Now showing items 13452-13471 of 13480

    • The z = 7.54 Quasar ULAS J1342+0928 Is Hosted by a Galaxy Merger

      Bañados, Eduardo; Novak, Mladen; Neeleman, Marcel; Walter, Fabian; Decarli, Roberto; Venemans, Bram P.; Mazzucchelli, Chiara; Carilli, Chris; Wang, Feige; Fan, Xiaohui; et al. (IOP PUBLISHING LTD, 2019-08-12)
      We present ALMA 0.'' 128 x 0.'' 20 (1.4 kpc x 1.0 kpc) resolution observations of the [C II] 158 mu m line and underlying dust continuum in the host galaxy of the most distant quasar currently known, ULAS J1342+0928 at z = 7.5413. Both the [C II] and continuum are detected and spatially resolved. The [C II] line is similar to 1.5 times more extended than the continuum emission, showing an elongated and complex structure of approximately 3.2 kpc x 6.4 kpc. Two separate peaks are clearly seen (greater than or similar to 6 sigma each) in three 100 km s(-1) width [C II] channel maps. The velocity field of the [C II] gas does not show evidence of a coherent rotation field but rather chaotic motion reminiscent of an ongoing merger.
    • Z boson production in Pb plus Pb collisions at root S-NN=5.02 TeV measured by the ATLAS experiment

      ATLUS Collaboration; Univ Arizona, Dept Phys (ELSEVIER, 2020)
      The production yield of Z bosons is measured in the electron and muon decay channels in Pb+Pb collisions at /S-NN = 5.02 TeV with the ATLAS detector. Data from the 2015 LHC run corresponding to an integrated luminosity of 0.49 nb(-1) are used for the analysis. The Z boson yield, normalised by the total number of minimum-bias events and the mean nuclear thickness function, is measured as a function of dilepton rapidity and event centrality. The measurements in Pb+Pb collisions are compared with similar measurements made in proton-proton collisions at the same centre-of-mass energy. The nuclear modification factor is found to be consistent with unity for all centrality intervals. The results are compared with theoretical predictions obtained at next-to-leading order using nucleon and nuclear parton distribution functions. The normalised Z boson yields in Pb+Pb collisions lie 1-3a above the predictions. The nuclear modification factor measured as a function of rapidity agrees with unity and is consistent with a next-to-leading-order QCD calculation including the isospin effect. (C) 2020 The Author(s). Published by Elsevier B.V.
    • z ∼ 2: An Epoch of Disk Assembly

      Simons, Raymond C.; Kassin, Susan A.; Weiner, Benjamin; Faber, Sandra M.; Trump, Jonathan R.; Heckman, Timothy M.; Koo, David C.; Pacifici, Camilla; Primack, Joel R.; Snyder, Gregory F.; et al. (IOP PUBLISHING LTD, 2017-06-30)
      We explore the evolution of the internal gas kinematics of star-forming galaxies from the peak of cosmic star formation at z similar to 2 to today. Measurements of galaxy rotation velocity V-rot, which quantify ordered motions, and gas velocity dispersion sigma(g), which quantify disordered motions, are adopted from the DEEP2 and SIGMA surveys. This sample covers a continuous baseline in redshift over 0.1 < z < 2.5, spanning 10 Gyr. At low redshift, nearly all sufficiently massive star-forming galaxies are rotationally supported (V-rot > sigma(g)). By z = 2, 50% and 70% of galaxies are rotationally supported at low (10(9)-10(10) M-circle dot) and high (10(10)-10(11) M-circle dot) stellar mass, respectively. For V-rot > 3 sigma(g), the percentage drops below 35% for all masses. From z = 2 to now, galaxies exhibit remarkably smooth kinematic evolution on average. All galaxies tend toward rotational support with time, and higher-mass systems reach it earlier. This is largely due to a mass-independent decline in sigma(g) by a factor of 3 since z - 2. Over the same time period, V-rot increases by a factor of 1.5 in low-mass systems but does not evolve at high mass. These trends in V-rot and sigma(g) are at a fixed stellar mass and therefore should not be interpreted as evolutionary tracks for galaxy populations. When populations are linked in time via abundance matching, sigma(g) declines as before and V-rot strongly increases with time for all galaxy populations, enhancing the evolution in V-rot sigma(g). These results indicate that z = 2 is a period of disk assembly, during which strong rotational support is only just beginning to emerge.
    • Zaraa Uul: An archaeological record of Pleistocene-Holocene palaeoecology in the Gobi Desert

