Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 26 of 26

Full-Text Articles in Life Sciences

For Shade And Comfort: Ornamental Plants In Nineteenth- Century Midwestern Domestic Landscapes, Cheryl Lyon-Jenness Dec 1998

For Shade And Comfort: Ornamental Plants In Nineteenth- Century Midwestern Domestic Landscapes, Cheryl Lyon-Jenness

Dissertations

This dissertation investigates the extent and type of ornamental plant use in nineteenth-century Midwestern domestic landscapes, considers reasons for expanded horticultural interest between 1850 and 1880, and explores the significance of ornamental plants as part of Midwestern material culture.

Content analysis of over seven hundred lithographic images of homes and homegrounds from three southeastern Michigan counties, combined with demographic information, confirmed widespread ornamental plant use among an economically and culturally diverse group of Midwesterners by the 1870s. A number of cultural trends encouraged this expanded horticultural interest Exploration of readily available midnineteenth- century newspapers, magazines, and advice manuals revealed that …


Mathematical Model Of Paper Discoloration By Ink Particles, Zbigniew W. Slotwinski Dec 1998

Mathematical Model Of Paper Discoloration By Ink Particles, Zbigniew W. Slotwinski

Masters Theses

The goal of this experiment is to investigate how changes in the size and number of ink particles will affect the final brightness of the filter pad.

It was assumed that any differences in brightness of the used Millipore filters were due to change in the average particle size, given the same mass of ink solids on each filter. However, such simplified interpretation of image analysis proved to be inadequate to solve this complex problem.

The correlation between the particle area, number of particles, and brightness drop was established using an algorithm based on the particle area and the square …


The Effect Of A Sheet Tension Controller On The Productivity Of A Papermachine, Timothy J. Rummel Nov 1998

The Effect Of A Sheet Tension Controller On The Productivity Of A Papermachine, Timothy J. Rummel

Honors Theses

This thesis proposal outlines a project in which the efficiency of a papermachine is increased by controlling the tension through the dryer section. The controlled tension is expected to reduce wet end breaks and to decrease the steam demand of the dryer section. The experiment will be run by placing a laser positioning sensor above the open draw of a papermachine and monitoring the position of the draw until an optimum height of the paper has been determined. Then an automatic drive controller will be connected to the wet end drive to maintain a constant draw height and the machine …


Characterization Of Metal-Regulated Genes In Pseudomonas Fluorescens, Melanie Pearson Aug 1998

Characterization Of Metal-Regulated Genes In Pseudomonas Fluorescens, Melanie Pearson

Honors Theses

One side effect of today's industrialized world is increased levels of heavy metals in the environment. Many of these metals are necessary for biological function as trace elements, but at higher concentrations are toxic. Other metals, such as cadmium, are not beneficial at any level, and have only deleterious effects on living organisms. Cadmium is primarily thought to interfere with normal biological function of proteins. Human exposure to cadmium appears to primarily damage the kidneys, but may also affect the liver, lungs, immune system, and central nervous system. Bacteria, however, have developed several methods for handling toxic heavy metals: cation …


Glucose Mediated Effects On Glucose-6-Phosphate Dehydrogenase Expression, Daryl Arkwright Jun 1998

Glucose Mediated Effects On Glucose-6-Phosphate Dehydrogenase Expression, Daryl Arkwright

Masters Theses

Circulating high glucose levels are believed to cause oxidative stress which is implicated in a number of pathological conditions such as cancer, aging, and diabetes. Oxidative stress regulates the expression of glucose-6-phosphate dehydrogenase (G6PDH), the key enzyme in the pentose phosphate pathway which provides reducing equivalents in the form of NADPH. These reducing equivalents are also required by fatty acid synthase (FAS), the enzyme which catalyzes fatty acid biosynthesis. We examined whether glucose, a known inducer of oxidative stress, could regulate either G6PDH or FAS activity in primary rat hepatocytes. We tested the effects of glucose alone or in combination …


Mechanism By Which Insulin And Its Mimetics, Selenite And Vanadate, Regulate Glucose-6-Phosphate Dehydrogenase Gene Expression, Sanjay M. Jivarj Jun 1998

