Instrumental signals of samples cannot be compared and/or analysed directly if their concentrations are unknown. Differences in overall concentration need to be removed at the data normalization step. The choice of normalization method has a profound effect on the final results of data analysis, and especially on biomarker identification. One of the possible approaches to deal with the 'size effect' is to work with size-irrelevant (log) ratios instead of the original variables. In the presented study, the performance of log-ratio methods, namely pairwise log-ratio (plr) and centered log-ratio (clr), is discussed for real and simulated data sets with different characteristics. It was found that the clr method can lead to distribution of local differences along an entire signal and as such, it should be avoided in all studies aiming to identify biomarkers.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.aca.2019.01.041 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
mRNA Expression of Mineralocorticoid and Glucocorticoid Receptors in Human and Mouse Sensory Neurons of the Dorsal Root Ganglia.
Anesth Analg
September 2024
From the Department of Anesthesiology, Pain Research Center, University of Cincinnati College of Medicine, Cincinnati, Ohio.
Background: Corticosteroid receptors, including mineralocorticoid receptor (MR) and glucocorticoid receptor (GR), play important roles in inflammatory pain in the dorsal root ganglion (DRG). Although it is widely known that activating the GR reduces inflammatory pain, it has recently been shown that MR activation contributes to pain and neuronal excitability in rodent studies. Moreover, little is known about the translation of this work to humans, or the mechanisms through which corticosteroid receptors regulate inflammatory pain.
View Article and Find Full Text PDFDoes the association between physical activity during work and leisure and blood pressure differ across sex? A cross-sectional compositional data analysis in a Danish population-based cohort.
BMC Public Health
November 2024
Department of Occupational and Social Medicine, Part of Copenhagen University Hospital, Holbaek Hospital, Gl. Ringstedvej 4B, Holbaek, 4300, Denmark.
Background: A proposed risk factor for cardiovascular disease is high occupational physical activity (OPA), which seems to increase blood pressure (BP), in contrast to leisure time physical activity. Increased BP may lead to hypertension that increase the risk of cardiovascular disease and premature death. Exposures to OPA differ across sex and also within occupational group.
View Article and Find Full Text PDFEnhancing ultrasonic attenuation images through multi-frequency coupling with total nuclear variation.
J Acoust Soc Am
October 2024
Laboratorio de Imágenes Médicas, Departamento de Ingenería, Pontificia Universidad Católica del Perú, San Miguel 15088, Peru.
Quantitative ultrasound is a non-invasive image modality that numerically characterizes tissues for medical diagnosis using acoustical parameters, such as the attenuation coefficient slope. A previous study introduced the total variation spectral log difference (TVSLD) method, which denoises spectral log ratios on a single-channel basis without inter-channel coupling. Therefore, this work proposes a multi-frequency joint framework by coupling information across frequency channels exploiting structural similarities among the spectral ratios to increase the quality of the attenuation images.
View Article and Find Full Text PDFExploring Iberian ham triacylglycerols: Unraveling the influence of growing area, season, breed, and feeding patterns through innovative compositional data analysis.
Food Chem
October 2024
Instituto de la Grasa, Food Quality Departament, Campus Universitario Pablo de Olavide, Building, 46. Ctra. Sevilla-Utrera, km 1. 41013, Sevilla. Electronic address:
This research examined the triacylglycerol composition of Iberian pig hams from Sevilla province, focusing on the influence of growing area, season, breed, age, montanera duration, and feeding types. Compositional data analysis (CoDA) tools and standard multivariate statistics were employed to analyse the original and CoDa-transformed data. ANOVA (ilr) and ANCOVA (log ratios) revealed significant effects of season, feeding type, and towns on triacylglycerol profiles, while montanera showed limited or no effect.
View Article and Find Full Text PDFSocioeconomic gradients in 24-hour movement patterns across weekends and weekdays in a working-age sample: evidence from the 1970 British Cohort Study.
J Epidemiol Community Health
July 2024
Institute of Sport, Exercise and Health, UCL, London, UK.
Article Synopsis
- - The study examined how socioeconomic factors like education, occupation, income, and deprivation influence movement behaviors in nearly 4,900 individuals aged 46, using accelerometers to track their activity over a week.
- - Results showed that individuals with higher education levels engaged in more exercise-like activities during the week and on weekends, while those without formal qualifications demonstrated different patterns of standing and walking on weekdays versus weekends.
- - Overall, the research highlights significant socioeconomic disparities in daily movement habits, indicating that these differences vary between weekdays and weekends, which may contribute to health inequalities.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!