1,721,153 research outputs found
The effect of emerging muscular abnormalities on proximate composition and NMR relaxation properties of chicken breast meat
No full textUNDERSTANDING THE ROLE OF HISTIDINE DIPEPTIDES ON POST-MORTEM PH DECLINE IN BROILER BREAST AND LEG MUSCLES
No full textThe role of histidine dipeptides on postmortem acidification of broiler muscles with different energy metabolism
Full text linkIt is generally held that the content of several free amino acids and dipeptides is closely related to the energy-supplying metabolism of skeletal muscles. Metabolic characteristics of muscles are involved in the variability of meat quality due to their ability to influence the patterns of energy metabolism not only in living animal but also during post-mortem time. Within this context, this study aimed at establishing whether the concentration of histidine dipeptides can affect muscle post-mortem metabolism, examining the glycolytic pathway of three chicken muscles (Pectoralis major, extensor iliotibialis lateralis and gastrocnemius internus as glycolytic, intermediate and oxidative-type, respectively) selected based on their histidine dipeptides content and ultimate pH. Thus, a total of 8 carcasses were obtained from the same flock of broiler chickens (Ross 308 strain, females, 49 days of age, 2.8 kg body weight at slaughter) and selected immediately after evisceration from the line of a commercial processing plant. Meat samples of about 1 cm3 were excised from bone-in muscles at 15, 60, 120 and 1,440 min post-mortem, instantly frozen in liquid nitrogen and used for the determination of pH, glycolytic metabolites, buffering capacity as well as histidine dipeptides content through 1H-NMR. Overall results suggest that glycolysis in leg muscles ceased already after 2 h post-mortem, while in breast muscle continued until 24 h, when it exhibited significantly lower pH values (P<0.05). However, considering its remarkable glycolytic potential, Pectoralis major muscle should have exhibited a greater and faster acidification, suggesting that its higher (P<0.05) histidine dipeptides’ content might have prevented a potentially stronger acidification process. Accordingly, breast muscle also showed greater (P<0.05) buffering ability in the pH range 6.0-7.0. Therefore, anserine and carnosine, being highly positively correlated with muscle’s buffering capacity (P<0.001), might play a role in regulating post-mortem pH decline, thus exerting an effect on muscle metabolism during pre-rigor phase and the quality of the forthcoming meat. Overall results also suggest that total histidine dipeptides content along with muscular ultimate pH represent good indicators for the energy-supplying metabolism of chicken muscles
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
A 1H NMR-Based Metabolomics Approach on Dietary Biomarker Research in Human Urine
No full textThe analysis of the metabolome has become particularly important in human studies, allowing the identification of typical and atypical metabolites in determined biofluids and tissues. This is clearly fundamental for medical investigations, since it could be possible to assess the presence or absence of certain diseases and syndromes or risk conditions. Another widespread use of the metabolomic approach is the research on specific dietary effects on the metabolic profile. It is necessary to take research further and investigate the presence of determined food molecules in fluids or tissues from individuals without a controlled dietary intervention. NMR spectroscopy techniques can be very useful in different nutrimetabonomics approaches, thanks to the quickness, high-throughput efficacy and high-reproducibility of its methods. In this paper the two main nutrimetabolomic strategies were highlighted, both greatly aided by the use of NMR spectroscopy. The first one requires a direct intervention on a sample population in order to assess the direct effects on the metabolome after the intake of a particular food product or category. In the other technique, instead, observational studies in free-eating populations are carried out. At first nutritional data is analysed in order to find possible dietary patterns, then these have to be proved by the inspection of biofluid spectra, in order to find molecules capable in discriminating among the dietary behaviours
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
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