25,984 research outputs found

    Isospin quantum number of D_{s0}^+(2317)

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    The D_s^+ pi^0 and D_s^{*+} gamma decays of the D_{s0}^+(2317) are studied by assigning it to various charmed strange scalar mesons. As a result, it is found that its assignment to an iso-triplet four-quark meson is favored by the severest experimental constraint on the ratio of the rates for these decays, while assigning it to an I=0 state (a four-quark or a conventional {c\bar{s}}) is inconsistent with this constraint.Comment: 6 pages, no figure, RevTeX4, references added and clarification of tex

    A unified acquisition system for acoustic data

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    A multichannel, acoustic AM carrier system was developed for a wide variety of applications, particularly for aircraft noise and sonic boom measurements. Each data acquisition channel consists of a condenser microphone, an acoustic signal converter, and a Zero Drive amplifier, along with peripheral supporting equipment. A control network insures continuous optimal tuning of the converter and permits remote calibration of the condenser microphone. With a 12.70-mm (1/2-in.) condenser microphone, the converter/Zero Drive amplifier combination has a frequency response from 0 Hz to 20 kHz (-3 db), a dynamic range exceeding 70 db, and a minimum noise floor of 50 db ref. 20 micro Pa) in the band 22.4 Hz to 22.4 kHz. The system requires no external impedance matching networks and is insensitive to cable length, at least up to 900 m (3,000 ft). System gain varies only + or - 1 db over the temperature range 4 to 54 C (40 to 130 F). Adapters are available to accommodate 23.77-mm (1-in.) and 6.35-mm (1/4-in.) microphones and to provide 30-db attenuation. A field test to obtain the acoustical time history of a helicopter flyover proved successful

    Lung lobe torsion in adult and juvenile pugs

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    This cases series of 13 pugs with lung lobe torsion (LLT) is the largest case series of pugs in the literature and the first to compare dogs presenting before and after 12 months of age. Similar to previous case series, the median age of pugs with LLT was 17 months; however six dogs were under 12 months of age (3 of 13 were 11–13 weeks at presentation). There were no differences between the dogs that presented younger or older than 12 months old with respect to sex, neuter status, lung lobe affected, duration and nature of clinical signs, time alive after discharge, and complications. The juvenile onset may suggest that some dogs are inherently at risk of LLT. This is intriguing and important as LLT may not be an intuitive diagnosis in a juvenile brachycephalic animal, and practitioners should be aware of this unusual presentation

    Conjugative transfer frequencies of mef(A)-containing Tn1207.3 to macrolide-susceptible Streptococcus pyogenes belonging to different emm types

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    The aim of this study was to examine the gene transfer potential of mef(A)-containing Tn120.3 to macrolide-susceptible Streptococcus pyogenes belonging to different emm types. Using the filter mating technique, Tn1207.3 was transferred by conjugation to 23 macrolide-susceptible recipients representing 11 emm types. PCR analysis confirmed the presence of the mef(A) gene and the comEC junction regions of the Tn1207.3 insertion in resultant transconjugants. Significant variation was found in the transfer frequency of Tn1207.3 to different Strep. pyogenes strains, and this phenomenon may contribute to the differences in mef(A) frequency observed among clinical isolates. Significance and Impact of the Study: The spread of antimicrobial resistance among pathogenic bacteria is an important problem, but the mechanisms of horizontal transfer between strains and species are often poorly understood. For instance, little is known on how macrolide resistance spreads between strains of the human pathogen Strep. pyogenes and why certain strains more commonly display resistance than others. Here, we show that Strep. pyogenes strains vary greatly in their ability to acquire a transposon encoding macrolide resistance by horizontal gene transfer in vitro. These data provide a novel insight into the transfer of antibiotic resistance between bacterial strains and offer an explanation for the differences in the frequency of resistance determinates and resistance seen among clinical isolates. © 2014 The Authors Letters in Applied Microbiology

    Monopoly and the incentive to innovate when adoption involves switchover disruptions

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    When considering the incentive of a monopolist to adopt an innovation, the textbook model assumes that it can instantaneously and seamlessly introduce the new technology. In fact, firms often face major problems in integrating new technologies. In some cases, firms have to (temporarily) produce at levels substantially below capacity upon adoption. We call such phenomena switchover disruptions, and present extensive evidence on them. If firms face switchover disruptions, then they may temporarily lose some unit sales upon adoption. If the firm loses unit sales, then a cost of adoption is the foregone rents on the sales of those units. Hence, greater market power will mean higher prices on those lost units of output, and hence a reduced incentive to innovate. We introduce switchover disruptions into some standard models in the literature, show they can overturn some famous results, and then show they can help explain evidence that firms in more competitive environments are more likely to adopt technologies and increase productivity.

    Draft genome sequence of the Streptococcus pneumoniae Avery strain A66

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    We have used HiSeq 2000 technology to generate a draft genome sequence of Streptococcus pneumoniae strain A66. This is a common study strain used in investigations of pneumococcal bacterium-host interactions and was used in the seminal genetic studies of Avery et al

    EnsembleSVM: A Library for Ensemble Learning Using Support Vector Machines

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    EnsembleSVM is a free software package containing efficient routines to perform ensemble learning with support vector machine (SVM) base models. It currently offers ensemble methods based on binary SVM models. Our implementation avoids duplicate storage and evaluation of support vectors which are shared between constituent models. Experimental results show that using ensemble approaches can drastically reduce training complexity while maintaining high predictive accuracy. The EnsembleSVM software package is freely available online at http://esat.kuleuven.be/stadius/ensemblesvm.Comment: 5 pages, 1 tabl

    Recent notes on the avifauna of Kalimantan

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    In the introduction to his Annotated checklist of the birds of Borneo, Smythies (1957) outlines the history of ornithological study on the island. A notable lack of field studies in Kalimantan (Indonesian Borneo) is apparent over the past fifty years. In the previous century, there had been some two dozen individuals collecting or studying, especially in the Banjarmasin area, but faunal studies virtually ceased after the outbreak of the Second World War. Pfeffer (1960-1961) took part in a French expedition to East Kalimantan, and Pearson (1975) published a brief list of birds in the Kutai reserve, the site of a field research station until it was destroyed by fire in 1983. Their data, and some unpublished records of a few others in the 1970's (J. T. Marshall, K. V. Thompson) are incorporated into the third edition of Smythies' The Birds of Borneo (1981).     The purpose of the present paper is to publish notes on Kalimantan birds to cover the period from those included in the latest edition of Smythies' work up to the present time, and thus to update the record in expectation of an increase in ornithological activity in the near future. There has been very little further study, and in acknowledgement to Smythies' third edition, the Earl of Cranbook writes: “I regret only that the book still retains such a strongly northern and north-western bias. The four provinces of Kalimantan encompass the greater part of the island of Borneo. Up-to-date ornithological knowledge of this area is sadly deficient, perhaps this edition will find its way into Indonesia and stimulate interest and comment”. The present paper contributes a little to redress this imbalance
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