Observation of Electron Bernstein Wave Heating in a Reversed Field Pinch.

The first observation of rf heating in a reversed field pinch (RFP) using the electron Bernstein wave (EBW) is demonstrated on the Madison Symmetric Torus. Propagation across and heating in a stochastic magnetic field is observed. Novel techniques are required to measure the suprathermal electron tail generated by EBW heating in the presence of intense Ohmic heating. rf-heated electrons directly probe the edge transport properties in the RFP; measured loss rates imply a large noncollisional radial diffusivity.

Depressive symptoms and rates of bone loss at the hip in older men.

UNLABELLED: In this prospective cohort study, depressive symptoms were associated with higher rates of bone loss in older men. Poorer performance on physical function tests partly explained the association between depressive symptoms and bone loss, suggesting that efforts to increase exercise and improve physical performance in depressed men may be beneficial. INTRODUCTION: The aim of this study was to ascertain whether depressive symptoms are associated with increased rates of bone loss at the hip in older men. METHODS: A population-based prospective cohort study of 2,464 community-dwelling men, aged 68 and older, enrolled in the Osteoporosis in Men Sleep Ancillary Study had depressive symptoms assessed by the Geriatric Depression Scale (GDS). Subjects were categorized as depressed if GDS ≥6 at the initial examination. Bone mineral density (BMD) at the hip was measured using dual-energy X-ray absorptiometry at the initial and follow-up examination (average 3.4 years between exams). Use of antidepressant medications was assessed by interview and verified from medication containers at the two examinations. A computerized dictionary was used to categorize type of medication. RESULTS: In a base model adjusted for age, race/ethnicity, and clinic site, the mean total hip BMD decreased 0.70 %/year in 136 men with a GDS score of ≥6 compared to 0.39 %/year in 2,328 men with a GDS score of <6 (p = 0.001). Walking speed and timed chair stand partly explained the association between depressive symptoms and rates of bone loss. CONCLUSION: Depression, as defined by a score of 6 or greater on the Geriatric Depression Scale, is associated with an increased rate of bone loss at the hip in this cohort of older men. Adjustment for walking speed and timed chair stand attenuated the strength of the association, suggesting that differences in physical functioning do partially explain the observed association.

Optimization studies of the ITER low field side reflectometer.

Microwave reflectometry will be used on ITER to measure the electron density profile, density fluctuations due to MHD/turbulence, edge localized mode (ELM) density transients, and as an L-H transition monitor. The ITER low field side reflectometer system will measure both core and edge quantities using multiple antenna arrays spanning frequency ranges of 15-155 GHz for the O-mode system and 55-220 GHz for the X-mode system. Optimization studies using the GENRAY ray-tracing code have been done for edge and core measurements. The reflectometer launchers will utilize the HE11 mode launched from circular corrugated waveguide. The launched beams are assumed to be Gaussian with a beam waist diameter of 0.643 times the waveguide diameter. Optimum launcher size and placement are investigated by computing the antenna coupling between launchers, assuming the launched and received beams have a Gaussian beam pattern.

Analysis of the ITER low field side reflectometer transmission line system.

A critical issue in the design of the ITER low field side reflectometer is the transmission line (TL) system. A TL connects each launcher to a diagnostic instrument. Each TL will typically consist of ∼42 m of corrugated waveguide and up to ten miter bends. Important issues for the performance of the TL system are mode conversion and reflections. Minimizing these issues are critical to minimizing standing waves and phase errors. The performance of TL system is analyzed and recommendations are given.

Collisional damping of electron bernstein waves and its mitigation by evaporated lithium conditioning in spherical-tokamak plasmas.

The first experimental verification of electron Bernstein wave (EBW) collisional damping, and its mitigation by evaporated Li conditioning, in an overdense spherical-tokamak plasma has been observed in the National Spherical Torus Experiment (NSTX). Initial measurements of EBW emission, coupled from NSTX plasmas via double-mode conversion to O-mode waves, exhibited <10% transmission efficiencies. Simulations show 80% of the EBW energy is dissipated by collisions in the edge plasma. Li conditioning reduced the edge collision frequency by a factor of 3 and increased the fundamental EBW transmission to 60%.

Electron Bernstein wave emission based diagnostic on National Spherical Torus Experiment (invited).

