1,721,041 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
Association between physical activity, physical performance, and inflammatory biomarkers in an elderly population: The InCHIANTI study
No full textBackground. Our aim was to determine the association between physical activity and physical performance, and inflammatory biomarkers in elderly persons. Methods. One thousand four persons aged 65 years or more, participants in a cross-sectional population-based study, were included. Interviewers collected information on self-reported physical activity during the previous year, Moreover. 841 participants performed a 400-meter walking test to assess physical performance. plasma concentrations of inflammatory biomarkers were determined. Results. Compared to sedentary men, men practicing light and moderate-high physical activity had a significantly lower erythrocyte sedimentation rate (-0.33 and -0.40 mm/h, p = .023 and p = .006, respectively), fibrinogen level (-43 and -39 mg/dL p = .001 and p = .004, respectively), and logarithm of C-reactive protein (CRP) (-0.43 and -0.73 mg/L; p = .025 and p < .001, respectively), whereas only those men practicing moderate-high physical activity had a significantly lower uric acid level (-0.57 mg/dL; p = .023), log(interleukin 6) levels (-0.33 pg/mL; p = .014), and log(tumor necrosis factor-alpha) (-0.31 pg/mL; p = .030). In women, those practicing tight and moderate-high physical activity had significantly lower uric acid (-0.45 and -0.34 mg/dL; p = .001 and p = .039, respectively) and log(interleukin 6) levels (-0.18 and -0.30 pg/mL; p = .043 and p = .004, respectively); only those women practicing moderate-high physical activity had significantly lower log(CRP) (-0.31 mg/L; p = .020). In women, when the analysis was adjusted for body mass index. the association between physical activity and CRP was no longer significant. Similar findings were observed when we carried these analyses according to physical performance. Conclusions. Current physical activity practice and performance are associated with inflammatory biomarkers. A significant beneficial association is already observed with light physical activity practice and intermediate performance
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
Erythropoietin and polyneuropathy in older persons
No full textIntroduction: Recent studies demonstrated that erythropoietin (EPO) have a number of non-erythropoietic effects including neuroprotection and vascular protection. Materials: Using data from a representative sample of older persons, we tested the hypothesis that EPO levels are correlated with peripheral nerve parameters (NVC and CMAP) assessed by surface ENG and with clinically diagnosed polyneuropathy. We selected 972 participants (aged 60-98 years) with complete data for the analyses. Results: We found a significant association between EPO and age-adjusted NCV and CMAP (for NCV: 0.57 +/- 0.26; p = 0.03 and for CMAP: 0.54 +/- 0.23; p = 0.02). In logistic regression models adjusting for age, sex and multiple potential confounders, higher EPO levels were associated with a significantly lower probability of having a clinical diagnosis of polyneuropathy (OR = 0.43; 95% Cl: 0.22-0.84). Discussion: These findings suggest that EPO is implicated in the pathogenesis of polyneuropathy in older persons. Whether low EPO is a risk factor for polyneuropathy should be tested in future longitudinal analyses. (C) 2008 Elsevier Ireland Ltd. All rights reserved
Carotenoids as protection against disability in older persons
No full textThe purpose was to examine the relationship of total plasma carotenoids, an indicator of fruit and vegetable intake, with walking speed and severe walking disability in older adults. Nine hundred twenty-eight men and women aged 65 to 102 years from the Invecchiare in Chianti (Aging in the Chianti Area [InCHIANTI]) study, a population-based cohort in Tuscany, Italy, were studied. Plasma carotenoids were measured at enrollment (1998-2000), and walking speed over 4 meters and 400 meters distance were assessed at enrollment and 6 years later (2004-2006). At enrollment, 85 of 928 (9.2%) participants had severe walking disability (defined as being unable to walk or having a walking speed at the 4-meter walking test < 0.4 m/sec). After adjusting for potential confounders, participants with high total plasma carotenoids were significantly less likely to have prevalent severe walking disability (odds ration [OR] 0.59, 95% confidence interval [CI] 0.38-0.90, p = 0.01) and had higher walking speed over 4 meters (,6 = 0.024, standard error [SE] = 0.011, p = 0.03) and over 400 meters (0 = 0.019, SE = 0.010, p = 0.04). Of 621 participants without severe walking disability at enrollment who were seen 6 years later, 68 (11.0%) developed severe walking disability. After adjusting for potential confounders, higher total plasma carotenoids were associated with a significantly lower risk of developing severe walking disability (OR 0.51, 95% CI 0.30-0.86, p = 0.01) and were associated with a less steep decline in 4-meter walking speed over a 6-year follow-up (n = 579; beta = 0.026, SE = 0.012, p = 0.03) and with lower incidence rates of being unable to successfully complete the 400-meter walking test at the 6-year follow-up visit (beta = -0.054, SE = 0.03, p = 0.04). High plasma carotenoids concentrations may be protective against the decline in walking speed and the development of severe walking disability in older adults
Predictivity of survival according to different equations for estimating renal function in community-dwelling elderly subjects
No full textBackground. Detection of subjects with early chronic kidney disease (CKD) is important because some will progress up to stage 5 CKD, and most are at high risk of cardiovascular morbidity and mortality. While validity and precision of estimated glomerular filtration rate (eGFR) equations in tracking true GFR have been repeatedly investigated, their prognostic performance for mortality has not been hitherto compared. This is especially relevant in an elderly population in whom the risk of death is far more common than progression. Methods. We analysed data of participants in the InCHIANTI study, a community-based cohort study of older adults. Twenty-four-hour creatinine clearance (Ccr), Cockcroft-Gault (C-G) and Modification of Diet in Renal Disease (MDRD)-derived equations (six and four input variables) were calculated at enrolment (1998-2000), and all-cause mortality and cardiovascular mortality were prospectively ascertained by Cox regression over a 6-year follow-up. Results. Of the 1270 participants, 942 (mean age 75 years) had complete data for this study. The mean renal function ranged from 77 ml/min/1.73 m(2) by Ccr to 64 ml/min/1.73 m(2) by C-G. Comparisons among equations using K/DOQI staging highlight relevant mismatches, with a prevalence of CKD ranging from 22% (MDRD-4) to 40% (C-G). Reduced renal function was a strong independent predictor of death. In a Cox model-adjusted for demographics, physical activity, comorbidities, proteinuria and inflammatory parameters-participants with Ccr 60-90 ml/min/1.73 m(2) and Ccr 90 ml/min/1.73 m(2). For the C-G, the group with values 90 ml/min/1.73 m(2) (HR 2.59, 95% CI: 1.13-5.91). The classification based on the MDRD formulae did not provide any significant prognostic information. The adjusted risk of all-cause mortality followed a similar pattern when Ccr and estimating equations were introduced as continuous variables or dichotomized as higher or lower than 60 ml/min. C-G was the best prognostic indicator of cardiovascular mortality. Possibly, Ccr and C-G are better prognostic indicators than MDRD-derived equations because they incorporate a stronger effect of age. Conclusions. In a South-European elderly population, the prevalence of CKD is high and varies widely according to the method adopted to estimate GFR. Researchers and clinicians who want to capture the prognostic information on mortality related to kidney function should use the Ccr or C-G formula and not MDRD equations. These results highlight the importance of strategies for early detection and clinical management of CKD in elderly subjects
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