Literatura académica sobre el tema "Cortex actine"

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Artículos de revistas sobre el tema "Cortex actine"

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CAVALCANTI, FERNANDA F., HANS TORE RAPP y MICHELLE KLAUTAU. "Taxonomic revision of Leucascus Dendy, 1892 (Porifera: Calcarea) with revalidation of Ascoleucetta Dendy & Frederick, 1924 and description of three new species". Zootaxa 3619, n.º 3 (28 de febrero de 2013): 275–314. http://dx.doi.org/10.11646/zootaxa.3619.3.3.

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Sponges of the genus Leucascus are frequently recognised as possessing anastomosed tubes with choanocytes, and cortical and atrial membranes with pinacocytes. In the last years, five species of other genera were transferred to Leucascus, and several other species were suggested but not formally included in this genus. In the present work, all these species accepted or suggested as Leucascus were revised. According to our results, Leucascus is now composed of nine species: L. clavatus, L. leptoraphis comb. nov., L. lobatus, L. neocaledonicus, L. protogenes comb. nov., L. roseus, L. simplex (type species), L. albus sp. nov., and L. flavus sp. nov. The presence of spines in the apical actine of the tetractines had never been observed in Leucascus, but it was found in all species with tetractines in their skeletons. Some species were transferred from Leucascus to the genus Ascoleucetta, which is revalidated here based on important differences in the cortex. Modifications are also proposed in the definition of both genera. Based on our results, the family Leucascidae is now composed of Ascaltis, Leucascus and Ascoleucetta.
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Staddon, Michael F., Edwin M. Munro y Shiladitya Banerjee. "Pulsatile contractions and pattern formation in excitable actomyosin cortex". PLOS Computational Biology 18, n.º 3 (30 de marzo de 2022): e1009981. http://dx.doi.org/10.1371/journal.pcbi.1009981.

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The actin cortex is an active adaptive material, embedded with complex regulatory networks that can sense, generate, and transmit mechanical forces. The cortex exhibits a wide range of dynamic behaviours, from generating pulsatory contractions and travelling waves to forming organised structures. Despite the progress in characterising the biochemical and mechanical components of the actin cortex, the emergent dynamics of this mechanochemical system is poorly understood. Here we develop a reaction-diffusion model for the RhoA signalling network, the upstream regulator for actomyosin assembly and contractility, coupled to an active actomyosin gel, to investigate how the interplay between chemical signalling and mechanical forces regulates stresses and patterns in the cortex. We demonstrate that mechanochemical feedback in the cortex acts to destabilise homogeneous states and robustly generate pulsatile contractions. By tuning active stress in the system, we show that the cortex can generate propagating contraction pulses, form network structures, or exhibit topological turbulence.
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Cytrynbaum, E. N., P. Sommi, I. Brust-Mascher, J. M. Scholey y A. Mogilner. "Early Spindle Assembly in Drosophila Embryos: Role of a Force Balance Involving Cytoskeletal Dynamics and Nuclear Mechanics". Molecular Biology of the Cell 16, n.º 10 (octubre de 2005): 4967–81. http://dx.doi.org/10.1091/mbc.e05-02-0154.

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Mitotic spindle morphogenesis depends upon the action of microtubules (MTs), motors and the cell cortex. Previously, we proposed that cortical- and MT-based motors acting alone can coordinate early spindle assembly in Drosophila embryos. Here, we tested this model using microscopy of living embryos to analyze spindle pole separation, cortical reorganization, and nuclear dynamics in interphase-prophase of cycles 11-13. We observe that actin caps remain flat as they expand and that furrows do not ingress. As centrosomes separate, they follow a linear trajectory, maintaining a constant pole-to-furrow distance while the nucleus progressively deforms along the elongating pole-pole axis. These observations are incorporated into a model in which outward forces generated by zones of active cortical dynein are balanced by inward forces produced by nuclear elasticity and during cycle 13, by Ncd, which localizes to interpolar MTs. Thus, the force-balance driving early spindle morphogenesis depends upon MT-based motors acting in concert with the cortex and nucleus.
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4

McCall, Patrick M., Frederick C. MacKintosh, David R. Kovar y Margaret L. Gardel. "Cofilin drives rapid turnover and fluidization of entangled F-actin". Proceedings of the National Academy of Sciences 116, n.º 26 (12 de junio de 2019): 12629–37. http://dx.doi.org/10.1073/pnas.1818808116.

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The shape of most animal cells is controlled by the actin cortex, a thin network of dynamic actin filaments (F-actin) situated just beneath the plasma membrane. The cortex is held far from equilibrium by both active stresses and polymer turnover: Molecular motors drive deformations required for cell morphogenesis, while actin-filament disassembly dynamics relax stress and facilitate cortical remodeling. While many aspects of actin-cortex mechanics are well characterized, a mechanistic understanding of how nonequilibrium actin turnover contributes to stress relaxation is still lacking. To address this, we developed a reconstituted in vitro system of entangled F-actin, wherein the steady-state length and turnover rate of F-actin are controlled by the actin regulatory proteins cofilin, profilin, and formin, which sever, recycle, and assemble filaments, respectively. Cofilin-mediated severing accelerates the turnover and spatial reorganization of F-actin, without significant changes to filament length. We demonstrate that cofilin-mediated severing is a single-timescale mode of stress relaxation that tunes the low-frequency viscosity over two orders of magnitude. These findings serve as the foundation for understanding the mechanics of more physiological F-actin networks with turnover and inform an updated microscopic model of single-filament turnover. They also demonstrate that polymer activity, in the form of ATP hydrolysis on F-actin coupled to nucleotide-dependent cofilin binding, is sufficient to generate a form of active matter wherein asymmetric filament disassembly preserves filament number despite sustained severing.
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Sanders, M. C. y Y. L. Wang. "Assembly of actin-containing cortex occurs at distal regions of growing neurites in PC12 cells". Journal of Cell Science 100, n.º 4 (1 de diciembre de 1991): 771–80. http://dx.doi.org/10.1242/jcs.100.4.771.

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Although actin filaments are known to be localized in the cortex of axons and in the growth cones of nerve cells, it is unclear how actin-containing structures are assembled during nerve growth. We have studied the formation of actin structures in growing neurites by microinjecting fluorescent phalloidin or actin into PC12 neuron-like cells to label endogenous actin filaments. Upon stimulation of neurite growth in cells microinjected with fluorescent phalloidin, little or no fluorescence was detected in nascent growth cones and adjacent neurites despite the presence of actin filaments in these regions, suggesting that actin filaments were primarily formed by de novo assembly rather than the transport and reorganization of pre-existing, phalloidin-labeled actin filaments. Time-lapse observations of the distribution of phalloidin-labeled actin filaments during neurite elongation confirmed that fluorescence associated with pre-existing neurite cortex spread out more slowly than the elongation of neurites. Furthermore, when a dark spot was photobleached with a laser microbeam along neurites of cells microinjected with either fluorescent phalloidin or actin, the spot showed no appreciable translocation during active neurite elongation. Taken together, these results suggest that de novo assembly of actin filaments plays a crucial role in the formation of growth cones and adjacent cortex in the distal region of neurites, but does not appear to require the anterograde or retrograde transport of cortical filaments, or the passive stretching of the proximal segment of the neurite cortex.
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Gilyazutdinova, Z. Sh, G. V. Sukhanova y A. A. Kilensky. "Hormone-active adrenal cortex tumors". Kazan medical journal 66, n.º 2 (15 de abril de 1985): 159. http://dx.doi.org/10.17816/kazmj61215.

