We describe a method to estimate embedding dimension from a time series. This method includes an estimate of the probability that the dimension estimate is valid. Such validity estimates are not common in algorithms for calculating the properties of dynamical systems. The algorithm described here compares the eigenvalues of covariance matrices created from an embedded signal to the eigenvalues for a covariance matrix of a Gaussian random process with the same dimension and number of points. A statistical test gives the probability that the eigenvalues for the embedded signal did not come from the Gaussian random process.
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http://dx.doi.org/10.1063/1.4975063 | DOI Listing |
Syst Biol
January 2025
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
As lineages become separated in time, they are expected to accumulate mutational (or developmental-genetic) differences that influence the macroevolutionary trajectories of those lineages even under similar environmental conditions. Here, we compare the dynamics of phenotypic evolution in radiations of scincid lizards from Australia and Madagascar that are separated by more than 100 million years of independent evolution and show rampant phenotypic parallelism. We collected linear measurements of the skull, limbs, and limb girdles from micro-CT scans of 94 Australian and 29 Malagasy species.
View Article and Find Full Text PDFMed Phys
January 2025
Department of Nuclear Medicine and Medical Physics, Karolinska University Hospital, Stockholm, Sweden.
Background: Modern reconstruction algorithms for computed tomography (CT) can exhibit nonlinear properties, including non-stationarity of noise and contrast dependence of both noise and spatial resolution. Model observers have been recommended as a tool for the task-based assessment of image quality (Samei E et al., Med Phys.
View Article and Find Full Text PDFHum Brain Mapp
January 2025
Queen Square Multiple Sclerosis Centre, Department of Neuroinflammation, UCL Queen Square Institute of Neurology, University College London, London, UK.
Disruptions to brain networks, measured using structural (sMRI), diffusion (dMRI), or functional (fMRI) MRI, have been shown in people with multiple sclerosis (PwMS), highlighting the relevance of regions in the core of the connectome but yielding mixed results depending on the studied connectivity domain. Using a multilayer network approach, we integrated these three modalities to portray an enriched representation of the brain's core-periphery organization and explore its alterations in PwMS. In this retrospective cross-sectional study, we selected PwMS and healthy controls with complete multimodal brain MRI acquisitions from 13 European centers within the MAGNIMS network.
View Article and Find Full Text PDFSchizophrenia (Heidelb)
December 2024
Section of Psychiatry, Laboratory of Molecular and Translational Psychiatry, Unit of Treatment-Resistant Psychiatric Disorders, Department of Neuroscience, Reproductive Sciences and Dentistry, University of Naples "Federico II", School of Medicine, Naples Italy, Via Pansini 5, 80131, Naples, Italy.
Few studies using Positron Emission Tomography with F-fluorodeoxyglucose (F-FDG-PET) have examined the neurobiological basis of antipsychotic resistance in schizophrenia, primarily focusing on metabolic activity, with none investigating connectivity patterns. Here, we aimed to explore differential patterns of glucose metabolism between patients and controls (CTRL) through a graph theory-based approach and network comparison tests. PET scans with F-FDG were obtained by 70 subjects, 26 with treatment-resistant schizophrenia (TRS), 28 patients responsive to antipsychotics (nTRS), and 16 CTRL.
View Article and Find Full Text PDFInt J Obes (Lond)
December 2024
School of Mental Health, Zhejiang Provincial Clinical Research Center for Mental Health, The Affiliated Wenzhou Kangning Hospital, Wenzhou Medical University, Wenzhou, China.
Background: Overwhelming evidence showed that obesity was associated with abnormal brain functional networks. However, the changes of structural covariance networks (SCNs) based on cortical thickness (CT) and cortical surface area (CSA) in obesity is still unclear.
Methods: In this study, 243 young adults with obesity and matched 243 lean individuals were enrolled from the Human Connectome Project Release S1200 dataset.
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