1,721,019 research outputs found
Regulation of cellular signals from nutritional molecules: a specific role for phytochemicals, beyond antioxidant activity
No full textPhytochemicals (PhC) are a ubiquitous class of plant secondary metabolites. A “recommended” human diet
should warrant a high proportion of energy from fruits and vegetables, therefore providing, among other
factors, a huge intake of PhC, in general considered “health promoting” by virtue of their antioxidant activity
and positive modulation, either directly or indirectly, of the cellular and tissue redox balance. Diet acts
through multiple pathways and the association between the consumption of specific food items and the risk
of degenerative diseases is extremely complex. Recent literature suggests that molecules having a chemical
structure compatible with a putative antioxidant capacity can actually “perform” activities and roles
independent of such capacity, interacting with cellular functions at different levels, such as affecting enzyme
activities, binding to membrane or nuclear receptors as either an elective ligand or a ligand mimic. Inductive
or signaling effects may occur at concentrations much lower than that required for effective antioxidant
activity. Therefore, the “antioxidant hypothesis” is to be considered in some cases an intellectual “shortcut”
possibly biasing the real understanding of the molecular mechanisms underlying the beneficial effects of
various classes of food items. In the past few years, many exciting new indications elucidating the
mechanisms of polyphenols have been published. Here, we summarize the current knowledge of the
mechanisms by which specific molecules of nutritional interest, and in particular polyphenols, play a role in
cellular response and in preventing pathologies. In particular, their direct interaction with nuclear receptors
and their ability to modulate the activity of key enzymes involved in cell signaling and antioxidant responses
are presented and discussed
RELATIVE EXPANSION OF EXTRACELLULAR WATER IN ELITE MALE-ATHLETES COMPARED TO RECREATIONAL SPORTSMEN
No full textThis study reports total body hydration and water distribution between the extracellular water (ECW) and the intracellular water (ICW) of a group of 15 elite male athletes compared with a group of 15 male subjects practising the same sport at 'amateur' level. Total body water (TBW) and ECW were assessed by means of deuterium and bromide dilution techniques respectively. Both TBW and body hydration were significantly higher in elite athletes than in non-competitive subjects (52.3 +/- 5.0 vs 46.1 +/- 4.2 litres p<0.001 and 63.2 +/- 1.9 vs 60.2 +/- 1.9% body weight, p<0.003 respectively). Likewise, both ECW the ratio of ECW to TBW were significantly higher in athletes than in control subjects (20.7 +/- 2.9 vs 16.1 +/- 1.8 litres, p<0.0001 and 0.40 +/- 0.06 vs 0.35 +/- 0.03, p<0.005 respectively). ICW was similar in both groups but the ICW to ECW ratio was significantly higher in the athletes compared to the recreational sportsmen (0.67 +/- 0.16 vs 0.54 +/- 0.07, p<0.01). These data suggest that assumptions regarding the chemical composition of the standard human body may not be valid in elite athletes
Relative expansion of extracellular water in elite Male athletes compared to recreational sportsmen
No full textThis study reports total body hydration and water distribution between the extracellular water (ECW) and the intracellular water (ICW) of a group of 15 elite male athletes compared with a group of 15 male subjects practising the same sport at 'amateur' level. Total body water (TBW) and ECW were assessed by means of deuterium and bromide dilution techniques respectively. Both TBW and body hydration were significantly higher in elite athletes than in non-competitive subjects (52·3 ± 5·0 vs 46·1 ± 4·2 litres p<0·001 and 63·2 ± 1·9 vs 60·2 ± 1·9% body weight, p<0·003 respectively). Likewise, both ECW the ratio of ECW to TBW were significantly higher in athletes than in control subjects (20·7 ± 2·9 vs 16·1 ± 1·8 litres, p<0·0001 and 0·40 ± 0·06 vs 0·35 ± 0·03, p<0·005 respectively). ICW was similar in both groups but the ICW to ECW ratio was significantly higher in the athletes compared to the recreational sportsmen (0·67 ± 0·16 vs 0·54 ± 0·07, p<0·01). These data suggest that assumptions regarding the chemical composition of the standard human body may not be valid in elite athletes. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted
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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