1,721,392 research outputs found
Serum Thyroxine Level and Cognitive Decline in Euthyroid Older Women
No full textBACKGROUND: Clinical and subclinical hypothyroidism is associated with cognitive impairment. OBJECTIVE: This study investigated the association between thyroxine (T(4)) and thyroid-stimulating hormone (TSH) level and change over time in cognitive performance in a sample of older women with normal thyroid gland function. METHODS: T(4) and TSH were measured at baseline in 628 women (> or = 65 years) enrolled in the Women's Health and Aging Study, a community-based study of physically impaired women. Cognitive function was assessed at baseline and after 1, 2, and 3 years, using the Mini-Mental State Examination (MMSE). Incident cognitive decline was defined as a decrease of more than one point/year in MMSE score between baseline and the end of the follow-up. The analysis included 464 subjects with normal thyroid gland function with a baseline and at least one follow-up MMSE. RESULTS: At baseline there was no association between T(4) and TSH level and cognitive function. In longitudinal analysis, adjusting for age, race, level of education, and other covariates, compared with women in the highest T(4) tertile (8.1 to 12.5 microg/dL), those in the lowest tertile (4.5 to 6.5 microg/dL) had a greater decline in MMSE score (-0.25 point/year vs -0.12 point/year; p = 0.04). A total of 95 women (20.5%) had cognitive decline during the study period (mean MMSE decline, 5.5 points). Compared with women in the highest T(4) tertile, those in the lowest tertile had a twofold risk of cognitive decline (adjusted relative risk, 1.97; 95% CI, 1.10 to 3.50). The results were not modified by baseline cognitive and physical function. There was no association between baseline TSH level and change in cognitive function. CONCLUSIONS: In older women, low T(4) levels, within the normal range, were associated with a greater risk of cognitive decline over a 3-year period. Thyroid hormone levels may contribute to cognitive impairment in physically impaired women
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
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
White matter lesions and the risk of incident hip fracture in older persons: results from the progetto veneto anziani study.
Full text linkBACKGROUND:
White matter lesions (WMLs) are associated with hypertension, an increased risk of falling, and impaired physical and cognitive performance that may affect the mechanical effect of falls.
METHODS:
We hypothesized that WMLs are a risk factor for hip fracture (HF). We studied a sample of 820 community-dwelling Italian persons 65 years and older from the cohort of the Progetto Veneto Anziani Study who underwent brain magnetic resonance imaging at baseline. Subjects were classified as having no lesions, focal lesions, or diffuse WMLs.
RESULTS:
Compared with those with no lesions, participants with diffuse WMLs were older, reported more falls, and had worse physical and cognitive performance, all factors implicated in the causal pathway to HF. During 9 years of follow-up, 51 HFs occurred. Hip fracture risk associated with diffuse WMLs markedly differed between participants younger than 80 years vs those 80 years and older. After adjustment among participants younger than 80 years, diffuse WMLs compared with no lesions were associated with a 2.7-fold (95% confidence interval, 1.1-7.1) increase in the risk of HF. Focal lesions were not statistically significantly associated with an increased risk of HF in the same age group (hazard ratio, 2.0; 95% confidence interval, 0.6-7.6). No associations between diffuse WMLs, focal lesions, and HF were evident among participants 80 years and older, possibly because of the limited sample size.
CONCLUSIONS:
White matter lesions represent an independent risk factor for HF in persons younger than 80 years. Older persons with diffuse WMLs should be considered candidates for multifactorial interventions aimed at reducing the risk of falling and fractures
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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