• Assessment of YAP gene polymorphisms and arsenic interaction in Mexican women with breast cancer

      Michel-Ramirez, Gladis; Recio-Vega, Rogelio; Lantz, R Clark; Gandolfi, A Jay; Olivas-Calderon, Edgar; Chau, Binh T; Amistadi, Mary Kay; Univ Arizona, Dept Cellular & Mol Med; Univ Arizona, Southwest Environm Hlth Sci Ctr; Univ Arizona, Dept Pharmacol & Toxicol; et al. (WILEY, 2019-10-21)
      The identification of gene-environment interactions related to breast cancer reveals the biological and molecular mechanisms underlying the disease and allows the distinction of women at high risk from women at lower risk, which could decrease the morbimortality of this neoplasm. The current study evaluated the association between polymorphisms rs1820453 and rs11225161 of the Yes-associated protein (YAP) gene in women with breast cancer exposed to arsenic (As) through drinking water. In total, 182 women were assessed for the frequency of YAP rs1820453 and rs11225161 polymorphisms and As urinary levels. The results demonstrated a positive and significant association between breast cancer and smoking, type of drinking water, and levels of AsIII , AsV and inorganic As (iAs) but not the YAP gene polymorphisms evaluated. In conclusion, our data showed that the source of drinking water and AsV and iAs urinary levels increased the risk for breast cancer, but no interactions between YAP gene polymorphisms and As urinary levels were found.
    • Comparative pharmacokinetic study of PEGylated gemcitabine and gemcitabine in rats by LC-MS/MS coupled with pre-column derivatization and MS technique

      Yin, Lei; Ren, Tianming; Zhao, Shiying; Shi, Meiyun; Gu, Jingkai; Univ Arizona, Coll Pharm (ELSEVIER, 2020-01-01)
      Gemcitabine is a small molecular antitumor compound used to treat many types of solid tumors. The clinical application of gemcitabine is limited by its short biological half-life, rapid metabolism and poor tumor tissue targeting. The covalent attachment of polyethylene glycol to gemcitabine is a promising technique to overcome these limitations. After PEGylation, PEGylated gemcitabine could be metabolized into gemcitabine and its metabolites in vivo. Due to the scale effect of PEGylated gemcitabine, the DMPK process of the original drug is greatly changed. Therefore, understanding the pharmacokinetic behavior of PEGylated gemcitabine, gemcitabine and the metabolite dFdU in vivo is really important to clarify the antitumoral activity of these compounds. It would also guide the development of other PEGylated drugs. Due to the complex structure and diverse physiochemical property of PEG, direct quantification analysis of PEGylated gemcitabine presented many challenges in terms of assay sensitivity, selectivity, and robustness. In this article, a data-independent acquisition method, MSALL-based approach using electrospray ionization (ESI) coupled quadrupole time of flight mass spectrometry (MS), was utilized for the determination of PEGylated gemcitabine in rat plasma. The technique consists of a Q1 mass window through all the precursor ions, fragmenting and recording all product ions. PEGylated gemcitabine underwent dissociation in collision cell to generate a series of PEG related ions at m/z 89.0604, 133.0868, 177.1129 of 2, 3, 4 repeating ethylene oxide subunits and PEGylated gemcitabine related ions at m/z 112.0514. PEGylated gemcitabine was detected by the high resolution extracted ions based on the specific compound. For gemcitabine and dFdU, the study used derivatization of these high polarity compounds with dansyl chloride to improve their chromatographic retention. This paper describes comparative pharmacokinetic study of PEGylated gemcitabine and gemcitabine in rats by LC-MS/MS coupled with pre-column derivatization and MSALL technique. The results show that PEGylation could reduce the drug clearance of the conjugated compounds and increase the drug plasma half-life. After administration of PEGylated gemcitabine, the exposure of the free gemcitabine in vivo is lower than administration of gemcitabine, which means that PEGylated gemcitabine possesses lower toxicity compared with gemcitabine.
    • Automatic Detection of Everyday Social Behaviours and Environments from Verbatim Transcripts of Daily Conversations

