Coherent control of collective atom phase for ultralong, inversion-free photon echoes

To overcome fundamental limitations of the \pi optical pulse-induced population inversion and optical decay-caused short storage time in conventional photon echoes, a coherent control of collective atoms is studied for inversion-free, optical decay-halted photon echoes, where the constraint of photon storage time is now replaced by a spin population decay process. Using phase-controlled double rephasing, an inversion-free photon echo scheme is obtained, where no spontaneous or stimulated emission-driven quantum noise exists. Thus, the present method can be applied for ultralong quantum memories in quantum repeaters for long-distance quantum communications.Comment: 4 pages, 4 figure

Distinctive ECG patterns in healthy black adults

Six ECG patterns are found more frequently in healthy black adults than in whites. These patterns are presumably benign, but also may resemble those of malignant disease. 1) Healthy black adults show higher QRS voltage, and more often meet ECG criteria for left ventricular hypertrophy (LVH). Associated repolarization abnormalities can produce ST segment elevation (STE) that resembles ST elevation MI (STEMI). 2) The pattern of benign anterior STE, seen often in males, is more common in black subjects. Similar to LVH, this pattern may falsely suggest STEMI. 3) Both early repolarization (ER) and benign inferolateral STE are more common in black patients. Although they may convey a higher risk of fatal arrhythmias or cardiac death in white populations, it does not appear that black subjects with these patterns show a similar risk. 4) The persistent juvenile T wave inversion pattern shows asymmetric T wave inversion (TWI) in V1-V4, without ST segment deviations. It is most common in black females, and is considered benign. However, this pattern can also resemble the anterior TWI of arrhythmogenic right ventricular cardiomyopathy (ARVC). 5) A pattern of anterior TWI with associated J point elevation is a common finding in the black population, especially athletes. It could suggest hypertrophic cardiomyopathy, but can be presumed to be a benign finding in black athletes, when TWI is limited to V1-V4 and preceded by J point elevation. 6) TWI in the lateral precordial leads, usually associated with end-QRS slurring or notches is seen much more often in apparently healthy black subjects than white subjects. Unlike the anterior TWI pattern, however, it cannot be presumed benign. In conclusion, awareness of these ECG patterns may help to avoid unnecessary diagnostic or therapeutic interventions, but also encourage appropriate investigations

Distinctive ECG patterns in healthy black adults

Six ECG patterns are found more frequently in healthy black adults than in whites. These patterns are presumably benign, but also may resemble those of malignant disease. 1) Healthy black adults show higher QRS voltage, and more often meet ECG criteria for left ventricular hypertrophy (LVH). Associated repolarization abnormalities can produce ST segment elevation (STE) that resembles ST elevation MI (STEMI). 2) The pattern of benign anterior STE, seen often in males, is more common in black subjects. Similar to LVH, this pattern may falsely suggest STEMI. 3) Both early repolarization (ER) and benign inferolateral STE are more common in black patients. Although they may convey a higher risk of fatal arrhythmias or cardiac death in white populations, it does not appear that black subjects with these patterns show a similar risk. 4) The persistent juvenile T wave inversion pattern shows asymmetric T wave inversion (TWI) in V1-V4, without ST segment deviations. It is most common in black females, and is considered benign. However, this pattern can also resemble the anterior TWI of arrhythmogenic right ventricular cardiomyopathy (ARVC). 5) A pattern of anterior TWI with associated J point elevation is a common finding in the black population, especially athletes. It could suggest hypertrophic cardiomyopathy, but can be presumed to be a benign finding in black athletes, when TWI is limited to V1-V4 and preceded by J point elevation. 6) TWI in the lateral precordial leads, usually associated with end-QRS slurring or notches is seen much more often in apparently healthy black subjects than white subjects. Unlike the anterior TWI pattern, however, it cannot be presumed benign. In conclusion, awareness of these ECG patterns may help to avoid unnecessary diagnostic or therapeutic interventions, but also encourage appropriate investigations

Correlation length in cuprates deduced from the impurity-induced magnetization

We report a new multi-nuclei based NMR method which allows us to image the staggered polarization induced by nonmagnetic Li impurities in underdoped O6.6 and slightly overdoped O7 YBa2Cu3O6+y above T_C. The spatial extension of the polarization xi_imp approximately follows a Curie law, increasing up to six lattice constants at T=80K at O6.6 in the pseudogap regime. Near optimal doping, the staggered magnetization has the same shape, with xi_imp reduced by a factor 2. xi_imp is argued to reveal the intrinsic magnetic correlation length of the pure system. It is found to display a smooth evolution through the pseudogap regime.Comment: 8 latex pages + 8 figures, to appear in Physical Review B, this resubmitted version is twice longer than the previous one : we detail here our method to determine the impurity-induced magnetizatio

