• Soil microbial community and abiotic soil properties influence Zn and Cd hyperaccumulation differently in Arabidopsis halleri

      Kushwaha, Priyanka; Neilson, Julia W.; Maier, Raina M.; Babst-Kostecka, Alicja; Department of Environmental Science, The University of Arizona (Elsevier BV, 2022-01)
      Soil contamination with trace metal(loid) elements (TME) is a global concern. This has focused interest on TME-tolerant plants, some of which can hyperaccumulate extraordinary amounts of TME into above-ground tissues, for potential treatment of these soils. However, intra-species variability in TME hyperaccumulation is not yet sufficiently understood to fully harness this potential. Particularly, little is known about the rhizosphere microbial communities associated with hyperaccumulating plants and whether or not they facilitate TME uptake. The aim of this study is to characterize the diversity and structure of Arabidopsis halleri rhizosphere-influenced and background (i.e., non-Arabidopsis) soil microbial communities in four plant populations with contrasting Zn and Cd hyperaccumulation traits, two each from contaminated and uncontaminated sites. Microbial community properties were assessed along with geographic location, climate, abiotic soil properties, and plant parameters to explain variation in Zn and Cd hyperaccumulation. Site type (TME-contaminated vs. uncontaminated) and location explained 44% of bacterial/archaeal and 28% of fungal community variability. A linear discriminant effect size (LEfSe) analysis identified a greater number of taxa defining rhizosphere microbial communities than associated background soils. Further, in TME-contaminated soils, the number of rhizosphere-defining taxa was 6-fold greater than in the background soils. In contrast, the corresponding ratio for uncontaminated sites, was 3 and 1.6 for bacteria/archaea and fungi, respectively. The variables analyzed explained 71% and 76% of the variance in Zn and Cd hyperaccumulation, respectively; however, each hyperaccumulation pattern was associated with different variables. A. halleri rhizosphere fungal richness and diversity associated most strongly with Zn hyperaccumulation, whereas soil Cd and Zn bioavailability had the strongest associations with Cd hyperaccumulation. Our results indicate strong associations between A. halleri TME hyperaccumulation and rhizosphere microbial community properties, a finding that needs to be further explored to optimize phytoremediation technology that is based on hyperaccumulation.
    • Do all facial emojis communicate emotion? The impact of facial emojis on perceived sender emotion and text processing

      Pfeifer, Valeria A.; Armstrong, Emma L.; Lai, Vicky Tzuyin; Department of Psychology, University of Arizona; Cognitive Science Program, University of Arizona (Elsevier BV, 2022-01)
      Facial emojis can express a variety of positive and negative emotions, and are commonly used in digital, written communication. However, little is known about how emojis impact text processing and how different emoji-text combinations give rise to a sender's mental state. In this study, we investigated how facial emojis with positive valence (= happy emojis) and facial emojis with negative valence (= upset emojis) embedded in emotionally ambiguous/neutral text affect the perceived mental state of the sender using ratings (Experiment 1) and the processing of the text messages using Event-Related Potentials (Experiment 2). We predicted that (1) the same text message with happy and upset emojis would convey different sender mental states, and (2) emoji valence would affect the processing of subsequent text in valence-specific ways. Our Experiment 1 results showed that while texts with upset emojis convey specific sender mental states, texts with happy emojis convey positive emotion more generally, with no further differentiation between emojis. In ERPs (Experiment 2), we found that emojis affect subsequent text processing at N400, and emoji valence affects processing downstream at the second word. We concluded that all facial-emojis impact text processing, but happy and upset emojis carry differential social-emotional salience and impact text processing differently when content becomes available.
    • Elevated temperatures drive abiotic and biotic degradation of organic matter in a peat bog under oxic conditions