      Yordanova, Kristina Y.; Demiray, Burcu; Mehl, Matthias R.; Martin, Mike; Univ Arizona, Dept Psychol (IEEE, 2019-03)
      Coding in social sciences is a process that involves the categorisation of qualitative or quantitative data in order to facilitate further analysis. Coding is usually a manual process that involves a lot of effort and time to produce codes with high validity and interrater reliability. Although automated methods for quantitative data analysis are largely used in social sciences, there are only a few attempts at automatically or semi-automatically coding the data collected in qualitative studies. To address this problem, in this work we propose an approach for automated coding of social behaviours and environments based on verbatim transcriptions of everyday conversations. To evaluate the approach, we analysed the transcripts from three datasets containing recordings of everyday conversations from: (1) young healthy adults (German transcriptions), (2) elderly healthy adults (German transcriptions), and (3) young healthy adults (English transcriptions). The results show that it is possible to automatically code the social behaviours and environments based on verbatim transcripts of the recorded conversations. This could reduce the time and effort researchers need to assign accurate codes to transcribed conversations.
    • Collective Action and Governance Activism

      Doidge, Craig; Dyck, Alexander; Mahmudi, Hamed; Virani, Aazam; Univ Arizona, Eller Coll Management (OXFORD UNIV PRESS, 2019-09)
      We examine how an investor collective action organization (ICAO) enhances activism by institutional investors. The ICAO initiated a new form of engagement-private meetings with independent directors to discuss governance proposals. Compared with a single investor acting alone, the ICAO has stronger incentives to engage in activism. Its dollar holdings and voting power are six times larger and predict direct access to the board and the firms it engages. Firms engaged by the ICAO are at least 58% more likely than non-engaged firms to adopt the ICAO's governance proposals that include adoption of majority voting, say-on-pay, and specific compensation policies. Engaged firms also increase CEO incentive pay. An event study around the announcement of the ICAO's formation shows a positive impact on value that increases in both dollar holdings and voting power. We conclude that institutional investors improve governance outcomes through collective action.
    • An Unexpected Romance: Reevaluating the Authorship of the Khosrow-nāma

      O'Malley, Austin; Middle East and North African Studies; Univ Arizona, Sch Middle Eastern & North African Studies (Middle East Medievalists, 2019)
      This article examines the authorship of the Khosrow-nāma, a Perso-Hellenic romance traditionally attributed to ʿAṭṭār. Forty years ago, Shafiʿi-Kadkani laid out a complex argument against ʿAṭṭār’s authorship. He claimed that the attribution was a result of a later forgery, basing his argument on internal chronological evidence, religious and stylistic markers, and the manuscript tradition. The present article systematically evaluates this argument, showing it to be less persuasive than it first appears. First, I introduce new manuscript evidence to demonstrate that the poem was circulating under ʿAṭṭār’s name already before the time of the alleged forgery. I then reassess the internal evidence to show that the Khosrow-nāma could, in fact, fit into a plausible chronology of ʿAṭṭār’s oeuvre. Next, I critique the stylistic and religious arguments against ʿAṭṭār’s authorship, arguing that the romance does not deviate from ʿAṭṭār’s undisputed works nearly as much as is often supposed. I conclude by suggesting that the available data are explained more easily by accepting ʿAṭṭār’s authorship than by adopting the theory of a later forgery.
    • Sediment Respiration Pulses in Intermittent Rivers and Ephemeral Streams

      Bogan, M. T.; Cid, N.; Univ Arizona, Sch Nat Resources & Environm (American Geophysical Union (AGU), 2019-10-16)
      Intermittent rivers and ephemeral streams (IRES) may represent over half the global stream network, but their contribution to respiration and carbon dioxide (CO2) emissions is largely undetermined. In particular, little is known about the variability and drivers of respiration in IRES sediments upon rewetting, which could result in large pulses of CO2. We present a global study examining sediments from 200 dry IRES reaches spanning multiple biomes. Results from standardized assays show that mean respiration increased 32-fold to 66-fold upon sediment rewetting. Structural equation modeling indicates that this response was driven by sediment texture and organic matter quantity and quality, which, in turn, were influenced by climate, land use, and riparian plant cover. Our estimates suggest that respiration pulses resulting from rewetting of IRES sediments could contribute significantly to annual CO2 emissions from the global stream network, with a single respiration pulse potentially increasing emission by 0.2-0.7%. As the spatial and temporal extent of IRES increases globally, our results highlight the importance of recognizing the influence of wetting-drying cycles on respiration and CO2 emissions in stream networks.
    • Assessing Gauge Undercatch Correction in Arctic Basins in Light of GRACE Observations