Mechanism By Which Insulin And Its Mimetics, Selenite And Vanadate, Regulate Glucose-6-Phosphate Dehydrogenase Gene Expression, Sanjay M. Jivarj

Masters Theses

Glucose-6-phosphate dehydrogenase (G6PDH) is a key enzyme of the pentose phosphate pathway. It controls the carbon flow through this pathway, producing reducing equivalents in the form of NADPH to meet the cellular need for reductive biosynthesis and the maintenance of the cellular redox state. Hepatic expression of G6PDH has been shown to be regulated by hormones, nutrients and some growth factors, however the mechanism by which these factors regulate G6PDH gene expression has not been characterized. Here we investigate the mechanism by which insulin and its mimetics, selenate and vanadate, regulate G6PDH gene expression.

Insulin exerts its tissue specific affect …


Stage-Dependent Expression Of Target-Derived Influences Stimulates Axon Outgrowth In Hirudo Medicinalis, Tina M. Harik Jun 1998

Stage-Dependent Expression Of Target-Derived Influences Stimulates Axon Outgrowth In Hirudo Medicinalis, Tina M. Harik

Masters Theses

Our lab has been investigating the development of neuronal phenotype and circuitry in Hirudo medicinalis. Early in embryogenesis the heart excitor (HE) motor neuron selectively extends multiple arbors into the body wall prior to heart tube (HT) formation. HE contact with HT primordium at later stages of development results in remodeling such that arbors are elaborated on the HT, while those in the body wall are retracted. HT-derived cues are necessary for HE remodeling (Jellies, 1995. Am. Zool. 35:529; Jellies and Kopp, 1995. Invert. Neurosci. 1:145). HT and body wall explants were co-cultured to investigate the possible influences of …


Chemically Enhanced Wet Pressing, Timothy Mishark May 1998

Chemically Enhanced Wet Pressing, Timothy Mishark

Paper Engineering Senior Theses

The problem of energy consumption is one of the largest confronting the paper industry today. One of the largest areas where this energy consumption occurs is the dryer section on the paper machine. If a legitimate way to reduce the load to the dryer section was developed, it would greatly benefit the paper industries financial situation. Some of the methods that have been used to reduce dryer load include; increasing the pressure in the press section, heating the press rolls in the press section, and applying chemicals to the felts which help inhibit rewetting. The latter item is what this …


The Effects Of Rose Bengal Application On The Production Of Salicylic Acid In Nahg Tobacco Plants, Nicole Christine Ott Apr 1998

The Effects Of Rose Bengal Application On The Production Of Salicylic Acid In Nahg Tobacco Plants, Nicole Christine Ott

Honors Theses

Plants have the ability to develop resistance to a wide range of pathogens following exposure to a single bacterium, fungus, or virus. This resistance occurs in all tissues, not only those that were previously infected. This mechanisms is termed systemic acquired resistance (SAR). The phenolic compound salicylic acid (SA) has been linked to SAR in tobacco, arabidopsis, and cucumber plants. Oxidative stress also causes SA production, which leads to SAR. An engineered tobacco plant (nahG) that does not have the ability to accumulate SA has been used as a research tool in investigations concerning SA activity. Rose Bengal …


The Effects Of Using Silicate And Borate In The Peroxide Bleaching Of Mechanical Pulp, Corey A. Bishop Apr 1998

The Effects Of Using Silicate And Borate In The Peroxide Bleaching Of Mechanical Pulp, Corey A. Bishop

Paper Engineering Senior Theses

In the peroxide bleaching process, sodium silicate is currently being used to control metal ions present in the pulp; these metal ions catalyze the decomposition of hydrogen peroxide, reducing the efficiency of the process. However, the addition of sodium silicate can cause scaling the fouling of equipment, wires, and felts. This, in turn, causes expensive downtime for scale removal. This experimental work involved replacing sodium silicate with a non-scale forming borate. This study determined if borate can replace silicate as a stabilizer in the peroxide bleaching process with equivalent bleach response. Rates of bleaching reactions were also determined in various …


