Reduction of salmonella contamination in pork carcasses by vaccination

Two field studies and one laboratory challenge were performed to evaluate of vaccination with a live, avirulent Salmonella choleraesuis vaccine (Enterisol® SC-54) to provide cross protection, reduce the level of internal culture and fecal shedding of multiple serovars of Salmonella. Barns of grow-finish pigs were vaccinated orally, via drinking water, or left as matched controls in the field studies. Ileocecal lymph nodes and spiral colon fecal material were collected at the abattoir from field studies. Three week old pigs were vaccinated intranasally and challenged at five weeks of age in the laboratory study. Internal organ culture and fecal shedding were measured two weeks following challenge with S typhimurium. In all three studies, vaccinated pigs had significantly lower culture prevalence of non S choleraesuis serovars (p\u3c0.05), and reduced fecal shedding in following laboratory challenge (p\u3c0.05). A nominal (p=0.07) trend to improved growth rate following laboratory challenge with S typhimurium challenge was also detected

Reduction of Salmonella choleraesuis contamination in pork carcasses by vaccination

Salmonellosis is a common clinical and subclinical infection of pigs. The species adapted serovar S choleraesuis predominantly produces a septicemic disease in swine. Disease in other species, including humans, is rare compared to enteric type infections from non host adapted serovars such as S typhimurium. However, when host adapted serovars infect alternate species, disease can be severe. Vaccination with an avirulent live S choleraesuis vaccine, Enterisol® SC-54, significantly reduces prevalence and quantity of infection in pigs. Additionally, those pigs that remain culture positive have two logs or more reduction in the quantity of S choleraesuis present. Vaccination of pigs as young as one day of age is successful. Where these infections are of concern in the human population, vaccination of pigs may provide dramatic reductions of the organism swine, reducing risk in food items of swine origin

A summary of the ECAS performance and cost results for MHD systems

The potential is examined of various advanced power plant concepts using coal and coal-derived fuel. The results indicate that open cycle coal fired direct preheat MHD systems have potentially one of the highest coal-pile-to-bus-bar efficiencies and also one of the lowest costs of electricity (COE) of the systems studied. Closed cycle MHD systems may have the potential to approach the efficiency and COE of open cycle MHD. The 1200-1500 F liquid metal MHD systems studied do not appear to have the potential of exceeding the efficiency or competing with the COE of advanced steam plants

Design Methodology for a Very High Frequency Resonant Boost Converter

This paper introduces a design methodology for a resonant boost converter topology that is suitable for operation at very high frequencies. The topology we examine features a low parts count and fast transient response, but suffers from higher device stresses compared to other topologies that use a larger number of passive components. A numerical design procedure is developed for this topology that does not rely on time-domain simulation sweeps across parameters. This allows the optimal converter design to be found for a particular main semiconductor switch. If an integrated power process is used where the designer has control over layout of the semiconductor switch, the optimal combination of converter design and semiconductor layout can be found. To validate the proposed converter topology and design approach, a 75-MHz prototype converter is designed and experimentally demonstrated. The performance of the prototype closely matches that predicted by the design procedure, and the converter achieves good efficiency over a wide input voltage range

Economically sustainable riparian buffer to promote bank stability and reduce gully erosion and phosphorus runoff in the Loess Hills

The project considered what types and configurations of vegetative buffers might be effective in slowing soil loss at a Loess Hills site

Magnetohydrodynamics (MHD) Engineering Test Facility (ETF) 200 MWe power plant. Design Requirements Document (DRD)

A description and the design requirements for the 200 MWe (nominal) net output MHD Engineering Test Facility (ETF) Conceptual Design, are presented. Performance requirements for the plant are identified and process conditions are indicated at interface stations between the major systems comprising the plant. Also included are the description, functions, interfaces and requirements for each of these major systems. The lastest information (1980-1981) from the MHD technology program are integrated with elements of a conventional steam electric power generating plant

Low-Mach-number turbulence in interstellar gas revealed by radio polarization gradients

The interstellar medium of the Milky Way is multi-phase, magnetized and turbulent. Turbulence in the interstellar medium produces a global cascade of random gas motions, spanning scales ranging from 100 parsecs to 1000 kilometres. Fundamental parameters of interstellar turbulence such as the sonic Mach number (the speed of sound) have been difficult to determine because observations have lacked the sensitivity and resolution to directly image the small-scale structure associated with turbulent motion. Observations of linear polarization and Faraday rotation in radio emission from the Milky Way have identified unusual polarized structures that often have no counterparts in the total radiation intensity or at other wavelengths, and whose physical significance has been unclear. Here we report that the gradient of the Stokes vector (Q,U), where Q and U are parameters describing the polarization state of radiation, provides an image of magnetized turbulence in diffuse ionized gas, manifested as a complex filamentary web of discontinuities in gas density and magnetic field. Through comparison with simulations, we demonstrate that turbulence in the warm ionized medium has a relatively low sonic Mach number, M_s <~ 2. The development of statistical tools for the analysis of polarization gradients will allow accurate determinations of the Mach number, Reynolds number and magnetic field strength in interstellar turbulence over a wide range of conditions.Comment: 5 pages, 3 figures, published in Nature on 13 Oct 201