1,721,001 research outputs found
Effect of Two Doses of Different Zinc Sources (Inorganic vs. Chelated form) on the Epithelial Proliferative Activity and the Apoptotic Index of Intestinal Mucosa of Early-weaned Pigs Orally Challenged with E. coli K88
Full text linkWe aimed to assess the effect of two doses of different sources, inorganic (zinc oxide) or chelated (zinc glutamate chelate) on morphology and turn-over of the small intestine of early-weaned pigs orally challenged with enterotoxigenic E. coli K88 (ETEC). Sixty pigs weaned at 21 days were assigned to one of the following 5 diets: control (C); C+Zinc oxide (ZnO), either a 200 or a 2,500 mg Zn/kg dose; or C+zinc chelate with glutamic acid (Glu-Zn), either a 200 or a 2,500 mg Zn/kg dose. On d 2, the pigs were orally inoculated with 1.5 ml of a 1010 CFU/ml E. coli K88ac O148 suspension. Zinc supplements did not improve the performance of the pigs, but on d 5 they reduced the ETEC faecal excretion, and this was mainly due to high zinc doses (p<0.05). The villous height was improved by the zinc supplements in the duodenal tract (p<0.01) whatever the source and the level, whereas no effect was seen in the other two tracts. The diet did not affect apoptosis and mitosis counts, while ETEC-susceptible pigs had more mitotic cells in the villi than non-susceptible pigs, particularly in the jejunum (p<0.01). The duodenum had fewer mitotic cells in the villi (p<0.05) and in the crypts (p<0.01) and more apoptotic cells in the villi. High dietary doses of ZnO or Zn-Glutamate improve villous height of the duodenum, but not of the jejunum and the ileum, and do not affect the epithelial proliferative activity and apoptotic index of intestinal mucosa of early-weaned pigs orally challenged with ETEC
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
The influence of fat protection of calcium formate on growth and intestinal defence in Escherichia coli K88-challenged weanling pigs,
Full text linkAn experiment was conducted to test whether free or fat-protected dietary calcium formate improve the growth and health of weanling pigs which may or may not be susceptible to the intestinal adhesion of enterotoxigenic E. coli (ETEC), when orally challenged with ETEC.
Sixty pigs, weaned at 21 days of age (day 0), were divided into three groups (20 pigs each), balanced for number, litter and live weight, and fed the same base diet but three different 30.5 g/kg supplementations: a control (CO – with dicalcium phosphate, calcium sulphate, lard and sepiolite,); a free calcium formate (FF), with this additive, monosodium phosphate and lard; a fat-protected calcium formate (PF), with this additive and monosodium phosphate only. The final diets did not differ for total calcium and phosphorus content. The pigs, individually penned, were orally challenged with 1.5 ml of a 1010 CFU Escherichia coli K88 suspension on day 2 and sacrificed on day 7 or 8.
Data were analysed using analysis of variance with a 3-factor design, including diet, block, sensitivity of intestinal villus to ETEC adhesion, and 1st level interactions. The factor diet never interacted with the others.
Compared to the control diet, the formate supplementations improved growth (P<0.05), feed intake (P=0.062) and G:F (gain:feed) ratio (P=0.063). Both forms of formate addition reduced the faecal score (P=0.062), days of diarrhoea (P<0.05) and total E. coli faecal excretion (P<0.05) but not E. coli K88 faecal excretion, and increased villus height in the small intestine (P<0.05). The number of enterocytes and goblet cells in the ileum was not changed by formate supplementations. In saliva, total IgA activity tended to be reduced by acidifiers (P=0.067). The anti-K88 IgA in the saliva, the blood and the jejunum secretion, and the expression of the TNFα gene in the stomach and jejunum wall were not affected by the diet. The pH of the stomach, the duodenum and the ileum was not affected while the formate reduced the pH in the colon and the caecum.
Fat-protected calcium formate did not improve the results obtained with free formate supplementation.
Calcium formate has a growth-promoting effect in weanling pigs challenged with E. coli K88, independently of their susceptibility to the intestinal adhesion of this strain. Its action seems to be more related to a general control of the total E. coli rather than of E. coli K88. At the same dietary concentration, no particular advantage comes from using the protected formate instead of the free additive
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
- …
