20,762 research outputs found

    Protecting privacy of users in brain-computer interface applications

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    Machine learning (ML) is revolutionizing research and industry. Many ML applications rely on the use of large amounts of personal data for training and inference. Among the most intimate exploited data sources is electroencephalogram (EEG) data, a kind of data that is so rich with information that application developers can easily gain knowledge beyond the professed scope from unprotected EEG signals, including passwords, ATM PINs, and other intimate data. The challenge we address is how to engage in meaningful ML with EEG data while protecting the privacy of users. Hence, we propose cryptographic protocols based on secure multiparty computation (SMC) to perform linear regression over EEG signals from many users in a fully privacy-preserving(PP) fashion, i.e., such that each individual's EEG signals are not revealed to anyone else. To illustrate the potential of our secure framework, we show how it allows estimating the drowsiness of drivers from their EEG signals as would be possible in the unencrypted case, and at a very reasonable computational cost. Our solution is the first application of commodity-based SMC to EEG data, as well as the largest documented experiment of secret sharing-based SMC in general, namely, with 15 players involved in all the computations

    A thin layer angiogenesis assay: a modified basement matrix assay for assessment of endothelial cell differentiation

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    BACKGROUND: Basement matrices such as Matrigel™ and Geltrex™ are used in a variety of cell culture assays of anchorage-dependent differentiation including endothelial cell tube formation assays. The volumes of matrix recommended for these assays (approximately 150 μl/cm(2)) are costly, limit working distances for microscopy, and require cell detachment for subsequent molecular analysis. Here we describe the development and validation of a thin-layer angiogenesis (TLA) assay for assessing the angiogenic potential of endothelial cells that overcomes these limitations. RESULTS: Geltrex™ basement matrix at 5 μl/cm(2) in 24-well (10 μl) or 96-well (2 μl) plates supports endothelial cell differentiation into tube-like structures in a comparable manner to the standard larger volumes of matrix. Since working distances are reduced, high-resolution single cell microscopy, including DIC and confocal imaging, can be used readily. Using MitoTracker dye we now demonstrate, for the first time, live mitochondrial dynamics and visualise the 3-dimensional network of mitochondria present in differentiated endothelial cells. Using a standard commercial total RNA extraction kit (Qiagen) we also show direct RNA extraction and RT-qPCR from differentiated endothelial cells without the need to initially detach cells from their supporting matrix. CONCLUSIONS: We present here a new thin-layer assay (TLA) for measuring the anchorage-dependent differentiation of endothelial cells into tube-like structures which retains all the characteristics of the traditional approach but with the added benefit of a greatly lowered cost and better compatibility with other techniques, including RT-qPCR and high-resolution microscopy. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12860-014-0041-5) contains supplementary material, which is available to authorized users

    Dynamic breakage and fragmentation of brittle single particle of various sizes and strength

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    2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Widespread translational control contributes to the regulation of Arabidopsis photomorphogenesis

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    Environmental light regulates and optimizes plant growth and development. Genomic profiling of polysome-associated mRNA reveals that light stimulates dramatic changes in translational regulation, which contribute more to light-induced gene expression changes than transcriptional regulation

    A remote anomaly detection system for Slocum underwater gliders

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    Marine Autonomous Systems (MAS) operating at sea beyond visual line of sight need to be self-reliant, as any malfunction could lead to loss or pose a risk to other sea users. In the absence of fully automated on-board control and fault detection tools, MAS are piloted and monitored by experts, resulting in high operational costs and limiting the scale of observational fleets that can be deployed simultaneously. Hence, an effective anomaly detection system is fundamental to increase fleet capacity and reliability. In this study, an on-line, remote fault detection system is developed for underwater gliders. Two alternative methods are analysed using time series data: feedforward deep neural networks estimating the glider’s vertical velocity and an autoencoder. The systems are trained using field data from four baseline deployments of Slocum gliders and tested on six deployments of vehicles suffering from adverse behaviour. The methods are able to successfully detect a range of anomalies in the near real time data streams, whilst being able to generalise to different glider configurations. The autoencoder’s error in reconstructing the original signals is the clearest indicator of anomalies. Thus, the autoencoder is a prime candidate to be included into an all-encompassing condition monitoring system for MAS