      AminiTabrizi, Roya; Dontsova, Katerina; Graf Grachet, Nathalia; Tfaily, Malak M.; Department of Environmental Science, The University of Arizona (Elsevier BV, 2022-01)
      Understanding the effects of elevated temperatures on soil organic matter (SOM) decomposition pathways in northern peatlands is central to predicting their fate under future warming. Peatlands role as carbon (C) sink is dependent on both anoxic conditions and low temperatures that limit SOM decomposition. Previous studies have shown that elevated temperatures due to climate change can disrupt peatland's C balance by enhancing SOM decomposition and increasing CO2 emissions. However, little is known about how SOM decomposition pathways change at higher temperatures. Here, we used an integrated research approach to investigate the mechanisms behind enhanced CO2 emissions and SOM decomposition under elevated temperatures of surface peat soil collected from a raised and Sphagnum dominated mid-continental bog (S1 bog) peatland at the Marcel Experimental Forest in Minnesota, USA, incubated under oxic conditions at three different temperatures (4, 21, and 35 °C). Our results indicated that elevated temperatures could destabilize peatland's C pool via a combination of abiotic and biotic processes. In particular, temperature-driven changes in redox conditions can lead to abiotic destabilization of Fe-organic matter (phenol) complexes, previously an underestimated decomposition pathway in peatlands, leading to increased CO2 production and accumulation of polyphenol-like compounds that could further inhibit extracellular enzyme activities and/or fuel the microbial communities with labile compounds. Further, increased temperatures can alter strategies of microbial communities for nutrient acquisition via changes in the activities of extracellular enzymes by priming SOM decomposition, leading to enhanced CO2 emission from peatlands. Therefore, coupled biotic and abiotic processes need to be incorporated into process-based climate models to predict the fate of SOM under elevated temperatures and to project the likely impacts of environmental change on northern peatlands and CO2 emissions.
    • Development of aquaculture protocols and gonadal differentiation of green sunfish (Lepomis cyanellus)

      Teal, Chad N.; Schill, Daniel J.; Fogelson, Susan B.; Roberts, Colby M.; Fitzsimmons, Kevin; Bonar, Scott A.; Arizona Cooperative Fish and Wildlife Research Unit, School of Natural Resources and the Environment, University of Arizona; University of Arizona, School of Natural Resources and the Environment (Elsevier BV, 2022-01)
      We provide detailed rearing methods and describe green sunfish (Lepomis cyanellus) gonadal development and histological differentiation for both sexes. Developing in-depth aquaculture protocols and describing the gonadal differentiation of green sunfish could facilitate strategies to control nuisance populations, enhance stocking programs, and provide information for this species' use in bioassay trials or toxicology studies. Our methods resulted in consistent year-round production of green sunfish and allowed us to identify the timing of their gonadal differentiation through histological assessment. Our spawning methods provided year-round volitional spawns from green sunfish broodstock. Our rearing methods involved weaning larval green sunfish off live nauplii and onto only artificial diets by 37 days post-hatch (dph). Most of the offspring generation reached sexual maturity by 213 dph. Green sunfish are gonochoristic, with testes and ovaries differentiating directly from undifferentiated gonads. Ovaries begin to differentiate by 39 dph and testes begin to differentiate by 69 dph. This information can provide biologists consistent means to produce this Centrachid and understand their gonadal development.
    • Arid Ecosystem Vegetation Canopy-Gap Dichotomy: Influence on Soil Microbial Composition and Nutrient Cycling Functional Potential

