• 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.
    • Iron-activated persulfate oxidation degrades aqueous Perfluorooctanoic acid (PFOA) at ambient temperature

      Tran, Thien; Abrell, Leif; Brusseau, Mark L.; Chorover, Jon; Arizona Laboratory for Emerging Contaminants, The University of Arizona; Department of Environmental Science, The University of Arizona (Elsevier BV, 2021-10)
      Perfluorooctanoic acid (PFOA, C8HF15O2) is an industrial surfactant that is highly resistant to natural breakdown processes such as those mediated by heat, hydrolysis, photolysis, and biodegradation. Many efforts have been developed to breakdown PFOA to less harmful species due to its widespread human exposure and potential toxicity. However, these methods require high temperature or specialized equipment with serious disadvantages of high energy cost for long-term use. We investigated the effectiveness of PFOA degradation by ferrous iron-activated persulfate oxidation (IAPO) under various aqueous geochemical conditions. Approximately 64% of PFOA (initial concentration = 1.64 μmol L−1) was degraded after 4 h under illuminated anoxic conditions at ambient temperature. This degradation rate and magnitude support the potential use of IAPO as a novel inexpensive and environmentally friendly method to remediate PFOA in soil and groundwater. © 2021 Elsevier Ltd
    • Source identification of PM2.5 carbonaceous aerosol using combined carbon fraction, radiocarbon and stable carbon isotope analyses in Debrecen, Hungary

      Major, István; Furu, Enikő; Varga, Tamás; Horváth, Anikó; Futó, István; Gyökös, Brigitta; Somodi, Gábor; Lisztes-Szabó, Zsuzsa; Jull, A.J. Timothy; Kertész, Zsófia; et al. (Elsevier BV, 2021-08)
      In this study, PM2.5 aerosol samples collected continuously in Debrecen, Hungary from December 2011 to July 2014 were processed and analysed. Mass concentration and ratios of PM2.5 aerosol, organic and elemental carbon fractions, in addition, radio and stable carbon isotopes were evaluated together to obtain a better sight into the possible local and regional sources. For the studied period, the mean mass concentration of PM2.5 aerosol and the constituting total, organic and elemental carbon were 23.6, 5.8, 5.0 and 0.8 μg m−3, respectively. In all cases, the mean for the heating periods were on average 2–3 times that of the vegetation (i.e. heating-free) periods. The relatively high mean secondary organic carbon concentration of 4.1 μg m−3 and OC/EC ratio of 6.9 suggested the dominance of combustion processes in winter and, based on the higher contemporary carbon fraction of 0.77, wood fuels prevailed over coal or oil. The average δ13C of the tested wood fuels implies that combustion of black locust, oak and beech was a significant factor in forming the mean δ13C of PM2.5 of −25.6‰ during the heating months. The mean δ13C of −26.7‰ in summer was more influenced by emissions from transportation and the surrounding vegetation. In addition, using coupled backward trajectory modeling (HYSPLIT) and visualization of open fire events (FIRMS), we presume that the conspicuously enriched δ13C values of PM2.5 collected in October of the observation years were probably caused by long-range transport of particles derived from agricultural combustion of C4 plants close to the southern and eastern Hungarian borders. © 2021 Elsevier B.V.
    • Oxidative phosphorylation K0.5ADP in vitro depends on substrate oxidative capacity: Insights from a luciferase-based assay to evaluate ADP kinetic parameters

