146 research outputs found
Molecular epidemiology of Streptococcus uberis clinical mastitis in dairy herds: strain heterogeneity and transmission
Multi Locus Sequence Typing was successfully completed on 494 isolates of S. uberis from clinical mastitis cases in a study of 52 commercial dairy herds over a 12 month period. In total, 195 sequence types (STs) were identified. S. uberis mastitis cases occurring in different cows within the same herd and attributed to a common ST were classified as 'potential transmission events' (PTE). Clinical cases attributed to 35 of the 195 STs identified in this study were classified PTE. PTE were identified in 63% of herds. PTE associated cases, which include the first recorded occurrence of that ST in that herd (Index case) and all persistent infections with that PTE ST represented 40% of all the clinical mastitis cases and occurred in 63% of herds. PTE associated cases accounted for over 50% of all S. uberis clinical mastitis cases in 33% of herds. Nine sequence types (ST 5, 6, 20, 22, 24, 35, 233, 361, and 512), eight of which grouped within a clonal complex (sharing at least four alleles), were statistically overrepresented (OVR STs). The findings indicate that 38% of all clinical mastitis cases and 63% of the potential transmission events attributed to S. uberis in dairy herds may be caused by the nine most prevalent strains. The findings suggest that to a small subset of sequence types are disproportionally important in the epidemiology of S. uberis mastitis in the UK with cow to cow transmission of S. uberis potentially occurring in the majority of UK herds and may be the most important route of infection in many herds
Quantum saturation and condensation of excitons in CuO: a theoretical study
Recent experiments on high density excitons in CuO provide evidence for
degenerate quantum statistics and Bose-Einstein condensation of this nearly
ideal gas. We model the time dependence of this bosonic system including
exciton decay mechanisms, energy exchange with phonons, and interconversion
between ortho (triplet-state) and para (singlet-state) excitons, using
parameters for the excitonic decay, the coupling to acoustic and low-lying
optical phonons, Auger recombination, and ortho-para interconversion derived
from experiment. The single adjustable parameter in our model is the
optical-phonon cooling rate for Auger and laser-produced hot excitons. We show
that the orthoexcitons move along the phase boundary without crossing it (i.e.,
exhibit a ``quantum saturation''), as a consequence of the balance of entropy
changes due to cooling of excitons by phonons and heating by the non-radiative
Auger two-exciton recombination process. The Auger annihilation rate for
para-para collisions is much smaller than that for ortho-para and ortho-ortho
collisions, explaining why, under the given experimental conditions, the
paraexcitons condense while the orthoexcitons fail to do so.Comment: Revised to improve clarity and physical content 18 pages, revtex,
figures available from G. Kavoulakis, Physics Department, University of
Illinois, Urban
Atomic diffraction from nanostructured optical potentials
We develop a versatile theoretical approach to the study of cold-atom
diffractive scattering from light-field gratings by combining calculations of
the optical near-field, generated by evanescent waves close to the surface of
periodic nanostructured arrays, together with advanced atom wavepacket
propagation on this optical potential.Comment: 8 figures, 10 pages, submitted to Phys. Rev.
