Status of Three Species of Freshwater Snails (Gastropoda: Pleuroceridae) in the Lower Ohio River Basin, Illinois

Illinois Department of Natural Resources Wildlife Preservation Fund Grant/Contract No: RC08-L20WWe report on a status survey of Lithasiaspp. (Gastropoda:Pleuroceridae) we conducted in the Ohio River basin, Illinois. Prior to oursurvey, only three Lithasiaspecies were known to occur in Illinois; however,through our efforts, we found a fourth species (Lithasia geniculata). Thedistribution of L. armigeraand L. verrucosadoes not appear to have changedwithin Illinois, whereas the distribution of L. obovataappears to be declining inIllinois, which prompted us to nominate it for inclusion on the state list ofendangered and threatened species for Illinois by the Illinois Endangered SpeciesProtection Board.Lithasia geniculatahas been recorded only in one location, andwe feel it should be considered for state endangeredINHS Technical Report Prepared for Illinois Department of Natural Resources Wildlife Preservation Fun

Biologically Significant Illinois Streams: An Evaluation of the Streams of Illinois based on Aquatic Biodiversity: Part 1

Part 1: Text. See Reference ID-1365 for Part 2: AtlasReport issued on: December 31, 1991INHS Technical Report prepared for Illinois Dept. of Conservation, Illinois Dept. of Energy and Natural Resource

Biological Assessments of Six Selected Fishes, Amphibians, and Mussels in Illinois

ID: 8758; issued November 1, 1996INHS Technical Report prepared for Illinois Department of Natural Resources, Division of Natural Heritag

The image ray transform for structural feature detection

The use of analogies to physical phenomena is an exciting paradigm in computer vision that allows unorthodox approaches to feature extraction, creating new techniques with unique properties. A technique known as the "image ray transform" has been developed based upon an analogy to the propagation of light as rays. The transform analogises an image to a set of glass blocks with refractive index linked to pixel properties and then casts a large number of rays through the image. The course of these rays is accumulated into an output image. The technique can successfully extract tubular and circular features and we show successful circle detection, ear biometrics and retinal vessel extraction. The transform has also been extended through the use of multiple rays arranged as a beam to increase robustness to noise, and we show quantitative results for fully automatic ear recognition, achieving 95.2% rank one recognition across 63 subjects

Uncovering Multiple Populations with Washington Photometry: I. The Globular Cluster NGC 1851

The analysis of multiple populations (MPs) in globular clusters (GCs) has become a forefront area of research in astronomy. Multiple red giant branches (RGBs), subgiant branches (SGBs), and even main sequences (MSs) have now been observed photometrically in many GCs. UV photometry has been crucial in discovering and analyzing these MPs, but the Johnson U and the Stromgren and Sloan u filters that have generally been used are relatively inefficient and very sensitive to reddening and atmospheric extinction. In contrast, the Washington C filter is much broader and redder than these competing UV filters. Here we investigate the use of the Washington system to uncover MPs using only a 1-meter telescope. Our analysis of the well-studied GC NGC 1851 finds that the C filter is both very efficient and effective at detecting its previously discovered MPs in the RGB and SGB. Remarkably, we have also detected an intrinsically broad MS best characterized by two distinct but heavily overlapping populations that cannot be explained by binaries, field stars, or photometric errors. The MS distribution is in very good agreement with that seen on the RGB, with ~30% of the stars belonging to the second population. There is also evidence for two sequences in the red horizontal branch, but this appears to be unrelated to the MPs in this cluster. Neither of these latter phenomena have been observed previously in this cluster. The redder MS stars are also more centrally concentrated than the blue MS. This is the first time MPs in a MS have been discovered from the ground, and using only a 1-meter telescope. The Washington system thus proves to be a very powerful tool for investigating MPs, and holds particular promise for extragalactic objects where photons are limited.Comment: 25 pages, 10 figure

Ultracold neutral plasma expansion in two dimensions

We extend an isothermal thermal model of ultracold neutral plasma expansion to systems without spherical symmetry, and use this model to interpret new fluorescence measurements on these plasmas. By assuming a self-similar expansion, it is possible to solve the fluid equations analytically and to include velocity effects to predict the fluorescence signals. In spite of the simplicity of this approach, the model reproduces the major features of the experimental data

The feasibility of a programmed heat shield for solar cell performance control

Feasibility of programmed heat shield for temperature and power control for spacecraft on-board powe