Digital Commons Network^™

Synthetic Hydrogel As An Artificial Vitreous Body. A One-Year Animal Study Of Its Effects On The Retina, T. V. Chirila, I. J. Constable, Y. Hong, S. Vijayasekaran, M. F. Humphrey, P. D. Dalton, S. G. Tahija, M. A. L. Maley, M. J. H. Cuypers, C. Sharp, S. R. Moore, M. J. Davies

Cells and Materials

A hydrogel with a high water content was assessed in vitro and in vivo as a possible vitreous substitute. From a large series of polymers produced by the aqueous polymerization of methyl acrylamidoglycolate methyl ether (MAGME), a gel synthesized in 80% water was selected for an animal study. The gel was injected intravitreally into rabbit eyes and followed clinically by ophthalmoscopy, tonometry, and fundus photography. The gel was clinically well tolerated, but after 6 months ophthalmoscopy revealed progressive pallor of the optic nerve head. The eyes were enucleated one year after injection of polymer. Histopathological examination by light microscopy of …

Three-Dimensional Morphology And Platelet Adhesion On Pyrolytic Carbon Heart Valve Materials, S. L. Goodman, K. S. Tweden, R. M. Albrecht

Cells and Materials

Low-temperature isotropic pyrolytic carbon (LTIC) is the preferred material for mechanical heart valve prosthetics due to its durability and good thromboresistance, although thromboembolic complications remain a significant clinical problem. LTlC morphology has been previously studied using scanning (SEM) and transmission electron microscopy (TEM), and scanning tunneling microscopy (STM). However, these microscopies have limitations with imaging rough surfaces. In this study, LTIC valve leaflets from CarboMedics, Inc. and St. Jude Medical, Inc. were prepared and polished exactly as used in clinical prosthetics, and examined at magnifications up to macromolecular resolution using stereo-pair low-voltage SEM (LV -SEM). LV -SEM reveals that LTIC …

Co-Culture Of Endothelial Cells And Smooth Muscle Cells In A Flow Environment: An Improved Culture Model Of The Vascular Wall?, Thierry Ziegler, Keith A. Robinson, R. Wayne Alexander, Robert M. Nerem

Cells and Materials

Numerous studies have demonstrated that the neighboring smooth muscle cells (SMC) influence the morphology, cytoskeleton and growth of co-cultured endothelial cells (EC). Also, flow-induced laminar shear stress has been shown to induce cell elongation, F-actin reorganization and growth inhibition in cultured EC. We investigated the effect of neighboring SMC and collagen matrix on the response of EC to shear stress. The co-culture system was made by growing porcine aortic SMC in a gel of collagen type I and then seeding porcine aortic EC (P AEC) on the top surface. Then the co-culture was exposed to steady, laminar shear stress of …

Optical Bone Chambers As Tools For Studying The Bone-Implant Interface: A Review, Howard Winet

Cells and Materials

Bone chamber intravital microscopy combines the control volume of in vitro models and the chemical complexity of in vivo models to optimize the study of bone physiology in situ. As an optical tool it provides a window to dynamic events at the tissue level of magnification. In particular, it allows measures of microvascular events: (1) in space by magnifying local perfused vasculature and microcirculation at any instant, and (2) in time by providing the same volume of tissue for weekly viewing of an evolving process such as bone healing. This quartz-bearing titanium screw has revealed a consistent order for …

Some Biological And Physical Properties Of Laser Deposited Hydroxyapatite Based Films, Tatjana Dostalova, Lucie Himmlova, Miroslav Jelinek, Jirina Bartova

Cells and Materials

The preliminary results of biological and physical tests of hydroxyapatite thin films deposited on dental implants by a new technology with the KrF excimer laser ablation method were evaluated. Biological and physical properties were studied and analyzed by the lymphocyte proliferation test and scanning electron microscopy (SEM), X-ray analysis, Rutherford backscattering analysis (RBS) and particle induced X-ray emission (PIXE) methods. Ten bioceramic films from 45 samples had very good physical and biological properties. Creation of hydroxyapatite thin films with laser ablation can have a positive effect on adhesion of the film and protection for corrosion.

