12466 research outputs found
Sort by
Microeconomic Systems as a Computational Science: A Computational Platform for Microeconomic System Simulation and Human-Subject Experimentation
Get PDFThis dissertation investigates how economics experiments are conducted and details a new computational framework for the description and provisioning of experiments. In addition to the text of this dissertation a novel computational economics platform called mTree has been developed. mTree provides economists with the ability to describe microeconomic systems using a simple set of constructs in the Python programming language. An mTree microeconomic system can be used to run computational simulations of a microeconomic system as well as host and conduct human-subject experiments using the same underlying codebase. This represents capabilities not offered by other frameworks.The first chapter provides background on various issues surrounding economics experiments. One criticism of experimental techniques is that they lack generalizability to non-laboratory settings. The chapter describes the source of this criticism and suggests that an underlying and unaddressed problem relates to the manner of description of microeconomic systems. A further task of the chapter concerns the additional challenge of ensuring replicability of experiments and that using a richer description of underlying microeconomic systems can provide more than a procedural and protocol-oriented description of an experiment. It concludes by suggesting that the tools available from computer science can be employed to provide improved frameworks and description languages for economic systems. The second chapter suggests that microeconomic systems align well with work in the field of computer science investigating distributed systems. Arguably, a microeconomic system is in fact a distributed computation problem that presents many of the same challenges faced by computer scientists. From this a new computational framework for describing microeconomic systems is offered utilizing capabilities of a computing technique called an actor system. This new framework is called mTree and can be used for describing microeconomic systems as well as conducting simulations of the microeconomic system as well as human-subject experiments utilizing the same underlying codebase. The final chapter provides several examples of microeconomic systems implemented in the mTree framework. These examples include a variety of microeconomic systems for use with human-subject experiments. The examples include both computer simulation code of the microeconomic system as well as human subject experiment implementations of the examples. The various microeconomic systems provided in this chapter are meant to serve as both a tutorial on the use of the mTree framework as well a set of reusable components for future experiments and simulations
Ground-based Light Curve Follow-up Validation Observations of TESS Object of Interest TOI-4064.01
Get PDFThere have be 6,788 exo-planet candidates found by TESS alone, yet only 383 of them has been confirmed. We aimed to aid in the validation of these possible exo-planets, by checking for false positives (NEBs/EBs) and by using the transit method to analyze TOI 4064.01. Ultimately we did not receive a detection of a transit, possibly due to the dimness of the star or noise in our exposures
TRANSPORT PHENOMENON OF PER-POLYFLUOROALKYL SUBSTANCES (PFAS) THROUGH COMPOSITE LANDFILL LINERS
No full textThis work is embargoed by the author and will not be publicly available until May 2028.Per-polyfluoroalkyl substances (PFAS) are a group of man-made fluorinated organic chemicals that are found in a variety of domestic products such as food packaging, carpets, upholstery, water-repellent paints, and non-stick cookware. PFAS exist in the environment in abundance and have been reported in soil sediment, ground waters, surface waters, and landfill leachate. PFAS have also been reported in human blood serum and animal fatty tissues and have the potential to bind to human body proteins and bio-accumulate in triglycerides present in the liver ultimately causing adverse health effects including cancers and thyroid hormone deficiency. The physical structure of PFAS typically comprises a partially or fully fluorinated carbon chain (non-polar body) with a functional group (polar head). The presence of a fluorinated nonpolar body and a polar head gives PFAS its characteristic unique set of properties. PFAS are (1) thermally and chemically very stable,(2) acidic, and (3) hydrophobic and lipophobic surfactants and hence often referred to as the “forever chemicals.” PFAS are classified into various families based on their length, structural features, and functional groups. Landfills are the end destination of various domestic products containing PFAS. Their presence in the leachate of the municipal solid waste (MSW) landfills with concentrations up to 3500 ng/L have been reported in the literature which is extremely high compared to the U.S. Environmental Protection Agency established health advisory level of 4 ng/L for drinking water. There is a potential risk of transport/leakage of PFAS from the existing landfill liners which can lead to a serious environmental hazard. Therefore it is vital to evaluate the effectiveness of the existing landfill liners in containing these chemicals and to determine if any potential leakage can occur. The objectives of this research are (1) To evaluate the integrity of the typical MSW liner materials such as high-density polyethylene (HDPE) geomembrane (GM), and compacted clay liner (CCL) to transport PFAS under different pH. (2) Create a model to predict the long-term (e.g., 30 yr) mass-flux of PFAS through the landfill liner. To achieve these objectives a series of laboratory tests were conducted, which include batch adsorption and column diffusion tests to understand the partitioning behavior and diffusion behavior respectively. The partitioning and diffusion coefficients were calculated for the landfill liner components independently. The results of these tests were incorporated into a transport model representing various liner profiles (i.e. CCL, and GM+CCL). which will help to predict the long-term flux of PFAS through landfill liner systems at different pH conditions, which will establish a better understanding of PFAS migration through landfill liner systems. The outcome of this study presents the efficiency of existing landfill liners in containing PFAS.2028-05-1
Understanding the Impact of the Madden-Julian Oscillation and the North Atlantic Subtropical High on Atlantic Tropical Cyclone Variability
