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\"Are aliens among us? Flip over this book to find out more!\"--Cover.

Chronic myeloid leukemia (CML) and mantle cell lymphoma (MCL) are hematologic malignancies that originate from different oligopotent progenitor stem cells, namely, common myeloid and lymphoid progenitor cells, respectively. Although blastic transformation of CML can occur in the lymphoid lineage and CML has been related to non-Hodgkin lymphoma on transformation, to our knowledge, de novo and synchronous occurrence of CML and MCL has not been reported. Herein, we report the first case of synchronous CML and MCL in an otherwise healthy 38-year-old man. Potential etiologies and pathological relationships between the two malignancies are explored, including the possibility that the downstream effects of BCR-ABL may link it to an overexpression of cyclin D1, which is inherent to the etiology of MCL.

The Christmount Preserve is a botanically diverse and ecologically rich area of approximately 155 ha of southern Appalachian forest held in conservation easement. We conducted a floristic inventory of the preserve to inform conservation efforts on the property. Although the plant diversity within the preserve is an important attraction for residents and visitors, information on its flora is limited. This study builds upon a brief but informative 1996 report of the North Carolina Natural Heritage Program summarizing the preserve's attributes as a natural area. A total of 317 specimens of vascular plants were collected during 2018–2020 to develop a vouchered flora of the preserve. These specimens documented 221 species in 165 genera and 84 families, 4.5% of which are not native to the Appalachian Mountain region. We found three plant taxa that are listed by the North Carolina Natural Heritage Program: Coreopsis latifolia, Hypericum buckleyi, and Robinia hispida var. fertilis. Plant community types found on the property include large areas of Rich Cove Forest, Acidic Cove Forest, and Montane Oak-Hickory Forest, but also included small patches of Pine-Oak/Heath–High Elevation Subtype, a globally imperiled plant association, along the high ridgelines. The information presented here will be used to help guide management efforts as well as educational programming by the managing organization, Christmount Christian Association (CCA).

Social capital is an important resource that can be mobilized for purposive action or competitive gain. The distribution of social capital in social–ecological systems can determine who is more productive at extracting ecological resources and who emerges as influential in guiding their management, thereby empowering some while disempowering others. Despite its importance, the factors that contribute to variation in social capital among individuals have not been widely studied. We adopt a network perspective to examine what determines social capital among individuals in social–ecological systems. We begin by identifying network measures of social capital relevant for individuals in this context, and review existing evidence concerning their determinants. Using a complete social network dataset from Hawaii’s longline fishery, we employ social network analysis and other statistical methods to empirically estimate these measures and determine the extent to which individual stakeholder attributes explain variation within them. We find that ethnicity is the strongest predictor of social capital. Measures of human capital (i.e., education, experience), years living in the community, and information-sharing attitudes are also important. Surprisingly, we find that when controlling for other factors, industry leaders and formal fishery representatives are generally not well connected. Our results offer new quantitative insights on the relationship between stakeholder diversity, social networks, and social capital in a coupled social–ecological system, which can aid in identifying barriers and opportunities for action to overcome resource management problems. Our results also have implications for achieving resource governance that is not only ecologically and economically sustainable, but also equitable.

For many students, school attendance is a critical issue. There have been a number of studies conducted concerning attendance numbers. These studies have shown that poor attendance often affects grades, graduation rates, and socioeconomic status post-high school. The purpose of this study was to first investigate the reasons behind absences and attitudes towards school and classes as a result of missed days. The second purpose was to determine if a weekly mentoring meeting had any noticeable affect on attendance. The targeted pool of students consisted of those who had been identified as chronically absent the previous semester. An initial set of open ended questions and a demographics questionnaire was used to gather preliminary information. Afterwards, students were asked to participate in weekly meetings to discuss reasons behind any occurring absences the previous week, and if any opportunities arose that were not taken advantage of and why were they not taken advantage of. Some findings were 1) peer relations, school environment, and classroom subjects affects students’ experiences in school, 2) in light of the COVID-19 pandemic, students were unaware of the accumulation of absences that had amassed the previous school year, 3) personal decisions highly influence a student’s decision to miss school, 4) many of the students had no concern for days missed, and 5) having a weekly mentoring meeting had a positive affect on decreasing the number of days missed.

