1,720,956 research outputs found
Immunolocalisation of vasoactive intestinal peptide and substance P in the developing gut of Dicentrarchus labrax (L.)
This study was carried out on the sea bass (Dicentrarchus labrax) to follow, during development, the appearance and distribution of substance P (SP) and vasoactive intestinal peptide (VIP), which act on gut motility. The results suggest that SP and VIP play an important role as neuromodulators, influencing the motility of the digestive tract starting from the early stages of gut development, even prior to exotrophic feeding. In the peptidergic nervous system, the appearance of immunoreactivity to SP began at the rectum and followed a distal to proximal gradient, whereas for VIP, it began proximally and progressed along a proximal to distal gradient. The two peptides also appeared in gut epithelial cells. In some regions, all the cells were positive. From this distribution of positive cells, we conclude that these peptides may also have other roles, besides being neurotransmitters in the enteric nervous system and hormones of the gastro-entero-pancreatic system. VIP and SP might have paracrine and/or autocrine activity in the physiological maturation of the gut epithelium, as it has already been hypothesised for other peptides
Il sistema nervoso in sviluppo di Dicentraurchus labrax (L.): primi dati immunoistochimici
Viene descritta la comparsa e localizzazione di colecistochina e encefaline nel sistema nervoso durante lo sviluppo larvale di spigol
I peptidi regolativi del tratto digerente nello sviluppo di Dicentrarchus labrax (L.).
In this study we present tje occurrence of gut regulatory peptides (Substance P, CCK and some POMC-derived molecules) during the first larval phases in Dicentrarchus labrax (Osteichtyes). The immunohistochemical tests were carried out in specimens of 2, 4 and 18 days from hatching
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Indagini istologiche e immunoistochimiche sull'apparato digerente nel teleosteo Dicentrarchus labrax (L.) in sviluppo.
Viene descritta la comparsa e localizzazione di alcuni peptidi gastrointestinali durante lo sviluppo larvale della spigola
Variations on the Author
“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
We 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
Dispelling the Myths Behind First-author Citation Counts
We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
