keyword
MENU ▼
Read by QxMD icon Read
search

small-world

keyword
https://www.readbyqxmd.com/read/29212921/bold-temporal-variability-differentiates-wakefulness-from-anesthesia-induced-unconsciousness
#1
Alex T Baria, Maria Virginia Centeno, Mariam E Ghantous, Pei-Ching Chang, Daniele Procissi, A Vania Apkarian
Even though a number of findings, based on information content or information integration, are shown to define neural underpinnings characteristic of a conscious experience, the neurophysiological mechanism of consciousness is still poorly understood. Here, we investigated the brain activity and functional connectivity changes that occur in the isoflurane anesthetized unconscious state in contrast to the awake-state in rats (awake and/or anesthetized n=68 rats). We examined nine information measures previously shown to distinguish between conscious states; BOLD variability, functional connectivity strength, modularity, weighted modularity, efficiency, clustering coefficient, small-worldness, and spatial and temporal Lempel-Ziv complexity measure...
December 6, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/29209197/asymmetry-of-hemispheric-network-topology-reveals-dissociable-processes-between-functional-and-structural-brain-connectome-in-community-living-elders
#2
Yu Sun, Junhua Li, John Suckling, Lei Feng
Human brain is structurally and functionally asymmetrical and the asymmetries of brain phenotypes have been shown to change in normal aging. Recent advances in graph theoretical analysis have showed topological lateralization between hemispheric networks in the human brain throughout the lifespan. Nevertheless, apparent discrepancies of hemispheric asymmetry were reported between the structural and functional brain networks, indicating the potentially complex asymmetry patterns between structural and functional networks in aging population...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/29205445/analysis-of-the-u-s-patient-referral-network
#3
Chuankai An, A James O'Malley, Daniel N Rockmore, Corey D Stock
In this paper, we analyze the US Patient Referral Network (also called the Shared Patient Network) and various subnetworks for the years 2009 to 2015. In these networks, two physicians are linked if a patient encounters both of them within a specified time interval, according to the data made available by the Centers for Medicare and Medicaid Services. We find power law distributions on most state-level data as well as a core-periphery structure. On a national and state level, we discover a so-called small-world structure as well as a "gravity law" of the type found in some large-scale economic networks...
December 4, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/29201640/connectome-analysis-with-diffusion-mri-in-idiopathic-parkinson-s-disease-evaluation-using-multi-shell-multi-tissue-constrained-spherical-deconvolution
#4
Koji Kamagata, Andrew Zalesky, Taku Hatano, Maria Angelique Di Biase, Omar El Samad, Shinji Saiki, Keigo Shimoji, Kanako K Kumamaru, Kouhei Kamiya, Masaaki Hori, Nobutaka Hattori, Shigeki Aoki, Christos Pantelis
Parkinson's disease (PD) is a progressive neurodegenerative disorder that affects extensive regions of the central nervous system. In this work, we evaluated the structural connectome of patients with PD, as mapped by diffusion-weighted MRI tractography and a multi-shell, multi-tissue (MSMT) constrained spherical deconvolution (CSD) method to increase the precision of tractography at tissue interfaces. The connectome was mapped with probabilistic MSMT-CSD in 21 patients with PD and in 21 age- and gender-matched controls...
2018: NeuroImage: Clinical
https://www.readbyqxmd.com/read/29195323/small-world-networks-exhibit-pronounced-intermittent-synchronization
#5
Anshul Choudhary, Chiranjit Mitra, Vivek Kohar, Sudeshna Sinha, Jürgen Kurths
We report the phenomenon of temporally intermittently synchronized and desynchronized dynamics in Watts-Strogatz networks of chaotic Rössler oscillators. We consider topologies for which the master stability function (MSF) predicts stable synchronized behaviour, as the rewiring probability (p) is tuned from 0 to 1. MSF essentially utilizes the largest non-zero Lyapunov exponent transversal to the synchronization manifold in making stability considerations, thereby ignoring the other Lyapunov exponents. However, for an N-node networked dynamical system, we observe that the difference in its Lyapunov spectra (corresponding to the N - 1 directions transversal to the synchronization manifold) is crucial and serves as an indicator of the presence of intermittently synchronized behaviour...
November 2017: Chaos
https://www.readbyqxmd.com/read/29179739/subjective-cognitive-impairment-and-brain-structural-networks-in-chinese-gynaecological-cancer-survivors-compared-with-age-matched-controls-a-cross-sectional-study
#6
Yingchun Zeng, Andy S K Cheng, Ting Song, Xiujie Sheng, Yang Zhang, Xiangyu Liu, Chetwyn C H Chan
BACKGROUND: Subjective cognitive impairment can be a significant and prevalent problem for gynaecological cancer survivors. The aims of this study were to assess subjective cognitive functioning in gynaecological cancer survivors after primary cancer treatment, and to investigate the impact of cancer treatment on brain structural networks and its association with subjective cognitive impairment. METHODS: This was a cross-sectional survey using a self-reported questionnaire by the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) to assess subjective cognitive functioning, and applying DTI (diffusion tensor imaging) and graph theoretical analyses to investigate brain structural networks after primary cancer treatment...