      Behrangi, Ali; Singh, Alka; Song, Yang; Panahi, Milad; Univ Arizona, Dept Hydrol & Atmospher Sci; Univ Arizona, Dept Geosci (AMER GEOPHYSICAL UNION, 2019-10-09)
      Precipitation measurements at gauges are often considered as reference truth for evaluation of satellite precipitation products. However, gauges may contain large errors. A major source of gauge‐measurement error is snowfall undercatch in high latitudes. We show that the two popular correction factors (CFs) used in the Global Precipitation Climatology Centre monitoring and the Global Precipitation Climatology Project products are different by more than 50%. The CFs can be as large as 3; thus, the choice of CF introduces large uncertainties. Here, in light of observation of storage change from the Gravity Recovery and Climate Experiment (GRACE) and by using the mass conservation principle, we assess the two popular CFs over six Arctic basins. By investigating monthly time series and multiyear precipitation rates over the studied basins using GRACE‐based analysis, the CF based on Fuchs dynamic correction model used in Global Precipitation Climatology Centre monitoring is preferred.
    • Velocity Field Estimation on Density‐Driven Solute Transport With a Convolutional Neural Network

      Kreyenberg, Philipp J.; Bauser, Hannes H.; Roth, Kurt; Univ Arizona, Biosphere 2 (AMER GEOPHYSICAL UNION, 2019-08-01)
      Recent advances in machine learning open new opportunities to gain deeper insight into hydrological systems, where some relevant system quantities remain difficult to measure. We use deep learning methods trained on numerical simulations of the physical processes to explore the possibilities of closing the information gap of missing system quantities. As an illustrative example we study the estimation of velocity fields in numerical and laboratory experiments of density‐driven solute transport. Using high‐resolution observations of the solute concentration distribution, we demonstrate the capability of the method to structurally incorporate the representation of the physical processes. Velocity field estimation for synthetic data for both variable and uniform concentration boundary conditions showed equal results. This capability is remarkable because only the latter was employed for training the network. Applying the method to measured concentration distributions of density‐driven solute transport in a Hele‐Shaw cell makes the velocity field assessable in the experiment. This assessability of the velocity field even holds for regions with negligible solute concentration between the density fingers, where the velocity field is otherwise inaccessible.
    • Seasonal and Topographic Variations in Ecohydrological Separation Within a Small, Temperate, Snow‐Influenced Catchment

      Knighton, James; Souter‐Kline, Valessa; Volkman, Till; Troch, Peter A.; Kim, Minseok; Harman, Ciaran; Morris, Chelsea; Buchanan, Brian; Walter, M. Todd; Univ Arizona, Biosphere 2 (AMER GEOPHYSICAL UNION, 2019-08-02)
      The hypothesis of ecohydrological separation (ES) proposes that the water contained in surface soils is not uniformly extracted by root water uptake nor uniformly displaced by infiltration. Rather vegetation selectively removes water held under tension, and water infiltrating wet soil will bypass much of the water‐filled pore space. Methodological differences across previous studies have contributed to disagreement concerning the prevalence of ES. We measured stable isotopes of O and H in precipitation, snowpack, canopy throughfall, and stream water over a period of 18 months in a temperate catchment. At six locations across a wetness gradient, we sampled bulk soil water isotopes weekly and xylem water of Eastern hemlock and American beech stems seasonally. We used these observations in a soil column model including StorAge Selection functions to estimate the isotopic composition and ages of groundwater recharge and ET. Our findings suggest ES may exist with spatial and temporal heterogeneity. Root water uptake ages possibly vary between Eastern hemlock and American beech, suggesting functional strategies for water uptake may control the presence of ES. Newly infiltrated water bypassing the shallow soil was the most likely explanation for bulk soil isotopic measurements made at upslope locations during the winter and summer seasons, whereas rapid displacement of stored soil water by infiltrated waters was the most likely during the spring and fall seasons. Future research incorporating high temporal frequency soil and plant xylem water isotopic measurements applied to StorAge Selection functions may provide a useful framework for understanding rooting zone isotope dynamics.
    • Energy development reveals blind spots for ecosystem conservation in the Amazon Basin

