1,721,145 research outputs found
IlLEGAL USE OF GROWTII PROMOTING AGENTS AND ALTERATIONS IN BOVINE FEMALE REPRODUCTIVE SYSTEM
No full textIntroduction·
The P1-agonist clenbuterol is a drug that finds wide application in. veterinary medicine as
. bronchodilator and tocolytic agent. In recent years, ìt has been more and more utiIized as repartitioning agent to improve the performance of meat animals. In faci. clenbuterol long-term administration improves growth rate, reduce fat deposition and increase protein accretion in cattle, pigs and poultry. From this point of view, clenbuterol treatment should fulfil producers and consumers demands (1). Thus, in Italy, veal calves are reasonably suspected to be systematically treated with P-agonists in order to stimulate growth. Nevertheless, a field study carried out on
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regularly slaughtered veal calves. revealed a ratber constant involvement of the female genital tract consisting in anatomical and histopathological changes associated with biochemicallesions (23). The alterations present in the female reproductive system of veal calve s, sequestrated by the Judicial Authority for illegal treatment with clenbuterol, were investigated. In the urine of six male belonging to the same herd, clenbuterol were found in not allowed amounts.
Materials and methods The histological investigations were performed on the uteri, ovaries and major vestibolar glands of 15 crossbred veal calves, 2-4 months old. Tissue samples were fIxed in buffered formalin (10%) and tben paraffIn-wax embedded sections were stained by routine methods (Haematoxilin-eosin, Van Gieson, Azan, Pas-reaction). Major vestibolar glands were processed using more specifIc techniques (Alcian-Pas pH 2.6 and Alcian pH 1). Just after slaughtering, tissue samples (about 1 g) were dissected from the vagina (A), the body (B), and the uterine horns (C) and then frozen at -80"C in order to assay cytosolic estrogen and progesterone receptor concentrations using a modified dextrancoated charcoal method (3). The results obtained by the Scatchard analysis, are expressed as femtomoles of specifIcally bound hormone per mg of protein (mean values±S.E.M.). The hormonal status, was evaluated on serom samples obtained from clotted blood drawn from the jugular vein of each animaI. Estradiol and progesterone serom level were measured using RIA techniques (Estradiol Double Antibodl and Progesterone Coat-A-CountO DPC Los Angeles, USA).
----,1 Results The lumen of the vagina and of the uteros was constantly filled with an abnormal collection of transparent mucus, and in all examined animals
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microcystic ovaries were presento From the histological point of view, the cervical part of the uteros showed pluristratification of the endometrial epithelium, frequently associated with squamous metaplasia of the inner layer. In the oldest calves, glandular hyperplasia and hypersecretion were detected. Endometrial cysts were also presento The major vestibular glands showed hyperplasia of ductal and glandular epithelium with ectasic lumina filled with
·0 I I J~~P~w_...I._~~~-L~~~' t
Pas positive or Alcian-Pas positive material;
r scattered foci of mononuclear cells and metaplastic transformation were occasionally found. In the ovaries, atretic tertiary folli cles associated witb normal ones were seen. The number of uterine estrogen and progesterone receptors reached high concentrations mainly in tbe
Figure 1. Uterine estrogen and progesterone uterine body (B) and horns (C) (estrogenreceptor concentrations (mean values±S.E.M.)
receptors, B: 480± 98, C: 487 ± 130; progesterin veal calves. A=vagina, B=body, C=horns one receptors, B: 632 ± 118, C: 1137 ± 292). In (n= 15) the vagina (A) only the estrogen receptors are
particularly elevated (A: 123+22), whereas progesterone receptor levels are normal (Fig. 1). RIA investigations revealed that neitber traces of estradiol nor progesterone were present in the examined sera.
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Diseussion The histological pictures, reveal a morphological and physiological status incompatible with the immature age of the animals. On the other hand, these findings suggest a condition of exogenous stimulation by growth-promoting or anabolic agents. Moreover, the high concentrations of estrogen and progesterone receptors at uterine level, when compared with normal values (4), also indicate an abnormal disposition of the receptorial status. It is well established that estrogenic treatments induce steroid receptors syntesis, but recently, clenbuterol treatment has been related with uterine estrogen and progesterone receptors increase in rat and pigs (5), without affecting or at least inhibiting hormonal serum levels.
Reterences
1.
VanbeHe M., 1990, New technology governing nutrient partÌtioning in meat animals. Atti Conf. Int. Sanita Prod. Bovina Mediterraneo, 1, 459.
2.
Girardi C., Badino P., Re G., Dacasto M., Biolatti 8., Brusa F., Di Carlo F., 1990, Stato recettoriale e reperti anatomo ed istopatologici del tratto genitale femminile in vitelli a carne bianca. Atti Soc. Il. Buiatria, 22, 375.
3.
Di Carlo F., Racca S., Conti G., Gallo E., Muccioli G., Sapino A., Bussolati G. 1984, Effeets of long-term administration of high doses of medroxyprogesterone aeetate on hormone receptors and target organs in the female rat. J. Endocr. 103, 'll37.
4.
Re G., Badino P., Conti G., Dacasto M., Di Carlo F., Girardi c., 1989, Distribution of eytoplasmic estrogen (ER) and progesterone (PgR) receptors in bovine genital traet. Pharmaool. Res., 21, suppl.1, 79.
5 Re G., Badino P., Tartari E., Biolatti B., Di Carlo F., Girardi C., 1990, Clenbuterol long-term administration in fmishing female pigs. Note 1: effeets on oestrogen and progesterone receptor distribution and ooncentration in genital tract. Schweiz. Arch. Tierheilk., 132, 455
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
Caratterizzazione dei recettori ß-adrenergici nella muscolatura liscia dell'ileo di bovino
No full textVariations 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
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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
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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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