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

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

But what do they think it means? The Text/image relationship in informational communication

To better understand how an audience processes information transmitted via image, text, or both, this study presented four different versions of the same message to four groups of RIT students. The message consisted of the following content: text only, text with images depicting evenly spaced years, text with images depicting irregularly spaced years, and text with irregularly spaced years. Subjects were instructed to look at the message for a set amount of time and then complete a questionnaire. Those who were given messages that had images and text felt less confused or misled than those who were given messages containing images only. Subjects reported that images and text both have the potential to mislead when trying to inform, but that the preferred method for acquiring information is that which employs both images and text together

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

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

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

Electron Diffraction Study of Rhenium Fluorides. II. Structure, Pseudorotation, and Anharmonic Coupling of Modes in ReF7

Significant departures from D5hD5h symmetry are indicated by the gas‐phase electron diffraction data for ReF7. Observed scattered intensities, corrected for heavy‐atom effects as discussed in the preceding paper, are adequately represented by structures with static deformations of either C2C2 or CsCs symmetry of the following character. A puckering of the ring of five fluorines (maximum out‐of‐plane displacement ≈ 9°) is accompanied by a movement of each axial fluorine from the reference axis of ≈ 8° in the direction which provides maximum avoidance of fluorines on the rhenium coordination sphere. Equally compatible with the data is the much more reasonable dynamic pseudorotation model in which vibrational displacements carry the molecule from C2C2 to CsCs to C2C2 configurations. The tenfold character of the hindering potential and modest displacements preclude an appreciable barrier. A pronounced skewing of the envelope of axial–equatorial, FaFeFaFe, distances reveals a coupling in phase of the e1′e1′ axial bend to the e2″e2″ ring puckering vibration through the S2(e2″)S(e1′)S2(e2″)S(e1′) cubic term in the potential‐energy function. The skewing, which moves the maximum of the FaFeFaFe distribution peak inside the distribution center of gravity, results in an apparent “anharmonic shrinkage” of the nonbonded peak by an amount exceeding the well‐known “Bastiansen–Morino” harmonic shrinkage. It is to be noted that the equatorial pseudorotation problem closely resembles that for cyclopentane in reduced mass, in displacement, and therefore, presumably, in frequency. The structure itself may be understood in terms of bond–bond repulsions thrusting the equatorial atoms out of plane; the out‐of‐plane displacement, in turn, induces an axial bend. The actual structure, however, exhibits too large an axial bend to conform to the simple repelling points‐on‐a‐sphere model of Gillespie and too small a deviation from D5hD5h to correspond to the close packing of hard atoms around the rhenium.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70852/2/JCPSA6-53-6-2235-1.pd

Electron Diffraction Study of Rhenium Fluorides. I. Heavy‐Atom Corrections and Structure of ReF6

To date, no theoretical models for electron molecular scattering have been developed which bring calculated scattered intensities from heavy atoms into satisfactory agreement with experiment. Preparatory to an electron diffraction study of ReF7, a molecule with an uncertain and possibly complex structure, an investigation of ReF6 was undertaken. The simplicity of the hexafluoride's geometry (OhOh symmetry) allows an empirical characterization of the discrepancy between experimental and calculated intensities, a discrepancy which can be attributed chiefly to the behavior of ReF interference terms rather than to uncertainties in structural parameters. After a structure analysis of ReF6, the observed difference signal (Iobs − Icalc)(Iobs−Icalc) was used with appropriate scaling to modify ReF7 intensities before structural parameters for the heptafluoride were refined. Parameters determined for ReF6, e.g., rg(ReF)  =  1.832 ± 0.004Årg(ReF)=1.832±0.004Å and lg(ReF)  =  0.044Ålg(ReF)=0.044Å, are in excellent agreement with those reported from diffraction studies of other 5d5d transition‐metal hexafluorides. Results for ReF7 are reported in Paper II.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70103/2/JCPSA6-53-6-2231-1.pd

Does blending an RGP lens move or remove plastic?

