1,720,971 research outputs found
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
Sex-dependent effects of restraint on nociception and pituitary-adrenal hormones in the rat
No full textThe sex-dependent effects of acute restraint (RT) on nociceptive and pituitary-adrenal responses were investigated in the rat. In a first experiment, the effect of 30 min RT on pain sensitivity was evaluated through repeated use of the tail withdrawal test during and after treatment. RT induced an increase in the nociceptive threshold, i.e., analgesia, in males and females, but the duration and time-course of this effect varied between sexes. The latencies returned to approximately control values in females in the second half of RT, but in males they remained higher for the whole period of RT and immediately afterwards. Twenty-four hours later, males displayed longer latencies than controls in response to simple reexposure to the environment. In a second experiment, ACTH and corticosterone plasma levels were measured immediately after 15 or 30 min of RT. ACTH and corticosterone were higher in restrained animals than in controls after both periods of treatment, and in both sexes; however, females showed higher basal and stress corticosterone levels than males. The role played by corticosteroids in the nociceptive responses of the two sexes is discussed
Neuroendocrine and behavioral effects of CRH blockade and stress male rats
No full textOur previous data have shown that restraint (RT), a mild nonpainful stressor, acutely impairs nonsocial and social behavior in male rats. Corticotropin-releasing hormone (CRH) is a regulator of these behavioral responses. To evaluate whether CRH mediates the neuroendocrine and behavioral alterations present 24 h after restraint stress, we administered the CRH antagonist ct-helical CRH9-41, (alpha-hCRH) intracerebroventricularly to male rats and we compared its effects with those of saline. Twenty-four hours after treatment, nonsocial behaviors were significantly decreased by alpha-hCRH, this effect being independent of RT. Among social behaviors, only introductory activity showed significant differences as a result of both RT and alpha-hCRH. The concentrations of ACTH in the plasma and those of beta-endorphin in the anterior and neurointermediate lobes of the pituitary were affected by alpha-hCRH treatment. The effect on ACTH was simply related to the administration of the alpha-hCRH, while for beta-endorphin, significant interactions between alpha-hCRH and RT were found. On the whole, these results point to the role played by CRH in the control of neuronal mechanisms involved in the stress-induced effects
Offline consolidation of spatial memory: Do the cerebellar output circuits play a role? A study utilizing a Morris water maze protocol in male Wistar rats
Full text linkTo address whether the cerebellum takes part to spatial memory consolidation related to navigation, male Wistar rats were trained daily (4 days), in a Morris water maze to found a submerged escape platform by use of distal cues (place training test). Retention of the allocentric map was evaluated in the probe test (without platform), before the place test. Bilateral shutdown of deep cerebellar nuclei was carried by infusion of the GABA-A agonist muscimol (0.25 μl at 1 μg/μl) immediately after each place test. Histology revealed a dorsal dentate nucleus (DDN) group, with muscimol diffusion confined to dentate nuclei, and a ventromedial/dentate nuclei (VMDN) group, with muscimol additionally involving fastigial, interpositus and vestibular nuclei. In the place test, Vehicle, DDN and VMDN groups reduced latency and distance to the platform over the 4 days and within the single day, indicative of efficient acquisition and working memory; navigational trajectories however differed in that, while Vehicle and DDN groups evolved to use direct paths, VMDN group indulged to navigate in proximity to the platform, suggesting an impairment in refining the spatial map. In the probe test VMDN, unlike Vehicle and DDN animals, failed to develop a preference for the quadrant where the platform was previously located, indicating a consolidation deficit. In conclusion, ventromedial cerebellar related structures may contribute to the process of consolidation of an allocentric spatial memory: their inactivation may have impaired the offline integration of idiothetic information with allothetic signals within the navigational network, leading to a coarse resolution map. © 2019 Elsevier B.V
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
- …
