The Costs of Human Salmonellosis Attributable to Pork: A Stochastic Farm-to-Fork Analysis

Few farm-to-table analyses of the risk pathways for foodborne illnesses exist, and no such analysis exists for the case of salmonellosis and pork products. This paper presents a Monte Carlo simulation model of the US pork system and the transmission pathways of Salmonella. For the year 2000, we estimate the cost of illness attributable to porkborne Salmonella at $45.7 million, with an estimated 43,505 cases of salmonellosis attributable to pork occurring annually.Food Consumption/Nutrition/Food Safety,

DO ANTIBIOTICS REDUCE PRODUCTION RISK FOR U.S. PORK PRODUCERS?

Production risk from live weight variation of market pigs has become a more important concern in U.S. swine production. Packers are concerned about the variation in carcass size because of the demand for standardized cuts and the use of automation in the slaughter process. Swine producers care about standardized pigs because of revenue implications and possible links to animal health and productivity. Pig size variation can be due to various condition and inputs including antibiotics. However, discussions on risk reduction from antibiotic use have generally not been considered. Our work extends previous studies by systematically examining the aspects of production risk reduction and highlights the potential results of banning antibiotics from a risk perspective. Using data from National Animal Health Monitoring System 2000 survey data and PigCHAMP, we identify the relationship between antibiotic use and production risk by an econometric model. Applying production costs for feeder to market pigs and a price matrix, the uncertainty in profits is evaluated. The impacts of risk on the decision making of swine producers are examined under the framework of expected utility and stochastic dominance analysis. Our results show that production risk from weight variability of market hogs is important in determining profits and utility under a pricing system. Production risk (i.e. weight gain variability) is related to the use of sub-therapeutic antibiotics. Swine producers could decrease production risk and enhance utility by adjusting antibiotic use. These results offer some support for optimal use of sub-therapeutic antibiotics.production risk, antibiotics, swine, utility, stochastic dominance, Livestock Production/Industries, Risk and Uncertainty, Q10, Q12, Q14.,

Approximations of thermoelastic and viscoelastic control systems

Well-posed models and computational algorithms are developed and analyzed for control of a class of partial differential equations that describe the motions of thermo-viscoelastic structures. An abstract (state space) framework and a general well-posedness result are presented that can be applied to a large class of thermo-elastic and thermo-viscoelastic models. This state space framework is used in the development of a computational scheme to be used in the solution of a linear quadratic regulator (LQR) control problem. A detailed convergence proof is provided for the viscoelastic model and several numerical results are presented to illustrate the theory and to analyze problems for which the theory is incomplete

AN ECONOMETRIC ANALYSIS OF THE ECONOMIC CONTRIBUTION OF SUBTHERAPEUTIC ANTIBIOTIC USE IN PORK PRODUCTION

There is growing concern among public health experts regarding the diminishing efficacy of antimicrobial therapy in human and veterinary medicine, and some have called for a ban on subtherapeutic antibiotic use in pork production. This paper develops an econometric analysis to identify the economic contributions of subtherapeutic antibiotic use in swine production.Livestock Production/Industries,

Magnetized Iron Atmospheres for Neutron Stars

Using a Hartree-Fock formalism, we estimate energy levels and photon cross sections for atomic iron in magnetic fields B ~ 10^13 G. Computing ionization equilibrium and normal mode opacities with these data, we construct LTE neutron star model atmospheres at 5.5 < Log(T_eff) < 6.5 and compute emergent spectra. We examine the dependence of the emergent spectra on T_eff and B. We also show the spectral variation with the angle between the magnetic field and the atmosphere normal and describe the significant limb darkening in the X-ray band. These results are compared with recent detailed computations of neutron star H model atmospheres in high fields and with low field Fe and H model atmospheres constructed from detailed opacities. The large spectral differences for different surface compositions may be discernible with present X-ray data; we also note improvements needed to allow comparison of Fe models with high quality spectra.Comment: 18 pages with 5 eps figures, accepted for publication in ApJ Replaced due to clerical error only: one more author, no new conten

Farm-Level Impacts of Banning Growth- Promoting Antibiotic Use in U.S. Pig Grower/Finisher Operations

Antibiotics have been used by pig producers for several decades, and are now used routinely. This study documents the current productivity and economic impacts of the use of antibiotics for growth promotion (AGP) by pig grower/finishers at the farm level. We evaluate the impacts of an AGP ban, and use of AGP by all pig grower/finishers for 61S90 days (a more production-efficient level), using data from the National Animal Health Monitoring System Swine 2000 Survey. Findings indicate that pig productivity improves with AGP. Relative to current use, an AGP ban would decrease producer profits by $1,400 per 1,020-head barn, and profits would increase by$1,992 for each grower/finisher barn when AGP is fed for 61 to 90 days. There is increasing concern about the use of antibiotics in animal production, partly because of the selection for antibiotic resistance. Thus, a careful examination of the value of AGP in pork production is warranted.antibiotics, antimicrobial resistance, growth promotion, pigs, production, Agricultural and Food Policy, Health Economics and Policy, Livestock Production/Industries,