Electrodynamics of Media

Contains reports on four research projects.Joint Services Electronics Program (Contract DAAB07-76-C-1400)California Institute of Technology (Contract 953524)National Science Foundation (Grant ENG76-01654)National Aeronautics and Space Administration (Contract NAS5-24139

Electrodynamics of Media

Contains research objectives and summary of research.Joint Services Electronics Program (Contract DAAB07-71-C-0300)California Institute of Technology (Contract 953524

Inhaled corticosteroids and risk of pneumonia in newly diagnosed COPD

SummaryIntroductionThe use of inhaled corticosteroids (ICS) in COPD may be associated with an increased risk of pneumonia. Little is known of this risk in newly diagnosed COPD patients. The objective of this study was to determine if the use of ICS among newly diagnosed COPD patients is associated with an increased risk of pneumonia hospitalizations.MethodsUsing data from the Department of Veterans Affairs and Centers for Medicare and Medicaid Services, a nested case–control study was performed. We identified patients 65 years of age or older with a new diagnosis of COPD from 1998 to 2002. A total of 145,586 patients were identified. Cases were defined based on hospitalization for pneumonia and exposure was prior use of ICS. Up to 10 controls were matched for each case based on age, sex, month and year of the case. The association between ICS use and pneumonia was evaluated with conditional logistic regression controlling for age, comorbidities, medication classes associated with the risk of pneumonia, and markers of COPD severity.ResultsThere were 13,995 cases of pneumonia. The cohort was predominantly male with an average age of 75.1 (SD=5.4) years. The rate of pneumonia was 6.4 per 100 person-years. After adjustment for covariates, patients with current use of ICS were 1.38 (95% CI, 1.31–1.45) times more likely to have a hospitalization for pneumonia than those without current use of ICS.ConclusionsThe use of ICS among patients with newly diagnosed COPD is associated with an increased risk of hospitalization for pneumonia

Remote sensing of Earth terrain

Remote sensing of earth terrain is examined. The layered random medium model is used to investigate the fully polarimetric scattering of electromagnetic waves from vegetation. The model is used to interpret the measured data for vegetation fields such as rice, wheat, or soybean over water or soil. Accurate calibration of polarimetric radar systems is essential for the polarimetric remote sensing of earth terrain. A polarimetric calibration algorithm using three arbitrary in-scene reflectors is developed. In the interpretation of active and passive microwave remote sensing data from the earth terrain, the random medium model was shown to be quite successful. A multivariate K-distribution is proposed to model the statistics of fully polarimetric radar returns from earth terrain. In the terrain cover classification using the synthetic aperture radar (SAR) images, the applications of the K-distribution model will provide better performance than the conventional Gaussian classifiers. The layered random medium model is used to study the polarimetric response of sea ice. Supervised and unsupervised classification procedures are also developed and applied to synthetic aperture radar polarimetric images in order to identify their various earth terrain components for more than two classes. These classification procedures were applied to San Francisco Bay and Traverse City SAR images

Electrodynamics of Media

Contains research objectives and summary of research on three projects and reports on five research projects.Joint Services Electronics Program (Contract DAAB07-74-C-0630)California Institute of Technology (Contract 953524

Electrodynamics of Media

Contains research objectives, summary of research and reports on two research projects.Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DAAB07-71-C-0300U. S. Army Research Office - Durham (Contract l)AHC04-72-C-0044)California Institute of Technology Contract 953524M.I.T. Sloan Fund for Basic Researc

Retinal Changes in a Mutant Form of Goldfish with Megalophthalmia

The retinal changes of a mutant strain of goldfish with megalophthalmia were studied by histology, electron microscopy and biochemistry. Changes in the morphology of the pigment epithelium, decrease in number of photoreceptors, thinning out of retinal layers and the existence of spaces in the retina were all features as the eyes grew in size. Invasion of macrophages was also evident in the retina. A decrease in leucine uptake per milligram of retina was also detected as the eye grew beyond 0.8 millilitre in volume. These changes, although related to volume changes (i.e., growth) of the eyes, were found to have little relationship with increase of intraocular pressure as intraocular pressures in the growing eyes of the mutant strain did not change much. Goldfish from a control strain with similar eye volumes and sizes (ages) were used for comparison and similar changes as in the mutant were not apparent

Electrodynamics of Media

Contains research objectives, summary of research and reports on three research projects.Joint Services Electronics Program (Contract DAAB07-75-C-1346)California Institute of Technology (Contract 953524