Palumbo J.D.,U.S. Department of Agriculture |
O'Keeffe T.L.,U.S. Department of Agriculture |
Vasquez S.J.,County of Fresno |
Mahoney N.E.,U.S. Department of Agriculture
Letters in Applied Microbiology | Year: 2011
Aims: To determine incidence and levels of ochratoxin A (OTA) in California raisins and to isolate and characterize OTA-producing fungi from California raisin vineyard populations. Methods and Results: Forty raisin clusters sampled from four California vineyards in the San Joaquin Valley were analysed for OTA content using immunoaffinity and HPLC methods. OTA was detected in 93% of the samples, at levels from 0·06 to 11·4ngg-1. From these raisin samples, a total of 400 strains of Aspergillus were isolated and analysed for OTA production. Twelve isolates (3%), from five raisin samples, produced OTA. These isolates were identified as Aspergillus carbonarius, based on morphological characteristics and multilocus sequence analysis. Levels of OTA produced by these isolates on raisin agar ranged from 0·9 to 15μgg-1. Conclusions: OTA is a common contaminant of raisin vineyards, but average levels are much lower than EU regulatory limits for dried fruit. The primary species responsible for OTA contamination in California raisins is A. carbonarius. Significance and Impact of the Study: This study illustrates that low-level OTA contamination of raisins occurs in California and that ecological studies of A. carbonarius within the Aspergillus section Nigri population on raisins are warranted to monitor ochratoxigenic potential of the crop. No claim to US Government works. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.
Mu A.,University of California at San Francisco |
Rutledge J.,County of Fresno |
Mills P.,University of California at San Francisco |
Paul S.,University of California at San Francisco
Journal of the International Association of Providers of AIDS Care | Year: 2014
Objective: The incidence of Kaposis sarcoma (KS) decreased dramatically after the introduction of highly active antiretroviraltherapy (HAART). This study determined the ongoing incidence of and mortality from KS in HIV-infected adults from 1998-2012in Fresno County, California. The role of virologic control and immune reconstitution was assessed.Methods: Incident caseswere identified from the state Electronic HIV/AIDS Reporting System (EHARS), the California Cancer Registry, and hospitalrecords of the county HIV treatment center.Results: From 1998-2012, the average incidence of KS was 0.51 cases per 100,000person-years. Of the 66 cases of KS there were 20 deaths, with 85% of the mortality occurring in the first 12 months. Amongpatients on HAART achieving HIV RNA <400 copies/uL, but with a <50 cell/uL increase in CD4 count there was no improvementin mortality.Conclusions: The incidence of KS remains stable since 1998 with a 12-month mortality of 30%. © The Author(s) 2013.
Gassmann A.J.,Iowa State University |
Hannon E.R.,University of Arizona |
Hannon E.R.,County of Fresno |
Sisterson M.S.,U.S. Department of Agriculture |
And 3 more authors.
Journal of Economic Entomology | Year: 2012
The evolution of resistance by pests can reduce the efficacy of transgenic crops that produce insecticidal toxins from Bacillus thuringiensis (Bt). However, fitness costs may act to delay pest resistance to Bt toxins. Meta-analysis of results from four previous studies revealed that the entomopathogenic nematode Steinernema riobrave (Rhabditida: Steinernematidae) imposed a 20% fitness cost for larvae of pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), that were homozygous for resistance to Bt toxin Cry1Ac, but no significant fitness cost was detected for heterozygotes. We conducted greenhouse and laboratory selection experiments to determine whether S. riobrave would delay the evolution of pink bollworm resistance to Cry1Ac. We mimicked the high dose/refuge scenario in the greenhouse with Bt cotton (Gossypium hirsutum L.) plants and refuges of non-Bt cotton plants, and in the laboratory with diet containing Cry1Ac and refuges of untreated diet. In both experiments, half of the replicates were exposed to S. riobrave and half were not. In the greenhouse, S. riobrave did not delay resistance. In the laboratory, S. riobrave delayed resistance after two generations but not after four generations. Simulation modeling showed that an initial resistance allele frequency >0.015 and population bottlenecks can diminish or eliminate the resistance-delaying effects of fitness costs. We hypothesize that these factors may have reduced the resistance-delaying effects of S. riobrave in the selection experiments. The experimental and modeling results suggest that entomopathogenic nematodes could slow the evolution of pest resistance to Bt crops, but only under some conditions. © 2012 Entomological Society of America.
Smith N.J.,County of Fresno
Pan-Pacific Entomologist | Year: 2010
Parammoplanus (Pate) is reviewed and redescribed. Relationships between Parammoplanus, Ammoplanus and Ammoplanellus are discussed. Sixteen new species are described: brooksi, cavifrons, flavidus, foveatus, griswoldi, heydoni, hiatus, irwini, montanus, parkeri, succinacius, texanus, verrucosus, woolleyi, yanegai and zolnerowichi using male genitalia to help designate species limits. The subspecies lenape lenape (Pate) and lenape olamentke (Pate) are raised to the specific level. Two species groups, Irwini and Olamentke are defined. A key to the species is included. © 2009 Pacific Coast Entomological Society.
Allan C.,University of California at Davis |
Crisosto C.H.,University of California at Davis |
Michailides T.,University of California Kearney Research and Extension Center |
Brar G.S.,County of Fresno |
Ferguson L.,University of California at Davis
Acta Horticulturae | Year: 2016
California's 300,000 acre pistachio industry consists of over 90% Pistacia vera. Cultivars with different harvest timing would relieve the pressure on processing facilities. A recently identified cultivar, 'Pete I' harvests earlier, but is producing unacceptably high percentages of early season aborted nuts, which abscise, as well as partially filled and blank nuts. Both overload the hullers and float tanks. Field observations suggested insect pressure and/or fungal infestation. In an insect exclusion study, flower buds were both covered by insect-impermeable mesh and left uncovered on the 'Pete I' trees for the season until harvest. The resulting clusters showed no significant difference in the final percentage of aborted nuts between the bagged and unbagged samples. Laboratory plating of early-and mid-season nuts for fungal pathogens detected none beyond background levels. Therefore, high percentages of blanking and partially filled nuts in the 'Pete I' pistachio cultivar were not due to either insect or fungal pressures. Other possibilities are pollen or ovule incompatibility, or self-thinning through embryo abortion.