3,278 research outputs found
Characterisation of the MuSIC muon beam and design of the Eu-XFEL LPD/CCC interface firmware
As it is now known that neutrinos oscillate, this entails that lepton number is not a conserved quantity and required modification of the Standard Model. The same mechanism also allows charged leptons to violate lepton number, but at an immeasurable rate. Therefore any observation of e.g. a muon decaying to an electron in the absence of neutrinos would be a signal of physics beyond the Standard Model. A test facility, but also an experiment capable of searching for such a kinematic effect has been set-up in Osaka, Japan. The thesis ‘Initial Measurements at the MuSIC Beam-Line’ documents several exper- iments that were carried out using the MuSIC muon beam in Osaka. The experiments focused on understanding the beam and characterising it. Three main measurements were made: total charged particle flux, muon flux and muon momentum spectrum. Each experiment used plastic scintillators and MPPCs to detect the charged particles. Muons were identified by looking for muon decays between two scintillators. Data acquisition was performed using NIM for signal shaping and logic; and CAMAC or VME for readout via TDC and ADC modules. In addition to direct experimental measurements, a simulation of MuSIC was made using the ‘G4Beamline’ and ‘Geant4’ packages which allowed detailed interrogation of the exper- iment to aid understanding of the results. It also provided a test bed upon which to refine the setup for later measurements. These measurements allow us to confirm the performance of the novel pion capture solenoid which is an integral part of several future experiments (primarily COMET but also proposed neutrino factories). In addition to this core work, the thesis deals with my services writing firmware for the LPD detector being built for the XFEL project in Hamburg, Germany. The firmware is an interface between the generic clock and control card (being developed at UCL) and the custom ASIC (being developed at RAL). The interface was written using VHDL and receives, translates, interprets then transmits control instructions to the detector
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Comparisons of host mitochondrial, nuclear and endosymbiont bacterial genes reveal cryptic fig wasp species and the effects of Wolbachia on host mtDNA evolution and diversity
Background
Figs and fig-pollinating wasp species usually display a highly specific one-to-one association. However, more and more studies have revealed that the "one-to-one" rule has been broken. Co-pollinators have been reported, but we do not yet know how they evolve. They may evolve from insect speciation induced or facilitated by Wolbachia which can manipulate host reproduction and induce reproductive isolation. In addition, Wolbachia can affect host mitochondrial DNA evolution, because of the linkage between Wolbachia and associated mitochondrial haplotypes, and thus confound host phylogeny based on mtDNA. Previous research has shown that fig wasps have the highest incidence of Wolbachia infection in all insect taxa, and Wolbachia may have great influence on fig wasp biology. Therefore, we look forward to understanding the influence of Wolbachia on mitochondrial DNA evolution and speciation in fig wasps.
Results
We surveyed 76 pollinator wasp specimens from nine Ficus microcarpa trees each growing at a different location in Hainan and Fujian Provinces, China. We found that all wasps were morphologically identified as Eupristina verticillata, but diverged into three clades with 4.22-5.28% mtDNA divergence and 2.29-20.72% nuclear gene divergence. We also found very strong concordance between E. verticillata clades and Wolbachia infection status, and the predicted effects of Wolbachia on both mtDNA diversity and evolution by decreasing mitochondrial haplotypes.
