711 research outputs found

    Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (Coleoptera: Curculionidae) from Alfalfa Samples

    Get PDF
    A modified Berlese funnel system was developed to extract alfalfa weevil larvae (Hypera postica) from quadrats 30.5 cm on a side. Data from this system were comp.wed with simultaneous data from a hand sorting extraction system. In most instances, the modified Berlese system was as efficient as the hand sorting method and the number of man hours required to process samples by hand was far greater than that required by the Berlese system

    Influences of Host Density, Temperature, and Parasite Age on the Reproductive Potential of \u3ci\u3eBathyplectes Curculionis\u3c/i\u3e (Hymenoptera: Ichneumonidae), an Endoparasite of the Alfalfa Weevil (Coleoptera: Curculionidae)

    Get PDF
    Alfalfa weevil larvae were exposed to Bathyplectes curculionis (Thomson) to determine the effect of host density, temperature, and parasite age on the reproductive potential of curculionis. Percent parasitism was found to be inversely proportional to host density and most of the parasites distributed their eggs randomly regardless of host density. The number of eggs deposited was largely independent of temperature. Peak egg laying was reached in three days from which point the parasite\u27s capabilities diminished with increasing age. The longevity of ovipositing females was shorter than females that were not exposed to larvae

    Disease as a Larval Mortality Factor in Alfalfa Weevil, \u3ci\u3eHypera Postica\u3c/i\u3e (Coleoptera: Curculionidae) Populations in Illinois

    Get PDF
    During the 1974 growing season, larvae of the alfalfa weevil, Hypera postica (Gyllenhal), were examined for pathogens. Three larvae out of 715 examined were infected with a microsporidium. This infection was present in both Washington and Mason counties in Illinois

    Low Velocity Granular Drag in Reduced Gravity

    Full text link
    We probe the dependence of the low velocity drag force in granular materials on the effective gravitational acceleration (geff) through studies of spherical granular materials saturated within fluids of varying density. We vary geff by a factor of 20, and we find that the granular drag is proportional to geff, i.e., that the granular drag follows the expected relation Fprobe = {\eta} {\rho}grain geff dprobe hprobe^2 for the drag force, Fprobe on a vertical cylinder with depth of insertion, hprobe, diameter dprobe, moving through grains of density {\rho}grain, and where {\eta} is a dimensionless constant. This dimensionless constant shows no systematic variation over four orders of magnitude in effective grain weight, demonstrating that the relation holds over that entire range to within the precision of our data

    Estimating equations for biomarker based exposure estimation under non-steady-state conditions

    Get PDF
    Unrealistic steady-state assumptions are often used to estimate toxicant exposure rates from biomarkers. A biomarker may instead be modeled as a weighted sum of historical time-varying exposures. Estimating equations are derived for a zero-inflated gamma distribution for daily exposures with a known exposure frequency. Simulation studies suggest that the estimating equations can provide accurate estimates of exposure magnitude at any reasonable sample size, and reasonable estimates of the exposure variance at larger sample sizes

    Electron‐Diffraction Study of Ammonia and Deuteroammonia

    Full text link
    The gas‐phase structures of NH3 and ND3 molecules were determined by the sector‐microphotometer method of electron diffraction. The following internuclear distances rgrg and mean amplitudes lele with estimated standard errors were obtained: For NH3, rg(N − H)  =  1.0302 ± 0.002Å,rg(H − H)  =  1.662 ± 0.010Å,le(N − H)  =  0.0731 ± 0.002Å,le(H − H)  =  0.125 ± 0.006Årg(N−H)=1.0302±0.002Å,rg(H−H)=1.662±0.010Å,le(N−H)=0.0731±0.002Å,le(H−H)=0.125±0.006Å, and for ND3, rg(N − D)  =  1.0266 ± 0.003Å,rg(D − D)  =  1.654 ± 0.008Å,le(N − D)  =  0.0611 ± 0.002Å,le(D − D)  =  0.101 ± 0.006Årg(N−D)=1.0266±0.003Å,rg(D−D)=1.654±0.008Å,le(N−D)=0.0611±0.002Å,le(D−D)=0.101±0.006Å, with the parameter ÎșÎș representing bond‐stretching anharmonicity fixed at 1.0 × 10−5 and 0.5 × 10−5 Å3 for N☒H and N☒D, respectively. Effects of anharmonicity and isotope differences in the structural parameters analogous to those in CH4 and CD4 were observed. The rα0rα0 and rere bond distances calculated from the above rgrg distances are found to be consistent with the corresponding rzrz and rere distances derived from the spectroscopic rotational constants of Benedict and Plyler. The isotope effects reported by Bell and by Halevi for the dipole moment and polarizability of ammonia are discussed briefly in the light of the present results.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69943/2/JCPSA6-49-6-2488-1.pd

    Retrospective Exposure Estimation and Predicted versus Observed Serum Perfluorooctanoic Acid Concentrations for Participants in the C8 Health Project

