Torsion Galois representations over CM fields and Hecke algebras in the derived category

We construct algebras of endomorphisms in the derived category of the cohomology of arithmetic manifolds, which are generated by Hecke operators. We construct Galois representations with coefficients in these Hecke algebras and apply this technique to sharpen recent results of P. Scholze

Surgical management of aortic root disease in Marfan syndrome and other congenital disorders associated with aortic root aneurysms

Elective root replacement in Marfan syndrome has improved life expectancy in affected patients. Three forms of surgery are now available: total root replacement (TRR) with a valved conduit, valve sparing root replacement (VSRR) and personalised external aortic root support (PEARS) with a macroporous mesh sleeve. TRR can be performed irrespective of aortic dimensions and a mechanical replacement valve is a secure and near certain means of correcting aortic valve regurgitation but has thromboembolic and bleeding risks. VSRR offers freedom from anticoagulation and attendant risks of bleeding but reoperation for aortic regurgitation runs at 1.3% per annum. A prospective multi-institutional study has found this to be an underestimate of the true rate of valve-related adverse events. PEARS conserves the aortic root anatomy and optimises the chance of maintaining valve function but average follow-up is under 5 years and so the long-term results are yet to be determined. Patients are on average in their 30s and so the cumulative lifetime need for reoperation, and of any valve-related complications, are consequently substantial. With lowering surgical risk of prophylactic root replacement, the threshold for intervention has reduced progressively over 30 years to 4.5 cm and so an increasing number of patients who are not destined to have a dissection are now having root replacement. In evaluation of these three forms of surgery, the number needed to treat to prevent dissection and the balance of net benefit and harm in future patients must be considered

Random Matrix Theory and Chiral Symmetry in QCD

Random matrix theory is a powerful way to describe universal correlations of eigenvalues of complex systems. It also may serve as a schematic model for disorder in quantum systems. In this review, we discuss both types of applications of chiral random matrix theory to the QCD partition function. We show that constraints imposed by chiral symmetry and its spontaneous breaking determine the structure of low-energy effective partition functions for the Dirac spectrum. We thus derive exact results for the low-lying eigenvalues of the QCD Dirac operator. We argue that the statistical properties of these eigenvalues are universal and can be described by a random matrix theory with the global symmetries of the QCD partition function. The total number of such eigenvalues increases with the square root of the Euclidean four-volume. The spectral density for larger eigenvalues (but still well below a typical hadronic mass scale) also follows from the same low-energy effective partition function. The validity of the random matrix approach has been confirmed by many lattice QCD simulations in a wide parameter range. Stimulated by the success of the chiral random matrix theory in the description of universal properties of the Dirac eigenvalues, the random matrix model is extended to nonzero temperature and chemical potential. In this way we obtain qualitative results for the QCD phase diagram and the spectrum of the QCD Dirac operator. We discuss the nature of the quenched approximation and analyze quenched Dirac spectra at nonzero baryon density in terms of an effective partition function. Relations with other fields are also discussed.Comment: invited review article for Ann. Rev. Nucl. Part. Sci., 61 pages, 11 figures, uses ar.sty (included); references added and typos correcte

News media coverage of euthanasia: A content analysis of Dutch national newspapers

© 2013 Rietjens et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: The Netherlands is one of the few countries where euthanasia is legal under strict conditions. This study investigates whether Dutch newspaper articles use the term ‘euthanasia’ according to the legal definition and determines what arguments for and against euthanasia they contain. Methods: We did an electronic search of seven Dutch national newspapers between January 2009 and May 2010 and conducted a content analysis. Results: Of the 284 articles containing the term ‘euthanasia’, 24% referred to practices outside the scope of the law, mostly relating to the forgoing of life-prolonging treatments and assistance in suicide by others than physicians. Of the articles with euthanasia as the main topic, 36% described euthanasia in the context of a terminally ill patient, 24% for older persons, 16% for persons with dementia, and 9% for persons with a psychiatric disorder. The most frequent arguments for euthanasia included the importance of self-determination and the fact that euthanasia contributes to a good death. The most frequent arguments opposing euthanasia were that suffering should instead be alleviated by better care, that providing euthanasia can be disturbing, and that society should protect the vulnerable. Conclusions: Of the newspaper articles, 24% uses the term ‘euthanasia’ for practices that are outside the scope of the euthanasia law. Typically, the more unusual cases are discussed. This might lead to misunderstandings between citizens and physicians. Despite the Dutch legalisation of euthanasia, the debate about its acceptability and boundaries is ongoing and both sides of the debate are clearly represented

