1,720,971 research outputs found
Characterization of wines by nuclear magnetic resonance: a work study on wines from the Basilicata region in Italy
No full textWe explored the possibility of differentiating Italian wines produced in different regions by means of nuclear magnetic resonance (NMR) techniques. Ten commercial red Aglianico wines were selected from different areas of the Basilicata region in the south of Italy. Some important components of these wines were identified by the assignments of their (1)H and (13)C resonances using one- and two-dimensional homonuclear and heteronuclear NMR experiments. These data were compared with those obtained from 10 Aglianico wines produced in Campania, another southern Italian region. Differences were found among the wines according to their geographical origin and vintage. A fine discrimination of Aglianico wines from Basilicata and Campania was obtained, suggesting that the selected NMR parameters may be a valuable tool for wine authenticity control
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
Metabolic analysis of human follicular fluid by 1H NMR spectroscopy
No full textThe correct evaluation of oocyte quality is one of the crucial aspects to succeed in assisted reproductive techniques. Non mature or poor quality oocytes will not be fertilized or will give rise to embryo with low implantation potential. Morphological evaluation is still the primary method of embryo estimation during in vitro fertilization (IVF) cycles although with modest predictive value [1]. Follicular fluid (FF) is the in-vivo environment where the oocytes and, later, the embryos develop; contains metabolites important for oocyte growth and development and its composition may indicate embryo viability and oocyte quality. FF is a superfluous and easily available product which is aspirated together with oocyte and represent an optimal source of potential biomarkers of oocyte quality [2].
NMR-based metabolomics of biological fluids is widely applied as NMR is capable of simultaneously detecting a wide variety of metabolites with accuracy and reproducibility with quick responses and minimal sample preparation. The NMR metabolic profile of human FF was studied both from healthy oocyte donors [3] and women affcted by polycystic ovary syndrome [4]. NMR metabolomics was used to determine the relationship between FF metabolite composition, oocyte developmental potential and embryo viability [5]. NMR-based metabolic profiling of FF and plasma was used in a pilot study on IVF patients [6].
The aim of this study is to verify if NMR metabolomics can really be used for identifying suitable biomarkers in FF to select optimal quality oocytes with competence to fertilization, embryo development and, hopefully, positive pregnancy.
1.Singh R, Sinclair KD (2007) Theriogenology 68S, S56-S62
2.Revelli A et al. (2009) Reprod Biol Endocrinol 7:40
3.Piñero-Sagredo E et al (2010) NMR Biomed 23, 485-495
4.Arya BK et al (2012) Med Hypotheses 78(4), 475-478
5.Wallace M et al (2012) Fertil Steril 97(5),1078-1084.e8
6.McRae C et al (2012) Fertil Steril 98(5),1449-1457.e
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
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