      Anderson, Elizabeth P; Osborne, Tracey; Maldonado‐Ocampo, Javier A; Mills‐Novoa, Megan; Castello, Leandro; Montoya, Mariana; Encalada, Andrea C; Jenkins, Clinton N; Univ Arizona, Sch Geog & Dev (WILEY, 2019-10-02)
      Energy development – as manifested by the proliferation of hydroelectric dams and increased oil and gas exploration – is a driver of change in Amazonian ecosystems. However, prevailing approaches to Amazonian ecosystem conservation that focus on terrestrial protected areas and Indigenous territories do not offer sufficient insurance against the risks associated with energy development. Here, we explore three related areas of concern: the exclusion of subsurface rights on Indigenous lands; the absence of frameworks for freshwater ecosystem conservation; and downgrading, downsizing, degazettement (loss of protection), and reclassification of protected areas. We consider these issues from the perspectives of multiple countries across the Amazon Basin, and link them directly to energy development. Finally, we offer suggestions for addressing the challenges of energy development for Amazon ecosystem conservation through existing policies, new approaches, and international collaboration.
    • Kinematic focus point method for particle mass measurements in missing energy events

      Kim, Doojin; Matchev, Konstantin T.; Shyamsundar, Prasanth; Univ Arizona, Dept Phys (SPRINGER, 2019-10-14)
      We investigate the solvability of the event kinematics in missing energy events at hadron colliders, as a function of the particle mass ansatz. To be specific, we reconstruct the neutrino momenta in dilepton tt¯-like events, without assuming any prior knowledge of the mass spectrum. We identify a class of events, which we call extreme events, with the property that the kinematic boundary of their allowed region in mass parameter space passes through the true mass point. We develop techniques for recognizing extreme events in the data and demonstrate that they are abundant in a realistic data sample, due to expected singularities in phase space. We propose a new method for mass measurement whereby we obtain the true values of the mass parameters as the focus point of the kinematic boundaries for all events in the data sample. Since the masses are determined from a relatively sharp peak structure (the density of kinematic boundary curves), the method avoids some of the systematic errors associated with other techniques. We show that this new approach is complementary to previously considered methods in the literature where one studies the solvability of the kinematic constraints throughout the mass parameter space. In particular, we identify a problematic direction in mass space of nearly 100% solvability, and then show that the focus point method is effective in lifting the degeneracy.
    • The effects of hydroxypropyl-beta-cyclodextrin on olfaction in mouse models of Niemann-Pick C1 Disease

      Erickson, Robert; Univ Arizona, Sch Med, Dept Pediat (SPRINGER HEIDELBERG, 2019-08)
      The Npc1(nih/nih)-null model and the Npc1(nmf164/nmf164) hypomorph models of Niemann-Pick C1 (NPC1) disease show defects in olfaction. We have tested the effects of the life-prolonging treatment hydroxypropyl-beta-cyclodextrin (HPBCD) on olfaction and neural stem cell numbers when delivered either systemically or by nasal inhalation. Using the paradigm of finding a hidden cube of food after overnight food deprivation, Npc1(nih/nih) homozygous mice showed a highly significant delay in finding the food compared with wild-type mice. Npc1(nmf164/nmf164) homozygous mice showed an early loss of olfaction which was mildly corrected by somatic delivery of HPBCD which also increased the number of neural stem cells in the mutant but did not change the number in wild-type mice. In contrast, nasal delivery of this drug, at 1/5 the dosage used for somatic delivery, to Npc1(nmf164/nmf164) mutant mice delayed loss of olfaction but the control of nasal delivered saline did so as well. The nasal delivery of HPBCD to wild-type mice caused loss of olfaction but nasal delivery of saline did not. Neural stem cell counts were not improved by nasal therapy with HPBCD. We credit the delay in olfaction found with the treatment, a delay which was also found for time of death, to a large amount of stimulation the mice received with handling during the nasal delivery.
    • Can emergency physicians perform extended compression ultrasound for the diagnosis of lower extremity deep vein thrombosis