      Kushwaha, Priyanka; Neilson, Julia W.; Barberán, Albert; Chen, Yongjian; Fontana, Catherine G.; Butterfield, Bradley J.; Maier, Raina M.; Department of Environmental Science, University of Arizona (American Society for Microbiology, 2021-12-11)
      Increasing temperatures and drought in desert ecosystems are predicted to cause decreased vegetation density combined with barren ground expansion. It remains unclear how nutrient availability, microbial diversity, and the associated functional capacity vary between the vegetated canopy and gap soils. The specific aim of this study was to characterize canopy versus gap microsite effect on soil microbial diversity, the capacity of gap soils to serve as a canopy soil microbial reservoir, nitrogen (N)-mineralization genetic potential (ureC gene abundance) and urease enzyme activity, and microbial-nutrient pool associations in four arid-hyperarid geolocations of the western Sonoran Desert, Arizona, United States. Microsite combined with geolocation explained 57% and 45.8% of the observed variation in bacterial/archaeal and fungal community composition, respectively. A core microbiome of amplicon sequence variants was shared between the canopy and gap soil communities; however, canopy soils included abundant taxa that were not present in associated gap communities, thereby suggesting that these taxa cannot be sourced from the associated gap soils. Linear mixed-effects models showed that canopy soils have significantly higher microbial richness, nutrient content, and organic N-mineralization genetic and functional capacity. Furthermore, ureC gene abundance was detected in all samples, suggesting that ureC is a relevant indicator of N mineralization in deserts. Additionally, novel phylogenetic associations were observed for ureC, with the majority belonging to Actinobacteria and uncharacterized bacteria. Thus, key N-mineralization functional capacity is associated with a dominant desert phylum. Overall, these results suggest that lower microbial diversity and functional capacity in gap soils may impact ecosystem sustainability as aridity drives openspace expansion in deserts.
    • Phytoextraction efficiency of Arabidopsis halleri is driven by the plant and not by soil metal concentration

      Dietrich, Charlotte C.; Tandy, Susan; Murawska-Wlodarczyk, Kamila; Banaś, Angelika; Korzeniak, Urszula; Seget, Barbara; Babst-Kostecka, Alicja; Department of Environmental Science, The University of Arizona (Elsevier BV, 2021-12)
      The hyperaccumulation trait allows some plant species to allocate remarkable amounts of trace metal elements (TME) to their foliage without suffering from toxicity. Utilizing hyperaccumulating plants to remediate TME contaminated sites could provide a sustainable alternative to industrial approaches. A major hurdle that currently hampers this approach is the complexity of the plant-soil relationship. To better anticipate the outcome of future phytoremediation efforts, we evaluated the potential for soil metal-bioavailability to predict TME accumulation in two non-metallicolous and two metallicolous populations of the Zn/Cd hyperaccumulator Arabidopsis halleri. We also examined the relationship between a population's habitat and its phytoextraction efficiency. Total Zn and Cd concentrations were quantified in soil and plant material, and bioavailable fractions in soil were quantified via Diffusive Gradients in Thin-films (DGT). We found that shoot TME accumulation varied independent from both total and bioavailable soil TME concentrations in metallicolous individuals. In fact, hyperaccumulation patterns appear more plant- and less soil-driven: one non-metallicolous population proved to be as efficient in accumulating Zn on non-polluted soil as the metallicolous populations in their highly contaminated environment. Our findings demonstrate that in-situ information on plant phytoextraction efficiency is indispensable to optimize site-specific phytoremediation measures. If successful, hyperaccumulating plant biomass may provide valuable source material for application in the emerging field of green chemistry. © 2021 Elsevier Ltd
    • When and why we disclose distress on SNSs: Perceived affordances, disclosure goals, and anticipated negative evaluations

      Zhao, Pengfei; Lapierre, Matthew A.; Rains, Stephen A.; Segrin, Chris; Department of Communication, University of Arizona (Elsevier BV, 2021-12)
      Social networking sites (SNSs) offer unprecedented opportunities for broadcasting self-disclosure. However, questions regarding when and why people tend to post distressing information on SNSs have received insufficient scholarly attention. Rooted in the functional approach of self-disclosure, we investigated how perceived SNS affordances (i.e., network accessibility, visibility, and visibility control) are associated with broadcasting distress disclosure tendencies on SNSs via disclosure goals. Working with 398 college students, we found that people disclose distress on SNSs for seeking support and expressing emotions. However, anticipated negative evaluations can lessen the associations between disclosure goals and distress disclosures on SNSs. Furthermore, the results revealed that network accessibility was indirectly associated with distress disclosures on SNSs via support-seeking goals while visibility control was indirectly related to distress disclosures via emotion expression goals. The indirect effects indicate the importance of studying disclosure goals when investigating the associations between affordances and disclosures. Together, this study advances our understanding regarding online distress disclosures by integrating SNS affordances, disclosures goals, and subjective risks.
    • Applying molecular dynamics simulation to take the fracture fingerprint of polycrystalline SiC nanosheets