      Willis, Wayne; Willis, Elizabeth; Kuzmiak-Glancy, Sarah; Kras, Katon; Hudgens, Jamie; Barakati, Neusha; Stern, Jennifer; Mandarino, Lawrence; Department of Medicine, Division of Endocrinology, University of Arizona (Elsevier BV, 2021-08)
      The K0.5ADP of oxidative phosphorylation (OxPhos) identifies the cytosolic ADP concentration which elicits one-half the maximum OxPhos rate. This kinetic parameter is commonly measured to assess mitochondrial metabolic control sensitivity. Here we describe a luciferase-based assay to evaluate the ADP kinetic parameters of mitochondrial ATP production from OxPhos, adenylate kinase (AK), and creatine kinase (CK). The high sensitivity, reproducibility, and throughput of the microplate-based assay enabled a comprehensive kinetic assessment of all three pathways in mitochondria isolated from mouse liver, kidney, heart, and skeletal muscle. Carboxyatractyloside titrations were also performed with the assay to estimate the flux control strength of the adenine nucleotide translocase (ANT) over OxPhos in human skeletal muscle mitochondria. ANT flux control coefficients were 0.91 ± 0.07, 0.83 ± 0.06, and 0.51 ± 0.07 at ADP concentrations of 6.25, 12.5, and 25 μM, respectively, an [ADP] range which spanned the K0.5ADP. The oxidative capacity of substrate combinations added to drive OxPhos was found to dramatically influence ADP kinetics in mitochondria from several tissues. In mouse skeletal muscle ten different substrate combinations elicited a 7-fold range of OxPhos Vmax, which correlated positively (R2 = 0.963) with K0.5ADP values ranging from 2.3 ± 0.2 μM to 11.9 ± 0.6 μM. We propose that substrate-enhanced capacity to generate the protonmotive force increases the OxPhos K0.5ADP because flux control at ANT increases, thus K0.5ADP rises toward the dissociation constant, KdADP, of ADP-ANT binding. The findings are discussed in the context of top-down metabolic control analysis. © 2021 Elsevier B.V.
    • Rapid erosion of the central Transantarctic Mountains at the Eocene-Oligocene transition: Evidence from skewed (U-Th)/He date distributions near Beardmore Glacier

      He, John; Thomson, Stuart N.; Reiners, Peter W.; Hemming, Sidney R.; Licht, Kathy J.; Department of Geosciences, University of Arizona (Elsevier BV, 2021-08)
      Apatite (U-Th)/He thermochronology has the potential to reconstruct records of erosional exhumation that are critical to understanding interactions between climate, tectonics, and the cryosphere at high latitudes on million-year timescales. However this approach is often hindered by the problem of intrasample single-grain date dispersion. Here we present an extensive new apatite (U-Th)/He dataset (n = 361) from the central Transantarctic Mountains of East Antarctica between 160°E to 170°W and 84 to 86°S, and show that apparently uninterpretable data in most samples are a reflection of inadequate sampling of skewed date distributions. We outline a workflow for interpreting such dispersed data and demonstrate that geologically meaningful age interpretations are possible in the case of rapidly cooled samples, despite the wide array of potential causes for date dispersion. We show that for samples and compilations with a large number of single-grain analyses (n > ∼25), the youngest probability distribution peak represents the most likely time of fast cooling through the apatite (U-Th)/He closure temperature. When fewer grains are analyzed, the youngest peak is represented best by the minimum date or first quartile date, depending on sample size. Using this workflow, we show that since the latest Eocene, up to 8.8 km of exhumation occurred to incise the deepest point of the Beardmore Glacier trough. Rapid incision began at c. 37-34 Ma (at the latest by 34±3 Ma), coinciding with or slightly preceding the initiation of Antarctic glaciation at the Eocene-Oligocene transition, and contributed to at least 2.6 km of exhumation within the first 3-6 million years, at an apparent exhumation rate of no less than 0.4 mm/a. © 2021 Elsevier B.V.
    • Okun loops and anelastic relaxation in the G7

      Hawkins, Raymond J.; Li, Yichu; Wyant College of Optical Sciences, University of Arizona (Elsevier BV, 2021-08)
      We show that Okun loops – loop deviations from Okun's law – are an expected outcome of extending Okun's law to allow for observed time dependence in the response of unemployment to a change in output, and are an example of anelastic relaxation in economics. We extend prior work on these loops by documenting their regular appearance in the United States economy since WWII and their appearance in all G7 countries. We also find that the anelastic form of Okun's law provides a statistically significant and operationally parsimonious representation of output–unemployment dynamics in all G7 countries.
    • Thunderstorm and fair-weather quasi-static electric fields over land and ocean

