1,720,984 research outputs found
Building of prediction models by using Mid-Infrared spectroscopy and fatty acid profile to discriminate the geographical origin of sheep milk
No full textGeographical authentication of sheep milk is an issue related to the production of cheeses labelled with a Protected Designation of Origin (PDO). To this purpose we investigated both the capability of the fatty acid composition and the capability of the Mid-InfraRed (MIR) spectra of 250 samples of sheep milk (gathered in different areas of the region Sardinia) to discriminate the samples as what regards their geographical origin. Genetic Algorithms (GA) were applied to the fatty acid profile and to the spectra to select the informative variables for developing discriminant models able to correctly classify the samples. The models were validated on unknown samples obtaining correct predictions of 96% using the selected fatty acids and of 99% using the selected MIR spectral regions. For routine control analysis, MIR spectroscopy is preferred for being a non-destructive, cheap and real-time analytical method
Effect of different forage species supplemented with two carbohydrate sources on short and medium chain fatty acids in sheep milk
Full text linkSixty four Sarda dairy sheep fed with diets based on fresh forage were allocated to eight groups to evaluate the effect of corn or beet pulp based supplementation on milk fatty acid composition. Four forage species were compared: annual ryegrass (RY,Lolium rigidumGaudin), sulla (SU,Hedysarum coronariumL.), burr medic (BM,Medicago polymorphaL.), and garland, a daisy forb, (CH,Chrysanthemum coronariumL.). The supplements were iso-nitrogenous but differed in carbohydrate composition consisting either of 60% (DM) of corn (concentrate C) or 40% sugar beet pulp (concentrate BP). The supplementation was iso-energetic (500 and 530 g/d, respectively).
Overall during winter period (growing stage of the forages) SU and RY groups showed higher levels of atherogenicity
index and C16:0. In winter period BP outperformed C for palmitic acid. In spring AI showed a trend similar to that of winter. Moreover C concentrate gave a better level of AI and myristic acid than BP. This study confirms that forage species and, to a lesser extent, carbohydrate source in the supplement markedly affect mediumchain FA profile and hence atherogenicity index in sheep milk
Effect of different pastures on CLA content in milk and sheep cheese
Full text linkIt is known that milk composition included conjugated linoleic acid (CLA) is affected by animal feeding system (Cabidduet al., 2001). In Sardinia dairy sheep feeding is mainly based on pastures. Most of them are characterised by self-regenerating species, like annual ryegrass (Lolium rigidumGaudin) and burr medic (Medicago polymorphaL.). Non conventional species belonging to the Compositae family such as (Chrysanthemum coronariumL.) seem interesting for sheep feeding when other herbages decrease in quality (late spring- early summer). It was observed thatC. coronariumestablishes rapidly, can be grazed early in the growing season and persist where other pasture species
may disappear; for these reasons it can be considered a valuable source of food. Moreover a preliminary
study with dairy sheep fed fresh forage ofC. coronariumshowed relatively high levels of CLA in milk
(Molle G.pers.com.) The aim of the present work was to study the influence of different pastures on milk composition, with particular reference to CLA and its precursors
Prediction of fatty acid content in sheep milk by Mid-Infrared spectrometry with a selection of wavelengths by Genetic Algorithms
No full textSheep breeding is one of the most widespread activities in Sardinia (Italy), and milk produced here is of crucial economic importance for the region. In order to make the milk payment system used in Sardinia more rewarding to the quality of milk, we developed Partial Least Square regression models to predict the concentration of the major fatty acids (measured with a GC-FID reference method) from the Mid-Infrared spectra of hundreds of Sardinian sheep milk samples collected in the period 2011-2013. Genetic Algorithms were used in order to select the most informative spectral subsets and therefore reduce the complexity of the model and in many cases also reduce the prediction error. Models obtained had a good predictive ability, with errors in the range of tenths of a gram of fatty acid on Kg of milk, and an acceptable precision for an immediate introduction on sheep milk payment in Sardinia
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
Incorporation of probiotic bacteria (Lactobacillus acidophilus and Bifidobacterium ssp.) in Argentinean ovine cheese
Full text linkThe market of cheeses from ewe’s milk has been growing steadily in Argentina. The nutritional benefits of these products can be enhanced by adding probiotic cultures. In the present study, the survival of a mix of probiotic microorganisms (Lactobacillus acidophilus La-5 and Bifidobacterium animalis ssp. lactis Bb12) in a semi-hard ovine cheese, manufactured with a technology previously developed in our institute was evaluated. Besides, the effect of its incorporation on the chemical composition and ripening parameters of cheeses, including the fatty acid composition and CLA production, was investigated. Experimental cheeses made with Bb12 and La-5 retained counts of the probiotic strains at the required therapeutic level (107 CFU g−1 ). No significant differences were detected between experimental and control cheeses with respect to the different parameters evaluated: gross composition, nitrogen fractions, lipolysis, fatty acids profiles of cheese fat including CLA, and volatile fraction. Results demonstrated that the ovine cheese matrix seems to be suitable for delivery of probiotic microorganisms.Fil: Perotti, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Lactologia Industrial; ArgentinaFil: Wolf, Irma Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Lactologia Industrial; ArgentinaFil: Addis, Margherita. AGRIS Sardegna. Dipartamento per la ricerca nelle produzioni animali (DIRPA), Sardegna; ItaliaFil: Comunian, Roberta. AGRIS Sardegna. Dipartamento per la ricerca nelle produzioni animali (DIRPA), Sardegna; ItaliaFil: Paba, Antonio. AGRIS Sardegna. Dipartamento per la ricerca nelle produzioni animali (DIRPA), Sardegna; ItaliaFil: Meinardi, Carlos Alberto. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentin
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
- …
