1,720,975 research outputs found
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
First trimester combined screening test in pregnancies derived from blastocyst transfer
No full textObjective To investigate whether first trimester combined screening for major fetal trisomies is influenced by assisted reproduction techniques from blastocyst transfer, with or without cryopreservation. Study design retrospective case-control analysis involving 298 singleton pregnancies with euploid fetuses recruited between 2012 and 2014. Forty-seven women conceived with fresh blastocysts from in vitro fertilization cycles (fresh-blasto), 51 with frozen-thawed blastocysts (frozen-blasto) and 200 were natural conceptions (controls). All cases underwent ultrasound assessment at 11+0-13+6 weeks with measurements of crown rump length, nuchal translucency, free β-hCG and PAPP-A concentrations. The outcome of pregnancy was recorded (gestational age at birth, birth weight, obstetric complications). Results Baseline characteristics and pregnancy outcomes did not differ substantially among the study groups. The median delta nuchal translucency was significantly higher both in frozen-blasto group (median: 0.27 mm; Interquartile Range [IQR]: 0.02-0.44; p < 0.001) and in fresh-blasto group (median: 0.17 mm; IQR: 0.04-0.39; p = 0.014) as compared to control group (median: 0.06 mm; IQR: -0.08 to 0.20), whereas it was not different in the frozen-blasto compared to the fresh-blasto group. The median free β-hCG multiples of the median (MoMs) was significantly higher both in frozen-blasto group (median 1.15; IQR 0.83-2.11; p = 0.001) and in fresh-blasto group (median 0.95; IQR 0.52-1.48; p = 0.001) as compared to control group (median 0.99; IQR 0.57-1.26), and it was also higher in frozen-blasto group compared to fresh-blasto group (p < 0.001). The three groups showed no significant differences in the median PAPP-A MoMs. The median delta crown rump length was also not significantly different among the three groups. Conclusions in assisted reproduction technique pregnancies from blastocyst transfer, with or without cryopreservation, both the nuchal translucency measurement and free β-hCG concentration are higher as compared to spontaneous conceptions, whereas PAPP-A does not show any significant difference. These features are apparently unrelated to the outcome of pregnancy and may be due to alterations or delays in embryogenesis or placentation with potential relevance for the screening test performance
Evaluation of uterine arteries doppler and estrogen milieu in oocyte donation pregnancies
No full textIntroduction: The number of oocyte donation (OD) cycles have dramatically increased. While OD pregnancies face increased risks of obstetrical complications, especially pregnancy-induced hypertension and pre-eclampsia (PE), little is known about the physiology and the physiopathology of placentation.
Method: We performed a prospective cohort study to analyze uterine arteries Doppler Pulsatility index (PI) and serum maternal 17 β – estradiol at 11+0-13+6 weeks’ gestation. Three groups of singleton pregnancies were studied: OD, in vitro fertilization pregnancies with autologous oocytes from fresh cycles (Autologous IVF) and spontaneous pregnancies. Outcomes were collected to include only physiological pregnancies.
Results: The analysis by weeks showed a decreased uterine arteries PI between 11 and 13+6 weeks with a similar trend in all groups, but mean uterine artery PI at 11-13+6 weeks were significantly lower in OD recipients compared to Spontaneous Pregnancies and Autologous IVF (1.415 (DS 0.486) vs. 1.679 (DS 0.456) vs. 1.706 (DS 0.481) - p < 0.05). In spontaneous pregnancies,maternal serum levels of 17 β – estradiol grows between 11 and 13+6 weeks, with mean level of 2423 pg/ml at 11.5 weeks, 2521 pg/ml at 12.5 weeks and 4654 pg/ml at 13.5 weeks. Interestingly, in the same cohort we found a higher value in female fetuses with a mean of 3204 pg/ml (DS 1634) compared to the mean value of male fetuses of 2436 pg/ml (DS 1170) with a ratio female/male of 17 β – estradiol maternal serum concentration of 1,31 (IC95%: 1.04 – 1.65). Maternal serum levels of 17 β – estradiol in OD - oocyte recipients were significantly lower than in IVF and spontaneous pregnancies (1705.33 (DS 380.61) vs. 2121.50 (DS 1387.62) vs. 2844.93 (1516,29) p < 0.05).
Conclusion: Mean uterine artery PI and 17-β estradiol at 11-13+6 weeks were significantly lower in OD recipients compared to Spontaneous Pregnancies and Autologous IVF. Oocyte donation has a significant impact on placentation in the first trimester of pregnanc
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
