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BARRIERS AND OPPORTUNITIES IN ACHIEVING WASHINGTON STATE’S TARGET OF A 100 PERCENT CLEAN ENERGY GRID BY 2045
Get PDFThis study examines barriers and opportunities in Washington State’s transformation to a clean electric grid by 2045. It includes a review of background information needed to understand the electric system in the region such as the current energy mix, infrastructure, and utility setup, as well as how the region is changing due to climate impacts and increasing energy demand. It describes the state’s Clean Energy Transformation Act, which is driving the transition, and its interaction with the state’s Climate Commitment Act, which covers emissions from all sectors. Barriers to the transition include a jurisdictional mismatch between state lines and electric service areas, unspecified energy purchases that cross state boundaries, transmission constraints, and a huge need for new renewable energy resources and balancing technologies. However, these challenges present opportunities for greater grid flexibility and resilience, equity, and regional collaboration in addition to greenhouse gas reductions and cleaner air. The study concludes with a discussion of policy successes, failures, and unresolved issues, and recommends further policy actions for Washington’s legislature to consider
HEAVEN’S DOOR: CHAPTERS ONE THROUGH SIX
No full textWhat happens to an Ivy League grad bent on discovering the bohemian world of arts and music when he hitchhikes to the Klondike while his father—a wealthy mining lobbyist on his deathbed—waits for him to return home and take over the family business?
Jeffrey Woodward's worldview is turned upside down in the remote Northwestern Canada of the early 1980's as he witnesses the slow but steady demise of a world’s last pristine wilderness and its indigenous inhabitants by the forces of greed and ignorance
Opportunities to Mitigate Climate Change’s Impact on Satellite Operations
Get PDFClimate change in the upper atmosphere has important implications on the debris environment and the safety and security of satellite operations in low Earth orbit (LEO). Higher carbon dioxide concentrations cool and contract the upper atmosphere and reduce orbital drag, causing orbital debris and other uncontrollable space objects to remain in orbit for longer. The increase in the orbital lifetime of space debris both raises the density of orbital pollution in LEO and the risk of on-orbit collisions between satellites and debris, threatening the ability to leverage space for critical economic, scientific, and national defense purposes.
The international community has relied on multilateral and non-binding guidelines to promote more sustainable space operations that reduce the generation of additional debris. These measures have been unable to arrest the growth of orbital and are inadequate to regulate a space operational environment increasingly dominated by larger satellite megaconstellations. The aim of this study was to identify current debris mitigation policies, measure their level of effectiveness, and establish a set of comprehensive policies, financial frameworks, and technical capabilities that could be tailored to mitigating and remediating space debris in LEO
EXPERIMENTS AND EXPERIENCES: CURRENT ISSUES IN SCIENCE AND MEDICINE
Get PDFIn this anthology, I explore topics in human health or nature by connecting individual experiences and ideas to larger stories of what's happening in the world around us. My work contains reported articles, creative nonfiction essays, and opinion pieces. From migraines, microbes, and medicines to Venus flytraps and vanishing lakes, this collection illustrates how scientific research and personal narratives complement each other and highlight the needs and means for positive change
Machine Learning-Accelerated Structure Characterization for Advanced Materials Design
No full textThis thesis primarily focuses on integrating first-principles calculations with machine learning (ML) algorithms to accelerate materials modeling and characterization.
In the simulation realm, this thesis includes research that applies (time-dependent) density functional theory (TD)DFT across various materials, enabling the calculation of their structures and Electron Energy Loss Spectroscopy (EELS) and X-ray Absorption Spectroscopy (XAS) profiles. This includes exploring chemisorption of gases, which has provided detailed insights into adsorbate electronic structures, thereby enriching our understanding of chemisorption processes and advancing EELS applications in nanostructured surface characterization, especially in catalysis. My study on hydrogen doping in VO2 has demonstrated an effective method for the quantitative mapping of dopant distribution in quantum materials, providing pivotal insights for the design of future neuromorphic devices. Another significant aspect of my research is the investigation into alkali-metal-doped MnOx-CeO2 passive NOx absorbers. Through comprehensive DFT simulations, we have unraveled the structure of this novel material and its intricate mechanisms of NOx absorption and release, contributing significantly to advancements in low-temperature combustion and emissions control.
