Introduction: Total volume of distribution (V(T)) determined by graphical analysis (GA) of PET data suffers from a noise-dependent bias. Likelihood estimation in GA (LEGA) eliminates this bias at the region of interest (ROI) level, but at voxel noise levels, the variance of estimators is high, yielding noisy images. We hypothesized that incorporating LEGA V(T) estimation in a Bayesian framework would shrink estimators towards prior means, reducing variability and producing meaningful and useful voxel images.
Methods: Empirical Bayesian estimation in GA (EBEGA) determines prior distributions using a two-step k-means clustering of voxel activity. Results obtained on eight [(11)C]-DASB studies are compared with estimators computed by ROI-based LEGA.
Results: EBEGA reproduces the results obtained by ROI LEGA while providing low-variability V(T) images. Correlation coefficients between average EBEGA V(T) and corresponding ROI LEGA V(T) range from 0.963 to 0.994.
Conclusions: EBEGA is a fully automatic and general approach that can be applied to voxel-level V(T) image creation and to any modeling strategy to reduce voxel-level estimation variability without prefiltering of the PET data.
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http://dx.doi.org/10.1016/j.nucmedbio.2010.02.004 | DOI Listing |
Cognition
January 2025
Institute of Systems and Information Engineering, University of Tsukuba, Ibaraki 305-8573, Japan. Electronic address:
Pain perception is not solely determined by noxious stimuli, but also varies due to other factors, such as beliefs about pain and its uncertainty. A widely accepted theory posits that the brain integrates prediction of pain with noxious stimuli, to estimate pain intensity. This theory assumes that the estimated pain value is adjusted to minimize surprise, mathematically defined as errors between predictions and outcomes.
View Article and Find Full Text PDFTheor Appl Genet
January 2025
Horticultural Sciences Department, University of Florida, Gainesville, FL, 32611, USA.
In tetraploid F1 populations, traditional segregation distortion tests often inaccurately flag SNPs due to ignoring polyploid meiosis processes and genotype uncertainty. We develop tests that account for these factors. Genotype data from tetraploid F1 populations are often collected in breeding programs for mapping and genomic selection purposes.
View Article and Find Full Text PDFAging Clin Exp Res
January 2025
Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, 710054, Shaanxi, China.
Objective: This study aims to analyze adverse drug events (ADE) related to romosozumab from the second quarter of 2019 to the third quarter of 2023 from FAERS database.
Methods: The ADE data related to romosozumab from 2019 Q2 to 2023 Q3 were collected. After data normalization, four signal strength quantification algorithms were used: ROR (Reporting Odds Ratios), PRR (Proportional Reporting Ratios), BCPNN (Bayesian Confidence Propagation Neural Network), and EBGM (Empirical Bayesian Geometric Mean).
Mol Autism
January 2025
Department of Special Education, University of Haifa, Haifa, Israel.
Background: Alterations in sensory perception, a core phenotype of autism, are attributed to imbalanced integration of sensory information and prior knowledge during perceptual statistical (Bayesian) inference. This hypothesis has gained momentum in recent years, partly because it can be implemented both at the computational level, as in Bayesian perception, and at the level of canonical neural microcircuitry, as in predictive coding. However, empirical investigations have yielded conflicting results with evidence remaining limited.
View Article and Find Full Text PDFJ Genet Genomics
January 2025
Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA. Electronic address:
The QTL by environment interaction (Q×E) effect is hard to detect because there are no effective ways to control the genomic background. In this study, we propose a novel linear mixed model that simultaneously analyzes data from multiple environments to detect Q×E interactions. This model incorporates two different kinship matrices derived from the genome-wide markers to control both main and interaction polygenic background effects.
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