2,868 research outputs found

    Trap Response of Michigan Social Wasps (Hymenoptera: Vespidae) to the Feeding Attractants Acetic Acid, Isobutanol, and Heptyl Butyrate.

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    Nine species of social wasps were captured in traps baited with acetic acid, isobutanol, heptyl butyrate and combinations of acetic acid and either isobutanol or heptyl butyrate. Three yellowjacket species in the Vespula rufa species group were captured in traps (Vespula acadica (Sladen), Vespula consobrina (Saussure), Vespula vidua (Saussure)). They responded similarly, with attraction only to heptyl butyrate. Three yellowjacket species in the Vespula vulgaris species group were also captured in traps (Vespula vulgaris (L.), Vespula flavorpilosa Jacobson, Vespula maculifrons (Buyyson)). They responded similarly, with attraction primarily to the combination of acetic acid and isobutanol. The bald-faced hornet, Dolichovespula maculata (L.), was attracted to acetic acid and was more strongly attracted to the combination of acetic acid and isobutanol. The aerial yellowjacket, Dolichovespula arenaria (Fabr.), was attracted to isobutanol, and was more strongly attracted to the combination of acetic acid and isobutanol. These results add to our understanding of how to target various species of social wasps with chemical lures

    The Stink Bugs (Hemiptera: Heteroptera: Pentatomidae) of Washington State

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    Froeschner (1988) recorded 23 species of stink bugs (Hemiptera: Heteroptera: Pentatomidae) from Washington State. Based on material primarily housed in the M. T. James Entomological Collection at Washington State University, the number of species is increased to 51. Three species recorded by Froeschner (1988) were not found in our collections: Apateticus crocatus (Uhler), Chlorochroa rossiana Buxton and Thomas, and Tepa rugulosa (Say). Species recorded from Washington State for the first time are: Apoecilus bracteatus (Fitch), Perillus bioculatus (Fabricius), Podisus maculiventris (Say), P. pallens (Stål), P. placidus Uhler, P. serieventris Uhler, Zicrona caerulea (Linnaeus), Halyomorpha halys (Stål), Brochymena quadripustulata (Fabricius), B. sulcata Van Duzee, Acrosternum hilare (Say), Aelia americana Dallas, Banasa euchlora Stål, B. tumidifrons Thomas and Yonke, Chlorochroa congrua Uhler, Coenus delius (Say), Cosmopepla uhleri Montandon, Dendrocoris pini Montandon, Euschistus servus (Say), E. tristigmus (Say), E. variolarius (Palisot), Holcostethus limbolarius (Say), Neottiglossa sulcifrons Stål, N. undata (Say), Prionosoma podopioides (Uhler), Tepa yerma (Rolston), Trichopepla grossa (Van Duzee), and Amaurochrous vanduzeei Barber and Sailer

    Worker policing by egg eating in the ponerine ant Pachycondyla inversa

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    We investigated worker policing by egg eating in the ponerine ant Pachycondyla inversa, a species with morphologically distinct queens and workers. Colonies were split into one half with the queen and one half without. Workers in queenless colony fragments started laying unfertilized male eggs after three weeks. Worker-laid eggs and queen-laid eggs were introduced into five other queenright colonies with a single queen and three colonies with multiple queens, and their fate was observed for 30 min. Significantly more worker-laid eggs (range of 35–62%, mean of 46%) than queen-laid eggs (range of 5–31%, mean of 15%) were eaten by workers in single-queen colonies, and the same trend was seen in multiple-queen colonies. This seems to be the first well-documented study of ants with a distinct caste polymorphism to show that workers kill worker-laid eggs in preference to queen-laid eggs. Chemical analyses showed that the surfaces of queen-laid and worker-laid eggs have different chemical profiles as a result of different relative proportions of several hydrocarbons. Such differences might provide the information necessary for differential treatment of eggs. One particular alkane, 3,11-dimeC27, was significantly more abundant on the surfaces of queen-laid eggs. This substance is also the most abundant compound on the cuticles of egg layers

    Tuning of the Rashba effect in Pb quantum well states via a variable Schottky barrier

