Digital Commons Network^™

Mechanisms Of T Helper Cell Modulation In A Simulated Space Radiation Environment, Asma Rizvi

Loma Linda University Electronic Theses, Dissertations & Projects

Exposure to solar particle events (SPEs) poses the most serious threat to astronaut health. Due to this radiation environment, exploration of the solar system beyond Earth’s orbit entails many risks for the crew on these deep space missions. Depression or dysfunction of the immune system is a major concern due to its high radio-sensitivity; potential consequences include overwhelming infection, development of cancer, fibrosis, and poor wound healing. Astronauts are also exposed to low dose/low dose rate (LDR) radiation. A three month stay at the international space station exposes them to ~ 0.05 Gy of radiation.

C57BL/6 mice received LDR gamma-radiation …

Automatic Guidance System Development Using Low Cost Ranging Devices, Santosh Pitla, Joe D. Luck, Scott A. Shearer

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Autonomous guidance of agricultural vehicles for various field operations serves to increase productivity. Low cost infra-red ranging devices were used in this study to estimate the guidance directrix (offset distance (d) and heading error angle (Ø)). Two kinds of tracks were used for evaluating the performance of the infra-red sensors, one track was made of a cardboard in the laboratory and the other track was made of wheat crop in the field. The cardboard track consisted of straight parallel and non parallel edges whereas the wheat crop track had a series of different edges including few curves. From the results …

Sensor Ranging Technique For Determining Corn Plant Population, Joe D. Luck, Santosh Pitla, Scott A. Shearer

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Mapping of corn plant population can provide useful information for making field management decisions. This research focused on using low cost infra-red sensors to count plants. The voltage output data from the sensors were processed using an algorithm developed to extract plant populations. Preliminary investigations were conducted using sensors mounted on a stationary track for laboratory testing and on a row crop tractor for field testing. Repeated measurements were taken on a manually counted corn row. Visual inspection of the data from the field test indicated the potential to identify corn stalks based on approximate physical widths of the stalks. …

Effects Of Ambient Velocity Shear On Nonlinear Internal Wave Associated Mixing At The Columbia River Plume Front, Jiayi Pan, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Large-amplitude nonlinear internal waves (NLIWs) are frequently observed propagating away from Columbia River tidal plume fronts. They are generated because of the deceleration of the frontal bulge. During the River Influences on Shelf Ecosystems project cruises, the velocity, density structure and acoustic backscatter of the plume fronts and frontal NLIWs were observed using a towed vehicle, vessel-mounted instrumentation, and a vessel X band radar. These observations indicate that in the presence of strong ambient velocity shear, the NLIWs with maximum amplitudes occur well below the density interface and at a depth deeper than in the absence of shear. This deepening …

Development Of A Cell Depositing System Using Inkjet Technology, Jason Robert Ozaeta

Master's Theses

In the past decade, advances in tissue engineering have allowed researchers to fabricate simple tissues. However, the process of creating these native tissues is a time consuming and inefficient process. A scaffold must first be fabricated then exposed to a sea of cells in the hopes of seeding. Furthermore, even though cells may have attached, more time must be spent in order to allow the cells to migrate to their ideal locations. To deal with this problem, researchers have investigated whether rapid prototyping principals could be adapted to facilitate the cell seeding process by placing cells in their respective locations …

Bronchial Circulation Angiogenesis In The Rat Quantified With Spect And Micro-Ct, Christian Wieholt, David L. Roerig, John B. Gordon, Steven Thomas Haworth, Robert C. Molthen, Anne V. Clough

Biomedical Engineering Faculty Research and Publications

Introduction

As pulmonary artery obstruction results in proliferation of the bronchial circulation in a variety of species, we investigated this angiogenic response using single photon emission computed tomography (SPECT) and micro-CT.

Materials and methods

After surgical ligation of the left pulmonary artery of rats, they were imaged at 10, 20, or 40 days post-ligation. Before imaging, technetium-labeled macroaggregated albumin (^99mTc MAA) was injected into the aortic arch (IA) labeling the systemic circulation. SPECT/micro-CT imaging was performed, the image volumes were registered, and activity in the left lung via the bronchial circulation was used as a marker of bronchial …

Biomechanical And Radiographic Evaluation Of An Ovine Model For The Human Lumbar Spine, Nina E. Easley, M. Wang, Linda M. Mcgrady, Jeffrey M. Toth