A century of sea level measurements at Newlyn, SW England
The Newlyn Tidal Observatory is the most important sea level station in the UK. It commenced operations in 1915 as part of the Second Geodetic Levelling of England and Wales, and the mean sea level determined from the tide gauge during the first six years (May 1915-April 1921) defined Ordnance Datum Newlyn (ODN) which became the national height datum for the whole of Great Britain. The 100 years of sea level data now available have contributed significantly to many studies in oceanography, geology and climate change. This paper marks the centenary of this important station by reviewing the sea level (and, more recently, detailed land level) measurements and Newlyn’s contributions to UK cartography, geodesy and sea-level science in general. Recommendations are made on how sea and land level measurements at Newlyn might be
enhanced in the future
Predictors of 1-year compliance with adaptive servoventilation in patients with heart failure and sleep disordered breathing: preliminary data from the ADVENT-HF trial
Despite its effectiveness in suppressing sleep disordered breathing (SDB), positive airway pressure therapy (PAP) is not always well tolerated by patients and long-term adherence can be problematic. Recently, two multicentre, randomised clinical trials (RCTs) tested the effects of PAP for patients with cardiovascular disease and co-existing SDB on morbidity and mortality with negative outcomes [1, 2]. Relatively poor adherence to PAP therapy (mean 3.7 and 3.3 h·day-1, respectively) in these two trials might have contributed to their poor results. Indeed, higher PAP use per day is associated with better clinical outcomes than lower use [3]
Dust Devil Sediment Transport: From Lab to Field to Global Impact
The impact of dust aerosols on the climate and environment of Earth and Mars is complex and forms a major area of research. A difficulty arises in estimating the contribution of small-scale dust devils to the total dust aerosol. This difficulty is due to uncertainties in the amount of dust lifted by individual dust devils, the frequency of dust devil occurrence, and the lack of statistical generality of individual experiments and observations. In this paper, we review results of observational, laboratory, and modeling studies and provide an overview of dust devil dust transport on various spatio-temporal scales as obtained with the different research approaches. Methods used for the investigation of dust devils on Earth and Mars vary. For example, while the use of imagery for the investigation of dust devil occurrence frequency is common practice for Mars, this is less so the case for Earth. Modeling approaches for Earth and Mars are similar in that they are based on the same underlying theory, but they are applied in different ways. Insights into the benefits and limitations of each approach suggest potential future research focuses, which can further reduce the uncertainty associated with dust devil dust entrainment. The potential impacts of dust devils on the climates of Earth and Mars are discussed on the basis of the presented research results
A novel formulation of inhaled sodium cromoglicate (PA101) in idiopathic pulmonary fibrosis and chronic cough: a randomised, double-blind, proof-of-concept, phase 2 trial
Background Cough can be a debilitating symptom of idiopathic pulmonary fibrosis (IPF) and is difficult to treat. PA101 is a novel formulation of sodium cromoglicate delivered via a high-efficiency eFlow nebuliser that achieves significantly higher drug deposition in the lung compared with the existing formulations. We aimed to test the efficacy and safety of inhaled PA101 in patients with IPF and chronic cough and, to explore the antitussive mechanism of PA101, patients with chronic idiopathic cough (CIC) were also studied. Methods This pilot, proof-of-concept study consisted of a randomised, double-blind, placebo-controlled trial in patients with IPF and chronic cough and a parallel study of similar design in patients with CIC. Participants with IPF and chronic cough recruited from seven centres in the UK and the Netherlands were randomly assigned (1:1, using a computer-generated randomisation schedule) by site staff to receive PA101 (40 mg) or matching placebo three times a day via oral inhalation for 2 weeks, followed by a 2 week washout, and then crossed over to the other arm. Study participants, investigators, study staff, and the sponsor were masked to group assignment until all participants had completed the study. The primary efficacy endpoint was change from baseline in objective daytime cough frequency (from 24 h acoustic recording, Leicester Cough Monitor). The primary efficacy analysis included all participants who received at least one dose of study drug and had at least one post-baseline efficacy measurement. Safety analysis included all those who took at least one dose of study drug. In the second cohort, participants with CIC were randomly assigned in a study across four centres with similar design and endpoints. The study was registered with ClinicalTrials.gov (NCT02412020) and the EU Clinical Trials Register (EudraCT Number 2014-004025-40) and both cohorts are closed to new participants. Findings Between Feb 13, 2015, and Feb 2, 2016, 24 participants with IPF were randomly assigned to treatment groups. 28 participants with CIC were enrolled during the same period and 27 received study treatment. In patients with IPF, PA101 reduced daytime cough frequency by 31·1% at day 14 compared with placebo; daytime cough frequency decreased from a mean 55 (SD 55) coughs per h at baseline to 39 (29) coughs per h at day 14 following treatment with PA101, versus 51 (37) coughs per h at baseline to 52 (40) cough per h following placebo treatment (ratio of least-squares [LS] means 0·67, 95% CI 0·48–0·94, p=0·0241). By contrast, no treatment benefit for PA101 was observed in the CIC cohort; mean reduction of daytime cough frequency at day 14 for PA101 adjusted for placebo was 6·2% (ratio of LS means 1·27, 0·78–2·06, p=0·31). PA101 was well tolerated in both cohorts. The incidence of adverse events was similar between PA101 and placebo treatments, most adverse events were mild in severity, and no severe adverse events or serious adverse events were reported. Interpretation This study suggests that the mechanism of cough in IPF might be disease specific. Inhaled PA101 could be a treatment option for chronic cough in patients with IPF and warrants further investigation
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