Generalized valence bond wave functions in quantum Monte Carlo

We present a technique for using quantum Monte Carlo (QMC) to obtain high quality energy differences. We use generalized valence bond (GVB) wave functions, for an intuitive approach to capturing the important sources of static correlation, without needing to optimize the orbitals with QMC. Using our modifications to Walker branching and Jastrows, we can then reliably use diffusion quantum Monte Carlo to add in all the dynamic correlation. This simple approach is easily accurate to within a few tenths of a kcal/mol for a variety of problems, which we demonstrate for the adiabatic singlet-triplet splitting in methylene, the vertical and adiabatic singlet-triplet splitting in ethylene, 2+2 cycloaddition, and Be_2 bond breaking

EXPLAINING DIFFERENCES IN PRICES RECEIVED BY FARMERS: TESTING THEORY BASED ON ACTUAL FARMER TRANSACTIONS

There has been considerable normative research about how farmers should make marketing decisions, but little positive research on what farmers really do. Regressions of gender, total volume, timing, and frequency of sales on the average weighted price received are used to test hypotheses regarding gender differences, myopic loss aversion, economies of size, and market efficiency.Marketing,

Sublethal Behavioral and Physiological Effects of the Biomedical Bleeding Process on the American Horseshoe Crab, Limulus polyphemus

The hemolymph of the American horseshoe crab, Limulus polyphemus, is harvested from over 500,000 animals annually to produce Limulus amebocyte lysate (LAL), a medically important product used to detect pathogenic bacteria. Declining abundance of spawning Limulus females in heavily harvested regions suggests deleterious effects of this activity, and while mortality rates of the harvest process are known to be 10%–30%, sublethal behavioral and physiological effects are not known. In this study, we determined the impact of the harvest process on locomotion and hemocyanin levels of 28 female horseshoe crabs. While mortality rates after bleeding (18%) were similar to previous studies, we found significant decreases in the linear and angular velocity of freely moving animals, as well as changes in their activity levels and expression of circatidal behavioral rhythms. Further, we found reductions in hemocyanin levels, which may alter immune function and cuticle integrity. These previously unrecognized behavioral and physiological deficits suggest that the harvest of LAL may decrease female fitness, and thus may contribute to the current population decline

SOUTHERN AGRICULTURE UNDER THE 2002 FARM BILL: A REPRESENTATIVE FARMS APPROACH

The 2002 Farm Bill affects economic activity of farms and ranches in the southern United States. Using stochastic simulation techniques, key financial variables were projected for 39 representative farms and ranches in ten southern states. Results indicate 24 of 39 farms studied have more than a 40 percent likelihood of having annual cash flow deficits during the period 2002 through 2007. Results are largely consistent across commodities and between moderate and large size farms in the same geographic area.Agricultural and Food Policy,

High-Order Stabilized Finite Elements on Dynamic Meshes

The development of dynamic mesh capability for turbulent flow simulations using the Streamlined Upwind Petrov-Galerkin (SUPG) discretization is described. The current work extends previous research to include high-order spatial accuracy, including the satisfaction of the discrete geometric conservation law (GCL) on curved elements. Two closely-related schemes are described and the ability of these schemes to satisfy the GCL, while also maintaining temporal accuracy and conservation is assessed. Studies indicate that although one scheme discretizes the time derivative in conservative form, both schemes exhibit temporal conservation errors that decrease according to the expected design order of accuracy. The source of the temporal conservation errors is examined, and it is demonstrated that many finite-volume and finite-element schemes can also be expected to have difficulty strictly satisfying conservation in time. The effects on conservation are examined and, while present in the simulations, are seen to be negligible for the problems considered

Impact of Hired Foreign Labor on Milk Production and Herd Size in the United States

Foreign labor has become increasingly important component of U.S. agriculture. Disruption in the supply of agricultural labor has been argued to significantly affect agricultural production. This study analyzes the impacts of foreign labor shortages on the dairy industry using national survey data. The results suggest that a 30 percent hired foreign labor shortage will result in 10.1 billion pound decline in total U.S. milk production. This is equivalent to a loss of 458.9 thousand dairy cows. One of the key implications of this study is the need for immigration or labor policies that help maintain consistent labor availability and stability of the dairy farm workforce.Agricultural and Food Policy, Financial Economics, Productivity Analysis,

Accounts from a Claims Reuse Experience: Design of an Airline Fares Tracker

Previous research efforts have led to the establishment of a repository of claims as reusable knowledge entities. Through the analysis, design, and prototyping of a notification system aimed at monitoring airfares across time, airlines, and location, this paper presents the various work-products resulting from a scenario-based design approach coupled with the Claims Reuse Library to support reuse-centric claims analysis. Finally, we share our experience and findings using the Claims Reuse Library as a core to knowledge transfer

Standardizing methods and procedures for mouse retinal flat mounts and glial cell counts

poster abstractIntroduction: The mammalian retina contains neuronal cells as well as a number of non-neuronal glial cells. The different types of glial cells include Müller glia, retinal astrocytes, and microglia. Müller glial cells and astrocytes nourish neurons and microglia act as sentinels that respond to injury or disease within the nervous system. The long-term goal of our laboratory has been to study interactions between microglia, Muller glia and astrocytes in healthy and diseased tissue. The focus of the present study was to develop a technique that would allow the laboratory to study changes in cell number in retinal flat mounts and cultures. Methods: Immunohistochemistry (IHC) was performed to fluorescently label mature murine retinal tissue. Retinal flat-mounts were stained with SOX2, a nuclear marker for glial cells or IBA1 for microglial cells, and counter-stained with Hoechst solution to label all nuclei. Pure cultures of mouse microglial cells treated with liposomal clodronate (a drug which specifically targets and ablates microglia) and vehicle were counter stained with Hoechst solution. Cell counts were performed on the images of the fluorescently labeled samples using Image-J software. Results: Convolutions were used to filter images of immunolabeled cultures and retinal flat mounts to make the images clear enough to capture cell number. The cell count assistance protocol yielded acceptable cell count results of the stained cells and determined a detectable difference in the number of clodronate treated cells versus vehicle treated control cells. The images produced of the retinal flat-mounts were analyzed to determine the percentage of SOX2 positive Müller glia in the mature murine retinal tissue. Conclusion: A modified Image J program could be used to determine cellular number in cultures and retinal flat mounts. Mentor: Teri L Belecky-Adams, Department of Biology, Indiana University-Purdue University Indianapoli

Representative Farms Economic Outlook for the January 2004 FAPRI/AFPC Baseline

The farm level economic impacts of the Farm Security and Rural Investment Act of 2002 on representative crop and livestock operations are projected in this report. The analysis was conducted over the 2001-2008 planning horizon using FLIPSIM, AFPC’s whole farm simulation model. Data to simulate farming operations in the nation’s major production regions came from two sources: - Producer panel cooperation to develop economic information to describe and simulate representative crop, livestock, and dairy farms, and - Projected prices, policy variables, and input inflation rates from the Food and Agricultural Policy Research Institute (FAPRI) January 2004 Baseline. The FLIPSIM policy simulation model incorporates the historical risk faced by farmers for prices and production. This report presents the results of the January 2004 Baseline in a risk context using selected simulated probabilities and ranges for annual net cash farm income values. The probability of a farm experiencing annual cash flow deficits and the probability of a farm losing real net worth are included as indicators of the cash flow and equity risks facing farms through the year 2008.Agribusiness, Agricultural and Food Policy, Crop Production/Industries,