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graph theory connectivity

Jilei Zhang, Jingjing Su, Mengxing Wang, Ying Zhao, Qi-Ting Zhang, Qian Yao, Haifeng Lu, Hui Zhang, Ge-Fei Li, Yi-Lan Wu, Yi-Sheng Liu, Feng-Di Liu, Mei-Ting Zhuang, Yan-Hui Shi, Tian-Yu Hou, Rong Zhao, Yuan Qiao, Jianqi Li, Jian-Ren Liu, Xiaoxia Du
Long-term headache attacks may cause human brain network reorganization in patients with migraine. In the current study, we calculated the topologic properties of functional networks based on the Brainnetome atlas using graph theory analysis in 29 female migraineurs without aura (MWoA) and in 29 female age-matched healthy controls. Compared with controls, female MWoA exhibited that the network properties altered, and the nodal centralities decreased/increased in some brain areas. In particular, the right posterior insula and the left medial superior occipital gyrus of patients exhibited significantly decreased nodal centrality compared with healthy controls...
December 4, 2017: Scientific Reports
Minji Lee, Robert D Sanders, Seul-Ki Yeom, Dong-Ok Won, Kwang-Suk Seo, Hyun Jeong Kim, Giulio Tononi, Seong-Whan Lee
Reliable electroencephalography (EEG) signatures of transitions between consciousness and unconsciousness under anaesthesia have not yet been identified. Herein we examined network changes using graph theoretical analysis of high-density EEG during patient-titrated propofol-induced sedation. Responsiveness was used as a surrogate for consciousness. We divided the data into five states: baseline, transition into unresponsiveness, unresponsiveness, transition into responsiveness, and recovery. Power spectral analysis showed that delta power increased from responsiveness to unresponsiveness...
December 1, 2017: Scientific Reports
Elzbieta Olejarczyk, Wojciech Jernajczyk
The present study evaluated brain connectivity using electroencephalography (EEG) data from 14 patients with schizophrenia and 14 healthy controls. Phase-Locking Value (PLV), Phase-Lag Index (PLI) and Directed Transfer Function (DTF) were calculated for the original EEG data and following current source density (CSD) transformation, re-referencing using the average reference electrode (AVERAGE) and reference electrode standardization techniques (REST). The statistical analysis of adjacency matrices was carried out using indices based on graph theory...
2017: PloS One
Shelli R Kesler, Arvind Rao, Douglas W Blayney, Ingrid A Oakley-Girvan, Meghan Karuturi, Oxana Palesh
We aimed to determine if resting state functional magnetic resonance imaging (fMRI) acquired at pre-treatment baseline could accurately predict breast cancer-related cognitive impairment at long-term follow-up. We evaluated 31 patients with breast cancer (age 34-65) prior to any treatment, post-chemotherapy and 1 year later. Cognitive testing scores were normalized based on data obtained from 43 healthy female controls and then used to categorize patients as impaired or not based on longitudinal changes. We measured clustering coefficient, a measure of local connectivity, by applying graph theory to baseline resting state fMRI and entered these metrics along with relevant patient-related and medical variables into random forest classification...
2017: Frontiers in Human Neuroscience
Meysam Siyah Mansoory, Mohammad Ali Oghabian, Amir Homayoun Jafari, Alireza Shahbabaie
Introduction: Graph theoretical analysis of functional Magnetic Resonance Imaging (fMRI) data has provided new measures of mapping human brain in vivo. Of all methods to measure the functional connectivity between regions, Linear Correlation (LC) calculation of activity time series of the brain regions as a linear measure is considered the most ubiquitous one. The strength of the dependence obligatory for graph construction and analysis is consistently underestimated by LC, because not all the bivariate distributions, but only the marginals are Gaussian...
September 2017: Basic and Clinical Neuroscience
Jeffrey N Browndyke, Miles Berger, Patrick J Smith, Todd B Harshbarger, Zachary A Monge, Viral Panchal, Tiffany L Bisanar, Donald D Glower, John H Alexander, Roberto Cabeza, Kathleen Welsh-Bohmer, Mark F Newman, Joseph P Mathew
OBJECTIVES: Older adults often display postoperative cognitive decline (POCD) after surgery, yet it is unclear to what extent functional connectivity (FC) alterations may underlie these deficits. We examined for postoperative voxel-wise FC changes in response to increased working memory load demands in cardiac surgery patients and nonsurgical controls. EXPERIMENTAL DESIGN: Older cardiac surgery patients (n = 25) completed a verbal N-back working memory task during MRI scanning and cognitive testing before and 6 weeks after surgery; nonsurgical controls with cardiac disease (n = 26) underwent these assessments at identical time intervals...
