Sample records for ar dadm elektronu

  1. Synthesis and Crystal Structure of a Macrocycle [Cu(dadm)(mal)(H2O)]2·2H2O

    Institute of Scientific and Technical Information of China (English)

    林郑忠; 江飞龙; 陈莲; 洪茂椿


    The reaction of 4,4′-diaminodiphenylmethane (dadm), malonic acid (H2mal) and Cu(NO3)2 in aqueous solution results in a discrete binuclear Cu(II) macrocycle: [Cu(dadm)(mal)- (H2O)]2(2H2O. It crystallizes in monoclinic, space group P21/c with a = 15.231(3), b = 11.847(2), c = 9.801(2)A,Z= 106.75(3)o, V = 1693.5(6)A3, Z = 2, C32H40Cu2N4O12, Mr = 799.76, Dc = 1.568 g/cm3, λ(MoK() = 0.71073A, μ = 1.325 mm-1, F(000) = 828, the final R = 0.0531 and Wr = 0.1244 for 3421 observed reflections with I > 2σ(I). Each Cu(II) is coordinated by two oxygen atoms from a mal ligand, two nitrogen atoms from two dadm ligands and a water oxygen atom to form a triangle bipyramidal motif. The title compound possesses a distorted macrocycle enclosed by dadm with approximate dimensions of 8.3A× 5.9A.

  2. Ars disyecta Ars disyecta

    Directory of Open Access Journals (Sweden)

    Alejandra Castillo


    Full Text Available Bajo la nominación Ars Disyecta se busca exponer el vínculo entre artes visuales, feminismo y metamorfosis. Las prácticas artísticas feministas aquí presentadas se proponen perturbar el espacio metafórico heredado de la diferencia sexual (pensemos, por ejemplo, en las palabras engendramiento, matriz, vida, compenetración o invaginamiento. En este sentido, la nominación Ars disyecta pone en escena un conjunto de prácticas e intervenciones que intentan interrumpir la matriz de la diferencia, desestabilizando lo femenino desde aquellas figuras que se resisten a la lógica de la totalidad y de un tiempo propio. Buscando seguir la huella de un arte disyecto es que interrogaré en este ensayo aquellas autorías feministas que en el arte contemporáneo trafican con las huellas del contagio, la mutación y la alteridad.This article aims to present the relation between visual arts, feminism I and metamorphosis. The feminist artistic practices portrayed in this article attempt to question categories inherited from the metaphor of sexual difference such as engendering, matrix and life. From this perspective, Ars disyecta will establish a set of artistic practices and interventions that intend to interrupt the proper idea of «feminine difference». Following this line of argument, I will discuss in this article a few contemporary feminist works of art that could be defined by words such as contagious, mutation and otherness.

  3. Ars Electronica

    DEFF Research Database (Denmark)

    Kristensen, Thomas Bjørnsten


    Anmeldelse af Ars Electronica festivalen 3. - 8. september, 2009 i Linz, Østrig, der fejrede 30 års jubilæum under temaet "Human Nature". Festivalen fokuserer på interaktion mellem menneske, teknologi, kunst og samfund med særlig vægt på udviklingen af computeren og det digitale. Udgivelsesdato: 15.12...

  4. Ars Electronica

    DEFF Research Database (Denmark)

    Kristensen, Thomas Bjørnsten


    Anmeldelse af Ars Electronica festivalen 3. - 8. september, 2009 i Linz, Østrig, der fejrede 30 års jubilæum under temaet "Human Nature". Festivalen fokuserer på interaktion mellem menneske, teknologi, kunst og samfund med særlig vægt på udviklingen af computeren og det digitale. Udgivelsesdato: 15.12...

  5. Ar-Ar_Redux: rigorous error propagation of 40Ar/39Ar data, including covariances (United States)

    Vermeesch, P.


    Rigorous data reduction and error propagation algorithms are needed to realise Earthtime's objective to improve the interlaboratory accuracy of 40Ar/39Ar dating to better than 1% and thereby facilitate the comparison and combination of the K-Ar and U-Pb chronometers. Ar-Ar_Redux is a new data reduction protocol and software program for 40Ar/39Ar geochronology which takes into account two previously underappreciated aspects of the method: 1. 40Ar/39Ar measurements are compositional dataIn its simplest form, the 40Ar/39Ar age equation can be written as: t = log(1+J [40Ar/39Ar-298.5636Ar/39Ar])/λ = log(1 + JR)/λ Where λ is the 40K decay constant and J is the irradiation parameter. The age t does not depend on the absolute abundances of the three argon isotopes but only on their relative ratios. Thus, the 36Ar, 39Ar and 40Ar abundances can be normalised to unity and plotted on a ternary diagram or 'simplex'. Argon isotopic data are therefore subject to the peculiar mathematics of 'compositional data', sensu Aitchison (1986, The Statistical Analysis of Compositional Data, Chapman & Hall). 2. Correlated errors are pervasive throughout the 40Ar/39Ar methodCurrent data reduction protocols for 40Ar/39Ar geochronology propagate the age uncertainty as follows: σ2(t) = [J2 σ2(R) + R2 σ2(J)] / [λ2 (1 + R J)], which implies zero covariance between R and J. In reality, however, significant error correlations are found in every step of the 40Ar/39Ar data acquisition and processing, in both single and multi collector instruments, during blank, interference and decay corrections, age calculation etc. Ar-Ar_Redux revisits every aspect of the 40Ar/39Ar method by casting the raw mass spectrometer data into a contingency table of logratios, which automatically keeps track of all covariances in a compositional context. Application of the method to real data reveals strong correlations (r2 of up to 0.9) between age measurements within a single irradiation batch. Propertly taking

  6. ArArCALC—software for 40Ar/ 39Ar age calculations (United States)

    Koppers, Anthony A. P.


    ArArCALC is a Microsoft Excel ® 97-2000-XP application for performing calculations in 40Ar/ 39Ar geochronology. It is coded in Visual Basic for Applications and can be used under the Windows ® 95/98/NT/2000/ME/XP operating systems. ArArCALC provides an easy-to-use graphical interface for the calculation of age plateaus, total fusion ages and isochrons following the regression of 40Ar/ 39Ar mass spectrometry data. Results are stored in single Excel workbooks including nine different data tables and four different diagrams. Analytical, internal and external errors are calculated based on error propagation of all input parameters, analytical data and applied corrections. Finally, the age calculation results can be recalibrated with reference to the primary K-Ar standards (e.g. GA-1550, MMhb-1) in order to obtain more consistent absolute40Ar/ 39Ar age determinations. ArArCALC is distributed as freeware.

  7. Ars Himera / Irina Lobanova

    Index Scriptorium Estoniae

    Lobanova, Irina


    Iseloomustatakse praegust aega ja moodsat kunsti: valitseb vastutustundetus ja ebainimlikkus. Näited - professor von Hageni "Korpwelten" ja uusim kunstinähtus Ars Chimaera - eksponeerimise eesmärgil surrogaatsete elusolendite saamise kunst

  8. Ramon Llull's Ars Magna

    DEFF Research Database (Denmark)

    Jensen, Thessa


    intelligence and knowledge representation, which seeks to formalise language and knowledge in a way which can be translated into a computer program. And as Fidora’s and Sierra’s [4] anthology Ramon Llull: From the Ars Magna to Artificial Intelligence shows, Llull’s influence and relevance is profound in today......’s work on topics ranging from conceptual graphs and logical analysis, social choice theory and adaptive reasoning to Llull’s influence on Peirce’s pragmatic thinking. Llull is important, even now, on a whole other level. His ethical considera-tions when he wanted to convince people of the one true faith...... Llull: From the Ars Magna to Artificial Intelligence. Barcelona: Artificial Intelligence Research Institute (2011)....

  9. Combined K-Ar and 40Ar/39Ar dating of the upper Jaramillo reversal (United States)

    Guillou, Herve; Carracedo, Juan Carlos; Kissel, Catherine; Laj, Carlo; Nomade, Sebastien; Perez Torrado, Francisco Jose; Rodriguez Gonzalez, Alejandro; Wandres, Camille


    The Jaramillo subchron was first evidenced in 1966 (Doell and Dalrymple) through the Rhyolotic domes of the Valles Caldera, New Mexico (USA). 40Ar/39Ar studies achieved by Spell et McDougall (1992), Spell et Harrison (1993), Izett and Obradovich (1994) and Singer et al. (1994) defined the base of this subchron at 1053±6 ka, and the ceiling at 986±5 ka. Channell et al. (2009) delimited the age of the Jaramillo subchron by astronomic calibration (base 1071 ka, top 990 ka). To provide additional absolute ages on this geomagnetic period, which is critical to improve our knowledge of the earth magnetic field behaviour, we have carried out a study combining paleomagnetism and isotopic dating of a lava sequence from Tenerife island. This sequence of basaltic lava flows is some 500 m thick. The first 400 m present, based on field magnetometer measurements, normal polarity lavas, with dykes of normal and reverse polarity, passing at the top to reverse polarity lavas. Preliminary K-Ar ages bracketed this sequence between 1018 ± 18 ka and 978 ± 17 ka. Therefore, the upper Jaramillo reversal at least appeared to be potentially recorded in this sequence. A more detailed paleomagnetic study was then carried out to more precisely delimit the reversal itself (see Laj et al., session EMRP3.4). We have undertaken 40Ar/39Ar incremental heating and unspiked K-Ar experiments on groundmass from four transitionally magnetized flows. The first transitional flow is K-Ar dated at 993 ± 18 ka and 40Ar/39Ar dated at 991 ± 13 ka, the second at 981 ± 17 ka (K-Ar) and 1000 ± 13 ka (40Ar/39Ar), the third at 950 ± 17 ka (K-Ar) and 1000 ± 8 ka (40Ar/39Ar) and the fourth at 984 ± 17 ka (K-Ar) and 977 ± 12 (40Ar/39Ar). 40Ar/39Ar ages and K-Ar ages (relative to FCT 28.02 Ma) are indistinguishable at 2σ. The age of the upper boundary of the Jaramillo event calculated combining 40Ar/39Ar ages and K-Ar ages is 992 ± 6 ka, in agreement with previous estimates.

  10. Ars Electronica tulekul / Rael Artel

    Index Scriptorium Estoniae

    Artel, Rael, 1980-


    6.-11. IX toimub Austrias Linzis "Ars Electronica" festival, mille teema on "Code - The Language of Our Time". Festivali kavast, osalejatest, ava-performance'ist "Europe - A Symphonic Vision", näitusest "Cyberarts 2003. Prix Ars Electronica"

  11. Ars Electronica tulekul / Rael Artel

    Index Scriptorium Estoniae

    Artel, Rael, 1980-


    6.-11. IX toimub Austrias Linzis "Ars Electronica" festival, mille teema on "Code - The Language of Our Time". Festivali kavast, osalejatest, ava-performance'ist "Europe - A Symphonic Vision", näitusest "Cyberarts 2003. Prix Ars Electronica"

  12. Photoionization of Ar VIII (United States)

    Liang, Liang; Jiang, Wen-xian; Zhou, Chao


    The photoionization cross section, energy levels and widths of 22 Rydberg series (in the autoionization region) for Na-like Ar VIII were investigated by using of R-matrix method. The relativistic distorted-wave method is used to calculate the radial functions, and QB method of Quigly-Berrington [Quigley et al. 1998] is employed to calculate the resonance levels and widths. We have identified the formant in the figure of the photoionization cross section.


    Directory of Open Access Journals (Sweden)



    Full Text Available Stemming is a main step used to process textual data. It is usually used in several types of applications such as: text mining, information retrieval (IR, and natural language processing (NLP. A major task in stemming is to standardize words; which can be achieved by reducing each word to its base (root or stem. Arabic stemming is not an easy task. Unlike other languages, Arabic language is a highly inflected language, since it uses many inflectional forms. Researchers are divided on the benefit of using stemming in fields of IR, NLP...etc., since in Arabic the morphological variants of a certain word are not always semantically related. The aim of this paper is to design and implement a new Arabic light stemmer (ARS which is not based on Arabic root patterns. Instead, it depends on well defined mathematical rules and several relations between letters. A series of tests were conducted on ARS stemmer to compare its effectiveness with the effectiveness of two other Arabic stemmers. Test shows clearly the effectiveness superiority of ARS compared to effectiveness of these two Arabic stemmers.

  14. Ramon Llull's Ars Magna

    DEFF Research Database (Denmark)

    Jensen, Thessa

    ; conceived and written in the late 13th century by a lay-monk whose life alone would be worth a Hollywood movie. In this paper I will take a brief look at Llull’s life and work, before explaining the four main parts of his Ars Magna. Finally, I will try to give a new perspec-tive on how the Ars Magna still...... might be a viable and valuable approach to understand some of the challenges and possibilities found in computer science and ethics. Vita Llull was born in 1232 in Palma de Mallorca, a melting pot for different cul-tures and religions at the time. Being educated at the king’s court, Llull learned...... the trade of the troubadour as well as reading and writing in Catalan. He became a devout Christian later in life only after he had married. Jesus showed himself to Llull on several occasions, and eventually Llull resumed his rather debauched life and decided to dedicate the rest of his life to three...

  15. 40Ar/39Ar age calibration against counted annuallayers

    DEFF Research Database (Denmark)

    Storey, Michael; Stecher, Ole


    worth exploring for an improved absolute age basis for the 40Ar/39Ar system is through cross-calibration with counted annual layers (e.g. tree rings, varves and ice cores). North Atlantic Ash Zone (NAAZ) II is found within the dated part of the annual Greenland ice core record. NAAZ II has been...

  16. Neutron-hole states in 45Ar from p(46Ar,d)45Ar reactions

    CERN Document Server

    Lu, F; Tsang, M B; Bazin, D; Coupland, D; Henzl, V; Henzlova, D; Kilburn, M; Lynch, W G; Rogers, A M; Sanetullaev, A; Sun, Z Y; Youngs, M; Charity, R J; Sobotka, L G; Famiano, M; Hudan, S; Horoi, M; Ye, Y L


    To improve the effective interactions in the pf shell, it is important to measure the single particle- and hole- states near the N=28 shell gap. In this paper, the neutron spectroscopic factors of hole-states from the unstable neutron-rich 45Ar (Z=18, N=27) nucleus have been studied using 1H(46Ar, 2H)45Ar transfer reaction in inverse kinematics. Comparison of our results with the particle-states of 45Ar produced in 2H(44Ar, H)45Ar reaction shows that the two reactions populate states with different angular momentum. Using the angular distributions, we are able to confirm the spin assignments of four low-lying states of 45Ar. These are the ground state (f7/2), the first-excited (p3/2), the s1/2 and the d3/2 states. While large basis shell model predictions describe spectroscopic properties of the ground and p3/2 states very well, they fail to describe the s1/2 and d3/2 hole-states.

  17. Ars Poetica : [luuletused] / Mats Traat

    Index Scriptorium Estoniae

    Traat, Mats, 1936-


    Sisu: Ars poetica ; Veepeegel ; Kontrollõed ; Mandariiniriik ; Nikolai Siamashvili (1888-1911) ; Kolmekümne kolmas aasta ; Kiri linast 1966 ; Italmaz Nuriyev ; Rudolf Rimmelile mõeldes ; Gennadi Aigi

  18. Ars Poetica : [luuletused] / Mats Traat

    Index Scriptorium Estoniae

    Traat, Mats, 1936-


    Sisu: Ars poetica ; Veepeegel ; Kontrollõed ; Mandariiniriik ; Nikolai Siamashvili (1888-1911) ; Kolmekümne kolmas aasta ; Kiri linast 1966 ; Italmaz Nuriyev ; Rudolf Rimmelile mõeldes ; Gennadi Aigi

  19. Pulsed discharge production Ar* metastables (United States)

    Han, Jiande; Heaven, Michael C.; Emmons, Daniel; Perram, Glen P.; Weeks, David E.; Bailey, William F.


    The production of relatively high densities of Ar* metastables (>1012 cm-3) in Ar/He mixtures, at total pressures close to 1 atm, is essential for the efficient operation of an optically pumped Ar* laser. We have used emission spectroscopy and diode laser absorption spectroscopy measurements to observe the production and decay of Ar* in a parallel plate pulsed discharge. With discharge pulses of 1 μs duration we find that metastable production is dominated by processes occurring within the first 100 ns of the gas break-down. Application of multiple, closely spaced discharge pulses yields insights concerning conditions that favor metastable production. This information has been combined with time-resolved measurements of voltage and current. The experimental results and preliminary modeling of the discharge kinetics are presented.

  20. Analysis list: Ar [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Ar Gonad,Kidney,Prostate + mm9,,,http://dbarchive.bioscience

  1. Analysis list: AR [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available AR Blood,Breast,Prostate + hg19 http:...//,,,http:

  2. 40Ar/39Ar dating of Daqingshan thrust

    Institute of Scientific and Technical Information of China (English)

    LIU Zhenghong; XU Zhongyuan; YANG Zhensheng


    The Daqingshan thrust system, to the south of the Shiguai Mesozoic basin, is a complex system of top-to- the-north thrusting tectonic sheets. The thrust system has a complicated evolution due to multi-stage thrusting. In order to date the thrusting events, syntectonic muscovite and biotite grains are respectively analyzed with normal 40Ar/39Ar dating and laser 40Ar/39Ar dating, which yield 2 isochron ages, i.e. 193.74 ± 3.88 Ma and 121.6 ± 1.6 Ma. These ages suggest that faults within the Daqingshan thrust system formed during 2 stages of thrusting, one the early Indosinian and the other the late Yanshanian. The isotopic dating is consistent with field geological relations. Indosinan deformation is evidenced by top-to-the-north thrusting, with the occurrence of a series of large-scale east-west trending thrust faults and folds, while the Yanshanian thrusting is characterized by top-to-the-NNW thrusting. It is superposed on and modifies early Indosinian thrust faults.

  3. "Ars Electronica 2009" / Raivo Kelomees

    Index Scriptorium Estoniae

    Kelomees, Raivo, 1960-


    30. "Ars Electronica" festival "Human Nature" ("Inimese loomus") Linzis. Osaka ülikooli professori Hiroshi Ishiguro mehaanilis-digitaalsest nukust. Hübriidkunsti kategoorias peapreemia saanud Eduardo Kaci inimtaimest. Konverentsidest. Näitusest "See this Sound", mis oli pühendatud helile kujutavas kunstis

  4. "Ars Electronica 2009" / Raivo Kelomees

    Index Scriptorium Estoniae

    Kelomees, Raivo, 1960-


    30. "Ars Electronica" festival "Human Nature" ("Inimese loomus") Linzis. Osaka ülikooli professori Hiroshi Ishiguro mehaanilis-digitaalsest nukust. Hübriidkunsti kategoorias peapreemia saanud Eduardo Kaci inimtaimest. Konverentsidest. Näitusest "See this Sound", mis oli pühendatud helile kujutavas kunstis

  5. AR DOC: Augmented reality documentaries

    DEFF Research Database (Denmark)

    Vistisen, Peter


    Augmented Reality Documentaries (AR DOC) er et ’lille’ Shareplay projekt (ansøgte midler augmented reality cross media løsninger, til at skabe engagerende publikumsformidling...... indenfor oplevelsesindustrien. Projektet har genereret ny viden omkring, hvordan fysisk og digital formidling kan understøttes via Augmented Reality som formidlingsformat....

