332 research outputs found

    Beyond peer observation of teaching

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    Evolutionary Computing for Operating Point Analysis of Nonlinear Circuits

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    The DC operating point of an electronic circuit is conventionally found using the Newton-Raphson method. This method is not globally convergent and can only find one solution of the circuit at a time. In this paper, evolutionary computing methods, including Genetic Algorithms, Evolutionary Programming, Evolutionary Strategies and Differential Evolution are explored as possible alternatives to Newton-Raphson. These techniques have been implemented in a trial simulator. Results are presented showing that Evolutionary Computing methods are globally convergent and can find multiple solutions to circuits. The CPU time for these new methods is poor compared with Newton-Raphson, but better implementations and the use of hybrid methods suggest that further work in this area would prove fruitful

    Sub-analysis of cyp-guides data: Assessing the prevalence and impact of drug-gene interactions in an ethnically diverse cohort of depressed individuals

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    Minority groups are underrepresented in pharmacogenomics (PGx) research. Recent sub-analysis of CYP-GUIDES showed reduced length of stay (LOS) in depressed patients with CYP2D6 sub-functional status. Our primary objective was to determine whether PGx guided (G) versus standard treatment (S) influenced LOS among different race/ethnic groups. Secondary objectives included prevalence of drug-gene interactions (DGIs) and readmission rates (RAR). Retrospective sub-analysis of CYP-GUIDES data comprising CYP2D6 phenotypes was reclassified using standardized CYP2D6 genotype to phenotype recommendations from the Clinical Pharmacogenetics Implementation Consortium (CPIC) and Dutch Pharmacogenetics Working Group (DPWG)

    Interplay of septin amphipathic helices in sensing membrane-curvature and filament bundling

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    © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Woods, B. L., Cannon, K. S., Vogt, E. J. D., Crutchley, J. M., & Gladfelter, A. S. Interplay of septin amphipathic helices in sensing membrane-curvature and filament bundling. Molecular Biology of the Cell, 32(20), (2021): mbcE20050303, https://doi.org/10.1091/mbc.E20-05-0303.The curvature of the membrane defines cell shape. Septins are GTP-binding proteins that assemble into heteromeric complexes and polymerize into filaments at areas of micron-scale membrane curvature. An amphipathic helix (AH) domain within the septin complex is necessary and sufficient for septins to preferentially assemble onto micron-scale curvature. Here we report that the nonessential fungal septin, Shs1, also has an AH domain capable of recognizing membrane curvature. In a septin mutant strain lacking a fully functional Cdc12 AH domain (cdc12-6), the C-terminal extension of Shs1, containing an AH domain, becomes essential. Additionally, we find that the Cdc12 AH domain is important for regulating septin filament bundling, suggesting septin AH domains have multiple, distinct functions and that bundling and membrane binding may be coordinately controlled.This work was supported by National Institutes of Health (NIH) Grant no. R01GM-130934 to A.S.G. B.L.W. was supported by the NIH Training Grant no. 2T32AI052080-16. K.S.C. and E.J.D.V. were supported in part by a grant from the National Institute of General Medical Sciences under award T32 GM119999

    The photodecomposition product μ-oxalato-1κ^2O,O′:2κ^2O″,O‴-bis{bis[2-(2-pyridyl)phenyl-κ^2C,N]iridium(III)}–acetone (1/1.974)

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    An attempt to grow crystals of [Ir(ppy)_2(vacac)], (I), from an acetone-d_6 solution formed instead crystals of [{Ir(ppy)_2}_2(μ-oxalato)] acetone solvate, (II), [Ir_2(C_(11)H_8N)_4(C_2O_4)]·1.974C_3H_6O, where ppy is the phenyl­pyridine anion and vacac is vin­ylacetyl­acetonate. Each Ir^(III) ion in (II) is in a pseudo-octa­hedral coordination environment, where the pyridine N atoms are trans to each other and the phen­yl C atoms are trans to the O atoms of the oxalate bridging ligand. There are two crystallographically independent dimer molecules, each lying on an inversion centre. It is suggested that the oxalate ligand is formed in a series of steps initiated by the aldol condensation of acetone with vacac

    Enhancement Of Stereo Imagery By Artificial Texture Projection Generated Using A Lidar

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    Passive stereo imaging is capable of producing dense 3D data, but image matching algorithms generally perform poorly on images with large regions of homogenous texture due to ambiguous match costs. Stereo systems can be augmented with an additional light source that can project some form of unique texture onto surfaces in the scene. Methods include structured light, laser projection through diffractive optical elements, data projectors and laser speckle. Pattern projection using lasers has the advantage of producing images with a high signal to noise ratio. We have investigated the use of a scanning visible-beam LIDAR to simultaneously provide enhanced texture within the scene and to provide additional opportunities for data fusion in unmatched regions. The use of a LIDAR rather than a laser alone allows us to generate highly accurate ground truth data sets by scanning the scene at high resolution. This is necessary for evaluating different pattern projection schemes. Results from LIDAR generated random dots are presented and compared to other texture projection techniques. Finally, we investigate the use of image texture analysis to intelligently project texture where it is required while exploiting the texture available in the ambient light image

    Crack detection in "as-cast" steel using laser triangulation and machine learning

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    We describe a high-accuracy inspection system designed to automatically detect cracks in "as-cast" steel slabs. Real-time slab inspection requires instrumentation capable of withstanding high temperatures above the steel surface as well as coping with the dirty and dusty environment present in a steel mill. Crack detection is also challenging due to the presence of oxidation scale on the slab surface. A bespoke laser triangulation system has been developed, providing images at 250 fps with a calibrated surface resolution of 97 μm from a 1m standoff distance. Cracks are detected using a combination of morphological detection and SVM classifier. Results are reported from laboratory testing and from extended trials at a production steel mill

    High-Yield Method for Isolation and Culture of Endothelial Cells from Rat Coronary Blood Vessels Suitable for Analysis of Intracellular Calcium and Nitric Oxide Biosynthetic Pathways

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    We describe here a method for isolating endothelial cells from rat heart blood vessels by means of coronary microperfusion with collagenase. This methods makes it possible to obtain high amounts of endothelial cells in culture which retain the functional properties of their in vivo counterparts, including the ability to uptake fluorescently-labeled acetylated low-density lipoproteins and to respond to vasoactive agents by modulating intracellular calcium and by upregulating intrinsic nitric oxide generation. The main advantages of our technique are: (i) good reproducibility, (ii) accurate sterility that can be maintained throughout the isolation procedure and (iii) high yield of pure endothelial cells, mainly due to microperfusion and temperature-controlled incubation with collagenase which allow an optimal distribution of this enzyme within the coronary vascular bed
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