    Get PDF
    Background: People living or working in eastern Ohio and western West Virginia have been exposed to perfluorooctanoic acid (PFOA) released by DuPont Washington Works facilities

    Rate of Decline in Serum PFOA Concentrations after Granular Activated Carbon Filtration at Two Public Water Systems in Ohio and West Virginia

    Get PDF
    Drinking water in multiple water districts in the Mid-Ohio Valley has been contaminated with perfluorooctanoic acid (PFOA), which was released by a nearby DuPont chemical plant. Two highly contaminated water districts began granular activated carbon filtration in 2007.To determine the rate of decline in serum PFOA, and its corresponding half-life, during the first year after filtration.Up to six blood samples were collected from each of 200 participants from May 2007 until August 2008. The primary source of drinking water varied over time for some participants; our analyses were grouped according to water source at baseline in May-June 2007.For Lubeck Public Service District customers, the average decrease in serum PFOA concentrations between May-June 2007 and May-August 2008 was 32 ng/mL (26%) for those primarily consuming public water at home (n = 130), and 16 ng/mL (28%) for those primarily consuming bottled water at home (n = 17). For Little Hocking Water Association customers, the average decrease in serum PFOA concentrations between November-December 2007 and May-June 2008 was 39 ng/mL (11%) for consumers of public water (n = 39) and 28 ng/mL (20%) for consumers of bottled water (n = 11). The covariate-adjusted average rate of decrease in serum PFOA concentration after water filtration was 26% per year (95% confidence interval, 2528% per year).The observed data are consistent with first-order elimination and a median serum PFOA half-life of 2.3 years. Ongoing follow-up will lead to improved half-life estimation

    Biomechanical and Statistical Effects of Changing the Three-Point Line in Division III Women’s Basketball

    Get PDF
    The NCAA has recently changed the distance for the three-point line in women’s basketball, which may affect shooting mechanics for a three-point shot. While the fundamental movements of the shot should not be affected by increasing distance, some elements of the shot may need to change to propel the ball the required distance. PURPOSE: To analyze the effect of increased distance of the basketball three-point line on shot kinematics and shooting performance of female basketball players. METHODS: Ten players (19.0±0.6 yrs, 173.7±8.7 cm, 64.0±8.2 kg) from an NCAA Division III Women’s Basketball team shot from the current three-point line, 20’9” from the basket, and the old line, 19’9” from the basket. Shots were compared using knee range of motion (ROM), release height, release velocity, and release angle as measured using a motion analysis system. Two separate cameras filmed the shooter and flight of the ball from a sagittal view at 60 Hz. Three-point field goal (FG) and three-point FG made per game statistics for all Division III women’s basketball teams were also compared for the 2009-10, 2010-11, and 2011-12 seasons. RESULTS: Shots taken from the new three-point line resulted in about 3% faster velocities at release (7.82±0.23 m/s) than those from the old line (7.60±0.19 m/s) (t(19)=4.17, p=0.001). Further, the Cohen-d calculation displayed a large effect of shooting distance on release velocity. The mean release velocity from the new line would be greater than 93% of the release velocities from the old line (d=0.933). Use of the new line in the 2011-12 season resulted in a 1.6% reduction of three-point FG percentage (28.50±3.73%) than the previous two seasons (29.98±3.74% and 30.12±3.78%, respectively)(F(2, 1266)=24.34, p\u3c0.001), as found by the Tukey post hoc test where the percentage from 2011-12 was less than the 2009-10 season (p\u3c0.01) and the 2010-11 season (p\u3c0.01). The 2011-12 season also produced a 7.9% decrease in the number of three-point FG made per game (4.46±1.40 shots/game) than the 2010-11 season (4.84±1.40 shots/game), but not the 2009-10 season (4.68±1.37 shots/game)(F(2, 1268)=12.64, p\u3c0.01), as found by a Tukey post hoc test finding that 2011-12 was less than 2010-11 (p\u3c0.01), but not different than 2009-10 (p=0.09). CONCLUSION: The increase in the three-point line distance required an increase in the release velocity to perform successfully, which had a meaningful negative effect on the performance of Division III women’s basketball players

    An interferometric complementarity experiment in a bulk Nuclear Magnetic Resonance ensemble

    Full text link
    We have experimentally demonstrated the interferometric complementarity, which relates the distinguishability DD quantifying the amount of which-way (WW) information to the fringe visibility VV characterizing the wave feature of a quantum entity, in a bulk ensemble by Nuclear Magnetic Resonance (NMR) techniques. We primarily concern on the intermediate cases: partial fringe visibility and incomplete WW information. We propose a quantitative measure of DD by an alternative geometric strategy and investigate the relation between DD and entanglement. By measuring DD and VV independently, it turns out that the duality relation D2+V2=1D^{2}+V^{2}=1 holds for pure quantum states of the markers.Comment: 13 page, 5 PS figure
    • 

    corecore