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    Spin-orbit interaction (SOI) in low-dimensional systems results in the fascinating property of spin-momentum locking. In a Rashba system the inversion symmetry normal to the plane of a two-dimensional (2D) electron gas is broken, generating a Fermi surface spin texture reminiscent of spin vortices of different radii. This can be exploited in a spin-based field-effect transistor (spin- FET), where the Rashba system forms a 2D channel between ferromagnetic (FM) source and drain electrodes. The electron spin precesses when propagating through the Rashba channel and spin orientations (anti)parallel to the drain give (low) high conductivity. Crucial is the possibility to tune the momentum splitting, and consequently the precession angle, through an external parameter. Here we show that this can be achieved in Pb quantum well states through the doping dependence of the Schottky barrier, opening up the possibility of a terahertz spin-FET.Comment: 8 pages, 7 figure

    Amson Mohr

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    Amson Mohr was born in Bavaria about 1848 and immigrated to the United States arriving in Savannah prior to 1866. He became partner. in Lippman, Bro.,& Co., a wholesale and retail dry goods store. Later he was a partner .ln Oppenheimer, Mohr & Co. and then in the Mohr Bro. Co. Amson was one of the incorporating members of the Liberty Mfg. Co. and the American Mfg. Co. He was a founding member and director of the Germania Bank. He married Miss Carrie Epstein of St. Louis, Mo. They had three sons; Ivan, Melvin and Bertram. Amson died about 1919.https://digitalcommons.georgiasouthern.edu/sav-bios-lane/1194/thumbnail.jp

    Photometric Calibration of the Supernova Legacy Survey Fields

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    We present the photometric calibration of the Supernova Legacy Survey (SNLS) fields. The SNLS aims at measuring the distances to SNe Ia at (0.3<z<1) using MegaCam, the 1 deg^2 imager on the Canada-France-Hawaii Telescope (CFHT). The uncertainty affecting the photometric calibration of the survey dominates the systematic uncertainty of the key measurement of the survey, namely the dark energy equation of state. The photometric calibration of the SNLS requires obtaining a uniform response across the imager, calibrating the science field stars in each survey band (SDSS-like ugriz bands) with respect to standards with known flux in the same bands, and binding the calibration to the UBVRI Landolt standards used to calibrate the nearby SNe from the literature necessary to produce cosmological constraints. The spatial non-uniformities of the imager photometric response are mapped using dithered observations of dense stellar fields. Photometric zero-points against Landolt standards are obtained. The linearity of the instrument is studied. We show that the imager filters and photometric response are not uniform and publish correction maps. We present models of the effective passbands of the instrument as a function of the position on the focal plane. We define a natural magnitude system for MegaCam. We show that the systematics affecting the magnitude-to-flux relations can be reduced if we use the spectrophotometric standard star BD +17 4708 instead of Vega as a fundamental flux standard. We publish ugriz catalogs of tertiary standards for all the SNLS fields.Comment: 46 pages, 23 figures. Accepted by Astronomy and Astrophysics. Online material available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/ or alternatively from: http://supernovae.in2p3.fr/snls3/regnault09_cds.tar.g

    Positive effective Q12 electrostrictive coefficient in perovskites

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    It is demonstrated that for classical perovskites such as BaTiO3, SrTiO3 and PbTiO3 electrostrictive strain induced by an electric field may not obey traditionally considered "extension along the field, contraction perpendicular to it" behavior if a sample is cut obliquely to the cubic crystallographic directions

    Detection of the Red Giant Branch Stars in M82 Using the Hubble Space Telescope

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    We present color-magnitude diagrams and luminosity functions of stars in two halo regions of the irregular galaxy in M82, based on F555W and F814W photometry taken with the Hubble Space Telescope and Wide Field Planetary Camera 2. The I-band luminosity function shows a sudden jump at I~23.95 mag, which is identified as the tip of the red giant branch (TRGB). Adopting the Lee et al. (1993) calibration of the TRGB based on the RR Lyrae distances to Galactic globular clusters, we obtain the distance modulus of (m-M)_0=27.95 +- 0.14 (random) +- 0.16 (systematic) mag. This corresponds to a linear distance of 3.9 +- 0.3 (random) +- 0.3 (systematicf) Mpc, which agrees well with the distance of M81 deteremined from the HST observations of the Cepheid variable stars. In addition, we observe a significant number of stars apparently brighter than the TRGB. However, with the current data, we cannot rule out whether these stars are blends of fainter stars, or are indeed intermediate-age asymptotic giant branch stars.Comment: 8 figure
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