78,007 research outputs found

    Light Trap Records of \u3ci\u3ePhyllophaga\u3c/i\u3e (Coleoptera: Scarabaeidae) in Wisconsin, 1984-1987

    Get PDF
    Phyllophaga adults (June beetles) were surveyed from 1984 through 1987 at five locations in Wisconsin using black light traps. Data were collected at each location for three consecutive years. A total of 9,259 specimens representing 13 species were collected during the survey. Species captured, sex ratios, and flight periods for abundant species were recorded for each location. Species abundance differed from previous surveys of Phyllophaga in Wisconsin. Possible reasons for observed shifts in species abundance are discussed

    Index statistical properties of sparse random graphs

    Get PDF
    Using the replica method, we develop an analytical approach to compute the characteristic function for the probability PN(K,λ)\mathcal{P}_N(K,\lambda) that a large N×NN \times N adjacency matrix of sparse random graphs has KK eigenvalues below a threshold λ\lambda. The method allows to determine, in principle, all moments of PN(K,λ)\mathcal{P}_N(K,\lambda), from which the typical sample to sample fluctuations can be fully characterized. For random graph models with localized eigenvectors, we show that the index variance scales linearly with N1N \gg 1 for λ>0|\lambda| > 0, with a model-dependent prefactor that can be exactly calculated. Explicit results are discussed for Erd\"os-R\'enyi and regular random graphs, both exhibiting a prefactor with a non-monotonic behavior as a function of λ\lambda. These results contrast with rotationally invariant random matrices, where the index variance scales only as lnN\ln N, with an universal prefactor that is independent of λ\lambda. Numerical diagonalization results confirm the exactness of our approach and, in addition, strongly support the Gaussian nature of the index fluctuations.Comment: 10 pages, 5 figure

    On the Flow Curve of Colloids Presenting Shear-Induced Phase Transitions

    Get PDF
    This work deals with the evaluation of the flow curve of colloidal systems that develop fluid phases with different mechanical properties, namely shear-banding fluids. The problem involved is that, as different fluid phases coexist in the flow domain of the rheometric cell, measured data cannot be directly converted into rheometric functions. In order to handle this problem, a shear stress vs. shear rate constitutive relation is introduced to interpret the steady state flow curves. The relation derives from a phenomenological description of structural changes, and involves the possibility of multivalued shear rates under a given shear stress. Numerical predictions satisfactorily match up to experimental data of wormlike micellar solutions. A crucial aspect is the adequate computation of the shear rate function from raw data measured in the rheometric cell.Comment: 12 page

    Floquet Analysis of Atom Optics Tunneling Experiments

    Get PDF
    Dynamical tunneling has been observed in atom optics experiments by two groups. We show that the experimental results are extremely well described by time-periodic Hamiltonians with momentum quantized in units of the atomic recoil. The observed tunneling has a well defined period when only two Floquet states dominate the dynamics. Beat frequencies are observed when three Floquet states dominate. We find frequencies which match those observed in both experiments. The dynamical origin of the dominant Floquet states is identified.Comment: Accepted in Physical Review

    Residents\u27 Perceptions And Attitudes Towards Native American Gaming (NAG) In Kansas: Demographics, Policies & Future Development

    Full text link
    This study applies a tourism model developed by Perdue, Long, and Allen ( 1990) to investigate residents\u27 perceptions of Native American Gambling in Kansas. A survey was administered to 1038 households, on a population proportionate basis, in Brown County (35 .65% ), Doniphan County (25.30% ), and Jackson County (39.05% ). Results indicated several relationships among perceived impacts of NAG development, including the respondent\u27s gender, gaming trips, age, employment status, and income level. Additionally, this study identified an association or dependence between the resident\u27s perceived future of the community and support for additional NAG development, support for restrictive NAG development policies, and support for additional taxes
    corecore