1,093 research outputs found

    Development of a Silent Speech Interface for Augmented Reality Applications

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    Adoption of Augmented and Virtual Reality (AR and VR) interfaces in the aerospace and defense fields has been inhibited by conspicuous and cumbersome input mechanisms such as gestures and spoken voice recognition. Silent speech interfaces using non-invasive electromyography (EMG) sensors are posited as a means for controlling AR and VR interfaces with potential for inconspicuous and high bandwidth input. Our objective is to develop a silent speech interface that receives input from subvocalizations via skin surface EMG sensors, which is then decoded into commands for controlling a heads-up-display built on a Microsoft HoloLens. EMG sensors are placed on the Digastric, Stylohyoid, Sternohyoid, and Cricothyroid muscles located on the anterior cervical region. The collected data is used to train a convolutional neural network that functions as a classifier, determining the subject’s subvocal input against a word library. The user will equip the wearable interface and use it to silently send commands through subvocalizations to control an AR device. Effectiveness of the wearable interface will be defined by word recognition accuracies in mouthed trials using the current command library. Future work includes expanding the dataset used to train the recognition model and live demonstration in controlling an augmented reality interface

    Contracting the Facebook API

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    In recent years, there has been an explosive growth in the popularity of online social networks such as Facebook. In a new twist, third party developers are now able to create their own web applications which plug into Facebook and work with Facebook's "social" data, enabling the entire Facebook user base of more than 400 million active users to use such applications. These client applications can contain subtle errors that can be hard to debug if they misuse the Facebook API. In this paper we present an experience report on applying Microsoft's new code contract system for the .NET framework to the Facebook API.We wrote contracts for several classes in the Facebook API wrapper which allows Microsoft .NET developers to implement Facebook applications. We evaluated the usefulness of these contracts during implementation of a new Facebook application. Our experience indicates that having code contracts provides a better and quicker software development experience.Comment: In Proceedings TAV-WEB 2010, arXiv:1009.330

    Enhancing 1α-Hydroxylase Activity with the 25-Hydroxyvitamin D-1α-Hydroxylase Gene in Cultured Human Keratinocytes and Mouse Skin

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    1α,25-Dihydroxyvitamin D3 (1α,25(OH)2D3) and its analogs are used to treat psoriasis because of their potent antiproliferative activity. They have the potential for causing hypercalcemia, however, and patients often become resistant to the drug. We examined the feasibility of enhancing the cutaneous production of 1α,25(OH)2D3 using a human 25-hydroxyvitamin D-1α-hydroxylase (1α-OHase) plasmid. The 1α-OHase gene was fused to the green fluorescent protein gene (1α-OHase-GFP) driven by the cytomegalovirus promoter. Transfection of cultured normal human keratinocytes with the 1α-OHase-GFP plasmid resulted in a marked increase in the expression of 1α-OHase-GFP in the mitochondria. Transfection of keratinocytes with 1α-OHase-GFP or 1α-OHase plasmids in vitro enhanced the 1α-OHase activity substantially and increased the sensitivity of the keratinocytes to the antiproliferative effect of 25(OH)D3. The 1α-OHase-GFP plasmid was topically applied to shaved C57/BL6 mice. Twenty-four hours after topical application, immunohistochemical analysis of the skin for 1α-OHase-GFP revealed the presence of 1α-OHase-GFP in the epidermis and epidermal appendages including the hair follicles. The results from this study offer a unique new approach for the topical treatment of hyperproliferative disorders such as psoriasis and skin cancer using the 1α-OHase gene that could locally increase the production of 1α,25(OH)2D3 without causing hypercalcemia or resistance

    Tapering practices of New Zealand's elite raw powerlifters

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    Pritchard, HJ, Tod, DA, Barnes, MJ, Keogh, JW, and McGuigan, MR. Tapering practices of New Zealand's elite raw powerlifters. J Strength Cond Res 30(7): 1796-1804, 2016-The major aim of this study was to determine tapering strategies of elite powerlifters. Eleven New Zealand powerlifters (28.4 ± 7.0 years, best Wilks score of 431.9 ± 43.9 points) classified as elite were interviewed, using semistructured interviews, about their tapering strategies. Interviews were transcribed verbatim and content analyzed. Total training volume peaked 5.2 ± 1.7 weeks from competition while average training intensity (of 1 repetition maximum) peaked 1.9 ± 0.8 weeks from competition. During tapering, volume was reduced by 58.9 ± 8.4% while intensity was maintained (or slightly reduced) and the final weight training session was performed 3.7 ± 1.6 days out from competition. Participants generally stated that tapering was performed to achieve full recovery; that accessory work was removed around 2 weeks out from competition; and deadlifting takes longer to recover from than other lifts. Typically participants stated that trial and error, and changes based on "feel" were the sources of tapering strategies; equipment used and movements performed during tapering are the same as in competition; nutrition was manipulated during the taper (for weight cutting or performance aims); and poor tapering occurred when too long (1 week or more) was taken off training. These results suggest that athletes may benefit from continuing to strength train before important events with reduced volume and maintained intensity. Only exercises that directly assist sports performance should remain in the strength program during tapering, to assist with reductions in fatigue while maintaining/improving strength expression and performance

