18525 research outputs found
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Black Power and African Diasporic Religions: The Spiritual and Cultural Trajectory of Black Empowerment, 1965-2015
No full textThis dissertation project centers on the overlooked work of activists whose organizing efforts during the Black Power era converged with their subsequent initiation into African diasporic religions like Haitian Vodou or Lucumí, the Cuban variant of the Yoruba religion. It examines the activists’ adoption of these religions and the effects their faiths had on their approaches to communal liberation. As such, it is the first historical study to systematically analyze African Americans’ involvement in African diasporic religions through the lens of their activism. The study integrates the histories of these activist-practitioners into the broader history of the Black liberation struggle in the United States. This dissertation project thus contributes to an increasing body of scholarship seeking to diversify our understanding of the religious influences on the Black liberation struggle beyond the scope of Black churches and mosques. Analytically, it tackles two major questions: first, by reconstructing the devotees’ Black Power activism, this study illustrates in what ways their time in the movement was formative for their decision to initiate into these religions. Here, I am not only referring to how their activism nurtured their interest to learn more about Africa and the diaspora but also to how their status as an often marginalized and vilified group of radical activists prepared them to become a religious minority within a racialized minority. Second, by examining the continuities and changes in their theoretical and practical work, this study illuminates the imprint their religions left on their personal lives as well as their activism. Knowing what inspired them to become religious vanguards helps us better account for variations in African American activism. At the same time, the interrogation of their religiously inspired activism renders new insight into the spiritual dimension of the long struggle for Black liberation and the evolution of increasingly popular religions in the United States
Nanoscale Spectroscopy of Semiconductor Defects
No full textWide-bandgap semiconductors are of great interest as a solution to meet the increasingly demanding requirements of power electronics. However, commercialization is challenged by the presence of extended defects. Many spectroscopic and microscopic techniques have been applied to the identification and characterization of these defects. These techniques are typically limited to providing either spectroscopic or microscopic information. Scattering-type scanning nearfield optical microscopy (s-SNOM) and nano Fourier transform infrared Spectroscopy (nano-FTIR) are nondestructive characterization methods that enable infrared microscopy and spectroscopy at spatial resolutions far exceeding the diffraction limit (< 20 nanometers). Characterization of two classes of extended defects, in-grown stacking fault (IGSF) and threading dislocations (TD) was performed using these techniques, resulting in the observation of a novel 3C-SiC IGSF and large strain induced phonon shifts in the vicinity of TDs
The Relationship Between Trauma Exposure and Memory Impairment: The Mediating Effect of Anxiety, Depression, and Sleep Disturbance
No full textCourse: PSY 4999- Honors Thesis
Faculty Mentor: Dr. Antonia KaczkurkinThe impact of trauma on individuals can have a profound and lasting effect on wellbeing. Ongoing research in the field is interested in the neurocognitive impact of trauma, including its effect on memory. However, there are some discrepancies regarding the direction of various effects found. While some studies find that trauma does not impact memory at all or they attribute the effects to mediators, others have found there to be an independent effect. Furthermore, few studies have examined the relationship between trauma exposure and memory impairment in youth. The current study aims to provide further clarification to the literature by analyzing longitudinal data from the Adolescent Brain Cognitive Development (ABCD) Study and hypothesizes that trauma exposure is associated with episodic memory impairment, and that anxious-depressive symptoms and sleep disturbances mediate this relationship.Thesis completed in partial fulfillment of the requirements of the Honors Program in Psychological Science
Mechanochemical Exploration of the p-Block
No full textAs environmental concerns over organic solvents rise and chemists become more aware of the interference solvents can play in reactions, solvent-free methods have grown in popularity, including mechanochemical methods. Mechanochemical reactions are induced by the direct absorption of mechanical energy, commonly through grinding or milling, with little or no solvent. Organometallic chemistry has advanced through removing the solvent and using mechanochemical methods for synthesis. This dissertation seeks to enhance the fundamental understanding of ball milling through the preparation of bulky allyl complexes of p-block metals, specifically aluminum, germanium, arsenic, and antimony. Heteroleptic aluminum complexes of the formula [(NHC)xAlCl3 nA′n] [NHC = N-heterocyclic carbene; A′ = [1,3-(SiMe3)2C3H3]−; x = 0−1; n = 0−3], were prepared and examined as initiators for L-lactide polymerization, a biodegradable polymer. [AlA′3], which is only accessible via ball milling, was the most active for polymerization. A homoleptic germanium tetra(allyl) ([GeA′4]) was accessed through halide metathesis of germanium halides and K[A′]. [GeA′4] is