      Janz, L.; Rosen, A.M.; Bukhchuluun, D.; Odsuren, D.; School of Anthropology, University of Arizona (Public Library of Science, 2021)
      Environmentally-based archaeological research at Zaraa Uul, including zooarchaeology, phytolith analysis, and radiocarbon dating, is the first of its kind in Mongolia and presents critical new insight on the relationship between periods of occupational intensity and climatic amelioration from the earliest anatomically modern humans to the adoption of pastoralism. The palaeoenvironmental and faunal record of Zaraa Uul show that Early-Middle Holocene hydrology and species distributions were distinct from all other periods of human occupation. Holocene hunter-gatherers inhabited an ecosystem characterized by extensive marshes, riparian shrub and arboreal vegetation along the hill slopes and drainages. The exploitation of species associated with riparian and wetland settings supports the hypothesis of, but suggests an earlier timing for, oasis-based logistical foraging during the Early-Middle Holocene of arid Northeast Asia. The onset of wetter conditions at 8500 cal BP agrees with other regional studies, but multiple lines of evidence present the first integrated fieldand laboratory-based record of human-environment relationships in arid East Asia during the Holocene Climatic Optimum. We compare it to Late Pleistocene climatic amelioration, and highlight specific responses of the hydrological, vegetative and faunal communities to climate change in arid Northeast Asia. © 2021 Janz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
    • Zazaki Language Interview

      Karimi, Simin; Department of Linguistics, University of Arizona; Karimi, Simin; Smith, Ryan Walter; Keskin, Mesut (2015-12-01)
    • ZBP-89 negatively regulates self-renewal of liver cancer stem cells via suppression of Notch1 signaling pathway

      Wang, Nuozhou; Li, Ming-Yue; Liu, Yi; Yu, Jianqing; Ren, Jianwei; Zheng, Zhiyuan; Wang, Shanshan; Yang, Shucai; Yang, Sheng-Li; Liu, Li-Ping; et al. (ELSEVIER IRELAND LTD, 2019-12-23)
      Liver cancer stem cells (LCSCs) initiate hepatocellular carcinoma (HCC) and contribute to its recurrence and treatment resistance. Studies have suggested ZBP-89 as a candidate tumor suppressor in HCC. We explored the role of ZBP-89 in the regulation of LCSCs. This study was performed in liver tissue samples from 104 HCC patients, 2 cell lines and mouse tumor models. We demonstrated that ZBP-89 was weakly expressed in LCSCs. Patients with high expression of LCSC markers displayed reduced survivals and higher recurrence rates after curative surgical operation. The expression of ZBP-89 was predictive for decreased recurrence. LCSC markers were negatively correlated with ZBP-89 in HCC tissues and in enriched liver tumor spheres. The exogenous expression of ZBP-89 attenuated the tumor-sphere formation and secondary colony formation capabilities of LCSCs in vitro and tumorigenicity in vivo. Furthermore, the negative effect of ZBP-89 on cancer sternness was Notch1-dependent. Localized with Notch1 intracellular domain (NICD1) in the nucleus, ZBP-89 repressed the Notch1 signaling pathway by competitive binding to NICD1 with MAML1. Collectively, ZBP-89 negatively regulates HCC sternness via inhibiting the Notch1 signaling.
    • ZBTB32 restrains antibody responses to murine cytomegalovirus infections, but not other repetitive challenges

