595 research outputs found

    On stirling numbers of the second kind

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    AbstractWe first find inequalities between the Stirling numbers S(n, r) for fixed n, then introduce functions L and U such that L(n, r)≀S(n, r)≀U(n, r), and finally obtain the asymptotic value n/log n for the value of r for which S(n, r) is maximal

    Eimeria chinchillae De Vos & Van der Westhuizen, 1968 and other Eimeria spp. from three South African rodent species

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    Eimeria chinchillae De Vos & Van der Westhuizen, 1968, an organism originally described from the chinchilla and subsequently shown to be transmissible to other rodents, was found to occur naturally in Rhabdomys pumilio (Sparrman, 1784) in South Africa. The morphology of the oocysts, the site of development of the endogenous stages and the prepatent period of the infection were similar to those of E. chinchillae obtained from chinchillas and transmitted experimentally to R. pumilio. The identity of the organism was confirmed by the successful infection of chinchillas. Three additional Eimeria spp. were found in R. pumilio. Oocysts of Eimeria pumilioi n. sp. measured 18 by 12 ”, those of Eimeria rhabdomyis n. sp., 13 by 12 ” and those of Eimeria pretoriensis n. sp., 24 by 19 ”. Two Eimeria spp. were also found in Praomys (Mastomys) natalensis (Smith, 1834). Oocysts of Eimeria mastomyis n. sp. measured 27 by 21 ” and those of Eimeria theileri n. sp. 20 by 17 ”. A single Eimeria sp., Eimeria otomyis n. sp., was found in Otomys irroratus (Brants, 1827). The oocysts measured 20 by 15 ”.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format..mn201

    Microfluidics for Small-Angle X-ray Scattering

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    Small-angle X-ray scattering is a well-established biophysical technique, whilst micro-fluidics is proving to be a convenient technology for creating miniaturised multifunctional devices. Both fields are highly versatile and find use in multiple scientific disciplines. Together, they offer the potential to obtain structural information on biomacromolecules, nanoparticles and condensed matter, in a high-throughput manner and with enhanced time-resolution capabilities. This chapter provides practical design considerations for X-ray-based microfluidic systems and examines some of the existing microfluidic platforms used in conjunction with small-angle X-ray scattering. As the exclusive advantages of microfluidics become recognised and accessible, the prevalence of microfluidic sample environments in X-ray scattering measurements will hopefully increase

    Statistical inaccuracies over use of facial skin care products and sunscreens in the aetiology of frontal fibrosing alopecia: reply from authors.

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    We did not perform a matched one-to-one comparison between FFA subjects and controls, we compared two groups with similar ages. The only continuous variable was age. The responses to the questions posed were categorical. We therefore maintain that a Fisher's exact test rather than a McNemar's test was an appropriate method for analyzing the results

    Genomic Deletion Marking an Emerging Subclone of Francisella tularensis subsp. holarctica in France and the Iberian Peninsula

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    P. 7465-7470Francisella tularensis subsp. holarctica is widely disseminated in North America and the boreal and temperate regions of the Eurasian continent. Comparative genomic analyses identified a 1.59-kb genomic deletion specific to F. tularensis subsp. holarctica isolates from Spain and France. Phylogenetic analysis of strains carrying this deletion by multiple-locus variable-number tandem repeat analysis showed that the strains comprise a highly related set of genotypes, implying that these strains were recently introduced or recently emerged by clonal expansion in France and the Iberian PeninsulaS

    Fragments of equality in representative politics

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    Deploying a broadly interpretive approach, the article explores the extent to which, and the ways in which, equality is enacted in non-elective as well as elective representation. It argues that the fleeting and fragmentary equalities evident in non-elective representation are democratically significant, and that examining them can enhance understanding of the democratic promise and limits of different modes of representation

    <i>Leishmania</i> <i>major</i> UDP-sugar pyrophosphorylase salvages galactose for glycoconjugate biosynthesis

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    AbstractLeishmaniases are a set of tropical and sub-tropical diseases caused by protozoan parasites of the genus Leishmania whose severity ranges from self-healing cutaneous lesions to fatal visceral infections. Leishmania parasites synthesise a wide array of cell surface and secreted glycoconjugates that play important roles in infection. These glycoconjugates are particularly abundant in the promastigote form and known to be essential for establishment of infection in the insect midgut and effective transmission to the mammalian host. Since they are rich in galactose, their biosynthesis requires an ample supply of UDP-galactose. This nucleotide-sugar arises from epimerisation of UDP-glucose but also from an uncharacterised galactose salvage pathway. In this study, we evaluated the role of the newly characterised UDP-sugar pyrophosphorylase (USP) of Leishmania major in UDP-galactose biosynthesis. Upon deletion of the USP encoding gene, L. major lost the ability to synthesise UDP-galactose from galactose-1-phosphate but its ability to convert glucose-1-phosphate into UDP-glucose was fully maintained. Thus USP plays a role in UDP-galactose activation but does not significantly contribute to the de novo synthesis of UDP-glucose. Accordingly, USP was shown to be dispensable for growth and glycoconjugate biosynthesis under standard growth conditions. However, in a mutant seriously impaired in the de novo synthesis of UDP-galactose (due to deficiency of the UDP-glucose pyrophosphorylase) addition of extracellular galactose increased biosynthesis of the cell surface lipophosphoglycan. Thus under restrictive conditions, such as those encountered by Leishmania in its natural habitat, galactose salvage by USP may play a substantial role in biosynthesis of the UDP-galactose pool. We hypothesise that USP recycles galactose from the blood meal within the midgut of the insect for synthesis of the promastigote glycocalyx and thereby contributes to successful vector infection

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio
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