highly stable, unlike the related [SnA′4], which decomposes when exposed to air or dissolved in solution. The stability of the two systems was explored with computational and experimental studies. Tris(allyl) complexes of arsenic and antimony were prepared with salt metathesis, as two diastereomers; the ratio of diastereomers varies with mechanochemical or solution preparation. The difference in selectivity is attributed to the layered crystal lattices of the EX3 reagents, which template the stereochemistry. The effect of mechanochemical variables on isomer selectivity was explored, including the milling apparatus, milling media, liquid assisted grinding, and use of different reagents. The extent to which the anisotropic lattice is degraded during synthesis affects the diastereomeric ratio. Synthetic chemists commonly find themselves asking the question, what is the best solvent for this reaction? We seek to answer the question: what happens when there is no solvent
Design and Evaluation of Soft Robotic Powered Hand Orthoses to Assist the Neurologically Impaired
No full textStroke and other neurological events affect millions of people across the globe every year, leaving more than half of them with significant upper limb impairment (over 350,000 annually in the US alone). After conducting customer discovery of over 150 members of the ecosystem, two populations with specific needs emerged. One category of patients has spastic (stiff) hands and needs help stretching, while the other group has flaccid hands and requires grasping assistance. While some therapeutic and assistive technologies exist, current at-home rehabilitation devices are inadequate. This work describes the customer discovery journey as well as the design and evaluation of a soft robotic powered hand orthosis for each patient demographic, with the goals of helping patients regain their independence and reducing hands-on time for caregivers and therapists. The prototypes developed are OrthoHand Extend, a simple therapeutic stretching aid, and OrthoHand Flex, a 3D printed grasping aid. The prototypes were tested on three neuro patients, and neared or exceeded the target design constraints. Most notably, OrthoHand Extend was able to comfortably stretch the spastic patients’ hands with increased consistency, and OrthoHand Flex enabled a stroke survivor with flaccid hands to perform previously unachievable activities of daily living. Furthermore, both prototypes are significantly faster to don and doff than any in literature. One is easily custom-sized and 3D-printed, while the other is made of inexpensive fabric. Both are designed to be powered by a portable, fluid powered actuation unit that patients could take home. These orthoses have the potential to revolutionize neurorehabilitation by making assistive devices more accessible to patients and lay the foundation for clinical trials and further device development
Advancements in our Understanding of Enteric Formation and Function
No full textEstablishing the Enteric nervous system (ENS) relies heavily upon migration, colonization, and proper neural diversification to ensure a functional digestive tract. This dissertation investigates the role of Sox10 in ENS development and its potential implications for ENS function. Single-cell RNA sequencing during early ENS development reveals distinct neuronal trajectories and upregulation of Hox gene regulatory network activity as cells transition toward neuronal states. Differential expression analysis identifies significant downregulation of Hoxa6 within Branch C, indicating the involvement of Hox genes in neuronal diversification. Comparisons between Sox10+/+ and Sox10Dom/+ lineages highlight differences in the cellular landscape, underscoring Sox10's regulatory role in ENS development. Additionally, introducing the Sox10 MS mouse model aims to enhance cost-effectiveness and efficiency in Sox10-related studies. This model detects spontaneous calcium activity at the wavefront of migrating enteric progenitors and increased calcium activity in the enteric glia of Sox10Dom/+ offspring, suggesting Sox10's involvement in calcium signaling within the mature ENS. The data presented in this thesis serve as a foundation for further exploration of ENS development at the transcriptomic level and expand the available tools for research in enteric studies
Genetic and Molecular Dissection of the Corkscrew Phosphatase in Synaptic Function and Neurological Disease
No full textCytoplasmic protein tyrosine phosphatase non-receptor type 11 (PTPN11) and Drosophila homolog Corkscrew (Csw) regulate the mitogen-activated protein kinase (MAPK) pathway via a conserved autoinhibitory mechanism. Disease causing loss-of-function (LoF) and gain-of-function (GoF) mutations both disrupt this autoinhibition to potentiate MAPK signaling. At the Drosophila neuromuscular junction (NMJ) synapse, LoF/GoF mutations elevate transmission strength and reduce activity-dependent (AD) synaptic depression. Fragile X Mental Retardation Protein (FMRP) binds csw mRNA and neuronal Csw protein is elevated in Drosophila fragile X mental retardation 1 (dfmr1) nulls. Trans-heterozygous csw/+; dfmr1/+ recapitulate elevated presynaptic pERK activation and function. In LoF/GoF mutations, the synaptic vesicles (SV) colocalized Synapsin phosphoprotein is highly elevated at rest, but quickly reduced with stimulation, suggesting a larger SV reserve pool with greatly heightened activity-dependent recruitment. Transmission electron microscopy of mutants reveals an elevated number of SVs clustered at the presynaptic active zones, suggesting that the increased SV availability is causative for the elevated neurotransmission. Thus, a FMRP and PTPN11 MAPK/ERK regulative mechanism controls basal and AD neurotransmission strength
