ABOUT THIS COLLECTION

This open access archive contains publications from University of Arizona faculty, researchers and staff, primarily open-access versions of formally published journal articles. The collection includes published articles and final accepted manuscripts submitted by UA faculty under the UA Open Access Policy. The collection also includes books, book chapters, book reviews, presentations, data, and other scholarly materials submitters have chosen to make available in the repository.

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Recent Submissions

  • What Do Librarians Need to Know about Quantitative Methods in Digital Humanities?

    Froehlich, Heather; University of Arizona Libraries (Association of College & Research Libraries (ACRL), 2024)
  • Informed consent for artificial intelligence in emergency medicine: A practical guide

    Iserson, Kenneth V; Department of Emergency Medicine, The University of Arizona (Elsevier, 2023-11-25)
    As artificial intelligence (AI) expands its presence in healthcare, particularly within emergency medicine (EM), there is growing urgency to explore the ethical and practical considerations surrounding its adoption. AI holds the potential to revolutionize how emergency physicians (EPs) make clinical decisions, but AI's complexity often surpasses EPs' capacity to provide patients with informed consent regarding its use. This article underscores the crucial need to address the ethical pitfalls of AI in EM. Patient autonomy necessitates that EPs engage in conversations with patients about whether to use AI in their evaluation and treatment. As clinical AI integration expands, this discussion should become an integral part of the informed consent process, aligning with ethical and legal requirements. The rapid availability of AI programs, fueled by vast electronic health record (EHR) datasets, has led to increased pressure on hospitals and clinicians to embrace clinical AI without comprehensive system evaluation. However, the evolving landscape of AI technology outpaces our ability to anticipate its impact on medical practice and patient care. The central question arises: Are EPs equipped with the necessary knowledge to offer well-informed consent regarding clinical AI? Collaborative efforts between EPs, bioethicists, AI researchers, and healthcare administrators are essential for the development and implementation of optimal AI practices in EM. To facilitate informed consent about AI, EPs should understand at least seven key areas: (1) how AI systems operate; (2) whether AI systems are understandable and trustworthy; (3) the limitations of and errors AI systems make; (4) how disagreements between the EP and AI are resolved; (5) whether the patient's personally identifiable information (PII) and the AI computer systems will be secure; (6) if the AI system functions reliably (has been validated); and (7) if the AI program exhibits bias. This article addresses each of these critical issues, aiming to empower EPs with the knowledge required to navigate the intersection of AI and informed consent in EM.
  • Magical thinking: Its effect on emergency medical care

    Iserson, Kenneth V; Department of Emergency Medicine, The University of Arizona (Elsevier, 2023-07-26)
    Magical thinking is a cognitive process characterized by beliefs in supernatural causality and the power of rituals. Grounded in personal convictions rather than objective reality, it involves subjective beliefs rather than magic tricks. Magical thinking's effects range from potentially positive, such as bringing hope and comfort, to negative consequences, including delays in seeking appropriate medical care and refusing evidence-based treatments. This article provides an overview of magical thinking, including its prevalence, diverse forms, and influence on patients, families, and emergency physicians (EPs). This article offers guidelines for recognizing signs of magical thinking and emphasizes the importance of respectful and empathetic interactions with patients and their families. Highlighting both the benefits and detriments of magical thinking in Emergency Medical (EM) care, the article discusses the knowledge and tools needed to optimize patient outcomes. It acknowledges the varying belief systems and cultural practices that contribute to the prevalence of magical thinking. For physicians and other EM professionals, addressing magical thinking requires cultural competence and empathetic engagement. Active listening and shared decision-making are essential to promote positive patient outcomes. By recognizing and understanding magical thinking and fostering effective communication, EPs can navigate the delicate balance of addressing patients' beliefs while delivering evidence-based care.
  • Orchestrating the critical: Library instruction programs and our labor (BTAA Keynote)

    Pagowsky, Nicole; University of Arizona Libraries (2024-04-18)
    Conceptualizing and incorporating critical information literacy into our instruction programs at the intersections of pedagogy, campus dynamics, relationships with faculty, threats to higher education, and burnout in our labor of primarily one-shot instruction models. Discussions for more sustainable library instruction programs are brought forward with an example of UArizona Libraries' critical information literacy tutorials that engage a Teach the Teacher approach.
  • From magical thinking to suicide: Understanding emergency physicians' psychological struggle