      Situ-LaCasse, Elaine; Guirguis, Helpees; Friedman, Lucas; Patanwala, Asad E; Cohen, Seth E; Adhikari, Srikar; Univ Arizona, Dept Emergency Med, Coll Med; Univ Arizona, Banner Univ Med Ctr; Univ Arizona, Coll Med; Univ Arizona, Coll Pharm (ZHEJIANG UNIV SCH MEDICINE, 2019-08)
      Background: Current point-of-care ultrasound protocols in the evaluation of lower extremity deep vein thrombosis (DVT) can miss isolated femoral vein clots. Extended compression ultrasound (ECUS) includes evaluation of the femoral vein from the femoral vein/deep femoral vein bifurcation to the adductor canal. Our objective is to determine if emergency physicians (EPs) can learn ECUS for lower extremity DVT evaluation after a focused training session. Methods: Prospective study at an urban academic center. Participants with varied ultrasound experience received instruction in ECUS prior to evaluation. Two live models with varied levels of difficult sonographic anatomy were intentionally chosen for the evaluation. Each participant scanned both models. Pre- and post-study surveys were completed. Results: A total of 96 ultrasound examinations were performed by 48 participants (11 attendings and 37 residents). Participants' assessment scores averaged 95.8% (95% CI 93.3%-98.3%) on the easier anatomy live model and averaged 92.3% (95% CI 88.4%-96.2%) on the difficult anatomy model. There were no statistically significant differences between attendings and residents. On the model with easier anatomy, all but 1 participant identified and compressed the proximal femoral vein successfully, and all participants identified and compressed the mid and distal femoral vein. With the difficult anatomy, 97.9% (95% CI 93.8%-102%) identified and compressed the proximal femoral vein, whereas 93.8% (95% CI 86.9%-100.6%) identified and compressed the mid femoral vein, and 91.7% (95% CI 83.9%-99.5%) identified and compressed the distal femoral vein. Conclusion: EPs at our institution were able to perform ECUS with good reproducibility after a focused training session.
    • Multimodal Graph Analysis of Cyber Attacks

      Ghose, Nimimesh; Lazos, Loukas; Rozenblit, Jerzy; Breiger, Ronald; Univ Arizona, Dept Elect & Comp Engn (IEEE, 2019-04)
      The limited information on the cyberattacks available in the unclassified regime, hardens standardizing the analysis. We address the problem of modeling and analyzing cyberattacks using a multimodal graph approach. We formulate the stages, actors, and outcomes of cyberattacks as a multimodal graph. Multimodal graph nodes include cyberattack victims, adversaries, autonomous systems, and the observed cyber events. In multimodal graphs, single-modality graphs are interconnected according to their interaction. We apply community and centrality analysis on the graph to obtain in-depth insights into the attack. In community analysis, we cluster those nodes that exhibit "strong" inter-modal ties. We further use centrality to rank the nodes according to their importance. Classifying nodes according to centrality provides the progression of the attack from the attacker to the targeted nodes. We apply our methods to two popular case studies, namely GhostNet and Putter Panda and demonstrate a clear distinction in the attack stages.
    • Assessment of the Crop Water Stress Index and Color Quality of Bur Clover (Medicago polymorpha L.) Under Different Irrigation Regimes

      Bijanzadeh, Ehsan; Barati, Vahid; Emam, Yahya; Pessarakli, Mohammad; Univ Arizona, Sch Plant Sci (TAYLOR & FRANCIS INC, 2019-10-28)
      Relationship between canopy temperature and soil moisture is important for using the potential of canopy temperature as an indicator of crop water stress. A two-year field experiment was carried out during June to September 2016 and 2017 at the Research Station of College of Agriculture, Darab, Shiraz University, Iran, to determine crop water stress index (CWSI) for bur clover. Irrigation regimes including well-watered [Irrigation according to 100% field capacity (FC)], mild water stress (75% FC), severe water stress (50% FC), and most severe water stress (25% FC) were arranged in a randomized complete block design with four replications. In 2016, CWSI values showed an increasing trend from June (0.066 in well-watered) to August (0.821 in most severe water stress) as a result of higher vapor pressure deficit (VPD) and depression in canopy-air temperature differences (Tc-Ta). A similar trend was observed in the second year. In both years, by increase in mean temperature from June to August, Tc-Ta differential increased and the highest monthly average value of CWSI for all treatments was obtained in August. By enhancing water stress, the color grading score decreased sharply (from 6 to 3) and stayed constant (2) for August and September. Also, a negative relationship was observed between CWSI and dry matter production (R-2 = 0.88**) and color quality (R-2 = 0.94**). It was concluded that mild water stress (75% FC) with mean seasonal CWSI being ranged about 0.198 to 0.294, without any loss in visual color quality might be the best irrigation regime for bur clover production.
    • Locality domains and morphological rules: Phases, heads, node-sprouting and suppletion in Korean honorification

