1,721,067 research outputs found
GENETIC AND GENOMIC BACKGROUND OF LACTOSE IN BOVINE MILK
Full text linkNella comunità scientifica, l’interesse per il lattosio del latte bovino è emerso solo in tempi recenti, grazie alla correlazione con la salute della mammella e al sempre più crescente bisogno di caratteri alternativi come nuovi indicatori per fini selettivi. Inoltre, in alcuni mercati, il lattosio in forma solida ha un valore economico elevato grazie all’utilizzo nell’industria alimentare e farmaceutica. Negli ultimi anni si è osservato un crescente numero di pubblicazioni riguardanti la correlazione fra la concentrazione di lattosio (LP) e le cellule somatiche del latte. Queste ultime sono infatti uno degli indicatori di mastite più diffusi e utilizzati al mondo, sia sotto forma di conta di cellule (SCC), sia come punteggio (SCS). Per quanto concerne la produzione giornaliera di lattosio (LY), questa risulta responsabile della quantità di acqua presente negli alveoli e quindi del volume di latte prodotto.
Gli obiettivi di questa tesi sono stati: i) caratterizzare fenotipicamente LP e LY identificando le maggiori fonti di variazione; ii) stimarne i parametri genetici; iii) calcolare le correlazioni fenotipiche e genetiche con la produzione di latte, la concentrazione di grasso e proteina, le proprietà coagulative, l’indice crioscopico e il contenuto minerale del latte; iv) stimare le correlazioni genetiche di LP con caratteri di salute rilevati da veterinari, incluse mastite e chetosi; v) identificare le regioni del genoma bovino che influenzano in maniera significativa LP e LY, comparandole con quelle identificate per mastite e SCS in altri studi.
Il Capitolo 1 fornisce una panoramica delle principali fonti di variazione di LP e LY, e presenta le correlazioni genetiche e fenotipiche con produzione di latte, percentaule di grasso, percentuale di proteina e SCS. Nel Capitolo 2 vengono considerati alcuni caratteri maggiormente legati ad aspetti tecnologici del latte: indice crioscopico, proprietà coagulative e contenuto dei maggiori minerali presenti. Le correlazioni di LP e LY con le maggiori patologie che interessano la vacca da latte (mastite, chetosi, febbre da latte, ritenzione di placenta e cisti ovariche) sono presentate nel Capitolo 3. Infine, i risultati ottenuti dallo studio di associazione genome-wide sono riportati nel Capitolo 4.
I risultati del presente lavoro di tesi hanno fatto emergere il potenziale ruolo di LP come indicatore di salute della mammella e di resistenza alla mastite nella bovina da latte. Tuttavia, considerando la variabilità limitata del carattere, dovranno essere studiati dei caratteri derivati da LP, magari sfruttando l’andamento di LP durante il corso della vita della bovina. Questi caratteri, se informativi, variabili ed ereditabili, potranno essere considerati validi candidati per massimizzare la risposta alla selezione nel medio-lungo periodo
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
Characterization of electrical conductivity in individual milk of cattle breeds reared in Alpine area
No full textMastitis is one of the most relevant sources of economic loss in dairy farms. Since direct information on udder health traits is generally difficult and expensive to collect, indirect indicators are often considered at individual level to check udder health status. Milk electrical conductivity (EC, mS) is positively correlated with mastitis, due to the increase of Na+ and Clconcentrations when an intramammary infection occurs. This trait has been recently introduced in the routine analyses of the South Tyrol Dairy Association laboratory (Bolzano, Italy) for individual milk samples. In order to conduct a preliminary characterization of milk EC in Bolzano province, 96,722 test-day records from 2,209 single-breed herds of Brown Swiss, Holstein Friesian, Simmental, Alpine Grey and Pinzgauer cows for the period from March to December 2017 were retrieved from the database of the South Tyrol Dairy Association. The analysis of variance included the fixed effects of stage of lactation (12 classes), parity (6 classes), breed and their interactions; random factors were animal and herd-test-date nested within breed. All fixed effects included in the model were significant in explaining EC variation, with least squares means for breed effect ranging from 5.43 ± 0.02 mS (Pinzgauer) to 5.58 ± 0.01 mS (Holstein Friesian). Contrast estimates between breeds were significant, except for the comparison between Brown Swiss and Alpine Grey. Breed-specific EC lactation curves exhibited similar shapes, even if with different intercept values. The trends of EC among parities were similar between the five breeds, with a progressive increase of EC in subsequent lactations. Pearson’s correlations computed for each subset of breed highlighted that EC correlated with SCS in all breeds, with values that ranged from 0.22 (Holstein Friesian) to 0.35 (Pinzgauer). Moreover, EC strongly negatively associated with lactose percentage, with an average value of -0.75. These findings will be useful to better address future investigations and to understand how to exploit this milk feature
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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