    Iserson, Kenneth V; Department of Emergency Medicine, The University of Arizona (Elsevier, 2024-01-03)
    Recent literature has explored the psychological well-being of physicians, addressing conditions like perfectionism, imposter phenomenon/syndrome (IP), depression, burnout, and, less frequently, magical thinking. But recognizing the connections among these psychological factors is vital for developing targeted interventions to prevent or alleviate their impact. This article examines the often-sequential emergence of these five conditions within a physician's career, with a specific emphasis on their prevalence among emergency physicians (EPs), who must manage a diverse array of acute illnesses and injuries. The descent into psychological distress initiates with magical thinking—in this case, the belief that perfection is possible despite evidence to the contrary—leading to the pursuit of maladaptive perfectionism. If unaddressed, this trajectory may lead to depression, burnout, and in some cases, suicide. Understanding this continuum lays the groundwork for devising a systematic approach to enhance physicians' mental health. The article delves into detailed descriptions of these psychological conditions, encompassing their prevalence, individual impact, how they are integrated into this continuum and potential preventive or corrective methods. Recognizing unrealistic expectations as a major contributor to burnout, depression, and even suicide within the medical profession, the article advocates for the development of targeted interventions and support structures to assist medical students and professionals in managing IP. Practical strategies involve acknowledging unrealistic expectations, setting attainable goals, seeking support, taking breaks, and prioritizing self-care. Addressing this pervasive issue aims to cultivate a culture where medical professionals can thrive, ensuring optimal care for patients.
  • Strength in arms: empowering older adults against the risk of slipping and falling-a theoretical perspective

    Lee-Confer, Jonathan; Department of Physical Therapy, University of Arizona (Frontiers Media, 2024-03-08)
    Background: Slips and falls are a serious health concern, particularly among older adults. Current physical therapy protocols strengthen the legs to improve balance. However, arm movements help maintain balance during a slip incident. Understanding how arm movements improve balance may help clinicians develop more comprehensive fall-prevention protocols to improve patient outcomes. Clinical question: What limitations exist in current fall prevention protocols for reducing falls in older adults during slip incidents, and what new strategies can enhance these outcomes? Key results: Slip incidents often result in a sideways loss of balance, leading to hip fractures in older adults. During a slip, the legs do not produce sideways motion and are less effective in regaining balance in this direction. Contrary, the arms produce 100 + degrees of abduction and this motion reduces falls by 200%+ during a slip incident. Notably, older adults exhibit 35.7% decreased arm abduction acceleration responses compared to younger adults during a slip incident. This delay may be attributed to age-related decreases in type II fibers of the deltoid. High-velocity and ballistic training have been shown to improve the proportion and size of type II fibers as well as improve fall outcomes when focused on the lower extremities. Clinical application: Therefore, I propose incorporating arm abductor training, alongside leg exercises, as a cost-effective and low-risk intervention to enhance the slip responses in older adults. In light of its minimal risk and considerable potential benefits, starting arm abductor exercises with older adults is a sensible move.
  • Cobalt enhanced the drought-stress tolerance of rice (Oryza sativa L.) by mitigating the oxidative damage and enhancing yield attributes