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Gilyazutdinova, Z. Sh, G. V. Sukhanova y A. A. Kalensky. "Hormone-active adrenal cortex tumors". Kazan medical journal 66, n.º 2 (15 de abril de 1985): 103–5. http://dx.doi.org/10.17816/kazmj60734.

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Considering the comparative rarity of hormonally active tumors of the adrenal cortex with androgenic effect and the complexity of their diagnosis, we present our observations. From 1980 to 1983, among women with neuroendocrine pathology, 4 patients aged 23 to 27 years were diagnosed with adrenal cortex tumors.
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8

Koester, Darius V., Kabir Husain, Elda Iljazi, Scott Hansen, Dyche R. Mullins, Madan Rao y Satyajit Mayor. "In Vitro Reconstitution of Remodeling Actin Asters - Steps towards a Minimal Active Actomyosin Cortex". Biophysical Journal 106, n.º 2 (enero de 2014): 170a. http://dx.doi.org/10.1016/j.bpj.2013.11.964.

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Eda, Masatoshi, Shigenobu Yonemura, Takayuki Kato, Naoki Watanabe, Toshimasa Ishizaki, Pascal Madaule y Shuh Narumiya. "Rho-dependent transfer of Citron-kinase to the cleavage furrow of dividing cells". Journal of Cell Science 114, n.º 18 (15 de septiembre de 2001): 3273–84. http://dx.doi.org/10.1242/jcs.114.18.3273.

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Citron-kinase (Citron-K) is a Rho effector working in cytokinesis. It is enriched in cleavage furrow, but how Rho mobilizes Citron-K remains unknown. Using anti-Citron antibody and a Citron-K Green Fluorescence Protein (GFP)-fusion, we monitored its localization in cell cycle. We have found: (1) Citron-K is present as aggregates in interphase cells, disperses throughout the cytoplasm in prometaphase, translocates to cell cortex in anaphase and accumulates in cleavage furrow in telophase; (2) Rho colocalizes with Citron-K in the cortex of ana- to telophase cells and the two proteins are concentrated in the cleavage furrow and to the midbody; (3) inactivation of Rho by C3 exoenzyme does not affect the dispersion of Citron-K in prometaphase, but prevented its transfer to the cell cortex, and Citron-K stays in association with the midzone spindles of C3 exoenzyme-treated cells. To clarify further the mechanism of the Rho-mediated transfer and concentration of Citron-K in cleavage furrow, we expressed active Val14RhoA in interphase cells expressing GFP-Citron-K. Val14RhoA expression transferred Citron-K to the ventral cortex of interphase cells, where it formed band-like structures in a complex with Rho. This structure was localized at the same plane as actin stress fibers, and they exclude each other. Disruption of F-actin abolished the band and dispersed the Citron-K-Rho-containing patches throughout the cell cortex. Similarly, in dividing cells, a structure composed of Rho and Citron-K in cleavage furrow excludes cortical actin cytoskeleton, and disruption of F-actin disperses Citron-K throughout the cell cortex. These results suggest that Citron-K is a novel type of a passenger protein, which is dispersed to the cytoplasm in prometaphase and associated with midzone spindles by a Rho-independent signal. Rho is then activated, binds to Citron-K and translocates it to cell cortex, where the complex is then concentrated in the cleavage furrow by the action of actin cytoskeleton beneath the equator of dividing cells.
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Hurtley, Stella M. "Actin cortex controls cell migration". Science 368, n.º 6496 (11 de junio de 2020): 1201.11–1203. http://dx.doi.org/10.1126/science.368.6496.1201-k.

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Tesis sobre el tema "Cortex actine"

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Pontani, Léa-Laetitia. "Etude biomimétique du cortex cellulaire et ses applications". Paris 6, 2009. https://tel.archives-ouvertes.fr/tel-00922820.

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Le cytosquelette des cellules est une structure composite et versatile qui leur confère des propriétés mécaniques extrêmement complexes. En particulier, le cortex d’actine qui s'assemble de manière dynamique sous la membrane cellulaire fournit la force nécessaire aux déformations et au mouvement de la cellule : la polymérisation de l'actine permet aux filaments en formation de pousser la membrane et les moteurs moléculaires génèrent des forces contractiles. L’utilisation de systèmes biomimétiques permet d’isoler des modules particuliers du cytosquelette pour les étudier indépendamment de façon simplifiée. Une expérience de reconstitution du cortex d’actine in vitro a été mise au point dans ce but. Les protéines et métabolites nécessaires pour la polymérisation de l’actine sont ainsi introduits dans un liposome et la réaction est localisée à la membrane, en y greffant l'activateur de la polymérisation de l'actine, sur le modèle du cortex cellulaire. Une fois la polymérisation déclenchée, nous sommes arrivés à reproduire un gel d’actine à la membrane, formant une coque. Les propriétés mécaniques de ce système simplifié sont alors étudiées par des expériences qui caractérisent leur dynamique d’étalement sur des surfaces. Les résultats sont comparés à ceux obtenus sur des cellules, et reproduisent une bonne partie des comportements cellulaires. On utilise également ces liposomes dans une situation physiologique: l’internalisation de la toxine de Shiga dans les cellules et nous montrons que la toxine est internalisée dans un système aussi épuré que des liposomes comportant un cortex reconstitué, prouvant le rôle important de l'actine dans ce processus.
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2

Salbreux, Guillaume. "Modélisation des instabilités du cortex d'actine". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2008. http://tel.archives-ouvertes.fr/tel-00382577.

