6,460 research outputs found
TelosRFID an ad-hoc wireless networking capable multi-protocol RFID reader system
Radio Frequency IDentification (RFID) is rapidly being adopted as a powerful tool used in object tracking access control, telemedicine and inventory management. Its basic architecture endows reader devices with the capability to wirelessly read stored data off of RFID tags. Because of competing standards, there is no unified air protocol for RFID communication. The proliferation of competing standards, paired with the proprietary nature of commercial readers, can make maintaining and upgrading an RFID infrastructure expensive and time-consuming. Part of the solution that this thesis proposes is an RFID reader which supports custom air protocol implementations. To further reduce the costs associated with the adoption of a new infrastructure, RFID readers would benefit from supporting ad-hoc wireless networking. This feature mitigates the need for an installed infrastructure and facilitates immediate deployment of RFID systems. The development of a multi-protocol RFID reader with ad-hoc wireless capabilities will be a boon for both the commercial and academic sectors. This thesis outlines the design of an ad-hoc wireless networking capable multi-protocol RFID reader system called TelosRFID. The name TelosRFID stems from the system\u27s combination of Crossbow Telos rev. B (TelosB) ZigBee motes with a custom 13.56MHz RFID reader board. The TelosRFID reader board is a custom hardware device that can communicate with 13.56MHz RFID tags. It runs custom firmware in order to control tag communications, manage tag presence monitoring, and relay tag information through the ZigBee network (via its attached TelosB mote.) The system is designed to be demonstratably useful. Its functionality can be visibly confirmed, and configuration errors are easily detected at every component in the system. This framework provides a reliable and established baseline for future enhancements to the system\u27s feature set
Long-Term Profile Variability of Double-Peaked Emmission Lines in AGNs
An increasing number of AGNs exhibit broad, double-peaked Balmer emission
lines, which arise from the outer regions of the accretion disk which fuels the
AGN. The line profiles vary on timescales of 5--10 years. Our group has
monitored a set of 20 double-peaked emitters for the past 8 years (longer for
some objects). Here we describe a project to characterize the variability
patterns of the double-peaked H alpha line profiles and compare with those of
two simple models: a circular disk with a spiral arm and an elliptical disk.Comment: 2 pages, 1 figure, to appear in the proceedings of "The Interplay
among Black Holes, Stars and ISM in Galactic Nuclei", IAU 222, eds. T.
Storchi Bergmann, L.C. Ho, and H.R. Schmit
Platelet-Rich Plasma Injection With Percutaneous Needling for Recalcitrant Lateral Epicondylitis: Comparison of Tenotomy and Fenestration Techniques.
Background: Recalcitrant lateral epicondylitis (LE) is a common debilitating condition, with numerous treatment options of varying success. An injection of platelet-rich plasma (PRP) has been shown to improve LE, although it is unclear whether the method of needling used in conjunction with a PRP injection is of clinical importance.
Purpose: To determine whether percutaneous needle tenotomy is superior to percutaneous needle fenestration when each is combined with a PRP injection for the treatment of recalcitrant LE.
Study Design: Cohort study; Level of evidence, 3.
Methods: A total of 93 patients with recalcitrant LE were treated with a PRP injection and percutaneous needle fenestration (n = 45) or percutaneous needle tenotomy (n = 48) over a 5-year study interval. Preoperative patient data, including visual analog scale for pain (VAS-P), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), and Patient-Rated Tennis Elbow Evaluation (PRTEE) scores and grip strength, were obtained from a chart review and compared with postoperative values obtained prospectively. Secondary outcomes included the incidence of complications, need for additional interventions, return to work, and patient satisfaction.
Results: At a mean follow-up of 40 months, significant improvements in VAS-P (mean, -6.1; 95% CI, -6.8 to -5.5; P \u3c .0001), QuickDASH (mean, -46; 95% CI, -52 to -40; P \u3c .0001), and PRTEE (mean, -57; 95% CI, -64 to -50; P \u3c .0001) scores and grip strength (mean, +6.1 kg; 95% CI, 4.9 to 7.3; P \u3c .0001) were observed across the entire study cohort, with no significant differences noted between the fenestration and tenotomy groups. Nine of 45 patients (22%) underwent additional procedures to treat recurrent symptoms in the fenestration group compared with 5 of 48 patients (10%) in the tenotomy group (P = .05). No complications occurred in any patients, and no patients expressed dissatisfaction with their treatment course.
