Noninvasive Ventilation Protocol Development

Endotracheal intubation results in many serious complications including regurgitation, vocal cord paralysis, and death. Noninvasive ventilation using bi-level positive airway pressure has been shown to provide the necessary support without intubation and is also associated with better outcomes if trialed prior to endotracheal intubation. A noninvasive ventilation protocol was applied in a rural acute care facility. Results: The average length of stay for acute respiratory failure decreased from 5.32 to 4.44 days, while intubations fell from 41.9% to zero, and mortality fell from 9.7% to zero during the pilot period. Five cases met criteria for noninvasive ventilation, and three received prompt intervention with lengths of stay of two to four days. One did not have CO2 levels assessed upon admission resulting in delayed noninvasive ventilation, and a twelve-day stay. The fifth refused the therapy and was discharged on hospice

Making the Journey Personal: A Self-Study of the Intersections of Curriculum, Practice, and Identity

The Obama\u27s unveiled their official portraits for the National Portrait Gallery in 2018, forever changing the presidential tone by being the first portraits of Black Americans in these roles but also because they selected two Black artists to depict them, Kehinde Wiley and Amy Sherald. As a White woman, secondary school art educator of diverse students, I witnessed this event as a significant moment in time. Discussing what was immediately visible: portraiture, compositional formats, and use of pattern, but I was unsure how to connect the layered meanings of each portrait. As a veteran teacher, I had implemented different curricula yet had questioned what and how I taught influenced by my White identity. Ongoing growth needed to continue around social justice work and inequities by examining how identity intertwined with curriculum and pedagogy. This led to a qualitative inquiry of my curriculum choices and pedagogical practices to (a) document curriculum choices and pedagogical practices, and (b) analyze this data to identify affordances, limitations, and tensions. The study pulled from postmodernism augmented by critical art pedagogy, critical social justice, and critical whiteness. The self-study, in combination with an arts-based methodology, focused on Titus Kaphar, a contemporary artist who addressed racial inequities in their art. Interweaving self-study reflections with collages facilitated unpacking layers of my identity through vulnerability and listening to what was spoken as much as to what was unsaid. Across multiple rounds of coding, three intersections emerged in response to the research questions: identity/curriculum, identity/practice, and identity/artmaking. Learning how my White identity informed each intersection proffered a lens on biases and colorblindness. This study served to remind me that as I continue to challenge the presence of my Whiteness, my biases, and my colorblindness with critical humility –– it is a journey, not a destination

Geospatial and genomic tools for conserving the Critically Endangered blue-eyed black lemur (Eulemur flavifrons) and the sportive lemurs (genus Lepilemur)

Madagascar’s lemurs are the most endangered group of mammals in the world, with 94% of species threatened with extinction. Forest loss is one the greatest threat to these arboreal primates, but hunting, habitat degradation, and climate change also threaten their survival. Lemurs are a diverse group of more than 100 species; and their ecological traits shape how species respond to anthropogenic pressure. Incorporating knowledge of species’ ecological niches and evolutionary histories can contextualize threats and improve conservation assessments. In this dissertation, I investigate what constitutes suitable habitat for lemurs in light of the threats present, their sensitivity to forest fragmentation, their dispersal ability, and their ecological uniqueness. I obtained data about lemur distributions in two ways. First, I conducted field surveys of the Critically Endangered blue-eyed black lemur (Eulemur flavifrons), which only occurs in the ecotone between eastern rainforest and western dry forest in the Sahamalaza region. I also surveyed the range of sister species, the black lemur (E. macaco), which inhabits nearby eastern rainforest in the Manogarivo region. I focused on areas that have not been surveyed recently and on the poorly studied boundary between the species to collect observations from the breadth of these species’ ecological ranges. I also documented threats, including incursions into protected areas, and collected fecal samples to test whether whole genomes could be obtained noninvasively for analyses of local adaptation in these species. Second, I searched online databases and published literature for GPS localities for all species of lemur. I used these records, along with the ones collected in the field, to construct ecological niche models for nearly all species of lemur using Maxent. For the blue-eyed black lemur and the black lemur, I estimated the remaining area they can occupy based on these models and the threat survey data. Next, I examined the role of not just forest loss, but forest degradation, in determining where lemur species occur. I used high-resolution forest cover maps to determine lemurs’ tolerance for characteristics of degraded forest, including distance to the edge and mean patch size. I then limited species niche model to only intact, forested habitat. Lastly, using the sportive lemurs (genus Lepilemur) as an example, I evaluate how the inability to disperse across large rivers has influenced ecological niche diversity. I also examine what limited dispersal ability will mean for these species as climate change causes their ranges to shift. Field surveys in the Sahamalaza and Manongarivo regions revealed extensive threats to blue-eyed black lemurs, from traps to cattle incursions and fire. I found no evidence of sympatry, but did locate an undocumented population of E. flavifrons north of the Andranomalaza River. Madagascar National Parks (MNP) managed protected areas appear to have less human incursion than NGO-managed protected areas. Further investigation of the ecological distinctiveness of these species is possible via non-invasive methods: I sequenced whole genomes at 2.3x coverage from eight of the fecal samples collected during this study. While SNPs indicating a loss of function did not reveal any patterns, sequencing additional samples could make studies of local adaptation and population genetic diversity possible. At the regional scale, forest conversion is a grave threat to lemurs. When forest loss and degradation are considered in habitat models, lemur species have lost 51% of their habitat in the last 30 years. Proximity to a forest edge rendered more forested areas too degraded for lemurs than did mean patch size. This result is likely the influence of human contact nearer the forest edge. I recommend urgent support for reserves like Beanka, Tsimembo Forest, Ranobe PK 32, and Amoron’i Onilahy, which have highly suitable, intact forest for many lemur species. Spaces like these will be important for conserving the remarkable diversity within the sportive lemur clade. Though their distribution is largely explained by riverine barriers, I show a role for ecological niche divergence and local adaptation in accelerating allopatric speciation. These same rivers will limit their ability to track climatically suitable areas as climate change progresses: sportive lemurs as a group will lose nearly a quarter of their accessible habitat to climate change by the 2070s. While my results are focused on the particulars of lemur conservation in Madagascar, the methods I have presented here are broadly applicable to other threatened species. Piggybacking fecal sample collection onto rapid field surveys is straightforward. The possibility of obtaining whole genomes from non-invasive samples presents a new way to answer questions about local adaptation without risking injury to other arboreal study subjects, like Neotropical monkeys, or for elusive species like big cats. For threatened species, their climatic niche only dictates part of their distribution. The habitat quantification pipeline presented here takes advantage of thirty-five years of research in Madagascar to estimate species’ tolerance for forest fragmentation. While these records are impressive for primates, they are dwarfed by those available for passerines, through scientific literature and online repositories like eBird. By integrating field surveys, ecological niche modeling, and non-invasive genomics, we can begin to understand the complex threats facing species like lemurs and the options for ensuring their survival