    A metabolite binding protein moonlights as a bile- responsive chaperone

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    Bile salts are secreted into the gastrointestinal tract to aid in the absorption of lipids. In addition, bile salts show potent antimicrobial activity in part by mediating bacterial protein unfolding and aggregation. Here, using a protein folding sensor, we made the surprising discovery that the Escherichia coli periplasmic glycerol- 3- phosphate (G3P)- binding protein UgpB can serve, in the absence of its substrate, as a potent molecular chaperone that exhibits anti- aggregation activity against bile salt- induced protein aggregation. The substrate G3P, which is known to accumulate in the later compartments of the digestive system, triggers a functional switch between UgpB’s activity as a molecular chaperone and its activity as a G3P transporter. A UgpB mutant unable to bind G3P is constitutively active as a chaperone, and its crystal structure shows that it contains a deep surface groove absent in the G3P- bound wild- type UgpB. Our work illustrates how evolution may be able to convert threats into signals that first activate and then inactivate a chaperone at the protein level in a manner that bypasses the need for ATP.SynopsisThe periplasmic glycerol- 3- phosphate binding protein, UgpB, was found to have dual functions, as a metabolite binding protein and as a bile- responsive molecular chaperone. Stomach- acid induced stripping of its glycerol- 3- phosphate substrate functions as a switch that activates the chaperone activity of UgpB.A tripartite periplasmic protein folding sensor and Tn- Seq uncover UgpB as a new chaperone.UgpB prevents bile- induced protein aggregation when in its G3P- free form.Stomach acid- induced G3P stripping activates UgpB chaperone function.Crystal structure of a G3P- nonbinding variant of UgpB reveals opening of a deep surface groove when compared to the structure of G3P- bound wild- type UgpB.A periplasmic folding sensor reveals a mechanism by which stomach acid- induced G3P stripping remodels UgpB into a chaperone that prevents bile- induced bacterial protein aggregation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163430/6/embj2019104231.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163430/5/embj2019104231-sup-0002-EVFigs.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163430/4/embj2019104231-sup-0006-SDataFig3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163430/3/embj2019104231.reviewer_comments.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163430/2/embj2019104231_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163430/1/embj2019104231-sup-0005-SDataFig2.pd

    Unsupervised anomaly detection for underwater gliders using generative adversarial networks

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    An effective anomaly detection system is critical for marine autonomous systems operating in complex and dynamic marine environments to reduce operational costs and achieve concurrent large-scale fleet deployments. However, developing an automated fault detection system remains challenging for several reasons including limited data transmission via satellite services. Currently, most anomaly detection for marine autonomous systems, such as underwater gliders, rely on intensive analysis by pilots. This study proposes an unsupervised anomaly detection system using bidirectional generative adversarial networks guided by assistive hints for marine autonomous systems with time series data collected by multiple sensors. In this study, the anomaly detection system for a fleet of underwater gliders is trained on two healthy deployment datasets and tested on other nine deployment datasets collected by a selection of vehicles operating in a range of locations and environmental conditions. The system is successfully applied to detect anomalies in the nine test deployments, which include several different types of anomalies as well as healthy behaviour. Also, a sensitivity study of the data decimation settings suggests the proposed system is robust for Near Real-Time anomaly detection for underwater gliders

    Retrograde semaphorin-plexin signalling drives homeostatic synaptic plasticity.

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    Homeostatic signalling systems ensure stable but flexible neural activity and animal behaviour. Presynaptic homeostatic plasticity is a conserved form of neuronal homeostatic signalling that is observed in organisms ranging from Drosophila to human. Defining the underlying molecular mechanisms of neuronal homeostatic signalling will be essential in order to establish clear connections to the causes and progression of neurological disease. During neural development, semaphorin-plexin signalling instructs axon guidance and neuronal morphogenesis. However, semaphorins and plexins are also expressed in the adult brain. Here we show that semaphorin 2b (Sema2b) is a target-derived signal that acts upon presynaptic plexin B (PlexB) receptors to mediate the retrograde, homeostatic control of presynaptic neurotransmitter release at the neuromuscular junction in Drosophila. Further, we show that Sema2b-PlexB signalling regulates presynaptic homeostatic plasticity through the cytoplasmic protein Mical and the oxoreductase-dependent control of presynaptic actin. We propose that semaphorin-plexin signalling is an essential platform for the stabilization of synaptic transmission throughout the developing and mature nervous system. These findings may be relevant to the aetiology and treatment of diverse neurological and psychiatric diseases that are characterized by altered or inappropriate neural function and behaviour
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