Bulletin of Computer Science and Electrical Engineering (BCSEE)
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Anomaly Detection with Graph Neural Networks Utilizing Graph Data
No full textGraphs and network structures are powerful tools for modeling and analyzing complex systems, such as power distribution networks, water distribution networks, and communication networks. By analyzing the topological features of a graph, we can better understand how the nodes in the network are connected and how they interact with one another. This is especially important in anomaly detection, as anomalies often result in changes to the underlying structure of the network. Graph-based models provide a way to represent complex data in a structured and organized manner, allowing us to gain insights into the behavior of the system being studied. Recently, Graph Neural Networks (GNNs) have shown promise in detecting anomalies in graph-structured data. In this dissertation, I propose a framework for anomaly detection with Graph Neural networks (GNNs) that explicitly leverages the graph topology and node attributes. In addition to node attributes/features, we incorporate graph topological features, such as centrality and clustering coefficients, to improve the performance of our model. Our experiments demonstrate that adding these topological features improves the accuracy of anomaly detection in attributed networks compared to traditional autoencoders that do not simultaneously consider graph topology and node attributes. Our results suggest that incorporating graph topology (represented by structural components and node attributes) is a key factor for effective anomaly detection with GNNs.</p
Optical Interferometric Microscopy Using Controlled Phase Shifting Algorithms
No full textTopographic surface profiling is a powerful tool for characterizing physical features of surfaces at a micro or nanoscopic scale. This technique provides information about height and roughness of a surface for surface quality control in manufacturing, characterization of biological surfaces, and identification of defects in lithography processes. By providing accurate and precise measurements of surface topography, this technique enables researchers and engineers to optimize surface properties and performance.Non-contact optical interferometric microscopy (OIM) measures the surface profile by optically illuminating a surface and retrieves the reflected light with interference to obtain accurate surface height information. The OIM consists a broadband light source with a center wavelength of 540 nm and a spectral bandwidth of 40 nm, a 50:50 beam splitter, a pair of 10 x objective lenses, a piezoelectric actuator, a reference mirror, and a monochrome CMOS camera. The fringes resulted from the sample surface reflected beam and the reference mirror reflected beam on the camera are acquired with controlled phase changes through the piezoelectric actuator. By evaluating the interference fringes with phases, we can obtain the object surface topographic contour image. Our single-camera OIM technique can produce a surface topography with a field of view of 310 μm x 230 μm, 3.31 nm axial resolution, 270 nm height range, and 488 nm width resolution
Analysis of Crime Patterns Using Multi-Modal Techniques: Remote Sensing, Geospatial Analysis, and Photogrammetry
No full textEven though there are numerous elements affecting crime, this research targets possible environmental factors using multi-modal techniques combining remote sensing, geospatial analysis, and photogrammetry using drone mapping. First, the correlation between vegetation and crime was examined by retrieving NDVI and Land Surface Temperature (LST) values from NASA’s Landsat-5 TM satellite imagery (30m resolution) on January 31, 2007, and comparing them with a total number of 1,012 burglary cases in the urban areas of Miami-Dade County. Poisson regression analysis revealed a positive correlation between the total number of burglaries and the mean values of NDVI (β=.03, p<.005) and LST (β=.31,p<.001) at the ZIP code level. Next, the relationship between environmental factors and crime was analyzed by using four daytime and four nighttime drone surveys (1.6 cm pixel accuracy), and 7,434 crime incidents in the city of Coral Gables between 2017 and 2022. The kernel density function was utilized to generate heat maps that display the distribution of crime incidents. The findings showed that crime incidents are frequently concentrated around the northeastern part of the city and along US-1. As evidenced from the analysis, greater levels of criminal activities were observed in neighborhoods with higher numbers of renters, newer residences, businesses, public parks, empty parcels, accessibility with public transportation and thoroughfares, and walkability with sidewalks. On the other hand, neighborhoods with greater numbers of streetlights and additional light sources, privately-owned one- or two-story building homes, and bigger parcel areas, reported fewer incidents of crime. In addition, the results revealed that one of the most desirable targets of crime is corner houses. Furthermore, one of the most effective crime prevention methods is restricting visibility and accessibility of targets. Lastly, the outcomes of this study have important implications for police departments, urban planners, and policymakers to develop evidence-based approaches for crime prevention.</p
