Determination of residues of isofenphos and its phosphoramidate analogue

A method is described for the gas chromatographic determination of residues of isofenphos (BAY 92114, O-ethyl O-2-isopropoxycarbonylphenyl isopropylphosphor-amidothioate) and its phosphoramidate which is a potential metabolite. When potato, cabbage, rapeseed and a sandy loam soil were fortified with 0.01, 0.1 and 1.0 mg/kg and analysed by the method described, the recoveries ranged from 76 to 98%. The limits of detection of the method were 0.5 and 1.0 ng for isofenphos and isofenphos oxygen analogue respectively. Degradation under field conditions of isofenphos to its oxygen analogue was demonstrated in a sample of field-treated potatoes.     

Effects of a single dose of an intranasal feline herpesvirus 1, calicivirus, and panleukopenia vaccine on clinical signs and virus shedding after challenge with virulent feline herpesvirus 1

The objective of this study was to determine whether intranasal administration of a commercially available FVRCP vaccine to kittens lessened clinical signs and feline herpesvirus 1 (FHV-1) viral shedding when compared to unvaccinated control kittens after FHV-1 challenge. Three groups of 10 unvaccinated kittens were administered one dose of vaccine 6 days (group 1), 4 days (group 2), or 2 days (group 3) before challenge, respectively. One group was maintained as unvaccinated controls (group 4). FHV-1 challenge was then induced and the kittens were observed for 14 days. When the grouped vaccinated kitten results (groups 1-3) were compared to group 4 results, clinical scores following challenge were significantly lower (P<0.05) and significantly lower body temperatures (P<0.05) were detected on days 0, 5 and 9 post-challenge. When evaluated by individual group, group 1 and group 2 kittens had significantly lower clinical scores (P<0.05) than group 4 kittens post-challenge. In addition, FHV-1 shedding was lower in group 1 kittens when compared to group 4 kittens on day 6 after challenge (P<0.05). Administration of this vaccine within several days prior to exposure lessened clinical signs of disease and FHV-1 shedding compared to unvaccinated kittens.     

Comparative evaluation of molecular diagnostic tests for Nucleospora salmonis and prevalence in migrating juvenile salmonids from the Snake River, USA

Nucleospora salmonis is an intranuclear microsporidian that primarily infects lymphoblast cells and contributes to chronic lymphoblastosis and a leukemia-like condition in a range of salmonid species. The primary goal of this study was to evaluate the prevalence of N. salmonis in out-migrating juvenile hatchery and wild Chinook salmon Oncorhynchus tshawytscha and steelhead O. mykiss from the Snake River in the U.S. Pacific Northwest. To achieve this goal, we first addressed the following concerns about current molecular diagnostic tests for N. salmonis: (1) nonspecific amplification patterns by the published nested polymerase chain reaction (nPCR) test, (2) incomplete validation of the published quantitative PCR (qPCR) test, and (3) whether N. salmonis can be detected reliably from nonlethal samples. Here, we present an optimized nPCR protocol that eliminates nonspecific amplification. During validation of the published qPCR test, our laboratory developed a second qPCR test that targeted a different gene sequence and used different probe chemistry for comparison purposes. We simultaneously evaluated the two different qPCR tests for N. salmonis and foundthat both assays were highly specific, sensitive, and repeatable. The nPCR and qPCR tests had good overall concordance when DNA samples derived from both apparently healthy and clinically diseased hatchery rainbow trout were tested. Finally, we demonstrated that gill snips were a suitable tissue for nonlethal detection of N. salmonis DNA in juvenile salmonids. Monitoring of juvenile salmonid fish in the Snake River over a 3-year period revealed low prevalence of N. salmonis in hatchery and wild Chinook salmon and wild steelhead but significantly higher prevalence in hatchery-derived steelhead. Routine monitoring of N. salmonis is not performed for all hatchery steelhead populations. At present, the possible contribution of this pathogen to delayed mortality of steelhead has not been determined.     

