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The plateau of human mortality: Demography of longevity pioneers
Get PDFTheories about biological limits to life span and evolutionary shaping of human longevity depend on facts about mortality at extreme ages, but these facts have remained a matter of debate. Do hazard curves typically level out into high plateaus eventually, as seen in other species, or do exponential increases persist? In this study, we estimated hazard rates from data on all inhabitants of Italy aged 105 and older between 2009 and 2015 (born 1896-1910), a total of 3836 documented cases. We observed level hazard curves, which were essentially constant beyond age 105. Our estimates are free from artifacts of aggregation that limited earlier studies and provide the best evidence to date for the existence of extreme-age mortality plateaus in humans
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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Understanding Risk Aversion in Older Americans: New Approaches Using Genetic Data
Get PDFIn this dissertation, I explore the nature and role of risk aversion among older Americans from a variety of perspectives. Risk preferences are important to demographers for several reasons. First, risk preferences are fundamental to most individual-level demographic events, including to financial decision-making, health behaviors, labor market decisions, migration, and marriage and family-formation. Second, there is substantial evidence that risk aversion increases with age. With age also comes increased responsibility in terms of making specific financial and health decisions. In the age of decreasing pensions, older persons must make significant decisions about their financial portfolios and finances in light of pending retirement decisions. In fact, the decision to retire is itself one in which risk plays a role. Third, health behaviors, which are a function of one's riskiness, often display their effects at older ages. I explore the genetic nature of risk aversion through a number of approaches. Taking advantage of a newly-released database with over two million pieces of genetic variants, I examine the specific genetic nature of risk aversion through two genomic techniques: a Genome-Wide Association study (GWAS) and a Genome-Wide Complex Trait Analysis (GCTA). I provide evidence that risk aversion is a highly complex trait that is a function of a large number of possibly interactive genetic variants. Through the GWAS, I show that the number of genetic variants influencing individual-level differences in risk aversion is numerous and that these variants are likely to be scattered across the genome. The GCTA, while using a separate methodological approach, confirms this finding. I argue that the intricate nature of the genetic underpinnings to risk aversion should be better understood in order to more precisely model economic decisions involving risk preferences.I also characterize risk aversion from a non-genetic perspective. Using panel data of risk aversion collected over nearly two decades, I use longitudinal methods to explore the extent to which the relationship between hypothetical risk and measurable risky behaviors remain consistent across both time and among individuals. As a follow-up, I examine the specific time period following the 2008 recession to examine any change in the relationship in portfolio allocations relative to stated risk tolerance for individuals after the global financial crisis. I conclude that the relationship between measured risk and risky behaviors remains relatively constant across the 15 years prior to the global financial crisis. The analysis also shows that the relationship between risk and financial assets does in fact change slightly after the global financial crisis, though the statistical evidence is not very strong. This dissertation provides a contribution to the understanding of the complex nature of risk aversion and is on of the first to characterise it's genetic influences. This research helps to answer questions on the economic, social and biological drivers and consequences of risk aversion among older Americans
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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