Safety of a modified-live combination vaccine against respiratory and reproductive diseases in pregnant cows

A combination vaccine (Bovi-Shield FP4 + L5, Pfizer Animal Health) containing modified-live virus (MLV) components against bovine herpesvirus-1 (BHV-1), bovine viral diarrhea virus BVDV), parainfluenza virus-3 (PI3), bovine respiratory syncytial virus (BRSV), and inactivated cultures of Leptospira canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona was evaluated for safety in pregnant beef and dairy animals. Heifers vaccinated prebreeding with the minimum immunizing dose (lowest antigen level initiating immunizing effects) of the vaccine's MLV BHV-1 or BVDV components and during pregnancy (approximately 200 days of gestation) with vaccine containing 10x doses of the same BHV-1 and BVDV components delivered live, healthy calves that were determined to be serologically negative (titer less than 1:2) for neutralizing antibodies to BHV-1 and BVDV prior to nursing. Additionally, in three field safety studies, previously vaccinated cows and heifers that received a field dose (vaccine containing antigen levels required for commercial sale of the MLV combination vaccine during either the first, second, or third trimester of pregnancy had abortion rates similar to those of pregnant cows and heifers vaccinated during the same stage of pregnancy with sterile water diluent.     

Rapid late Pleistocene incision of Atlantic passive-margin river gorges

The direct and secondary effects of rapidly changing climate caused large rivers draining the Atlantic passive margin to incise quickly into bedrock beginning about 35,000 years ago. Measured in samples from bedrock fluvial terraces, 10-beryllium shows that both the Susquehanna and Potomac Rivers incised 10- to 20-meter-deep gorges along steep, convex lower reaches during the last glacial cycle. This short-lived pulse of unusually rapid down-cutting ended by 13,000 to 14,000 years ago. The timing and rate of downcutting are similar on the glaciated Susquehanna and unglaciated Potomac Rivers, indicating that regional changes, not simply glacial meltwater, initiated incision.     

Multi‐seasonal field release and spermatization trials of transgenic hypovirulent strains of Cryphonectria parasitica containing cDNA copies of hypovirus CHV1‐EP713

Three indigenous field strains of the chestnut blight fungus, Cryphonectria parasitica collected in 1996 from a test site in the Meshomasic State Forest, Connecticut, USA, were engineered to contain a chromosomally integrated full‐length infectious cDNA copy of the severe, virulence‐attenuating hypovirus CHV1‐EP713. These transgenic hypovirulent strains were introduced into the test site after it had been clear‐cut, as sprayed conidia in multiple applications over 4 years, beginning in 1997. Evidence was obtained for cytoplasmic transmission of cDNA‐derived hypovirus RNA and for recovery of transgenic strains from canker tissue of the spray‐treated trees. However, there was no indication of spread of transgenic strains or cDNA‐derived viral RNA to the control plot or outside the treatment plot. A single transgenic C. parasitica isolate was identified from a total of 156 isolates recovered from 1330 insects representing five insect orders. Only 2.6% of the 1082 C. parasitica bark isolates recovered during the course of this study were vegetatively compatible with the untransformed input strains. Transgenic ascospore progeny were produced by 40% of the perithecia collected in 1999 and by only 7.3% of the perithecia collected in 2000. A concurrent field release study performed in the Monongahela National Forest in West Virginia in 1998 and 1999 with transgenic hypovirulent strains constructed with the same CHV1‐EP713 cDNA‐containing plasmid identified seasonal application dates and delivery methods that resulted in very high levels of transgenic ascospore production. Results of the combined field release studies are discussed in terms of requirements for improved formulations and delivery methods and the importance of balancing ecological fitness and virulence attenuation.     

