keyword
MENU ▼
Read by QxMD icon Read
search

Feedforward

keyword
https://www.readbyqxmd.com/read/28432122/dual-regulation-of-stat1-and-stat3-by-the-tumor-suppressor-protein-pml-contributes-to-ifn%C3%AE-mediated-inhibition-of-angiogenesis
#1
Kuo-Sheng Hsu, Xuan Zhao, Xiwen Cheng, Dongyin Guan, Ganapati H Mahabeleshwar, Yu Liu, Ernest Borden, Mukesh K Jain, Hung-Ying Kao
IFNs are effective in inhibiting angiogenesis in preclinical models and in treating several angio-proliferative disorders. However, the detailed mechanisms of IFNα-mediated anti-angiogenesis are not completely understood. Stat1/2/3 and PML are IFNα downstream effectors and are pivotal regulators of angiogenesis. Here, we investigated PML's role in the regulation of Stat1/2/3 activity. In Pml knockout (KO) mice, ablation of Pml largely reduces IFNα angiostatic ability in Matrixgel plug assays. This suggested an essential role for PML in IFNα's anti-angiogenic function...
April 21, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28428010/a-strategy-of-faster-movements-used-by-elderly-humans-to-lift-objects-of-increasing-weight-in-ecological-context
#2
Thomas Hoellinger, Joseph McIntyre, Lena Jami, Sylvain Hanneton, Guy Cheron, Agnes Roby-Brami
It is not known whether, during the course of ageing, changes occur in the motor strategies used by the CNS for lifting objects of different weights. Here, we analysed the kinematics of object-lifting in two different healthy groups (young and elderly people) plus one well known deafferented patient (GL). The task was to reach and lift onto a shelf an opaque cylindrical object with changing weight. The movements of the hand and object were recorded with electromagnetic sensors. In an ecological context (i.e...
April 17, 2017: Neuroscience
https://www.readbyqxmd.com/read/28414802/neuronal-cell-fate-specification-by-the-molecular-convergence-of-different-spatio-temporal-cues-on-a-common-initiator-terminal-selector-gene
#3
Johannes Stratmann, Stefan Thor
The extensive genetic regulatory flows underlying specification of different neuronal subtypes are not well understood at the molecular level. The Nplp1 neuropeptide neurons in the developing Drosophila nerve cord belong to two sub-classes; Tv1 and dAp neurons, generated by two distinct progenitors. Nplp1 neurons are specified by spatial cues; the Hox homeotic network and GATA factor grn, and temporal cues; the hb -> Kr -> Pdm -> cas -> grh temporal cascade. These spatio-temporal cues combine into two distinct codes; one for Tv1 and one for dAp neurons that activate a common terminal selector feedforward cascade of col -> ap/eya -> dimm -> Nplp1...
April 17, 2017: PLoS Genetics
https://www.readbyqxmd.com/read/28413823/long-term-predictive-and-feedback-encoding-of-motor-signals-in-the-simple-spike-discharge-of-purkinje-cells
#4
Laurentiu S Popa, Martha L Streng, Timothy J Ebner
Most hypotheses of cerebellar function emphasize a role in real-time control of movements. However, the cerebellum's use of current information to adjust future movements and its involvement in sequencing, working memory, and attention argues for predicting and maintaining information over extended time windows. The present study examines the time course of Purkinje cell discharge modulation in the monkey (Macaca mulatta) during manual, pseudo-random tracking. Analysis of the simple spike firing from 183 Purkinje cells during tracking reveals modulation up to 2 s before and after kinematics and position error...
March 2017: ENeuro
https://www.readbyqxmd.com/read/28410433/simple-biochemical-networks-allow-accurate-sensing-of-multiple-ligands-with-a-single-receptor
#5
Vijay Singh, Ilya Nemenman
Cells use surface receptors to estimate concentrations of external ligands. Limits on the accuracy of such estimations have been well studied for pairs of ligand and receptor species. However, the environment typically contains many ligands, which can bind to the same receptors with different affinities, resulting in cross-talk. In traditional rate models, such cross-talk prevents accurate inference of concentrations of individual ligands. In contrast, here we show that knowing the precise timing sequence of stochastic binding and unbinding events allows one receptor to provide information about multiple ligands simultaneously and with a high accuracy...