      Jash, Arijita; Zhou, You W; Gerardo, Diana K; Ripperger, Tyler J; Parikh, Bijal A; Piersma, Sytse; Jamwal, Deepa R; Kiela, Pawel R; Boon, Adrianus C M; Yokoyama, Wayne M; et al. (NATURE PUBLISHING GROUP, 2019-10-24)
      ZBTB32 is a transcription factor that is highly expressed by a subset of memory B cells and restrains the magnitude and duration of recall responses against hapten-protein conjugates. To define physiological contexts in which ZBTB32 acts, we assessed responses by Zbtb32-/- mice or bone marrow chimeras against a panel of chronic and acute challenges. Mixed bone marrow chimeras were established in which all B cells were derived from either Zbtb32-/- mice or control littermates. Chronic infection of Zbtb32-/- chimeras with murine cytomegalovirus led to nearly 20-fold higher antigen-specific IgG2b levels relative to controls by week 9 post-infection, despite similar viral loads. In contrast, IgA responses and specificities in the intestine, where memory B cells are repeatedly stimulated by commensal bacteria, were similar between Zbtb32-/- mice and control littermates. Finally, an infection and heterologous booster vaccination model revealed no role for ZBTB32 in restraining primary or recall antibody responses against influenza viruses. Thus, ZBTB32 does not limit recall responses to a number of physiological acute challenges, but does restrict antibody levels during chronic viral infections that periodically engage memory B cells. This restriction might selectively prevent recall responses against chronic infections from progressively overwhelming other antibody specificities.
    • ZBTB38 is dispensable for antibody responses

      Wong, Rachel; Bhattacharya, Deepta; Univ Arizona, Dept Immunobiol (PUBLIC LIBRARY SCIENCE, 2020-09-21)
      Members of the broad complex, tram track, bric-a-brac and zinc finger (BTB-ZF) family of transcription factors, such as BCL-6, ZBTB20, and ZBTB32, regulate antigen-specific B cell differentiation, plasma cell longevity, and the duration of antibody production. We found that ZBTB38, a different member of the BTB-ZF family that binds methylated DNA at CpG motifs, is highly expressed by germinal center B cells and plasma cells. To define the functional role of ZBTB38 in B cell responses, we generated mice conditionally deficient in this transcription factor. Germinal center B cells lacking ZBTB38 dysregulated very few genes relative to wild-type and heterozygous littermate controls. Accordingly, mice with hematopoietic-specific deletion ofZbtb38showed normal germinal center B cell numbers and antibody responses following immunization with hapten-protein conjugates. Memory B cells from these animals functioned normally in secondary recall responses. Despite expression of ZBTB38 in hematopoietic stem cells, progenitors and mature myeloid and lymphoid lineages were also present in normal numbers in mutant mice. These data demonstrate that ZBTB38 is dispensable for hematopoiesis and antibody responses. These conditional knockout mice may instead be useful in defining the functional importance of ZBTB38 in other cell types and contexts.
    • ZFOURGE: Using Composite Spectral Energy Distributions to Characterize Galaxy Populations at 1 < z < 4

      Forrest, Ben; Tran, Kim-Vy H.; Broussard, Adam; Cohn, Jonathan H.; Kennicutt, Jr., Robert C.; Papovich, Casey; Allen, Rebecca; Cowley, Michael; Glazebrook, Karl; Kacprzak, Glenn G.; et al. (IOP PUBLISHING LTD, 2018-08-20)
      We investigate the properties of galaxies as they shut off star formation over the 4 billion years surrounding peak cosmic star formation. To do this, we categorize similar to 7000 galaxies from 1 < z < 4 into 90 groups based on the shape of their spectral energy distributions (SEDs) and build composite SEDs with R similar to 50 resolution. These composite SEDs show a variety of spectral shapes and also show trends in parameters such as color, mass, star formation rate, and emission-line equivalent width. Using emission-line equivalent widths and strength of the 4000 angstrom break, D(4000), we categorize the composite SEDs into five classes: extreme emission line, star-forming, transitioning, post-starburst, and quiescent galaxies. The transitioning population of galaxies shows modest H alpha emission (EWREST similar to 40 angstrom) compared to more typical star-forming composite SEDs at log(10)(M/M-circle dot) similar to 10.5 (EWREST similar to 80 A). Together with their smaller sizes (3 kpc vs. 4 kpc) and higher Sersic indices (2.7 vs. 1.5), this indicates that morphological changes initiate before the cessation of star formation. The transitional group shows a strong increase of over 1 dex in number density from z similar to 3 to z similar to 1, similar to the growth in the quiescent population, while post-starburst galaxies become rarer at z less than or similar to 1.5. We calculate average quenching timescales of 1.6 Gyr at z similar to 1.5 and 0.9 Gyr at z similar to 2.5 and conclude that a fast-quenching mechanism producing post-starbursts dominated the quenching of galaxies at early times, while a slower process has become more common since z similar to 2.
    • Zinc complexes of diflunisal: Synthesis, characterization, structure, antioxidant activity, and in vitro and in silico study of the interaction with DNA and albumins

