32 research outputs found
Young’s Modulus: Building a Device to Measure Material Strength to Understand Interatomic Bond Stiffness
Young’s Modulus is an equation that is to measure the strength in different materials. A common application of Young’s Modulus is measuring the breaking point of cables. The understanding of the Young’s Modulus equation and its applications is a standard part of the introductory undergraduate physics sequence. We sought to construct a lab apparatus that would enable physics undergraduate students to measure and verify the results of the Young’s Modulus equation. These macroscopic measurements can then be used to further understand inter-atomic bond stiffness. This poster reviews the design, construction, and testing of a Young’s Modulus lab experiment. This lab will be used by undergraduate students at Northwestern College, thus offering a further experimental application of a topic that was previously taught only theoretically.
Designing and Building an Inverted Microscope
Iowa Stonybrook Lasers And DNA Course Embedded Research (ISLAND CURE) is a new research collaboration group that is focused on undergraduate research for both the students and the professors. The goal of this research collaboration was to create physics apparatuses to make biochemical measurements. One of the tools we are developing is an infrared optical tweezing system. This requires an inverted microscope to facilitate the trap. To observe one of these measurements, an inverted microscope is required to observe the sample. Inverted microscopes can be expensive, and our budget is limited. To overcome this issue, our research group decided to create our own inverted microscope with the minimal budget we had. This microscope can now be used for optical tweezing and observation of a live sample
Building a Mach Zehnder Interferometer with Limited Resources
Interferometers are simple optical devices that function by splitting a coherent light beam. The beam is recombined using beam splitters and mirrors. The addition of the two light beams produces interference patterns in the forms of fringes which can be used to study the path taken by the two beams. This is old technology and we sought to construct an interferometer using rudimentary and cast-off equipment. The purpose is to show that modern physics concepts can be measured inexpensively and by undergraduate student design. Though we had no optics table and or optical mounts, by careful alignment and adjustments to the equipment, we were able to produce fringes whose intensity could measure phase changes of a light beam as it goes through various mediums. We were able to determine and learn more about the properties of light and produce successful results. This demonstrates a method of introducing modern physics lab applications at a low cost
The Effects of a Prescribed Burn on Small Mammals in an Ohio Tallgrass Prairie
Prescribed burning is used on prairies for increased prairie health and to manage the communities of organisms that rely on the prairie’s natural resources. Small mammals are also affected by the burning of prairies. Previous research by Chance in 1986 and Cook in 1950 has established that burning decreases the small mammal capture rates in the burned area because of the habitat loss and rapid change of habitat post-burn that stresses the animals and leads to lower reproductive levels (Chance, 1986). Other studies by Francl and Small also showed that small mammal populations did not return to pre-burn numbers even after 16 months of evaluation (Francl, K. E., & Small, C. J., 2013). We hypothesize that small mammal populations will decrease in the prairie after burning because of a lack of habitat and food source and that they will emigrate from the burning site to nearby prairie or similar habitat.
We will use baited Sherman live traps placed at 25 meter intervals in order to estimate the various small mammal populations in each of the observed habitats. We will plot the capture locations on a map of the area in order to track how stress affects the shift of population density
Analysis of a Putative Promoter in Mycobacteriophage JacoRen57
JacoRen57 is a cluster AB mycobacteriophage that infects Mycobacterium smegmatis mc²155. We recently reported on the characterization of a putative promoter in JacoRen57 using an mCherry reporter construct. This promoter is present in a gap upstream of a gene that is present in all AB phages. In all cases, these are forward genes immediately following a long series of reverse genes. The genes are most frequently identified as a RecA-like DNA recombinases but also as RepA by bioinformatics. To further analyze this putative promoter and gene product, NWC Molecular Genetics students cloned the RecA-like DNA recombinase into an E. coli expression vector with a TVMV removable N-terminal His-tag. They expressed and we purified the tagged protein and are using it to immunize Balb/c mice. We plan to use the antiserum to confirm RecA-like DNA recombinase expression patterns when JacoRen57 infects M. smegmatis
Comparing Common Techniques for Calculating Parasite Prevalence
Raccoons (Procyon lotor) are the final host for raccoon roundworms (Baylisascaris procyonis). Raccoon roundworm is the leading cause of a dangerous neurological disease, known as larva migrans encephalopathy. Diagnostic tools for detecting the presence of B. procyonis within a raccoon population include necropsy, fecal flotation, and latrine analysis. Necropsies yield the highest measure of prevalence, with fecal flotation and latrine analysis often underestimating infection rates. We necropsied 225 raccoons gathered from 10 townships of Clark and Greene Counties in Ohio. We collected fecal samples from 95 raccoons negative for B. procyonis at necropsy. We suspended the feces in Sheather’s solution to float any eggs, and prepared slides from this solution. Nearly 14% of raccoons negative at necropsy for B. procyonis possessed eggs in their feces. We used a chi squared test for equality of distributions to determine the likelihood that a positive fecal analysis is related to B. procyonis prevalence or to the area in which the raccoon was trapped. These data will help us determine how well fecal analyses estimate parasite prevalence
Does Baylisascaris procyonis Impact Raccoon (Procyon lotor) Genetics?
