Excitons of Composite Fermions

The low-energy excitations of filled Landau levels (LL's) of electrons involve promotion of a single electron from the topmost filled LL to the lowest empty LL. These are called excitons or collective modes. The incompressible fractional quantum Hall states are understood as filled LL's of composite fermions, and the low-energy neutral excitations are excitons of composite fermions. New techniques are developed to study large systems, which provide detailed information about the dispersions of the composite fermion excitons. In particular, it is found that the interaction energy of the exciton is well described by the `unprojected' composite fermion theory.Comment: 40 pages including 13 postscript figures; accepted for publication in Physical Review B (1996); related paper in cond-mat/951113

Nonlinear Micromechanical Casimir Oscillator

The Casimir force between uncharged metallic surfaces originates from quantum mechanical zero point fluctuations of the electromagnetic field. We demonstrate that this quantum electrodynamical effect has a profound influence on the oscillatory behavior of microstructures when surfaces are in close proximity (<= 100 nm). Frequency shifts, hysteretic behavior and bistability caused by the Casimir force are observed in the frequency response of a periodically driven micromachined torsional oscillator.Comment: 4 pages, 4 figures; added and rearranged references; added comments on sensitivit

Imaging Microwave Electric Fields Using a Near-Field Scanning Microwave Microscope

By scanning a fine open-ended coaxial probe above an operating microwave device, we image local electric fields generated by the device at microwave frequencies. The probe is sensitive to the electric flux normal to the face of its center conductor, allowing different components of the field to be imaged by orienting the probe appropriately. Using a simple model of the microscope, we are able to interpret the system's output and determine the magnitude of the electric field at the probe tip. We show images of electric field components above a copper microstrip transmission line driven at 8 GHz, with a spatial resolution of approximately 200 $\mu$m.Comment: 10 pages, 3 eps-figures, accepted by Appl. Phys. Let

Doing research with children and young people who do not use speech for communication

Despite emphasis in policy on participation of disabled children, we still know relatively little about how to obtain the views of disabled children with significant communication impairment and their views are often overlooked in planning and service provision. This article describes how the views of children who do not use speech were accessed in research aiming to identify disabled children and young people's priorities regarding outcomes of social care and support services. The main challenge was to develop a method that was reliable, non-threatening, enjoyable and relevant to individual children, as well as enabling children to think beyond their everyday life and express what they aspire to

Theory and Applications of X-ray Standing Waves in Real Crystals

Theoretical aspects of x-ray standing wave method for investigation of the real structure of crystals are considered in this review paper. Starting from the general approach of the secondary radiation yield from deformed crystals this theory is applied to different concreat cases. Various models of deformed crystals like: bicrystal model, multilayer model, crystals with extended deformation field are considered in detailes. Peculiarities of x-ray standing wave behavior in different scattering geometries (Bragg, Laue) are analysed in detailes. New possibilities to solve the phase problem with x-ray standing wave method are discussed in the review. General theoretical approaches are illustrated with a big number of experimental results.Comment: 101 pages, 43 figures, 3 table

Reporting transparency and completeness in trials : Paper 3 – trials conducted using administrative databases do not adequately report elements related to use of databases

Acknowledgments The development of CONSORT-ROUTINE and the present review were funded by grants from the Canadian Institutes of Health Research (PI Thombs, #PJT-156172; PIs Thombs and Kwakkenbos, #PCS-161863) and from the United Kingdom National Institute of Health Research (NIHR) Clinical Trials Unit Support Funding (PI Juszczak, Co-PI Gale, supported salary of SM). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. Dr. Langan was supported by a Wellcome Senior Clinical Fellowship in Science (205039/Z/16/Z). Dr. Moher is supported by a University Research Chair (uOttawa). Dr. Gale was supported by the United Kingdom Medical Research Council through a Clinician Scientist Fellowship. Dr. Thombs was supported by a Tier 1 Canada Research Chair.Peer reviewedPublisher PD

Impact of smoking and smoking cessation on overweight and obesity: Scotland-wide, cross-sectional study on 40,036 participants

&lt;p&gt;Background: Weight control is cited by some people, especially adolescent girls, as a reason for commencing smoking or not quitting. The aim of this study was to explore the relationship between smoking behaviour and being overweight or obese, overall and by age and sex sub-groups.&lt;/p&gt; &lt;p&gt;Methods: We used data from the six Scottish Health Surveys conducted to date (1995--2010) to undertake a population-based, cross-sectional study on 40,036 participants representative of the adult (&#62;=16 years) Scottish population. Height and weight were measured by a trained interviewer, not self-reported.&lt;/p&gt; &lt;p&gt;Results: 24,459 (63.3%) participants were overweight (BMI &gt;=25 kg/m2) and 9,818 (25.4%) were obese (BMI &#62;=30 kg/m2). Overall, current smokers were less likely to be overweight than never smokers. However, those who had smoked for more than 20 years (adjusted OR 1.54, 95% CI 1.41-1.69, p &#60; 0.001) and ex-smokers (adjusted OR 1.18, 95% CI 1.11-1.25, p &#60; 0.001) were more likely to be overweight. There were significant interactions with age. Participants 16--24 years of age, were no more likely to be overweight if they were current (adjusted OR 1.01, 95% CI 0.84-1.20, p = 0.944) or ex (adjusted OR 0.88, 95% CI 0.67-1.14, p = 0.319) smokers. The same patterns pertained to obesity.&lt;/p&gt; &lt;p&gt;Conclusions: Whilst active smoking may be associated with reduced risk of being overweight among some older adults, there was no evidence to support the belief among young people that smoking protects them from weight gain. Making this point in educational campaigns targeted at young people may help to discourage them from starting to smoke.&lt;/p&gt

Estimating the Cost of Executive Stock Options: Evidence from Switzerland

It is often argued that Black-Scholes (1973) values overstate the subjective NEWLINE value of stock options granted to risk-averse and under-diversified executives. NEWLINE We construct a “representative” Swiss executive and extend the certainty- NEWLINE equivalence approach presented by Hall and Murphy (2002) to assess NEWLINE the value-cost wedge of executive stock options. Even with low coefficients NEWLINE of relative risk aversion, the discount can be above 50% compared to the NEWLINE Black-Scholes values. Regression analysis reveals that the equilibrium level NEWLINE of executive compensation is explained by economic determinant variables NEWLINE such as firm size and growth opportunities, whereas the managers’ pay-forperformance NEWLINE sensitivity remains largely unexplained. Firms with larger NEWLINE boards of directors pay higher wages, indicating potentially unresolved NEWLINE agency conflicts. We reject the hypothesis that cross-sectional differences in NEWLINE the amount of executive pay vanish when risk-adjusted values are used as NEWLINE the dependent variable

Pranolium

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72226/1/j.1527-3466.1983.tb00447.x.pd