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Depression, ADLs, and Physical Activity in Adults with Alzheimer\u27s Disease
No full textAlzheimer’s disease (AD), the most common form of dementia, causes progressive cognitive decline that often impairs the ability to perform Activities of Daily Living (ADLs). Difficulties with ADLs can contribute to depression and other mental health challenges. Since many ADLs require motor skills, physical activity may help maintain independence, thus reducing depression. This study examined whether physical activity mediates the relationship between depression and ADL performance in individuals with AD. Data were obtained from a publicly available Kaggle dataset. After filtering for participants who self-reported their weekly hours of physical activity, depression diagnosis, and ability to complete ADLs, the resulting sample was 648 participants. A mediation analysis using linear regression was conducted to examine whether physical activity influenced the relationship between depression and ADL performance. Results showed that physical activity did not significantly predict depression (F(1,646) = 0.964, p = .327) or ADL completion (F(1,646) = 0.538, p = .464). Depression also did not significantly predict ADL performance, either directly or indirectly through physical activity, indicating no evidence of a mediating effect. These findings indicate that physical activity may not independently mitigate depressive symptoms or improve daily functioning in individuals with Alzheimer’s disease. Future studies should consider including a control group and more nuanced measures of mental health to better clarify potential relationships among these variables
The effect of leaf composition and structure on decomposition rates in Primula sp. and Allium schoenoparsum
No full textDecomposition is the process by which dead organic matter is broken down by bacteria and fungi. Leaves are a prominent form of organic matter that decomposes and enriches soil by returning nutrients. In this experiment, chive and primrose leaves were investigated. Chive leaves are thinner and softer, while primrose leaves are thicker and more dense, supporting our hypothesis that Chive leaf litter will decompose faster than primrose leaf litter because chives have a lower lignin content and are structurally narrower, making them easier to decompose. For this experiment, we placed around 4 grams of both species into a series of 4 groups of porous wire gridded leaf litter bags on the 5th floor green roof of the Janet Ayres Building in 4 separate locations to allow natural decomposition to take place through physical breakdown, chemical leaching, and microbial activity. Every 3 weeks, we collected 4 leaf bags, which were dried and re-weighed to determine mass loss as an indicator of decomposition rate. Our results showed that the chives decomposed much faster than the primrose, and the primrose did not fully decompose since we started the litter bags, while all the chives had fully decomposed
Assembly and Testing of a Closed Cycle Cryostat
No full textClosed cycle cryocoolers are commonly used in laboratories as they provide long-term, low-cost, low-maintenance operation. This project covers the assembly and testing of an Advanced Research Systems DE-202 closed cycle cryostat to provide a low temperature apparatus for undergraduate research and advanced laboratory projects. This system is useful for many applications including optics, condensed matter physics, spectroscopy, electrical characterization, microscopy, superconductivity, crystallography, and biological studies.
Cryostat assembly involved research and planning to build a custom frame for the cryocooler, assemble vacuum, water, gas and electrical systems, leak test, and fit components to laboratory utilities. Once setup is complete, the actual base temperature and thermal response of the system during cooldown and heating phases will be recorded at the sample holder. The results will determine proper functionality of the equipment, a necessary prelude to performing further experimentation
Developmental Effects on Zebrafish Embryos Exposed to Alcohol
No full textZebrafish are a good organism model due to their similarities with human biology. The transparency of their embryos allows for an easier view to see the developmental stages of the embryos, and easily and accurately note any mutations or defects in any of the embryos. In addition, they make excellent candidates to track potential effects that mirror human embryos with ethanol and alcohol will have on their developmental stages. The aim of this study was to measure the genetic size developmental differences of the embryo’s lens, eyes, and heart that are given 1% alcohol and 2% alcohol. This study’s experimental design consisted of breeding the zebrafish on one day, once they laid eggs then we would create 3 different groups of alcohol and eggs. There was a control group that consisted of only eggs and 10 mL of egg water, a 1% group that contained 1% of alcohol and 10mL of egg water in a petri dish with the eggs, and a 2% group of eggs that were in same environment with 2% of alcohol and 10mL of egg water. After each condition was created, imaging would take place next to view how they embryos have developed.
