1,720,973 research outputs found
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
Infectious esophagitis by papilloma virus. A clinical case
No full textIntroduction: The esophagus may be affected by several infective agents, which cause mucosa alterations of various degree, and which can determine either light symptons or critical clinical problems with a high mortality risk. These diseases very often affect patients with reduced immunocompetence. Some of the infectious agents most frequently involved in esophageal infections are Herpes virus, Candida, CMV, HIV. Infectious esophagitis from HPVs are rare in the western countries. The greater number of registered cases have been discovered in the East. Hypotesis is that HPV is a possible etiologic agent in esophageal carcinogenesis, most probaby acting synergistically with physical, chemical, and/or nutritional factors in some high-risk areas of China. Although there are specific endoscopic aspect for infectious esophagitis from different agents, it is difficult to make a differential diagnosis and therefore biopsies, cultures and brushing have a particular importance. The bioptic area is a critical point for histological diagnosis of infectious oesophagitis. Infact, in case of suspected infection from herpes virus, the biopsies must be made on the mucosa surrounding the ulcerative lesion, whereas, for the cytomegalovirus, the specimen must be obteined from the ulcerative crater. Other important procedure, in case of supposed infectiouse disease, is culture, especially with the “shell vial” technique. Epidemiological and experimental evidences suggest the possibility that HPV infection increases the cancer risk for the oral cavity, pharynx and upper aerodigestive tract. However, histologic changes, suggesting HPV infection, are occasionally found adjacent to squamous cell carcinoma or in squamous papilloma of the esophagus, but the relationship between HPV infection and benign and malignant squamous lesions of the esophagus is not yet clear.
It is important to differenziate infective esophagitis from gastroesophageal reflux esophagitis in order to perform an up-to-date treatment.
Clinical Case: A 25 year old woman was hospitalized in the Federico II University Dept. of General Surgery for arising of retrosternal pain, odynophagia and dysphagia, both for solids and liquids. These symptoms had begun six days before admission. Bioumoral routine tests showed no abnormalities. No pathognomonic symptoms for gastroesophageal reflux nor caustic assumption was referred. The esophago-gastro-duodenoscopy showed, in midium esophagus, a large and deep ulcerative lesion, which involved the whole lumen between 26 and 30 cm. The lesion was thickened and covered by fibrin. Several bioptic tests were performed: IgG anti-varicella-zoster virus, anti-herpes simplex virus, anti-Epstein-Barr-vca were positive. The anti-HIV 1-2 test was negative. No lymphocytic alteration was observed. The histological diagnosis was “active chronic inflammatory infiltration and fibrinoleukocyte exudate”, which is direct sign of ulcerative lesion. Cytologic changes of coilocytic type (giving evidence for HPV infection) were observed. Examination of oral cavity, pharynx and upper respiratory tract gived no evidence of lesions by HPV or other causes.
The patient received therapy consisting in mucosal protectives (sucralphate) and Total Parenteral Nutrition. At EGDS, performed two weeks later, the lesion appeared completely healed.
References
1. Chang F., Syrjanen S., Shen Q., et al. Evaluation of HPV, CMV, HSV and EBV in esophageal squamous cell carcinomas fom a high-incidence area of China. Anticancer Res 2000 20(5C): 3935-40.
2. Chen L., Yang L., Sun Z. et al. Detection of human papillomaviral infection on Kazakh patients with esophageal squamous cell carcinoma in Xinjiang Chinese Journal of Clinical Oncology 2009; 6 (1): 64-67
3. de Villiers E.M., Lavergne D., Chang F., et al. An interlaboratory study to determine the presence of human papillomaviruses DNA in esophageal carcinoma from China. Int J Cancer 1999; 81(2): 225-8.
4. Franceschi S., Munoz N., Bosch XF et al. Human papillomavirus and cancers of the upper aerodigestive tract: a review of epidemiological and experimental evidence. Cancer Epidemiol Biomarkers Prev 1996; 5 (7): 567-75.
5. Kamangar F., Qiao Y.L., Schiller J.T. et al. Human papillomavirus serology and the risk of esophageal and gastric cancers: Results from a cohort in a high-risk region in China. International Journal of Cancer 2006; 119 (3): 579-58
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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