Reduced order models for control of fluids using the Eigensystem Realization Algorithm

In feedback flow control, one of the challenges is to develop mathematical models that describe the fluid physics relevant to the task at hand, while neglecting irrelevant details of the flow in order to remain computationally tractable. A number of techniques are presently used to develop such reduced-order models, such as proper orthogonal decomposition (POD), and approximate snapshot-based balanced truncation, also known as balanced POD. Each method has its strengths and weaknesses: for instance, POD models can behave unpredictably and perform poorly, but they can be computed directly from experimental data; approximate balanced truncation often produces vastly superior models to POD, but requires data from adjoint simulations, and thus cannot be applied to experimental data. In this paper, we show that using the Eigensystem Realization Algorithm (ERA) \citep{JuPa-85}, one can theoretically obtain exactly the same reduced order models as by balanced POD. Moreover, the models can be obtained directly from experimental data, without the use of adjoint information. The algorithm can also substantially improve computational efficiency when forming reduced-order models from simulation data. If adjoint information is available, then balanced POD has some advantages over ERA: for instance, it produces modes that are useful for multiple purposes, and the method has been generalized to unstable systems. We also present a modified ERA procedure that produces modes without adjoint information, but for this procedure, the resulting models are not balanced, and do not perform as well in examples. We present a detailed comparison of the methods, and illustrate them on an example of the flow past an inclined flat plate at a low Reynolds number.Comment: 22 pages, 7 figure

Empirical Legal Studies Before 1940: A Bibliographic Essay

The modern empirical legal studies movement has well-known antecedents in the law and society and law and economics traditions of the latter half of the 20th century. Less well known is the body of empirical research on legal phenomena from the period prior to World War II. This paper is an extensive bibliographic essay that surveys the English language empirical legal research from approximately 1940 and earlier. The essay is arranged around the themes in the research: criminal justice, civil justice (general studies of civil litigation, auto accident litigation and compensation, divorce, small claims, jurisdiction and procedure, civil juries), debt and bankruptcy, banking, appellate courts, legal needs, legal profession (including legal education), and judicial staffing and selection. Accompanying the essay is an extensive bibliography of research articles, books, and reports

Aqua Ammonia's Economic Potential as a Preservative for Stored High-Moisture Corn

Potential demand for treatment of onfarm stored corn is sufficient to justify a profitable local supply of aqua ammonia by farm supply firms that operate convertor units. A 500-ton (considered a minimum) seasonal output would necessitate about a $30 per ton supply price delivered at the farm. The supply price could decrease to about$22 per ton at a 4,000-ton output (maximum for small convertor plants). Aqua ammonia treatment costs would amount to only about one-third the usual drying costs and one-fourth to one-fifth the cost of treatment with organic chemicals. Additional potential advantages include: (1) less care and movement of stored grain, (2) added nonprotein nitrogen to stored grain, and (3) savings of the critically short gas energy used for drying

Arsenic-related chromosomal alterations in bladder cancer

Background: Previous studies have demonstrated that ingestion of arsenic in drinking water is a strong risk factor for several forms of cancer, including bladder cancer. It is not known whether arsenic-related cancers are genetically similar to cancers in unexposed individuals or what mechanisms of carcinogenesis may underlie their formation. This study was designed to compare chromosomal alterations in bladder cancers of arsenic-exposed individuals to provide insight into the mechanism of how arsenic may induce or promote cancer. Methods: A case–case study was conducted in Argentina and Chile examining chromosomal alterations in bladder tumor DNA in 123 patients who had been exposed to arsenic in their drinking water. Patients were placed into one of four arsenic exposure categories according to their average 5-year peak arsenic exposure. Patients were also classified as ever smokers or never smokers. Comparative genomic hybridization was used to identify chromosomal alterations throughout the genome. All statistical tests were two-sided. Results: The total number of chromosomal alterations was higher in individuals exposed to higher arsenic levels (5.7 ± 5.1, 5.6 ± 5.1, 7.3 ± 7.4, and 9.1 ± 6.5 [mean ± standard deviation] chromosomal alterations per tumor with increasing arsenic exposure; P trend =.02, adjusted for stage and grade). The trend was stronger in high-grade (G2–G3) tumors (6.3 ± 5.5, 8.3 ± 4.7, 10.3 ± 7.8, and 10.5 ± 6.4 alterations per tumor; P trend =.01) than it was in low-grade (G1

