1,720,966 research outputs found
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
Validation of the A&D UA-774 (UA-767Plus) device for self-measurement of blood pressure.
No full textTo determine the accuracy of the UA-774 (UA-767Plus) blood pressure monitor developed by the A&D Company.Device evaluation was performed according to the modified British Hypertension Society (BHS) protocol released in 1993. Eighty-five subjects with characteristics outlined in the BHS protocol were recruited among those attending the outpatient clinic of the Department of Cardiovascular Disease, Hospital 'R. Silvestrini', Perugia, Italy. The A&D blood pressure monitor was evaluated according to the various steps of the protocol. Sequential readings were taken for the main validation test. Outcome was classified according to the criteria of BSH recommendations, which are based on four areas of accuracy differing from the mercury standard by 5, 10 and 15 mmHg, or more.The device achieved a grade A for systolic and a grade A for diastolic blood pressure. Mean blood pressure difference (+/-1 SD) between device and observers was -1.01+/-7.14 mmHg for systolic blood pressure and -1.42+/-7.61 mmHg for diastolic blood pressure. There was no systematic change in the device-observed difference over a wide range of blood pressure valuesThese data show that the A&D UA-774 (UA-767Plus) device satisfies the BSH recommendations for accuracy for systolic and diastolic blood pressure
Prognostic value of lipoprotein fractions in essential hypertension.
No full textTo evaluate distribution and prognostic value of total cholesterol and lipoprotein fractions in essential hypertension.In a prospective cohort study, 2649 initially untreated subjects with essential hypertension (aged 51, 46.5\% women) were investigated at entry and followed for a mean of 5.6 years (range: 1-16).At entry, subjects with total cholesterol (TC) > or =240 mg/dl (> or =6.22 mmol/l) or high-density lipoprotein (HDL) cholesterol (HDL-C) or =160 mg/dl (4.13 mmol/l) or TC/HDL-C ratio >6 were 47.7\%. TC, HDL-C, LDL-C and triglycerides (TG) did not show any association with office or 24-h ambulatory blood pressure (BP). During follow-up there were 167 first cardiac events and 122 first cerebrovascular events. TC, HDL-C, LDL-C and TC/HDL-C ratio showed an association with cardiac events, but not with cerebrovascular events. TG did not show any association with cardiac or cerebrovascular events. After adjustment for age, sex, diabetes, smoking, left ventricular (LV) hypertrophy and 24-h pulse pressure, the hazard ratio for cardiac events was 1.83 (95\% CI 1.23-2.71) in association with a TC > or =6.22 mmol/l, 2.23 with a HDL-C or =4.91 mmol/l (95\% CI 1.48-5.42) and 3.90 with a TC/HDL-C ratio >6.0 (95\% CI 2.23-6.81). When forced in the same model, HDL-C and LDL-C showed an independent association with cardiac events.Abnormalities of TC and lipoproteins are common in essential hypertension. HDL-C and LDL-C independently predict the risk of cardiac, but not cerebrovascular, events. Their predictive value is independent of several confounding factors including LV hypertrophy and ambulatory BP
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
Prognostic significance of serial changes in left ventricular mass in essential hypertension.
No full textIncreased left ventricular (LV) mass predicts an adverse outcome in patients with essential hypertension. The purpose of this study was to determine the relation between changes in LV mass during antihypertensive treatment and subsequent prognosis.Procedures including echocardiography and 24-hour ambulatory blood pressure (BP) monitoring were performed in 430 patients with essential hypertension before therapy and after 1217 patient-years. Months or years after the follow-up visit, 31 patients suffered a first cardiovascular morbid event. The patients with a decrease in LV mass from the baseline to follow-up visit were compared with those with an increase in LV mass. There were 15 events (1.78 per 100 person-years) in the group with a decrease in LV mass and 16 events (3.03 per 100 person-years) in the group with an increase in LV mass (P=.029). In a Cox model, the lesser cardiovascular risk in the group with a decrease in LV mass (hazard ratio [HR], 0.46; 95\% CI, 0.22 to 0.99) remained significant (P=.04) after adjustment for age (HR, 1.06; 95\% CI, 1.03 to 1.10; P=.0008) and baseline LVH at ECG (HR, 3.85; 95\% CI, 1.52 to 9.78; P=.012). In that model, baseline LV mass bordered on statistical significance (HR, 1.01; 95\% CI, 1.00 to 1.03; P=.06). In the subset with LV mass > 125 g/m2 at the baseline visit (26\% of subjects), the event rate was lower among the subjects who achieved regression of LVH than in those who did not (1.58 versus 6.27 events per 100 person-years; P=.002). This difference held in the multivariate analysis (HR, 0.18; 95\% CI, 0.05 to 0.68).In essential hypertension, a reduction in LV mass during treatment is a favorable prognostic marker that predicts a lesser risk for subsequent cardiovascular morbid events. Such an association is independent of baseline LV mass, baseline clinic and ambulatory BP, and degree of BP reduction
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