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Geometric Shapes that Sing and Move: An Interdisciplinary Lesson with Pre-service Teachers
No full textOur work shares a practical example of an interdisciplinary lesson in which two teacher educators collaborated to integrate mathematics and music in an elementary mathematics methods course. This paper describes the process of collaboration in designing the lesson and shares original instructional resources to be used in the classroom. We also discuss what the pre-service teachers participating in the lesson shared about their learning experience, and what we, the teacher educators, learned from this experience. In presenting this work we aim to promote the opening of spaces in teacher preparation programs that allow pre-service teachers to develop their own instructional resources, while seeking opportunities to create interdisciplinary instruction in their own classrooms.Educatio
Understanding and Harnessing the Blinking Behavior of Emitters for Single-Molecule Imaging
No full textThe visualization of biological systems can provide insight into the structure of sub-cellular components. By overcoming the diffraction limit of light, super-resolution microscopy can image structures on a nano-scale level with incredible resolution. Multicolor super-resolution imaging with fluorescent probes is a popular method for analyzing the interactions of different facets of biological systems. Typically, experiments involving multiple probes within a single system require fluorescent molecules with distinguishable emission spectra in order to provide multicolor images. The small number of available and compatible probes of different spectra further limits the production of these images. To address this limitation, we describe Blinking-Based Multiplexing (BBM), a method for identifying probes based not on their spectra, but on their intrinsic fluctuations in emission intensity under continuous excitation (so-called blinking). This thesis describes the development of BBM, and its applications for distinguishing three spectrally-overlapped emitters, Rhodamine 6G (R6G), CdSe/ZnS quantum dots (QD), and pyrromethene 605 (PM605), a fluorescent probe from the promising BODIPY class of molecules. As a first step, the blinking mechanisms of all three emitters are determined by analyzing the on- and off-time durations for emitters on glass under continuous excitation. Using change point detection and logistic regression analyses, we determine that R6G can be distinguished from QD and PM605 with minimum classification accuracies of 92.5% and 76.1% respectively. To understand photophysical properties responsible for low R6G/PM605 classification accuracy, we next investigate the underlying mechanism for PM605 emission at two excitation powers, 1.05 µW and 0.787 µW. First determine the functional form that best represents the on- and off-time distributions using goodness-of-fit tests based on the Kolmogorov-Smirnov statistic and maximum likelihood estimation. We find that the data fits a power-law distribution and a log-normal distribution, which is consistent with the Albery model for dispersive electron transfer. In addition, using fit parameters, we quantify the rates of entry to and exit from the dark state and determine that PM605 blinking is a dispersive process. This study reveals the blinking mechanism of PM605 and demonstrates BBM to be an effective method for distinguishing spectrally-overlapped, small-molecule fluorophores.ChemistryBachelors of Science (BS
Numerical Modeling Of Coastal Sea Level Anomaly, Gulf Stream Slowdown, And Cross-Shelf Mixing In South Atlantic Bight During Hurricane Matthew
No full textAs Hurricane Matthew of 2016 passed by the South Atlantic Bight (SAB), a storm tide reaching 1 – 2 m, an elevated post-hurricane abnormal water level (PHAWL), and a pro-longed Gulf Stream (GS) slowdown were recorded. In contrast to the short burst of storm surge by the hurricane, PHAWL produces a more gradual coastal sea level rise ranging between 0.5 – 0.8 meters, which lasts for 7 – 20 days SAB-wide and corresponds to a 15-25% reduction in the GS transport. A 3D unstructured grid, baroclinic model SCHISM was applied to the Western Atlantic Ocean where the open boundary condition was specified at longitude 60 degrees west based on HYCOM, and the atmospheric forcing and pressure were specified at the sea surface based on ECMWF. The 3D model results compared excellently with the 6 tidal gauge records in the SAB (R2 from 0.94 – 0.98). The simulation included an extra-tropical cyclone atmospheric forcing that arrived at the mid-Atlantic region shortly after Matthew downgraded to a tropical storm offshore of North Carolina, which generated a coastally