• Connected Community Classification (C3): Development, Validation, and Geospatial Application for Population Health Promotion and Equity

      Skiba, Meghan B; Lind, Kimberly E; Felion, Carlie M; Krupnik, Christopher; Segrin, Chris; Advanced Nursing Practice and Science Division, College of Nursing, University of Arizona Cancer Center, University of Arizona; Department of Health Promotion Sciences, Mel and Enid Zuckerman College of Public Health, University of Arizona; Department of Mining and Geological Engineering, College of Engineering, University of Arizona; Department of Communication, College of Social and Behavioral Sciences, University of Arizona (LIPPINCOTT WILLIAMS & WILKINS, 2024-03-01)
      CONTEXT: Social determinants of health (SDOH) impact population health. Leveraging community-level strengths related to SDOH through a social infrastructure perspective can optimize health behaviors and health outcomes to promote health equity. OBJECTIVE: Our aims were to develop, validate, and apply the Connected Community Classification (C3) as comprehensive community-level measure of protective SDOH and structural factors in the Four Corners states region of the United States. DESIGN: C3 was developed using an iterative principal component analysis of publicly available data mapped to 5 SDOH domains. Regional clustering of C3 by zip code tabulation area (ZCTA) was identified using spatial autocorrelation methods. MAIN OUTCOMES: In adjusted spatial autoregressive models, we analyzed the association of C3 with high-risk health behaviors and chronic disease prevalence using publicly available data for population-level estimates of fruit and vegetable intake, physical activity, obesity, smoking, alcohol use, coronary heart disease (CHD), diabetes, and cancer. RESULTS: C3 was found to be reliable and valid; a C3 value of 10 indicates communities with greater connection (high), while a value of 1 indicates communities with greater separation (low) to social infrastructure. Lower connection, as measured by C3, was significantly inversely associated with lower fruit and vegetable intake, lower physical activity, and higher rates of obesity, smoking, CHD, diabetes, and cancer. C3 was significantly positively associated with heavy alcohol use. CONCLUSIONS: These findings demonstrate that communities connected to social infrastructure have better population health outcomes. C3 captures protective community attributes and can be used in future applications to assist health researchers, practitioners, nonprofits, and policymakers to advance social connection and health equity in geographically diverse underserved regions.
    • Radar-Based Fall Detection: A Survey

      Hu, Shuting; Cao, Siyang; Toosizadeh, Nima; Barton, Jennifer; Hector, Melvin G.; Fain, Mindy J.; Department of Electrical and Computer Engineering, University of Arizona; Department of Biomedical Engineering, University of Arizona; Department of Medicine, University of Arizona (Institute of Electrical and Electronics Engineers (IEEE), 2024-02-05)
      Fall detection, particularly critical for high-risk demographics like the elderly, is a key public health concern, where timely detection can greatly minimize harm. With the advancements in radio frequency (RF) technology, radar has emerged as a powerful tool for human fall detection. Traditional machine learning (ML) algorithms, such as support vector machines (SVM) and <italic>k</italic>-nearest neighbors (kNN), have shown promising outcomes. However, deep learning (DL) approaches, notably convolutional neural networks (CNNs) and recurrent neural networks (RNNs), have outperformed in learning intricate features and managing large, unstructured datasets. This survey offers an in-depth analysis of radar-based fall detection, with emphasis on micro-Doppler, range-Doppler, and range-Doppler-angles techniques. We discuss the intricacies and challenges in fall detection and emphasize the necessity for a clear definition of falls and appropriate detection criteria, informed by diverse influencing factors. We present an overview of radar signal-processing principles and the underlying technology of radar-based fall detection, providing an accessible insight into ML and DL algorithms. After examining 74 research articles on radar-based fall detection published since 2000, we aim to bridge current research gaps and underscore the potential future research strategies, emphasizing the real-world applications possibility and the unexplored potential of DL in improving radar-based fall detection.
    • Achieving Nearly 100% Photoluminescence Quantum Efficiency in Organic Radical Emitters by Fine‐Tuning the Effective Donor‐Acceptor Distance

