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https://www.readbyqxmd.com/read/28226435/resting-state-eeg-network-change-in-alpha-and-beta-bands-after-upper-limb-amputation
#1
Yuanyuan Lyu, Xiaoli Guo, Zhuo Wang, Shanbao Tong, Yuanyuan Lyu, Xiaoli Guo, Zhuo Wang, Shanbao Tong, Yuanyuan Lyu, Xiaoli Guo, Zhuo Wang, Shanbao Tong
To investigate the reorganization of functional brain network following amputation, twenty-two right-hand amputees and twenty-four age- and education-matched controls participated in a resting-state EEG study. EEG networks in alpha and beta bands were constructed using phase synchronization. Both global and local network parameters were compared between amputees and healthy controls. In the aspect of global connectivity, amputees showed increased clustering coefficient (C), decreased characteristic path length (L) and increased small worldness (S) in alpha band, and an increase of L in beta band...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28213111/childhood-maltreatment-is-associated-with-alteration-in-global-network-fiber-tract-architecture-independent-of-history-of-depression-and-anxiety
#2
Kyoko Ohashi, Carl M Anderson, Elizabeth A Bolger, Alaptagin Khan, Cynthia E McGreenery, Martin H Teicher
Childhood maltreatment is a major risk factor for psychopathology. It is also associated with alterations in the network architecture of the brain, which we hypothesized may play a significant role in the development of psychopathology. In this study, we analyzed the global network architecture of physically healthy unmedicated 18-25 year old subjects (n=262) using diffusion tensor imaging (DTI) MRI and tractography. Anatomical networks were constructed from fiber streams interconnecting 90 cortical or subcortical regions for subjects with no-to-low (n=122) versus moderate-to-high (n=140) exposure to maltreatment...
February 16, 2017: NeuroImage
https://www.readbyqxmd.com/read/28167818/emergent-hyperbolic-network-geometry
#3
Ginestra Bianconi, Christoph Rahmede
A large variety of interacting complex systems are characterized by interactions occurring between more than two nodes. These systems are described by simplicial complexes. Simplicial complexes are formed by simplices (nodes, links, triangles, tetrahedra etc.) that have a natural geometric interpretation. As such simplicial complexes are widely used in quantum gravity approaches that involve a discretization of spacetime. Here, by extending our knowledge of growing complex networks to growing simplicial complexes we investigate the nature of the emergent geometry of complex networks and explore whether this geometry is hyperbolic...
February 7, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28129401/impact-of-bounded-noise-and-rewiring-on-the-formation-and-instability-of-spiral-waves-in-a-small-world-network-of-hodgkin-huxley-neurons
#4
Yuangen Yao, Haiyou Deng, Chengzhang Ma, Ming Yi, Jun Ma
Spiral waves are observed in the chemical, physical and biological systems, and the emergence of spiral waves in cardiac tissue is linked to some diseases such as heart ventricular fibrillation and epilepsy; thus it has importance in theoretical studies and potential medical applications. Noise is inevitable in neuronal systems and can change the electrical activities of neuron in different ways. Many previous theoretical studies about the impacts of noise on spiral waves focus an unbounded Gaussian noise and even colored noise...
2017: PloS One
https://www.readbyqxmd.com/read/28129055/task-linked-diurnal-brain-network-reorganization-in-older-adults-a-graph-theoretical-approach
#5
John A E Anderson, Saman Sarraf, Tarek Amer, Buddhika Bellana, Vincent Man, Karen L Campbell, Lynn Hasher, Cheryl L Grady
Testing older adults in the morning generally improves behavioral performance relative to afternoon testing. Morning testing is also associated with brain activity similar to that of young adults. Here, we used graph theory to explore how time of day (TOD) affects the organization of brain networks in older adults across rest and task states. We used nodes from the automated anatomical labeling atlas to construct participant-specific correlation matrices of fMRI data obtained during 1-back tasks with interference and rest...
October 19, 2016: Journal of Cognitive Neuroscience
https://www.readbyqxmd.com/read/28125912/olfactory-network-differences-in-master-sommeliers-connectivity-analysis-using-granger-causality-and-graph-theoretical-approach
#6
Karthik R Sreenivasan, Xiaowei Zhuang, Sarah Banks, Virendra Mishra, Zhengshi Yang, Gopikrishna Deshpande, Dietmar Cordes
Previous studies investigating the differences in olfactory processing and judgments between trained sommeliers and controls have shown increased activations in brain regions involving higher-level cognitive processes in sommeliers. However, there is little information about the influence of expertise on causal connectivity and topological properties of the connectivity networks between these regions. Therefore, the current study focuses on addressing these questions in a functional magnetic resonance imaging (fMRI) study of olfactory perception in Master Sommeliers...
January 26, 2017: Brain Connectivity
https://www.readbyqxmd.com/read/28113670/dynamic-functional-segregation-and-integration-in-human-brain-network-during-complex-tasks
#7
Shen Ren, Junhua Li, Fumihiko Taya, Joshua deSouza, Nitish Thakor, Anastasios Bezerianos
The analysis of the topology and organisation of brain networks is known to greatly benefit from network measures in graph theory. However, to evaluate dynamic changes of brain functional connectivity, more sophisticated quantitative metrics characterising temporal evolution of brain topological features are required. To simplify conversion of time-varying brain connectivity to a static graph representation is straightforward but the procedure loses temporal information that could be critical in understanding the brain functions...
