1,721,211 research outputs found
Fiabe e leggende: le più belle dell'Africa
No full textUna raccolta di racconti per far conoscere la complessità e la ricchezza del continente africano per scuola primaria e secondaria di primo grado. IL volume è stato un supporto per l'attività condotta nelle scuole di diverse regioni d'Italia "Favolare l'Africa"
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Ulteriori osservazioni sullo sviluppo delle propaggini del corpo dei neuroni dei gangli spinali
No full textModificazioni quantitative del condrioma nei neuroni dei gangli spinali di coniglio nel corso dell’invecchiamento
No full textWe studied the mitochondria of the neuronal perikaryon in the spinal ganglia of 12, 42 and 79 month-old rabbits. Both the volume of the perikaryon and the total mitochondrial mass within the perikaryon increased significantly passing from young adult to old animals. Hence, there is no net loss of mitochondria in these neurons with age. Since, however, the volume of the perikaryon increased by more than 63% while the total mitochondrial mass within the perikaryon increased by only 18%, the mean percentage of perikaryal volume occupied by mitochondria decreased with age. This decrease is only in very minor part a consequence of lipofuscin accumulation, so that the ratio between the total mitochondrial mass and the functionally active volume of cytoplasm decreased with age. Moreover, while the mitochondrial structure did not change, mitochondrial size increased with age. Finally, in each of the three age groups both the mean percentage volume of mitochondria and the mean mitochondrial size were very similar in large light and in small dark neurons
Influenza del microambiente perineuronale sullo sviluppo delle propaggini del corpo delle cellule nervose dei gangli spinali
No full textTo investigate whether the outgrowth of the slender projections arising from the Perikaryon of spinal ganglion neurons is influenced by environmental factors or is solely controlled by factors intrinsic to the neuron, we have examined nerve cell bodies arranged in pairs. These nerve cell bodies, which can occasionally be found in spinal ganglia, are in immediate contact with each other along more or less extensive portions of their surfaces, while along the remaining portions of their surfaces they contact satellite cells. For each nerve cell body we have, therefore, quantitatively compared the extent of the projections on portions of the surface which are under the control of the same intrinsic factors, but are in contact with different microenvironments. By means of a quantitative study carried out on 104 paired neurons in the spinal ganglia of 3 adult rats, we have found that the overall development of the perikaryal projections is significantly greater in those portions of the surface in contact with satellite cells than in the portions in contact with another neuron. This result suggests that the outgrowth of perikaryal projections is influenced by environmental factors. Further investigations are required to characterize these factors
Organizzazione in gruppi dei corpi dei neuroni sensitivi dei gangli spinali di coniglio. Modificazioni nel corso della vita postnatale
No full textUlteriori indagini sulle relazioni fra microambiente perineuronale e sviluppo delle propaggini del corpo dei neuroni dei gangli spinali
No full textWhile the outgrowth of the slender projections from the perikaryon of spinal ganglion neurons is an intrinsic property of these neurons, it is also influenced by the surrounding microenvironment. To obtain evidence concerning whether the outgrowth of these projections is influenced by one or both components of the perineuronal microenvironment (satellite cells plus extracellular matrix) we have taken advantage of a rare arrangement of these neurons. In the spinal ganglia of adult animals nerve cell bodies are occasionally arranged in pairs, the two nerve cell bodies of the pair being separated by a satellite cell sheet lacking a basal lamina, while along the remaining portions of their surfaces they are enveloped by a satellite cell sheath, in turn surrounded by a basal lamina and connective tissue. By means of a quantitative study on 108 paired neurons in the spinal ganglia of 3 adult rats, we have found that the overall development of the perikaryal projections does not differ significantly in those surface domains associated only with satellite cells compared with those domains associated with both satellite cells and extracellular matrix. This finding suggests that, in the adult rat, neuron-satellite cell interactions rather than factors in the extracellular matrix play a role in promoting the outgrowth of perikaryal projections from spinal ganglion neurons
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