Get PDFTropical cyclone (TC) frequencies in the Atlantic Ocean have multiple influences of variability. Two important ones at subseasonal timescale are the Madden-Julian Oscillation (MJO) and North Atlantic Subtropical High (NASH). A detailed analysis into the combined effects of these together could be helpful in determining higher or lower TC frequencies in the Atlantic subregions – Caribbean, Gulf of Mexico, etc. – and the Atlantic as a whole. An established relationship could also be beneficial for forecasting TCs on a subseasonal timescale. This investigation identifies combinations of this corelationship utilizing contingency tables and chi-square independence analysis. It is shown there is a possible relationship between MJO and NASH where certain MJO phases modulate the NASH's location and explain some TC frequency patterns. For the Gulf of Mexico, a combination of MJO phases 1-4 and a western NASH extension results in much higher TC counts than expected for a null hypothesis of no MJO/NASH effect. For the North American east coast, MJO phases 1 through 4 and a northeast NASH extension result in the most TCs. Vertical wind shear values related to MJO phases and observed NASH locations support these findings
Why Millennials Attend Mainline Churches Despite National Decline—A Qualitative Research Project
Get PDFWhy do some millennials choose to attend mainline churches in the United States despite the decline in overall church attendance within this demographic? While the decline in religious participation among U.S. adults born between the years 1981 and 1996 is evident in studies from leading religious research institutes, little research delves into why some millennials choose to act differently than the social norm and engage with churches. Even less information is available about their desire to attend mainline denominations. Addressing these gaps in empirical research, this study employs a qualitative approach to explore the motivations of millennials newly attending mainline churches in the metropolitan Washington DC area.
Evidence gathered through in-depth interviews reveals a predominant theme: 100 percent of the study’s participants value the opportunity to build relationships at their church.
This commonality surpasses all other categories of church values, including denominational preferences, emphasizing the significance of community in the participants’ church experience. Other commonalities among the study’s participants reveal that they are demographically homogeneous and highly experienced with attending churches.
The qualitative approach of this study limits its research sample, but also provides benefits. Using in-depth interviews as a research method required a non-representative sample that is not generalizable to all U.S. millennials attending mainline churches, yet open-ended questioning offered nuanced insights from the participants' storytelling about the factors that have influenced their decisions to attend their churches. The findings reveal what matters to the participants about the churches they are a part of, offering valuable information for church leaders facing the challenge of building future generations of the church amidst declining attendance
Investigating Reproductive Senescence in Captive Asian Elephants (Elephas maximus) Through Long-term Hormone Monitoring
Get PDFWhether or not elephants experience reproductive senescence, or the decline of reproductive function with age, has been a matter of some debate among researchers. While it has been shown to occur in other non-human species, data on reproductive senescence in both extant species of elephant have produced mixed results. In this study, statistical methods were applied to two previously published data sets on captive Asian elephants (Elephas maximus) to determine if age-related changes in reproductive and metabolic hormones could be detected. Multinomial regression analysis found that younger individuals (15.8-35.8 years old) had significantly higher average progestogen levels than older individuals (45.8-55.8 years old). For a separate subgroup of 11 longitudinally profiled individuals, mean hormone concentrations were profiled on an individual level across approximately 10-20 years. Interestingly, no significant age-associated changes were detected for progesterone, but the levels of several other hormones changed significantly, including that for reproductive hormones FSH and LH, both of which increased with age, and metabolic hormones, namely, cortisol, which has increased, and total T3, which has decreased. These results warrant further attention from researchers seeking to determine how Asian elephants experience reproductive aging, particularly in the North American population that is composed predominantly of post-reproductive females
The Spectre of Benigno
No full textThis thesis has been embargoed for 5 years. It will not be available until April 2027 at the earliest.This thesis is a historical fiction novel set in Japanese occupied Philippines during World War II. Inspired by real family events, this story is told from the perspective of a young Filipina named Maura, who discovers the body of her Lolo, Benigno, after he was murdered by a Japanese sniper. She discovers that he was an important ally to the Americans. Under the shadow of her dead grandfather, Maura will work her way into the guerrilla resistance against the Japanese. As her thirst for revenge introduces her to both the horror and complications of war, she quickly learns that for a young woman, occupation means exploitation. To the Filipinos, she is a beacon of hope. To the Americans, she is a prized pawn in a network of resistance fighters. And to the Japanese, she is to be controlled both body and mind. Navigating these complicated allegiances will unravel her every conceit regarding what is good and evil; what causes are just and right.2027-04-2
Project 5: Regional and Seasonal Variation of Cyanotoxins
Get PDFBackground: Harmful Algal Blooms (HABs) and their toxins thrive in warm, nutrient-rich freshwater conditions, and can produce harmful cyanotoxins. Typically, these cyanotoxins take the form of hepatotoxins, dermatoxins, or neurotoxins. Exposure to cyanotoxins can occur in various fashions, including skin-to-water contact, inhalation of fumes, ingestion of contaminated water, and indirect ingestion through contaminated water sources or aquatic animals [1]. Exposure to microcystins, a common hepatotoxin found in cyanobacteria blooms, has been linked to fatal liver damage in both humans and dogs [3]. Additional evidence connects cyanotoxin BMAA to neurodegenerative diseases, such as ALS and Parkinson’s disease [5]. Minimal treatment options are widely available. Government bodies therefore focus their efforts on cyanobacterial toxicosis prevention, commonly issuing public safety alerts and advisory warnings around peak HAB exposure areas [3].