April 14, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28398244/piezoelectric-actuated-phase-shifter-based-on-external-laser-interferometer-design-control-and-experimental-validation
#6
Peng-Zhi Li, Xiao-Dong Wang, Yong-Xin Sui, De-Fu Zhang, Dong-Fang Wang, Li-Jian Dong, Ming-Yang Ni
To improve the phase-shifting accuracy, this paper presents a novel integrated framework for design, control and experimental validation of the piezoelectric actuated phase shifter with a trade-off between accuracy and cost. The piezoelectric actuators with built-in sensors are adopted to drive the double parallel four-bar linkage flexure hinge-based mechanisms. Three mechanisms form the tripod structure of the assembled phase shifter. Then, a semi-closed loop controller with inner feedback and outer feedforward loops via the external laser interferometer is developed for accurate positioning of the phase shifter...
April 11, 2017: Sensors
https://www.readbyqxmd.com/read/28392606/design-of-an-embedded-inverse-feedforward-biomolecular-tracking-controller-for-enzymatic-reaction-processes
#7
Mathias Foo, Jongrae Kim, Rucha Sawlekar, Declan G Bates
Feedback control is widely used in chemical engineering to improve the performance and robustness of chemical processes. Feedback controllers require a 'subtractor' that is able to compute the error between the process output and the reference signal. In the case of embedded biomolecular control circuits, subtractors designed using standard chemical reaction network theory can only realise one-sided subtraction, rendering standard controller design approaches inadequate. Here, we show how a biomolecular controller that allows tracking of required changes in the outputs of enzymatic reaction processes can be designed and implemented within the framework of chemical reaction network theory...
April 6, 2017: Computers & Chemical Engineering
https://www.readbyqxmd.com/read/28386448/elasticity-improves-handgrip-performance-and-user-experience-during-visuomotor-control
#8
Michael Mace, Paul Rinne, Jean-Luc Liardon, Catherine Uhomoibhi, Paul Bentley, Etienne Burdet
Passive rehabilitation devices, providing motivation and feedback, potentially offer an automated and low-cost therapy method, and can be used as simple human-machine interfaces. Here, we ask whether there is any advantage for a hand-training device to be elastic, as opposed to rigid, in terms of performance and preference. To address this question, we have developed a highly sensitive and portable digital handgrip, promoting independent and repetitive rehabilitation of grasp function based around a novel elastic force and position sensing structure...
February 2017: Royal Society Open Science
https://www.readbyqxmd.com/read/28374125/edge-detection-based-on-hodgkin-huxley-neuron-model-simulation
#9
Hayat Yedjour, Boudjelal Meftah, Olivier Lézoray, Abdelkader Benyettou
In this paper, we propose a spiking neural network model for edge detection in images. The proposed model is biologically inspired by the mechanisms employed by natural vision systems, more specifically by the biologically fulfilled function of simple cells of the human primary visual cortex that are selective for orientation. Several aspects are studied in this model according to three characteristics: feedforward spiking neural structure; conductance-based model of the Hodgkin-Huxley neuron and Gabor receptive fields structure...
April 3, 2017: Cognitive Processing
https://www.readbyqxmd.com/read/28374012/activation-of-ras-erk-signaling-and-gsk-3-by-amyloid-precursor-protein-and-amyloid-beta-facilitates-neurodegeneration-in-alzheimer-s-disease
#10
Lisa Kirouac, Alexander J Rajic, David H Cribbs, Jaya Padmanabhan
It is widely accepted that amyloid β (Aβ) generated from amyloid precursor protein (APP) oligomerizes and fibrillizes to form neuritic plaques in Alzheimer's disease (AD), yet little is known about the contribution of APP to intracellular signaling events preceding AD pathogenesis. The data presented here demonstrate that APP expression and neuronal exposure to oligomeric Aβ42 enhance Ras/ERK signaling cascade and glycogen synthase kinase 3 (GSK-3) activation. We find that RNA interference (RNAi)-directed knockdown of APP in B103 rat neuroblastoma cells expressing APP inhibits Ras-ERK signaling and GSK-3 activation, indicating that APP acts upstream of these signal transduction events...