  6. USDA-ARS Quartlerly News (United States)

    This quarterly article is an update of research going on at The USDA-ARS Thad Cochran Southern Horticultural Laboratory in Poplarville, MS to be published in the Louisiana Nursery and Landscape Associations (LANLA) quarterly newsletter. This is one of three publications that I am sending out to the ...

  7. Book review: Advances in 40Ar/39Ar dating: From archaeology to planetary sciences (United States)

    Cosca, Michael A.


    The recently published book Advances in 40Ar/39Ar Dating: From Archaeology to Planetary Sciences is a collection of 24 chapters authored by international scientists on topics ranging from decay constants to 40Ar/39Ar dating of extraterrestrial objects. As stated by the editors in their introduction, these chapters were assembled with the goal of providing technique-specific examples highlighting recent advances in the field of 40Ar/39Ar dating. As this is the first book truly dedicated to 40Ar/39Ar dating since the second edition printing of the argon geochronologist’s handbook Geochronology and Thermochronology by the 40Ar/39Ar Method (McDougall and Harrison 1999), a new collection of chapters highlighting recent advances in 40Ar/39Ar geochronology offers much to the interested reader.

  8. Armenian Astronomical Society (ArAS) activities (United States)

    Mickaelian, A. M.


    A review on the activities and achievements of Armenian Astronomical Society (ArAS) and Armenian astronomy in general during the last years is given. ArAS membership, ArAS electronic newsletters (ArASNews), ArAS webpage, Annual Meetings, Annual Prize for Young Astronomers (Yervant Terzian Prize) and other awards, international relations, presence in international organizations, local and international summer schools, science camps, astronomical Olympiads and other events, matters related to astronomical education, astronomical heritage, amateur astronomy, astronomy outreach and ArAS further projects are described and discussed.

  9. ar

    Directory of Open Access Journals (Sweden)

    P. Fanlo

    Full Text Available A pesar de que el pulmón es el órgano diana por excelencia de la tuberculosis, cualquier otro órgano y sistema puede verse afectado. En este trabajo se revisan las formas de tuberculosis extrapulmonar a excepción de la pleural que requieren del facultativo, en ocasiones, su más valiosa pericia diagnóstica. Desde la temida meningitis tuberculosa, pasando por la afectación insidiosa de la espondilodiscitis, la llamativa afectación ganglionar, la afectación genitourinaria, la pericarditis, para terminar las formas menos frecuentes como la ocular o la cutánea. En cada apartado indicaremos lo más característico con la finalidad de que pueda servir de orientación diagnóstica y terapéutica.

  10. ARS - Helsinki - 2006 / Galina Balashova

    Index Scriptorium Estoniae

    Balashova, Galina


    Steven Holli projekteeritud Kiasma muuseumihoonest Helsingis. Kontseptuaalkunsti näitusest ARS 06 "Reaalsustunne" Kiasmas. Eestlastest esineb Mark Raidpere. Vene kunstnikegrupi AEC+F ja vene kunstnike Juri Vassiljevi ning Aleksandr Ponomarjovi töödest näitusel. Ka Gerda Steineri & Jörg Lenzlingeri (Šveits), Martin & Munoz'i (USA, Hispaania), arvutigraafik Charles Sandisoni (SB), videokunstnik Bill Viola (USA) jt. töödest

  11. ARS - Helsinki - 2006 / Galina Balashova

    Index Scriptorium Estoniae

    Balashova, Galina


    Steven Holli projekteeritud Kiasma muuseumihoonest Helsingis. Kontseptuaalkunsti näitusest ARS 06 "Reaalsustunne" Kiasmas. Eestlastest esineb Mark Raidpere. Vene kunstnikegrupi AEC+F ja vene kunstnike Juri Vassiljevi ning Aleksandr Ponomarjovi töödest näitusel. Ka Gerda Steineri & Jörg Lenzlingeri (Šveits), Martin & Munoz'i (USA, Hispaania), arvutigraafik Charles Sandisoni (SB), videokunstnik Bill Viola (USA) jt. töödest

  12. Ars Industrialis,

    Directory of Open Access Journals (Sweden)

    Frédérique Mingant


    Full Text Available The website was created in 2005, when the association Ars Industrialis came into being. The association was founded by a group of philosophers and jurists, on the initiative of philosopher Bernard Stiegler, the former director of the IRCAM (Institut de Recherche et Coordination Acoustique/Musique–Institute of Research and Coordination on Acoustic/Music and the current director of the Department of cultural development at the Centre Georges Pompidou (French National Arts C...

  13. Ars Industrialis,


    Frédérique Mingant


    The website was created in 2005, when the association Ars Industrialis came into being. The association was founded by a group of philosophers and jurists, on the initiative of philosopher Bernard Stiegler, the former director of the IRCAM (Institut de Recherche et Coordination Acoustique/Musique–Institute of Research and Coordination on Acoustic/Music) and the current director of the Department of cultural development at the Centre Georges Pompidou (French National Arts C...

  14. Occurrences of Excess 40Ar in Hydrothermal Tourmaline:Interpretations from 40Ar-39Ar Dating Results by Stepwise Heating

    Institute of Scientific and Technical Information of China (English)

    QIU Huaning; PU Zhiping; DAI Tongmo


    The occurrences of excess 40Ar within a hydrothermal tourmaline is discussed in term of the analysis data of syngenetic muscovite and tourmaline from the Lushui hydrothermal tin-tungsten deposit in western Yunnan, China, using the 40Ar-39Ar stepwise heating technique. About 80% excess 40Ar was released in the last step when the tourmaline was fused, corresponding to a release of only ~3% 39Ar (K), which indicates that most excess 40Ar was held in the mineral lattice rather than in the channels parallel to the Z-axis. This suggests that the excess 40Ar was incorporated during crystallization and not diffused into the tourmaline during the post-crystallization history.

  15. Ars Memorativa, Ars Oblivionis in Middle English Religious Plays

    Directory of Open Access Journals (Sweden)

    Ciobanu Estella Antoaneta


    Full Text Available This paper investigates the multi-layered violence of religious representation in the late medieval York biblical plays, with a focus on the Supper at Emmaus. I read Emmaus (Y40, a play which commemorates the Crucifixion and openly encourages strong anti-Judaism, alongside scenes in an early predecessor pageant, The Crucifixion (Y35, within their contemporary devotional and mnemonic practices, i.e. the confessional Book of Margery Kempe and Thomas Bradwardine’s tract on ars memorativa. Emmaus in particular demonstrates how a fundamentally violent ars memorativa, the legacy of ancient rhetoric to the Middle Ages, also underpins the instruction of the laity in the basics of Christian faith, here with the aid of highly musical prosody and repetition, and thereby hones a biased, intolerant and violence-inured Christian collective memory. To study the York play’s position relative to late medieval mnemonic practices, I frame my analysis within memory studies, enriched with the more specific insights offered by social-psychological, neurobiological and cognitivist studies of memory.

  16. PF-AR upgrading project

    CERN Document Server

    Kasuga, T


    The upgrading project of the dedicated pulse X-ray source PF-AR has been completed by the end of the 2001 fiscal year. Machine commissioning exclusively using the injector linac was successfully accomplished in the beginning of January 2002. After fine tuning of the machine and cleaning of the vacuum system with the beams from the middle of January to the middle of March, routine operation for users has begun in April. The historical details, commissioning and results of the project are reported. (author)

  17. Interpretation of discordant 40Ar/39Ar age-spectra of mesozoic tholeiites from antarctica (United States)

    Fleck, R.J.; Sutter, J.F.; Elliot, D.H.


    Conventional K-Ar ages of tholeiitic basalts of the Ferrar Group in the central Transantarctic Mountains indicate significant loss of radiogenic 40Ar from this unit over much of its outcrop area. Argon loss varies inversely with amount of devitrified matrix in the basalts, which have not been thermally or tectonically disturbed since extrusion. 40Ar/19Ar age-spectra of these tholeiites are generally discordant and indicate significant inhomogeneity in the distribution of radiogenic 40Ar with respect to 39Ar, but are distinctly different from release patterns of thermally disturbed samples. Amounts of argon redistribution vary directly with amounts of devitrification and are reflected in progressive modification of the age spectra. A model of redistribution of radiogenic 40Ar by devitrification of originally glassy matrix is suggested that is consistent with disturbance of the conventional K-Ar systematics as well as the 40Ar/39Ar age-spectra. Samples with substantial redistribution but minor loss of radiogenic argon yield age spectra whose apparent ages decrease from low-temperature to high-temperature steps, similar to those reported for some lunar basalts, breccias, and soils. Modification of all the age spectra is attributed to redistribution of radiogenic 40Ar during progressive devitrification, although 39Ar-recoil effects suggested by Turner and Cadogan (1974) may be a factor in some cases. Where devitrification involves most potassium sites within the basalt, 40Ar/39Ar age-plateaux may be formed that have no geologic significance. ?? 1977.

  18. Ars grammatica de Dionisio Tracio

    Directory of Open Access Journals (Sweden)

    Beltrán Jorge Enrique


    Full Text Available

    Ars Grammatica de Dionisio Tracio (170-90 a. C fue la primera gramática griega que se escribió. Su contenido y método fueron modelos que siguieron las gramáticas escolares posteriores. La versión española que se presenta ahora responde a la necesidad que se tenía en nuestro medio de una traducción completa de este texto. Finalmente, se acompaña la traducción de una introducción y de abundantes notas, en un intento por hacerla comprensible para el hablante del español, no necesariamente conocedor de la lengua griega.

  19. GPS-Based AR Games Development Potential

    Directory of Open Access Journals (Sweden)

    Gregorius Alvin Raditya Santoso


    Full Text Available The application of new technologies in a game is not a new thing. One example is the application of Augmented Reality (AR technology in game. Many people do not know the application of AR technology in game, although the application of this technology is able to produce a game with unique gameplay. In addition, since AR game is GPS-based, it offers new gaming experience, that is, playing outdoors in which the real world becomes the game arena. This advantage gives the AR technology a huge potential to be developed into a game

  20. 40Ar/39Ar Interlaboratory Calibration into the Holocene. (United States)

    Heizler, M. T.; Jicha, B.; Koppers, A. A. P.; Miggins, D. P.


    Advances in 40Ar/39Ar analytical precision for very young rocks requires collaborative efforts amongst argon geochronology labs to demonstrate age reproducibility commensurate with high precision. NM Tech (NMT), the University of Wisconsin (UW) and Oregon State University (OSU) have each dated Quaternary flux monitor standard AC-2 sanidine (~1.185 Ma), a blind sanidine described as being 50-100 ka (BS) and sanidine from the Qixiangshan (QIX) flow (~10 ka), Changbaishan volcano, China. The samples were irradiated in a single package with FC-2 sanidine (28.201 Ma) as the flux monitor and the irradiated material was distributed amongst the labs. Heizler was present during analysis at both OSU and UW and Jicha attended OSU during analysis. Physical presence was key towards gaining understanding of individual protocols and prompted valuable discussions. Analyses were carried out on single crystals using total fusion and/or step heating approaches. Age agreement was achieved within 2s uncertainty that ranged between (0.03-0.3%, 0.13-0.37% and 1.8-2.6%) for AC-2, BS and QIX, respectively. Each lab found AC-2 to vary somewhat beyond a normal distribution and to yield an age relative to FC-2 of ~1.185 Ma that is ~1.3% (~5-10 sigma) lower than some published estimates. A key cause of the variation between this study and previous results may be variable gas pressure equilibration times between extraction line and mass spectrometer coupled with variable choices to estimate time zero by other laboratories. The majority of our efforts concentrated on the QIX sanidine where prior data obtained by our labs revealed a factor of two spread in age (~11 and 23 ka) based on experiments carried out by total fusion and bulk incremental heating. By conducting single crystal age spectrum analysis we were able to mitigate effects of melt inclusion hosted excess argon and xenocrystic contamination towards obtaining analytical agreement with apparent ages near 10 ka. However, philosophical

  1. Re-Evaluation of Ar-39 - Ar-40 Ages for Apollo Lunar Rocks 15415 and 60015 (United States)

    Park, J.; Nyquist, L. E.; Bogard, D. D.; Garrison, D. H.; Shih, C.-Y.


    We re-analyzed 39Ar-40Ar ages of Apollo lunar highland samples 15415 and 60015, two ferroan anorthosites analyzed previously in the 1970 s, with a more detailed approach and with revised decay constants. From these samples we carefully prepared 100-200 mesh mineral separates for analysis at the Noble Gas Laboratory at NASA-Johnson Space Center. The Ar-39-Ar-40 age spectra for 15415 yielded an age of 3851 +/- 38 Ma with 33-99% of Ar39 release, roughly in agreement with previously reported Ar-Ar ages. For 60015, we obtained an age of 3584 +/- 152 Ma in 23-98% of Ar39 release, also in agreement with previously reported Ar-Ar ages of approximately 3.5 Ga. Highland anorthosites like these are believed by many to be the original crust of the moon, formed by plagioclase floatation atop a magma ocean, however the Ar-Ar ages of 15415 and 60015 are considerably younger than lunar crust formation. By contrast, recently recovered lunar anorthosites such as Dhofar 489, Dhofar 908, and Yamato 86032 yield older Ar-Ar ages, up to 4.35 Ga, much closer to time of formation of the lunar crust. It follows that the Ar-Ar ages of the Apollo samples must have been reset by secondary heating, and that this heating affected highland anorthosites at both the Apollo 15 and Apollo 16 landing sites but did not affect lunar highland meteorites. One obvious consideration is that while the Apollo samples were collected from the near side of the moon, these lunar meteorites are thought to have originated from the lunar far side

  2. Modification of stearic acid in Ar and Ar-O2 pulsed DC discharge

    Directory of Open Access Journals (Sweden)

    Euclides Alexandre Bernardelli


    Full Text Available Stearic acid (CH3(CH216COOH was treated with Ar and Ar-O2 (10% pulsed DC discharges created by a cathode-anode confined system to elucidate the role of oxygen in plasma cleaning. The treatment time (5 to 120 minutes and plasma gas mixture (Ar and Ar-O2 were varied, and the results showed that the mass variation of stearic acid after Ar-O2 plasma exposure was greater than that of pure Ar plasma treatment. Thus, compared to Ar*, active oxygen species (O and O2, in all states enhance the etching process, regardless of their concentration. During the treatments, a liquid phase developed at the melting temperature of stearic acid, and differential thermal analyses showed that the formation of a liquid phase was associated with the breakage of bonds due to treatment with an Ar or Ar-O2 plasma. After treatment with Ar and Ar-O2 plasmas, the sample surface was significantly modified, especially when Ar-O2 was utilized. The role of oxygen in the treatment process is to break carbonaceous chains by forming oxidized products and/or to act as a barrier again ramification, which accelerates the etching of stearic acid.

  3. Study of the symbiotic star AR Pavonis

    Directory of Open Access Journals (Sweden)

    C. Quiroga


    Full Text Available We present a study of the optical spectra and linear polarization of the eclipsing binary AR Pavonis. The optical spectra were obtained between 1990 and 1998, and polarimetric data between 1995 and 1998. From spectroscopic variations along the orbital motion we analized the nature of the system. Polarimetric studies indicate that AR Pav has intrinsic polarization.

  4. The Coronae of AR Lac

    CERN Document Server

    Huenemoerder, D P; Drake, J J; Sanz-Forcada, J; Canizares, Claude R.; Drake, Jeremy J.; Huenemoerder, David P.; Sanz-Forcada, Jorge


    We observed the coronally active eclipsing binary, AR Lac, with the High Energy Transmission Grating on Chandra for a total of 97 ks, spaced over five orbits, at quadratures and conjunctions. Contemporaneous and simultaneous EUV spectra and photometry were also obtained with the Extreme Ultraviolet Explorer. Significant variability in both X-ray and EUV fluxes were observed, dominated by at least one X-ray flare and one EUV flare. We saw no evidence of primary or secondary eclipses. X-ray flux modulation was largest at high temperature, indicative of flare heating of coronal plasma. Line widths interpreted in terms of Doppler broadening suggest that both binary stellar components are active. From line fluxes obtained from total integrated spectra, we have modeled the emission measure and abundance distributions. A strong maximum was found in the differential emission measure, characterized by peaks at log T = 6.9 and 7.4, together with a weak but significant cooler maximum near log T=6.2, and a moderately str...

  5. Revised error propagation of 40Ar/39Ar data, including covariances (United States)

    Vermeesch, Pieter


    The main advantage of the 40Ar/39Ar method over conventional K-Ar dating is that it does not depend on any absolute abundance or concentration measurements, but only uses the relative ratios between five isotopes of the same element -argon- which can be measured with great precision on a noble gas mass spectrometer. The relative abundances of the argon isotopes are subject to a constant sum constraint, which imposes a covariant structure on the data: the relative amount of any of the five isotopes can always be obtained from that of the other four. Thus, the 40Ar/39Ar method is a classic example of a 'compositional data problem'. In addition to the constant sum constraint, covariances are introduced by a host of other processes, including data acquisition, blank correction, detector calibration, mass fractionation, decay correction, interference correction, atmospheric argon correction, interpolation of the irradiation parameter, and age calculation. The myriad of correlated errors arising during the data reduction are best handled by casting the 40Ar/39Ar data reduction protocol in a matrix form. The completely revised workflow presented in this paper is implemented in a new software platform, Ar-Ar_Redux, which takes raw mass spectrometer data as input and generates accurate 40Ar/39Ar ages and their (co-)variances as output. Ar-Ar_Redux accounts for all sources of analytical uncertainty, including those associated with decay constants and the air ratio. Knowing the covariance matrix of the ages removes the need to consider 'internal' and 'external' uncertainties separately when calculating (weighted) mean ages. Ar-Ar_Redux is built on the same principles as its sibling program in the U-Pb community (U-Pb_Redux), thus improving the intercomparability of the two methods with tangible benefits to the accuracy of the geologic time scale. The program can be downloaded free of charge from

  6. 40Ar/39Ar ages of lunar impact glasses: Relationships among Ar diffusivity, chemical composition, shape, and size

    CERN Document Server

    Zellner, N E B


    Lunar impact glasses, quenched melts produced during cratering events on the Moon, have the potential to provide not only compositional information about both the local and regional geology of the Moon but also information about the impact flux over time. We present in this paper the results of 73 new 40Ar/39Ar analyses of well-characterized, inclusion-free lunar impact glasses and demonstrate that size, shape, chemical composition, fraction of radiogenic 40Ar retained, and cosmic ray exposure (CRE) ages are important for 40Ar/39Ar investigations of these samples. Specifically, analyses of lunar impact glasses from the Apollo 14, 16, and 17 landing sites indicate that retention of radiogenic 40Ar is a strong function of post-formation thermal history in the lunar regolith, size, and chemical composition. Based on the relationships presented in this paper, lunar impact glasses with compositions and sizes sufficient to have retained 90% of their radiogenic Ar during 750 Ma of cosmic ray exposure at time-integra...

