479 research outputs found

    A Step Towards Enhancing Spectrum Utilization by Implementing a Spectrum Sensing Cognitive Radio Using an RTL-SDR

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    In this paper, a spectrum sensing cognitive radio using the RTL-SDR interfaced with Simulink in MATLAB was developed. It performed spectrum sensing and signal prediction between the ranges of 25MHz to 1.5GHz, the tuner range of the RTL-SDR. The RF spectrum occupancy was explored by choosing specific centre frequencies between 25MHz to 1.5GHz in real time using the RTL-SDR. Tests were carried out in real time to ascertain the workability and efficiency of the RTL-SDR cognitive radio. The efficiency of the cognitive radio reduced as the false alarm probability increased. The cognitive radio’s efficiency also reduced in high noise signal floors

    Summary Report: National Evaluation of Learn and Serve America

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    In 1993, the Nalional and Community Service Trust Act (PL. 103-82) established the Learn and Serve America School and Community-Based Programs to support school and Community-Based efforts to involve school-aged youth in community service. The Learn and Serve program is administered by the Corporation for National Service and funded through grants to states and national organizations, and through them to individual school districts, schools, and community organizations. In 1994-95, the first year of the program, the Corporation awarded approximately $30 million in grants supporting over 2,000 local efforts involving over 750,000 school-aged youth

    A randomized placebo-controlled trial of methotrexate in psoriatic arthritis.

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    OBJECTIVE: MTX is widely used to treat synovitis in PsA without supporting trial evidence. The aim of our study was to test the value of MTX in the first large randomized placebo-controlled trial (RCT) in PsA. METHODS: A 6-month double-blind RCT compared MTX (15 mg/week) with placebo in active PsA. The primary outcome was PsA response criteria (PsARC). Other outcomes included ACR20, DAS-28 and their individual components. Missing data were imputed using multiple imputation methods. Treatments were compared using logistic regression analysis (adjusted for age, sex, disease duration and, where appropriate, individual baseline scores). RESULTS: Four hundred and sixty-two patients were screened and 221 recruited. One hundred and nine patients received MTX and 112 received placebo. Forty-four patients were lost to follow-up (21 MTX, 23 placebo). Twenty-six patients discontinued treatment (14 MTX, 12 placebo). Comparing MTX with placebo in all randomized patients at 6 months showed no significant effect on PsARC [odds ratio (OR) 1.77, 95% CI 0.97, 3.23], ACR20 (OR 2.00, 95% CI 0.65, 6.22) or DAS-28 (OR 1.70, 95% CI 0.90, 3.17). There were also no significant treatment effects on tender and swollen joint counts, ESR, CRP, HAQ and pain. The only benefits of MTX were reductions in patient and assessor global scores and skin scores at 6 months (P = 0.03, P < 0.001 and P = 0.02, respectively). There were no unexpected adverse events. CONCLUSIONS: This trial of active PsA found no evidence for MTX improving synovitis and consequently raises questions about its classification as a disease-modifying drug in PsA. Trial registration. Current Controlled Trials, www.controlled-trials.com, ISRCTN:54376151
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