Search

Dogs with rapid cardiac pacing-induced heart failure were analyzed after daily treadmill exercise to determine the aerobic training on the properties of intrinsic left ventricular (LV) systolic and diastolic function. Treadmill exercise in dogs exposed to rapid cardiac pacing attenuated abnormalities in resting hemodynamics and other manifestations of chronic heart failure. The effects of exercise training on heart function also involved small changes in LV systolic properties and larger changes in diastolic myocardial properties.

We report on a novel 6 channel optical spectrometer (further on called mini-DOAS instrument) for aircraftborne nadir and limb measurements of atmospheric trace gases, liquid and solid water, and spectral radiances in the UV/vis and nearIR spectral ranges. The spectrometer was developed for measurements from aboard the HALO (http://www.halo.dlr.de/) research aircraft during dedicated research missions. Here we report on the relevant instrumental details and the novel scaling method used to infer the mixing ratios of UV/vis absorbing trace gases from their absorption measured in limb geometry. The uncertainties of the scaling method are assessed for NO2 and BrO measurements. Some first results are reported along with complementary measurements and comparisons with model predictions for a selected HALO research flight from Cape Town to Antarctica, which was performed during the research mission ESMVal on 13 September 2012. [ABSTRACT FROM AUTHOR]

We quantify quasar color variability using an unprecedented variability database--ugriz photometry of 9093 quasars from Sloan Digital Sky Survey (SDSS) Stripe 82, observed over 8 years at ~60 epochs each. We confirm previous reports that quasars become bluer when brightening. We find a redshift dependence of this blueing's in a given set of bands (e.g., g and r), but show that it is the result of the flux contribution from less-variable or delayed emission lines in the different SDSS bands at different redshifts. After correcting for this effect, quasar color variability is remarkably uniform, and independent not only of redshift, but also of quasar luminosity and black hole mass. The color variations of individual quasars, as they vary in brightness on year timescales, are much more pronounced than the ranges in color seen in samples of quasars across many orders of magnitude in luminosity. This indicates distinct physical mechanisms behind quasar variability and the observed range of quasar luminosities at a given black hole mass--quasar variations cannot be explained by changes in the mean accretion rate. We do find some dependence of the color variability on the characteristics of the flux variations themselves, with last, low-amplitude, brightness variations producing more color variability. The observed behavior could arise if quasar variability results from flares or ephemeral hot spots in an accretion disk. [ABSTRACT FROM AUTHOR]