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CreatorTitleDescriptionSubjectDate
76 Gesteland, Raymond F.; Atkins, John F.; Felden, Brice; McCutcheon, John P.Probing the structure of the Escherichia coli 10Sa RNA (tmRNA)The conformation of the Escherichia coli 10Sa RNA (tmRNA) in solution was investigated using chemical and enzymatic probes. Single- and double-stranded domains were identified by hydrolysis of tmRNA in imidazole buffer and by lead(II)-induced cleavages. Ribonucleases T1 and S1 were used to map unpai...Covariation; Pseudoknot; Structural Probing; 10Sa RNA; tmRNA1997
77 Christensen, Douglas A.Dispersion effects in fiber optic interferometryAn extended analysis of the effects of uncompensated fiber dispersion on the fringe visibility of a fiber optic interferometer is developed, with particular emphasis on stellar interferometry. Both material and waveguide dispersion for single-mode, polarization-preserving fibers are considered. It...Stellar interferometry; Fiber optics; Statistical optics1997
78 Horch, Kenneth W.Electrical stimulation of the ventral lumbo-sacral spinal cord results in mixed recruitment order of quadriceps and tibialis anterior motor unitsPulse width modulated, twitch recruitment curves for quadriceps and tibialis anterior were obtained by stimulating their respective motor activation pools in the ventral lumbo-sacral portion of the spinal cord. The duration of the twitch responses were analyzed as a function of stimulus strength ...Quadriceps; Tibialis anterior; Ventral lumbo-sacral spinal cord; Reversed recruitment1997
79 Normann, Richard A.; Jones, Kelly E.Advanced demultiplexing system for physiological stimulationA CMOS very large scale integration (VLSI) chip has been designed and built to implement a scheme developed for multiplexing/demultiplexing the signals required to operate an intracortical stimulating electrode array. Because the use of radio telemetry in a proposed system utilizing this chip may im...Electrode Array; Stimulation; Telemetry; Microelectrodes; Transistors1997
80 Gesteland, Raymond F.; Atkins, John F.; Ingram, Jennifer A.; Kelly, Paul J.; Grentzmann, GuidoDual-luciferase reporter system for studying recoding signalsA new reporter system has been developed for measuring translation coupling efficiency of recoding mechanisms such as frameshifting or readthrough. A recoding test sequence is cloned in between the renilla and firefly luciferase reporter genes and the two luciferase activities are subsequently measu...Amino Acid Sequence; Genes, Reporter; HIV; Antizyme; Translation1998
81 Christensen, Douglas A.; Herron, James N.Rapid clinical diagnostics assays using injection-molded planar waveguidesThe goal of our research program is to develop an evanescent wave immunoassay system that can be used in point-of-care and critical care settings. Several key attributes are required to accomplish this goal: (i) the assay system should be at least as sensitive as present day immunoassays; (ii) assay...Planar waveguides; Creatine phosphokinase MB (CK-MB); Cardiac troponin I (cTnl); Diagnostics; Evanescence; Fluorescence; Human chorionic gonadotropin (hCG)1998
82 Normann, Richard A.; Shah, Maulik R.Study of printed spiral coils for neuroprosthetic transcranial telemetry applicationsWe have explored the use of printed spiral coils (PSC's) for neuroprosthetic transcranial telemetry applications. We fabricated two-dimensional PSC's on a thin (25 microns) polyimide substrate using copper (35 microns) as a conducting material. All the coils had a fixed inner diameter of 1.0 cm. We ...Blindness; Neuroprosthesis; Transcranial Telemetry System; Prosthesis Design1998
83 Christensen, Douglas A.Plasma-etched polymer waveguides for intrachip optical interconnectsOptical intrachip communication offers the potential advantages of high speed and lack of electrical interference. We report on progress made on an interconnect design using GaAs LEDs, polymer waveguides, and photodiodes in a silicon substrate. The polymer waveguides are fabricated in polyimide or p...Polymer waveguides; Intrachip interconnects; LEDs1998