      Molaei, Fatemeh; Zarghami Dehaghani, Maryam; Salmankhani, Azam; Fooladpanjeh, Sasan; Sajadi, S. Mohammad; Esmaeili Safa, Mohammad; Abida, Otman; Habibzadeh, Sajjad; Hamed Mashhadzadeh, Amin; Saeb, Mohammad Reza; et al. (Elsevier BV, 2021-12)
      Graphene-like nanosheets are the key elements of advanced materials and systems. The mechanical behavior of the structurally perfect 2D nanostructures is well documented, but that of polycrystalline ones is less understood. Herein, we applied molecular dynamics simulation (MDS) to take the fracture fingerprint of polycrystalline SiC nanosheets (PSiCNS), where monocrystalline SiC nanosheets (MSiCNS) was the reference nanosheet. The mechanical responses of defect-free and defective MSiCNS and PSiCNS having regular cracks and circular-shaped notches were captured as a function of temperature (100–1200 K), such that elevated temperatures were unconditionally deteriorative to the properties. Moreover, larger cracks and notches more severely decreased the strength of PSiCNS, e.g. Young's modulus dropped to ca. 41% by the crack enlargement. The temperature rise similarly deteriorated the failure stress and Young's modulus of PSiCNS. However, the stress intensity factor increased by the enlargement of the crack length but decreased against temperature. We believe that the findings of the present study can shed some light on designing mechanically stable nanostructures for on-demand working conditions. © 2021 Elsevier B.V.
    • The Bramson delay in a Fisher–KPP equation with log-singular nonlinearity

      Bouin, Emeric; Henderson, Christopher; Department of Mathematics, University of Arizona (Elsevier BV, 2021-12)
      We consider a class of reaction–diffusion equations of Fisher–KPP type in which the nonlinearity (reaction term) f is merely C1 at u=0 due to a logarithmic competition term. We first derive the asymptotic behavior of (minimal speed) traveling wave solutions that is, we obtain precise estimates on the decay to zero of the traveling wave profile at infinity. We then use this to characterize the Bramson shift between the traveling wave solutions and solutions of the Cauchy problem with localized initial data. We find a phase transition depending on how singular f is near u=0 with quite different behavior for more singular f. This is in contrast to the smooth case, that is, when f∈C1,δ, where these behaviors are completely determined by f′(0). In the singular case, several scales appear and require new techniques to understand. © 2021 Elsevier Ltd
    • Involvement of T-type calcium channels in the mechanism of low dose morphine-induced hyperalgesia in adult male rats

      Abbasloo, Elham; Abdollahi, Farzaneh; Saberi, Arezoo; Esmaeili-Mahani, Saeed; Kaeidi, Ayat; Akhlaghinasab, Fereshteh; Sheibani, Vahid; Thomas, Theresa Currier; Kobeissy, Firas Hosni; Oryan, Shahrbanoo; et al. (Elsevier BV, 2021-12)
      It has been shown that systemic and local administration of ultra-low dose morphine induced a hyperalgesic response via mu-opioid receptors. However, its exact mechanism(s) has not fully been clarified. It is documented that mu-opioid receptors functionally couple to T-type voltage dependent Ca+2 channels. Here, we investigated the role of T-type calcium channels, amiloride and mibefradil, on the induction of low-dose morphine hyperalgesia in male Wistar rats. The data showed that morphine (0.01 μg i.t. and 1 μg/kg i.p.) could elicit hyperalgesia as assessed by the tail-flick test. Administration of amiloride (5 and 10 μg i.t.) and mibefradil (2.5 and 5 μg i.t.) completely blocked low-dose morphine-induced hyperalgesia in spinal dorsal horn. Amiloride at doses of 1 and 5 mg/kg (i.p.) and mibefradil (9 mg/kg ip) 10 min before morphine (1 μg/kg i.p.) inhibited morphine-induced hyperalgesia. Our results indicate a role for T-type calcium channels in low dose morphine-induced hyperalgesia in rats.
    • Water storage and release policies for all large reservoirs of conterminous United States

