in this paper, we develop a numerical resolution of the space-time fractional advection-dispersion equation. we utilize spectral-collocation method combining with a product integration technique in order to discretize the terms involving spatial fractional order derivatives that leads to a simple evaluation of the related terms. by using bernstein polynomial basis, the problem is transformed in...

The evolution in space and time of crime risk and criminal density is modeled by a coupled system of partial differential equations, and solved with a semi-implicit method using finite differences. Under appropriate conditions, isolated stationary hot spots of high criminal activity form.

This paper presents a general 8th-order PDE method to generate Bézier surfaces from the boundary with position and tangent vector information. We extend the work on generating biharmonic Bézier surfaces by Monterde to generating Bézier surfaces based on a general 4th-order PDE. And further the results are extended to generate tetraharmonic Bézier surfaces by a general 8th-order PDE. The solutio...

Cyclic adenosine monophosphate (cAMP) is an important modulator of platelet responses to agonists. Cyclic nucleotide phosphodiesterase (PDE) controls intracellular cAMP concentrations by hydrolyzing it to AMP. The major PDE activity in platelets is PDE3A (cyclic guanosine monophosphate [cGMP]-inhibited PDE). To obtain structural information on platelet PDE3A, we cloned the enzyme cDNA from a hu...

Amplitudes of cardiac contractions initiated by Ca2+-induced Ca2+ release (CICR) are proportional to the magnitude of Ca2+ current (ICa-L). However, large contractions accompanied by little inward current have been reported in some but not all studies in which cells were dialyzed with different analogs of cAMP. This study compares the effects of different phosphodiesterase (PDE)-resistant and P...

Nerve growth factor (NGF) has been shown to increase cyclic AMP in PC12 cells and to potentiate the actions of other agents that raise cyclic AMP. In our studies, NGF causes over 50% loss of PDE 2 activity (cyclic GMP-stimulated cyclic nucleotide phosphodiesterase) in PC12 cells within 24 h. After 72 h of NGF treatment, cyclic AMP hydrolysis in PC12 extracts is no longer cyclic GMP-stimulated. ...

Phosphodiesterases (PDEs) catalyze the hydrolysis of the second messengers cAMP and cGMP. However, little is known about how PDE activity regulates cyclic nucleotide signals in vivo because, outside of specialized cells, there are few methods with the appropriate spatial and temporal resolution to measure cyclic nucleotide concentrations. We have previously demonstrated that adenovirus-expresse...

It is known that cAMP and cGMP are important for vasorelaxation, and cyclic nucleotide phosphodiesterases (PDEs) regulate their levels. Balloon angioplasty (BAL) is associated with reduced cAMP and cGMP levels, and inhibition of PDE-3 reduces restenosis. In this study, we found that BAL increased PDE-3 activity, which affected vasoreactivity of rat aortic rings 24-h post-BAL; these were compare...

PURPOSE To characterize the spatial and temporal expression of key structural and phototransduction cascade proteins in the monkey cone outer segment (OS). METHODS Retinas from Macaca monkeys from ages fetal day (Fd) 89 through adulthood were double labeled using immunofluorescence for short (S) or long/medium (L/M) wavelength-sensitive cone opsin and either a structural protein (peripherin) ...