September 9, 2016: IEEE Transactions on Neural Systems and Rehabilitation Engineering
https://www.readbyqxmd.com/read/28110506/antibiotic-discovery-throughout-the-small-world-initiative-a-molecular-strategy-to-identify-biosynthetic-gene-clusters-involved-in-antagonistic-activity
#8
Elizabeth Davis, Tyler Sloan, Krista Aurelius, Angela Barbour, Elijah Bodey, Brigette Clark, Celeste Dennis, Rachel Drown, Megan Fleming, Allison Humbert, Elizabeth Glasgo, Trent Kerns, Kelly Lingro, MacKenzie McMillin, Aaron Meyer, Breanna Pope, April Stalevicz, Brittney Steffen, Austin Steindl, Carolyn Williams, Carmen Wimberley, Robert Zenas, Kristen Butela, Hans Wildschutte
The emergence of bacterial pathogens resistant to all known antibiotics is a global health crisis. Adding to this problem is that major pharmaceutical companies have shifted away from antibiotic discovery due to low profitability. As a result, the pipeline of new antibiotics is essentially dry and many bacteria now resist the effects of most commonly used drugs. To address this global health concern, citizen science through the Small World Initiative (SWI) was formed in 2012. As part of SWI, students isolate bacteria from their local environments, characterize the strains, and assay for antibiotic production...
January 22, 2017: MicrobiologyOpen
https://www.readbyqxmd.com/read/28108742/altered-brain-structural-networks-in-attention-deficit-hyperactivity-disorder-children-revealed-by-cortical-thickness
#9
Tian Liu, Yanni Chen, Chenxi Li, Youjun Li, Jue Wang
This study investigated the cortical thickness and topological features of human brain anatomical networks related to attention deficit/hyperactivity disorder. Data were collected from 40 attention deficit/hyperactivity disorder children and 40 normal control children. Interregional correlation matrices were established by calculating the correlations of cortical thickness between all pairs of cortical regions (68 regions) of the whole brain. Further thresholds were applied to create binary matrices to construct a series of undirected and unweighted graphs, and global, local, and nodal efficiencies were computed as a function of the network cost...
January 18, 2017: Oncotarget
https://www.readbyqxmd.com/read/28095198/effects-of-small-world-rewiring-probability-and-noisy-synaptic-conductivity-on-slow-waves-cortical-network
#10
Ramazan Tekin, Mehmet Emin Tagluk
Physiological rhythms play a critical role in the functional development of living beings. Many biological functions are executed with an interaction of rhythms produced by internal characteristics of scores of cells. While synchronized oscillations may be associated with normal brain functions, anomalies in these oscillations may cause or relate the emergence of some neurological or neuropsychological pathologies. This study was designed to investigate the effects of topological structure and synaptic conductivity noise on the spatial synchronization and temporal rhythmicity of the waves generated by cells in the network...
March 2017: Neural Computation
https://www.readbyqxmd.com/read/28076982/from-structure-to-activity-using-centrality-measures-to-predict-neuronal-activity
#11
Jack McKay Fletcher, Thomas Wennekers
It is clear that the topological structure of a neural network somehow determines the activity of the neurons within it. In the present work, we ask to what extent it is possible to examine the structural features of a network and learn something about its activity? Specifically, we consider how the centrality (the importance of a node in a network) of a neuron correlates with its firing rate. To investigate, we apply an array of centrality measures, including In-Degree, Closeness, Betweenness, Eigenvector, Katz, PageRank, Hyperlink-Induced Topic Search (HITS) and NeuronRank to Leaky-Integrate and Fire neural networks with different connectivity schemes...
November 16, 2016: International Journal of Neural Systems
https://www.readbyqxmd.com/read/28042667/the-difficulties-of-systematic-reviews
#12
REVIEW
Martin J Westgate, David B Lindenmayer
The need for robust evidence to support conservation actions has driven the adoption of systematic approaches to research synthesis in ecology. However, applying systematic review to complex or open questions remains challenging, and this task is becoming more difficult as the quantity of scientific literature increases. Here, we draw on the science of linguistics for guidance as to why the process of identifying and sorting information during systematic review remains so labor-intensive, and to provide potential solutions...
January 2, 2017: Conservation Biology: the Journal of the Society for Conservation Biology
https://www.readbyqxmd.com/read/27996049/intelligence-and-eeg-measures-of-information-flow-efficiency-and-homeostatic-neuroplasticity
#13
R W Thatcher, E Palmero-Soler, D M North, C J Biver
The purpose of this study was to explore the relationship between the magnitude of EEG information flow and intelligence. The electroencephalogram (EEG) was recorded from 19 scalp locations from 371 subjects ranging in age from 5 years to 17.6 years. The Wechler Intelligence Scale for Children (WISC-R) was administered for individuals between 5 years of age and 16 years and the Weschler Adult Intelligence Scale revised (WAIS-R) was administered to subjects older than 16 years to estimate I.Q. The phase slope index estimated the magnitude of information flow between all electrode combinations for difference frequency bands...
