Syzygies of Curves in Products of Projective Spaces

Motivated by toric geometry, we lift machinery for understanding syzygies of curves in projective space to the setting of products of projective spaces. Using this machinery, we show an analogue of an influential result of Gruson, Peskine, and Lazarsfeld that gives a bound on the regularity of a possibly singular curve given its degree and the dimension of the ambient projective space. To do so, we show new results linking the shape of multigraded resolutions of a sheaf to its regularity region.Comment: 17 pages; added revisions according to referee comment

History of Fisheries in the State of Washington

"The first systematic researches bearing upon the economic marine fishes of the western coast of North America were conducted in 1879 and 1880…

Panel Discussion presentation: Data-Intensive Science with High Performance Computing Leveraging

John W. Cobb, PhD, is Researcher, Computer Science and Mathematics Division, Oak Ridge National Laboratory. Outline of presentation: Data Begets Science • The data lifecycle – the workflow of data driven science • Data at Scale • HPC at Scale • Pathfinder exemplar: eBird occurrence maps • Data management challenges • DataONE project • Dryad • Role of libraries as data repositories • DMPTool • Open data movemen

Separation of fission products from irradiated uranium by peroxide precipitation

Aqueous precipitation of uranium as the peroxide has been used as a purification procedure since the early days of the Manhattan Project. The procedure has successfully produced an extremely pure product when handled in small batches. Heretofore peroxide precipitation has been utilized for relatively pure fuel from gaseous diffusion plants or in purifying column extraction products from salvage processes. A search of the unclassified literature had rendered no information upon the feasibility of separating fission products and fuel cladding materials by selective precipitation of uranium peroxide. The primary objective of this research was to produce a uranium oxide which is suitable free from nuclear poisons so that the uranium may immediately be refabricated for use as reactor fuel. The purified product must be decontaminated with respect to the radioactive impurities so that fuel fabrication may proceed with the use of standard fabrication techniques. The product of precipitation, uranium peroxide, should settle at a rate which will allow a continuous processing method to be employed. A secondary objective was to discover a technique which would improve the existing purification procedures presently in use substituting on precipitation where two or more are presently required. The effect of organic complexing on the settling rate of the precipitate was studied in an effort to improve the technology of single stage purification

Asymmetric phase-transfer-catalyzed synthesis of five-membered cyclic gamma-Amino acid precursors

The first example of an intramolecular enantioselective Michael addition of nitronates onto conjugated systems utilizing a chiral phase-transfer catalyst is described. A range of five-membered gamma-nitro esters with up to three stereocentres have been prepared and the relative and absolute configurations proven by chemical and crystallographic methods. The products are rapidly obtained and are precursors to five-membered cyclic gamma-amino acids