Effectiveness Of Vegetative Filter Strips In Controlling Losses Of Surface-Applied Poultry Litter Constituents, Indrajeet Chaubey, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr., D. Jeff Nichols

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) have been shown to have high potential for reducing nonpoint source pollution from cultivated agricultural source areas, but information from uncultivated source areas amended with poultry litter is limited. Simulated rainfall was used in analyzing effects of VFS length (0, 3.1, 6.1, 9.2, 15.2, and 21.4 m) on quality of runoff from fescue (Festuca arundinacea Schreb.) plots (1.5 x 24.4 m) amended with poultry litter (5 Mg/ha). The VFS reduced mass transport of ammonia-nitrogen (NH₃-N), total Kjeldahl nitrogen (TKN), ortho-phosphorus (PO₄-P), total phosphorus (TP), chemical oxygen demand (COD), and total suspended …

Vehicle Maintenance Pollution Prevention, University Of Northern Iowa. Small Business Pollution Prevention Center.

Iowa Waste Reduction Center Book Gallery

Pollution prevention can be defined as: "The use of materials, processes, or practices that reduces or eliminates the creation of pollutants or wastes at the source.” (EPA) Pollution prevention represents a shift away from the old school of thought, “pollution control,” in which waste was not dealt with until after it was generated. Through pollution prevention, we look at the processes that generate the waste to see if we can avoid creating a waste in the first place, or at least reduce the hazardous nature of the waste. When this is not possible, the next best solution to prevent wastes …

Kentucky Traffic Accident Facts 1995 Report, Kentucky Transportation Center, Kentucky State Police

Kentucky Transportation Center Research Report

No abstract provided.

Alternative Approaches To On-Farm Research And Technology Exchange, Charles A. Francis, Victoria Mundy, Rhonda Janke, James King

CARI Extension and Education Materials for Sustainable Agriculture

Decision Case Studies are Ideal for On-Farm Research by R. Kent Crookston (University of Minnesota)

Use of On-Farm Research by Farmers for Technology Development and Transfer by Stewart Wuest, Baird Miller, Stephen Guy, Russ Karow, Rojer Veseth, and Donald Wysocki (Washington State University, University of Idaho, and Oregon State University)

Best Information for Choosing Crop Varieties by Dale Hicks and Robert Stucker (University of Minnesota)

Adaptability Analysis for Diverse Environments by Peter Hildebrand and John Russell (University of Florida and Washington State University)

Complementary Abilities and Objectives in On-Farm Research by Derrick Exner (Iowa State University)

Credibility of On-Farm Research …

Webwork: Integrated Programming Environment Tools For National And Grand Challenges, Geoffrey C. Fox, Wojtek Furmanski, Marina Chen, Claudio Rebbi, James H. Cowie

Physics - All Scholarship

Challenging-scale problems consistently demand solutions that fuse geographically distributed and heterogeneous data, personnel, expertise, and resources. For example, national health care problems require collaboration among experts of fields as diverse as medical informatics, public policy, robotics, and high performance computing to solve problems ranging from telemedicine to cost management and quality control. Indeed, many National Challenges include Grand Challenges as subcomponents. We can pose the Integrated Challenge as the solution of etaproblems hosted on world-wide metacomputers linking all three aspects: simulation, information processing, and collaboration. We suggest a hybrid approach to Integrated Challenges that combines World-Wide Web (WWW) technologies with …

Regional Variation In Temperature Humidity Index For Poultry Housing, Richard S. Gates, Hanzhong Zhang, Donald G. Colliver, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

A building thermal model was used to compute hourly values of temperature humidity index (THI) for a broiler house with and without an evaporative misting system. Hourly summer time weather data for 238 U.S.A. locations covering 30 years were used to develop extreme occurrences of THI. Results were incorporated into a Geographical Information System (GIS) database to create isolines of THI and percentage of hours exceeding a heat stress threshold. Regional variations in misting as a suitable cooling technique are presented in terms of hours reduction in annual heat stress. The technique may be used for assisting in management decisions …

A Silicon Knife Design And Fabrication, Mingli Wang

Theses

In this thesis, the design and fabrication of a silicon knife is described. The device design is based on the principle of oxidation sharpening.

