1,721,615 research outputs found
Short-term effect of testosterone treatment on reduced bone-density in boys with constitutional delay of puberty
No full textWe studied bone mineral content (BMC), bone mineral density (BMD), cortical thickness/total width (CT/TW) ratio and cortical area/total area (CA/TA) ratio in boys with constitutional delay of puberty and the effect of short-term testosterone treatment on bone mass. Seventeen boys (age 13.1-15.8 years) who met the family history and the clinical criteria of constitutional delay of puberty were selected and enrolled in the study. All subjects were eating a diet assuring an adequate intake of calories and calcium. A subset of 8 boys (group A) was treated with testosterone depot (100 mg/month x 6 months) while 9 boys (group B) were not. At inclusion, BMC and BMD were reduced in the patients according to their chronological age (BMC -4.04 +/- 1.34 standard deviation scores [SDS]; BMD -2.95 +/- 0.56 SDS), statural age (BMC -1.75 +/- 0.79 SDS; BMD -1.69 +/- 0.78 SDS), and bone age (BMC -1.80 +/- 0.65 SDS; BMD -1.86 +/- 0.68 SDS). No significant differences between the groups were found (group A: BMC 0.480 +/- 0.57 g/cm, BMD 0.488 +/- 0.037 g/cm(2), CT/TW ratio 0.43 +/- 0.4, CA/TA ratio 0.68 +/- 0.04; group B: BMC 0.476 +/- 0.060, p = NS vs. group A; BMD 0.491 +/- 0.036 g/cm(2), p = NS vs. group A, CT/TW ratio 0.42 +/- 0.05, p = NS vs. group A; CA/TA ratio 0.67 +/- 0.06, p = NS vs. group A). At 12 months of follow-up, BMC, BMD, CT/TW ratio, and CA/TA ratio significantly increased in group A (BMC 0.70 +/- 0.13 g/cm, Delta +41.1 +/- 28.8%, p < 0.003 vs. 0 month; BMD 0.617 +/- 0.082 g/cm(2), Delta + 26.2 +/- 13.6%, p < 0.005 vs. 0 month; CT/TW ratio 0.52 +/- 0.05, Delta +20.59 +/- 10.65%, p < 0.001 vs. 0 month; CA/TA ratio 0.77 +/- 0.05, Delta +13.60 +/- 6.65%, p < 0.004 vs 0 month), but not in group B (BMC: 0.48 +/- 0.05 g/cm; Delta +5.1 +/- 7.8%, p = NS vs. 0 month; BMD: 0.492 +/- 0.037 g/cm(2); Delta +0.54 +/- 8.7%, p = NS vs. 0 month; CA/TA ratio 0.44 +/- 0.04, Delta +4.04 +/- 6.75%, p = NS vs. 0 month; CA/TA ratio 0.68 +/- 0.05, Delta +2.39 +/- 5.90%, p = NS vs. 0 month). We conclude that boys with constitutional delay of puberty have reduced BMC and BMD. The delay in statural and bone ages did not totally account for the decreased bone mass. Testosterone treatment for 6 months significantly increased BMC, BMD, CT/TW ratio, and CA/TA ratio in these patients, but definitive conclusions on the efficacy of the treatment in improving adult bone mass can be drawn only when our patients reach early adulthood
Horvitz-Thompson estimation with randomized response and nonresponse
No full textWe consider the nonstandard situation where the randomized response theory is applied in a nonresponse set-up. The customary Horvitz-Thompson estimator for the population total of a sensitive variable is adjusted to take into account missing data, true response and randomized response, and the expression of its variance and the corresponding estimator provided. Finally, a numerical study is carried out to investigate how the estimation process can be affected by scrambled responses and how possible improvements in respondent cooperation can compensate for certain levels of nonresponse
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
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