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Item type: Item , Access status: Open Access , Consequences of Adolescent Sport-Related Concussion: Examining Clinical Function Outcomes 5-15 Years Following a Sport-Related Concussion or Musculoskeletal Injury.(2025-11-05) Moore, Jacalyn Anne Marie; Schneider, Kathryn; Emery, Carolyn; Whittaker, Jackie; Smirl, Jonathan; Leung, FelixSport-related concussions (SRC) may impact multiple physiological systems, including cervical spine function, oculomotor, vestibular, and balance systems. However, the long-term effects of adolescent SRCs remain unclear. Recognizing that SRC and musculoskeletal (MSK) injuries can alter sensorimotor function and brain connectivity, this study incorporated MSK-injured and uninjured (UI) controls to delineate effects specific to concussion. This historical cohort study examined symptoms and function 5–15 years post-injury in individuals with prior SRC (n=100), MSK injury (n=100), or no injury (n=88). Measures included the Post-Concussion Symptom Scale (PCSS), Vestibular Ocular Motor Screening (VOMS), cervical spine function, vestibulo-ocular reflex (VOR), and dynamic balance. Results showed that some individuals with adolescent SRC reported more symptoms and had deficits in cervical spine and balance function compared to MSK and UI groups. These findings suggest SRC may have persistent effects in some cases and highlights the importance of long-term follow-up and further research into contributing factors.Item type: Item , Access status: Open Access , Investigating Pestivirus Infections in Barren-ground and Dolphin Union Caribou: Strain Identification and Diagnostic Test Refinement(2025-10-31) Olson, Jessie Rose Mae; Meer, Frank van der; Marle, Guido van; Jenne, Craig; Kutz, SusanBarren-ground caribou populations in the Arctic have been declining. One unexplored aspect of caribou health is viral ecology, which is limited by sampling challenges and the lack of caribou-specific diagnostics. Pestiviruses are of interest in northern caribou herds as antibodies against pestiviruses have been detected in Canadian caribou, but the species in circulation have not been identified. Pestiviruses’ capacity to negatively impact developing fetuses, persistently infect animals, and affect the overall health status of a population make this viral genus an important area of research. This project aimed to i) identify circulating pestivirus strains through RT-PCR testing and ii) develop caribou-specific pestivirus antibody tests (ELISAs). Pestivirus presence was assessed in 132 caribou tissue samples, specifically spleens, lymph nodes and placental tissues using a 'pan-pesti' RT-PCR targeting the conserved 5’ UTR region of the viral genome; however, RT-PCR testing did not uncover the strain circulating. To address caribou diagnostic limitations, a caribou-specific indirect ELISA was developed against the E2 glycoprotein of border disease virus (BDV) genotypes 1, 2, 3, and 8. Recombinant proteins were expressed in HEK293S cells using a pFRT-E2 expression vector and confirmed by Western blot. The ELISA employed anti-deer HRP-conjugated secondary antibodies, a previously validated HRP-conjugate in caribou serology studies. Results demonstrated significant antibody binding affinity towards BDV1, supported through mixture distribution modeling, with some sample cross-reactivity observed against all four BDV strains. These findings suggest possible exposure to BDV1, a BDV1-like virus, and/or multiple pestivirus strains. Although RT-PCR did not identify specific viral genomes, the novel caribou-specific ELISA developed here provides new insights into pestivirus exposure in caribou. The detection of BDV1-seropositive samples indicates circulation of a BDV1-like virus, while observed cross-reactivity highlights the potential for multiple pestivirus lineages in northern caribou populations.Item type: Item , Access status: Open Access , Investigating the molecular mechanism of membrane permeabilization by apolipoprotein L 7C(2025-11-04) Huang, Song; Canton, Johnathan; Yates, Robin; Surewaard, Bas; Gilch, SabineA central function of our immune system is to recognize and neutralize potential threats to organismal homeostasis and survival. Not surprisingly, there is a division of labor in the immune system wherein certain immune cells harbor adaptations that allow them to neutralize unique threats. This is evident in certain viral infections and in tumor development, where one immune cell type in particular, the type 1 conventional dendritic cell (cDC1) appears to serve a nonredundant role in the generation of effective anti-viral and anti-tumor immunity. This is believed to result from the ability of cDC1s to promote CD8⁺ T cell responses through the cross presentation (XP) of exogenous antigens. This process is essential for the clearance of intracellular pathogens, such as viruses, and the activation of tumor-specific cytotoxic T cells, making cDC1s attractive targets for vaccine development and cancer immunotherapy. Despite their importance, the molecular mechanisms underlying XP remain incompletely understood. Two main pathways of XP have been proposed: the vacuolar pathway and the phagosome-to-cytosol pathway. In the latter, antigens internalized via endocytosis or phagocytosis are hypothesized to translocate into the cytosol for proteasomal degradation. However, the mechanism by which phagosomal cargo enters the cytosol remains unclear. Recent hypotheses suggest that phagosomal membrane disruption may facilitate antigen escape, potentially mediated by pore-forming proteins (PFPs). Perforin-2, a MACPF-domain-containing PFP, has been implicated in XP, but its specificity and mechanism of action in targeting endosomal membranes remain uncertain. Identifying regulators that directly mediate phagosomal rupture is thus of critical importance. In this thesis, I identify APOL7C, a member of the apolipoprotein L family, as a candidate regulator of phagosomal rupture. Bulk RNA sequencing of murine tumor-derived dendritic cells (MuTuDCs) revealed Apol7c as a highly upregulated gene upon activation with innate immune stimuli. This was subsequently validated by RT-qPCR in both In vivo and in vitro settings. Single-cell RNA sequencing further demonstrated that Apol7c expression is enriched in cDC1 and migratory dendritic cells. To study the localization and function of APOL7C, we engineered APOL7C::mCherry-expressing RawKB and MuTuDC cell lines. Fluorescence imaging revealed that APOL7C localizes to phagosomes containing antigenic cargo and colocalizes with Galectin-3, a known marker of membrane damage, suggesting a potential role in membrane lesion formation. This was further validated by focused ion beam-scanning electron microscopy (FIB-SEM), which confirmed phagosomal disruption. I then generated Apol7c ⁻/⁻ mice to examine the functional consequences of Apol7c deletion. Compared to C57BL/6 wild-type controls, APOL7C -deficient mice exhibited significantly reduced CD8⁺ T cell responses in two separate in vivo models, supporting the hypothesis that APOL7C is involved in XP. To explore the molecular mechanism of phagosomal lesion formation, I hypothesized that, similar to other PFPs, APOL7C may require oligomerization. Blue native gel electrophoresis demonstrated APOL7C oligomer formation following phagosome recruitment. To further investigate oligomerization, we generated a double-expressing RawKB cell line co-expressing APOL7C::mCherry and APOL7C::FLAG::GFP. Co-immunoprecipitation assays confirmed APOL7C oligomerization, which was further supported by studies using a nonfunctional APOL7C mutant in conjunction with TIRF and STED microscopy. Finally, I sought to identify interacting partners of APOL7C through proteomics analysis. Among the candidates, ArfGAP with FG repeats 1 (AGFG1), a GTPase-activating protein, emerged as a prominent interactor. This interaction was validated by immunogold electron microscopy, fluorescence imaging, flow cytometry, and co-immunoprecipitation assays.Item type: Item , Access status: Open Access , Precise and reliable mapping of functional brain networks in adults and children(2025-11-04) Rai, Shefali Sanjana; Bray, Signe Lauren; Harris, Ashley; Sotero-Diaz, RobertoAs children grow, they undergo rapid changes in brain function and organization, which have important implications for both typical and atypical development. Functional connectivity (FC), as measured by functional magnetic resonance imaging (fMRI), is a powerful tool for studying changes in large-scale brain network organization. However, its application in developmental neuroscience has encountered challenges, including measurement reliability, susceptibility to head motion, and an incomplete understanding of how brain network topography changes with age. To address these barriers, this thesis applied a precision fMRI approach, where large quantities of fMRI data are collected per participant, to assess the reliability of FC and map individualized functional networks in both adults and children. First, I assessed factors affecting the reliability of functional connectivity, namely task conditions and BOLD signal properties, using an adult precision fMRI dataset. I found that while tasks generally reduced FC reliability relative to resting-state, they enhanced reliability within task-engaged regions. Additionally, I established that there was a non-linear relationship between BOLD signal properties (i.e., temporal signal-to-noise ratio) and FC reliability, with the temporal standard deviation of the