The Use Of Borax To Inhibit The Brightness Reversion Of Bleached Ctmp, Chad J. Longcore Apr 1998

The Use Of Borax To Inhibit The Brightness Reversion Of Bleached Ctmp, Chad J. Longcore

Paper Engineering Senior Theses

This thesis evaluated the ability of Borax to inhibit the yellowing process of paper that was made from bleached chemithermomechanical pulp (BCTMP). Paper made from BCTMP has a tendency to lose brightness (photoyellow) when exposed to ultra violet (UV) light. The light initiates a series of chemical reactions to take place that results in the formation of yellow ketone and quinone products. A combination of boric acid and borax was applied to the surface of the paper to interfere with these chemical reactions and prevent the formation of the yellow products that cause photoyellowing. The effectiveness of these additives was …


The Recycling Of Vacuum Formed Products And The Effect On Use Characteristics, Robert J. Miles Apr 1998

The Recycling Of Vacuum Formed Products And The Effect On Use Characteristics, Robert J. Miles

Paper Engineering Senior Theses

Vacuum formed products, commonly called molded pulp, are a superb alternative to expanded polystyrene (Styrofoam) in many current packaging applications. This movement from the petroleum based products of the past to innovative new wood fiber based packaging is due to many reasons including economic benefit, environmental stigma, and/or legislative intervention. The current dilemma is dealing with the inherent fiber characteristics, contaminants, and product composition of molded pulp products. As more of these products appear in secondary waste streams, there is a need for information pertaining these parameters. Unfortunately, very little technical information is available due to the high level of …


The Effects Of Cationic Additives On Ink-Jet Coating Formulations, Sean Frank Apr 1998

The Effects Of Cationic Additives On Ink-Jet Coating Formulations, Sean Frank

Paper Engineering Senior Theses

The recent popularity of ink jet printers has led to the invention of an entire new line of paper coatings. These formulations often require cationic additives to achieve proper print quality. The effect of these cationic additives and their interaction with latexes is studied. This project investigated whether a high solids ink jet coating applied via blade coating can give satisfactory print quality, and the extent of interactions among latex and cationic additives (delete). The experimental design consisted of two different base formulations that were varied by addition levels of polyvinylpyrollidone (PVP), silica, latex, and cationic polymer. These formulations were …


An Evaluation Of Never-Dried Pulp At Multiple Freeness Levels, Timothy Clifford Liverance Apr 1998

An Evaluation Of Never-Dried Pulp At Multiple Freeness Levels, Timothy Clifford Liverance

Paper Engineering Senior Theses

Recycled paper is a viable and economical source of useful wood fiber for paper manufacture. Two of the largest contributors to today's paper waste stream are Mixed-Office Waste (Softwood Kraft Pulp) and Newsprint (Stone Groundwood Pulp). When paper is recycled the fibers are unavoidably, and irreversibly damaged. This damage is caused by Hornification (irreversible effect of re-drying fibers) and from the morphological changes on the fiber surface and structure from repeated re-slurring. The combination of these effects will affect the actual strength of the fiber, the bonding potential of the fiber and the freeness of the pulp (drainage rate equivalent). …


Eliminating Coating Flakes With Ultrasound, Ryan Zarbaugh Apr 1998

Eliminating Coating Flakes With Ultrasound, Ryan Zarbaugh

Paper Engineering Senior Theses

As paper mills took to reuse as much internal waste as possible, problems in the system can be introduced. The buildup of deposits or fluctuations of chemicals can occur when more broke is introduced. In mills that add a layer of coating to the paper problems associated with the coating can be introduced. At Champion International in Hamilton, Ohio, a heavy layer of coating added to the sheet introduces the problem of coating flakes to the system.

It was hypothesized that the use of the ultrasonic cavitation mechanism should be able to break the flakes apart and reduce the overall …


The Effects Of Directional Drying On Binder Migration, Bruce Johnston Apr 1998

The Effects Of Directional Drying On Binder Migration, Bruce Johnston

Paper Engineering Senior Theses

Binder migration or the nonuniform distribution of binder is a coating problem for many printing grades of coated paper. Binder migration causes mottle, dusting, non-porous coating and other problems in printing paper. Also, many coating dryers have extra capacity that cannot be utilized. The extra capacity goes wasted because at higher drying rates unacceptable binder migration would result.

