Topographic placement of management practices in riparian zones to reduce water quality impacts from pastures

Riparian buffers, a best management practice (BMP), lessen environmental impacts caused by pasture-based agriculture by excluding livestock from streams and removing sediment and nutrients from overland flow before they enter the watercourse. Geospatial data analysis of digital elevation models (DEMs) can improve BMP placement by ensuring that BMPs intercept flow paths. Livestock heavy use areas and riparian buffers within 100?m of the stream were digitized using aerial photography of Spring Creek watershed (Pennsylvania, USA). Flow path lengths and stream entry points from heavy use areas, from all agricultural land uses, and from a random sample of points were calculated using 1, 10, and 30?m DEM resolutions. Euclidean distances identified the nearest stream entry point regardless of topography. Drainage areas for each streambank cell were evaluated using each DEM resolution. Topographic calculations differed significantly from Euclidean, with median differences of 14.3?m for flow path length and 24.1?m between stream entry points for the 10?m DEM. Existing buffers intercepted runoff from only 23?% of heavy use areas. Drainage areas ranged from one to hundreds of DEM cells. Any DEM is an arbitrary representation of a continuous surface; both resolution and processing method affect the suitability of such a representation for any given purpose. We found that 30?m DEMs did not provide reasonable flow path estimates at the scale of grazing agriculture in this region, while Pennsylvania 1?m DEMs were minimally smoothed during DEM preparation, resulting in erratic flow paths. The 10?m DEMs were the most suitable available DEM product, and should be used in conjunction with site visits for planning pasture BMP placement.     

Monoclonal antibodies specific for Campylobacter fetus lipopolysaccharides

Four monoclonal antibodies (mAbs) (M1357, M1360, M1823 and M1825) which reacted with Campylobacter fetus lipopolysaccharide (LPS) core region epitopes were produced and characterized. Reactivity of these mAbs with C. fetus core LPS epitopes was determined by enzyme-linked immunosorbent assay (ELISA) with whole cell proteinase K digests and phenol-water extracted LPS, and by immunoblotting with proteinase K digests. The specificities of the four mAbs were evaluated using an indirect ELISA. One of the mAbs reacted with 42 and three of the mAbs reacted with 41 of the 42 C. fetus strains examined. No reaction was observed between the four mAbs and 32 non-C. fetus bacteria tested, with the exception of one mAb with one organism. The four mAbs reacted with serotype A and B strains indicating the presence of shared epitopes in C. fetus LPS core oligosaccharides. The specificities of three mAbs previously produced to C. fetus LPS O-antigens (M1177, M1183 and M1194) were also evaluated and no reaction was observed with these mAbs and the 32 non-C. fetus bacteria tested. Strong immunofluorescence reactions were observed with the anti-O chain mAbs and selected C. fetus strains of the homologous serotype. These anti-LPS core oligosaccharide and anti-LPS O chain mAbs are highly specific for C. fetus and are potentially useful as immunodiagnostic reagents for detection, identification and characterization of C. fetus.     

Hyperkeratosis and other complications in animals. Chlorinated hydrocarbons as possible causative agents.

Extract

This experiment was designed primarily to compare the efficacy of two heat-concentrated synthetic medium tuberculins, one prepared from strains of Mycobacterium bovis and the other from Mycobacterium tuberculosis, when used in tuberculin testing of cattle.     

Intraperitoneal vaccination of rams against brucella epididymitis

Extract

Sir, —In reply to the letter of Quinlivan and Wallace in this issue, I must state that their comments give me no reason to modify or retract my comments in Surveillance (1978) No.5.     

Source relationships between streambank soils and streambed sediments in a mercury-contaminated stream

Purpose

In contaminated streams, understanding the role of streambank and streambed source contributions is essential to developing robust remedial solutions. However, identifying relationships can be difficult because of the lack of identifying signatures in source and receptor pools. East Fork Poplar Creek (EFPC) in Oak Ridge, TN, USA received historical industrial releases of mercury that contaminated streambank soils and sediments. Here, we determined relationships between the contaminated streambank soils and sand-sized streambed sediments.

Materials and methods

Field surveys revealed the spatial trends of the concentrations of inorganic total mercury (Hg) and methyl mercury (MeHg), Hg lability as inferred by sequential extraction, particle size distribution, and total organic carbon. Statistical tests were applied to determine relationships between streambank soil and streambed sediment properties.

Results and discussion

Concentrations of Hg in streambank soils in the upper reaches averaged 206 mg kg^?1 (all as dry weight) (n?=?457), and 13 mg kg^?1 in lower reaches (n?=?321), while sand-sized streambed sediments were approximately 16 mg kg^?1 (n?=?57). Two areas of much higher Hg and MeHg concentrations in streambank soils were identified and related to localized higher Hg concentrations in the streambed sediments; however, most of the streambank soils have similar Hg concentrations to the streambed sediments. The molar ratio of Hg to organic carbon, correlation between MeHg and Hg, and particle size distributions suggested similarity between the streambank soils and the fine sand-sized fraction (125–250 μm) collected from the streambed sediments. Mercury in the fine sand-sized streambed sediments, however, was more labile than Hg in the streambank soils, suggesting an in-stream environment that altered the geochemistry of sediment-bound Hg.

Conclusions

This study revealed major source areas of Hg in streambank soils, identified possible depositional locations in streambed sediments, and highlighted potential differences in the stability of Hg bound to streambank soils and sediments. This work will guide future remedial decision making in EFPC and will aid other researchers in identifying source–sink linkages in contaminated fluvial systems.

     

National Meat Case Study 2004: Product labeling information, branding, and packaging trends

Fresh meat retail cases in 104 supermarkets across 5 regions of the United States were audited for the use of packaging types and materials, branding, and cooking/nutritional information. Frequency means were separated for species of beef, ground beef, pork, chicken, turkey, lamb, and veal. Traditional polyvinyl chloride overwrap was used on 47.0% of packages in the fresh meat case nationwide and was the most frequent packaging type for beef, ground beef, pork, lamb, and veal. The use of modified atmosphere packaging was greatest (P < 0.001) in ground beef (33.2%) and turkey (45.1%) products. The 3 most common tray colors in the fresh meat retail case on a national level were white (39.6%), yellow (22.4%), and black (11.5%). Foam trays were used in 72.6% of all packages in the retail meat case. In 2004, 60.2% of all packages were case-ready. Chicken (94.8%) and turkey (95.6%) products utilized case-ready packaging systems more (P < 0.001) than any other species. On a national level, 50.1% of all products carried a national brand, 12.2% carried a store brand, and the remaining 37.7% of products in the fresh meat case in 2004 were not branded. Chicken was most (P < 0.001) likely to carry a natural brand label. Labels with cooking instructions were found most (P < 0.001) on pork (37.3%) and turkey products (48.1%). Chicken (20.4%) and turkey products (20.7%) were most (P < 0.001) likely to have the cooking instructions printed on the packaging material compared with all other species. Labels with nutritional information were most (P < 0.001) likely to be found on turkey products (55.7%) in the fresh meat case compared with any other species. On the national level, 6.1% of all packages reported in the fresh meat case in 2004 were value-added.