Understanding the Movement Ecology of Leatherback Sea Turtles (Dermochelys Coriacea) along the Northwest Atlantic Shelf
No full textLeatherback sea turtles (Dermochelys coriacea) perform extensive migrations from tropical nesting beaches to distant foraging grounds where they primarily consume gelatinous zooplankton. Over the past two decades, there has been increasing knowledge on the movement patterns of the Northwest Atlantic population. However, there is still much to understand in terms of leatherback movement ecology along the east and gulf coasts of the United States. This dissertation uses satellite telemetry data from 66 leatherbacks tagged off the coasts of Florida, North Carolina, and Massachusetts. I used hidden Markov models (HMMs) to elucidate latent behaviors along the east coast of the United States to determine areas of foraging behavior. Results from the HMMs suggest an important foraging area exists within the southern portion of the Mid-Atlantic Bight as well as an overwintering area in the South Atlantic Bight. Dive behavior analyses compare locations in the Gulf of Mexico and the Northwest Atlantic shelf, uncovering challenges influenced by regional climates that affect energy acquisition for return migrations to nesting beaches. The SDMs highlight suitable habitat along the Mid Atlantic Bight and Southern New England in the summer and fall as well as suitable habitat in the South Atlantic Bight in the Spring and Winter. Projections of leatherback distributions under climate change allude to habitats shifting farther north toward Newfoundland in the summer and fall, as well as decreased suitable habitats in the winter and spring. The findings from this dissertation should be used as a baseline for our understanding of leatherback ecology along the United States coastline especially with the looming threats of offshore development (e.g., windfarms) and climate change
The Role of RAGE Inhibition in Breast Cancer Metastasis
No full textThe Receptor for Advanced Glycation Endproducts (RAGE) and its ligands are overexpressed in various inflammatory states, including diabetes, Alzheimer’s disease, and different cancers, especially solid cancers. Our lab has shown that targeting RAGE, through RNA interference, use of RAGE-specific small molecule inhibitor (FPS-ZM1), and use of genetic knockout in mice, decreases tumor growth and metastasis in triple-negative breast cancer models. Although we have shown that RAGE knockdown in 4T1 cells decreases tumor growth and lung metastases in the BALB/c mice, we did not show the effects of FPS-ZM1 in syngeneic mouse models. There are two main reasons why it is crucial to study RAGE in a syngeneic model: 1. the effects of the host, the tumor microenvironment, and the pre-metastatic niche in cancer are not recapitulated in an immunocompromised mouse model (e.g., human cancer cells or tumor xenograft model), and 2. RAGE is expressed in many cell types that make up the tumor microenvironment and the premetastatic niche, including B cells and T cells. Here, we sought to establish different murine syngeneic breast cancer models and test the impact of various RAGE inhibitors (FPS-ZM1, FPS-ZM1 analogs, and TTP488). We further showed the anti-metastatic effect of FPS-ZM1 in different syngeneic, metastatic breast cancer mouse models. For the first time, we showed that TTP488, mainly used in Alzheimer’s disease models, decreases tumor growth and lung metastasis in different murine breast cancer models, and its effects were more significant than FPS-ZM1. In summary, RAGE-specific small molecule inhibitors may have therapeutic potential as an anti-metastatic agent in breast cancer.</p
Nucleic Acid-Based Sensing Strategies for Pathogen Detection
No full textThis work focuses on the development nucleic acid sensing strategies for the detection of different pathogens. Foodborne bacterial contamination has continued to increase in recent years, creating a worsening public health threat. This has created a need for improvements in detection. Current accepted methodologies are often time-consuming, laborious, and expensive. As such attentions have shifted to on-site detection – however these methods still require improvement in their sensitivities and run time. Two field-deployable assays were developed targeting foodborne pathogens that do not require advanced personnel or fancy equipment to run. Both assays have the needed sensitivities and a reduction in sample to answer time when compared to gold standard and other existing techniques. It is important to also consider alternative materials for sensing applications. New materials and approaches help pave the progress in the field of biosensing and have reaching impacts in biomedical and analytical applications. More specifically, in the field of molecular aptamer beacons and stem loop probes there are many materials that are employed for signal generation and for quenching. However, some of these materials can be environmentally unfriendly or require complex chemistry and steps to be used in sensing platforms. One alternative quencher we explored is graphene oxide, which has already seen use in many biomedical and sensing applications.Together these projects work towards a broader goal of optimizing these nucleic acid-based systems for their desired end goal. This is achieved by the improvement in sensitivity, specificity, cost, and time. These optimization parameters are important not just in on-site detection but in laboratory-based systems as well.</p