Conclusion: A PRP injection with concomitant percutaneous needling is an effective treatment for recalcitrant LE, with sustained improvements in pain, strength, and function demonstrated at a mean follow-up of longer than 3 years. Although the method of concomitant needling does not appear to have a significant effect on treatment outcomes, more aggressive needle tenotomy is less likely to require conversion to open tenotomy than needle fenestration in the short term to midterm
Phospholipid environment alters hormone-sensitivity of the purified insulin receptor kinase
Insulin receptor kinase, affinity-purified by adsorption and elution from immobilized insulin, is stimulated 2-3-fold by insulin in detergent solution. Reconstitution of the receptor kinase into leaky vesicles containing phosphatidylcholine and phosphatidylethanolamine (1:1, w/w) by detergent removal on Sephadex G-50 results in the complete loss of receptor kinase sensitivity to activation by insulin. Insulin receptors in these vesicles also exhibit an increase in their apparent affinity for 125I-insulin (Kd = 0.12 nM versus 0.76 nM). Inclusion of 8.3-16.7% phosphatidylserine into the reconstituted vesicles restores 40-50% of the insulin-sensitivity to the receptor kinase. An elevated apparent affinity for 125I-insulin of insulin receptors in vesicles containing phosphatidylcholine and phosphatidylethanolamine is also restored to the value observed in detergent solution by the inclusion of phosphatidylserine in the reconstituted system. The effect of phosphatidylserine on insulin receptor kinase appears specific, because cholesterol, phosphatidylinositol and phosphatidic acid are all unable to restore insulin-sensitivity to the receptor kinase. Autophosphorylation sites on the insulin receptor as analysed by h.p.l.c. of tryptic 32P-labelled receptor phosphopeptides are not different for insulin receptors autophosphorylated in detergent solution or for the reconstituted vesicles in the presence or absence of phosphatidylserine. These data indicate that the phospholipid environment of insulin receptors can modulate its binding and kinase activity, and phosphatidylserine acts to restore insulin-sensitivity to the receptor kinase incorporated into phosphatidylcholine/phosphatidylethanolamine vesicles
Growth and form of the mound in Gale Crater, Mars: Slope wind enhanced erosion and transport
Ancient sediments provide archives of climate and habitability on Mars. Gale Crater, the landing site for the Mars Science Laboratory (MSL), hosts a 5-km-high sedimentary mound (Mount Sharp/Aeolis Mons). Hypotheses for mound formation include evaporitic, lacustrine, fluviodeltaic, and aeolian processes, but the origin and original extent of Gale’s mound is unknown. Here we show new measurements of sedimentary strata within the mound that indicate ∼3° outward dips oriented radially away from the mound center, inconsistent with the first three hypotheses. Moreover, although mounds are widely considered to be erosional remnants of a once crater-filling unit, we find that the Gale mound’s current form is close to its maximal extent. Instead we propose that the mound’s structure, stratigraphy, and current shape can be explained by growth in place near the center of the crater mediated by wind-topography feedbacks. Our model shows how sediment can initially accrete near the crater center far from crater-wall katabatic winds, until the increasing relief of the resulting mound generates mound-flank slope winds strong enough to erode the mound. The slope wind enhanced erosion and transport (SWEET) hypothesis indicates mound formation dominantly by aeolian deposition with limited organic carbon preservation potential, and a relatively limited role for lacustrine and fluvial activity. Morphodynamic feedbacks between wind and topography are widely applicable to a range of sedimentary and ice mounds across the Martian surface, and possibly other planets
A pediatric digital storytelling system for third year medical students: The Virtual Pediatric Patients
BACKGROUND: Computer-based patient simulations (CBPS) are common, effective, instructional methods for medical students, but have limitations. The goal of this project was to describe the development of a CBPS designed to overcome some of these limitations and to perform an online evaluation. METHODS: In 1996, patients and families experiencing a common pediatric problem were interviewed, photographed and a chart review completed. A digital storytelling template was developed: 1. patient's story, evaluation and clinical course, 2. problem-based approach to the evaluation, and 3. discussion of disease process. The media was digitized and placed onto the Internet. The digital stories and a 10-question online survey were pilot tested. Online survey responses were collected from 1999–2003. Overall use of the digital stories was measured by computer server logs and by the number of hyperlinks to the CBPS. RESULTS: Eight stories were created using this system. Over 4.5 years, 814,148 digital story pages were read by 362,351 users. Hyperlink citations from other websites to the CBPS were 108. Online survey respondents (N = 393) described the overall quality as excellent or very good (88.4%). The stores were clearly written (92%) at an appropriate level (91.4%). Respondents felt they could begin to evaluate a similar case presentation (95.4%), and would remember the case in the future (91%). CONCLUSIONS: A new type of CBPS, the digital storytelling system, has been developed and evaluated which and appears to be successful in overcoming some of the limitations of earlier CBPS by featuring patient's stories in their own words, by focusing on problems rather than diseases, and by having stories that are quick for students to work through
Mid-infrared optical sensing using sub-wavelength gratings
Optical sensing has shown great potential for both quantitative and qualitative analysis of compounds. In particular sensors which are capable of detecting changes in refractive index at a surface as well as in bulk material have received much attention. Much of the recent research has focused on developing technologies that enable such sensors to be deployed in an integrated photonic device. In this work we demonstrate experimentally, using a sub-wavelength grating the detection of ethanol in aqueous solution by interrogating its large absorption band at 9.54 μm. Theoretical investigation of the operating principle of our grating sensor shows that in general, as the total field interacting with the analyte is increased, the corresponding absorption is also increased. We also theoretically demonstrate how sub-wavelength gratings can detect changes in the real part of the refractive index, similar to conventional refractive index (RI) sensors
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