    Tourky, Shaimaa M.N.; Shukry, Wafaa M.; Hossain, Mohammad Anwar; Siddiqui, Manzer H.; Pessarakli, Mohammad; Elghareeb, Eman M.; School of Plant Sciences, The University of Arizona (Elsevier BV, 2023-06-13)
    Water scarcity is one of the most important abiotic factors limiting rice growth and productivity. The application of nutrients affects various physiological and biochemical mechanisms to curtail water deficiency, but little is known about the ameliorative effects of cobalt (Co) on rice. Our study aimed to investigate the advantageous effects of soaking in Co at the optimum concentration (10 and 44.5 µM) on morpho-physiological traits and oxidative stress, during the vegetative and reproductive stages, also assessing yield attributes, in two rice varieties (Sakha 104, drought-sensitive, and Giza 178, drought-tolerant). Treatments included control (100% field capacity (FC)), moderate drought stress (75 % FC), and severe drought stress (50 % FC) either alone or in combination with Co. A water deficit and oxidative stress affected Giza 178 less than Sakha 104. Co application significantly enhanced the performance of two rice varieties under drought stress by increasing plant height, biomass, water content, tillering, leaf area, pigments (chlorophyll a, carotenoids, total chlorophyll), sugars (soluble sugars, and total carbohydrates), and Co content (shoot and root). Also, Co significantly increased the performance of the antioxidant system by elevating the concentration of total phenols, flavonoids, proline, and antioxidant enzymes (catalase, peroxidase, and polyphenol oxidase), while significantly decreasing chlorophyll b, malondialdehyde, and 2,2-diphenyl-1-picryl-hydrazyl. Yield attributes such as the number of tillers, panicle parameters (number, length, and weight), 100-grain weight, harvest index, and grain nutritive value (sugars, vitamin B, and Co contents) were significantly enhanced by Co in both varieties. However, the maximum performance was observed in Giza 178.
  • A Novel Implementation Methodology for Error Correction Codes on a Neuromorphic Architecture

    Hassan, Sahil; Dattilo, Parker; Akoglu, Ali; Department of Electrical and Computer Engineering, University of Arizona (Institute of Electrical and Electronics Engineers (IEEE), 2023-06-12)
    The Internet of Things infrastructure connects a massive number of edge devices with an increasing demand for intelligent sensing and inferencing capability. Such data-sensitive functions necessitate energy-efficient and programmable implementations of error correction codes (ECCs) and decoders. The algorithmic flow of ECCs with concurrent accumulation and comparison types of operations are innately exploitable by neuromorphic architectures for energy-efficient execution - an area that is relatively unexplored outside of machine learning applications. For the first time, we propose a methodology to map the hard-decision class of decoder algorithms on a neuromorphic architecture. We present the implementation of the Gallager B (GaB) decoding algorithm on a TrueNorth-inspired architecture that is emulated on the Xilinx Zynq ZCU102 MPSoC. Over this reference implementation, we propose architectural modifications at the neuron block level that result in a reduction of energy consumption by 31% with a negligible increase in resource usage while achieving the same error correction performance.
  • Extreme precipitation stable isotopic compositions reveal unexpected summer monsoon incursions in the Qilian Mountains

    Zhao, Liangju; Dong, Xiying; Liu, Xiaohong; Wang, Ninglian; Eastoe, Christopher J; Wei, Na; Xie, Cong; Liu, Hang; Han, Chuntan; Hua, Ting; et al. (Elsevier B.V., 2023-07-24)
    Isotope composition and moisture sources of precipitation are important for understanding water cycles and reconstructing paleoclimate. Based on 15-years' precipitation stable Isotope composition (δ18O and δ2H) from four stations of the Qilian Mountains, we found unique δ18O and δ2H features associated with the incursion of the summer monsoon over the Qilian Mountains, northwestern China. In 12 of the 15 years, similar seasonal variations of δ18O and δ2H confirmed a dominant source of moisture from Westerly circulation, and higher intercepts of the local meteoric water line (LMWL) indicated strong recycling of continental moisture. However, in August 2016 and 2018, extremely low slopes and intercepts of the LMWL, and more negative δ18O and δ2H revealed substantial contributions of the Asian summer monsoon to precipitation of the Qilian Mountains, with extremely heavy precipitation in August 2016. The column moisture flux, land-sea thermal contrast, correlations of precipitation δ18O with East Asian Summer Monsoon Index and Westerlies Index, HYSPLIT modeling results and precipitation δ18O along backward trajectories confirmed incursions of the summer monsoon in August 2016 and 2018. Our redefining of the boundary of the summer monsoon region confirmed the summer monsoon incursion zone can extend to the west of longitude 96°E and north of latitude 40°N in strong monsoon years, corresponding to boundaries of monsoon incursions in the mid-Holocene. Temperature correlated with precipitation δ18O at monthly and shorter time scales, but not for whole seasons or at yearly scale, revealing that summer monsoon incursions are therefore more likely than changing temperature to explain the multi-year cycles in the Qilian Mountains ice archives. Continent-scale shifts in atmospheric circulation strongly influence water resources in the Qilian mountains, and may change in frequency as climate warms. This study therefore has important implications for understanding water resources in the Qilian mountains in the past and into the future.
  • Electrochemical leaching of critical materials from lithium-ion batteries: A comparative life cycle assessment

