Showing papers by "University of Arizona published in 2022"

The theory and applications of iteration methods

Abstract: The Theory and Applications of Iteration Methods focuses on an abstract iteration scheme that consists of the recursive application of a point-to-set mapping. Each chapter presents new theoretical results and important applications in engineering, dynamic economic systems, and input-output systems. At the end of each chapter, case studies and numerical examples are presented from different fields of engineering and economics. Following an outline of general iteration schemes, the authors extend the discrete time-scale Liapunov theory to time-dependent, higher order, nonlinear difference equations. The monotone convergence to the solution is examined in and comparison theorems are proven . Results generalize well-known classical theorems, such as the contraction mapping principle, the lemma of Kantorovich, the famous Gronwall lemma, and the stability theorem of Uzawa. The book explores conditions for the convergence of special single- and two-step methods such as Newton's method, modified Newton's method, and Newton-like methods generated by point-to-point mappings in a Banach space setting. Conditions are examined for monotone convergence of Newton's methods and their variants. Students and professionals in engineering, the physical sciences, mathematics, and economics will benefit from the book's detailed examples, step-by-step explanations, and effective organization.

Distinguishing Multisystem Inflammatory Syndrome in Children From COVID-19, Kawasaki Disease and Toxic Shock Syndrome

Abstract: Distinguishing multisystem inflammatory syndrome in children (MIS-C) from coronavirus disease 2019 (COVID-19), Kawasaki disease (KD), and toxic shock syndrome (TSS) can be challenging. Because clinical management of these conditions can vary, timely and accurate diagnosis is essential.Data were collected from patients <21 years of age hospitalized with MIS-C, COVID-19, KD, and TSS in 4 major health care institutions. Patient demographics and clinical and laboratory data were compared among the 4 conditions, and a diagnostic scoring tool was developed to assist in clinical diagnosis.A total of 233 patients with MIS-C, 102 with COVID-19, 101 with KD, and 76 with TSS were included in the analysis. Patients with MIS-C had the highest prevalence of decreased cardiac function (38.6%), myocarditis (34.3%), pericardial effusion (38.2%), mitral regurgitation (31.8%) and pleural effusion (34.8%) compared with patients with the other conditions. Patients with MIS-C had increased peak levels of C-reactive protein and decreased platelets and lymphocyte nadir counts compared with patients with COVID-19 and KD and elevated levels of troponin, brain natriuretic peptide and pro-brain natriuretic peptide compared with COVID-19. Diagnostic scores utilizing clinical findings effectively distinguished MIS-C from COVID-19, KD, and TSS, with internal validation showing area under the curve ranging from 0.87 to 0.97.Compared with COVID-19, KD, and TSS, patients with MIS-C had significantly higher prevalence of cardiac complications, elevated markers of inflammation and cardiac damage, thrombocytopenia, and lymphopenia. Diagnostic scores can be a useful tool for distinguishing MIS-C from COVID-19, KD, and TSS.

Opportunistic experiments to constrain aerosol effective radiative forcing

Abstract: Aerosol-cloud interactions (ACIs) are considered to be the most uncertain driver of present-day radiative forcing due to human activities. The nonlinearity of cloud-state changes to aerosol perturbations make it challenging to attribute causality in observed relationships of aerosol radiative forcing. Using correlations to infer causality can be challenging when meteorological variability also drives both aerosol and cloud changes independently. Natural and anthropogenic aerosol perturbations from well-defined sources provide "opportunistic experiments" (also known as natural experiments) to investigate ACI in cases where causality may be more confidently inferred. These perturbations cover a wide range of locations and spatiotemporal scales, including point sources such as volcanic eruptions or industrial sources, plumes from biomass burning or forest fires, and tracks from individual ships or shipping corridors. We review the different experimental conditions and conduct a synthesis of the available satellite datasets and field campaigns to place these opportunistic experiments on a common footing, facilitating new insights and a clearer understanding of key uncertainties in aerosol radiative forcing. Cloud albedo perturbations are strongly sensitive to background meteorological conditions. Strong liquid water path increases due to aerosol perturbations are largely ruled out by averaging across experiments. Opportunistic experiments have significantly improved process-level understanding of ACI, but it remains unclear how reliably the relationships found can be scaled to the global level, thus demonstrating a need for deeper investigation in order to improve assessments of aerosol radiative forcing and climate change.

