Neutrophils are a type of white blood cell in the human immune system that can migrate through tissues to respond to sites of injuries and infections. In the laboratory, we can recapitulate neutrophil migration under controlled experimental conditions by using a cell line, called HL-60, that was originally derived from a person with leukemia. These cells can be cultured to imitate the behavior of neutrophils, and specifically they are able to migrate while we watch them on the microscope. First, I determined how HL-60 cell migration depends on the physical nature of the substrate they are crawling on. I compared cell migration under three different conditions: 1) uncoated plastic, 2) plastic treated to make the surface stickier for cells, and 3) plastic coated with a protein, BSA, to make the surface less sticky. I found that cells moved faster and with straighter paths on the uncoated plastic. Next, I used a drug, CK666, which is known to inhibit a protein that is important in the assembly of the cell’s actin cytoskeleton, the mechanical driver of cell migration. As expected, I found that the cells moved more slowly in the presence of the drug. Also, I found that the drug made the cells move in less straight paths. Finally, I explored how the HL-60 cells responded when I exposed them to an electric field. Electric fields are thought to arise naturally at sites of skin wounds. I observed that the cells moved toward the cathode of the electric field. I am currently analyzing whether the cells also move faster or straighter when there is an electric field present. In future experiments, I plan to determine whether mutating specific proteins thought to be involved in cell motility can change the behavior of the HL-60 cells on the microscope.

There is an existing ideology prevalent in our culture that radicalized, and gendered subjects are expected to endure copious amounts of pain when it pertains to their menstrual cycles. I call this into question and aim to explore alternative methods of alleviating dysmenorrhea beyond hormonal contraceptives and SSRIs. Focusing specifically on BIPOC menstruating populations, I have been the primary investigator of a study examining the effects of community dance and affinity spaces on menstrual pain management. Participants come into the dance studio weekly to engage in various open dance practices with others, in addition to journaling, guided massage, and discussion. The dance practices range from traditional Chinese practices like Qigong to local community dance practices like Dance Church. In addition to weekly sessions, I host quarterly BIPOC Jams open to the public, to share the knowledge with the wider community, cultivating a space for BIPOC to engage in freedom dreaming, community building, and collective healing. I will explore what a future of community healthcare would look like, moving away from Western models of healthcare that focuses solely on the individual. Drawing from practices like community acupuncture where the healing experience happens with others rather than in isolation, I am curious to investigate how having a shared dancing experience impacts and shifts the emotional and physical well-being of participants. I am exploring the care relationships that form in BIPOC affinity spaces and how dance as a language facilitates a different type of embodied healing. I will be presenting the structure that I have used for weekly sessions and the BIPOC Jams. I will also share excerpts of participant experiences and reflections from both spaces. I am drawing upon existing theories around care work, somatic abolition, and pain management to develop a practice of community care that builds upon existing discourse. 

Plastic is a prevalent and useful material, experiencing a 230-fold increase in production from 1950 to 2019. However, problems revolving around plastic production and disposal are becoming increasingly clear. In 2015 virgin plastic production was responsible for 4.5% of global greenhouse emissions, with the United states collecting only 9% of plastic waste for recycling. For polystyrene, a common plastic in food storage containers, less than 1% was recycled. The decomposition of polystyrene can also release dangerous chemicals, such as additives Bisphenol A (BPA) and polystyrene oligomers, directly linked to human health hazards such as diabetes, breast cancer, reproductive harm, thyroid regulation issues, heart diseases, and liver problems. To prevent both the need for new plastic and decrease plastic decomposition products from harming both humans and the environment, it is critical to develop a circular plastic economy, where plastic waste is broken down back into the chemical building blocks, or monomers, which can be re-manufactured into new high-quality plastics. The use of basic heterogeneous catalysts, such as zinc oxide (ZnO) can improve the yields of polystyrene deconstruction back into monomers compared to other chemical recycling techniques such as pyrolysis and acid-catalysis. To further improve yields, it is critical to understand the impact of relative basicity of ZnO on styrene yield. To examine base strength effects, the relative basicity of ZnO will be systematically varied through alterations in pretreatment methods. Reactions were tested in a mini-batch reactor at 623K over three hours using a 10:1 substrate to catalyst ratio, with product distribution examined using Gas chromatography-mass spectrometry (GC-MS) and a flame ionization detector (FID). 

