1,720,965 research outputs found
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
Analisi della regione al 5’ del gene della caseina as1 di capra.
No full textIl locus della caseina as1 (CSN1S1) di capra si caratterizza per almeno 15 alleli associati a diversi livelli di sintesi (da 3,5 a 0,0 g/l per allele). Attualmente sono noti gran parte degli eventi molecolari che li caratterizzano.In particolare la delezione di una C al 23° nt del 9° esone caratterizzerebbe l’allele CSN1S1N associato ad un contenuto apparentemente nullo di caseina as1 (EMBL n°AJ504711) mentre l’associazione di tale mutazione con due inserzioni di 11 e 3 bp nel 9° introne è responsabile dell’allele F associato ad un contenuto ridotto (~0,45g/l) (EMBL n°X56462). L’obiettivo del presente lavoro è stato quello di evidenziare mutazioni nella regione al 5’ degli alleli N e F eventualmente implicate nella regolazione del gene.
Il DNA genomico è stato estratto dai leucociti ottenuti da campioni di sangue di tre capre con genotipo CSN1S1FF, NN e AA, quest’ultimo scelto quale riferimento positivo. Mediante PCR è stata amplificata e in seguito sequenziata la regione al 5’ del gene, utilizzando primer disegnati sulla sequenza caprina (EMBL n°AJ504710) e bovina (EMBL n°X59856).
La regione al 5’ del gene CSN1S1 di capra (1976 nt a monte del 1° esone) contiene almeno una TATA Box correttamente posizionata, un sito Cap, un fattore di crescita GATA, una Milk Box (CTCCTCAGAATTTCTT, da -157 a -142), un sito per il recettore del progesterone (PR, da -132 a -126) e per un fattore specifico della ghiandola mammaria (MPBF, GAATTCTTAGAATT, da -101 a -88) che, a sua volta, contiene una sequenza consenso GAS (TTCNNNGAA, sito di attivazione dell’interferone gamma).Tra i nt -64/-43 si localizza un’ampia sequenza (GAAACCACARAATTAGCATNTT), in generale ben conservata nei geni delle caseine calcio sensibili, che rappresenta il sito di elementi regolatori in cis: Simian virus 40 (SV40)-type enhancer, Nuclear Factor Octamer-1 (NF Oct-1) e YYI common factor, quest’ultimo elemento necessario per una corretta trascrizione. Sono altresì individuabili diversi altri siti di legame dei fattori YY1 e NF Oct-1, così come almeno due di pregnancy-specific mammary nuclear factor (PMF) (da +8 a +16 e da -1146 a -1135) e due dell’Activator Protein (AP-1) (da -855 a -849 e da -181 a -175). Il confronto della sequenze degli alleli CSN1S1A, F e N ha messo in evidenza un totale di 25 siti variabili (singole sostituzioni/delezioni nt) delle quali 21 sembrerebbero specifiche dell’allele F e una sola dell’allele N.
CONCLUSIONI - I nostri risultati indicano che nessuna delle mutazioni che caratterizzano l’allele F sembrerebbero alterare i siti di regolazione genica, mentre ulteriori indagini si rendono necessarie per valutare il ruolo della mutazione specifica dell’allele N sull’apparente assenza di sintesi proteica ad esso associata
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
A MvaI PCR-RFLP detecting a silent allele at the goat a-lactalbumin locus.
No full textIn this paper we report the identification of a silent
allele at the goat LALBA locus and describe a method
based on PCR-RFLP (Polymerase Chain Reaction Restriction
Fragment Length Polymorphism) for its detection
The goat as1-casein gene: gene structure and promoter analysis
No full textThe level of αs1-casein in goat milk shows strong variations determined by at least 15 alleles associated with four different efficiencies of protein synthesis. The nucleotide sequence of the whole goat αs1-casein-encoding gene (CSN1S1) plus 1973 nucleotides at the 5′ flanking region and 610 nucleotides at the 3′ flanking region was determined and aligned with its bovine counterpart. The gene is spread over 16.7 kb and consists of 19 exons varying in length from 24 bp (exons 5, 6, 7, 8, 10, 13 and 16) to 385 bp (exon 19) and 18 introns from 90 bp of intron 10 to 1685 bp of intron 2. Furthermore, highly conserved sequences, mainly located in the 5′ flanking region, were found between this gene and other casein-encoding genes. Finally, seven interspersed repeated elements (10 in the bovine CSN1S1 gene) were also identified at four different locations of the sequenced region: 5′ untranscribed region and introns 2, 8 and 11
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