Purely Organic Emitters for Multiresonant Thermally Activated Delay Fluorescence: Design of Highly Efficient Sulfur and Selenium Derivatives

Abstract: Multiresonance thermally activated delayed fluorescence (MR-TADF) emitters based on nitrogen- and/or oxygen-substituted organoboron molecules can exhibit high photoluminescence quantum yields, color purity, and thermal and chemical stability. Therefore, these emitters have recently attracted great interest for application in organic light-emitting diodes (OLEDs). The compositional diversity of MR-TADF materials is, however, limited to the use mainly of nitrogen and oxygen as electron-rich heteroatoms. Here, we expand the chemical range of these materials by considering the replacement of the O atoms with either S or Se atoms, with the objective of enhancing spin–orbit coupling via the heavy-atom effect. We theoretically evaluate the influence of these substitutions on the emissive properties. We investigate three series of MR molecules with structural motifs based on the following: (i) DOBNA (5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene); (ii) OAB-ABP (5,12-dioxa-8b-aza-16b,19b-diboraanthra[1,9-ab]benzo[j]perylene); and (iii) the variation of the positions of the chalcogen atoms within the OAB-ABP framework. The results of highly correlated quantum-chemical calculations show that the chemical nature and positions of the chalcogen atoms have a crucial impact on the photophysical properties. Several of the molecules incorporating sulfur or selenium are found to exhibit both high-energy emissive states and large reverse intersystem crossing rates, which makes them promising candidates as efficient deep-blue emitters.

Semi-synthesis and cytotoxicity evaluation of pyrimidine, thiazole, and indole analogues of argentatins A–C from guayule (Parthenium argentatum) resin

Abstract: Argentatins A–C (1–3), the major cycloartane-type triterpenoids of guayule resin, a byproduct of commercial rubber production, were converted into their pyrimidine (7–12), thiazole (13–15), and indole (16–18) analogues by a molecular hybridization approach. The cytotoxic activities of these fused heterocyclic analogues 7–18 were compared with those of argentatins A–C (1–3) against a panel of three sentinel human cancer cell lines [NCI-H460 (non-small cell lung), MCF-7 (breast adenocarcinoma), and SF-268 (central nervous system glioma)], and normal human fibroblast (WI-38) cells. The cytotoxicity data suggest that the pyrimidine analogues 7 and 8 (derived from 1), 9 and 10 (derived from 2), and 12 (derived from 3) had significantly enhanced activity compared to the parent compounds or their thiazole (13–15) and indole (16–18) analogues. These findings indicate that triterpenoid constituents of guayule resin may be exploited to obtain value-added products with potential applications in anticancer drug discovery.

What makes a megaplasmid

Abstract: Naturally occurring plasmids come in different sizes. The smallest are less than a kilobase of DNA, while the largest can be over three orders of magnitude larger. Historically, research has tended...

Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run

Abstract: Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully-coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow the frequency and frequency time-derivative of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets.

Engineering of flat bands and Dirac bands in two-dimensional covalent organic frameworks (COFs): relationships among molecular orbital symmetry, lattice symmetry, and electronic-structure characteristics

Abstract: Two-dimensional covalent organic frameworks (2D-COFs), also referred to as 2D polymer networks, display unusual electronic-structure characteristics, which can significantly enrich and broaden the fields of electronics and spintronics. In this Focus article, our objective is to lay the groundwork for the conceptual description of the fundamental relationships among the COF electronic structures, the symmetries of their 2D lattices, and the frontier molecular orbitals (MOs) of their core and linker components. We focus on monolayers of hexagonal COFs and use tight-binding model analyses to highlight the critical role of the frontier-MO symmetry, in addition to lattice symmetry, in determining the nature of the electronic bands near the Fermi level. We rationalize the intriguing feature that, when the core unit has degenerate highest occupied MOs [or lowest unoccupied MOs], the COF highest valence band [or lowest conduction band] is flat but degenerate with a dispersive band at a high-symmetry point of the Brillouin zone; the consequences of having such band characteristics are briefly described. Multi-layer and bulk 2D COFs are found to maintain the salient features of the monolayer electronic structures albeit with a reduced bandgap due to the interlayer coupling. This Focus article is thus meant to provide an effective framework for the engineering of flat and Dirac bands in 2D polymer networks.