  7. Spatial evaluation of Ar-systematics in rocks from the British Channel Islands: a UV laserprobe Ar/Ar study of excess 40Ar (United States)

    Schwenzer, S. P.; Sherlock, S.; Kelley, S. P.


    The Ar-Ar method is a powerful tool for constraining thermal histories of metamorphic and plutonic rocks, most commonly undertaken on potassium rich mineral separates rather than whole rocks. While this approach usually yields reasonable thermal histories, it is rarely as precise as dating volcanics, and such rocks are also frequently contaminated by excess argon, artificially elevating the Ar-Ar ages. Understanding the evolution of excess argon represents a challenge; whilst it is possible to discern the ‘sink’ as the host mineral now contaminated by excess argon, examining the ‘source’ and ‘transport’ mechanism is more challenging. The approach we have taken here is to combine measurements of potassium rich and potassium poor minerals to understand the argon reservoirs and argon transfer between minerals, grain boundaries and fluids. Considering the system as a whole provides a method for understanding the complete history of the rock and thus assessing any interactions which may impact on the interpretation of ages and thermal history [Kelley, 2002, Chem. Geol. 188]. Here we have studied a series of plutonic and metamorphic basement samples from the British Channel Islands with different ages and post-emplacement histories, namely Icart Gneiss, Perelle Quartz Diorite, L’Ancresse Granodiorite, and Bordeaux Diorite. The formation age of Icart Gneiss is ~2000 Ma [D’Lemos et al., 1990, Geol. Soc. Spec. Pub. 51]. Ar-Ar ages of hornblendes and biotites from quartz diorites on Guernsey and Sark range between 606 and 596 Ma [Dallmeyer et al. 1991, J. Geol. Soc. London 148], whilst U-Pb zircon ages are in the range 710 to 613 Ma [Dallmeyer et al. 1991; Samson & D’Lemos 1998, J. Geol. Soc. London 155; Miller et al. 1999, Tectonophysics 132]. Detailed petrograpic (microscope, electron microprobe) investigations established the crystallization and deformation history of the samples, and revealed that post-magmatic alteration is unevenly distributed. This

  8. 40Ar/39Ar Ages of Carbonaceous Xenoliths in 2 HED Meteorites (United States)

    Turrin, B.; Lindsay, F. N.; Park, J.; Herzog, G. F.; Delaney, J. S.; Swisher, C. C., III; Johnson, J.; Zolensky, M.


    The generally young K/Ar and 40Ar/39Ar ages of CM chondrites made us wonder whether carbonaceous xenoliths (CMX) entombed in Howardite–Eucrite–Diogenite (HED) meteorites might retain more radiogenic 40Ar than do ‘free-range’ CM-chondrites. To find out, we selected two HED breccias with carbonaceous inclusions in order to compare the 40Ar/39Ar release patterns and ages of the inclusions with those of nearby HED material. Carbonaceous inclusions (CMXs) in two HED meteorites lost a greater fraction of radiogenic 40Ar than did surrounding host material, but a smaller fraction of it than did free-range CM-chondrites such as Murchison or more heavily altered ones. Importantly, however, the siting of the CMXs in HED matrix did not prevent the 40Ar loss of about 40 percent of the radiogenic 40Ar, even from phases that degas at high laboratory temperatures. We infer that carbonaceous asteroids with perihelia of 1 astronomical unit probably experience losses of at least this size. The usefulness of 40Ar/39Ar dating for samples returned from C-type asteroids may hinge, therefore, on identifying and analyzing separately small quantities of the most retentive phases of carbonaceous chondrites.

  9. Escuela Pública y Proyecto Roma. Dadme una escuela y cambiaré el mundo

    Directory of Open Access Journals (Sweden)



    Full Text Available Este trabajo pone de manifiesto las condiciones que debe reunir una escuela pública para cumplir el valor de lo público. Por eso, hablar de escuela pública es hablar de justicia social y de equidad en educación, y de una escuela de calidad para todos y todas. Hoy en día en la escuela publica es necesario y urgente reflexionar y hacer cambios didácticos en el papel del docente, en el discente y en el currículum. En coherencia con ello, se presenta el Proyecto Roma como modelo educativo y de investigación alternativo que cumple con los Derechos Humanos y busca la mejora de la escuela pública.

  10. Instrumentation development for In Situ 40Ar/39Ar planetary geochronology (United States)

    Morgan, Leah; Munk, Madicken; Davidheiser-Kroll, Brett; Warner, Nicholas H.; Gupta, Sanjeev; Slaybaugh, Rachel; Harkness, Patrick; Mark, Darren


    The chronology of the Solar System, particularly the timing of formation of extra-terrestrial bodies and their features, is an outstanding problem in planetary science. Although various chronological methods for in situ geochronology have been proposed (e.g., Rb-Sr, K-Ar), and even applied (K-Ar), the reliability, accuracy, and applicability of the 40Ar/39Ar method makes it by far the most desirable chronometer for dating extra-terrestrial bodies. The method however relies on the neutron irradiation of samples, and thus a neutron source. Herein, we discuss the challenges and feasibility of deploying a passive neutron source to planetary surfaces for the in situ application of the 40Ar/39Ar chronometer. Requirements in generating and shielding neutrons, as well as analysing samples are described, along with an exploration of limitations such as mass, power and cost. Two potential solutions for the in situ extra-terrestrial deployment of the 40Ar/39Ar method are presented. Although this represents a challenging task, developing the technology to apply the 40Ar/39Ar method on planetary surfaces would represent a major advance towards constraining the timescale of solar system formation and evolution.

  11. Ars Baltica-verkoston puheenjohtajuus Suomeen Risto Ruohoselle

    Index Scriptorium Estoniae


    1990. a. loodud võrgustiku Ars Baltica sekretariaat (Ars Baltica Contact Point & Communication Center) tuleb Kielist Tallinnasse Eesti kultuuriministeeriumi kuni aastani 2002 (Suur-Karja 23). Ars Baltica (ühendus)

  12. Ars Baltica-verkoston puheenjohtajuus Suomeen Risto Ruohoselle

    Index Scriptorium Estoniae


    1990. a. loodud võrgustiku Ars Baltica sekretariaat (Ars Baltica Contact Point & Communication Center) tuleb Kielist Tallinnasse Eesti kultuuriministeeriumi kuni aastani 2002 (Suur-Karja 23). Ars Baltica (ühendus)

  13. Ars ornata / Kadri Mälk

    Index Scriptorium Estoniae

    Mälk, Kadri, 1958-


    V rahvusvaheline ehtekunsti konverents 'Ars ornata Europeana' juuni lõpus Stockholmis. New Yorgis elava kuraatori Charon Kranseni ja prantsuse ehtekunstniku Christophe Burger' juhitud vestlusringidest. 1997. a. Pariisis loodud International Craft Design Association'ist (ICDA).

  14. Differential AR algorithm for packet delay prediction

    Institute of Scientific and Technical Information of China (English)


    Different delay prediction algorithms have been applied in multimedia communication, among which linear prediction is attractive because of its low complexity. AR (auto regressive) algorithm is a traditional one with low computation cost, while NLMS (normalize least mean square) algorithm is more precise. In this paper, referring to ARIMA (auto regression integrated with moving averages) model, a differential AR algorithm (DIAR) is proposed based on the analyses of both AR and NLMS algorithms. The prediction precision of the new algorithm is about 5-10 db higher than that of the AR algorithm without increasing the computation complexity.Compared with NLMS algorithm, its precision slightly improves by 0.1 db on average, but the algorithm complexity reduces more than 90%. Our simulation and tests also demonstrate that this method improves the performance of the average end-to-end delay and packet loss ratio significantly.

  15. "Ars Ornata" Mediterrania / Kadri Mälk

    Index Scriptorium Estoniae

    Mälk, Kadri, 1958-


    VI rahvusvaheline ehtekunstinäitus "Ars Ornata" juuni lõpus Barcelonas. Konverentsist, peanäitusest (osalejad Eestist), ehtekunstiõpetust andvast kõrgkoolist Escola Massana'st Barcelonas, õppejõude. Eesti ehtekunsti tulevikust.

  16. ARS 01 Helsingi Kiasmas / Tarmo Virki

    Index Scriptorium Estoniae

    Virki, Tarmo


    Helsingis Kiasmas avatud rahvusvahelisest kunstinäitusest ARS 01 alapealkirjaga "Avanevaid perspektiive", kus esines oma töödega ka Marko Mäetamm. Näituse raames toimuvast Santiago Sierra kunstiprojektist kodututega

  17. ARS 01 Helsingi Kiasmas / Tarmo Virki

    Index Scriptorium Estoniae

    Virki, Tarmo


    Helsingis Kiasmas avatud rahvusvahelisest kunstinäitusest ARS 01 alapealkirjaga "Avanevaid perspektiive", kus esines oma töödega ka Marko Mäetamm. Näituse raames toimuvast Santiago Sierra kunstiprojektist kodututega

  18. Ars ornata / Kadri Mälk

    Index Scriptorium Estoniae

    Mälk, Kadri, 1958-


    V rahvusvaheline ehtekunsti konverents 'Ars ornata Europeana' juuni lõpus Stockholmis. New Yorgis elava kuraatori Charon Kranseni ja prantsuse ehtekunstniku Christophe Burger' juhitud vestlusringidest. 1997. a. Pariisis loodud International Craft Design Association'ist (ICDA).

  19. 40Ar/39Ar ages of the AD 79 eruption of Vesuvius, Italy (United States)

    Lanphere, Marvin; Champion, Duane; Melluso, Leone; Morra, Vincenzo; Perrotta, Annamaria; Scarpati, Claudio; Tedesco, Dario; Calvert, Andrew


    The Italian volcano, Vesuvius, erupted explosively in AD 79. Sanidine from pumice collected at Casti Amanti in Pompeii and Villa Poppea in Oplontis yielded a weighted-mean 40Ar/39Ar age of 1925±66 years in 2004 (1σ uncertainty) from incremental-heating experiments of eight aliquants of sanidine. This is the calendar age of the eruption. Our results together with the work of Renne et al. (1997) and Renne and Min (1998) demonstrate the validity of the 40Ar/39Ar method to reconstruct the recent eruptive history of young, active volcanoes.

  20. Dating samples of lunar soil from the Mare Crisium by the Ar/39/-Ar/40/ technique (United States)

    Shanin, L. L.; Arakeliants, M. M.; Bogatikov, O. A.; Ivanenko, V. V.; Pupyrev, Iu. G.; Tarasov, L. S.; Frikh-Khar, D. I.


    Two samples (dolerite and gabbro fragments) from a depth of 184 cm in the Luna 24 core are dated using the Ar(39)-Ar(40) technique. The values obtained are found to be lower than all published isotopic ages for the Luna 24 samples. An analysis of possible dating errors of the lunar samples, together with the good agreement of the results from the Ar(39)-Ar(40) technique of geochronologic standards and anorthosite from the Korosten pluton with the results from Rb-Sr, U-Pb, and Sm-Nd methods, attests the reliability of the values.

  1. 40Ar/ 39Ar systematics and argon diffusion in amber: implications for ancient earth atmospheres (United States)

    Landis, G. P.; Snee, L. W.


    Argon isotope data indicate retained argon in bulk amber (matrix gas) is radiogenic [ 40Ar/ 39Ar ≃32o] than the much more abundant surface absorbed argon [ 40Ar/ 39Ar ≃295.5]. Neutron-induced 39Ar is retained in amber during heating experiments to 150° -250°C, with no evidence of recoiled 39Ar found after irradiation. A maximum permissible volume diffusion coefficient of argon in amber (at ambient temperature) D≤1.5 x 10 -17 cm 2S -1 is calculated from 39Ar retention. 40Ar/ 39Ar age calculations indicate Dominican Republic amber is ≃ 45 Ma and North Dakota amber is ≃ 89 Ma, both at least reasonable ages for the amber based upon stratigraphic and paleontological constraints and upon the small amount of radiogenic 40Ar. To date, over 300 gas analyses of ambers and resins of Cretaceous to Recent age that are geographically distributed among fifteen noted world locations identify mixtures of gases in different sites within amber (Berner and Landis, 1988). The presence of multiple mixing trends between compositionally distinct end-members gases within the same sample and evidence for retained radiogenic argon within the amber argue persuasivley against rapid exchange by diffusion of amber-contained gases with moder air. Only gas in primary bubbles entrapped between successive flows of tree resin has been interpreted as original "ancient air", which is an O 2-rich end-member gas with air-like N 2/Ar ratios. Gas analyses of these primary bubbles indicate atmospheric O 2 levels in the Late Cretaceous of ≃ 35%, and that atmospheric O 2 dropped by early Tertiary time to near a present atmospheric level of 21% O 2. A very low argon diffusion coefficient in amber persuasively argues for a gas in primary bubbles trapped in amber being ancient air (possibly modified only by O 2 reaction with amber).

  2. ArsP: a methylarsenite efflux permease. (United States)

    Chen, Jian; Madegowda, Mahendra; Bhattacharjee, Hiranmoy; Rosen, Barry P


    Trivalent organoarsenic compounds are far more toxic than either pentavalent organoarsenicals or inorganic arsenite. Many microbes methylate inorganic arsenite (As(III)) to more toxic and carcinogenic methylarsenite (MAs(III)). Additionally, monosodium methylarsenate (MSMA or MAs(V)) has been used widely as an herbicide and is reduced by microbial communities to MAs(III). Roxarsone (3-nitro-4-hydroxybenzenearsonic acid) is a pentavalent aromatic arsenical that is used as antimicrobial growth promoter for poultry and swine, and its active form is the trivalent species Rox(III). A bacterial permease, ArsP, from Campylobacter jejuni, was recently shown to confer resistance to roxarsone. In this study, C. jejuni arsP was expressed in Escherichia coli and shown to confer resistance to MAs(III) and Rox(III) but not to inorganic As(III) or pentavalent organoarsenicals. Cells of E. coli expressing arsP did not accumulate trivalent organoarsenicals. Everted membrane vesicles from those cells accumulated MAs(III) > Rox(III) with energy supplied by NADH oxidation, reflecting efflux from cells. The vesicles did not transport As(III), MAs(V) or pentavalent roxarsone. Mutation or modification of the two conserved cysteine residues resulted in loss of transport activity, suggesting that they play a role in ArsP function. Thus, ArsP is the first identified efflux system specific for trivalent organoarsenicals.

  3. ArDroneXT - Ar.Drone 2 eXTension for swarming and service hosting


    Autefage, Vincent; Chaumette, Serge


    This is an Operating System Setup Guide.; This report explains how to upgrade an Ar.Drone 2 for swarming and services hosting. In other words, it gives the technical information required to easily create a swarm of Ar.Drone 2 sharing a Wi-Fi network. Moreover, it describes the process to install new services and applications on the drone.

  4. A Refined Astronomically Calibrated 40Ar/39Ar Age for Fish Canyon Sanidine

    DEFF Research Database (Denmark)

    Rivera, Tiffany; Storey, Michael; Zeeden, Christian


    Intercalibration between the astronomical and radio-isotopic dating methods provides a means to improving accuracy and reducing uncertainty of an integrated, multi-chronometer geologic timescale. Here we report a high-precision 40Ar/39Ar age for the Fish Canyon sanidine (FCs) neutron fluence...

  5. A refined astronomically calibrated 40Ar/39Ar age for Fish Canyon sanidine

    NARCIS (Netherlands)

    Rivera, T.A.; Storey, M.; Zeeden, C.; Hilgen, F.J.; Kuiper, K.


    Intercalibration between the astronomical and radio-isotopic dating methods provides a means to improving accuracy and reducing uncertainty of an integrated, multi-chronometer geologic timescale. Here we report a high-precision 40Ar/39Ar age for the FishCanyon sanidine (FCs) neutron fluence monitor,

  6. Modeling Augmented Reality User Interfaces with SSIML/AR

    Directory of Open Access Journals (Sweden)

    Arnd Vitzthum


    Full Text Available Augmented Reality (AR technologies open up new possibilities especially for task-focused domains such as assembly and maintenance. However, it can be noticed that there is still a lack of concepts and tools for a structured AR development process and an application specification above the code level. To address this problem we introduce SSIML/AR, a visual modeling language for the abstract specification of AR applications in general and AR user interfaces in particular. With SSIML/AR, three different aspects of AR user interfaces can be described: The user interface structure, the presentation of relevant information depending on the user’s current task and the integration of the user interface with other system components. Code skeletons can be generated automatically from SSIML/AR models. This enables the seamless transition from the design level to the implementation level. In addition, we sketch how SSIML/AR models can be integrated in an overall AR development process.

  7. AR-扩增实境

    Institute of Scientific and Technical Information of China (English)


    1、什么是AR-扩增实境?AR-扩增实境(Augmented Reality,简称AR),简单地说,就是把虚拟的物体和现实的场景进行嫁接。这是一种实时地计算摄影机影像的位置及角度并加上相应图像的技术,这种技术的目标是在屏幕上把虚拟世界套在现实世界并进行互动。

  8. 40Ar/39Ar and K/Ar dating of low grade metamorphism: examples on metabasites from Central Chile (United States)

    Aguirre, L.; Feraud, G.; Fuentes, F.; Delbar, M.; Morata, D.


