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Full-Text Articles in Life Sciences

Expression Of Α4Β1 Integrin On Tissue Eosinophils In The August Rat, John C. Phipps Dec 1996

Expression Of Α4Β1 Integrin On Tissue Eosinophils In The August Rat, John C. Phipps

Masters Theses

The integrin α4β1 is expressed on a wide variety of peripheral leukocytes, and functions in recruitment of these cells to sites of inflammaiton. We infected august (AUG) rats with the helminth parasite Nippostrongylus brasiliensis and later used leukocytes from the peritoneum of the sensitized animals and antibodies against α4β1 integrin to localize that adhesion molecule on the cell surfaces after antigen challenge. We found that after antigen challenge, eosinophils, monocytes, and small lymphocytes, but not mast cells, expressed α4β1 integrin if the animals had been previously infected, but cells from uninfected animals did not show expression of this molecule. Our …


Expression And Regulation Properties Of Pseudomonas L-Arabinose Utilization Plasmids, Mary E. Barecki Dec 1996

Expression And Regulation Properties Of Pseudomonas L-Arabinose Utilization Plasmids, Mary E. Barecki

Masters Theses

The L-arabinose utilization pathway in Pseudomonas fluorescens is a unique metabolic pathway. In Pseudomonas, L-arabinose is converted to the end product α-ketogluterate and does not involve phosphorylated intermediates. This differs from the well studied L-arabinose pathway found in Escherichia coli which contains phosphorylated intermediates.

The enzymes of the L-arabinose pathway have been shown to be induced in the presence of L-arabinose in P. saccharophila. The current study determined regulatory properties of previously cloned chromosomal fragments of P. fluorescens which confer an L-arabinose positive phenotype to the surrogate host, Pseudomonas putida. Cells of P. putida containing plasmids pPZ221, …


The Effects Of Benzo(A)Pyrene And Dimethylbenzanthracene On Cultured Porcine Aortic Endothelial Function, Michelle Lynn Kagey Dec 1996

The Effects Of Benzo(A)Pyrene And Dimethylbenzanthracene On Cultured Porcine Aortic Endothelial Function, Michelle Lynn Kagey

Masters Theses

Polycyclic aromatic hydrocarbons are environmental contaminants which have been shown to initiate and promote atherosclerosis and carcinogenesis in various animal species. These findings have been based primarily on the increase in incidence and size of smooth muscle cell tumors in these animals were exposed to benzo(a)pyrene (BaP) or dimethylbenzanthracene (DMBA). The endothelium has also been identified as an important mediator in vascular disease and atherogenesis, although the endothelial response to these PAHs has not been investigated. Thus, the focus of this study was on characterization of the endothelial response to BaP and DMBA. Concentration/response relationships for these chemicals were examined, …


Strength Properties Of Steam Exploded Laser Printed Papers, Dhamodharan Srinivasan Dec 1996

Strength Properties Of Steam Exploded Laser Printed Papers, Dhamodharan Srinivasan

Masters Theses

The mam objective of this study was to investigate the effect of steam explosion pulping on the strength properties of recycled fibers. The properties considered were zerospan tensile strength, tensile breaking length, tensile stretch, tensile energy absorption, scott bond and pentosan content. This study also examined the important operating parameters that affect the properties. Laser printed waste paper was pulped by the steam explosion process. The experiments were statistically modeled to cover the various process variables. Chemical addition, residence time, pressure, and dispersant level were varied during the steam explosion experiments. Chemical addition was kept at four levels and other …


The Flora And Ecology Of Seidman Park, Kent County, Michigan, Pamela J. Laureto Aug 1996

The Flora And Ecology Of Seidman Park, Kent County, Michigan, Pamela J. Laureto

Masters Theses

A floristic study of Seidman Park, Kent County, Michigan was performed. The study identified 521 vascular plants belonging to 96 families and 284 genera. The plant communities of Seidman Park were delimited by identification of dominant species and observation of the physical environment. It was believed that communities existed within the upland forest that could not be identified by observation alone. The use of Non-Metric Multidimensional Scaling (NMS) ordination techniques identified three communities within the upland forest. These were a xeric community, a dry-mesic community and a nutrient-rich community. Three sub-communities of the dry-mesic community were also identified.


The Factors Influencing Electrographic Toner Flotation, Udaykumar Ratilal Raval Jun 1996

The Factors Influencing Electrographic Toner Flotation, Udaykumar Ratilal Raval

Masters Theses

Conventional deinking is the process of removing the ink from usable paper fiber. Electrographic toners are hydrophobic in nature because they have negligible negative charge. A study of the effect of fundamental properties leading to electrographic toner flotation in presence of free fibers has not been reported.