March 2017: ENeuro
https://www.readbyqxmd.com/read/28373704/noise-processing-by-signaling-networks
#11
Styliani Kontogeorgaki, Rubén J Sánchez-García, Rob M Ewing, Konstantinos C Zygalakis, Ben D MacArthur
Signaling networks mediate environmental information to the cell nucleus. To perform this task effectively they must be able to integrate multiple stimuli and distinguish persistent signals from transient environmental fluctuations. However, the ways in which signaling networks process environmental noise are not well understood. Here we outline a mathematical framework that relates a network's structure to its capacity to process noise, and use this framework to dissect the noise-processing ability of signaling networks...
April 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28367561/cancerous-perturbations-within-the-erk-pi3k-akt-and-wnt-%C3%AE-catenin-signaling-network-constitutively-activate-inter-pathway-positive-feedback-loops
#12
Rahul Rao Padala, Rishabh Karnawat, Satish Bharathwaj Viswanathan, Abhishek Vijay Thakkar, Asim Bikas Das
Perturbations in molecular signaling pathways are a result of genetic or epigenetic alterations, which may lead to malignant transformation of cells. Despite cellular robustness, specific genetic or epigenetic changes of any gene can trigger a cascade of failures, which result in the malfunctioning of cell signaling pathways and lead to cancer phenotypes. The extent of cellular robustness has a link with the architecture of the network such as feedback and feedforward loops. Perturbation in components within feedback loops causes a transition from a regulated to a persistently activated state and results in uncontrolled cell growth...
April 3, 2017: Molecular BioSystems
https://www.readbyqxmd.com/read/28360844/recurrent-network-dynamics-a-link-between-form-and-motion
#13
Jeroen Joukes, Yunguo Yu, Jonathan D Victor, Bart Krekelberg
To discriminate visual features such as corners and contours, the brain must be sensitive to spatial correlations between multiple points in an image. Consistent with this, macaque V2 neurons respond selectively to patterns with well-defined multipoint correlations. Here, we show that a standard feedforward model (a cascade of linear-non-linear filters) does not capture this multipoint selectivity. As an alternative, we developed an artificial neural network model with two hierarchical stages of processing and locally recurrent connectivity...
2017: Frontiers in Systems Neuroscience
https://www.readbyqxmd.com/read/28355147/glimpse-google-glass-interface-for-sensory-feedback-in-myoelectric-hand-prostheses
#14
Marko Markovic, Hemanth Karnal, Bernhard Graimann, Dario Farina, Strahinja Dosen
OBJECTIVE: Providing sensory feedback to the user of the prosthesis is an important challenge. The common approach is to use tactile stimulation, which is easy to implement but requires training and has limited information bandwidth. In this study, we propose an alternative approach based on augmented reality. APPROACH: We have developed the GLIMPSE, a Google Glass application which connects to the prosthesis via a Bluetooth interface and renders the prosthesis states (EMG signals, aperture, force and contact) using augmented reality (see-through display) and sound (bone conduction transducer)...
March 29, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28351197/the-human-central-pattern-generator-for-locomotion
#15
Karen Minassian, Ursula S Hofstoetter, Florin Dzeladini, Pierre A Guertin, Auke Ijspeert
The ability of dedicated spinal circuits, referred to as central pattern generators (CPGs), to produce the basic rhythm and neural activation patterns underlying locomotion can be demonstrated under specific experimental conditions in reduced animal preparations. The existence of CPGs in humans is a matter of debate. Equally elusive is the contribution of CPGs to normal bipedal locomotion. To address these points, we focus on human studies that utilized spinal cord stimulation or pharmacological neuromodulation to generate rhythmic activity in individuals with spinal cord injury, and on neuromechanical modeling of human locomotion...