Objective: This research examines how HAB blooms and cyanobacteria outbreaks vary both regionally and seasonally across the United States from 2008-2018
Integrated Analysis of Single Nucleotide Variants and their Functional Annotations for Improved Rare Disease Variant Classifications
Get PDFRare diseases effect 1 in 10 individuals in the US. Most rare diseases are genetic and exhibit Mendelian inheritance. Some of these phenotypes are caused by a single nucleotide variation in the human genome. To date, there have been no comprehensive studies on the global landscape of single nucleotide variants associated with rare diseases, with the goal of explaining the high impact of these variations. Availability of the reference genome and multiple variation databases, that catalog population wide variants and clinical associations, now make it feasible for the large-scale analysis of rare disease associated single nucleotide variants.Understanding the exact variation and determining factors differentiating rare disease SNVs from others, requires detailed explorations of multiple data sets providing details on the associated genes, and functional annotations at both variant and gene level. Efforts will also be required in formatting, analyzing, and understanding of each of these individual data sets using multiple possible mechanisms. As part of this research, rare disease relevant details including genic associations, and prevalence, pathway and disease hierarchical associations, and functional annotations were thoroughly analyzed. An integrated approach using both relational and graph databases was implemented to carefully review, explore, and integrate various data sets. Multiple annotations at the variant level were obtained to understand the type of variation and overlap with functional and regulatory genomic regions. Missense variants were further explored, using protein annotations, allele frequencies of the alternate allele, types of amino acid and cDNA substitution, and evolutionary conservation. Analysis showed that while common diseases can be associated with all protein coding genes, rare disease associated genes are more likely to play vital roles in developmental and cellular processes. The ultra-rare diseases are more likely associated with a single gene and common diseases have polygenic associations. SNVs in rare diseases tend to have a drastic impact, and a single nucleotide change can lead to a debilitating phenotype. Studies on rare and common diseases should treat diseases as occurring on a continuous spectrum rather than binary variables. Missense variants differentiating pathogenic and benign rare disease variants show marked differences in the protein features they overlap and the type of amino acid substitution. These differences were exploited to derive custom scores, which were in turn used to improve a classification model using evolutionary scores and allele frequencies. In summary, we have successfully shown that rare disease associated genes show characteristic differences compared to the overall protein coding and common disease associated genes. The single nucleotide variants occurring in these genes are more likely to have a drastic impact on the protein, where the protein is either not encoded or loses critical functionality. Pathogenic missense variants, in addition to occurring in highly conserved locations, disrupt important protein features and/or have substitutions that alter protein structure/function in a significant manner
Lamplighters Groups: Their Presentations, Caylely Graphs, and Generating Automata
Get PDFThe focus of this paper is the traditional lamplighter group L2 = (Z/2Z) wrZ and the broader class of lamplighter groups LG = Gwr Z, where G is a finite group. These groups have seen direct use in papers such as [7], in which Grigorchuk, Linnell, Schick, and Z˙ uk show there is a closed Riemannian manifold (with the HNN-extension of L2 as its fundamental group) that has a rational L2-Betti number. Other results rely on generalizing or building atop the lamplighter group, as is done by Brieussel and Zheng in [3] to expand the known possible speed, entropy, isoperimetric profile, return probability, and compression gap attainable by random walks on finitely generated groups.
This paper provides the algebraic background needed to understand the definition of the traditional lamplighter group, as well as its presentation, Caylely graph, and representation as an automaton group. All three of these constructions provide distinct avenues to generalize the lamplighter group. The sort of generalization discussed in this paper—moving from L2 to LG—is quite natural from the perspective of the lamplighter group’s Cayley graph and presentation. The case of finding a suitable automaton to generate such generalizations is more interesting; only some lamplighter groups LG can be generated by automata. When G is a finite Abelian group, then LG can be generated by the Cayley machine C(G) of G, and when G is a finite Non-Abelian group there is no automaton which can generate the group. These Cayley machines are interesting in their own right, so we explore the more general structure of the groups generated by Cayley machines