      Choi, Jaehoon; Harley, Heidi; Univ Arizona, Dept Linguist (Springer Science and Business Media LLC, 2019-11)
      Korean subject honorification and Korean negation have both affixal and suppletive exponents. In addition, Korean negation has a periphrastic realization involving an auxiliary verb. By examining their interaction, we motivate several hypotheses concerning locality constraints on the conditioning of suppletion and the insertion of dissociated morphemes (‘node-sprouting’). At the same time, we come to a better understanding of the nature of Korean subject honorification. We show that Korean honorific morphemes are ‘dissociated’ or ‘sprouted,’ i.e., introduced by morphosyntactic rule in accordance with morphological well-formedness constraints, like many other agreement morphemes. We argue that the conditioning domain for node-sprouting is the syntactic phase. In contrast, our data suggest that the conditioning domain for suppletion is the complex X0, as proposed by Bobaljik (2012). We show that the ‘spanning’ hypotheses concerning exponence (Merchant 2015; Svenonius 2012), the ‘linear adjacency’ hypotheses (Embick 2010), and ‘accessibility domain’ hypothesis (Moskal 2014, 2015a, 2015b; Moskal and Smith 2016) make incorrect predictions for Korean suppletion. Finally, we argue that competition between honorific and negative suppletive exponents reveals a root-outwards effect in allomorphic conditioning, supporting the idea that insertion of vocabulary items proceeds root-outwards (Bobaljik 2000).
    • Coarse muscovite veins and alteration in porphyry systems

      Runyon, Simone E.; Seedorff, Eric; Barton, Mark D.; Steele-MacInnis, Matthew; Lecumberri-Sanchez, Pilar; Mazdab, Frank K.; Univ Arizona, Dept Geosci (ELSEVIER, 2019-10)
      Coarse muscovite veins and alteration occur in porphyry copper and porphyry molybdenum-copper systems within the Laramide arc in Arizona, as well as at the Yerington district in Nevada. This work describes coarse muscovite in veins and altered wall rock in porphyry systems in this region and documents mineral assemblages, mineral compositions, spatial and temporal relationships, and hydrogen isotopic compositions. Coarse hydrothermal muscovite is documented in the roots of porphyry Cu +/- Mo systems, as well as in and above the ore bodies in porphyry Mo-Cu systems, and it is compared to coarse hydrothermal muscovite (greisen) in lode Sn-W-Mo systems. Basin and Range extension has exposed coarse hydrothermal muscovite in several Laramide and Jurassic porphyry Cu (+/- Mo) systems, at paleodepths of 3 to 12 km: Miami-Inspiration, Sierrita-Esperanza, Copper Basin (Crown King), Granite Mountain (roots of the Ray porphyry system), Gunnison (Texas Canyon stock), Grayback (Kelvin-Riverside district), Sycamore Canyon, the New Cornelia mine (Ajo district), and two systems in the Yerington district. Muscovite is the dominant mica in these coarse muscovite veins and associated alteration, with common K-feldspar and albite (An(00-)(06)), common accessory hematite, rutile, pyrite, and apatite, and rare accessory chalcopyrite, fluorite, molybdenite, wolframite, and scheelite. Coarse hydrothermal muscovite yields delta D compositions that suggest formation from fluids that are dominantly magmatic-hydrothermal in origin. Whole-rock compositions of coarse hydrothermal muscovite show common gains in K and loss of Ca +/- Na. Coarse muscovite veins and alteration in porphyry copper systems postdate mineralized potassic veins and form too deeply to overlap with shallower acidic forms of alteration (sericitic, advanced argillic). Variation in mineral assemblage, mineral compositions, and mineralization of coarse hydrothermal muscovite correlate with the composition of Laramide stocks. Porphyry Mo-Cu systems contain coarse muscovite alteration assemblages with the highest mineral diversity and trace-element enrichment. Coarse muscovite veins and alteration in porphyry Mo-Cu systems related to stocks ranging from quartz monzonite to granite in composition form at shallower paleodepths and occur within and above the associated orebodies. In contrast, coarse muscovite veins and alteration associated with subalkaline porphyry copper systems occur at deeper levels, in some cases overlapping with the bottom of potassic alteration and the ore body but extending well into the roots of the system in the underlying granitoid cupola. In these latter systems, zones of coarse muscovite alteration typically are poorly mineralized and mineral assemblages are less varied. These characteristics suggest that coarse muscovite-forming fluids are predominately of magmatic-hydrothermal origin and exsolved from late-stage, fractionated magmas of the larger pluton that sourced porphyry stocks and dikes responsible for porphyry copper mineralization. In some instances, however, the exposed coarse muscovite alteration is associated with a petrologically unrelated, commonly more felsic, later intrusion, rather than being related to late exsolution of fluid from the same crystallizing stock or batholith.
    • Toward a Universal μ-Agonist Template for Template-Based Alignment Modeling of Opioid Ligands

