862 research outputs found
Genetic landscape of autism spectrum disorder in Vietnamese children
Autism spectrum disorder (ASD) is a complex disorder with an unclear aetiology and an estimated global prevalence of 1%. However, studies of ASD in the Vietnamese population are limited. Here, we first conducted whole exome sequencing (WES) of 100 children with ASD and their unaffected parents. Our stringent analysis pipeline was able to detect 18 unique variants (8 de novo and 10 ×-linked, all validated), including 12 newly discovered variants. Interestingly, a notable number of X-linked variants were detected (56%), and all of them were found in affected males but not in affected females. We uncovered 17 genes from our ASD cohort in which CHD8, DYRK1A, GRIN2B, SCN2A, OFD1 and MDB5 have been previously identified as ASD risk genes, suggesting the universal aetiology of ASD for these genes. In addition, we identified six genes that have not been previously reported in any autism database: CHM, ENPP1, IGF1, LAS1L, SYP and TBX22. Gene ontology and phenotype-genotype analysis suggested that variants in IGF1, SYP and LAS1L could plausibly confer risk for ASD. Taken together, this study adds to the genetic heterogeneity of ASD and is the first report elucidating the genetic landscape of ASD in Vietnamese children
Increase in regularity and decrease in variability seen in electroencephalography (EEG) signals from alert to fatigue during a driving simulated task.
Driver fatigue is a prevalent problem and a major risk for road safety accounting for approximately 20-40% of all motor vehicle accidents. One strategy to prevent fatigue related accidents is through the use of countermeasure devices. Research on countermeasure devices has focused on methods that detect physiological changes from fatigue, with the fast temporal resolution from brain signals, using the electroencephalogram (EEG) held as a promising technique. This paper presents the results of nonlinear analysis using sample entropy and second-order difference plots quantified by central tendency measure (CTM) on alert and fatigue EEG signals from a driving simulated task. Results show that both sample entropy and second-order difference plots significantly increases the regularity and decreases the variability of EEG signals from an alert to a fatigue state
Effects of mental fatigue on 8-13Hz brain activity in people with spinal cord injury.
Brain computer interfaces (BCIs) can be implemented into assistive technologies to provide 'hands-free' control for the severely disabled. BCIs utilise voluntary changes in one's brain activity as a control mechanism to control devices in the person's immediate environment. Performance of BCIs could be adversely affected by negative physiological conditions such as fatigue and altered electrophysiology commonly seen in spinal cord injury (SCI). This study examined the effects of mental fatigue from an increase in cognitive demand on the brain activity of those with SCI. Results show a trend of increased alpha (8-13Hz) activity in able-bodied controls after completing a set of cognitive tasks. Conversely, the SCI group showed a decrease in alpha activity due to mental fatigue. Results suggest that the brain activity of SCI persons are altered in its mechanism to adjust to mental fatigue. These altered brain conditions need to be addressed when using BCIs in clinical populations such as SCI. The findings have implications for the improvement of BCI technology
Prediction of freezing of gait using analysis of brain effective connectivity
© 2014 IEEE. Freezing of gait (FOG) is a debilitating symptom of Parkinson's disease (PD), in which patients experience sudden difficulties in starting or continuing locomotion. It is described by patients as the sensation that their feet are suddenly glued to the ground. This, disturbs their balance, and hence often leads to falls. In this study, directed transfer function (DTF) and partial directed coherence (PDC) were used to calculate the effective connectivity of neural networks, as the input features for systems that can detect FOG based on a Multilayer Perceptron Neural Network, as well as means for assessing the causal relationships in neurophysiological neural networks during FOG episodes. The sensitivity, specificity and accuracy obtained in subject dependent analysis were 82%, 77%, and 78%, respectively. This is a significant improvement compared to previously used methods for detecting FOG, bringing this detection system one step closer to a final version that can be used by the patients to improve their symptoms
Using EEG spatial correlation, cross frequency energy, and wavelet coefficients for the prediction of Freezing of Gait in Parkinson's Disease patients