Results showed that alcohol exposure caused developmental defects as the eggs developed into embryos. Specifically, the size of the eyes and lens became smaller, while the size of the heart increased significantly compared to the control group. The importance of this study is to showcase the potential mechanisms by which alcohol can negatively affect genetic development of humans
Utilizing β-gal to visualize selective transport of the SSA4 gene in S.Cerevisiae
No full textIn eukaryotic cells such as Saccharomyces cerevisiae, protein synthesis begins with the transport of mRNA from the nucleus to the cytoplasm. In order for mRNA to leave the nucleus, it must first bind to specific transport proteins which can then facilitate transport via the nuclear pore complex (NPC), a selectively permeable membrane within the cell\u27s nuclear envelope. Under environmental stress, such as heat shock, S. cerevisiae cells modulate transport rates. In this case, in heat stress or “heat shock” most mRNA transcripts will remain in the nucleus. The SSA4 transcript encodes for a chaperone protein which facilitates the subsequent export of this otherwise “stuck” material. This then raises the question at hand, how does this transcript go about exporting mRNA from the nucleus under these conditions, while other transcripts do not? To investigate this mechanism overall, my project focuses on developing a tangible, phenotypic reporter system for selective SSA4 transport under a select set of conditions. Furthermore, I have inserted a bacterial plasmid containing the β-gal gene into the SSA4 locus in wild type S. cerevisiae. With this integration, we expect to see the production of a visible blue expression in the presence of the X-gal substrate within our S. cerevisiae cultures following heat stress or “heat shock”. The β-gal gene was inserted to the SSA4 gene locus using CRISPR-Cas9 technology and was inserted into a wild type strain of S. cerevisiae (yeast), we later confirmed this via. a series of PCR analysis. These repeatable methods can be used in future implications by utilizing modified S.cerevisiae strains that will reflect identifiable proteins involved in this molecular mechanism, among others
The Effect of Acidic Environments on Cosmos sulphureus Decomposition
No full textThe study of plant decomposition is an area of interest across the ecological research community. Understanding decomposition rates can help ecologists predict changes in ecosystems across different geographic ranges over time. Leaf litter decomposition represents an important factor of nutrient cycling within these ecosystems that may be impacted by environmental conditions like acid rain or chemical pollutants. Exposure of Cosmos sulphureus leaf litter under acidic conditions was hypothesized to have a different rate of decomposition than untreated leaf litter due to the favorable chemistry acid-base reaction conditions. Over the course of eight weeks, a solution of acetic acid (vinegar) was applied to two groups of litter bags each week. The other two groups of litter bags served as the negative control and decomposed under typical environmental conditions. The groups treated with vinegar demonstrated a faster rate of decomposition than the control group. These results indicate that acidic exposure to vinegar does increase the rate of decomposition in Cosmos sulphureus, which could potentially increase the availability of nutrients in the environment. However, the accelerated decomposition has the chance to disrupt ecosystems that rely on slower, more stable nutrient cycling. Future applications of this research may assist environmental managers in implementing practices aimed at mitigating nutrient imbalances in ecosystems that experience neutral or basic pH conditions
Evaluating E. coli as an Indicator of Pathogenic Contamination in the Cumberland River Using Nanopore Sequencing
No full textUrban freshwater systems provide both recreational opportunities and drinking water resources, making pathogen exposure a critical public health concern. The U.S. Environmental Protection Agency (USEPA) has recommended Escherichia coli (E. coli) as an indicator of fecal and pathogenic contamination since 1986. However, with advances in environmental DNA sequencing, tools such as Oxford Nanopore’s MinION now enable broader microbial analysis beyond E. coli. This study investigates the relationship between E. coli abundance, pathogenic bacterial presence, and overall microbial diversity in the Cumberland River, a major freshwater source in Nashville, Tennessee. Using IDEX Colilert quantification of E. coli and environmental DNA sequencing with Oxford Nanopore’s MinION, we assessed microbial community composition across multiple sites and time points. Regression analyses demonstrated that E. coli abundance significantly predicts both total bacterial richness and the number of known human pathogens, which supports its use as an indicator organism of water contamination. While no significant differences in overall bacterial richness were detected between sites or sampling weeks, E. coli levels exhibited both spatial and temporal variation. These results suggest that E. coli effectively reflects both overall microbial activity and pathogen presence in urban freshwater systems. However, integrating MinION nanopore sequencing may enhance water quality monitoring by collecting more specific microbial data that traditional methods may overlook
Investigating Cell Death Pathways in Pompe Disease
No full textLysosomes are crucial components of eukaryotic cells that break down damaged or aged organelles, ingested pathogens, and other large molecules. Dysfunctional enzymes within or surrounding lysosomal pathways result in lysosomal storage diseases (LSDs), inherited metabolic disorders that can be fatal due to the accumulation of cellular waste products. These disorders typically result in neurodegeneration. However, the exact mechanism of cell death has yet to be elucidated. Previous work from Niemann Pick Type C Disease, suggests that impaired mitophagy leads to apoptosis through the intrinsic cell death pathway. However, this has yet to be investigated for the other LSDs. We investigated mitophagy in Pompe disease by inducing the disorder with acarbose and utilized immunofluorescent and live cell microscopy to observe changes to mitophagic flux. Our findings suggest that impaired mitophagy may be a common impairment between different LSDs
