2,307 research outputs found
Sub-luminous type Ia supernovae from the mergers of equal-mass white dwarfs with M~0.9 M_sun
Type Ia supernovae (SNe Ia) are thought to result from thermonuclear
explosions of carbon-oxygen white dwarf stars. Existing models generally
explain the observed properties, with the exception of the sub-luminous
1991-bg-like supernovae. It has long been suspected that the merger of two
white dwarfs could give rise to a type Ia event, but hitherto simulations have
failed to produce an explosion. Here we report a simulation of the merger of
two equal-mass white dwarfs that leads to an underluminous explosion, though at
the expense of requiring a single common-envelope phase, and component masses
of ~0.9 M_sun. The light curve is too broad, but the synthesized spectra, red
colour and low expansion velocities are all close to what is observed for
sub-luminous 1991bg-like events. While mass ratios can be slightly less than
one and still produce an underluminous event, the masses have to be in the
range 0.83-0.9 M_sun.Comment: Accepted to Natur
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The impact generated by public and charity-funded research in the UK: A systematic literature review
Objective: To identify, synthesize and critically assess the empirical evidence of the impact generated by public and charity funded health research in the United Kingdom.
Methods: We conducted a systematic literature review of the empirical evidence published in English in peer-reviewed journals between 2006 and 2017. Studies meeting the inclusion criteria were selected and their findings were analysed using the Payback Framework into five main categories: knowledge, benefits to future research and research use, benefits from informing policy and product development, health and health sector benefits and broader economic benefits. We assessed the studies for risk of selection, reporting and funding bias.
Results: Thirteen studies met the inclusion criteria. The majority of the studies (10 out of 13) assessed impact at multiple domains including the main 5 key themes of the Payback Framework. All of them showed a positive impact of funded research on outcomes. Of those studies, one presented low risk of bias (8%), 6 studies were classified as presenting moderate risk of bias (46%) and 6 studies presented high risk of bias (46%).
Conclusions: Empirical evidence on the impact of public and charity funded research is still limited and subject to funding and selection bias. More work is needed to establish the causal effects of funded research on academic outcomes, policy, practice and the broader economy
Major depressive disorder and current psychological distress moderate the effect of polygenic risk for obesity on body mass index
We are grateful to the families who took part in GS:SFHS, the GPs and Scottish School of Primary Care for their help in recruiting them, and the whole GS team, which includes academic researchers, clinic staff, laboratory technicians, clerical workers, IT staff, statisticians and research managers. This work is supported by the Wellcome Trust through a Strategic Award, reference 104036/Z/14/Z. The Chief Scientist Office of the Scottish Government and the Scottish Funding Council provided core support for Generation Scotland. GS:SFHS was funded by a grant from the Scottish Government Health Department, Chief Scientist Office, number CZD/16/6. We acknowledge with gratitude the financial support received for this work from the Dr Mortimer and Theresa Sackler Foundation. PT, DJP, IJD and AMM are members of The University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology, part of the cross council Lifelong Health and Wellbeing Initiative (MR/K026992/1). Funding from the Biotechnology and Biological Sciences Research Council and Medical Research Council is gratefully acknowledged. DJM is an NRS Career Fellow, funded by the CSO. Supplementary Information accompanies the paper on the Translational Psychiatry websitePeer reviewedPublisher PD
A search for the decay modes B+/- to h+/- tau l
We present a search for the lepton flavor violating decay modes B+/- to h+/-
tau l (h= K,pi; l= e,mu) using the BaBar data sample, which corresponds to 472
million BBbar pairs. The search uses events where one B meson is fully
reconstructed in one of several hadronic final states. Using the momenta of the
reconstructed B, h, and l candidates, we are able to fully determine the tau
four-momentum. The resulting tau candidate mass is our main discriminant
against combinatorial background. We see no evidence for B+/- to h+/- tau l
decays and set a 90% confidence level upper limit on each branching fraction at
the level of a few times 10^-5.Comment: 15 pages, 7 figures, submitted to Phys. Rev.
