12,241 research outputs found

    Asymmetries Between Strange and Antistrange Particle Production in Pion-Proton Interactions

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    Recent measurements of the asymmetries between Feynman xx distributions of strange and antistrange hadrons in πA\pi^- A interactions show a strong effect as a function of xFx_F. We calculate strange hadron production in the context of the intrinsic model and make predictions for particle/antiparticle asymmetries in these interactions.Comment: version to be published in Nucl. Phys. A, 46 pages LaTeX, 15 .eps figure

    Bait sprays against the European cherry fruit fly Rhagoletis cerasi: Status Quo & Perspectives

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    Bait spray experiments against Rhagoletis cerasi were carried out in 2005 to 2007. The main principle of this method is to use food (e.g. sugar and proteins) as baits for the flies with small amounts of insecticides, which is applied on parts of the cherry tree. Main focus was aimed at laboratory and field cage experiments using the commercial GF-120 Naturalyte Fruit Fly BaitTM with the insecticide spinosad, which is registered against North American cherry fruit fly species in the US and Canada. Furthermore, additional bait spray formulations as alternatives to GF-120 were used to define the right food bait quality for a high attractiveness and low reproduction ability. Beyond, the negative effect on reproduction of flies for azadirachtin (neem) was shown. During this project, promising results, e.g. efficacies up to 99 % with infestation rates below the infestation threshold were obtained. From 2008 on, other insecticides, like azadirachtin (neem) and pyrethrine in an appropriate food bait mixture will be used. Questions like efficacy, adequate concentrations, persistence, rainfastness and practicability in commercial cherry orchards will be answered

    Life History and Laboratory Rearing of \u3ci\u3eCorythucha Juglandis\u3c/i\u3e (Hemiptera: Tingidae) With Descriptions of Immature Stages

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    The life history of Corythucha juglandis was investigated in Jackson and Alexander counties. Illinois. August 1981-December 1985 and the immature stages were described. The bug was also raised from egg to adult under controlled laboratory conditions. This apparently bivoltine species overwintered as adults that became active in late April-early May. began feeding on the undersides of black walnut leaflets, and reproduced shortly thereafter. The seasonal occurrence of the adults and subsequent immature stages is discussed. Adults were last observed in mid-October. C. juglandis was reared on black walnut leaflets under a 16L:8D photoperiod at ca. 23.9°C. The pre-ovipositional, ovipositionaL and post-ovipositional periods averaged 14.0, 50.3, and 11.9 days, respectively: average fecundity was 118.6. The incubation period, and 1st, 2nd, 3rd, 4th, and 5th stadia averaged 16.4,4.3,3.8,4.2,4.6, and 6.7 days, respectively

    A List of the Odonata of the La Rue-pine Hills Ecological Area

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    A survey of the adult odonate fauna of the La Rue-Pine Hills Ecological Area, Union County, Illinois, was conducted during 1983-1985. Thirty six. species were collected including the damselfly Telebasis byersi Westfall; this damselfly is known to occur in Illinois only at Pine Hills

    Magnetic Field Seeding by Galactic Winds

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    The origin of intergalactic magnetic fields is still a mystery and several scenarios have been proposed so far: among them, primordial phase transitions, structure formation shocks and galactic outflows. In this work we investigate how efficiently galactic winds can provide an intense and widespread "seed" magnetisation. This may be used to explain the magnetic fields observed today in clusters of galaxies and in the intergalactic medium (IGM). We use semi-analytic simulations of magnetised galactic winds coupled to high resolution N-body simulations of structure formation to estimate lower and upper limits for the fraction of the IGM which can be magnetised up to a specified level. We find that galactic winds are able to seed a substantial fraction of the cosmic volume with magnetic fields. Most regions affected by winds have magnetic fields in the range -12 < Log B < -8 G, while higher seed fields can be obtained only rarely and in close proximity to wind-blowing galaxies. These seed fields are sufficiently intense for a moderately efficient turbulent dynamo to amplify them to the observed values. The volume filling factor of the magnetised regions strongly depends on the efficiency of winds to load mass from the ambient medium. However, winds never completely fill the whole Universe and pristine gas can be found in cosmic voids and regions unaffected by feedback even at z=0. This means that, in principle, there might be the possibility to probe the existence of primordial magnetic fields in such regions.Comment: 14 pages, 5 figures. Accepted for publications by MNRAS. A high resolution version of the paper is available at http://astronomy.sussex.ac.uk/~sb207/Papers/bb.ps.g

    Odonata at a Small Woodland Pond in Southern Illinois

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    A survey of the adult odonate fauna of a small woodland pond in Pope County, Illinois, was conducted during 1983--·1984. Twenty-four species were collected including Aeshna mutata and Anax longipes. In addition, Libellula vibrans was collected in 1982, and Aeshna sp. (probably u. umbrosa) observed the same year but not collected

    Heavy flavor in heavy-ion collisions at RHIC and RHIC II

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    In the initial years of operation, experiments at the Relativistic Heavy Ion Collider (RHIC) have identified a new form of matter formed in nuclei-nuclei collisions at energy densities more than 100 times that of a cold atomic nucleus. Measurements and comparison with relativistic hydrodynamic models indicate that the matter thermalizes in an unexpectedly short time, has an energy density at least 15 times larger than needed for color deconfinement, has a temperature about twice the critical temperature predicted by lattice QCD, and appears to exhibit collective motion with ideal hydrodynamic properties - a "perfect liquid" that appears to flow with a near-zero viscosity to entropy ratio - lower than any previously observed fluid and perhaps close to a universal lower bound. However, a fundamental understanding of the medium seen in heavy-ion collisions at RHIC does not yet exist. The most important scientific challenge for the field in the next decade is the quantitative exploration of the new state of nuclear matter. That will require new data that will, in turn, require enhanced capabilities of the RHIC detectors and accelerator. In this report we discuss the scientific opportunities for an upgraded RHIC facility - RHIC II - in conjunction with improved capabilities of the two large RHIC detectors, PHENIX and STAR. We focus solely on heavy flavor probes. Their production rates are calculable using the well-established techniques of perturbative QCD and their sizable interactions with the hot QCD medium provide unique and sensitive measurements of its crucial properties making them one of the key diagnostic tools available to us.Comment: 96 pages, 53 figures. Accepted for publication in Physics Reports. Fixed typo in Fig. 15 captio

    Effects of Various Split Developmental Photophases and Constant Light During Each 24 Hour Period on Adult Morphology in \u3ci\u3eThyanta Calceata\u3c/i\u3e (Hemiptera: Pentatomidae)

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    Rearing immatures of Thyanta calceata in a range of split photophases during each 24 h period and in constant light showed that the adult dimorphic response in color and pu- bescence could be produced; individuals reared in photoperiods in which each scotophase was at least 2 h in length generally developed into the fall/spring morph

    Imprinting Light Phase on Matter Wave Gratings in Superradiance Scattering

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    Superradiance scattering from a Bose-Einstein condensate is studied with a two-frequency pumping beam. We demonstrate the possibility of fully tuning the backward mode population as a function of the locked initial relative phase between the two frequency components of the pumping beam. This result comes from an imprinting of this initial relative phase on two matter wave gratings, formed by the forward mode or backward mode condensate plus the condensate at rest, so that cooperative scattering is affected. A numerical simulation using a semiclassical model agrees with our observations.Comment: 6 pages, 11 figure
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