24 research outputs found

    Ethofumesate-resistant annual bluegrass (Poa annua) in grass seed production systems

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    The prolific seed production and polyploidy of annual bluegrass allow for the rapid development of herbicide resistance. Ethofumesate-resistant annual bluegrass plants were identified in the 1990s in grass seed production in Oregon, but their prevalence and distribution are not well documented. Therefore a dose–response experiment was initiated to determine the potential level of ethofumesate resistance in seed production systems. Seeds from 55 annual bluegrass populations were obtained from three sources: seed production fields (31 populations), the seed cleaning process (6 populations), and seed testing lots prior to retail distribution (18 populations). Additionally, two populations, one with known ethofumesate resistance and one with known susceptibility, were identified in preliminary testing and used as controls in this experiment. Seed from each collected population was increased. Individual seedlings were then transplanted into separate cone-tainers, grown to a size of 2 to 3 tillers in the greenhouse, and then sprayed using a compressed air track spray chamber with 10 doses of ethofumesate at 0, 0.56, 1.1, 2.8, 5.6, 8.4, 11.2, 16.8, 22.4, and 44.8 kg ai ha−1, with 0.84 to 2.2 kg ha−1 as the label application rate for perennial ryegrass. The resistant to susceptible ratio of populations across all sources ranged from 0.5 to 5.5. The most resistant populations found in production fields, seed cleaning, and seed testing lots had the effective dose necessary to kill 50% of the population (ED50) of 12.1, 9.4, and 13.1 kg ha−1, respectively. Furthermore, 68% of the populations found in production fields had ED50 higher than 6 kg ha−1, indicating common annual bluegrass resistance in grass seed production. As such, growers should implement integrated weed management strategies, as herbicides alone will likely be ineffective at controlling annual bluegrass

    Tribute to Professor David Bruck

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    A tribute to Professor David I. Bruck, who served on the faculty of the Washington and Lee University School of Law from 2004 to 2020. Bruck directed W&L\u27s death penalty defense clinic, the Virginia Capital Case Clearinghouse, also known as VC3 . He became Professor of Law, Emeritus in 2020

    Recovered memories, satanic abuse, Dissociative Identity Disorder and false memories in the UK: a survey of Clinical Psychologists and Hypnotherapists

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    An online survey was conducted to examine psychological therapists’ experiences of, and beliefs about, cases of recovered memory, satanic / ritualistic abuse, Multiple Personality Disorder / Dissociative Identity Disorder, and false memory. Chartered Clinical Psychologists (n=183) and Hypnotherapists (n=119) responded. In terms of their experiences, Chartered Clinical Psychologists reported seeing more cases of satanic / ritualistic abuse compared to Hypnotherapists who, in turn, reported encountering more cases of childhood sexual abuse recovered for the first time in therapy, and more cases of suspected false memory. Chartered Clinical Psychologists were more likely to rate the essential accuracy of reports of satanic / ritualistic abuse as higher than Hypnotherapists. Belief in the accuracy of satanic / ritualistic abuse and Multiple Personality Disorder / Dissociative Identity Disorder reports correlated negatively with the belief that false memories were possible

    Search for high-energy neutrino emission from hard X-ray AGN with IceCube

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    Active Galactic Nuclei (AGN) are powerful astronomical objects with very high luminosities. Theoretical arguments suggest that these objects are capable of accelerating particles to energies of 1020 eV. In environments with matter or photon targets, cosmic-ray interactions transpire leading to the production of pionic gamma rays and neutrinos. Since the AGN environment is rich in gas, dust and photons, they are promising candidate sources of high-energy astrophysical neutrinos. While the neutrinos manage to escape, the gamma rays may further interact and cascade down to hard X-rays in environments with sufficiently large photon or gas targets. We have used 12 years of IceCube data to perform a stacked search and a point source search for high-energy neutrino emission from hard X-ray AGN sampled from Swift-BAT Spectroscopic Survey (BASS) and present the results of these two analyses

    Citrate-Capped Gold Nanoparticle Electrophoretic Heat Production in Response to a Time-Varying Radio-Frequency Electric Field

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    The evaluation of heat production from gold nanoparticles (AuNPs) irradiated with radio-frequency (RF) energy has been problematic due to Joule heating of their background ionic buffer suspensions. Insights into the physical heating mechanism of nanomaterials under RF excitations must be obtained if they are to have applications in fields such as nanoparticle-targeted hyperthermia for cancer therapy. By developing a purification protocol that allows for highly stable and concentrated solutions of citrate-capped AuNPs to be suspended in high-resistivity water, we show herein, for the first time, that heat production is only evident for AuNPs of diameters ≤10 nm, indicating a unique size-dependent heating behavior not previously observed. Heat production has also shown to be linearly dependent on both AuNP concentration and total surface area and was severely attenuated upon AuNP aggregation. These relationships have been further validated using permittivity analysis across a frequency range of 10 MHz–3 GHz as well as static conductivity measurements. Theoretical evaluations suggest that the heating mechanism can be modeled by the electrophoretic oscillation of charged AuNPs across finite length scales in response to a time-varying electric field. It is anticipated these results will assist future development of nanoparticle-assisted heat production by RF fields for applications such as targeted cancer hyperthermia

    Practice Patterns and Outcomes of Retrievable Vena Cava Filters in Trauma Patients: An AAST Multicenter Study

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    BACKGROUND: The purpose of this study is to describe practice patterns and outcomes of posttraumatic retrievable inferior vena caval filters (R-IVCF). METHODS: A retrospective review of R-IVCFs placed during 2004 at 21 participating centers with follow up to July 1, 2005 was performed. Primary outcomes included major complications (migration, pulmonary embolism [PE], and symptomatic caval occlusion) and reasons for failure to retrieve. RESULTS: Of 446 patients (69% male, 92% blunt trauma) receiving R-IVCFs, 76% for prophylactic indications and 79% were placed by interventional radiology. Excluding 33 deaths, 152 were Gunter-Tulip (G-T), 224 Recovery (R), and 37 Optease (Opt). Placement occurred 6 ± 8 days after admission and retrieval at 50 ± 61 days. Follow up after discharge (5.7 ± 4.3 months) was reported in 51%. Only 22% of R-IVCFs were retrieved. Of 115 patients in whom retrieval was attempted, retrieval failed as a result of technical issues in 15 patients (10% of G-T, 14% of R, 27% of Opt) and because of significant residual thrombus within the filter in 10 patients (6% of G-T, 4% of R, 46% Opt). The primary reason R-IVCFs were not removed was because of loss to follow up (31%), which was sixfold higher (6% to 44%, p = 0.001) when the service placing the R-IVCF was not directly responsible for follow up. Complications did not correlate with mechanism, injury severity, service placing the R-IVCF, trauma volume, use of anticoagulation, age, or sex. Three cases of migration were recorded (all among R, 1.3%), two breakthrough PE (G-T 0.6% and R 0.4%) and six symptomatic caval occlusions (G-T 0, R 1%, Opt 11%) (p \u3c 0.05 Opt versus both G-T and R). CONCLUSION: Most R-IVCFs are not retrieved. The service placing the R-IVCF should be responsible for follow up. The Optease was associated with the greatest incidence of residual thrombus and symptomatic caval occlusion. The practice patterns of R-IVCF placement and retrieval should be re-examined. © 2007 Lippincott Williams & Wilkins, Inc
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