National Spherical Torus Experiment (NSTX) is a spherical tokamak (ST) that operates with n(e) up to 10(20) m(-3) and B(T) less than 0.6 T, cutting off low harmonic electron cyclotron (EC) emission widely used for T(e) measurements on conventional aspect ratio tokamaks. The electron Bernstein wave (EBW) can propagate in ST plasmas and is emitted at EC harmonics. These properties suggest thermal EBW emission (EBE) may be used for local T(e) measurements in the ST. Practically, a robust T(e)(R,t) EBE diagnostic requires EBW transmission efficiencies of >90% for a wide range of plasma conditions. EBW emission and coupling physics were studied on NSTX with an obliquely viewing EBW to O-mode (B-X-O) diagnostic with two remotely steered antennas, coupled to absolutely calibrated radiometers. While T(e)(R,t) measurements with EBW emission on NSTX were possible, they were challenged by several issues. Rapid fluctuations in edge n(e) scale length resulted in >20% changes in the low harmonic B-X-O transmission efficiency. Also, B-X-O transmission efficiency during H modes was observed to decay by a factor of 5-10 to less than a few percent. The B-X-O transmission behavior during H modes was reproduced by EBE simulations that predict that EBW collisional damping can significantly reduce emission when T(e)<30 eV inside the B-X-O mode conversion (MC) layer. Initial edge lithium conditioning experiments during H modes have shown that evaporated lithium can increase T(e) inside the B-X-O MC layer, significantly increasing B-X-O transmission.

Reasons for underuse of angiotensin-converting enzyme inhibitors in patients with heart failure and left ventricular dysfunction.

We reviewed the records of 242 patients admitted over 1 year with heart failure and an ejection fraction < or = 45% to assess the use of angiotensin-converting enzyme inhibitors. Most patients were treated with angiotensin-converting enzyme inhibitors. However, an important minority (8%) had no apparent reason for the lack of this treatment, highlighting the need for strategies to increase the use of these beneficial agents.

Cardiopulmonary resuscitation on television. Miracles and misinformation.

BACKGROUND: Responsible, shared decision making on the part of physicians and patients about the potential use of cardiopulmonary resuscitation (CPR) requires patients who are educated about the procedure's risks and benefits. Television is an important source of information about CPR for patients. We analyzed how three popular television programs depict CPR. METHODS: We watched all the episodes of the television programs ER and Chicago Hope during the 1994-1995 viewing season and 50 consecutive episodes of Rescue 911 broadcast over a three-month period in 1995. We identified all occurrences of CPR in each episode and recorded the causes of cardiac arrest, the identifiable demographic characteristics of the patients, the underlying illnesses, and the outcomes. RESULTS: There were 60 occurrences of CPR in the 97 television episodes--31 on ER, 11 on Chicago Hope, and 18 on Rescue 911. In the majority of cases, cardiac arrest was caused by trauma; only 28 percent were due to primary cardiac causes. Sixty-five percent of the cardiac arrests occurred in children, teenagers, or young adults. Seventy-five percent of the patients survived the immediate arrest, and 67 percent appeared to have survived to hospital discharge. CONCLUSIONS: The survival rates in our study are significantly higher than the most optimistic survival rates in the medical literature, and the portrayal of CPR on television may lead the viewing public to have an unrealistic impression of CPR and its chances for success. Physicians discussing the use of CPR with patients and families should be aware of the images of CPR depicted on television and the misperceptions these images may foster.

Effects of a postdischarge clinic on housestaff satisfaction and utilization of hospital services.

This randomized, controlled clinical trial evaluated the effect of a postdischarge clinic on housestaff education and patient utilization of hospital services. Medicine housestaff were randomized either to attend a clinic once a week in which they saw all eligible patients they had recently discharged from the hospital, or to continue with usual discharge practices. We enrolled 751 patients, 312 on intervention teams and 439 on control teams. Intervention housestaff did not feel that the clinic took too much time and felt that they better knew how patients did after discharge. Fewer intervention patients had emergency room visits (28.0% to 20.8%, p = .03) in the 30 days after discharge. Length of stay, readmission rates, and mortality were similar for the two groups. We conclude that a postdischarge clinic can improve resident education and reduce postdischarge emergency room utilization.