keyword
MENU ▼
Read by QxMD icon Read
search

tensor network

keyword
https://www.readbyqxmd.com/read/28337409/network-degeneration-and-dysfunction-in-presymptomatic-c9orf72-expansion-carriers
#1
Suzee E Lee, Ana C Sias, Maria Luisa Mandelli, Jesse A Brown, Alainna B Brown, Anna M Khazenzon, Anna A Vidovszky, Theodore P Zanto, Anna M Karydas, Mochtar Pribadi, Deepika Dokuru, Giovanni Coppola, Dan H Geschwind, Rosa Rademakers, Maria Luisa Gorno-Tempini, Howard J Rosen, Bruce L Miller, William W Seeley
Hexanucleotide repeat expansions in C9ORF72 are the most common known genetic cause of familial and sporadic frontotemporal dementia and amyotrophic lateral sclerosis. Previous work has shown that patients with behavioral variant frontotemporal dementia due to C9ORF72 show salience and sensorimotor network disruptions comparable to those seen in sporadic behavioral variant frontotemporal dementia, but it remains unknown how early in the lifespan these and other changes in brain structure and function arise...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28334875/white-matter-changes-in-paediatric-multiple-sclerosis-and-monophasic-demyelinating-disorders
#2
Giulia Longoni, Robert A Brown, Parya MomayyezSiahkal, Colm Elliott, Sridar Narayanan, Amit Bar-Or, Ruth Ann Marrie, E Ann Yeh, Massimo Filippi, Brenda Banwell, Douglas L Arnold
Most children who experience an acquired demyelinating syndrome of the central nervous system will have a monophasic disease course, with no further clinical or radiological symptoms. A subset will be diagnosed with multiple sclerosis, a life-long disorder. Using linear mixed effects models we examined longitudinal diffusion properties of normal-appearing white matter in 505 serial scans of 132 paediatric participants with acquired demyelinating syndromes followed for a median of 4.4 years, many from first clinical presentation, and 106 scans of 80 healthy paediatric participants...
March 14, 2017: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/28330962/distinct-white-matter-alterations-following-severe-stroke-longitudinal-dti-study-in-neglect
#3
Roza M Umarova, Lena Beume, Marco Reisert, Christoph P Kaller, Stefan Klöppel, Irina Mader, Volkmar Glauche, Valerij G Kiselev, Marco Catani, Cornelius Weiller
OBJECTIVE: To distinguish white matter remodeling directly induced by stroke lesion from that evoked by remote network dysfunction, using spatial neglect as a model. METHODS: We examined 24 visual neglect/extinction patients and 17 control patients combining comprehensive analyses of diffusion tensor metrics and global fiber tracking with neuropsychological testing in the acute (6.3 ± 0.5 days poststroke) and chronic (134 ± 7 days poststroke) stroke phases. RESULTS: Compared to stroke controls, patients with spatial neglect/extinction displayed longitudinal white matter alterations with 2 defining signatures: (1) perilesional degenerative changes characterized by congruently reduced fractional anisotropy and increased radial diffusivity (RD), axial diffusivity, and mean diffusivity, all suggestive of direct axonal damage by lesion and therefore nonspecific for impaired attention network and (2) transneuronal changes characterized by an increased RD in contralesional frontoparietal and bilateral occipital connections, suggestive of primary periaxonal involvement; these changes were distinctly related to the degree of unrecovered neglect symptoms in chronic stroke, hence emerging as network-specific alterations...
March 22, 2017: Neurology
https://www.readbyqxmd.com/read/28325573/brain-network-characteristics-separating-individuals-at-clinical-high-risk-for-psychosis-into-normality-or-psychosis
#4
Soo-Hee Choi, Sunghyon Kyeong, Kang Ik K Cho, Je-Yeon Yun, Tae Young Lee, Hye Yoon Park, Sung Nyun Kim, Jun Soo Kwon
We aimed to separate individuals at clinical high risk for psychosis (CHR) state into subgroups according to neurobiological characteristics using structural and functional network constructs and examine their clinical characteristics. Structural diffusion tensor imaging and resting-state functional magnetic resonance imaging were performed in 61 healthy controls (HC), 57 individuals at CHR and 29 patients with schizophrenia (SZ). The main outcome was a likelihood ratio calculated from measures of structural and functional network efficiencies, coupling strength of structural and functional networks, and a disease-specific data analysis, resulting in the most probable classification of CHR into HC or SZ...