      Turner, Sean W.D.; Steyaert, Jennie Clarice; Condon, Laura; Voisin, Nathalie; University of Arizona (Elsevier BV, 2021-12)
      Large-scale hydrological and water resource models (LHMs) require water storage and release schemes to represent flow regulation by reservoirs. Owing to a lack of observed reservoir operations, state-of-the-art LHMs deploy a generic reservoir scheme that may fail to represent local operating behaviors. Here we introduce a new dataset of bespoke water storage and release policies for 1,930 reservoirs of conterminous United States. The Inferred Storage Targets and Release Functions (ISTARF-CONUS) dataset relies on a new inventory of observed daily reservoir operations (ResOpsUS) to generate reservoir operating rules for 595 data-rich reservoirs. These functions are developed in a standardized form that allows for extrapolation of operating schemes to 1,335 data-scarce reservoirs—leading to the first inventory of empirically derived reservoir operating policies for all large CONUS reservoirs documented in the Global Reservoir and Dams (GRanD) database. Evaluation of the new scheme in daily simulations forced with observed inflow demonstrates substantial and robust improvement for both release and storage relative to the popular Hanasaki method. Performance of the extrapolation approach for data-scarce reservoirs is evaluated with leave-one-out validation and is shown to also offer modest gains on average over Hanasaki. ISTARF-CONUS may be readily adopted in any LHM featuring large reservoirs of the conterminous United States.
    • Risk factors of sepsis among patients with qSOFA<2 in the emergency department

      Shibata, Junichiro; Osawa, Itsuki; Ito, Honoka; Soeno, Shoko; Hara, Konan; Sonoo, Tomohiro; Nakamura, Kensuke; Goto, Tadahiro; Department of Economics, University of Arizona (Elsevier BV, 2021-12)
      Objective: Studies have suggested that qSOFA can be used for early detection of sepsis immediately upon arrival at the emergency department (ED). Despite this, little is known about the risk factors associated with the subsequent diagnosis of sepsis among patients with qSOFA<2 in the ED. Methods: This is a retrospective cohort study using ED data from a large tertiary medical center in Japan, 2018–2020. We included adult patients (aged ≥18 years) presenting to the ED with suspected infection (e.g., having a fever) and qSOFA<2. We identified patients who developed sepsis based on the Sepsis-3 criteria, and compared patient characteristics (e.g., demographics, vital signs upon the initial triage, chief complaint, and comorbidities) between patients who developed sepsis or not. Additionally, we identified the potential risk factors of sepsis among patients with qSOFA<2 using a multivariable logistic regression model. Results: We identified 151 (7%) patients who developed sepsis among 2025 adult patients with suspected infection and qSOFA<2. Compared with patients who did not develop sepsis, patients who developed sepsis were likely to be older and have vital signs suggestive of imminent sepsis (e.g., high respiratory rate). In the multivariable logistic regression model, the potential risk factors of sepsis among patients with qSOFA<2 were older age (adjusted OR, 1.92 [95%CI 1.19–3.19]), vital signs suggestive of imminent sepsis (e.g., adjusted OR of altered mental status, 3.50 [95%CI 2.25–5.50]), receipt of oxygen therapy upon arrival at the ED (adjusted OR, 1.91 [95%CI 1.38–2.26]), chief complaint of sore throat (adjusted OR, 2.15 [95%CI 1.08–4.13]), and the presence of comorbid diabetes mellitus, ischemic heart disease, and chronic kidney disease (e.g., adjusted OR of diabetes mellitus, 1.47 [95%CI 1.10–1.96]). On the contrary, chief complaint of abdominal and chest pain were associated with a lower risk of sepsis (e.g., adjusted OR of abdominal pain, 0.26 [95%CI 0.14–0.45]). Conclusions: We found that older age, vital signs prognosticating sepsis, and the presence of some comorbidities were the potential risk factors of sepsis in patients with qSOFA<2. These potential risk factors could be useful to efficiently recognize patients who might develop sepsis in the ED.
    • Non-abelian orbifolds of lattice vertex operator algebras

