9,767 research outputs found

    Review of the South American whip scorpions (Thelyphonida: Arachnida)

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    The literature concerning South American thelyphonids presently supports recognition of about ten recent species of thelyphonids representing two genera. Comparative and diagnostic features deduced from this literature and from study of some of these species are provided herein together with a discussion of the relevant morphological characters. A general review of the biology, distribution and diversity of the Thelyphonida is also provided. The genus Amauromastigon is synonymized with Mastigoproctus on subjective grounds. At least one species is known by fossils from the Lower Cretaceous of Brazil and is discussed relative to its possible relationships to Recent American taxa

    Notes on nomenclature in Xylotrupes Hope (Scarabaeidae: Dynastinae: Dynastini)

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    A list of taxa belonging to Xylotrupes Hope (Scarabaeidae: Dynastinae: Dynastini) is presented which incorporates several taxonomic actions: X. australicus darwinia Rowland comb. nov.; X. damarensis Rowland stat. nov.; X. lorquini zideki Rowland comb. nov.; X. macleayi szekessyi Endrödi comb. nov.; X. pachycera Rowland stat. nov.; X. philippinensis philippinensis Endrödi stat. nov.; X. philippinensis peregrinus Rowland comb. nov.; X. sumatrensis tanahmelayu Rowland comb. nov.; X. tadoana Rowland stat. nov.; X. telemachos Rowland stat. nov.; X. wiltrudae Silvestre stat. nov. Two new taxa are described: X. carinulus sp. nov. and X. clinias buru ssp. nov. Lectotypes are designated for X. lamachus Minck and X. clinias Schaufuss. Xylotrupes lamachus is found to be a junior subjective synonym of X. ulysses (Guérin-Méneville), new synonymy

    Implementing quantum logic gates with GRAPE: principles and practicalities

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    We briefly describe the use of GRAPE pulses to implement quantum logic gates in NMR quantum computers, and discuss a range of simple extensions to the core technique. We then consider a range of difficulties which can arise in practical implementations of GRAPE sequences, reflecting non-idealities in the experimental systems used.Comment: 15 pages rspublic including 4 figures. This is the original manuscript preprint form which differs slightly from the final accepted version (Phil Trans Roy Soc A in press

    Liquid-core low-refractive-index-contrast Bragg fiber sensor

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    We propose and experimentally demonstrate a low-refractive-index-contrast hollow-core Bragg fiber sensor for liquid analyte refractive index detection. The sensor operates using a resonant sensing principle- when the refractive index of a liquid analyte in the fiber core changes, the resonant confinement of the fiber guided mode will also change, leading to both the spectral shifts and intensity changes in fiber transmission. As a demonstration, we characterize the Bragg fiber sensor using a set of NaCl solutions with different concentrations. Strong spectral shifts are obtained with the sensor experimental sensitivity found to be ~1400nm/RIU (refractive index unit). Besides, using theoretical modeling we show that low-refractive-index-contrast Bragg fibers are more suitable for liquid-analyte sensing applications than their high-refractive-index-contrast counterparts.Comment: 3 pages, 4 figure

    On the asymptotic stability of feedback control systems containing a single time- varying element

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    Asymptotic stability of feedback control systems containing single time varying elemen

    Endocrine disrupting effects on the nesting behaviour of male three-spined stickleback Gasterosteus aculeatus L

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    The analysis of patterns of temporal variability in the nesting behaviour of male threespined stickleback (Gasterosteus aculeatus) exposed to the synthetic oestrogen, 17β-ethinylestradiol, revealed immediate, but transient, treatment-related effects. Gluing frequency and time spent near nest were significantly reduced in exposed fish at the beginning of the experiment. The expression of these behaviours subsequently recovered and there was no effect of treatment on nest building success. The potential causes and implications of these findings are discussed

    L- and K-band LMSS propagation measurements using MARECS-B, OLYMPUS, and ACTS

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    L-band measurements of land mobile satellite systems (LMSS) propagation effects were last made at the end of 1988, but some voids were left in the database, making modeling of low elevation roadside tree shadowing and multipath reflections difficult for some path geometries. Transmission of a pilot tone from MARECS-B at 55 deg West during Sep. and Dec. 1991 gave an opportunity to fill the gaps in the experimental results. Two campaigns during which fade data were obtained at elevation angles from 7 deg to 40 deg are described. Below 15 deg, specular terrain reflections in a non-shadowing, hilly environment were observed to introduce significant fading. Although the reflecting surface was at a distance of up to several km, it is shown that the reflected signals are delayed by less than 1 microsec. Mobile measurements were also attempted receiving the 20 GHz Olympus beacon, but antenna pointing problems restricted first results to straight-line driving

    Excavations at the Viking Barrow Cemetery at Heath Wood, Ingleby, Derbyshire

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    The cemetery at Heath Wood, Ingleby, Derbyshire, is the only known Scandinavian cremation cemetery in the British Isles. It comprises fifty-nine barrows, of which about one-third have been excavated on previous occasions, although earlier excavators concluded that some were empty cenotaph mounds. From 1998 to 2000 three barrows were examined. Our investigations have suggested that each of the barrows contained a burial, although not all contain evidence of a pyre. A full report of the 1998-2000 excavations is provided, alongside a summary of the earlier finds. The relationship of Heath Wood to the neighbouring site at Repton is examined, in order to understand its significance for the Scandinavian settlement of the Danelaw. It is concluded that Heath Wood may have been a war cemetery of the Viking Great Army of AD 873-8
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