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Le cortex d'actine est une fine couche de gel d'une épaisseur de l'ordre du micron, attaché à la membrane lipidique de la cellule. Il est constitué d'un réseau de filaments d'actine qui sont constamment polymérisés à la membrane puis dépolymérisés, dans un mouvement de « tapis roulant ». Des moteurs moléculaires, les myosines, génèrent des contraintes internes dans le gel.Le cortex contrôle ainsi les variations de forme de la cellule. Dans cette thèse nous utilisons le modèle des gels actifs pour explorer certaines propriétés du cortex d'actine. Le gel est décrit a l'échelle mésoscopique comme un matériau viscoélastique nématique dans lequel les myosines utilisent l'énergie fournie par l'hydrolyse de l'ATP pour produire des contraintes actives, c'est à dire plaçant le système hors d'équilibre thermodynamique. Dans un premier temps nous étudions de quelle façon l'épaisseur du cortex peut être régulée, et nous discutons l'apparition d'instabilités actives dans la couche. Nous utilisons l'instabilité du gel ainsi décrite pour interpréter l'observation expérimentale d'oscillations de formes de fibroblastes induites par des canaux calciques mecanosensibles. ­­En incluant un paramètre d'ordre nématique dans notre description, nous montrons que soumettre le cortex à une concentration inhomogène de myosines doit conduire à l'apparition d'un flux de filaments et à la formation d'un anneau, ainsi qu'observé dans plusieurs systèmes expérimentaux, en particulier lors de la cytocinèse. Nous terminons ce travail par une analyse de la mécanique de formation d'un bleb unique induit par une rupture artificielle du cortex par ablation laser.
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Pontani, Lea-Laetitia. "Etude Biomimétique du cortex cellulaire et ses applications". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2009. http://tel.archives-ouvertes.fr/tel-00922820.

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Le cytosquelette des cellules est une structure composite et versatile qui leur confère des propriétés mécaniques extrêmement complexes. En particulier, le cortex d'actine qui s'assemble de manière dynamique sous la membrane cellulaire fournit la force nécessaire aux déformations et au mouvement de la cellule : la polymérisation de l'actine permet aux filaments en formation de pousser la membrane et les moteurs moléculaires génèrent des forces contractiles. L'utilisation de systèmes biomimétiques permet d'isoler des modules particuliers du cytosquelette pour les étudier indépendamment de façon simplifiée. Une expérience de reconstitution du cortex d'actine in vitro a été mise au point dans ce but. Les protéines et métabolites nécessaires pour la polymérisation de l'actine sont ainsi introduits dans un liposome et la réaction est localisée à la membrane, en y greffant l'activateur de la polymérisation de l'actine, sur le modèle du cortex cellulaire. Une fois la polymérisation déclenchée, nous sommes arrivés à reproduire un gel d'actine à la membrane, formant une coque. Les propriétés mécaniques de ce système simplifié sont alors étudiées par des expériences qui caractérisent leur dynamique d'étalement sur des surfaces. Les résultats sont comparés à ceux obtenus sur des cellules, et reproduisent une bonne partie des comportements cellulaires. On utilise également ces liposomes dans une situation physiologique: l'internalisation de la toxine de Shiga dans les cellules et nous montrons que la toxine est internalisée dans un système aussi épuré que des liposomes comportant un cortex reconstitué, prouvant le rôle important de l'actine dans ce processus.
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4

Foussard, Hélène. "Les protéines LRCH : premières études chez la Drosophile". Toulouse 3, 2010. http://thesesups.ups-tlse.fr/1096/.

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Les protéines Ezrin, Radixin, et Moesin (ERM) permettent de réguler la liaison des protéines membranaires aux filaments d'actine. De nombreuses études ont montré l'implication des protéines ERM dans diverses tumeurs caractérisées par un fort pouvoir métastatique. L'équipe a récemment démontré que la dMoesin, l'unique protéine ERM de Drosophile, est requise pour l'organisation du cortex cellulaire et du fuseau mitotique pour la division cellulaire. Pour mieux comprendre les fonctions de la dMoesin, l'équipe a recherché ses partenaires fonctionnels. Un crible génétique a été réalisé et, parmi les interacteurs génétiques de la dMoesin ainsi identifiés, nous nous sommes concentrés sur la protéine dLRCH, identifiée indépendamment comme partenaire physique de la dMoesin dans un crible double hybride. DLRCH est une protéine pionnière caractérisée par la présence simultanée de domaines LRR (Leucin Rich Repeat) et CH (Calponin Homology). Nous montrons que dLRCH définit une famille de protéines évolutivement conservée de fonction encore inconnue et avons identifié 4 gènes codant pour des protéines LRCH (hLRCH) chez l'Homme. Mon projet de thèse a consisté en l'étude de la fonction éventuelle de cette nouvelle famille de protéines, les protéines LRCH, au cours de la division cellulaire. Au cours de cette étude, nous montrons que dLRCH colocalise avec la dMoesin au sillon de clivage au cours de la division cellulaire chez la Drosophile, ainsi que les protéines hLRCH avec les protéines ERM dans les cellules humaines. Grâce à une analyse fonctionnelle de dLRCH, nous mettons en évidence que son absence perturbe l'organisation du cortex mitotique, sans toutefois bloquer la division cellulaire. Pour étudier les conséquences de l'absence de dLRCH sur la physiologie de l'organisme, nous avons généré un allèle nul de ce gène chez la Drosophile. Nous montrons que le gène dlrch est exprimé dans de nombreux tissus au cours du développement, plus fortement dans certains tissus comme par exemple les gonades. Bien que nous ayons établi que dLRCH n'est pas essentiel à la division cellulaire in vivo, l'absence de dLRCH ne perturbe pas le développement ni la viabilité de la Drosophile, mais entraîne une stérilité complète, ce uniquement chez les femelles. Les individus mutants présentent également une moindre résistance aux conditions extrêmes. Ces travaux constituent donc la première étude fonctionnelle des protéines LRCH chez la Drosophile
Comparative genomics has revealed an unexpected level of conservation for gene products across the evolution of animal species. However, the molecular function of only a few proteins has been investigated experimentally, and the role of many animal proteins still remains unknown. Here we report the characterization of a novel family of evolutionary conserved proteins, which display specific features of cytoskeletal scaffolding proteins, referred to as LRCHs. Taking advantage of the existence of a single lrch gene in flies, dlrch, we explored its function in cultured cells, and show that dLRCH act to stabilize the cell cortex during cell division. DLRCH depletion leads to ectopic cortical blebs and alters positioning of the mitotic spindle. We further examined the consequences of dLRCH deletion throughout development and adult life. Although dlrch is not essential for cell division in vivo, flies lacking dlrch display a reduced fertility and fitness, particularly when raised at extreme temperatures. These results support the idea that some cytoskeletal regulators are important to buffer environmental variations and ensure the proper execution of basic cellular processes, such as the control of cell shape, under environmental variations
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5

Rosfelter, Anne. "Le positionnement du fuseau mitotique chez le zygote d'ascidie et son rôle dans la répartition des organelles". Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS063.

