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Ductility of Steels Listed in AISI S100-16 Supp. 2 - 2020
No full textThis listing provides a database summarizing the ductility of all steels listed in AISI S100-16 with Supplement 2 - 2020.N/
SELECTIVE HIGH SCHOOL ADMISSIONS AND EFFECTS: HOW SCHOOLS SHAPE STUDENTS’ HIGH SCHOOL AND POSTSECONDARY DESTINATIONS
No full textAmong the various types of high schools within urban school districts are selective high schools, open enrollment schools that select the students they enroll through competitive admissions processes. Demand for these schools may be largely related to their college preparatory missions as well as their higher mean academic and college-going outcomes compared to other schools within their districts. Building upon prior literature that has examined selective high schools’ effects, this dissertation uses administrative data from a large, urban school district along with multiple large-scale educational datasets, to conduct three studies that center selective high schools in analyses of school effects on students’ academic outcomes. The first study focuses on entry into selective high schools by examining middle grades schools’ effects on students’ eligibility for admission to selective high schools. The following two studies focus specifically on selective career and technical education (CTE) high schools, which offer CTE courses to all of their students with the goal of preparing them for the workforce and postsecondary educations, to investigate their effects on students’ college readiness. Findings from the second study suggested that the schools are only significantly — and negatively — associated with two of three indicators of college readiness. Following this, the third study found no causal effects of selective CTE high schools on students’ college enrollment. Findngs from these studies provide a nuanced understanding of schools’ effects on student trajectories from middle school to college
TESTING THE BRAAK HYPOTHESIS BY INVESTIGATING THE MOLECULAR MECHANISMS BY WHICH ALPHA-SYNUCLEIN AGGREGATES CAN BE TRANSPORTED ALONG THE VAGAL SENSORY NEURONS AND WHAT MODULATES THIS TRANSPORT
No full textLewy bodies composed by alpha-synuclein (α-syn) aggregates may be found in the gut of PD patients before they present in the brain, consistent with Braak’s hypothesis of centripetal transmission of Parkinson’s disease (PD). It was recently shown that trans neuronal propagation of pathologic a-synuclein from the gut to the brain can result in PD in mice. However, the neuronal pathways from the gut to the CNS have yet to be fully understood. Although it is widely believed that vagal motor neurons are involved, sensory fibers are more logical candidates for such transport. We therefore hypothesized that pathological α-syn aggregates originating in the gut are taken up by the vagus sensory nerve terminals in the gut and transported by specific motor proteins in the vagus sensory nerve to the brain. Our aim was to study the axonal transport of α-syn aggregates along the vagal sensory neurons. In our study, a successful in vitro model of the polarized vagal sensory neurons was established. In this model, the cultured vagal sensory neurons were able to take up and transport α-syn preformed fibrils (PFF) without exhibiting overt toxicity. In addition, fluorescently tagged PFF injected in the gut of the mice were observed in the vagal sensory ganglia (nodose) 5 weeks post injection, which evidenced the role of the vagal sensory neurons in transportation of α-syn. Two molecular motors, kinesin, and dynein were identified via immunoprecipitation for transporting α-syn aggregates along the vagus nerve. Electrical stimulation sped up the transportation of α-syn aggregates along the cultured vagal sensory neurons, revealing the activity-dependent nature of α-syn transportation. This study contributed significantly to understanding the gut-centric PD pathogenesis and paved the way for developing novel therapeutics to prevent the progression of the gut-centric PD
DEVELOPMENT OF NEW METHODS FOR MATERIALS SCIENCE: TO ACCELERATE SIMULATIONS AND AUTOMATE ANALYSIS OF EXPERIMENTAL DATA
No full textHigh-throughput simulations and characterization are essential for accelerating material development and reducing lab-to-market time. Considerable efforts have been devoted to the development of new algorithms and techniques to reduce the computational costs of materials simulations and streamline the quantitative analysis of experimental data, leveraging the latest advances in theories of material computation and machine learning paradigms. This thesis exemplifies such efforts in three projects.
The first project develops a set of algorithms for the dynamic generation of optimized generalized Monkhorst-Pack k-point grids, which were shown to be capable of greatly reducing the computational costs of electronic structure calculations of crystalline materials. The new set of algorithms reduces the computational overhead in the search for efficient grids and eliminates the need for a pre-generated database by transforming the problem from an enumeration of three-dimensional superlattices to an enumeration of two-dimensional superlattices and a small set of symmetry-permitted shifts. A lightweight C++ library with a Python interface and a stand-alone Java application are developed for integration with existing DFT software.
