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Full-Text Articles in Engineering

Molecular Modeling Of Proteins And Peptides Related To Cell Attachment In Vivo And In Vitro, Wanhua Zhao Jul 2006

Molecular Modeling Of Proteins And Peptides Related To Cell Attachment In Vivo And In Vitro, Wanhua Zhao

Doctoral Dissertations

Polypeptides constitute half of the dry mass of the cell, they form the bulk of the extracellular matrix (ECM), and they are a common element of extra- and intracellular signaling pathways. There is increasing interest in the development of computational methods in polypeptide and protein engineering on all length scales. This research concerns the development of computational methods for study of polypeptide interactions related to cell attachment in vivo and in vitro.

Polypeptides are inherently biocompatible, and an astronomical range of unique sequences can be designed and realized in massive quantities by modern methods of synthesis and purification. These macromolecules ...


Development Of Self-Assembled Monolayer-Based Cell Culture Platform Towards Fabrication Of A Three-Dimensional Bioreactor, Rajendra Kandoor Aithal Apr 2006

Development Of Self-Assembled Monolayer-Based Cell Culture Platform Towards Fabrication Of A Three-Dimensional Bioreactor, Rajendra Kandoor Aithal

Doctoral Dissertations

The extracellular matrix (ECM) plays an important role in regulating a number of cellular properties and functions like cell differentiation, cell synthesis and degradation, cell viability and proliferation, cell function, and cell aging. Surface modification of planar substrates with self-assembled monolayers (SAMs) is a promising technique to achieve stable ECMs.

In this work, substrates such as silicon (Si), gallium arsenide (GaAs) and indium tin oxide (ITO) substrates were modified with SAMS containing amino (-NH2), methyl (-CH3), thiol (-SH) and carboxylic (-COOH) end groups and characterized using contact angle measurements, surface infrared (IR) spectroscopy and atomic force microscopy (AFM). Different cell ...


Integration Of Remote Sensing And Crop Growth Modeling For Nitrogen Management Decision Support In Corn , Kelly Robert Thorp Jan 2006

Integration Of Remote Sensing And Crop Growth Modeling For Nitrogen Management Decision Support In Corn , Kelly Robert Thorp

Retrospective Theses and Dissertations

This dissertation describes efforts to move toward a completely integrated remote sensing and crop growth modeling tool for developing precision nitrogen management recommendations for corn. Aerial hyperspectral remote sensing imagery collected throughout the 2004 growing season was used to estimate corn plant stand density, and a machine vision system was used to map corn population on the ground. Multiple linear regression analysis was used to assess the ability of all combinations of three reflectance bands to estimate corn plant population at resolutions of 2 m, 6 m, and 10 m. Coefficients of multiple determination of up to 0.82 were ...


Soybean Sphingolipid Content As Affected By Palmitate Content And By Seed Development Stage , Liping Wang Jan 2006

Soybean Sphingolipid Content As Affected By Palmitate Content And By Seed Development Stage , Liping Wang

Retrospective Theses and Dissertations

Sphingolipids (SL) are both structural and functional lipids with potential health benefits. To determine the relationship between palmitate and SL contents, methods for column separation and quantification using high-performance liquid chromatography - evaporative light scattering detector were developed for glucosylceramide (GlcCer) and ceramide (Cer) in 15 soybeans lines in which palmitate content ranged from 3.7 to 40.3%. Significant differences were observed among lines for GlcCer (83.4-397.6 nmol/g) and Cer (8.4-20.7 nmol/g) contents on a dry weight basis (dwb). But these contents were not significantly affected by the palmitate content of soybeans seeds. To ...


Comparison Of Soy-Flour Hydrolysates For Wood Adhesive Systems , John F. Schmitz Jr. Jan 2006

Comparison Of Soy-Flour Hydrolysates For Wood Adhesive Systems , John F. Schmitz Jr.

Retrospective Theses and Dissertations

Soy-protein-based adhesives have not been used extensively in wood products since the 1960's because of poor performance, stability, and water-resistance issues compared to petroleum-based adhesives. The early soy-protein adhesives were made from defatted flours and were dispersed in alkaline solutions to denature proteins and make more polar amino acid groups available for adhesion bonding. Recent research has focused on soy flour adhesives due to increased phenol prices and environmental concerns related to the use and exposure to formaldehyde. Soy protein isolates can be modified in highly caustic alkaline solutions to reduce viscosity and improve adhesive properties, but the price ...


Analysis Of The Influence Of Soil Temperature And Soil Surface Conditions On Soil Moisture Estimation Using The Theta Probe , Geetika Dilawari Jan 2006

Analysis Of The Influence Of Soil Temperature And Soil Surface Conditions On Soil Moisture Estimation Using The Theta Probe , Geetika Dilawari

Retrospective Theses and Dissertations

Soil moisture is an important component of numerous systems, influencing crop development, and runoff and infiltration partitioning, among other things. However, due to its spatial and temporal variability, it is difficult to estimate soil moisture consistently using conventional techniques such as gravimetric sampling, which is point-based and time-consuming. Therefore, to overcome this drawback in soil moisture estimation and mapping, and to facilitate its measurement spatially and temporarily, remote sensing in microwave, visible, near infrared and short wave infrared is being explored and is proving to be a promising technique. But to develop models using spectral data there is a need ...