      Tarushi, Alketa; Kakoulidou, Chrisoula; Raptopoulou, Catherine P.; Psycharis, Vassilis; Kessissoglou, Dimitris P.; Zoi, Ioanna; Papadopoulos, Athanasios N.; Psomas, George; Department of Chemistry and Biochemistry, University of Arizona (ELSEVIER SCIENCE INC, 2017-05)
      From the reaction of ZnCl2 with the non-steroidal anti-inflammatory drug diflunisal (Hdifl), complex [Zn(difl-O)(2)(MeOH)(4)], 1 was formed, while in the presence of a N,N'-donor heterocyclic ligand 2,2'-bipyridylamine (bipyam), 2,2'-bipyridine (bipy), 1,10-phenanthroline (phen) and 2,2'-dipyridylketone oxime (Hpko), the complexes [Zn(difl-O,O')(2)(bipyam)], 2, [Zn(difl-O,O')(2)(bipy)], 3, [Zn(difl-O,O')(2)(phen)], 4 and [Zn(difl-O)2(Hpko)(2)], 5 were isolated, respectively. The complexes were characterized by physicochemical and spectroscopic techniques and the crystal structures of complexes 2, 3 and 5 were determined by X-ray crystallography. The ability of the complexes to scavenge 1,1-diphenyl-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals and to inhibit soybean lipoxygenase was studied and the complexes were more active than free Hdifl. The interaction of the complexes with serum albumins was monitored by fluorescence emission spectroscopy and the corresponding binding constants were calculated. UV-vis spectroscopy, viscosity measurements and fluorescence emission spectroscopy for the competitive studies of the complexes with ethidium bromide were employed to investigate the interaction of the complexes with calf-thymus DNA and revealed intercalation as the most possible DNA-binding mode. Computational techniques were used to identify possible binding sites of albumins and DNA, and determine the druggability of human and bovine serum albumins with the five novel complexes. The majority of the complexes are stronger binders than the free Hdifl. This is the first study incorporating experimental and computational results to explore the binding activity of metal-NSAID complexes with DNA and serum albumins, suggesting their application as potential metallodrugs.
    • Zinc Intake and Risk of Prostate Cancer: Case-Control Study and Meta-Analysis

