1,721,070 research outputs found
Validation of a single‐stage fixed‐rate step test for the prediction of maximal oxygen uptake in healthy adults
No full textHealthcare professionals with limited access to ergospirometry remain in need of valid and simple submaximal exercise tests to predict maximal oxygen uptake (VO2max). Despite previous validation studies concerning fixed-rate step tests, accurate equations for the estimation of VO2max remain to be formulated from a large sample of healthy adults between age 18–75 years (n > 100). The aim of this study was to develop a valid equation to estimate VO2max from a fixed-rate step test in a larger sample of healthy adults. A maximal ergospirometry test, with assessment of cardiopulmonary parameters and VO2max, and a 5-min fixed-rate
single-stage step test were executed in 112 healthy adults (age 18–75 years). During the step test and subsequent recovery, heart rate was monitored continuously. By linear regression analysis, an equation to predict VO2max from the step test was formulated. This equation was assessed for level of agreement by displaying
Bland–Altman plots and calculation of intraclass correlations with measured VO2max. Validity further was assessed by employing a Jackknife procedure. The linear regression analysis generated the following equation to predict VO2max (l min 1) from the step test: 0054(BMI)+0612(gender)+3359(body height in m)+0019(fitness index) 0012(HRmax) 0011(age) 3475. This equation explained 78% of the variance in measured VO2max (F = 6615, P<0001). The level of agreement and intraclass correlation was high (ICC = 094, P<0001)
between measured and predicted VO2max. From this study, a valid fixed-rate single-stage step test equation has been developed to estimate VO2max in healthy adults. This tool could be employed by healthcare professionals with limited access to ergospirometry.This study was partially funded by the scientific chair ‘De Onderlinge Ziekenkas preventie’ and by a research grant from
Hartcentrum Hasselt, Belgium
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
An equivalence test for comparing DNA sequences
No full textThe practice of sequence alignment is constantly oscillating between the risk of overlooking important structure and that of discovering any arbitrarily defined kind of structure anywhere. On the other hand, the use of a condensed consensus sequence may lead to a substantial loss in valuable information. While adopting a Mahalanobis-type index we allow for a certain degree of uncertainty in the measurements. This uncertainty may be caused by inaccurate measurements or ambiguity.In this paper, we test the similarity between DNA sequences within the framework of equivalence testing, accounting for both variances and covariances between frequencies of nucleotides. Statistical methods for testing equivalence were first developed in the context of pharmacokinetics and later extended to the field of clinical trials. Nowadays, (bio)equivalence tests seem to be less frequently used outside the drug testing field, including statistical genetics
Neuromuscular electrical stimulation as a possible mean to prevent muscle tissue wasting in artificially ventilated and sedated patients at the intensive care unit : a pilot study
No full textObjective: The aim of this study was to explore if electrical stimulation could prevent muscle atrophy.
Material and Methods: Patients were hospitalized for postoperative coronary artery bypass graftin, chronic obstructive pulmonary disease, ventilatory failure, or acute cerebro-vascular accident, and were divided into an intervention group or a control group. The intervention group underwent daily 30 minute training with an intermittent neuromuscular electrical stimulation applied to the right quadriceps muscle. Heart rate, respiration rate, systolic and diastolic blood pressure, and oxygen saturation were monitored before, during, and after electrical stimulation. Circumference of both thighs was measured.
Results: The intervention resulted in a significant reduction of muscle atrophy in the stimulated as compared with the non-stimulated limb (p < 0.05), without making any impact on cardiovascular, respiratory and, hemodynamic characteristics.
Conclusions: Muscle atrophy is prevented by intermittent neuromuscular electrical stimulation while this intervention showed no obvious impact on the cardio-respiratory conditions of the patients
Neuromuscular electrical stimulation as a possible mean to prevent muscle tissue wasting in artificially ventilated and sedated patients at the intensive care unit : a pilot study
No full textObjective: The aim of this study was to explore if electrical stimulation could prevent muscle atrophy.
Material and Methods: Patients were hospitalized for postoperative coronary artery bypass graftin, chronic obstructive pulmonary disease, ventilatory failure, or acute cerebro-vascular accident, and were divided into an intervention group or a control group. The intervention group underwent daily 30 minute training with an intermittent neuromuscular electrical stimulation applied to the right quadriceps muscle. Heart rate, respiration rate, systolic and diastolic blood pressure, and oxygen saturation were monitored before, during, and after electrical stimulation. Circumference of both thighs was measured.
Results: The intervention resulted in a significant reduction of muscle atrophy in the stimulated as compared with the non-stimulated limb (p < 0.05), without making any impact on cardiovascular, respiratory and, hemodynamic characteristics.
Conclusions: Muscle atrophy is prevented by intermittent neuromuscular electrical stimulation while this intervention showed no obvious impact on the cardio-respiratory conditions of the patients
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