We measured the timecourse of brightness processing by briefly presenting brightness illusions and then masking them. Brightness induction (brightness contrast) was visible when presented for only 58 ms, was stronger at short presentation times, and its visibility did not depend on spatial frequency. We also found that White's illusion was visible at 82 ms. Together, these results suggest that ...

Several psychophysical studies have shown that transparency can have drastic effects on brightness and lightness. However, the neural processes generating these effects have remained unresolved. Several lines of evidence suggest that the early visual cortex is important for brightness perception. While single cell recordings suggest that surface brightness is represented in the primary visual c...

A primordial degree of circular polarization of the Cosmic Microwave Background is not observationally excluded. The hypothesis of primordial dichroism can be quantitatively falsified if the plasma is magnetized prior to photon decoupling since the initial V-mode polarization affects the evolution of the temperature fluctuations as well as the equations for the linear polarization. The observed...

Context. Asteroseismology of Sun-like stars is undergoing rapid expansion with, for example, new data from the CoRoT mission and continuation of ground-based campaigns. There is also the exciting upcoming prospect of NASA’s Kepler mission, which will allow the asteroseismic study of several hundred Sun-like targets, in some cases for periods lasting up to a few years. Aims. The seismic mode par...

a study was carried out on totally chlorine-free (tcf) bleachability of dimethyl formamide (dmf) treated bagasse pulps exposed to cz-3 and fp 90031-sp strains of white-rot fungus ceriporiopsis subvermispora. this process involved an oxygen and peroxide stage bleaching sequence. the effect of enzymatic stage on bleachability properties was studied and compared with control pulps, processed witho...

The inhomogeneous brightness distribution of BATSE detected gamma-ray bursts has been considered strong evidence for their cosmological origin. However, subclasses of gamma-ray bursts have been shown to have significantly more homogeneous brightness distributions. Pendleton et al. (1997) have found such a result for gamma-ray bursts with no detectable emission at energies >300 keV. Accordingly,...

The Gamma Ray Burst GRB920229 has four extreme and unprecedented properties; a rise in brightness with an e-folding time scale of 220 ± 30μs, a fall in brightness with an e-folding time scale of 400± 100μs, a large change in spectral shape over a time of 768μs, and a sharp spectral cutoff to high energies with ∆E/E = 18%. The rapid changes occur during a spike in the light curve which was seen ...

Background: The major limitation in human vision is refractive error. Auxiliary equipment and methods for these people are not always available. In addition, limited range of accommodation in adult people when switching from a far point to a near point is not simply possible. In this paper, we are looking for solutions to use the facilities of digital image processing and displaying to improve ...

Surface brightness data can distinguish between a Friedman-Robertson-Walker expanding universe and a nonexpanding universe. For surface brightness measured in AB magnitudes per angular area, all FRW models, regardless of cosmological parameters, predict that surface brightness declines with redshift as (z+1), while any non-expanding model predicts that surface brightness is constant with distan...

Interoduction: Ultrasound images have often low contrast due to small differences in acoustic impedance between different tissues. Air or gas microbubbles that surrounded by membrane are most of the contrast agents in ultrasound imaging. Problems such as instability in sound pressure and inability in penetrating from the blood vessel into body tissues limited the use of microbubbles into the in...