Biomedical Engineering Faculty Research and Publications

While various species of animal models have been used in preclinical investigations of spinal implant devices to assess their biological adaptation and biomechanical performance, few studies have made comprehensive comparisons to validate their suitability of modelling the human spine. The purpose of this study was to assess essential biomechanical behaviours and disc morphology of the ovine lumbar model. Flexibility testing was conducted on the spines (L3—L4 and L4—L5) of nine skeletally matured sheep. Segmental rotation and intradiscal pressure were measured and load sharing between the intervertebral disc and posterior elements were calculated on the basis of a simplified parallel spring …

Removal And Recovery Of Fermentation-Produced Volatile Organic Compounds By A Novel Liquid Membrane-Based Pervaporation Technique, Atsawin Thongsukmak

Dissertations

Pervaporation is an energy -- efficient alternative to distillation for removing volatile organic compounds (VOCs) from water especially solvents from their dilute solutions in a fermentation broth. Liquid membranes have high selectivities for removing solvents from aqueous solutions compared with polymeric membranes or ceramic membranes; however liquid membranes have stability problems due to various losses. The loss of liquid membrane (LM) to the feed solution leads to toxicity for the organisms in a fermentation broth. A new liquid membrane based pervaporation technique has been developed to achieve high selectivity, ensure stability and prevent contamination of the fermentation broth. Trioctylamine (TOA) …

Altered Brain Activity In Autistic Children Versus Healthy Controls While Performing Simple Tasks Using Fmri, Donald Martin Adams Jr.

Theses

Functional magnetic resonance imaging (fMRI) studies dealing with Autistic children have primarily been concerned with cognitive facial recognition. Recent studies have demonstrated that Autistic children, when compared to healthy matched controls, exhibit higher neuronal activity when identifying patterns or objects, but lower levels of activity in regards to facial recognition.

The objective of this study was to examine both facial and object recognition and compare them to simple sensorimotor tasks. All subjects were administered 5 stimuli each lasting 320 seconds. Subjects were instructed to use a button press box to identify between a Person/Object and an Arrow/Object. They were then …

Thermal And Morphological Analysis Of Collagen-Plla Electrospun Blends, Angana Banerjee

Theses

Electrospinning of bovine Type I collagen and Poly (L-lactic acid) produces blended nanofiber scaffolds that may have application in tissue engineering, wound dressing and drug delivery.

The goal of this research work was to produce and characterize blended nanofibers of a protein, collagen, and a synthetic polymer, poly (L-lactic acid). This study focuses on the in-depth analysis of the appearance of the structural relaxation occurring at the glass transition temperature of PLLA in the collagen-PLLA blended electrospun mats. It is speculated that occurrence of this thermal event is more prominent in PLLA with high molecular weight due to the presence …

The Synergistic Effect Of Pulsed Electromagnetic Fields And Demineralized Bone Matrix On The Osteogenic Differentiation Of Mesenchymal Stem Cells, John Manocchio

Theses

Orthopaedic bone grafting continues to be a mainstay in the treatment of non unions and other difficult to heal bone defects. Tissue engineering strategies have focused on providing bone graft materials that are osteoconductive, osteoinductive and osteogenic in order to achieve optimal bone healing. Furthermore, electrical stimulation technologies such as pulsed electromagnetic fields (PEMF) have been used to enhance the effectiveness of bone graft materials. PEMP has been shown to have a synergistic effect with BMP-2 and it was hypothesized that PEMF would have the same effect with demineralized bone matrix (DBM). In the present study human mesenchymal stem cells …

A Comparative Study Of Common Crosslinking Agents For Electrospun Collagen Scaffolds, Pallavi Masih

Theses

Cartilage injury is one of the leading causes of knee pain in the world. Over two million Americans suffer from cartilage injury every year, resulting in swelling, pain or joint impairment, causing it difficult to maintain an active life style. Synthetic grafts are used extensively to restore tissue functions. The major drawback limiting successful incorporation of synthetic grafts in body is their lower ability to integrate to natural tissue, poor biocompatibility which often results in triggering immunogenic responses, causing graft rejection. Collagen is thus studied and used excessively as a successful implantable material. The reason being that it is natural …

Process-Structure-Property Relationships Of Resorbable Desamino Tyrosine Derived Polymers : Effect Of Backbone Chemistry And Assembly On Drug Delivery, Pinar Nebol

Theses

The selection the correct biomaterial for a specific medical application plays an important role for the success of both application and the device. Since different applications require different properties, investigation and improvement of biomaterials with different properties are very important. L-tyrosine derived polymers enable the manipulation of the properties of the material by changing backbone or pendent chain structure. L-tyrosine derived polyarylate is one of the class of these materials.