The OM-85 bacterial lysate inhibits SARS-CoV-2 infection of epithelial cells by downregulating SARS-CoV-2 receptor expression

Abstract: Treatments for coronavirus disease 2019, which is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), are urgently needed but remain limited. SARS-CoV-2 infects cells through interactions of its spike (S) protein with angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) on host cells. Multiple cells and organs are targeted, particularly airway epithelial cells. OM-85, a standardized lysate of human airway bacteria with strong immunomodulating properties and an impeccable safety profile, is widely used to prevent recurrent respiratory infections. We found that airway OM-85 administration inhibits Ace2 and Tmprss2 transcription in the mouse lung, suggesting that OM-85 might hinder SARS-CoV-2/host cell interactions.We sought to investigate whether and how OM-85 treatment protects nonhuman primate and human epithelial cells against SARS-CoV-2.ACE2 and TMPRSS2 mRNA and protein expression, cell binding of SARS-CoV-2 S1 protein, cell entry of SARS-CoV-2 S protein-pseudotyped lentiviral particles, and SARS-CoV-2 cell infection were measured in kidney, lung, and intestinal epithelial cell lines, primary human bronchial epithelial cells, and ACE2-transfected HEK293T cells treated with OM-85 in vitro.OM-85 significantly downregulated ACE2 and TMPRSS2 transcription and surface ACE2 protein expression in epithelial cell lines and primary bronchial epithelial cells. OM-85 also strongly inhibited SARS-CoV-2 S1 protein binding to, SARS-CoV-2 S protein-pseudotyped lentivirus entry into, and SARS-CoV-2 infection of epithelial cells. These effects of OM-85 appeared to depend on SARS-CoV-2 receptor downregulation.OM-85 inhibits SARS-CoV-2 epithelial cell infection in vitro by downregulating SARS-CoV-2 receptor expression. Further studies are warranted to assess whether OM-85 may prevent and/or reduce the severity of coronavirus disease 2019.

Recent COVID-19 vaccination has minimal effects on the physiological responses to graded exercise in physically active healthy people

Abstract: Recent COVID-19 vaccination does not affect a large number of physiological responses to graded exercise, indicating that vaccination is unlikely to impair exercise capacity in normal healthy people. Heart rate and norepinephrine levels were elevated in response to exercise after the two-dose Pfizer mRNA vaccination compared to controls. Small elevations in cardiovascular and neuroendocrine responses to exercise after recent COVID-19 vaccination could have implications for exercise performance in elite athletes and warrants investigation.

A hydrologist's guide to open science

Abstract: Abstract. Open, accessible, reusable, and reproducible hydrologic research can have a significant positive impact on the scientific community and broader society. While more individuals and organizations within the hydrology community are embracing open science practices, technical (e.g., limited coding experience), resource (e.g., open access fees), and social (e.g., fear of weaknesses being exposed or ideas being scooped) challenges remain. Furthermore, there are a growing number of constantly evolving open science tools, resources, and initiatives that can be overwhelming. These challenges and the ever-evolving nature of the open science landscape may seem insurmountable for hydrologists interested in pursuing open science. Therefore, we propose the general “Open Hydrology Principles” to guide individual and community progress toward open science for research and education and the “Open Hydrology Practical Guide” to improve the accessibility of currently available tools and approaches. We aim to inform and empower hydrologists as they transition to open, accessible, reusable, and reproducible research. We discuss the benefits as well as common open science challenges and how hydrologists can overcome them. The Open Hydrology Principles and Open Hydrology Practical Guide reflect our knowledge of the current state of open hydrology; we recognize that recommendations and suggestions will evolve and expand with emerging open science infrastructures, workflows, and research experiences. Therefore, we encourage hydrologists all over the globe to join in and help advance open science by contributing to the living version of this document and by sharing open hydrology resources in the community-supported repository (https://open-hydrology.github.io, last access: 1 February 2022).