Appropriate disclosure of a diagnosis of dementia : identifying the key behaviours of 'best practice'
Background: Despite growing evidence that many people with dementia want to know their diagnosis, there is wide variation in attitudes of professionals towards disclosure. The disclosure of the diagnosis of dementia is increasingly recognised as being a process rather than a one-off behaviour. However, the different behaviours that contribute to this process have not been comprehensively defined. No intervention studies to improve diagnostic disclosure in dementia have been reported to date. As part of a larger study to develop an intervention to promote appropriate disclosure, we sought to identify important disclosure behaviours and explore whether supplementing a literature review with other methods would result in the identification of new behaviours. Methods: To identify a comprehensive list of behaviours in disclosure we conducted a literature review, interviewed people with dementia and informal carers, and used a consensus process involving health and social care professionals. Content analysis of the full list of behaviours was carried out. Results: Interviews were conducted with four people with dementia and six informal carers. Eight health and social care professionals took part in the consensus panel. From the interviews, consensus panel and literature review 220 behaviours were elicited, with 109 behaviours over-lapping. The interviews and consensus panel elicited 27 behaviours supplementary to the review. Those from the interviews appeared to be self-evident but highlighted deficiencies in current practice and from the panel focused largely on balancing the needs of people with dementia and family members. Behaviours were grouped into eight categories: preparing for disclosure; integrating family members; exploring the patient's perspective; disclosing the diagnosis; responding to patient reactions; focusing on quality of life and well-being; planning for the future; and communicating effectively. Conclusion: This exercise has highlighted the complexity of the process of disclosing a diagnosis of dementia in an appropriate manner. It confirms that many of the behaviours identified in the literature (often based on professional opinion rather than empirical evidence) also resonate with people with dementia and informal carers. The presence of contradictory behaviours emphasises the need to tailor the process of disclosure to individual patients and carers. Our combined methods may be relevant to other efforts to identify and define complex clinical practices for further study.This project is funded by UK Medical Research Council, Grant reference number G0300999
Evidence for an excess of B -> D(*) Tau Nu decays
Based on the full BaBar data sample, we report improved measurements of the
ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B -> D(*) l Nu), where l is either e or
mu. These ratios are sensitive to new physics contributions in the form of a
charged Higgs boson. We measure R(D) = 0.440 +- 0.058 +- 0.042 and R(D*) =
0.332 +- 0.024 +- 0.018, which exceed the Standard Model expectations by 2.0
sigma and 2.7 sigma, respectively. Taken together, our results disagree with
these expectations at the 3.4 sigma level. This excess cannot be explained by a
charged Higgs boson in the type II two-Higgs-doublet model. We also report the
observation of the decay B -> D Tau Nu, with a significance of 6.8 sigma.Comment: Expanded section on systematics, text corrections, improved the
format of Figure 2 and included the effect of the change of the Tau
polarization due to the charged Higg
Measurement of CP-violation asymmetries in D0 to Ks pi+ pi-
We report a measurement of time-integrated CP-violation asymmetries in the
resonant substructure of the three-body decay D0 to Ks pi+ pi- using CDF II
data corresponding to 6.0 invfb of integrated luminosity from Tevatron ppbar
collisions at sqrt(s) = 1.96 TeV. The charm mesons used in this analysis come
from D*+(2010) to D0 pi+ and D*-(2010) to D0bar pi-, where the production
flavor of the charm meson is determined by the charge of the accompanying pion.
We apply a Dalitz-amplitude analysis for the description of the dynamic decay
structure and use two complementary approaches, namely a full Dalitz-plot fit
employing the isobar model for the contributing resonances and a
model-independent bin-by-bin comparison of the D0 and D0bar Dalitz plots. We
find no CP-violation effects and measure an asymmetry of ACP = (-0.05 +- 0.57
(stat) +- 0.54 (syst))% for the overall integrated CP-violation asymmetry,
consistent with the standard model prediction.Comment: 15 page
Type Ia Supernovae as Stellar Endpoints and Cosmological Tools
Empirically, Type Ia supernovae are the most useful, precise, and mature
tools for determining astronomical distances. Acting as calibrated candles they
revealed the presence of dark energy and are being used to measure its
properties. However, the nature of the SN Ia explosion, and the progenitors
involved, have remained elusive, even after seven decades of research. But now
new large surveys are bringing about a paradigm shift --- we can finally
compare samples of hundreds of supernovae to isolate critical variables. As a
result of this, and advances in modeling, breakthroughs in understanding all
aspects of SNe Ia are finally starting to happen.Comment: Invited review for Nature Communications. Final published version.
Shortened, update
Study of the reaction e^{+}e^{-} -->J/psi\pi^{+}\pi^{-} via initial-state radiation at BaBar
We study the process with
initial-state-radiation events produced at the PEP-II asymmetric-energy
collider. The data were recorded with the BaBar detector at center-of-mass
energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454
. We investigate the mass
distribution in the region from 3.5 to 5.5 . Below 3.7
the signal dominates, and above 4
there is a significant peak due to the Y(4260). A fit to
the data in the range 3.74 -- 5.50 yields a mass value
(stat) (syst) and a width value (stat)(syst) for this state. We do not
confirm the report from the Belle collaboration of a broad structure at 4.01
. In addition, we investigate the system
which results from Y(4260) decay
Evaluation of a minimally invasive glucose biosensor for continuous tissue monitoring
We describe here a minimally invasive glucose biosensor based on a microneedle array electrode fabricated from an epoxy-based negative photoresist (SU8 50) and designed for continuous measurement in the dermal compartment with minimal pain. These minimally invasive, continuous monitoring sensor devices (MICoMS) were produced by casting the structures in SU8 50, crosslinking and then metallising them with platinum or silver to obtain the working and reference electrodes, respectively. The metallised microneedle array electrodes were subsequently functionalised by entrapping glucose oxidase in electropolymerised polyphenol (PP) film. Sensor performance in vitro showed that glucose concentrations down to 0.5 mM could be measured with a response times (T90) of 15 s. The effect of sterilisation by Co60 irradiation was evaluated. In preparation for further clinical studies, these sensors were tested in vivo in a healthy volunteer for a period of 3–6 h. The sensor currents were compared against point measurements obtained with a commercial capillary blood glucometer. The epoxy MICoMS devices showed currents values that could be correlated with these
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