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This paper describes the development of an electronic neuron emulator that has both passive and active electrical properties of a neuron as seen from a single electrode. The main utility of this device is for testing electrophysiological equipment such as a single-electrode voltage clamp or a patch-clamp amplifier. Each spike of the action potential is generated by a limited amount of charge stored...
A cotraining-based approach is introduced for constructing high-performance classifiers for P300-based brain-computer interfaces (BCIs), which were trained from very little data. It uses two classifiers: Fisher's linear discriminant analysis and Bayesian linear discriminant analysis progressively teaching each other to build a final classifier, which is robust and able to learn effectively from unlabeled...
Glaucoma is the second leading cause of blindness. Glaucoma can be diagnosed through measurement of neuro-retinal optic cup-to-disc ratio (CDR). Automatic calculation of optic cup boundary is challenging due to the interweavement of blood vessels with the surrounding tissues around the cup. A Convex Hull based Neuro-Retinal Optic Cup Ellipse Optimization algorithm improves the accuracy of the boundary...
The central nervous system is composed of many different interacting neurons all working together to provide sensory, motor, and visceral signals to the specific organism. The environment in which those neurons operate is crucial to the survival of the organism. Some environmental factors may include pH, temperature, or the intra-and extracellular ion concentration. If any of these factors are changed...
Dimethylformamide (DMF) is a hydrophilic aprotic solvent often used in peptide coupling, an essential process in the pharmaceutical industry. Its use in biological study is typically in the role of a peptide solvent when evaluating the efficacy of peptides and their effect on the cellular membrane. In evaluating the effect of the peptide gramicidin on neurons of the central nervous system (CNS) of...
Gramicidin is a pore-forming peptide which exhibits lethal properties against a large spectrum of cells. It forms monovalent cation-specific channel in the lipid bilayer of a cellular membrane with limited permeability to anions or polyvalent cations. Both ions and water move through the pore which is formed by the peptide backbone. We detected formation of pores induced by the dimerization of gramicidin...
This paper outlines the construction of a neuronal feedback control system. The circuit developed is discussed with design considerations for electrode resistance and power supply noise. To verify the design, tests with the Neuron Emulator, developed at the University of Rhode Island, were performed. This device has shown to be an inexpensive means to current clamp neurons with potential to voltage...
The effect of changing posture from supine to standing on the heart rate variability (HRV) was analyzed on the EUROBAVAR data set using power spectral analysis. Power spectral analysis has been commonly used to provide indices of autonomic cardiovascular modulation. Although the interpretation of power spectra is in dispute, it is generally agreed that the high-frequency (HF) power components represent...
High dimension complex dynamical systems, such as those found in physiological processes, are often accompanied by nonstationarity. In many cases, the nonstationarity is caused by a physiologically significant event such as the prelude to ventricular fibrillation in cardiac arrest or the change of stasis by introducing pharmaceuticals. A need exists to be able to detect and monitor this change. Most...
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