Microbial activity at gigapascal pressures

We observed physiological and metabolic activity of Shewanella oneidensis strain MR1 and Escherichia coli strain MG1655 at pressures of 68 to 1680 megapascals (MPa) in diamond anvil cells. We measured biological formate oxidation at high pressures (68 to 1060 MPa). At pressures of 1200 to 1600 MPa, living bacteria resided in fluid inclusions in ice-VI crystals and continued to be viable upon subsequent release to ambient pressures (0.1 MPa). Evidence of microbial viability and activity at these extreme pressures expands by an order of magnitude the range of conditions representing the habitable zone in the solar system.     

Strong association of de novo copy number mutations with autism

We tested the hypothesis that de novo copy number variation (CNV) is associated with autism spectrum disorders (ASDs). We performed comparative genomic hybridization (CGH) on the genomic DNA of patients and unaffected subjects to detect copy number variants not present in their respective parents. Candidate genomic regions were validated by higher-resolution CGH, paternity testing, cytogenetics, fluorescence in situ hybridization, and microsatellite genotyping. Confirmed de novo CNVs were significantly associated with autism (P = 0.0005). Such CNVs were identified in 12 out of 118 (10%) of patients with sporadic autism, in 2 out of 77 (3%) of patients with an affected first-degree relative, and in 2 out of 196 (1%) of controls. Most de novo CNVs were smaller than microscopic resolution. Affected genomic regions were highly heterogeneous and included mutations of single genes. These findings establish de novo germline mutation as a more significant risk factor for ASD than previously recognized.     

Molecular characterization, ecology, and epidemiology of a novel Tymovirus in Asclepias viridis from Oklahoma

Native virus-plant interactions require more understanding and their study will provide a basis from which to identify potential sources of emerging destructive viruses in crops. A novel tymovirus sequence was detected in Asclepias viridis (green milkweed), a perennial growing in a natural setting in the Tallgrass Prairie Preserve (TGPP) of Oklahoma. It was abundant within and frequent among A. viridis plants and, to varying extents, within other dicotyledonous and one grass (Panicum virgatum) species obtained from the TGPP. Extracts from A. viridis containing the sequence were infectious to a limited number of species. The virus genome was cloned and determined to be closely related to Kennedya yellow mosaic virus. The persistence of the virus within the Oklahoma A. viridis population was monitored for five successive years. Virus was present in a high percentage of plants within representative areas of the TGPP in all years and was spreading to additional plants. Virus was present in regions adjacent to the TGPP but not in plants sampled from central and south-central Oklahoma. Virus was present in the underground caudex of the plant during the winter, suggesting overwintering in this tissue. The RNA sequence encoding the virus coat protein varied considerably between individual plants (≈3%), likely due to drift rather than selection. An infectious clone was constructed and the virus was named Asclepias asymptomatic virus (AsAV) due to the absence of obvious symptoms on A. viridis.     

Natural hazards and genetic diversity in rice

Rice crop diversity hasdecreased dramatically in the recent past.Understanding the causes that underlie theevident genetic erosion is critical for thefood security of subsistence rice farmers andbiodiversity. Our study shows that farmers inthe northeastern Philippines had a markedreduction in rice diversity from 1996 to 1998.The ultimate causes were a drought resultingfrom the El Niño phenomenon in 1997 andflooding due to two successive typhoons in1998. The proximate causes, however, includedlocal water control factors, limitations in thehousehold and village-level seedinfrastructure, farm location in relation tothe goods and services necessary to obtainseeds, policies and programs of the Departmentof Agriculture, and the characteristics of therice varieties themselves. The implications ofour study are that genetic erosion is notalways the result of purposeful acts by farmersnor is it necessarily gradual. Improvingon-farm seed technology will stabilize the seedproduction, distribution, and use system andthereby enhance household food security.Ultimately, rice diversity will be improvedonly if diversity is a safe and viable optionfor farmers. Therefore, public policy thatsupports farmers who maintain a diverse set ofcultivars is critical for any on-farmconservation strategy.