      Mahmoud, Abeer M.; Al-Alem, Umaima; Dabbous, Firas; Ali, Mohamed M.; Batai, Ken; Shah, Ebony; Kittles, Rick A.; Univ Arizona, Coll Med, Dept Surg (PUBLIC LIBRARY SCIENCE, 2016-11-08)
      Zinc is an essential dietary element that has been implicated in the pathogenesis of prostate cancer, a cancer that disproportionately affects men of African descent. Studies assessing the association of zinc intake and prostate cancer have yielded inconsistent results. Furthermore, very little is known about the relationship between zinc intake and prostate cancer among African Americans. We examined the association between self-reported zinc intake and prostate cancer in a hospital-based case-control study of African Americans. We then compared our results with previous studies by performing a meta-analysis to summarize the evidence regarding the association between zinc and prostate cancer. Newly diagnosed African American men with histologically confirmed prostate cancer (n = 127) and controls (n = 81) were recruited from an urban academic urology clinic in Washington, DC. Controls had higher zinc intake, with a mean of 14 mg/day versus 11 mg/day for cases. We observed a non-significant, non-linear increase in prostate cancer when comparing tertiles of zinc intake (OR (<6.5 vs 6.5-12.5mg/day) 1.8, 95% CI: 0.6,5.6; OR (<6.5 vs >12.5mg/day) 1.3, 95% CI: 0.2,6.5). The pooled estimate from 17 studies (including 3 cohorts, 2 nested case-control, 11 case-control studies, and 1 randomized clinical trial, with a total of 111,199 participants and 11,689 cases of prostate cancer) was 1.07 (hi vs lo) 95% CI: 0.98-1.16. Using a dose-response meta-analysis, we observed a non-linear trend in the relationship between zinc intake and prostate cancer (p for nonlinearity = 0.0022). This is the first study to examine the relationship between zinc intake in black men and risk of prostate cancer and systematically evaluate available epidemiologic evidence about the magnitude of the relationship between zinc intake and prostate cancer. Despite of the lower intake of zinc by prostate cancer patients, our meta-analysis indicated that there is no evidence for an association between zinc intake and prostate cancer.
    • ZIPping to pain relief: the role (or not) of PKMzeta in chronic pain

      Price, Theodore; Ghosh, Sourav; Department of Pharmacology, The University of Arizona School of Medicine, Arizona, USA; Department of Cellular and Molecular Medicine, The University of Arizona School of Medicine, Arizona, USA; Bio5 Institute, The University of Arizona School of Medicine, Arizona, USA; Graduate Interdisciplinary Program in Neuroscience, The University of Arizona School of Medicine, Arizona, USA (BioMed Central, 2013)
      Chronic pain remains a significant clinical problem despite substantial advances in our understanding of how persistent nociceptor stimulation drives plasticity in the CNS. A major theme that has emerged in this area of work is the strong similarity between plasticity involved in learning and memory in CNS regions such as cortex and hippocampus with mechanisms underlying chronic pain development and maintenance in the spinal dorsal horn and other CNS areas such as anterior cingulate cortex (ACC). We, and others have recently implicated an atypical PKC (aPKC), called PKMzeta, in the maintenance of pain plasticity based on biochemical assays and the use of a peptide pseudosubstrate inhibitor called ZIP. These studies indicate remarkable parallels between the potential role of PKMzeta as a key molecule for the maintenance of long-term memory and long-term potentiation (LTP) and the maintenance of a chronic pain state. On the other hand, very recent studies have disputed the specificity of ZIP and called into question the role of PKMzeta as a memory maintenance molecule. Here we critically review the evidence that PKMzeta might represent a new target for the reversal of certain chronic pain states. Furthermore, we consider whether ZIP might have other aPKC or even non-aPKC targets and the significance of such off-target effects for evaluating maintenance mechanisms of chronic pain. We conclude that, current controversies aside, utilization of ZIP as a tool to interrogate maintenance mechanisms of chronic pain and further investigations into the potential role of PKMzeta, and other aPKCs, in pain plasticity are likely to lead to further insights with the potential to unravel the enigma that is the disease of chronic pain.
    • Zircon M127 - A Homogeneous Reference Material for SIMS U-Pb Geochronology Combined with Hafnium, Oxygen and, Potentially, Lithium Isotope Analysis