trapped wave (CTW) propagating southward along the SAB. It is noted that the simulation was capable of modeling both phenomena: PHAWL and the GS slowdown. By parsing through model results before and after the event, we found that the dynamic height tilted upwards on the coastal side (downwards on the open ocean side), the thickness of the surface mixed layer deepened to around 60 m, the slope of the cross-shelf density gradient decreased, and strong vertical velocities ranging from 0.5 to 1.0 mm/s in both upwelling and downwelling were found in the interior of the ocean. By ageostrophic analysis, we identified a window that overlaps with the period of the hurricane and CTW when active ageostrophic activities were identified, which includes the frontogenesis of the density field, increased cross-shelf velocity with reversal at depth, and large alternations of the vertical shear, all of which are hallmarks of submesoscale processes. After the active period, most of the state variables return to quiescence (i.e., in geostrophic balance) with the exception of ageostrophic shear which stays negative to bring down the modeled vertical shear. The negative vertical shear indicates the GS has slowed down, consistent with the thermal wind equation. Further analysis of the flow field of the fine-grid model result during the ageostrophic peak reveals different sized eddies emerged spontaneously. These eddies are part of the ageostrophic motions with a horizontal scale of 20 – 50 km and a vertical extent of 500 m deep, and have signatures in temperature, salinity, and vorticity as well. They facilitated intense vertical velocities and lateral stirring resulting in horizontal mixing and dispersion of the density field. Based on the analyses, the evidence indicates that the hurricane and CTW disturbances served as triggers setting off a chain reaction of sub-mesoscale instability which created ageostrophic motions and lateral mixing causing the cross-shelf horizontal density gradient to slump, eventually leading to the slowdown of the GS.Virginia Institute of Marine ScienceMaster of Science (M.Sc.
Confluences Of Power / “That The Water Shall Remain Smooth”
No full text“Confluences of Power: Mobility and Resistance in the Riverine Worlds of the Powhatan, 1570-1722” explores colonial policy designed to restrict the mobility of Powhatan peoples throughout early Virginia and considers how Indigenous groups navigated these imposed boundaries. Specifically, I argue that policies developed intentionally to prevent Native peoples from navigating the tidewater riverine system ultimately failed to constrain Powhatan movement, as individuals from the Pamunkey, Mattaponi, and other groups continued to transgress physical and legal boundaries well past the era of formal treaties of the 1670s that classified them as tributaries. Focusing largely on colonial attempts to restrict Indigenous movement and punitive measures against those who crossed boundaries regardless, this paper nonetheless attempts to center Powhatan relations to their environment, particularly waterways, in Indigenous reactions to colonial coercion. My second paper, “That the Water Shall Remain Smooth:” Ojibwe Ecological Knowledge, Place-Making, and Mobility in the Lake of the Woods Region, 1790-1873,” considers the role of specific environments and Ojibwe places within the Lake of the Woods basin during the nineteenth century as U.S. and Canadian settler colonial powers worked to establish the international boundary line through the region. Here, I focus less on colonial restrictions to Indigenous mobility, and more on the extent to which such limitations were not possible in the Lake of the Woods region, making places that were culturally, spiritually, and economically significant to the Ojibwe more significant than settler boundaries in the lives of the Anishinaabeg as well as the British and American traders, explorers, diplomats, and surveyors who moved through the area. In order to foreground the role of Ojibwe environments and the relations they engendered, I examine three key spaces within the waterscapes of the region—rivers, lakeshores, and islands within lakes—as well as the specific places that the Ojibwe constructed within them. I argue that each space offered different advantages to the Ojibwe who used them, as well as engendering specific relationships and kinds of engagement with the settlers who also depended on these areas and the Ojibwe people and places they contained. Ultimately, I contend that such places allowed the Ojibwe to resist the division of their lands and attempts to curtail their mobility at a key moment in the border-making process during the first half of the nineteenth century.HistoryMaster of Arts (M.A.