      Gemünden, Thomas; Keller, Christoph A.; Department of Mathematics, University of Arizona (Elsevier BV, 2021-11)
      We construct orbifolds of holomorphic lattice vertex operator algebras for non-abelian finite automorphism groups G. To this end, we construct twisted modules for automorphisms g together with the projective representation of the centralizer of g on the twisted module. This allows us to extract the irreducible modules of the fixed-point VOA VG, and to compute their characters and modular transformation properties. We then construct holomorphic VOAs by adjoining such modules to VG. Applying these methods to extremal lattices in d=48 and d=72, we construct more than fifty new holomorphic VOAs of central charge 48 and 72, many of which have a very small number of light states.
    • Exfoliated bentonite/alginate nanocomposite hydrogel enhances intestinal delivery of probiotics by resistance to gastric pH and on-demand disintegration

      Kim, Jihyun; Hlaing, Shwe Phyu; Lee, Juho; Saparbayeva, Aruzhan; Kim, Sangsik; Hwang, Dong Soo; Lee, Eun Hee; Yoon, In-Soo; Yun, Hwayoung; Kim, Min-Soo; et al. (Elsevier BV, 2021-11)
      In this study, we developed Lactobacillus rhamnosus GG (LGG)-encapsulating exfoliated bentonite/alginate nanocomposite hydrogels for protecting probiotics by delaying gastric fluid penetration into the nanocomposite and their on-demand release in the intestine. The pore size of the bentonite/alginate nanocomposite hydrogels (BA15) was two-fold smaller than that of alginate hydrogel (BA00). Following gastric pH challenge, the survival of LGG in BA15 decreased by only 1.43 log CFU/g as compared to the 6.25 log CFU/g decrease in alginate (BA00). Further, the internal pH of BA15 decreased more gradually than that of BA00. After oral administration in mice, BA15 maintained shape integrity during gastric passage, followed by appropriate disintegration within the target intestinal area. Additionally, a fecal recovery experiment in mice showed that the viable counts of LGG in BA15 were six-fold higher than those in BA00. The findings suggest the exfoliated bentonite/alginate nanocomposite hydrogel as a promising platform for intestinal delivery of probiotics.
    • The ghost-box-ball system: A unified perspective on soliton cellular automata, the RSK algorithm and phase shifts

      Ercolani, Nicholas M.; Ramalheira-Tsu, Jonathan; Department of Mathematics, The University of Arizona (Elsevier BV, 2021-11)
      In this paper, we introduce the ghost-box-ball system, which is an extended version of the classical soliton cellular automaton. It is initially motivated as a mechanism for making precise a connection between the Schensted insertion (of the Robinson–Schensted–Knuth correspondence) and the dynamical process of the box-ball system. In addition to this motivation, we explore generalisations of classical notions of the box-ball system, including the solitonic phenomenon, the asymptotic sorting property, and the invariant shape construction. We analyse the ghost-box-ball system beyond its initial relevance to the Robinson–Schensted–Knuth correspondence, unpacking its relationship to its underlying dynamical evolution on a coordinatisation and using a mechanism for augmenting a regular box-ball configuration to study the classical ultradiscrete phase shift phenomenon. © 2021 Elsevier B.V.
    • PS3: The Pheno-Synthesis software suite for integration and analysis of multi-scale, multi-platform phenological data

