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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Faecal steroid analysis in two captive female cheetahs
No full textIntroduction and aim. Cheetahs (Acinonyx jubatus), as most wild felid species, is an induced
ovulator and reproduces poorly in captivity, a problem attributed to inappropriate husbandry (1).
Monitoring endocrine activity is essential for assessing the reproductive potential, but hormonal
determination trough blood serum sampling is an unpractical procedure in these species, as it
requires anaesthesia and restraint. It has been demonstrated in the domestic cat that estrogens and
progesterone are secreted into faeces (1,2) and some Authors already applied this method to other
wild felids (1,3,4), as well as to cheetahs (5,6). However, cheetah management, i.e. social groups
and caging situations, was not standardized throughout the period of the study or a low number of
samples were collected during short time periods. The aim of the present work was to evaluate the
dynamic of faecal estrogens and progesterone throughout an entire year in two cheetahs constantly
housed with conspecific males in the Northern of Italy.
Materials and methods. Two female cheetahs (Geijsha and Duchessa, 2 years of age) maintained
at Le Cornelle Animal Park (Valbrembo, BG, Italy) and housed with 3 conspecific males were
included in this study. Faecal samples were collected daily for one year (from August 2007 to July
2008) and immediately frozen and stored at -20°C. Faecal oestradiol (E2) and progesterone (P4)
metabolites were extracted from fresh samples as previously described in dry samples (1). The
metabolites were quantified using radioimmunoassay. Basal E2 and P4 values and the duration of
the estrous cycle on the whole sampling period were calculated according to the method proposed
by Brown et al., 1996 (6). Data are resumed as mean ±SD.
Results. Faecal E2 basal values were 21.6+5.8 ng/g and 19.3+5.1 ng/g with peak concentrations
ranging from 30.6 to 73.8 ng/g and from 29.6 to 164.8 in Geijsha and Duchessa, respectively.
Estrous cycle duration was 10.4±3 (n=13, range, 6-15 days) and 11.3 ± 6.9 days (n=10, range, 5-23
days) in the two females. The males did not show any interest in the females which did not display
evident behavioural signs of estrus throughout the year. Faecal P4 basal values of 112.6+41.5 ng/g
and 100.6+23.4 ng/g remained at baseline values all year. In addition, none of the female were
continuously cyclic: follicular activity was interrupted by anestrous periods of 1 to 4 months in
duration and not associated with season.
Conclusions. These data suggest that captive cheethas show a discontinuos ovarian ciclicity which
duration and anestrus periods are similar to those described in the literature (6) in which estrous
cycle duration from 10.4±1 to 19±2.2 days and anestrous periods of 2 to 5 months are reported. In
the present study extraction of steroid metabolites was performed from fresh faecal sample, thus a
comparison with hormonal concentrations in dry samples reported by other authors is not possible.
It is generally accepted that behavioural signs of estrous are difficult to interpret in cheetahs,
however lack of mating and of subsequent luteal phase were likely due to the continous presence of
males which sexual interest was inhibited. Thus, adequacy of husbandry conditions is necessary and
enforced social living should be avoided in order to increase reproductive activity of captive
cheethas.
Aknowledgements. We thank E. Benedetti, N. Benedetti and Dr. R. Schneider of Le Cornelle
Animal Park for logistical support and sample collection. This study was supported by PUR 2008.
References. 1) Brown et al., Biol Reprod 1994;51:776-86; 2) Shille et al., Zoo Biol 1984;3:201-09;
3) Brown et al., J Reprod Fertil 2001;Suppl 57:71-82; 4) Graham et al., Zoo Biol 1995;14:233-37;
5) Czekala et al., Zoo Biol 1994;13: 119-28; 6) Brown et al., J Reprod Fertil 1996;106:337-46
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Bioenergetic/oxidative balance in feline morulae and blastocysts produced in vitro after temporary oocyte holding at room temperature versus cold ovary storage.
No full textMaternal aging is associated with an increase in embryonic aneuploidy and early miscarriage, as a result of
errors in chromosome segregation [1]. Failure to achieve correct alignment of the chromosomes on the
spindle is an important factor contributing to mis-segregation errors in oocytes [2,3]. Since little data is
available in horses, the aim of this study was to evaluate the effect of maternal aging on spindle
morphology and the incidence of chromosomes misalignment. Cumulus oocyte complexes (COCs) were
recovered from slaughtered mares, divided into groups depending on mare age (young, < 15 years; old, ≥15
years) and matured in vitro for 26h. After maturation and denudation, only the oocytes that had reached
MII were used and these were further subdivided into Control and Nocodazole groups (total = 4 groups;
n=20 per group). Oocytes in the Nocodazole groups were incubated for 10 min in medium containing 20
μM Nocodazole, to induce tubulin depolymerization, washed and then incubated for 2 hrs in maturation
medium. In order to destabilize any tubulin fibers not properly attached to the kinetochores samples were
subjected to cold shock, fixed and stored at 4 ̊C prior to immunofluorescent staining for DNA and alphatubulin. Spindle morphology and the incidence of chromosome misalignment were evaluated by confocal
microscopy and 3D image analysis (Imaris 8.3). Spindle morphology was scored as normal (fusiform,
bipolar) or abnormal (tri- or tetra-polar, severely misshapen), chromosome misalignment was scored as
absent, mild (1-5 misaligned chromosomes) or severe (>5 misaligned chromosomes). Oocytes from aged
mares showed higher rates of mild and severe chromosome misalignments when compared to those from
young mares, both in normal condition (mild 37 vs 5%; severe 11 vs 0%) and after Nocodazole treatment
(mild 42 vs 15%; severe 21 vs 0%). Moreover, oocytes from old mares were more likely to show abnormal
spindle morphology both under control conditions (5 vs 0%) and after Nocodazole treatment (10 vs 0%).
Although nocodazole treatment did not result in a significant increase in chromosome misalignment and
spindle abnormalities, the incidence of chromosomal misalignments increased numerically in both aged
and young groups (total % of misalignment without treatment 47.4 and 4.5% vs 63.2 and 15% after
nocodazole treatment). We suggest that the compromised ability to form a normal meiotic spindle and
correctly align the chromosomes observed in MII oocytes from aged mares might reflect an impaired
function of the spindle assembly check point components, and explain the age-related reduction in oocyte
developmental competence
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