    Dating low to very low-grade burial metamorphic assemblages is often difficult because of (1) few mineral phases compositionally suitable to apply the 40Ar/39Ar and K-Ar methods, and (2) small amount in which these phases are commonly found. K-feldspar adularia, sericitic mica, and celadonite are the best known K-bearing secondary minerals. We present some successful attempts to analyse two distinct secondary phases from a same volcanic formation that allow to test the validity of the measured ages. These ages have been also compared with the crystallisation age of the volcanic rocks in which the secondary phases were lately developed. Adularia and sericite were selected from basic lava flows from a 3 to 13 km thick Cretaceous sequence from the Coastal Range of central Chile, at two different locations: the Bustamante Hill (west from Santiago), and the Cordón de Chacana, c. 80 km further north. Adularia came from a low-variance assemblage with pumpellyite, chlorite and low-albite contained in amygdules whereas sericite was present in milky-white strongly sericitized plagioclase crystals. While small clusters of rare fresh plagioclase grains from lava flows from Bustamante and Chacana displayed concordant plateau ages 119.4 ± 2.4 (2 sigma) and 118.7 ± 0.6 Ma, respectively, the adularia from the same formations gave sensibly younger ages around 94 Ma (high temperature steps), and 96.8 ± 0.2 Ma (plateau age) in Bustamante and Chacana, respectively. Sericite ages were measured in situ into single crystals of strongly transformed plagioclases. The relative proportion of sericite and plagioclase corresponding to each degasing step was monitored by measuring the Ca/K ratio (deduced from 37ArCa/39Ar_K). While intermediate ages were measured on some sericite of both sites (corresponding to a variable but permanent contribution of plagioclase on each step), a plateau age of 97.0 ± 1.6 Ma (concordant with adularia) could be obtained on a strongly sericitized plagioclase

  9. Comparative 40Ar/39Ar and K-Ar dating of illite-type clay minerals: A tentative explanation for age identities and differences (United States)

    Clauer, Norbert; Zwingmann, Horst; Liewig, Nicole; Wendling, Raymond


    The 40K/40Ar (K-Ar) and 40Ar/39Ar dating methods are applied here to the same, very small, micrometric illite-type particles that crystallized under low-temperature (samples with a total of fifteen size fractions from advantages, such as the plateaus obtained by incremental step heating of the various size fractions, even if not translatable straight as ages of the illite populations; they allow identification of two generations of authigenic illite that formed at about 200 and 175 Ma, and one detrital generation. However, 40Ar/39Ar dating of clay minerals remains challenging as technical factors, such as the non-standardized encapsulation, may have potential unexpected effects. Both dating methods have their limitations: (1) K-Ar dating requires relatively large samples (ca. 10-20 mg) incurring potential sample homogeneity problems, with two aliquots required for K and Ar analysis for an age determination, also inducing a higher analytical uncertainty; (2) an identified drawback of 40Ar/39Ar dating is Ar recoil and therefore potential loss that occurs during neutronic creation of 39Ar from 39K, mostly in the finer mineral particles. If all the recoiled 39Ar is redistributed into adjacent grains/minerals, the final 40Ar/39Ar age of the analyzed size fraction remains theoretically identical, but it is not systematic in clay-type material. The finest grain sizes (e.g., convenient and straightforward use supported by a standardized and well-controlled technical approach. The present comparison of the two Ar-dating methods as applied to clay material shows that neither method is presently outdated, and that they are even of reciprocal use. Both methods have distinct application fields in clay geochronology and complementary application fields in clay crystallography.

  10. Moving Beyond the Androgen Receptor (AR): Targeting AR-Interacting Proteins to Treat Prostate Cancer. (United States)

    Foley, Christopher; Mitsiades, Nicholas


    Medical or surgical castration serves as the backbone of systemic therapy for advanced and metastatic prostate cancer, taking advantage of the importance of androgen signaling in this disease. Unfortunately, resistance to castration emerges almost universally. Despite the development and approval of new and more potent androgen synthesis inhibitors and androgen receptor (AR) antagonists, prostate cancers continue to develop resistance to these therapeutics, while often maintaining their dependence on the AR signaling axis. This highlights the need for innovative therapeutic approaches that aim to continue disrupting AR downstream signaling but are orthogonal to directly targeting the AR itself. In this review, we discuss the preclinical research that has been done, as well as clinical trials for prostate cancer, on inhibiting several important families of AR-interacting proteins, including chaperones (such as heat shock protein 90 (HSP90) and FKBP52), pioneer factors (including forkhead box protein A1 (FOXA1) and GATA-2), and AR transcriptional coregulators such as the p160 steroid receptor coactivators (SRCs) SRC-1, SRC-2, SRC-3, as well as lysine deacetylases (KDACs) and lysine acetyltransferases (KATs). Researching the effect of-and developing new therapeutic agents that target-the AR signaling axis is critical to advancing our understanding of prostate cancer biology, to continue to improve treatments for prostate cancer and for overcoming castration resistance.

  11. Modification of stearic acid in Ar and Ar-O{sub 2} pulsed DC discharges

    Energy Technology Data Exchange (ETDEWEB)

    Bernardelli, E.A.; Souza, T.; Maliska, A.M.; Kleinjohann, K.J.; Bendo, T. [Federal University of Santa Catarina (UFSC), Florianopolis, SC (Brazil); Mafra, M. [Nancy-Universite (France). Institut Jean Lamour; CNRS, Nancy (France); Belmonte, T. [Federal University of Technology from Parana (UTFPR), Curitiba, PR (Brazil)


    Stearic acid (C{sub 1}8H{sub 36}O{sub 2}) was treated into Ar and Ar-O{sub 2}(10%) pulsed DC discharge created by a cathode-anode confined system. The samples were placed at the floating potential. The results show that the mass variation of the stearic acid samples after Ar-O{sub 2} plasma exposure is more important than the pure Ar plasma treatments. This comportment demonstrate that the oxygen actives species (O and O{sub 2} in all states) strongly enhance the etching process with regards to A{sup *} species, regardless of their concentration. After treatment by Ar and Ar-O{sub 2} plasma, analyses by X-ray diffraction show a significant structural modification of the samples surface, utilizing Ar-O{sub 2} plasma the modification was more pronounced. The chemical composition evolution shows that the acid function is etched preferentially in the beginning of the treatment (about 5 min) and that after 10 min the carbonic chains seems to be functionalized by oxygen. (author)

  12. Ar-Ar Impact Heating Ages of Eucrites and Timing of the LHB (United States)

    Bogard, Donald; Garrison, Daniel


    Eucrites and howardites, more than most meteorite types, show extensive impact resetting of their Ar-39-Ar-40 (K-Ar) ages approximately equal to 3.4-4.1 Ga ago, and many specimens show some disturbance of other radiometry chronometers as well. Bogard (1995) argued that this age resetting occurred on Vesta and was produced by the same general population of objects that produced many of the lunar impact basins. The exact nature of the lunar late heavy bombardment (LHB or 'cataclysm') remains controversial, but the timing is similar to the reset ages of eucrites. Neither the beginning nor ending time of the lunar LHB is well constrained. Comparison of Ar-Ar ages of brecciated eucrites with data for the lunar LHB can resolve both the origin of these impactors and the time period over which they were delivered to the inner solar system. This abstract reports some new Ar-Ar age data for eucrites, obtained since the authors' 1995 and 2003 papers.

  13. Ar-40/Ar-39 Ages of Maskelynite Grains from ALHA 77005 (United States)

    Turrin, B.; Park, J.; Herzog, G. F.; Lindsay, F. N.; Delaney, J. S.; Nyquist, L. E.; Swisher, C., III


    We present Ar-40/Ar-39 measurements for twelve small (20-60 micro-g) maskelynite samples from the heavily shocked martian meteorite ALHA 77005. The reported modal composition for ALHA 77005 is 50-60% olivine (Fa28), 30-40% pyroxene (Wo5Fs23En72), approx.8% maskelynite (An53), and approx.2% opaques by volume [1]). The meteorite is usually classified as a lherzolite. Previous Studies - Ar-40/Ar-39 results from previous work display disturbed release spectra [2,3]. In study [2], Ar-40/Ar-39 measurements on a 52-mg whole-rock sample produced an extremely disturbed release spec-trum, with all calculated apparent ages > 1 Ga, (Fig. 1). In a subsequent study [3], a light and a dark phase were analyzed. A 2.3-mg sample of the light, relatively low-K phase produced a disturbed release spectrum. For the first 20% of the Ar-39(sub K), most of the apparent ages exceeded >1 Ga; the remaining 80% yielded ages between 0.3-0.5 Ga. The integrated age for this phase is 0.9 Ga.

  14. TBLR1 as an AR coactivator selectively activates AR target genes to inhibit prostate cancer growth (United States)

    Daniels, Garrett; Li, Yirong; Gellert, Lan Lin; Zhou, Albert; Melamed, Jonathan; Wu, Xinyu; Zhang, Xinming; Zhang, David; Meruelo, Daniel; Logan, Susan K.; Basch, Ross; Lee, Peng


    Androgen Receptor (AR), a steroid hormone receptor, is critical for prostate cancer growth. However, activation of AR by androgens can also lead to growth suppression and differentiation. Transcriptional cofactors play an important role in this switch between proliferative and anti-proliferative AR target gene programs. TBLR1, a core component of the nuclear receptor corepressor (NCoR) complex, shows both co-repressor and co-activator activities on nuclear receptors, but little is known about its effects on AR and prostate cancer. We characterized TBLR1 as a coactivator of AR in prostate cancer cells and the activation is both phosphorylation and 19S proteosome dependent. We showed that TBLR1 physically interacts with AR and directly occupies the androgen response elements of affected AR target genes in an androgen-dependent manner. TBLR1 is primarily localized in the nucleus in benign prostate cells and nuclear expression is significantly reduced in prostate cancer cells in culture. Similarly, in human tumor samples, the expression of TBLR1 in the nucleus is significantly reduced in the malignant glands compared to the surrounding benign prostatic glands (p<0.005). Stable ectopic expression of nuclear TBLR1 leads to androgen-dependent growth suppression of prostate cancer cells in vitro and in vivo by selective activation of androgen regulated genes associated with differentiation (e.g. KRT18) and growth suppression (e.g. NKX3.1), but not cell proliferation of the prostate. Understanding the molecular switches involved in the transition from AR dependent growth promotion to AR dependent growth suppression will lead to more successful prostate cancer treatments. PMID:24243687

  15. Potassium Isotopic Compositions of NIST Potassium Standards and 40Ar/39Ar Mineral Standards (United States)

    Morgan, Leah; Tappa, Mike; Ellam, Rob; Mark, Darren; Higgins, John; Simon, Justin I.


    Knowledge of the isotopic ratios of standards, spikes, and reference materials is fundamental to the accuracy of many geochronological methods. For example, the 238U/235U ratio relevant to U-Pb geochronology was recently re-determined [1] and shown to differ significantly from the previously accepted value employed during age determinations. These underlying values are fundamental to accurate age calculations in many isotopic systems, and uncertainty in these values can represent a significant (and often unrecognized) portion of the uncertainty budget for determined ages. The potassium isotopic composition of mineral standards, or neutron flux monitors, is a critical, but often overlooked component in the calculation of K-Ar and 40Ar/39Ar ages. It is currently assumed that all terrestrial materials have abundances indistinguishable from that of NIST SRM 985 [2]; this is apparently a reasonable assumption at the 0.25per mille level (1s) [3]. The 40Ar/39Ar method further relies on the assumption that standards and samples (including primary and secondary standards) have indistinguishable 40K/39K values. We will present data establishing the potassium isotopic compositions of NIST isotopic K SRM 985, elemental K SRM 999b, and 40Ar/39Ar biotite mineral standard GA1550 (sample MD-2). Stable isotopic compositions (41K/39K) were measured by the peak shoulder method with high resolution MC-ICP-MS (Thermo Scientific NEPTUNE Plus), using the accepted value of NIST isotopic SRM 985 [2] for fractionation [4] corrections [5]. 40K abundances were measured by TIMS (Thermo Scientific TRITON), using 41K/39K values from ICP-MS measurements (or, for SRM 985, values from [2]) for internal fractionation corrections. Collectively these data represent an important step towards a metrologically traceable calibration of 40K concentrations in primary 40Ar/39Ar mineral standards and improve uncertainties by ca. an order of magnitude in the potassium isotopic compositions of standards.

  16. 78 FR 9448 - Arkansas Disaster #AR-00061 (United States)


    ... ADMINISTRATION Arkansas Disaster AR-00061 AGENCY: U.S. Small Business Administration. ACTION: Notice SUMMARY: This is a Notice of the Presidential declaration of a major disaster for Public Assistance Only for the... Disaster Assistance, U.S. Small Business Administration, 409 3rd Street SW., Suite 6050, Washington,...

  17. "Ars Dictaminis" and Modern Rhetorical Practice. (United States)

    Sewell, Ernestine P.

    Although not all the problems of writing are solved by practice in letter writing, a review of the classical texts on "ars dictaminis"--letter writing--creates a strong argument for its increased use as an exercise in college composition classrooms. By incorporating the lessons of dictamen as a device for achieving rhetorical modes--narration,…

  18. User Interface Design for Military AR Applications (United States)


    SI: AUGMENTED REALITY User interface design for military AR applications Mark A. Livingston • Zhuming Ai • Kevin Karsch • Gregory O. Gibson Received...several visual representations fundamental to SA. The UI M. A. Livingston (&) Z. Ai K. Karsch G. O. Gibson Naval Research Laboratory, Washington

  19. "ARS 01", perspektiivide avamine / Helen Kivisoo

    Index Scriptorium Estoniae

    Kivisoo, Helen


    30. IX 2001-20. I 2002 Kiasmas kuuendat korda toimuvast rahvusvahelisest näitusest "ARS", kus Eestist osaleb Marko Mäetamm. Kuraatorid Tuula Arkio, Maaretta Jaukkuri, Patrik Nyberg, Jari-Pekka Vanhala. Teemaks "kolmas ruum". Näituse kajastamisest.

  20. Theoretical prediction on vibrational spectra of [Ar…Ar-H]+

    Institute of Scientific and Technical Information of China (English)

    LI; Wei(李巍); ZHAO; Xinsheng(赵新生)


    Centrosymmetric linear [Ar-H-Ar]+ and asymmetric linear [Ar…Ar-H]+ are two stable configurations of [Ar2H]+. Based on the global potential energy surface of [Ar2H]+ provided by our group recently, we calculated the vibrational spectra of [Ar…Ar-H]+ with total angular momentum J = 0 by time-dependent quantum mechanical method, and the influence of quantum tunneling effect on vibrational spectra was found. With the help of the observation on the eigenstate functions and the modified potential energy surface, assignments were made to the spectra. The strong coupling between the excited bending mode of [Ar-H-Ar]+ and the vibrational states of [Ar…Ar-H]+ was discussed.

  1. Metalloregulatory properties of the ArsD repressor. (United States)

    Chen, Y; Rosen, B P


    The plasmid-encoded arsenical resistance (ars) operon of plasmid R773 produces resistance to trivalent and pentavalent salts of the metalloids arsenic and antimony in cells of Escherichia coli. The first two genes in the operon, arsR and arsD, were previously shown to encode trans-acting repressor proteins. ArsR controls the basal level of expression of the operon, while ArsD controls maximal expression. Thus, action of the two repressors form a homeostatic regulatory circuit that maintains the level of ars expression within a narrow range. In this study, we demonstrate that ArsD binds to the same site on the ars promoter element as ArsR but with 2 orders of magnitude lower affinity. The results of gel shift assays demonstrate that ArsD is released from the ars DNA promoter by phenylarsine oxide, sodium arsenite, and potassium antimonyl tartrate (in order of effectiveness), the same inducers to which ArsR responds. Using the quenching of intrinsic tryptophan fluorescence to measure the affinity of the repressor for inducers, apparent Kd values for Sb(III) and As(III) of 2 and 60 microM, respectively, were obtained. These results demonstrate that the arsR-arsD pair provide a sensitive mechanism for sensing a wide range of environmental heavy metals.

  2. Construction of a chimeric ArsA-ArsB protein for overexpression of the oxyanion-translocating ATPase. (United States)

    Dou, D; Owolabi, J B; Dey, S; Rosen, B P


    Resistance to toxic oxyanions of arsenic and antimony in Escherichia coli is conferred by the conjugative R-factor R773, which encodes an ATP-driven anion extrusion pump. The ars operon is composed of three structural genes, arsA, arsB, and arsC. Although transcribed as a single unit, the three genes are differentially expressed as a result of translational differences, such that the ArsA and ArsC proteins are produced in high amounts relative to the amount of ArsB protein made. Consequently, biochemical characterization of the ArsB protein, which is an integral membrane protein containing the anion-conducting pathway, has been limited, precluding studies of the mechanism of this oxyanion pump. To overexpress the arsB gene, a series of changes were made. First, the second codon, an infrequently used leucine codon, was changed to a more frequently utilized codon. Second, a GC-rich stem-loop (delta G = -17 kcal/mol) between the third and twelfth codons was destabilized by changing several of the bases of the base-paired region. Third, the re-engineered arsB gene was fused 3' in frame to the first 1458 base pairs of the arsA gene to encode a 914-residue chimeric protein (486 residues of the ArsA protein plus 428 residues of the mutated ArsB protein) containing the entire re-engineered ArsB sequence except for the initiating methionine. The ArsA-ArsB chimera has been overexpressed at approximately 15-20% of the total membrane proteins. Cells producing the chimeric ArsA-ArsB protein with an arsA gene in trans excluded 73AsO2- from cells, demonstrating that the chimera can function as a component of the oxyanion-translocating ATPase.

  3. Recoil ion charge state distributions in low energy Ar{sup q+} {minus} Ar collisions

    Energy Technology Data Exchange (ETDEWEB)

    Vancura, J.; Marchetti, V.; Kostroun, V.O.


    We have measured the recoil ion charge state distributions in Ar{sup q+} -- Ar (8{le}q{le}16) collisions at 2.3 qkeV and 0.18qkeV by time of flight (TOF) spectroscopy. For Ar{sup 8-16+}, recoil ion charge states up to 6+ are clearly present, indicating that the 3p subshell in the target atom is being depleted, while for Ar{sup 10-16+}, there is evidence that target 3s electrons are also being removed. Comparison of the recoil ion charge state spectra at 2.3 and 0.18 qkeV shows that for a given projectile charge, there is very little dependence of the observed recoil target charge state distribution on projectile energy.

  4. The effects of retrograde reactions and of diffusion on 39Ar-40Ar ages of micas

    DEFF Research Database (Denmark)

    Allaz, Julien; Engi, Martin; Berger, Alfons


    Effects of metamorphic reactions occurring during decompression were explored to understand their influence on 39Ar-40Ar ages of micas. Monometamorphic metasediments from the Lepontine Alps (Switzerland) were studied. Collected samples reached lower amphibolite facies during the Barrovian....../K and Cl/K ratios) did not change and the resulting ages can be interpreted unambiguously. In mineral separates containing two white micas, Ca/K and Cl/K ratios were variable, reflecting non-simultaneous laboratory degassing of the two heterochemical Ar-reservoirs. These ratios were used to identify each...... Ar reservoir and to unravel the age. In a chlorite-margarite-biotite-calcschist equilibrated near 560 °C and 0.65 GPa, biotite, margarite, and muscovite all yield ages around 18 Ma. At slightly higher grade (560-580 °C, 0.8-0.9 GPa), the assemblage muscovite-paragonite-plagioclase is at equilibrium...

  5. The new 39Ar/40Ar dating facility of the LSCE, background and performances. (United States)

    Scaillet, S.; Nomade, S.; Guillou, H.; Scaillet-Vita, G.