Plastics have transformed the modern materials landscape, as they have a large range of applications at low costs. With this widespread and consistent use it is seen that production will continue to increase, reaching over 1.1 billion tons per year. Of this, only around 16% of plastics are recycled, with complex polymer recycling rates even lower. Remaining plastics are primarily landfilled or incinerated, leading to associated environmental impacts. In response to this issue, chemical recycling methods such as hydrogenolysis have been developed. However, these methods are limited by their ability to separate or otherwise handle mixed plastic waste feedstocks. This work investigates ruthenium-catalyzed hydrogenolysis of mixed polyolefin waste to determine the impact of mixed feedstocks on catalytic activity.  The system of pure polyethylene (PE) and polypropylene (PP) mixtures is studied as PE and PP are two of the most commonly produced plastics, together comprising nearly 50% of all plastics produced. Model compounds tetracosane and squalane are used as analogs of PE and PP, respectively. These compounds are simpler than their polymer counterparts while possessing similar structural elements, therefore making for an easier determination of mechanistic pathways and kinetic parameters. Reactions are performed in 10mL stainless steel reactor systems using a ruthenium on carbon (Ru/C) catalyst. Squalane and tetracosane are mixed at various ratios, maintaining 1g of substrate and 100 mg of Ru/C per reaction. Relatively mild conditions of 225°C, 20 bar of hydrogen are held for 1 hour. Preliminary results find the C-C bonds in tetracosane cleave to a greater extent than in squalane, with much of the squalane preserved. Likewise, reactions with a higher percent of tetracosane result in more bond cleavage compared to squalane-rich reactions. This indicates that branched polymer substrates may decrease overall catalytic activity compared to linear polymer substrates. 

Recent technological breakthroughs have allowed important advances in the description of deep reefs (below 30 m). However most research has been restricted to the upper section of deep reefs (down to 80 m) and has primarily focused on fish and coral communities. By contrast, the composition of the lower portion of deep reefs, and of non-coral habitat-forming communities remains limited. This work focuses on how the composition and structure of habitat-forming communities change across the entire depth range of a tropical reef-dominated ecosystem, from 5 to 300 m. Using a combination of SCUBA and manned submersible diving, benthic transects were performed in  Curaçao , an island in the Southern Caribbean Sea. Using a combination of morphology, taxonomy, and trait ecology, I will evaluate the faunal breaks of habitat-forming communities with depth. In addition to providing one of the first descriptions of the diversity and community structure of habitat-forming communities across the entire range of a reef’s slope, this work will contextualize over a decade of deep-reef fish observations conducted at this study site. This study will also provide insights into the vertical reef connectivity and resilience, informing future management efforts of deep Caribbean reefs. 

Understanding the structure and habitat preferences of deep-reef fishes is crucial for effective conservation management. Mesophotic ecosystems, occurring between 40 and 150 m, are understudied ecosystems with limited biodiversity assessments, although their importance in supporting species of commercial interest is established.  In particular, very few studies have described mesophotic fish assemblages in the Mediterranean, where essential fish ecosystems face increasing pressures from human activities. This study investigates fish species composition, abundance, and depth distribution at two sites in the Aegean Sea (Eastern Mediterranean).  Fish observations were collected by technical rebreather divers from the surface to 90 meters depth, along with information on habitat and fishing pressure. I will complement this dataset with information collected from the IUCN to identify patterns in species distribution, vulnerability, and habitat associations. This study will provide valuable insights into the community structure and habitat associations of mesophotic fish assemblages, ultimately contributing to conservation strategies that protect vulnerable marine ecosystems in the Mediterranean.

The formation of the neural tube is a critical event in embryonic development. Morphogenic signals guide a layer of embryonic cells to fold and create the neural tube, which serves as the precursor to the brain and spinal cord. When the neural tube fails to close properly, neural tube defects arise. Spina bifida is the most common neural tube defect, affecting 1 in 1,000 births. Although surgical procedures can be used to treat it, they often result in complications involving serious disabilities and infections. While neural tube defects are believed to have a multifactorial etiology, which includes a genetic component, proposed causative mutations that lead to the development of spina bifida in humans have yet to be thoroughly examined. Recently, mutations in the gene for a G-protein coupled receptor known as GPR161 were identified in infants with spina bifida. However, the role of GPR161 variants in the development of spina bifida is not fully understood. Utilizing CRISPR/Cas9 technology in human induced pluripotent stem cells, I have generated GPR161 knockout and point mutation lines and differentiated them into neural progenitors in a 2D model while also developing a 3D organoid system. Using these models, I will investigate the downstream pathways involved in the formation and patterning of the neural tube that could be influenced by the mutations. This includes the sonic hedgehog pathway, Wnt pathway, and assessing neural differentiation markers. I will evaluate these markers through various assays, including immunofluorescence and real-time quantitative PCR. Through these efforts, we will enhance our understanding of a genetic component in the etiology of spina bifida while demonstrating the value that induced pluripotent stem cells can have in studying human development and treating human diseases by recapitulating them in human models in vitro.

