1,722,601 research outputs found
Viruses and cryoglobulinemia
No full textCirculating cryoglobulins have been reported in association with several acute and chronic viral diseases. In all of the reported cases, the viruses involved have been hepatotropic, lymphocytotropic or both. Among the hypotheses concerning the causes of cryoglobulinemia, two possible pathways have been more frequently debated: an impairment of the macrophagic system of the liver, with the consequent impairment of the clearance of gut antigens and immunoglobulins, as the first ring of a chain of events including the activation of the B cell compartment with increased production (and decreased clearance) of cryoglobulins; and a low-grade malignant lymphomatous process involving rheumatoid factor producing clones. Recent evidence of a close association between hepatitis C virus (HCV) and "essential" mixed cryoglobulinemia has focused the attention of several researchers on the mechanisms by which the virus is capable of causing cryoglobulin synthesis. The open questions include: (1) Why do only a minority of chronically HCV-infected people (mainly "sporadically" infected elderly women) develop a cryoglobulinemic syndrome? (2) What kind of mechanisms can up- or down-regulate cryoglobulin production? (3) Are immunoregulatory mechanisms involved? (4) Is there a connection between HCV infection and the low-grade malignant lymphoma hypothesis identifying cryoglobulinemias as the consequence of the slow proliferation of CD5+ B cells? and (5) Are particular HCV genotypes specifically involved in causing cryoglobulinemias? Several of these questions still remain unanswered. HCV has been detected in the peripheral blood mononuclear cells of both cryoglobulinemic and non-cryoglobulinemic infected subjects; on the other hand, the detection of viral RNA in the bone marrow cells of virtually all cryoglobulinemic patients suggests that this might be related to the pathogenesis of the disease
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
The AIDS epidemic
No full textAIDS epidemic began about 15 years ago; since then, the number of new cases have increased over time. By the end of 1994, 1,025,073 AIDS cases had been reported to the WHO, with a 20% increase in the number of cases since December 1993. As is now evident that the majority of cases occur in developing countries, under-diagnosis, under-reporting and delays in reporting explain the big difference existing between reported and estimated AIDS cases, giving a 4.5 million cumulative AIDS cases worldwide, as of late 1994. In the industrialized countries, the spread of HIV infection began in the late 1970's or early 1980's among homosexual men and IVDU's. Heterosexual transmission was, at first, very limited, though recent data has shown an increase in its diffusion. On the contrary, in Sub-Saharan Africa and the Caribbean, transmission was almost exclusively heterosexual. High rates of infection among young women led to a corresponding increase of perinatal transmission, infecting more than 1.5 million children since the beginning of the pandemic. The estimated number of HIV infections worldwide, as of late 1994, is of 17 millions. Thus, even if some evidence indicates a possible decline of the pandemic in industrialized countries over the next few years, probably because heterosexual transmission was less common, developing countries appear to present an increasing number of HIV infections in young people and, consequently, in children. The real impact of such an epidemic is stressed by the fact that HIV is becoming the leading cause of death among, young people, both in industrialized and developing countries.(ABSTRACT TRUNCATED AT 250 WORDS
Mortality of intravenous drug users living in Milan, Italy: role of HIV-1 infection. COMCAT Study Group
No full textTo study the trend in mortality from 1980 to 1991 in a cohort of 2432 intravenous drug users (IVDU) enrolled between 1 November 1980 and 31 December 1988. In addition, to evaluate the impact of HIV-1 infection on mortality
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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