The knife is made from a silicon wafer and can be made to be any chosen length up to 150 mm. It was made with the same basic procedures used in semiconductor chip manufacturing. This type of processing/manufacturing results in a knife with a high degree of sharpness and smoothness compared with existing knife technology.

The knife fabrication plan combines IC processing, techniques including anisotropic and isotropic etching of silicon, plasma dry etching and chemical etching …

Visage: Improving The Ballistic Vulnerability Modeling And Analysis Process, Brett F. Grimes

Theses and Dissertations

The purpose of this thesis was to improve the process of modeling and analyzing ballistic vulnerability data. This was accomplished by addressing two of the more urgent needs of vulnerability analysts; the ability to display fault tree data and to edit target descriptions. A vulnerability data visualization program called VISAGE was modified to meet these needs. VISAGE was originally created to preview static shotline plots and subsequently grew into a full-featured visualization package for vulnerability target descriptions and analyses data. The next logical step in the programs evolution was to include the needed editing and fault tree display capabilities. The …

Theoretically Optimal Duty Cycles For Chest And Abdominal Compression During External Cardiopulmonary Resuscitation, Charles F. Babbs, Keir Thelander

Weldon School of Biomedical Engineering Faculty Publications

Objective: To use an electronic model of human circulation to compare the hemodynamic effects of different durations of chest compression during external CPR, both with, and without interposed abdominal compression (IAC). Methods: An electrical analog model of human circulation was studied on digital computer workstations using SPICE, a general-purpose circuit simulation program. In the model the heart and blood vessels were represented as resistive-capacitive networks, pressures as voltages, blood flow as electric current, blood inertia as inductance, and cardiac and venous valves as diodes. External pressurization of the heart and great vessels, as would occur in IAC-CPR, was simulated by …

Preliminary Results Of Deferoxamine And L1 Treatment Of Spinal Cord Ischemia, David G. Reuter, Willis A. Tacker Jr, Charles F. Babbs, Stephen F. Badylak, William D. Voorhees, Peter E. Konrad

Weldon School of Biomedical Engineering Faculty Publications

No abstract provided.

A Guide To Floodplain Cattle Fencing, Department Of Agriculture, Western Australia, Main Roads, Western Australia

Animal production and livestock published reports

A seminar and workshop was held at Fitzroy Crossing in October 1993 to address the consequences of flooding to landholders and communities.

Damage to flood plain fencing was identified as one of the major concerns to landholders.

An outcome from the workshop was the decision to draw on local knowledge and collate information on options for fence and floodgate designs.

This information was to be made available to land holders and other interested parties - hence this publication.

Acuta Enews December 1994, Vol. 23, No. 12

ACUTA Newsletters

In This Issue

Board report

President's message

George Mason University becomes "virtual campus"

Phone fraud at Salve Regina

Campus-wide network at James Madison

From ACUTA Headquarters

Experimental Definition For Implantation Of The Afit Cortical Multielectrode Array, Adam G. Spenik

Theses and Dissertations

A two-dimensional multiplexed array of 256 electrodes (16 x 16) has been fabricated using conventional CMOS fabrication techniques. The size and spacing of the electrodes (160 x 160 µm squares with center-to-center spacing of 250 µm) approximate that of the cortical columns. The device is mounted on a small biocompatible package and a protocol to implant this package on the visual cortex of a ferret and a Rhesus monkey was developed and approved. An instrumentation setup to record the data from the device is described as well as the methods used to demultiplex the data. Testing of the device in …

Design, Fabrication, Modeling, And Optical Characterization Of Organic Polymer Nonlinear Directional Couplers, John N. Berry

