Quantum state estimation and large deviations

In this paper we propose a method to estimate the density matrix \rho of a d-level quantum system by measurements on the N-fold system. The scheme is based on covariant observables and representation theory of unitary groups and it extends previous results concerning the estimation of the spectrum of \rho. We show that it is consistent (i.e. the original input state \rho is recovered with certainty if N \to \infty), analyze its large deviation behavior, and calculate explicitly the corresponding rate function which describes the exponential decrease of error probabilities in the limit N \to \infty. Finally we discuss the question whether the proposed scheme provides the fastest possible decay of error probabilities.Comment: LaTex2e, 40 pages, 2 figures. Substantial changes in Section 4: one new subsection (4.1) and another (4.2 was 4.1 in the previous version) completely rewritten. Minor changes in Sect. 2 and 3. Typos corrected. References added. Accepted for publication in Rev. Math. Phy

Decision making and risk management in adventure sports coaching

Adventure sport coaches practice in environments that are dynamic and high in risk, both perceived and actual. The inherent risks associated with these activities, individuals’ responses and the optimal exploitation of both combine to make the processes of risk management more complex and hazardous than the traditional sports where risk management is focused almost exclusively on minimization. Pivotal to this process is the adventure sports coaches’ ability to make effective judgments regarding levels of risk, potential benefits and possible consequences. The exact nature of this decision making process should form the basis of coaching practice and coach education in this complex and dynamic field. This positional paper examines decision making by the adventure sports coach in these complex, challenging environments and seeks to stimulate debate whilst offering a basis for future research into this topic

PERICLES Deliverable 4.3:Content Semantics and Use Context Analysis Techniques

The current deliverable summarises the work conducted within task T4.3 of WP4, focusing on the extraction and the subsequent analysis of semantic information from digital content, which is imperative for its preservability. More specifically, the deliverable defines content semantic information from a visual and textual perspective, explains how this information can be exploited in long-term digital preservation and proposes novel approaches for extracting this information in a scalable manner. Additionally, the deliverable discusses novel techniques for retrieving and analysing the context of use of digital objects. Although this topic has not been extensively studied by existing literature, we believe use context is vital in augmenting the semantic information and maintaining the usability and preservability of the digital objects, as well as their ability to be accurately interpreted as initially intended.PERICLE

An exploratory cluster randomised trial of a university halls of residence based social norms marketing campaign to reduce alcohol consumption among 1st year students

<p>Aims: This exploratory trial examines the feasibility of implementing a social norms marketing campaign to reduce student drinking in universities in Wales, and evaluating it using cluster randomised trial methodology.</p> <p>Methods: Fifty residence halls in 4 universities in Wales were randomly assigned to intervention or control arms. Web and paper surveys were distributed to students within these halls (n = 3800), assessing exposure/contamination, recall of and evaluative responses to intervention messages, perceived drinking norms and personal drinking behaviour. Measures included the Drinking Norms Rating Form, the Daily Drinking Questionnaire and AUDIT-C.</p> <p>Results: A response rate of 15% (n = 554) was achieved, varying substantially between sites. Intervention posters were seen by 80% and 43% of students in intervention and control halls respectively, with most remaining materials seen by a minority in both groups. Intervention messages were rated as credible and relevant by little more than half of students, though fewer felt they would influence their behaviour, with lighter drinkers more likely to perceive messages as credible. No differences in perceived norms were observed between intervention and control groups. Students reporting having seen intervention materials reported lower descriptive and injunctive norms than those who did not.</p> <p>Conclusions: Attention is needed to enhancing exposure, credibility and perceived relevance of intervention messages, particularly among heavier drinkers, before definitive evaluation can be recommended. A definitive evaluation would need to consider how it would achieve sufficient response rates, whilst hall-level cluster randomisation appears subject to a significant degree of contamination.</p&gt

Policing UK Honour-Based Abuse Crime

This book examines the different forms that honour-based abuse crimes take, and analyses the discretionary police practices employed when responding to these incidents. Honour-based abuse is an incident or crime involving violence, threats of violence, intimidation, coercion or abuse committed in order to protect or defend the honour of an individual, family and or community for a perceived breach of their code of behaviour. Based on unique UK police data, it includes examination of one hundred honour abuse cases and interviews with fifteen predominantly detective specialist police officers that investigate this crime. This book recognises the challenges encountered when policing honour-based abuse and offers recommendations for addressing them. It will particularly benefit police forces in England and Wales, the Home Office, scholars in gendered violence and policing and non-government organisations (charities supporting victims) by highlighting some of the issues associated with policing, partnership working arrangements and safeguarding victims of honour-based abuse crimes