November 28, 2017: BMC Cancer
https://www.readbyqxmd.com/read/29176705/disrupted-brain-network-in-children-with-autism-spectrum-disorder
#7
Ke Zeng, Jiannan Kang, Gaoxiang Ouyang, Jingqing Li, Junxia Han, Yao Wang, Estate M Sokhadze, Manuel F Casanova, Xiaoli Li
Alterations in brain connectivity have been extensively reported in autism spectrum disorder (ASD), while their effects on the topology of brain network are still unclear. This study investigated whether and how the brain networks in children with ASD were abnormally organized with resting state EEG. Temporal synchronization analysis was first applied to capture the aberrant brain connectivity. Then brain network topology was characterized by three graph analysis methods including the commonly-used weighted and binary graph, as well as minimum spanning tree (MST)...
November 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29167088/network-neuroscience-theory-of-human-intelligence
#8
REVIEW
Aron K Barbey
An enduring aim of research in the psychological and brain sciences is to understand the nature of individual differences in human intelligence, examining the stunning breadth and diversity of intellectual abilities and the remarkable neurobiological mechanisms from which they arise. This Opinion article surveys recent neuroscience evidence to elucidate how general intelligence, g, emerges from individual differences in the network architecture of the human brain. The reviewed findings motivate new insights about how network topology and dynamics account for individual differences in g, represented by the Network Neuroscience Theory...
November 2, 2017: Trends in Cognitive Sciences
https://www.readbyqxmd.com/read/29147147/collective-behavior-of-large-scale-neural-networks-with-gpu-acceleration
#9
Jingyi Qu, Rubin Wang
In this paper, the collective behaviors of a small-world neuronal network motivated by the anatomy of a mammalian cortex based on both Izhikevich model and Rulkov model are studied. The Izhikevich model can not only reproduce the rich behaviors of biological neurons but also has only two equations and one nonlinear term. Rulkov model is in the form of difference equations that generate a sequence of membrane potential samples in discrete moments of time to improve computational efficiency. These two models are suitable for the construction of large scale neural networks...
December 2017: Cognitive Neurodynamics
https://www.readbyqxmd.com/read/29118724/alternations-of-white-matter-structural-networks-in-first-episode-untreated-major-depressive-disorder-with-short-duration
#10
Yi Lu, Zonglin Shen, Yuqi Cheng, Hui Yang, Bo He, Yue Xie, Liang Wen, Zhenguang Zhang, Xuejin Sun, Wei Zhao, Xiufeng Xu, Dan Han
It is crucial to explore the pathogenesis of major depressive disorder (MDD) at the early stage for the better diagnostic and treatment strategies. It was suggested that MDD might be involving in functional or structural alternations at the brain network level. However, at the onset of MDD, whether the whole brain white matter (WM) alterations at network level are already evident still remains unclear. In the present study, diffusion MRI scanning was adopt to depict the unique WM structural network topology across the entire brain at the early stage of MDD...
2017: Frontiers in Psychiatry
https://www.readbyqxmd.com/read/29111486/gray-matter-network-measures-are-associated-with-cognitive-decline-in-mild-cognitive-impairment
#11
Ellen Dicks, Betty M Tijms, Mara Ten Kate, Alida A Gouw, Marije R Benedictus, Charlotte E Teunissen, Frederik Barkhof, Philip Scheltens, Wiesje M van der Flier
Gray matter networks are disrupted in Alzheimer's disease and related to cognitive impairment. However, it is still unclear whether these disruptions are associated with cognitive decline over time. Here, we studied this question in a large sample of patients with mild cognitive impairment with extensive longitudinal neuropsychological assessments. Gray matter networks were extracted from baseline structural magnetic resonance imaging, and we tested associations of network measures and cognitive decline in Mini-Mental State Examination and 5 cognitive domains (i...
October 6, 2017: Neurobiology of Aging
https://www.readbyqxmd.com/read/29096205/stochastic-spike-synchronization-in-a-small-world-neural-network-with-spike-timing-dependent-plasticity
#12
Sang-Yoon Kim, Woochang Lim
We consider the Watts-Strogatz small-world network (SWN) consisting of subthreshold neurons which exhibit noise-induced spikings. This neuronal network has adaptive dynamic synaptic strengths governed by the spike-timing-dependent plasticity (STDP). In previous works without STDP, stochastic spike synchronization (SSS) between noise-induced spikings of subthreshold neurons was found to occur in a range of intermediate noise intensities. Here, we investigate the effect of additive STDP on the SSS by varying the noise intensity...