    Precise and accurate timescales are increasingly needed in most disciplines of the Earth sciences. To contribute to this challenging task, a new 39Ar/40Ar laboratory, specifically devoted to the dating of very recent (down to 1 ka) volcanic products, has been developed at the LSCE (CEA-IPSL-UVSQ, France). In this contribution, we present the first data obtained from this new facility. The laboratory comprises a VG 5400 mass spectrometer coupled with a high sensitivity and high dynamic range ion counting system. Gas extraction is achieved with a 25 watts C02 laser or a double vacuum furnace depending of the analyzed samples. The full metal vacuum and purification line feature a GP50 and a compact Ti flash getters which permit extremely low blank for all Argon isotopes (e.g. ~ 3.0 10e-19 Moles for 36Ar). Both analytical protocols and hardware were specifically developed and optimized to date extremely young samples. Analytical performances including protocols, flux monitoring as well mass spectrometer discrimination correction method will be presented in the light of data obtained over the last 10 months. All samples were irradiated, under cadmium, in the Β-1 position (~1.0 10e+13 fast n cm-2 s-1) of the 70MWh-1 OSIRIS reactor (Pierre Süe laboratory, CEA-Saclay, France). Irradiation package is composed of home-design Aluminium disks constituting a 4 cm stack (10 to 30 unknowns/irradiation). Analyzed neutrons flux standards indicate less than 1% variation along the 4cm stack and validate the use of this reactor for high-precision 39Ar/40Ar dating. The precision and accuracy of the facility has been checked from cross-comparison of international single grain standards including FCs (28.02Ma), ACR-2 (1.194Ma) and TCR (28.32Ma) using the most recent recommended values for these monitors. A total of 80 grains in two irradiations (10 and 120 minutes) will be presented in details. Results from single-grain analyses agree within errors with those proposed by Renne et al

  6. 40Ar* loss in experimentally deformed muscovite and biotite with implications for 40Ar/39Ar geochronology of naturally deformed rocks (United States)

    Cosca, M.; Stunitz, H.; Bourgeix, A.-L.; Lee, J.P.


    The effects of deformation on radiogenic argon (40Ar*) retentivity in mica are described from high pressure experiments performed on rock samples of peraluminous granite containing euhedral muscovite and biotite. Cylindrical cores, ???15mm in length and 6.25mm in diameter, were drilled from granite collected from the South Armorican Massif in northwestern France, loaded into gold capsules, and weld-sealed in the presence of excess water. The samples were deformed at a pressure of 10kb and a temperature of 600??C over a period 29 of hours within a solid medium assembly in a Griggs-type triaxial hydraulic deformation apparatus. Overall shortening in the experiments was approximately 10%. Transmitted light and secondary and backscattered electron imaging of the deformed granite samples reveals evidence of induced defects and for significant physical grain size reduction by kinking, cracking, and grain segmentation of the micas.Infrared (IR) laser (CO2) heating of individual 1.5-2.5mm diameter grains of muscovite and biotite separated from the undeformed granite yield well-defined 40Ar/39Ar plateau ages of 311??2Ma (2??). Identical experiments on single grains separated from the experimentally deformed granite yield results indicating 40Ar* loss of 0-35% in muscovite and 2-3% 40Ar* loss in biotite. Intragrain in situ ultraviolet (UV) laser ablation 40Ar/39Ar ages (??4-10%, 1??) of deformed muscovites range from 309??13 to 264??7Ma, consistent with 0-16% 40Ar* loss relative to the undeformed muscovite. The in situ UV laser ablation 40Ar/39Ar ages of deformed biotite vary from 301 to 217Ma, consistent with up to 32% 40Ar* loss. No spatial correlation is observed between in situ 40Ar/39Ar age and position within individual grains. Using available argon diffusion data for muscovite the observed 40Ar* loss in the experimentally treated muscovite can be utilized to predict average 40Ar* diffusion dimensions. Maximum 40Ar/39Ar ages obtained by UV laser ablation overlap those

  7. On concentration of $^{42}$Ar in the Earth's atmosphere

    CERN Document Server

    Barabash, A S


    Data from the DBA liquid argon ionization chamber experiment have been used to obtain an estimate on the concentration of $^{42}$Ar in the Earth's atmosphere, $6.8^{+1.7}_{-3.2}\\cdot10^{-21}$ atoms of $^{42}$Ar per atom of $^{40}$Ar corresponding to the $^{42}$Ar activity of $1.2^{+0.3}_{-0.5}$ $\\mu$Bq per cubic meter of air.

  8. On concentration of 42Ar in the Earth's atmosphere (United States)

    Barabash, A. S.; Saakyan, R. R.; Umatov, V. I.


    Data from the DBA liquid argon ionization chamber experiment have been used to obtain an estimate on the concentration of 42Ar in the Earth's atmosphere, 6 .8-3.2+1.7 ·10-21 atoms of 42Ar per atom of 40Ar corresponding to the 42Ar activity of 1 .2-0.5+0.3 μBq per cubic meter of air.

  9. Enseñar un oficio, proponer una forma


    Vitale, Daniele


    El oficio de enseñar. Enseñar a través de la técnica, enseñar por vía de la cultura. Una ciudadela de figuras. Imitación y relación personal. Enseñar a partir de un sistema. Partir del inicio. Posponer la realidad Peer Reviewed

  10. Growth Rate Estimates of Supergene Manganese Nodule by 40Ar/39Ar Isotopic Dating

    Institute of Scientific and Technical Information of China (English)

    Li Jianwei; Vasconcelos P M


    Increasing world-class, high-grade, and metals-enriched supergene manganese ore deposits have been discovered in the last two decades, making them more and more economically important. However, data on the timing and duration of their formation are sparse, mainly due to the difficulties extracting datable minerals suited to traditional radiometric dating methods. Hollandite, cryptomelane, coronadite, todorokite, and manjiroite are common manganese oxide minerals in supergene environments. These minerals host potassium of variable amounts from 0.1 wt% to 5.0 wt% in their structural sites. This geochemical property provides possibility to date supergene manganese ores by using K-Ar and 40Ar/39Ar methods. In this study, we perform 40Ar/39Ar dating on a 7.1-cm-thick botryoidal manganese nodule from an ancient weathering profile at Mount Tabor, central Queensland, Australia. Laser microprobe incremental analyses of distinct growth bands, from the inner core through the intermediate bands to the outermost crusts of the nodule, have yielded high quality 40Ar/39Ar ages at 27.3 Ma, 20.9 Ma, 19.2 Ma, and 16.1 Ma, respectively. The age results permit preliminary estimates on the average growth rates of the nodule varying from 4.7×10-3 mm/ka to 7.6×10-3 mm/ka to 9.0×10-3 mm/ka, from the core to the rim. Results of this study are of significance in our understanding of the mode, mechanism, process, and climatic conditions in the formation of supergene manganese ore deposits.

  11. Regulation of AR Degradation and Function by Ubiquitylation (United States)


    STATEMENT Approved for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The pathways that normally mediate AR...ligase (CHIP) may mediate the polyubiquitylation and proteasome degradation of AR that fails to fold appropriately and bind ligand. However, there are...pathways that normally mediate the ubiquitin dependent or independent degradation of AR, which might be targeted therapeutically, remain to be

  12. Antarlides: A New Type of Androgen Receptor (AR) Antagonist that Overcomes Resistance to AR-Targeted Therapy. (United States)

    Saito, Shun; Fujimaki, Takahiro; Panbangred, Watanalai; Igarashi, Yasuhiro; Imoto, Masaya


    Prostate cancer is treated with androgen receptor (AR) antagonists but most patients experience disease progression after long-term treatment with these compounds. Therefore, new AR antagonists are required for patient follow-up treatment. In the course of screening for a new AR antagonist, we isolated the novel compounds antarlides A-E (1-5) from Streptomyces sp. BB47. Antarlides are mutually isomeric with respect to the double bond and have a 22-membered-ring macrocyclic structure. The full stereostructure of 1 was established by chemical modifications, including methanolysis, the Trost method, acetonide formation, and the PGME method. 1-5 inhibited the binding of androgen to ARs in vitro. In addition, 2 inhibited the transcriptional activity of not only wild-type AR but also mutant ARs, which are seen in patients with acquired resistance to clinically used AR antagonists. Therefore, antarlides are a potent new generation of AR antagonists that overcome resistance.

  13. Tracking fluid action in Little Sark Pluton (Channel Islands, UK): a UV laserprobe Ar/Ar study of excess 40Ar (United States)

    Schwenzer, S. P.; Schwanethal, J.; Tindle, A. G.; Kelley, S. P.; Sherlock, S. C.


    Little Sark pluton (Channel Islands, UK) is a weakly to moderately deformed pluton of quartz diorite composition. Zircon from Little Sark has been dated as 611.4(+2.1/-1.3) Ma [Miller et al. 1991, Tectonophysics, 312], whereas titanite has an age of 606.2±0.6 Ma. Hornblende yields an Ar-Ar age of 606.4±3.4 Ma [Dallmeyer et al., 1991, J. Geol. Soc. London 148]. The rocks show evidence for post-magmatic hydrous alteration including chloritisation of biotite, and sericite formation in feldspar. We investigated the alteration in order to understand its influence on the Ar-Ar system. Detailed petrographic investigations of two samples indicate different deformation levels - S1, (less deformed), and S2 (more deformed). The feldspar is andesine to oligoclase in composition, but contains K-rich areas with patchy and sometimes cleavage guided sericitization. Mafic minerals include hornblende and biotite (the latter partially chloritized). Ar-Ar investigations were carried out using high spatial resolution UV laser ablation gas release in combination with a Nu instruments Noblesse gas mass spectrometer using spots of 80 to 140 μm diameter. Mafic minerals in S1 have highly variable 38Ar/39Ar and 37Ar/39Ar ratios and unusually high atmospheric contents for such old samples, possibly reflecting the presence of fluid inclusions associated with the sericite, particularly in the feldspar. The apparent ages in their entirety range from 429 to 668 Ma. Hornblende yields homogeneous apparent ages, whereas the younger and older ages are measured in both micas and feldspars, whose apparent ages range from 245-670 Ma. The modal age for feldspar is around 400-450 Ma, but this may not have geological meaning. Sample S2 shows many of the same features as S1. Mafic minerals span a slightly smaller age range and feldspars display apparent ages of ~245-645 Ma with a mode around 480 Ma. The alteration of both samples appears to have been accompanied by the introduction of 40Ar-rich fluids

  14. The thermal history of the Lhasa Block, South Tibetan Plateau based on FTD and Ar-Ar dating

    CERN Document Server

    Yang, T F; Lo Chong Huah; Chung, S L; Tien, R L; Xu, R; Deng, W


    Twelve basement samples were collected from South Tibet Plateau for FTD and Ar-Ar analysis to demonstrate their uplifting history since Cenozoic era. The preliminary results from different minerals with different closure temperatures, including apatite and zircon for fission-track dating, and K-feldspar, biotite for Ar-Ar dating, show that at least four stages of thermal history can be recognized in the studied area.

  15. Measuring 36Ar without H35Cl interference (United States)

    Saxton, John


    Noble gas measurements are usually made in static mode, when the mass spectrometer sensitivity is inversely proportional to volume: this makes the building of very large instruments to obtain high mass resolution impracticable. A particularly challenging interference has hitherto been H35Cl, which differs in mass from 36Ar by 1 part in 3937. We have developed a method which makes improved use of the available MRP to remove interferences, and used it to obtain HCl-free 36Ar measurements on a multicollector instrument with MRP of only ~6000 (MRP= mass resolving power = m/dm 5-95% on side of peak). By arranging that the target mass position on a minor isotope (e.g. 36Ar), from which the interference must be removed, coincides with the ~50% point on the side of a major isotope (e.g. 40Ar), it is possible both to set the mass accurately and to verify the mass position and stability during measurements. The peak top of 40Ar is measured in a separate mass step. Two small corrections are necessary. One compensates for the residual HCl tail at the 36Ar position. The other arises because the peak is not totally flat in the region of interest: 40Ar and 36Ar+HCl are measured on the peak top, whilst 36Ar is measured at the extreme edge, with slightly lower efficiency. The required correction parameters can be obtained from a series of air calibrations with different target/interference ratios. With samples containing 4x10-15to 3x10-14moles of 40Ar, 36Ar/40Ar was measured, without HCl interference, to a 1σ precision of 0.5%, only slightly worse than counting statistics. This is potentially useful for 40Ar/39Ar dating, where 36Ar is used to correct for trapped air, and may be particularly significant for smaller or younger samples.

  16. Ar + NO microwave plasmas for Escherichia coli sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Hueso, Jose L; Rico, Victor J; Cotrino, Jose; Gonzalez-Elipe, Agustin R [Instituto de Ciencia de Materiales de Sevilla, Centro Mixto CSIC-Universidad de Sevilla, Centro de Investigaciones Cientificas Isla de la Cartuja, Avda. Americo Vespucio 49, 41092 Sevilla (Spain); Frias, Jose E [Instituto de BioquImica Vegetal y FotosIntesis (IBVF-CSIC). Centro de Investigaciones CientIficas Isla de la Cartuja. Avda Americo Vespucio, 49, 41092 Sevilla (Spain)], E-mail:


    Ar + NO microwave discharges are used for sterilization and the results are compared with additional experiments with Ar, O{sub 2} and N{sub 2}-O{sub 2} plasma mixtures. The NO{sup *} species produced in the Ar-NO mixtures remain up to long distances from the source, thus improving the sterilization efficiency of the process. E. coli individuals exposed to the Ar + NO plasma undergo morphological damage and cell lysis. Combined effects of etching (by O{sup *} and Ar{sup *} species) and UV radiation (from deactivation of NO{sup *} species) are responsible for the higher activity found for this plasma mixture. (fast track communication)

  17. 40Ar/39Ar ages of the older eruptive units of Somma-Vesuvius volcano, Italy (United States)

    Lanphere, M. A.; Calvert, A. T.; Scarpati, C.; Melluso, L.; Morra, V.; Perrotta, A.; Thornber, C.; Cioni, R.; Champion, D. E.


    40Ar/ 39Ar ages have been measured on the older major explosive eruptions of Somma-Vesuvius volcano in Italy. These eruptions all have pumice fall, and pyroclastic surge and flow deposits. The eruptive history of Somma-Vesuvius volcano has previously been based on uncalibrated 14C ages, mostly on carbon from paleosols, reported by Delibrias and others (1979) and Sigurdsson and others (1985). These assigned ages, plus measured 14C ages, calibrated 14C ages (denoted as 14C*) and 40Ar/ 39Ar ages (all in years) are: Mercato Tuff ~8500 years 14C=8263±29, 14C*=9250±49, 40Ar/ 39Ar=9155±461, 9541±460 Verde Tuff ~15000 years 14C=14420±130, 14C*=17200±380, 40Ar/ 39Ar=18456±302 Pomici di Base ~17000 years 14C=17229±398, 14C*=20360±139, 40Ar/ 39Ar=21759±306, 21568±328 The assigned ages are from Delibrias (1979). The 14C ages (Aleisso and others, 1971, 1973, 1974, 1978) use 1σ counting errors reported by laboratories. The uncertainty in calibrated 14C ages (above) are these reported uncertainties plus 1σ uncertainties of the calibration curves in IntCal04 (Reimer and others, 2004). The uncertainties in 40Ar/ 39Ar ages are 1σ errors. Pomici di Base and Mercato samples were analyzed twice. The weighted mean of plateau ages for Pomici di Base fall unit is 21,670 ± 224 years, and the weighted mean of isochron ages is 21,313 ± 408 years. The weighted mean of plateau ages for Mercato Tuff is 9348 ± 326 years, and the weighted mean of isochron ages is 9577 ± 332 years. The period of time from 0-12.4 ka used in calibrating 14C ages is based on dendrochronologically-dated tree ring samples. The calibration older than 12.4 ka is based on marine samples, primarily corals, and the marine calibrations are in dispute. The calibrated 14C ages above are based on IntCal04. Chui and others (2007) have presented another calibration based on fossil corals. In the younger part of their record, less than 30,000 years, the age difference averages less than 100 years. Aleisso and

  18. Ar-Ar and Rb-Sr Ages of the Tissint Olivine-phyric Martian Shergottite (United States)

    Park, J.; Herzog, G. F.; Nyquist, L. E.; Shih, C.-Y.; Turin, B.; Lindsay, F. N.; Delaney, J. S.; Swisher, C. C., III; Agee, C.


    The fifth martian meteorite fall, Tissint, is an olivine-phyric shergottite that contains olivine macrocrysts (approximately 1.5 mm) [1]. [2] reported the Sm-Nd age of Tissint as 596 plus or minus 23 Ma along with Rb-Sr data that defined no isochron. [3] reported Lu-Hf and Sm-Nd ages of 583 plus or minus 86 Ma and 616 plus or minus 67 Ma, respectively. The cosmic-ray exposure ages of Tissint are 1.10 plus or minus 0.15 Ma based on 10Be [4], and 1.0-1.1 Ma, based on 3He, 21Ne, and 38Ar [5,6].We report Ar-Ar ages and Rb-Sr data.

  19. MEIS1 functions as a potential AR negative regulator

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Liang [Department of Urology, Chinese PLA Medical School/Chinese PLA General Hospital, Beijing 100853 (China); Department of Urology, Civil Aviation General Hospital/Civil Aviation Medical College of Peking University, Beijing 100123 (China); Li, Mingyang [Department of Gastroenterology, Nan Lou Division, Chinese PLA Medical School/Chinese PLA General Hospital, Beijing 100853 (China); Feng, Fan [Department of Pharmacy, General Hospital of Shenyang Military Command, Shenyang 110016 (China); Yang, Yutao [Beijing Institute for Neuroscience, Capital Medical University, Beijing 100069 (China); Hang, Xingyi [National Scientific Data Sharing Platform for Population and Health, Beijing 100730 (China); Cui, Jiajun, E-mail: [Department of Cancer and Cell Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267 (United States); Gao, Jiangping, E-mail: [Department of Urology, Chinese PLA Medical School/Chinese PLA General Hospital, Beijing 100853 (China)


    The androgen receptor (AR) plays critical roles in human prostate carcinoma progression and transformation. However, the activation of AR is regulated by co-regulators. MEIS1 protein, the homeodomain transcription factor, exhibited a decreased level in poor-prognosis prostate tumors. In this study, we investigated a potential interaction between MEIS1 and AR. We found that overexpression of MEIS1 inhibited the AR transcriptional activity and reduced the expression of AR target gene. A potential protein–protein interaction between AR and MEIS1 was identified by the immunoprecipitation and GST pull-down assays. Furthermore, MEIS1 modulated AR cytoplasm/nucleus translocation and the recruitment to androgen response element in prostate specific antigen (PSA) gene promoter sequences. In addition, MEIS1 promoted the recruitment of NCoR and SMRT in the presence of R1881. Finally, MEIS1 inhibited the proliferation and anchor-independent growth of LNCaP cells. Taken together, our data suggests that MEIS1 functions as a novel AR co-repressor. - Highlights: • A potential interaction was identified between MEIS1 and AR signaling. • Overexpression of MEIS1 reduced the expression of AR target gene. • MEIS1 modulated AR cytoplasm/nucleus translocation. • MEIS1 inhibited the proliferation and anchor-independent growth of LNCaP cells.