Characterization of 6-oxo-M1dG in Xenopus Egg Extracts
No full textGenome integrity is established through the high fidelity and efficient replication of cellular DNA as well as the ability to repair DNA when DNA damage or errors occur. A wide array of genotoxins can interfere with DNA synthesis by blocking DNA helicase or polymerase activity at replication forks, either directly or indirectly. Failure to employ repair mechanisms in a proper manner can result in genetic mutations, genomic instability, and cancer. A primary response to genotoxins is replication fork reversal, which involves reannealing of parental DNA strands and extrusion of nascent DNA strands to form a reversed fork. Fork reversal is thought to support error-free bypass of DNA lesions and regulate the rate of DNA synthesis. The nascent DNA strands of replication forks are degraded by exonucleases in a process known as ‘Nascent Strand Degradation' (NSD), which is thought to convert the reversed fork back to a replication fork so that DNA synthesis can resume. Although NSD is important for genome stability, too much NSD causes genome instability. Thus, NSD must be triggered efficiently but not overly triggered to ensure genome stability. Our lab has previously used Xenopus egg extracts to show that uncoupling causes NSD and fork reversal. However, a major question from this work was how do these events occur naturally in response to damaged DNA? To study this, we utilized 6-oxo-M1dG, a model DNA lesion that blocks polymerase function while also being resistant to more canonical DNA repair pathways, such as Translesion Synthesis. Our data shows that the non-bulky polymerase-blocking DNA lesion, 6-oxo-M1dG, is able to block DNA synthesis and stall DNA replication in the presence of a singular replication fork. Strikingly, the convergence of two replication forks allows for the efficient bypass of 6-oxo-M1dG in a CMG unloading-independent mechanism. Additionally, 6-oxo-M1dG is not readily repaired by any active mechanism in Xenopus egg extracts, making it a model DNA lesion to study replication-coupled DNA repair pathways
Creating Education Spaces of Belonging: The Intersection of Community, Purpose, and Reciprocity
No full textThe study examines how a decidedly Black community-based education space (CBES) cultivates a sense of community and belonging among Black adolescents. Qualitative data indicate that site personnel, specifically the Servant Leader Interns (SLIs), play a key role in fostering belonging through micro-level processes. Reciprocity within classrooms, wherein SLIs create space for scholars to voice their expectations and feedback, is identified as critical for building trust and breaking down hierarchical barriers between educators and students. The study highlights the importance of sensemaking in navigating cultural processes at the site. By demonstrating care, trustworthiness, and creating safe spaces, adults in the CBES establish belonging for scholars. Overall, the findings shed light on the strategies and dynamics involved in creating a sense of community and belonging within a Black CBES
Optimizing Ternary Nanocarriers for Stable and Non-Toxic Delivery of Rictor/mTORC2 RNAi Against Triple Negative Breast Cancer
No full textTriple negative breast cancer (TNBC) is a highly aggressive BC subtype with limited molecularly targeted therapies. Aberrant activation of the phosphatidylinositol 3-kinase/ mammalian target of rapamycin (PI3K/mTOR) pathway is often seen in TNBC but attempts to target this pathway have been altogether ineffective for TNBC patients. Less is known regarding the signaling complex mTOR complex 2 (mTORC2) which is a central integrative node of the PI3K/mTOR pathway and regulates pro-oncogenic activities such as tumor cell survival, motility/metastasis, and chemoresistance. However, small molecule inhibitors that potently and selectively block mTORC2 do not exist. Here, we leverage short interfering RNA (siRNA) technology to block expression of Rictor, an mTORC2-required cofactor, to test the therapeutic utility of mTORC2 signaling inhibition in TNBC.
siRNA therapies are a promising strategy for treating diseases that lack druggable targets, but their systemic delivery is limited by rapid kidney clearance, low cellular uptake, and poor endosome disruption. siRNA-carrying nanoparticles (si-NPs) can improve siRNA delivery to target organs but continue to face delivery challenges such as limited stability, off-target toxicities, and suboptimal tumor accumulation. Ternary si-NPs containing siRNA, an NP core-forming polymer, and an NP surface-forming polymer have the potential to improve tumor silencing activity because of the participation of both polymers in siRNA encapsulation and pH-responsive endosome disruptive activity. Through concomitant structure-function optimization of the core-forming polymer ratio and molecular weight, we identified a lead ternary si-NP with enhanced stability, potent tumor gene silencing activity, and minimal toxicity.
To enable therapeutic Rictor knockdown in TNBCs in vivo, we utilized our optimized si-NP for intravenous delivery of siRictor, resulting in robust tumor siRNA accumulation, Rictor knockdown, and mTORC2 inhibition. Selective mTORC2 inhibition using siRictor in vivo decreased tumor cell proliferation, survival, and tumor growth in TNBC tumor-bearing mice, and increased paclitaxel-induced tumor growth inhibition. Together, this work supports Rictor ablation as an effective approach for therapeutic mTORC2-selective blockade and identifies a novel RNAi nanotechnology for treatment of PI3K-active TNBC