Late prehistoric Guale bioarchaeology

104 p. : ill., maps ; 26 cm.Includes bibliographical references (p. 66-69).The setting -- Previous work at South End Mound I -- Later excavations and bioarchaeological study -- Methods of analysis -- The South End Mound I individuals -- Artifacts / David Hurst Thomas and Jessica McNeil -- Resource utilization and dietary reconstruction / Elizabeth J. Reitz, Clark Spencer Larsen and Margaret J. Schoeninger -- Patterns of community health: pathology -- Dental and skeletal size and morphology."South End Mound I is one of more than 50 mortuary sites (mostly burial mounds) excavated by Clarence Bloomfield Moore (1897) during his five-month expedition to the Georgia coast, and it is one of seven mounds he described on St. Catherines Island. The mound was subsequently tested by Larsen and Thomas (1986), who reported on a small sample of fragmentary human remains left at the site by Moore. This monograph reports on human remains recovered from a large-scale excavation undertaken by Larsen. This excavation revealed that Moore disturbed skeletal remains, but these remains were left in the general location of their original discovery. Our conjoining of fragmentary bones and teeth allowed identification of 26 of the 50 skeletons encountered by Moore. Importantly, this sample provides the only late prehistoric (Irene period) skeletal series from St. Catherines Island, allowing for the first time temporal comparisons with both earlier prehistoric populations (e.g., Johns Mound) and later historic populations (Santa Catalina de Guale) from the island. Analysis of faunal remains and stable isotope ratios of carbon and nitrogen indicates that the population consumed a variety of terrestrial and marine fauna, along with significant amounts of maize in diet. Analysis of dental caries prevalence is consistent with this reconstruction. In addition, presence of skeletal infections indicates poorer health in general relative to prehistoric St. Catherines Islanders. At least some of the periosteal reactions displayed on tibiae reflect treponematosis (nonvenereal syphilis). The overall pattern of health is strikingly similar to contemporary late prehistoric populations from the Georgia coast in particular and to the Eastern Woodlands of North America in general. Lastly, study of body size and postcranial skeletal morphology indicates a similar pattern of activity and lifestyle as for other groups from the Georgia Bight during the late prehistoric era. Overall, this bioarchaeological analysis reveals that the shift from a foraging lifeway to one that incorporated maize agriculture likely had a profound impact on health and lifestyle"--P. 5

P53 alterations in bladder tumors from arsenic and tobacco exposed patients

Previous studies demonstrated that tobacco and arsenic exposure are risk factors for bladder cancer. A case-case study was conducted to compare p53 mutations in 147 bladder tumors from South American patients by tobacco and arsenic exposure. Information on residential history and lifestyle factors was collected. The prevalence of p53 mutations and protein expression was examined in relation to tumor stage, grade, patient age, gender, tobacco and arsenic exposure. Smokers were grouped as ever/never smokers and by pack years of exposure (0, 1-20, >20). Patients were also grouped into four arsenic exposure categories based on the average of the five highest years arsenic concentration in their drinking water: group 1, non-detectable to 300 μg/l (n = 30). The proportion of tumor samples with p53 mutations and P53 immunopositivity increased strongly with both stage and grade, but not with arsenic exposure or smoking. The prevalence of tumors containing mutational transitions increased markedly with tumor stage (from 14 to 52%, Ptrend = 0.005) and grade (from 11 to 48%, Ptrend = 0.004) and was higher in smokers than in non-smokers (34 versus 18%, respectively, P = 0.10). An increasing trend was observed with pack years of smoking (P = 0.09). The majority of mutations in tumors from both smokers and non-smokers were G → A transitions, however, in smokers a preference for G → A transitions at CpG sites was observed (P = 0.07, two-tailed) and a positive trend was observed with pack years of exposure (P = 0.04). A hotspot was found at codon 273 in 12% of the tumors from smokers but was not observed in never smokers (P = 0.05) and a positive trend was observed with pack years of tobacco exposure (P = 0.001). Neither stage nor grade demonstrated a preference for CpG site mutation, suggesting that these changes may be early exposure-related events in carcinogenesis and are not related to tumor progression. Arsenic exposure was not associated with an increased prevalence of p53 mutation or P53 immunopositivity and there was no evidence of interaction between arsenic and smoking with these outcome variables.Fil: Moore, Lee E. University of California, San Francisco Cancer Center, San Francisco, CA, United StatesFil: Smith, Allan H. University of Washington, Seattle, WA, United StatesFil: Eng, Clarence. University of California, San Francisco Cancer Center, San Francisco, CA, United StatesFil: Devries, Sandy. University of California, San Francisco Cancer Center, San Francisco, CA, United StatesFil: Kalman, Dave. University of Washington, Seattle, WA, United StatesFil: Bhargava, Vivek. University of California, San Francisco Cancer Center, San Francisco, CA, United StatesFil: Chew, Karen. University of California, San Francisco Cancer Center, San Francisco, CA, United StatesFil: Ferreccio, Catterina. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; ArgentinaFil: Rey, Omar A. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; ArgentinaFil: Hopenhayn, Claudia. University of Kentucky, Lexington, KY, United StatesFil: Biggs, Mary Lou. University of Washington, Seattle, WA, United StatesFil: Bates, Michael N. Arsenic Health Research Program, School of Public Health, University of California, Berkeley, CA 7360, 140 Warren Hall, United State