      Lu, Chen; Cho, Eunkyung; Wan, Keke; Wu, Chunxiao; Gao, Yuhang; Coropceanu, Veaceslav; Brédas, Jean‐Luc; Li, Feng; Department of Chemistry and Biochemistry, The University of Arizona (Wiley, 2024-02-05)
      Donor-acceptor (D–A•) type luminescent organic radicals have received widespread attention as efficient doublet emitters. However, their generally low photoluminescence quantum efficiency (PLQE) and limited photostability restrict their various applications. Since unraveling the relationship between structure and properties of D–A• type luminescent radicals remains a challenge, here, a series of tri(2,4,6-trichlorophenyl)methyl (TTM) radical derivatives, which differ by the location of their ring fusion sites and nature of their heteroatoms, is synthesized. The PLQE of isomers varies by ten times as a function of ring fusion sites. In particular, the PLQE of a radical undergoing ring fusion at the carbazole 3,4-position is as high as 98.0%. Quantum-chemical calculations show that in the case of overlapping holes and electrons, by increasing the effective distance between the D and A moieties, the radiative transition rates of the radicals increase. Also, decreasing the electronic coupling between the charge-transfer and local-excited states and avoiding large geometrical distortions between the ground state (D0)_and the first excited state (D1) can significantly reduce the nonradiative transition rates. This work offers a design strategy to obtain efficient and stable luminescent radicals by modifying the sites of ring fusion, which allows control of the radiative and nonradiative transition rates.
    • Meeting Report Dendroclimatology Conference in Tucson, May 2023

      Frank, David C.; Anchukaitis, Kevin J.; Leavitt, Steven W.; Lab. of Tree-Ring Research, University of Arizona; School of Geography, Development & Environment, University of Arizona (Tree-Ring Society, 2024-02-05)
    • Improved amplification of fecal DNA supports non-invasive microsatellite genotyping of lesser long-nosed bats (Leptonycteris yerbabuenae)

      Walker, John-Lee Sky; Steidl, Robert J.; Wolf, Sandy A.; Lee, Ming-Min; Arnold, A. Elizabeth; School of Natural Resources and the Environment, The University of Arizona; School of Plant Sciences, The University of Arizona; Department of Ecology and Evolutionary Biology, The University of Arizona; Bio5 Institute, The University of Arizona (Springer Science and Business Media LLC, 2024-02-04)
      Feces of animals that forage on nectar and fruit, including many species of bats, often contain DNA that is low in quality and quantity. We developed an approach based on DNA from feces gathered passively to generate microsatellite data for individual lesser long-nosed bats (Leptonycteris yerbabuenae), which are important pollinators for columnar cacti and agave across much of Mexico and in the southwestern U.S. We collected feces from roosts near the U.S-Mexico border and developed a two-step amplification approach to characterize five highly polymorphic microsatellite loci from fecal DNA. Addition of a multiplex PCR step improved amplification success and conserved DNA extracts with a minimal increase in cost. In our initial screening of 433 samples, five focal loci distinguished individuals reliably, with a probability of identity (i.e., the probability of two unrelated individuals having the same microsatellite profile by chance) of 7.5E-09. Repeated analyses revealed a genotyping error rate < 2%. We explore the benefits and limits of our approach for population studies of lesser long-nosed bats and other nectivorous and frugivorous species that provide key ecosystem services and are often of conservation concern.
    • Knowledge distillation under ideal joint classifier assumption

      Li, Huayu; Chen, Xiwen; Ditzler, Gregory; Roveda, Janet; Li, Ao; Department of Electrical & Computer Engineering at the University of Arizona; Department of Biomedical Engineering, The University of Arizona; BIO5 Institute, The University of Arizona (Elsevier Ltd, 2024-02-03)
      Knowledge distillation constitutes a potent methodology for condensing substantial neural networks into more compact and efficient counterparts. Within this context, softmax regression representation learning serves as a widely embraced approach, leveraging a pre-established teacher network to guide the learning process of a diminutive student network. Notably, despite the extensive inquiry into the efficacy of softmax regression representation learning, the intricate underpinnings governing the knowledge transfer mechanism remain inadequately elucidated. This study introduces the ‘Ideal Joint Classifier Knowledge Distillation’ (IJCKD) framework, an overarching paradigm that not only furnishes a lucid and exhaustive comprehension of prevailing knowledge distillation techniques but also establishes a theoretical underpinning for prospective investigations. Employing mathematical methodologies derived from domain adaptation theory, this investigation conducts a comprehensive examination of the error boundary of the student network contingent upon the teacher network. Consequently, our framework facilitates efficient knowledge transference between teacher and student networks, thereby accommodating a diverse spectrum of applications.
    • Art and emotion processing among arab breast cancer survivors: An exploratory study

      Hebi, Maimounah; Czamanski-Cohen, Johanna; Azaiza, Faisal; Weihs, Karen L.; College of Medicine, Department of Psychiatry, The University of Arizona (Elsevier BV, 2024-02-01)
      Art therapy (AT) has demonstrated potential for improving the well-being of breast cancer (BC) survivors, but limited research exists on emotion processing (EP) of Arab women in this context. Thus, this study delves into the relationship between EP and the art-making of Arab BC survivors in an AT group intervention to provide an in-depth understanding of their unique experience. We hypothesized that openly expressing emotions in the face of life-threatening events, such as BC, might be difficult for individuals from collective cultures with a strong emphasis on social harmony. We conducted a mixed-methods exploratory study (N = 62) with a visual analysis of 22 drawings and a textual analysis of reports from five art therapists. Positive correlations were observed between conservation values, acceptance of emotions, values, and artistic elements. Acceptance of emotions correlated negatively with space in drawing. Textual analysis of therapist reports revealed two themes—coping strategies and mixed emotions—corresponding to phenomena observed in the drawings. The women reported that art-making in a group facilitated access to their inner emotions, reinforced personal boundaries, and provided a safe space for addressing complex experiences. The AT group also offered socialization with women in similar circumstances. We conclude that AT provided these Arab BC survivors a culturally sensitive means of safely processing emotions through creative visual expression. Further research is needed to examine if AT is also helpful to BC survivors from other collectivist ethno-cultures.
    • Transcriptome analysis of reproductive tract tissues of male river prawn Macrobrachium americanum

      Martín-Manzo, Miriam Victoria; Morelos-Castro, Rosa María; Munguia-Vega, Adrian; Soberanes-Yepiz, Maritza Lourdes; Cortés-Jacinto, Edilmar; Conservation Genetics Laboratory, The University of Arizona (Springer Science and Business Media B.V., 2024-02-01)
      The cDNA library was constructed and sequenced for each tissue to identify novel transcripts. A combined transcriptome with the three tissues was assembled using Trinity software. Unigenes were annotated using BLASTx and BLAST2GO. The transcriptome assembly generated 1,059,447 unigenes, of which 7222 genes had significant hits (e-value < 1 × 10-5) when compared against the Swiss-Prot database. Around 75 genes were related to sex determination, testis development, spermatogenesis, spermiogenesis, fertilization, maturation of testicular cells, neuropeptides, hormones, hormone receptors, and/or embryogenesis.
    • The impact of multifunctional enkephalin analogs and morphine on the protein changes in crude membrane fractions isolated from the rat brain cortex and hippocampus

      Ujcikova, Hana; Lee, Yeon Sun; Roubalova, Lenka; Svoboda, Petr; Department of Pharmacology, University of Arizona (Elsevier Inc., 2024-02-01)
      Endogenous opioid peptides serve as potent analgesics through the opioid receptor (OR) activation. However, they often suffer from poor metabolic stability, low lipophilicity, and low blood-brain barrier permeability. Researchers have developed many strategies to overcome the drawbacks of current pain medications and unwanted biological effects produced by the interaction with opioid receptors. Here, we tested multifunctional enkephalin analogs LYS739 (MOR/DOR agonist and KOR partial antagonist) and LYS744 (MOR/DOR agonist and KOR full antagonist) under in vivo conditions in comparison with MOR agonist, morphine. We applied 2D electrophoretic resolution to investigate differences in proteome profiles of crude membrane (CM) fractions isolated from the rat brain cortex and hippocampus exposed to the drugs (10 mg/kg, seven days). Our results have shown that treatment with analog LYS739 induced the most protein changes in cortical and hippocampal samples. The identified proteins were mainly associated with energy metabolism, cell shape and movement, apoptosis, protein folding, regulation of redox homeostasis, and signal transduction. Among these, the isoform of mitochondrial ATP synthase subunit beta (ATP5F1B) was the only protein upregulation in the hippocampus but not in the brain cortex. Contrarily, the administration of analog LYS744 caused a small number of protein alterations in both brain parts. Our results indicate that the KOR full antagonism, together with MOR/DOR agonism of multifunctional opioid ligands, can be beneficial in treating chronic pain states by reducing changes in protein expression levels but retaining analgesic efficacy.
    • An integrated analytical modeling framework for determining site-specific soil screening levels for PFAS

      Smith, Jacob; Brusseau, Mark L.; Guo, Bo; Department of Environmental Science, University of Arizona; Department of Hydrology and Atmospheric Sciences, University of Arizona (Elsevier BV, 2024-02-01)
      Soils at many contaminated sites have accumulated a significant amount of per- and polyfluoroalkyl substances (PFAS) and may require remediation to mitigate leaching to groundwater. USEPA's current approaches for determining soil screening levels (SSLs) were developed for non-PFAS contaminants. Because many PFAS are interfacially-active with unique leaching behaviors in soils, the current non-PFAS-specific soil screening models may not be applicable. Following USEPA's general methodology, we develop a new modeling framework representing PFAS-specific transport processes for determining site-specific SSLs for PFAS-contaminated sites. We couple a process-based analytical model for PFAS leaching in the vadose zone and a dilution factor model for groundwater in an integrated framework. We apply the new modeling framework to two typical types of contaminated sites. Comparisons with the standard USEPA SSL approach suggest that accounting for the PFAS-specific transport processes may significantly increase the SSL for some PFAS. For the range of soil properties and groundwater recharge rates examined, while SSLs determined with the new model are less than a factor of 2 different from the standard-model values for less interfacially-active shorter-chain PFAS, they are up to two orders of magnitudes greater for more interfacially-active longer-chain PFAS. The new analytical modeling framework provides an effective tool for deriving more accurate site-specific SSLs and improving site characterization and remedial efforts at PFAS-contaminated sites.
    • Language development, linguistic input, and linguistic racism

      Figueroa, Megan; Department of Psychology, University of Arizona (Wiley, 2024-01-31)
      Language development is both remarkable and unremarkable. It is remarkable because children learn the language(s) around them, signed or spoken, without explicit instruction or correction. It is unremarkable because children have done this for thousands of years without worldwide incident or catastrophe. Yet, much research on this organic developmental phenomenon relies on an empirical falsehood: “quality” linguistic input is necessary to facilitate language development. “Quality” is a value judgment, not a structural feature of any human language. I argue selectively legitimizing some linguistic input as “quality” is possible only through mischaracterizing what language is. This falsehood is also linguistic racism because it is based on a deficit perspective of the early linguistic experiences of a subset of children, specifically racialized children. I explore how linguistic racism stalls our collective understanding of language development and promotes an environment of bad science. This article is categorized under: Linguistics > Language Acquisition Psychology > Language Neuroscience > Development.
    • Predictors of persistence of post-chemotherapy symptoms among survivors of solid tumor cancers

      Sikorskii, Alla; Badger, Terry; Segrin, Chris; Crane, Tracy E.; Cunicelli, Nathan; Chalasani, Pavani; Arslan, Waqas; Given, Charles; Department of Communication, University of Arizona; College of Medicine, University of Arizona, Phoenix, AZ, United States; et al. (Springer Science and Business Media LLC, 2024-01-30)
      Context: Late or residual symptoms diminish quality of life for many cancer survivors after completion of treatment. Objectives: Examine risk factors associated with persisting symptom burden after chemotherapy and the lack of symptom improvement over time. Methods: Survivors who completed curative-intent chemotherapy within two years for solid tumors were enrolled into a symptom management trial. There were 375 survivors with two or more comorbid conditions or one comorbid condition and elevated depressive symptoms (pre-defined risk factors in the trial design) who received interventions and 71 survivors without these risk factors who did not receive interventions. For all survivors, symptoms were assessed at intake, 4, and 13 weeks and categorized as mild, moderate, or severe based on the interference with daily life. The probabilities of moderate or severe symptoms and symptom improvement were analyzed using generalized mixed-effects models in relation to comorbidity, depressive symptoms, age, sex, race/ethnicity, employment, time since chemotherapy completion, and physical function. Multiple symptoms were treated as nested within the survivor. Results: Moderate or severe symptoms at baseline and the lack of improvement over time were associated with younger age and lower physical function over and above a greater number of comorbidities and elevated severity of depressive symptoms. Conclusion: Risk factors identified in this research (younger age, lower physical function, greater comorbidity, and higher depressive symptoms) can be used to allocate resources for post-treatment symptom management for cancer survivors in order to relieve symptoms that do not necessarily resolve with time.
    • Release mechanism and interactions of cadmium and arsenic co-contaminated ferrihydrite by simulated in-vitro digestion assays

      Bai, Bing; Kong, Shuqiong; Root, Robert A.; Liu, Ruiqi; Wei, Xiaguo; Cai, Dawei; Chen, Yiyi; Chen, Jie; Yi, Zhihao; Chorover, Jon; et al. (Elsevier BV, 2024-01-26)
      Cadmium (Cd) and arsenic (As) co-contamination is widespread and threatens human health, therefore it is important to investigate the bioavailability of Cd and As co-exposure. Currently, the interactions of Cd and As by in vitro assays are unknown. In this work, we studied the concurrent Cd-As release behaviors and interactions with in vitro simulated gastric bio-fluid assays. The studies demonstrated that As bioaccessibility (2.04 to 0.18 ± 0.03%) decreased with Cd addition compared to the As(V) single system, while Cd bioaccessibility (11.02 to 39.08 ± 1.91%) increased with As addition compared to the Cd single system. Release of Cd and As is coupled to proton-promoted and reductive dissolution of ferrihydrite. The As(V) is released and reduced to As(Ⅲ) by pepsin. Pepsin formed soluble complexes with Cd and As. X-ray photoelectron spectroscopy showed that Cd and As formed Fe-As-Cd ternary complexes on ferrihydrite surfaces. The coordination intensity of As-O-Cd is lower than that of As-O-Fe, resulting in more Cd release from Fe-As-Cd ternary complexes. Our study deepens the understanding of health risks from Cd and As interactions during environmental co-exposure of multiple metal(loid)s.
    • Conductive gradient hydrogels allow spatial control of adult stem cell fate

      Song, Shang; McConnell, Kelly W.; Shan, Dingying; Chen, Cheng; Oh, Byeongtaek; Sun, Jindi; Poon, Ada S. Y.; George, Paul M.; Departments of Neuroscience GIDP, Materials Science and Engineering, BIO5 Institute, The University of Arizona; Department of Biomedical Engineering, The University of Arizona (Royal Society of Chemistry (RSC), 2024-01-25)
      Electrical gradients are fundamental to physiological processes including cell migration, tissue formation, organ development, and response to injury and regeneration. Current electrical modulation of cells is primarily studied under a uniform electrical field. Here we demonstrate the fabrication of conductive gradient hydrogels (CGGs) that display mechanical properties and varying local electrical gradients mimicking physiological conditions. The electrically-stimulated CGGs enhanced human mesenchymal stem cell (hMSC) viability and attachment. Cells on CGGs under electrical stimulation showed a high expression of neural progenitor markers such as Nestin, GFAP, and Sox2. More importantly, CGGs showed cell differentiation toward oligodendrocyte lineage (Oligo2) in the center of the scaffold where the electric field was uniform with a greater intensity, while cells preferred neuronal lineage (NeuN) on the edge of the scaffold on a varying electric field at lower magnitude. Our data suggest that CGGs can serve as a useful platform to study the effects of electrical gradients on stem cells and potentially provide insights on developing new neural engineering applications.
    • Affectionate Communication Mediates the Effects of Minority Stress on Mental Wellness for LGBTQIA+ Adults

      Hesse, Colin; Floyd, Kory; Department of Communication, University of Arizona (Informa UK Limited, 2024-01-24)
      As a prosocial behavior, affectionate communication evidences a stress-buffering effect, ameliorating the deleterious effects of stressors on stress. Although much previous research has documented such an effect on physiological stress reactivity, the present study examines the ability of trait-level affectionate communication to mediate the effect of minority stress on mental wellness for LGBTQIA+ adults. Using a sample of U.S. American LGBTQIA+ adults (N = 494), this project demonstrates that psychological stress and depressive symptoms are negatively associated with trait affectionate communication and that trait affectionate communication partially mediates the effect of minority stress on these outcomes.
    • A health monitoring technique for spherical structures based on multi-acoustic source localization

      Zhou, Zixian; Cui, Zhiwen; Liu, Jinxia; Kundu, Tribikram; Department of Civil and Architectural Engineering and Mechanics, University of Arizona; Department of Aerospace and Mechanical Engineering, Materials Science and Engineering Department, University of Arizona (SAGE Publications, 2024-01-23)
      Multi-acoustic source localization (MASL) technique has important applications in the early warning and maintenance of spherical structures. Without solving complex nonlinear equations and without knowing the wave velocity distribution a priori, this work demonstrates the feasibility of MASL on the surface of spherical structures using L-shaped sensor clusters. The positions of multiple acoustic sources can be localized using only time difference of arrival values. Relative location determination and relative probability density analysis have been presented and verified to eliminate two types of pseudo-sources. Simulations are performed for isotropic and anisotropic spherical shells. The proposed technique is validated experimentally for stainless steel spherical shells. Simulation and experimental results show that the proposed technique can enable MASL in spherical structures without knowing the wave velocity in the material.
    • Multilevel Monte Carlo methods for the Grad-Shafranov free boundary problem

      Elman, Howard C.; Liang, Jiaxing; Sánchez-Vizuet, Tonatiuh; Department of Mathematics, The University of Arizona (Elsevier BV, 2024-01-19)
      The equilibrium configuration of a plasma in an axially symmetric reactor is described mathematically by a free boundary problem associated with the celebrated Grad-Shafranov equation. The presence of uncertainty in the model parameters introduces the need to quantify the variability in the predictions. This is often done by computing a large number of model solutions on a computational grid for an ensemble of parameter values and then obtaining estimates for the statistical properties of solutions. In this study, we explore the savings that can be obtained using multilevel Monte Carlo methods, which reduce costs by performing the bulk of the computations on a sequence of spatial grids that are coarser than the one that would typically be used for a simple Monte Carlo simulation. We examine this approach using both a set of uniformly refined grids and a set of adaptively refined grids guided by a discrete error estimator. Numerical experiments show that multilevel methods dramatically reduce the cost of simulation, with cost reductions typically on the order of 60 or more and possibly as large as 200. Adaptive griding results in more accurate computation of geometric quantities such as x-points associated with the model.
    • Nectar robbers and simulated robbing differ in their effects on nectar microbial communities

