1,721,119 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
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
Effect of GnRH administration on pituitary response in buffalo.
No full textThe aim of this study was to verify the pituitary response to a GnRH administration on day 6 post-insemination in buffalo. The trial was carried out in January on 21 pluriparous Italian Mediterranean Buffaloes (DIM=118±50 days). The animals were synchronized by using the Ovsynch-TAI Program (Neglia et al., 2003) and inseminated twice, 16 and 40 hours after the last administration of GnRH. Blood samples were collected just before GnRH administration (time 0 – T0) and 30 minutes (time 1 – T1), 3 hours (time 3 – T3) and 24 hours (time 24 – T24) after administration, in order to determine LH, FSH and E2 levels. The administration of 12 μg of Buserelin acetate (Figure 1) significantly (P<0.01) increased LH and FSH blood levels after 30 minutes (T1) and after 3 hours (T3), lowering to the initial values after 24 hours (T24). Therefore the use of GnRH or its analogous represents a good tool in order to increase P4 levels in buffalo species
Validation of a commercial ELISA kit to measure 11-oxoetiocholanolone in equine and bovine feces
No full textFeces are a noninvasive and easily collectible matrix that may help determine cumulative hormone metabolite concentrations over medium-to-long times. To date, 11-oxoetiocholanolone, an important metabolite of cortisol, has been measured in equine and bovine feces solely by an in-house enzyme immunoassay (EIA). Therefore, we validated the use of a commercial ELISA kit (11-oxoetiocholanolone ELISA kit; Cayman Chemical), which had been validated on sheep feces and human urine, to measure 11-oxoetiocholanolone in feces from 42 horses and 32 bulls. The ELISA kit had good precision (intra- and inter-assay CVs: 5.8% and 11.2% for equine feces; 9.9% and 11.2% for bovine feces, respectively), analytical sensitivity (0.186 ng/mL for both equine and bovine feces), and accuracy (parallelism and recovery tests) in determining 11-oxoetiocholanolone concentrations in feces from both species. We found ranges of 11-oxoetiocholanolone concentrations of 1–109 ng/g in equine feces and 40–302 ng/g in feces of bulls. The Cayman Chemical ELISA kit offers a simple and accessible means of analysis of 11-oxoetiocholanolone in equine and bovine fecal samples
Dehydroepiandrosterone sulfate concentrations in claws from dogs from birth to 60 days of age.
No full textBecause of the limited knowledge on dog perinatology and due
to the known usefulness of claws as a non-invasive matrix for long-term retrospective
hormone accumulation investigations (1, 2), this study aimed to
assess possible changes of dehydroepiandrosterone sulfate (DHEA-S) concentrations,
the major fetal steroid, in newborn puppy-claws and to evaluate
the possible effect of some maternal and neonatal parameters on DHEA-S
claw accumulation. Methods: The study was performed on 60 largely purebred
viable, normal and healthy puppies. Tip claws were individually collec -
ted by trimming at birth and after regrowth at 30 and 60 days of age. Pooled
individual claws were stored at room temperature until analysis by RIA.
Possible effects of maternal age and parity, type of parturition, litter size,
and newborn gender were statistically assessed. Results: The mean ± SD
DHEA-S claw-concentration decreased significantly (p < 0.001) from birth
(209 ± 148.00 pg/mg) to 30 days (94 ± 45.85 pg/mg) and further to 60 days
(60 ± 74.02 pg/mg) of age. Claw-DHEA-S values at birth were somewhat
higher, but with a lower SD, in comparison to data reported for 1–3 weeks
old human babies (1). No influence of maternal age and parity, type of parturition,
litter size, and newborn gender was found. The trend of a decrease
is in agreement with data reported for cortisol in dead puppies (2), and suggests,
beside the role of cortisol, the important effects of DHEA-S around
the time of birth, also in puppies, as reported for human babies (1).
1. Tegethoff et al. Biological Psychology 2011; 87: 414–420.
2. Veronesi et al. Theriogenology 2015; 84: 791–796
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