      Nasdala, Lutz; Corfu, Fernando; Valley, John W.; Spicuzza, Michael J.; Wu, Fu-Yuan; Li, Qiu-Li; Yang, Yue-Heng; Fisher, Chris; Münker, Carsten; Kennedy, Allen K.; et al. (WILEY-BLACKWELL, 2016-12)
      In this article, we document a detailed analytical characterisation of zircon M127, a homogeneous 12.7 carat gemstone from Ratnapura, Sri Lanka. Zircon M127 has TIMS-determined mean U-Pb radiogenic isotopic ratios of 0.084743 +/- 0.000027 for Pb-206/U-238 and 0.67676 +/- 0.00023 for Pb-207/U-235 (weighted means, 2s uncertainties). Its Pb-206/U-238 age of 524.36 +/- 0.16 Ma (95% confidence uncertainty) is concordant within the uncertainties of decay constants. The delta O-18 value (determined by laser fluorination) is 8.26 +/- 0.06 parts per thousand VSMOW (2s), and the mean Hf-176/Hf-177 ratio (determined by solution ICP-MS) is 0.282396 +/- 0.000004 (2s). The SIMS-determined delta Li-7 value is -0.6 +/- 0.9 parts per thousand (2s), with a mean mass fraction of 1.0 +/- 0.1 mu g g(-1) Li (2s). Zircon M127 contains similar to 923 mu g g(-1) U. The moderate degree of radiation damage corresponds well with the time-integrated self-irradiation dose of 1.82 x 10(18) alpha events per gram. This observation, and the (U-Th)/He age of 426 +/- 7 Ma (2s), which is typical of unheated Sri Lankan zircon, enable us to exclude any thermal treatment. Zircon M127 is proposed as a reference material for the determination of zircon U-Pb ages by means of SIMS in combination with hafnium and stable isotope (oxygen and potentially also lithium) determination.
    • Zircon U-Pb Geochronology Constrains Continental Expression of Great Meteor Hotspot Magmatism

      Kinney, S.T.; MacLennan, S.A.; Keller, C.B.; Schoene, B.; Setera, J.B.; VanTongeren, J.A.; Olsen, P.E.; Department of Geosciences, University of Arizona (Blackwell Publishing Ltd, 2021)
      The New England-Québec Igneous Province is considered to be a continental expression of Great Meteor Hotspot magmatism, though other geodynamic scenarios have been suggested. Existing geochronologic data lack the needed accuracy and precision to permit tests of potential causal mechanisms. We provide zircon U-Pb ages for four igneous centers and a suite of plate reconstructions and show that the duration between magmatism in each branch of this province is ca. 3–6 Myr shorter and ca. 10 Myr older than predicted if the spatial-temporal distribution of magmatism conformed to a well-defined age progression. However, in addition to uncertainties in plate reconstructions, variable regional crustal thickness or lithospheric topography likely played a role in mediating the rates of melt transport to emplacement depth and we therefore cannot reject the hotspot hypothesis. Our results place the best-available chronological constraints on continental magmatism associated with one of the oldest and longest-lived hotspots. © 2021. American Geophysical Union. All Rights Reserved.
    • Zircon, titanite, and apatite (U-Th)/He ages and age-eU correlations from the Fennoscandian Shield, southern Sweden

      Guenthner, William R.; Reiners, Peter W.; Drake, Henrik; Tillberg, Mikael; Univ Arizona, Dept Geosci; Department of Geology; University of Illinois at Urbana-Champaign; Urbana Illinois USA; Department of Geosciences; University of Arizona; Tucson Arizona USA; Department of Biology and Environmental Science; Linnaeus University; Kalmar Sweden; Department of Biology and Environmental Science; Linnaeus University; Kalmar Sweden (AMER GEOPHYSICAL UNION, 2017-07)
      Craton cores far from plate boundaries have traditionally been viewed as stable features that experience minimal vertical motion over 100-1000Ma time scales. Here we show that the Fennoscandian Shield in southeastern Sweden experienced several episodes of burial and exhumation from similar to 1800Ma to the present. Apatite, titanite, and zircon (U-Th)/He ages from surface samples and drill cores constrain the long-term, low-temperature history of the Laxemar region. Single grain titanite and zircon (U-Th)/He ages are negatively correlated (104-838Ma for zircon and 160-945Ma for titanite) with effective uranium (eU=U+0.235xTh), a measurement proportional to radiation damage. Apatite ages are 102-258Ma and are positively correlated with eU. These correlations are interpreted with damage-diffusivity models, and the modeled zircon He age-eU correlations constrain multiple episodes of heating and cooling from 1800Ma to the present, which we interpret in the context of foreland basin systems related to the Neoproterozoic Sveconorwegian and Paleozoic Caledonian orogens. Inverse time-temperature models constrain an average burial temperature of similar to 217 degrees C during the Sveconorwegian, achieved between 944Ma and 851Ma, and similar to 154 degrees C during the Caledonian, achieved between 366Ma and 224Ma. Subsequent cooling to near-surface temperatures in both cases could be related to long-term exhumation caused by either postorogenic collapse or mantle dynamics related to the final assembly of Rodinia and Pangaea. Our titanite He age-eU correlations cannot currently be interpreted in the same fashion; however, this study represents one of the first examples of a damage-diffusivity relationship in this system, which deserves further research attention.
    • A Zone of Preferential Ion Heating Extends Tens of Solar Radii from the Sun

