2,640 research outputs found

    An atypical presentation of cystic fibrosis: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>The presentation of cystic fibrosis is dependant upon which organs are affected. Common presentations include chronic respiratory infections and malabsorption. Patients with atypical disease tend to present late in childhood or as adults. Eye manifestations of cystic fibrosis are less well known.</p> <p>Case presentation</p> <p>A 14-year-old Caucasian boy presented with tiredness and difficulty seeing at night, over a period of 6 months. Good vision was only described in bright conditions. There was no history of jaundice, steatorrhea or diarrhoea.</p> <p>Conclusion</p> <p>This is the first reported case of newly diagnosed cystic fibrosis-related liver disease in a teenage boy, whose presenting symptom was night blindness secondary to vitamin A deficiency.</p

    The startup cartography project: measuring and mapping entrepreneurial ecosystems

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    This paper presents the Startup Cartography Project, which offers a new set of entrepreneurial ecosystem statistics for the United States from 1988-2016. The SCP combines state-level business registration records with a predictive analytics approach to estimate the probability of “extreme” growth (IPO or high-value acquisition) at or near the time of founding for all newlyregistered firms in a given year. The results indicate the ability of predictive analytics to identify high-potential start-ups at founding (using a variety of different approaches and measures). The SCP then leverages estimates of entrepreneurial quality to develop four entrepreneurial ecosystem statistics, including the rate of start-up formation, average entrepreneurial quality, the quality-adjusted quantity of entrepreneurship, and entrepreneurial ecosystem performance over time. These statistics offer sharp insight into patterns of regional entrepreneurship, their correlation with regional economic growth and the evolution of entrepreneurial ecosystems over time. The SCP includes both a public-access dataset at the state, MSA, county, and zip code level, as well as an interactive map, the U.S. Startup Map, that allows academic and policy users to assess entrepreneurial ecosystems at an arbitrary level of granularity (from the level of states down to individual street addresses).https://www.startupcartography.com/researc

    Molecular Epidemiology of Campylobacter Isolates from Poultry Production Units in Southern Ireland

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    This study aimed to identify the sources and routes of transmission of Campylobacter in intensively reared poultry farms in the Republic of Ireland. Breeder flocks and their corresponding broilers housed in three growing facilities were screened for the presence of Campylobacter species from November 2006 through September 2007. All breeder flocks tested positive for Campylobacter species (with C. jejuni and C. coli being identified). Similarly, all broiler flocks also tested positive for Campylobacter by the end of the rearing period. Faecal and environmental samples were analyzed at regular intervals throughout the rearing period of each broiler flock. Campylobacter was not detected in the disinfected house, or in one-day old broiler chicks. Campylobacter jejuni was isolated from environmental samples including air, water puddles, adjacent broiler flocks and soil. A representative subset of isolates from each farm was selected for further characterization using flaA-SVR sub-typing and multi-locus sequence typing (MLST) to determine if same-species isolates from different sources were indistinguishable or not. Results obtained suggest that no evidence of vertical transmission existed and that adequate cleaning/disinfection of broiler houses contributed to the prevention of carryover and cross-contamination. Nonetheless, the environment appears to be a potential source of Campylobacter. The population structure of Campylobacter isolates from broiler farms in Southern Ireland was diverse and weakly clonal

    Continuous heating of a giant X-ray flare on Algol

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    Giant flares can release large amounts of energy within a few days: X-ray emission alone can be up to ten percent of the star's bolometric luminosity. These flares exceed the luminosities of the largest solar flares by many orders of magnitude, which suggests that the underlying physical mechanisms supplying the energy are different from those on the Sun. Magnetic coupling between the components in a binary system or between a young star and an accretion disk has been proposed as a prerequisite for giant flares. Here we report X-ray observations of a giant flare on Algol B, a giant star in an eclipsing binary system. We observed a total X-ray eclipse of the flare, which demonstrates that the plasma was confined to Algol B, and reached a maximum height of 0.6 stellar radii above its surface. The flare occurred around the south pole of Algol B, and energy must have been released continously throughout its life. We conclude that a specific extrastellar environment is not required for the presence of a flare, and that the processes at work are therefore similar to those on the Sun.Comment: Nature, Sept. 2 199

    Anti-nausea effects and pharmacokinetics of ondansetron, maropitant and metoclopramide in a low-dose cisplatin model of nausea and vomiting in the dog: a blinded crossover study

