keyword
MENU ▼
Read by QxMD icon Read
search

dynamical network

keyword
https://www.readbyqxmd.com/read/28646764/adaptive-near-optimal-neuro-controller-for-continuous-time-nonaffine-nonlinear-systems-with-constrained-input
#1
Kasra Esfandiari, Farzaneh Abdollahi, Heidar Ali Talebi
In this paper, an identifier-critic structure is introduced to find an online near-optimal controller for continuous-time nonaffine nonlinear systems having saturated control signal. By employing two Neural Networks (NNs), the solution of Hamilton-Jacobi-Bellman (HJB) equation associated with the cost function is derived without requiring a priori knowledge about system dynamics. Weights of the identifier and critic NNs are tuned online and simultaneously such that unknown terms are approximated accurately and the control signal is kept between the saturation bounds...
June 21, 2017: Neural Networks: the Official Journal of the International Neural Network Society
https://www.readbyqxmd.com/read/28646563/cohesive-network-reconfiguration-accompanies-extended-training
#2
Qawi K Telesford, Arian Ashourvan, Nicholas F Wymbs, Scott T Grafton, Jean M Vettel, Danielle S Bassett
Human behavior is supported by flexible neurophysiological processes that enable the fine-scale manipulation of information across distributed neural circuits. Yet, approaches for understanding the dynamics of these circuit interactions have been limited. One promising avenue for quantifying and describing these dynamics lies in multilayer network models. Here, networks are composed of nodes (which represent brain regions) and time-dependent edges (which represent statistical similarities in activity time series)...
June 24, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28646471/decoding-early-myelopoiesis-from-dynamics-of-core-endogenous-network
#3
Hang Su, Gaowei Wang, Ruoshi Yuan, Junqiang Wang, Ying Tang, Ping Ao, Xiaomei Zhu
A decade ago mainstream molecular biologists regarded it impossible or biologically ill-motivated to understand the dynamics of complex biological phenomena, such as cancer genesis and progression, from a network perspective. Indeed, there are numerical difficulties even for those who were determined to explore along this direction. Undeterred, seven years ago a group of Chinese scientists started a program aiming to obtain quantitative connections between tumors and network dynamics. Many interesting results have been obtained...
May 29, 2017: Science China. Life Sciences
https://www.readbyqxmd.com/read/28646260/salt-appetite-and-the-influence-of-opioids
#4
Craig M Smith, Andrew J Lawrence
Due to the biological importance of sodium and its relative scarcity within many natural environments, 'salt appetite' has evolved whereby dietary salt is highly sought after and palatable when tasted. In addition to peripheral responses, salt depletion is detected within the brain via circumventricular organs and 11β-hydroxysteroid dehydrogenase type 2 (HSD2) neurons to increase salt appetite. Salt appetite is comprised of two main components. One component is the incentive salience or motivation for salt (i...
June 24, 2017: Neurochemical Research
https://www.readbyqxmd.com/read/28646090/cellular-functions-of-wasp-family-proteins-at-a-glance
#5
REVIEW
Olga Alekhina, Ezra Burstein, Daniel D Billadeau
Proteins of the Wiskott-Aldrich syndrome protein (WASP) family function as nucleation-promoting factors for the ubiquitously expressed Arp2/3 complex, which drives the generation of branched actin filaments. Arp2/3-generated actin regulates diverse cellular processes, including the formation of lamellipodia and filopodia, endocytosis and/or phagocytosis at the plasma membrane, and the generation of cargo-laden vesicles from organelles including the Golgi, endoplasmic reticulum (ER) and the endo-lysosomal network...
June 23, 2017: Journal of Cell Science
https://www.readbyqxmd.com/read/28645844/modelling-and-interpreting-mesoscale-network-dynamics
#6
REVIEW
Ankit N Khambhati, Ann E Sizemore, Richard F Betzel, Danielle S Bassett
Recent advances in brain imaging techniques, measurement approaches, and storage capacities have provided an unprecedented supply of high temporal resolution neural data. These data present a remarkable opportunity to gain a mechanistic understanding not just of circuit structure, but also of circuit dynamics, and its role in cognition and disease. Such understanding necessitates a description of the raw observations, and a delineation of computational models and mathematical theories that accurately capture fundamental principles behind the observations...
June 20, 2017: NeuroImage
https://www.readbyqxmd.com/read/28645841/how-do-self-interest-and-other-need-interact-in-the-brain-to-determine-altruistic-behavior
#7
Jie Hu, Yue Li, Yunlu Yin, Philip R Blue, Hongbo Yu, Xiaolin Zhou
Altruistic behavior, i.e., promoting the welfare of others at a cost to oneself, is subserved by the integration of various social, affective, and economic factors represented in extensive brain regions. However, it is unclear how different regions interact to process/integrate information regarding the helper's interest and recipient's need when deciding whether to behave altruistically. Here we combined an interactive game with functional Magnetic Resonance Imaging (fMRI) and transcranial direct current stimulation (tDCS) to characterize the neural network underlying the processing/integration of self-interest and other-need...
