1,723,617 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Aging Population : Challenges and Opportunities in a Life Course Perspective
No full textIn most Western countries the mean longevity for both men and women has increased dramatically over the past 100 years. This was first attributable to a reduction in perinatal and child mortality when deliveries became safer and conditions for children more healthy, such as better nutrition. In recent decades another trend is visible, that is, a reduction of the negative impact of chronic disease in midlife and a postponement of life-threatening medical conditions until old age. This is why the mean life expectancy now reaches around 80 years in many developed countries, even if there is still a substantial gap to the shorter life span of many people living in developing countries, but also in the former Soviet Union. To better understand this demographic transition we need to consider the influence of environmental and social factors, as our genetic setup will not change in the shorter time perspective (centuries). On the other hand we also need a deeper understanding of the influence of early life programming on adult health and longevity to fully grasp the shifting demography of human populations, in a life course perspective
Telomere Biology and Vascular Aging
No full textTelomeres form the end segment of the DNA helix and shorten with every cell division until getting so short that the cell stops dividing and will undergo programmed cell death (apoptosis). Research has supported the view that telomere length could be regarded as a marker of biological aging, even if methodological problems could interfere with the interpretation of telomere length in cross-sectional studies when causality cannot be proven. Ideally the telomere attrition rate should be calculated based on repeated measurements during follow-up. So far, epidemiological studies have supported the role of short telomeres being predictive of coronary heart disease (CHD) events but not stroke, based on meta-analysis. A genetic risk score based on several genetic markers of telomere biology is associated with CHD risk, which proves that a true causal and unconfounded relationship may exist. Future intervention studies will hopefully reveal whether telomere length is possible to influence by lifestyle improvements or drug therapy in randomized, controlled studies
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