1,720,990 research outputs found
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
Relationship of 25-hydroxyvitamin D with all-cause and cardiovascular disease mortality in older community-dwelling adults
No full textBACKGROUND/OBJECTIVES:
Vitamin D deficiency is associated with cardiovascular disease, osteoporosis, poor muscle strength, falls, fractures and mortality. Although older adults are at a higher risk of vitamin D deficiency, the relationship of serum 25-hydroxyvitamin D (25(OH)D) with all-cause and cardiovascular disease mortality has not been well characterized in the elderly. We hypothesized that low serum 25(OH)D levels predicted mortality in older adults.
SUBJECTS/METHODS:
Serum 25(OH)D as well as all-cause and cardiovascular disease mortality were examined in 1006 adults, aged > or =65 years, who participated in the InCHIANTI (Invecchiare in Chianti, Aging in the Chianti Area) study, a population-based, prospective cohort study of aging in Tuscany, Italy. Serum 25(OH)D levels were measured at the time of enrollment in 1998-1999, and participants were followed up for mortality.
RESULTS:
During 6.5 years of follow-up, 228 (22.7%) participants died, of whom 107 died due to cardiovascular diseases. Compared with participants in the highest quartile of serum 25(OH)D (>26.5 ng/ml) (to convert to nmol/l, multiply by 2.496), those in the lowest quartile (<10.5 ng/ml) had increased risk of all-cause mortality (Hazard Ratio (H.R.) 2.11, 95% Confidence Interval (95% C.I.): 1.22-3.64, P=0.007) and cardiovascular disease mortality (H.R. 2.64, 95% C.I.: 1.14-4.79, P=0.02), in multivariate Cox proportional hazards models that adjusted for age, sex, education, season, physical activity and other potential confounders.
CONCLUSIONS:
Older community-dwelling adults with low serum 25(OH)D levels are at higher risk of all-cause and cardiovascular disease mortali
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
Progression of lower-extremity disability in older women with diabetes: the Women's Health and Aging Study
No full textOBJECTIVE: Older patients with diabetes are more likely to have a higher prevalence of multiple risk factors for physical disability, as a result of diabetic complications. We evaluated the pace of decline in lower-extremity function and the risk for progression of disability in older women with diabetes. RESEARCH DESIGN AND METHODS: We conducted a 3-year longitudinal cohort study of a random sample of 729 physically impaired older women (age > or =65 years) living in the community (Baltimore, MD). Diabetes was ascertained by standard criteria. Self-reported functional status and objective performance measures were assessed at baseline and over six semiannual follow-up visits. RESULTS: The baseline prevalence of diabetes was 14.4%. After adjustment for age and compared with women without diabetes, those with diabetes had an RR of 1.8 (95% CI 1.3-2.5) for incident mobility disability and 1.6 (1.2-2.1) for incident activity of daily living disability. The increased incidence of new disability associated with diabetes was paralleled by a greater decline in objective measures of lower-extremity function. Adjustment for multiple risk factors for disability did not significantly attenuate the risk for disability associated with diabetes. CONCLUSIONS: In older patients, impaired lower-extremity function is a long-term diabetic complication. Comprehensive assessment of older diabetic patients should include a standardized evaluation of lower-extremity performance
Relationship of 25-hydroxyvitamin D with all-cause and cardiovascular disease mortality in older community-dwelling adults
No full textBACKGROUND/OBJECTIVES:
Vitamin D deficiency is associated with cardiovascular disease, osteoporosis, poor muscle strength, falls, fractures and mortality. Although older adults are at a higher risk of vitamin D deficiency, the relationship of serum 25-hydroxyvitamin D (25(OH)D) with all-cause and cardiovascular disease mortality has not been well characterized in the elderly. We hypothesized that low serum 25(OH)D levels predicted mortality in older adults.
SUBJECTS/METHODS:
Serum 25(OH)D as well as all-cause and cardiovascular disease mortality were examined in 1006 adults, aged > or =65 years, who participated in the InCHIANTI (Invecchiare in Chianti, Aging in the Chianti Area) study, a population-based, prospective cohort study of aging in Tuscany, Italy. Serum 25(OH)D levels were measured at the time of enrollment in 1998-1999, and participants were followed up for mortality.
RESULTS:
During 6.5 years of follow-up, 228 (22.7%) participants died, of whom 107 died due to cardiovascular diseases. Compared with participants in the highest quartile of serum 25(OH)D (>26.5 ng/ml) (to convert to nmol/l, multiply by 2.496), those in the lowest quartile (<10.5 ng/ml) had increased risk of all-cause mortality (Hazard Ratio (H.R.) 2.11, 95% Confidence Interval (95% C.I.): 1.22-3.64, P=0.007) and cardiovascular disease mortality (H.R. 2.64, 95% C.I.: 1.14-4.79, P=0.02), in multivariate Cox proportional hazards models that adjusted for age, sex, education, season, physical activity and other potential confounders.
CONCLUSIONS:
Older community-dwelling adults with low serum 25(OH)D levels are at higher risk of all-cause and cardiovascular disease mortali
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