1,720,958 research outputs found
Mitral deceleration index is associated with aortic root dilatation and not to biventricular structural changes in essential hypertension
No full textBackground and aim. The ratio of deceleration time to early mitral wave velocity (mitral deceleration index, MDI) has been recently shown to predict cardiovascular events more precisely than deceleration time alone in human hypertension. Data, however, about the relationship of this parameter with cardiac structure are scant. In the present study, we investigated such an association in uncomplicated essential hypertensives. Methods. A total of 329 hypertensive subjects categorized in tertiles of MDI were considered for the analysis. All patients underwent the following procedures: (i) physical examination and clinic blood pressure measurement; (ii) routine laboratory investigations; (iii) M-mode, two-dimensional and Doppler echocardiography aimed at a comprehensive assessment of left- and right-sided chambers. Results. Unadjusted left ventricular (LV) mass, right ventricular (RV) and aortic root diameter were significantly higher in the upper MDI tertile, but only aortic root diameter remained significant after adjustment for covariates. A progressive, non-significant increase in biventricular hypertrophy occurred across the MDI tertiles. In a multivariate analysis, MDI was significantly associated with age (β = 0.229, p = 0.001) and aortic root diameter (β = 0.226, p = 0.001); this was not the case for deceleration time alone. No association between MDI and LV as well as RV structural parameters was found. Conclusion. Our findings indicate that MDI is unrelated to LV and RV structural changes. Altered LV diastolic function, as assessed by MDI but not by deceleration time alone, is independently associated with aortic root dilatation, a phenotype predictive of incident cardiovascular morbidity and mortality
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
Left ventricular hypertrophy and abdominal aorta size in essential hypertension
No full textAIM: To investigate the association between subclinical organ damage and abdominal aortic diameter in a large cohort of uncomplicated essential hypertensive patients. Methods: Subclinical markers of organ damage (i.e. left ventricular mass, carotid intima-media thickness and plaques, microalbuminuria and retinal changes) and abdominal aortic diameter (ultrasonography) were assessed in 2430 (mean age 53 ± 13 years) untreated and treated hypertensive patients included in the Evaluation of Target Organ Damage in Hypertension (ETODH) study. Results: In the whole study population, left ventricular mass index was the most important correlate (β = 0.418, P < 0.0001) of the absolute abdominal aortic diameter and, after age, (β = 0.268, P < 0.0001) of abdominal aortic diameter indexed to body surface area (abdominal aorta index, AAI). In a sex-based analysis, a stepwise increase in left ventricular mass index as well as in prevalence of left ventricular hypertrophy (LVH), carotid intima-media thickness and plaques occurred from the lower to the upper quartile of AAI in men, but not in women. No correlations were found between AAI and microalbuminuria or retinal changes. Conclusion: Our findings support a sex-specific relation between abdominal aorta size and subclinical organ damage by showing that LVH in hypertensive men is an independent correlate for enlarged abdominal aorta. On the basis of these data, diagnostic protocols for detecting subclinical alterations in the abdominal aorta should be optimized
Is the nocturnal fall in blood pressure reduced in essential hypertensive patients with metabolic syndrome?
No full textObjective: The aim of this study was to examine whether an impaired reduction in nocturnal blood pressure (BP), defined on the basis of two periods of ambulatory BP monitoring (ABPM), is present in hypertensive patients with metabolic syndrome, as defined by the NCEP criteria. Methods: 460 grade 1 and 2 untreated essential hypertensives (mean age 45.9 ± 11.9 years) referred for the first time to our outpatient hospital clinic underwent the following procedures: 1) medical history and physical examination; 2) repeated clinic BP measurements; 3) routine examinations; 4) ABPM over two 24-hour periods within 4 weeks. Metabolic syndrome was defined as at least three of the following alterations: increased waist circumference, increased triglycerides, decreased HDL-cholesterol, increased BP, or high fasting glucose. Nocturnal dipping was defined as a night-time reduction in average SBP and DBP > 10% compared to average daytime values. Results: The 135 patients with metabolic syndrome (group I) were similar for age, gender and known duration of hypertension to the 325 patients without it (group II). There were no significant differences between the two groups in average 48-hour, daytime, night-time SBP/DBP values and the percentage nocturnal SBP and DBP decrease (-17.7/-15.7 vs.-18.4/-16.2, p = ns). A reproducible nocturnal dipping (decrease in BP > 10% from mean daytime in both ABPM periods) and non-dipping profile (decrease in BP ≤ 10% in both ABPM periods) was found in 74 (54.8%) and 29 (21.4%) in group I and in 169 (52.1%) and 73 (22.4%) in group II, respectively (p = ns); 32 patients (23.7%) in group I and 83 patients (25.5%) in group II had a variable dipping profile (p = ns). Conclusions: This study shows that no significant difference exists in nocturnal BP patterns, assessed by two ABPMs, in untreated essential hypertensive patients with metabolic syndrome compared to those without it
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
- …