      Wilson, Jennifer G.; Cummins, Kenneth L.; Department of Hydrology and Atmospheric Sciences, University of Arizona (Elsevier BV, 2021-08)
      Natural lightning and the associated clouds are known to behave differently over land and ocean, but many questions remain. We expand the related observational datasets by obtaining simultaneous quasi-static electric field observations over coastal land, near-shore water, and deep ocean regions during both fair-weather and thunderstorm periods. Oceanic observations were obtained using two 3-m NOAA buoys that were instrumented with Campbell Scientific electric field mills to measure the quasi-static electric fields. These data were compared to selected electric field records from the existing on-shore electric field mill suite of 31 sensors at Kennedy Space Center (KSC). Lightning occurrence times, locations and peak current estimates for both onshore and ocean were provided by the U.S. National Lightning Detection Network. The buoy instruments were first evaluated on-shore at the Florida coast, and the first system was calibrated for field enhancements and to confirm proper behavior of the system in elevated-field environments. The buoys were then moored 20 mi and 120 mi off the coast of KSC in February (20 mi) and August (120 mi) 2014. Diurnal fair-weather fields at both ocean sites matched will with each other and with those found during the Carnegie cruise, but mean values were 33% smaller, due at least in-part to constraints on the calibration procedure. Diurnal fair-weather fields variations at coastal and inland sites were a poorer match than offshore, likely because the offshore environment is “cleaner” with limited variations in local space charge, lower surface aerosol densities, little surface heating to disturb the surface charge layer during fair weather, and fewer local radioactive sources to modulate the near-surface electrical conductivity. Storm-related static fields were 4-5× larger at both oceanic sites than over land, likely due to decreased screening by near-surface space charge produced by corona current. The time-evolution of the electric field and field changes during storm approach are sufficiently different over land and ocean to warrant further study. This work shows the quality, accuracy, and reliability of these data, and has demonstrated the practicality of off-shore electric field measurements for safety- and launch-related decision making at KSC.
    • How do non-human primates represent others' awareness of where objects are hidden?

      Horschler, Daniel J.; Santos, Laurie R.; MacLean, Evan L.; School of Anthropology, University of Arizona; Cognitive Science Program, University of Arizona; Department of Psychology, University of Arizona; College of Veterinary Medicine, University of Arizona (Elsevier BV, 2021-07)
      Although non-human primates (NHPs) generally appear to predict how knowledgeable agents use knowledge to guide their behavior, the cognitive mechanisms that enable this remain poorly understood. We assessed the conditions under which NHPs' representations of an agent's awareness break down. Free-ranging rhesus macaques (Macaca mulatta) watched as an agent observed a target object being hidden in one of two boxes. While the agent could no longer see the boxes, the box containing the object flipped open and the object either changed in size/shape (Experiment 1) or color (Experiment 2). Monkeys looked longer when the agent searched for the object incorrectly rather than correctly following the color change (a non-geometric manipulation), but not the size/shape change (a geometric manipulation). Even though the agent maintained knowledge of the object's location in both cases, monkeys no longer expected the agent to search correctly after it had been geometrically (but not non-geometrically) manipulated. Experiment 3 confirmed that monkeys were sensitive to the color manipulation used in Experiment 2, making it unlikely that a failure to perceive the color manipulation accounted for our findings. Our results show that NHPs do not always expect that knowledgeable agents will act on their knowledge to obtain their goals, consistent with heuristic-based accounts of how NHPs represent others' mental states. These findings also suggest that geometric changes that occur outside the agent's perceptual access may disrupt attribution of awareness more so than non-geometric changes. © 2021 Elsevier B.V.
    • Estimation of root zone soil moisture from ground and remotely sensed soil information with multisensor data fusion and automated machine learning

