A laminated energetic electrostatic analyzer for 0-5 keV charged particles.

A compact electrostatic energy bandpass filter based on a laminated analyzer design has been developed to measure charged particle fluxes at energies ranging from 0 to 5 keV. The sensor head has been successfully tested against a low energy magnetically filtered plasma source and an ion beam source capable of producing energetic ions in the range of 100-1250 eV. Additionally, the instrument has demonstrated the ability to accurately measure negative spacecraft frame charging using a low Earth orbit plasma simulator. The effects of the spacecraft frame charging on the measured energy distribution measurements and the impact regarding the derived charged particle density and temperature parameters are also examined.

High-precision fringe tracking invariant to systematic model errors.

We present a new approach to processing of interferometric data, which dramatically improves operation on the smallest fraction of the fringe (approximately 1/1,000 of a wavelength and beyond). In particular, this approach, dubbed the variation-invariant subspace tracking approach (VISTA), makes it possible to operate a Michelson interferometer in a highly stable mode in which the estimation of optical path delay becomes invariant (insensitive) to a large class of systematic model errors. This previously unknown invariance property of interferometry follows from the fundamental odd-even symmetry of the channeled spectrum and its derivatives. VISTA offers a powerful algorithmic alternative for alleviating technological challenges in the design of high-precision long-baseline spaceborne interferometers.

The significance of comorbidity in advanced laryngeal cancer.

INTRODUCTION: Cancer patients often have concurrent diseases and conditions known as comorbidities. The aim of this project is to demonstrate the significance of comorbidity in the treatment and outcomes of advanced laryngeal carcinoma. METHODS: A retrospective medical record review of 182 patients with previously untreated T3 or T4 squamous carcinomas of the larynx treated at M. D. Anderson between 1990 and 1995 was performed. Demographic, patient-specific, tumor-specific, and outcome measures information were collected. Comorbidity was coded using the Modified Medical Comorbidity Index. Univariate and multivariate analysis with the use of life survival analysis techniques and logistic regression were performed. RESULTS: The median age at diagnosis was 59.5 years. Most patients were men (69.2%) and Caucasian (73.1%). Laryngeal preservation was performed in 90 patients, and surgical resection was performed in 92 patients. Patients in the two treatment groups had similar comorbidity, locoregional control (65%), and 5-year survival (37.3%). Patients with either moderate or severe comorbidity had significantly worse overall survival (p = .00014) and worse 5-year survival than those with no or mild comorbidity (21.8% vs 46.3%, p = .003). CONCLUSIONS: This study demonstrates that comorbidity is significantly associated with survival in a group of patients with identical histology, site, and stage. Comorbid status should be incorporated into the assessment of prognosis and outcome to improve and optimize the management of head and neck cancer patients.

Effects of sodium bicarbonate ingestion on anaerobic performance: a meta-analytic review.

Many researchers have investigated the effects of induced metabolic alkalosis, by ingestion of sodium bicarbonate, on anaerobic exercise performance. But the results have been inconsistent and often contradictory. The purpose of this review was to synthesize the varied findings using a meta-analytic approach. Twenty-nine investigations met our inclusion criteria. Results show that NaHCO3 ingestion clearly results in a more alkaline extracellular environment. The dosage, however, was only moderately related to the increase in pH and HCO3-. Overall, performance was enhanced but the range of effect sizes was large, -0.12 to 2.87. In studies that measured time to exhaustion, there was a mean 27 +/- 20% increase in duration. The treatment effect, however, was only weakly related to the degree of induced alkalosis. But in comparing the 19 studies that showed a positive treatment effect with the 16 that showed no effect, the former were associated with a greater increase in pH following ingestion of a somewhat larger dosage, and a greater decrease in pH with exercise.