In this dissertation, three studies were presented that involve the spectroscopic characterization of either nonlinear optical or biophotonic materials. The first study (Chapter 3) proposed judicious bulky substitution of cyanine-like, polymethine dyes with large intensity dependent refractive indices to effectively mitigate aggregation between dyes in thin film polymer blends of interest for all-optical signal processing applications in the near infrared (NIR). Linear characterization and Z-scan measurements of these blends at 1550 nm confirmed that bulky groups suppress aggregation in the solid state, thus lowering two-photon absorption (2PA) and improving the nonlinear optical performance of these films. The second study (Chapter 4) proposed a series of planar, fused-ring, organic, quadrupolar chromophores of type A-π-D-π-A with the potential to demonstrate large 2PA cross-sections for optical limiting applications in the NIR. Nondegenerate 2PA measurements revealed that these compounds have large 2PA cross sections and spectral coverage in the NIR, which can be controlled synthetically via structural changes in the core and acceptor groups at the molecule’s periphery. The third study (Chapters 5-6) proposed high refractive index replicas of photonic crystal-like hole patterns harvested from Coscinodiscus wailessii diatom frustules as sustainably-producible, biophotonic elements for lensless light focusing of NIR radiation at the micro-scale. Linear spectrophotometric and imaging measurements confirmed that these replicas concentrate NIR light via diffraction, which can be manipulated with changes in the index of the frustule through solid-gas conversion chemistries with excellent shape preservation.

Pressure-gain combustion has been a topic of research interest for several decades. Due to the potential of pressure-gain thermodynamic cycles of increasing gas turbine efficiency by more than 10%, they offer a strategy to combat the growing problem of continually scarcer resources by simultaneous enforcement of ever stricter emissions controls. Furthermore, when hydrogen is used as a fuel, emissions of CO2, a known greenhouse gas, are eliminated. Hydrogen can also be obtained using electrolysis powered by renewable energy sources. In times of less demand, excess energy can be used to produce hydrogen, which can then later be used for combustion-based energy generation when demand once again rises. Gas turbines offer an ideal platform for this technology, due to their fast response times when compared to other sources of combustion-based energy. One type of pressure-gain combustion is known as pulse detonation combustion. Using this cyclical concept, the fuel is combusted by means of a detonation wave propagating at around 2000 m/s. Because of the speed of propagation, there is no time for the gas to expand during the combustion process and almost the entirety of the energy release is directed towards increases in pressure and temperature. This cycle is known as the Fickett-Jacobs cycle. Due to energy considerations, a flame is typically ignited by a low-energy ignition source and accelerated until it transitions to a detonation. This process is called the deflagration-to-detonation transition (DDT) and is the main focus of this work. Reducing the run-up distance to detonation has a direct impact on efficiency. Thus, it is worthwhile to achieve this transition over as short a distance as possible. In this thesis, various methods of shortening the run-up distance to DDT using obstacles are investigated. Experiments to characterize the initial flame acceleration caused by a single obstacle concluded that the geometry of the obstacle plays only a minor role when compared to its blockage ratio. Furthermore, when multiple orifice plates are used, the optimal separation distance was found to be just over two tube diameters. Experiments on a separate test bench confirmed this finding also in regards to DDT and found that a tube diameter of around 40mm is necessary to obtain reliable DDT over a reasonable run-up length using orifice plates. The results of these initial studies aided in designing a modular pulse detonation combustion test bench. Using oxygen enrichment to simulate the operating conditions of a micro gas turbine, DDT was achieved using only 2-3 orifice plates when a wave-reflecting geometry was used at the inlet of the detonation chamber to support initial flame acceleration. Further investigations on a shock-focusing nozzle were successful in producing reliable DDT over a length of just 158 mm. Using this nozzle, a local explosion is initiated ahead of a fast accelerating turbulent flame by reflection and focusing of the leading shock. The result is a pressure increase in the region of focus in excess of 50 bar. The process is also found to be very deterministic. Therefore, this geometry presents a very promising means of producing DDT for pulse detonation combustion applications.

