Saturday Session March 31, 2007
Saturday Session Photo Archive

Surface Modifications of Platinum and Tungsten by Sintering

Kelly Schwartzbauer
Beta Iota Chapter, Bethel University

Sintering is a technique used to fuse powder particles together to create an object with increased surface area.  Improved mechanical and electrical properties and increased strength are often desired results.  For example, powder injection molding requires sintering to increase the density of raw metal powder particles together in a mold.  The strength of bonding between particles is determined by the length of time spent at the sintering temperature.  In this study, sintering was employed to achieve a thin, porous coating on metal wire surfaces.  

       The sintering process requires binding powder to the substrate surface prior to heating.  Obtaining a uniform coating on the wires proved challenging and the method of powder and binder application was varied.  The wires were also etched to roughen their surfaces.  Pressureless sintering on etched platinum (Pt) and titanium (Ti) wires was performed in a high-vacuum furnace to avoid oxide film formation on the wire surfaces at elevated temperatures.  Pt powder (28 micron) and Ti powder (3 micron) were sintered onto Pt and Ti wires respectively with the sintering temperature just below the melting point of each metal.   Optical and scanning electron microscopy (SEM) revealed that Ti sintered wires possessed a uniform, porous coating whereas Pt wires showed areas of variable thickness.  Subsequent texturing treatments resulted in surface modifications that were compared between the two metals, as shown by SEM images of the topography at various magnifications.  This groundwork sintering research forms the foundation for future experiments. (Audio-mp3)

The Effect of Fertilizers on Dry Weight and Nutritional Content of Alfalfa

Miki Mannino
Beta Chapter, McKendree College

       Experimentation was done on Timothy alfalfa plants to determine if their dry weight and nutritional content could be altered by different fertilizers.  Agriculture is tightly linked to the cost of raising livestock, which impacts the food industry as well.  Alfalfa is used for livestock feed in the winter and as a protein supplement during other months of the year.  Therefore, the cost of alfalfa production is directly correlated with the cost of livestock.  The agricultural economy depends on the ability of farmers to produce alfalfa in sufficient quantities and with economic efficiency.  If fertilizers can be used to increase production of the crop without an increase in price, the farming economy will soar.  Therefore, experimentation was done to determine the most cost efficient fertilizer for agricultural use. 

       Five different fertilizers were used.  Boron and Phosphorous were the synthetic bases used to imitate commercially manufactured fertilizers.  Cow, rabbit, and horse manure were the organic fertilizers, commonly used by farmers due to their availability.  In order to test the effects of these fertilizers, three plants were tested within each group, and three more were kept as control plants.  All alfalfa was grown in a greenhouse with regulated temperature and water for each plant.  Each plant was treated with its respective fertilizer on a strict schedule, and the plants were allowed to grow for 28 days.  After this time, the plants were cut and weighed before a protein assay was performed.  The amount of protein was compared to the dry weights, and statistical analyses were done to determine if the findings were significant.  This information, coupled with cost comparison can help agriculturalists make the correct choice when deciding what is economically feasible for crop fertilization. (Audio-mp3)

MAP Kinase Activation During Progressive Dehydration in Two Species of Amphibian: Bufomarinus and Rana catesbeiana

Kia Nicholson and Dr. Jeffrey Duerr;
Beta Beta Chapter, George Fox University

Comparative vertebrate studies into physiological responses to adverse conditions can yield great insight into the design of robust systems and then provide fundamental knowledge of stress adaptations.  The classically studied cellular stress response is the mitogen-activated protein kinase (MAPK) pathway.  In mammals, there are four known MAPKs: JNK, p38, BMK, and ERK.   p38 is a MAPK which responds to environmental stresses such as heat, oxidation, ionizing radiation, and hyper-osmotic shock.  The ERK MAPK is known to respond to growth factors and other mitogens by triggering cascades which activate transcription (Cowan and Storey, 2003).  JNK is known to be activated when an organism is confronted with osmotic stress, heat shock, and UV exposure.  Generally JNK activation leads to apoptosis, although occasionally it may trigger cell survival pathways.  The effects of dehydration on anuran amphibian blood flow rates have been previously investigated and suggested that a terrestrial toad (Bufo marinus) possessed a greater tolerance of dehydration as measure by cardiovascular performance relative to a more aquatic species (Rana catesbeiana). The initial goal of this study was to examine the effect of progressive dehydration on MAPK family activation in cardiac tissue from two species of anuran amphibians: Rana catesbeiana and Bufo marinus.  Western blot analysis indicated that the pERK increase by three-fold in Bufo and 2-fold in Rana.  pJNK levels remained unaffected in Bufo whereas in Rana they initially decreased, but then rebounded to baseline levels.  pp38 levels in Rana did not exhibit any significant change over the range of dehydration examined.  p38 phosphorylation in Bufo increased initially and then remained stable.  The physiological consequences of ERK activation in response to osmotic stress in anuran cardiomyocytes remain to be investigated. (Audio-mp3)

The Pharmacological Effects of the Aqueous Extract of Caulophyllum thalictroides (Blue Cohosh) on Isolated Mus musculus Uteri

Jennifer Berger and Dr. Teresa DeGolier
Beta Iota Chapter, Bethel University

       The roots and rhizomes of Caulophyllum thalictroides (blue cohosh), traditionally used as an aid for childbirth, contain several active alkaloids and saponins, which act directly on uterine smooth muscle resulting in an oxytocic response. The historical use of this herbal supplement has been well documented, but there are few clinical studies addressing its efficacy and potential side effects.        This research investigated the physiological and pharmacological responses of blue cohosh on isolated strips of murine uterine tissue. Uterine horns from mice were suspended in a smooth muscle bath and exposed to the aqueous extract of blue cohosh (0.037-23.8 mg). All tissues showed an increase in the strength of contractile force and these forces were significantly greater with higher doses (P=0.0001). The stages of estrous were determined by vaginal smears and dose-dependency was consistent in all stages of estrous observed (diestrus, estrus, metestrus). Blocking experiments showed that uterine tissues given a control dose of blue cohosh, followed by the nicotinic receptor antagonist curare, resulted in a 70% decrease in contractile response following a second application of blue cohosh. This is consistent with the proposed mechanism for blue cohosh.  (Audio-mp3)

Analysis of Expression of Bone Morphogenetic Protein 4 (BMP4) in the Frog Xenopus laevis

Adam J. Gilbertsen and Dr. Bryan Hyatt
Beta Iota Chapter, Bethel University

Members of the BMP family are expressed in the form of intercellular signaling proteins in both mesenchymal and epithelial cells within developing embryos.  Bone morphogenetic proteins (including BMP-4) have been found to influence lung differentiation and lung morphogenesis.  It has been speculated that BMP4 limits FGF10-mediated bud out growth though the role BMP4 is not entirely clear. However, it must have a critical role as BMP4-null mice experience early embryonic death.  In order to examine the role of BMP4 in lung development of Xenopus, we have examined BMP4 expression in several developmental stages.  The expression of BMP-4 was found throughout Xenopus early lung development and also in adult lung, heart and liver tissues. (Audio-mp3)

The Effects of Caffeine and Nicotine on the Oxygen Consumption of the Worm, Lumbricolus variegatus.

Michael Flesch
Pi Chapter, Millikin University

       Currently little knowledge or completed research exists on the metabolism of the California Blackworms, Lumbriculus variegatus.  Some physiological changes of the Blackworm that have been researched include work done by Drews (1999) where he found that many toxicants, including caffeine and nicotine, have effects on the Blackworm such as increased heart rate and changes in nerve conduction. 

     This project examines the way in which caffeine and nicotine affects the oxygen consumption in these worms.  A Clark-type Rank Oxygen Electrode was used to measure the oxygen consumption before and after exposure to caffeine or nicotine. The mean oxygen consumption or basal metabolic rate of the untreated worms was 0.835 µlO2/g/min.  The basal metabolic rate appears to be comparable to other poikilotherms but much less than homeotherms.  When exposed to 0.2mM nicotine the oxygen consumption increased to 1.33 µlO2/g/min. This is a change of 59.66%.  The mean oxygen consumption of the worms when exposed to 3 mM aqueous caffeine increased to 1.03 µg/g/min, an increase of 23.91%.  Finally the mean oxygen consumption of worms exposed to 6mM caffeine was 1.08 µg/g/min an increase of 28.91%.

     These results that were obtained correlate well with those observed by Drews.  Based upon the fact that both caffeine and nicotine are known CNS stimulants that increase blood pressure and neuron conduction, we believed that it would indicative to infer that the metabolism and oxygen consumption of the worms upon the administration of caffeine and nicotine would increase as well.  The results that we obtained did support our hypothesis that the physiological increases in heart rate and neuronal

conduction would cause proportional increases in the metabolic rate; however, this relationship between an increase in the heart rate and the neuronal conduction and an increase in the metabolic rate is not the same for all organisms. and in some organisms the correlation is inversely proportional.  (Audio-mp3)