Development of an approximate method for quantum optical models and their pseudo-Hermicity

An approximate method is suggested to obtain analytical expressions for the eigenvalues and eigenfunctions of the some quantum optical models. The method is based on the Lie-type transformation of the Hamiltonians. In a particular case it is demonstrated that $E\times \epsilon$ Jahn-Teller Hamiltonian can easily be solved within the framework of the suggested approximation. The method presented here is conceptually simple and can easily be extended to the other quantum optical models. We also show that for a purely imaginary coupling the $E\times \epsilon$ Hamiltonian becomes non-Hermitian but $P\sigma _{0}$-symmetric. Possible generalization of this approach is outlined.Comment: Paper prepared fo the "3rd International Workshop on Pseudo-Hermitian Hamiltonians in Quantum Physics" June 2005 Istanbul. To be published in Czechoslovak Journal of Physic

Understanding the Spatial Clustering of Severe Acute Respiratory Syndrome (SARS) in Hong Kong

We applied cartographic and geostatistical methods in analyzing the patterns of disease spread during the 2003 severe acute respiratory syndrome (SARS) outbreak in Hong Kong using geographic information system (GIS) technology. We analyzed an integrated database that contained clinical and personal details on all 1,755 patients confirmed to have SARS from 15 February to 22 June 2003. Elementary mapping of disease occurrences in space and time simultaneously revealed the geographic extent of spread throughout the territory. Statistical surfaces created by the kernel method confirmed that SARS cases were highly clustered and identified distinct disease “hot spots.” Contextual analysis of mean and standard deviation of different density classes indicated that the period from day 1 (18 February) through day 16 (6 March) was the prodrome of the epidemic, whereas days 86 (15 May) to 106 (4 June) marked the declining phase of the outbreak. Origin-and-destination plots showed the directional bias and radius of spread of superspreading events. Integration of GIS technology into routine field epidemiologic surveillance can offer a real-time quantitative method for identifying and tracking the geospatial spread of infectious diseases, as our experience with SARS has demonstrated

Assessing the Predictive Validity of Simple Dementia Risk Models in Harmonized Stroke Cohorts

BACKGROUND AND PURPOSE: Stroke is associated with an increased risk of dementia. To assist in the early identification of individuals at high risk of future dementia, numerous prediction models have been developed for use in the general population. However, it is not known whether such models also provide accurate predictions among stroke patients. Therefore, the aim of this study was to determine whether existing dementia risk prediction models that were developed for use in the general population can also be applied to individuals with a history of stroke to predict poststroke dementia with equivalent predictive validity. METHODS: Data were harmonized from 4 stroke studies (follow-up range, ≈12–18 months poststroke) from Hong Kong, the United States, the Netherlands, and France. Regression analysis was used to test 3 risk prediction models: the Cardiovascular Risk Factors, Aging and Dementia score, the Australian National University Alzheimer Disease Risk Index, and the Brief Dementia Screening Indicator. Model performance or discrimination accuracy was assessed using the C statistic or area under the curve. Calibration was tested using the Grønnesby and Borgan and the goodness-of-fit tests. RESULTS: The predictive accuracy of the models varied but was generally low compared with the original development cohorts, with the Australian National University Alzheimer Disease Risk Index (C-statistic, 0.66) and the Brief Dementia Screening Indicator (C-statistic, 0.61) both performing better than the Cardiovascular Risk Factors, Aging and Dementia score (area under the curve, 0.53). CONCLUSIONS: Dementia risk prediction models developed for the general population do not perform well in individuals with stroke. Their poor performance could have been due to the need for additional or different predictors related to stroke and vascular risk factors or methodological differences across studies (eg, length of follow-up, age distribution)

A Review of the Global Literature on Dental Therapists: In the Context of the Movement to Add Dental Therapists to the Oral Health Workforce in the United States (Executive Summary)

This executive summary documents evidence that dental therapists can effectively expand access to dental care, especially for children, and is technically competent, safe and effective

Measurement of the atmospheric muon depth intensity relation with the NEMO Phase-2 tower

The results of the analysis of the data collected with the NEMO Phase-2 tower, deployed at 3500 m depth about 80 km off-shore Capo Passero (Italy), are presented. Cherenkov photons detected with the photomultipliers tubes were used to reconstruct the tracks of atmospheric muons. Their zenith-angle distribution was measured and the results compared with Monte Carlo simulations. An evaluation of the systematic effects due to uncertainties on environmental and detector parameters is also included. The associated depth intensity relation was evaluated and compared with previous measurements and theoretical predictions. With the present analysis, the muon depth intensity relation has been measured up to 13 km of water equivalent.Comment: submitted to Astroparticle Physic

The quest for successful Atlantic salmon restoration: perspectives, priorities, and maxims

