1,720,966 research outputs found
αS1-casein in goat milk: identification of genetic variants by Capillary Zone Electrophoresis compared to Isoelectric Focusing
Full text linkAlphaS1casein fraction in caprine milk is characterized by an important polymorphism due to substitution, deletion of amino acids and post trascriptional modifications (Grosclaudeet al., 1994; Ferrantiet al., 1997). This structural polymorphism is associated to a quantitative variability
in protein expression related to different milk quality and dairy properties (Pierreet al., 1998; Remeuf, 1993; Vassalet al., 1994). Classical electrophoretic methods were applied to characterize the phenotypic variants at αS1-casein fraction (Addeoet al., 1988; Russoet al., 1986). During the last ten years capillary electrophoresis became an analytical technique for rapid and automated analysis requiring
small sample volume and small solvent waste. These characteristics, together with the high resolution
and the chance to give quantitative results, made this technique a useful tool in studying milk protein
characterization and in detecting adulteration (Cattaneoet al., 1996a; 1996b) in different application
fields. CZE was applied to the study of caprine milk proteins to quantify high, medium and low αS1-
casein content and to identify genetic variants αS1A, B and C on the basis of their different migration time (Recioet al., 1997). The aim of this work was to test a CZE procedure able to identify and discriminate the main αS1caprine variants A, B, E and F through specific and repeatable electromigration patterns. Comparison between CZE and IEF assays is discussed
Polymorphism of αS1-casein in goat milk: identification of A, B, E and F variants by biochemical and genetic analysis
Full text linkMany researches, related to genetic polymorphism of αS1-casein in goat milk, showed a marked variability and implications in milk and dairy product traits. The genetic variants (from A to G) were associated with four levels of expression: 3,6 g/L per A, B and C (“strong” alleles); 1,6 g/L per E (“medium” allele); 0,6 g/L per F (“weak” allele) and 0 g/L per O (“null” allele). Differences existing among the A, B, C, D, E, F, G and O have been described (Grosclaudeet al., 1994). To analyze genetic polymorphism of caseins from goat milk, distinct electrophoretic (Russoet al., 1986; Addeoet al., 1988) and chromatographic techniques (Jaubert and Martin, 1992; Iamettiet al., 1999) were applied. In last years, the advancement in technological field is allowing the research of primary structure of protein variants (Ferrantiet al., 1997; Trujilloet al., 2000) and basic sequence of new alleles (Martinet al., 1999; Bevilacquaet al., 2002; Ramunnoet al., 2002). In this work, we employed electrophoretic protein separation (IEF and SDS-PAGE), chromatographic analysis (RP-HPLC) and molecular biology techniques based on polymerase chain reaction (real-time PCR) to detect αS1-CN genetic variants from goat milk.
The utility of protein and DNA analysis combination was discussed
Effects of lactation stage, parity, beta-lactoglobulin genotype and milk SCC on whey protein composition in Sarda dairy ewes
Full text linkIn 90 Sarda dairy ewes the effects of lactation stage, parity, beta-lactoglobulin genotypes, and somatic cell count (SCC) on
the milk content of total protein (TP), casein (CN), whey protein (WP) and its fractions alpha-lactalbumin (ALA), beta-lactoglobulin
(BLG), serum albumin (SA), immunoglobulin (IG) and lactoferrin (LF) were analysed using a linear mixed model.
Mean values of variables (g/l) were: TP (54.0), CN (43.0), WP (11.0), BLG (4.78), ALA (1.37), SA (0.61), IG (3.83) and
LF (0.28). The lactation stage significantly affected all the variables analysed. TP, CN and WP concentrations tended to
increase throughout lactation, with the increase of WP being more pronounced than the corresponding variation in CN.
There was no definite trend in BLG content, whereas ALA concentration decreased as lactation progressed. The parity
affected almost all variables studied. WP concentration differed significantly only between the second and fourth parity
(10.45 vs 11.44 g/l). BLG and SA concentrations were significantly lower in the youngest ewes. The BLG genotype affected
milk yield, but no effects were observed on the components of the milk. The SCC influenced almost all variables studied.
The TP concentration was significantly higher in milk with SCC >1,000,000 (55.0 g/l) than in milk with lower SCC
(53.4 g/l). This was mainly due to the increase of WP (12.52 and 10.24 g/l in milk with SCC above and below
1,000,000/ml respectively), especially in those WP fractions originating from blood
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
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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