28,235 research outputs found

    A Bait Attractant Study of the Nitidulidae (Coleoptera) at Shawnee State Forest in Southern Ohio

    Get PDF
    Four baits were tested for efficacy in attracting sap beetles (Nitidulidae) at two sites in the Shawnee State Forest over two collection periods in 1992. Species taken were categorized into three groups: abundant, moderate, and uncommon. At Site 1, nitidulids displayed a strong preference for whole wheat bread dough, followed by fermenting brown sugar, and fermenting malt/molasses solution, and vinegar, respectively. Site 2 collections showed a similar trend to Site 1, but the order of preference was switched for brown sugar and malt/molasses solution. Of the 20 species collected, six species were abundant, seven species were moderate, and seven species were locally uncommon

    Quantum Decoherence in a D-Foam Background

    Get PDF
    Within the general framework of Liouville string theory, we construct a model for quantum D-brane fluctuations in the space-time background through which light closed-string states propagate. The model is based on monopole and vortex defects on the world sheet, which have been discussed previously in a treatment of 1+1-dimensional black-hole fluctuations in the space-time background, and makes use of a T-duality transformation to relate formulations with Neumann and Dirichlet boundary conditions. In accordance with previous general arguments, we derive an open quantum-mechanical description of this D-brane foam which embodies momentum and energy conservation and small mean energy fluctuations. Quantum decoherence effects appear at a rate consistent with previous estimates.Comment: 16 pages, Latex, two eps figures include

    A Migration Study of \u3ci\u3eStelidota Geminata\u3c/i\u3e (Coleoptera: Nitidulidae)

    Get PDF
    The strawberry sap beetle, Stelidota geminata (Say), is a major pest of strawberries in the northeastern United States. Further knowledge of the migratory habits of this insect pest can enhance the effectiveness of pest management strategies. This nitidulid was shown to migrate from its overwintering sites to one of its primary reproductive sites, strawberry fields, in late May. The beetle population peaked in the third week in July, 1993 in the strawberry field and then gradually declined. In 1994, the peak, as well as the total population, was much greater than in 1993. Furthermore, S. geminata was concentrated in the transition areas surrounding the strawberry fields prior to the ripening of the fruit

    Do Three Dimensions tell us Anything about a Theory of Everything?

    Full text link
    It has been conjectured that four-dimensional N=8 supergravity may provide a suitable framework for a `Theory of Everything', if its composite SU(8) gauge fields become dynamical. We point out that supersymmetric three-dimensional coset field theories motivated by lattice models provide toy laboratories for aspects of this conjecture. They feature dynamical composite supermultiplets made of constituent holons and spinons. We show how these models may be extended to include N=1 and N=2 supersymmetry, enabling dynamical conjectures to be verified more rigorously. We point out some special features of these three-dimensional models, and mention open questions about their relevance to the dynamics of N=8 supergravity.Comment: 20 pages Latex, 2 eps figure

    Censored Glauber Dynamics for the mean field Ising Model

    Full text link
    We study Glauber dynamics for the Ising model on the complete graph on nn vertices, known as the Curie-Weiss Model. It is well known that at high temperature (β<1\beta < 1) the mixing time is Θ(nlog⁡n)\Theta(n\log n), whereas at low temperature (β>1\beta > 1) it is exp⁡(Θ(n))\exp(\Theta(n)). Recently, Levin, Luczak and Peres considered a censored version of this dynamics, which is restricted to non-negative magnetization. They proved that for fixed β>1\beta > 1, the mixing-time of this model is Θ(nlog⁡n)\Theta(n\log n), analogous to the high-temperature regime of the original dynamics. Furthermore, they showed \emph{cutoff} for the original dynamics for fixed β<1\beta<1. The question whether the censored dynamics also exhibits cutoff remained unsettled. In a companion paper, we extended the results of Levin et al. into a complete characterization of the mixing-time for the Currie-Weiss model. Namely, we found a scaling window of order 1/n1/\sqrt{n} around the critical temperature βc=1\beta_c=1, beyond which there is cutoff at high temperature. However, determining the behavior of the censored dynamics outside this critical window seemed significantly more challenging. In this work we answer the above question in the affirmative, and establish the cutoff point and its window for the censored dynamics beyond the critical window, thus completing its analogy to the original dynamics at high temperature. Namely, if β=1+δ\beta = 1 + \delta for some δ>0\delta > 0 with δ2n→∞\delta^2 n \to \infty, then the mixing-time has order (n/δ)log⁡(δ2n)(n / \delta)\log(\delta^2 n). The cutoff constant is (1/2+[2(ζ2β/δ−1)]−1)(1/2+[2(\zeta^2 \beta / \delta - 1)]^{-1}), where ζ\zeta is the unique positive root of g(x)=tanh⁡(βx)−xg(x)=\tanh(\beta x)-x, and the cutoff window has order n/δn / \delta.Comment: 55 pages, 4 figure

    Evolution of the Stellar Mass--Metallicity Relation - I: Galaxies in the z~0.4 Cluster Cl0024

    Get PDF
    We present the stellar mass-stellar metallicity relationship (MZR) in the Cl0024+1654 galaxy cluster at z~0.4 using full spectrum stellar population synthesis modeling of individual quiescent galaxies. The lower limit of our stellar mass range is M∗=109.7M⊙M_*=10^{9.7}M_\odot, the lowest galaxy mass at which individual stellar metallicity has been measured beyond the local universe. We report a detection of an evolution of the stellar MZR with observed redshift at 0.037±0.0070.037\pm0.007 dex per Gyr, consistent with the predictions from hydrodynamical simulations. Additionally, we find that the evolution of the stellar MZR with observed redshift can be explained by an evolution of the stellar MZR with their formation time, i.e., when the single stellar population (SSP)-equivalent ages of galaxies are taken into account. This behavior is consistent with stars forming out of gas that also has an MZR with a normalization that decreases with redshift. Lastly, we find that over the observed mass range, the MZR can be described by a linear function with a shallow slope, ([Fe/H]∝(0.16±0.03)log⁡M∗[Fe/H] \propto (0.16 \pm 0.03) \log M_*). The slope suggests that galaxy feedback, in terms of mass-loading factor, might be mass-independent over the observed mass and redshift range.Comment: 22 pages, 10 figures. Accepted for publication in Ap
    • …
    corecore