128,208 research outputs found

    Abundance and Identification of the Leafmining Guild on Apple in the Mid-Atlantic States

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    The leafmining guild on apple in the northeastern United States was studied from 1983 to 1988. Ten species of leafminers, all Lepidoptera, were encountered during the sampling. Phyllonorycter spp. (P. blancardella and P. crataegella) were the most ubiquitous and most abundant throughout the region. Lyonetia speculella was also abundant in both managed and unmanaged orchards, indicating a potential to become a pest. Bucculatrix pomiloliella and Coptodisca splendorilerella were abundant in unmanaged orchards, but were only rarely found in managed orchards. Coleophora serratella, Stigmella pomivorella, Parornix geminatella, Tischeria malifoliella, and Recurvaria nanella were also found. A key to the most important leafminer species on apple in the mid-Atlantic states, based on leafmine characteristics, is presented

    Selfadjoint and mm sectorial extensions of Sturm-Liouville operators

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    The self-adjoint and mm-sectorial extensions of coercive Sturm-Liouville operators are characterised, under minimal smoothness conditions on the coefficients of the differential expression.Comment: accepted by IEOT, in IEOT 201

    NICMOS Photometry of the Unusual Dwarf Planet Haumea and its Satellites

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    We present here Hubble Space Telescope NICMOS F110W and F160W observations of Haumea, and its two satellites Hi'iaka and Namaka. From the measured (F110W-F160W) colors of ā€“1.208 Ā± 0.004, ā€“1.48 Ā± 0.06, and ā€“1.4 Ā± 0.2 mag for each object, respectively, we infer that the 1.6 Ī¼m water-ice absorption feature depths on Hi'iaka and Namaka are at least as deep as that of Haumea. The light curve of Haumea is detected in both filters, and we find that the infrared color is bluer by ~2%-3% at the phase of the red spot. These observations suggest that the satellites of Haumea were formed from the collision that produced the Haumea collisional family

    The Hubble Wide Field Camera 3 Test of Surfaces in the Outer Solar System: The Compositional Classes of the Kuiper Belt

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    We present the first results of the Hubble Wide Field Camera 3 Test of Surfaces in the Outer Solar System (H/WTSOSS). The purpose of this survey was to measure the surface properties of a large number of Kuiper belt objects and attempt to infer compositional and dynamical correlations. We find that the Centaurs and the low-perihelion scattered disk and resonant objects exhibit virtually identical bifurcated optical colour distributions and make up two well defined groups of object. Both groups have highly correlated optical and NIR colours which are well described by a pair of two component mixture models that have different red components, but share a common neutral component. The small, H606ā‰³5.6H_{606}\gtrsim5.6 high-perihelion excited objects are entirely consistent with being drawn from the two branches of the mixing model suggesting that the colour bifurcation of the Centaurs is apparent in all small excited objects. On the other hand, objects larger than H606āˆ¼5.6H_{606}\sim5.6 are not consistent with the mixing model, suggesting some evolutionary process avoided by the smaller objects. The existence of a bifurcation amongst all excited populations argues that the two separate classes of object existed in the primordial disk before the excited Kuiper belt was populated. The cold classical objects exhibit a different type of surface which has colours that are consistent with being drawn from the red branch of the mixing model, but with much higher albedos.Comment: Accepted to the Astrophysical Journal. 49 Pages, 15 Figure

    Insects Associated with Michigan Bumblebees (\u3ci\u3eBombus\u3c/i\u3e Spp.)

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    (excerpt) Studies of insect associates of bumblebees are not new. For example, Tuck (1896, 1897) reported over 50 species of insects associated with nests of British bumblebees. Sladen (1912) discussed nest associates and parasites of European bumblebees, and Plath (1934) published similar data for American bumblebees. Postner (1952) published more detailed data. He listed over 60 taxa of insects associated with bumblebees near Erlangen, Germany

    Solving the electrical control of magnetic coercive field paradox

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    The ability to tune magnetic properties of solids via electric voltages instead of external magnetic fields is a physics curiosity of great scientific and technological importance. Today, there is strong published experimental evidence of electrical control of magnetic coercive fields in composite multiferroic solids. Unfortunately, the literature indicates highly contradictory results. In some studies, an applied voltage increases the magnetic coercive field and in other studies the applied voltage decreases the coercive field of composite multiferroics. Here, we provide an elegant explanation to this paradox and we demonstrate why all reported results are in fact correct. It is shown that for a given polarity of the applied voltage, the magnetic coercive field depends on the sign of two tensor components of the multiferroic solid: magnetostrictive and piezoelectric coefficient. For a negative applied voltage, the magnetic coercive field decreases when the two material parameters have the same sign and increases when they have opposite signs, respectively. The effect of the material parameters is reversed when the same multiferroic solid is subjected to a positive applied voltage
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