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31	Holographic imaging of cold atoms Turner, Lincoln David Unknown Date (has links) (PDF) This thesis presents a new optical imaging technique which measures the structure of objects without the use of lenses. Termed diffraction-contrast imaging (DCI), the method retrieves the object structure from a Fresnel diffraction pattern of the object, using a deconvolution algorithm. DCI is particularly adept at imaging highly transparent objects and this is demonstrated by retrieving the structure of an almost transparent cloud of laser-cooled atoms. Applied to transparent Bose-Einstein condensates, DCI should allow the non-destructive imaging of the condensate while requiring only the minimum possible apparatus of a light source and a detector. (For complete abstract open document)
32	The Development of Image Processing Algorithms in Cryo-EM Rui Yan (6591728) 15 May 2019 (has links) Cryo-electron microscopy (cryo-EM) has been established as the leading imaging technique for structural studies from small proteins to whole cells at a molecular level. The great advances in cryo-EM have led to the ability to provide unique insights into a wide variety of biological processes in a close to native, hydrated state at near-atomic resolutions. The developments of computational approaches have significantly contributed to the exciting achievements of cryo-EM. This dissertation emphasizes new approaches to address image processing problems in cryo-EM, including tilt series alignment evaluation, simultaneous determination of sample thickness, tilt, and electron mean free path based on Beer-Lambert law, Model-Based Iterative Reconstruction (MBIR) on tomographic data, minimization of objective lens astigmatism in instrument alignment and defocus and magnification dependent astigmatism of TEM images. The final goal of these methodological developments is to improve the 3D reconstruction of cryo-EM and visualize more detailed characterization. Biophysics Structural Biology Computational Biology cryo electron microscopy cryo electron tomography image processing algorithms Beer-Lambert Law alignment accuracy thickness determination mean free path inelastic scattering least square methods Model-Based Iterative Reconstruction contrast improvement missing wedge artifacts reduction missing information restoration subtomogram averaging astigmatism correction objective lens stigmators single-pass tuning strategy defocus-dependent astigmatism magnification-dependent astigmatism

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Holographic imaging of cold atoms

The Development of Image Processing Algorithms in Cryo-EM