A Study of Estimation Techniques and of Mechatronic System Design and Testing

This thesis is a collection of two projects that the author worked on during his master\u27s studies at Clemson University. The first project--adaptive camera calibration--involves the design and simulation of an estimator for the calibration parameters of a camera. The second project--basket drive wear testing--includes the design of a test plan for measuring wear on a mechatronic system

A Method for Finding Galaxy Groups in Early Formation Stages Applied to RESOLVE and ECO

The most common galaxy group finding algorithm, Friends-of-Friends (FoF), finds "settled'' groups that share a common dark matter halo but misses groups that are in earlier stages of formation and have not yet merged halos. We present a new algorithm that is designed to find groups like the Local Group that are gravitationally bound but do not yet share a common halo and are not identified as FoF groups. We use escape velocity to test whether settled groups are bound to other nearby settled groups (including "groups'' of one solitary galaxy). We statistically correct for projection effects present in observational data using mock catalogs containing simulated three-dimensional data. We apply the boundness method to RESOLVE and ECO, two large volume-limited surveys of galaxies in the local Universe. Using our boundness method increases the number of multiple galaxy systems that are identified and decreases the number of single galaxy systems. We find evidence that the bound systems we identify are truly groups in the early stages of formation, based on comparisons of large scale environment and virialization state with settled groups. We identify "Local Group analogues" that are similar to the real Local Group. We find 32 Local Group analogues in RESOLVE and 229 in ECO. In RESOLVE and ECO, about 13% of all multiple-galaxy systems are Local Group analogues and about 8% of all galaxies belong to a Local Group analogue. Local Group analogues are among the most virialized systems found by the boundness method in RESOLVE and ECO, with a median crossing time about three times shorter than other bound multi-group systems with similar masses. To determine how well the boundness method finds systems like the Local Group, we identify a population of Local Group analogues in the mock catalogs. FoF finds only 6% of the Local Group analogues, whereas the boundness method finds 97%. We compare properties of different categories of bound systems in RESOLVE and ECO, focusing on their evolutionary connection, and find that gas content may be higher in small settled groups (FoF groups with halo mass < 10^12 M_sun) than in proto-groups (bound multi-group systems with system mass < 10^12 M_sun) at fixed virialization state.Bachelor of Scienc

Finding myself in medicine

In this article (part one of a two-article piece), I, Erin Nissen Castelloe, a woman who has worked almost twenty years as a doctor, first in the practice of Family Medicine and later as a Pharmaceutical Medicine consultant, ponder the next phase of my career. In an attempt to understand myself and my experiences in medicine – and to connect with others who may share my belief that medicine (and those who practice it) must evolve in order to empower and serve – I share my personal story: the influences and idealism that led me to medicine; the best career advice I ever received (from a patient, not a doctor); my past and present frustrations with clinical medicine; my struggles to balance my personal and professional aspirations; my growing dissatisfaction with a career in Pharmaceutical Medicine; and, ultimately, my attempts to collect, sow, and cultivate ideas that may – nurtured with tinctures of time and collaboration – become strong, new branches on the magnificent tree of medicine

Tincture of time

In this article (part two of a two-article piece), I, Erin Nissen Castelloe, meditate on long-standing frustrations originating from my personal experiences in clinical medicine. My exit from clinical medicine can most succinctly be attributed to burnout, burnout triggered by inadequate time to address my patients’ needs and complete the tasks mandated by the healthcare delivery system in which I worked. Self- and system-imposed pressures to meet my professional obligations led to chronic overwork, reduced personal time, sleep deprivation, exhaustion, and ultimately, recognition that my work situation was unsustainable. For more than ten years, I have questioned my decision to leave clinical medicine, hashing and rehashing the circumstances leading up to it. I am ready to let go of the questions that have haunted me, but I want to do so deliberately, considering them carefully before I release them. Therefore, with high hopes – to understand my past, accept it, and move boldly into my future in medicine – I searched the literature, focusing on burnout in physicians and physicians-in-training; the role of time pressures in burnout; and the value of physicians spending adequate and high-quality time with patients

Social interaction style of children and adolescents with high-functioning autism spectrum disorder

Qualitative differences in social interaction style exist within the autism spectrum. In this study we examined whether these differences are associated with (1) the severity of autistic symptoms and comorbid disruptive behavior problems, (2) the child's psycho-social health, and (3) executive functioning and perspective taking skills. The social interaction style of 156 children and adolescents (6-19 years) with high-functioning autism spectrum disorder (HFASD) was determined with the Wing Subgroups Questionnaire. An active-but-odd social interaction style was positively associated with symptoms of autism, attention deficit and hyperactivity. Furthermore, an active-but-odd social interaction style was negatively associated with children's psycho-social health and positively with executive functioning problems. Social interaction style explains part of the heterogeneity among children with HFASD

The RESOLVE and ECO Gas in Galaxy Groups Initiative: The Group Finder and the Group H i–Halo Mass Relation