Parkinson's Disease (PD) patients with Freezing of Gait (FOG) often experience sudden and unpredictable failure in their ability to start or continue walking, making it potentially a dangerous symptom. Emerging knowledge about brain connectivity is leading to new insights into the pathophysiology of FOG and has suggested that electroencephalogram (EEG) may offer a novel technique for understanding and predicting FOG. In this study we have integrated spatial, spectral, and temporal features of the EEG signals utilizing wavelet coefficients as our input for the Multilayer Perceptron Neural Network and k-Nearest Neighbor classifier. This approach allowed us to predict transition from walking to freezing with 87 % sensitivity and 73 % accuracy. This preliminary data affirms the functional breakdown between areas in the brain during FOG and suggests that EEG offers potential as a therapeutic strategy in advanced PD. © 2013 IEEE
Service Development Life Cycle for Hybrid Cloud Environments
With increasing adoption of cloud computing there is a need to provide methodological and tool support for the development of enterprise applications that utilize cloud services. Traditional approaches that assume that services are developed and deployed on-premise are not suitable for hybrid cloud environments, where a significant part of enterprise applications is delivered in the form of cloud services provided by autonomous cloud providers. In this paper we describe a Service Development Life Cycle for hybrid cloud environments and a prototype system designed to support this life cycle
Service repository for cloud service consumer life cycle management
© IFIP International Federation for Information Processing 2015. With rapid uptake of various types of cloud services many organizations are facing issues arising from their dependence on externally provided cloud services. In order to enable operation in this rapidly evolving environment, end user organizations need new methods and tools that support entire life-cycle of cloud services from the perspective of service consumers. Service repositories play a key role in supporting service consumer SDLC (Systems Development Life-Cycle) maintaining information that is used during the various life-cycle phases. In this paper we briefly describe service consumer SDLC and propose a design of service repository that supports information requirements throughout the service life-cycle
An instability criterion for nonlinear standing waves on nonzero backgrounds
A nonlinear Schr\"odinger equation with repulsive (defocusing) nonlinearity
is considered. As an example, a system with a spatially varying coefficient of
the nonlinear term is studied. The nonlinearity is chosen to be repelling
except on a finite interval. Localized standing wave solutions on a non-zero
background, e.g., dark solitons trapped by the inhomogeneity, are identified
and studied. A novel instability criterion for such states is established
through a topological argument. This allows instability to be determined
quickly in many cases by considering simple geometric properties of the
standing waves as viewed in the composite phase plane. Numerical calculations
accompany the analytical results.Comment: 20 pages, 11 figure
Semi-autonomous wheelchair developed using a unique camera system configuration biologically inspired by equine vision
This paper is concerned with the design and development of a semi-autonomous wheelchair system using cameras in a system configuration modeled on the vision system of a horse. This new camera configuration utilizes stereoscopic vision for 3-Dimensional (3D) depth perception and mapping ahead of the wheelchair, combined with a spherical camera system for 360-degrees of monocular vision. This unique combination allows for static components of an unknown environment to be mapped and any surrounding dynamic obstacles to be detected, during real-time autonomous navigation, minimizing blind-spots and preventing accidental collisions with people or obstacles. This novel vision system combined with shared control strategies provides intelligent assistive guidance during wheelchair navigation and can accompany any hands-free wheelchair control technology. Leading up to experimental trials with patients at the Royal Rehabilitation Centre (RRC) in Ryde, results have displayed the effectiveness of this system to assist the user in navigating safely within the RRC whilst avoiding potential collisions. © 2011 IEEE
Combining ICA Clustering and Power Spectral Density for Feature Extraction of Mental Fatigue of Spinal Cord Injury Patients
© 2019 IEEE. This paper presents the combination of clustering-based independent component analysis (ICASSO) and power spectral density (PSD) as a features extractor of mental fatigue from spinal cord injury (SCI) patients. Initially, the results show that SCI and abled-bodied groups have no differences in EEG for alert and mental fatigue states. Further, the coefficient determination (R2) is calculated for testing the variation of data alert vs. fatigue on the SCI group, resulting in a lower R2 for proposed combination of ICASSO and PSD method compared to the PSD method only. With the lower R2 values, this shows that the proposed method ICASSO and PSD is able to provide superior distinction for separating fatigue vs. alert data variation. The statistical significance is found across four EEG bands and EEG channels
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