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Recent results from the DIII-D tokamak have provided significant contributions to the understanding of many of the elements of tokamak physics and the application of this understanding to the design of next generation devices including ITER and CIT. The limitations of magnetohydrodynamic stability on the values of plasma beta (the ratio of kinetic pressure to the containing pressure of the magnetic field) that can be attained has been experimentally demonstrated and found to be described by existing theory. Values of beta (10.7%) well in excess of those required for proposed devices (ITER and CIT) have been demonstrated. Regimes of confinement (H-mode) have been established that scale favorably to proposed next generation devices, and experiments demonstrating the dependence of the energy confinement on plasma size have been completed. Understanding of confinement is rapidly developing especially in the areas of bulk transport and the role of turbulence in the plasma edge. Key experimental results in areas of plasma transport and edge plasma phenomena are in agreement with theories based on short wavelength turbulence. Control of the divertor heat loads and impurity influx has been demonstrated, and new progress has been made in the understanding of plasma edge phenomena. Experiments with ion Bernstein wave heating have not found regimes in which these waves can produce effective central ion heating. Electron cyclotron current drive experiments have demonstrated 70 kA of driven current in 400 kA discharges.

The authors' data indicate that the L-mode to H-mode transition in the DIII-D tokamak is associated with the sudden reduction in anomalous, fluctuation-connected transport across the outer midplane of the plasma. In addition to the reduction in edge density and magnetic fluctuations observed at the transition, the edge radial electric field becomes more negative after the transition. They have determined the scaling of the H-mode power threshold with various plasma parameters; the roughly linear increase with plasma density and toroidal field are particularly significant. Control of the ELM frequency and duration by adjusting neutral beam input power has allowed us to produce H-mode plasmas with constant impurity levels and durations up to 5 s. Energy confinement time in ohmic H-mode plasmas and in deuterium H-mode plasmas with deuterium beam injection can exceed saturated ohmic confinement times by at least a factor of two. Energy confinement times above 0.3 s have been achieved in these beam-heated plasmas with plasma currents in the range of 2.0 to 2.5 MA. Local transport studies have shown that electron and ion thermal diffusivities and angular momentum diffusivity are comparable in magnitude and all decrease with increasing plasma current.

This paper draws from a larger analysis of literature on lesbian, gay, bisexual, and transgendered (LGBT) youth to illustrate how the dominant rhetorical frameworks construct an individual-LGBT student-in identity crises and 'at risk.' Taylor and Whittier's (1992) framework for understanding 'identity construction' in social movement actors is offered as another perspective from which to analyze the experiences of LGBT youth in schools. As an example, a study about a gaystraight alliance (GSA) in Salt Lake City illustrates how LGBT student political activism is a foundation upon which gay and lesbian students resist heterosexist school climates and construct positive identities. The author suggests supporting LGBT grass-roots activism may be a more fruitful approach to school reform than current programs designed by school personnel to 'assist' LGBT students. [ABSTRACT FROM AUTHOR]

Screening has become central to the effective prevention of several diseases, but implementation suffers from difficulties with targeting and rates of compliance. Such issues are also complicated by the need to consider legal provisions regarding confidentiality of patients and other human rights issues. Screening has been an inexact science in relation to eg faecal occult blood testing for colorectal cancer, false positive and false negative tests for HIV and there have been inadequate quality controls in breast cancer screening programmes. The public need to be made aware of what the screening programmes really offer, balanced against the expectations they may have. There needs to be a clearer understanding of the nature of the contractual and other legal rights of patients/consumers as against providers. A positive screening test may carry adverse consequences as well as benefits. It could alert an insurance company to a risk and lead to additional weighting or even outright rejection for life insurance policies. Job prospects may also be affected for employees. The method of informing patients in relation to screening and screening failure has already been considered by the courts. Realistic information about both screening and treatment efficiency needs to be offered to patients so that they can have a real understanding of what can and cannot be achieved by current science. The development of understanding of the human genome makes the need for clearer legislation in this are more urgent.Public Health (2001) 115, 218–221. [ABSTRACT FROM AUTHOR]

We present a working review of survey methods based on market research technology. The structure of questionnaires, their distribution and analysis, are considered, together with techniques for increasing response rates. [ABSTRACT FROM AUTHOR]

Particle confinement behavior during 2.45 GHz lower-hybrid current drive has been investigated on the Versator II tokamak [Phys. Fluids 29, 1985 (1986)]. It is found that during combined Ohmic and rf current drive the global particle confinement time τp increases by up to a factor of 2 compared to purely Ohmically driven discharges, as observed in earlier 800 MHz experiments at lower densities ne ≤6×1012 cm-3. In the present experiments, τp increases have been observed at densities up to ne =2×1013 cm-3. [ABSTRACT FROM AUTHOR]

Increases in average density have been observed during lower-hybrid current-drive experiments (LHCD) on the Versator II tokamak [Phys. Rev. Lett. 48, 152 (1982)], and on other LHCD experiments where inductive-Ohmic and lower-hybrid current drive are combined. In the present experiment it is found that this density increase is the result of an improvement in global particle confinement time τ[sub p] in comparison to purely Ohmic discharges with similar plasma parameters. Furthermore, it is found that the improved confinement deteriorates when the anomalous Doppler relaxation instability of the anisotropic high-energy electron tail becomes unstable during LHCD, and the loss rate of tail electrons increases. However, energetic electron losses alone are at least an order of magnitude too small to explain this deterioration in particle confinement. [ABSTRACT FROM AUTHOR]