1,720,971 research outputs found
Effect of Thiamine Pyrophosphate (Bicarbossilasi®) Administration on the Exercising Horse Metabolism
Get PDFThiamine pyrophosphate (TPP) is the phosphorylated and active form of thiamine (Vitamin B1). We hypothesized that the administration of thiamine in its immediately available active form could provide the metabolic pathways for a supplement able to promote the metabolism of ketoacids and to reduce lactate accumulation in exercising horses. Ten horses were conditioned for 20 days to daily standardized exercise. All horses underwent a first “stress test” (ST) consisting in 1,200 meters at maximum speed on track, and were checked before and after for clinical and clinical pathology parameters. After the ST, the same animals were administered TPP (Bicarbossilasi®, ©Teknofarmas.p.a., Torino, Italy), 1 mg/Kg b.w., I.V., twice daily for seven days. At the end of treatment, a second stress test (STTPP) was performed. Post-exercise serum lactate concentration resulted in significantly lower levels (p< 0.05) after treatment with TPP (ST vs STTPP). These data suggest that supplementation with thiamine in its active form improves glucose metabolism and prevents lactate accumulation in muscle, enhancing aerobic capacity and metabolic pathways of glucose utilization during exercise
Expression and activity of CYP 1A1 in different brain regions of control and beta-naphthoflavone-treated pigs
No full textExpression and activity of CYP 1A1 in different brain regions of control and beta-naphthoflavone-treated pigs
Gervasi, P.G.1, Chirulli, V.1, Zaghini, A.2, Vaccaro, E.3, Fiorio, R.3, Longo, V.3, Marvasi, L.2
1 Ins. Clinical Physiology, Metabolism, Pisa, Italy; 2 Bologna University, Patologia Veterinaria, Bologna, Italy; 3 Ins. Clinical Physiology, Metabolism, PISA, Italy
The expression of the cytochrome P450 1A1 (CYP 1A1) and its related activities along with the Ah Receptor were investigated in liver and brain regions from control pigs and pigs treated with beta-naphthoflavone (30 mg/kg i.p. for 4 days). By RT-PCR analysis, using specific primers, it was demonstrated that mRNA of CYP 1A1 and AhR were expressed, although at different extent, in the liver, cortex, midbrain and cerebellum. However, the beta-naphthoflavone treatment had no apparent effect on expression pattern of this isoform, unlike liver, in any brain region. Then, some enzymatic activities (ethoxyresorufin O-deethylase and methoxyresorufin O-demethylase), known markers for the CYP 1A1/2, were studied in microsomes of liver and microsomes and mitochondria of cortex, midbrain and cerebellum from control and beta-naphthoflavone treated pigs. The enzymatic analysis revealed a presence of these activities about 3-4 times higher in mitochondria than in microsomes from all the brain regions examined. However, in contrast to the behaviour of the liver, beta-naphthoflavone treatment did not induce the cerebral activities. Despite the presence of AhR, the CYP1A1 in the pig brain was resistant to beta-naphthoflavone induction suggesting that there is a different regulation mechanism of this enzyme between the brain and liver
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
In vitro formation of metabolic-intermediate cytochrome P450 complexes in rabbit liver microsomes by tiamulin and various macrolides
No full textTiamulin and a number of macrolides were evaluated as to their ability in forming metabolic-intermediate (MI) complexes with cytochrome P450 in liver microsomes from rabbits bred for meat production. Complex formation, which occurred only in preparations where the expression of P450 3A was increased as the result of rifampicin pre-treatment and with different kinetics, was in the order tiamulin > erythromycin > TAO approximate to roxithromycin approximate to tylosin and did not take place with tilmicosin and spiramycin. Most of the tested compounds underwent an oxidative N-dealkylation and a good relationship could be found between the rate of N-dealkylase activity in induced preparations and the aptitude in generating MI complexes. Although the results from in vitro studies should be interpreted with caution, it is suggested that the potential for in vivo drug interactions also exists in the rabbit for tiamulin and for four out of the six tested macrolide
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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