Quantum Oscillations in Cux_xBi2_2Se3_3 in High Magnetic Fields

Cu$_x$Bi$_2$Se$_3$ has drawn much attention as the leading candidate to be the first topological superconductor and the realization of coveted Majorana particles in a condensed matter system. However, there has been increasing controversy about the nature of its superconducting phase. This study sheds light on present ambiguity in the normal state electronic state, by providing a complete look at the quantum oscillations in magnetization in Cu$_x$Bi$_2$Se$_3$ at intense high fields up to 31T. Our study focuses on the angular dependence of the quantum oscillation pattern in a low carrier concentration. As magnetic field tilts from along the crystalline c-axis to ab-plane, the change of the oscillation period follows the prediction of the ellipsoidal Fermi surface. As the doping level changes, the 3D Fermi surface is found to transform into quasi-cylindrical at high carrier density. Such a transition is potentially a Lifshitz transition of the electronic state in Cu$_x$Bi$_2$Se$_3$.Comment: 6 pages, 6 figures, submitted to Phys. Rev.

Bulk Rotational Symmetry Breaking in Kondo Insulator SmB6

Kondo insulator samarium hexaboride (SmB6) has been intensely studied in recent years as a potential candidate of a strongly correlated topological insulator. One of the most exciting phenomena observed in SmB6 is the clear quantum oscillations appearing in magnetic torque at a low temperature despite the insulating behavior in resistance. These quantum oscillations show multiple frequencies and varied effective masses. The origin of quantum oscillation is, however, still under debate with evidence of both two-dimensional Fermi surfaces and three-dimensional Fermi surfaces. Here, we carry out angle-resolved torque magnetometry measurements in a magnetic field up to 45 T and a temperature range down to 40 mK. With the magnetic field rotated in the (010) plane, the quantum oscillation frequency of the strongest oscillation branch shows a four-fold rotational symmetry. However, in the angular dependence of the amplitude of the same branch, this four-fold symmetry is broken and, instead, a twofold symmetry shows up, which is consistent with the prediction of a two-dimensional Lifshitz-Kosevich model. No deviation of Lifshitz-Kosevich behavior is observed down to 40 mK. Our results suggest the existence of multiple light-mass surface states in SmB6, with their mobility significantly depending on the surface disorder level.Comment: 15 pages, 9 figure

Gas Phase Efficiencies on Distillation Trays

Chemical Engineerin

Froth Formation above Distillation Trays

Chemical Engineerin

Magnetic Field Enhanced Superconductivity in Epitaxial Thin Film WTe2.

In conventional superconductors an external magnetic field generally suppresses superconductivity. This results from a simple thermodynamic competition of the superconducting and magnetic free energies. In this study, we report the unconventional features in the superconducting epitaxial thin film tungsten telluride (WTe2). Measuring the electrical transport properties of Molecular Beam Epitaxy (MBE) grown WTe2 thin films with a high precision rotation stage, we map the upper critical field Hc2 at different temperatures T. We observe the superconducting transition temperature T c is enhanced by in-plane magnetic fields. The upper critical field Hc2 is observed to establish an unconventional non-monotonic dependence on temperature. We suggest that this unconventional feature is due to the lifting of inversion symmetry, which leads to the enhancement of Hc2 in Ising superconductors

Hysteretic Magnetotransport in SmB6 at Low Magnetic Fields

Utilizing Corbino disc structures, we have examined the magnetic field response of resistivity for the surface states of SmB6 on different crystalline surfaces at low temperatures. Our results reveal a hysteretic behavior whose magnitude depends on the magnetic field sweep rate and temperature. Although this feature becomes smaller when the field sweep is slower, a complete elimination or saturation is not observed in our slowest sweep-rate measurements, which is much slower than a typical magnetotransport trace. These observations cannot be explained by quantum interference corrections such as weak anti-localization. Instead, they are consistent with behaviors of glassy surface magnetic ordering, whose magnetic origin is most likely from samarium oxide (Sm2O3) forming on the surface during exposure to ambient conditions