1,720,988 research outputs found
The Blue Zones: areas of exceptional longevity around the world
No full textThe aim of this study was to compare the level of population longevity and
the characteristics of four geographic areas where unusually high proportions of
long-lived individuals have been observed. For these areas (Ogliastra in Sardinia,
Okinawa in Japan, the Nicoya peninsula in Costa Rica and the island of Ikaria
in Greece). The term of ‘blue zone’ (BZ) given to these areas is defined as a
limited region where the population shares a common lifestyle and environment
and whose exceptional longevity has been accurately verified. This paper discusses
the use of different indexes to measure the longevity of a population. As a
preliminary result of our investigations we confirm the exceptional level of
male longevity in the Sardinian BZ and both male and female longevity in
Okinawa. Considering possible explanations, we observed that BZ populations
are geographically and/or historically isolated (islands and mountainous regions).
These populations succeeded in maintaining a traditional lifestyle implying an
intense physical activity that extends beyond the age of 80, a reduced level of
stress and intensive family and community support for their oldest olds as well
as the consumption of locally produced food. This is likely to have facilitated the
accumulation of ideal conditions capable of limiting the factors that negatively
impact on health in most Western populations. These people experienced the
epidemiological transition—and its implications—in relative recent times, and their
remarkably good health status during ageing could be the result of a delicate balance
between the benefits of the traditional lifestyle and those of modernity (increased
wealth, better medical care). All these factors could have promoted an ideal milieu
for the emergence of long-lived phenotypes at the population level
Fertility history and post-reproductive survival: Villagrande (1830-2013)
No full textWe have analyzed the relationship between the fertility of mothers who survived age 50 (n=522) and their overall lifespan. We found that, adjusting for potential confounders (year of mothers’ birth, survival of spouse), delayed childbirth is associated with a reduced mortality risk (HR: 0.969), in particular, a 3-year delay in the average age at delivery is associated with a 10% reduction in mortality. These findings support the hypothesis that a delay in childbearing is favorable to a mother's survival. We also found that a higher proportion of male children decreases the mortality risk of the mother and that the survival of mothers whose average age at the birth of sons is > 35 is consistently better (p=0.005; log-rank test). Such results are in disagreement with other recent findings and we suggest further investigations of the impact of the socio-cultural characteristics
Fertility History, Children's Gender, and Post-Reproductive Survival in a Longevous Population
No full textThe question of whether mothers' fertility history influences their post-reproductive survival has been addressed frequently in the scientific literature. Using data from Villagrande Strisaili, Sardinia, where longevity is higher than anywhere else in Europe, we analyzed the relationship between the fertility pattern of mothers who survived past age 50 (n = 539) and their post-reproductive lifespan. We find that, after adjustment for potential confounders (mothers' birth cohort, survival of spouse), the mothers who on average delivered their children later displayed a reduced mortality risk (‒2.9 percent for each additional year), supporting previously reported findings. We also find that a male-skewed offspring ratio was associated with decreased mortality risk of mothers, with longer survival of mothers who delivered their sons above age 35 (p = 0.005), a result not found for daughters. So far, no biological explanation has been suggested for the positive effect of delivering sons later in life. We conjecture that in our dataset stronger nonbiological factors such as gender-specific sociocultural and economic factors may have masked the negative effect reported in other populations, for which a biological explanation was proposed
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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