3,510 research outputs found
Disease associated with equine coronavirus infection and high case fatality rate.
BackgroundEquine coronavirus (ECoV) is associated with clinical disease in adult horses. Outbreaks are associated with a low case fatality rate and a small number of animals with signs of encephalopathic disease are described.ObjectivesThe aim of this study is to describe the epidemiological and clinical features of two outbreaks of ECoV infection that were associated with an high case fatality rate.Animals14 miniature horses and 1 miniature donkey testing fecal positive for ECoV from two related disease outbreaks.MethodsRetrospective study describing the epidemiological findings, clinicopathological findings, and fecal viral load from affected horses.ResultsIn EcoV positive horses, 27% (4/15) of the animals died or were euthanized. Severe hyperammonemia (677 μmol/L, reference range ≤ 60 μmol/L) was identified in one animal with signs of encephalopathic disease that subsequently died. Fecal viral load (ECoV genome equivalents per gram of feces) was significantly higher in the nonsurvivors compared to animals that survived (P = .02).Conclusions and clinical importanceEquine coronavirus had a higher case fatality rate in this group of miniature horses than previously reported in other outbreaks of varying breeds. Hyperammonemia could contribute to signs of encephalopathic disease, and the fecal viral load might be of prognostic value in affected horses
All-Optical Control of the Silicon-Vacancy Spin in Diamond at Millikelvin Temperatures.
The silicon-vacancy center in diamond offers attractive opportunities in quantum photonics due to its favorable optical properties and optically addressable electronic spin. Here, we combine both to achieve all-optical coherent control of its spin states. We utilize this method to explore spin dephasing effects in an impurity-rich sample beyond the limit of phonon-induced decoherence: Employing Ramsey and Hahn-echo techniques at temperatures down to 40 mK we identify resonant coupling to a substitutional nitrogen spin bath as limiting decoherence source for the electron spin.This research has been partially funded by the European Community’s Seventh Framework Programme (FP7/2007-2013) under Grant agreement No. 611143 (DIADEMS). M. A. gratefully acknowledges financial support by the European Research Council ERC Consolidator Grant Agreement No. 617985 and the EPSRC National Quantum Technologies Programme NQIT EP/M013243/1. B. P. thanks Wolfson College (University of Cambridge) for financial support. P. B. gratefully acknowledges financial support by the Deutsche Forschungsgemeinschaft (Grants No. BU2510/2-1, No. INST256/415-1)
Electronic and Structural Properties of a 4d-Perovskite: Cubic Phase of SrZrO
First-principles density functional calculations are performed within the
local density approximation to study the electronic properties of SrZrO, an
insulating 4d-perovskite, in its high-temperature cubic phase, above 1400 K, as
well as the generic 3d-perovskite SrTiO, which is also a d^0-insulator and
cubic above 105 K, for comparison reasons. The energy bands, density of states
and charge density distributions are obtained and a detailed comparison between
their band structures is presented. The results are discussed also in terms of
the existing data in the literature for both oxides.Comment: 5 pages, 2 figure
The electron accelerator for the AWAKE experiment at CERN
The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long proton bunch extracted from the SPS interacts with a high power laser and a 10 m long rubidium vapour plasma cell to create strong wakefields allowing sustained electron acceleration. The electron bunch to probe these wakefields is supplied by a 20 MeV electron accelerator. The electron accelerator consists of an RF-gun and a short booster structure. This electron source should provide beams with intensities between 0.1 and 1 nC, bunch lengths between 0.3 and 3 ps and an emittance of the order of 2 mm mrad. The wide range of parameters should cope with the uncertainties and future prospects of the planned experiments. The layout of the electron accelerator, its instrumentation and beam dynamics simulations are presented
The effect of fermentation process on bioactive properties, essential oil composition and phenolic constituents of raw fresh and fermented sea fennel (Crithmum maritimum L.) leaves
800-804The influence of fermentation on antioxidant activity, total phenol, total flavonoid and phenolic compounds of sea fennel and also volatile compounds of sea fennel essential oil was investigated and compared with fresh samples. Antioxidant activity, total fenolic and flavonoid contents decresed from 89.79 to 63.13%; from 259.58 to 77.92 mg/100 g; from 2114.67 to 390.50 mg/100 g, respectively. Twenty-six and thirty-three components of sea fennel oils were identified in raw and fermented sea fennel, accounting to about 99.99% and 99.44% of the total oil, respectively. The raw and fermented sea fennel leaves contained 22.31 and 1.32% sabinene, 12.08% and 7.45% limonene, 10.30% and 11.61% β-phellandrene, 8.59% and 9.17% (Z)-β-ocimene, 7.08% and 3.55% α-pinene, 28.36% and 42.05% γ-terpinene, 2.57% and 8.64% terpinene-4-ol, respectively. Dominant phenolic compounds were (+)-catechin, gallic acid, 3,4-dihydroxybenzoic acid and p-coumaric acid. Generally, all of the phenolic compounds reduced the effect of microorganisms during,. However, essential oil contents of sea fennel were not effected from fermentation process