Blending of RGP lenses is widely used to Increase patient comfort while wearing the lenses. The blending process smooths the peripheral curves of the lens, but it has not been determined if this process moved or actually removed the lens material. Twenty fluoroperm 30 bicurve, unfinished lenses were weighed on a Sartorius analytical balance to the ten-thousandth of a gram. The lenses were then modified with a tool that would simulate the blending process and reweighed. The data was then compared using a paired one-tailed t-Test and the results were shown to have a statistically significant lower lens weight. Thus, we determined that blending actually removes the lens material

Influence of Nonbonded Interactions on Molecular Geometry and Energy: Calculations for Hydrocarbons Based on Urey—Bradley Field

A modified Urey—Bradley potential energy function comprised of quadratic terms for bond stretches, bond‐angle bends, and torsional displacements together with analytical expressions for pairwise nonbonded interactions was chosen to represent the force field for hydrocarbon molecules. Quadratic constants were taken from the spectroscopic U☒B analyses of Schachtschneider and Snyder [Spectrochim. Acta 19, 117 (1963)], while the nonbonded functions adopted were those proposed by Bartell [J. Chem. Phys. 32, 827 (1960)]. Reference bond angles for the quadratic terms were taken to be 109.5° or 120° for tetrahedral or trigonal coordination, respectively. Reference single‐bond lengths and the torsional constant were adjusted to fit the experimental data for CH4 and C2H6. Double bonds and ring bonds in cyclopropyl compounds were considered to be rigid. The above selections served to establish a universal model force field for hydrocarbons with no remaining adjustable parameters. The potential energy functions for a variety of saturated hydrocarbons and several olefins and cyclopropyl derivatives were minimized with respect to independent structure parameters (i.e., bond stretches, bends, and internal rotations). Even though all C☒H (and C☒C) bonds were input to be identical to those in CH4 (and C2H6) except for nonbonded environment, the bond lengths and angles corresponding to the minimum potential energy exhibited an appreciable variation from molecule to molecule, as did also the strain energies of geometric and rotational isomers. Calculated trends in structures, isomerization energies, and barriers to rotation agreed quite well with experimentally observed trends, provided that experimental isomerization energies were corrected to 0°K and zero‐point energies were taken into account. Some novel features of the results and applications of the model for predicting deformations in strained systems are discussed. The present study differs from previous work in the area of ``molecular mechanics'' in the use of a more general force field, in allowing the strained molecules to relax in all degrees of freedom (except for unsaturated groups and cyclopropyl rings), in the selection of molecular systems, and in a detailed comparison with experiment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70433/2/JCPSA6-47-10-3736-1.pd

Assessing the effects of exposure timing on biomarker expression using β-estradiol

Temporal and spatial variability in estrogenicity has been documented formanytreated wastewater effluents with the consequences of this variability on the expression of biomarkers of endocrine disruption being largely unknown. Laboratory exposure studies usually utilize constant exposure concentrations which may produce biological effects that differ from those observed in organisms exposed in natural environments. In this study, we investigated the effects of differential timing of exposures with 17β - estradiol (E2) on a range of fathead minnow biomarkers to simulate diverse environmentally relevant exposure profiles. Two 21-day, replicate experiments were performed exposing mature male fathead minnows to E2 at time-weighted mean concentrations (similar average exposure to the contaminant during the 21-day exposure period; 17 ng E2/L experiment 1; 12 ng E2/L experiment 2) comparable to E2 equivalency values (EEQ) reported for several anthropogenically altered environments. A comparable time-weighted mean concentration of E2 was applied to five treatments which varied in the daily application schema: E2 was either applied at a steady rate (ST), in a gradual decreasing concentration (HI), a gradual increasing concentration (LO), applied intermittently (IN), or at a randomly varying concentration (VA). We assessed a range of widely used physiological (vitellogenin mRNA induction and plasma concentrations), anatomical (body and organ indices, secondary sex characteristics, and histopathology), and behavioral (nest holding) biomarkers reported to change following exposure to endocrine active compounds (EACs). All treatments responded with a rise in plasma vitellogenin concentration when compared with the ethanol carrier control. Predicatively, vitellogenin mRNA induction, which tracked closely with plasma vitellogenin concentrations in most treatments was not elevated in the HI treatment, presumably due to the lack of E2 exposure immediately prior to analysis. The ability of treatment male fish to hold nest sites in direct competition with control males was sensitive to E2 exposure and did yield statistically significant differences between treatments and carrier control. Other biological endpoints assessed in this study (organosomatic indices, secondary sex characteristics) varied little between treatments and controls. This study indicates that a broad suite of endpoints is necessary to fully assess the biological consequences of fish exposure to estrogens and that for at least field studies, a combination of vitellogenin mRNA and plasma vitellogenin analysis are most promising in deciphering exposure histories of wild-caught and caged fishes