Atlantic salmon is often a focal species of restoration efforts throughout the north Atlantic and it is therefore an excellent case study for how best to design programmes to address and mitigate threats and correct population declines. This perspective is written to promote the work that has been accomplished towards restoration of Atlantic salmon populations and synthesize how we believe the lessons can be used effectively to support efforts by management agencies to restore populations. We reviewed where restoration is needed for Atlantic salmon, agreed on definitions for three levels of successful restoration, and then applied these criteria to 49 published papers focused on Atlantic salmon restoration. We identified 16 successful examples of restoration among 49 papers reviewed and discussed what interventions led to success versus failure. We then addressed key questions about when hatchery stocking should be used as part of a restoration measure and whether local restoration efforts are enough when these wide-ranging species encounter broad-scale changes in the north Atlantic, specifically related to issues of climate change and to marine survival. We advise to avoid restoration as much as possible by protecting and managing existing populations and when restoration is necessary, problems should be identified and addressed in partnership with river users. With appropriate resources and research to resolve ongoing mysteries, restoration of lost Atlantic salmon populations is absolutely feasible

Si ocurrió un evento adverso piense en decir “lo siento”

Fundamento. La información al paciente víctima de un evento adverso (EA) presenta ciertas particularidades en función del marco legal del país en el que se produzca, especialmente en lo referido al ofrecimiento de una disculpa. En el presente trabajo se pretende establecer los límites y las condiciones que debemos considerar a la hora de trasladar una disculpa al paciente que ha sufrido un EA. Método. Conferencia de consenso entre 26 profesionales de distintas comunidades autónomas, instituciones y perfiles profesionales con experiencia acreditada en la gestión de sistemas de Seguridad del Paciente y Derecho Penal de diferentes ámbitos laborales (sanidad, aseguradoras, inspección, académico). Resultados. El paciente, tras un EA además de ser informado, debiera recibir una disculpa expresada en términos neutros (manifestación empática y de pesar por lo sucedido), sin que el informante se identifique a sí mismo como responsable del daño, culpabilice a terceros, ni ofrezca una compensación en nombre de la compañía aseguradora. El profesional que se siente más directamente involucrado en el incidente es normalmente el menos indicado para informar y disculparse. El informante debe ajustarse al tipo y gravedad del EA. La normativa y condiciones del seguro de responsabilidad aconsejan no ofrecer información concreta sobre la magnitud de la compensación. Conclusiones. La disculpa debe medirse en función del marco normativo que rige en cada país. En nuestro caso procede una respuesta de empatía hacia el paciente, manifestando pesar por lo sucedido (decir lo siento) que puede facilitar la relación con el paciente, reducir su desconfianza y el número de litigios. Background. Disclosing information to a patient who is a victim of an adverse event (AE) presents some particularities depending on the legal framework in the country where the AE occurred. The aim of this study is to identify the limits and conditions when apologizing to a patient who has suffered an AE. Methods. A consensus conference involving 26 professionals from different autonomous communities, institutions, and profiles (health, insurance, inspection, academic) with accredited experience in patient safety management systems and criminal law. Results. Open disclosure should include an apology expressed in neutral terms (showing empathy and regret for what has happened) without the informant being identified as responsible for the damage, blaming third parties, or offering compensation on behalf of the insurance company. The professional who feels most directly involved in the incident is usually the least likely to report it and apologise. The informant profile must conform to the type and severity of the AE. The rules and conditions of liability insurance advise against providing specific information on the amount of compensation. Conclusions. The apology should be offered in terms of the regulatory framework in force in each country. In Spain, an appropriate response of empathy for the patient is warranted, expressing regret for what happened (apologising), which can facilitate the relationship with the patient, mitigate their mistrust, and reduce the number of disputes

Star Formation and Dynamics in the Galactic Centre

The centre of our Galaxy is one of the most studied and yet enigmatic places in the Universe. At a distance of about 8 kpc from our Sun, the Galactic centre (GC) is the ideal environment to study the extreme processes that take place in the vicinity of a supermassive black hole (SMBH). Despite the hostile environment, several tens of early-type stars populate the central parsec of our Galaxy. A fraction of them lie in a thin ring with mild eccentricity and inner radius ~0.04 pc, while the S-stars, i.e. the ~30 stars closest to the SMBH (<0.04 pc), have randomly oriented and highly eccentric orbits. The formation of such early-type stars has been a puzzle for a long time: molecular clouds should be tidally disrupted by the SMBH before they can fragment into stars. We review the main scenarios proposed to explain the formation and the dynamical evolution of the early-type stars in the GC. In particular, we discuss the most popular in situ scenarios (accretion disc fragmentation and molecular cloud disruption) and migration scenarios (star cluster inspiral and Hills mechanism). We focus on the most pressing challenges that must be faced to shed light on the process of star formation in the vicinity of a SMBH.Comment: 68 pages, 35 figures; invited review chapter, to be published in expanded form in Haardt, F., Gorini, V., Moschella, U. and Treves, A., 'Astrophysical Black Holes'. Lecture Notes in Physics. Springer 201

Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

The $B^0$-$\bar B^0$ oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives $\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)}$ ps$^{-1}$.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results