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Après la fécondation d’un ovocyte, un aster de microtubules se forme autour de l’ADN mâle. Cet aster spermatique permet d’amener le pro-noyau femelle jusqu’au pro-noyau mâle pour qu’ils puissent fusionner. Il permet aussi de déplacer l’ADN fusionné jusqu’au centre de la cellule pour assurer une division cellulaire équitable. Les mécanismes de centration d’un aster ou d’un fuseau ont donné lieu à de nombreuses recherches, que ce soit par modélisation, expérimentalement chez des espèces telles C. elegans, P. lividus, M.musculus ou in vitro sur des extraits de Xenopus laevis. Trois mécanismes principaux se dégagent : le pushing, le cortical pulling et le cytoplasmic pulling (ou bulk pulling). En étudiant le déplacement de l’aster et du fuseau mitotique chez le zygote de l’ascidie P. mammillata j’ai découvert un système qui combine ces trois mécanismes en s’appuyant sur l’alternance des étapes du cycle cellulaire. En méiose, l’aster utilise la polymérisation des microtubules qui le composent pour pousser contre le cortex d’actine et s’en décoller (pushing). Arrivé en interphase, l’aster retourne contre le cortex grâce à une traction qu’exerce la membrane sur les microtubules (cortical pulling). Enfin à l’entrée en mitose, la traction membranaire cesse et libère les asters du fuseau mitotique, qui cèdent donc aux forces exercées par le transport d’organelles vers le centre de l’aster (cytoplasmic pulling) qui semblent constantes durant le cycle cellulaire. Cela permet de centrer le fuseau. En même temps que l’aster se forme et se déplace, une réorganisation des compartiments intracellulaires se met en place. Pour comprendre de quelle manière l’organisation intracellulaire peut être perturbée par la formation de l’aster, j’ai étudié le cas du vitellus. En effet, le vitellus, qui est présent sous forme de vésicules, est initialement abondant et homogène dans l’ovocyte non fécondé. Cependant, dès que l’aster apparaît, sa répartition change et les vésicules de vitellus sont exclues de la zone contenant l’aster. Cette exclusion générée à la formation de l’aster chez le zygote, est maintenue au cours du développement. Dans mes travaux, j’ai pu observer qu’elle est majoritairement due à l’accumulation à l’aster d’autres organelles comme le réticulum endoplasmique. La fonction de transport des microtubules de l’aster suffit donc à réorganiser complètement la cellule en excluant certaines organelles et en en accumulant d’autres. Les déplacements de l’aster et du fuseau mitotique, leur régulation par le cycle cellulaire, et la réorganisation intracellulaire, identifiés ici chez le zygote d’ascidie, s’appuient sur le fonctionnement d’éléments fondamentaux d’une cellule, à savoir : les microtubules, le cortex d’actine, le réticulum endoplasmique, les protéines du cycle cellulaire, etc. Les découvertes présentées revêtent ainsi une portée universelle, adaptable aux spécificités de différents types cellulaires
After oocyte fertilization, a microtubule aster forms around the male DNA. The sperm aster brings the female pro-nucleus to the male pro-nucleus so they can fuse, but it also moves the fused nuclei to the cell center to ensure an equitable cell division. Numerous studies performed in vitro, by modeling or experimentally in species such as C. elegans, P. lividus, and M. musculus, addressed the aster and spindle centration mechanisms. Three main mechanisms emerged; pushing, cortical pulling, and cytoplasmic pulling. By studying aster centration in the zygote of the ascidian P. mammillata, I discovered a system that combines these three mechanisms based on the cell cycle stages. In meiosis, the aster uses the polymerization of its microtubules to push against the actin cortex and move away from it (pushing). Once in interphase, the aster returns to the cortex by a pull exerted by the membrane on the microtubules (cortical pulling). At mitosis entry, cortical pulling stops, and releases the mitotic spindle's asters. In consequence, the asters give in to the forces exerted by the transport of organelles to the aster center (cytoplasmic pulling), that appeared constant during the cell cycle. Cytoplasmic pulling hence participate in centering the spindle While the aster forms and moves, the intracellular compartments reorganize. To understand how intracellular organization can be disrupted by aster formation, I studied the case of yolk. The yolk, in the form of vesicles (called granules or platelets), is initially abundant and homogeneous in the unfertilized oocyte. However, as soon as the aster appears, its distribution changes and the yolk platelets are excluded from the region containing the aster. This exclusion generated by the aster formation in the zygote is maintained during development. I observed that yolk exclusion is mainly due to the accumulation at the aster of other organelles such as the endoplasmic reticulum. The transport function of the aster microtubules is therefore sufficient to completely reorganize the cell by excluding some organelles and accumulating others. The movements of the aster and the spindle, their regulation by cell cycle, and the intracellular reorganization, identified here in the ascidian zygote, rely on basic elements of a cell, namely: the microtubules, the actin cortex, the endoplasmic reticulum, the proteins of the cell cycle, etc. Thus, the discoveries presented here cover a broad scope, and seem adaptable to the specificities of different cell types
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Paluch, Ewa. "Motilité cellulaire sur des systèmes simplifiés : de l' oscillation au mouvement dirigé". Paris 7, 2005. http://www.theses.fr/2005PA077075.

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Lieleg, Oliver. "Model systems of the actin cortex". kostenfrei, 2008. http://mediatum2.ub.tum.de/doc/672641/672641.pdf.

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Yonis, Amina Yahya. "Molecular control of actin cortex organisation and dynamics". Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10043285/.

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The cortex is a ~100nm thick layer of F-actin located under the cell membrane, rich in myosin II and actin-binding proteins. It is essential for cytokinesis, cell locomotion, and tissue morphogenesis. Despite its importance, our knowledge of the cortex is poor. Two actin nucleators, Diaph1 and the Arp2/3 complex, have been shown to generate actin filaments in the cortex. The actin networks generated by these nucleators display clear differences in their organisation and the actin-binding proteins they recruit. Therefore, cells may be able to rapidly control their cortical mechanical properties by regulating the activity of each nucleator. When I searched for regulators of mDia1 and Arp2/3 in a proteomic analysis of the cortex, I found four candidate nucleation promotion factors (NPFs): IQGAP1, NCKIPSD, Fli-I and the WAVE complex. Interestingly, IQGAP1 and NCKIPSD interact with both Diaph1 and the Arp2/3 complex, suggesting they may participate in crosstalk. I examined the role of each NPF in the generation and maintenance of cortical actin. After examining the localisation of each NPF, I determined their impact on cortical assembly by examining how their depletion affected bleb size. Indeed, reduction in Arp2/3 activity leads to smaller blebs, while large blebs result from a decrease in Diaph1 activity. IQGAP1 and NCKIPSD depletion yielded large bleb phenotypes, WAVE gave a small bleb phenotype consistent with its role in regulating Arp2/3, and Fli-I depletion had no phenotype. Next, I examined changes in F-actin network organisation after NPF depletion with scanning electron microscopy. The density and interconnection of the network were altered, further suggesting the importance of IQGAP1, NCKIPSD and WAVE in controlling the organisation of the actin cortex. I showed that NPF depletion significantly affected successful completion of mitosis in HeLa cells. Finally, in collaboration with other students, I examined how NPFs controlled properties of cell mechanics.
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Bovellan, M. K. "Assembly and composition of the cellular actin cortex". Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1357426/.

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The actin cortex is a thin layer of F-actin, actin regulating proteins, and myosin under the cell membrane. It has a fundamental role in cell morphogenesis, motility, mitosis, cytokinesis, and cell shape maintenance. Yet, how the cell cortex forms as well as the protein composition of the cortex remain unknown. In this study using M2 melanoma cell blebs and metaphase HeLa cells I describe proteins needed for cortex reassembly and reveal the protein composition of the actin cortex. Blebs represent a natural situation in which the membrane is transiently devoid of an actin cortex. Thus the formation of a new actin cortex in the bleb can be studied. Blebs also provide a cell fraction enriched in F-actin cortex, making them an ideal model to study cortex proteomics. After having shown that no nucleation independent mechanism participate in cortex reassembly in membrane blebs, I discovered by localisation and silencing studies, that formin Diaph1 and the Arp2/3 complex are needed for the cortex nucleation, as both localised to the cortex and depletion of either led to cortical defects. Simultaneous depletion of Diaph1 and the Arp2/3 complex led to disappearance of the cellular cortex, suggesting that together they provide the majority of the F-actin in the cortex. Cortex composition studies of blebs isolated from blebbing cells revealed the presence of many actin binding proteins at the cortex. Localisation and depletion studies revealed that capping, and effective actin turnover are essential for cortical stability and that flightless-I may regulate cortex nucleation together with Rho GTPases. These findings have important implications for our understanding of cortical properties, which are not only important for cell morphogenesis and shape maintenance, but facilitate tumour growth and dissemination.
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Bohec, Pierre. "Etude du comportement hors-équilibre du cortex cellulaire". Paris 7, 2012. http://www.theses.fr/2012PA077039.

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La cellule est capable, en consommant l'énergie issue de l'hydrolyse de l’ATP, d'exercer des forces qui prennent leurs origines dans des réactions biochimiques. Un élément important de la cellule est le cytosquelette, composé principalement de microtubules et de filaments d'actine, il en constitue l'architecture et lui. Donne l'essentiel de ses propriétés mécaniques. Il est composé de polymères réticulés et, du point de vue de la rhéologie, a un comportement viscoélastique. Au sein du cytosquelette, des processus tels que la polymérisation de l'actine ou des microtubules permettent d'exercer des forces. Des protéines, de la famille des moteurs moléculaires, ont pour rôle spécifique de convertir l'énergie stockée sous forme chimique en énergie mécanique. L'activité mécanique hors-équilibre de la cellule est donc directement reliée à ces forces d'origine biochimique. Dans ce travail, nous avons étudié la distribution statistique des forces d'origine biochimique s'exerçant sur une bille de taille micrométrique attachée au cortex d'actine par l'intermédiaire des récepteurs de l'adhésion cellulaire : les intégrines. L'étude des forces d'origine biologique est inséparable de la connaissance des forces d'origine thermique car à cette échelle micrométrique la contribution des forces thermiques n'est pas négligeable. Les forces s'exerçant sur la sonde ont donc deux origines possibles : biologique ou thermique. Notre approche expérimentale est basée sur la combinaison de deux techniques de microrhéologie, active et passive, ce qui nous permet de calculer la fonction d'autocorrélation temporelle des forces exercées sur une sonde accrochée à J'actine corticale et de la comparer à la fonction d'autocorrélation des forces thermiques estimée via le théorème de fluctuation-dissipation. La différence entre ces deux spectres nous donne une idée de la contribution des forces d'origine biologique au mouvement de la bille et une mesure de l'écart du système à l'équilibre thermodynamique. Afin d'étudier plus en détail ce système de bille subissant des forces de la part de l'actine corticale, nous avons étudié l'effet de la variation de la densité de ligand recouvrant la bille. La question qui nous a animés tout au long de ce travail est l'origine de ces forces biologiques ou plus exactement la nature du composant du cytosquelette qui exerce ces forces athermiques. Dans un premier temps, nous avons étudié l'influence de la température sur ces forces biologiques. Nous avons ensuite étudié l'effet de la déplétion de l'ATP dans la cellule, de la dépolymérisation de l'actine et de l'inhibition des moteurs moléculaires de la famille des myosines
By consuming energy from the hydrolysis of ATP, cells are able to exert forces that stem from biochemical reactions. A central element of cells is the cytoskeleton, which is mainly composed of microtubules and actin filaments and accounts for the architecture and most of the mechanical properties of the cells. It is made of crosslinked polymers and, in terms of rheology, has a viscoelastic behavior. Within the cytoskeleton, processes such as actin or microtubule polymerization can exert forces. Proteins from the molecular motor family have the specific role of conveiting the energy stored in chemical form into mechanical energy. The out-of-equilibrium mechanical activity of thé cell is directly related to these forces of biochemical origin. In this work, we studied the statistical distribution of biochemical forces exerted on a micrometer-sized bead attached to the actin cortex through cell adhesion receptors: integrins. The study of the forces of biological on gin is inseparable from knowledge of the forces of thermal origin because, at this microscopic scale, the contribution of thermal forces is not negligible. The forces actin g on the probe have two possible origins: biological or thermal. Our experimental approach is based on the combination of two microrheology techniques, active and passive, which allows us to calculate the temporal autocorrelation function of the forces exerted on a probe attached to the cortical actin and compare it to the autocorrelation function of the estimated thermal forces via the fluctuation-dissipation theorem. The difference between these two spectra gives us an idea of the contribution of the forces of biological origin to the movement of the bead and a measure of the deviation of the System from thermodynamic equilibrium. To further investigate this System, i. E. A bead undergoing forces from the cortical actin, we studied the effect of varying the ligand coating density on the bead. The question that has driven us throughout this work is the origin of these biological forces or, more precisely the nature of the component of the cytoskeleton that exerts these athermal forces. Initially, we studied the influence of temperature on these biological forces. We then studied the effect of depletion of ATP in the cell, of the depolymerization of actin and of the inhibition of molecular motors of the myosin family
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Libros sobre el tema "Cortex actine"

1

Rodríguez, Claudia B. La prescripción: Según la jurisprudencia de la corte. Buenos Aires: AD-HOC, 2000.

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Salgado, José María. Los derechos de incidencia colectiva en la jurisprudencia de la Corte Suprema de Justicia de la Nación. Buenos Aires: Rubinzal-Culzoni Editores, 2010.

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Solera, Juan Manuel Gómez. La prescripción en derecho administrativo-tributario: Conjura contra su existencia durante el procedimiento determinativo, en sentencia no. 385-F-2006 de la Sala Primera de la Corte Suprema de Justicia. San José: EJC, Editorial Jurídica Continental, 2012.

