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Controllo genetico della stagionalità riproduttiva in ovini di razze autoctone
Full text linkGenetic control of reproductive seasonality in native sheep
Reproductive physiology in sheep can change with latitudes. It’s normally characterized by seasonality, and is regulated by photoperiod’s exposure. The aim of this study was to investigate the GPR54, MTNR1a and KiSS1 genes polymorphisms in Sardinian and Slovenian local breeds, in order to determine if there is an association with reproductive seasonality. The PCR-SSCP analysis was carried out on 250, 130, and 106 bp fragment, respectively from GPR54 exons 1 and 2 and KiSS1 exon 1, while for the 824 bp fragment from MTNR1A gene exon 2 was also added RFLP analysis, using MnlI and Rsa1 endonucleases. Some polymorphic sites were found: G1035A at the Kiss1 gene exon 1 leading to GG (75,7 %), GA (21,3 %) and AA (3 %) genotypes; C606T and G612A at the MTNR1A exon 2, leading to genotypes CC (42,5 %), CT (31 %) and TT (26,5 %), and GG (51,5 %), GA (34,75%) and AA (13,75 %), respectively. These two last polymorphisms showed to influence the reproductive recovery in Sarda breed. No polymorphism was found in the exon 1 and 2 of the GPR54 gene. Statistical analysis showed no correlation between genotypes and reproductive seasonality in Slovenian breed sheep. The effect of the gene genotypes, in Slovenian s sheeps, maybe was masked by management e of males put inside the group during decreasing of photoperiod, therefore already favorable at the beginning of the reproductive activity. The low frequency of genotypes found for KISS1 and GPR54 genes does not allow us to highlight possible influences of these mutations on reproductive activity
Presentazione [Immagini dell'Italia unita]
No full textPresentazione del libro: Immagini dell'Italia unit
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
Influences of melatonin treatment, melatonin receptor 1A (MTNR1A) and kisspeptin (KiSS-1) gene polymorphisms on first conception in Sarda ewe lambs.
No full textInfluences of melatonin treatment, melatonin receptor 1A (MTNR1A) and kisspeptin (KiSS-1) genes polymorphisms on first conception in Sarda ewe lambs
No full textIn order to investigate if the melatonin receptor 1A (MTNR1A) and kisspeptin (KiSS-1) genes influence the reproductive response to melatonin treatment, 510 Sarda ewe lambs were divided into groups C (control) and M; Group M received one melatonin implant (18mg). After 35 days rams were introduced for 40 days and subsequent lambing dates and number of newborns were recorded. The MTNR1A gene Exon II and KiSS-1 gene Exon I were amplified and genotyped by restriction fragment length polymorphism (RFLP) and single-strand conformation polymorphism analysis. Two single nucleotide polymorphisms (SNPs; C606T and G612A) in MTNR1A and one (G1035A) in KiSS-1 were found. The most frequent genotypes were G/G (63%) and C/C (53%) for MTNR1A and G/G (92%) for KiSS-1. Treated animals showed a higher lambing rate (P<0.05) and an advanced lambing date (P<0.05) compared with controls. The three SNPs did not influence the onset of reproductive activity. The majority of the G/G animals of Group M lambed before 190 days after ram introductio
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