June 20, 2017: NeuroImage
https://www.readbyqxmd.com/read/28645224/a-symphony-of-cyclases-specificity-in-diguanylate-cyclase-signaling
#8
Kurt M Dahlstrom, George A O'Toole
Cyclic diguanylate (c-di-GMP) is a near universal signaling molecule produced by diguanylate cyclases that can direct a variety of bacterial behaviors. A major area of research over the last several years has been aimed at understanding how a cell with dozens of diguanylate cyclases can deploy a given subset of them to produce a desired phenotypic outcome without undesired cross talk between c-di-GMP-dependent systems. Several models have been put forward to address this question, including specificity of cyclase activation, tuned binding constants of effector proteins, and physical interaction between cyclases and effectors...
June 23, 2017: Annual Review of Microbiology
https://www.readbyqxmd.com/read/28644911/interictal-oscillations-and-focal-epileptic-disorders
#9
Maxime Lévesque, Pariya Salami, Zahra Shiri, Massimo Avoli
Neuronal network oscillations represent a main feature of the brain activity recorded in the EEG under normal and pathological conditions such as epilepsy. Specific oscillations occur between seizures in patients and in animal models of focal epilepsy, and thus they are termed interictal. According to their shape and intrinsic signal frequency, interictal oscillations are classified as spikes and high frequency oscillations (HFOs). Interictal spikes are recorded in the "wideband" EEG signal and consist of large-amplitude events that usually last less than 1 s; HFOs, in contrast, are extracted by amplifying the appropriately filtered EEG signal, and are usually categorized as ripples (80-200 Hz) and fast ripples (250-500 Hz)...
June 23, 2017: European Journal of Neuroscience
https://www.readbyqxmd.com/read/28644888/fragmentation-of-the-mitochondrial-network-in-skin-in-vivo
#10
Daniel Mellem, Martin Sattler, Sonja Pagel-Wolff, Sören Jaspers, Horst Wenck, Michael Alexander Rübhausen, Frank Fischer
Mitochondria form dynamic networks which adapt to the environmental requirements of the cell. We investigated the aging process of these networks in human skin cells in vivo by multiphoton microscopy. A study on the age-dependency of the mitochondrial network in young and old volunteers revealed that keratinocytes in old skin establish a significantly more fragmented network with smaller and more compact mitochondrial clusters than keratinocytes in young skin. Furthermore, we investigated the mitochondrial network during differentiation processes of keratinocytes within the epidermis of volunteers...
2017: PloS One
https://www.readbyqxmd.com/read/28644841/low-dimensional-spike-rate-models-derived-from-networks-of-adaptive-integrate-and-fire-neurons-comparison-and-implementation
#11
Moritz Augustin, Josef Ladenbauer, Fabian Baumann, Klaus Obermayer
The spiking activity of single neurons can be well described by a nonlinear integrate-and-fire model that includes somatic adaptation. When exposed to fluctuating inputs sparsely coupled populations of these model neurons exhibit stochastic collective dynamics that can be effectively characterized using the Fokker-Planck equation. This approach, however, leads to a model with an infinite-dimensional state space and non-standard boundary conditions. Here we derive from that description four simple models for the spike rate dynamics in terms of low-dimensional ordinary differential equations using two different reduction techniques: one uses the spectral decomposition of the Fokker-Planck operator, the other is based on a cascade of two linear filters and a nonlinearity, which are determined from the Fokker-Planck equation and semi-analytically approximated...
June 23, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28644840/linking-structure-and-activity-in-nonlinear-spiking-networks
#12
Gabriel Koch Ocker, Krešimir Josić, Eric Shea-Brown, Michael A Buice
Recent experimental advances are producing an avalanche of data on both neural connectivity and neural activity. To take full advantage of these two emerging datasets we need a framework that links them, revealing how collective neural activity arises from the structure of neural connectivity and intrinsic neural dynamics. This problem of structure-driven activity has drawn major interest in computational neuroscience. Existing methods for relating activity and architecture in spiking networks rely on linearizing activity around a central operating point and thus fail to capture the nonlinear responses of individual neurons that are the hallmark of neural information processing...
June 23, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28644626/2d-h-bond-network-as-the-topmost-skin-to-the-air-water-interface
#13
Simone Pezzotti, Daria Ruth Galimberti, Marie-Pierre Gaigeot
We provide a detailed description of the structure of water at the interface with the air (liquid-vapor LV interface) from state-of-the-art DFT-based molecular dynamics simulations. For the first time, a two-dimensional (2D) H-bond extended network has been identified and fully characterized, demonstrating that interfacial water is organized into a 2D sheet with H-bonds oriented parallel to the instantaneous surface and following its spatial and temporal oscillations. By analyzing the nonlinear vSFG (vibrational sum frequency generation) spectrum of the LV interface in terms of layer-by-layer signal, we demonstrate that the 2D water sheet is solely responsible for the spectral signatures, hence providing the interfacial 3...