March 18, 2017: Schizophrenia Research
https://www.readbyqxmd.com/read/28316772/neural-circuitry-at-age-6%C3%A2-months-associated-with-later-repetitive-behavior-and-sensory-responsiveness-in-autism
#5
Jason J Wolff, Meghan R Swanson, Jed T Elison, Guido Gerig, John R Pruett, Martin A Styner, Clement Vachet, Kelly N Botteron, Stephen R Dager, Annette M Estes, Heather C Hazlett, Robert T Schultz, Mark D Shen, Lonnie Zwaigenbaum, Joseph Piven
BACKGROUND: Restricted and repetitive behaviors are defining features of autism spectrum disorder (ASD). Under revised diagnostic criteria for ASD, this behavioral domain now includes atypical responses to sensory stimuli. To date, little is known about the neural circuitry underlying these features of ASD early in life. METHODS: Longitudinal diffusion tensor imaging data were collected from 217 infants at high familial risk for ASD. Forty-four of these infants were diagnosed with ASD at age 2...
2017: Molecular Autism
https://www.readbyqxmd.com/read/28315957/right-sided-dominance-of-the-bilateral-vestibular-system-in-the-upper-brainstem-and-thalamus
#6
Marianne Dieterich, V Kirsch, T Brandt
MRI diffusion tensor imaging tractography was performed on the bilateral vestibular brainstem pathways, which run from the vestibular nuclei via the paramedian and posterolateral thalamic subnuclei to the parieto-insular vestibular cortex. Twenty-one right-handed healthy subjects participated. Quantitative analysis revealed a rope-ladder-like system of vestibular pathways in the brainstem with crossings at pontine and mesencephalic levels. Three structural types of right-left fiber distributions could be delineated: (1) evenly distributed pathways at the lower pontine level from the vestibular nuclei to the pontine crossing, (2) a moderate, pontomesencephalic right-sided lateralization between the pontine and mesencephalic crossings, and (3) a further increase of the right-sided lateralization above the mesencephalic crossing leading to the thalamic vestibular subnuclei...
March 18, 2017: Journal of Neurology
https://www.readbyqxmd.com/read/28294464/assessing-connectivity-related-injury-burden-in-diffuse-traumatic-brain-injury
#7
Berkan Solmaz, Birkan Tunç, Drew Parker, John Whyte, Tessa Hart, Amanda Rabinowitz, Morgan Rohrbach, Junghoon Kim, Ragini Verma
Many of the clinical and behavioral manifestations of traumatic brain injury (TBI) are thought to arise from disruption to the structural network of the brain due to diffuse axonal injury (DAI). However, a principled way of summarizing diffuse connectivity alterations to quantify injury burden is lacking. In this study, we developed a connectome injury score, Disruption Index of the Structural Connectome (DISC), which summarizes the cumulative effects of TBI-induced connectivity abnormalities across the entire brain...
March 15, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28294147/criticality-enhanced-magnetocaloric-effect-in-quantum-spin-chain-material-copper-nitrate
#8
Jun-Sen Xiang, Cong Chen, Wei Li, Xian-Lei Sheng, Na Su, Zhao-Hua Cheng, Qiang Chen, Zi-Yu Chen
In this work, a systematic study of Cu(NO3)2·2.5 H2O (copper nitrate hemipentahydrate, CN), an alternating Heisenberg antiferromagnetic chain model material, is performed with multi-technique approach including thermal tensor network (TTN) simulations, first-principles calculations, as well as magnetization measurements. Employing a cutting-edge TTN method developed in the present work, we verify the couplings J = 5.13 K, α = 0.23(1) and Landé factors g∥= 2.31, g⊥ = 2.14 in CN, with which the magnetothermal properties have been fitted strikingly well...
March 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28293484/structural-and-functional-hyperconnectivity-within-the-sensorimotor-system-in-xenomelia
#9
Jürgen Hänggi, Deborah A Vitacco, Leonie M Hilti, Roger Luechinger, Bernd Kraemer, Peter Brugger
INTRODUCTION: Xenomelia is a rare condition characterized by the persistent and compulsive desire for the amputation of one or more physically healthy limbs. We highlight the neurological underpinnings of xenomelia by assessing structural and functional connectivity by means of whole-brain connectome and network analyses of regions previously implicated in empirical research in this condition. METHODS: We compared structural and functional connectivity between 13 xenomelic men with matched controls using diffusion tensor imaging combined with fiber tractography and resting state functional magnetic resonance imaging...
