Search

A strategy for developing sediment transport information for storm water planning and management is described. The strategy links location-based and intensity-based development scenarios with potential water quality impacts to a stream system and at a watershed outlet and (1) is based on sediment transport calculations; (2) develops information that supports community decision making; and (3) is consistent with the Environmental Protection Agency (EPA) Phase II storm water requirements and other guidance on watershed management. The strategy is an effort to incorporate the impact of site-specific watershed characteristics into storm water ordinances. This effort was undertaken to provide a rational means for a community to differentiate the sediment contributions from alternative scenarios at alternative locations. One of the options available with differentiation information is the ability to negotiate and approve pollutant 'trades' between different development practices in different locations such that water quality standards are maintained throughout the trading area. The Agricultural Non-Point Source (AGNPS) pollutant modeling system was used in the community of Ashland, Mo. to provide an example of the methodology. CE Database subject headings: Watershed management; Hydrologic models; Storm water management; Nonpoint pollution; Remote sensing; Geographic information systems; Sediment transport; Water quality.

The current study tested the hypothesis that removal of maltose binding protein (MBP) from recombinant antigen used for plate coating would improve the specificity of a commercial Anaplasma antibody competitive enzyme-linked immunosorbent assay (cELISA). The number of 358 sera with significant MBP antibody binding (≥30%I) in Anaplasma-negative herds was 139 (38.8%) when tested using the recombinant major surface protein 5 (rMSP5)-MBP cELISA without MBP adsorption. All but 8 of the MBP binders were rendered negative (<30%I) using the commercial rMSP5-MBP cELISA with MBP adsorption, resulting in 97.8% specificity. This specificity was higher than some previous reports, so to improve the specificity of the commercial cELISA, a new recombinant antigen designated rMSP5–glutathione S-transferase (GST) was developed, eliminating MBP from the antigen and obviating the need for MBP adsorption. Using the rMSP5-GST cELISA, only 1 of 358 Anaplasma-negative sera, which included the 139 sera with significant (≥30%I) MBP binding in the rMSP5-MBP cELISA without MBP adsorption, was positive. This resulted in an improved diagnostic specificity of 99.7%. The rMSP5-GST cELISA without MBP adsorption had comparable analytical sensitivity to the rMSP5-MBP cELISA with MBP adsorption and had 100% diagnostic sensitivity when tested with 135 positive sera defined by nested polymerase chain reaction. Further, the rMSP5-GST cELISA resolved 103 false-positive reactions from selected sera with possible false-positive reactions obtained using the rMSP5-MBP cELISA with MBP adsorption and improved the resolution of 29 of 31 other sera. In summary, the rMSP5-GST cELISA was a faster and simpler assay with higher specificity, comparable sensitivity, and improved resolution in comparison with the rMSP5-MBP cELISA with MBP adsorption. [ABSTRACT FROM AUTHOR]

Abstract: Infection of the heifer mammary gland with common mastitis pathogens, particularly staphylococci, prior to calving is well documented. Efforts to eliminate pre-partum intramammary infections (IMI) in heifers have focused primarily on intramammary antibiotic therapy shortly before or at the time of calving. Few studies have evaluated vaccination of heifers against staphylococcal mastitis. The objectives of the present study were to evaluate the efficacy of a commercially available Staphylococcus aureus bacterin in protecting against staphylococcal IMI (S. aureus and coagulase-negative staphylococci (CNS)), to study the effect of vaccination on milk SCC, and to evaluate the milk antibody isotype response to vaccination using a lactating cow model. Ninety Holstein–Friesian lactating dairy cows of various parities were systematically assigned to a vaccinated (n =44) or control (n =46) group. Vaccinates received two 5ml doses of the bacterin 14 days apart starting on day 0. Quarter milk samples for bacterial culture were collected prior to each vaccination and approximately monthly thereafter for 6 months. Composite milk samples were collected on days 0, 14, 28, 49 and 70 for IgA, IgG1, IgG2, and IgM determinations and somatic cell count. No animals in either group developed a new S. aureus IMI after vaccination. The numbers of mammary quarters that developed a new CNS IMI, time to new CNS IMI, milk somatic cell count, and milk antibody isotype sample-to-positive ratio did not significantly differ between groups (P >0.05). In a herd with a 3% prevalence of S. aureus IMI and a 30% prevalence of CNS IMI, the vaccine did not reduce the new staphylococcal IMI rate. There may be insufficient vaccine-induced opsonizing antibody in milk to facilitate phagocytosis and clearance of staphylococci from the mammary gland. [Copyright &y& Elsevier]

A competitive-inhibition enzyme-linked immunosorbent assay (cELISA) was evaluated for the detection of serum antibodies to the surface envelope (SU) of caprine arthritis-encephalitis virus (CAEV) in goats. This assay utilized 96-well microtiter plates containing CAEV-63 SU captured by monoclonal antibody (MAb) F7-299 and measured the competitive displacement of horseradish peroxidase-conjugated MAb GPB 74A binding by undiluted goat sera (F. Ozyörük, W. P. Cheevers, G. A. Hullinger, T. C. McGuire, M. Hutton, and D. P. Knowles, Clin. Diagn. Lab. Immunol. 8:44-51, 2001). Two hundred serum samples from goats in the United States were used to determine the sensitivity and specificity of cELISA based on the immunoprecipitation (IP) of [(35)S]methionine-labeled viral antigens as a standard of comparison. A positive cELISA was defined as >33.2% inhibition of MAb 74A binding based on 2 standard deviations above the mean percent inhibition of 140 IP-negative serum samples. At this cutoff value, there were 0 of 60 false-negative sera (100% sensitivity) and 5 of 140 false-positive sera (96.4% specificity). Additional studies utilized IP-monitored cELISA to establish a CAEV-free herd of 1,640 dairy goats.