Search results for "Standard deviation"
showing 10 items of 282 documents
A meta-analysis of the validity of FFQ targeted to adolescents.
2015
AbstractObjectiveThe present work is aimed at meta-analysing validity studies of FFQ for adolescents, to investigate their overall accuracy and variables that can affect it negatively.DesignA meta-analysis of sixteen original articles was performed within the ASSO Project (Adolescents and Surveillance System in the Obesity prevention).SettingThe articles assessed the validity of FFQ for adolescents, compared with food records or 24 h recalls, with regard to energy and nutrient intakes.SubjectsPearson’s or Spearman’s correlation coefficients, means/standard deviations, kappa agreement, percentiles and mean differences/limits of agreement (Bland–Altman method) were extracted. Pooled estimates…
Repeatability of in-vitro optical quality measurements of intraocular lenses with a deflectometry technique effect of the toricity
2018
Aim To evaluate the repeatability of an optical device for measuring the Zernike coefficients of toric intraocular lenses (IOLs) and assess whether its toricity has any impact in its repeatability. Methods An experienced technician used the NIMO TR1504 to measure the Zernike coefficients 30 times for an aperture of 4.50 mm for all lenses included. The IOLs included were divided into two group: toric and non-toric ones. The cylindrical powers of the toric lenses included in the present study were 1.00, 1.50, 2.25, 3.00 and 3.75 D. Finally, the repeatability of the NIMO TR1504 was described in terms of within subject standard deviation (Sw) and repeatability limit. Results The Sw was smaller …
Observation and Measurement of Forward Proton Scattering in Association with Lepton Pairs Produced via the Photon Fusion Mechanism at ATLAS
2020
The observation of forward proton scattering in association with lepton pairs (eþe− þ p or μþμ− þ p) produced via photon fusion is presented. The scattered proton is detected by the ATLAS Forward Proton spectrometer, while the leptons are reconstructed by the central ATLAS detector. Proton-proton collision data recorded in 2017 at a center-of-mass energy of ffiffiffi s p ¼ 13 TeV are analyzed, corresponding to an integrated luminosity of 14.6 fb−1. A total of 57 (123) candidates in the ee þ p (μμ þ p) final state are selected, allowing the background-only hypothesis to be rejected with a significance exceeding 5 standard deviations in each channel. Proton-tagging techniques are introduced f…
Do ventilatory parameters influence outcome in patients with severe acute respiratory infection? Secondary analysis of an international, multicentre1…
2021
Purpose: To investigate the possible association between ventilatory settings on the first day of invasive mechanical ventilation (IMV) and mortality in patients admitted to the intensive care unit (ICU) with severe acute respiratory infection (SARI). Materials and methods: In this pre-planned sub-study of a prospective, multicentre observational study, 441 patients with SARI who received controlled IMV during the ICU stay were included in the analysis. Results: ICU and hospital mortality rates were 23.1 and 28.1%, respectively. In multivariable analysis, tidal volume and respiratory rate on the first day of IMV were not associated with an increased risk of death; however, higher driving pr…
Solid sampling Fourier transform infrared determination of Mancozeb in pesticide formulations
2004
Abstract A series of approaches have been assayed for FTIR determination of Mancozeb in several solid commercial fungicides using different calibration strategies. The simplest procedure was based on the use of the ratio between the absorbance of a characteristic band of Mancozeb and that of a KSCN internal standard measured in the FTIR spectra obtained from KBr pellets. It was employed the quotient between peak height absorbance values at 1525 cm−1 for Mancozeb and 2070 cm−1 for KSCN. In these conditions a precision as relative standard deviation (RSD) of 0.6% and a relative accuracy error of 0.8% (w/w) were found. For complex formulations, containing other compounds with characteristic ab…
Effect of cooking on oxalate content of pulses using an enzymatic procedure.
2003
An enzymatic method proposed for the determination of oxalate in urine is adapted for the estimation of soluble oxalate content in beans, chickpeas and lentils. Oxalates were extracted in water by refluxing for 2 h. The method is based on the oxidation of oxalate by the oxidase and the determination of the resulting hydrogen peroxide, which in presence of peroxidase, 3-methyl-2 benzotiazinolone and 3-dimethylamino benzoic, gives an indamine compound with an absorption maximum at 590 nm. The linearity (from 0.015 to 0.6 mM) of the method is adequate to the analysis of oxalate contents in pulses, and the inter-day precision of the method expressed as relative standard deviation was good (3.01…
Personal Gains from Materials in Social Networks
2021
Importance of gains from social networks is analyzed in great extent in many countries by many researchers as social networks are reaching more and more importance. Research methods applied: analysis of scientific publications, survey of social network users on gains from materials in social networks. For evaluations by respondents in survey it was used evaluation scale 1–6 as it is used in grading system in Germany. Survey data results are analyzed by indicators of descriptive statistics – indicators of central tendency or location: arithmetic mean, median, mode and indicator of variability – standard deviation. In the research there were found differences by countries in use of social net…
Within subject variability of HDL-cholesterol in HIV-infected patients
2019
Background and objective: Within-subject variability of cardiovascular risk factors may influence the development of cardiovascular disease. We aimed to improve knowledge on HDL-cholesterol variability and its clinical significance in HIV-infected patients, a population at high risk of cardiovascular disease.Methods: This was a cohort study to quantify the variability of HDL-cholesterol between two consecutive visits and to determine factors associated with such variability, in a group of HIV-infected patients.Results: A total of 307 patients were included, mean ± standard deviation of their age was 45.1 ± 8.5 years, and 225 of them (73.3%) were male. The absolute difference (after squaring…
Repeatability assessment of biometric measurements with different refractive states and age using a swept-source biometer
2018
Background We aim to assess if refractive error or age may influence the repeatability of measurements using a swept-source biometer. Methods A total of 61 subjects were evaluated with IOLMaster 700 acquiring measurements of axial length (AL), central corneal thickness (CCT), white-to-white distance (WTW), anterior aqueous depth (AQD), lens thickness (LT), and keratometry (K) readings. Repeatability was evaluated classifying the sample according to the refractive state and age by the calculation of the within-subject standard deviation (Sw), coefficient of repeatability, and intraclass correlation coefficient. Results Very similar Sw was acquired among groups for AL, CCT, and WTW. Differenc…
Quantifying foot placement variability and dynamic stability of movement to assess control mechanisms during forward and lateral running
2015
Research has indicated that human walking is more unstable in the secondary, rather than primary plane of progression. However, the mechanisms of controlling dynamic stability in different planes of progression during running remain unknown. The aim of this study was to compare variability (standard deviation and coefficient of variation) and dynamic stability (sample entropy and local divergence exponent) in anterior–posterior and medio-lateral directions in forward and lateral running patterns. For this purpose, fifteen healthy, male participants ran in a forward and lateral direction on a treadmill at their preferred running speeds. Coordinate data of passive reflective markers attached …