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    Nausea is a subjective sensation which is difficult to measure in non-verbal species. The aims of this study were to determine the efficacy of three classes of antiemetic drugs in a novel low dose cisplatin model of nausea and vomiting and measure change in potential nausea biomarkers arginine vasopressin (AVP) and cortisol. A four period cross-over blinded study was conducted in eight healthy beagle dogs of both genders. Dogs were administered 18 mg/m2 cisplatin intravenously, followed 45 min later by a 15 min infusion of either placebo (saline) or antiemetic treatment with ondansetron (0.5 mg/kg; 5-HT3 antagonist), maropitant (1 mg/kg; NK1 antagonist) or metoclopramide (0.5 mg/kg; D2 antagonist). The number of vomits and nausea associated behaviours, scored on a visual analogue scale, were recorded every 15 min for 8 h following cisplatin administration. Plasma samples were collected to measure AVP, cortisol and antiemetic drug concentrations

    Strong Interactions of Single Atoms and Photons near a Dielectric Boundary

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    Modern research in optical physics has achieved quantum control of strong interactions between a single atom and one photon within the setting of cavity quantum electrodynamics (cQED). However, to move beyond current proof-of-principle experiments involving one or two conventional optical cavities to more complex scalable systems that employ N >> 1 microscopic resonators requires the localization of individual atoms on distance scales < 100 nm from a resonator's surface. In this regime an atom can be strongly coupled to a single intracavity photon while at the same time experiencing significant radiative interactions with the dielectric boundaries of the resonator. Here, we report an initial step into this new regime of cQED by way of real-time detection and high-bandwidth feedback to select and monitor single Cesium atoms localized ~100 nm from the surface of a micro-toroidal optical resonator. We employ strong radiative interactions of atom and cavity field to probe atomic motion through the evanescent field of the resonator. Direct temporal and spectral measurements reveal both the significant role of Casimir-Polder attraction and the manifestly quantum nature of the atom-cavity dynamics. Our work sets the stage for trapping atoms near micro- and nano-scopic optical resonators for applications in quantum information science, including the creation of scalable quantum networks composed of many atom-cavity systems that coherently interact via coherent exchanges of single photons.Comment: 8 pages, 5 figures, Supplemental Information included as ancillary fil

    Dimension-Six Terms in the Standard Model Lagrangian

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    When the Standard Model is considered as an effective low-energy theory, higher dimensional interaction terms appear in the Lagrangian. Dimension-six terms have been enumerated in the classical article by Buchmueller and Wyler [3]. Although redundance of some of those operators has been already noted in the literature, no updated complete list has been published to date. Here we perform their classification once again from the outset. Assuming baryon number conservation, we find 15 + 19 + 25 = 59 independent operators (barring flavour structure and Hermitian conjugations), as compared to 16 + 35 + 29 = 80 in Ref.[3]. The three summed numbers refer to operators containing 0, 2 and 4 fermion fields. If the assumption of baryon number conservation is relaxed, 4 new operators arise in the four-fermion sector.Comment: 16 pages, no figures, v3: Redundant B-violating operator remove

    Constraining noncommutative field theories with holography

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    An important window to quantum gravity phenomena in low energy noncommutative (NC) quantum field theories (QFTs) gets represented by a specific form of UV/IR mixing. Yet another important window to quantum gravity, a holography, manifests itself in effective QFTs as a distinct UV/IR connection. In matching these two principles, a useful relationship connecting the UV cutoff ΛUV\Lambda_{\rm UV}, the IR cutoff ΛIR\Lambda_{\rm IR} and the scale of noncommutativity ΛNC\Lambda_{\rm NC}, can be obtained. We show that an effective QFT endowed with both principles may not be capable to fit disparate experimental bounds simultaneously, like the muon g−2g-2 and the masslessness of the photon. Also, the constraints from the muon g−2g-2 preclude any possibility to observe the birefringence of the vacuum coming from objects at cosmological distances. On the other hand, in NC theories without the UV completion, where the perturbative aspect of the theory (obtained by truncating a power series in ΛNC−2 \Lambda_{\rm NC}^{-2}) becomes important, a heuristic estimate of the region where the perturbative expansion is well-defined E/ΛNCâ‰Č1E/ \Lambda_{\rm NC} \lesssim 1, gets affected when holography is applied by providing the energy of the system EE a ΛNC\Lambda_{\rm NC}-dependent lower limit. This may affect models which try to infer the scale ΛNC\Lambda_{\rm NC} by using data from low-energy experiments.Comment: 4 pages, version to be published in JHE
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