1,720,965 research outputs found
Home-Based, Moderate-Intensity Exercise Training Using a Metronome Improves the Breathing Pattern and Oxygen Saturation During Exercise in Patients With COPD
No full textPURPOSE:
One of the well-known but less-investigated effects of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD) is the change in breathing pattern toward a more efficient one (higher tidal volume [VT], lower breathing frequency). Evidence suggests this change can be obtained only with supervised, high-intensity exercise training (ExTr). However, some patients either do not have such programs available or are unable to exercise at higher intensity. We evaluated the effects of a 12-wk, moderate-intensity, home-monitored ExTr program using a metronome on the breathing pattern, oxygen saturation (SpO2), and dyspnea during exercise in patients with COPD.
METHODS:
Twenty-one patients with COPD (7 female, aged 64-85 yr) performed spirometry, incremental, and endurance walking tests (at 60% of maximal walking speed) on a treadmill before and after training. During the endurance test, patients were equipped with an instrument that continuously monitored ventilation (VE), breathing pattern, and SpO2. Patients trained at home for 12 wk, 30 min/d for at least 4 d/wk at moderate intensity. A metronome paced the walking speed.
RESULTS:
Sixteen patients completed the program. After training, a significant change was observed in breathing pattern (lower VE and VE/VT ratio; P < .001), a higher SpO2 (P < .001), and a lower dyspnea perception at the same work intensity (P < .01). The VE/VT ratio and SpO2 during exercise were significantly related (r = 0.56, P = .001).
CONCLUSION:
A change in breathing pattern towards more efficient ventilation can be obtained with a moderate, home-monitored ExTr program with a pace that is controlled by a metronome. Decreased VE/VT was associated with an improved SpO2 during exercis
Efficacy and tolerability of yoga breathing in patients with chronic obstructive pulmonary disease: a pilot study.
No full text
Periodic Breathing, Arterial Oxyhemoglobin Saturation, and Heart Rate during Sleep at High Altitude
No full textInsalaco, Giuseppe, Salvatore Romano, Adriana Salvaggio, Luca Pomidori, Gaia Mandolesi, and Annalisa Cogo. Periodic breathing, arterial oxyhemoglobin saturation, and heart rate during sleep at high altitude. 13:258-262, 2012. - The aim of this study was to investigate the effects of acclimatization to high altitude on periodic breathing (PB), arterial oxygen saturation (Sao 2), and heart rate (HR). Nine male elite climbers, age 24-52 years underwent overnight cardiorespiratory monitoring at sea level and at Everest North Base Camp (5180 m), during the first (BC1) and the tenth (BC2) nights. PB was commonplace in all subjects at high altitude. PB cycle duration increased (p<0.0001) from BC1 (21.7±1.9 s) to BC2 (26.7±2.1 s). Mean Sao2 from BC1 to BC2, significantly increased during wakefulness (77.4±3.4% vs. 82.5±2.8%; p<0.001) and during sleep regular breathing (73.3±3.8% vs. 77.8±2.9%; p=0.022). During PB, mean higher Sao2 was 75.3±3.6% at BC1 and 82.4±2.9% at BC2 (p<0.001); mean lower Sao2 was 68.2±4.0% at BC1 and 74.5±4.3% at BC2 (p<0.01). During PB, mean higher HR was 72.4±8.8 b/min at BC1 and 63.3±6.0 b/min at BC2 (p<0.0002); mean lower HR were 53.6±7.5% at BC1 and 43.6±7.3% at BC2 (p<0.0001). The mean Sao2 during PB compared with Sao2 at night without PB was unchanged. Acclimatization to high altitude resulted in an overall increase in Sao2 along with an increase in the PB cycle duration and a decrease in HR. © Copyright 2012, Mary Ann Liebert, Inc. 2012
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
Early oxygen desaturation is related to acute mountain sickness (AMS) development during acute high altitude (HA) exposure
No full textEarly desaturation during acute HA exposure (hypobaric chamber) has been reported to be significantly related to AMS development. We aimed to study the hypoxic profile and the AMS development during the ascent from Alagna (1200m) to Capanna Regina Margherita (4559m) with an overnight stay in Rifugio Gnifetti (3647m).
Forty-four (8F) subjects (mean age 37.412.7) were recruited at the cable care station in Alagna, equipped with a 24-h data memory pulse oximeter (Pulsox-3Si,Minolta, Osaka, Japan) and asked to fill the Lake Louise questionnaire. Only data from Alagna to Rifugio Gnifetti and the subsequent night are reported. Fifteen subjects (34%) showed a LL score ≥3 (AMS+). In Alagna, SpO2 data were similar (94.5%1.6 vs 95%1.4 n.s.) but during HA exposure AMS+ group had a significantly lower SpO2: at Punta Indren (3275m) after a 30-45 minutes cable car ascent (84%4.5 vs 86.8%3.7 p <0.049; in Rifugio Gnifetti during 3 hours rest after the arrival (84%2.1 vs 86.11.9 p<0.01) and during the subsequent night (76.7%3.8 vs 79.1%3.4 p 0.049). There was no significant difference during the 2 hours exercise to reach Rifugio Gnifetti (81.3%2.9 vs 82.1%2.5 n.s.). No difference was found in the lower peak SpO2 during the night but the AMS+ group always spent more time with a lower SpO2: percentage of total time spent with SpO2 <85% at rest in Rifugio Gnifetti was 56%20.6 vs 34%18 p 0.017; percentage of total time spent with SpO2<75% during the night was 35%27 vs 18%19 p 0.036.
We conclude that in subjects who develop subsequent AMS, hypoxemia is always more pronounced and prolonged than in healthy subjects; the new finding is that the higher desaturation occurs very early at the beginning of altitude exposure
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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