On the ML front, a tailored method based on non-negative robust principal component analysis has been developed to overcome challenges in traditional EELS spectral imaging, such as noise reduction and spectral deconvolution. This advancement facilitates the characterization of nanomaterial systems with improved spatial-temporal resolution and signal-to-noise ratios, revealing intricate details about their structural, chemical, and electronic properties. Further extending the scope of my work, I have integrated multimodal ab initio simulations with ML for structure characterization. Leveraging XAS/EELS data across multiple elements, we have successfully predicted local structures and properties in complex materials such as lithium nickel manganese cobalt oxide compounds. Our multimodal approach not only boosts accuracy in characterization but also strengthens noise resilience and enhances the analysis of complex constructs, which single data sources struggle to capture precisely.
Overall, this thesis pioneers new methodologies in material characterization by synergizing spectroscopic analysis, theoretical insights, and machine learning. This multidisciplinary framework significantly enhances our understanding of nanoscale material properties and paves the way for innovative materials design, marking a significant leap forward in materials science
Expanding Nature's Toolbox: Unlocking Novel Synthetic Mechanisms in Biology Through Evolutionary Protein Design
No full textThe quest to expand the catalytic repertoire of enzymes beyond their natural functions has led to the emerging field of engineering enzymes for new-to-nature chemistry. This ambitious endeavor involves redesigning and repurposing natural enzymes to catalyze reactions not found in biological systems, thereby unlocking novel pathways for synthetic chemistry. In recent years, biomimetic catalysis and directed evolution have become pivotal strategies in engineering enzymes for new functions. Biomimetic approaches draw inspiration from nature's catalytic machinery, mimicking enzymatic reactions and substrate activation. On the other hand, directed evolution harnesses the power of iterative mutation and selection to optimize enzyme performance, enabling the evolution of catalysts with tailored activities.
This thesis details the systematic expansion of nature’s catalytic repertoire and to uncover enzymes capable of catalyzing reactions traditionally considered beyond the scope of biological systems. Chapter I chronicles the discovery and engineering of svHPPE, a non-heme iron enzyme to asymmetrically catalyze the formation of C-F bond via a redox radical relay enzyme system. Chapter II describes the discovery and evolution of aoHMS for the catalysis of regioselective and enantioselective C(sp3)-H azidation via a deconstructive radical ring opening process. Chapter III details the machine learning assisted engineering of aoHMS toward a chemodivergent selective variant for both C-F bond and C-N3 bond formation.
Overall, the work presented in this thesis expands the repertoire of reactions that can be catalyzed by non-heme iron enzymes and demonstrates the bridging of the expansive catalytic scopes of synthetic chemistry while harnessing the robust selectivities that enzymes uniquely offer. The ultimate goal is to apply these biocatalytic tools to a broader spectrum of transformations that align with the diverse and evolving interests of the scientific and industrial communities
WHEN IT HAPPENS A NOVEL EXCERPT
Get PDF“Hailing a Taxi in Hamamatsu, and Others” is a collection of short stories centered around the macabre, and the notion that there truly is something lurking in the shadows. In this collection, author Natalie Matheny explores the world of literal and figurative ghosts. Each of the stories in this collection present a protagonist struggling with their own inner demons, while simultaneously trying to make sense of unexplainable and supernatural events. The second piece of this collection, “When It Happens”, is an excerpt from a larger work of fiction. Four strangers from vastly different walks of life are brought together by a sudden catastrophic event that sends the world into havoc, and forces the strangers to acknowledge the creatures that lie within the folds of our perceived understanding.