March 2017: Brain and Behavior
https://www.readbyqxmd.com/read/28293162/ensemble-classification-of-alzheimer-s-disease-and-mild-cognitive-impairment-based-on-complex-graph-measures-from-diffusion-tensor-images
#10
Ashkan Ebadi, Josué L Dalboni da Rocha, Dushyanth B Nagaraju, Fernanda Tovar-Moll, Ivanei Bramati, Gabriel Coutinho, Ranganatha Sitaram, Parisa Rashidi
The human brain is a complex network of interacting regions. The gray matter regions of brain are interconnected by white matter tracts, together forming one integrative complex network. In this article, we report our investigation about the potential of applying brain connectivity patterns as an aid in diagnosing Alzheimer's disease and Mild Cognitive Impairment (MCI). We performed pattern analysis of graph theoretical measures derived from Diffusion Tensor Imaging (DTI) data representing structural brain networks of 45 subjects, consisting of 15 patients of Alzheimer's disease (AD), 15 patients of MCI, and 15 healthy subjects (CT)...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28291264/abnormal-white-matter-structural-connectivity-in-adults-with-obsessive-compulsive-disorder
#11
J Gan, M Zhong, J Fan, W Liu, C Niu, S Cai, L Zou, Ya Wang, Yi Wang, C Tan, R C K Chan, X Zhu
Obsessive-compulsive disorder (OCD) is a complex and severe psychiatric disorder whose pathogenesis is not fully understood. Recent studies have shown white matter (WM) alterations in adults with OCD, but the results have been inconsistent. The present study investigated WM structure in OCD patients with the hypothesis that large-scale brain networks may be disrupted in OCD. A total of 24 patients with OCD and 23 healthy controls (HCs) were scanned with diffusion tensor imaging. A tract-based spatial statistics (TBSS) approach was used to detect differences across the whole brain in patients with OCD vs HCs; post hoc fiber tractography was applied to characterize developmental differences between the two groups...
March 14, 2017: Translational Psychiatry
https://www.readbyqxmd.com/read/28290074/abnormal-brain-white-matter-network-in-young-smokers-a-graph-theory-analysis-study
#12
Yajuan Zhang, Min Li, Ruonan Wang, Yanzhi Bi, Yangding Li, Zhang Yi, Jixin Liu, Dahua Yu, Kai Yuan
Previous diffusion tensor imaging (DTI) studies had investigated the white matter (WM) integrity abnormalities in some specific fiber bundles in smokers. However, little is known about the changes in topological organization of WM structural network in young smokers. In current study, we acquired DTI datasets from 58 male young smokers and 51 matched nonsmokers and constructed the WM networks by the deterministic fiber tracking approach. Graph theoretical analysis was used to compare the topological parameters of WM network (global and nodal) and the inter-regional fractional anisotropy (FA) weighted WM connections between groups...
March 13, 2017: Brain Imaging and Behavior
https://www.readbyqxmd.com/read/28290071/structural-connectivity-in-spatial-attention-network-reconstruction-from-left-hemispatial-neglect
#13
Takaaki Hattori, Kenji Ito, Chika Nakazawa, Yoshiyuki Numasawa, Mayumi Watanabe, Shigeki Aoki, Hidehiro Mizusawa, Sumio Ishiai, Takanori Yokota
Left hemispatial neglect (neglect) is an impaired state of spatial attention. We aimed to reconstruct structural connectivity in the spatial attention network and to identify disconnection patterns underlying neglect. We enrolled 59 right-handed patients who had their first-ever infarction in the right hemisphere and classified them into neglect group (34 patients with neglect) and control group (25 patients without neglect). The neglect group was further subcategorized into 6 subgroups based on infarcted vascular territories...
March 13, 2017: Brain Imaging and Behavior
https://www.readbyqxmd.com/read/28289940/the-effect-of-hippocampal-function-volume-and-connectivity-on-posterior-cingulate-cortex-functioning-during-episodic-memory-fmri-in-mild-cognitive-impairment
#14
Janne M Papma, Marion Smits, Marius de Groot, Francesco U Mattace Raso, Aad van der Lugt, Henri A Vrooman, Wiro J Niessen, Peter J Koudstaal, John C van Swieten, Frederik M van der Veen, Niels D Prins
OBJECTIVES: Diminished function of the posterior cingulate cortex (PCC) is a typical finding in early Alzheimer's disease (AD). It is hypothesized that in early stage AD, PCC functioning relates to or reflects hippocampal dysfunction or atrophy. The aim of this study was to examine the relationship between hippocampus function, volume and structural connectivity, and PCC activation during an episodic memory task-related fMRI study in mild cognitive impairment (MCI). METHOD: MCI patients (n = 27) underwent episodic memory task-related fMRI, 3D-T1w MRI, 2D T2-FLAIR MRI and diffusion tensor imaging...