    Adhikari, Birendra; Chowdhury, Nighat A.; Diaz, Luis A.; Jin, Hongyue; Saha, Apurba K.; Shi, Meng; Klaehn, John R.; Lister, Tedd E.; Department of Systems and Industrial and Engineering, University of Arizona (Elsevier BV, 2023-03-21)
    The manufacturing of lithium-ion batteries (LIB) requires critical materials such as cobalt (Co) and lithium (Li) that are essential for clean-energy products including electric vehicles. Because of their rapidly increasing demand and limited supply, the recycle and reuse of these materials from end-of-life LIB have garnered a lot of interest. Electrochemical leaching has emerged as a sustainable method to extract critical materials out of LIB, so life cycle assessment was conducted to compare the environmental impacts with traditional peroxide-based leaching and another emerging technology – SO2-based leaching. The results showed that electrochemical leaching reduces the global warming potential (GWP) by 80%−87% compared to peroxide-based leaching due to a lower acid consumption, avoidance of hydrogen peroxide, and regeneration of reducing agent iron (II) sulfate and compares well with SO2-based leaching in most impact categories. The analysis suggested renewable energy can further reduce the environment footprint of electrochemical leaching.
  • A comparative techno-economic analysis of combined oil and power production from pyrolysis and co-pyrolysis plants utilizing rice straw and scrap rubber tires

    Khan, Shoaib Raza; Zeeshan, Muhammad; Fatima, Salsabeel; Ciolkosz, Daniel; Dimitriou, Ioanna; Jin, Hongyue; Department of Systems & Industrial Engineering, University of Arizona (Elsevier BV, 2023-05-11)
    In this study, three pyrolysis and co-pyrolysis plants processing rice straw (RS) and scrap rubber tire (SRT) to produce oil and power (i.e., electricity) at 30 t/hr capacity are simulated using SuperPro Designer software. The objective of the study is to comparatively evaluate the techno-economic performance of hypothetical (co-)pyrolysis plants at commercial scale. The RS production is estimated in 36 districts of Punjab, Pakistan through GIS mapping and the location and capacity of the plants are selected accordingly. The RS plant has the lowest capital and annual operating costs of $53.70 million and $43.70 million, respectively however, it is not economically feasible under current conditions due to its low quantity and quality of the produced oil. The base cases of SRT and co-feed (RS and SRT) plants are found to be viable with capital costs of $66.90 million and $68.30 million, and annual operating costs of $77.20 million and $70.30 million respectively. The co-pyrolysis plant produces the highest oil (main product) yield of 74 kilotons annually and power of 4801 KWe with the lowest unit production cost of $950/tonne. Consequently, the co-pyrolysis plant offers the highest economic performance with $35.55 million of net present value (NPV) estimated at a discount rate of 15% over 20 years of plant life. The payback period (PBT), internal rate of return (IRR) and gross margin (GM) are 5.08 years, 34.67% and 21.35% respectively. Sensitivity analysis suggests that the NPV is sensitive to the oil selling price, feedstock cost, and capital investment for all plants. Moreover, economy of scale analysis quantified the effects of different processing capacities on the economic metrics such as NPV, PBT, capital cost, and operating cost.
  • Reactive responses of the arms increase the Margins of Stability and decrease center of mass dynamics during a slip perturbation