November 21, 2017: Human Brain Mapping
Neil P Oxtoby, Sara Garbarino, Nicholas C Firth, Jason D Warren, Jonathan M Schott, Daniel C Alexander
Model-based investigations of transneuronal spreading mechanisms in neurodegenerative diseases relate the pattern of pathology severity to the brain's connectivity matrix, which reveals information about how pathology propagates through the connectivity network. Such network models typically use networks based on functional or structural connectivity in young and healthy individuals, and only end-stage patterns of pathology, thereby ignoring/excluding the effects of normal aging and disease progression. Here, we examine the sequence of changes in the elderly brain's anatomical connectivity over the course of a neurodegenerative disease...
2017: Frontiers in Neurology
Yan Tang, Xue Xiao, Hua Xie, Chang-Min Wan, Li Meng, Zhen-Hua Liu, Wei-Hua Liao, Bei-Sha Tang, Ji-Feng Guo
Familial Parkinson's disease (PD) is often caused by mutation of a certain gene, while sporadic PD is associated with variants of genes which can influence the susceptibility to PD. The goal of this study was to investigate the difference between the two forms of PD in terms of brain abnormalities using resting-state functional MRI and graph theory. Thirty-one familial PD patients and 36 sporadic PD patients underwent resting-state functional MRI scanning. Frequency-dependent functional connectivity was calculated for each subject using wavelet-based correlations of BOLD signal over 246 brain regions from Brainnetome Atlas...
2017: Frontiers in Neuroanatomy
Stewart J Wiseman, Tom Booth, Stuart J Ritchie, Simon R Cox, Susana Muñoz Maniega, Maria Del C Valdés Hernández, David Alexander Dickie, Natalie A Royle, John M Starr, Ian J Deary, Joanna M Wardlaw, Mark E Bastin
OBJECTIVE: To assess brain structural connectivity in relation to cognitive abilities in healthy ageing, and the mediating effects of white matter hyper-intensity (WMH) volume. METHODS: MRI data were analysed in 558 members of the Lothian Birth Cohort 1936. Brains were segmented into 85 regions and combined with tractography to generate structural connectomes. WMH volume was quantified. Relationships between whole-brain connectivity, assessed using graph theory metrics, and four major domains of cognitive ability (visuospatial reasoning, verbal memory, information processing speed and crystallized ability) were investigated, as was the mediating effects of WMH volume on these relationships...
November 14, 2017: Human Brain Mapping
Vinzenz Fleischer, Angela Radetz, Dumitru Ciolac, Muthuraman Muthuraman, Gabriel Gonzalez-Escamilla, Frauke Zipp, Sergiu Groppa
Network science provides powerful access to essential organizational principles of the human brain. It has been applied in combination with graph theory to characterize brain connectivity patterns. In multiple sclerosis (MS), analysis of the brain networks derived from either structural or functional imaging provides new insights into pathological processes within the gray and white matter. Beyond focal lesions and diffuse tissue damage, network connectivity patterns could be important for closely tracking and predicting the disease course...
November 1, 2017: Neuroscience
Kenneth A Weber, Amy I Sentis, Olivia N Bernadel-Huey, Yufen Chen, Xue Wang, Todd B Parrish, Sean Mackey
The spinal cord has an active role in the modulation and transmission of the neural signals traveling between the body and the brain. Recent advancements in functional magnetic resonance imaging (fMRI) have made the in vivo examination of spinal cord function in humans now possible. This technology has been recently extended to the investigation of resting state functional networks in the spinal cord, leading to the identification of distinct patterns of spinal cord functional connectivity. In this study, we expand on the previous work and further investigate resting state cervical spinal cord functional connectivity in healthy participants (n = 15) using high resolution imaging coupled with both seed-based functional connectivity analyses and graph theory-based metrics...
November 1, 2017: Neuroscience
Ankush Bansal, Tiratha Raj Singh, Rajinder Singh Chauhan
For understanding complex biological systems, a systems biology approach, involving both the top-down and bottom-up analyses, is often required. Numerous system components and their connections are best characterised as networks, which are primarily represented as graphs, with several nodes connected at multiple edges. Inefficient network visualisation is a common problem related to transcriptomic and genomic datasets. In this article, we demonstrate an miRNA analysis framework with the help of Jatropha curcas healthy and disease transcriptome datasets, functioning as a pipeline derived from the graph theory universe, and discuss how the network theory, along with gene ontology (GO) analysis, can be used to infer biological properties and other important features of a network...