      Wu, Zhijun; Hruby, Victor J; Univ Arizona, Dept Chem & Biochem (AMER CHEMICAL SOC, 2019-10-22)
      Opioid ligands are a large group of G-protein-coupled receptor ligands possessing high structural diversity, along with complicated structure–activity relationships (SARs). To better understand their structural correlations as well as the related SARs, we developed the innovative template-based alignment modeling in our recent studies on a variety of opioid ligands. As previously reported, this approach showed promise but also with limitations, which was mainly attributed to the small size of morphine as a template. With this study, we set out to construct an artificial μ-agonist template to overcome this limitation. The newly constructed template contained a largely extended scaffold, along with a few special μ-features relevant to the μ-selectivity of opioid ligands. As demonstrated in this paper, the new template showed significantly improved efficacy in facilitating the alignment modeling of a wide variety of opioid ligands. This report comprises of two main parts. Part 1 discusses the general construction process and the structural features as well as a few typical examples of the template applications and Part 2 focuses on the template refinement and validation.
    • Magnetization switching using topological surface states

      Li, Peng; Kally, James; Zhang, Steven S-L; Pillsbury, Timothy; Ding, Jinjun; Csaba, Gyorgy; Ding, Junjia; Jiang, J S; Liu, Yunzhi; Sinclair, Robert; et al. (AMER ASSOC ADVANCEMENT SCIENCE, 2019-08-30)
      Topological surface states (TSSs) in a topological insulator are expected to be able to produce a spin-orbit torque that can switch a neighboring ferromagnet. This effect may be absent if the ferromagnet is conductive because it can completely suppress the TSSs, but it should be present if the ferromagnet is insulating. This study reports TSS-induced switching in a bilayer consisting of a topological insulator Bi2Se3 and an insulating ferromagnet BaFe12O19. A charge current in Bi2Se3 can switch the magnetization in BaFe12O19 up and down. When the magnetization is switched by a field, a current in Bi2Se3 can reduce the switching field by ~4000 Oe. The switching efficiency at 3 K is 300 times higher than at room temperature; it is ~30 times higher than in Pt/BaFe12O19. These strong effects originate from the presence of more pronounced TSSs at low temperatures due to enhanced surface conductivity and reduced bulk conductivity.
    • THE EQUALITY NORM MEETS THE EVOLUTION OF PROPERTY IN THE LAW OF “TAKINGS”

      Rose, Carol M.; Univ Arizona, Law Coll (CAMBRIDGE UNIV PRESS, 2018-12-04)
      A norm of equal treatment is cited regularly in the American jurisprudence of property takings under the Fifth and Fourteenth Amendments to the Constitution, as a benchmark of fair treatment of owners. According to an increasingly prevalent version of this equality norm, courts should look to parity of treatment among property owners in investigating whether particular regulations take property. This essay argues, however, that such an equality norm is misplaced, and that courts should judge fairness by the criterion of expectationincluding reasonable expectations of regulation.A norm of equality becomes problematic in the face of the economic theory of the evolution of property. This theory posits that as resources become more congested, their uses carry increasing common pool costs or externalitiesa scenario that should predictably result in more stringent resource managementup to and including the establishment of regulatory regimes as well as property rights themselves. This evolutionary pattern, however, places earlier and later resource users in different positions vis-a-vis both common pool externalities and regulatory responses, and their different temporal positions fragment the meaning of equal treatment and destabilize it as a jurisprudential norm. This essay argues that while equal treatment may be a benchmark for special or invidious cases, like those relating to civil rights, the great bulk of takings cases involve regulatory responses to congesting resources, where a norm of equal treatment breaks down. Thus, in seeking fair treatment, takings jurisprudence should downplay equality and instead look to the understanding of property as a basis of expectationsbut those expectations should include the anticipation of reasonable regulatory responses to resource congestion.