March 1, 2017: Neuroscientist: a Review Journal Bringing Neurobiology, Neurology and Psychiatry
https://www.readbyqxmd.com/read/28350336/sensor-fault-and-delay-tolerant-control-for-networked-control-systems-subject-to-external-disturbances
#16
Shi-Yuan Han, Yue-Hui Chen, Gong-You Tang
In this paper, the problem of sensor fault and delay tolerant control problem for a class of networked control systems under external disturbances is investigated. More precisely, the dynamic characteristics of the external disturbance and sensor fault are described as the output of exogenous systems first. The original sensor fault and delay tolerant control problem is reformulated as an equivalence problem with designed available system output and reformed performance index. The feedforward and feedback sensor fault tolerant controller (FFSFTC) can be obtained by utilizing the solutions of Riccati matrix equation and Stein matrix equation...
March 28, 2017: Sensors
https://www.readbyqxmd.com/read/28348530/paradigm-shifts-in-voluntary-force-control-and-motor-unit-behaviors-with-the-manipulated-size-of-visual-error-perception
#17
Yi-Ching Chen, Yen-Ting Lin, Gwo-Ching Chang, Ing-Shiou Hwang
The detection of error information is an essential prerequisite of a feedback-based movement. This study investigated the differential behavior and neurophysiological mechanisms of a cyclic force-tracking task using error-reducing and error-enhancing feedback. The discharge patterns of a relatively large number of motor units (MUs) were assessed with custom-designed multi-channel surface electromyography following mathematical decomposition of the experimentally-measured signals. Force characteristics, force-discharge relation, and phase-locking cortical activities in the contralateral motor cortex to individual MUs were contrasted among the low (LSF), normal (NSF), and high scaling factor (HSF) conditions, in which the sizes of online execution errors were displayed with various amplification ratios...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28341164/expectation-violation-and-attention-to-pain-jointly-modulate-neural-gain-in-somatosensory-cortex
#18
Francesca Fardo, Ryszard Auksztulewicz, Micah Allen, Martin J Dietz, Andreas Roepstorff, Karl J Friston
The neural processing and experience of pain are influenced by both expectations and attention. For example, the amplitude of event-related pain responses is enhanced by both novel and unexpected pain, and by moving the focus of attention towards a painful stimulus. Under predictive coding, this congruence can be explained by appeal to a precision-weighting mechanism, which mediates bottom-up and top-down attentional processes by modulating the influence of feedforward and feedback signals throughout the cortical hierarchy...
March 21, 2017: NeuroImage
https://www.readbyqxmd.com/read/28334225/pom-thalamocortical-input-drives-layer-specific-microcircuits-in-somatosensory-cortex
#19
Nicholas J Audette, Joanna Urban-Ciecko, Megumi Matsushita, Alison L Barth
Higher-order thalamic nuclei, such as the posterior medial nucleus (POm) in the somatosensory system or the pulvinar in the visual system, densely innervate the cortex and can influence perception and plasticity. To systematically evaluate how higher-order thalamic nuclei can drive cortical circuits, we investigated cell-type selective responses to POm stimulation in mouse primary somatosensory (barrel) cortex, using genetically targeted whole-cell recordings in acute brain slices. We find that ChR2-evoked thalamic input selectively targets specific cell types in the neocortex, revealing layer-specific modules for the summation and processing of POm input...
March 10, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/28331874/the-importance-of-constructive-feedback-implications-of-top-down-regulation-in-the-development-of-neural-circuits
#20
Andrew D Thompson, Chinfei Chen
Neural circuits in sensory pathways develop through a general strategy of overproduction of synapses followed by activity-driven pruning to fine-tune connectivity for optimal function. The early visual pathway, consisting of the retina → visual thalamus → primary visual cortex, has served for decades as a powerful model system for probing the mechanisms and logic of this process. In addition to these feedforward projections, the early visual pathway also includes a substantial feedback component in the form of corticothalamic projections from the deepest layer of primary visual cortex...
2017: Neurogenesis (Austin, Tex.)
keyword
keyword
86626
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"