658 research outputs found

    Insecticide Toxicity, Synergism, and Resistance in the German Cockroach (Dictyoptera: Blattellidae)

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    The toxicity of, synergism of, and resistance to insecticides in four strains of German cockroach, Blattella germanica (L.), were investigated. Toxicity of nine insecticides by topical application to the susceptible strain varied \u3e2,000-fold, with deltamethrin (LD50 = 0.004 μg per cockroach) and malathion (LD50 = 8.4 μg per cockroach) being the most and least toxic, respectively. Resistance to pyrethrins (9.5-fold) in the Kenly strain was unaffected by the synergists piperonyl butoxide (PBO) or S,S,S-tributylphosphorotrithioate( DEE), suggesting that metabolism is not involved in this case. Malathion resistance in the Rutgers strain was suppressible with PBO, implicating oxidative metabolism as a resistance mechanism. The Ectiban-R strain was resistant to all the pyrethroids tested, and cypermethrin resistance was not suppressible with PBO or DEE. These findings support results of previous studies that indicated this strain has a kdr-like mechanism. Bendiocarb resistance in both the Kenly and Rutgers strains was partially suppressed by either PBO or DEE, suggesting that oxidative and hydrolytic metabolism are involved in the resistance. Trends between the effects of the synergists on the susceptible versus resistant strains are discussed

    Aerodynamic Characteristics of a Revised Target Drone Vehicle at Mach Numbers from 1.60 to 2.86

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    An investigation has been conducted in the Langley Unitary Plan wind tunnel to determine the aerodynamic characteristics of a revised target drone vehicle through a Mach number range from 1.60 to 2.86. The vehicle had canard surfaces and a swept clipped-delta wing with twin tip-mounted vertical tails

    Molecular Hydrogen in the FUSE Translucent Lines of Sight: The Full Sample

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    We report total abundances and related parameters for the full sample of the FUSE survey of molecular hydrogen in 38 translucent lines of sight. New results are presented for the "second half" of the survey involving 15 lines of sight to supplement data for the first 23 lines of sight already published. We assess the correlations between molecular hydrogen and various extinction parameters in the full sample, which covers a broader range of conditions than the initial sample. In particular, we are now able to confirm that many, but not all, lines of sight with shallow far-UV extinction curves and large values of the total-to-selective extinction ratio, RVR_V = AVA_V / E(BV)E(B-V) -- characteristic of larger than average dust grains -- are associated with particularly low hydrogen molecular fractions (fH2f_{\rm H2}). In the lines of sight with large RVR_V, there is in fact a wide range in molecular fractions, despite the expectation that the larger grains should lead to less H2_2 formation. However, we see specific evidence that the molecular fractions in this sub-sample are inversely related to the estimated strength of the UV radiation field and thus the latter factor is more important in this regime. We have provided an update to previous values of the gas-to-dust ratio, NN(Htot_{\rm tot})/E(BV)E(B-V), based on direct measurements of NN(H2_2) and NN(H I). Although our value is nearly identical to that found with Copernicus data, it extends the relationship by a factor of 2 in reddening. Finally, as the new lines of sight generally show low to moderate molecular fractions, we still find little evidence for single monolithic "translucent clouds" with fH2f_{\rm H2} \sim 1.Comment: 35 pages, 5 tables, 7 figures, accepted for publication in The Astrophysical Journal Supplements Serie

    The X-ray Properties of z>4 Quasars

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    We report on a search for X-ray emission from quasars with redshifts greater than four using the ROSAT public database. Our search has doubled the number of z>4 quasars detected in X-rays from 6 to 12. Most of those known prior to this work were radio-loud and X-ray selected sources; our study increases the number of X-ray detected, optically selected z>4 quasars from one to seven. We present their basic X-ray properties and compare these to those of lower redshift quasars. We do not find any evidence for strong broad-band spectral differences between optically selected z>4 quasars and those at lower redshifts.Comment: 7 pages, 4 figures included, LaTeX emulateapj.sty, accepted for publication in the Astronomical Journa

    The use of radio-iodinated toluidine blue for myocardial scintigrams,

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33788/1/0000043.pd

    The Vehicle, November 1960, Vol. 3 no. 1

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    CONTENTS To the ReaderStaffpage 2 N’ = N : 1Donald C. Blairpage 3 ConsistencyDonald C. Blairpage 3 Unto MeLinda Kay Campbellpage 4 The Meek Shall InheritE. J. B. page 5 The Infinite QuestLarry W. Dudleypage 6 Dreamer’s DawnMike Hindmanpage 7 BirthNancy Coepage 7 The Lost DutchmanDonald C. Blairpage 8 W. E. Noonan IRobert S. Hodgepage 8 A Soldier’s OrdealDonald E. Shephardsonpage 9 Personal PossessionMary Beilpage 11 Thine The GloryDonald C. Blairpage 12 The ThornJan Holstlawpage 13 A Lord’s Day MorningLinda Campbellpage 14 Observations of a 6-Year-OldTom McPeakpage 15 Jewels of TimeJudith Jerintspage 16 LavenderE. J. B. page 16https://thekeep.eiu.edu/vehicle/1008/thumbnail.jp

    In Vitro and In Vivo availability of some commercial prednisolone tablets

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    The in vitro dissolution rates of prednisolone from five commercially available 5- mg prednisolone tablets were determined in distilled water. The dissolution studies were repeated on the fastest- and slowest-dissolving brands using 0.01% polysorbate 80 in 0.1 N HCl as the dissolution medium. A two-way crossover bioavailability study was performed in 12 human male adult volunteers comparing the fastest- and slowest-dissolving brands. The plasma samples were assayed for prednisolone by a radioimmunoassay method. Statistical analysis of the data for the two brands showed no significant differences between average plasma levels of prednisolone at any sampling time. The results suggest that on the average the in vivo rates of dissolution of the two brands were essentially the same, and in vitro dissolution in 0.01% polysorbate 80–0.1 N HCl medium was better correlated with these in vivo results than dissolution in water .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45041/1/10928_2005_Article_BF01062144.pd

    CCAT-prime: a novel telescope for submillimeter astronomy

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    The CCAT-prime telescope is a 6-meter aperture, crossed-Dragone telescope, designed for millimeter and sub-millimeter wavelength observations. It will be located at an altitude of 5600 meters, just below the summit of Cerro Chajnantor in the high Atacama region of Chile. The telescope's unobscured optics deliver a field of view of almost 8 degrees over a large, flat focal plane, enabling it to accommodate current and future instrumentation fielding >100k diffraction-limited beams for wavelengths less than a millimeter. The mount is a novel design with the aluminum-tiled mirrors nested inside the telescope structure. The elevation housing has an integrated shutter that can enclose the mirrors, protecting them from inclement weather. The telescope is designed to co-host multiple instruments over its nominal 15 year lifetime. It will be operated remotely, requiring minimum maintenance and on-site activities due to the harsh working conditions on the mountain. The design utilizes nickel-iron alloy (Invar) and carbon-fiber-reinforced polymer (CFRP) materials in the mirror support structure, achieving a relatively temperature-insensitive mount. We discuss requirements, specifications, critical design elements, and the expected performance of the CCAT-prime telescope. The telescope is being built by CCAT Observatory, Inc., a corporation formed by an international partnership of universities. More information about CCAT and the CCAT-prime telescope can be found at www.ccatobservatory.org.Comment: Event: SPIE Astronomical Telescope + Instrumentation, 2018, Austin, Texas, USA; Proceedings Volume 10700, Ground-based and Airborne Telescopes VII; 107005X (2018
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