Mitosis produces two genetically identical daughter cells, each inheriting their own nucleus and a full set of replicated chromosomes from the parent cell. Inaccurate chromosome segregation can result in severe consequences like cancer and developmental defects. Microtubules are dynamic cytoskeletal components that provide the forces necessary to segregate chromosomes into their respective daughter cells during mitosis. The kinetochore is an assembly of proteins and protein complexes located on the centromere that binds to microtubule ends to attach chromosomes to the force-generating microtubules. The accurate segregation of chromosomes relies on the ability of the kinetochore to strongly bind chromosomes to microtubule ends. Ndc80 complex is an outer kinetochore component that binds microtubule ends and is required for proper chromosome segregation. Emerging cellular data suggests that multiple Ndc80 complexes interact with one microtubule end to facilitate chromosome separation. In vivo data suggests multiple Ndc80 complexes are arranged around microtubules. To closely model the native kinetochore-microtubule interface, we have begun to assemble a structured particle of multiple Ndc80 complexes in vitro using designed proteins that form oligomers. The particles have different geometries and stoichiometries. A method to couple Ndc80 complex to the designed protein was developed. We then tested the coupling efficiency under different temperatures and concentrations to optimize the reaction and ensure complete particle assembly. We found that the reaction goes nearly to completion with a 3:1 ratio of Ndc80 complex to designed protein at room temperature with a reaction time of thirty minutes. We will now measure the stoichiometries of the particles, which are designed to have four, five, or six Ndc80 complexes. Successful formation of these organized particles will allow us to measure the effect of geometry and stoichiometry on the ability of the Ndc80 complex to make strong attachments to microtubules.

During mitosis, chromosomes are organized and separated by the dynamic mitotic spindle. The kinetochore plays a central role in proper chromosome segregation. It is recruited by specialized sites on the chromosome, known as centromeres, and forms attachments to the spindle microtubule. The Dam1 and Ndc80 complexes are essential microtubule-binding elements of the outer kinetochore in budding yeast. The Ndc80 complex bridges the kinetochore to the dynamic microtubule tip, while the Dam1 complex enhances the Ndc80 complex’s residence time on microtubules and load bearing ability. It was previously reported that swapping yeast histone proteins with human histone proteins resulted in poor complementation, in higher frequencies of aneuploidy, and impaired adaption to novel nutrient environments. Several mutations in the Dam1 complex and one mutation In the Ndc80 complex were found to independently rescue these defects. To determine how these mutations rescue human histone swapping in budding yeast, we purified mutant versions of the Dam1 and Ndc80 complexes. We used an optical trap to measure if the mutations alter the amount of force required to break attachments to a dynamic microtubule. A difference in rupture force between wild type and mutant proteins tells us that the mutations rescue histone swapping by changing the load bearing ability of the kinetochore-microtubule interface. Further study is needed to determine the mechanism for rescue. A null result tells us that further research is required, and a novel interaction may be present. This research will uncover differences in human and yeast kinetochore structure and function.

Digital badges are part of a larger informal credentialing system with many uses for tracking and rewarding extracurricular achievement. Scout badges, videogame trophies, and badges on educational websites like Khan Academy are all examples of microcredentials that represent one’s experiences and skills. This research is part of a larger six-year study that has explored the role of digital badges in encouraging youth to connect their out-of-school science learning to other aspects of their lives. My work specifically focuses on uncovering sources of support students receive in their daily lives to pursue science as a career or field of study, and how digital badges fit into their existing support systems. This study aimed to answer the following three research questions: 1. What factors influence students’ science identities? 2. What are the primary supports students receive to develop their science identities? 3. How do students perceive the role of badges in supporting their science identities? Using interviews, case studies, and surveys I was able to assess students’ relationships with science and the support they received from various sources to continue developing their interest in science. I used qualitative coding methods to identify common themes in each participant’s experience using the badge system. This study’s preliminary results indicate that students did not find the badge system useful in developing their science identities. Data from the participant interviews suggests that this is partially because the badges were not integrated into participants’ existing support systems like their friend groups and families. The findings of this study support a central idea of sociocultural learning theory—that students’ interest in topics is sustained through their interactions with others. Insights from this study could be used to inform the approach of programs that encourage students to participate in STEM.

 The Civil Rights Movement is credited as the paragon of social justice movements because it was able to champion the fight for equal rights through the strategy of non-violence. Post-movement, social justice organizations in the U.S have continued to build on utilizing non-violence, but the extent to which it has helped to generate awareness and further social justice issues remains unknown. This literature review captures the similarities and contrast between how the Civil Rights movement utilized non-violence to further its cause as compared to present-day social justice movements. First, the review delves into the strategic advocating history of the Civil Rights Movement to identify and reflect on the effectiveness of various non-violent techniques that were used. Then, various techniques such as peaceful protests, mass petitions, and boycotts are assessed in relation to their ability to create an effect for social equity on an interpersonal, grassroots, and legislative level. The relationship between non-violence and its role in the progression of equity issues is an ever-changing one. There are numerous ways to advocate for a cause and the review captures whether such techniques are solely based on a non-violent essence or if there is a degree of violence that is involved in creating much needed societal change. In addition to this, the research shows how effectively present-day social justice movements are utilizing these techniques to champion their respective causes. This comparative analysis of the literature will continue to contribute to the ongoing discussion around how modern social justice movements can efficiently advocate for human rights.

Public Perception surrounding the sexual exploitation of adolescent girls in history is marred by the manipulation of social elite classes. Bestselling books on Madame De Pompadour, the royal mistress to King Louis XV, falsely claim Madame De Pompadour facilitated a brothel of adolescent poor girls for her royal lover to sexually exploit. While her true involvement was much less proactive, the shifting of blame from established elitists like Louis XV to outsiders like Madame De Pompadour is a long-standing practice within elite upper-class culture. A study of eighteenth-century court behavior aids in illuminating the reasoning behind modern day cases of sexual exploitation within elite classes including that of Jeffrey Epstein and his sex trafficking ring. These “self-fashioning” outsiders, Pompadour and Epstein, infiltrated high social ranks without elite backgrounds and disrupted the established authority within elite culture. By comparing eighteenth-century to twenty-first century elite culture, this literature review is an attempt to understand how attacking an outsider to upper class culture, instead of high-ranking members, has been historically used to maintain the social elite established order. A review of academic research provides some answers for how members avoid public scrutiny for sexually exploiting adolescent girls and how manipulating public attention has been a historically prevalent tool in diverting responsibility to the “self-fashioning” outsider. With future research, we can expose how “self-fashioning,” in the context of the Middle Ages and the Renaissance, carried over into elite culture practices of the eighteenth century and is still prevalent in the twenty-first century. This future research can aid in shedding light on centuries of abuse and recycling of misinformation.