1,720,958 research outputs found
Roles of nitric oxide, nitrite and myoglobin on myocardial efficiency in trout (Oncorhynchus mykiss) and goldfish (Carassius auratus): Implications for hypoxia tolerance
No full textThe roles of nitric oxide synthase activity (NOS), nitrite and myoglobin (Mb) in the regulation of myocardial function during hypoxia were examined in trout and goldfish, a hypoxia-intolerant and hypoxia-tolerant species, respectively. We measured the effect of NOS inhibition, adrenaline and nitrite on the O2 consumption rate and isometric twitch force development in electrically paced ventricular preparations during hypoxia, and measured O 2 affinity and nitrite reductase activity of the purified heart Mbs of both species. Upon hypoxia (9% O2), O2 consumption and developed force decreased in both trout and goldfish myocardium, with trout showing a significant increase in the O2 utilization efficiency, i.e. the ratio of twitch force to O2 consumption, suggesting an increased anaerobic metabolism. NOS inhibition enhanced myocardial O2 consumption and decreased efficiency, indicating that mitochondrial respiration is under a tone of NOS-produced NO. When trout myocardial twitch force and O2 consumption are enhanced by adrenaline, this NO tone disappears. Consistent with its conversion to NO, nitrite reduced O2 consumption and increased myocardial efficiency in trout but not in goldfish. Such a difference correlates with the lower O2 affinity measured for trout Mb that would increase the fraction of deoxygenated heme available to catalyze the reduction of nitrite to NO. Whereas low-affinity trout Mb would favor O 2 diffusion within cardiomyocytes at high in vivo O2 tensions, goldfish Mb having higher O2 affinity and higher nitrite reductase activity appears better suited to facilitate O2 diffusion and nitrite reduction in the heart during severe hypoxia, a condition particularly well tolerated by this species
Integrating nitric oxide, nitrite and hydrogen sulfide signaling in the physiological adaptations to hypoxia: a comparative approach
No full textHydrogen sulfide (H(2)S), nitric oxide (NO) and nitrite (NO(2)(-)) are formed in vivo and are of crucial importance in the tissue response to hypoxia, particularly in the cardiovascular system, where these signaling molecules are involved in a multitude of processes including the regulation of vascular tone, cellular metabolic function and cytoprotection. This report summarizes current advances on the mechanisms by which these signaling pathways act and may have evolved in animals with different tolerance to hypoxia, as presented and discussed during the scientific sessions of the annual meeting of the Society for Experimental Biology in 2011 in Glasgow. It also highlights the need and potential for a comparative approach of study and collaborative effort to identify potential link(s) between the signaling pathways involving NO, nitrite and H(2)S in the whole-body responses to hypoxia
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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