1,721,173 research outputs found
Learning perceptual skills: behavioral probes into adult cortical plasticity
No full textRecent studies of the improvement of perceptual performance as a function of training - perceptual learning - have provided new insights into the neuronal substrates of this type of skill learning in the adult brain. Issues such as where in the brain, when and under what conditions practice-related changes occur are under investigation. The results of these studies suggest that a behaviorally relevant degree of plasticity is retained in the adult cortex, even within early, low-level representations in sensory and motor processing streams. The acquisition and retention of skills may share many characteristics with the functional plasticity subserving early-life learning and development. While the specificity of learning provides localization constraints, an important clue to the nature of the underlying neuronal changes is the time course of learning
Nitric oxide synthase in the adult and developing thalamus: Histochemical and immunohistochemical study in the rat
No full textThe distribution of neuronal elements that express nitric oxide synthase (NOS), the synthetic enzyme of the free radical nitric oxide, was investigated in the adult and developing rat thalamus by means of NADPH-diaphorase (NADPH-d) histochemistry, which is a marker of NOS. Immunocytochemistry was also used to confirm the equivalence between the histochemical pattern of staining and the distribution of the expression of the neuronal NOS isoform. In the adult thalamus, NADPH-d-positive and NOS-immunoreactive perikarya were selectively concentrated along the midline (in the paraventricular, rhomboid, and central medial nuclei) and in the dorsal and ventral lateral geniculate nuclei. Isolated clusters of stained neurons were also observed in the lateral posterior nucleus, in the dorsal part of the medial geniculate nucleus, and in the ventromedial nucleus. Positive perikarya were either absent or very sparse in the other thalamic nuclei. Many thalamic domains were, however, characterized by distinct patterns of NADPH-d-positive fibers, preterminal and terminal-like elements. The highest density of stained neuropil was observed in the anteroventral and anteromedial nuclei, in several of the midline nuclei, in the anterior intralaminar nuclei, and in the lateral and medial geniculate nuclei. Although histochemical reactivity was observed in the thalamus at birth, the intensity and the pattern of distribution of staining observed in adulthood was not achieved until the end of the third postnatal week. The NADPH-d histochemical positivity followed discrete developmental schedules in various thalamic domains, and different areas reached a mature pattern at different ages. In addition, populations of transiently stained neuronal cell bodies were observed in the medial thalamus during the first two postnatal weeks. These results show discrete patterns of expression of NOS in the adult and developing thalamus and suggest that nitric oxide may be involved in selected physiological and developmental roles in different thala mic domains
“L’intervento organizzativo autogestito. Sviluppi e applicazioni dell’Audit dell’apprendimento organizzativo ”
No full textFIG. 1 in Ecological distribution and reproductive period of the hermit crab Loxopagurus loxochelis (Anomura, Diogenidae) on the northern coast of São Paulo State, Brazil
No full textFIG. 1. Map of the Ubatuba region showing the transects sampled.Published as part of Bertini, G., Fransozo, A. & Braga, A. A., 2004, Ecological distribution and reproductive period of the hermit crab Loxopagurus loxochelis (Anomura, Diogenidae) on the northern coast of São Paulo State, Brazil, pp. 2331-2344 in Journal of Natural History 38 (18) on page 2333, DOI: 10.1080/00222930310001625905, http://zenodo.org/record/467618
FIG. 4 in Ecological distribution and reproductive period of the hermit crab Loxopagurus loxochelis (Anomura, Diogenidae) on the northern coast of São Paulo State, Brazil
No full textFIG. 4. Loxopagurus loxochelis. Temporal distribution of individuals collected in the Ubatuba region from January to December 2000.Published as part of Bertini, G., Fransozo, A. & Braga, A. A., 2004, Ecological distribution and reproductive period of the hermit crab Loxopagurus loxochelis (Anomura, Diogenidae) on the northern coast of São Paulo State, Brazil, pp. 2331-2344 in Journal of Natural History 38 (18) on page 2336, DOI: 10.1080/00222930310001625905, http://zenodo.org/record/467618
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Calcolo del piano di imaging
No full textTechnical Report WP1.1_B Dept. of Information Engineering, Univ. of Pis
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