      Babaeian, Ebrahim; Paheding, Sidike; Siddique, Nahian; Devabhaktuni, Vijay K.; Tuller, Markus; Department of Environmental Science, the University of Arizona (Elsevier BV, 2021-07)
      Root zone soil moisture (RZSM) estimation and monitoring based on high spatial resolution remote sensing information such as obtained with an Unmanned Aerial System (UAS) is of significant interest for field-scale precision irrigation management, particularly in water-limited regions of the world. To date, there is no accurate and widely accepted model that relies on UAS optical surface reflectance observations for RZSM estimation at high spatial resolution. This study is aimed at the development of a new approach for RZSM estimation based on the fusion of high spatial resolution optical reflectance UAS observations with physical and hydraulic soil information integrated into Automated Machine Learning (AutoML). The H2O AutoML platform includes a number of advanced machine learning algorithms that efficiently perform feature selection and automatically identify complex relationships between inputs and outputs. Twelve models combining UAS optical observations with various soil properties were developed in a hierarchical manner and fed into AutoML to estimate surface, near-surface, and root zone soil moisture. The addition of independently measured surface and near-surface soil moisture information to the hierarchical models to improve RZSM estimation was investigated. The accuracy of soil moisture estimates was evaluated based on a comparison with Time Domain Reflectometry (TDR) sensors that were deployed to monitor surface, near-surface and root zone soil moisture dynamics. The obtained results indicate that the consideration of physical and hydraulic soil properties together with UAS optical observations improves soil moisture estimation, especially for the root zone with a RMSE of about 0.04 cm3 cm−3. Accurate RZSM estimates were obtained when measured surface and near-surface soil moisture data was added to the hierarchical models, yielding RMSE values below 0.02 cm3 cm−3 and R and NSE values above 0.90. The generated high spatial resolution RZSM maps clearly capture the spatial variability of soil moisture at the field scale. The presented framework can aid farm scale precision irrigation management via improving the crop water use efficiency and reducing the risk of groundwater contamination. © 2021 Elsevier Inc.
    • Investigation of thermal properties of crystalline alpha quartz by employing different interatomic potentials: A molecular dynamic study

      Molaei, Fatemeh; Moghadam, Mostafa Safdari; Nouri, Shahrzad; Mining and Geological Engineering Department, The University of Arizona (Elsevier BV, 2021-07)
      In the present work, the thermal properties of crystalline α-quartz, including thermal conductivity (TC) and thermal expansion coefficient (TEC), are studied using the non-equilibrium molecular dynamics (NEMD) simulation method. Since there is a dependence on interatomic potentials in simulation results, the thermal conductivity and thermal expansion coefficient of crystalline α- quartz is computed using various force fields in a temperature range from 200 K to 1000 K compare which concurs better with experimental findings. Arising from the present molecular dynamic simulation by different force fields such as Tersoff, Vashishta, Stillinger-Weber, Meam, BKS, ReaxFF, and Morse, the thermal conductivities that were carried out using the ReaxFF and BKS are more accurate. It is also founded that predicted thermal conductivity at higher temperatures shows a better agreement with experimental values. In terms of TEC, Tersoff and SW corroborate the experimental remarks and give a smaller magnitude of TEC in z direction. On the other hand, in contradiction with the other force fields, Meam potential presents no significant TEC variation with temperature alteration. © 2021 Elsevier B.V.
    • ThryvOn™ Cotton, Frequently Asked Questions

      Ellsworth, Peter C.; Bordini, Isadora; Pier, Naomi; Entomology / Maricopa Agricultural Center (The University of Arizona (Tucson, AZ), 2021-06-09)
      ThryvOn™ cotton is genetically engineered to resist injury by Frankliniella thrips and Lygus bugs. ThryvOn cotton is a major addition to the cotton IPM strategy. It will provide a new mode of action for diminishing the impacts of thrips and Lygus in cotton. This IPM Short should answer frequently asked questions of stakeholders and help growers and pest control advisors establish and discuss their expectations.
    • Development of Aquaculture Protocols and Gonadal Differentiation of Red Shiner

      Teal, Chad N.; Schill, Daniel J.; Fogelson, Susan B.; Bonar, Scott A.; Arizona Cooperative Fish and Wildlife Research Unit, School of Natural Resources and the Environment, University of Arizona (Wiley, 2021-06-03)
      Developing detailed rearing methods and describing the onset of gonadal differentiation in Red Shiners Cyprinella lutrensis could facilitate the development of novel techniques to control or enhance populations, enable toxicology studies, and help construct bioassays. In this study, we develop and report aquaculture practices for Red Shiner that ensure consistent year-round production in laboratory settings and evaluate the timing of sexual differentiation via histological gonad examinations. Our methods resulted in a mean of 56.00% (SD = 8.98%) survival through the larval stages of development, and we obtained spawns from captive-reared Red Shiners 138 d posthatch. Red Shiners are gonochoristic, and both ovaries and testes differentiate directly from undifferentiated gonads. Ovaries begin to differentiate in females 45 d posthatch, while testes begin differentiating in males 105 d posthatch. This study provides in-depth protocols for the closed-cycle aquaculture of Red Shiners and describes the gonadal differentiation and development of both sexes. © 2020 American Fisheries Society
    • Direct interaction of the ATP-sensitive K+ channel by the tyrosine kinase inhibitors imatinib, sunitinib and nilotinib

