1,720,978 research outputs found
Monoclonal antibodies against human CD34 antigens do not cross-react with ovine umbilical cord blood cells
Full text linkCD34 is a cell surface glycoprotein expressed by hematopoietic progenitors and endothelial cells. It is widely used in the clinic for isolation of human hematopoietic stem cells. In recent years large animals are gaining increasing importance in biomedical research for the study and therapy of human diseases. Sheep has proved to be an useful experimental model for preclinical trials in transplantation procedures. Unfortunately, the lack of specie-specific monoclonal antibodies (MABS) recognizing hemopoietic progenitor cells hampers the use of this animal in experimental hematology. The aim of this paper was to determine whether commercial monoclonal antibodies specific for human CD34 molecule could cross-react with hematopoietic progenitor cells (HPC) present in sheep umbilical cord blood (UCB). Six anti-human CD34 MABS, recognizing the three different epitope classes, were tested in flow cytometry on purified mononuclear cells (MNC) isolated from cord blood of both species. None of the MABS used in this trial seemed to be able to identify HPC from sheep UCB. These data suggest that the panel of monoclonal antibodies used for cross reactivity detection has to be expanded with recently produced reagents. Further studies should be directed towards the production of ovine specific anti CD34 MABS
Stress responses in lambs castrated with three different methods
Full text linkThe present work was conducted to evaluate the animal response to stress in lambs caused by three
different castration techniques. Forty-six male lambs aged 4-5 months were randomly allocated to one
of four groups including Burdizzo (B), scrotal ablation (SA), orchiectomy (OR) and control handling
(H). Local anaesthesia (lidocaine 2%) was administered in both spermatic cords and the scrotal neck
of lambs before each treatment. Blood samples were collected at -30, -10, +1, +20, +40, +60, +120,
and +180 minutes. Serum cortisol concentrations were determined using a competitive immunoassay
and the area under the curve (AUC) was calculated for each lamb. The following biochemical parameters
were assayed for each animal at each time point: alanine aminotransferase (ALT), aspartate aminotransferase
(AST), lactate dehydrogenase (LDH), creatine kinase (CK) and glucose (GLU). The time
needed for total lesion resolution and weight gain of each animal was recorded. Orchiectomy elicits the
greatest cortisol response, significantly greater than that seen in similarly handled controls (P≤0.01),
Burdizzo and scrotal ablation groups (P≤0.05). The serum cortisol AUC was higher in the scrotal ablation
group (P≤0.05) than controls, but lower than in the orchiectomy group (P≤0.05). The Burdizzo group
didn’t differ from controls. Serum glucose levels of the castrated lambs differed significantly from the
control group, following a trend similar to cortisol. No change was seen in ALT, AST, LDH or CK. No difference
in weight gain was seen among the groups. Our results suggest that use of the Burdizzo is the
preferable castration technique for adult lambs, while scrotal ablation is a valid surgical alternative to
orchiectomy and permits more rapid wound healing that is ideal for extensive management where flocks
are not under close observation
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
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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