622 research outputs found

    SEASONAL FLIGHT ACTIVITY OF THE MAIZE WEEVIL, \u3ci\u3eSITOPHlLUS ZEAMAIS\u3c/i\u3e MOTSCHULSKY (COLEOPTERA: CURCULIONIDAE), AND THE RICE WEEVIL, \u3ci\u3eS. ORYZAE\u3c/i\u3e (L.), IN SOUTH CAROLINA

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    Flight activity of Sitophilus zeamais Motschulsky (Coleoptera: Curculionidne) and S. oryzae (L.) was monitored during 1987-88 with sticky traps at three sites in South Carolina. Weevils were caught from late March to early November. The results indicate that temperature is the major factor determining seasonal flight activity of these weevils. More S. zeamais than S. oryzae were trapped at all sites. Sitophilus oryzae were abundant only at the site at which wheat was stored. There was no apparent pattern to flight activity within a storage site. The results indicate that there is little night activity around bins in which recommended pest control practices are followed

    SEASONAL ABUNDANCE OF MAIZE AND RICE WEEVILS (COLEOPTERA: CURCULIONIDAE) IN SOUTH CAROLINA

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    Seasonal abundance of Sitophilus zeamais (SZ) and S. oryzae (SO) outside grain bins was monitored during 1986-88 with com-filled bait packets at three grain storage sites in southern South Carolina. Com was the predominant commodity stored at all sites. SZ were abundant and caught year-round at all sites, whereas SO were abundant and caught year-round only at the site at which wheat was stored regularly. Most weevils were caught during weeks when average temperatures were at or above 20°C. Catches generally peaked in fall, after newly-harvested grain was placed into storage. Catches fell during winter, began to rise in spring. peaked again during summer, and declined again in late summer. Results indicate that grain is susceptible to infestation by Sitophilus spp. year-round in South Carolina

    Stock Performance Prior to Federal Holidays

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    The purpose of this study is to understand the impact of Federal holidays on a stock price. This research analyzed stock performance for the five trading days before each of the ten Federal holidays. Forty data points are found by the difference between a buy price (six days before a holiday) and a selling price (one day before a holiday). A 95% confidence interval is calculated using the difference of two sample means of the buy and sell prices. The mean buy price and sell prices were different enough to show an investible opportunity. This shows Federal holidays impact stock prices

    A Possible Cepheid-Like Luminosity Estimator for the Long Gamma-Ray Bursts

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    We present a possible Cepheid-like luminosity estimator for the long gamma-ray bursts based on the variability of their light curves. To construct the luminosity estimator, we use CGRO/BATSE data for 13 bursts, Wind/KONUS data for 5 bursts, Ulysses/GRB data for 1 burst, and NEAR/XGRS data for 1 burst. Spectroscopic redshifts, peak fluxes, and high resolution light curves are available for 11 of these bursts; partial information is available for the remaining 9 bursts. We find that the isotropic-equivalent luminosities L of these bursts positively correlate with a rigorously-constructed measure V of the variability of their light curves. We fit a model to these data that accommodates both intrinsic scatter (statistical variance) and extrinsic scatter (sample variance). If one excludes GRB 980425 from the fit on the grounds that its association with SN 1998bw at a redshift of z = 0.0085 is not secure, the luminosity estimator spans approx. 2.5 orders of magnitude in L, and the slope of the correlation between L and V is positive with a probability of 1 - 1.4 x 10^-4 (3.8 sigma). Although GRB 980425 is excluded from this fit, its L and V values are consistent with the fitted model, which suggests that GRB 980425 may well be associated with SN 1998bw, and that GRB 980425 and the cosmological bursts may share a common physical origin. If one includes GRB 980425 in the fit, the luminosity estimator spans approx. 6.3 orders of magnitude in L, and the slope of the correlation is positive with a probability of 1 - 9.3 x 10^-7 (4.9 sigma). Independently of whether or not GRB 980425 should be included in the fit, its light curve is unique in that it is much less variable than the other approx. 17 light curves in our sample for which the signal-to-noise is reasonably good.Comment: Accepted to The Astrophysical Journal, 31 pages, 13 figures, LaTe

    Career Decision Self‐Efficacy of Transgender People: Pre‐ and Posttransition

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    Although the mental health needs of transgender and gender‐nonconforming (TGNC) people have recently been addressed more directly than in the past (Bockting, Miner, Swinburne Romine, Hamilton, & Coleman, 2013; dickey, Reisner, & Juntunen, 2015; Meier, Pardo, Labuski, & Babcock, 2013), there remains a dearth of information related to vocational development of this population. Some of the considerations in career counseling and vocational development among TGNC people include differences in developmental concerns related to gender transition, gender presentation, passing (e.g., being perceived by others in one\u27s affirmed gender), and binary and fluid gender identities (Beemyn & Rankin, 2011; Harrison, Grant, & Herman, 2012). In the present study, we consider gender transition with regard to career decision self‐efficacy (CDSE) among TGNC people pre‐ and posttransition