We present the design and fabrication of 3D printed holographic beamforming antennas. The antennas utilize additively manufactured hollow rectangular waveguides that feed radiating rectilinear slots inserted into the upper conducting wall. The lengths of the individual slots are altered to implement a holographic beamforming solution designed using a coupled dipole formalism. For rapid verification, the designed antennas are fabricated using a desktop dual-extrusion fused filament 3D printer. The body of each antenna and its inner conducting surface are respectively printed using polylactic acid and biodegradable conductive polyester composite material (i.e., Electrifi), which is later deposited with a layer of copper on its surface to improve surface conductivity and reduce surface roughness. The beamforming performance of the fabricated antennas is confirmed via experiments. The 3D printed metasurface antennas using the proposed fabrication technique illustrate emerging capabilities in the rapid prototyping of complex electromagnetic structures.

Historical approaches to natural resource management have largely viewed resource managers, resource users, and the resources as distinct and separate components. This perspective has highlighted the conceptual boundaries between management, social systems and ecosystems. Recent failures in this normative approach however, such as major declines in fisheries, have challenged this traditional perspective. Many management institutions are now adopting a systems perspective which embeds resource management within the human system, and the human system within the broader ecosystem. This new paradigm has produced new frameworks like ecosystem-based management and theoretical tools such as coupled social-ecological systems (SES). These new frameworks are thought to be more beneficial for natural resource management decision-making since they acknowledge important links between social and eco-systems and include more complexity. This complexity, however, presents new challenges as managers and researchers now seek ways to characterize the components, relationships, and dynamics within these systems as a way to inform natural resource policies. To address some of these challenges, this dissertation research seeks to better understand the role that stakeholder knowledge plays in influencing natural resource management in a model SES, mid-Atlantic marine fisheries. I begin by characterizing the SES and outlining differences in knowledge systems by evaluating representations of stakeholder mental models. Next, through interview data collected from fishery managers and scientists, I categorize the conceptual risks within the SES to outline the goals of management and what policies in SES seek to address. Then, I evaluate factors which affect trust of fishery management institutions from the perspective of resource users. Finally, I offer recommendations on how to align knowledge systems between resource users and resource management toward shared goals.

This dissertation describes investigations into the chemical and morphological characterization of III-V strained layered heterostructures by high-resolution x-ray diffraction. The purpose of this work is two-fold. The first was to use high-resolution x-ray diffraction coupled with transmission electron microscopy to characterize structurally a quaternary AlGaAsSb/InGaAsSb multiple quantum well heterostructure laser device. A method for uniquely determining the chemical composition of the strain quaternary quantum well, information previously thought to be unattainable using high resolution x-ray diffraction is thoroughly described. The misconception that high-resolution x-ray diffraction can separately find the well and barrier thickness of a multi-quantum well from the pendellösung fringe spacing is corrected, and thus the need for transmission electron microscopy is motivated. Computer simulations show that the key in finding the well composition is the intensity of the −3rd order satellite peaks in the diffraction pattern. The second part of this work addresses the evolution of strain relief in metastable multi-period InGaAs/GaAs multi-layered structures by high-resolution x-ray reciprocal space maps. Results are accompanied by transmission electron and differential contrast microscopy. The evolution of strain relief is tracked from a coherent “pseudomorphic” growth to a dislocated state as a function of period number by examining the x-ray diffuse scatter emanating from the average composition (zeroth-order) of the multi-layer. Relaxation is determined from the relative positions of the substrate with respect to the zeroth-order peak. For the low period number, the diffuse scatter from the multi-layer structure region arises from periodic, coherent crystallites. For the intermediate period number, the displacement fields around the multi-layer structure region transition to random coherent crystallites. At the higher period number, displacement fields of overlapping dislocations from relaxation of the random crystallites cause the initial stages of relaxation of the multi-layer structure. At the highest period number studied, relaxation of the multi-layer structure becomes bi-modal characterized by overlapping dislocations caused by mosaic block relaxation and periodically spaced misfit dislocations formed by 60°-type dislocations. The relaxation of the multi-layer structure has an exponential dependence on the diffuse scatter length-scale, which is shown to be a sensitive measure of the onset of relaxation.