    Characteristics of starch-based films with different amylose contents plasticised by 1-ethyl-3-methylimidazolium acetate

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    Starch-based films plasticised by an ionic liquid, 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]), were prepared by a simple compression moulding process, facilitated by the strong plasticisation effect of [Emim][OAc]. The effects of amylose content of starch (regular vs. high-amylose maize) and relative humidity (RH) during ageing of the samples on a range of structural and material characteristics were investigated. Surprisingly, plasticisation by [Emim][OAc] made the effect of amylose content insignificant, contrary to most previous studies when other plasticisers were used. In other words, [Emim][OAc] changed the underlying mechanism responsible for mechanical properties from the entanglement of starch macromolecules (mainly amylose), which has been reported as a main responsible factor previously. The crystallinity of the plasticised starch samples was low and thus was unlikely to have a major contribution to the material characteristics, although the amylose content impacted on the crystalline structure and the mobility of amorphous parts in the samples to some extent. Therefore, RH conditioning and thus the sample water content was the major factor influencing the mechanical properties, glass transition temperature, and electrical conductivity of the starch films. This suggests the potential application of ionic liquid-plasticised starch materials in areas where the control of properties by environmental RH is desired

    Quantum Inequalities and Singular Energy Densities

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    There has been much recent work on quantum inequalities to constrain negative energy. These are uncertainty principle-type restrictions on the magnitude and duration of negative energy densities or fluxes. We consider several examples of apparent failures of the quantum inequalities, which involve passage of an observer through regions where the negative energy density becomes singular. We argue that this type of situation requires one to formulate quantum inequalities using sampling functions with compact support. We discuss such inequalities, and argue that they remain valid even in the presence of singular energy densities.Comment: 18 pages, LaTex, 2 figures, uses eps

    Human glutathione transferase T2-2 discloses some evolutionary strategies for optimization of the catalytic activity of glutathione transferases.

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    Steady state, pre-steady state kinetic experiments, and site-directed mutagenesis have been used to dissect the catalytic mechanism of human glutathione transferase T2-2 with 1-menaphthyl sulfate as co-substrate. This enzyme is close to the ancestral precursor of the more recently evolved glutathione transferases belonging to Alpha, Pi, and Mu classes. The enzyme displays a random kinetic mechanism with very low k(cat) and k(cat)/K(m)((GSH)) values and with a rate-limiting step identified as the product release. The chemical step, which is fast and causes product accumulation before the steady state catalysis, strictly depends on the deprotonation of the bound GSH. Replacement of Arg-107 with Ala dramatically affects the fast phase, indicating that this residue is crucial both in the activation and orientation of GSH in the ternary complex. All pre-steady state and steady state kinetic data were convincingly fit to a kinetic mechanism that reflects a quite primordial catalytic efficiency of this enzyme. It involves two slowly interconverting or not interconverting enzyme populations (or active sites of the dimeric enzyme) both able to bind and activate GSH and strongly inhibited by the product. Only one population or subunit is catalytically competent. The proposed mechanism accounts for the apparent half-site behavior of this enzyme and for the apparent negative cooperativity observed under steady state conditions. These findings also suggest some evolutionary strategies in the glutathione transferase family that have been adopted for the optimization of the catalytic activity, which are mainly based on an increased flexibility of critical protein segments and on an optimal orientation of the substrate

    Multihospital Outbreak of Clostridium difficile Ribotype 027 Infection: Epidemiology and Analysis of Control Measures

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    Objective. To report a large outbreak of Clostridium difficile infection (CDI; ribotype 027) between June 2007 and August 2008, describe infection control measures, and evaluate the impact of restricting the use of fluoroquinolones in controlling the outbreak. Design. Outbreak investigation in 3 acute care hospitals of the Northern Health and Social Care Trust in Northern Ireland. Interventions. Implementation of a series of CDI control measures that targeted high-risk antibiotic agents (ie, restriction of fluoroquinolones), infection control practices, and environmental hygiene. Results. A total of 318 cases of CDI were identified during the outbreak, which was the result of the interaction between C. difficile ribotype 027 being introduced into the affected hospitals for the first time and other predisposing risk factors (ranging from host factors to suboptimal compliance with antibiotic guidelines and infection control policies). The 30-day all-cause mortality rate was 24.5%; however, CDI was the attributable cause of death for only 2.5% of the infected patients. Time series analysis showed that restricting the use of fluoroquinolones was associated with a significant reduction in the incidence of CDI (coefficient, —0.054; lag time, 4 months; P = .003). Conclusion. These findings provide additional evidence to support the value of antimicrobial stewardship as an essential element of multifaceted interventions to control CDI outbreaks. The present CDI outbreak was ended following the implementation of an action plan improving communication, antibiotic stewardship, infection control practices, environmental hygiene, and surveillanc
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