A model of learning mechanisms in the brain.
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
We have implemented two analog VLSI computational sensors for sensing and encoding high dynamic range images by exploiting temporal dimension of photoreception. The first sensor is a multi-integration time photoreceptor that automatically adapts to use different integration periods depending on light intensity. It exhibits a dynamic range 128 times larger than that of a single integration period photoreceptor, approximately 1:128000. The second sensor is an intensity-to-time processing paradigm that is based on the notion that stronger stimuli elicit responses before weaker ones. The paradigm sorts pixels of sensed images by their intensities, thus achieving information-theoretic optimal encoding of images. It handles dynamic range of approximately 1:1000000. Both implementations can operate at standard video rate of 30framess(-1).
Explore the source record for details and available documents.
During the spring of 1981 a massive intoxication broke out in Spain, which is presently attributed to the ingestion of denatured rape oil, and which has been called 'Toxic Syndrome' (TS). We studied 51 patients affected by the TS one year after the onset of their disease, analyzing their vestibular responses in the caloric test with the help of an analog-digital computer. A significant decrease in the number of nystagmic beats of the affected patients can be observed, while the rest of the parameters studied show similar values to those found simultaneously in 30 normal subjects. It is suggested that these differences are yet another manifestation of the polyneuropathy found in intoxication by denatured rape oil.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In the preceding paper (Balázs, Machiyama, Hammond, Julian & Richter, 1970) the flux of gamma-aminobutyrate (GABA) was found, in guinea-pig brain-cortex slices incubated in glucose-saline medium, to represent about 10% of the total tricarboxylic acid cycle flux, as opposed to other estimates, which are as high as 40%. However, the latter value was deduced from experimental results by methods that made no allowance for the metabolic compartmentation of glutamate: a mathematical investigation was therefore undertaken to show that this omission necessarily leads to an overestimation of GABA flux. The magnitude of this over-estimation was shown by computer simulation methods to be of such an order as to bring the corrected value into agreement with the lower value. Computer simulation methods were also used to evaluate the GABA flux from the experimental results presented by Balázs et al. (1970) and a value of 0.0315mumol/min per g wet wt. was obtained. This value was also shown to be consistent, in the simulated system, with the experimentally observed time-courses for the radioactivity and quantity of aspartate. Since there is now evidence that GABA is itself a metabolically compartmented intermediate this possibility was considered mathematically, but it was found that in this case the assumption of compartmentation had little effect upon the value of GABA flux deduced on the basis of GABA homogeneity.