This study investigates the behavior of the tyrosine derived polyarylates under in vitro conditions. The change of structure caused by incubation in phosphate buffer solution and the effect on the …

Design And Construction Of A Novel Transpalpebral Ophthalmic Tonometer, Philippe R. Moinot

Theses

Glaucoma -- a degeneration of the optic nerve- is a leading cause of blindness which is primarily caused by large fluctuations in intraocular pressure (lOP) known as diurnal variations. Because these peak in the early morning dropping off rapidly, a self administrable and inexpensive lOP home testing procedure is highly desirable. The approach contained herein -- unlike traditional Goldman applanation tonometry which requires the use of ophthalmic anesthetics and complex diagnostic equipment- describes a novel lOP measurement method consisting of concavation of the cornea or sclera through the palpebra superior by the spherical tip of an optoelectronic photodetector suspended in …

Radiation-Induced Osteoporosis: Bone Quantity, Architecture, And Increased Resorption Following Exposure To Ionizing Radiation, Jeffrey Willey

All Dissertations

Skeletal complications from radiation therapy have been described for breast, brain, pelvic, and blood cancers. These problems include atrophy, fractures, and osteoradionecrosis. Improved survivorship rates of cancer patients receiving radiotherapy increases the importance of understanding the causal mechanisms and long-term effects of radiation-induced bone loss. One such long-term effect is bone fractures following radiation therapy for cancer treatment. The incidence of hip fractures is significantly increased following targeted radiotherapy for cancer. This decline in bone health can have a severe impact on the patient's functional capabilities. This damage to bone following irradiation is thought to involve damage to both osteoblasts …

Synthesis Of Corn-Derived Carbohydrate Derivatives As Effective Multifunctional Sunscreen, Xianhong Feng

Theses

The eighty-years-old sunscreen industry is sustained by the growing incidence of skin cancer and the continual exploration of skin aging. From the UVB-induced erythema to the UVA-induced persistent pigment darkening, scientists have used versatile methods to reveal that not only does UVB damage skin but also that longer wavelengths such as UVAIL (290nm ~ 340nm) and UVAL rays (340nm ~ 400nm) trigger skin cancer, premature skin aging and immunosuppression.

To meet a significant demand for improved photoprotection, a broad-spectrum sunscreen with a high extinction coefficient has been desired. As part of our ongoing studies on isosorbide-cinnamate derivatives, this work have …

Interactions Between Adult Human Mesenchymal Stem Cells And Nanofibrous Scaffolds Of Different Compositions, Lisamarie Moore

Theses

Stem cells have become increasingly important in the biomedical field because they have the potential to invade and regenerate damaged tissue. In particular, the bone marrow contains meesenchymal stem cells (MSCs) that have the capacity to differentiate into many cell lineages. The incorporation of MSCs within a multidimensional biomaterial provides a delivery vehicle to areas of injury. Natural and synthetic biomaterials can be made into scaffolds to represent different types of tissues. The ratio of synthetic to natural biomaterials in the scaffold influences the interaction with MSCs. This thesis created two different nanofibrous scaffolds by a process of electrospinning. The …

Emotional Speech Corpus Construction, Annotation And Distribution, Brian Vaughan, Charlie Cullen, Spyros Kousidis, John Mcauley

Conference papers

This paper details a process of creating an emotional speech corpus by collecting natural emotional speech assets, analysisng and tagging them (for certain acoustic and linguistic features) and annotating them within an on-line database. The definition of specific metadata for use with an emotional speech corpus is crucial, in that poorly (or inaccurately) annotated assets are of little use in analysis. This problem is compounded by the lack of standardisation for speech corpora, particularly in relation to emotion content. The ISLE Metadata Initiative (IMDI) is the only cohesive attempt at corpus metadata standardisation performed thus far. Although not a comprehensive …

Development Of A Colorimetric Test For Quantification Of Uranium In Drinking Water, Amy Ratliff

All Theses

A new method was developed for the determination of uranium in groundwater above 30µg/L (30ppb). This concentration is the maximum contaminant level (MCL) for uranium in drinking water, which was set in December 2003 by the US EPA under the provisions of the Safe Drinking Water Act. The method is rapid and requires little technical training to conduct, allowing it to be used by consumers, in the laboratory, or in the field. The two-step technique involves preconcentrating uranium using a U/TEVA-2 extraction chromatographic resin followed by complexation with a pyridylazo indicator dye, Br-PADAP. At neutral pH, a counter ion is …

Chemisorption Of Oxygen Onto Activated Carbon Can Enhance The Stability Of Biological Perchlorate Reduction In Fixed Bed Biofilm Reactors, Young Chul Choi, Xu Li, Lutgarde Raskin, Eberhard Morgenroth