      Fröbom, Robin; Berglund, Erik; Aspinwall, Craig A.; Lui, Weng-Onn; Nilsson, Inga-Lena; Larsson, Catharina; Bränström, Robert; Department of Chemistry and Biochemistry and Department of Biomedical Engineering, University of Arizona (Elsevier BV, 2021-06)
      The ATP-regulated K+ channel (KATP) plays an essential role in the control of many physiological processes, and contains a ATP-binding site. Tyrosine kinase inhibitors (TKI) are commonly used drugs, that primarily target ATP-binding sites in tyrosine kinases. Herein, we used the patch-clamp technique to examine the effects of three clinically established TKIs on KATP channel activity in isolated membrane patches, using a pancreatic β-cell line as a KATP channel source. In excised inside-out patches, the activity of the KATP channel was dose-dependently inhibited by imatinib with half-maximal concentration of approximately 9.4 μM. The blocking effect of imatinib was slow and reversible. No effect of imatinib was observed on either the large (KBK) or the small (KSK) conductance, Ca2+-regulated K+ channel. In the presence of ATP/ADP (ratio 1) addition of imatinib increased channel activity approximately 1.5-fold. Sunitinib and nilotinib were also found to decrease KATP channel activity. These findings are compatible with the view that TKIs, designed to interact at the ATP-binding pocket on the tyrosine receptor, also interact at the ATP-binding site on the KATP channel. Possibly, this might explain some of the side effects seen with TKIs.
    • Sourcing bighorn sheep from the Homol’ovi Settlement Cluster, Northeastern Arizona, through strontium isotope (87Sr/86Sr) analysis

      Sheets, Kimberly A.; Duff, Andrew I.; Thornton, Erin K.; Charles Adams, E.; Arizona State Museum, University of Arizona (Elsevier BV, 2021-06)
      Archaeologists have recovered bighorn sheep (Ovis canadensis) remains from villages within the Homol'ovi Settlement Cluster (1260–1400 CE) in the Middle Little Colorado River Valley. Today, there are no extant populations of bighorn sheep in the middle Little Colorado River Valley, and the Grand Canyon is the nearest known living population, over a 100 km away. To determine the most likely procurement location for these animals, we integrated archaeological and ethnohistorical information with strontium isotope (87Sr/86Sr) analysis of bighorn sheep teeth from two sites within the Cluster. We consider four potential procurement locations: The Grand Canyon, San Francisco Peaks, White Mountains, and Black Mesa. The contemporary descendants of these villages, the Hopi, have unique ancestral and religious connections to each of these potential locations, which aids in the interpretation of 87Sr/86Sr values. When these different threads of evidence are examined, they indicate the most likely location of procurement of these animals is the wider Black Mesa area 84 km north, with procurement from the Grand Canyon or a locally extirpated population also being possible candidates. © 2021 Elsevier Ltd
    • The Fe/S ratio of pyrrhotite group sulfides in chondrites: An indicator of oxidation and implications for return samples from asteroids Ryugu and Bennu