Both parts of this thesis aim to interweave supernatural elements while challenging the boundaries of what it means to be human
MYCOBACTEROIDES ABSCESSUS IN THE TWENTY-FIRST CENTURY: RESPONSE TO NOVEL AGENTS AND MYCOMEMBRANE STRESS IN BIOFILMS
Get PDFMycobacteroides abscessus (M. abscessus or Mab), formerly Mycobacterium abscessus, is an environmental nontuberculous mycobacterium and a causative pathogen described as an “antibiotic nightmare” of pulmonary and soft tissue infections due to its intrinsic resistance to first-line treatments. Seventy-four years have elapsed since the microbe first debuted in modern science and there is still much to learn about this mysterious “clinical nightmare”. Treatment outcomes remain poor and recent developments in mycobacterial metabolomics, mycomembrane characterization, and biofilms highlight the large gaps in knowledge of the basic mechanisms of Mab physiology, virulence, and drug susceptibility under the current disease paradigm.
This work explores the perplexing physiology of Mab and the unresolved challenges the pathogen presents in the clinical setting. With the objective to making valuable contributions towards our understanding of Mab pathobiology and developing data-driven antimicrobial chemotherapies, Chapter One showcases early preclinical testing of omadacycline, a novel tetracycline derivative, for the treatment of pulmonary Mab disease and represents a thorough example of antimicrobial stewardship research undertaken amid the ongoing AMR crisis. Chapter Two showcases a biofilm model that explores Mab pathophysiology in the characterization of the mycomembrane and extracellular matrix response to genetic deletion of an atypical peptidoglycan target: the L,D-transpeptidase enzyme. Lastly, Chapter Three surveys biofilm-formation capabilities and compositions of a Mab subspecies abscessus clinical isolate library in search of the clinical significance of the biofilm phenotype. In all, this work provides a review of the pressing challenges and novel avenues available to explore in twenty-first century investigations into the pathobiology and treatment of Mab
SYNAPTIC VESICLE RESOLUTION
Get PDFNeurotransmitter is released from dedicated sites of synaptic vesicle fusion within a synapse. Following fusion, vacated sites are rapidly replenished by new vesicles. These replacement vesicles are assumed to be located near release sites and used stochastically. Here, we find that replacement vesicles are clustered around this region by Intersectin-1 (Itsn1). Specifically, Itsn1 forms molecular condensates with Endophilin A1 (EndoA1) and sequesters vesicles near release sites. Without Itsn1, the number of vesicles within 20 nm of the plasma membrane is reduced, and consequently, vacated sites cannot be replenished rapidly, leading to synaptic depression. Mutations in Itsn1 that disrupt EndoA1 binding result in similar phenotypes. In the absence of Endophilin, this replacement pool of vesicles is available but cannot be accessed, suggesting that EndoA1 is needed to mobilize these vesicles. Thus, our work describes a region within a synapse where replacement vesicles are harbored for release site replenishment.
Following exocytosis, compensatory endocytosis maintains the membrane surface area of secretory cells. At chemical synapses, ultrafast endocytosis maintains such homeostasis. This endocytic pathway is spatiotemporally coupled to exocytosis; it initiates within 50 ms at the region next to the active zone where vesicles fuse. However, the coupling mechanism is unknown. Here, we demonstrate that filamentous actin is organized as a ring, surrounding the active zone at mouse hippocampal synapses. Assuming the membrane area conservation is due to this actin ring, our theoretical model suggests that flattening of fused vesicles exerts lateral compression in the membrane, resulting in rapid formation of endocytic pits at the border between the active zone and the surrounding actin-enriched region. Consistent with this model, our data show that ultrafast endocytosis requires sufficient compression by exocytosis of multiple vesicles and does not initiate when actin organization is disrupted, either pharmacologically or by ablation of the actin-binding protein Epsin1. Our work suggests that membrane mechanics underlie the rapid coupling of exocytosis to endocytosis at synapses. Finally, I look at correlative light and electron microscopy technologies that will elucidate synaptic processes by enabling localization of molecules at the ultrastructural level. Together, my work focuses on the resolution of intermediate synaptic vesicle states
SEASONS OF CHANGE: REFLECTIONS ON WORLDS IN FLUX
No full textThis collection of writing—made up of personal essays, nature writing, features, a braided essay, a news article, and even a short fiction piece—explores worlds in flux against the backdrop of climate change, rapid development, personal growth, pandemics, and more. It delves not only into the seasons we experience in a calendar year, but the shifts, both monumental and barely perceptible, that we encounter in our lives and in the world around us