Age-related macular degeneration arises from irreversible photoreceptor loss. Photoreceptors, rods and cones, are specialized cells in the retina that allow light and color detection. My project investigates the role of retinoic acid (RA) on cone and cone-opsin development to understand the timeline of cone specification and development. RA, an endogenously synthesized vitamin A derivative present in the retina during development, drives rod photoreceptor differentiation, but its effect on cone development is still unknown. To understand RA’s role in opsin development, I use a retinosphere (RS) model, an in vitro system to culture human fetal retina. More specifically, I used RS from 70 to 90 days old (D70-D90) and cultured the RS until D100, when the cone-opsin onset occurs. I then fixed, cryosectioned, and immunostained the two conditions for S-opsin, M/L opsin, and NR2E3 (rod marker) and investigated changes in the density of cone opsin-positive cells between the two conditions using confocal microscopy. My findings showed that the condition containing exogenous RA had a decreased density of opsin-positive cells. To confirm that the observed effect is due to RA, I mimic the experiment by instead using WIN18446, an RA inhibitor. I then determined if RA's effects are dose-dependent. My results showed that increasing the concentration of exogenous RA amplified my previous findings. The next step is to understand the timeline of cone specification and development by using RS of a younger age, before cone-opsin onset. These results will allow my mentors and me to use our knowledge about RA to determine if inhibiting endogenous RA synthesis in the retina will play a role in developing therapeutics involving cone regeneration to aid in cone-related macular diseases and injuries.

Global plastic production has already surpassed 300 million tons annually, which poses serious environmental challenges due to the limited recycling and effective management of plastic waste. Current mechanical recycling methods are not efficient, since only a small fraction of plastic waste goes through recycling processes, resulting in severe environmental degradation and pollution. In view of this, the use of bimetallic nanoparticles as catalysts is critically evaluated in the case of plastic recycling. In this Literature Review, I look into different metal combinations, such as ruthenium-platinum, ruthenium-nickel, and ruthenium-cobalt bimetallic catalysts. These catalysts are known to have great potential for enhancing the selectivity and efficiency of the hydrogenolysis process, hence increasing the conversion of plastic into more valuable hydrocarbons like fuels and chemicals. It intends to draw attention to various advances in chemical recycling methods that may offer sustainable solutions to the global plastic waste crisis through a critical review of the synthesis methods, catalytic mechanisms, and practical applications of these bimetallic catalysts. Further work on the unique properties of the bimetallic nanoparticles provides insight into their catalytic role in enhancing efficient C-C bond cleavage in plastic, ultimately providing higher yields of desirable products and reduced formation of unwanted byproducts.

Retinal cell degeneration is one of the leading causes of blindness and vision loss caused by retinal diseases and is irreversible in humans. However, regeneration of retinal cells occurs after injury in some non-mammalian vertebrates and mimicking these strategies in humans could evolve treatment options for the visually impaired. Previous research in the Reh lab discovered a way to generate new neurons by reprogramming Müller glia (MG), a support cell of the retina, through overexpression of the proneural Ascl1 transcription factor in the mouse retina. To stimulate reprogramming, we used a lentiviral construct with a glial specific promoter (HES1) to drive the expression of ASCL1. However, HES1 represses its own expression by binding specific DNA sequences called N boxes which regulate gene transcription and expression, thus creating a negative feedback loop. In order to limit the negative feedback loop, we designed two new constructs using the HES1 promoter with modifications to the N box sequences. While the current construct has a reprogramming efficiency of approximately 25 percent, the aim of my project is to use constructs with modified N boxes to increase the ratio of MG reprogramming into neurons and verify specificity of the new constructs to MG cells. My research with mouse MG has shown that constructs with N box modifications significantly increase Ascl1 expression as compared to the construct with no modifications. These results seem promising and if reproducible, I will proceed with applying this strategy to human MG by using an in vitro culture system of retinal organoids.