1,721,072 research outputs found
The deep venous system in the puerperium: an ultrasound study
No full textObjective: To study the vessel wall diameter and blood flow velocity within the proximal deep venous system of the leg in the puerperium and to compare these measures with respect to the left versus right leg, 4th versus 42nd postnatal day, and vaginal versus caesarean delivery.Design: A combined longitudinal and cross-sectional observational study.Setting: The ultrasound department of a teaching maternity hospital.Results: A reduction in vessel diameter and an increase in flow velocity was observed between the 4th and 42nd postnatal day. Vessel diameter was greater and flow velocity was reduced in the left compared to the right leg. In those delivered by caesarean section, a trend towards reduced flow velocity in the proximal deep leg veins was observed when compared with those delivered vaginally.Conclusions: These data suggest possible physiological mechanisms behind previous clinical observations relating to the period of greatest risk of deep vein thrombosis in the puerperium, the relative preponderance of left sided deep vein thrombosis and the risk of deep vein thrombosis associated with caesarean section.<br/
An ultrasound study of gestational and postural changes in the deep venous system of the leg in pregnancy
No full textObjective: To investigate gestational and postural changes in diameter and blood flow in the proximal deep leg veins during pregnancy.Design: A longitudinal, prospective observational study.Setting: The ultrasound department of a teaching maternity hospital.Population: Twenty-four healthy women with uncomplicated singleton pregnancies.Methods: Real-time and duplex Doppler ultrasound assessments of the vessel diameter, flow velocity and respiratory flow fluctuation in the proximal deep leg veins of women serially measured from the first trimester of pregnancy to six weeks postnatally.Main outcome measures: The effects of increasing gestation and the adoption of the left lateral position on the above parameters.Results: An increase in vessel diameter and a fall in flow velocity with increasing gestation was observed. However, no change in venous flow variation was observed. Delivery had reverse effects. Flow velocity was slower in the left than the right legs, but on adoption of the left lateral position an increase in flow velocity and venous flow variation was observed in both legs during pregnancy.Conclusions: These data are consistent with the observed increase in incidence and pattern of deep venous thrombosis in pregnancy and may aid interpretation of duplex Doppler ultrasound examinations for deep venous thrombosis in pregnancy. Postural changes should be part of this evaluation. The gravid uterus may not be the sole cause for postural changes in deep venous flow velocity.<br/
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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