Understanding the transport and metabolism of 3,4-dihydroxy-L-phenylalanine (L-dopa) in the human brain is necessary to better treat people with Parkinson's disease. This disease is caused by an insufficient amount of dopamine (DA) produced in the brain. Positron emission tomography (PET) imaging has been used to study the activity of the dopamine producing enzyme, aromatic amino acid decarboxylase (dopa decarboxylase), in conjunction with a radio labeled analog of L-dopa, 6-[18F]fluoro-L-dopa or F-dopa. In this paper, using reaction coefficients calculated by Gjedde from PET scans, a set of differential equations representing the mass balance of all the reactions and diffusion from L-dopa to dopamine in the blood and brain was created.
lectronic noses, small electronic instruments with carbon sensing films, provide an artificial version of our olfactory system. In conjunction with pattern recognition techniques, electronic noses can be used to identify odor combinations, perform rudimentary perceptual analysis, and classify unknown odors. Although many different algorithms, from statistical analysis to biologically-inspired neural networks, have been implemented as e-nose pattern recognition techniques, no perfect algorithm has been found. This paper explores the creation and implementation of a novel identification system that uses an outside database to extrapolate the identity of an unknown odor.
Millions of people suffer from various diseases of the central nervous system such as stroke, Parkinson's disease, Alzheimer's disease, and hydrocephalus. To improve the treatment options available, a better understanding of the intracranial dynamics is required. The understanding of intracranial dynamics leads to quantification of fluid flow, cerebrospinal blood pressure, and extension of brain vasculature during the cardiac cycle. One such quantification method, used to simulate the physiological conditions in the brain, is the computer program MATLAB, and one proposed approach is using a "compartmental" model, where arteries, veins, choroids plexus, and other areas and vessels in the brain are lumped as compartments to simulate the intracranial dynamics under normal and hydrocephalic conditions.