      Kasper, J. C.; Klein, Kristopher G.; Weber, T.; Maksimovic, M.; Zaslavsky, A.; Bale, S. D.; Maruca, B. A.; Stevens, M. L.; Case, A. W.; Univ Arizona, Lunar & Planetary Lab (IOP PUBLISHING LTD, 2017-11-07)
      The extreme temperatures and nonthermal nature of the solar corona and solar wind arise from an unidentified physical mechanism that preferentially heats certain ion species relative to others. Spectroscopic indicators of unequal temperatures commence within a fraction of a solar radius above the surface of the Sun, but the outer reach of this mechanism has yet to be determined. Here we present an empirical procedure for combining interplanetary solar wind measurements and a modeled energy equation including Coulomb relaxation to solve for the typical outer boundary of this zone of preferential heating. Applied to two decades of observations by the Wind spacecraft, our results are consistent with preferential heating being active in a zone extending from the transition region in the lower corona to an outer boundary 20-40 solar radii from the Sun, producing a steady-state super-massproportional a-to-proton temperature ratio of 5.2-5.3. Preferential ion heating continues far beyond the transition region and is important for the evolution of both the outer corona and the solar wind. The outer boundary of this zone is well below the orbits of spacecraft at 1 au and even closer missions such as Helios and MESSENGER, meaning it is likely that no existing mission has directly observed intense preferential heating, just residual signatures. We predict that the Parker Solar Probe will be the first spacecraft with a perihelion sufficiently close to the Sun to pass through the outer boundary, enter the zone of preferential heating, and directly observe the physical mechanism in action.
    • A Zone of Preferential Ion Heating Extends Tens of Solar Radii from the Sun

      Kasper, J. C.; Klein, K. G.; Weber, T.; Maksimovic, M.; Zaslavsky, A.; Bale, S. D.; Maruca, B. A.; Stevens, M. L.; Case, A. W.; Univ Arizona, Lunar & Planetary Lab (IOP Publishing, 2017-11-07)
      The extreme temperatures and nonthermal nature of the solar corona and solar wind arise from an unidentified physical mechanism that preferentially heats certain ion species relative to others. Spectroscopic indicators of unequal temperatures commence within a fraction of a solar radius above the surface of the Sun, but the outer reach of this mechanism has yet to be determined. Here we present an empirical procedure for combining interplanetary solar wind measurements and a modeled energy equation including Coulomb relaxation to solve for the typical outer boundary of this zone of preferential heating. Applied to two decades of observations by the Wind spacecraft, our results are consistent with preferential heating being active in a zone extending from the transition region in the lower corona to an outer boundary 20–40 solar radii from the Sun, producing a steady-state super-massproportional α-to-proton temperature ratio of 5.2–5.3. Preferential ion heating continues far beyond the transition region and is important for the evolution of both the outer corona and the solar wind. The outer boundary of this zone is well below the orbits of spacecraft at 1 au and even closer missions such as Helios and MESSENGER, meaning it is likely that no existing mission has directly observed intense preferential heating, just residual signatures. We predict that the Parker Solar Probe will be the first spacecraft with a perihelion sufficiently close to the Sun to pass through the outer boundary, enter the zone of preferential heating, and directly observe the physical mechanism in action.
    • Zur Mehrsprachigkeitsforschung in der interkulturellen Literaturwissenschaft: Wende, Romanze, Rückkehr?

