1,720,959 research outputs found
Perception of dyspnea during exercise-induced bronchoconstriction
After strenuous physical exercise, many subjects show a significant bronchoconstriction and report dyspnea. Despite this clinical condition being a commonly encountered situation during daily life, which may be responsible for substantial disability there is little information on the relationship between the perception of dyspnea and exercise-induced bronchoconstriction (EIB) after a standardized exercise challenge. For these reasons, we evaluated 200 consecutive outpatients (median age 13 years, ranging from 5 to 56 years) referred to our laboratory to perform an exercise test out of suspicion of EIB. On exercise challenge, perception of dyspnea was rated on a modified bipolar Borg scale immediately before each FEV1 measurement. Sixty-nine (35%) subjects had a positive exercise challenge, defined as a decrease of at least 20% in FEV1 from baseline. Both the onset and the decay of dyspnea preceded those of bronchoconstriction. Overall, the rating of dyspnea in the laboratory was well related with the reports of exercise-related symptoms. Similarly, 36 of 77 (47%) asthmatics with a history of exertional symptoms and 24 of 65 patients (40%) without a history had a positive challenge. Asthmatics reporting exertional symptoms perceived a greater magnitude of dyspnea after exercise independently from the degree of bronchoconstriction. Overall, dyspnea was significantly but loosely correlated to the magnitude of decrease in FEV1, being also influenced by age, gender and BMI. CONCLUSIONS: We conclude that dyspnea recorded in the laboratory after exercise test is related to exertional symptoms reported during real life, but not completely related to EIB. The rating of dyspnea is a well-suited model to study naturally occurring exercise-induced dyspnea and a useful tool to enlarge the results of an exercise challenge
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
We 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
Increased lung surfactant phosphatidylcholine in patients affected by lysosomal storage diseases.
Sandhoff disease, Gaucher disease type I and sialidosis type I are lysosomal storage disorders caused, respectively, by deficiency of activity of beta-hexosaminidase (storage of GM(2) and GA(2) ganglioside), glucosylceramidase (storage of glucosylceramide) and alpha-neuraminidase (storage of glucopeptides and/or oligosaccharides). Progressive clinical systemic and neurological dysfunctions are observed. In these pathologies, respiratory infections often lead to death. Elevation of the lung surfactant phosphatidylcholine (PC) has previously been reported in the Hexb mouse, a model of Sandhoff disease. We evaluated phospholipids in the lung surfactant of patients affected by the described lysosomal diseases, observing a statistically significant increase of total lipid phosphate in the patients as compared with controls. Moreover, higher levels of PC in patients affected by sialidosis (3.6-fold) and Gaucher (4-fold) disease, and of PC (4.15-fold) and phosphatidylethanolamine (2.3-fold) in a patient affected by Sandhoff disease were noted. The latter confirms the previous results in the Hexb mouse. We suggest that changes in phospholipid metabolism can be common in different lysosomal storage disorders and can increase the susceptibility to respiratory infections, usually present in these disorder
koamabayili/VECTRON-author-checklist: VECTRON author checklist
We 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.
Author-wise bibliometric analysis based on entropy.</p
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