      Schrader, Devin L.; Davidson, Jemma; McCoy, Timothy J.; Zega, Thomas J.; Russell, Sara S.; Domanik, Kenneth J.; King, Ashley J.; Lunar and Planetary Laboratory, University of Arizona (Elsevier BV, 2021-06)
      Determining compositional trends among individual minerals is key to understanding the thermodynamic conditions under which they formed and altered, and is also essential to maximizing the scientific value of small extraterrestrial samples, including returned samples and meteorites. Here we report the chemical compositions of Fe-sulfides, focusing on the pyrrhotite-group sulfides, which are ubiquitous in chondrites and are sensitive indicators of formation and alteration conditions in the protoplanetary disk and in small Solar System bodies. Our data show that while there are trends with the at.% Fe/S ratio of pyrrhotite with thermal and aqueous alteration in some meteorite groups, there is a universal trend between the Fe/S ratio and degree of oxidation. Relatively reducing conditions led to the formation of troilite during: (1) chondrule formation in the protoplanetary disk (i.e., pristine chondrites) and (2) parent body thermal alteration (i.e., LL4 to LL6, CR1, CM, and CY chondrites). Oxidizing and sulfidizing conditions led to the formation of Fe-depleted pyrrhotite with low Fe/S ratios during: (1) aqueous alteration (i.e., CM and CI chondrites), and (2) thermal alteration (i.e., CK and R chondrites). The presence of troilite in highly aqueously altered carbonaceous chondrites (e.g., CY, CR1, and some CM chondrites) indicates they were heated after aqueous alteration. The presence of troilite, Fe-depleted pyrrhotite, or pyrite in a chondrite can provide an estimate of the oxygen and sulfur fugacities at which it was formed or altered. The data reported here can be used to estimate the oxygen fugacity of formation and potentially the aqueous and/or thermal histories of sulfides in extraterrestrial samples, including those returned by the Hayabusa2 mission and due to be returned by the OSIRIS-REx mission in the near future. © 2021 The Author(s)
    • On the Readability of Abstract Set Visualizations

      Wallinger, Markus; Jacobsen, Ben; Kobourov, Stephen; Nollenburg, Martin; Dept. of Computer Science, University of Arizona (Institute of Electrical and Electronics Engineers (IEEE), 2021-06)
      Set systems are used to model data that naturally arises in many contexts: social networks have communities, musicians have genres, and patients have symptoms. Visualizations that accurately reflect the information in the underlying set system make it possible to identify the set elements, the sets themselves, and the relationships between the sets. In static contexts, such as print media or infographics, it is necessary to capture this information without the help of interactions. With this in mind, we consider three different systems for medium-sized set data, LineSets, EulerView, and MetroSets, and report the results of a controlled human-subjects experiment comparing their effectiveness. Specifically, we evaluate the performance, in terms of time and error, on tasks that cover the spectrum of static set-based tasks. We also collect and analyze qualitative data about the three different visualization systems. Our results include statistically significant differences, suggesting that MetroSets performs and scales better. © 1995-2012 IEEE.
    • Exploiting the HSP60/10 chaperonin system as a chemotherapeutic target for colorectal cancer

      Ray, Anne-Marie; Salim, Nilshad; Stevens, Mckayla; Chitre, Siddhi; Abdeen, Sanofar; Washburn, Alex; Sivinski, Jared; O'Hagan, Heather M.; Chapman, Eli; Johnson, Steven M.; et al. (Elsevier BV, 2021-06)
      Over the past few decades, an increasing variety of molecular chaperones have been investigated for their role in tumorigenesis and as potential chemotherapeutic targets; however, the 60 kDa Heat Shock Protein (HSP60), along with its HSP10 co-chaperone, have received little attention in this regard. In the present study, we investigated two series of our previously developed inhibitors of the bacterial homolog of HSP60/10, called GroEL/ES, for their selective cytotoxicity to cancerous over non-cancerous colorectal cells. We further developed a third “hybrid” series of analogs to identify new candidates with superior properties than the two parent scaffolds. Using a series of well-established HSP60/10 biochemical screens and cell-viability assays, we identified 24 inhibitors (14%) that exhibited > 3-fold selectivity for targeting colorectal cancer over non-cancerous cells. Notably, cell viability EC50 results correlated with the relative expression of HSP60 in the mitochondria, suggesting a potential for this HSP60-targeting chemotherapeutic strategy as emerging evidence indicates that HSP60 is up-regulated in colorectal cancer tumors. Further examination of five lead candidates indicated their ability to inhibit the clonogenicity and migration of colorectal cancer cells. These promising results are the most thorough analysis and first reported instance of HSP60/10 inhibitors being able to selectively target colorectal cancer cells and highlight the potential of the HSP60/10 chaperonin system as a viable chemotherapeutic target.
    • Parametric dog-bone-shaped tunable cylindrical fluidic lens

