1,721,472 research outputs found
Patients who have had fractures ?f the distal forearm do not lose bone as expected
No full textEditor - Women's lifetime risk of experiencing a fracture of the distal forearm is 15%.x Such fractures are associated with considerable pain and morbidity. They are also associated with an increased risk of vertebral fracture,2 although these anatomical sites have different bone compositions, with the forearm being composed predominantly of cortical bone whereas the spin
Genetic influence on bone turnover in postmenopausal twins.
No full textPostmenopausal bone mass is determined by both peak bone mass and subsequent bone loss. Previous studies have shown that peak bone mass is under genetic influence mediated partly by factors affecting bone formation. The rate of bone loss increases markedly after the menopause, but is highly variable from subject to subject. The aims of this study were to determine whether postmenopausal bone turnover was under genetic control, which should be linked to the genetic influence on the rate of postmenopausal bone loss. A classical twin study was performed that compared the intraclass correlations in monozygotic (MZ) twins with those in dizygotic (DZ) twins, with any difference assumed to be due to genetic factors. Markers of bone formation and resorption were measured in 240 untreated postmenopausal twins, aged 45-69 yr, on the average 12.3 yr (SD, 6.0) postmenopause, including 61 MZ pairs and 59 DZ pairs. The intraclass correlation coefficient of MZ twin pairs, rMZ (95% confidence interval), for 2 specific markers of bone formation, serum osteocalcin and bone-specific alkaline phosphatase, were higher than the corresponding rDZ [0.67 (range, 0.59-0.75) vs. 0.48 (range, 0.35-0.61; P = 0.06) for osteocalcin and 0.53 (range, 0.41-0.65) vs. 0.21 (range, 0.01-0.41; P = 0.02) for bone-specific alkaline phosphatase]. For serum propeptide of type I collagen, a type I collagen synthesis marker that exhibits only a slight increase after menopause, a high proportion of its variance was explained by genetic factors [rMZ = 0.82 (0.77-0.87), rDZ = 0.33 (0.16-0.50); P < 0.001]. The correlations for bone resorption measured by three distinct urinary markers, total deoxypyridinoline and two cross-linked type I collagen peptides (CrossLaps and NTX), that increase markedly after menopause were higher in MZ than in DZ pairs, but the difference reached significance only for NTX (P = 0.03). For urinary free dexoypyridinoline, a marker reflecting bone collagen degradation that increases moderately after menopause, the proportion of the variance explained by genetic factors was highly significant (P = 0.002). In conclusion, our data indicate that a proportion of the variance in postmenopausal levels of both bone formation and resorption markers are explained by genetic factors, but this contribution was clearly significant only for markers that do not change markedly at the menopause. These data suggest that the contribution of genetic factors to overall postmenopausal bone turnover and possibly bone loss is likely to be small
Determinants of pressure pain threshold in adult twins: evidence that shared environmental influences predominate
No full textThe objective of this study was to examine the relative contribution of genetic and environmental factors in determining pain perception in a classical twin study. Dolorimeter measurements of pressure pain threshold (PPT) were recorded in 609 healthy female-female twin pairs of whom 269 pairs were monozygotic (MZ) and 340 were dizygotic (DZ). There was a strong correlation (R) in PPT in both MZ and DZ pairs (R(MZ) = 0.57, 95% confidence interval (CI): [0.49, 0.65]; R(DZ) = 0.51, 95% CI: [0.42, 0.59]). The slight excess in intraclass correlation observed in MZ when compared with DZ twins corresponds to a heritability for PPT of only 10% and is not statistically significant. Neither estimate of intraclass correlation was substantially altered after adjusting for a range of potential confounding variables including age, current tobacco and alcohol use, current analgesic use, psychological status assessed by the general health questionnaire, and social class. The dolorimeter measurements were shown to be reliable (between observer agreement R = 0.66; within observer agreement R = 0.70-0.76) and stable over time. In conclusion, these data suggest that there is no significant genetic contribution to the strong correlation in PPT that is observed in twin pairs. These findings reinforce the view that learned patterns of behaviour within families are an important determinant of perceived sensitivity to pain.</p
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
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
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