1,721,011 research outputs found
Intrauterine growth of normal thyroid
No full textIn this study we describe fetal thyroid growth during gestation and establish normal reference values using a simple linear ultrasound measurement of the thyroid. A total of 1180 normal singleton pregnancies, with no known risk factors for thyroid disorders, were enrolled from 12 to 39 weeks of gestation. The thyroid antero - posterior diameter was measured on a transverse axial plane through the fetal neck. The best fit regression was a power equation: thyroid diameter = 0.2412 weeks1.0278 (r2 = 0.55). The percentiles smoothed curves were calculated for each week. In conclusion, the results of the present study support previous findings that the fetal thyroid grows between 12 and 39 weeks of gestation with a steepest increase during the second trimester, that is when the fetal thyroid becomes functionally active. The normal ranges of this simple index of thyroid growth can be useful both as screening and for the clinical evaluation of pregnant patients with thyroid disorders
Fetal nutrition : a review
Full text linkKnowledge of fetal nutrient supply has greatly increased in the last decade due to the availability of fetal blood samples
obtained under relatively steady-state conditions. These studies, together with studies utilizing stable isotope methodologies,
have clarified some aspects of the supply of the major nutrients for the fetus such as glucose, amino acids and fatty acids. At the
same time, the relevance of intrauterine growth has been recognized not only for the well-being of the neonate and child, but
also for later health in adulthood. The major determinants of fetal nutrient availability are maternal nutrition and metabolism
together with placental function and metabolism. The regulation of the rate of intrauterine growth is the result of complex
interactions between genetic inheritance, endocrine environment and availability of nutrients to the fetus
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
Evaluation of fetal growth and fetal well-being
No full textThis article reviews the actual knowledge and future developments of ultrasound techniques for the evaluation of fetal growth and well-being. Sonography allows the visualization of the fetus in utero and is utilized worldwide for the evaluation of fetal growth and well-being. Fetal biometry assessment is performed in the second half of pregnancy when deviations of fetal growth can be best recognized through alterations of fetal abdominal circumference growth. Doppler velocimetry of utero-placental vessels identifies alterations of placental perfusion and is valuable in the assessment of fetal brain, heart, and liver perfusion, thus being utilized in the timing of delivery. Recently, three-dimensional ultrasound evaluation of fetal organs and placenta is being developed
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
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