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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
Identification of activin A and follistatin in human milk
No full textActivin A is a dimeric protein member of the transforming growth factor-beta (TGF-beta) family: it is synthesized by a variety of organs and follistatin is an activin-binding protein. A sensitive and specific assays for bioactive dimeric activin A and follistatin have recently allowed to measure these proteins in blood and other biological fluids, giving a new insights into their possible physiological role. Since human breast is able to produce activin A, the aim of the present study was to evaluate whether it and follistatin are measurable in breast milk of women during lactation. Concentrations of activin A and follistatin were measured in milk samples collected at 3, 5 and 30 days after delivery by using specific and sensitive two-site ELISAs. For the first time the presence of immunoreactive activin A and follistatin in human milk has been shown; no significant different concentration between the third and the fifth day after delivery was found. Furthermore, no difference of activin A and follistatin concentration between the whole and the skim milk or between spontaneous delivery and cesarean section was found. Milk activin A and follistatin concentrations after 1 month of lactation were significantly decreased (P < 0.01). Activin A and follistatin are present in human milk in high concentrations in the first week of lactation, while decrease after a month suggesting a possible role as growth factors in human milk
Endometrial expression and secretion of activin A, but not follistatin, increase in the secretory phase of the menstrual cycle
No full textOBJECTIVE:
Activin A is a growth factor expressed by human endometrium, and its biologic effects are counteracted by follistatin. We evaluate whether activin A and follistatin mRNA and peptide expression as well as protein secretion from human endometrium change throughout the menstrual cycle.
METHODS:
In 25 healthy fertile patients, uterine washing fluid was retrieved by hydrosonography. In a subgroup (n = 13), endometrial tissue samples were collected by hysteroscopy during the proliferative (n = 6) or secretory (n = 7) phase of the menstrual cycle. Activin and follistatin mRNA and peptide expression were evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and by immunohistochemistry (IHC), respectively. Activin A and follistatin levels were assayed in uterine washing fluids by specific enzyme-linked immunosorbent assays and evaluated according to the endometrial thickness and menstrual cycle days.
RESULTS:
Both activin A and follistatin mRNAs were expressed by human endometrium, and their peptides immunolocalized both in proliferative and secretory endometrial epithelial and stromal cells. A significant increase in immunoreactive activin betaA but not in follistatin was observed in glandular epithelium during the secretory phase. Activin A but not follistatin was significantly (P <.0001) higher in the washing fluids collected during the secretory than proliferative phase of the menstrual cycle. In addition, a significant correlation was found between activin A, but not follistatin, and menstrual cycle days (P <.0001) or endometrial thickness (P <.0001).
CONCLUSIONS:
Both activin A and follistatin mRNAs are expressed by human endometrium; however, activin A but not follistatin peptide expression and secretion were increased in the secretory phase of the menstrual cycle, suggesting an important role in human endometriu
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
Urocortin in endometrial and ovarian cancer: low lewels are related to an immune system regulations
No full textMaternal position during non-stress test and fetal heart rate patterns
No full textObjective. The aim of the study was to determinate whether maternal position during the non-stress test (NST) in different weeks of pregnancy influences fetal heart rate patterns.
Materials and methods. A total of 1055 NST lasting 30 min were performed in 368 autochthonous mothers with low-risk pregnancies. On the basis of maternal position during the test we divided into three groups: reclining, sitting, and walking. The cardiotocographic parameters considered were: number of minutes of reactive NST with minimum length, number of fetal movements, fetal heart rate baseline, number of large accelerations, number of dubious NST, and number of variable decelerations.
Results. Fetal heart rate patterns in low-risk pregnancies were studied using NST in different gestational ages and in different maternal positions. Differences in heart rate were found in relationship to both gestational age and maternal position. The minimum length of NST necessary to record at least three large accelerations was significantly different in relationship to both gestational age and maternal position. The number of fetal movements perceived by the mother was greater in the reclining position than in sitting or walking. Together with the progression of pregnancy, the number of dubious NST decreased in all subgroups, especially in the sitting position. The greatest number of variable decelerations was observed in the reclining position and it was increased with pregnancy progression. The NST duration did not vary greatly in the reclining position, but in the sitting position or during walking, the time taken to record the three large accelerations required to define the trace as reactive, decreased significantly with the progression of pregnancy
Conclusions. Non-stress test in sitting position or during walking should be encouraged because fetal reactivity is more quickly observed
Abnormal umbilical artery Doppler waveforms and cord blood inhibin a and inhibin B levels
No full textInhibin A and inhibin B are glycoprotein hormones produced by human placenta and by several fetal organs during pregnancy. They are secreted in maternal circulation in increasing amounts from early until term pregnancy, and in umbilical cord blood levels are significantly lower than in maternal serum and do not differ from mid-pregnancy to term gestation. In the present study, we aimed to determine whether secretion of inhibin A and inhibin B into the fetal circulation is increased in pregnancies complicated by umbilical-placental vascular insufficiency. A group of women (n = 13) with abnormal Doppler umbilical artery flow velocimetry and a group of control women (n = 11) with uncomplicated term pregnancies and normal umbilical artery flow velocity waveforms were studied. In each woman, inhibin A and inhibin B concentrations were estimated in umbilical cord artery and vein. In the two groups of women, mean inhibin A levels did not differ between umbilical cord artery and vein. In addition, no difference was retrieved both in umbilical cord artery and vein values between healthy controls and patients with abnormal Doppler umbilical artery flow velocimetry. On the contrary, inhibin B levels were significantly higher in samples from umbilical cord vein than artery, in both groups of pregnant women (both p < 0.001). However, women with abnormal Doppler umbilical artery flow velocimetry had inhibin B levels significantly higher than healthy controls (p = 0.005) only in the umbilical cord artery, but not in the vein. In the presence of abnormal Doppler umbilical artery flow velocity, the concentrations of inhibin B are increased in the arterial umbilical circulation, suggesting that inhibin B is released from multiple fetal sources as a response to hypoxemic stress. As inhibins may affect the hypothalamus-pituitary-adrenal axis which plays an important role in the mechanisms of adaptations to the post-natal life, inhibin B in fetal circulation might then be beneficial to a fetus whose intrauterine survival is threatened by impaired umbilical-placental blood flo
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