  20. AR-Signaling in Human Malignancies: Prostate Cancer and Beyond

    Directory of Open Access Journals (Sweden)

    Michael T. Schweizer


    Full Text Available In the 1940s Charles Huggins reported remarkable palliative benefits following surgical castration in men with advanced prostate cancer, and since then the androgen receptor (AR has remained the main therapeutic target in this disease. Over the past couple of decades, our understanding of AR-signaling biology has dramatically improved, and it has become apparent that the AR can modulate a number of other well-described oncogenic signaling pathways. Not surprisingly, mounting preclinical and epidemiologic data now supports a role for AR-signaling in promoting the growth and progression of several cancers other than prostate, and early phase clinical trials have documented preliminary signs of efficacy when AR-signaling inhibitors are used in several of these malignancies. In this article, we provide an overview of the evidence supporting the use of AR-directed therapies in prostate as well as other cancers, with an emphasis on the rationale for targeting AR-signaling across tumor types.

  1. Enseñar a ser


    García Barreno, Pedro


    El «Informe Delors», cuyo texto fue presentado hace ahora diez años, señala que cualquier proyecto educativo para el siglo XXI debe contemplar dos acciones. «Enseñar a conocer, a hacer, a vivir juntos, a ser», y garantizar el acceso de todos a ello. El siglo que concluyó apenas media docena de años, ha estado cargado de inmensas paradojas: entre grandes males, extraordinarios logros y no pocas esperanzas inalcanzadas. Marcado por dos guerras mundiales, po...

  2. AR Alternative Splicing and Prostate Cancer Progression (United States)


    evolutionary origin and sequence divergence, with relative ages (oldest to youngest) L1M1 > L1MA3 > L1PB2 > L1PREC2 > L1PA7 > L1PA5 (41, 42). Figure...variant of the human AR, which was originally identified via 5 0 rapid amplification of cDNA ends (RACE) with RNA isolated from human placenta tissue...prerequisite for tran- scriptional activation. However, this theory has not been rigor- ously tested. Therefore, we transfected cells with diverse trun

  3. Unveiling Turrialba (Costa Rica) volcano's latest geological evolution through new 40Ar/39Ar, ages (United States)

    Ruiz Cubillo, P.; Turrin, B. D.; Soto, G. J.; Del Potro, R.; Gagnevin, D.; Gazel, E.; Mora Fernandez, M.; Carr, M. J.; Swisher, C. C.


    Step-heating 40Ar/39Ar dating experiments on whole rock matrix were performed on samples from eight key lava flow units from Turrialba, the easternmost volcano of the Central Volcanic Range of Costa Rica. Our results, together with available corrected 14C ages, recent mapping and new geochemical analyses, are part of a study to reconstruct Turrialba’s evolution. The project is being conducted as part of wider studies because of the increase in volcanic activity during the last three years. The geochemical compositions of the lava flow units span the range from basalts to dacites, and commonly have high K2O concentrations, making them good candidates for 40Ar/39Ar radiometric dating. The ages reported here correspond to the Paleo Turrialba (600-250 ka) and Neo Turrialba (< 250 ka) temporal stages. Sample TUR-38 (251 ± 4 ka) belongs to the latest unit of Paleo Turrialba stage, known as Finca Liebres volcano, while the remaining seven samples belong to Neo Turrialba: TUR-30 (99 ± 3 ka), TUR-19 (90 ± 4 ka), TUR-32 (62 ± 2 ka) TUR-33 (61 ± 2 ka), TUR-12 (25 ± 1.9 ka), TUR-36 (10 ± 3 ka) and TUR-08 (3 ± 3 ka). All the obtained ages in this study are in agreement with the local stratigraphy and prior 14C age determinations, adding robustness to our results. According to ages obtained and the areal distribution of the sampled units, the most important construction period of the massif was during the Neo-Turrialba stage which has passed through two important constructing episodes, around 100-60 ka and 10 ka-present. Although our results include some very young ages, all of them meet the established evaluation criteria used for plateau and isochron ages, commonly used for 40Ar/39Ar dating. Furthermore, we used a protocol that closely monitors the mass spectrometer mass discrimination during the measurements to provide additional control. Three of the eight 40Ar/39Ar ages reported here are remarkably young (25 ka or less). Two of those are the samples with the

  4. The role of mitochondrial fusion and StAR phosphorylation in the regulation of StAR activity and steroidogenesis. (United States)

    Castillo, Ana F; Orlando, Ulises; Helfenberger, Katia E; Poderoso, Cecilia; Podesta, Ernesto J


    The steroidogenic acute regulatory (StAR) protein regulates the rate-limiting step in steroidogenesis, i.e. the delivery of cholesterol from the outer (OMM) to the inner (IMM) mitochondrial membrane. StAR is a 37-kDa protein with an N-terminal mitochondrial targeting sequence that is cleaved off during mitochondrial import to yield 30-kDa intramitochondrial StAR. StAR acts exclusively on the OMM and its activity is proportional to how long it remains on the OMM. However, the precise fashion and the molecular mechanism in which StAR remains on the OMM have not been elucidated yet. In this work we will discuss the role of mitochondrial fusion and StAR phosphorylation by the extracellular signal-regulated kinases 1/2 (ERK1/2) as part of the mechanism that regulates StAR retention on the OMM and activity.

  5. Astronomical calibration of 40Ar/39Ar reference minerals using high-precision, multi-collector (ARGUSVI) mass spectrometry (United States)

    Phillips, D.; Matchan, E. L.; Honda, M.; Kuiper, K. F.


    The new generation of multi-collector mass spectrometers (e.g. ARGUSVI) permit ultra-high precision (1%) in 40K decay constants and the ages of natural reference minerals that form the basis of the technique. For example, reported ages for widely used 40Ar/39Ar reference materials, such as the ca. 28 Ma Fish Canyon Tuff sanidine (FCTs) and the ca. 1.2 Ma Alder Creek Rhyolite sanidine (ACRs), vary by >1%. Recent attempts to independently calibrate these reference minerals have focused on K-Ar analyses of the same minerals and inter-comparisons with astronomically tuned tephras in sedimentary sequences and U-Pb zircon ages from volcanic rocks. Most of these studies used older generation (effectively single-collector) mass spectrometers that employed peak-jumping analytical methods to acquire 40Ar/39Ar data. In this study, we reassess the inter-calibration and ages of commonly used 40Ar/39Ar reference minerals Fish Canyon Tuff sanidine (FCTs), Alder Creek Rhyolite sanidine (ACRs) and Mount Dromedary biotite (MD2b; equivalent to GA-1550 biotite), relative to the astronomically tuned age of A1 Tephra sanidine (A1Ts), Faneromeni section, Crete (Rivera et al., 2011), using a multi-collector ARGUSVI mass spectrometer. These analyses confirm the exceptional precision capability (0.1% in the 40Ar/39Ar ages of reference minerals without consideration of recoil artefacts, thus limiting the benefits of high precision multi-collector analyses. Significant improvement to the accuracy of the 40Ar/39Ar method (<0.1%) will require further inter-laboratory 40Ar/39Ar studies utilizing multi-collector mass spectrometry, additional constraints on recoil 39ArK loss from reference minerals, further resolution of discrepancies between astronomically tuned sedimentary successions and refinement of the 238U/206Pb zircon age cross-calibration approach.

  6. Behavior of argon gas release from manganese oxide minerals as revealed by 40Ar/39Ar laser incremental heating analysis

    Institute of Scientific and Technical Information of China (English)


    Manganese oxides in association with paleo- weathering may provide significant insights into the multiple factors affecting the formation and evolution of weathering profiles, such as temperature, precipitation, and biodiversity. Laser probe step-heating analysis of supergene hollandite and cryptomelane samples collected from central Queensland, Australia, yield well-defined plateaus andconsistent isochron ages, confirming the feasibility dating very-fined supergene manganese oxides by 40Ar/39Ar technique. Two distinct structural sites hostingAr isotopes can be identified in light of their degassing behaviors obtained byincremental heating analyses. The first site, releasing its gas fraction at thelaser power 0.2-0.4 W, yields primarily 40Aratm, 38Aratm, and 36Aratm (atmospheric Ar isotopes). The second sites yield predominantly 40Ar* (radiogenic 40Ar),39ArK, and 38ArK (nucleogenic components), at ~0.5-1.0 W. There is no significant Ar gas released at the laser power higher than 1.0 W, indicating the breakdown of the tunnel sites hosting the radiogenic and nucleogenic components. The excellent match between the degassing behaviors of 40Ar*, 39ArK, and 38ArK suggests that these isotopes occupy the same crystallographic sites and that 39ArK lossfrom the tunnel site by recoil during neutron irradiation and/or bake-out procedure preceding isotopic analysis does not occur. Present investigation supports that neither the overwhelming atmospheric 40Ar nor the very-fined nature of the supergene manganese oxides poses problems in extracting meaningful weathering geochronological information by analyzing supergene manganese oxides minerals.

  7. Identification of an AR mutation-negative class of androgen insensitivity by determining endogenous AR activity

    NARCIS (Netherlands)

    Hornig, N.C.; Ukat, M.; H.U. Schweikert (H.); O. Hiort (Olaf); Werner, R.; S.L.S. Drop (Stenvert); M.L. Cools (Martine); I.A. Hughes (Ieuan A.); L. Audí (Laura); S.F. Ahmed (S. Faisal); Demiri, J.; Rodens, P.; Worch, L.; Wehner, G.; Kulle, A.E.; Dunstheimer, D.; Müller-Roßberg, E.; T. Reinehr (Thomas); Hadidi, A.T.; Eckstein, A.K.; Van Der Horst, C.; Seif, C.; R. Siebert (Reiner); O. Ammerpohl (Ole); P-M. Holterhus (Paul-Martin)


    textabstractContext: Only approximately 85%of patients with a clinical diagnosis complete androgen insensitivity syndrome and less than 30%with partial androgen insensitivity syndrome can be explained by inactivating mutations in the androgen receptor (AR) gene. Objective: The objective of the study

  8. New high-precision 40Ar/39Ar ages on Oligocene volcanic rocks of northwestern Kenya (United States)

    Brown, Francis H.; Jicha, Brian R.


    New, high-precision 40Ar/39Ar ages from volcanic rocks in northwestern Kenya are provided for some areas of exposure in this remote area. We report seven 40Ar/39Ar ages generated from single crystal total fusion experiments on alkali feldspar separated from volcanic rocks in the Mogila, Songot, and Lokwanamur Ranges and the Gatome valley. A rhyolite from the lower part of the sequence in the Mogila Range yielded ages of 32.31 ± 0.06 Ma and 32.33 ± 0.07 Ma, and a rhyolite near the top of that sequence yielded 31.67 ± 0.04 Ma. A single sample from the Songot Range yielded an age of 32.49 ± 0.07 Ma, slightly older than the rocks collected from Mogila. In both ranges the early Oligocene rhyolites are underlain by basalts, as is also the case in the Labur Range. Ages of 25.95 ± 0.03 Ma, 25.91 ± 0.04 Ma, and 27.15 ± 0.03 Ma were measured on alkali feldspar from rhyolites from the Lokwanamur Range, and the nearby Gatome valley. All of these rocks are part of an episode of widespread volcanism in northwestern Kenya in the mid-to late Oligocene that is not currently known from the Ethiopian Rift Valley.

  9. 40Ar/39Ar Ages for the Sentinel-Arlington Volcanic Field, Southwestern Arizona (United States)

    Cave, S. R.; Greeley, R.; Champion, D. E.; Turrin, B. D.


    The Sentinel Plains lava field and proximate small (history as well as the timing of the ancient Gila River interactions that led to the development of the Painted Rock transverse drainage. The absolute timing was determined in order datermine causal relationships with local tectonism. The SAVF basal contact is ~30 m above the Holocene surface where exposed along the current river channel; and the lavas show similar amounts mantling by aeolian dust, development of pedogenic calcium carbonate, and subsequent incision by radial ephemeral drainages. Relative timing of eruptive events was determined by stratigraphic and embayment relationships. Continuity of distal flows exposed in cross-sections to their source vents could be established using field work, and confirmed using geomagnetic secular variation and geochemical analyses. Edifices generally corresponded to discreet geomagnetic inclination, declination, and paleointensity values. Older eruptive events exhibited normal polarity, while stratigraphically younger events exhibited reversed polarity. Most lavas were alkali olivine basalt with a range of unnormalized SiO2 weight percentages ranging from 47.16-51.48. Geochronology using 40Ar/39Ar method revealed an age of 1.94 +/- 0.85 Ma for Painted Rock Low Shield (New Mexico Geochronology Research Laboratory), 1.64 +/- 0.14 Ma for Theba Low Shield (Rutgers University) and 1.24 +/- 0.040 Ma for Wild Horse Low Shield (Rutgers University). Some ages were precise enough to correspond to the Matuyama reversed polarity epoch, with SAVF initiation possibly within the Olduvai normal polarity event. These dates represent an overall improvement in precision and accuracy over previous dates (values corresponding to 6.20 Ma to 1.28 Ma) collected in the late 1970s and early 1980s using K-Ar technique. The 40Ar/39Ar ages correspond to expected magnetic polarities and stratigraphic sequences.

  10. Androgen Receptor-Mediated Growth Suppression of HPr-1AR and PC3-Lenti-AR Prostate Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Young-Chae Kim

    Full Text Available The androgen receptor (AR mediates the developmental, physiologic, and pathologic effects of androgens including 5α-dihydrotestosterone (DHT. However, the mechanisms whereby AR regulates growth suppression and differentiation of luminal epithelial cells in the prostate gland and proliferation of malignant versions of these cells are not well understood, though they are central to prostate development, homeostasis, and neoplasia. Here, we identify androgen-responsive genes that restrain cell cycle progression and proliferation of human prostate epithelial cell lines (HPr-1AR and PC3-Lenti-AR, and we investigate the mechanisms through which AR regulates their expression. DHT inhibited proliferation of HPr-1AR and PC3-Lenti-AR, and cell cycle analysis revealed a prolonged G1 interval. In the cell cycle, the G1/S-phase transition is initiated by the activity of cyclin D and cyclin-dependent kinase (CDK complexes, which relieve growth suppression. In HPr-1AR, cyclin D1/2 and CDK4/6 mRNAs were androgen-repressed, whereas CDK inhibitor, CDKN1A, mRNA was androgen-induced. The regulation of these transcripts was AR-dependent, and involved multiple mechanisms. Similar AR-mediated down-regulation of CDK4/6 mRNAs and up-regulation of CDKN1A mRNA occurred in PC3-Lenti-AR. Further, CDK4/6 overexpression suppressed DHT-inhibited cell cycle progression and proliferation of HPr-1AR and PC3-Lenti-AR, whereas CDKN1A overexpression induced cell cycle arrest. We therefore propose that AR-mediated growth suppression of HPr-1AR involves cyclin D1 mRNA decay, transcriptional repression of cyclin D2 and CDK4/6, and transcriptional activation of CDKN1A, which serve to decrease CDK4/6 activity. AR-mediated inhibition of PC3-Lenti-AR proliferation occurs through a similar mechanism, albeit without down-regulation of cyclin D. Our findings provide insight into AR-mediated regulation of prostate epithelial cell proliferation.

  11. A method for intercalibration of U-Th-Pb and 40Ar- 39Ar ages in the Phanerozoic (United States)

    Villeneuve, Mike; Sandeman, Hamish A.; Davis, William J.


    The increasing analytical precision of 40Ar- 39Ar geochronological data and its use in studies that combine U-Pb and 40Ar- 39Ar data has necessitated derivation of a means to intercalibrate ages between the two isotopic systems. The primary determinants inhibiting accurate cross calibration are uncertainty in decay constant values and uncertainty in 40Ar∗/ 40K (usually presented as apparent age) for 40Ar- 39Ar standards, notably those derived from the Fish Canyon Tuff. By utilizing a monazite- and biotite bearing Oligocene ash flow tuff (MAC-83) as the primary standard material, precise U-Th-Pb and 40Ar- 39Ar ages can be derived. Because both isotopic systems should reflect closure during the instantaneous eruption event, the 24.21 ± 0.10 Ma 207Pb/ 235U age should match the age resulting from 40Ar- 39Ar biotite analysis. This forced equivalence will partly offset the effects of decay constant uncertainty. Furthermore, by co-irradiating Fish Canyon Tuff sanidine with MAC-83 biotite, the apparent age for Fish Canyon Tuff sanidine is back-calculated to 27.98 ± 0.15 Ma, relative to the MAC-83 207Pb/ 235U age. Hence, intercalibration between the two isotopic systems in a relative sense can be accomplished, allowing for a direct and valid comparison of ages. It is also shown that forcing equivalence of the two isotopic systems minimizes the effect of decay constant uncertainty for samples of Phanerozoic age.

  12. Identification and analysis of ARS function of six plant MARs

    Institute of Scientific and Technical Information of China (English)

    LI Hong; YANG Yutao; ZHANG Kewei; ZHENG Chengchao


    Six plant MARs isolated from tobacco and Arabdiposis were investigated for their ARS activity in yeast.The results showed that among the six plant MARs, only TM1 and AM4 had strong ARS activity which was almost the same as that of ARS from yeast chromosome. In order to further identify the core region of the two MARs for the ARS activity, a series of subclones were created by PCR strategy,and the corresponding subclones were designated as TM1-1,TM1-2, TM1-3, AM4-1, AM4-2 and AM4-3, respectively. Our studies revealed that TM1-3 and AM4-3 not only had higher ARS activity, but also displayed higher transformation frequency, plasmid stability and growth rate compared to their intact MARs, TM1 and AM4. These data present an important clue for further elucidating the relationship between MAR and ARS.

