5,467 research outputs found

    A new species of Bolbelasmus Boucomont, 1911 (Insecta Coleoptera Geotrupidae) from Sicily (Italy).

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    Authors have examined all available sicilian specimens belonging to the genus Bolbelasmus, collected between 1893 and 2010, previously identified as B. gallicus e B. unicornis. They conclude that both species have to be excluded from the sicilian fauna and describe the new species B. romanorum, which is characterized by peculiar punctures on the clypeus, the head and the pronotum, and by the shape of the clypeus, the head and the aedeagus sclerites. They compare the new species with all the taxa currently known in the Mediterranean. Further, they show oscillograms of both sexes of the new species, which, as other Bolbelasmus, stridulates vigorously; they also detect for the first time the pars stridens, consisting in a series of small bristles on the lower outer border of wings; the insect emits its sound moving actively the abdomen, the friction of the wing on the first abdominal tergite, particularly swollen, produces the stridulation

    Determining the Physical Properties of the B Stars I. Methodology and First Results

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    We describe a new approach to fitting the UV-to-optical spectra of B stars to model atmospheres and present initial results. Using a sample of lightly reddened stars, we demonstrate that the Kurucz model atmospheres can produce excellent fits to either combined low dispersion IUE and optical photometry or HST FOS spectrophotometry, as long as the following conditions are fulfilled: 1) an extended grid of Kurucz models is employed, 2) the IUE NEWSIPS data are placed on the FOS absolute flux system using the Massa & Fitzpatrick (1999) transformation, and 3) all of the model parameters and the effects of interstellar extinction are solved for simultaneously. When these steps are taken, the temperatures, gravities, abundances and microturbulence velocities of lightly reddened B0-A0 V stars are determined to high precision. We also demonstrate that the same procedure can be used to fit the energy distributions of stars which are reddened by any UV extinction curve which can be expressed by the Fitzpatrick & Massa (1990) parameterization scheme. We present an initial set of results and verify our approach through comparisons with angular diameter measurements and the parameters derived for an eclipsing B star binary. We demonstrate that the metallicity derived from the ATLAS 9 fits to main sequence B stars is essentially the Fe abundance. We find that a near zero microturbulence velocity provides the best-fit to all but the hottest or most luminous stars (where it may become a surrogate for atmospheric expansion), and that the use of white dwarfs to calibrate UV spectrophotometry is valid.Comment: 17 pages, including 2 pages of Tables and 6 pages of Figures. Astrophysical Jounral, in pres

    Semi-Teleparallel Theories of Gravitation

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    A class of theories of gravitation that naturally incorporates preferred frames of reference is presented. The underlying space-time geometry consists of a partial parallelization of space-time and has properties of Riemann-Cartan as well as teleparallel geometry. Within this geometry, the kinematic quantities of preferred frames are associated with torsion fields. Using a variational method, it is shown in which way action functionals for this geometry can be constructed. For a special action the field equations are derived and the coupling to spinor fields is discussed.Comment: 14 pages, LaTe

    A new algorithm for the identification of dives reveals the foraging ecology of a shallow-diving seabird using accelerometer data

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    The identification of feeding events is crucial to our understanding of the foraging ecology of seabirds. Technology has made small devices, such as time-depth recorders (TDRs) and accelerometers available. However, TDRs might not be sensitive enough to identify shallow dives, whereas accelerometers might reveal more subtle behaviours at a smaller temporal scale. Due to the limitations of TDRs, the foraging ecology of many shallow-diving seabirds has been poorly investigated to date. We thus developed an algorithm to identify dive events in a shallowdiving seabird species, the Scopoli’s shearwater, using only accelerometer data. The accuracy in the identification of dives using either accelerometers or TDRs was compared. Furthermore, we tested if the foraging behaviour of shearwaters changed during different phases of reproduction and with foraging trip type. Data were collected in Linosa Island (35°51′33″N; 12°51′34″E) from 12 June to 8 September 2015 by deploying accelerometer data loggers on 60 Scopoli’s shearwaters. Four birds were also equipped with TDRs. TDRs recorded only 17.7% of the dives detected by the accelerometers using the algorithm. A total of 82.3% of dives identified by algorithm were too short or shallow to be detected by TDRs. Therefore, TDRs were not accurate enough to detect most of the dives in Scopoli’s shearwaters, which foraged mostly close to the sea surface. Our data showed that birds performed shorter foraging trips and dived more frequently in the early chick-rearing period compared with the late chick-rearing and incubation phases. Furthermore, parents dived more frequently during short foraging trips. Our results suggest that Scopoli’s shearwaters maximised their foraging effort (e.g. number of dives, short trips) during shorter foraging trips and during early chick-rearing

