8,844 research outputs found
A Snapshot of J. L. Synge
A brief description is given of the life and influence on relativity theory
of Professor J. L. Synge accompanied by some technical examples to illustrate
his style of work
Do Time Trade-off values fully capture attitudes that are relevant to health related choices?
Previous research has shown that demographics, beliefs and self-reported own health influence TTO values. Our hypothesis is that attitudes towards length and quality of life influence TTO values, but should no longer affect a set of related choices that are based on respondentsâ own TTO scores. A representative sample of 1339 respondents was asked their level of agreement to four statements relating to the importance of quality and length of life. Respondents then went on to value 4 EQ-5D 5L states using an online interactive survey and a related set of 6 pairwise health related choice questions, set up so that respondents should be indifferent between choice options. We explored the impact of attitudes using regression analysis for TTO values and a logit model for choices. TTO values were correlated with the attitudes and were found to have a residual impact on the choices. In particular, those respondents who preferred quality of life over length of life gave less weight to the differences in years and more weight to differences in quality of life in these choice. We conclude that although the TTO responses reflect attitudes, these attitudes continue to affect health related choices
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On Automorphisms and Focal Subgroups of Blocks
Given a p-block B of a finite group with defect group P and fusion system on P, we show that the rank of the group is invariant under stable equivalences of Morita type. The main ingredients are the construction, due to BrouĂ© and Puig, a theorem of Weiss on linear source modules, arguments of Hertweck and Kimmerle applying Weissâ theorem to blocks, and connections with integrable derivations in the Hochschild cohomology of block algebras
A Review of Drive Cycles for Electrochemical Propulsion
Automotive drive cycles have existed since the 1960s. They started as requirements as being solely used for emissions testing. During the past decade, they became popular with scientists and researchers in the testing of electrochemical vehicles and power devices. They help simulate realistic driving scenarios anywhere from system to component-level design. This paper aims to discuss the complete history of these drive cycles and their validity when used in an electrochemical propulsion scenario, namely with the use of proton exchange membrane fuel cells (PEMFC) and lithium-ion batteries. The differences between two categories of drive cycles, modal and transient, were compared; and further discussion was provided on why electrochemical vehicles need to be designed and engineered with transient drive cycles instead of modal. Road-going passenger vehicles are the main focus of this piece. Similarities and differences between aviation and marine drive cycles are briefly mentioned and compared and contrasted with road cycles. The construction of drive cycles and how they can be transformed into a âpower cycleâ for electrochemical device sizing purposes for electrochemical vehicles are outlined; in addition, how one can use power cycles to size electrochemical vehicles of various vehicle architectures are suggested, with detailed explanations and comparisons of these architectures. A concern with using conventional drive cycles for electrochemical vehicles is that these types of vehicles behave differently compared to combustion-powered vehicles, due to the use of electrical motors rather than internal combustion engines, causing different vehicle behaviours and dynamics. The challenges, concerns, and validity of utilising âgeneral useâ drive cycles for electrochemical purposes are discussed and critiqued
Vigorous star formation hidden by dust in a galaxy at
Near-infrared surveys have revealed a substantial population of enigmatic
faint galaxies with extremely red optical-to-near-infrared colours and with a
sky surface density comparable to that of faint quasars. There are two
scenarios for these extreme colours: (i) these distant galaxies have formed
virtually all their stars at very high redshifts and, due to the absence of
recently formed stars, the colours are extremely red and (ii) these distant
galaxies contain large amounts of dust, severely reddening the rest-frame
UV--optical spectrum. HR10 () is considered the archetype of the
extremely red galaxies. Here we report the detection of the continuum emission
from HR10 at 850m and at 1250m, demonstrating that HR10 is a very
dusty galaxy undergoing a major episode of star formation. Our result provides
a clear example of a high-redshift galaxy where the star formation rate
inferred from the ultraviolet luminosity would be underestimated by a factor up
to 1000, and shows that great caution should be used to infer the global star
formation history of the Universe from optical observations only.Comment: 12 pages, 1 figure, Nature, in press (30 April 1998
Lithium-sulfur battery diagnostics through distribution of relaxation times analysis
Electrochemical impedance spectroscopy (EIS) is widely used in battery analysis as it is simple to implement and non-destructive. However, the data provided is a global representation of all electrochemical processes within the cell and much useful information is ambiguous or inaccessible when using traditional analysis techniques. This is a major challenge when EIS is used to analyse systems with complex cell chemistries, like lithium-sulfur (Li-S), one of the strongest candidates to supersede conventional Li-ion batteries. Here we demonstrate the application of distribution of relaxation times (DRT) analysis for quantitative deconvolution of EIS spectra from Li-S batteries, revealing the contributions of (eight) distinct electrode processes to the total cell polarisation. The DRT profile is shown to be strongly dependent on cell state-of-charge, offering a route to automated and on-board analysis of Li-S cells
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Audio Cartography: Visual Encoding of Acoustic Parameters