March 13, 2017: European Radiology
https://www.readbyqxmd.com/read/28269510/network-effects-and-pathways-in-deep-brain-stimulation-in-parkinson-s-disease
#15
N Koirala, V Fleischer, O Granert, G Deuschl, M Muthuraman, S Groppa
Deep brain stimulation of subthalamic nucleus (STN-DBS) became a standard therapeutic option in Parkinson's disease (PD), even though the underlying modulated network of STN-DBS is still poorly described. Probabilistic tractography and connectivity analysis as derived from diffusion tensor imaging (DTI) were performed together with modelling of implanted electrode positions and linked postoperative clinical outcome. Fifteen patients with idiopathic PD without dementia were selected for DBS treatment. After pre-processing, probabilistic tractography was run from cortical and subcortical seeds of the hypothesized network to targets represented by the positions of the active DBS contacts...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28269498/detecting-spatially-highly-resolved-network-modules-a-multi-subject-approach
#16
Britta Pester, Feliberto de la Cruz, Karl-Jurgen Bar, Herbert Witte, Lutz Leistritz
The connectivity analysis of spatially highly resolved data results in networks comprising an immense number of nodes and edges which makes it hard or even impossible to investigate the high-dimensional (HD) network as a whole. A solution to this problem is offered by a connectivity-based segmentation of the HD networks into subsets of functionally similar nodes (network modules) that exhibit pronounced interaction. However, an investigation of the results at group level is problematic as identified modules are not assigned to each other across different subjects...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28266655/intact-sensory-motor-network-structure-and-function-in-far-from-onset-premanifest-huntington-s-disease
#17
Martin Gorges, Hans-Peter Müller, Isabella Maria Sophie Mayer, Gesa Sophie Grupe, Thomas Kammer, Georg Grön, Jan Kassubek, G Bernhard Landwehrmeyer, Robert Christian Wolf, Michael Orth
Structural and functional changes attributable to the neurodegenerative process in Huntington's disease (HD) may be evident in HTT CAG repeat expansion carriers before the clinical manifestations of HD. It remains unclear, though, how far from motor onset a consistent signature of the neurodegenerative process in HD can be detected. Twelve far from onset preHD and 22 age-matched healthy control participants underwent volumetric structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), and resting-state functional MRI (11 preHD, 22 controls) as well as electrophysiological measurements (12 preHD, 13 controls)...
March 7, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28265121/brain-structural-and-functional-signatures-of-impulsive-compulsive-behaviours-in-parkinson-s-disease
#18
F Imperiale, F Agosta, E Canu, V Markovic, A Inuggi, M Jecmenica-Lukic, A Tomic, M Copetti, S Basaia, V S Kostic, M Filippi
This study assessed brain structural and functional alterations in patients with Parkinson's disease and impulsive-compulsive behaviours (PD-ICB) compared with controls and PD no-ICB cases. Eighty-five PD patients (35 PD-ICB) and 50 controls were recruited. All subjects underwent three-dimensional T1-weighted, diffusion tensor (DT), and resting state functional magnetic resonance imaging (RS fMRI). We assessed cortical thickness with surface-based morphometry, subcortical volumes using FIRST, DT MRI metrics using region of interest and tractography approaches, and RS fMRI using a model free approach...
March 7, 2017: Molecular Psychiatry
https://www.readbyqxmd.com/read/28263927/the-ivim-signal-in-the-healthy-cerebral-gray-matter-a-play-of-spherical-and-non-spherical-components
#19
Tim Finkenstaedt, Markus Klarhoefer, Christian Eberhardt, Anton S Becker, Gustav Andreisek, Andreas Boss, Cristina Rossi
The intra-voxel incoherent motion (IVIM) model assumes that blood flowing in isotropically distributed capillary segments induces a phase dispersion of the MR signal, which increases the signal attenuation in diffusion-weighted images. However, in most tissue types the capillary network has an anisotropic micro-architecture. In this study, we investigated the possibility to indirectly infer the anisotropy of the capillary network in the healthy cerebral gray matter by evaluating the dependence of the IVIM signal from the direction of the diffusion-encoding...
March 3, 2017: NeuroImage
https://www.readbyqxmd.com/read/28256850/density-induced-phase-transitions-in-the-schwinger-model-a-study-with-matrix-product-states
#20
Mari Carmen Bañuls, Krzysztof Cichy, J Ignacio Cirac, Karl Jansen, Stefan Kühn
We numerically study the zero temperature phase structure of the multiflavor Schwinger model at nonzero chemical potential. Using matrix product states, we reproduce analytical results for the phase structure for two flavors in the massless case and extend the computation to the massive case, where no analytical predictions are available. Our calculations allow us to locate phase transitions in the mass-chemical potential plane with great precision and provide a concrete example of tensor networks overcoming the sign problem in a lattice gauge theory calculation...
February 17, 2017: Physical Review Letters
keyword
keyword
92751
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"