Defining frequent attendance in general practice

Background: General practitioners (GPs) or researchers sometimes need to identify frequent attenders (FAs) in order to screen them for unidentified problems and to test specific interventions. We wanted to assess different methods for selecting FAs to identify the most feasible and effective one for use in a general (group) practice. Methods: In the second Dutch National Survey of General Practice, data were collected on 375 899 persons registered with 104 practices. Frequent attendance is defined as the top 3% and 10% of enlisted patients in each one-year age-sex group measured during the study year. We used these two selections as our reference standard. We also selected the top 3% and 10% FAs (90 and 97 percentile) based on four selection methods of diminishing preciseness. We compared the test characteristics of these four methods. Results: Of all enlisted patients, 24 % did not consult the practice during the study year. The mean number of contacts in the top 10% FAs increased in men from 5.8 (age 15-24 years) to 17.5 (age 64-75 years) and in women from 9.7 to 19.8. In the top 3% of FAs, contacts increased in men from 9.2 to 24.5 and in women from 14 to 27.8. The selection of FAs becomes more precise when smaller age classes are used. All selection methods show acceptable results (kappa 0.849 - 0.942) except the three group method. Conclusion: To correctly identify frequent attenders in general practice, we recommend dividing patients into at least three age groups per se

A mathematical and computational review of Hartree-Fock SCF methods in Quantum Chemistry

We present here a review of the fundamental topics of Hartree-Fock theory in Quantum Chemistry. From the molecular Hamiltonian, using and discussing the Born-Oppenheimer approximation, we arrive to the Hartree and Hartree-Fock equations for the electronic problem. Special emphasis is placed in the most relevant mathematical aspects of the theoretical derivation of the final equations, as well as in the results regarding the existence and uniqueness of their solutions. All Hartree-Fock versions with different spin restrictions are systematically extracted from the general case, thus providing a unifying framework. Then, the discretization of the one-electron orbitals space is reviewed and the Roothaan-Hall formalism introduced. This leads to a exposition of the basic underlying concepts related to the construction and selection of Gaussian basis sets, focusing in algorithmic efficiency issues. Finally, we close the review with a section in which the most relevant modern developments (specially those related to the design of linear-scaling methods) are commented and linked to the issues discussed. The whole work is intentionally introductory and rather self-contained, so that it may be useful for non experts that aim to use quantum chemical methods in interdisciplinary applications. Moreover, much material that is found scattered in the literature has been put together here to facilitate comprehension and to serve as a handy reference.Comment: 64 pages, 3 figures, tMPH2e.cls style file, doublesp, mathbbol and subeqn package

Control of star formation by supersonic turbulence

Understanding the formation of stars in galaxies is central to much of modern astrophysics. For several decades it has been thought that stellar birth is primarily controlled by the interplay between gravity and magnetostatic support, modulated by ambipolar diffusion. Recently, however, both observational and numerical work has begun to suggest that support by supersonic turbulence rather than magnetic fields controls star formation. In this review we outline a new theory of star formation relying on the control by turbulence. We demonstrate that although supersonic turbulence can provide global support, it nevertheless produces density enhancements that allow local collapse. Inefficient, isolated star formation is a hallmark of turbulent support, while efficient, clustered star formation occurs in its absence. The consequences of this theory are then explored for both local star formation and galactic scale star formation. (ABSTRACT ABBREVIATED)Comment: Invited review for "Reviews of Modern Physics", 87 pages including 28 figures, in pres

Towards an asset-based approach to promoting and sustaining well-being for people with aphasia and their families: an international exploratory study

Background: There is growing interest in interventions that promote positive outcomes and well-being for people with aphasia (PWA) and their families, but provision is inconsistent. An asset-based approach, based on the theory of salutogenesis, focuses on what makes you well rather than ill. This approach has been used successfully across a variety of research fields, including health and social care research and practice, and has the potential to provide coherent strategies to support people living successfully with aphasia. Aim: To explore the relevance and potential of an asset-based approach to promoting and sustaining well-being for PWA and their families, across contexts and cultures. Methods & procedures: Exploratory case studies were carried out in the United Kingdom (UK), Norway, Israel, Ireland, and Denmark in a variety of settings. Following an interpretative paradigm, we used qualitative methods including: interviews; appreciative inquiry; group discussions; and participatory action research. 95 PWA and 25 family members were asked to identify assets within themselves and their communities that promote, sustain and maintain well-being, by responding to: “What makes you feel good/well/healthy?” Data were analysed using thematic analysis. Outcomes & results: An asset-based approach proved to be a powerful means for PWA and family members to explore what helps them live well with aphasia. Key themes were identified: (1) personal journey; (2) helping others; (3) connecting to self; (4) connecting to others; (5) recreation; and (6) personal attributes. Self-identification of assets, within the person and their community, and connections to these, helped PWA and their family members to maintain well-being, overcome barriers and regain confidence. Using this approach, focusing on the person’s recognition, activation and mobilisation of assets, could enhance the person’s understanding and restore meaning around the stroke and onset of aphasia. Conclusion: This novel exploratory research demonstrates the relevance and potential across diverse cultural contexts of taking an asset-based approach to promoting and sustaining well-being for PWA and their families. Focusing on maintaining connections to these assets and developing meaning around the event, could prevent some of the negative sequela of stroke. The “patient–professional” relationship must transform into a collaborative partnership, with time and flexibility needed to introduce this approach. Further research should examine how service providers and PWA could develop and operationalise an asset-based approach in clinical and community settings and identify if there is an optimum timing for introducing this approach along the stroke pathway

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE