1941 research outputs found
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P300 Event Related Potentials from Rat Brain to Cues for Reinforcement and Non-Reinforcement
No full textAdvisor: W. D. KlipecThe P300 Event Related Potential (ERP) is a time locked, averaged EEG to task relevant stimuli. Previous research in our laboratory has shown that the P300 ERP in rats is a correlate of the brains recognition of a conditioned reinforcer. More recently, we found that the P300 ERP to a tone that
predicted reinforcement was indistinguishable from one that predicted non-reinforcement, linking the P300 ERP to the information in the cue even when the information was predicting the absence of a reinforcer. Here we compared the P300 ERP to the click of a food hopper under two conditions. In one condition (cued reinforcement) a tone signaled a click that was followed by food delivery. In the other condition, the absence of the tone signaled that the click would not be followed by food delivery (non-cued non reinforcement). We found that the P300 ERP to the non-cued non-reinforcement click rapidly disappeared suggesting that the absence of the tone was informative, predicting nonreinforcement
and eliminating the response to the click. We are currently gathering data in a condition
where the probability of food delivery following a click is 0.5, but there are no cues to provide information about the relevance of the click. Pending completion and analysis, these data will also be reported at DUCURS.Drake University, College of Arts and Sciences, Department of Psycholog
A Study of the ATLAS Tile Calorimeter LASER Calibration System Dynamic
No full textAdvisor: Claudio Santoni ; Renato Febbraro of University of MichiganATLAS is a general-purpose high-energy physics detector. The LASER system is one of three hardware calibration systems of the ATLAS tile calorimeter. In order to cover the whole tile calorimeter dynamic, the LASER light sent by the system goes through a filter wheel with eight filters. After the light passes the LASER head, it is split into two parts. Once part is sent to a timing photomultiplier
tube and three photodiodes which measure the LASER pulses. The second part goes through the filter wheel before being measured by a fourth photodiode. Each of the eight filters applies a specific attenuation factor to the light. Our goal was to analyze data generated by the LASER system in order to measure these attenuation factors and therefore the dynamic of the LASER system.Drake University, College of Arts and Sciences, Department of Physics and Astronomy ; University of Michiga
Using Reycled Computers to Construct a Beowulf Cluster for Molecular Modeling
No full textAdvisor: Maria Bohorquez ; Timothy UrnessThe process of using recycled computers to construct a Beowulf cluster in order to simulate the molecular dynamics of a chemical system is explored. The cluster was assembled using used computers taken out of service due to upgrades, and would otherwise be discarded. When assembled in a cluster, the computer performed the numerically-intensive process of molecular modeling roughly four times faster than a current machine using synthetic benchmarks. The cluster was used to run a molecular modeling program NAMD. We used the cluster and NAMD to analyze an experiment to
study a biologically active lipid called DOPC in the form of a monolayer. The monolayer was constructed using VMD (Visual Molecular Dynamics). It consists of DOPC molecules on the air/water interface. An energy minimization process is carried out before molecular dynamics can be calculated in order to render the system in its most probable physical state.Drake University, College of Arts and Sciences, Department of Mathematics and Computer Science, Department of Chemistr
Searching for Bediasite Tektites in Texas
No full textAdvisor: Charles NelsonThirty-five million years ago a very large object collided with the earth in the Chesapeak Bay area of the United States east coast. During the collision, molten earthly material was created. It "splashed"
up and rained back down in Georgia and Texas. The glassy material rocks (ejecta) that fell to the earth from this collision are called tektites. The tektites that fell and have been found by a number of collectors and scientists over the years are named after a town and the native inhabitants that lived near the current town of Bedias, Texas. A summary of the six years of research done on these extraordinary
rocks will be presented in the form of a poster along with real examples of the bediasite tektites on display.Drake University, College of Arts and Sciences, Department of Physics and Astronom
The Last WACs : A Case Study Of Women In Leadership Focusing On Women In The Last Direct Commissioning Class Of The Women's Army Corps
Get PDF312 leaves. Advisor: Janice M. WalkerThis study gave voice to an untold story, the story of how the glass ceiling affected a unique population – women Army officers. The women Army officers in this study joined the service during the post Vietnam era, just as women were being integrated into the Army as full and equal partners with their male counterparts. None of the women from the last direct commissioning class of the Women’s Army Corps (WAC) attained the rank of general officer. Through case study and the women’s own words, this study focused on whether the most successful of these women encountered a barrier or series of barriers that kept them from being promoted to general officer or if they chose to opt out.
The successful women Army officers in this study were confident, competent leaders; they had a highly developed personal code of conduct; they were pioneers and role models for the women Army officers who followed them; they sought stability; and they viewed their service as a vocation which continues today.
All five participants encountered a series of barriers on their leadership journey as women Army officers. Two of the women made conscious decisions to opt out in order to provide family stability. Additionally, the women benefited from their experience of being women Army officers educationally, financially, and by gaining skills and knowledge which helped them in their post-retirement careers. Their roles as pioneers and tokens added layers of complexity to their leadership journey.
