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A record number of incoming international students from China are studying in universities in the United States today. It is important to understand this group for several reasons. Chinese students compose the largest group of international population in the U.S. Higher Education and learning about them assists with a better institutional practice including internationalization strategies. It is also important to assess their well-being in a foreign environment to improve student services. This research explores students’ perceptions and feelings in residence halls. It investigated factors that affect first-year undergraduate Chinese international students’ sense of belonging by exploring their experiences at Boston College. Using a qualitative and phenomenological approach, this study examined feedbacks from international Chinese students and provides important insights into their daily experiences. This study focused on exploring Chinese international students’ relationships with their roommates, and residential staff, to find out if these relationships influenced their sense of belonging to the community. As a partial replicate, partial follow-up study of Yao’s (2014) research, both guided by Hurtado (2013)’s framework, findings suggested that multiple elements serve as barriers and bridges to Chinese international students’ adaptation process, which include the influences of language, cultural difference, staff professionalism, and institutional internationalization plan. The study concluded with implications for practice at Boston College which may potentially be of interest to other institutions. Suggestions for future research are also identified. The study indicated a critical need for university staff to assess, examine, and explore the diverse campus culture by paying more attention to a sense of belonging to continue with the facilitation of internationalization for the overall success of international students.

Warehouse Scale Computers (WSCs) promise high cost-efficiency by amortizing power, cooling, and management overheads. WSCs today host a large variety of jobs with two broad performance requirements categories: latency-critical (LC) and best-effort (BE). Ideally, to fully utilize all hardware resources, WSC operators can simply fill all the nodes with computing jobs. Unfortunately, because colocated jobs contend for shared resources, systems with high loads often experience performance degradation, which negatively impacts the Quality of Service (QoS) for LC jobs. In fact, service providers usually over-provision resources to avoid any interference with LC jobs, leading to significant resource inefficiencies. In this dissertation, I explore opportunities across different system-abstraction layers to improve the cost-efficiency of dataceters by increasing resource utilization of WSCs with little or no impact on the performance of LC jobs. The dissertation has three main components. First, I explore opportunities to improve the throughput of multicore systems by reducing the performance variation of LC jobs. The main insight is that by reshaping the latency distribution curve, performance headroom of LC jobs can be effectively converted to improved BE throughput. I develop, implement, and evaluate a runtime system that achieves this goal with existing hardware. I leverage the cache partitioning, per-core frequency scaling, and thread masking of server processors. Evaluation results show the proposed solution enables 30% higher system throughput compared to solutions proposed in prior works while maintaining at least as good QoS for LC jobs. Second, I study resource contention in near-future heterogeneous memory architectures (HMA). This study is motivated by recent developments in non-volatile memory (NVM) technologies, which enable higher storage density at the cost of same performance. To understand the performance and QoS impact of HMAs, I design and implement a performance emulator in the Linux kernel that runs unmodified workloads with high accuracy, low overhead, and complete transparency. I further propose and evaluate multiple data and resource management QoS mechanisms, such as locality-aware page admission, occupancy management, and write buffer jailing. Third, I focus on accelerated machine learning (ML) systems. By profiling the performance of production workloads and accelerators, I show that accelerated ML tasks are highly sensitive to main memory interference due to fine-grained interaction between CPU and accelerator tasks. As a result, memory resource contention can significantly decreases the performance and efficiency gains of accelerators. I propose a runtime system that leverages existing hardware capabilities and show 17% higher system efficiency compared to previous approaches. This study further exposes opportunities for future processor architectures

Alzheimer's disease is characterized in part by the aggregation of tau protein into filamentous inclusions. Tau aggregation is not only a robust marker of disease progression, but also contributes directly to degeneration in affected neurons. In this context, the mechanism of tau filament formation and its modulation by posttranslational modification are of fundamental importance. To clarify the forces that drive neurofibrillary lesion formation, the mechanism of tau filament formation is investigated in vitro and in cellular models. First, we clarify that the aggregation reaction is triggered by environmental conditions that stabilize assembly-competent conformations. It also shows that planar aromatic dyes capable of binding the intermediate state with high affinity are also capable of triggering fibrillization. Dye-mediated tau aggregation is characterized in detail and demonstrated as a novel approach to study tau aggregation mechanism in vitro. Using one of these small molecule dyes as inducer, role of proteolytic post-translational modification on tau aggregation is studied. The data show that C-terminal proteolysis can modulate tau filament accumulation through decreasing critical concentration and also through directly augmenting the efficiency of the nucleation reaction. Similarly, Congo Red, another planar aromatic dye identified in above experiment, is applied to tau stable cell line to establish a new cell culture model of tauopathy. Formation of detergent insoluble aggregates is both time and agonist concentration dependent without relating to tau hyperphosphorylation. Results also suggest that conformational changes associated with aggregation are incompatible with microtubule binding, and that aggregation can be toxic in the presence of cellular stress that compromises proteasome function. Tau hyperphosphorylation precedes neuritic lesion formation in Alzheimer's disease, suggesting it participates in the tau fibrillization reaction pathway. Candidate tau protein kinases include casein kinase 1 (CK1) family, which highly overexpress in Alzheimer's disease brain and colocalize with neuritic and granulovacuolar lesions. Here we show that Ckidelta phosphorylates tau in vivo. Next, we demonstrate that dysbindin structural homologue CK1BP is an isoform-selective binding partner of human casein kinase-1 and that the acidic domain of dysbindin and its paralogs in humans may function to recruit CK1 isoforms to protein complexes involved in multiple biological functions.

Stabilization of mercury-containing wastes has received considerable attention recently, due to concerns about air emissions from typically used thermal treatment technologies. Because of the extremely low solubility of mercuric sulfide, sulfide-induced stabilization is considered to be an effective way to immobilize mercury while minimizing mercury emissions. However, little is known of the mechanisms involved. In addition, the process of sulfide-induced stabilization of mercury-containing wastes has not been sufficiently developed; therefore, further research is needed to optimize the process-controlling parameters. In this study, the stabilization of mercury-containing wastes was performed using sodium sulfide. Primary stabilization variables such as stabilization pH, sulfide/mercury (S/Hg) molar ratio, and stabilization time were investigated. Mercury stabilization effectiveness was evaluated using the Toxicity Characteristic Leaching Procedure (TCLP) and constant pH leaching tests. The effectiveness of mercury immobilization by sulfide was tested in the presence of various concentrations of interfering ions. The results demonstrate that stabilization pH and sulfide dosage have significant effects on the stabilization efficacy. It was found that the most effective mercury stabilization occurs at pH 6 combined with a sulfide/mercury molar ratio of 1. The mercury stabilization efficiency reached 99%, even in the presence of interferents. The constant pH leaching results indicate that sulfide-treated mercury wastes produce significantly higher mercury concentrations in high pH (pH >10) leachants relative to others. Nevertheless, the mercury stabilization efficiency was still as high as 99%, even with exposure of the wastes to high pH leachants. Therefore, it is concluded that sulfide-induced stabilization is an effective way to stabilize mercury-containing wastes. The treatment optimization study indicates that the combined use of increased dosage of sulfide and ferrous ions (S/Hg = 2 and Fe/Hg = 3 at pH = 6) can significantly reduce the interferences by chloride and/or phosphate during sulfide-induced mercury immobilization. Visual MINTEQ simulation results indicate that the precipitation of cinnabar is the main mechanism that contributes to the mercury stabilization by sulfide. However, the formation of soluble mercury sulfide species at excess sulfide dosage due to the common ion effect can cause mercury remobilization from sulfide sludge under conditions that can exist in the landfills.