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Leveraging High-Performance Cloud Computing to Model Underwater Acoustic Propagation and Scattering From Time-Evolving Rough Sea-Surfaces Using the Finite-Difference Time-Domain Method
No full textThis dissertation presents a two-dimensional (2D) Finite-difference Time-domain (FDTD) model for simulating underwater acoustic propagation and scattering from a one-dimensional (1D) time-evolving rough sea-surface. The techniques discussed are extendable to three spatial dimensions. Traditional acoustic modeling techniques often rely on a frozen sea-surface assumption, which proves inadequate for long-duration signals interacting with the time-evolving boundary at many different wave height displacements during its transit. To address this, a new FDTD update equation incorporating a variable subgrid is developed, significantly enhancing spatial accuracy at the boundary without increasing computational cost or compromising stability.
The model\u27s accuracy is rigorously validated against established methods for various boundary conditions: the Image Method (IM) for static smooth surfaces, the Modified Image Method (MIM) for dynamic (evolving over time) smooth surfaces, and the Helmholtz Integral Equation (HIE) for static rough surfaces. Quantitative signal similarity metrics, including the normalized correlation coefficient and mean squared error, demonstrate the FDTD model\u27s ability to accurately capture both scattering due to roughness and time contraction/dilation effects caused by motion. Notably, the model reveals that discrepancies in reflected signals from traditional methods that stem from the frozen sea-surface assumption, which can be mitigated by accounting for ray path length differences due to boundary translation.
Furthermore, this dissertation details the development of a high-performance cloud computing (HPCC) architecture for acoustic modeling simulations and an accompanying framework with a user-friendly extensible Underwater Acoustic Modeling (UAM) package written in Matlab, Python and BASH. This infrastructure facilitates distributed simulations, drastically reducing computation times for large-scale, realistic underwater modeling scenarios. The validated FDTD model, coupled with the HPCC framework, offers a robust tool for investigating the complex interactions of broadband acoustic signals with dynamic ocean environments, providing crucial insights for the design of next-generation sound navigation and ranging (SONAR) systems
Guide to Wetland and Riparian Plant Families of Pacific Northwest Rangelands
No full textThis document contains a quick, non-technical, pictured-based field guide to wetland and riparian plant families of Pacific Northwest rangelands in eastern Oregon, eastern Washington, and northeastern California. It contains approximately 100 taxa including 40 common plant families and 60 common genera and species. The intended audience for this guide includes wetland professionals, restoration practitioners, land managers, botanists, naturalists, and anyone interested in wetland plants
Lagging Brain Gene Expression Patterns of Drosophila Melanogaster Young Adult Males Confound Comparisons Between Sexes
Get PDFMany species, including fruit flies (Drosophila melanogaster), are sexually dimorphic. Phenotypic variation in morphology, physiology, and behavior can affect development, reproduction, health, and aging. Therefore, designating sex as a variable and sex-blocking should be considered when designing experiments. The brain regulates phenotypes throughout the lifespan by balancing survival and reproduction, and sex-specific development at each life stage is likely. Changes in morphology and physiology are governed by differential gene expression, a quantifiable molecular marker for age- and sex-specific variations. We assessed the fruit fly brain transcriptome at three adult ages for gene expression signatures of sex, age, and sex-by-age: 6698 genes were differentially expressed between sexes, with the most divergence at 3 days. Between ages, 31.1% of 6084 differentially expressed genes (1890 genes) share similar expression patterns from 3 to 7 days in females, and from 7 to 14 days in males. Most of these genes (90.5%, 1712) were upregulated and enriched for chemical stimulus detection and/or cilium regulation. Our data highlight an important delay in male brain gene regulation compared to females. Because significant delays in expression could confound comparisons between sexes, studies of sexual dimorphism at phenotypically comparable life stages rather than chronological age should be more biologically relevant
The Roots of Ethno-Political Strife in Ceylon: The Dividing Power of British Colonialism
Get PDFA bloody civil war has rocked Sri Lanka for decades, as the Sinhalese and Tamil populations fight each other for recognition, access, and control. Since the 1950s, each group has feared domination by the other, resulting in bitter battles on the ballots and in the streets to assert or retain power and subjugate the culture of the other. Each conflict perpetuates the vicious circle of retaliation and retribution through the generations, and the roots of this divide can be directly traced to the colonial occupation of the island in the 1800s. What began with the Dutch and became refined by the British was a complete and systematic domination that hooked the island nation known as Ceylon into dependence on the global economy, undermined the cultures of its native inhabitants, and ultimately divided them along ethnic lines. This paper examines how Britain’s colonial rule sowed the seeds of resentment that all but ensured any unity post independence would be short-lived.
Part of the panel: Asia in Collision Moderator: Professor Jennifer Kern
Exposing the Truth Behind the Stanford Prison Experiment
Get PDFIn 1971 Philiip Zimbardo, a Stanford University professor, designed an experiment to study human behaviors in the prison system. He sought to understand the effectiveness of the prison system, however, the experiment ended early due to the ethical concerns toward participants. It is considered one of the most important psychological experiments, not for what it helped reform, but for what it pointed out about the importance of safety for research participants. Calling upon primary sources from participants and the researchers’ findings, as well as secondary sources primarily from psychologists and research ethics, the research reveals that this study was unreliable due to the significant flaws in its design. This paper argues that the Stanford Prison Experiment should not be used as a tool for understanding the prison system, but rather as an example of how lack of oversight compromises scientific findings. This experiment demonstrates the necessity for safety and ethical protocol for research participants, serving better as a cautionary tale for the responsibility of scientists.