Theses and Dissertations

This research was an investigation into the suitability of a recently developed polymer, polyphenylene, as a material for integrated optical circuits (IOCs). Polymers show great promise in the area of IOCs because of material processing advantages, compatibility with most existing integrated circuit technology, and relatively strong nonlinear optical characteristics. This thesis contains an overview of: dielectric waveguides, linear and nonlinear directional coupler theory; various models useful in the design and analysis of optical waveguides; the fabrication of three different waveguide designs; the experimental apparatus and procedure used to optically characterize the waveguides; and the experimental results of the characterization. Waveguiding …

Characterization And Redesign Of The Afit Multielectrode Array, Richard G. Darenberg Jr.

Theses and Dissertations

Since 1978, faculty and graduate students from the Air Force Institute of Technology (AFIT) have been working on an implantable circuit array that can record visual signals from the brain or stimulate the brain. In the current design the circuit is a 16 x 16 array of pads, each pad being 160 x 160 micrometers with 250 micrometers spacing with an 'L' shaped reference pad used as a ground reference. The array is multiplexed so that only one I-O line is required to access all 256 pads. This research was twofold: first to analyze the existing circuit and identify sources …

Head Related Transfer Function Approximation Using Neural Networks, John K. Millhouse

Theses and Dissertations

This thesis determines whether an artificial neural network (ANN) can approximate the Armstrong Aerospace Medical Research Laboratories (AAMRL) head related transfer functions (HRTF) data obtained from research at AAMRL during the fall of 1988. The first test determines whether HRTF lends any support in sound localization when compared to no HRTF (Interaural Time Delay only). There is a statistically significant interaction between the location of the sound and whether the HRTF or no HRTF is used. When this interaction is removed using the alternate F.Value, the statistics give the result of equal means for the filters and azimuth. This means …

Application Of Lawn Fertilizers And Pesticides In Salt Lake Valley Recharge Areas, Ghassan R. Musharrafieh, Larry Sager, Howard M. Deer, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Homeowners, chemical applicators, and commercial lawncare companies apply chemicals to lawns and ornamentals overlying the recharge zone of Salt Lake Valley's principal aquifer. These applied fertilizers, herbicides, insecticides, and fungicides can potentially leach far enough to contaminate ground water. This report summarizes a study conducted in 1993-1994 to determine the type, rate, and frequency of applying chemicals to lawns and ornamentals in the recharge zone. Surveyed are lawncare companies, chemical applicators, schools, churches, hospitals, parks, homeowners, and government documents and community and state regulations. Results will help assess the potential impact of these applications on future ground water quality.

Expression Of A Functional Human Complement Inhibitor In A Transgenic Pig As A Model For The Prevention Of Xenogeneic Hyperacute Organ Rejection., William L. Fodor, Barry L. Williams, Louis A. Martis, Josaeph A. Madri, Scott A. Rollins, James W. Knight, William H. Velander, Stephen P. Squinto

Papers in Biotechnology

ABSTRACT The serious shortage of human organs available for transplantation has engendered a heightened interest in the use of animal organs (xenografts) for transplantation. However, the major barrier to successful discordant xenogeneic organ transplantation is the phenomenon of hyperacute rejection. Hyperacute rejection results from the deposition of high-titer preformed antibodies that activate serum complement on the luminal surface of the vascular endothelium, leading to vessel occlusion and graft failure within minutes to hours. Although endogenous membrane-associated complement inhibitors normally protect endothelial cells from autologous complement, they are species restricted and thus confer limited resistance to activated xenogeneic complement. To address …

Computer-Aided Instruction In Dynamics: Does It Improve Learning?, Ralph E. Flori

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Since 1992, the authors have been developing and testing BEST Dynamics software (Basic Engineering Software for Teaching Dynamics) with the goal of transforming how engineering dynamics is taught at the University of Missouri-Rolla, USA. This paper introduces the "BEST" Dynamics and its classroom implementation, raises questions concerning the cognitive impact of the software, attempts to classify the type of learning environment used in BEST Dynamics, and gives some new directions that are being taken based on the authors'' observations and experiences.