October 12, 2017: Neural Networks: the Official Journal of the International Neural Network Society
https://www.readbyqxmd.com/read/29081731/human-fetal-brain-connectome-structural-network-development-from-middle-fetal-stage-to-birth
#13
Limei Song, Virendra Mishra, Minhui Ouyang, Qinmu Peng, Michelle Slinger, Shuwei Liu, Hao Huang
Complicated molecular and cellular processes take place in a spatiotemporally heterogeneous and precisely regulated pattern in the human fetal brain, yielding not only dramatic morphological and microstructural changes, but also macroscale connectomic transitions. As the underlying substrate of the fetal brain structural network, both dynamic neuronal migration pathways and rapid developing fetal white matter (WM) fibers could fundamentally reshape early fetal brain connectome. Quantifying structural connectome development can not only shed light on the brain reconfiguration in this critical yet rarely studied developmental period, but also reveal alterations of the connectome under neuropathological conditions...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/29077021/the-pattern-of-microrna-binding-site-distribution
#14
Fangyuan Zhang, Degeng Wang
Micro-RNA (miRNA or miR) regulates at least 60% of the genes in the human genome through their target sites at mRNA 3'-untranslated regions (UTR), and defects in miRNA expression regulation and target sites are frequently observed in cancers. We report here a systematic analysis of the distribution of miRNA target sites. Using the evolutionarily conserved miRNA binding sites in the TargetScan database (release 7.1), we constructed a miRNA co-regulation network by connecting genes sharing common miRNA target sites...
October 27, 2017: Genes
https://www.readbyqxmd.com/read/29073337/altered-brain-networks-in-psychogenic-erectile-dysfunction-a-resting-state-fmri-study
#15
J Chen, Y Chen, G Chen, Y Dai, Z Yao, Q Lu
Various neuroimaging studies had identified changes of cerebral activity and structures during the processes of sexual arousal. The identified brain regions were also believed to regulate emotional and cognitive processes. Yet, little was known about the neural mechanisms underlying psychogenic erectile dysfunction. Moreover, brain mechanisms mediating the processing of sexual arousal by these psychological processes were unclear. To investigate this issue, graph theory was applied to evaluate the topological properties of functional brain networks among 24 psychogenic erectile dysfunction patients and 26 healthy controls...
November 2017: Andrology
https://www.readbyqxmd.com/read/29067129/dynamical-responses-to-external-stimuli-for-both-cases-of-excitatory-and-inhibitory-synchronization-in-a-complex-neuronal-network
#16
Sang-Yoon Kim, Woochang Lim
For studying how dynamical responses to external stimuli depend on the synaptic-coupling type, we consider two types of excitatory and inhibitory synchronization (i.e., synchronization via synaptic excitation and inhibition) in complex small-world networks of excitatory regular spiking (RS) pyramidal neurons and inhibitory fast spiking (FS) interneurons. For both cases of excitatory and inhibitory synchronization, effects of synaptic couplings on dynamical responses to external time-periodic stimuli S(t) (applied to a fraction of neurons) are investigated by varying the driving amplitude A of S(t)...
October 2017: Cognitive Neurodynamics
https://www.readbyqxmd.com/read/29066804/on-the-relevance-of-the-alpha-frequency-oscillation-s-small-world-network-architecture-for-cognitive-flexibility
#17
Nicole Wolff, Nicolas Zink, Ann-Kathrin Stock, Christian Beste
Cognitive flexibility is a major requirement for successful behavior. nNeural oscillations in the alpha frequency band were repeatedly associated with cognitive flexibility in task-switching paradigms. Alpha frequencies are modulated by working memory load and are used to process information during task switching, however we do not know how this oscillatory network communication is modulated. In order to understand the mechanisms that drive cognitive flexibility, ERPs, oscillatory power and how the communication within these networks is organized are of importance...
October 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29061395/large-scale-cortical-volume-correlation-networks-reveal-disrupted-small-world-patterns-in-parkinson-s-disease
#18
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
https://www.readbyqxmd.com/read/29060032/change-in-functional-networks-for-transitions-between-states-of-consciousness-during-midazolam-induced-sedation
#19
Minji Lee, Robert D Sanders, Seul-Ki Yeom, Dong-Ok Won, Hwi-Jae Kim, Bo-Ram Lee, Kwang-Suk Seo, Hyun Jeong Kim, Giulio Tononi, Seong-Whan Lee
How brain dynamics change across conscious states, including reliable signatures of the transitions between unconsciousness and consciousness, remains unclear. In this work, we addressed the changes in functional brain networks during self-titrated midazolam sedation using high-density electroencephalography (EEG) in ten subjects. We were particularly interested in the underlying network alterations, identified with graph theory, associated with transitions between states of consciousness. The weighted Phase Lag Index (wPLI) was used as the connectivity estimator between two signals...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/29054694/the-resilient-brain-and-the-guardians-of-sleep-new-perspectives-on-old-assumptions
#20
REVIEW
Liborio Parrino, Anna Elisabetta Vaudano
Resilience is the capacity of a system, enterprise or a person to maintain its core purpose and integrity in the face of dramatically changed circumstances. In human physiology, resilience is the capacity of adaptively overcoming stress and adversity while maintaining normal psychological and physical functioning. In this review, we investigate the resilient strategies of sleep. First, we discuss the concept of brain resilience, highlighting the modular structure of small-world networking, neuronal plasticity and critical brain behavior...
October 17, 2017: Sleep Medicine Reviews
keyword
keyword
53943
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"