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Carbonaceous aerosols and PM10 were monitored from September 8 to November 30, 2002, in a semi-urban site (Tsinghua University) in Beijing. Daily concentrations of OC and EC ranged from 7.1 to 65.9 microgCm(-3) and from 1.3 to 26.1 microgCm(-3), with the overall average concentrations of 21.2 microgCm(-3) and 7.3 microgCm(-3), respectively. The diurnal(More)
Higher visual cortical areas are involved in the perception of complex stimuli, such as the optic flow created by self-motion. On the other hand, area 18 is thought to extract primitive visual features, feeding higher cortical areas for further processing. In this study, we applied optical imaging of intrinsic signals in the central, lower visual field of(More)
A neuroecological equation of the Lotka-Volterra type for mean firing rate is derived from the conventional membrane dynamics of a neural network with lateral inhibition and self-inhibition. Neural selection mechanisms employed by the competitive neural network receiving external inputs are studied with analytic and numerical calculations. A remarkable(More)
We investigate what computational mechanisms give rise to the nonlinearity of complex cell responses in the primary visual cortex. Complex cells are characterized by their nonlinear spatial properties such as spatial phase invariance and nonlinear spatial additivity. We carried out network simulations to estimate the second-order Wiener-like kernels for(More)
To elucidate the effect of visual experience on the development of orientation maps, we conducted intrinsic signal optical imaging of the visual cortex of kittens that were continuously exposed to a single orientation through cylindrical-lens-fitted goggles under a freely moving condition starting at post-natal week 3. We observed a rapid reorganization of(More)
A long-standing question in neuroscience is how the brain controls movement that requires precisely timed muscle activations. Studies using Pavlovian delay eyeblink conditioning provide good insight into this question. In delay eyeblink conditioning, which is believed to involve the cerebellum, a subject learns an interstimulus interval (ISI) between the(More)