    Lee-Confer, Jonathan S; Finley, James M; Kulig, Kornelia; Powers, Christopher M; Department of Physical Therapy, University of Arizona (Elsevier Ltd, 2023-07-22)
    Although reactive arm motions are important in recovering from a slip event, the biomechanical influences of upper extremity motions during slipping are not clear. The purpose of the current study was to determine whether reactive arm motions during slip recovery leads to increased margins of stability (MoS), and decreased center of mass (CoM) velocity and excursion. Thirty-two participants were randomized into 2 conditions: arms free and arms constrained. Participants traversed a 10-meter walkway and were exposed to an unexpected slip while wearing a protective harness. Anterior-posterior and medial–lateral MoS, as well as the CoM excursion and velocity during the slip perturbation was quantified using a three-dimensional motion capture system. In the frontal plane, individuals with their arms unconstrained demonstrated greater MoS (0.06 ± 0.03 vs −0.01 ± 0.02 m, p < 0.01), decreased CoM excursion (0.05 ± 0.02 vs 0.08 ± 0.01 m, p = 0.015), and a reduced CoM velocity (0.07 ± 0.03 vs. 0.14 ± 0.02 m/s, p < 0.01) compared to individuals with their arms constrained. In the sagittal plane, individuals with their arms unconstrained demonstrated, decreased CoM excursion (0.83 ± 0.13 vs 1.14 ± 0.20 m, p < 0.01) reduced CoM velocity (1.71 ± 0.08 vs. 1.79 ± 0.07 m/s, p = 0.02), but no differences in margins of stability (0.89 ± 0.13 vs 0.94 ± 0.10 m, p = 0.32). Our findings demonstrate that arm motions during a slip perturbation act to restore balance by minimizing displacement and velocity of the body CoM during a slip event in the frontal plane.
  • Extreme isotopic heterogeneity in impact melt rocks: Implications for Martian meteorites

    Jaret, Steven J.; Rasbury, E. Troy; Reiners, Peter; Spray, John G.; Thompson, Lucy M.; Hemming, Sidney R.; Thompson, Michelle S.; Department of Geosciences, University of Arizona (Geological Society of America, 2023-02-07)
    Lead isotope ratios have been determined in multiple feldspar grains from hand samples of impact melt rock at the Manicouagan and Sudbury impact structures in Canada. The results reveal an extreme range of isotope values. This indicates that melt sheets are not homogeneous with respect to Pb at the millimeter scale. Such heterogeneity is significantly larger than that seen in non-impact-generated igneous rocks. Individual Pb isotope ratios of feldspars from Martian shergottites show a large range in 206Pb/204Pb values within one sample, more similar to the terrestrial impact melt sheets than to nonimpact igneous rocks. We suggest crystallization from impact melt sheets rather than volcanic sources as a petrogenetic model for some of the Martian shergottites.
  • The Poisson geometry of Plancherel formulas for triangular groups

    Ercolani, Nicholas M.; Department of Mathematics, University of Arizona (Elsevier BV, 2023-05-30)
    In this paper we establish the existence of canonical coordinates for generic co-adjoint orbits on triangular groups. These orbits correspond to a set of full Plancherel measure on the associated dual groups. This generalizes a well-known coordinatization of co-adjoint orbits of a minimal (non-generic) type originally discovered by Flaschka. The latter had strong connections to the classical Toda lattice and its associated Poisson geometry. Our results develop connections with the Full Kostant–Toda lattice and its Poisson geometry. This leads to novel insights relating the details of Plancherel theorems for Borel Lie groups to the invariant theory for Borels and their subgroups. We also discuss some implications for the quantum integrability of the Full Kostant Toda lattice.
  • Democratizing Law Librarianship: Reducing Barriers to Entry through Alternative Pathways to the Profession and Increased Support to Students. A Call to Action

    Miguel-Stearns, Teresa M.; Laskowski, Casandra; University of Arizona, James E. Rogers College of Law, Daniel F. Cracchiolo Law Library (Informa UK Limited, 2024-04-02)
    Law librarianship is a constantly evolving profession driven by the evolution of law practice, legal education, government, and law itself. Changes in these drivers are in turn influenced by factors such as technology, culture, client needs, American Bar Association Standards, bar exams, diversity and access efforts, faculty research, instructional trends, and law school rankings. Law librarians proudly keep up with these changes—and even stay ahead of them—as we impart new knowledge and skills to users of law libraries and legal information resources. As we proceed through the third decade of the twenty-first century, the legal information profession is engaged in dialogue about the perpetually shrinking pools of qualified candidates for law librarian positions. Additionally, law librarians have been lamenting for decades that the legal information profession does not accurately reflect the diversity in our communities. The literature reflects that those conversations began in earnest in the 1970s and continue today. This article addresses both compelling issues and offers concrete strategies to tackle them simultaneously, thoughtfully, and intentionally. The entire profession is invited to play a role in this effort.
  • Asymmetric motivated reasoning in investor judgment