Using a Cultural Humilty Framework for LGBTGEQIAP+ Affirming Counseling Training
Get PDFExcerpt from publication: "Although enhanced visibility has created more space for LGBTGEQIAP+ ways of being over the past few decades, anti- LGBTGEQIAP+ discourse, legislation, and acts of violence have increased in the U.S. in recent years. However, the number of LGBTGEQIAP+ Americans who self-realize their sexual, affectional, and gender expansive identities continues to increase, especially among younger generations (Jones, 2023)..."Educatio
Ceramics of Chthonic Cults: A Comparative Analysis of Pottery from Mediterranean Chthonic Sanctuaries
No full textThis thesis examines the ritual practices of different chthonic cults across the ancient Mediterranean by studying the ceramic evidence from each site. The sites that are discussed are Atsipadhes Korakias and Ayios Yeoryios sto Vouno (Crete and Kythera), Eleusis and the City Eleusinion (Greece), Pyrgi (Italy), Abydos (Egypt), and Tavira (Iberia). These sites cover a broad geographical range of the ancient Mediterranean and reflect the religious practices of different cultures, including the Minoans, Greeks, Egyptians, Etruscans, and Romans. By examining sites across a broad geographic range, I show the interconnected nature of the ancient Mediterranean and the influences different peoples had on one another. I also look at a variety of geographic locations and ritual practices to consider how these cultures interacted within their ritual settings and the shared religious customs of the ancient Mediterranean. In particular, I consider the form, function, and decoration of ceramic vessels from each cult site. Ceramic vessels are significant because they offer evidence for ritual activity that otherwise does not survive in the archaeological record. By examining the pottery from these sanctuaries, I analyze the shared or different ritual practices at each site and look at how these customs influenced each other through patterns of exchange. The evidence from each sanctuary is significant for understanding the diversity of cultural practices in the ancient Mediterranean and understanding the cultural and political interactions between different subcultures in the broader region.Classical StudiesBachelors of Arts (BA
Iron Catalyst With Tetradentate Ligand For Electro- And Photocatalytic Hydrogen Evolution And Modified Photosensitizer For Toxic Metal Detection In Water
No full textAlternative energy sources need to be explored to prevent worsening impacts of climate change. Water splitting through artificial photosynthesis (AP) can produce hydrogen gas that can be used for energy. When hydrogen gas is burned to produce electricity, water is the only byproduct, making it a clean energy source. The reductive half reaction of AP to generate hydrogen consists of a catalyst, a photosensitizer, and a sacrificial electron donor. Established catalysts for hydrogen evolution integrate rare, expensive metals such as platinum, which would be unsustainable for scaling up photocatalytic hydrogen evolution. Our group developed an iron-based catalyst capable of generating hydrogen photocatalytically with both pure and impure, natural water sources. Our group has also attempted to modify our photosensitizers to enhance photocatalytic hydrogen production, but found that these adjustments are better suited for the fluorescence-based detection of toxic metals in water. High concentrations of toxic metals in drinking water are associated with health defects and premature deaths globally. Our modified photosensitizer can detect iron (III), palladium (II), aluminum (III), and molybdenum (V) below governmental regulatory limits. The modified photosensitizer shows potential in determining the safety of drinking water samples.ChemistryMaster of Science (M.Sc.
Vibrant Schools: Its Measure, Antecedents, And Correlates
Get PDFVibrant schools prioritize curiosity, creativity, playfulness, collaborative learning, critical thinking, individuality, and empathy, fostering an environment that respects the voices of teachers and students while reducing standardization (Clement et al., 2018; Clement et al., 2017; Tschannen-Moran & Clement, 2018). The purpose of this three-article dissertation was to understand the psychometric properties of Vibrant School Scale (VSS) and its relationship with efficacy constructs, trust, and wellbeing. Multi-stage clustered sampling was used to recruit 50 schools. 35 schools had more than five participants, which was required for multilevel analysis. In total, there were 495 teachers and leaders participating in the study. The first study validated the VSS with 19 items at the school level and three subscales at the individual level. The second study found strong correlations among efficacy constructs and vibrant schools. Teacher self-efficacy was found as a predictor at only the individual level while collective efficacy and leader self-efficacy contributed at the school level. The third study found strong correlations among faculty trust in students, faculty wellbeing, and vibrant schools. Vibrant schools significantly contributed to explaining faculty wellbeing while faculty trust did not contribute independently to the model. This dissertation, with its comprehensive analysis, elucidates the practical implications and benefits of fostering vibrancy in educational institutions. Collectively, these studies provide an in-depth and nuanced perspective on the characteristics that render schools vibrant, the processes by which they attain this state, and the positive outcomes they generate.EducationDoctor of Philosophy (Ph.D.