  13. Eurekan deformation on Prins Karls Forland, Svalbard - new insights from Ar40/Ar39 muscovite dating (United States)

    Faehnrich, Karol; Schneider, David; Manecki, Maciej; Czerny, Jerzy; Myhre, Per Inge; Majka, Jarosław; Kośmińska, Karolina; Barnes, Christopher; Maraszewska, Maria


    Eurekan deformation has been proven to be a complex sequence of tectonic episodes, dominated by compression in the Circum Arctic region. It was associated with early Cenozoic collision of Eurasia, North America and Greenland plates producing fold-thrust belt style of deformation. Timing of this enigmatic event has not yet been extensively resolved by radiometric dating (Piepjohn et al. 2016, Journal of the Geological Society, 173(6), 1007-1024). Reinhardt et al. (2013, Z. Dt. Ges. Geowiss., 164 (1), 131-147) dated syn-tectonic volcanic ashes at c. 60 Ma and 54 Ma on Ellesmere Island, Canada. Tagner et al. (2011, Earth and Planetary Science Letters, 303(3), 203-214) interpreted c. 49-47 Ma 40Ar/39Ar ages on trachyte flows in northern Greenland as peak compression during the Eurekan event. On Svalbard, Tessensohn et al. (2001, Geologisches Jahrbuch, B 91, 83-104) reported K/Ar whole rock ages ranging from c. 67 to 49 Ma for the slates from Svartfjella-Eidembukta-Daudmannsodden Lineament. Bentonite layers in the Central Tertiary Basin are as young as c. 56 Ma (Charles et al. 2011, Geochem. Geophys. Geosyst., 12, 1-19), predating latest deformation. Moreover, Barnes et al (2017, in prep.) applied (U-Th)/He thermochronology along the western margin of Svalbard and resolved Early to Middle Eocene heating, likely documenting burial related to thrusting. Here we present new results from 40Ar/39Ar muscovite dating of ductile to brittle shear zone on Prins Karls Forland, Svalbard, indicating Eurekan age of thrusting. Prins Karls Forland is dominated by Neoproterozoic siliciclastic metasediments (comprising Caledonian basement) regionally metamorphosed to greenschist facies conditions. A ˜1 km wide ductile to brittle shear zone (the Bouréefjellet shear zone) separates the amphibolite facies Pinkie Unit from the lower grade upper structural unit, the Grampianfjella Formation (Faehnrich et al. 2016, EGU 2016). The age of the amphibolite facies metamorphism (c. 370-355 Ma

  14. Progress on using deuteron-deuteron fusion generated neutrons for 40Ar/39Ar sample irradiation (United States)

    Rutte, Daniel; Renne, Paul R.; Becker, Tim; Waltz, Cory; Ayllon Unzueta, Mauricio; Zimmerman, Susan; Hidy, Alan; Finkel, Robert; Bauer, Joseph D.; Bernstein, Lee; van Bibber, Karl


    We present progress on the development and proof of concept of a deuteron-deuteron fusion based neutron generator for 40Ar/39Ar sample irradiation. Irradiation with deuteron-deuteron fusion neutrons is anticipated to reduce Ar recoil and Ar production from interfering reactions. This will allow dating of smaller grains and increase accuracy and precision of the method. The instrument currently achieves neutron fluxes of ˜9×107 cm-2s-1 as determined by irradiation of indium foils and use of the activation reaction 115In(n,n')115mIn. Multiple foils and simulations were used to determine flux gradients in the sample chamber. A first experiment quantifying the loss of 39Ar is underway and will likely be available at the time of the presentation of this abstract. In ancillary experiments via irradiation of K salts and subsequent mass spectrometric analysis we determined the cross-sections of the 39K(n,p)39Ar reaction at ˜2.8 MeV to be 160 ± 35 mb (1σ). This result is in good agreement with bracketing cross-section data of ˜96 mb at ˜2.45 MeV and ˜270 mb at ˜4 MeV [Johnson et al., 1967; Dixon and Aitken, 1961 and Bass et al. 1964]. Our data disfavor a much lower value of ˜45 mb at 2.59 MeV [Lindström & Neuer, 1958]. In another ancillary experiment the cross section for 39K(n,α)36Cl at ˜2.8 MeV was determined as 11.7 ± 0.5 mb (1σ), which is significant for 40Ar/39Ar geochronology due to subsequent decay to 36Ar as well as for the determination of production rates of cosmogenic 36Cl. Additional experiments resolving the cross section functions on 39K between 1.5 and 3.6 MeV are on their way using the LICORNE neutron source of the IPN Orsay tandem accelerator. Results will likely be available at the time of the presentation of this abstract. While the neutron generator is designed for fluxes of ˜109 cm-2s-1, arcing in the sample chamber currently limits the power—straightforwardly correlated to the neutron flux—the generator can safely be run at. Further

  15. Enseñar a ser

    Directory of Open Access Journals (Sweden)

    García Barreno, Pedro


    Full Text Available El «Informe Delors», cuyo texto fue presentado hace ahora diez años, señala que cualquier proyecto educativo para el siglo XXI debe contemplar dos acciones. «Enseñar a conocer, a hacer, a vivir juntos, a ser», y garantizar el acceso de todos a ello. El siglo que concluyó apenas media docena de años, ha estado cargado de inmensas paradojas: entre grandes males, extraordinarios logros y no pocas esperanzas inalcanzadas. Marcado por dos guerras mundiales, por genocidios, por la acelerada degradación de la biosfera o por la miseria de una masa de marginados frente al creciente bienestar de los privilegiados.…

  16. Plasma AR and abiraterone-resistant prostate cancer. (United States)

    Romanel, Alessandro; Gasi Tandefelt, Delila; Conteduca, Vincenza; Jayaram, Anuradha; Casiraghi, Nicola; Wetterskog, Daniel; Salvi, Samanta; Amadori, Dino; Zafeiriou, Zafeiris; Rescigno, Pasquale; Bianchini, Diletta; Gurioli, Giorgia; Casadio, Valentina; Carreira, Suzanne; Goodall, Jane; Wingate, Anna; Ferraldeschi, Roberta; Tunariu, Nina; Flohr, Penny; De Giorgi, Ugo; de Bono, Johann S; Demichelis, Francesca; Attard, Gerhardt


    Androgen receptor (AR) gene aberrations are rare in prostate cancer before primary hormone treatment but emerge with castration resistance. To determine AR gene status using a minimally invasive assay that could have broad clinical utility, we developed a targeted next-generation sequencing approach amenable to plasma DNA, covering all AR coding bases and genomic regions that are highly informative in prostate cancer. We sequenced 274 plasma samples from 97 castration-resistant prostate cancer patients treated with abiraterone at two institutions. We controlled for normal DNA in patients' circulation and detected a sufficiently high tumor DNA fraction to quantify AR copy number state in 217 samples (80 patients). Detection of AR copy number gain and point mutations in plasma were inversely correlated, supported further by the enrichment of nonsynonymous versus synonymous mutations in AR copy number normal as opposed to AR gain samples. Whereas AR copy number was unchanged from before treatment to progression and no mutant AR alleles showed signal for acquired gain, we observed emergence of T878A or L702H AR amino acid changes in 13% of tumors at progression on abiraterone. Patients with AR gain or T878A or L702H before abiraterone (45%) were 4.9 and 7.8 times less likely to have a ≥50 or ≥90% decline in prostate-specific antigen (PSA), respectively, and had a significantly worse overall [hazard ratio (HR), 7.33; 95% confidence interval (CI), 3.51 to 15.34; P = 1.3 × 10(-9)) and progression-free (HR, 3.73; 95% CI, 2.17 to 6.41; P = 5.6 × 10(-7)) survival. Evaluation of plasma AR by next-generation sequencing could identify cancers with primary resistance to abiraterone.

  17. Practical reactor production of {sup 41}Ar from argon clathrate

    Energy Technology Data Exchange (ETDEWEB)

    Mercer, J.R. E-mail:; Duke, M.J.M.; McQuarrie, S.A


    The radionuclide {sup 41}Ar has many ideal properties as a gas flow tracer. However, the modest cross-section of {sup 40}Ar for thermal neutron activation makes preparation of suitable activities of {sup 41}Ar technically difficult particularly for low flux reactors. Argon can however be trapped in a molecular complex called a clathrate that can then be irradiated. We prepared argon clathrate and explored its irradiation and stability characteristics. Argon clathrate can be used to provide gigabecquerel quantities of {sup 41}Ar even with low power reactors.

  18. 40Ar/39Ar dates from the West Siberian Basin: Siberian flood basalt province doubled. (United States)

    Reichow, Marc K; Saunders, Andrew D; White, Rosalind V; Pringle, Malcolm S; Al'Mukhamedov, Alexander I; Medvedev, Alexander I; Kirda, Nikolay P


    Widespread basaltic volcanism occurred in the region of the West Siberian Basin in central Russia during Permo-Triassic times. New 40Ar/39Ar age determinations on plagioclase grains from deep boreholes in the basin reveal that the basalts were erupted 249.4 +/- 0.5 million years ago. This is synchronous with the bulk of the Siberian Traps, erupted further east on the Siberian Platform. The age and geochemical data confirm that the West Siberian Basin basalts are part of the Siberian Traps and at least double the confirmed area of the volcanic province as a whole. The larger area of volcanism strengthens the link between the volcanism and the end-Permian mass extinction.

  19. 40Ar-39Ar age of carbonatite-alkaline magmatism in Sung Valley, Maghalaya, India

    Indian Academy of Sciences (India)

    Jyotiranjan S Ray; Kanchan Pande


    40Ar-39Ar analyses of one alkali pyroxenite whole rock and two phlogopite separates of calcite carbonatites from the Sung Valley carbonatite-alkaline complex, which is believed to be a part of the Rajmahal-Bengal-Sylhet (RBS) ood basalt province, yielded indistinguishable plateau ages of 108.8 ± 2.0 Ma, 106:4 ± 1.3 Ma and 107.5 ± 1.4 Ma, respectively. The weighted mean of these ages, 107.2 ± 0.8 Ma, is the time of emplacement of this complex. This implies that Sung Valley complex and probably other such complexes in the Assam-Meghalaya Plateau postdate the main ood basalt event (i.e., the eruption of tholeiites) in the RBS province by ∼10 Ma.

  20. Acoustic resonance spectroscopy (ARS): ARS300 operations manual, software version 2.01

    Energy Technology Data Exchange (ETDEWEB)



    Acoustic Resonance Spectroscopy (ARS) is a nondestructive evaluation technology developed at the Los Alamos National Laboratory. The ARS technique is a fast, safe, and nonintrusive technique that is particularly useful when a large number of objects need to be tested. Any physical object, whether solid, hollow, or fluid filled, has many modes of vibration. These modes of vibration, commonly referred to as the natural resonant modes or resonant frequencies, are determined by the object`s shape, size, and physical properties, such as elastic moduli, speed of sound, and density. If the object is mechanically excited at frequencies corresponding to its characteristic natural vibrational modes, a resonance effect can be observed when small excitation energies produce large amplitude vibrations in the object. At other excitation frequencies, i.e., vibrational response of the object is minimal.

  1. 40Ar/39Ar Age of the Lathrop Wells Volcanic Center, Yucca Mountain, Nevada. (United States)

    Turrin, B D; Champion, D; Fleck, R J


    Paleomagnetic and (40)Ar/(39)Ar analyses from the Lathrop Wells volcanic center, Nevada, indicate that two eruptive events have occurred there. The ages (136 +/- 8 and 141 +/- 9 thousand years ago) for these two events are analytically indistinguishable. The small angular difference (4.7 degrees ) between the paleomagnetic directions from these two events suggests they differ in age by only about 100 years. These ages are consistent with the chronology of the surficial geological units in the Yucca Mountain area. These results contradict earlier interpretations of the cinder-cone geomorphology and soil-profile data that suggest that at least five temporally discrete eruptive events occurred at Lathrop Wells approximately 20,000 years ago.

  2. Cooling age of Dabie orogen, China, determined by 40Ar-39Ar and fission track techniques

    Institute of Scientific and Technical Information of China (English)

    陈江峰; 谢智; 刘顺生; 李学明; K.A.Foland


    Based on 40Ar-39Ar results of hornblendes and biotites and fission track dating results of apatites separated from the same rock samples, cooling history of rocks from Dabie orogen is discussed. Rocks from both Southern Dabie Terrain (SDT) and Northern Dabie Terrain (NDT) have an early fast cooling followed by a more recent slow cooling. Rocks from SDT cooled to about 540℃ at about 190 Ma B.C., while rocks from NDT cooled to about 540℃ at 125 Ma B C. Until about 110-120 Ma B.C., rocks from both SDT and NDT cooled to about 100℃. This suggests that a relative movement among rocks from SDT, NDT and ul-Ira-high pressure metamorphic rocks exis-ts before 110-120 Ma B.C.

  3. Laser step-heating 40Ar/39Ar dating on young volcanic rocks

    Institute of Scientific and Technical Information of China (English)

    WANG Fei; HE Huaiyu; ZHU Rixiang; YANG Liekun; SANG Haiqing; WANG Yinglan


    An attempt was made to use CO2 laser step-heating method to date the late Pleistocene basaltic groundmass (DF-2) from Tengchong volcanic field. Among the fourteen heating steps, ten define a good inverse isochron (MSWD = 1.4) with an age of 32.2 ± 7.1 ka (2 σ).The inverse isochron also shows that the initial argon isotopic ratio is 297.1±2.0 (2σ)which is the same as the atmospheric argon at the 2σ error level. Study indicates that it is a useful means to date young volcanic groundmass with low K content by using CO2 laser step-heating 40Ar/39Ar method.

  4. Implications of 40Ar/39Ar Geochronology for Fluid Transfer and Magma Generation Across Southeastern Guatemala (United States)

    Walker, J.; Bemis, K.; Cameron, B.; Noll, K.; Singer, B.; Zhang, X.; Ruscitto, D.; Roggensack, K.; Olney, J.


    Behind-the-front , or back-arc, monogenetic volcanism extends some 110 km across southeastern Guatemala providing an important window into fluid transfer and melting in the Central American subduction zone. New 40Ar/39Ar incremental heating measurements on basaltic lavas from cinder cones in southeastern Guatemala place important temporal constraints on this across-arc volcanism. Behind-the-front (BVF) volcanism has been notably long-lived: from 1070 ± 22 ka to 137 ± 25 ka. The morphologies of some undated cinder cones suggest that BVF volcanism has probably extended into the Holocene. Most morphological parameters for the dated cinder cones show no systematic changes with age, suggesting that cone degradation is rapid in the tropical climate of Guatemala, quickly approaching a morphological equilibrium stabilized by the thick vegetative cover. The volumes of cinder cones, however, have consistently increased towards the present. In additon, Ar/Ar ages become younger towards Pacaya volcano on the volcanic front, indicating a southwestward migration of eruptive activity with time. Some incompatible element concentrations and ratios, such as Ba, La, and La/Y, decrease with time suggesting increasing amounts of melting in the mantle wedge, consistent with the production of larger and larger cinder cones. Increasing melting, however, does not appear to be directly related to fluid transfer from the slab as the Ba/La, Ba/Th and U/Th ratios of basalts erupted from the dated cinder cones have also declined over time. Thus, the new age constraints suggest the increasing influence of decompression, versus flux, melting in the BVF region, an influence that has also spread into Pacaya volcano on the volcanic front (Cameron et al., 2002).

  5. Spatial autocorrelation method using AR model; Kukan jiko sokanho eno AR model no tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, H.; Obuchi, T.; Saito, T. [Iwate University, Iwate (Japan). Faculty of Engineering


    Examination was made about the applicability of the AR model to the spatial autocorrelation (SAC) method, which analyzes the surface wave phase velocity in a microtremor, for the estimation of the underground structure. In this examination, microtremor data recorded in Morioka City, Iwate Prefecture, was used. In the SAC method, a spatial autocorrelation function with the frequency as a variable is determined from microtremor data observed by circular arrays. Then, the Bessel function is adapted to the spatial autocorrelation coefficient with the distance between seismographs as a variable for the determination of the phase velocity. The result of the AR model application in this study and the results of the conventional BPF and FFT method were compared. It was then found that the phase velocities obtained by the BPF and FFT methods were more dispersed than the same obtained by the AR model. The dispersion in the BPF method is attributed to the bandwidth used in the band-pass filter and, in the FFT method, to the impact of the bandwidth on the smoothing of the cross spectrum. 2 refs., 7 figs.

  6. 75 FR 12163 - Class E Airspace; Mountain View, AR (United States)


    ... Federal Aviation Administration 14 CFR Part 71 Class E Airspace; Mountain View, AR AGENCY: Federal... proposes to amend Class E airspace at Mountain View, AR. Decommissioning of the Wilcox non-directional beacon (NDB) at Mountain View Wilcox Memorial Field Airport has made this action necessary for the...

  7. Aspects of What Makes or Breaks a Museum AR Experience

    DEFF Research Database (Denmark)

    Madsen, Claus B.; Madsen, Jacob Boesen; Morrison, Ann


    The paper critically evaluates central aspects of an iPad AR application developed for a museum context. The application is designed for children aged 8 to 12 and mixes AR and mini-game elements to convey dramatized historical events. The game has been deployed for roughly 3 months and the findin...

  8. Regulation of AR Degradation and Function by Ubiquitylation (United States)


    Identify ubiquitylation sites associated with degradation of the unliganded AR. We have used liquid chromatography followed by tandem mass spectrometry (LC...unmodified AR band in another gel slice). Protein in gel slices was then digested with trypsin (which leaves a gly-gly tag on ubiquitin-modified proteins

  9. 40Ar/39Ar and (U-Th)/He model age signatures of elusive Mercurian and Venusian meteorites (United States)

    Jourdan, Fred; Eroglu, Ela


    No meteorites from Mercury and Venus have been conclusively identified so far. In this study, we develop an original approach based on extensive Monte Carlo simulations and diffusion models to explore the radiogenic argon (40Ar*) and helium (4He*) loss behavior and the range of 40Ar/39Ar and (U-Th)/He age signatures expected for a range of crystals if meteorites from these planets were ever to be found. We show that we can accurately date the crystallization age of a meteorite from both Mercury and Venus using the 40Ar/39Ar technique on clinopyroxene (± orthopyroxene) and that its 40Ar/39Ar age should match the Pb-Pb age. At the surface of Mercury, phases like albite and anorthite will exhibit a complete range of 40Ar* loss ranging from 0% to 100%, whereas merrillite and apatite will show 100% 4He* loss. By measuring the crystal size and diffusion parameters of a series of plagioclase crystals, one can inverse the 40Ar* loss value to estimate the maximum temperature experienced by a rock, and narrow down the possible pre-ejection location of the meteorite at the surface of Mercury. At the surface of Venus, plagioclase and phosphate phases will only record the age of ejection. The (U-Th)/He systematics of merrillite and apatite will be, respectively, moderately and strongly affected by 4He* loss during the transit of the meteorite from its host planet to Earth. Finally, meteorites from Mercury or Venus will each have their own 40Ar/39Ar and (U-Th)/He isotopic age and 38Arc cosmic ray exposure age signatures over a series of different crystal types, allowing to unambiguously recognize a meteorite for any of these two planets using radiogenic and cosmogenic noble gases.