We present a four-step group-finding algorithm for the Gas in Galaxy Groups (G3) initiative, a spin-off of the z ∼ 0 REsolved Spectroscopy Of a Local VolumE (RESOLVE) and Environmental COntext (ECO) surveys. In preparation for future comparisons to intermediate redshift (e.g., the LADUMA survey), we design the group finder to adapt to incomplete, shallow, or nonuniform data. We use mock catalogs to optimize the group finder’s performance. Compared to friends-of-friends (with false-pair splitting), the G3 algorithm offers improved completeness and halo-mass recovery with minimal loss of purity. Combining it with the volume-limited H i census data for RESOLVE and ECO, we examine the H i content of galaxy groups as a function of group halo mass. Group-integrated H i mass M H I,grp rises monotonically over halo masses M halo ∼ 1011–1014.5 M ⊙, pivoting in slope at M halo ∼ 1011.4 M ⊙, the gas-richness threshold scale. We present the first measurement of the scatter in this relation, which has a median of ∼0.3 dex and is asymmetric toward lower M H I,grp. We discuss interesting tensions with theoretical predictions and prior measurements of the M H I,grp–M halo relation. In an appendix, we release RESOLVE DR4 and ECO DR3, including updates to survey redshifts, photometry, and group catalogs, as well as a major expansion of the ECO H i inventory with value-added data products

Erratum: “The RESOLVE and ECO Gas in Galaxy Groups Initiative: The Group Finder and the Group H i–Halo Mass Relation” (2023, ApJ, 956, 51)

Erratum to “The RESOLVE and ECO Gas in Galaxy Groups Initiative: The Group Finder and the Group H i–Halo Mass Relation

The RESOLVE and ECO Gas in Galaxy Groups Initiative: The Group Finder and the Group HI–Halo Mass Relation

We present a four-step group-finding algorithm for the Gas in Galaxy Groups (G3) initiative, a spin-off of the z ∼ 0 REsolved Spectroscopy Of a Local VolumE (RESOLVE) and Environmental COntext (ECO) surveys. In preparation for future comparisons to intermediate redshift (e.g., the LADUMA survey), we design the group finder to adapt to incomplete, shallow, or nonuniform data. We use mock catalogs to optimize the group finder’s performance. Compared to friends-of-friends (with false-pair splitting), the G3 algorithm offers improved completeness and halo-mass recovery with minimal loss of purity. Combining it with the volume-limited H I census data for RESOLVE and ECO, we examine the H I content of galaxy groups as a function of group halo mass. Group-integrated H I mass M rises monotonically over halo masses M ∼ 10–10 M, pivoting in slope at M ∼ 10M, the gas-richness threshold scale. We present the first measurement of the scatter in this relation, which has a median of ∼0.3 dex and is asymmetric toward lower M I,grp. We discuss interesting tensions with theoretical predictions and prior measurements of the M–M relation. In an appendix, we release RESOLVE DR4 and ECO DR3, including updates to survey redshifts, photometry, and group catalogs, as well as a major expansion of the ECO H I inventory with value-added data products. © 2023. The Author(s). Published by the American Astronomical SocietyWe are grateful to the anonymous referee, whose feedback has improved the quality of this work. We also thank Adrienne Erickcek, Andrew Mann, Mugdha Polimera, Matthew Bershady, Joshua Oppor, Jeremy Darling, Hayley Roberts, and Amir Kazemi-Moridani for valuable feedback at varying stages of the project. Z.L.H., S.J.K., and E.R.C. acknowledge support for this research from National Science Foundation (NSF) grant AST-1814486. Z.L.H. and D.S.C. are also supported through a North Carolina Space Grant Graduate Research Fellowship. S.J.K. and D.S.C. acknowledge support from NSF grant AST-2007351. A.J.B. acknowledges support from NSF grant AST-1814421. K.M.H. acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science, Innovation and Universities through the "Center of Excellence Severo Ocho" awarded to the Instituto de Astrofisica de Andalucia (SEV-2017-0709), via participation in SKA-SPAIN, funded by the Ministry of Science and Innovation (MCIN), and financial support from grant RTI2018-096228-B-C31 (MCIU/AEI/FEDER,UE)

Phylogenetics Applied to Genotype/Phenotype Association and Selection Analyses with Sequence Data from Angptl4 in Humans

Genotype/phenotype association analyses (Treescan) with plasma lipid levels and functional site prediction methods (TreeSAAP and PolyPhen) were performed using sequence data for ANGPTL4 from 3,551 patients in the Dallas Heart Study. Biological assays of rare variants in phenotypic tails and results from a Treescan analysis were used as “known” variants to assess the site prediction abilities of PolyPhen and TreeSAAP. The E40K variant in European Americans and the R278Q variant in African Americans were significantly associated with multiple lipid phenotypes. Combining TreeSAAP and PolyPhen performed well to predict “known” functional variants while reducing noise from false positives

The Origins of African Plasmodium vivax; Insights from Mitochondrial Genome Sequencing

Plasmodium vivax, the second most prevalent of the human malaria parasites, is estimated to affect 75 million people annually. It is very rare, however, in west and central Africa, due to the high prevalence of the Duffy negative phenotype in the human population. Due to its rarity in Africa, previous studies on the phylogeny of world-wide P. vivax have suffered from insufficient samples of African parasites. Here we compare the mitochondrial sequence diversity of parasites from Africa with those from other areas of the world, in order to investigate the origin of present-day African P. vivax. Mitochondrial genome sequencing revealed relatively little polymorphism within the African population compared to parasites from the rest of the world. This, combined with sequence similarity with parasites from India, suggests that the present day African P. vivax population in humans may have been introduced relatively recently from the Indian subcontinent. Haplotype network analysis also raises the possibility that parasites currently found in Africa and South America may be the closest extant relatives of the ancestors of the current world population. Lines of evidence are adduced that this ancestral population may be from an ancient stock of P. vivax in Africa