Two parameter Deformed Multimode Oscillators and q-Symmetric States

Two types of the coherent states for two parameter deformed multimode oscillator system are investigated. Moreover, two parameter deformed $gl(n)$ algebra and deformed symmetric states are constructed.Comment: LaTeX v1.2, 14 pages with no figure

Communication in cross-cultural consultations in primary care in Europe: the case for improvement. The rationale for the RESTORE FP 7 project

The purpose of this paper is to substantiate the importance of research about barriers and levers to the implementation of supports for cross-cultural communication in primary care settings in Europe. After an overview of migrant health issues, with the focus on communication in cross-cultural consultations in primary care and the importance of language barriers, we highlight the fact that there are serious problems in routine practice that persist over time and across different European settings. Language and cultural barriers hamper communication in consultations between doctors and migrants, with a range of negative effects including poorer compliance and a greater propensity to access emergency services. It is well established that there is a need for skilled interpreters and for professionals who are culturally competent to address this problem. A range of professional guidelines and training initiatives exist that support the communication in cross-cultural consultations in primary care. However, these are commonly not implemented in daily practice. It is as yet unknown why professionals do not accept or implement these guidelines and interventions, or under what circumstances they would do so. A new study involving six European countries, RESTORE (REsearch into implementation STrategies to support patients of different ORigins and language background in a variety of European primary care settings), aims to address these gaps in knowledge. It uses a unique combination of a contemporary social theory, normalisation process theory (NPT) and participatory learning and action (PLA) research. This should enhance understanding of the levers and barriers to implementation, as well as providing stakeholders, with the opportunity to generate creative solutions to problems experienced with the implementation of such interventions

Normal Ordering for Deformed Boson Operators and Operator-valued Deformed Stirling Numbers

The normal ordering formulae for powers of the boson number operator $\hat{n}$ are extended to deformed bosons. It is found that for the `M-type' deformed bosons, which satisfy $a a^{\dagger} - q a^{\dagger} a = 1$, the extension involves a set of deformed Stirling numbers which replace the Stirling numbers occurring in the conventional case. On the other hand, the deformed Stirling numbers which have to be introduced in the case of the `P-type' deformed bosons, which satisfy $a a^{\dagger} - q a^{\dagger} a = q^{-\hat{n}}$, are found to depend on the operator $\hat{n}$. This distinction between the two types of deformed bosons is in harmony with earlier observations made in the context of a study of the extended Campbell-Baker-Hausdorff formula.Comment: 14 pages, Latex fil

Reliability and validity of the IPAQ-L in a sample of Hong Kong Urban older adults: does neighborhood of residence matter?

This study examined reliability and validity of the Chinese version of the International Physical Activity Questionnaire–Long Form (IPAQ-LC) in Chinese seniors, including moderating effects of neighborhood walkability and socioeconomic status (SES) on reliability and validity. The IPAQ-LC was interviewer-administered (n = 96), accelerometer and 7-day walk-diary data were collected (n = 94), and the IPAC-LC was readministered (N = 92). Acceptable reliability was found for all measures of physical activity (PA) overall and across different types of neighborhood. Participants from highly walkable neighborhoods were more reliable at estimating walking for transport. Participants from low-SES areas were less reliable at estimating leisure-time PA and sitting but more reliable at estimating transport-related walking. IPAQ-LC walking was significantly related to light- but not moderate-intensity accelerometry-based PA. It was moderately to strongly related to a 7-day diary of walking. The data imply slow-paced walking, probably due to age, climate, and terrain. The findings suggest that the IPAQ-LC’s reliability and validity are acceptable in Chinese seniors

Quantum Field Theory with Nonzero Minimal Uncertainties in Positions and Momenta

A noncommutative geometric generalisation of the quantum field theoretical framework is developed by generalising the Heisenberg commutation relations. There appear nonzero minimal uncertainties in positions and in momenta. As the main result it is shown with the example of a quadratically ultraviolet divergent graph in $\phi^4$ theory that nonzero minimal uncertainties in positions do have the power to regularise. These studies are motivated with the ansatz that nonzero minimal uncertainties in positions and in momenta arise from gravity. Algebraic techniques are used that have been developed in the field of quantum groups.Comment: 52 pages LATEX, DAMTP/93-33. Revised version now includes a chapter on the Poincare algebra and curvature as noncommutativity of momentum spac