Our sonic environment is the matter of subject in multiple domains which developed individual means of its description. As a result, it lacks an established visual language through which knowledge can be connected and insights shared. We provide a visual communication framework for the systematic and coherent documentation of sound in large-scale environments. This consists of visual encodings and mappings of acoustic parameters into distinct graphic variables that present plausible solutions for the visualization of sound. These candidate encodings are assembled into an application-independent, multifunctional, and extensible design guide. We apply the guidelines and show example maps that acts as a basis for the exploration of audio cartography
Use of endovascular embolization to treat a ruptured arteriovenous malformation in a pregnant woman: a case report
<p>Abstract</p> <p>Introduction</p> <p>Pregnancy has been linked to increased rates of arteriovenous malformation rupture. This link remains a matter of debate and very few studies have addressed the management of arteriovenous malformation in pregnancy. Unruptured arteriovenous malformations in pregnant woman generally warrant conservative management due to the low rupture risk. When pregnant women present with ruptured arteriovenous malformation, however, surgery is often indicated due to the increased risk of re-rupture and associated mortality. Endovascular embolization is widely accepted as an important component of contemporary, multimodal therapy for arteriovenous malformations. Although rarely curative, embolization can facilitate subsequent surgical resection or radiosurgery. No previous reports have been devoted to the endovascular management of an arteriovenous malformation in a pregnant woman.</p> <p>Case presentation</p> <p>A 23-year-old Caucasian woman presented with headache and visual disturbance after the rupture of a left parieto-occipital arteriovenous malformation in the 22nd week of her pregnancy. After involving high-risk obstetric consultants and taking precautions to shield the fetus from ionizing radiation, we proceeded with a single stage of endovascular embolization followed soon after by open surgical resection of the arteriovenous malformation. There were several goals for the angiography in this patient: to better understand the anatomy of the arteriovenous malformation, including the number and orientation of feeding arteries and draining veins; to look for associated pre-nidal or intra-nidal aneurysms; and to partially embolize the arteriovenous malformation via safely-accessible feeders to facilitate surgical resection and minimize blood loss and operative morbidity.</p> <p>Conclusion</p> <p>From our experience and review of the literature, we maintain that ruptured arteriovenous malformations in pregnancy may be managed in a similar manner to those in non-gravid women. Precautions should be taken to reduce the operative time and exposure of the fetus to ionizing radiation and contrast agents.</p
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Sporormiella as a tool for detecting the presence of large herbivores in the Neotropics
The reliability of using the abundance of Sporormiella spores as a proxy for the presence and abundance of megaherbivores was tested in southern Brazil. Mud-water interface samples from nine lakes, in which cattle-use was categorized as high, medium, or low, were assayed for Sporormiella representation. The sampling design allowed an analysis of both the influence of the number of animals using the shoreline and the distance of the sampling site from the nearest shoreline. Sporormiella was found to be a reliable proxy for the presence of large livestock. The concentration and abundance of spores declined from the edge of the lake toward the center, with the strongest response being in sites with high livestock use. Consistent with prior studies in temperate regions, we find that Sporormiella spores are a useful proxy to study the extinction of Pleistocene megafauna or the arrival of European livestock in Neotropical landscapes
Understanding why primary care doctors leave direct patient care: a systematic review of qualitative research
This is the final version. Available on open access from BMJ Publishing Group via the DOI in this recordData availability statement: All data relevant to the study are included in the article or uploaded as supplementary information. No additional data available.Background UK general practitioners (GPs) are leaving direct patient care in significant numbers. We undertook a systematic review of qualitative research to identify factors affecting GPsâ leaving behaviour in the workforce as part of a wider mixed methods study (ReGROUP).
Objective To identify factors that affect GPsâ decisions to leave direct patient care.
Methods Qualitative interview-based studies were identified and their quality was assessed. A thematic analysis was performed and an explanatory model was constructed providing an overview of factors affecting UK GPs. Non-UK studies were considered separately.
Results Six UK interview-based studies and one Australian interview-based study were identified. Three central dynamics that are key to understanding UK GP leaving behaviour were identified: factors associated with low job satisfaction, high job satisfaction and those linked to the doctorâpatient relationship. The importance of contextual influence on job satisfaction emerged. GPs with high job satisfaction described feeling supported by good practice relationships, while GPs with poor job satisfaction described feeling overworked and unsupported with negatively impacted doctorâpatient relationships.
Conclusions Many GPs report that job satisfaction directly relates to the quality of the doctorâpatient relationship. Combined with changing relationships with patients and interfaces with secondary care, and the gradual sense of loss of autonomy within the workplace, many GPs report a reduction in job satisfaction. Once job satisfaction has become negatively impacted, the combined pressure of increased patient demand and workload, together with other stress factors, has left many feeling unsupported and vulnerable to burn-out and ill health, and ultimately to the decision to leave general practice
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