Search results for "coefficient of variation"

Concordance of assays designed for the quantification of JAK2V617F: a multicenter study

2008

Background Many different techniques have been designed for the quantification of JAK2 V617F allelic burden, sometimes producing discrepant results. Design and Methods JAK2 V617F quantification techniques were compared among 16 centers using 11 assays based on quantitative polymerase chain reaction (with mutation-specific primers or probes, or fluorescent resonance energy transfer/melting curve analysis), allele-specific polymerase chain reaction, conventional sequencing or pyrosequencing. Results A first series of blinded samples (granulocyte DNA, n=29) was analyzed. Seven assays (12 centers) reported values inside the mean±2SD; the mean coefficient of variation was 31%. Sequencing techniq…

Reproducibility of pulse wave velocity and augmentation index derived from non-invasive occlusive oscillometric tonometry analysis in adolescents

2018

The aim of this study was to investigate the short-term reproducibility of aortic pulse wave velocity (PWVao) and augmentation index (AIx%) assessed by the non-invasive oscillometric device. Altogether of 55 (19 boys, 36 girls) adolescents 16-19-years-of-age participated in the study. PWVao and AIx% were measured during the same laboratory visit at 2 min intervals using the Arteriograph™ device. Peak oxygen uptake (VO2peak ) was assessed by the maximal exercise test on a cycle ergometer and body fat percentage by bioelectrical impedance analysis. We studied reproducibility using intraclass correlation coefficients (ICC), coefficient variation with the root-means-square method expressed as p…

Influence of a Commercial Lead Apron on Patient Skin Dose Delivered During Oral and Maxillofacial Examinations under Cone Beam Computed Tomography (C…

2017

The purpose of this paper is to investigate the impact of a commercial lead apron on patient skin dose delivered during maxillofacial CBCT in five critical regions by means of solid-state-dosimetry. Five anatomical regions (thyroid gland, left and right breast, gonads, back of the phantom torso) in an adult female anthropomorphic phantom were selected for dose measurement by means of the highly sensitive solid-state dosimeter QUART didoSVM. Ten repeated single exposures were assessed for each patient body region for a total of five commercial CBCT devices with and without a lead apron present. Shielded and non-shielded exposures were compared under the paired Wilcoxon test, with absolute an…

Technical Report: Repeatability of Contrast Sensitivity Test in Children

2020

Contrast sensitivity (CS) in children is not routinely measured in the clinical setting, although CS losses have been found in amblyopic and premature children. Thus simple visual acuity measurements do not completely assess their quality of vision. To evaluate contrast sensitivity in children, a reliable and easy test, sampling the entire spatial frequency range, is necessary. Purpose This study aimed to evaluate the repeatability and normal range of the contrast sensitivity function measured using the Topcon CC-100 instrument, in children aged between 4 and 9 years, for use as a diagnostic tool. Methods Contrast sensitivity was measured in 25 children, 11 boys and 14 girls, with normal or…

Short-Term Precision Error of Bone Strain Index, a New DXA-Based Finite Element Analysis Software for Assessing Hip Strength

2020

Abstract Bone Strain Index (BSI) is a new finite element analysis tool applied to hip dual energy X-ray absorptiometry scans. The aim of this study was to assess the short-term precision error of BSI on the proximal femur, both on a phantom and patients. The International Society for Clinical Densitometry guidelines were followed for short-term precision error assessment. Dual energy X-ray absorptiometry measurements were performed on an anthropomorphic femur phantom that was scanned twice for 30 times, for a total of 60 scans. For the in vivo part, 30 subjects were scanned twice. BSI precision error was compared to that of bone mineral density (BMD). Both for the phantom and the in vivo st…

Sprint Time Differences Between Single- and Dual-Beam Timing Systems

2014

Valid and reliable measures of sprint times are necessary to detect genuine changes in sprinting performance. It is currently difficult for practitioners to assess which timing system meets this demand within the constraints of a proper cost-benefit analysis. The purpose of this investigation was to quantify sprint time differences between single-beam (SB) and dual-beam (DB) timing systems. Single-beam and DB photocells were placed at 0, 20, and 40 m to compare 0-20 and 20-40 m sprint times. To control for the influence of swinging limbs between devices, 2 recreationally active participants cycled as fast as possible through the track 25 times with a 160-cm tube (18 cm diameter) vertically …

Comparing cetacean abundance estimates derived from spatial models and design-based line transect methods

2007

Spatial modelling is increasingly being used as an alternative to conventional design- based line transect sampling to estimate cetacean abundance. This new method combines line transect sampling with spatial analysis to predict animal abundance based on the relationship of ani- mals observed to environmental factors. It presents several advantages including: (1) the ability to use data collected from 'platforms of opportunity', (2) the ability to estimate abundance for any defined subarea within the study area, and (3) the possibility for increased precision if covariates explain sufficient variability in the data. One study has been conducted to compare spatial modelling with conventional…

Comparison of disc diffusion assay with the CLSI reference method (M27-A2) for testing in vitro posaconazole activity against common and uncommon yea…

2007

Objectives To evaluate the suitability of disc diffusion (DD) assay for testing posaconazole activity and to corroborate its activity against recently isolated yeasts by the CLSI reference microdilution M27-A2 method. Methods A total of 224 yeast isolates (7 species with 52 to 11 isolates each, and 15 species with 1 to 6 isolates) were evaluated, 125 were recent bloodstream isolates, 30 isolates from other sources and six ATCC isolates that included amphotericin B-resistant Candida albicans ATCC 200955, Candida lusitaniae (ATCC 200950, 200951, 200952 and 200953) and amphotericin B- and itraconazole-resistant Candida tropicalis ATCC 200956. MICs were determined at 24 and 48 h by following th…

2020

Purpose To investigate short-term training and recovery-related effects on heart rate during a standardized submaximal running test. Methods Ten elite badminton players (7 females and 3 males) were monitored during a 12-week training period in preparation for the World Championships. Exercise heart rate (HRex) and perceived exertion were measured in response to a 5-min submaximal shuttle-run test during the morning session warm-up. This test was repeatedly performed on Mondays after 1–2 days of pronounced recovery (‘recovered’ state; reference condition) and on Fridays following 4 consecutive days of training (‘strained’ state). In addition, the serum concentration of creatine kinase and u…

Modification of longitudinal relaxation time (T1) as a biomarker of patellar cartilage degeneration

2010

Abstract Objectives To study the viability of longitudinal relaxation time ( T1 ) of patellar cartilage as a biomarker of the degree of degeneration. Material and methods We included 15 subjects classified into three groups according to clinical criteria (pain, functional limitation, and duration of symptoms) and imaging criteria as follows: (a) normal (3 men, 2 women; age 30 ± 14 years), (b) with initial degeneration of the patellar cartilage (3 men, 2 women; age 30 ± 6 years), or (c) with advanced degeneration (3 men, 2 women; age 57 ± 10 years). All underwent MRI examination using special echo-gradient sequences to segment the cartilage and calculate the T1 maps. We selected the entire c…