Experimental infection of pregnant goats with bovine viral diarrhea virus (BVDV) 1 or 2     

Thomas Passler  Kay P Riddell  Misty A Edmondson  Manuel F Chamorro  John D Neill  Bruce W Brodersen  Heather L Walz  Patricia K Galik  Yijing Zhang  Paul H Walz 《Veterinary research》2014,45(1):38

Infections with bovine viral diarrhea virus (BVDV) of the genus pestivirus, family Flaviviridae, are not limited to cattle but occur in various artiodactyls. Persistently infected (PI) cattle are the main source of BVDV. Persistent infections also occur in heterologous hosts such as sheep and deer. BVDV infections of goats commonly result in reproductive disease, but viable PI goats are rare. Using 2 BVDV isolates, previously demonstrated to cause PI cattle and white-tailed deer, this study evaluated the outcome of experimental infection of pregnant goats. Pregnant goats (5 goats/group) were intranasally inoculated with BVDV 1b AU526 (group 1) or BVDV 2 PA131 (group 2) at approximately 25–35 days of gestation. The outcome of infection varied considerably between groups. In group 1, only 3 does became viremic, and 1 doe gave birth to a stillborn fetus and a viable PI kid, which appeared healthy and shed BVDV continuously. In group 2, all does became viremic, 4/5 does aborted, and 1 doe gave birth to a non-viable PI kid. Immunohistochemistry demonstrated BVDV antigen in tissues of evaluated fetuses, with similar distribution but reduced intensity as compared to cattle. The genetic sequence of inoculated viruses was compared to those from PI kids and their dam. Most nucleotide changes in group 1 were present during the dam’s acute infection. In group 2, a similar number of mutations resulted from fetal infection as from maternal acute infection. Results demonstrated that BVDV may cause reproductive disease but may also be maintained in goats.  相似文献   

Association of dhurrin levels and post-flowering non-senescence with resistance to stalk rot pathogens in Sorghum bicolor     

Funnell-Harris  Deanna L.  Sattler  Scott E.  O&#;Neill  Patrick M.  Toy  John J.  Bernhardson  Lois F.  Kilts  Mark R.  Khasin  Maya 《European journal of plant pathology / European Foundation for Plant Pathology》2022,162(1):237-246

European Journal of Plant Pathology - Aflatoxin contamination is common in several crops, including maize, in warm agricultural areas. For over 40 years, there have been many efforts to...  相似文献   

High-Energy Charged Particles in the Innermost Jovian Magnetosphere     

HM Fischer  E Pehlke  G Wibberenz  LJ Lanzerotti  JD Mihalov 《Science (New York, N.Y.)》1996,272(5263):856-858

The energetic particles investigation carried by the Galileo probe measured the energy and angular distributions of the high-energy particles from near the orbit of Io to probe entry into the jovian atmosphere. Jupiter's inner radiation region had extremely large fluxes of energetic electrons and protons; intensities peaked at approximately2.2RJ (where RJ is the radius of Jupiter). Absorption of the measured particles was found near the outer edge of the bright dust ring. The instrument measured intense fluxes of high-energy helium ions (approximately62 megaelectron volts per nucleon) that peaked at approximately1.5RJ inside the bright dust ring. The abundances of all particle species decreased sharply at approximately1.35RJ; this decrease defines the innermost edge of the equatorial jovian radiation.  相似文献   

Evaluation of variable number tandem repeat (VNTR) loci in molecular typing of Mycobacterium bovis isolates from Ireland   总被引：3，自引：0，他引：3  

Roring S  Scott AN  Glyn Hewinson R  Neill SD  Skuce RA 《Veterinary microbiology》2004,101(1):65-73

Various sets of short tandem repeats such as the exact tandem repeats (ETRs), mycobacterial interspersed repetitive units (MIRUs) and variable number tandem repeat (VNTR) loci, have recently been described as effective tools in strain typing M. tuberculosis complex isolates, representative of global diversity. This study extends our previous study, evaluating the discrimination of a further 17 MIRU_VNTR loci individually and comparing the resolution of published VNTR sets and spoligotyping using a panel of 47 local M. bovis field isolates, including known epidemiologically linked isolates and 9 M. tuberculosis complex reference isolates. Individual loci differed greatly in their discrimination. The discriminatory capacity of novel combinations of the most discriminating VNTR loci was also assessed. In the panel of 47 M. bovis isolates, 17 unique profiles were resolved using VNTR set 1, whilst the MIRUs and ETRs resolved the panel into 11 and 6 profiles, respectively. A novel combination of 10 highly discriminatory VNTRs was determined, which resolved 30 unique profiles. The configuration of a multi-locus VNTR-based assay and its ability to provide a flexible, convenient and high-resolution genotyping method is discussed. We suggest a panel of VNTR markers which may be widely suitable for molecular epidemiological studies of M. bovis. However, the number and combination of informative VNTR markers selected needs to be determined empirically with reference to locally prevalent strains and will depend on the epidemiological study requirements.  相似文献   