      Luizzi, Victoria J.; Harrington, Alison H.; Bronstein, Judith L.; Arnold, A. Elizabeth; Department of Ecology and Evolutionary Biology, The University of Arizona; School of Plant Sciences, The University of Arizona; Bio5 Institute, The University of Arizona (Wiley, 2024-01-17)
      Floral nectar contains microbes that can influence nectar chemistry and pollinator visitation, and these microbial communities can be affected by pollinators in turn. Some flowers are also visited by nectar robbers, which feed on nectar through holes cut in floral tissue. If nectar robbers alter nectar microbial communities, they might have unexpected impacts on pollinator visitation. We investigated whether robbing could affect nectar microbial communities directly, by introducing microbes, or indirectly, by triggering a plant response to floral damage. We applied four treatments to flowers of Tecoma × “Orange Jubilee” (Bignoniaceae) in an arboretum setting: flowers were (1) covered to exclude all visitors; (2) available to both pollinators and nectar robbers and robbed naturally by carpenter bees; (3) available to pollinators only but cut at the base to simulate nectar robbing damage; or (4) available to pollinators only. We found that nectar in flowers accessible to any visitors was more likely to contain culturable microbes than flowers from which visitors were excluded. Microbial community composition and beta diversity were similar across treatments. Among flowers containing culturable microbes, flowers available to pollinators and nectar robbers had higher microbial abundance than flowers with simulated robbing, but there were no differences between flowers available to pollinators and robbers and unwounded flowers from which robbers were excluded. Overall, our results suggest that floral damage can affect some features of nectar microbial communities, but specific effects of nectar robbing are limited compared with the influence of visitation in general.
    • Study of Jupiter’s interior: Comparison of 2, 3, 4, 5, and 6 layer models

      Militzer, Burkhard; Hubbard, William B.; Lunar and Planetary Laboratory, The University of Arizona (Elsevier BV, 2024-01-17)
      With the goal of matching spacecraft measurements from Juno and Galileo missions, we construct ensembles of 2, 3, 4, 5, and 6 layer models for Jupiter's interior. All except our two layer models can match the planet's gravity field as measured by the Juno spacecraft. We find, however, that some model types are more plausible than others. In the best three layer models, for example, the transition from molecular to metallic hydrogen needs to be at ∼500 GPa while theory and experiments place this transition at ∼100 GPa. Four layer models with a single sharp boundary between core and mantle would be short-lived due to rapid convective core erosion. For this reason, we favor our five layer models that include a dilute core surrounded by a stably stratified core transition layer. Six layer models with a small compact core are also possible but with an upper limit of 3 Earth masses for such a compact core. All models assume a 1 bar temperature of 166.1 K, employ physical equations of state, and are constructed with the nonperturbative Concentric Maclaurin Spheroid (CMS) method. We analyze the convergence of this method and describe technical steps that are needed to make this technique so efficient that ensembles of models can be generated.
    • Discerning Obstacles and Opportunities: A Framework for Evaluating Power

      Friesen, Rebecca; Cimetta, Adriana D.; University of Arizona (SAGE Publications Inc., 2024-01-17)
      Understanding what hinders or facilitates the implementation of change strengthens formative assessments. We propose a framework for interrogating the relational, political, discursive, and structural dimensions of power-shaping change efforts. In addition, we describe the application of this framework to a change initiative to better understand the influences on the project. Although evaluators usually only consider how power affects the evaluation process, exposing how these dimensions of power influence an initiative can reveal obstacles and opportunities and lead to the formation of more effective initiatives.