11,732 research outputs found

    Null device for hand controller Patent

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    Manual control mechanism for adjusting control rod to null positio

    Solid-state switching used to speed up capacitive integrator

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    Capacitive integrator circuit using Silicon Controlled Switches /SCS/ insures output voltage linearly proportional to input pulse width. This circuit provides high input impedance and relatively low output impedance

    Variable duration pulse integrator Patent

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    Variable duration pulse integrator design for integrating pulse duration modulated pulses with elimination of ripple conten

    Variable width pulse integrator Patent

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    Solid state integrator for converting variable width pulses into analog voltag

    Analyzing the 2011 NAEP Results: Where Does Arkansas Stand Now?

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    State education policymakers in Arkansas, and in all states around the country, take great interest in the state assessment scores published each year and are pleased when they are able to present positive results. This has certainly been the case in Arkansas with the annual publication of the results of student performance on the state Benchmark exams. While the state exams provide useful information that allow policymakers to compare schools and districts within Arkansas, they do not allow policymakers to assess the performance of Arkansas students relative to other students in the nation

    Innovation 2.0: Grantmaking to Transform America's Education Systems

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    As social and technological forces reshape the environment, the educational landscape is being similarly transfigured as parents, employers, policymakers and students grow impatient with incremental efforts to reform a broken system. Too often such efforts have proven both slow and inadequate to the evolving needs of learners: Innovations have been inequitably distributed, promising solutions have been difficult to implement at scale. Yet the signs of widespread change are real, and there is little doubt that transformation has begun

    Quality Counts 2012

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    In an attempt to gauge the educational progress of the nation and each state, Education Week has published state report cards since 1997 in its annual Quality Counts series. The 16th annual report - Quality Counts 2012 - was released in January. Overall, Arkansas ranked 5th among the 50 states and was one of only nine states in the U.S. that received a B. This policy brief examines Arkansas’ rank in each category of the report as well as the quality of the report itself

    The Housing Crisis in a Free Economy

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    Improving binding affinity through cyclization

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    Cancer chemotherapy results in systematic damage as the drugs used are also toxic to benign tissue. Sensitizing a cancer cell to therapy by interfering with the DNA repair mechanisms would decrease overall toxicity, as the necessary dosage of chemotherapy drugs would be lowered. The Hartman lab developed a peptide (8.6) that binds with a KD of 1 μM to the C-terminal domain of breast cancer associated protein (BRCA1), blocking homologous recombination. The crystal structure of the peptide shows the tyrosine and threonine residues are close together, suggesting that by cyclizing these positions, the peptide may already be constrained into its bound conformation. A series of dibromomethylnaphthalene linkers of various length were synthesized and cyclized through alkylation of the cysteine residues on peptide 8.6. The binding of the cyclic peptides with the BRCA1 (BRCT)2 domain will be compared to peptide 8.6 through the use of fluorescence polarization.https://scholarscompass.vcu.edu/uresposters/1248/thumbnail.jp

    Modulation of swimming in the gastropod Melibe leonina by nitric oxide

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    Nitric oxide (NO) is a gaseous intercellular messenger produced by the enzyme nitric oxide synthase. It has been implicated as a neuromodulator in several groups of animals, including gastropods, crustaceans and mammals. In this study, we investigated the effects of NO on the swim motor program produced by isolated brains and by semi-intact preparations of the nudibranch Melibe leonina. The NO donors sodium nitroprusside (SNP, 1 mmol l–1) and S-nitroso-N-acetylpenicillamine (SNAP, 1 mmol l–1) both had a marked effect on the swim motor program expressed in isolated brains, causing an increase in the period of the swim cycle and a more erratic swim rhythm. In semi-intact preparations, the effect of NO donors was manifested as a significant decrease in the rate of actual swimming. An NO scavenger, reduced oxyhemoglobin, eliminated the effects of NO donors on isolated brains, supporting the assumption that the changes in swimming induced by donors were actually due to NO. The cGMP analogue 8-bromoguanosine 3′,5′-cyclic monophosphate (1 mmol l–1) produced effects that mimicked those of NO donors, suggesting that NO is working via a cGMP-dependent mechanism. These results, in combination with previous histological studies indicating the endogenous presence of nitric oxide synthase, suggest that NO is used in the central nervous system of Melibe leonina to modulate swimming
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