    Supergauge interactions and electroweak baryogenesis

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    We present a complete treatment of the diffusion processes for supersymmetric electroweak baryogenesis that characterizes transport dynamics ahead of the phase transition bubble wall within the symmetric phase. In particular, we generalize existing approaches to distinguish between chemical potentials of particles and their superpartners. This allows us to test the assumption of superequilibrium (equal chemical potentials for particles and sparticles) that has usually been made in earlier studies. We show that in the Minimal Supersymmetric Standard Model, superequilibrium is generically maintained -- even in the absence of fast supergauge interactions -- due to the presence of Yukawa interactions. We provide both analytic arguments as well as illustrative numerical examples. We also extend the latter to regions where analytical approximations are not available since down-type Yukawa couplings or supergauge interactions only incompletely equilibrate. We further comment on cases of broken superequilibrium wherein a heavy superpartner decouples from the electroweak plasma, causing a kinematic bottleneck in the chain of equilibrating reactions. Such situations may be relevant for baryogenesis within extensions of the MSSM. We also provide a compendium of inputs required to characterize the symmetric phase transport dynamics.Comment: 49 pages, 9 figure

    Cosmological Challenges in Theories with Extra Dimensions and Remarks on the Horizon Problem

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    We consider the cosmology that results if our observable universe is a 3-brane in a higher dimensional universe. In particular, we focus on the case where our 3-brane is located at the Z2Z_2 symmetry fixed plane of a Z2Z_2 symmetric five-dimensional spacetime, as in the Ho\v{r}ava-Witten model compactified on a Calabi-Yau manifold. As our first result, we find that there can be substantial modifications to the standard Friedmann-Robertson-Walker (FRW) cosmology; as a consequence, a large class of such models is observationally inconsistent. In particular, any relationship between the Hubble constant and the energy density on our brane is possible, including (but not only) FRW. Generically, due to the existence of the bulk and the boundary conditions on the orbifold fixed plane, the relationship is not FRW, and hence cosmological constraints coming from big bang nucleosynthesis, structure formation, and the age of the universe difficult to satisfy. We do wish to point out, however, that some specific choices for the bulk stress-energy tensor components do reproduce normal FRW cosmology on our brane, and we have constructed an explicit example. As our second result, for a broad class of models, we find a somewhat surprising fact: the stabilization of the radius of the extra dimension and hence the four dimensional Planck mass requires unrealistic fine-tuning of the equation of state on our 3-brane. In the last third of the paper, we make remarks about causality and the horizon problem that apply to {\it any} theory in which the volume of the extra dimension determines the four-dimensional gravitational coupling. We point out that some of the assumptions that lead to the usual inflationary requirements are modified.Comment: 15 page REVTeX file; to appear in Phys. Rev. D; clarified the statement of being able to obtain any power dependence of the Hubble expansion rate on the energy density; added reference

    String windings in the early universe

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    We study string dynamics in the early universe. Our motivation is the proposal of Brandenberger and Vafa, that string winding modes may play a key role in decompactifying three spatial dimensions. We model the universe as a homogeneous but anisotropic 9-torus filled with a gas of excited strings. We adopt initial conditions which fix the dilaton and the volume of the torus, but otherwise assume all states are equally likely. We study the evolution of the system both analytically and numerically to determine the late-time behavior. We find that, although dynamical evolution can indeed lead to three large spatial dimensions, such an outcome is not statistically favored.Comment: 26 pages, LaTeX, 4 eps figure

    Development and testing of a fiber/multianode photomultiplier system for use on FiberGLAST

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    A scintillating fiber detector is currently being studied for the NASA Gamma-Ray Large Area Space Telescope (GLAST) mission. This detector utilizes modules composed of a thin converter sheet followed by an x, y plane of scintillating fibers to examine the shower of particles created by high energy gamma-rays interacting in the converter material. The detector is composed of a tracker with 90 such modular planes and a calorimeter with 36 planes. The two major component of this detector are the scintillating fibers and their associated photodetectors. Here we present current status of development and test result of both of these. The Hamamatsu R5900-00-M64 multianode photomultiplier tube (MAPMT) is the baseline readout device. A characterization of this device has been performed including noise, cross- talk, gain variation, vibration, and thermal/vacuum test. A prototype fiber/MAPMT system has been tested at the Center for Advanced Microstructures and Devices at Louisiana State University with a photon beam and preliminary results are presented

    Warped Tachyonic Inflation in Type IIB Flux Compactifications and the Open-String Completeness Conjecture

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    We consider a cosmological scenario within the KKLT framework for moduli stabilization in string theory. The universal open string tachyon of decaying non-BPS D-brane configurations is proposed to drive eternal topological inflation. Flux-induced `warping' can provide the small slow-roll parameters needed for successful inflation. Constraints on the parameter space leading to sufficient number of e-folds, exit from inflation, density perturbations and stabilization of the Kahler modulus are investigated. The conditions are difficult to satisfy in Klebanov-Strassler throats but can be satisfied in T^3 fibrations and other generic Calabi-Yau manifolds. This requires large volume and magnetic fluxes on the D-brane. The end of inflation may or may not lead to cosmic strings depending on the original non-BPS configuration. A careful investigation of initial conditions leading to a phenomenologically viable model for inflation is carried out. The initial conditions are chosen on the basis of Sen's open string completeness conjecture. We find time symmetrical bounce solutions without initial singularities for k=1 FRW models which are correlated with an inflationary period. Singular big-bang/big-crunch solutions also exist but do not lead to inflation. There is an intriguing correlation between having an inflationary universe in 4 dimensions and 6 compact dimensions or a big-crunch singularity and decompactification.Comment: 43 pages, 9 figures. v3: Typos correcte
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