Conclusions
Our study reveals that the pollinating wasp E. verticillata on F. microcarpa has diverged into three cryptic species, and Wolbachia may have a role in this divergence. The results also indicate that Wolbachia strains infecting E. verticillata have likely resulted in selective sweeps on host mitochondrial DNA
A web-based simulation of a longitudinal clinic used in a 4-week ambulatory rotation: a cohort study
<p>Abstract</p> <p>Background</p> <p>Residency training takes place primarily on inpatient wards. In the absence of a resident continuity clinic, internal medicine residents rely on block rotations to learn about continuity of care. Alternate methods to introduce continuity of care are needed.</p> <p>Methods</p> <p>A web-based tool, Continuity of Care Online Simulations (COCOS), was designed for use in a one-month, postgraduate clinical rotation in endocrinology. It is an interactive tool that simulates the continuing care of any patient with a chronic endocrine disease. Twenty-three residents in internal medicine participated in a study to investigate the effects of using COCOS during a clinical rotation in endocrinology on pre-post knowledge test scores and self-assessment of confidence.</p> <p>Results</p> <p>Compared to residents who did the rotation alone, residents who used COCOS during the rotation had significantly higher improvements in test scores (% increase in pre-post test scores +21.6 [standard deviation, SD, 8.0] vs. +5.9 [SD 6.8]; p < .001). Test score improvements were most pronounced for less commonly seen conditions. There were no significant differences in changes in confidence. Residents rated COCOS very highly, recommending its use as a standard part of the rotation and throughout residency.</p> <p>Conclusion</p> <p>A stand-alone web-based tool can be incorporated into an existing clinical rotation to help residents learn about continuity of care. It has the most potential to teach residents about topics that are less commonly seen during a clinical rotation. The adaptable, web-based format allows the creation of cases for most chronic medical conditions.</p
NKX2-5 regulates vessel remodelling in scleroderma-associated pulmonary arterial hypertension.
NKX2-5 is a member of the homeobox-containing transcription factors critical in regulating tissue differentiation in development. Here, we report a role for NKX2-5 in vascular smooth muscle cell phenotypic modulation in vitro and in vascular remodelling in vivo. NKX2-5 is up-regulated in scleroderma (SSc) patients with pulmonary arterial hypertension. Suppression of NKX2-5 expression in smooth muscle cells, halted vascular smooth muscle proliferation and migration, enhanced contractility and blocked the expression of the extracellular matrix genes. Conversely, overexpression of NKX2-5 suppressed the expression of contractile genes (ACTA2, TAGLN, CNN1) and enhanced the expression of matrix genes (COL1) in vascular smooth muscle cells. In vivo, conditional deletion of NKX2-5 attenuated blood vessel remodelling and halted the progression to hypertension in the mouse chronic hypoxia mouse model. This study revealed that signals related to injury such as serum and low confluence, which induce NKX2-5 expression in cultured cells, is potentiated by TGFβ and further enhanced by hypoxia. The effect of TGFβ was sensitive to ERK5 and PI3K inhibition. Our data suggest a pivotal role for NKX2-5 in the phenotypic modulation of smooth muscle cells during pathological vascular remodelling and provide proof of concept for therapeutic targeting of NKX2-5 in vasculopathies
A multidisciplinary investigation into the talent development processes at an English football academy: a machine learning approach
This is the final version. Available on open access from MDPI via the DOI in this record. Data Availability Statement: Data can be obtained via the lead authorThe talent development processes in youth football are both complex and multidimensional.
The purpose of this two-fold study was to apply a multidisciplinary, machine learning approach
to examine: (a) the developmental characteristics of under-9 to under-16 academy players (n = 98;
Study 1), and (b) the characteristics of selected and deselected under-18 academy players (n = 18;
Study 2). A combined total of 53 factors cumulated from eight data collection methods across two
seasons were analysed. A cross-validated Lasso regression was implemented, using the glmnet
package in R, to analyse the factors that contributed to: (a) player review ratings (Study 1), and
(b) achieving a professional contract (Study 2). Results showed non-zero coefficients for improvement
in subjective performance in 15 out of the 53 analysed features, with key findings revealing advanced
percentage of predicted adult height (0.196), greater lob pass (0.160) and average dribble completion
percentage (0.124), more total match-play hours (0.145), and an older relative age (BQ1 vs. BQ2:
0.133; BQ1 vs. BQ4: 0.060) were the most important features that contributed towards player
review ratings. Moreover, PCDEQ Factor 3 and an ability to organise and engage in quality practice
(PCDEQ Factor 4) were important contributing factors towards achieving a professional contract.