84 Normann, Richard A.; Maynard, Edwin M.Neural interface for a cortical vision prosthesisThe development of a cortically based vision prosthesis has been hampered by a lack of basic experiments on phosphene psychophysics. This basic research has been hampered by the lack of a means to safely stimulate large numbers of cortical neurons. Recently, a number of laboratories have developed a...Neuroprosthetics; Artificial Vision; Electrode Arrays; Multielectrode Recordings; Biocompatibility1999
85 Normann, Richard A.; Maynard, Edwin M.Neuronal interactions improve cortical population coding of movement directionInteractions among groups of neurons in primary motor cortex (MI) may convey information about motor behavior. We investigated the information carried by interactions in MI of macaque monkeys using a novel multielectrode array to record simultaneously from 12-16 neurons during an arm-reaching task. ...Motor Cortex; Monkey; Population Coding; Movement1999
86 Horch, Kenneth W.Selective activation of muscle groups in the feline hindlimb thorough electrical microstimulation of the ventral lumbo-sacral spinal cordSelective activation of muscle groups in the feline hindlimb by electrical stimulation of the ventral lumbo-sacral spinal cord was investigated. Spinal cord segments L5 to S1 were mapped using a penetrating tungsten needle electrode. Locations that produced isolated contraction of quadriceps, ti...Functional electrical stimulation; Motor pools; Spinal chord stimulation2000
87 Christensen, Douglas A.Planar waveguide biosensors for nucleic acid hybridization reactionsOligonucleotide probes derived from (1) the T3 RNA polymerase promoter sequence (T3) and (2) prostate-specific antigen messenger RNA (PSA) were prepared and labeled with a red-emitting fluorescent dye (Cy5). The complimentary oligonucleotides (anti T3 and anti PSA) were prepared and labeled with bio...Planar waveguides; Evanescence; Fluorescence; Glandular kallikrein; MDx; Molecular diagnostics; Nucleic acid; PSA; Oligonucleotide probes2000
88 Horch, Kenneth W.Muscle recruitment through electrical stimulation of the lumbo-sacral spinal cordThe goal of this study was to determine the feasibility of producing graded muscle contraction in individual muscles or muscle groups by electrically stimulating motor neurons in the lumbo-sacral spinal cord. Recruitment curves were obtained for quadriceps, tibialis anterior and triceps surae/pl...Functional neuromuscular stimulation (FNS); Motor pools, Muscle recruitment, Spinal cord stimulation2000
89 Christensen, Douglas A.; Furse, Cynthia M.Problem and treatment of DC offsets in FDTD simulationsThis paper discusses the causes of and some solutions to the commonly observed problem of dc field offsets in finite-difference time-domain (FDTD) simulations. DC electric and magnetic field offsets are shown to be valid calculated responses of the modeled systems, resulting from interaction betwee...Finite-difference time-domain method; Direct current offsets; Waveforms2000-08
90 Christensen, Douglas A.Using the cardiovascular system to illustrate fundamental laws and principles in a freshman courseOur Fundamentals of Bioengineering I course is organized around key physical and engineering laws and principles. A semester-long Major Project is assigned which integrates many of these principles by modeling the human systemic cardiovascular system, using both Matlab computer analysis and assembly...Matlab2002
91 Horch, Kenneth W.; Christensen, Douglas A.Accelerated 4-year bachelors/masters degree program in biomedical engineeringIn response to the need for providing advanced engineering education in a shorter time period than is currently possible by traditional curricula, we have created an Accelerated Dual Degree program in biomedical engineering. The purpose of this pilot program is to attract the brightest students, g...Accelerated; Dual-degrees; Education2002
92 Horch, Kenneth W.; Christensen, Douglas A.Accelerated 4-year bachelors/masters degree program in biomedical engineeringIn response to the need for providing advanced engineering education in a shorter time period than is currently possible by traditional curricula, we have created an Accelerated Dual Degree program in biomedical engineering. The purpose of this pilot program is to attract the brightest students, g...Accelerated dual-degree program2002
