4,733 research outputs found

    A Comparison of a Brain-Computer Interface and an Eye Tracker: Is There a More Appropriate Technology for Controlling a Virtual Keyboard in an ALS Patient?

    Get PDF
    The ability of people affected by amyotrophic lateral sclerosis (ALS), muscular dystrophy or spinal cord injuries to physically interact with the environment, is usually reduced. In some cases, these patients suffer from a syndrome known as locked-in syndrome (LIS), defined by the patient’s inability to make any move-ment but blinks and eye movements. Tech communication systems available for people in LIS are very limited, being those based on eye-tracking and brain-computer interface (BCI) the most useful for these patients. A comparative study between both technologies in an ALS patient is carried out: an eye tracker and a visual P300-based BCI. The purpose of the study presented in this paper is to show that the choice of the technology could depend on user®s preference. The evaluation of performance, workload and other subjective measures will allow us to determine the usability of the systems. The obtained results suggest that, even if for this patient the BCI technology is more appropriate, the technology should be always tested and adapted for each user.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Aharanov-Bohm excitons at elevated temperatures in type-II ZnTe/ZnSe quantum dots

    Full text link
    Optical emission from type-II ZnTe/ZnSe quantum dots demonstrates large and persistent oscillations in both the peak energy and intensity indicating the formation of coherently rotating states. Furthermore, the Aharanov-Bohm (AB) effect is shown to be remarkably robust and persists until 180K. This is at least one order of magnitude greater than the typical temperatures in lithographically defined rings. To our knowledge this is the highest temperature at which the AB effect has been observed in semiconductor structures

    α<sub>1L</sub>-adrenoceptors mediate contraction of human erectile tissue

    Get PDF
    α1-adrenoceptor antagonists can impact upon sexual function and have potential in the treatment of erectile dysfunction. Human erectile tissue contains predominantly α1A-adrenoceptors, and here we examined whether contractions of this tissue are mediated by the functional phenotype, the α1L-adrenoceptor. Functional experiments using subtype selective agonists and antagonists, along with radioligand ([3H]tamsulosin) binding assays, were used to determine the α1-adrenoceptor population. A61603, a α1A-adrenoceptor agonist, was a full agonist with a potency 21-fold greater than that of noradrenaline. The α1A- and α1D-adrenoceptor antagonist tamsulosin antagonized noradrenaline responses with high affinity (pKD = 9.7 ± 0.3), whilst BMY7378 (100 nM) (α1D-adrenoceptor antagonist) failed to antagonize responses. In contrast, relatively low affinity estimates were obtained for both prazosin (pKD = 8.2 ± 0.1) and RS17053 (pKD = 6.9 ± 0.2), antagonists which discriminate between the α1A- and α1L-adrenoceptors. [3H]Tamsulosin bound with high affinity to the receptors of human erectile tissue (pKD = 10.3 ± 0.1) with a receptor density of 28.1 ± 1.4 fmol mg−1 protein. Prazosin displacement of [3H]tamsulosin binding revealed a single homogenous population of binding sites with a relatively low affinity for prazosin (pKi = 8.9). Taken together these data confirm that the receptor mediating contraction in human erectile tissue has the pharmacological properties of the α1L-adrenoceptor. Keywords: Erectile tissue, α1-adrenoceptor subtypes, α1L-adrenoceptor, Tamsulosin, Prazosi

    Separated flow

    Get PDF
    A brief overview of flow separation phenomena is provided. Langley has many active research programs in flow separation related areas. Three cases are presented which describe specific examples of flow separation research. In each example, a description of the fundamental fluid physics and the complexity of the flow field is presented along with a method of either reducing or controlling the extent of separation. The following examples are discussed: flow over a smooth surface with an adverse pressure gradient; flow over a surface with a geometric discontinuity; and flow with shock-boundary layer interactions. These results will show that improvements are being made in the understanding of flow separation and its control

    A Nanosatellite Mission to Investigate Equatorial Ionospheric Plasma Depletions: The U. S. Air Force Academy’s FalconSat-2

