By a News Reporter-Staff News Editor at Journal of Mathematics -- Investigators discuss new findings in Algorithms. According to news reporting from Berkeley, California, by VerticalNews journalists, research stated, "X-ray nanocrystallography allows the structure of a macromolecule to be determined from a large ensemble of nanocrystals. However, several parameters, including crystal sizes, orientations, and incident photon flux densities, are initially unknown and images are highly corrupted with noise."
The news correspondents obtained a quote from the research from the University of California, "Autoindexing techniques, commonly used in conventional crystallography, can determine orientations using Bragg peak patterns, but only up to crystal lattice symmetry. This limitation results in an ambiguity in the orientations, known as the indexing ambiguity, when the diffraction pattern displays less symmetry than the lattice and leads to data that appear twinned if left unresolved. Furthermore, missing phase information must be recovered to determine the imaged object's structure. We present an algorithmic framework to determine crystal size, incident photon flux density, and orientation in the presence of the indexing ambiguity. We show that phase information can be computed from nanocrystallographic diffraction using an iterative phasing algorithm, without extra experimental requirements, atomicity assumptions, or knowledge of similar structures required by current phasing methods."
According to the news reporters, the research concluded: "The feasibility of this approach is tested on simulated data with parameters and noise levels common in current experiments."
For more information on this research see: Algorithmic framework for X-ray nanocrystallographic reconstruction in the presence of the indexing ambiguity. Proceedings of the National Academy of Sciences of the United States of America, 2014;111(2):593-598. Proceedings of the National Academy of Sciences of the United States of America can be contacted at: Natl Acad Sciences, 2101 Constitution Ave NW, Washington, DC 20418, USA. (National Academy of Sciences - www.nasonline.org/; Proceedings of the National Academy of Sciences of the United States of America - www.nasonline.org/publications/pnas/)
Our news journalists report that additional information may be obtained by contacting J.J. Donatelli, University of California, Lawrence Berkeley Natl Lab, Berkeley, CA 94720, United States.
Keywords for this news article include: Berkeley, California, Algorithms, United States, North and Central America
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