      Morisette, Jeffrey T.; Duffy, Katharyn A.; Weltzin, Jake F.; Browning, Dawn M.; Marsh, R. Lee; Friesz, Aaron M.; Zachmann, Luke J.; Enns, Kyle D.; Landau, Vincent A.; Gerst, Katharine L.; et al. (Elsevier BV, 2021-11)
      Phenology is the study of recurring plant and animal life-cycle stages which can be observed across spatial and temporal scales that span orders of magnitude (e.g., organisms to landscapes). The variety of scales at which phenological processes operate is reflected in the range of methods for collecting phenologically relevant data, and the programs focused on these collections. Consideration of the scale at which phenological observations are made, and the platform used for observation, is critical for the interpretation of phenological data and the application of these data to both research questions and land management objectives. However, there is currently little capacity to facilitate access, integration and analysis of cross-scale, multi-platform phenological data. This paper reports on a new suite of software and analysis tools – the “Pheno-Synthesis Software Suite,” or PS3 – to facilitate integration and analysis of phenological and ancillary data, enabling investigation and interpretation of phenological processes at scales ranging from organisms to landscapes and from days to decades. We use PS3 to investigate phenological processes in a semi-aride, mixed shrub-grass ecosystem, and find that the apparent importance of seasonal precipitation to vegetation activity (i.e., “greenness”) is affected by the scale and platform of observation. We end by describing potential applications of PS3 to phenological modeling and forecasting, understanding patterns and drivers of phenological activity in real-world ecosystems, and supporting agricultural and natural resource management and decision-making.
    • Monitoring agroecosystem productivity and phenology at a national scale: A metric assessment framework

      Browning, Dawn M.; Russell, Eric S.; Ponce-Campos, Guillermo E.; Kaplan, Nicole; Richardson, Andrew D.; Seyednasrollah, Bijan; Spiegal, Sheri; Saliendra, Nicanor; Alfieri, Joseph G.; Baker, John; et al. (Elsevier BV, 2021-11)
      Effective measurement of seasonal variations in the timing and amount of production is critical to managing spatially heterogeneous agroecosystems in a changing climate. Although numerous technologies for such measurements are available, their relationships to one another at a continental extent are unknown. Using data collected from across the Long-Term Agroecosystem Research (LTAR) network and other networks, we investigated correlations among key metrics representing primary production, phenology, and carbon fluxes in croplands, grazing lands, and crop-grazing integrated systems across the continental U.S. Metrics we examined included gross primary productivity (GPP) estimated from eddy covariance (EC) towers and modelled from the Landsat satellite, Landsat NDVI, and vegetation greenness (Green Chromatic Coordinate, GCC) from tower-mounted PhenoCams for 2017 and 2018. Overall, our analysis compared production dynamics estimated from three independent ground and remote platforms using data for 34 agricultural sites constituting 51 site-years of co-located time series. Pairwise sensor comparisons across all four metrics revealed stronger correlation and lower root mean square error (RMSE) between end of season (EOS) dates (Pearson R ranged from 0.6 to 0.7 and RMSE from 32.5 to 67.8) than start of season (SOS) dates (0.46 to 0.69 and 40.4 to 66.2). Overall, moderate to high correlations between SOS and EOS metrics complemented one another except at some lower productivity grazing land sites where estimating SOS can be challenging. Growing season length estimates derived from 16-day satellite GPP (179.1 days) were significantly longer than those from PhenoCam GCC (70.4 days, padj &lt; 0.0001) and EC GPP (79.6 days, padj &lt; 0.0001). Landscape heterogeneity did not explain differences in SOS and EOS estimates. Annual integrated estimates of productivity from EC GPP and PhenoCam GCC diverged from those estimated by Landsat GPP and NDVI at sites where annual production exceeds 1000 gC/m−2 yr−1. Based on our results, we developed a “metric assessment framework” that articulates where and how metrics from satellite, eddy covariance and PhenoCams complement, diverge from, or are redundant with one another. The framework was designed to optimize instrumentation selection for monitoring, modeling, and forecasting ecosystem functioning with the ultimate goal of informing decision-making by land managers, policy-makers, and industry leaders working at multiple scales.
    • Conceptual framework for balancing society and nature in net-zero energy transitions