    Spin-orbit induced mixed-spin ground state in RRNiO3_3 perovskites probed by XAS: new insight into the metal to insulator transition

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    We report on a Ni L2,3_{2,3} edges x-ray absorption spectroscopy (XAS) study in RRNiO3_3 perovskites. These compounds exhibit a metal to insulator (MIMI) transition as temperature decreases. The L3_{3} edge presents a clear splitting in the insulating state, associated to a less hybridized ground state. Using charge transfer multiplet calculations, we establish the importance of the crystal field and 3d spin-orbit coupling to create a mixed-spin ground state. We explain the MIMI transition in RRNiO3_3 perovskites in terms of modifications in the Ni3+^{3+} crystal field splitting that induces a spin transition from an essentially low-spin (LS) to a mixed-spin state.Comment: 4 pages, 4 figures, accepted as PRB - Rapid Comm. Dez. 200

    A Novel Approach for an Integrated Straw tube-Microstrip Detector

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    We report on a novel concept of silicon microstrips and straw tubes detector, where integration is accomplished by a straw module with straws not subjected to mechanical tension in a Rohacell ®^{\circledR} lattice and carbon fiber reinforced plastic shell. Results on mechanical and test beam performances are reported on as well.Comment: Accepted by Transactions on Nuclear Science (2005). 11 pages, 9 figures, uses lnfprep.st

    Linearization of nonlinear connections on vector and affine bundles, and some applications

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    A linear connection is associated to a nonlinear connection on a vector bundle by a linearization procedure. Our definition is intrinsic in terms of vector fields on the bundle. For a connection on an affine bundle our procedure can be applied after homogenization and restriction. Several applications in Classical Mechanics are provided

    On Effective Constraints for the Riemann-Lanczos System of Equations

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    There have been conflicting points of view concerning the Riemann--Lanczos problem in 3 and 4 dimensions. Using direct differentiation on the defining partial differential equations, Massa and Pagani (in 4 dimensions) and Edgar (in dimensions n > 2) have argued that there are effective constraints so that not all Riemann tensors can have Lanczos potentials; using Cartan's criteria of integrability of ideals of differential forms Bampi and Caviglia have argued that there are no such constraints in dimensions n < 5, and that, in these dimensions, all Riemann tensors can have Lanczos potentials. In this paper we give a simple direct derivation of a constraint equation, confirm explicitly that known exact solutions of the Riemann-Lanczos problem satisfy it, and argue that the Bampi and Caviglia conclusion must therefore be flawed. In support of this, we refer to the recent work of Dolan and Gerber on the three dimensional problem; by a method closely related to that of Bampi and Caviglia, they have found an 'internal identity' which we demonstrate is precisely the three dimensional version of the effective constraint originally found by Massa and Pagani, and Edgar.Comment: 9pages, Te

    State Legislative Update

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    Senate Bill 1970 was introduced in the Florida Senate on March 2, 2004. It was initially referred to the Senate Judiciary Committee where it passed on April 19 with an 8-0 vote. Senate Bill 1970 was read for the first time in the Senate on April 21. The bill passed the full Senate on April 24 with a 39-0 vote. It was then sent to the full House on April 26 where it was substituted for House Bill 1765. Senate Bill 1970 was read and passed in the House on April 27 with a 114-0 vote. The bill was presented to Govenor Bush for signature on June 9 and signed into law on June 10, 2004
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