Search results for "Coefficient of Variation"
showing 10 items of 77 documents
Evaluation of a multispectral diffuse optical spectroscopy device for assessment of cardiometabolic risk related alterations of body composition
2013
Cardiometabolic diseases encompass a combination of conditions which lead to an increase in the risk of cardiovascular disease and diabetes. With the increasing percentage of the population becoming overweight, it is important to diagnose when the excess adipose tissue becomes malign. The development of a safe, mobile, non-invasive method that would be easy to perform, and low-cost, but also would offer an accurate assessment of subcutaneous adipose tissue (SAT) both in lean and in obese persons is required. A prototype device using an optical method for measurement of the SAT in vivo has been developed, it contains multiple LEDs with four wavelengths (660nm, 780nm, 870nm, 940nm) distribute…
Development of a nomogram for the estimation of long-term adherence to clozapine therapy using neutrophil fluorescence
2018
Aims: Previously, we have reported an association between clozapine use and elevated FL3 neutrophil fluorescence, a flow-cytometric parameter for cell viability. Here, we developed and evaluated a pharmacokinetic-pharmacodynamic model relating FL3-fluorescence to clozapine exposure and derived a nomogram for estimation of long-term adherence. Methods: Data from 27 patients initiating clozapine were analysed using nonlinear mixed effects modelling. A previously described pharmacokinetic model for clozapine was coupled to a FL3 fluorescence model. For this, an effect compartment with clozapine concentrations as input and a first order decay rate as output was linked with an Emax model to FL3-…
Uniqueness verification of blue fraction as a parameter of spectral irradiance quantification
2021
The spectral distribution of global irradiance is measured in the optimal tilt (45° south) plane of array for the calender year 2020 in Grimstad, Norway. In this work the spectral distribution is quantified in terms of the Blue Fraction (BF). The uniqueness of BF has been tested and reported using the same methodology used for uniqueness verification of average photon energy (APE). The results show that the coefficient of correlation between the APE and BF was 0.98, meaning a possible bijective relation between these two parameters whereby both indicate a similar spectrum. The percentage contribution of integrated irradiance (Rc) was calculated for 25 nm wavelength bins for the BF region 35…
The influence of preparation methodology on the concentrations of heavy metals in Pleurozium schreberi moss samples prior to use in active biomonitor…
2020
AbstractActive biomonitoring is used to assess environmental pollution of elements such as heavy metals by indicator species such as mosses. They are used, among others, in urbanized areas where no indicator species are found. In such study areas, mosses collected from sites considered to be ecologically clean shall be exposed. In this context, it is very important to prepare the mosses properly before the exposure, so that the information received about the condition of the environment is reliable. In 2018, studies were conducted in the forested areas of southern Poland—in Opolskie Province. Pleurozium schreberi mosses were used in these studies. Atomic absorption spectrometry with flame a…
NMR relaxation times of trabecular bone—reproducibility, relationships to tissue structure and effects of sample freezing
2010
Nuclear magnetic resonance (NMR) spectroscopy provides a potential tool for non-invasive evaluation of the trabecular bone structure. The objective of this study was to determine the reproducibility of the NMR relaxation parameters (T(2), Carr-Purcel-T(2), T(1ρ)) for fat and water and relate those to the structural parameters obtained by micro-computed tomography (μCT). Especially, we aimed to evaluate the effect of freezing on the relaxation parameters. For storing bone samples, freezing is the standard procedure during which the biochemical and cellular organization of the bone marrow may be affected. Bovine trabecular bone samples were stored at -20 °C for 7 days and measured by NMR spec…
Responsiveness to change and reliability of measurement of radiographic joint space width in osteoarthritis of the knee: a systematic review
2011
Import JabRef | WosArea Orthopedics; Rheumatology; International audience; Objective: The goal of this systematic review was to report the responsiveness to change and reliability of conventional radiographic joint space width (JSW) measurement. Method: We searched the PubMed and Embase databases using the following search criteria: [osteoarthritis (OA) (MeSH)] AND (knee) AND (X-ray OR radiography OR diagnostic imaging OR radiology OR disease progression) AND (joint space OR JSW or disease progression). We assessed responsiveness by calculating the standardized response mean (SRM). We assessed reliability using intra- and inter-reader intra-class correlation (ICC) and coefficient of variati…
Mass and energy flux estimates at different spatial resolutions in a heterogeneous area through a distributed energy-water balance model and remote s…
2012
Computed ET with the FEST-EWB model at high spatial resolution 10 m showed for the three days of analysis a mean relative error of 9.4% compared to AHS data, whereas for land surface temperature comparison a relative error of 1.6% was found. Then, LSTs from AHS and FEST-EWB were aggregated at decreasing spatial resolutions 50, 150, 300, 400, 500, 600, 750, and 1000 m, showing that the thermodynamic variability tends to disappear with a lower number of classes in the histograms and with a decrease of the coefficient of variation CV and of standard deviation values. At each scale, a similar behaviour was reported between each pair of images, with the values of standard deviation starting, res…
Respiratory mechanics measured by forced oscillations during mechanical ventilation through a tracheal tube
2011
The forced oscillation technique (FOT) allows the measurement of respiratory mechanics in the intensive care setting. The aim of this study was to compare the FOT with a reference method during mechanical ventilation through a tracheal tube. The respiratory impedance spectra were measured by FOT in nine anaesthetized pigs, and resistance and compliance were estimated on the basis of a linear resistance-compliance inertance model. In comparison, resistance and compliance were quantified by the multiple linear regression analysis (LSF) of conventional ventilator waveforms to the equation of motion. The resistance of the sample was found to range from 6 to 21 cmH(2)O s l(-1) and the compliance…
A simple high-performance liquid chromatography (HPLC) method for the measurement of pyridoxal-5-phosphate and 4-pyridoxic acid in human plasma.
2014
Abstract Background Low concentration of plasma pyridoxal-5-phosphate (PLP) is associated with hyperhomocysteinemia and inflammation. Most methods for the measurement of plasma PLP require large specimen volume and involve the use of toxic reagents. Methods We have developed a HPLC method for the measurement of PLP and 4-pyridoxic acid (4-PA) in plasma, which requires small specimen volume. The samples are prepared without adding any toxic reagents. Furthermore, we have examined whether intake of vitamin B 6 affects the concentration of plasma PLP and 4-PA. Results The coefficient of variation of the method was 6% and the recovery of the added vitamin in plasma was about 100%. The concentra…
Análisis tiempo-frecuencia de la fibrilación ventricular. Estudio experimental
2006
Introduction and objectives. The analysis of frequency variability during ventricular fibrillation has yielded inconsistent results. We used an experimental model of ventricular fibrillation, with a short timescale, to analyze variations in frequency and their associated spatial distribution. Methods. Epicardial recordings of ventricular fibrillation were made in 10 perfused isolated rabbit heart preparations using a multiple electrode system (i.e., 240 unipolar electrodes). Both spectral and time-frequency analysis were used to derive the dominant frequency in the anterolateral wall of the left ventricle. Results. Linear regression analysis showed that there was a good correlation between …