We consider generalizations of the Snyder algebra to a curved spacetime background with de Sitter symmetry. As special cases, we obtain algebras Yang model and triply relativity. discuss realizations these in terms canonical phase space coordinates, up fourth order deformation parameters. In case relativity also find exact realization, exploiting its algebraic relation model.

Amphetamine, a potent sympathomimetic amine, has powerful stimulant actions in the central nervous system. These actions are believed to be related to the influence of amphetamine on release and uptake of catecholamine neurotransmitters. The ['4C]deoxyglucose method makes it possible to study changes in cerebral metabolic rate in different areas of gray and white matter. Because of the close re...

The spectral turbulence model of Lorenz, as modified for surface quasigeostrophic dynamics by Rotunno and Snyder, is further modified to more smoothly approach nonlinear saturation. This model is used to investigate error growth starting from different distributions of the initial error. Consistent with an often overlooked finding by Lorenz, the loss of predictability generated by initial error...

The predominant biological hypothesis for a neurochemical defect in schizophrenia is currently the socalled "dopamine (DA) hypothesis." In its simplest form, this hypothesis states that schizophrenia may be related to a relative excess of DA-dependent neuronal activity. It is derived from pharmacologic evidence that drugs that decrease DA activity (e.g., the phenothiazines) may be antipsychotic...

the estimation of instantaneous peak discharge is important for watershed management because there is ainsufficient climatic and hydrologic data in countries such as iran. researchers have been forced to link constantparameters (geomorphology) and variable parameters (hydrology) to models with minimum dependence on climaticand hydrologic data for hydrologic estimation. the present study used a ...

Bedau, Snyder & Packard’s (1998) classification system for long-term evolutionary dynamics provides a test for openended evolution. Making this ALife test more rigorous, and passing it, are two of the most important open problems in the field. Previously (Channon, 2001) I presented the result that ‘Geb’, a system designed to verify and extend theories behind the generation of evolutionary emerg...