420 research outputs found

    Synergistic Trap Response of the False Stable Fly and Little House Fly (Diptera: Muscidae) to Acetic Acid and Ethanol, Two Principal Sugar Fermentation Volatiles

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    In an initial observation, large numbers of muscoid flies (Diptera) were captured as nontarget insects in traps baited with solutions of acetic acid plus ethanol. In subsequent field experiments, numbers of false stable fly Muscina stabulans (Fallén) and little house fly Fannia canicularis (L.) trapped with the combination of acetic acid plus ethanol were significantly higher than those trapped with either chemical alone, or in unbaited traps. Flies were trapped with acetic acid and ethanol that had been formulated in the water of the drowning solution of the trap, or dispensed from polypropylene vials with holes in the vial lids for diffusion of evaporated chemical. Numbers of both species of fly captured were greater with acetic acid and ethanol in glass McPhail traps, compared to four other similar wet trap designs. This combination of chemicals may be useful as an inexpensive and not unpleasant lure for monitoring or removing these two pest fly specie

    Comparison of a Synthetic Chemical Lure and Standard Fermented Baits for Trapping Drosophila suzukii (Diptera: Drosophilidae)

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    We determined the attractiveness of a new chemical lure compared with fermented food baits in use for trapping Drosophila suzukii Matsumura, spotted wing drosophila (Diptera: Drosophilidae), in Connecticut, New York, and Washington in the United States and at Dossenheim in Germany. The chemical lure (SWD lure) and food baits were compared in two types of traps: the dome trap and a cup trap. Regardless of trap type, numbers of male and female D. suzukii trapped were greater with the SWD lure compared with apple cider vinegar (ACV) baits at the Washington and New York sites, and were comparable with numbers of D. suzukii captured with a wine plus vinegar bait (W + V) at Germany site and a combination bait meant to mimic W + V at the Connecticut site. Averaged over both types of attractants, the numbers of D. suzukii captured were greater in dome traps than in cup traps in New York and Connecticut for both male and female D. suzukii and in Washington for male D. suzukii. No such differences were found between trap types at the Washington site for female and Germany for male and female D. suzukii. Assessments were also made of the number of large (>0.5 cm) and small (<0.5 cm) nontarget flies trapped. The SWD lure captured fewer nontarget small flies and more large flies compared with ACV bait in New York and fewer nontarget small flies compared with W + V in Germany, although no such differences were found in Washington for the SWD lure versus ACV bait and in Connecticut for the SWD lure versus the combination bait, indicating that these effects are likely influenced by the local nontarget insect community active at the time of trapping. In New York, Connecticut, and Germany, dome traps caught more nontarget flies compared with cup traps. Our results suggest that the four-component SWD chemical lure is an effective attractant for D. suzukii and could be used in place of fermented food-type bait

    -[3H]Glutamate labels the metabotropic excitatory amino acid receptor in rodent brain

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    A quantitative autoradiographic assay for a novel -[3H]glutamate binding site in rodent brain has been developed. Binding to this site was distinguished by its high affinity for quisqualate (QA), ibotenate, glutamate and trans-1-amino-cyclopentyl-1,3-dicarboxylic acid (trans-ACPD), but low affinity for [RS]-[alpha]-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), kainate and (NMDA). `AMPA-insensitive, QA-sensitive [3H]glutamate binding' (AiQsGB) had a heterogeneous distribution in rat brain with high levels observed in molecular layer of cerebellum, striatum, and lateral septum. AiQsGB was reduced in molecular layer of cerebellum in mice lacking Purkinje cells. AiQsGB appears to represent binding to the `metabotropic' neuronal excitatory amino acid receptor linked to phosphoinositide metabolism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28567/1/0000369.pd

    Evolution of the Density of States Gap in a Disordered Superconductor

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    It has only recently been possible to study the superconducting state in the attractive Hubbard Hamiltonian via a direct observation of the formation of a gap in the density of states N(w). Here we determine the effect of random chemical potentials on N(w) and show that at weak coupling, disorder closes the gap concurrently with the destruction of superconductivity. At larger, but still intermediate coupling, a pseudo-gap in N(w) remains even well beyond the point at which off-diagonal long range order vanishes. This change in the elementary excitations of the insulating phase corresponds to a crossover between Fermi- and Bose-Insulators. These calculations represent the first computation of the density of states in a finite dimensional disordered fermion model via the Quantum Monte Carlo and maximum entropy methods.Comment: 4 pages, 4 figure

    Spectroscopic Mass and Host-star Metallicity Measurements for Newly Discovered Microlensing Planet OGLE-2018-BLG-0740Lb

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    We report the discovery of the microlensing planet OGLE-2018-BLG-0740Lb. The planet is detected with a very strong signal of Δχ2∌4630\Delta\chi^2\sim 4630, but the interpretation of the signal suffers from two types of degeneracies. One type is caused by the previously known close/wide degeneracy, and the other is caused by an ambiguity between two solutions, in which one solution requires to incorporate finite-source effects, while the other solution is consistent with a point-source interpretation. Although difficult to be firmly resolved based on only the photometric data, the degeneracy is resolved in strong favor of the point-source solution with the additional external information obtained from astrometric and spectroscopic observations. The small astrometric offset between the source and baseline object supports that the blend is the lens and this interpretation is further secured by the consistency of the spectroscopic distance estimate of the blend with the lensing parameters of the point-source solution. The estimated mass of the host is 1.0±0.1 M⊙1.0\pm 0.1~M_\odot and the mass of the planet is 4.5±0.6 MJ4.5\pm 0.6~M_{\rm J} (close solution) or 4.8±0.6 MJ4.8\pm 0.6~M_{\rm J} (wide solution) and the lens is located at a distance of 3.2±0.53.2\pm 0.5~kpc. The bright nature of the lens, with I∌17.1I\sim 17.1 (V∌18.2V\sim 18.2), combined with its dominance of the observed flux suggest that radial-velocity (RV) follow-up observations of the lens can be done using high-resolution spectrometers mounted on large telescopes, e.g., VLT/ESPRESSO, and this can potentially not only measure the period and eccentricity of the planet but also probe for close-in planets. We estimate that the expected RV amplitude would be ∌60sin⁥i m s−1\sim 60\sin i ~{\rm m~s}^{-1}.Comment: 12 pages, 11 figures, 4 table

    Candidate Brown-dwarf Microlensing Events with Very Short Timescales and Small Angular Einstein Radii

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    Short-timescale microlensing events are likely to be produced by substellar brown dwarfs (BDs), but it is difficult to securely identify BD lenses based on only event timescales t_E because short-timescale events can also be produced by stellar lenses with high relative lens-source proper motions. In this paper, we report three strong candidate BD-lens events found from the search for lensing events not only with short timescales (t_E â‰Č 6 days) but also with very small angular Einstein radii (Ξ_E â‰Č 0.05 mas) among the events that have been found in the 2016–2019 observing seasons. These events include MOA-2017-BLG-147, MOA-2017-BLG-241, and MOA-2019-BLG-256, in which the first two events are produced by single lenses and the last event is produced by a binary lens. From the Monte Carlo simulations of Galactic events conducted with the combined t_E and Ξ_E constraint, it is estimated that the lens masses of the individual events are 0.051^(+0.100)_(−0.027) M⊙, 0.044^(+0.090)_(−0.023) M⊙, and 0.046^(+0.067)_(−0.023) M⊙/0.038^(+0.056)_(−0.019) M⊙ and the probability of the lens mass smaller than the lower limit of stars is ~80% for all events. We point out that routine lens mass measurements of short-timescale lensing events require survey-mode space-based observations
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