Developing A Quality Control Program For An Nirs -Based Service And Research Laboratory , Maureen Suryaatmadja Jan 2006

Developing A Quality Control Program For An Nirs -Based Service And Research Laboratory , Maureen Suryaatmadja

Retrospective Theses and Dissertations

The Iowa State University Grain Quality Laboratory (ISU-GQL) provides instrument calibration and measurement services for composition of agricultural products. The Laboratory is pursuing ISO 17025 accreditation. Quality control is one of the ISO 17025 requirements, therefore the objectives of this study are to develop quality control program for Near Infrared Spectroscopy (NIRS), supporting equipment and laboratory room conditions and to develop quality control program for the reference data. The first quality control program includes data from NIRS daily check samples, NIRS duplicate differences, NIRS real time prediction comparison to references, periodic checks and reviews of equipment supporting the NIRS calibration ...


Evaluation Of Computer Input Devices For Use In Standard Office Applications While Moving In An Off-Road Vehicle , Thorsten Baldus Jan 2006

Evaluation Of Computer Input Devices For Use In Standard Office Applications While Moving In An Off-Road Vehicle , Thorsten Baldus

Retrospective Theses and Dissertations

Advances in modern farming technology provide automation features that lighten the workload for operators of farming equipment. One of the many technologies incorporated in modern agricultural equipment is automated steering systems like the John Deere's Green-Star Auto-Trac System(TM), which is a hands-free steering system for straight-line driving applications. When using a machine that is equipped with one of these systems, the work load of the operator is lightened and enables the operator to perform other tasks while doing field work. Many people believe a tractor cab could become a mobile office in the near future with the operator ...


Computational Methods In The Study Of Carbohydrates And Carbohydrate-Active Enzymes , Anthony David Hill Jan 2006

Computational Methods In The Study Of Carbohydrates And Carbohydrate-Active Enzymes , Anthony David Hill

Retrospective Theses and Dissertations

Carbohydrates are important molecules in energy storage and cellular recognition. New methods are used and discussed to capture important structural details of created by the protein/carbohydrate interactions. In particular, the thermodynamics of carbohydrate binding are explored, and a new model to accurately calculate the free energy of binding is developed. Additionally, a new method of describing the pucker of carbohydrate ring with three coordinates is discussed. These methods are then applied to Family 1 Glycoside Hydrolases.


Carbon-13 Metabolic Flux Analysis Of Soybean Central Carbon Metabolism: Response To Temperature And Genotype Effects , Vidya Vaancheeswaran Iyer Jan 2006

Carbon-13 Metabolic Flux Analysis Of Soybean Central Carbon Metabolism: Response To Temperature And Genotype Effects , Vidya Vaancheeswaran Iyer

Retrospective Theses and Dissertations

Soybeans are a major source of high quality protein, edible oil, food products, and also several industrial non food applications such as paper coating, textiles and plastics. It is difficult to develop soybeans with high protein and high oil, however, due to the inverse relationship between these two components. Consequently, increasing seed protein concentration without adversely affecting the yield and oil content has been difficult to achieve. It has been demonstrated that the temperature and genotype of soybeans influence the protein or lipid composition considerably. However, the interactions between various pathways responsible for the changes in the composition are unknown ...


Dietary Strategies To Reduce Air Emissions From Laying Hen Operations , Wei Wu-Haan Jan 2006

Dietary Strategies To Reduce Air Emissions From Laying Hen Operations , Wei Wu-Haan

Retrospective Theses and Dissertations

The objectives of the current study were to evaluate the effectiveness of feeding a reduced emission diet (R) containing 6.9% of a gypsum-zeolite mixture and slightly reduced crude protein (CP) to 21-, 38-, and 59-wk old Hy-line W36 hens (trial 1, 2, and 3, respectively) on hen performance, emissions of NH3, H2S, NO, NO2, CO2 , CH4, non-methane total hydrocarbon, and apparent digestibility compared to feeding a commercial diet (C), and to compare different methods of estimating nutrient excretion from laying hens in environmental chambers. At each age, 640 hens were allocated randomly to one of eight environmental chambers for ...


Directed Growth And Selective Differentiation Of Neural Progenitor Cells Using A Synergistic Combination Of Topographical And Soluble Cues , Jennifer Behr Recknor Jan 2006

Directed Growth And Selective Differentiation Of Neural Progenitor Cells Using A Synergistic Combination Of Topographical And Soluble Cues , Jennifer Behr Recknor

Retrospective Theses and Dissertations

The purpose of this study is to develop strategies to facilitate nerve regeneration using a synergistic combination of guidance cues. We are investigating the cellular mechanisms of development using adult rat hippocampal progenitor cells (AHPCs) and have demonstrated that manipulating a combination of physical, chemical and biological cues can lead to oriented astrocyte and neural progenitor cell outgrowth and can influence progenitor cell differentiation. To provide physical guidance, micropatterned polystyrene (PS) substrates were fabricated and chemically modified with laminin. Astrocytes or AHPCs cultured on these substrates align along the grooves of the patterned surface extending highly elongated processes. To further ...


