1,721,012 research outputs found
Influence of acid-secretion blockers on gastric and hepatic alcohol dehydrogenase in rat
No full textThe effects of Cimetidine, Ranitidine, and Omeprazole on gastric and hepatic alcohol-dehydrogenase (ADH) activity was studied in rat. Two apparent values for Km were found for gastric ADH (220 mmol l-1 and 1043 mmol l-1 respectively) and one for hepatic ADH (0.54 mmol l-1). Cimetidine was shown to exert an uncompetitive inhibition of low Km gastric ADH with a Ki of 0.167 mmol l-1 and a competitive inhibition of high Km gastric ADH with a Ki 2.3 mmol l-1. Ranitidine was found to present non-competitive inhibition only on low Km gastric ADH with a Ki of 12 mmol l-1. Omeprazole affects only low Km gastric ADH with a Ki of 5.6 mmol l-1 and presents a linear-mixed type of inhibition. Hepatic ADH was shown to be competitively inhibited only by Cimetidine with a Ki of 6.0 mmol l-1 whereas no inhibition for either Ranitidine and Omeprazole was observed. These results confirm the inhibitory action of Cimetidine on both gastric and hepatic ADH; Ranitidine and Omeprazole show minor effects on ADHS activity and probably on first-pass metabolism
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
Hair cortisol: an indicator of HPA activity in relation to environmental perception in New Zealand White rabbit.
No full textAfter rodents, lagomorphs constitute the vast majority of subjects used in mammalian experimentation and rabbits are often used as animal models in surgery. Animal welfare in laboratory animals is governed by national and European laws; teams composed by different professionals with adequate knowledge and training must ensure it. The pursuit of animal welfare can also be facilitated by the introduction of an assurance system as good laboratory practice (GLP). The rabbit being a very sensitive species, the methods described above may not be adequate because the perception of environmental stressors may be evaluated anthropomorphically. To date, cortisol assessment in hair samples has been reported as a validated method to evaluate hypothalamic-pituitary-adrenal (HPA) axis activity in different species. The objective of this study was to evaluate HPA axis activity in rabbits before, during and after surgery (dorsal arthrodesis) by measuring hair cortisol. Six prepubertal female NZW rabbits were subjected to dorsal arthrodesis performed after a period of acclimatization that lasted 45 days from their arrival at the enclosure. Hair samples were shaved from the thigh region immediately before surgery. After surgery, at intervals of 40 days, new hair growth was collected from the same area for a period up to 405 days since the rabbits arrived to the enclosure. After methanolic extraction hair cortisol concentrations were determined by RIA. Mean hair cortisol concentration in rabbits at first sampling (before surgery, after acclimatization) was 1.45 ± 0.07 pg/mg (mean ± SE) but at the second sampling (40 days after surgery) it rose (P0.05) for a period lasting until 240 days since the surgery. At day 280 hair cortisol concentrations rose (P<0.05) to 3.34 ± 0.61 pg/mg. Similar (P<0.05) high levels were recorded at day 320 from the surgery that than decreased (P<0.05) to 1.25 ± 0.17 pg/mg at the last sampling. Concentrations at the first sampling were considered basal levels because of the long period of acclimatization undergone by the rabbits. At the second sampling hair cortisol concentrations were significantly higher than those recorded before and this could have been due to the surgical stress suffered by the rabbits previously. This was followed by a return to basal hair cortisol levels, which remained stable for several months. It seems that during that period the rabbits’ HPA axis was not stimulated until the new rise caused by a change of the enclosure operator. This modification activated the HPA axis as recorded by hair cortisol. At the last sampling hair cortisol concentration had dropped again to basal levels. These results indicate that hair cortisol reflected similar levels of activation of the HPA axis in response to two types of apparently different stressor, suggesting that environmental stressors may have been evaluated anthropomorphically. Hair cortisol, not affected by acute stress or by circadian rhythms, could be an additional important tool in animal welfare evaluation
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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