1,721,023 research outputs found
Distribution of preproenkephalin mRNA in the chicken and pigeon telencephalon
No full textBioassay and immunological studies have detected the presence of opioid peptides in the nervous system of representatives of all classes of vertebrates. The present study evaluates the expression and localization of preproenkephalin (PPE) mRNA to determine the sites of synthesis of the enkephalin peptides in the adult chicken and pigeon telencephalon using in situ hybridization histochemistry. We used a 500-base-pair chicken RNA probe corresponding to chicken PPE cDNA. In both the chicken and the pigeon telencephalon, the highest concentration of PPE mRNA-containing cells was observed in the lobus parolfactorius, paleostriatum augmentatum, nucleus accumbens, and septum. Distinct populations of labeled cells were also detected in the hyperstriatum accessorium, hippocampus, area parahippocampalis, nucleus of the diagonal band, cortex dorsolateralis, and cortex piriformis. Differences in PPE mRNA expression between chicken and pigeon were observed in several telencephalic regions. For instance, the bulbus olfactorius was heavily labeled in the pigeon, but was not labeled in the chicken, and numerous PPE mRNA-containing cells were present in the area parahippocampalis of pigeons but not of chickens. In contrast, in the hyperstriatum dorsale and hyperstriatum ventrale, numerous PPE mRNA-expressing cells were detected in the chicken but not in the pigeon. Overall, PPE mRNA-expressing cells were more numerous than enkephalin-immunoreactive cells described in previous studies. In addition, our results suggest that the general pattern of enkephalin expression in the avian telencephalon is similar to that found in other vertebrates. Finally, the results of the present study illustrate some differences in the pattern of PPE mRNA distribution between closely related species, indicating the existence of species-specific neurochemical pathways, which may influence and perhaps mediate different behaviors characteristics of these species
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
Posthatching development of preproenkephalin mRNA-expressing cell populations in the pigeon telencephalon
No full textEnkephalin peptides are highly expressed in the vertebrate telencephalon. Our previous investigations in the pigeon and in the chicken [26] suggested that the cellular distribution of these peptides is conserved in phylogenetically 'old' telencephalic regions (e.g. the basal ganglia), while it has species-specific organizations in areas (e.g. dorsomedial forebrain and bulbus olfactorius) that are likely to play important roles in species-specific behaviors. In the present study, we investigated the posthatching development of preproenkephalin (PPE) mRNA-containing cells in the pigeon forebrain using in situ hybridization histochemistry. These cells are densely distributed in the paleostriatal complex (corresponding to the mammalian caudate-putamen) at hatching, and their density progressively decreases during the first 9 days posthatching, when it is similar to that of adult pigeons. In the dorsomedial forebrain (corresponding to the mammalian hippocampus), PPE mRNA-expressing cells are present at hatching, and their density reaches a peak around the 6th day posthatching. In the bulbus olfactorius, the first PPE mRNA-containing cells are observed after 9 days posthatching. The developmental profile of PPE mRNA expression in these areas of the pigeon telencephalon shows remarkable similarities with the development of enkephalinergic cells in corresponding brain areas of mammals. As in the mammalian caudate-putamen, the developmental expression of enkephalin peptides in the paleostriatal complex is likely to be related to neuronal withdrawal from the mitotic cycle. The developmental pattern of expression of PPE mRNA in the dorsomedial forebrain suggests that enkephalin peptides contribute to the maturation of the behavioral functions of this area
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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