Their service, however, came at a personal cost. And while they did not have equal opportunity, the Army afforded them increased opportunity and equal pay
The Determination of the Amount of Vanillin in Commercially Available Products
No full textAdvisor: John N. GituaThe purpose of this study was to determine whether there is a correlation between the amounts of vanillin and the taste of the commercially available products. Extraction of vanillin from such products obtained from the local restaurants was achieved by using a combination of organic solvents and the
amounts of vanillin determined using the gas chromatographic (GC) technique. We anticipate that this study may be able to inform the consumer (us) whether the taste we enjoy from our favorite vanillin containing products is due to the amount of vanillin present or not.Drake University, College of Arts and Sciences, Department of Chemistr
Changes in Urine Specific Gravity and Bioelectrical Impedance Analysis Between Normal-Hydrated and Euhydrated States
No full textAdvisor: David S. SenchinaBACKGROUND: Urine specific gravity (USG) is a simple way to estimate the hydration of an individual that is directly proportional to urine osmolality. Bioelectrical impedance (BIA) is a way to measure % fat, % water, and % lean body mass in an individual. BIA analysis is used frequently as a
way to measure hydration status and body percentages accurately. PURPOSE: Our study measured the effects of extra water consumption on USG and BIA. HYPOTHESIS: We predicted that extra water consumption would cause a decrease in USG, a decrease in % body fat as determined by BIA, and increased in both total body water % and % lean mass by BIA. METHODS: Seventeen males and females between 20-22 years of age participated. Each participant came to the lab twice. All subjects
were instructed to keep a 1-day diet diary prior to their first visit. At the first visit, subjects provided a urine sample and had BIA performed. They were then randomly divided into two groups: the control group replicated their diet for the second visit, and the other group consumed an extra liter of water in addition to replicating their diet. Urine samples and BIA information were then collected again on the second visit. RESULTS: Extra water consumption was associated with a significant decreased in USG but not changes in BIA measurements. CONCLUSIONS: USG was affected by extra water consumption, but % body water, % fat mass, and % lean mass by BIA were not.Drake University, College of Arts and Sciences, Biochemistry, Cell, and Molecular Biology Departmen
The Expression of Endothelin Converting Enzyme-1 Insoforms in Murine Cells
No full textAdvisor: Andrew Brittingham ; Jeffrey Divino of Des Moines UniversityEndothelin-1 (ET-1) has been demonstrated to play a role in many physiological processes including vasoconstriction, cardiovascular homeostasis, inflammation, angiogenesis, and tissue regeneration. A critical step in the production of ET-1 is the conversion of the propeptide form, bigET-1, to ET-1 via
the action of endothelin converting enzyme-1 (ECE-1). There are four major ECE-1 isoforms: ECE1a, 1b, 1c, and 1d, which differ only in their NH2 terminus and subcellular locations. Here we describe our analysis of the expression of ECE-1 isoforms in murine bone marrow derived macrophages (BMM0), macrophage-like cell lines (RAW264, J774) and an endothelial cell line (bEND.3). For analysis, reverse transcription-polymerase chain reaction (RT-PCR) was performed using forward primers, unique to each major isoforms, and a common reverse primer. bEnd.3, J774 and BMM0 express mRNA encoding all four major isoforms of ECE-1, as well as previously reported splice variants (SV) of ECE-1b, 1c, and 1d. A novel splice variant, KC150, was identified in isoform 1c. These splice variants all lack exon 3, which encodes the trans-membrane domain of ECE-1. The absence of
a trans-membrane domain could be indicative of a secreted or cytosolic form of ECE-1. Our results also indicate that the RAW264 macrophage cell line expresses very low levels of ECE-1 encoding mRNA. This verifies our previous finding that RAW264 cells secrete only bigET-1, suggesting a deficiency
in ECE-1 expression. We hope to use these ECE-1 deficient cells as a model for over expressing individual ECE-1 isoforms and splice-variants, and examine their function in regulating macrophage ET-1 production.Drake University, College of Arts and Sciences, Department of Biology, Biochemistry, Cell and Molecular Biology Program ; Department of Microbiology, Des Moines Universit
The Amounts of Limonene on Orange Peels: Effects of Species or Geographical Location
No full textAdvisor: John N. GituaThe purpose of this study was to explore whether the concentration of limonene on orange peels is affected by either the species of the oranges or the geographical location of such oranges. Extraction of limonene from oranges sampled with the respect to a) species and b) origin was achieved via refluxing
of the well-divided orange peels in hexane and the amounts of limonene from the crude extract
determined using gas chromatographic technique (GC). This study (ongoing) will offer insights
as to how i) species or ii) geographical location or both affect the amount of limonene on the orange peels.Drake University, College of Arts and Sciences, Department of Chemistr
Isolation of Yeast Genes that Suppress the Chromosome Loss Defect of ysm's 22, 77, 83, and 84
No full textAdvisor: Heidi SleisterCancer cells display both chromosome rearrangements and abnormal numbers of chromosomes. High fidelity chromosome transmission requires the accuracy of multiple processes such as DNA replication, DNA repair, sister chromatid cohesion, mitotic spindle assembly, and chromosome segregation. Many of the gene products that function in these processes are conserved in eukaryotes. The simple eukaryote Saccharomyces cerevisiae (budding yeast) is an excellent model system for the study of chromosome transmission as its cell cycle is well-characterized, and it is amenable to genetic analysis. With the aim of identifying genes important for chromosome transmission, we previously generated a collection of YAC stability in mitosis (ysm) mutants that display increased loss of a yeast artificial chromosome (YAC). Four mutant strains (ysm's 22, 77, 83, 84) are particularly interesting as they display high levels of YAC loss and have at least one additional mutant phenotype related to a
process important for genome stability (e.g., DNA replication, mitotic spindle assembly). Isolation of suppressors of the YAC loss phenotype in these mutants may reveal the defective genes in these strains as well as genes whose products interact in the same or parallel pathways as the defective gene
product. To this end, ysm's 22, 77, 83, and 84 were transformed with a yeast genomic plasmid library, and plasmids that suppressed the YAC loss phenotype were isolated. We are in the process of verifying candidate suppressor plasmids by retransformation of the mutant strains and identifying the suppressing
genes by DNA sequencing. Analysis of these suppressors will contribute to our understanding of gene products, protein networks, and processes important for eukaryotic genome stability.Drake University, College of Arts and Sciences, Department of Biolog