Raccoons (Procyon lotor) are the final host for raccoon roundworms (Baylisascaris procyonis). Raccoon roundworm is the leading cause of a dangerous neurological disease, known as larva migrans encephalopathy. Phylogenetic trees illustrate co-evolutionary events between species living in a symbiotic relationship with each other. Throughout the coevolution of host and parasite, many aspects of a population affect the way the members interact with one another and with symbiotic species. In order to evaluate the relationship between host and parasite in regards to diet, we isolated DNA from intestinal wall tissue, amplified a portion of exon 2 from MHC II, and sent our samples to Ohio State University for sequencing. We calculated heterozygosities for the nine townships we surveyed. We used a chi-squared test for equality of distributions to test whether raccoons from townships with above 60% prevalence have different heterozygosity for this locus than other raccoons. These data will help us to understand the relationship between raccoons and raccoon roundworm
Does Baylisascaris procyonis Phylogeny Correlate with That of the Raccoon (Procyon lotor)
Baylisacaris procyonis, commonly known as the raccoon roundworm, is a parasite that inhabits the small intestine of the North American raccoon (Procyon lotor). Although humans do not typically become the definitive host, humans can become infected through handling soil containing eggs. B. procyonis can induce serious health complications in cases of human infection, including degenerative retinal and behavioral changes, coma, and even death. High prevalence of B. procyonis in a raccoon population increases the probability of transference to human hosts. In our study, we analyzed the genetic structure of B. procyonis harvested from raccoons of southwestern Ohio, and compared this to the genetic structure of the raccoons they inhabited. It is our hypothesis that the genetic structuring of the roundworms is the same as the genetic structuring of the raccoons. We isolated DNA from the roundworms using the method outlined in the DNA Minikit (Qiagen). Our research team isolated DNA from each roundworm sample and sent it to the Plant-Microbe Genomics Facility at The Ohio State University for gene amplification and sequencing. We built phylogenetic trees using these sequences, and compared these trees to some constructed for the raccoons. The correlations drawn between the raccoon and B. procyonis phylogenetic trees will help us better understand the relationship between the two species
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Macro-meso-microsystems integration in LTCC : LDRD report.
Low Temperature Cofired Ceramic (LTCC) has proven to be an enabling medium for microsystem technologies, because of its desirable electrical, physical, and chemical properties coupled with its capability for rapid prototyping and scalable manufacturing of components. LTCC is viewed as an extension of hybrid microcircuits, and in that function it enables development, testing, and deployment of silicon microsystems. However, its versatility has allowed it to succeed as a microsystem medium in its own right, with applications in non-microelectronic meso-scale devices and in a range of sensor devices. Applications include silicon microfluidic ''chip-and-wire'' systems and fluid grid array (FGA)/microfluidic multichip modules using embedded channels in LTCC, and cofired electro-mechanical systems with moving parts. Both the microfluidic and mechanical system applications are enabled by sacrificial volume materials (SVM), which serve to create and maintain cavities and separation gaps during the lamination and cofiring process. SVMs consisting of thermally fugitive or partially inert materials are easily incorporated. Recognizing the premium on devices that are cofired rather than assembled, we report on functional-as-released and functional-as-fired moving parts. Additional applications for cofired transparent windows, some as small as an optical fiber, are also described. The applications described help pave the way for widespread application of LTCC to biomedical, control, analysis, characterization, and radio frequency (RF) functions for macro-meso-microsystems
Implications of Central Obesity-Related Variants in LYPLAL1, NRXN3, MSRA, and TFAP2B on Quantitative Metabolic Traits in Adult Danes
Two meta-analyses of genome-wide association studies (GWAS) have suggested that four variants: rs2605100 in lysophospholipase-like 1 (LYPLAL1), rs10146997 in neuroxin 3 (NRXN3), rs545854 in methionine sulfoxide reductase A (MSRA), and rs987237 in transcription factor activating enhancer-binding protein 2 beta (TFAP2B) associate with measures of central obesity. To elucidate potential underlying phenotypes we aimed to investigate whether these variants associated with: 1) quantitative metabolic traits, 2) anthropometric measures (waist circumference (WC), waist-hip ratio, and BMI), or 3) type 2 diabetes, and central and general overweight and obesity.The four variants were genotyped in Danish individuals using KASPar®. Quantitative metabolic traits were examined in a population-based sample (n = 6,038) and WC and BMI were furthermore analyzed in a combined study sample (n = 13,507). Case-control studies of diabetes and adiposity included 15,326 individuals. The major G-allele of LYPLAL1 rs2605100 associated with increased fasting serum triglyceride concentrations (per allele effect (β) = 3%(1;5(95%CI)), p(additive) = 2.7×10(-3)), an association driven by the male gender (p(interaction) = 0.02). The same allele associated with increased fasting serum insulin concentrations (β = 3%(1;5), p(additive) = 2.5×10(-3)) and increased insulin resistance (HOMA-IR) (β = 4%(1;6), p(additive) = 1.5×10(-3)). The minor G-allele of rs10146997 in NRXN3 associated with increased WC among women (β = 0.55cm (0.20;0.89), p(additive) = 1.7×10(-3), p(interaction) = 1.0×10(-3)), but showed no associations with obesity related metabolic traits. The MSRA rs545854 and TFAP2B rs987237 showed nominal associations with central obesity; however, no underlying metabolic phenotypes became obvious, when investigating quantitative metabolic traits. None of the variants influenced the prevalence of type 2 diabetes.We demonstrate that several of the central obesity-associated variants in LYPLAL1, NRXN3, MSRA, and TFAP2B associate with metabolic and anthropometric traits in Danish adults. However, analyses were made without adjusting for multiple testing, and further studies are needed to confirm the putative role of LYPLAL1, NRXN3, MSRA, and TFAP2B in the pathophysiology of obesity