      Gramling, David; Univ Arizona, German Studies (TRANSCRIPT VERLAG, 2016-06)
    • α-Cyperone Confers Antidepressant-Like Effects in Mice Neuroplasticity Enhancement by SIRT3/ROS Mediated NLRP3 Inflammasome Deactivation

      Xia, Baomei; Tong, Yue; Xia, Changbo; Chen, Chang; Shan, Xin; Univ Arizona, Coll Med Phoenix, Dept Basic Med Sci (FRONTIERS MEDIA SA, 2020-10-08)
      alpha-Cyperone (Cy) is a major active compound of Cyperus rotundus that has various pharmacological activities. But whether Cy possesses antidepressant effect is unknown. In this study, we exposed mice to chronic unpredictable mild stress (CUMS) with or without intervention with Cy. Our results showed that Cy significantly improved the depressive phenotypes in sucrose preference test, tail suspension test and forced swimming test. Meanwhile, increased SIRT3 expression, reduced ROS production and activated NF-kappa B signal were detected in the hippocampus of mice. NLRP3 inflammasome related proteins including NLRP3, ASC, Caspase-1, IL-1 beta, IL-18 and GSDMD-N were downregulated after Cy administration. Synaptic proteins including Synapsin-1 and PSD-95 and dendritic spine density were improved after Cy treatment. Moreover, the protective effects of Cy in CUMS mice were compromised when co-administrated with SIRT3 inhibitor 3-TYP. Taken together, these findings suggested that Cy has therapeutic potential for treating depression and that this antidepressant effect may be attributed to SIRT3 stimulated neuroplasticity enhancement by suppressing NLRP3 inflammasome.
    • β-adrenergic receptor-mediated mitochondrial biogenesis improves skeletal muscle recovery following spinal cord injury

      Scholpa, Natalie E; Simmons, Epiphani C; Tilley, Douglas G; Schnellmann, Rick G; Univ Arizona, Coll Pharm, Dept Pharmacol & Toxicol; Univ Arizona, Coll Med, Dept Neurosci; Univ Arizona, Southwest Environm Hlth Sci Ctr; Univ Arizona, Ctr Innovat Brain Sci (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2019-12)
      In addition to local spinal cord dysfunction, spinal cord injury (SCI) can result in decreased skeletal muscle mitochondrial activity and muscle atrophy. Treatment with the FDA-approved β2-adrenergic receptor (ADRB2) agonist formoterol has been shown to induce mitochondrial biogenesis (MB) in both the spinal cord and skeletal muscle and, therefore, has the potential to address comprehensive mitochondrial and organ dysfunction following SCI. Female C57BL/6 mice were subjected to moderate contusion SCI (80 Kdyn) followed by daily administration of vehicle or formoterol beginning 8 h after injury, a clinically relevant time-point characterized by a 50% decrease in mtDNA content in the injury site. As measured by the Basso Mouse Scale, formoterol treatment improved locomotor recovery in SCI mice compared to vehicle treatment by 7 DPI, with continued recovery observed through 21 DPI (3.5 v. 2). SCI resulted in 15% body weight loss in all mice by 3 DPI. Mice treated with formoterol returned to pre-surgery weight by 13 DPI, while no weight gain occurred in vehicle-treated SCI mice. Remarkably, formoterol-treated mice exhibited a 30% increase in skeletal muscle mass compared to those treated with vehicle 21 DPI (0.93 v. 0.72% BW), corresponding with increased MB and decreased skeletal muscle atrophy. These effects were not observed in ADRB2 knockout mice subjected to SCI, indicating that formoterol is acting via the ADRB2 receptor. Furthermore, knockout mice exhibited decreased basal spinal cord and skeletal muscle PGC-1α expression, suggesting that ADRB2 may play a role in mitochondrial homeostasis under physiological conditions. These data provide evidence for systemic ADRB2-mediated MB as a therapeutic avenue for the treatment of SCI.