If binder migration could be controlled, coated paper with better printing characteristics could be produced at higher speeds. This would result in a better product operating at higher speeds and a more satisfactory product to the printers.

The objective of this thesis …


The Effects Of Multiple Recycles On Wheat Straw Fibers, Jeffrey S. Greaves Apr 1998

The Effects Of Multiple Recycles On Wheat Straw Fibers, Jeffrey S. Greaves

Paper Engineering Senior Theses

Ever since the late 1960' s, the concern for finding suitable replacements to wood fibers within a paper making medium has been one of the focuses for the industry. At the current time, there are only a limited amount of mills that actually utilize non-wood fibers in order to satisfy the demand for paper within developing countries. Much of the use of non-wood fibers stems from the fact that there are only limited amounts of suitable woody raw materials available to sustain their paper industry. Also, areas that dispose of their agricultural resdiues by burning the remaining stalks is starting …


An Analysis Of Fecal Coliform Bacteria As A Water Quality Indicator, Janet Heyl Vail Apr 1998

An Analysis Of Fecal Coliform Bacteria As A Water Quality Indicator, Janet Heyl Vail

Dissertations

The focus of this study is to assess the efficacy of fecal coliform bacteria as a microbiological water quality indicator. The scientific and educational context of fecal coliform bacteria is explored through analysis of large sets of water quality data, focused field monitoring projects, and review of commonly used resources for school-based and volunteer water-related studies. Analyzed data sets include long term sampling (10 years), multiple sites, daily samples, storm event samples, and other parameters monitored in parallel with bacteria. Special attention is given to data sets from Kent County, Michigan. A background reference site in Michigan unimpacted by humans …


A Comparison Between Two Phase System And Single Phase System In Stiff Beveled Blade Coating By Measuring The Blade Forces, Ravi Mohan Apr 1998

A Comparison Between Two Phase System And Single Phase System In Stiff Beveled Blade Coating By Measuring The Blade Forces, Ravi Mohan

Masters Theses

The effect of pigment particle interactions in a two-phase system on blade force is investigated. Three coating colors of 0%, 40% , and 55% solids, of the same high shear viscosity and density, were tested for blade force, blade run-in relationship. The Cylindrical Laboratory Coater was used to blade coat the coating on a polyester film. Blade deflection was measured by placing a probe in direct contact with the back side of the blade. A calibration plot between blade force and blade deflection was then used to determine the actual blade forces. A statistical analysis of the data reveals that …


A Kinematic And Kinetic Analysis Of First, Fourth, And Fifth Positions In The Classical Ballet Method, Mary Sue Hill Apr 1998

A Kinematic And Kinetic Analysis Of First, Fourth, And Fifth Positions In The Classical Ballet Method, Mary Sue Hill

Masters Theses

The problem of the study was to compare electromyography (EMG) responses, ground reaction forces, and torques on female college-age dancers' knees in selected positions. Subjects were 18 female dancers, aged 18 to 30 years, with 6 subjects from each of three levels: Ballet Technique I, II, and III. The rectus femoris, vastus lateralis, and vastus medialis were analyzed in a grande plie in three positions, (1) first, (2) fourth, and (3) fifth, with two phases: (1) eccentric, and (2) concentric. No differences in force or EMG data were found for the concentric phases of the three positions. Significant differences were …


Molecular Staging Of Colorectal Cancer: K-Ras Mutation Analysis Of Lymph Nodes Upstages Dukes’ B2 Patients, Jennifer S. Thebo Apr 1998

Molecular Staging Of Colorectal Cancer: K-Ras Mutation Analysis Of Lymph Nodes Upstages Dukes’ B2 Patients, Jennifer S. Thebo

Dissertations

The successful treatment of colorectal cancer depends upon the ability of staging systems to identify patients who are at risk for recurrence. The currently used systems fail in a significant number of patients. Multiple attempts have been made to improve upon these systems in order to provide better treatment for at-risk patients.