The Helicobacter pylori methylome is acid-responsive due to regulation by the two-component system ArsRS and the type I DNA methyltransferase HsdM1 (HP0463)
No full textIn addition to its role in genome protection, DNA methylation can regulate gene expression. In this study, we characterized the impact of acidity, phase variation, and the ArsRS TCS on the expression of the Type I m6A DNA methyltransferase HsdM1 (HP0463) of Helicobacter pylori 26695 and their subsequent effects on the methylome. Transcription of hsdM1 increases at least fourfold in the absence of the sensory histidine kinase ArsS, the major acid-sensing protein of H. pylori. hsdM1 exists in the phase-variable operon hsdR1-hsdM1. Phase-locking hsdR1 (HP0464), the restriction endonuclease gene, has significant impacts on the transcription of hsdM1. To determine the impacts of methyltransferase transcription patterns on the methylome, we conducted methylome sequencing on samples cultured at pH 7 or pH 5. We found differentially methylated motifs between these growth conditions and that deletions of arsS and/or hsdM1 interfere with the epigenetic acid response. Deletion of arsS leads to altered activity of HsdM1 and multiple other methyltransferases under both pH conditions indicating that the ArsRS TCS, in addition to direct effects on regulon transcription during acid acclimation, may also indirectly impact gene expression via regulation of the methylome. We determined the target motif of HsdM1 (HP0463) to be the complementary bipartite sequence pair 5′-TCAm6AVN6TGY-3′ and 3′-AGTN6GAm6ACA-5′. This complex regulation of DNA methyltransferases, and thus differential methylation patterns, may have implications for the decades-long persistent infection by H. pylori.Biolog
Mercury Most Fowl: A Meta-Analysis on the Effect of Mercury on Avian Reproduction
No full textMercury is a ubiquitous pollutant that is commonly found in aquatic food chains, accumulating as it moves up trophic levels (Malcolm, 2012). It enters the food web in plants and bacteria and moves up as it is eaten, ending up in the blood and tissue of birds and other top predators. Such biomagnification is not in question, as there have been countless studies on the accumulation of mercury in avian species, but its impacts are still debated (Whitney & Cristol, 2017). While mercury is toxic to life at high concentrations, there is a gap in the scientific literature on the sublethal effects of mercury on birds. Songbirds have been largely ignored as subjects of mercury exposure as they are a part of terrestrial food webs, while mercury pollution is best known from aquatic systems (Cristol et al., 2008). Recent findings of high levels of mercury in songbirds, however, suggest that the invertebrates they consume and feed to their young contain mercury. Because most birds are songbirds (Rosenberg et al., 2019), it is important to know how this large, understudied taxon is affected by mercury exposure. There are a variety of studies examining the effects of mercury on aquatic birds, but the results are often inconclusive or contradictory (Ackerman et al., 2008; Evers et al., 2008). Papers examining the effects of mercury on songbirds are even more inconclusive, particularly in the realm of reproductive effects (Whitney & Cristol, 2017). In order to determine whether mercury affects reproduction in birds across both aquatic and terrestrial habitats, all of the available published literature was gathered on the effects of mercury on bird hatching and fledging. Since mercury has known effects on reproduction on animals (Wolfe et al., 1998) and reproductive success is critical to conservation (Cummings, 2016), the scope of this project was limited to studies on reproductive endpoints. A meta-analysis was performed on all published articles and theses containing data on mercury levels along with hatching and/or fledging success. Results of this meta-analysis showed a statistically significant negative impact of mercury on hatching success in terrestrial birds, but no effect on hatching in aquatic birds. The heterogeneity in fledging success was not explained by mercury levels or habitat (aquatic vs. terrestrial). Further research or a more thorough and inclusive meta-analysis is needed to determine the effect of mercury on reproductive behaviors and physiological factors.Computational & Applied Mathematics & StatisticsBachelors of Science (BS