June 23, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28643166/structural-disorder-in-plant-proteins-where-plasticity-meets-sessility
#14
REVIEW
Alejandra A Covarrubias, Cesar L Cuevas-Velazquez, Paulette S Romero-Pérez, David F Rendón-Luna, Caspar C C Chater
Plants are sessile organisms. This intriguing nature provokes the question of how they survive despite the continual perturbations caused by their constantly changing environment. The large amount of knowledge accumulated to date demonstrates the fascinating dynamic and plastic mechanisms, which underpin the diverse strategies selected in plants in response to the fluctuating environment. This phenotypic plasticity requires an efficient integration of external cues to their growth and developmental programs that can only be achieved through the dynamic and interactive coordination of various signaling networks...
June 22, 2017: Cellular and Molecular Life Sciences: CMLS
https://www.readbyqxmd.com/read/28642740/multigenerational-influences-of-the-fut2-gene-on-the-dynamics-of-the-gut-microbiota-in-mice
#15
Philipp Rausch, Sven Künzel, Abdulhadi Suwandi, Guntram A Grassl, Philip Rosenstiel, John F Baines
The FUT2 gene encodes an α-1,2-fucosyltransferase responsible for the expression of ABO histo-blood-group antigens on mucosal surfaces and bodily secretions. Individuals who carry at least one functional allele are known as "secretors," whereas those homozygous for loss-of-function mutations are known as "non-secretors." Non-secretor individuals are more susceptible to chronic inflammatory disorders such as Crohn's Disease, which may be mediated by alterations in the microbiota. Here, we investigated the dynamics of microbial community assembly with respect to genotype using a Fut2-deficient mouse model, taking the genotype of the maternal lineage over two generations into account...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28642382/a-global-brain-state-underlies-c-elegans-sleep-behavior
#16
Annika L A Nichols, Tomáš Eichler, Richard Latham, Manuel Zimmer
How the brain effectively switches between and maintains global states, such as sleep and wakefulness, is not yet understood. We used brainwide functional imaging at single-cell resolution to show that during the developmental stage of lethargus, the Caenorhabditis elegans brain is predisposed to global quiescence, characterized by systemic down-regulation of neuronal activity. Only a few specific neurons are exempt from this effect. In the absence of external arousing cues, this quiescent brain state arises by the convergence of neuronal activities toward a fixed-point attractor embedded in an otherwise dynamic neural state space...
June 23, 2017: Science
https://www.readbyqxmd.com/read/28642285/state-dependent-tms-reveals-representation-of-affective-body-movements-in-the-anterior-intraparietal-cortex
#17
Noemi Mazzoni, Christianne Jacobs, Paola Venuti, Juha Silvanto, Luigi Cattaneo
In humans, recognition of others' actions involves a cortical network that comprises, among other cortical regions, the posterior superior temporal sulcus (pSTS), where biological motion is coded and the anterior intraparietal suclus (aIPS), where movement information is elaborated in terms of meaningful goal-directed actions. This action observation system (AOS) is thought to encode neutral voluntary actions, and possibly some aspects of affective motor repertoire, but the role of the AOS' areas in processing affective kinematic information has never been examined...
June 22, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28642229/evolutionary-dynamics-of-the-kinetochore-network-in-eukaryotes-as-revealed-by-comparative-genomics
#18
Jolien Je van Hooff, Eelco Tromer, Leny M van Wijk, Berend Snel, Geert Jpl Kops
During eukaryotic cell division, the sister chromatids of duplicated chromosomes are pulled apart by microtubules, which connect via kinetochores. The kinetochore is a multiprotein structure that links centromeres to microtubules, and that emits molecular signals in order to safeguard the equal distribution of duplicated chromosomes over daughter cells. Although microtubule-mediated chromosome segregation is evolutionary conserved, kinetochore compositions seem to have diverged. To systematically inventory kinetochore diversity and to reconstruct its evolution, we determined orthologs of 70 kinetochore proteins in 90 phylogenetically diverse eukaryotes...
June 22, 2017: EMBO Reports
https://www.readbyqxmd.com/read/28641416/water-anion-hydrogen-bonding-dynamics-ultrafast-ir-experiments-and-simulations
#19
Steven A Yamada, Ward H Thompson, Michael D Fayer
Many of water's remarkable properties arise from its tendency to form an intricate and robust hydrogen bond network. Understanding the dynamics that govern this network is fundamental to elucidating the behavior of pure water and water in biological and physical systems. In ultrafast nonlinear infrared experiments, the accessible time scales are limited by water's rapid vibrational relaxation (1.8 ps for dilute HOD in H2O), precluding interrogation of slow hydrogen bond evolution in non-bulk systems. Here, hydrogen bonding dynamics in bulk D2O were studied from the perspective of the much longer lived (36...
June 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28641269/a-model-based-tool-for-the-analysis-and-design-of-gene-regulatory-network
#20
Liliana Ironi, Ettore Lanzarone
Computational and mathematical models have significantly contributed to the rapid progress in the study of gene regulatory networks (GRN), but researchers still lack a reliable model-based framework for computer-aided analysis and design. Such tool should both reveal the relation between network structure and dynamics and find parameter values and/or constraints that enable the simulated dynamics to reproduce specific behaviors. This paper addresses these issues and proposes a computational framework that facilitates network analysis or design...
June 19, 2017: IEEE/ACM Transactions on Computational Biology and Bioinformatics
keyword
keyword
89510
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"