BOLD signal emerging as the strongest predictor of FC reliability. Second, I expanded my examination of FC reliability to a precision naturalistic fMRI dataset of both adults and children. Even with over 60 minutes of high-quality data, children had lower FC reliability than adults, with head motion increasing this gap. While certain functional connections showed higher reliability than others with as little as 5 minutes of low-motion data in both children and adults, I observed considerable gains in FC reliability when increasing data from 24 to 54 minutes for both groups. Given the use of naturalistic viewing paradigms for this study, I also asked whether more engaging stimuli achieved higher reliability and found the reverse to be true, where the less engaging videos yielded higher reliability but at the cost of increased head motion and reduced attention. Lastly, I applied individualized network mapping to compare functional network organization across adults and children. I found that children had predominantly similar network topography to adults and subtle differences were limited to specific network boundaries. Children also had greater uncertainty in their network assignments (i.e., lower confidence) and weaker within-network connectivity compared to adults. Individualized approaches further showed larger age-related effects and lower sensitivity to head motion effects in FC than the group-averaged approach, underscoring how group alignment may misrepresent age-related effects. Taken together, my work addresses key limitations in the developmental fMRI field and provides benchmarks for improving data quality, reliability, and techniques for individualized mapping.Item type: Item , Access status: Open Access , Structural Transition of Monohydrocalcite (CaCO3·H2O) to Calcite (CaCO3) on Heating(2025-11-04) Cheng, Lanyi; Antao, Sytle Medicia; Cuthbertson, Jennifer; Guatame Garcia, AdrianaMonohydrocalcite (CaCO3·H2O) is a hydrated calcium carbonate that has been discovered in various natural settings, including lacustrine environments, cold springs, speleothems, and marine environments. This study investigates fifteen data sets of a monohydrocalcite sample using synchrotron powder X-ray diffraction (XRD) at varying temperatures. Monohydrocalcite, a single phase mineral, transforms into calcite (CaCO3) as the temperature increases. The results show that pure monohydrocalcite exists within the temperature range from 50 to 148 °C in Stage 1, both monohydrocalcite and calcite coexist from 159.5 to 194.5 °C in Stage 2, while pure calcite exists beyond 194.5 °C in Stage 3. When monohydrocalcite is heated from room temperature up to 205 °C, distinct unit-cell parameters are obtained from 159.5 to 194.5 °C for both monohydrocalcite and calcite in Stage 2. Thereafter, calcite is the dominant phase. When the temperature is greater than 194.5 °C, monohydrocalcite entirely disappears; the dehydration process is completed, leaving only calcite. The unit-cell parameters a, c, and V of monohydrocalcite and calcite change with temperature. In Stage 1, the unit-cell parameters a, c, and V of monohydrocalcite increase with temperature ranging from 50 to 148 °C. In Stage 2, as the temperature increases from 159.5 to 194.5 °C, the unit-cell parameters of monohydrocalcite coexisting with calcite increase, while dehydration takes place simultaneously. In Stage 3, the a parameter of calcite decreases with temperature increasing from 194.5 to 205 °C, while the c parameter continues to increase, and V decreases slightly; dehydration is completed at 194.5 °C. In Stage 1, the average and the average bond distances of monohydrocalcite increase with temperature from 50 to 148 °C. In Stage 2, the average bond distance of monohydrocalcite coexisting with calcite also increases with temperature from iii 159.5 to 194.5 °C. The average bond distance changes gradually; the average bond distance decreases, and the average bond distance of calcite increases with temperature from 159.5 to 194.5 °C. Dehydration leads to the disappearance of the O-H bond and the rearrangement of Ca–Oc. In Stage 3, the average bond distance of calcite increases due to thermal expansion from 194.5 to 205 °C. The average bond distance in calcite decreases as the temperature rises from 194.5 to 205 °C. In Stage 1, isotropic displacement parameters UCa, UC, and UO of monohydrocalcite increase from 50 to 148 °C and UOw fluctuates. In Stage 2, UCa and UO of monohydrocalcite coexisting with calcite fluctuate with temperature increasing from 159.5 to 194.5 °C; UC increases in Stage 2, and dehydration leads to the rearrangement of atomic positions. In Stage 3, the UC of calcite decreases with increasing temperature from 194.5 to 205 °C, and UCa and UO increase with temperature.