Building Oriented Surface Generation Through Iges Specification, Jujiang Bao

Theses

This thesis focuses the use of Initial Graphics Exchange Specification to generate automatically three dimensional surfaces. Currently, different CAD systems utilize their own data formats to generate graphic databases which are not compatible with one another. Besides, most of the existing CAD systems require an interactive data input process which is very much time consuming. In order to solve above problems, an efficient algorithm has been developed in this research to automatically generate portable graphic database following ICES specifications. This portable graphic database can be adopted by different commercial CAD/CAM systems. Using the proposed method, the current design process can …

Correlation Between Tidal Volume Measured By Spirometry And Impedance Pneumography, Krithika Seshadri

Theses

In this study, an alternative method, impedance pneumography was used to measure the respiration volume. The respiration volume was measured both by using a conventional spirometer and an impedance pneumograph, and evaluated quantitatively in 17 subjects using linear and nonlinear regression algorithms.

Data were collected from 17 normal, healthy subjects during rest and paced breathing conditions. A technique was developed to measure tidal volume by impedance pneumography. The respiration volume measured by the spirometer was correlated with the volume measured by the pneumograph. Different electrode positions and postures were included in the study to determine the position and posture which …

Passive Radiosonde Transducer Design For Remote Pressure Sensing Applications, Yang Gao

Theses

Intracranial pressure can be measured to accuracies within 1 milliTorr using passive microtransponders that are micromachined using silicon as a base technology. These microtransponders can operate with either a dual-oscillator or a phase-locked loop frequency scanned control system.

The current work describes the design of a totally implantable microsensor for biomedical applications with the aim to monitor and measure the epidural intracranial pressure . The implanting microsensor is basically an RLC device in which capacitance varies with fluid pressure. The resonant frequency of RLC Series connected device varies with chemically etched diaphragm electrode spacing and thereby measures the variations with …

Santa Clara Magazine, Volume 36 Number 4, Fall 1994, Santa Clara University

Santa Clara Magazine

6 - THE MIND THIEF November is national Alzheimer's Disease Month, drawing attention to an illness that robs patients of their memories, their competence, sometimes their very personalities. By Maureen McInaney '85

12 - CREDIBILITY MAKES A DIFFERENCE A look at a key element of leadership: building trust. By James M. Kouzes and Barry Z. Posner

18 - PUTTING THE PIECES TOGETHER SCU's $125 million Challenge Campaign is transforming the University.

24 - NO PROBLEMO A racked-up knee, a forfeited football scholarship, an extra 50 pounds-no problemo. A work of short fiction. By Jan Maulhardt '90

28 - THE NUCLEAR …

Analysis Of Motor Vehicle-Deer Accidents In Kentucky, Kenneth R. Agent

Kentucky Transportation Center Research Report

An analysis of motor vehicle-deer (deer) accidents for the five-year period of 1989 through 1993 was conducted. There was an average of about 2,800 deer accidents per year. This type of accident was generally not severe with almost 96 percent property-damage-only accidents. Trends were noted in time and date of the accidents. The highest percentage of deer accidents occurred between 6 and 10 pm and in November and December. The percentage of this type of accident was highest in western and northern Kentucky and lowest in southeastern and central Kentucky. The accident rate for this type of accident was highest …

Modeling Trihalomethane Formation Potential From Wastewater Chlorination, Carol A. Mccormick

Theses and Dissertations

The deletion of federally mandated fecal coliform limits has led many states to review and modify their wastewater disinfection requirements. One issue in analyzing wastewater disinfection is the discharge of potentially carcinogenic halogenated organics formed during the chlorination process. This research investigates the formation of one class of the halogenated organics, the trihalomethanes. The applicability of using drinking water trihalomethane formation models for use with wastewater effluent is examined. Three models are compared for predictive capability by using measured trihalomethane values from previous research data. The results show that a previously developed model is applicable for use based on assumptions …