Changes in populations of the eyespot fungi Tapesia yallundae and T. acuformis under different fungicide regimes in successive crops of winter wheat, 1984–2000

Effects of regular treatments with the fungicides carbendazim and prochloraz applied to whole plots divided into subplots with different initial population mixtures of carbendazim-sensitive or carbendazim-resistant Tapesia yallundae or T. acuformis were studied in successive crops of winter wheat from 1984/85 to 1999/2000. In unsprayed and carbendazim-sprayed whole plots, a stable coexistence of about 50% each of T. yallundae and T. acuformis developed within five seasons, but in whole plots sprayed with prochloraz or prochloraz plus carbendazim, the proportion of T. acuformis increased to > 80%. A discrete time difference equation model was derived from knowledge of the biology of eyespot and competition theory to describe the population changes. The model was fitted to the data from treatments where coexistence occurred [subplots in unsprayed (1985–92) and carbendazim-sprayed (1985–89) whole plots], using nonlinear least squares regression. The optimized value of the resource overlap coefficient was small, suggesting niche differences between the two species. Populations were nearly 100% carbendazim-resistant in carbendazim-sprayed whole plots by July 1985 (one season) and in whole plots sprayed with prochloraz plus carbendazim by July 1986 (two seasons). In prochloraz-sprayed whole plots, the proportion of carbendazim-resistant isolates decreased more rapidly than in unsprayed whole plots in the 1980s, but by July 1992 a shift in populations in unsprayed and prochloraz-sprayed whole plots towards predominantly carbendazim-resistant strains had occurred.     

Dislocation-driven nanowire growth and Eshelby twist

Hierarchical nanostructures of lead sulfide nanowires resembling pine trees were synthesized by chemical vapor deposition. Structural characterization revealed a screwlike dislocation in the nanowire trunks with helically rotating epitaxial branch nanowires. It is suggested that the screw component of an axial dislocation provides the self-perpetuating steps to enable one-dimensional crystal growth, in contrast to mechanisms that require metal catalysts. The rotating trunks and branches are the consequence of the Eshelby twist of screw dislocations with a dislocation Burgers vector along the 110 directions having an estimated magnitude of 6 +/- 2 angstroms for the screw component. The results confirm the Eshelby theory of dislocations, and the proposed nanowire growth mechanism could be general to many materials.     

International conservation policy delivers benefits for birds in Europe

Conservation of the planet's biodiversity will depend on international policy intervention, yet evidence-based assessment of the success of such intervention is lacking. Poor understanding of the effectiveness of international policy instruments exposes them to criticism or abandonment and reduces opportunities to improve them. Comparative analyses of population trends provide strong evidence for a positive impact of one such instrument, the European Union's Birds Directive, and we identify positive associations between the rate of provision of certain conservation measures through the directive and the response of bird populations. The results suggest that supranational conservation policy can bring measurable conservation benefits, although future assessments will require the setting of quantitative objectives and an increase in the availability of data from monitoring schemes.     

Evaluation of nitrogen and organic matter balance in the feedlot as affected by level and source of dietary fiber.

A trial was conducted to determine the effect of level and source of dietary fiber on N and OM excretion by cattle on finishing diets. One hundred twenty steers were stratified by weight and allotted to one of the following treatments: 7.5% roughage (7.5% R), wet corn gluten feed (WCGF; 41.5% of dietary DM), and all-concentrate (All Con) diet. Cattle were fed for 87 d during the summer with 23.7 m2 of pen area per animal. Steers fed the WCGF diet had heavier final weights, greater DMI, and higher ADG (P < .01) than the 7.5% R and All Con treatments. Steers fed All Con had lower (P < .01) DMI than the other two treatments. Nitrogen and OM mass balances in the feedlot were quantified. Main components were nutrient input, retention, and excretion. Nitrogen and OM intake of steers fed WCGF were greater (P < .05) than those of steers fed the other treatments. The WCGF treatment had a greater percentage of fecal N output (P < .05). The All Con treatment had a greater (P < .01) percentage of urinary N than WCGF and 7.5% R diets. Steers fed the WCGF treatment excreted more (P < .01) OM compared with the other treatments, which led to more N and OM being removed in manure at cleaning. The All Con treatment had more (P < .01) N and OM in runoff than the other treatments. Nutrition can change site of fermentation, which affects the composition of excreted material; however, total amount of N excreted may be more important than route of excretion in decreasing N losses to the environment and maximizing recovery in manure.