    Elliott, W. Brooke; Hobson, Jessen L.; Van Landuyt, Ben W.; White, Brian J.; Eller College of Management, University of Arizona (Springer Science and Business Media LLC, 2023-06-23)
    We develop and test a refinement to motivated reasoning theory that predicts long investors are more prone than short investors to forming biased beliefs about the value of a stock. Our theory suggests that motivated reasoning is muted for short investors because the investing setting conveys a conventional preference for prices to rise that is directionally inconsistent with short investors’ incentivized preference for prices to fall. We examine this premise across four experiments. Experiment 1 tests our theory in an investing setting in which participants take either long or short positions. Compared to a rational benchmark for an unbiased judgment, we find that long traders’ estimates of future stock price exhibit upward bias while short traders’ estimates are unbiased. Consistent with motivated reasoning underlying these results, the magnitude of long traders’ bias becomes less pronounced as the amount of uncertainty in the information environment decreases. Experiment 2 suggests that direct experience with taking short positions can increase short traders’ propensity to engage in motivated reasoning. Experiments 3 and 4 provide additional evidence for our theory outside of the investing context. Overall our paper contributes new insights into differences between long and short investors and speaks to the broader literature on bias in judgment and decision-making that spans multiple fields.
  • The D3 receptor antagonist SR 21502 reduces cue-induced reinstatement of methamphetamine-seeking in rats

    Ranaldi, Robert; Timken, Patrick; Parasram, Daleya; Ali, Tasmia; Zhang, Sixue; Moukha-Chafiq, Omar; Augelli-Szafran, Corinne; Streicher, John M; Department of Pharmacology, College of Medicine and the Comprehensive Pain and Addiction Center, University of Arizona (Elsevier Ireland Ltd, 2023-04-12)
    There is as of yet no FDA-approved medication for methamphetamine use disorder. Although dopamine D3 receptor antagonists have been shown to be useful in reducing methamphetamine seeking in animal models their translation to the clinic has been hindered because currently tested compounds can produce dangerously high blood pressure. Thus, it is important to continue to explore other classes of D3 antagonists. We report here the effects of SR 21502, a selective D3 receptor antagonist, on cue-induced reinstatement (i.e., relapse) of methamphetamine-seeking in rats. In Experiment 1, rats were trained to self-administer methamphetamine under a fixed ratio schedule of reinforcement followed by extinction of the response. Then, animals were tested with one of several doses of SR 21502 on cue-induced reinstatement of responding. SR 21502 significantly reduced cue-induced reinstatement of methamphetamine-seeking. In Experiment 2, animals were trained to lever press for food under a PR schedule and tested with the lowest dose of SR 21502 that caused a significant reduction in Experiment 1. These animals responded on average 8 times more than the vehicle-treated rats in Experiment 1, eliminating the possibility that SR 21502-treated rats in Experiment 1 responded less because they were incapacitated. In summary, these data suggest that SR 21502 may selectively inhibit methamphetamine-seeking and may constitute a promising pharmacotherapeutic agent for methamphetamine or other drug use disorders.
  • Isotope record of groundwater recharge mechanisms and climate change in southwestern North America