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Justicia, Panama Corte Suprema de. Jurisprudencia reciente sobre prescripción penal: Fallo del 29 de Junio de 2010 de la Corte Suprema de Justicia : incidente de prescripción de la acción penal en el proceso penal seguido en contra de la licenciada Ana Matilde Gómez Ruibloba, Procuradora General de la Nación separada por la comisión de presuntos delitos contra la administración pública. Panamá: Cultural Portobelo, 2010.

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Passingham, Richard E. Understanding the Prefrontal Cortex. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198844570.001.0001.

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The primate prefrontal cortex sits at the top of the sensory, motor, and outcome processing hierarchies of the neocortex. It transforms sensory inputs into motor outputs, determining the response that is appropriate given the current context and desired outcome. This transformation involves conditional rules. The dorsal prefrontal cortex supports the learning of behavioural sequences, where the next action is conditional on the previous one. The ventral prefrontal cortex supports associations between objects, where the choice of one object is conditional on the presence of another object. However, because hierarchical processing supports the extraction of abstract representations, the primate prefrontal cortex is able to represent conditional rules that are abstract, meaning that they apply irrespective of the specific inputs. The selective advantage is that by learning these rules, primates can solve new problems rapidly when they have the same conditional logic as prior problems. The human prefrontal cortex has the same fundamental organization as in other primates. The dorsal prefrontal cortex supports the understanding of sequences and the ventral prefrontal cortex supports the ability to learn semantic associations. Thus the human prefrontal cortex has co-opted and elaborated mechanisms that were present in ancestral primates. These mechanisms can be used for new ends. For example, words have been associated with objects so as to communicate with others. This means that to understand human intelligence it is necessary to take into account the fact that the abstract rules are transmitted verbally from one generation to another.
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Vorel, Stanislav R. y Sarah H. Lisanby. Therapeutic potential of TMS-induced plasticity in the prefrontal cortex. Editado por Charles M. Epstein, Eric M. Wassermann y Ulf Ziemann. Oxford University Press, 2012. http://dx.doi.org/10.1093/oxfordhb/9780198568926.013.0038.

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This article discusses synaptic plasticity as a potential mechanism of enduring changes in function observed after relatively brief periods of repetitive (r)TMS. Plasticity is a use dependent enduring change in neural structure and function. The characteristics of plasticity are described in this article. Taking into account, the interactions between rTMS and pharmacological manipulations, this article explores how principles of synaptic plasticity may be exploited in the rational design of future rTMS paradigms in psychiatric disorders like major depressive disorder, obsessive-compulsive disorder, substance use disorders, schizophrenia etc. TMS is under active study in the treatment of a range of psychiatric and neurological disorders. Furthermore, this article discusses the implications for the interpretation of existing TMS literature and design of future interventions. TMS experiments of plasticity in the human motor cortex have been limited by the intensity and frequency of TMS protocols.
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Guillery, Ray. The subcortical motor centres. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198806738.003.0004.

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This chapter looks more closely at some of the subcortical motor centres that play a peripheral or an auxiliary role in the standard view: primarily the basal ganglia, the cerebellum, and the superior colliculus; also several brainstem centres. These all play a significant role in motor control and between them receive inputs from the majority of cortical areas. The colliculus serves as an example of a centre that in mammals is often dominated by the cortex. The cortical action may be direct or may involve a strong inhibitory pathway through the basal ganglia. The standard view assigns even quite simple actions to the motor cortex, although comparable actions can be controlled in our vertebrate ancestors by the midbrain tectum which corresponds to the mammalian superior and inferior colliculi. The interactive view has information about movements going to most parts of the cortex, and has all cortical areas contributing to motor control through phylogenetically old centres. For most cortical areas, we must still learn how their motor outputs influence our actions.
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Khan, Hasan-Uddin. Charles Correa (Architects in the Third World). Aperture, 1987.

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Charles Correa: Architect in India. Elsevier Science & Technology Books, 1987.

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Brinkmann, Svend. American Philosophies of Qualitative Research. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190247249.003.0005.

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This chapter introduces the philosophy of pragmatism and its application in the social sciences. In philosophy, there are disagreements between anti-realist pragmatists and realist pragmatists, but all strands of pragmatism conceive of the human being as an active, participating creature who knows the world through acting in it. Methodologically, the core of pragmatism is abduction. Unlike induction (going from many individual instances to general knowledge) and deduction (testing general hypotheses deduced from existing knowledge), abduction begins with a breakdown in our understanding of something and is oriented toward making the indeterminate more determinate in order to facilitate action. This chapter also argues that the pragmatist research ethos can often be described as “making the hidden dubious” because there is a focus on action—what we do, how we experience it, and what the consequences are—rather than on hidden social structures or deeper layers of the social world.
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Capítulos de libros sobre el tema "Cortex actine"

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Wu, Ye, Yoonmi Hong, Sahar Ahmad y Pew-Thian Yap. "Active Cortex Tractography". En Medical Image Computing and Computer Assisted Intervention – MICCAI 2021, 467–76. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-87234-2_44.

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Rhodes, Paul A. "Functional Implications of Active Currents in the Dendrites of Pyramidal Neurons". En Cerebral Cortex, 139–200. Boston, MA: Springer US, 1999. http://dx.doi.org/10.1007/978-1-4615-4903-1_3.

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Brinton, Roberta Diaz, Rose S. Yamazaki, Qi Chen y Michael Son. "Vasopressin Action in the Mammalian Cerebral Cortex". En Advances in Experimental Medicine and Biology, 211–13. Boston, MA: Springer US, 1998. http://dx.doi.org/10.1007/978-1-4615-4871-3_27.

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Barash, Shabtai y Mingsha Zhang. "Switching of Sensorimotor Transformations: Antisaccades and Parietal Cortex". En Percept, Decision, Action: Bridging the Gaps, 59–74. Chichester, UK: John Wiley & Sons, Ltd, 2008. http://dx.doi.org/10.1002/9780470034989.ch6.

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Fogassi, Leonardo. "Action Goal Representation and Action Understanding in the Cerebral Cortex". En Causality, Meaningful Complexity and Embodied Cognition, 57–73. Dordrecht: Springer Netherlands, 2009. http://dx.doi.org/10.1007/978-90-481-3529-5_3.

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Akkas, Nuri y Mina Kermanian. "Effect of Cortex Stiffness Variation on Cleavage in Animal Cells". En Biomechanics of Active Movement and Division of Cells, 67–85. Berlin, Heidelberg: Springer Berlin Heidelberg, 1994. http://dx.doi.org/10.1007/978-3-642-78975-5_3.

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Adams, Rick A., Karl J. Friston y Andre M. Bastos. "Active Inference, Predictive Coding and Cortical Architecture". En Recent Advances on the Modular Organization of the Cortex, 97–121. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-9900-3_7.