Evaluation of virulence factors in enterococcus species
Enterococci have recently become important due to their increased isolation rates in community-based and nosocomial infections and resistance to many antibiotics, including glycopeptides. The aim of this study was to evaluate the antimicrobial susceptible patterns and virulence factors of various clinical specimens; urine (n= 149), blood (n= 38), wound (n= 17), stool (n= 13), and other (n= 12) with a total of 229 enterococci including 138 E. faecalis and 91 E. faecium isolates. Aggregation factor (AF), enterococcus surface protein (esp), cytolysins and gelatinase encoding genes (asa1, esp, cylM, cylBcyl A, cylll, cylls, gelE, respectively) were investigated by molecular methods. Haemolysin production and gelatinase were studied phenotypically. A total of 30 isolates, 29 of E. faecium and one of E. faecalis isolates were resistant to vancomycin. High-level gentamicin and high-level streptomycin resistance in E. faecalis were 40.7% and 63.7% however, they were 47.1% and 55.8% in E. faecalis isolates. All strains were susceptible to linezolid. Ampicillin, penicillin and vancomycin resistance in E. faecium isolates were found to be higher than E. faecalis isolates (p= 0.001, p= 0.008 and p< 0.001). Asa1 (p< 0.001), cylll (p= 0.002) and cylls (p< 0.001) as well as gelatinase activity in isolates of E. faecalis were significantly higher than the isolates of E. faecium (p< 0.001). The most common virulence genes in our study were asa1 gene (45%), cyLs gene (33.2%) and esp gene (32.3%). Ciprofloxacin resistance in cylLL and cyLs gene positive isolates of E. faecalis were significantly higher compared to isolates that do not contain these genes (p= 0.035 and p= 0.047). Likewise, haemolysin producing E. faecium isolates were significantly more resistant to vancomycin compared to isolates that do not produce hemolysin (p< 0.001). When the virulence factors of vancomycin resistant and susceptible isolates were compared, the esp gene level in VRE E. faecium isolates was found to be 24.1%, while no esp gene was found in VRE E. faecalis isolates. The existence of asa1was negative in both VRE E. faecium and VRE E. faecalis isolates. The activity of hemolysin was found 42.3% for E. faecalis and 19.3% for E. faecium. In vancomycin-sensitive enterococcus (VSE) species, esp gene activity was 35.1% for E. faecalis, 29.4% for E. faecium, asa1 gene activity was 60.8% for E. faecalis and 47.1% for E. faecium, hemolysin activity was 52.8% for E. faecalis and 23.5% for E. faecium. In our study, it was found that VSE isolates have more virulence genes than VRE isolates. It should be kept in mind that VRE can causeinfections which are difficult-to-treat especially in hospitalized patients and VSE have significant virulence factors that can cause severe infections
On-demand semiconductor single-photon source with near-unity indistinguishability
Single photon sources based on semiconductor quantum dots offer distinct
advantages for quantum information, including a scalable solid-state platform,
ultrabrightness, and interconnectivity with matter qubits. A key prerequisite
for their use in optical quantum computing and solid-state networks is a high
level of efficiency and indistinguishability. Pulsed resonance fluorescence
(RF) has been anticipated as the optimum condition for the deterministic
generation of high-quality photons with vanishing effects of dephasing. Here,
we generate pulsed RF single photons on demand from a single,
microcavity-embedded quantum dot under s-shell excitation with 3-ps laser
pulses. The pi-pulse excited RF photons have less than 0.3% background
contributions and a vanishing two-photon emission probability.
Non-postselective Hong-Ou-Mandel interference between two successively emitted
photons is observed with a visibility of 0.97(2), comparable to trapped atoms
and ions. Two single photons are further used to implement a high-fidelity
quantum controlled-NOT gate.Comment: 11 pages, 11 figure
First Results from Commissioning of the Phin Photo Injector for CTF3
Installation of the new photo-injector for the CTF3 drive beam (PHIN) has been completed on a stand-alone test bench. The photo-injector operates with a 2.5 cell RF gun at 3 GHz, using a Cs2Te photocathode illuminated by a UV laser beam. The test bench is equipped with transverse beam diagnostic as well as a 90-degree spectrometer. A grid of 100 micrometer wide slits can be inserted for emittance measurements. The laser used to trigger the photo-emission process is a Nd:YLF system consisting of an oscillator and a preamplifier operating at 1.5 GHz and two powerful amplifier stages. The infrared radiation produced is frequency quadrupled in two stages to obtain the UV. A Pockels cell allows adjusting the length of the pulse train between 50 nanoseconds and 50 microseconds. The nominal train length for CTF3 is 1.272 microseconds (1908 bunches). The first electron beam in PHIN was produced in November 2008. In this paper, results concerning the operation of the laser system and measurements performed to characterize the electron beam are presented
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