    Eastoe, C.J.; Department of Geosciences, University of Arizona (Elsevier BV, 2023-02-24)
    Understanding the response of groundwater systems to changes in climate is crucial at a time when human-caused climate change appears to be increasing in magnitude and rate. Groundwater preserves records of past effects resulting from climate change at the time-scale of late Pleistocene-Holocene climate evolution. Detailed regional datasets provide opportunities for evaluating past changes as a means of anticipating future climate-groundwater relations. Isotope parameters δ18O, δ2H and uncorrected 14C, considered together in large groundwater datasets from southwestern North America, provide evidence of changes in groundwater recharge mechanisms and the climate changes that led to them. The evidence consists in positive shifts in δ18O and δ2H in paleowater recharge related to a 13–15 ka shift recorded in in δ18O of speleothem deposits, and as concurrent changes in recharge seasonality in the core area of the North American monsoon. A negative shift in δ18O and δ2H, most likely contemporaneous with a regional 51–55 ka change speleothem deposits, is recorded in certain basins with deep, confined groundwater. A14C threshold of 10 percent modern carbon serves empirically to distinguish paleowaters before and after the 13–15 ka event. A younger, negative isotope shift has occurred in Baja California. The 13–15 ka shift is regional but is not recorded in all basins studied and appears to be absent at the northwestern and southeastern limits of the study area. Relations among the isotope parameters may be complicated by factors such as isotope altitude effects, delayed melting of Pleistocene ice, changing degrees of evaporation in river water and introduction of anthropogenic 14C. Recharge mechanisms fall into two patterns: (1) dominant winter recharge with varying degrees of evaporation prior to infiltration, and (2) recharge in both summer and winter, but only during the wettest months. Pattern (2) replaced pattern (1) at 13–15 ka in the core area of the North American monsoon. Later, the present-day pattern of recharge from summer-fall rain associated with tropical depressions replaced predominant winter recharge in southern and eastern Baja California. A post-1950 negative shift in δ18O and δ2H, observed in southern Nevada and northern New Mexico, may be of anthropogenic origin and related to development of large-scale irrigation in California.
  • Addressing structural hurdles for metadata extraction from environmental impact statements

    Laparra, Egoitz; Binford‐Walsh, Alex; Emerson, Kirk; Miller, Marc L.; López‐Hoffman, Laura; Currim, Faiz; Bethard, Steven; School of Information, University of Arizona; School of Government and Public Policy, University of Arizona; James E. Rogers College of Law, University of Arizona; et al. (Wiley, 2023-06-14)
    Natural language processing techniques can be used to analyze the linguistic content of a document to extract missing pieces of metadata. However, accurate metadata extraction may not depend solely on the linguistics, but also on structural problems such as extremely large documents, unordered multi-file documents, and inconsistency in manually labeled metadata. In this work, we start from two standard machine learning solutions to extract pieces of metadata from Environmental Impact Statements, environmental policy documents that are regularly produced under the US National Environmental Policy Act of 1969. We present a series of experiments where we evaluate how these standard approaches are affected by different issues derived from real-world data. We find that metadata extraction can be strongly influenced by nonlinguistic factors such as document length and volume ordering and that the standard machine learning solutions often do not scale well to long documents. We demonstrate how such solutions can be better adapted to these scenarios, and conclude with suggestions for other NLP practitioners cataloging large document collections.
  • Simulating impact-induced shaking as a triggering mechanism for mass movements on Bennu

    Tang, Y.; Lauretta, D.S.; Ballouz, R.-L.; DellaGiustina, D.N.; Bennett, C.A.; Walsh, K.J.; Golish, D.R.; Lunar and Planetary Laboratory, University of Arizona (Elsevier BV, 2023-02-06)
    Observations of near-Earth asteroid Bennu have revealed a dynamic surface composed of unconsolidated material. The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) mission found numerous locations exhibiting evidence of mass movements of surface material. Mass movements can be a major factor in the surface evolution of a small near-Earth asteroid, and the Small Carry-on Impactor (SCI) experiment on asteroid Ryugu has shown that seismic shaking can trigger it. We selected one mass movement site on Bennu to conduct a detailed survey of the surface boulder arrangement and geomorphology. Using these data, we created dynamical simulations of mass movement events at this site initiated by seismic shaking, and we found a mass flux comparable to estimates from the site survey. The frequency ranges of the shakings are similar to what would be produced by a 0.5-m-diameter impactor, for which the expected crater size is of a scale widely seen on Bennu (32 m). In addition, the simulation exhibited the Brazil nut effect, where finer particles percolate towards greater depth, in this case up to 1.5 m. Our results demonstrate that impact-induced seismic shaking is a viable mechanism for the initiation of mass movements, and a plausible explanation for the scarcity of fine regolith, on Bennu's surface.

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