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Vogel, Sven K. "Reconstitution of a Minimal Actin Cortex by Coupling Actin Filaments to Reconstituted Membranes". En Cytoskeleton Methods and Protocols, 213–23. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3124-8_11.

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Mitzdorf, Ulla. "Cortical Information Processing as Viewed from the Mass-Action Domain of Evoked Potentials". En Information Processing in the Cortex, 247–51. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-49967-8_16.

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Schwichtenberg, Holger. "Active Directory". En Windows PowerShell 5.1 und PowerShell Core 6.1, 913–80. München: Carl Hanser Verlag GmbH & Co. KG, 2018. http://dx.doi.org/10.3139/9783446459236.054.

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Actas de conferencias sobre el tema "Cortex actine"

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Faghihpirayesh, Razieh, Tales Imbiriba, Mathew Yarossi, Eugene Tunik, Dana Brooks y Deniz Erdoğmuş. "Motor cortex mapping using active gaussian processes". En PETRA '20: The 13th PErvasive Technologies Related to Assistive Environments Conference. New York, NY, USA: ACM, 2020. http://dx.doi.org/10.1145/3389189.3389202.

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DALL’AGNOL, Letizzia, Alice Medeiros de SOUZA, Lilian Campos AMADEU, Eleni VOSNIADOU y Fernanda Ishida CORRÊA. "TRANSCRANIAL DIRECT STIMULATION IN THE NEUROMODULATION OF CONTROLLING MAIN SYMPTOMS OF PARKINSON’S DISEASE: A CASE STUDY". En SOUTHERN BRAZILIAN JOURNAL OF CHEMISTRY 2021 INTERNATIONAL VIRTUAL CONFERENCE. DR. D. SCIENTIFIC CONSULTING, 2022. http://dx.doi.org/10.48141/sbjchem.21scon.06_abstract_ishida.pdf.

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Parkinson’s disease (PD) is a central nervous system neurodegenerative disorder that primarily affects the motor system, decreasing motor coordination, balance and generating tremors, and a progressive loss of everyday mobility, including walking. This study was conducted to verify the effects of Transcranial Direct Current Stimulation (tDCS) on balance, motor control, and the quality of life in Parkinson’s disease patients. The patient received three treatments consisting of 10 sessions of 20 minutes each and a one-week interval between treatments. Active stimulation was applied on the primary motor cortex (M1), the dorsolateral prefrontal cortex (DLPFC), and the dorsolateral prefrontal cortex (D Sham-tDCS. DLPFC stimulation produced the best improvements in terms of motor control, balance, gait, and overall PD symptoms, as evaluated by different scales and questionnaires. As a result, active stimulation of the DLPFC produced superior outcomes and may contribute to treating Parkinson’s disease.
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Funamizu, Akihiro, Bernd Kuhn y Kenji Doya. "Action-dependent state prediction in mouse posterior parietal cortex". En 2015 International Conference on Intelligent Informatics and Biomedical Sciences (ICIIBMS). IEEE, 2015. http://dx.doi.org/10.1109/iciibms.2015.7439529.

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de Croon, Guido C. H. E. y Stefano Nolfi. "ACT-CORNER: Active corner finding for optic flow determination". En 2013 IEEE International Conference on Robotics and Automation (ICRA). IEEE, 2013. http://dx.doi.org/10.1109/icra.2013.6631243.

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ZHU, WEN-XUE, XIAO-MEI LIAN y LEI LUO. "EFFECTS OF DRYING ON ACTIVE COMPONENTS IN FOLIUM CORTEX EUCOMMIAE TEA". En The Proceedings of the 5th Asia-Pacific Drying Conference. World Scientific Publishing Company, 2007. http://dx.doi.org/10.1142/9789812771957_0143.

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Schwartz, Eric L. "Recent experimental measurements of topographic-map structure in primate V-1 and presentation of a miniature space-variant active vision system". En OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1993. http://dx.doi.org/10.1364/oam.1993.thv.1.

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This paper will present the history and current status of understanding of the spatial architecture of primary visual cortex (V-l, striate cortex, area 17) in primates. Special emphasis will be placed on experimental techniques, mathematical and computational analyses, and the relevance of V-l architecture to current work in machine vision. The intention is to provide an overview of the difficulties, both conceptual and experimental, which have characterized this field for the past fifty years, and to provide some insight into the importance of spatial architecture in visual cortex to both biological and machine vision.
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Liu, Qianhui, Dong Xing, Huajin Tang, De Ma y Gang Pan. "Event-based Action Recognition Using Motion Information and Spiking Neural Networks". En Thirtieth International Joint Conference on Artificial Intelligence {IJCAI-21}. California: International Joint Conferences on Artificial Intelligence Organization, 2021. http://dx.doi.org/10.24963/ijcai.2021/240.

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Event-based cameras have attracted increasing attention due to their advantages of biologically inspired paradigm and low power consumption. Since event-based cameras record the visual input as asynchronous discrete events, they are inherently suitable to cooperate with the spiking neural network (SNN). Existing works of SNNs for processing events mainly focus on the task of object recognition. However, events from the event-based camera are triggered by dynamic changes, which makes it an ideal choice to capture actions in the visual scene. Inspired by the dorsal stream in visual cortex, we propose a hierarchical SNN architecture for event-based action recognition using motion information. Motion features are extracted and utilized from events to local and finally to global perception for action recognition. To the best of the authors’ knowledge, it is the first attempt of SNN to apply motion information to event-based action recognition. We evaluate our proposed SNN on three event-based action recognition datasets, including our newly published DailyAction-DVS dataset comprising 12 actions collected under diverse recording conditions. Extensive experimental results show the effectiveness of motion information and our proposed SNN architecture for event-based action recognition.
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Takahashi, Marcela Tengler Carvalho, Paulo Rodrigo Bázan, Joana Bisol Balardin, Danielle de Sá Boasquevisque, Edson Amaro Júnior y Adriana Bastos Conforto. "Effect of transcranial direct current stimulation in the first weeks after stroke: a preliminary study". En XIII Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2021. http://dx.doi.org/10.5327/1516-3180.252.