Part of the panel: Crime and Punishment Moderator: Brenda Frin
Room 1: “Forgive the life you’ve lived”—Explaining Why Two Faculty and their Undergraduate Students co-edited Sharing Stories of Hope and Transformation in U.S. Higher Education: An eReader by Portland State University Studies (2024)
Get PDFThe presentation explains three main reasons why two Portland State University faculty from two disciplines (History and Comparative Literature)—and both teaching a first-year course called “Immigration, Migration, and Belonging”—co-edited an eReader with their undergraduate students (i.e., 1. to record students’ lived experiences as worthy of study, 2. disrupt notions in diverse students that they are a deficit in higher education; and 3. let diverse students see themselves in the struggles and achievements of their student peers). This eReader, Sharing Stories of Hope and Transformation in U.S. Higher Education: An eReader by Portland State University Studies, highlights stories of hope and transformation written by diverse students enrolled in University Studies, a general studies (i.e., essential studies) program. The eReader’s goal is to motivate first-year and transfer students to see that, in higher education, they are not alone in their personal, familial, and academic struggles—and personal, familial, and educational achievements. Finally, the presenters will describe the process of completing this open educational resource (i.e., gathering stories, editing them, and launching the eReader via in-person and Zoom book launches) and sharing it with the Portland State University community. The presentation is book-ended with student voices. The presentation will open with a brief excerpt reading by one of the book’s student co-authors. The presentation will end with the student co-author reflecting on what they learned from co-authoring this eReader
\u3ci\u3eOur Vision Is That Black Mothers and Birthing People, Fathers, and Partners Are Safe, Honored, and Respected Throughout Pregnancy and Parenthood\u3c/i\u3e : Black Birth Workers\u27 Agenda for Black Maternal Health in Oregon
Get PDFBlack women and Birthing People (BWBP) face disproportionate rates of mortality within the United States healthcare system. BWBP are three times more likely to suffer a pregnancy-related death than White women. Therefore, addressing and consulting with BWBP about the birthing experience that BWBP sustains when they are bearing children is imperative. The inclusion and application of this key knowledge and understanding should be emphasized and at the root of further development toward reproductive justice. This participatory story was led by Dr. Roberta Hunte. Interviews and focus groups with Black birth workers, birthing people, and public health professionals were conducted in 2023 to discuss maternal and child outcomes and possible recommendations for an agenda for Black maternal health in Oregon. In this thesis, we analyze field notes from perinatal workgroups, interpret their found themes and recommendations, and further discuss possible routes within society, from institutions to communities, to instill methods to best support maternal and child outcomes. We expect this approach to further healthcare outcomes and expectancy within the greater Portland community, supporting the development of a holistic birthing village and legislative policy
Quantitative Analysis Using MRI of Patients That Are High Risk for Pancreatic Cancer
Get PDFPancreatic ductal adenocarcinoma (PDAC) is a cancer that is detected in its later stages, causing its five-year survival rate of 2-9% (3). The majority of patients who develop PDAC unfortunately deal with a low survival rate due to the progression of the tumor in the body. Magnetic resonance imaging (MRI) can assess the structure of the tissue within organs in the body. These scans can also be used in order to detect and diagnose tumors, allowing them to be a generator of cancer biomarkers. PDAC isn’t distinguishable on conventional images, as the pancreas will appear normal, allowing the tumor progress into later stages. The signal that the MRI uses is determined by MR relaxation times, which are T1, T2, and T1ρ. This study utilizes MR relaxation times to detect possible changes in tissues of patients at high risk for PDAC, including: pancreatitis, an IPMN, cystic lesions, or familial/genetic risk. The mean values from each category were compared with one another. From the results, it was noted that the values from each of the different categories varied and weren’t the same, significantly in the T1 values. They were observed to be in decreasing order from severity (pancreatitis → IPMN → cyst → familial/genetic). This suggests that relaxation times can be used to detect whether a patient is at risk of developing another condition. Further research is needed to determine if this can be used in the future to detect other conditions as well, such as PDAC
Intrapersonal and Interpersonal Factors of Participation in Physical Activity and Resistance Training in Adolescent Girls: A Narrative Review
Get PDFLow rates of participation in physical activity and resistance training among adolescent girls are a concern due to increased health and injury risks. Adolescent girls participate in physical activity and resistance training at a lower rate than boys, which may explain higher rates of injury. Research examining physical activity of adolescent girls often utilizes an ecological framework, identifying intrapersonal, interpersonal, and environmental factors. Of these ecological levels, intrapersonal and interpersonal factors are modifiable without large costs.
Therefore, this review aimed to identify and summarize recent research that explores the intrapersonal and interpersonal factors associated with participation in physical activity and resistance training among adolescent girls. Emerging themes included self-efficacy, parental and peer support, gender norms, and social pressure. A lack of research on factors of participation in resistance training among adolescent girls was identified. Through a synthesis of ecological and motivational factors, suggestions for increasing physical activity and resistance training among adolescent girls were made