1,721,004 research outputs found
Determination of cyclopropenoid fatty acids in ewe milk fat by GC-MS after intravenous administration of sterculic acid
No full textCyclopropenoid fatty acids (CPEFA), found in oilseeds from Malvaceae and Sterculiaceae, have been shown to interfere with the endogenous synthesis of several bioactive lipids of dairy fat, such as cis-9, trans-11 18:2 and cis-9 18:1, by inhibiting Δ9-desaturase. No previous study has reported the presence of sterculic acid in animal fat and its incorporation in tissues after its administration, due to the lack of a proper methodology. In the present research, a GC-MS method based on cold base derivatization to fatty acids methylesters was developed to determine CPEFA in ewe milk triglycerides, after infusing sterculic acid (0.5 g/day) to six lactating ewes. An alternative derivatization based on silanyzation followed by GC-MS analysis was also tested, showing its possible applicability when CPEFA are present in the form of free fatty acids. Sterculic acid was detected in ewe milk triglycerides, demonstrating its incorporation from the bloodstream into milk by the mammary gland. The mean transfer rate represented 8.0 ± 1.0% of the daily dose. This study provides, for the first time, the presence of sterculic acid in milk fat, supporting the importance of understanding its occurrence in vivo and encouraging further research to determine whether it can be present in foods, such as dairy products, obtained under practical farming conditions
Study on the Effect of Ensiling Process and Ruminal Digestion on the Synthesis and Release of Cyclopropane Fatty Acids in Cow Feeding
No full textCyclopropane fatty acids (CPFA) were found in milk fat from cows fed maize silage and suggested to be synthesized by lactic acid bacteria during ensiling. This study aimed to elucidate some gaps of knowledge about the microbial synthesis of CPFA, to strengthen the current authentication method based on their detection in cheese fat and performed for Parmigiano Reggiano (UNI11650), whose Specifications forbid the use of silage. CPFA were screened in different ensiled cows' feeding by gas chromatography-mass spectrometry, and the effect of feed ingredients and ruminal digestion on CPFA microbial production were further examined by in vitro tests. Results showed that solely the environmental conditions developed in silos for specific plant materials (e.g., maize) are essential for the bacterial synthesis of CPFA, whereas rumen activity did not affect CPFA levels in feeds. This supports the suitability of using CPFA as biomarkers of a crop silage-based diet forbidden by certain PDO feedstock regulations
La relazione tra bullismo, cyberbullismo e problematiche alimentari in infanzia e adolescenza. Una rassegna della letteratura internazionale
No full textLa letteratura sui fattori di rischio dei disturbi alimentari è molto vasta così come gli studi sulle conseguenze psicologiche di bullismo e - più di recente - cyberbullismo. Meno indagata è la relazione tra esperienze di prevaricazione tra pari e sintomi alimentari. L’obiettivo della presente rassegna è fornire un approfondimento del tema attraverso la sistematizzazione dei principali contributi della letteratura internazionale che si focalizzano sulla relazione tra problemi alimentari e bullismo/cyberbullismo. Una revisione degli studi pubblicati nelle principali banche dati (PsychINFO, Scopus, Web of Science e PubMed) ha selezionato 41 articoli eleggibili. Una sintesi narrativa ne riporta i risultati che concordano nel ritenere che bullismo e cyberbullismo sono fattori di rischio di sintomi alimentari in infanzia e adolescenza, con il concorso di alcune variabili mediatrici/ moderatrici; le evidenze sono meno omogenee rispetto alla stabilità nel tempo di questa associazione. La rassegna evidenzia alcuni limiti della letteratura sul tema e linee future
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
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
Fresh-Cut Eruca Sativa Treated with Plasma Activated Water (PAW): Evaluation of Antioxidant Capacity, Polyphenolic Profile and Redox Status in Caco2 Cells
Get PDFPlasma Activated Water (PAW) has recently emerged as a promising non-chemical and non-thermal technology for the microbial decontamination of food. However, its use as a replacement for conventional disinfection solutions needs further investigation, as the impact of reactive species generated by PAW on nutritional food quality, toxicology, and safety is still unclear. The purpose of this study is to investigate how treatment with PAW affects the health-promoting properties of fresh-cut rocket salad (Eruca sativa). Therefore, the polyphenolic profile and antioxidant activity were evaluated by a combination of UHPLC-MS/MS and in vitro assays. Moreover, the effects of polyphenolic extracts on cell viability and oxidative status in Caco2 cells were assessed. PAW caused a slight reduction in the radical scavenging activity of the amphiphilic fraction over time but produced a positive effect on the total phenolic content, of about 70% in PAW-20, and an increase in the relative percentage (about 44-50%) of glucosinolate. Interestingly, the PAW polyphenol extract did not cause any cytotoxic effect and caused a lower imbalance in the redox status compared to an untreated sample. The obtained results support the use of PAW technology for fresh-cut vegetables to preserve their nutritional properties
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