A variety of oncogenes and tumor suppressor genes have been implicated in colorectal cancer. Mutations in one of these, K-ras, occur in 40-60% of colorectal carcinomas. However, the relationship between specific mutations and clinical outcome is unclear.

The purpose of this study was to determine whether or not …


Direct Measurement Of The Water Retention Of Coatings Under Shear, Mohana Sundaram Thiagarajan Apr 1998

Direct Measurement Of The Water Retention Of Coatings Under Shear, Mohana Sundaram Thiagarajan

Masters Theses

Coating water loss is one of the most critical concerns in coated paper production. The objective of this study was to determine directly the water retention value under dynamic conditions. The effect of shear rate on water transfer was documented for a delaminated clay coating color. The results showed a small change in water transfer at low shear rates, compared to the static condition. But at higher shear rate, the water transfer increased significantly. The water transfer increased with time, reaching an asymptotic limit at 300 seconds. This indicates that at higher retention time, the water transfer rate is reduced …


Characterization Of Swinepox Virus Secretory Polypeptides, Takeshi Shimamura Apr 1998

Characterization Of Swinepox Virus Secretory Polypeptides, Takeshi Shimamura

Masters Theses

Swinepox virus (SPV) is the only known member of the genus Suispoxvirus. SPV causes a mild disease in swine characterized by slight fever, and weight loss, associated with lesions restricted to the skin. There have been few studies on SPV. Other poxviruses, such as vaccinia virus, have been well characterized and the biological activities of their secretory polypeptides have been analyzed. This study describes a major SPV secretory polypeptide with an apparent molecular mass of 35kDa. Poxvirus encoded polypeptides secreted during infection are known to exhibit immunomodulatory activities. The 35kDa SPV secretory polypeptide was tested.for its ability to inhibit …


The Effect Of Ink Jet Coating Rheology On Screening, Burak Aksoy Apr 1998

The Effect Of Ink Jet Coating Rheology On Screening, Burak Aksoy

Masters Theses

Ink jet coating formulations are becoming of increasing importance due to rapid expansion in digital printing. These coatings have very specific ink absorption requirements, which are fulfilled by using polyvinyl alcohol and silica as binder and pigment, respectively. These coatings have unique rheological behavior and often have problems in industry during the filtering process. In this work, an attempt was made to relate filter blocking to the rheological behavior of the coating. A series of coatings were prepared and their rheological properties characterized. The solids content and pigment selection of the coating were altered in order to adjust the coating …


Effect Of Precalendering On Surface And Printing Properties Of Coated Sheets, Hariharan Venkata-Chinnaswamy Apr 1998

Effect Of Precalendering On Surface And Printing Properties Of Coated Sheets, Hariharan Venkata-Chinnaswamy

Masters Theses

This study focuses on the effect of different types of precalendering on coated woodfree paper for surface and printing properties as well as coat weight distribution and binder migration.

Precalendering enhanced the gloss and reduced the roughness of the coated paper at all coat weights. In the case of post-calendered papers, any differential effect achieved through various types of precalendering was recovered during post calendering. The final porosity values of precalendered and uncalendered sheets were more dependent on the coat weight at the high coat weights (10-18 g/m2 ). At low coat weights the type of precalendering influences the …


The Effects Of Potato, Corn And Wheat Starch On The Rheological Properties Of Pigmented Paper Coatings, Brian G. Hart Feb 1998

The Effects Of Potato, Corn And Wheat Starch On The Rheological Properties Of Pigmented Paper Coatings, Brian G. Hart

Paper Engineering Senior Theses

The paper industry is one of the largest users of commercial starch in the world. Starch has many uses in the papermaking process, including coating operations. In coating, starch has two main purposes: to work as a binder and to give desired rheological properties to the pigmented paper coating. Research was done examine the effects of three different starches on the rheological properties of pigmented paper coatings. The three starches were com, wheat, and potato. These starches were modified using the enzyme conversion process. The converted starches were added to the coating formulas and then tested for high and low …