordovicien, est regJee plus par des grands cycles eustatiques que par des mouvements tectoniques ou epirogeniques regionaux (les orogeneses caledoniennes, hercyniennes et cretacees des auteurs).