November 6, 2017: Scientific Reports
Atsuhiko Sugiyama, Daichi Sone, Noriko Sato, Yukio Kimura, Miho Ota, Norihide Maikusa, Tomoko Maekawa, Mikako Enokizono, Madoka Mori-Yoshimura, Yasushi Ohya, Satoshi Kuwabara, Hiroshi Matsuda
This study aimed to investigate abnormalities in structural covariance network constructed from gray matter volume in myotonic dystrophy type 1 (DM1) patients by using graph theoretical analysis for further clarification of the underlying mechanisms of central nervous system involvement. Twenty-eight DM1 patients (4 childhood onset, 10 juvenile onset, 14 adult onset), excluding three cases from 31 consecutive patients who underwent magnetic resonance imaging in a certain period, and 28 age- and sex- matched healthy control subjects were included in this study...
2017: PloS One
Elisabeth C Caparelli, Thomas J Ross, Hong Gu, Xia Liang, Elliot A Stein, Yihong Yang
Similarities on the cellular and neurochemical composition of the amygdaloid subnuclei suggests their clustering into subunits that exhibit unique functional organization. The topological principle of community structure has been used to identify functional subnetworks in neuroimaging data that reflect the brain effective organization. Here we used modularity to investigate the organization of the amygdala using resting state functional magnetic resonance imaging (rsfMRI) data. Our goal was to determine whether such topological organization would reliably reflect the known neurobiology of individual amygdaloid nuclei, allowing for human imaging studies to accurately reflect the underlying neurobiology...
October 31, 2017: Scientific Reports
Gregor N Simm, Markus Reiher
The construction of a reaction network containing all relevant intermediates and elementary reactions is necessary for the accurate description of chemical processes. In the case of a complex chemical reaction (involving, for instance, many reactants or highly reactive species), the size of such a network may grow rapidly. Here, we present a computational protocol that constructs such reaction networks in a fully automated fashion steered in an intuitive, graph-based fashion through a single graphical user interface...
November 8, 2017: Journal of Chemical Theory and Computation
Eric E Smith, Andrew E Beaudin
PURPOSE OF REVIEW: We review recent MRI research that addresses two important challenges in cerebral small vessel disease (SVD) research: early diagnosis, and linking SVD with cognitive impairment. First, we review studies of MRI measurements of blood flow and blood-brain barrier integrity. Second, we review MRI studies identifying neuroimaging correlates of SVD-related cognitive dysfunction, focusing on brain connectivity and white matter microarchitecture. This research is placed in context through discussion of recent recommendations for management of incidentally discovered SVD, and neuroimaging biomarker use in clinical trials...
October 27, 2017: Current Opinion in Neurology
Gabriel S Zamudio, Marco V José
In this work, we explicitly consider the evolution of the Standard Genetic Code (SGC) by assuming two evolutionary stages, to wit, the primeval RNY code and two intermediate codes in between. We used network theory and graph theory to measure the connectivity of each phenotypic graph. The connectivity values are compared to the values of the codes under different randomization scenarios. An error-correcting optimal code is one in which the algebraic connectivity is minimized. We show that the SGC is optimal in regard to its robustness and error-tolerance when compared to all random codes under different assumptions...
October 29, 2017: Origins of Life and Evolution of the Biosphere
Qiong Wu, Yang Gao, Ai-Shi Liu, Li-Zhi Xie, Long Qian, Xiao-Guang Yang
To date, the most frequently reported neuroimaging biomarkers in Parkinson's disease (PD) are direct brain imaging measurements focusing on local disrupted regions. However, the notion that PD is related to abnormal functional and structural connectivity has received support in the past few years. Here, we employed graph theory to analyze the structural co-variance networks derived from 50 PD patients and 48 normal controls (NC). Then, the small world properties of brain networks were assessed in the structural networks that were constructed based on cortical volume data...
October 20, 2017: Neuroscience Letters
Bing Liang Chua, Zhongxiang Dai, Nitish Thakor, Anastasios Bezerianos, Yu Sun
The importance of understanding mental fatigue can be seen from many studies that started back in past decades. It is only until recent years has mental fatigue been explored through connectivity network analysis using graph theory. Although previous studies have revealed certain properties of the mental fatigue network via graph theory, some of these findings seemingly conflict with one another. The differences in findings could be due to mental fatigue being caused by various factors or being analyzed using different methods...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Shengqian Zhang, Yuan Zhang, Yu Sun, Nitish Thakor, Anastasios Bezerianos
The research field of mental workload has attracted abundant researchers as mental workload plays a crucial role in real-life performance and safety. While previous studies have examined the neural correlates of mental workload in 2D scenarios (i.e., presenting stimuli on a computer screen (CS) environment using univariate methods (e.g., EEG channel power), it is still unclear of the findings of one that uses multivariate approach using graphical theory and the effects of a 3D environment (i.e., presenting stimuli on a Virtual Reality (VR))...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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