In the second project, a program is developed to accelerate the structure search of stable nanoclusters using machine-learned interatomic potentials and active learning. Interatomic potentials are updated on-the-fly during the exploration of the configuration space with DFT calculations on extrapolating structures and low-energy clusters in the genetic pool at each retraining stage, which guarantees accuracy of the final reported structures. Using this approach, new lowest-energy isomers of elemental aluminum clusters were found for 25 out of the 35 studied sizes.
The third project involves developing a program to automate the characterization of X-ray Phase Contrast Imaging (XPCI) of particles emitted from metal composite combustion. The program automates the laborious manual characterization process and provides statistical analysis of particles. It consists of three stages: particle detection, trajectory reconstruction, and property analysis. Gaussian mixture model and convolutional neural networks are evaluated for particle detection, while the Kalman filter is used for trajectory reconstruction. A shape detection procedure classifies particles based on their shapes, leveraging classic computer vision algorithms. Finally, a graph data structure is employed to identify complex events like microexplosions and collisions
A COLLECTION OF PERSONAL ESSAYS
No full textOriginally from Uganda, Ongwen writes about her experience relocating to America and the disorientation when she returns home to her country of birth and finds she does not fit—she has changed. In this essay collection, Ongwen also explores gender dysphoria with her preteen daughter. She chronicles a mother’s grief after a miscarriage and the challenge with fibroids. These personal essays shed light on her life as a woman, a mother and a Ugandan raising a family in America
SHORT CHATS WITH SPACE CATS
No full textThe “chats” in this thesis assume a variety of forms. These forms include flash nonfiction, essay, profile, and Q&A. One subject—space exploration—unites them. But space exploration does not happen in a vacuum. Not entirely, anyway. What also unites these forms are the “space cats,” the people behind the discovery and innovation, the conduits for our knowledge and wonder. These are educators, engineers, astrobiologists, and historians. Carla Johns, who occupies the first pages in “Medium of the Light Bucket,” exemplifies what I mean by conduit: “At Griffith Observatory in Los Angeles, photons spoke to Johns through telescopes, and Johns spoke to hundreds of people every night as she fielded questions about black holes, quasars, binary stars.” Johns, like the others in the pages of this thesis, illuminate our reality with the tool of science. My goal, in turn, is to illuminate these space cats with the tool of writing
Hegel and Spinoza on Freedom and Right
No full textIn this dissertation, I aim to explore Hegel’s political thought from a novel perspective, and even suggest that it may have unrecognized origins. In particular I propose that, as in his theoretical philosophy, Hegel can productively be read as navigating a prominent Spinozist challenge in his practical philosophy, too. Understood as such, Hegel appears both less liberal and more compelling as a political thinker than otherwise, I suggest. By ‘liberal’ I mean here a tendency emphasizing the freedoms and rights of the individual. In trying to clarify a neglected philosophical dialogue between Hegel and Spinoza, who I argue are both keen to think about politics from a more social perspective—and who will then ultimately emphasize the freedoms and rights of the community in at least a number of key cases, on my interpretation—I contribute to current scholarship not just by outlining how Hegel came to engage Spinoza’s Theological-Political Treatise at the very beginning of his philosophical career, but also primarily by reconstructing and negotiating Hegel’s and Spinoza’s relevant views in tandem (along with those of several related thinkers).
Spinoza’s political thought has been relatively neglected by historians of philosophy working in the Anglophone context, and thus there is already significant work to be done here. Across the four chapters of this dissertation, I aim to provide a deeper account of some of Spinoza’s political-philosophical views than is normally on offer, in order to then illustrate how Hegel may be seen as responding to Spinoza, which in turn always requires an interpretation of Hegel’s views on some given matter in each case. For instance: several studies have recently emerged focusing on what views Spinoza may have held concerning a right of revolution; but drawing upon claims developed throughout the dissertation concerning Hegel’s and Spinoza’s expressivist notions of freedom and their realist notions of right, I reject in a final chapter prominent interpretations of Spinoza’s views on the matter, and suggest that Spinoza indeed offers a qualified right of revolution—all to the end of then showing how Spinoza anticipates Hegel in this respect, where I must again carefully position my interpretation among others who have demurred here.
