985 resultados para neurofunctional reorganization
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The discovery of exhumed continental mantle and hyper-extended crust in present-day magma-poor rifted margins is at the origin of a paradigm shift within the research field of deep-water rifted margins. It opened new questions about the strain history of rifted margins and the nature and composition of sedimentary, crustal and mantle rocks in rifted margins. Thanks to the benefit of more than one century of work in the Alps and access to world-class outcrops preserving the primary relationships between sediments and crustal and mantle rocks from the fossil Alpine Tethys margins, it is possible to link the subsidence history and syn-rift sedimentary evolution with the strain distribution observed in the crust and mantle rocks exposed in the distal rifted margins. In this paper, we will focus on the transition from early to late rifting that is associated with considerable crustal thinning and a reorganization of the rift system. Crustal thinning is at the origin of a major change in the style of deformation from high-angle to low-angle normal faulting which controls basin-architecture, sedimentary sources and processes and the nature of basement rocks exhumed along the detachment faults in the distal margin. Stratigraphic and isotopic ages indicate that this major change occurred in late Sinemurian time, involving a shift of the syn-rift sedimentation toward the distal domain associated with a major reorganization of the crustal structure with exhumation of lower and middle crust. These changes may be triggered by mantle processes, as indicated by the infiltration of MOR-type magmas in the lithospheric mantle, and the uplift of the Brianconnais domain. Thinning and exhumation of the crust and lithosphere also resulted in the creation of new paleogeographic domains, the Proto Valais and Liguria-Piemonte domains. These basins show a complex, 3D temporal and spatial evolution that might have evolved, at least in the case of the Liguria-Piemonte basin, in the formation of an embryonic oceanic crust. The re-interpretation of the rift evolution and the architecture of the distal rifted margins in the Alps have important implications for the understanding of rifted margins worldwide, but also for the paleogeographic reconstruction of the Alpine domain and its subsequent Alpine compressional overprint.
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Production flow analysis (PFA) is a well-established methodology used for transforming traditional functional layout into product-oriented layout. The method uses part routings to find natural clusters of workstations forming production cells able to complete parts and components swiftly with simplified material flow. Once implemented, the scheduling system is based on period batch control aiming to establish fixed planning, production and delivery cycles for the whole production unit. PFA is traditionally applied to job-shops with functional layouts, and after reorganization within groups lead times reduce, quality improves and motivation among personnel improves. Several papers have documented this, yet no research has studied its application to service operations management. This paper aims to show that PFA can well be applied not only to job-shop and assembly operations, but also to back-office and service processes with real cases. The cases clearly show that PFA reduces non-value adding operations, introduces flow by evening out bottlenecks and diminishes process variability, all of which contribute to efficient operations management.
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RESUMEN: La emergencia de nuevas ciencias y tecnologías vienen acompañadas de nuevas dinámicas en la producción, el uso y la diseminación de nuevos conocimientos científicos y tecnológicos. Estas nuevas dinámicas se reflejan en la reorganización de las actividades científicas, en la creación o la reorientación de nuevas temáticas en la investigación, en la emergencia de nuevas preocupaciones y debates sobre los riesgos e implicaciones sociales, y en la participación de nuevos actores en el desarrollo de la ciencia y la tecnología, entre otros factores. En este artículo se presentan los resultados del estudio sobre las funciones de un organismo con orígenes filantrópicos y no gubernamental que ha sido central en el desarrollo de los sistemas microelectromecánicos (MEMS) en México. Las funciones que se analizan han sido y son desarrolladas en las diferentes etapas del desarrollo de esta tecnología emergente en este país. Además de mostrar las funciones desempeñadas por este tipo de organismo, este texto se cuestiona sobre la modelización de las relaciones entre las diferentes entidades presentes en el desarrollo e instalación de nuevas tecnologías. En las conclusiones intentamos avanzar algunos elementos para tomar en cuenta estos organismos y enriquecer los estudios sociales sobre las nuevas ciencias y tecnologías. ABSTRACT: The emergence of new sciences and technologies come with new dynamics in the production, use and dissemination of new scientific and technological knowledge. These new dynamics are reflected in the reorganization of scientific activities, in creating or redirecting new topics in research, in the emergence of new concerns and debates about the risks and social implications, and the participation of new actors in the development of science and technology, among other factors. This article presents the results of the study on the functions of an organism with philanthropic and non-governmental sources that has been central to the development of microelectromechanical systems (MEMS) in Mexico. The functions have been discussed and are developed at different stages of development of this emerging technology in this country. In addition to showing the functions of such a body, this text is questioned on modeling the relationships between the various entities in the development and deployment of new technologies. In the conclusions we try moving some elements to take into account these organisms and enrich social studies on the new sciences and technologies.
