1,720,963 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
Effect of ursodeoxycholic acid administration on bile duct proliferation and cholestasis in bile duct ligated rat.
No full textThe origin, mechanism, and significance of the bile duct proliferation (BDP) associated with cholestasis remain unexplained. This study examined the effect of oral administration of ursodeoxycholic acid (UDCA) on both BDP and cholestasis in the rat. After bile duct ligation, male Sprague-Dawley rats were treated for 30 days with either UDCA (5 mg/day) (group A) or saline solution (group B). Animals were sacrificed at day 30. The serum activity of aminotransferase (ALT, AST), alkaline phosphatase, and gamma-glutamyltransferase (GGT) was significantly lower (P < 0.01) in the UDCA-treated rats. Total serum bilirubin and total serum bile acids were lower (P < 0. 001) in group A. Moreover, the control of BA in bile was reduced also (P < 0. 02). Conversely, serum cholesterol levels were not different between the two groups. Histological examination showed that the number of ductular cells in the portal areas was significantly (P < 0. 001) reduced in UDCA-treated as compared to saline-treated rats. The replication activity, assessed as the number of bromodeaxyuridine-positive cells, was also significantly lower in treated animals (33 +/- 11 vs 64 +/- 22 per 1000 cells; P < 0. 001). Lobular bile ductules were three times larger in group B, and extrahepatic duct measurements confirmed this increase in size of the larger biliary ducts (P < 0.001). These findings demonstrate that UDCA reduces BDP in response to BD ligation. Although the mechanism(s) of this effect is still hypothetical, UDCA may reduce the level of irritating bile salts such as chenodeoxycholic acid and lithocolate and increase periductular bile acid recirculation. These data support the beneficial effect of UDCA treatment in chronic cholestatic disease
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
CCL4-induced liver cirrhosis and hepatocellular carcinoma in rats: relationship to plasma zinc, copper and estradiol levels.
No full textA number of biochemical events accompany the development of chronic liver disease and its evolution into hepatic cancer. Low plasma zinc and high plasma copper levels have been observed in individuals with advanced hepatocellular liver disease. Moreover, many investigators have demonstrated an increase in serum estradiol levels in individuals with chronic liver disease and hepatocellular carcinoma (HCC). In the present study, the relationship between these biochemical events and HCC was investigated in an animal model. Specifically, carbon tetrachloride (CCL4) was administered intragastrically to 20 female Sprague Dawley rats for 30 weeks. All 20 animals developed cirrhosis. Six (30%) developed HCC. Signifi cantly higher serum estradiol, zinc and copper levels were observed in the rats developing HCC as compared with those with cirrhosis alone (P less than or equal to 0.05, 0.01 and 0.001, respectively). A trend toward increased serum levels of progesterone, ALT and total bilirubin (0.1 greater than or equal to P less than or equal to 0.05) was found in the animals developing HCC. Na differences in serum testosterone and alkaline phosphatase levels were noted between animals with and without HCC. These studies demonstrate that in animals with experimental CCL4-induced cirrhosis and HCC serum levels of estradiol, zinc and copper are increased, as is the case in man
NK ACTIVITY DURING GRAFT-VERSUS-HOST DISEASE AND GRAFT-REJECTION IN RATS FOLLOWING INTESTINAL SEMIALLOGENIC AND ALLOGENIC TRANSPLANTATION WITH OR WITHOUT MESENTERIC LYMPHADENECTOMY
No full textGraft-versus-host disease (GVHD) and graft rejection are major problems following intestinal transplantation (IT). Natural killer (NK) cells may be important effector cells in both conditions. In this study, Sprague-Dawley (SD) or SD-Brown Norway (BN) F1 rat intestine was transplanted into BN recipients with and without associated graft mesenteric lymphadenectomy (GML). Cyclosporine (15 mg/kg day) was administered to all animals. Pieces of the intestinal graft were examined 4 days posttransplant and again at death. NK activity calculated using intestinal intraepithelial lymphocytes (IL) was determined utilizing an 18-hr cytotoxic assay assessing 51Cr release and the results are reported as lytic units. YAC-1 cells were used as the target. NK activity was reduced 4 days after IT both in native (8.02 +/- 0.64) and in grafted bowel (3.14 +/- 1.51), with histological evidence of rejection as compared with that of control bowel in ungrafted rats (21.1 +/- 2.14). Survival was increased, on mean, a total of 6 days with the addition of GML in both semiallogenic and allogenic transplanted rats. At the time of death, the NK activity in the native bowel had increased (17.1 +/- 3.02) and histologic evidence of GVHD was present. These data suggest that: (1) NK cells are important in GVHD and (2) both semiallogenic and allogenic transplants survive longer if they are combined with GML (P < or = 0.05 and P < or = 0.01, respectively)
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
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