In short, I argue in this dissertation that Hegel’s political philosophy is better understood, and reveals itself to be more progressive, when reconstructed as responding at least partly to Spinoza’s. I conclude with an Epilogue showing, on the basis of at least one prominent and neglected case—that of Martin Luther King, Jr.—how framing Hegel’s thought as I do in this dissertation also allows us to get a better grasp on important but neglected later engagements with it
TRACHEOSTOMY-RELATED PRESSURE INJURY DURING THE COVID-19 PANDEMIC
No full textBackground: Tracheostomy-related pressure injuries (TRPI) are a significant concern in the care of critically ill patients, leading to increased morbidity, hospital costs, and decreased quality of life. Furthermore, the COVID-19 pandemic has posed unique challenges in tracheostomy care. This study aims to identify key risk factors for TRPI and understand the impact of the COVID-19 pandemic on tracheostomy care.
Methods: A large-scale, multi-center, observational study of secondary electronic medical record (EMR) data was conducted to analyze the incidence and risk factors of TRPI. Records of encounters from 1 January 2019 to 31 December 2021 were included. Data were harmonized
from two different sources: the Global Tracheostomy Collaborative database and the Johns Hopkins hospital system EMR. Adults and children with a tracheostomy were analyzed
separately. Three-level multivariate logistic regression models were used to identify factors associated with TRPI incidence accounting for within-patient and within-hospital correlations.
Results: The primary analysis included 6,026 adult and 2,279 pediatric records from 27 hospitals, primarily from the United States, the United Kingdom, and Australia. ICU admission and increasing age and length of stay up to 60 days were common predictors of TRPI in adults
and children. Among adults, severe obesity, female sex, cuffed and fenestrated tracheostomy,
percutaneous insertion technique, and COVID-19 infection were positively associated with TRPI. In pediatric patients, diabetes mellitus and FlexTend tracheostomies were additionally associated with TRPI. COVID-19 pandemic-related factors demonstrated contrasting effects on
TRPI incidence in adult and pediatric populations. Hospital and patient-level cluster effects explained a substantial amount of model variance, highlighting the importance of unmeasured
factors such as local hospital practices.
Conclusion: This study provides crucial insights into the risk factors associated with TRPI and the effects of the COVID-19 pandemic on tracheostomy care. The findings can inform targeted
interventions to reduce TRPI incidence and improve tracheostomy care in future public health crises. An enhanced understanding of TRPI will ultimately contribute to better patient
outcomes, optimized resource allocation, and improved quality of life for those requiring tracheostomy
ANIMALS THAT SING
No full textIn Animals that Sing, I try to make sense of my place on our planet through my jaw-dropping astonishment for “the least of these.” For birds and bats and whales that sing. For monarchs who, with their inexplicable instinct, migrate despite having fewer and fewer places to land. For the humans making gorgeous games about butterflies and climate change and species extinction to remind us we can learn hard things, and sometimes change, when we remember how to play. For exquisitely housed mollusks who slurp each other alive with rasp-riddled suck-tongues. For dandelions who grow despite other’s efforts to extinguish them. And for myself, as it is my dumbfounded reverence for life that has kept me afloat through all of its joys and heartbreaks. I humbly attempt to amplify their voices with mine
GILDING LILY: THE SEARCH FOR HAPPINESS
No full textThis collection of work centers on my struggles with treatment-resistant depression and my exhaustive search for cures. I have been depressed as far back as my autobiographical memory goes—but I have also experienced tremendous joy. I look for ephemeral glimmers of happiness in my children, substances, a new form of magnetic brain stimulation, nature, sleep, humor, music, movement, God, the psychedelics psilocybin and ketamine, and electricity itself. I search for those flashes of lightness and euphoria, hoping to triangulate, capture, and hold them. I process my emotions through my experiences, therapy, and writing, whose boundaries sometimes blur.
I examine these issues through the lenses of multiple selves: scientist, writer, mother, journalist, advocate, and patient. At times, my work contrasts my disease with my immense privilege. Gilding Lily is a meditation on motherhood, femininity, illness, and hope. These essays explore how selves are both warped by tragedy and repaired with words