Overall, it appears the key factors associated with positive developmental outcomes are not always
technical and tactical in nature, where coaches often have their expertise. Indeed, the relative
importance of these factors is likely to change over time, and with age, although psychological
attributes appear to be key to reaching potential across the academy journey. The methodological
techniques used here also serve as an impetus for researchers to adopt a machine learning approach
when analysing multidimensional databases.Exeter City Football ClubUniversity of Exete
Internet-based medical education: a realist review of what works, for whom and in what circumstances
http://creativecommons.org/licenses/by/2.0
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Risk measures for direct real estate investments with non-normal or unknown return distributions
The volatility of returns is probably the most widely used risk measure for real estate. This is rather surprising since a number of studies have cast doubts on the view that volatility can capture the manifold risks attached to properties and corresponds to the risk attitude of investors. A central issue in this discussion is the statistical properties of real estate returns—in contrast to neoclassical capital market theory they are mostly non-normal and often unknown, which render many statistical measures useless. Based on a literature review and an analysis of data from Germany we provide evidence that volatility alone is inappropriate for measuring the risk of direct real estate.
We use a unique data sample by IPD, which includes the total returns of 939 properties across different usage types (56% office, 20% retail, 8% others and 16% residential properties) from 1996 to 2009, the German IPD Index, and the German Property Index. The analysis of the distributional characteristics shows that German real estate returns in this period were not normally distributed and that a logistic distribution would have been a better fit. This is in line with most of the current literature on this subject and leads to the question which indicators are more appropriate to measure real estate risks. We suggest that a combination of quantitative and qualitative risk measures more adequately captures real estate risks and conforms better with investor attitudes to risk. Furthermore, we present criteria for the purpose of risk classification
Limited effect of patient and disease characteristics on compliance with hospital antimicrobial guidelines
Objective: Physicians frequently deviate from guidelines that promote prudent use of antimicrobials. We explored to what extent patient and disease characteristics were associated with compliance with guideline recommendations for three common infections. Methods: In a 1-year prospective observational study, 1,125 antimicrobial prescriptions were analysed for compliance with university hospital guidelines. Results: Compliance varied significantly between and within the groups of infections studied. Compliance was much higher for lower respiratory tract infections (LRTIs; 79%) than for sepsis (53%) and urinary tract infections (UTIs; 40%). Only predisposing illnesses and active malignancies were associated with more compliant prescribing, whereas alcohol/ intravenous drug abuse and serum creatinine levels > 130 mu mol/l were associated with less compliant prescribing. Availability of culture results had no impact on compliance with guidelines for sepsis but was associated with more compliance in UTIs and less in LRTIs. Narrowing initial broad-spectrum antimicrobial therapy to cultured pathogens was seldom practised. Most noncompliant prescribing concerned a too broad spectrum of activity when compared with guideline-recommended therapy. Conclusion: Patient characteristics had only a limited impact on compliant prescribing for a variety of reasons. Physicians seemed to practise defensive prescribing behaviour, favouring treatment success in current patients over loss of effectiveness due to resistance in future patients
Spectral determination of the colour and vertical structure of dark spots in Neptune’s atmosphere
Previous observations of dark vortices in Neptune’s atmosphere, such as Voyager 2’s Great Dark Spot (1989), have been made in only a few broad-wavelength channels, hampering efforts to determine these vortices’ pressure levels and darkening processes. We analyse spectroscopic observations of a dark spot on Neptune identified by the Hubble Space Telescope as NDS-2018; the spectral observations were made in 2019 by the Multi Unit Spectroscopic Explorer (MUSE) of the Very Large Telescope (Chile). The MUSE medium-resolution 475–933 nm reflection spectra allow us to show that dark spots are caused by darkening at short wavelengths (700 nm). This bright feature is much deeper than previously studied dark-spot companion clouds and may be connected with the circulation that generates and sustains such spots
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