Visible Airglow Experiment data analysis

The Visible Airglow Experiment (VAE) was designed to provide detailed profiles of the distribution of excited states of atoms and molecules in the upper atmosphere. The studies supported during the funding period (1983 - 1989) have made significant contributions in the area of thermospheric aeronomy, and the progress during the first four years of this period has been reviewed by Hays et al. (1988). The investigations carried out have resulted in more than 20 publications, and these are summarized

Atmospheric scattering effects on ground-based Fabry-Perot measurements of thermospheric winds: An inversion technique

The theoretical development of a technique to recover velocities measured with a Fabry-Perot interferometer in the presence of scattered light is presented. Simulations are carried out which show that the inversion is effective in recovering actual velocities, especially in instances when the observed brightness is dominated by scattered light.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25593/1/0000137.pd

Optical effects of spacecraft-environment interaction Spectrometric observations of the DE-2 satellite

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76678/1/AIAA-25728-876.pd

Mesospheric 5577A green line and atmospheric motions--Atmosphere explorer satellite observations

Photometric measurements of the 5577A O(1S) green line mesospheric emission obtained by the Visible Airglow Experiment (VAE) on board the Atmosphere Explorer (AE) satellite have been analyzed. The inverted volume emission rate profiles showed a peak at approximately 96-97 km with a half-width of ~8 km. The diurnal variation of the intensity indicates the presence of a wave component with 10 ~ 12 h period, probably of solar semi-diurnal tide. Shorter time scale variations due to the presence of travelling waves were also observed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26532/1/0000071.pd

Thin discs, thick dwarfs and the effects of stellar feedback

We investigate the role of stellar mass in shaping the intrinsic thickness of galaxy discs by determining the probability distribution of apparent axis ratios (b/a) for two different samples that probe the faint end of the galaxy luminosity function. We find that the b/a distribution has a characteristic 'U-shape' and identify a limiting mass M_* ~ 2x10^9 M_sun below which low-mass galaxies start to be systematically thicker. This tendency holds for very faint (M_B ~ -8) dwarfs in the Local Volume, which are essentially spheroidal systems. We argue that galaxy shape is the result of the complex interplay between mass, specific angular momentum and stellar feedback effects. Thus, the increasing importance of turbulent motions in lower mass galaxies leads to the formation of thicker systems, a result supported by the latest hydrodynamical simulations of dwarf galaxy formation and other theoretical expectations. We discuss several implications of this finding, including the formation of bars in faint galaxies, the deprojection of HI line profiles and simulations of environmental effects on the dwarf galaxy population.Comment: 6 pages, 2 figures. Accepted for publication in MNRAS Letter

The High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76425/1/AIAA-1993-123-305.pd

Renal function stratified dose comparisons of eplerenone versus placebo in the EMPHASIS-HF trial.

BACKGROUND: Current heart failure guidelines recommend target eplerenone dose of 50 mg/day. We have examined the effect of different eplerenone doses based on pre-specified renal function stratification in the Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure (EMPHASIS-HF). METHODS AND RESULTS: In EMPHASIS-HF, the target dose of eplerenone/placebo was stratified at randomization according to estimated glomerular filtration rate (eGFR): 50 mg/day if eGFR ≥ 50 mL/min/1.73 m2 and ≤ 25 mg/day if eGFR 30-49 mL/min/1.73 m2 . Patients remained within these dose ranges during the trial (as per stratification). The primary outcome was a composite of heart failure hospitalization or cardiovascular mortality. Eplerenone was superior to placebo within each respective eGFR stratum [eplerenone vs. placebo in the eGFR ≥ 50 mL/min/1.73 m2 stratum: hazard ratio (HR) 0.58, 95% confidence interval (CI) 0.45-0.74; and eplerenone vs. placebo in the eGFR 30-49 mL/min/1.73 m2 stratum: HR 0.62, 95% CI 0.49-0.78; Pinteraction  = 0.89]. Despite receiving lower eplerenone doses, patients in the eGFR 30-49 mL/min/1.73 m2 stratum more often had hyperkalaemia, renal failure events, and drug discontinuation. CONCLUSION: In EMPHASIS-HF the eplerenone dose was stratified according to renal function and the treatment effect was not influenced by renal function: 25 mg/day in patients with eGFR 30-49 mL/min/1.73 m2 was as effective as 50 mg/day in patients with eGFR > =50 mL/min/1.73 m2 . However, patients with impaired renal function experienced more adverse events, despite reveiving lower eplerenone doses. Current guidelines do not recommend tailoring the dose of eplereone according to renal function but the current data suggest they should

The dayglow of the O2 atmospheric band system

The dayglow of the O2 atmospheric band system has been simulated by taking into account the three main production mechanisms of the O2(1[Sigma]) state: resonance fluorescence, a photochemical term due to quenching of O(1D), and a pure chemical process. Values of the g factor, which are involved in the resonant scattering of the O2 atmospheric bands (A, B and [gamma]), have been obtained as a function of altitude (0-120 km) and solar zenith angle using a line-by-line calculation. The values of the g factor, along with updated rate coefficients, have been used in the calculation of the production rate of O2(1[Sigma]) and the volume emission rate of the (O21[Sigma], [nu]' = 0)-(O23[Sigma], [nu]" = 0) transition. The results of these calculations are compared to observational measurements and are found to be in excellent agreement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26002/1/0000068.pd