1,721,039 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
In vitro meiosis resumption of feline oocytes isolated from vitrified ovarian tissue
No full textIntroduction and aim. In the preovulatory follicle, canine oocytes are exposed to high
concentrations of progesterone (P4) and estradiol (E2), and different concentrations of
gonadotrophins are present in the pre- and post-ovulatory environment, i.e. oviduct, where full
nuclear maturation occurs (1,2,3). Thus, two microenvironments characterized by the presence of
different hormonal concentrations contribute to the achievement of Metaphase II (MII) stage. In
vitro, maturation conditions should be based on these different pre- and post-ovulatory
environments and on the fact that cultural requirements for oocyte maturation may vary along the
time. Hence, the aim of this work was to study the influence of different bi-phasic systems with
gonadotrophins and steroids on in vitro maturation rates of canine oocytes.
Materials and Methods. Ovaries were collected from 14 anestrous bitches (various breeds, age 1-
7 y) by routine ovariohysterectomy and sliced in PBS-PVA to release the cumulus-oocyte
complexes (COCs). A total of 363 COCs grade I (two or more dense layers of cumulus cells and
darkly pigmented cytoplasm) were selected for culture. Oocytes were randomly allocated in three
different cultural systems with the base medium (BM) consisting of TCM-199 (Sigma Chemical
Co., USA), with antibiotics, 10% FBS, 2.2 mg/ml sodium bicarbonate and 20 μl/ml pyruvic acid.
The systems were as follows: in system A (control) oocytes (n. 91) were matured for 72h in BM
with 10 i.u./ml hCG (Sigma), 1 μg/ml P4 (Sigma), 1 μg/ml E2 (Sigma); in bi-phasic system B
oocytes (n. 120) were matured for 48h in BM with hCG and for 24h in BM with P4; in bi-phasic
system C oocytes (n. 124) were matured for 48h in BM with hCG, P4 and E2, and for 24h in BM
with P4. In systems B and C hormones were supplemented at the same doses as in system A.
Cumulus-oocyte complexes were incubated at 38°C, 5% CO2 in air and, at the end of maturation
(72h), were transferred to PBS containing 0.2% hyaluronidase (Sigma) for removal of cumulus cells
by repeated pipetting. Oocytes were stained with Hoechst 33342 (Sigma) for evaluation of meiotic
configuration. Data were analyzed by Chi-square test.
Results. Anaphase/Metaphase I rates were higher (P<0.02) in oocytes cultured in bi-phasic system
B (27.5%; 33/120) and C (29%; 36/124) when compared to control (13.2%; 12/91). Only three
oocytes from control group reached MII stage (3.3%), while higher rates (P<0.02) of oocytes
cultured in system B (11.7%; 14/120) and C (13.7%; 17/124) were able to complete meiosis.
Degeneration rate was remarkably lower (P<0.05) in C system (4%; 5/124) compared to B (12.5%;
15/120) and control (19.8%; 18/91).
Conclusions. These results suggest that the use of bi-phasic systems is beneficial for oocyte meiosis
in vitro, when compared to the continuous exposition (72h) to the same hormonal association
(control). This is the first time that a bi-phasic system with gonadotrophins and steroids had been
studied. As no differences were observed between the two associations of hormones (system B and
C), further investigation on the effect of other hormonal combinations and concentrations are
needed.
References.
1) De los Reyes et al., Theriogenology 2005;64:1-11. 2) Willingham-Rocky et al., Reproduction
2003;126:501-8. 3) Luvoni et al., Theriogenology 2005;63:41-59
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
Nullità di protezione dei contratti d’investimento mobiliare e l’ascesa del principio di buona fede
No full textIl contributo esamina il problema della nullità del contratto di intermediazione mobiliare e della rilevanza del principio di buona fede alla luce del recente formante giurisprudenziale
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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