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

Sleep is required to consolidate odor memory and remodel olfactory synapses

Animals with complex nervous systems demand sleep for memory consolidation and synaptic remodeling. Here, we show that, although the Caenorhabditis elegans nervous system has a limited number of neurons, sleep is necessary for both processes. In addition, it is unclear if, in any system, sleep collaborates with experience to alter synapses between specific neurons and whether this ultimately affects behavior. C. elegans neurons have defined connections and well-described contributions to behavior. We show that spaced odor-training and post-training sleep induce long-term memory. Memory consolidation, but not acquisition, requires a pair of interneurons, the AIYs, which play a role in odor-seeking behavior. In worms that consolidate memory, both sleep and odor conditioning are required to diminish inhibitory synaptic connections between the AWC chemosensory neurons and the AIYs. Thus, we demonstrate in a living organism that sleep is required for events immediately after training that drive memory consolidation and alter synaptic structures

Postnatal and Adult Aortic Heart Valves Have Distinctive Transcriptional Profiles Associated With Valve Tissue Growth and Maintenance Respectively

Heart valves are organized connective tissues of high mechanical demand. They open and close over 100,000 times a day to preserve unidirectional blood flow by maintaining structure-function relationships throughout life. In affected individuals, structural failure compromises function and often leads to regurgitant blood flow and progressive heart failure. This is most common in degenerative valve disease due to age-related wear and tear, or congenital malformations. At present, the only effective treatment of valve disease is surgical repair or replacement and this is often impermanent and requires anti-coagulation therapy throughout life. Therefore, there is a critical need to discover new alternatives. A promising therapeutic area is tissue regeneration and in non-valvular tissues this requires a tightly regulated genetic “growth program” involving cell proliferation. To explore this in heart valves, we performed RNA-seq analysis to compare transcriptional profiles of aortic valve tissue isolated from mice during stages of growth (postnatal day (PND) 2) and adult maintenance (4 months). Data analysis reveals distinct mRNA profiles at each time point and pathway ontology identifies associated changes in biological functions. The PND2 aortic valve is characterized by extensive cell proliferation and expression of mRNAs related to the extracellular matrix (ECM). At 4 months, proliferation is not significant and a differential set of ECM-related genes are expressed. Interestingly there is enrichment of the defense response biological process at this later time point. Together, these data highlight the unique transcriptome of the postnatal valve during stages of growth and maturation, as well as biological functions associated with adult homeostatic valves. These studies create a platform for future work exploring the molecular programs altered in the onset of heart valve disease after birth and provide insights for the development of mechanistic-based therapies

Loss of ADAMTS19 causes progressive non-syndromic heart valve disease

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