Search results for "morphometry"

Examining stability of independent component analysis based on coefficient and component matrices for voxel-based morphometry of structural magnetic …

2018

Independent component analysis (ICA) on group-level voxel-based morphometry (VBM) produces the coefficient matrix and the component matrix. The former contains variability among multiple subjects for further statistical analysis, and the latter reveals spatial maps common for all subjects. ICA algorithms converge to local optimization points in practice and the mostly applied stability investigation approach examines the stability of the extracted components. We found that the practically stable components do not guarantee to produce the practically stable coefficients of ICA decomposition for the further statistical analysis. Consequently, we proposed a novel approach including two steps: …

Comparison of Diffusion MRI Acquisition Protocols for the In Vivo Characterization of the Mouse Spinal Cord: Variability Analysis and Application to …

2016

Diffusion-weighted Magnetic Resonance Imaging (dMRI) has relevant applications in the microstructural characterization of the spinal cord, especially in neurodegenerative diseases. Animal models have a pivotal role in the study of such diseases; however, in vivo spinal dMRI of small animals entails additional challenges that require a systematical investigation of acquisition parameters. The purpose of this study is to compare three acquisition protocols and identify the scanning parameters allowing a robust estimation of the main diffusion quantities and a good sensitivity to neurodegeneration in the mouse spinal cord. For all the protocols, the signal-to-noise and contrast-to noise ratios…

The intravascular ultrasound morphometry of iliac veins in subjects without severe chronic venous insufficiency and its implications for treatment in…

2019

Objectives The purpose of this study is to report the intravascular ultrasound morphometry of iliac veins and its relation to demographic and anthropometric factors in subjects without chronic venous insufficiency. Methods Thirty-three patients, without chronic venous insufficiency – qualified to great saphenous vein stripping due to unilateral, primary varicose veins – participated in the study. During the surgery, left and right external iliac veins, common iliac veins and inferior vena cava were interrogated with intravascular ultrasound. The morphometric analysis included measurement of a cross-sectional area at normal, non-stenosed vein segments (ref-CSA) and at the point of the most p…

Mitochondrial DNA Gene Diversity and Morphological Variability of the Common Vole (Microtus arvalis) in France

2006

International audience

Taxonomy and conservation ofPancratium maritimum(Amaryllidaceae) and relatives in the Central Mediterranean

2015

Pancratium maritimum L. (Amaryllidaceae) is a geophyte occurring in the Mediterranean region, from the Black Sea to part of the Atlantic coast. This plant is receiving much attention from the international scientific community due to its value as a bioindicator, the potential industrial value of its chemical compounds, and its use as a commercial ornamental plant. Plant morphometry and sequences of three plastid DNA regions (rbcL, matK, trnH-psbA) were used to assess the phenotypic and genetic variability of this taxon and its closest congeneric species (in particular Pancratium linosae, from the volcanic island of Linosa) in the Central Mediterranean (Sicily, Tunisia and surrounding island…

Multivariate karyomorphometric analysis and taxonomic implications in Allium sect. Cupanioscordum (Amaryllidaceae)

2015

Significant karyological variation occurs amongst different taxa/populations in the A. cupani group. The ancestral diploid chromosome complement is 2n = 16 (x = 8), but populations of A. cupani s.l. also exhibit dysploidy (2n = 14), polyploidy (2n = 4x = 32, 2n = 4x = 30). These different chromosome assets are associated to specific diagnostic morphological characters and well-defined eco-geographical patterns, which cluster different taxa and populations in 5 series (Brullo&al. 1995, 2008). In order to test the impact of inter-and intra-specific variation in chromosome structure on the systematic treatment of the A. cupani group and its contribution to allow comparing and understanding aff…

EARLY HOLOCENE HUMAN DISPERSAL IN SICILY, ANALYSIS OF CRANIAL REMAINS FROM FAVIGNANA (EGADI ISLANDS)

2009

Effect of antipsychotic drugs on cortical thickness. A randomized controlled one-year follow-up study of haloperidol, risperidone and olanzapine.

2012

Abstract Background Imaging evidence indicates that brain alterations are primary to the full-blown onset of schizophrenia and seem to progress across time. The potential effects of antipsychotic medication on brain structure represent a key factor in understanding brain changes in psychosis. We aimed to investigate the effects of low doses of haloperidol, risperidone and olanzapine on cortical thickness. Method We investigated the effects of risperidone (N = 16), olanzapine (N = 18) and low doses of haloperidol (N = 18) in cortical thickness changes during 1-year follow-up period in a large and heterogeneous sample of schizophrenia spectrum patients. The relationship between cortical thick…

Neuroanatomical changes in early Parkinson’s disease with mild cognitive impairment: a VBM study; the Parkinson’s Disease Cognitive Impairment Study …

2021

Introduction: Mild cognitive impairment (MCI) is common in Parkinson’s disease (PD), but the underlying pathological mechanism has not been fully understood. Voxel-based morphometry could be used to evaluate regional atrophy and its relationship with cognitive performances in early PD-MCI. Patients and Methods: One hundred and six patients with PD were recruited from a larger cohort of patients, the Parkinson’s Disease Cognitive Impairment Study (PaCoS). Subject underwent a T1-3D MRI and a complete clinical and neuropsychological evaluation. Patients were divided into PD with normal cognition (PD-NC) and PD-MCI according to the MDS level II criteria–modified for PD-MCI. A subgroup of early …

Geomorphological and Morphometric Analyses of the Catanzaro Trough (Central Calabrian Arc, Southern Italy): Seismotectonic Implications

2022

In this work, we investigated the landscape response to the recent activity of the faults affecting the Catanzaro Trough, a seismically active structural basin that developed transversally to the Calabrian Arc (Southern Italy) during the Neogene–Quaternary. We carried out a geomorphological and morphometric study of the drainage networks and basins intercepted by the Quaternary faults that were previously mapped through remote and field analyses. The study confirms the occurrence north of the Catanzaro Trough of a WNW–ESE-oriented left-lateral strike-slip fault system (here named the South Sila Piccola Fault System), which accommodates the differential SE-ward migration of the u…