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Reorganization Process (reorganization + process)
Selected AbstractsComparison of commissural sprouting in the mouse and rat fascia dentata after entorhinal cortex lesionHIPPOCAMPUS, Issue 6 2003Domenico Del Turco Abstract Reactive axonal sprouting occurs in the fascia dentata after entorhinal cortex lesion. This sprouting process has been described extensively in the rat, and plasticity-associated molecules have been identified that might be involved in its regulation. To demonstrate causal relationships between these candidate molecules and the axonal reorganization process, it is reasonable to analyze knockout and transgenic animals after entorhinal cortex lesion, and because gene knockouts are primarily generated in mice, it is necessary to characterize the sprouting response after entorhinal cortex lesion in this species. In the present study, Phaseolus vulgaris -leucoagglutinin (PHAL) tracing was used to analyze the commissural projection to the inner molecular layer in mice with longstanding entorhinal lesions. Because the commissural projection to the fascia dentata is neurochemically heterogeneous, PHAL tracing was combined with immunocytochemistry for calretinin, a marker for commissural/associational mossy cell axons. Using both techniques singly as well as in combination (double-immunofluorescence) at the light or electron microscopic level, it could be shown that in response to entorhinal lesion mossy cell axons leave the main commissural fiber plexus, invade the denervated middle molecular layer, and form asymmetric synapses within the denervated zone. Thus, the commissural sprouting response in mice has a considerable translaminar component. This is in contrast to the layer-specific commissural sprouting observed in rats, in which the overwhelming majority of mossy cell axons remain within their home territory. These data demonstrate an important species difference in the commissural/associational sprouting response between rats and mice that needs to be taken into account in future studies. © 2003 Wiley-Liss, Inc. [source] Light-Induced Reorganization in Self-Assembled Liquid Crystal Gels: Electrically Switchable Diffraction Gratings,ADVANCED MATERIALS, Issue 17 2003Y. Zhao Electrically switchable diffraction gratings can be formed in the self-assembled cholesteric liquid crystal gels prepared using an azobenzene-containing gelator. The grating formation (see Figure) results from a light-induced reorganization process in these materials, which leads to the removal of the nanometer-sized fibrous aggregates of the gelator from the irradiated area to the non-irradiated area. [source] Structure and dynamics of silica-filled polymers by SANS and coherent SAXSMACROMOLECULAR SYMPOSIA, Issue 1 2002Erik Geissler Random crosslinking in elastomers gives birth to local variations in the crosslink density. When the network is swollen in a low-molecular-weight solvent, competition between the osmotic pressure and the local elastic constraints transforms these variations into differences in polymer concentration, the range and amplitude of which can be measured by small-angle X-ray or neutron scattering (SAXS or SANS). In filled systems, the distribution both of the polymer and of the elastic constraints is modified. By varying the proportion of deuterated solvent in the network, the scattering function of the polymer can be distinguished from that of the filler using SANS. Such measurements yield not only the internal surface area of the filler particles but also the fraction of that surface in contact with the polymer. The recently developed technique of quasi-elastic SAXS detects slow dynamic processes at wave vectors larger than those accessible with visible light lasers. This technique is used to investigate the dynamics of filler particles in uncrosslinked polymer melts. It is directly shown that the structural reorganization process of the filler following an external mechanical perturbation is diffusion-controlled. [source] VERTICAL AND HORIZONTAL ECONOMIES IN THE ELECTRIC UTILITY INDUSTRY: AN INTEGRATED APPROACHANNALS OF PUBLIC AND COOPERATIVE ECONOMICS, Issue 3 2009Massimiliano Piacenza ABSTRACT,:,The empirical literature on the cost structure of the electric utility industry traditionally focused on the measurement of specific technological properties: 1) scale economies in generation or distribution; 2) multi-product (or horizontal) scope economies at one particular stage; 3) multi-stage (or vertical) scope economies. By adopting an integrated approach, which simultaneously considers both horizontal and vertical aspects of the technology, we find the presence, on a sample of Italian electric utilities, of both vertical integration gains and horizontal scope economies at the downstream stage. In the light of recent regulatory reforms aiming at restructuring European electricity markets, our findings have important policy implications as for the proper configuration of the industry. Moreover, this methodology can be usefully applied to the study of the production structure of other public network utilities involved in similar vertical and horizontal reorganization processes. [source] | ||||||||||