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Background: There is limited information about effects of transcranial Direct Current Stimulation(tDCS), delivered within the first weeks post-stroke, on performance of the paretic upper limb and on connectivity between motor areas in the affected and unaffected hemispheres. Objectives: We compared changes in Fugl-Meyer Assessment of Motor Recovery(FMA) scores, connectivity between the primary motor cortex of the unaffected(M1UH) and the affected hemisphere(M1AH), as well as between M1UH and the premotor cortex of the unaffected hemisphere(PMUH) before and after 6 sessions of cathodal tDCS targeting the primary motor cortex of the unaffected hemisphere(M1UH) early after stroke in 13 patients. Methods: This hypothesis-generating substudy was a randomized parallel, two-arm, double-blind, sham-controlled clinical trial performed at the Albert Einstein Hospital. Subjects were randomized active(N=6) or sham(N=7) groups. Results: Clinically relevant differences in FMA scores(≥ 9 points) were observed more often in the sham than in the active group. Between-group differences in changes in FMA scores were not statistically significant(Mann-Whitney test, p=0.133) but the effect size was -0.619(rank biserial correlation). Connectivity measures(Fisher’s z- transform of ROI-to-ROI correlations) between M1AH-M1UH increased in 5/6 participants in the active, and in 2/7 in the sham group after treatment. Between-group differences in changes in connectivity(M1UH-M1AH or PMUH-M1AH) were not statistically significant. In contrast with M1AH-M1UH connectivity, improvements in motor performance were more frequent in the active than in the sham group. Conclusions: Effects of cathodal tDCS on motor performance and on Resting-state Functional Magnetic Resonance Imaging may have distinct underpinnings in subjects at an early stage after stroke.
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Huang, Lihong, Xian-gan Chen, Zhiyong Gao y Haihua Liu. "Human Action Recognition by Imitating the Simple Cells of Visual Cortex". En 2011 International Conference on Intelligent Computation and Bio-Medical Instrumentation (ICBMI). IEEE, 2011. http://dx.doi.org/10.1109/icbmi.2011.64.

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GAUDIELLO, ILARIA, MARCO TULLIO LIUZZA y DANIELE CALIGIORE. "PREFRONTAL CORTEX AND ACTION SEQUENCES: A REVIEW ON NEURAL COMPUTATIONAL MODELS". En Proceedings of Wivace 2008. WORLD SCIENTIFIC, 2009. http://dx.doi.org/10.1142/9789814287456_0011.

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Informes sobre el tema "Cortex actine"

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Gaeta, R. J., B. Murdock, A. Churny y N. Hunter. Performance Testing of the Active Core Exhaust (ACE) Fluidic Mixing System. Fort Belvoir, VA: Defense Technical Information Center, marzo de 2006. http://dx.doi.org/10.21236/ada449728.

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Busso, Matías y Samuel Berlinski. Challenges in Educational Reform: An Experiment on Active Learning in Mathematics. Inter-American Development Bank, marzo de 2015. http://dx.doi.org/10.18235/0011680.

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This paper reports the results of an experiment with secondary school students designed to improve their ability to reason, argument, and communicate using mathematics. These goals are at the core of many educational reforms. A structured pedagogical intervention was created that fostered a more active role of students in the classroom. The intervention was implemented with high fidelity and was internally valid. Students in the control group learned significantly more than those who received treatment. A framework to interpret this result is provided in which learning is the result of student-teacher interaction. The quality of such interaction deteriorated during the intervention.
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Powell, B. E., I. Henderson y R. F. Hall. The Growth of Corner Cracks Under the Conjoint Action of High and Low Cycle Fatigue. Fort Belvoir, VA: Defense Technical Information Center, febrero de 1988. http://dx.doi.org/10.21236/ada190510.

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McGarrity, J., C. Scozzie, J. Blackburn y M. DeLancey. Active in-core irradiation of SiC JFETs at 300 C in a TRIGA nuclear reactor. Office of Scientific and Technical Information (OSTI), diciembre de 1996. http://dx.doi.org/10.2172/481561.

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Rivas, Jorge y Antonio Vives. Private Infrastructure and the Inter-American Development Bank Group. Inter-American Development Bank, febrero de 1998. http://dx.doi.org/10.18235/0008894.

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This report provides a review of IDB Group activities supporting private participation in infrastructure between 1990 and 1997. It is intended to serve as a reference in the development of its infrastructure strategies. By compiling in a single document all the actions that promote private participation in infrastructure, a better appreciation will be developed, inside and outside the IDB Group, for the contribution it has made and the degree to which more action is required. Section II comments on the financial needs and sources of financing for infrastructure in Latin America and the Caribbean, highlighting the increasing importance of private financing. Section III is the core of the report, describing IDB Group actions for private infrastructure since 1990. This section is divided in four subsections according to the different fronts of activity as follows: (1) the IDB Group strategy, (2) the lending program, (3) the technical assistance program, and (4) nonfinancial activities. Section IV presents some conclusions and highlights that derive directly from a global overview of the Bank¿s seven year experience. Finally, the Annexes provide summary tables and a brief description of each project.
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Gilbert, E. R., D. D. Lanning, C. M. Dana y D. C. Hedengren. Evaluation of storing Shippingport Core II spent blanket fuel assemblies in the T Plant PWR Core II fuel pool without active cooling. Office of Scientific and Technical Information (OSTI), octubre de 1994. http://dx.doi.org/10.2172/10108233.

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LeBlanc, B., R. Bell y S. Batha. Active core profile and transport modification by application of Ion Bernstein Wave power in PBX-M. Office of Scientific and Technical Information (OSTI), enero de 1995. http://dx.doi.org/10.2172/10111028.

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Farr, J. y L. Cox. Core-level binding energy shifts of the light actinide tetrafluorides and dioxides. Office of Scientific and Technical Information (OSTI), octubre de 1989. http://dx.doi.org/10.2172/5555336.

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Gómez Mont, Constanza, Svante Persson y César Buenadicha Sánchez. Digital Tokens for Climate Action and Nature-Based Solutions: Exploration of Opportunities and Considerations. Inter-American Development Bank, abril de 2023. http://dx.doi.org/10.18235/0004834.

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Resumen
This report on digital tokens for climate action and nature-based solutions forms a valuable addition to the emerging body of knowledge and is specially intended to inform, inspire, and spur action for new, innovative, and potentially effective ways of providing financial resources and effective action for climate action and the conservation and regeneration of our natural capital. Using technology to lower costs and barriers to access, as well as a tool to generate social inclusion and democratize opportunities, is at the core of the intersection that we will be presenting in this document. Latin America and the Caribbean need to combine the opportunity that natural capital and biodiversity bring, with the acceleration of ecosystems of innovation and entrepreneurship aiming at inclusion and diversity. This report aims to add value in the understanding of how the harnessing of these digital tools can help untap opportunities in Latin America for climate action and the protection of its rich natural ecosystems.
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Armantier, Olivier y Charles Holt. Can Discount Window Stigma Be Cured? An Experimental Investigation. Federal Reserve Bank of New York, mayo de 2024. http://dx.doi.org/10.59576/sr.1103.

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A core responsibility of a central bank is to ensure financial stability by acting as the “lender of last resort” through its Discount Window. The Discount Window, however, has not been effective because its usage is stigmatized. In this paper, we study experimentally how such stigma can be cured. We find that, once a Discount Window facility is stigmatized, removing stigma is difficult. This result is consistent with the Federal Reserve’s experiences which have been unsuccessful at removing the stigma associated with its Discount Window.
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