1,721,088 research outputs found
Caratterizzazione genetica della razza Bracco Francese ed analisi comparative con le principali razze canine
No full textIl sequenziamento del genoma canino ha contribuito a migliorare l’accuratezza delle stime di diversità genetica ed ha anche generato diversi studi sulle relazioni tra le diverse razze allevate (Vaysse et al., 2011; Parker et al., 2017). Tuttavia, alcune razze rimangono ancora poco caratterizzate. È il caso del Bracco Francese tipo Pyrénées. Lo scopo di questo lavoro è stato quello di caratterizzare a livello genomico la razza e studiarne le relazioni con altre razze allevate nel mondo.
Sono stati raccolti i campioni di sangue da 48 individui. La genotipizzazione è stata condotta mediante l’Illumina CanineHD BeadChip (173.662 marcatori).
Diversi parametri di diversità genetica sono stati calcolati, come l’ eterozigosià osservata (Ho) ed attesa (He). La consanguineità (F) è stata stimata con il metodo delle Runs of homozygosity (ROH). La relazione genetica tra il Bracco Francese e altre razze canine è stata studiata utilizzando i dati genotipici di 532 individui appartenenti a 48 razze canine e 15 lupi, ottenuti dal progetto LUPA (Vaysse et al., 2011). È stata costruita una matrice di distanze genetiche per generare un albero filogenetico (neighbor joining). Il controllo di qualità dei dati genotipici, la stima degli indici di diversità genetica, il rilevamento dei segmenti ROH e la stima delle distanze genetiche sono state condotte utilizzando il software PLINK (Purcell et al., 2007).
I valori medi di Ho e He erano di 0,371±0,142 e 0,359±0,124. La consanguineità media stimata su base ROH (FROH) era di 0,112±0,023. Comparando questi valori con quelli riportati in letteratura, è emerso che la razza conserva ancora sufficienti livelli di variabilità genetica, utili per predisporre piani di conservazione e di miglioramento genetico.
Il multidimensional scaling (MDS) della matrice di distanze genetiche (C1) (Figura 1) ha rivelato tre cluster principali, con il Bracco Francese (BRA) altamente differenziato dalle altre razze. In particolare, la maggior parte delle moderne razze europee erano raggruppate insieme e parzialmente sovrapposte nel centro del grafico, suggerendo un flusso genico relativamente alto.
Si ritiene che il BRA sia imparentato con altre razze da ferma europee, ma la relazione esatta tra queste razze rimane poco chiara Sulla base dei risultati qui riportati, alcune razze come Weimaraner (WEI), Setter Inglese (EST) e Gordon Setter e (GOS) sembrano essere geneticamente più vicine al BRA. Simili risultati sono evidenziati in Figura 2, dove l'albero filogenetico ha confermato la stretta relazione tra BRA, EST e GOS.
L'albero ha anche mostrato che le razze con caratteristiche fenotipiche simili tendono a raggrupparsi insieme, come i retriever, setter, spaniel e terrier
Genetic improvement of small ruminant local breeds with nucleus and inbreeding control : a simulation study
No full textIn small ruminant local breeds of Southern Europe genetic selection is often constrained
by small population sizes, poor animal identification, inadequate animal performance
and pedigree recording, and organizational shortcomings. Under these conditions nucleus
breeding schemes can offer practical and cost effective solutions. The paper investigated
genetic gain in stochastically simulated dairy small ruminant nuclei of 100, 200 and 400
females, supporting commercial populations from 500 to 5000 females. In the nucleus, a
young sire selection scheme was used, with optimum contribution selection on a dairy trait,
at an annual inbreeding rate of 0.3%, corresponding to a generation inbreeding rate of 0.001.
Sires, both selected and not-select as sires of sires, after 1 year of use in the nucleus were
utilized in the commercial population for one, or alternatively, 2 years. Annual genetic gain
ranged from a minimum of 0.073 SD with 100 females nucleus supporting a commercial
population of 500 females, to a maximum of 0.138 SD with a 400 females nucleus supporting
a commercial population of 5000 females. Negligible differences in genetic gain
were observed between nuclei and corresponding commercial populations. When sires
were used for only 1 year in the commercial population, we observed 7.7 years of genetic
lag with the nucleus, that increased to 8.2 years when sires were used for 2 years. Results
showed that there are opportunities for selection even in populations of a few hundreds
of females. Considering a specific breeds, or a specific farming area, a cost benefit analysis
should be carried out to orientate the choice of nucleus size and strategy of use of sires
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
Genomic approaches to left-sided displacement of the abomasum in Italian Holstein cattle : results from a comprehensive research project
No full textP546 - Genomic Approaches to Left-Sided Abomasal Displacement in Italian Holstein Cattle: Results from a Comprehensive Research Project
A sample of 64 Italian Holstein cows was analysed to investigate the genetic architecture of left-sided abomasal displacement (LDA). LDA is one of the most common disorders of the digestive system in dairy breeds, causing economic losses due to treatment costs, premature culling, and reduction of milk yield. Among predisposing factors, LDA is induced by impaired abomasal motility that causes an accumulation of gas. Moreover, previous studies have shown the existence of a genetic component, with heritabilities estimated between 0.2 and 0.5. A total of 17 cases and 47 controls were available from 5 commercial herds. All cows were genotyped with the Illumina 50k bovine SNP chip. Two methods of analysis were used: a genome-wide association study (GWAS) of cases and controls and the analysis of runs of homozygosity (autozygosity-by-difference). In total, 39 SNPs located on 19 bovine (Bos taurus) chromosomes (BTA) showed associations with LDA (−log10 P-values >3.0). Two of these SNP, located on BTA13 and BTA12, showed genome-wide significant associations with LDA at −log10 P-values > 4. SNP on BTA12 is located in the region of SLITRK5 gene, a member of the SLITRK family. SLITRK genes are expressed predominantly in neural tissues with a neurite-modulating activity. On chromosome 14, a common stretch of homozygosity in cases and controls was detected, in the region close to the DGAT1 mutation
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
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