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The Department of Cultural Affairs was created in the state government reorganization in 1986. The department’s two divisions, the Iowa Arts Council and the State Historical Society (SHSI) have a much longer history of service to Iowans. With such a rich history, it is fitting that the Department of Cultural Affairs calls the State Historical Museum home, a facility which collects, preserves and showcases Iowa’s treasures that itself can trace its roots in state government back 120 years. Generations of Iowans have been touched by the programs and services provided through this department. Though organized as one department, the DCA has never undergone strategic planning as a single, cohesive organization. With a desire to move forward as a stronger, more unified entity, a departmentwide strategic planning process becomes critical to future success as the department continues to better assess its resources and expertise internally, while ensuring it is focused on the common goal of leveraging cultural resources across the state of Iowa.
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Recent experiments with amyloid-beta (Aß) peptides indicate that the formation of toxic oligomers may be an important contribution to the onset of Alzheimer's disease. The toxicity of Aß oligomers depend on their structure, which is governed by assembly dynamics. However, a detailed knowledge of the structure of at the atomic level has not been achieved yet due to limitations of current experimental techniques. In this study, replica exchange molecular dynamics simulations are used to identify the expected diversity of dimer conformations of Aß10-35 monomers. The most representative dimer conformation has been used to track the dimer formation process between both monomers. The process has been characterized by means of the evolution of the decomposition of the binding free energy, which provides an energetic profile of the interaction. Dimers undergo a process of reorganization driven basically by inter-chain hydrophobic and hydrophilic interactions and also solvation/desolvation processes.
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This study investigated behavioural and electro-cortical reorganizations accompanying intentional switching between two distinct bimanual coordination tapping modes (In-phase and Anti-phase) that differ in stability when produced at the same movement rate. We expected that switching to a less stable tapping mode (In-to-Anti switching) would lead to larger behavioural perturbations and require supplementary neural resources than switching to a more stable tapping mode (Anti-to-In switching). Behavioural results confirmed that the In-to-Anti switching lasted longer than the Anti-to-In switching. A general increase in attention-related neural activity was found at the moment of switching for both conditions. Additionally, two condition-dependent EEG reorganizations were observed. First, a specific increase in cortico-cortical coherence appeared exclusively during the In-to-Anti switching. This result may reflect a strengthening in inter-regional communication in order to engage in the subsequent, less stable, tapping mode. Second, a decrease in motor-related neural activity (increased beta spectral power) was found for the Anti-to-In switching only. The latter effect may reflect the interruption of the previous, less stable, tapping mode. Given that previous results on spontaneous Anti-to-In switching revealing an inverse pattern of EEG reorganization (decreased beta spectral power), present findings give new insight on the stability-dependent neural correlates of intentional motor switching. © 2010 Elsevier Ireland Ltd. All rights reserved
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BACKGROUND: An auditory perceptual learning paradigm was used to investigate whether implicit memories are formed during general anesthesia. METHODS: Eighty-seven patients who had an American Society of Anesthesiologists physical status of I-III and were scheduled to undergo an elective surgery with general anesthesia were randomly assigned to one of two groups. One group received auditory stimulation during surgery, whereas the other did not. The auditory stimulation consisted of pure tones presented via headphones. The Bispectral Index level was maintained between 40 and 50 during surgery. To assess learning, patients performed an auditory frequency discrimination task after surgery, and comparisons were made between the groups. General anesthesia was induced with thiopental and maintained with a mixture of fentanyl and sevoflurane. RESULTS: There was no difference in the amount of learning between the two groups (mean +/- SD improvement: stimulated patients 9.2 +/- 11.3 Hz, controls 9.4 +/- 14.1 Hz). There was also no difference in initial thresholds (mean +/- SD initial thresholds: stimulated patients 31.1 +/- 33.4 Hz, controls 28.4 +/- 34.2 Hz). These results suggest that perceptual learning was not induced during anesthesia. No correlation between the bispectral index and the initial level of performance was found (Pearson r = -0.09, P = 0.59). CONCLUSION: Perceptual learning was not induced by repetitive auditory stimulation during anesthesia. This result may indicate that perceptual learning requires top-down processing, which is suppressed by the anesthetic.