December 20, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27992590/statistical-analysis-of-bus-networks-in-india
#14
Atanu Chatterjee, Manju Manohar, Gitakrishnan Ramadurai
In this paper, we model the bus networks of six major Indian cities as graphs in L-space, and evaluate their various statistical properties. While airline and railway networks have been extensively studied, a comprehensive study on the structure and growth of bus networks is lacking. In India, where bus transport plays an important role in day-to-day commutation, it is of significant interest to analyze its topological structure and answer basic questions on its evolution, growth, robustness and resiliency...
2016: PloS One
https://www.readbyqxmd.com/read/27967099/stochastic-bifurcations-in-the-nonlinear-parallel-ising-model
#15
Franco Bagnoli, Raúl Rechtman
We investigate the phase transitions of a nonlinear, parallel version of the Ising model, characterized by an antiferromagnetic linear coupling and ferromagnetic nonlinear one. This model arises in problems of opinion formation. The mean-field approximation shows chaotic oscillations, by changing the couplings or the connectivity. The spatial model shows bifurcations in the average magnetization, similar to that seen in the mean-field approximation, induced by the change of the topology, after rewiring short-range to long-range connection, as predicted by the small-world effect...
November 2016: Physical Review. E
https://www.readbyqxmd.com/read/27967025/effect-of-long-range-interactions-on-the-phase-transition-of-axelrod-s-model
#16
Sandro M Reia, José F Fontanari
Axelrod's model with F=2 cultural features, where each feature can assume k states drawn from a Poisson distribution of parameter q, exhibits a continuous nonequilibrium phase transition in the square lattice. Here we use extensive Monte Carlo simulations and finite-size scaling to study the critical behavior of the order parameter ρ, which is the fraction of sites that belong to the largest domain of an absorbing configuration averaged over many runs. We find that it vanishes as ρ∼(q_{c}^{0}-q)^{β} with β≈0...
November 2016: Physical Review. E
https://www.readbyqxmd.com/read/27942449/resting-state-functional-network-disruptions-in-a-kainic-acid-model-of-temporal-lobe-epilepsy
#17
Ravnoor Singh Gill, Seyed M Mirsattari, L Stan Leung
We studied the graph topological properties of brain networks derived from resting-state functional magnetic resonance imaging in a kainic acid induced model of temporal lobe epilepsy (TLE) in rats. Functional connectivity was determined by temporal correlation of the resting-state Blood Oxygen Level Dependent (BOLD) signals between two brain regions during 1.5% and 2% isoflurane, and analyzed as networks in epileptic and control rats. Graph theoretical analysis revealed a significant increase in functional connectivity between brain areas in epileptic than control rats, and the connected brain areas could be categorized as a limbic network and a default mode network (DMN)...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/27940352/gray-matter-network-differences-between-behavioral-variant-frontotemporal-dementia-and-alzheimer-s-disease
#18
E G B Vijverberg, B M Tijms, J Dopp, Y J Hong, C E Teunissen, F Barkhof, P Scheltens, Y A L Pijnenburg
We set out to study whether single-subject gray matter (GM) networks show disturbances that are specific for Alzheimer's disease (AD; n = 90) or behavioral variant frontotemporal dementia (bvFTD; n = 59), and whether such disturbances would be related to cognitive deficits measured with mini-mental state examination and a neuropsychological battery, using subjective cognitive decline subjects as reference. AD and bvFTD patients had a lower degree, connectivity density, clustering, path length, betweenness centrality, and small world values compared with subjective cognitive decline...
February 2017: Neurobiology of Aging
https://www.readbyqxmd.com/read/27920733/chinese-writing-of-deaf-or-hard-of-hearing-students-and-normal-hearing-peers-from-complex-network-approach
#19
Huiyuan Jin, Haitao Liu
Deaf or hard-of-hearing individuals usually face a greater challenge to learn to write than their normal-hearing counterparts. Due to the limitations of traditional research methods focusing on microscopic linguistic features, a holistic characterization of the writing linguistic features of these language users is lacking. This study attempts to fill this gap by adopting the methodology of linguistic complex networks. Two syntactic dependency networks are built in order to compare the macroscopic linguistic features of deaf or hard-of-hearing students and those of their normal-hearing peers...
2016: Frontiers in Psychology
https://www.readbyqxmd.com/read/27917952/biodiversity-in-models-of-cyclic-dominance-is-preserved-by-heterogeneity-in-site-specific-invasion-rates
#20
Attila Szolnoki, Matjaž Perc
Global, population-wide oscillations in models of cyclic dominance may result in the collapse of biodiversity due to the accidental extinction of one species in the loop. Previous research has shown that such oscillations can emerge if the interaction network has small-world properties, and more generally, because of long-range interactions among individuals or because of mobility. But although these features are all common in nature, global oscillations are rarely observed in actual biological systems. This begets the question what is the missing ingredient that would prevent local oscillations to synchronize across the population to form global oscillations...
December 5, 2016: Scientific Reports
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