1,721,055 research outputs found
Exercise-induced biphasic responses and methacholine reactivity in asthma.
No full textBiphasic (early and late) asthmatic responses to exercise occurred in seven of 43
children with reproducible exercise-induced asthma. As biphasic allergen-induced
asthma is associated with a prolonged increase in nonspecific bronchial
hyperreactivity, this effect was not sought in the 43 asthmatic children. There
was no significant change in methacholine PD20 FEV1 before and after exercise
challenge, either in children who had early, or early and late, exercise
responses. Late reactions after allergen exposure are likely to be of
considerable clinical significance in relation to the enhancement of bronchial
responsiveness. It is reassuring that this is not the case for exercise
challenge, as it would have major implications in relation to the recommendations
that asthmatics should participate in normal activities and even in training
programs. Furthermore, it suggests that there are differences between the
pathophysiology of asthma induced by exercise and that produced by allergens
Double-blind trial of house-dust mite immunotherapy in asthmatic children resident at high altitude.
No full textTwenty-three Dermatophagoides pteronyssinus (Dpt)-sensitive asthmatic children
aged 7-14 years entered a double-blind, placebo-controlled trial of standardized
immunotherapy (IT) (Alpare) while resident at high altitude. Dpt sensitivity was
evaluated by skin prick tests at different allergen concentrations at the
enrollment and after 6 and 12 months of treatment. Bronchial hyperreactivity was
evaluated at the same time points, and on each occasion, histamine challenge and,
the following day, Dpt bronchial challenge were performed. All patients,
irrespective of active treatment, improved clinically and in lung function with
increased PC20 and Dpt-PD20. Alpare-treated patients had a significantly
decreased sensitivity on Dpt skin testing (P < 0.009) and felt that their asthma
had improved (P < 0.001) compared with placebo-treated subjects, but there was no
difference between the treatment groups in lung function or bronchial challenge
response. IT neither increased nor decreased bronchial histamine sensitivity. Our
results indicate that Dpt IT benefits asthmatic children, but improvement by
allergen avoidance at high altitude is even greater
Double-blind trial of house-dust mite immunotherapy in asthmatic children resident at high altitude
No full textTwenty-three Dermatophagoides pteronyssinus (Dpt)-sensitive asthmatic children aged 7-14 years entered a double-blind, placebo-controlled trial of standardized immunotherapy (IT) (Alpare) while resident at high altitude. Dpt sensitivity was evaluated by skin prick tests at different allergen concentrations at the enrollment and after 6 and 12 months of treatment. Bronchial hyperreactivity was evaluated at the same time points, and on each occasion, histamine challenge and, the following day, Dpt bronchial challenge were performed. All patients, irrespective of active treatment, improved clinically and in lung function with increased PC20 and Dpt-PD20. Alpare-treated patients had a significantly decreased sensitivity on Dpt skin testing (P < 0.009) and felt that their asthma had improved (P < 0.001) compared with placebo-treated subjects, but there was no difference between the treatment groups in lung function or bronchial challenge response. IT neither increased nor decreased bronchial histamine sensitivity. Our results indicate that Dpt IT benefits asthmatic children, but improvement by allergen avoidance at high altitude is even greater
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
EFFECTIVE ALLERGEN AVOIDANCE AT HIGH ALTITUDE REDUCES ALLERGEN-INDUCED BRONCHIAL HYPERESPONSIVENESS
No full textWe studied the effects of reduced allergen exposure on bronchial hypereactivity (BHR) in two groups of asthmatic children allergic to house dust mites (HDM) living at high altitude for 9 continuous mo. In the first group the serum levels of total and HDM-specific IgE showed significant decreases after 3 mo (p < 0.001 and p < 0.02, respectively) and after 9 mo (p < 0.001). Three months after returning home the total IgE levels had increased significantly (p < 0.001). The mean percentage fall in peak expiratory flow after exercise testing improved after 3 and 9 mo (p < 0.05), but it had deteriorated after 3 mo at home (p < 0.01). The methacholine PD20-FEV1 increased after 3 mo (p = 0.001) and further after 9 mo (p < 0.001), with a decrease after the 3-mo period at sea level (p = 0.01). In the second cohort there was a significant increase in HDM PD20-FEV1 after 6 and 9 mo (p < 0.001), with a slight decrease of magnitude of the allergen-induced late reaction. Histamine PD20-FEV1 significantly increased after 6 and 9 mo at high altitude, particularly in the challenges performed after the HDM bronchial provocation (p < 0.01). Our data demonstrate that allergen avoidance in asthmatic children not only decreases nonspecific BHR but also decreases allergen sensitivity, late allergen-induced bronchial reactions, and enhancement of BHR by allergen challenge
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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