A Child's Place in Modern Society, from Subject to Agent; Shifting Artistic and Cultural Perspectives in Cuba and Mexico
No full textThis dissertation examines the creation, perpetuation, and evolution of narratives about modern childhood in Cuba and Mexico, during the late nineteenth century, the mid-twentieth century, and the present. While many academic studies have analyzed children in terms of social, educational, and economic impacts, this dissertation reexamines children as a new class of consumers and agents in society, as evidenced by print culture and theatre for young audiences. An underlying theoretical framework I employ is Pierre Bourdieu's term, "cultural capital," to engage with these narratives by viewing children as important contributors to modern society which is inspired by Manon Van de Water's theorization of Bourdieu's term when considering the many people and institutions in society who continue to underestimate both children as a class and TYA as a genre.In the first chapter, I analyze the emergence of narratives of modern childhood in relation to nation-formation identity in a play for children, Los celos del Negro con Don Folías (1890-1913), as well as in various texts for children as produced by José Martí in La Edad de Oro (1889). In the second chapter, I analyze narratives about childhood related to difficulties with the congealment of national identities in Cuba and Mexico, with a focus on race in both Nicolás Guillén's 1943 play Poema con niños (1943) and Rosario Castellanos's novel Balún Canán (1957). In the third chapter, I examine two plays for children, Blanca Felipe Rivero's Ventana de estrellas (2010), and Micaela Gramajo and Daniela Arroio's Cosas pequeñas y extraordinarias (2016), in order to unpack the ways in which children are represented as active agents in society, capable of effectively dealing with trauma produced by the adults in their lives, such as family abandonment, infidelity, and forced migration
A Platform for Functional Discoveries to Optimize Algae Productivity
No full textThe development and adoption of biofuels as a renewable energy source is necessary as a replacement for petroleum-based fuel. Traditional fossil fuels are derived from a finite source and the use of which is environmentally detrimental, including contributing to increased carbon dioxide levels and global warming. Microalgae are strong candidates for the production of these biofuels as they are fast growing, tolerant of a wide variety of environmental conditions, and naturally produce valuable products.In this study I conduct an in-depth analysis of a little researched species, Nannochloris desiccata. This species was originally misidentified as belonging to the genus Chlorella, and after full genome sequencing and phylogenetic analysis was correctly classified. Growth and productivity analysis show that this is a halotolerant species showing competitive growth as compared to the highly productive species Picochlorum soloecismus and Chlorella sorokiniana. N. desiccata can produce up to 45% FAME/dry weight five-days after nitrogen depletion in marine media, showing potential as a valuable production species.To understand the mechanisms of growth I determined the diurnal cell cycle synchronization of Nannochloropsis salina. The cells in culture grow in size, including accumulation of neutral lipids and increasing chlorophyll content during the light cycle. In the last four hours of the light cycle, they replicate their DNA, either one or two times, then divide during the dark cycle. The transformation efficiency of these cells peaks as the cells are completing DNA replication and preparing to divide.Overall, the results of this study contribute to the wider field of algae biofuels by introducing the valuable properties of N. desiccata as a production species and demonstrating an approach to improving transformation efficiency
The Role of Epidermal Reactive Oxygen Species in Paclitaxel-Induced Cutaneous Sensory Axon Degeneration
No full textPeripheral neuropathy is a condition of axon degeneration in the hands and feet, which affects an estimated 30-40 million Americans, leading to pain, numbness, tingling, temperature sensitivity, and muscle weakness. The mechanisms are only beginning to emerge and hence there are no therapeutics with which to prevent or reverse this condition. Besides diabetes, a major cause of peripheral neuropathy is chemotherapy. This dissertation examines the mechanisms underlying chemotherapy-induced peripheral neuropathy (CIPN). The Rieger lab previously established that treatment with the chemotherapeutic agent, paclitaxel, activates Matrix-Metalloproteinase-13 (MMP-13) in the epidermis, and that MMP-13 inhibition prevents sensory neuron-specific CIPN in zebrafish and rodents. This dissertation provides evidence that MMP-13 is activated by the small reactive oxygen species, hydrogen peroxide (H2O2), in the epidermis and that epidermal H2O2 and mitochondrial damage act upstream of MMP-13 to promote cutaneous sensory axon degeneration via extracellular matrix degradation