1,720,967 research outputs found
Determination of intracellular water by multifrequency bioelectrical impedance.
No full textBody composition was measured in 57 healthy males by 40K measurements and by multifrequency bioelectrical impedance. Intracellular resistance (Ricf) was calculated from the impedance values using the Cole-Cole model. From total body potassium, intracellular water (ICW) was calculated. In addition, in 14 subjects, total body water (TBW) and extracellular water (ECW) was measured using deuterium oxide dilution and bromide dilution, respectively. Prediction formulas from the literature from impedance at different frequencies were used to predict TBW and ECW, and ICW was calculated as the difference of predicted TBW and ECW. Predicted and measured values of TBW, ECW and ICW did not always show the same values as measured. Generally the ICW from potassium was well correlated with calculated ICW from impedance values, correlation coefficients varying from 0.68 to 0.79, depending on the used prediction formula. From the impedance index H2/Ricf, body weight and age, ICW from potassium was predicted with stepwise multiple regression. The prediction formula was ICW = 0.37065.H2/Ricf - 0.132.age + 0.105.weight + 12.2. The prediction error was 1.9 kg and the explained variance 0.69. The residuals of this prediction formula were dependent on the level of ICW as measured by potassium. The same phenomenon was observed when ICW was calculated as the difference of predicted TBW and ECW. The results show that multifrequency impedance is able to predict ICW, however, the prediction is influenced by body water distribution
[Effects of prolonged administration of branched-chain amino acids on body composition and physical fitness]
No full textNo conclusive data are reported about the effects of long-term branched-chain amino-acids (BCAA) administration on metabolic and respiratory parameters during the sustained hand-grip test (SHGT). Bedside, few data are reported about the relationship between BCAA administration and body composition. Thus, BCAA (14 g/die; 50% L-Leucine, 25% L-Isoleucine, 25% L-Valine) were administered orally to 10 untrained male healthy subjects for 30 days. Before (T0) and after (T1) BCAA administration, oxygen uptake (VO2) and pulmonary ventilation (VE) were evaluated at rest ("baseline", B) and during SHGT. Body height and body weight, body mass index (BMI), fat mass (FM), fat-free mass (FFM), arm muscle area (AMA) and maximal voluntary contraction of forearm muscler (GS, grip strength) were also evaluated at T0 and T1. At T1 FFM increased significantly (T0: 62.3 +/- 7.6 kg; T1: 63.1 +/- 7.5 kg; mean +/- SD; p < 0.05), as well as GS (T0: 46.8 +/- 7.9; T1: 50.6 +/- 7.8; p < 0.01). At T0, VO2 increased significantly during the test (B: 271 +/- 36 ml/min; SHGT: 332 +/- 71 ml/min; p < 0.01), whereas at T1 no significant increase was observed (B: 271 +/- 50 ml/min; SHGT: 286 +/- 60 ml/min). We conclude that the physical fitness of BCAA treated subjects was improved, because of the decrease of O2 uptake during SHGT. Moreover, in our subjects, BCAA seemed to promote FFM-protein synthesis mostly
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
Within-subject variability in body composition using dual-energy X-ray absorptiometry
No full textThe reproducibility of dual-energy X-ray absorptiometry (DXA) measurements for total body composition and for segmental body composition was investigated in 22 healthy male subjects who underwent six consecutive measurements in 90 min. Body weight (mean +/- SD) and body height were 72.3 +/- 8.8 kg and 1.75 +/- 0.04 m respectively, and body mass index was 23.5 +/- 2.5 kg m(-2). Bone mineral content (BMC) was 3.30 +/- 0.36 kg, lean mass and fat mass as measured by DXA were 57.1 +/- 6.1 kg and 11.8 +/- 6.5 kg respectively. For BMC, the reproducibility, expressed as the coefficient of variation, was 12%, 1.5%, 2.5%, 4.1% and 3.1% for total body, legs, arms, trunk and abdominal respectively. For lean tissue and for fat tissue, these values were 1.5% and 50%; 1.8% and 2.1%, 8.3% and 11.7%, 26% and 10.0%, 3.9% and 10.7% respectively. It is concluded that the reproducibility for BMC is excellent, but that for lean tissue and for fat tissue the variability is relatively high, especially in body segments
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
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