    Get PDF
    An overview of the United States Air Force Academy’s (USAFA’s) FalconSat-2, a nanosatellite designed to investigate F region ionospheric plasma depletions, is presented. Instruments aboard FalconSat-2 will sample in situ plasma density and temperature at a rate of 10 Hz and 1.0 Hz, respectively. The choice of sampling rate provides for resolution of 2-10 km plasma depletions, important since plasma anisotropies of this scale size are known to disrupt Ultra High Frequency (UHF) radio transmissions. A novel sensor, the Miniature Electrostatic Analyzer (MESA), is presently under development by USAFA faculty and will be used to measure plasma density with its heritage flight aboard FalconSat-2. In addition, a traditional electron Retarding Potential Analyzer (RPA) will be used to measure plasma temperature and density, the latter of which will be used to validate the MESA performance on orbit. The mission’s scientific objectives require a low altitude (300-500 km), medium inclination (45 degrees) orbit; these requirements, coupled with the availability of launch opportunities through the Space Shuttle’s Hitchhiker Program, provide motivation to develop the FalconSat-2 mission for launch via the Hitchhiker’s Palette Ejection System (PES). The satellite bus design consists of a mixture of Commercial Off-The-Shelf (COTS) hardware and original design by USAFA cadets and faculty. Details of the mission and satellite design, as well as key challenges uniquely pertinent to undergraduate satellite programs, are addressed

    Simple, sensitive and species-specific assays for detecting quagga and zebra mussels (Dreissena rostriformis bugensis and D. polymorpha) using environmental DNA

    Get PDF
    Early detection is paramount for attempts to remove invasive non-native species (INNS). Traditional methods rely on physical sampling and morphological identification, which can be problematic when species are in low densities and/or are cryptic. The use of environmental DNA (eDNA) as a monitoring tool in freshwater systems is becoming increasingly acceptable and widely used for the detection of single species. Here we demonstrate the development and application of standard PCR primers for the detection of two freshwater invasive species which are high priority for monitoring in the UK and elsewhere: the Dreissenid mussels; Dreissena rostriformis bugensis (Andrusov, 1987) and D. polymorpha (Pallas, 1771). We carried out a rigorous validation process for testing the new primers, including DNA detection and degradation experiments in mesocosms, and a field comparison with traditional monitoring protocols. eDNA from single individuals of both mussel species could be detected within four hours of the start of the mesocosm experiment. In field trials, the two mussel species were detected at all sites where the species are known to be present, and eDNA consistently outperformed traditional kick-net sampling for species detection. These results demonstrate the applicability of standard PCR for eDNA detection of freshwater invasive species

    Robust Magnetic Polarons in Type-II (Zn,Mn)Te Quantum Dots

    Full text link
    We present evidence of magnetic ordering in type-II (Zn, Mn) Te quantum dots. This ordering is attributed to the formation of bound magnetic polarons caused by the exchange interaction between the strongly localized holes and Mn within the dots. In our photoluminescence studies, the magnetic polarons are detected at temperatures up to ~ 200 K, with a binding energy of ~ 40 meV. In addition, these dots display an unusually small Zeeman shift with applied field (2 meV at 10 T). This behavior is explained by a small and weakly temperature-dependent magnetic susceptibility due to anti-ferromagnetic coupling of the Mn spins

    Finishing Beef Cattle on Grass with Self-Fed By-Products

    Get PDF
    There has been increasing interest by consumers in beef from cattle that are finished or fattened “on grass” rather than in a conventional feedlot. Also recently, Iowa has had a proliferation of plants that produce ethanol from corn. The byproduct of this process is distillers dried grains with solubles (DDGS). The objective of this study was to feed beef cattle to market weight by grazing cool-season grass supplemented with self-fed by-product pellets

    Banking from Leeds, not London: regional strategy and structure at the Yorkshire Bank, 1859–1952

    Get PDF
    Industrial philanthropist Edward Akroyd created the Yorkshire Penny Savings Bank in 1859. Despite competition from the Post Office Savings Bank after 1861 and a serious reserve problem in 1911, it sustained his overall strategy to become a successful regional bank. Using archival and contemporary sources to build on recent scholarship illustrating how savings banks were integrated into local economies and the complementary roles of philanthropy and paternalism, we analyse an English regional bank's strategy, including an assessment of strategic innovation, ownership changes and management structure. This will demonstrate that the founder's vision continued, even though the 1911 crisis radically altered both strategy and structure
    • 

    corecore