Department of Civil and Environmental Engineering: Faculty Publications

Fixed bed biofilm reactors with granular activated carbon (GAC) or glass beads as support media were used to evaluate the influence of short-term (12 h) and long-term (23 days) increases of influent dissolved oxygen (DO) concentrations on biological perchlorate removal. The goal was to evaluate the extent by which chemisorption of oxygen to GAC can enhance the stability of biological perchlorate reduction. Baseline influent concentrations were 50 μg/L of perchlorate, 2 mg/L of acetate as C, and 1 mg/L of DO. Perchlorate removal in the glass bead reactor seized immediately after increasing influent DO concentrations from 1 to 4 mg/L …

Sticky Gecko Feet: The Role Of Temperature And Humidity, Peter H. Niewiarowski, Stephanie Lopez, Liehui Ge, Emily Hagan, Ali Dhinojwala

College of Polymer Science and Polymer Engineering

Gecko adhesion is expected to be temperature insensitive over the range of temperatures typically experienced by geckos. Previous work is limited and equivocal on whether this expectation holds. We tested the temperature dependence of adhesion in Tokay and Day geckos and found that clinging ability at 12 degrees C was nearly double the clinging ability at 32 degrees C. However, rather than confirming a simple temperature effect, our data reveal a complex interaction between temperature and humidity that can drive differences in adhesion by as much as two-fold. Our findings have important implications for inferences about the mechanisms underlying the …

High-Power Low-Frequency Ultrasound: A Review Of Tissue Dissection And Ablation In Medicine And Surgery, Brendan O'Daly, Edmund Morris, Graham Gavin, John O'Byrne, Garrett Mcguinness

Articles

High-power low-frequency ultrasound in the range 20–60 kHz has wide ranging clinical applications in surgical and medical instruments for biological tissue cutting, ablation or fragmentation, and removal. Despite widespread clinical application and common device operating characteristics, there is an incomplete understanding of the mechanism of tissue failure, removal and damage. The relative contribution of cavitation, direct mechanical impact and thermal effects to each process for specific tissue types remains unclear. Different and distinct mechanisms and rates of tissue removal are observed for interaction with soft and hard tissue types. Device operating parameters known to affect the interaction include frequency, peak–peak …

A Relational Model For Environmental And Water Resources Data, Jeffery S. Horsburgh, David G. Tarboton, David R. Maidment, Ilya Zaslavsky

Civil and Environmental Engineering Faculty Publications

Environmental observations are fundamental to hydrology and water resources, and the way these data are organized and manipulated either enables or inhibits the analyses that can be performed. The Observations Data Model presented here provides a new and consistent format for the storage and retrieval of point environmental observations in a relational database designed to facilitate integrated analysis of large data sets collected by multiple investigators. Within this data model, observations are stored with sufficient ancillary information (metadata) about the observations to allow them to be unambiguously interpreted and to provide traceable heritage from raw measurements to useable information. The …

Methods To Prioritize Placement Of Riparian Buffers For Improved Water Quality, M. D. Tomer, Michael G. Dosskey, Michael R. Burkart, Matthew J. Helmers, Dean E. Eisenhauer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Agroforestry buffers in riparian zones can improve stream water quality, provided they intercept and remove contaminants from surface runoff and/or shallow groundwater. Soils, topography, surficial geology, and hydrology determine the capability of forest buffers to intercept and treat these flows. This paper describes two landscape analysis techniques for identifying and mapping locations where agroforestry buffers can effectively improve water quality. One technique employs soil survey information to rank soil map units for how effectively a buffer, when sited on them, would trap sediment from adjacent cropped fields. Results allow soil map units to be compared for relative effectiveness of buffers …

Location-Based Hashing For Querying And Searching, Felix Ching

Computer Science and Computer Engineering Undergraduate Honors Theses

The rapidly growing information technology in modern days demands an efficient searching scheme to search for desired data. Locality Sensitive Hashing (LSH) is a method for searching similar data in a database. LSH achieves high accuracy and precision for locating desired data, but consumes a significant amount of memory and time. Based on LSH, this thesis presents two novel schemes for efficient and accurate data searching: Locality Sensitive Hashing-SmithWaterman (LSH-SmithWaterman) and Secure Min-wise Locality Sensitive Hashing (SMLSH). Both methods dramatically reduce the memory and time consumption and exhibit high accuracy in data searching. Simulation results demonstrate the efficiency of the …

