323,336 research outputs found
Le tre vie del rapporto uomo-animale: aspetti cognitivi, storico-filosofici e relazionali nella riflessione sul mondo animale.
No full textSi propone un percorso integrato che si articola secondo tre indirizzi: Il primo di impianto scientifico sperimentale e teorico metodologico, imbocca le vie regie della percezione visiva, della mente e della comunicazione animale. Il secondo, attestato sul versante storico filosofico, investe questioni cruciali quali il linguaggio, l'anima e i diritti degli animali. Infine il terzo introduce allo studio della bioetica animale, a una riflessione epistemologica sulla cura veterinaria e a un commento zooantropologico di un celebre passo di Saint Exupéry
Proteoglycan control of cell movement during wound healing and cancer spreading
No full textBy virtue of their multifunctional nature, proteoglycans (PGs) are thought to govern the process of cell movement in numerous physiological and pathological contexts, spanning from early embryonic development to tumour invasion and metastasis. The precise mode by which they influence this process is still fragmentary, but evidence is accruing that they may affect it in a multifaceted manner. PGs bound to the plasma membrane mediate the polyvalent interaction of the cell with matrix constituents and with molecules of the neighbouring cells' surfaces; they modulate the activity of receptors implicated in the recognition of these components; and they participate in the perception and convergence of growth- and motility-promoting cues contributed by soluble factors. Through some of these interactions several PGs transduce to pro-motile cells crucial intracellular signals that are likely to be essential for their mobility. A regulated shedding of certain membrane-intercalated PGs seems to provide an additional level of control of cell movement. Coincidentally, matrix-associated PGs may govern cell migration by structuring permissive and non-permissive migratory paths and, when directly secreted by the moving cells, may alternatively create favourable or hostile microenvironments. To exert this latter, indirect effect on cell movement, matrix PGs strongly rely upon their primary molecular partners, such as hyaluronan, link proteins, tenascins, collagens and low-affinity cell surface receptors, whereas a further finer control is provided by a highly regulated proteolytic processing of the PGs accounted by both the migrating cells themselves and cells of their surrounding tissues. Overall, PGs seem to play an important role in determining the migratory phenotype of a cell by initiating, directing and terminating cell movement in a spatio-temporally controlled fashion. This implies that the "anti-adhesive and/or "anti-migratory" properties that have previously been assigned to certain PGs may be re-interpreted as being a means by which these macromolecules elaborate haptotaxis-like mechanisms imposing directionality upon the moving cells. Since these conditions would allow cells to be led to given tissue locations and become immobilized at these sites, a primary function may be ascribed to PGs in the dictation of a "stop or go" choice of the migrating cells. © 2005 Elsevier B.V./International Society of Matrix Biology. All rights reserved
"Lo decisivo se juega en el presente". Un diálogo con Alejandro Cattaruzza sobre las representaciones colectivas y los usos del pasado en Argentina
No full textEn esta entrevista realizada al historiador argentino Alejandro Cattaruzza nos adentramos en su trayectoria personal y profesional para luego abordar una serie de temas y problemas teórico-metodológicos vinculados a los procesos de construcción de representaciones colectivas y los usos del pasado, a las disputas que se libran a su alrededor, así como a los modos en que aquellas representaciones y usos logran legitimidad, circulan y son recibidas en el espacio público.In this interview with Argentine historian Alejandro Cattaruzza we delve into his personal and professional career, and then address a series of theoretical and methodological issues and problems related to the processes of construction of collective representations and uses of the past, the disputes that are waged around them, as well as the ways in which these representations and uses gain legitimacy, circulate and are received in the public sphere.Fil: Amorebieta y Vera, María Laura. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.Fil: Dubois, Pamela Sofía. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.Fil: Herrera, Nicolás. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.Fil: Kahan, Emmanuel Nicolás. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina
Silver and gold doping of SiO2 glass by solid-state field-assisted diffusion
No full textIn this work, a solid-state field-assisted diffusion technique is used to induce diffusion of silver or gold ions into a silica matrix. The obtained systems are characterized by secondary ion mass spectrometry and Rutherford backscattering spectrometry. The metal/glass interface chemistry plays an important role in the behavior of the metals and, especially for Ag, a proper time is required for the deposited film to first oxidize and then diffuse into the matrix, owing to the external electric field. Diffusion of Ag in silica is observed to be very sensitive to the applied field at relatively high temperatures, being stopped when a high field value is applied. This behavior may be attributed to the low availability of sites and the build-up of local electric fields within the glass. As for gold, a quite peculiar behavior of the current density during the process was recorded, indicating that its behavior is even more complex than one could expect. In general, the presented preliminary experimental observations demonstrate the potential of the technique
S. Fenoaltea, L economia italiana dall'Unità alla grande Guerra, Roma/Bari 2006 [Rezension]
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