Combinatorial Assortment Optimization

Assortment optimization refers to the problem of designing a slate of products to offer potential customers, such as stocking the shelves in a convenience store. The price of each product is fixed in advance, and a probabilistic choice function describes which product a customer will choose from any given subset. We introduce the combinatorial assortment problem, where each customer may select a bundle of products. We consider a model of consumer choice where the relative value of different bundles is described by a valuation function, while individual customers may differ in their absolute willingness to pay, and study the complexity of the resulting optimization problem. We show that any sub-polynomial approximation to the problem requires exponentially many demand queries when the valuation function is XOS, and that no FPTAS exists even for succinctly-representable submodular valuations. On the positive side, we show how to obtain constant approximations under a "well-priced" condition, where each product's price is sufficiently high. We also provide an exact algorithm for $k$-additive valuations, and show how to extend our results to a learning setting where the seller must infer the customers' preferences from their purchasing behavior

Factors contributing to officers’ fatigue in high-speed maritime craft operations

Author name used in this publication: Jimmy J. M. Ng2005-2006 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Hidden Hearing Loss Impacts the Neural Representation of Speech in Background Noise

Many individuals with seemingly normal hearing abilities struggle to understand speech in noisy backgrounds. To understand why this might be the case, we investigated the neural representation of speech in the auditory midbrain of gerbils with “hidden hearing loss” through noise exposure that increased hearing thresholds only temporarily. In noise-exposed animals, we observed significantly increased neural responses to speech stimuli, with a more pronounced increase at moderate than at high sound intensities. Noise exposure reduced discriminability of neural responses to speech in background noise at high sound intensities, with impairment most severe for tokens with relatively greater spectral energy in the noise-exposure frequency range (2–4 kHz). At moderate sound intensities, discriminability was surprisingly improved, which was unrelated to spectral content. A model combining damage to high-threshold auditory nerve fibers with increased response gain of central auditory neurons reproduced these effects, demonstrating that a specific combination of peripheral damage and central compensation could explain listening difficulties despite normal hearing thresholds

Content analysis of Advance Directives completed by patients with advanced cancer as part of an Advance Care Planning intervention : insights gained from the ACTION trial

Purpose Writing an Advance Directive (AD) is often seen as a part of Advance Care Planning (ACP). ADs may include specific preferences regarding future care and treatment and information that provides a context for healthcare professionals and relatives in case they have to make decisions for the patient. The aim of this study was to get insight into the content of ADs as completed by patients with advanced cancer who participated in ACP conversations. Methods A mixed methods study involving content analysis and descriptive statistics was used to describe the content of completed My Preferences forms, an AD used in the intervention arm of the ACTION trial, testing the effectiveness of the ACTION Respecting Choices ACP intervention. Results In total, 33% of 442 patients who received the ACTION RC ACP intervention completed a My Preferences form. Document completion varied per country: 10.4% (United Kingdom), 20.6% (Denmark), 29.2% (Belgium), 41.7% (the Netherlands), 61.3% (Italy) and 63.9% (Slovenia). Content analysis showed that 'maintaining normal life' and 'experiencing meaningful relationships' were important for patients to live well. Fears and worries mainly concerned disease progression, pain or becoming dependent. Patients hoped for prolongation of life and to be looked after by healthcare professionals. Most patients preferred to be resuscitated and 44% of the patients expressed maximizing comfort as their goal of future care. Most patients preferred 'home' as final place of care. Conclusions My Preferences forms provide some insights into patients' perspectives and preferences. However, understanding the reasoning behind preferences requires conversations with patients

Barriers to e-commerce policy in logistics : an exploratory study of the Pearl River Delta, China

Author name used in this publication: J. M. J. Ng2008-2009 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe