1,720,956 research outputs found
Immotile Cilia Syndrome In Pigs - A Model For Human-disease
No full textThis paper describes the ultrastructural alterations observed in the tracheal epithelium of six sibling swine suffering from porcine immotile cilia syndrome (PICS) compared with those in human immotile cilia syndrome (HICS). As in some human cases, the tracheal epithelium of these pigs was lined by cilia-lacking cells. A variety of dynein defects in other pigs suffering from PICS have been previously observed. The spectrum of defects affords evidence that the PICS is genetically heterogeneous. Available data suggests that there are many similarities between HICS and PICS. Therefore, it is proposed that PICS may prove to be a useful animal model for the human disease
Abnormal Length of Respiratory Cilia In A Pig - An Ultrastructural-study
No full textThe authors report the first case of abnormal length of respiratory cilia in a domestic animal (18 mu m versus normal length about 5 mu m). These cilia lie on the carpet of cilia of normal length. The width of some of these cilia is also abnormal, measuring 0.5-0.6 mu m. Other cilia have hook-shaped tips that could be responsible for an effective beat. We suggest that the ineffective ciliary beat could also be due to the undulating movements of abnormally long cilia, and stress the need for further morphological and biochemical studies of respiratory cilia in pigs. Respiratory pathology is a very common finding in pigs and is responsible for remarkable economical losses
Atypical Cilia In the Oviductal Epithelium of Healthy Prepubertal Gilts
No full textSpecimens of the uterine tube epithelium (ampulla) were obtained from 20 healthy, prepubertal, ovariohysterectomized gilts. A 2 to 3% proportion of atypical cilia was observed. Of 6,600 transversely sectioned cilia, 122 (1.8%) had microtubular disorganization, whereas 444 of 48,080 totally examined cilia (0.9%) were compound, 104 (0.2%) were swollen, and 44 (0.09%) were intracytoplasmic
Primary Ciliary Dyskinesia In Pigs
No full textThe first description of a familial immotile cilia syndrome diagnosed through ovario-hysterectomy in six siblings of pigs has been performed. This report may indicate another possible cause of reproductive failure in domestic animals. In fact, the immotile cilia syndrome has not been considered from this point of view in veterinary medicine. This case emphasizes that a study about ciliary motility in the female reproductive tract in domestic animals is absolutely necessary to improve current knowledge about different causes of infertility. Up to date, it remains unknown what degree of ciliary motility is necessary for mammalian fertility in females
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
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