      Delafield, Gemma; Donnison, Caspar; Roddis, Philippa; Arvanitopoulos, Theodoros; Sfyridis, Alexandros; Dunnett, Sebastian; Ball, Thomas; Logan, Kathryn G.; Arizona Institutes for Resilience, University of Arizona (Elsevier BV, 2021-11)
      Transitioning to a low carbon energy future is essential to meet the Paris Agreement targets and Sustainable Development Goals (SDGs). To understand how societies can undertake this transition, energy models have been developed to explore future energy scenarios. These models often focus on the techno-economic aspects of the transition and overlook the long-term implications on both society and the natural environment. Without a holistic approach, it is impossible to evaluate the trade-offs, as well as the co-benefits, between decarbonisation and other policy goals. This paper presents the Energy Scenario Evaluation (ESE) framework which can be used to assess the impact of energy scenarios on society and the natural environment. This conceptual framework utilises interdisciplinary qualitative and quantitative methods to determine whether an energy scenario is likely to lead to a publicly acceptable and sustainable energy transition. Using the SDGs, this paper illustrates how energy transitions are interconnected with human development and the importance of incorporating environmental and socio-economic data into energy models to design energy scenarios which meet other policy priorities. We discuss a variety of research methods which can be used to evaluate spatial, environmental, and social impacts of energy transitions. By showcasing where these impacts will be experienced, the ESE framework can be used to facilitate engagement and decision-making between policymakers and local communities, those who will be directly affected by energy transitions. Outputs of the ESE framework can therefore perform an important role in shaping feasible and energy transitions which meet the Paris Agreement targets and SDGs.
    • Knowledge governance and learning: Examining challenges and opportunities in the Colorado River basin

      Gerlak, Andrea K.; Karambelkar, Surabhi; Ferguson, Daniel B.; University of Arizona, School of Geography, Development & Environment; University of Arizona, Climate Assessment for the Southwest (Elsevier BV, 2021-11)
      Knowledge is widely considered a key ingredient for effective and sustainable water governance. In the Colorado River basin, collaborative programs have been established over the past 50 years to inform decision-making in the basin on a range of concerns from water quality to endangered species recovery and ecosystem restoration. We embrace a knowledge governance perspective to examine the institutional arrangements underpinning the production and use of knowledge in the basin's collaborative programs. Through a review of programmatic documents and targeted interviews with program participants, we find a recurrent emphasis on science-based decision-making to address specific resource challenges across the programs. Our unpacking of the institutional design of the knowledge governance processes highlights two key challenges: (1) the institutional design has created a federal agency–advisory committee–technical committee triad structure that limits the saliency and legitimacy of diverse interests, as well as credibility of diverse ways of knowing and formalized learning processes and (2) a focus on the river in discrete, fragmented units that hinders a broader view of the river as a system and neglects cross-programmatic learning. These findings question if certain institutional design elements may serve to limit the ability of these programs to address new challenges facing the basin. We outline some potential steps to address these challenges with the aim of building more impactful, collaborative knowledge systems that leverage learning to not only lend saliency, credibility, and legitimacy to broad, inclusive, and diverse ways of knowing but also promote adaptiveness in a rapidly evolving socio-environmental system. © 2021 Elsevier Ltd
    • Current-conserving relativistic linear response for collisional plasmas

      Formanek, Martin; Grayson, Christopher; Rafelski, Johann; Müller, Berndt; Department of Physics, The University of Arizona (Elsevier BV, 2021-11)
      We investigate the response of a relativistic plasma to electromagnetic fields in the framework of the Boltzmann equation incorporating a collision term in the relaxation rate approximation selected in a form assuring current conservation. We obtain an explicit solution for the linearized perturbation of the Fermi–Dirac equilibrium distribution in terms of the average relaxation rate κ. We study the resulting covariant, gauge invariant, and current conserving form of the polarization tensor in the ultrarelativistic and non-relativistic limits. We evaluate the susceptibility in the ultrarelativistic limit and explore their dependence on κ. Finally, we study the dispersion relations for the longitudinal and transverse poles of the propagator. We show that for κ&gt;2ωp, where ωp is the plasma frequency, the plasma wave modes are overdamped. In the opposite case, κ≪ωp, the propagating plasma modes are weakly damped.