Genome Sequencing And Analysis Of The Biomass-Degrading Fungus Trichoderma Reesei (Syn. Hypocrea Jecorina), Diego Martinez, Randy M. Berka, Bernard Henrissat, Markku Saloheimo, Mikko Arvas, Scott E. Baker, Jarod Chapman, Olga Chertkov, Pedro M. Coutinho, Dan Cullen, Etienne G. J. Danchin, Igor V. Grigoriev, Paul Harris, Melissa Jackson, Christian P. Kubicek, Cliff S. Han, Isaac Ho, Luis F. Larrondo, Alfredo Lopez De Leon, Jon K. Magnuson, Sandy Merino, Monica Misra, Beth Nelson, Nicholas Putnam, Barbara Robbertse, Asaf A. Salamov, Monika Schmoll, Astrid Terry, Nina Thayer, Ann Westerholm-Parvinen, Conrad L. Schoch, Jian Yao, Ravi Barabote, Mary Anne Nelson, Chris Detter, David Bruce, Cheryl R. Kuske, Gary Xie, Paul Richardson, Daniel S. Rokhsar, Susan M. Lucas, Edward M. Rubin, Nigel Dunn-Coleman, Michael Ward, Thomas Brettin

United States Department of Energy: Publications

Trichoderma reesei is the main industrial source of cellulases and hemicellulases used to depolymerize biomass to simple sugars that are converted to chemical intermediates and biofuels, such as ethanol. We assembled 89 scaffolds (sets of ordered and oriented contigs) to generate 34 Mbp of nearly contiguous T. reesei genome sequence comprising 9,129 predicted gene models. Unexpectedly, considering the industrial utility and effectiveness of the carbohydrate-active enzymes of T. reesei, its genome encodes fewer cellulases and hemicellulases than any other sequenced fungus able to hydrolyze plant cell wall polysaccharides. Many T. reesei genes encoding carbohydrate-active enzymes are distributed nonrandomly in …

All Elephants Are Bigger Than All Mice, Sebastian Rudolph, Markus Krotzsch, Pascal Hitzler

Computer Science and Engineering Faculty Publications

We investigate the concept product as an expressive feature for description logics (DLs). While this construct allows us to express an arguably very common and natural type of statement, it can be simulated only by the very expressive DL SROIQ for which no tight worst-case complexity is known. However, we show that concept products can also be added to the DLs SHOIQ and SHOI, and to the tractable DL EL⁺⁺ without increasing the worst-case complexities in any of those cases. We therefore argue that concept products provide practically relevant expressivity at little cost, making them a good candidate …

Modeling Of Thermodynamically Coupled Reaction-Transport Systems, Yaşar Demirel

Yaşar Demirel Publications

Nonisothermal reaction-diffusion systems control the behavior of many transport and rate processes in physical, chemical and biological systems, such as pattern formation and chemical pumps. Considerable work has been published on mathematically coupled nonlinear differential equations by neglecting thermodynamic coupling between a chemical reaction and transport processes of mass and heat. This study presents the modeling of thermodynamically coupled system of a simple elementary chemical reaction with molecular heat and mass transport. The thermodynamic coupling refers that a flow occurs without or against its primary thermodynamic driving force, which may be a gradient of temperature or chemical potential or reaction …

Exploring The Potential For Electromangetophoretic Separation, Thomas Lewis

Chemical Engineering Undergraduate Honors Theses

Current research in mircofluidic technology is underway to develop automatic micro-analyzing chips for medical diagnostic testing. Diagnostic testing often requires separation of specific biological particles from a sample, and many of these molecules contain electric or magnetic properties. This project investigates the potential for separation in electromagnetophoretic and magnetophoretic microfluidic technology. In electromagnetophoresis, the Lorentz force acting on a current carrying medium in a homogeneous magnetic field creates a pressure gradient in the fluid, resulting in an applied force to particles present in the separation medium. This force causes the particle to have a velocity component that is perpendicular to …

Evaluating Arkansas Roadway Intersection Accidents Using Traffic Safety Analysis Methods: Generalized Estimating Equations And Roadway Observation, Jacob Mercer

Industrial Engineering Undergraduate Honors Theses

Considerable research has been made in recent years to evaluate road traffic safety. This is especially true with the United States, whose international rank in public safety is rapidly declining. In 2004, Arkansas ranked as the third highest in traffic fatalities among all the states. These are striking numbers that reflect the lack of attention that the state has received in terms of evaluating road traffic safety. Historically, this safety is measure by one of two methods: Statistical analyses of historical data or hands-on, observational analyses of present safety conditions. Rarely in research are both methods used within the same …