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Peripheral neurons can regenerate after axotomy; in this process, the role of cytoskeletal proteins is important because they contribute to formation and reorganization, growth, transport, stability and plasticity of axons. In the present study, we examined the effects of thyroid hormones (T3) on the expression of major cytoskeletal proteins during sciatic nerve regeneration. At various times after sciatic nerve transection and T3 local administration, segments of operated nerves from T3-treated rats and control rats were examined by Western blotting for the presence of neurofilament, tubulin and vimentin. Our results revealed that, during the first week after surgery, T3 treatment did not significantly alter the level of NF subunits and tubulin in the different segments of operated nerves compared to control nerves. Two or 4 weeks after operation, the concentration of NF-H and NF-M isoforms was clearly increased by T3 treatment. Moreover, under T3-treatment, NF proteins appeared more rapidly in the distal segment of operated nerves. Likewise, the levels of betaIII, and of acetylated and tyrosinated tubulin isotypes, were also up-regulated by T3-treatment during regeneration. However, only the tyrosinated tubulin form appeared earlier in the distal nerve segments. At this stage of regeneration, T3 had no effect on the level of vimentin expression. In conclusion, thyroid hormone improves and accelerates peripheral nerve regeneration and exerts a positive effect on cytoskeletal protein expression and transport involved in axonal regeneration. These results help us to understand partially the mechanism by which thyroid hormones enhance peripheral nerve regeneration. The stimulating effect of T3 on peripheral nerve regeneration may have considerable therapeutic potential.
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AIMS: A fundamental phenomenon in inflammation is the loss of endothelial barrier function, in which the opening of endothelial cell junctions plays a central role. However, the molecular mechanisms that ultimately open the cell junctions are largely unknown.¦METHODS AND RESULTS: Impedance spectroscopy, biochemistry, and morphology were used to investigate the role of caveolin-1 in the regulation of thrombin-induced opening of cell junctions in cultured human and mouse endothelial cells. Here, we demonstrate that the vascular endothelial (VE) cadherin/catenin complex targets caveolin-1 to endothelial cell junctions. Association of caveolin-1 with VE-cadherin/catenin complexes is essential for the barrier function decrease in response to the pro-inflammatory mediator thrombin, which causes a reorganization of the complex in a rope ladder-like pattern accompanied by a loss of junction-associated actin filaments. Mechanistically, we show that in response to thrombin stimulation the protease-activated receptor 1 (PAR-1) causes phosphorylation of caveolin-1, which increasingly associates with β- and γ-catenin. Consequently, the association of β- and γ-catenin with VE-cadherin is weakened, thus allowing junction reorganization and a decrease in barrier function. Thrombin-induced opening of cell junctions is lost in caveolin-1-knockout endothelial cells and after expression of a Y/F-caveolin-1 mutant but is completely reconstituted after expression of wild-type caveolin-1.¦CONCLUSION: Our results highlight the pivotal role of caveolin-1 in VE-cadherin-mediated cell adhesion via catenins and, in turn, in barrier function regulation.
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Aquesta pretén ser una revisió general dels processos cognitius normals i de la capacitat de reorganització cerebral en cas de dany cerebral adquirit (lesions i malalties neurodegeneratives).
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This issue review provides an update on the proposed sale of state land as defined in Senate File 2088, Government Reorganization and Efficiency Act, section 8.
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The state appropriates funds to support library services to Iowans through the State Library, the Library Service Areas, and state aid to local libraries known as Enrich Iowa. As a result of legislation enacted in 2010, the Iowa Library Association, or ILA, convened a committee to make recommendations regarding reorganization of state-funded library operations and services. The committee's recommendations have been approved by the ILA and endorsed by the State Commission of Libraries. The recommendations described involve the reorganization of the State Library and Library Service Areas.
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This issue review provides background on the establishment of full-time-equivalent, or FTE, positions and examines how FTE positions are used in the state's budgeting process. This issue review also provides historical information regarding FTE positions and personnel costs and the current status and outlook of FTE positions and salary expenditures for fiscal year 2011. In addition, this issue review outlines the new requirements included in Senate File 2088, Government Reorganization Efficiency Act, that will impact FTE levels and expenditure of salary dollars for fiscal 2011.
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We investigated how synaptic plasticity is related to the neurodegeneration process in the human dorsolateral prefrontal cortex. Pre- and postsynaptic proteins of Brodmann's area 9 from patients with Alzheimer's disease (AD) and age-matched controls were quantified by immunohistochemical methods and Western blots. The main finding was a significant increase in the expression of postsynaptic density protein PSD-95 in AD brains, revealed on both sections and immunoblots, while the expression of spinophilin, associated to spines, remained quantitatively unchanged despite qualitative changes with age and disease. Presynaptic protein alpha-synuclein indicated an increased immunohistochemical level, while synaptophysin remained unchanged. MAP2, a somatodendritic microtubule protein, as well as AD markers such as amyloid-beta protein and phosphorylated protein tau showed an increased expression on immunosections in AD. Altogether these changes suggest neuritic and synaptic reorganization in the process of AD. In particular, the significant increase in PSD-95 expression suggests a change in NMDA receptors trafficking and may represent a novel marker of functional significance for the disease.