Low-cost experimental unit and growth medium for testing soil effects on shrimp culture     

Gad Ritvo  Joe B Dixon  Tzachi M Samocha  Addison L Lawrence  William H Neill 《Aquacultural Engineering》1998,18(4):245-249

PVC pipes, 10 cm in diameter and 46 cm long, sealed at one end and filled with 18 ppt of artificial seawater and a 6-cm layer of substrate, were tested as experimental units for the culturing of penaeid shrimp. The growth substrate was prepared by mixing 70% quartz sand, 24% Georgia kaolin, 5% Gonzales bentonite and 1% Bermuda grass hay. One juvenile Penaeus vannamei was placed in each container and shrimp weight gain was monitored. In the first study (four replicates), shrimp grew to 8.15 g within 8 weeks at a rate of ≈1 g week⁻¹ with no mortality; thereafter, growth decreased and 25% mortality was observed. In the second study (seven replicates), the average weight of shrimp was 8.66 g in 10 weeks, with 29% mortality occurring between the seventh and eighth week. Experimental unit cost was $3.30.  相似文献   

Accumulation of Chemical Elements in Texas Shrimp Pond Soils   总被引：2，自引：0，他引：2  

Gad  Ritvo Joe B.  Dixon Addison L.  Lawrence Tzachi M.  Samocha William H.  Neill Michael E  Speed 《Journal of the World Aquaculture Society》1998,29(4):422-431

Abstract— This study evaluated changes in chemistry of shrimp pond soils over one production cycle. Several soil nutrients, pH, organic matter, and total soluble salts were analyzed in the upper 10 cm of pond-bottom soil on two Texas shrimp farms in two consecutive years. Soil concentrations of S, P, Ca, Mg, K, Na, Mn, and Zn increased from one year to the next, S increased by 400 ppm. Organic matter did not accumulate. The pH decreased in all pond soils, owing perhaps to the oxidation of organic matter and/or inorganic compounds. There was no statistical difference in shrimp yield between the two consecutive years. These results indicated that the accumulation of S and soluble salts derived from seawater and feed should be monitored and evaluated to prevent excessive chemical element loading of pond soil and discharge water.  相似文献   

Experimental demonstration of guiding and bending of electromagnetic waves in a photonic crystal   总被引：3，自引：0，他引：3  

SY Lin  E Chow  V Hietala  PR Villeneuve  JD Joannopoulos 《Science (New York, N.Y.)》1998,282(5387):274-276

The routing and interconnection of optical signals through narrow channels and around sharp corners are important for large-scale all-optical circuit applications. A recent computational result suggests that photonic crystals may offer a novel way of achieving this goal by providing a mechanism for guiding light that is fundamentally different from traditional index guiding. Waveguiding in a photonic crystal and near 100 percent transmission of electromagnetic waves around sharp 90 degree corners were observed experimentally. Bending radii were made smaller than one wavelength.  相似文献   

Seed longevity in terrestrial orchids - Potential for persistent in situ seed banks     

Dennis F. Whigham  John P. O’Neill  Bruce A. Caldwell 《Biological conservation》2006,129(1):24-30

Terrestrial orchids typically produce numerous small seeds that contain very small nutrient reserves. The seeds are structurally adapted for wind dispersal but little is known about their fate after dispersal. Some studies of seed viability in situ indicate survival for up to two years in temperate orchid species. Seeds stored in the laboratory may last much longer. We investigated seed viability of seven North American orchid species with seed packets buried in a range of soil and wood substrates within their natural habitats. In Goodyera pubescens most seeds germinated within one year. Four other species continued to germinate sparsely during the observation period, but after almost seven years many seeds were still viable. In one species, Liparis liliifolia, seeds that had been in situ for four years had germination rates as high as 68% when sown in vitro with a compatible fungus. The remaining two species did not germinate during the observation period but the seeds were judged to be intact and tested positively for viability after four years in the ground. These observations are interpreted as different species-specific strategies for in situ germination and their seed bank potential is discussed.  相似文献