A Review of GNSS/GPS in Hydrogeodesy: Hydrologic Loading Applications and Their Implications for Water Resource Research

Abstract: Hydrogeodesy, a relatively new field within the earth sciences, is the analysis of the distribution and movement of terrestrial water at Earth's surface using measurements of Earth's shape, orientation, and gravitational field. In this paper, we review the current state of hydrogeodesy with a specific focus on Global Navigation Satellite System (GNSS)/Global Positioning System measurements of hydrologic loading. As water cycles through the hydrosphere, GNSS stations anchored to Earth's crust measure the associated movement of the land surface under the weight of changing hydrologic loads. Recent advances in GNSS-based hydrogeodesy have led to exciting applications of hydrologic loading and subsequent terrestrial water storage (TWS) estimates. We describe how GNSS position time series respond to climatic drivers, can be used to estimate TWS across temporal scales, and can improve drought characterization. We aim to facilitate hydrologists' use of GNSS-observed surface deformation as an emerging tool for investigating and quantifying water resources, propose methods to further strengthen collaborative research and exchange between geodesists and hydrologists, and offer ideas about pressing questions in hydrology that GNSS may help to answer.

Dog Models of Aging.

Abstract: As the most phenotypically diverse mammalian species that shares human environments and access to sophisticated healthcare, domestic dogs have unique potential to inform our understanding of the determinants of aging. Here we outline key concepts in the study of aging and illustrate the value of research with dogs, which can improve dog health and support translational discoveries. We consider similarities and differences in aging and age-related diseases in dogs and humans and summarize key advances in our understanding of genetic and environmental risk factors for morbidity and mortality in dogs. We address health outcomes ranging from cancer to cognitive function and highlight emerging research opportunities from large-scale cohort studies in companion dogs. We conclude that studying aging in dogs could overcome many limitations of laboratory models, most notably, the ability to assess how aging-associated pathways influence aging in real-world environments similar to those experienced by humans. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 10 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Updated Prevalence of Urinary Incontinence in Women: 2015–2018 National Population-Based Survey Data

Abstract: This study aimed to update estimates of urinary incontinence (UI) prevalence and associated risk factors for adult women in the United States, using the National Health and Nutrition Examination Survey (NHANES).We used descriptive analysis of 2015-2018 NHANES weighted data for women to estimate prevalence and characterize UI types and severity. Logistic regression modeling determined adjusted associations with UI.Complete data were available for 5,006 women. In weighted analyses, 61.8% had UI, corresponding to 78,297,094 adult U.S. women, with 32.4% of all women reporting symptoms at least monthly. Of those with UI, 37.5% had stress urinary incontinence, 22.0% had urgency urinary incontinence, 31.3% had mixed symptoms, and 9.2% had unspecified incontinence. The prevalence of moderate or more severe UI by Sandvik Severity Index was 22.1%, corresponding to 28,454,778 adult U.S. women. In multivariate models, increasing age, body mass index ≥25, prior vaginal birth, anxiety, depression, functional dependence, and non-Hispanic White ethnicity and race were associated with any and moderate UI. Urinary incontinence was not associated with diabetes, education level, prior hysterectomy, smoking status, physical activity level, or current pregnancy status.More than 60% of community-dwelling adult women in the United States experience any UI and an increase from prior estimates (38%-49%) using NHANES data from 1999 to 2004; more than 20% experience moderate or more severe UI. Increases in UI prevalence may be related to population aging and increasing obesity prevalence. Age greater than 70 years, body mass index >40, and vaginal birth had the strongest association with UI in multivariate modeling.