93 Angelucci, Alessandra; Lund, Jennifer S.Circuits for local and global signal integration in primary visual cortexContrast-dependent changes in spatial summation and contextual modulation of primary visual cortex (V1) neuron responses to stimulation of their receptive field reveal long-distance integration of visual signals within V1, well beyond the classical receptive field (cRF) of single neurons. To identif...Primary Visual Cortex; Extrastriate Cortex; Feed-back Connections; Lateral Connections; SUrround Modulation; Macaque2002-10-01
94 Varner, Michael W.; Clark, Edward B.; Fernando, Kumari L.; Mathews, V. JohnRobust estimation of fetal heart rate variability using Doppler ultrasound.This paper presents a new measure of heart rate variability (HRV) that can be estimated using Doppler ultrasound techniques and is robust to variations in the angle of incidence of the ultrasound beam and the measurement noise. This measure employs the multiple signal characterization (MUSIC) algori...Prenatal Ultrasonography; Fetal Heart Rate; Blood Flow Velocity; Algorithms2003-08
95 Normann, Richard A.; Shoham, ShyEncoding mechanisms for sensory neurons studied with a multielectrode array in the cat dorsal root ganglionRecent advances in microelectrode array technology now permit a direct examination of the way populations of sensory neurons encode information about a limb's position in space. To address this issue, we recorded nerve impulses from about 100 single units simultaneously in the L6 and L7 dorsal root ...Sensory; Encoding; Multielectrode; Dorsal Root Ganglion; Cutaneour; Muscle2004
96 Normann, Richard A.; Clark, Gregory A.; McDonnall, DanielSelective motor unit recruitment via intrafascicular multielectrode stimulationRecruitment of force via independent asynchronous firing of large numbers of motor units produces the grace and endurance of physiological motion. We have investigated the possibility of reproducing this physiological recruitment strategy by determining the selectivity of access to large numbers of ...Funtional Neuromuscular Stimulation; Microelectrode Array; Neuroprosthesis; Intrafascicular Multielectrode Stimulation; Cats2004
97 Gesteland, Raymond F.; Atkins, John F.; Baranov, Pavel V.P-site tRNA is a crucial initiator of ribosomal frameshiftingThe expression of some genes requires a high proportion of ribosomes to shift at a specific site into one of the two alternative frames. This utilized frameshifting provides a unique tool for studying reading frame control. Peptidyl-tRNA slippage has been invoked to explain many cases of programmed ...Translation; Recoding; Kinetic Model; Frameshifting; Ribosome2004
98 Baehr, Wolfgang; Prestwich, Glenn D.Photoreceptor cGMP phosphodiesterase delta subunit (PDEdelta) functions as a prenyl-binding proteinBovine PDEdelta was originally copurified with rod cGMP phosphodiesterase (PDE) and shown to interact with prenylated, carboxymethylated C-terminal Cys residues. Other studies showed that PDEdelta can interact with several small GTPases including Rab13, Ras, Rap, and Rho6, all of which are prenylate...Fluorescence Resonance Energy Transfer; GTP Phosphohydrolases; Immunohistochemistry2004
99 Christensen, Douglas A.Bringing an integrative modeling experience to a freshman biomedical engineering courseAs an integrating lab experience in our Fundamentals of Bioengineering freshman course, we have included a Major Project that ties together many of the principles of biomechanics and bioelectricity covered in the lecture. It uses the human systemic cardiovascular system as a model. During the first...Matlab2004
100 Horch, Kenneth W.; Lawrence, Steve M.; Dhillon, Gurpreet S.Acute peripheral nerve recording characteristics of polymer-based longitudinal intrafascicular electrodesWe examined the recording characteristics of two different types of polymer-based longitudinal intrafascicular electrodes (LIFEs) in peripheral nerve: single-stranded (s-polyLIFEs) and multistranded (m-polyLIFEs). Recordings were also made from Pt-Ir wire-based electrodes (PtIrLIFEs) as a control. T...Sciatic Nerve; Intrafascicular Electrodes, Peripheral Nerve Recording2004
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