Flotation deinking of fused "sharp" toner fraction below 300 micron in the presence of free fibers was performed in the Hallimond tube. Cationic (Dodecyltrimethyl ammonium bromide - DTAB) and anionic (Sodium dodecyl sulfate - SDS) surfactants having similar molecular weights were used at two concentration levels and two pH levels. The effect of …


The Effects Of Fines, Drying Intensity And Recycling On Pulp And Paper Properties, Chiranjiv K. Singh Jun 1996

The Effects Of Fines, Drying Intensity And Recycling On Pulp And Paper Properties, Chiranjiv K. Singh

Masters Theses

The effects of fines level, drying intensity and recycling on pulp and paper properties of bleached softwood kraft were evaluated graphically and statistically.

Fiber fines (100-mesh) were mixed in proportions of 0, 10, 20, 40% with the long fiber fraction. These pulps were tested for fiber length distribution. Handsheets prepared from these pulps were dried at low (air dry) and high (220°F, 4.25 min) drying intensities. These handsheets were recycled and new handsheets were dried at the above drying levels.

Water retention values increased with increasing level of fines for virgin pulp. Recycling resulted in a 20% decrease in water …


The Effect Of Wet End Operations On Sizing Loss In Alkaline Papers, Suresh B. Cherukuri Apr 1996

The Effect Of Wet End Operations On Sizing Loss In Alkaline Papers, Suresh B. Cherukuri

Masters Theses

Changes in wet end of alkaline papermaking affect the size development as well as sizing loss. These changes include pH, alkalinity and type of filler used. Precipitated and ground varieties of carbonate fillers and the alkalinity associated with · them are believed to be the causes for the gradual sizing loss in alkaline papers due the accelerated hydrolysis reaction of sizing chemicals at higher alkalinity.

Precipitated and ground calcium carbonate fillers are used as fillers and compared to non carbonate filler such as kaolin clay for their response to size development and sizing loss at lower and higher alkalinity ranges …


The Effect Of Manganese Peroxidase On Peroxide Bleaching Of High Yield Pulps, Cyril Vusani Simelane Apr 1996

The Effect Of Manganese Peroxidase On Peroxide Bleaching Of High Yield Pulps, Cyril Vusani Simelane

Masters Theses

The main objective of this study was to investigate the effect of adding a pretreatment stage in conventional hydrogen peroxide bleaching of high yield pulps. To achieve this, three main variables considered crucial in the effectiveness of manganese peroxidase on the oxidation of lignin substructures, were chosen to evaluate the effect of this enzyme on high yield pulps. The responses to evaluate this effect were brightness, brightness reversion, pulp viscosity, and yield. Other properties included opacity, scattering and absorption coefficients, and the Hunter Lab values.

The pulps were bleached using two sequences Q(MnP), and Q(MnP)QP, to assess the effect of …


Effects Of Insulin And Insulin-Mimetics On Mrna Levels Of C-Fos And C-Jun In Primary Rat Hepatocytes In Culture, Guangmin Li Apr 1996

Effects Of Insulin And Insulin-Mimetics On Mrna Levels Of C-Fos And C-Jun In Primary Rat Hepatocytes In Culture, Guangmin Li

Masters Theses

Insulin is capable of regulating cellular and metabolic processes as well as gene expression. Selenate and vanadate are two compounds that have been found to mimic the action of insulin in several tissue and cell types. cFos and cJun are the products of immediate early responsive genes c-fos and c-jun. They are members of the family of the AP-1 (Activator Protein-1) transcription factors. AP-1 transcription factors bind as cJun.cJun homodimer or cJun.cFos heterodimer to the TRE found in the promoter regions of several genes. AP-1 is characterized by its ability to alter gene expression in response to various peptide …


The Effect Of Age And Recycling On Paper Quality, Zhuang Wu Apr 1996

The Effect Of Age And Recycling On Paper Quality, Zhuang Wu

Masters Theses

The effects of recycling paper that has undergone aging for different periods on paper and fiber properties like strength, weighted average fiber length, and water retention value were investigated in this study. Old Newspapers (ONP) with different periods of natural aging (between 1 to 10 months) were recycled repeatedly for up to six times. Another goal was the study of aging effects on paper properties using accelerated aging at high temperatures (105±2) °C. Four different aging times (24, 48, 72, and 144 hours) were employed.

The results showed that naturally aged ONP loses little in strength properties up to 7 …


The Role Of Nitric Oxide In The Modulation Of The Leukocyte-Endothelial Cell Interactions During Ischemia And Reperfusion, Fernando López-Neblina Apr 1996

The Role Of Nitric Oxide In The Modulation Of The Leukocyte-Endothelial Cell Interactions During Ischemia And Reperfusion, Fernando López-Neblina

Masters Theses

Nitric oxide (NO) is involved in several metabolic pathways and physiological phenomena. The role of NO in inflammation after ischemia and reperfusion (I/R) is controversial. The early phases of inflammation include the leukocyte-endothelial (L/EC) cell interactions which have been divided in rolling, activation, adhesion and migration.

The first experiment was to demonstrate the role of NO in a model of renal I/R. We demonstrated that exogenous NO improves survival and renal function tests after renal I/R, while endogenous NO does not appear to be an important contributor to renal I/R. We also demonstrated that NO modulate the infiltration of neutrophils …