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Spatial hearing refers to a set of abilities enabling us to determine the location of sound sources, redirect our attention toward relevant acoustic events, and recognize separate sound sources in noisy environments. Determining the location of sound sources plays a key role in the way in which humans perceive and interact with their environment. Deficits in sound localization abilities are observed after lesions to the neural tissues supporting these functions and can result in serious handicaps in everyday life. These deficits can, however, be remediated (at least to a certain degree) by the surprising capacity of reorganization that the human brain possesses following damage and/or learning, namely, the brain plasticity. In this thesis, our aim was to investigate the functional organization of auditory spatial functions and the learning-induced plasticity of these functions. Overall, we describe the results of three studies. The first study entitled "The role of the right parietal cortex in sound localization: A chronometric single pulse transcranial magnetic stimulation study" (At et al., 2011), study A, investigated the role of the right parietal cortex in spatial functions and its chronometry (i.e. the critical time window of its contribution to sound localizations). We concentrated on the behavioral changes produced by the temporarily inactivation of the parietal cortex with transcranial magnetic stimulation (TMS). We found that the integrity of the right parietal cortex is crucial for localizing sounds in the space and determined a critical time window of its involvement, suggesting a right parietal dominance for auditory spatial discrimination in both hemispaces. In "Distributed coding of the auditory space in man: evidence from training-induced plasticity" (At et al., 2013a), study B, we investigated the neurophysiological correlates and changes of the different sub-parties of the right auditory hemispace induced by a multi-day auditory spatial training in healthy subjects with electroencephalography (EEG). We report a distributed coding for sound locations over numerous auditory regions, particular auditory areas code specifically for precise parts of the auditory space, and this specificity for a distinct region is enhanced with training. In the third study "Training-induced changes in auditory spatial mismatch negativity" (At et al., 2013b), study C, we investigated the pre-attentive neurophysiological changes induced with a training over 4 days in healthy subjects with a passive mismatch negativity (MMN) paradigm. We showed that training changed the mechanisms for the relative representation of sound positions and not the specific lateralization themselves and that it changed the coding in right parahippocampal regions. - L'audition spatiale désigne notre capacité à localiser des sources sonores dans l'espace, de diriger notre attention vers les événements acoustiques pertinents et de reconnaître des sources sonores appartenant à des objets distincts dans un environnement bruyant. La localisation des sources sonores joue un rôle important dans la façon dont les humains perçoivent et interagissent avec leur environnement. Des déficits dans la localisation de sons sont souvent observés quand les réseaux neuronaux impliqués dans cette fonction sont endommagés. Ces déficits peuvent handicaper sévèrement les patients dans leur vie de tous les jours. Cependant, ces déficits peuvent (au moins à un certain degré) être réhabilités grâce à la plasticité cérébrale, la capacité du cerveau humain à se réorganiser après des lésions ou un apprentissage. L'objectif de cette thèse était d'étudier l'organisation fonctionnelle de l'audition spatiale et la plasticité induite par l'apprentissage de ces fonctions. Dans la première étude intitulé « The role of the right parietal cortex in sound localization : A chronometric single pulse study » (At et al., 2011), étude A, nous avons examiné le rôle du cortex pariétal droit dans l'audition spatiale et sa chronométrie, c'est-à- dire le moment critique de son intervention dans la localisation de sons. Nous nous sommes concentrés sur les changements comportementaux induits par l'inactivation temporaire du cortex pariétal droit par le biais de la Stimulation Transcrânienne Magnétique (TMS). Nous avons démontré que l'intégrité du cortex pariétal droit est cruciale pour localiser des sons dans l'espace. Nous avons aussi défini le moment critique de l'intervention de cette structure. Dans « Distributed coding of the auditory space : evidence from training-induced plasticity » (At et al., 2013a), étude B, nous avons examiné la plasticité cérébrale induite par un entraînement des capacités de discrimination auditive spatiale de plusieurs jours. Nous avons montré que le codage des positions spatiales est distribué dans de nombreuses régions auditives, que des aires auditives spécifiques codent pour des parties données de l'espace et que cette spécificité pour des régions distinctes est augmentée par l'entraînement. Dans « Training-induced changes in auditory spatial mismatch negativity » (At et al., 2013b), étude C, nous avons examiné les changements neurophysiologiques pré- attentionnels induits par un entraînement de quatre jours. Nous avons montré que l'entraînement modifie la représentation des positions spatiales entraînées et non-entrainées, et que le codage de ces positions est modifié dans des régions parahippocampales.