Ammonia Emissions From Manure Belt Laying Hen Houses And Manure Storage , Hong Li Jan 2006

Ammonia Emissions From Manure Belt Laying Hen Houses And Manure Storage , Hong Li

Retrospective Theses and Dissertations

Ammonia (NH3) emission is environmentally important because of its contribution to acidification of soil and water and increased nitrogen deposition in ecosystems. Ammonia emission rates (ER) of two commercial manure-belt (MB) layer houses with in Iowa were monitored for a full year. Ammonia ER showed considerable diurnal variation, but not as much in seasonal variation. Data from the 12-month monitoring revealed an annual average NH3 ER of 0.054 g d-1 hen-1(varying from 0.002 to 0.195 g d-1 hen-1) from the MB houses when the manure was removed daily. Results of the study contribute to the U ...


Hydrological Modification Of Subsurface Drainage Systems , Kyle Dean Riley Jan 2006

Hydrological Modification Of Subsurface Drainage Systems , Kyle Dean Riley

Retrospective Theses and Dissertations

Controlled Drainage (CD), a subsurface drainage management system, has been researched in many regions. Previous research has reported CD to reduce subsurface drainage and as a result reduce nitrate loading. CD has been reported to have little effect on nitrate concentrations, so exploring alternative treatments to reduce these concentrations would be constructive. This research was intended to measure the effect of CD on surface runoff, crop yield, water table depth, and to document a biofilter's effect on nitrate concentrations. CD increased surface runoff ranging from 53% to 130%, increased corn yield by 14% over two years, and decreased nitrate ...


Vegetative Filter Strip Assessment In The State Of Iowa, Manveen Bansal Jan 2006

Vegetative Filter Strip Assessment In The State Of Iowa, Manveen Bansal

Retrospective Theses and Dissertations

Vegetative filter strips (VFS) is one of the best management practices that uses natural processes to remove a portion of the sediment and other pollutants carried by runoff before the water enters a water-body. The project analyzes the flow accumulation of runoff with the help of Geographic Information Systems (GIS). The objectives for this project include (1) To determine the effectiveness of VFS by visual field observation and validation by flow mapping procedures in ArcGIS 9, (2) To compare the area ratios and percentage of flow along each stream segment at various resolutions for different sizes of the survey data ...


Use Of Precision Agriculture Technologies In Studying The Relationships Among Soil Ph, Calcium Carbonate Equivalent, Soybean Cyst Nematode Population Density, And Soybean Yield , Natalia Rogovska Jan 2006

Use Of Precision Agriculture Technologies In Studying The Relationships Among Soil Ph, Calcium Carbonate Equivalent, Soybean Cyst Nematode Population Density, And Soybean Yield , Natalia Rogovska

Retrospective Theses and Dissertations

Iron deficiency chlorosis (IDC) and soybean cyst nematode (SCN; Heterodera glycines) infestation are major factors that contribute to soybean (Glycine max Merr.) yield reduction in the Midwest. The IDC is often associated with soybean grown on high pH, calcareous soils. In addition, it was documented that SCN population density is higher in high pH soils. The objectives of this paper were to assess the proportion of within-field soybean yield and SCN variability that could be explained by soil pH, calcium carbonate equivalent (CCE), and a previously defined alkalinity stress index (ASI). Aerial images from 21 fields planted to SCN-resistant or ...


Soil Landscape Modeling In The Northwest Iowa Plains Region Of O'Brien County, Iowa , Daniel Alan Nath Jan 2006

Soil Landscape Modeling In The Northwest Iowa Plains Region Of O'Brien County, Iowa , Daniel Alan Nath

Retrospective Theses and Dissertations

Terrain analysis is a powerful tool which is useful to build prediction models in the Northwest Iowa Plains. To effectively explain variability of soil properties across the landscape using terrain analysis, models used for prediction of the former must adequately reflect the processes at relevant scales. Topographic roughness may be used as a tool to guide appropriate resolutions for selected landscapes. Although topography is one of many factors of soil formation, it can be a major factor in some landscapes to explain spatial variation in soil properties. This study was conducted to determine optimal grid resolution for predicting multiple soil ...


Diverse Effects Of Nanosecond Pulsed Electric Fields On Mammalian Cells, Jody Anne White Jan 2006

Diverse Effects Of Nanosecond Pulsed Electric Fields On Mammalian Cells, Jody Anne White

Theses and Dissertations in Biomedical Sciences

The continuing effort to manipulate cell-signaling pathways for therapeutic benefit has lead to the exploration of electric field effects on cells. Current electric field applications include electroporation of the plasma membrane for introduction of drugs, genes, or other macromolecules into cells. Modeling of how these pulsed electric fields affect cells depicts the cell as an excitable circuit. In this model, the electric fields, administered in short pulses to a cell, charge the plasma and internal membranes, which act as dielectric layers, and between these the cytoplasm acts as a conductive medium. The pulse lengths of this treatment are traditionally in ...