      Ozgur, Erol; Reetz, Daniel; Akhoundi, Farhad; O’Brien, Nicholas; Wycoff, Jaclyn; Voorakaranam, Ram; Blanche, Pierre-Alexandre; LaComb, Lloyd; Liang, Chen; Peyman, Gholam; et al. (The Optical Society, 2021-05-27)
      Tunable spherical fluidic lenses are among the most essential components in adaptive optics.However, fabricating cylindrical tunable lenses has proven more challenging, mainly due to the difficulty in eliminating the defocus component.We demonstrate a parametric approach to minimize the defocus in cylindrical tunable fluidic lenses. We theoretically model and experimentally verify that a dog-bone-shaped tunable cylindrical fluidic lens exhibits almost pure cylindrical performance within the range of 5 Dof astigmatism. We anticipate these results will facilitate the use of tunable cylindrical fluidic lenses in adaptive optics applications and particularly ophthalmic devices, where rapid and reliable wavefront correction is required. ©2021 Optical Society of America.
    • The timing and magnitude of changes to Hortonian overland flow at the watershed scale during the post‐fire recovery process

      Liu, Tao; McGuire, Luke A.; Wei, Haiyan; Rengers, Francis K.; Gupta, Hoshin; Ji, Lin; Goodrich, David C.; Department of Geosciences, University of Arizona; Department of Hydrology and Atmospheric Sciences, University of Arizona (Wiley, 2021-05-27)
      Extreme hydrologic responses following wildfires can lead to floods and debris flows with costly economic and societal impacts. Process-based hydrologic and geomorphic models used to predict the downstream impacts of wildfire must account for temporal changes in hydrologic parameters related to the generation and subsequent routing of infiltration-excess overland flow across the landscape. However, we lack quantitative relationships showing how parameters change with time-since-burning, particularly at the watershed scale. To assess variations in best-fit hydrologic parameters with time, we used the KINEROS2 hydrological model to explore temporal changes in hillslope saturated hydraulic conductivity (Ksh) and channel hydraulic roughness (nc) following a wildfire in the upper Arroyo Seco watershed (41.5 km2), which burned during the 2009 Station fire in the San Gabriel Mountains, California, USA. This study explored runoff-producing storms between 2008 and 2014 to infer watershed hydraulic properties by calibrating the model to observations at the watershed outlet. Modelling indicates Ksh is lowest in the first year following the fire and then increases at an average rate of approximately 4.2 mm/h/year during the first 5 years of recovery. The estimated values for Ksh in the first year following the fire are similar to those obtained in previous studies on smaller watersheds (<1.5 km2) following the Station fire, suggesting hydrologic changes detected here can be applied to lower-order watersheds. Hydraulic roughness, nc, was lowest in the first year following the fire, but increased by a factor of 2 after 1 year of recovery. Post-fire observations suggest changes in nc are due to changes in grain roughness and vegetation in channels. These results provide quantitative constraints on the magnitude of fire-induced hydrologic changes following severe wildfires in chaparral-dominated ecosystems as well as the timing of hydrologic recovery. © 2021 John Wiley & Sons Ltd.
    • The Speed of Traveling Waves in a FKPP-Burgers System

      Bramburger, Jason J.; Henderson, Christopher; Department of Mathematics, University of Arizona (Springer Science and Business Media LLC, 2021-05-26)
      We consider a coupled reaction–advection–diffusion system based on the Fisher-KPP and Burgers equations. These equations serve as a one-dimensional version of a model for a reacting fluid in which the arising density differences induce a buoyancy force advecting the fluid. We study front propagation in this system through the lens of traveling waves solutions. We are able to show two quite different behaviors depending on whether the coupling constant ρ is large or small. First, it is proved that there is a threshold ρ under which the advection has no effect on the speed of traveling waves (although the advection is nonzero). Second, when ρ is large, wave speeds must be at least O(ρ1 / 3). These results together give that there is a transition from pulled to pushed waves as ρ increases. Because of the complex dynamics involved in this and similar models, this is one of the first precise results in the literature on the effect of the coupling on the traveling wave solution. We use a mix of ordinary and partial differential equation methods in our analytical treatment, and we supplement this with a numerical treatment featuring newly created methods to understand the behavior of the wave speeds. Finally, various conjectures and open problems are formulated. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE, part of Springer Nature.