485 research outputs found

    A videotape of an optical lab, Just what the doctor ordered: The optical lab in perspective

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    A sixteen minute videotape of an optical lab was made. This tape was prepared to be used in classes of ophthalmic optics to explain to optometry students how a pair of glasses is made. An account of each step involved in the process is contained on the videotape

    A Local Correlation Score to Monitor Sensor Drift of Real-Time Environmental Data

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    2012 S.C. Water Resources Conference - Exploring Opportunities for Collaborative Water Research, Policy and Managemen

    Space Shuttle Program: Automatic rendezvous, proximity operations, and capture (category 3)

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    The NASA Johnson Space Center is actively pursuing the development and demonstration of capabilities for automatic rendezvous, proximity operations, and capture (AR&C) using the Space Shuttle as the active vehicle. This activity combines the technologies, expertise, tools, and facilities of the JSC Tracking and Communications Division (EE), Navigation, Control and Aeronautics Division (EG), Automation and Robotics Division (ER), and Structures and Mechanics Division (ES) of the Engineering Directorate and the Flight Design and Dynamics Division (DM) of the Mission Operations Directorate. Potential benefits of AR&C include more efficient and repeatable rendezvous, proximity operations, and capture operations; reduced impacts on the target vehicles (e.g., Orbiter RCS plume loads); reduced flight crew work loads; reduced ground support requirements; and reduced operational constraints. This paper documents the current JSC capabilities/tools/facilities for AR&C and describes a proposed plan for a progression of ground demonstrations and flight tests and demonstrations of AR&C capabilities. This plan involves the maturing of existing technologies in tracking and communications; guidance, navigation and control; mechanisms; manipulators; and systems management and integrating them into several evolutionary demonstration stages

    Data Quality Assessment Using a Sliding Window Cumulative Sum Control Chart

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    2012 S.C. Water Resources Conference - Exploring Opportunities for Collaborative Water Research, Policy and Managemen

    Comparative plasma catecholamine and hemodynamic responses to handgrip, cold pressor and supine bicycle exercise testing in normal subjects

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    Serial hemodynamic and plasma catecholamine responses were compared among 10 healthy men (27 ± 3 years) ( ± 1 standard deviation) during symptom-limited handgrip (33% maximal voluntary contraction for 4.4 ± 1.8 minutes), cold pressor testing (6 minutes) and symptom-limited supine bicycle exercise (22 ± 5 minutes). Plasma catecholamine concentrations were measured by radioenzymatic assays; ejection fraction and changes in cardiac volumes were assessed by equilibrium radionuclide angiography. During maximal supine exercise, plasma norepinephrine and epinephrine concentrations increased three to six times more than during either symptom-limited handgrip or cold pressor testing. Additionally, increases in heart rate, systolic blood pressure, rate-pressure product, stroke volume, ejection fraction and cardiac output were significantly greater during bicycle exercise than during the other two tests. A decrease in ejection fraction of 0.05 units or more was common in young normal subjects during the first 2 minutes of cold pressor testing (6 of 10 subjects) or at symptom-limited handgrip (3 of 10), but never occurred during maximal supine bicycle exercise.The magnitude of hemodynamic changes with maximal supine bicycle exercise was greater, more consistent and associated with much higher sympathetic nervous system activation, making this a potentially more useful diagnostic stress than either handgrip exercise or cold pressor testing

    PERP, a host tetraspanning membrane protein, is required for Salmonella-induced inflammation

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    Salmonella enterica Typhimurium induces intestinal inflammation through the activity of type III secreted effector (T3SE) proteins. Our prior results indicate that the secretion of the T3SE SipA and the ability of SipA to induce epithelial cell responses that lead to induction of polymorphonuclear transepithelial migration are not coupled to its direct delivery into epithelial cells from Salmonella. We therefore tested the hypothesis that SipA interacts with a membrane protein located at the apical surface of intestinal epithelial cells. Employing a split ubiquitin yeast-two-hybrid screen, we identified the tetraspanning membrane protein, p53 effector related to PMP-22 (PERP), as a SipA binding partner. SipA and PERP appear to have intersecting activities as we found PERP to be involved in proinflammatory pathways shown to be regulated by SipA. In sum, our studies reveal a critical role for PERP in the pathogenesis of S. Typhimurium, and for the first time demonstrate that SipA, a T3SE protein, can engage a host protein at the epithelial surface

    Availability: A Metric for Nucleic Acid Strand Displacement Systems

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    DNA strand displacement systems have transformative potential in synthetic biology. While powerful examples have been reported in DNA nanotechnology, such systems are plagued by leakage, which limits network stability, sensitivity, and scalability. An approach to mitigate leakage in DNA nanotechnology, which is applicable to synthetic biology, is to introduce mismatches to complementary fuel sequences at key locations. However, this method overlooks nuances in the secondary structure of the fuel and substrate that impact the leakage reaction kinetics in strand displacement systems. In an effort to quantify the impact of secondary structure on leakage, we introduce the concepts of availability and mutual availability and demonstrate their utility for network analysis. Our approach exposes vulnerable locations on the substrate and quantifies the secondary structure of fuel strands. Using these concepts, a 4-fold reduction in leakage has been achieved. The result is a rational design process that efficiently suppresses leakage and provides new insight into dynamic nucleic acid networks

    Stories of Hell and Healing: Internet Users’ Construction of Benzodiazepine Distress and Withdrawal

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    Abstract Benzodiazepines are a group of drugs used mainly as sedatives, hypnotics, antiepileptics, and muscle relaxants. Consumption is recommended for 2 to 4 weeks only, due to fast onset of dependency and potentially distressing withdrawal symptoms. Few peer-review studies have drawn on the user experiences and language to appreciate firsthand experiences of benzodiazepine withdrawal or discontinuation syndrome. We looked extensively at patient stories of benzodiazepine withdrawal and recovery on Internet support sites and YouTube. Our analysis indicated that users employ rich metaphors to portray the psychologically disturbing and protracted nature of their suffering. We identified seven major themes: hell and isolation, anxiety and depression, alienation, physical distress, anger and remorse, waves and windows, and healing and renewal. By posting success stories, ex-users make known that “healing” can be a long, unpredictable process, but distress does lessen, and recovery can happen

    Cyberinfrastructure for Preservation of Stream and River Ecology

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    2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio
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