Projections and idempotents with fixed diagonal and the homotopy problem for unit tight frames

We investigate the topological and metric structure of the set of idempotent operators and projections which have prescribed diagonal entries with respect to a fixed orthonormal basis of a Hilbert space. As an application, we settle some cases of conjectures of Larson, Dykema, and Strawn on the connectedness of the set of unit-norm tight frames.Comment: New title and introductio

The Changing Face of Veterinary Practice: A Special Focus on Rural America

Rural and food animal veterinary practice is evolving in response to changes in society, veterinary student demographics, and business opportunities available in the 21st century. The gravitation of veterinarians toward metropolitan areas has created a perception of under-serviced animal health needs in rural communities. Many rural communities are heavily reliant on agriculture; therefore, this perceived need for veterinarians influences the food animal industry as a whole. Veterinary colleges have changed in response to the increased number of students who are interested in companion animal medicine. These changes have resulted in diminished large animal content in the professional curricula, attrition of the number of faculty teaching food animal medicine, increases in the number of faculty dedicated to small animal curriculum, and an overwhelming sense that the veterinary program is centered around training in preparation for a career in companion animal practice. A multitude of factors likely contribute to the continued gravitation of veterinary students toward small animal practice. Veterinary colleges must strive to maintain a balanced, open-minded view of the profession so that students have an equal opportunity to choose a path that best suits their desires and interests

Optical Spectroscopy of Disordered Materials and X-Ray Scattering from Surfaces

Contains reports on two research projects.Joint Services Electronics Program (Contract DAAG29-83-K-0003

Comparison of classification algorithms to predict outcomes of feedlot cattle identified and treated for Bovine Respiratory Disease

Bovine respiratory disease (BRD) continues to be the primary cause of morbidity and mortality in feedyard cattle. Accurate identification of those animals that will not finish the production cycle normally following initial treatment for BRD would provide feedyard managers with opportunities to more effectively manage those animals. Our objectives were to assess the ability of different classification algorithms to accurately predict an individual calf’s outcome based on data available at first identification of and treatment for BRD and also to identify characteristics of calves where predictive models performed well as gauged by accuracy. Data from 23 feedyards in multiple geographic locations within the U.S. from 2000 to 2009 representing over one million animals were analyzed to identify animals clinically diagnosed with BRD and treated with an antimicrobial. These data were analyzed both as a single dataset and as multiple datasets based on individual feedyards and partitioned into training, testing, and validation datasets. Classifiers were trained and optimized to identify calves that did not finish the production cycle with their cohort. Following classifier training, accuracy was evaluated using validation data. Analysis was also done to identify sub-groups of calves within populations where classifiers performed better compared to other sub-groups. Accuracy of individual classifiers varied by dataset. The accuracy of the best performing classifier by dataset ranged from a low of 63% in one dataset up to 95% in a different dataset. Sub-groups of calves were identified within some datasets where accuracy of a classifiers were greater than 98%; however these accuracies must be interpreted in relation to the prevalence of the class of interest within those populations. We found that by pairing the correct classifier with the data available, accurate predictions could be made that would provide feedlot managers with valuable information

Time-Resolved Spectroscopy of Condensed Matter

Contains a report on one research project.Joint Services Electronics Program (Contract DAAG29-80-C-0104)National Science Foundation (Grant DMR78-23555

Time-Resolved Spectroscopy of Condensed Matter

Contains reports on three research projects.Joint Services Electronics Program (Contract DAAG29-78-C-0020)National Science Foundation (Grant DMR78-23555)National Science Foundation (Grant DMR76-80895

Dynamics of Phase Behavior of a Polymer Blend Under Shear Flow

We study the dynamics of the phase behavior of a polymer blend in the presence of shear flow. By adopting a two fluid picture and using a generalization of the concept of material derivative, we construct kinetic equations that describe the phase behavior of polymer blends in the presence of external flow. A phenomenological form for the shear modulus for the blend is proposed. The study indicates that a nonlinear dependence of the shear modulus of the blend on the volume fraction of one of the species is crucial for a shift in the stability line to be induced by shear flow.Comment: 16 pages, late