  10. Laser fusion 40Ar/39Ar dating on young volcanic rocks.%(极)年轻火山岩激光熔蚀40Ar/39Ar定年

    Institute of Scientific and Technical Information of China (English)

    周晶; 季建清; Alan DEINO; 龚俊峰; 韩宝福; 涂继耀; 桑海清; 徐剑光


    It is extremely difficult to date young volcanic rocks.Accurate 40Ar/39Ar dating research and practice of young volcanic rocks in China put forward several notable and important points during the process of 40Ar/39 Ar dating for young volcanic rocks.Because of the low background level,small sample quantity,and high sensitivity of modem noble gas isotope mass spectrometry device,laser ablation 40Ar/39Ar dating technique has been used in depth application in volcanic rocks dating.With the laser in 40Ar/39Ar dating of young and modern volcanic rocks,the discrepancy of Nier value and initial argon isotope ratio in Quaternary samples may cause a remarkable deviation between K-Ar apparent age and 40 Ar/39 Ar apparent age.The deviation show exponential increase for samples younger than 0.2Ma,but it is not so notable for samples older than 2Ma.There out,the boundary of young and modern volcanic rocks,which is applied to 40 Ar/39 Ar system,is assigned at 0.2Ma:rocks aged 2 ~ 0.2Ma is defined as young volcanic rock,while rocks aged younger than 0.2Ma is defined as modem volcanic rock.The phenocrysts,which are from different argon isotope fractionation system,should be rejected from the sample during 40Ar/39 Ar dating.According to rock texture and grain size of mineral,the matrix should be picked with ideal grain size.In normal cases,about 0.2mm (or 60 ~ 80 mesh) is recommended; Cooling time after irradiation of fast neutron reactor should not be no more than three months,or else it may cause an error on 37 Ar measurement,and consequently on final results.As neutron-flux monitor,standards should be characteristic of high homogeneity during laser 40Ar/39Ar dating.In calibrating the international and domestic standards we have,we find that SB-778-Bi,Bern4M and BT-1 can be ideal standard samples with good homogeneity.We also find that the isochron age calculated from the laser 40Ar/39Ar data of the phenocryst and matrix,which were cooled and crystallized at the same time

  11. AR Sco: A White Dwarf Synchronar

    CERN Document Server

    Katz, J I


    The emission of the white dwarf-M dwarf binary AR Sco is driven by the rapid synchronization of its white dwarf, rather than by accretion. This requires a comparatively large magnetic field $\\sim 100$ gauss at the M dwarf and $\\sim 10^8$ gauss on the white dwarf, larger than the fields of most intermediate polars but within the range of fields of known magnetic white dwarfs. The spindown power is dissipated in the atmosphere of the M dwarf by magnetic reconnection, accelerating particles that produce the observed synchrotron radiation. The displacement of the optical maximum from conjunction may be explained either by dissipation in a bow wave as the white dwarf's magnetic field sweeps past the M dwarf or by a misaligned white dwarf's rotation axis and oblique magnetic moment. In the latter case the rotation axis precesses with a period of decades, predicting a drift in the orbital phase of maximum. Binaries whose emission is powered by synchronization may be termed synchronars, in analogy to magnetars.

  12. AR Sco: A Precessing White Dwarf Synchronar? (United States)

    Katz, J. I.


    The emission of the white dwarf–M dwarf binary AR Sco is driven by the rapid synchronization of its white dwarf, rather than by accretion. Synchronization requires a magnetic field ∼100 Gauss at the M dwarf and ∼ {10}8 Gauss at the white dwarf, larger than the fields of most intermediate polars but within the range of fields of known magnetic white dwarfs. The spindown power is dissipated in the atmosphere of the M dwarf, within the near zone of the rotating white dwarf’s field, by magnetic reconnection, accelerating particles that produce the observed synchrotron radiation. The displacement of the optical maximum from conjunction may be explained either by dissipation in a bow wave as the white dwarf’s magnetic field sweeps past the M dwarf or by a misaligned white dwarf rotation axis and oblique magnetic moment. In the latter case the rotation axis precesses with a period of decades, predicting a drift in the orbital phase of the optical maximum. Binaries whose emission is powered by synchronization may be termed synchronars, in analogy to magnetars.

  13. ``Smoking From The Same Pipe": Developement of an 40Ar/39Ar Datting Intercalibration PIpette System (Invited) (United States)

    Turrin, B. D.; Swisher, C. C.; Deino, A.; Hemming, S. R.; Hodges, K.; Renne, P. R.


    The precision and accuracy of Ar isotope ratio measurements is one of the main limiting factors in the uncertainties of an 40Ar/39Ar age. Currently, it is relatively common to measure Ar isotopic ratios to a precision of 1-2‰ or better on an intralaboratory basis. This level of analytical precision equates to a comparable level of precision (1-3‰) in the calculated age, depending on the extent of atmospheric Ar contamination, importance of nucleogenic interference corrections, and other factors. However, it has become clear that improving the precision of mass spectrometry is not the only bottleneck towards improving the accuracy and precision of 40Ar/39Ar dating in general. Rather, the most urgent issue is interlaboratory reproducibility. This became obvious in a recent EARTHTIME initiative undertaken to intercalibrate two commonly used 40Ar/39Ar standards [the Fish Canyon sanidine (FCs) and the Alder Creek sanidine (ACs)]. This effort revealed variations amongst laboratories (at the 1-2% level), an order of magnitude greater than the internal analytical precisions. To address these issues, we have proposed (to NSF) to construct two identical pipette systems loaded to identical starting pressures and with identical isotopic compositions. One pipette system will travel between participating 40Ar/39Ar labs and the second system will not travel and serve as the “Master” system to test for any fractionation or undocumented depletion of the traveling pipette system. In order to ensure delivery of uniform amounts of homogenous gas, the pipette system will be computer-controlled with preprogrammed routines and lockouts to prevent compromising the reservoirs. The pipette systems will deliver three gas samples with different isotopic ratios at two different pressures/concentrations. One pipette bulb will be of atmospheric isotopic composition, and the other two pipette bulbs will have 40Ar*/39ArK ratios corresponding to co-irradiated ACs and FCs fixed by their

  14. 40Ar/39Ar geochronology and exhumation of mylonitized metamorphic complex in Changle-Nanao ductile shear zone

    Institute of Scientific and Technical Information of China (English)

    王志洪; 卢华复


    New 40Ar/39Ar plateau ages from rocks of Changle-Nanao ductile shear zone are 107.9 Ma(Mus), 108.2 Ma(Bi), 107. 1 Ma(Bi), 109. 2 Ma(Hb) and 117. 9 Ma(Bi) respectively, which are concordant with their isochron ages and record the formation age of the ductile shear zone. The similarity and apparent overlap of the cooling ages with respective closure temperatures of 5 minerals document initial rapid uplift during 107-118 Ma following the collision between the Min-Tai microcontinent and the Min-Zhe Mesozoic volcanic arc. The 40Ar/39Ar plateau ages, K-Ar date of K-feldspar and other geochronologic information suggest that the exhumation rate of the ductile shear zone is about 0.18-1.12 mm/a in the range of 107-70 Ma, which is mainly influenced by tectonic extension.

  15. Evaluation of the IPCC Models (AR4 and AR5) in the Precipitation Simulation in the Northeast of Brazil (United States)

    Alves, José; Vasconcelos Junior, Francisco; Chaves, Rosane; Silva, Emerson; Servain, Jacques; Costa, Alexandre; Sombra, Sérgio; Barbosa, Augusto; Dos Santos, Antonio


    With the simulations of the models used in the latest reports from the Intergovernmental Panel on Climate Change (IPCC), comparative studies are necessary between observations and the so-called historical run (C20) and future projections of the AR4 (A2) and AR5 (RCP8.5) experiments, in order to assess whether the AR5 models had a better performance in the representation of physical processes. This article compares the sensitivity of IPCC models (AR4 and AR5) in representing the anuall average and seasonal rainfall variation (summer and autumn) in three regions of the Northeast of Brazil between 1979 and 2000, using the CMAP - CPC (Merged Analysis of Precipitation) data as reference. The projections made by these models for the period 2040-2070 were also analyzed.

  16. Ar Ar dating of authigenic K-feldspar: Quantitative modelling of radiogenic argon-loss through subgrain boundary networks (United States)

    Mark, D. F.; Kelley, S. P.; Lee, M. R.; Parnell, J.; Sherlock, S. C.; Brown, D. J.


    We have analysed two distinct generations of authigenic K-feldspar in Fucoid Bed sandstones from An-t-Sron and Skiag Bridge, NW Highlands, Scotland, which have experienced post-growth heating to levels in excess of the predicted Ar-closure temperature. Authigenic K-feldspars show microtextural similarities to patch perthites; that is subgrains separated by dislocation-rich boundary networks that potentially act as fast diffusion pathways for radiogenic argon. The two generations of authigenic K-feldspar in the Fucoid Bed sandstones can be distinguished by different microtextural zones, bulk mineral compositions, fluid-inclusion populations, and inferred temperatures and chemistries of parent fluids. Ar-Ar age data obtained using high-resolution ultraviolet laser ablation, show that the first cementing generation is Ordovician and the second cementing generation is Silurian. Modelling of Ar diffusion using subgrain size as the effective diffusion dimension and a simplified tectono-thermal thrust model assuming transient heating of the Fucoid Beds is inconsistent with observed data. Removal of heat from the thrust zone through rapid flushing of heated fluids rather than transient heating can be invoked to explain the observed Ar-Ar ages for both generations of cement. Alternatively, Ar-diffusion modelling using overgrowth thickness as the effective diffusion dimension instead of subgrain size also yields models that are consistent with both the Fucoid Bed palaeothermal maxima and determined Ar-Ar age ages for the two generations of K-feldspar cement. Based on this alternate explanation, we propose a theoretical microtextural model that highlights fundamental differences between the microtextures of deuterically formed patch perthites and authigenic K-feldspars, explaining the apparent robustness of authigenic K-feldspar with respect to Ar-retention.

  17. Ar-40/Ar-39 age determinations for the Rotoiti eruption, New Zealand (United States)

    Flude, S.; Storey, M.


    The contemporaneous Rotoiti and Earthquake Flat ignimbrites, erupted from the Taupo Volcanic zone, New Zealand, form a distinctive tephrostratigraphic horizon in the Southern Pacific. Radioisotopic dating results for these eruptions remain controversial, with published ages ranging from 35.1 × 2.8 ka [1] to 71 × 6 ka [2], with 61.0 × 1.5 ka [3] often being cited as the most widely accepted age. These eruptions are difficult to date as their age is near the limit for various radiometric dating techniques, which are complicated by a large proportion of inherited material (xenocrysts) and a lack of phases suitable for dating. Glass-bearing plutonic blocks erupted with the Rotoiti and Earthquake Flat ignimbrites have previously been interpreted as deriving from a slowly cooled and incompletely solidified magma body that was sampled by the eruptions. They contain large vugs lined with euhedral quartz, sanidine and biotite crystals, indicating that these crystals grew in a gas or aqueous fluid rich environment and are interpreted to have formed shortly before or during eruption. Here we will present Ar-40/Ar-39 ages for sanidines and biotites extracted from vugs in lithic blocks erupted as part of the Earthquake Flat ignimbrite. We show that, even for vug-lining material, inherited ages remain a problem and are the likely source of the wide variation in published radiometric ages. Nevertheless, many of the Ar-40/Ar-39 ages are much younger than the 61 ka age [3] and are more consistent with the recent stratigraphic, C-14 and U-238/Th-230+(U-Th)/He ages that have been suggested (e.g. [4,5]). 1. Whitehead, N. & Ditchburn, R. New Zealand Journal of Geology and Geophysics 37, 381-383 (1994). 2. Ota, Y., Omura, A. & Iwata, H. New Zealand Journal of Geology and Geophysics 32, 327-331 (1989). 3. Wilson, C. J. N. et al. Quaternary Science Reviews 26, 1861-1870 (2007). 4. Molloy, C., Shane, P. & Augustinus, P. Geological Society of America Bulletin 121, 1666-1677 (2009). 5

  18. High-precision 40Ar/39Ar age for the Jehol Biota (United States)

    Chang, S.; Zhang, H.; Renne, P. R.; Fang, Y.


    Abundant fossils of the terrestrial Jehol Biota, including plants, insects, dinosaurs, birds, mammals and freshwater invertebrates, were discovered from the Yixian Formation and the overlying Jiufotang Formation in Inner Mongolia, Hebei Province and Liaoning Province, northeastern China. Because of the exceptional preservation of fossils, the Jehol Biota is one of the most important Mesozoic fossil outcrops and referred to as a "Mesozoic Pompeii". The Jehol Biota has provided a rare opportunity to address questions about the origin of birds, the evolution of feathers and flight, the early diversification of angiosperms and the timing of the radiation of placental mammals. The Tuchengzi Formation, which lies unconformably just below the Yixian Formation and consists mainly of variegated sandstones, is less fossiliferous than the two overlying formations. However, dinosaur tracks, silicified wood and compressed plants are found in this formation. A systematic 40Ar/39Ar dating of the Yixian and the Jiufotang formations was undertaken to provide a framework for understanding the timing and duration of the Jehol Biota and evolutionary events represented within it. Furthermore, determining the absolute age of the Tuchengzi Formation provides information to interpret abundant dinosaur tracks within and provide better age constrains for the beginning of the Jehol Biota. Here we present robust high-precision 40Ar/39Ar data for six tuff samples and two basalt samples collected from the Tuchengzi, the Yixian and the Jiufotang formations near the classic outcrops in western Liaoning, NE China. We obtain an age of 139.5 ± 1.0 Ma for the uppermost Tuchengzi Formation, an age of 129.7 ± 0.5 Ma for a basaltic lava from the bottom of the Yixian Formation and an age of 122.1 ± 0.3 Ma for a tuff from the base of the overlying Jiufotang Formation. Our data indicate that the Yixian Formation was deposited during the Early Cretaceous, the Barremian to early Aptian, within a time span

  19. 40Ar/(39)Ar dating of the Kapthurin Formation, Baringo, Kenya. (United States)

    Deino, Alan L; McBrearty, Sally


    The(40)Ar/(39)Ar radiometric dating technique has been applied to tuffs and lavas of the Kapthurin Formation in the Tugen Hills, Kenya Rift Valley. Two variants of the(40)Ar/(39)Ar technique, single-crystal total fusion (SCTF) and laser incremental heating (LIH) have been employed to date five marker horizons within the formation: near the base, the Kasurein Basalt at 0.61+/-0.04 Ma; the Pumice Tuff at 0.543+/-0.004 Ma; the Upper Kasurein Basalt at 0.552+/-0.015 Ma; the Grey Tuff at 0.509+/-0.009 Ma; and within the upper part of the formation, the Bedded Tuff at 0.284+/-0.012 Ma. The new, precise radiometric age determination for the Pumice Tuff also provides an age for the widespread Lake Baringo Trachyte, since the Pumice Tuff is the early pyroclastic phase of this voluminous trachyte eruption. These results establish the age of fossil hominids KNM-BK 63-67 and KNM-BK 8518 at approximately 0.510-0.512 Ma, a significant finding given that few Middle Pleistocene hominids are radiometrically dated. The Kapthurin hominids are thus the near contemporaries of those from Bodo, Ethiopia and Tanzania. A flake and core industry from lacustrine sediments in the lower part of the formation is constrained by new dates of 0.55-0.52 Ma, a period during which the Acheulian industry, characterized by handaxes, is known throughout East Africa. Points, typical of the Middle Stone Age (MSA), are found in Kapthurin Formation sediments now shown to date to between 0.509+/-0.009 Ma and 0.284+/-0.012 Ma. This date exceeds previous estimates for the age of the MSA elsewhere in East Africa by 49 ka, and establishes the age of Acheulian to MSA transition for the region. Evidence of the use of the Levallois technique for the manufacture of both small flakes and biface preforms, the systematic production of blades, and the use and processing of red ochre also occurs in this interval. The presence of blades and red ochre at this depth is important as blades signify a high degree of technical

  20. The development of AR book for computer learning (United States)

    Phadung, Muneeroh; Wani, Najela; Tongmnee, Nur-aiynee


    Educators need to provide the alternative educational tools to foster learning outcomes of students. By using AR technology to create exciting edutainment experiences, this paper presents how augmented reality (AR) can be applied in the education. This study aims to develop the AR book for tenth grade students (age 15-16) and evaluate its quality. The AR book was developed based on ADDIE framework processes to provide computer learning on software computer knowledge. The content was accorded with the current Thai education curriculum. The AR book had 10 pages in three topics (the first was "Introduction," the second was "System Software" and the third was "Application Software"). Each page contained markers that placed virtual objects (2D animation and video clip). The obtained data were analyzed in terms of average and standard deviation. The validity of multimedia design of the AR book was assessed by three experts in multimedia design. A five-point Likert scale was used and the values were X¯ =4 .84 , S.D. = 1.27 which referred to very high. Moreover, three content experts, who specialize in computer teaching, evaluated the AR book's validity. The values determined by the experts were X¯ =4 .69 , S.D. = 0.29 which referred to very high. Implications for future study and education are discussed.

  1. Expression of ER and AR in lung cancer

    Directory of Open Access Journals (Sweden)

    Shuling WANG


    Full Text Available Background and objective Epidemiology of lung cancer differs between sexes and it might be partially explained by different sex hormone levels in women and men. There are some epidemiological data indicating that gender is a significant, independent prognostic factor in lung cancer. The aim of this study is to determine expression of ER (estrogen receptor and AR (androgen receptor in lung cancer, and evaluate the relationship between their expression and clinical or pathologic characteristics. Methods Immunohistochemistry assay was used to detect expression of ER and AR. Results Positive expression of ER and AR were 14.3%(15/105 and 20%(21/105. Positive expression of ER had no relationship with age, gender, pathology, histological differentiation, TNM staging, size of tumor and lymph node metastasis. Although age, gender, pathology, histological differentiation and size of tumor had no effect on the expression of AR, positive rate of AR in staging III lung cancer was significantly higher than that in staging I lung cancer. The different AR expression was significant between N0 and N2 lymph node metastasis ( Chisquare= 4.7828,P=0.0287. Conclusion The expression of ER has no relationship with biological behavior. Positive expression of AR may be correlated with the progression and the lymph node metastasis of lung cancer.

  2. Jurassic cooling ages in Paleozoic to early Mesozoic granitoids of northeastern Patagonia: 40Ar/39Ar, 40K-40Ar mica and U-Pb zircon evidence (United States)

    Martínez Dopico, Carmen I.; Tohver, Eric; López de Luchi, Mónica G.; Wemmer, Klaus; Rapalini, Augusto E.; Cawood, Peter A.


    U-Pb SHRIMP zircon crystallization ages and Ar-Ar and K-Ar mica cooling ages for basement rocks of the Yaminué and Nahuel Niyeu areas in northeastern Patagonia are presented. Granitoids that cover the time span from Ordovician to Early Triassic constitute the main outcrops of the western sector of the Yaminué block. The southern Yaminué Metaigneous Complex comprises highly deformed Ordovician and Permian granitoids crosscut by undeformed leucogranite dikes (U-Pb SHRIMP zircon age of 254 ± 2 Ma). Mica separates from highly deformed granitoids from the southern sector yielded an Ar-Ar muscovite age of 182 ± 3 Ma and a K-Ar biotite age of 186 ± 2 Ma. Moderately to highly deformed Permian to Early Triassic granitoids made up the northern Yaminué Complex. The Late Permian to Early Triassic (U-Pb SHRIMP zircon age of 252 ± 6 Ma) Cabeza de Vaca Granite of the Yaminué block yielded Jurassic mica K-Ar cooling ages (198 ± 2, 191 ± 1, and 190 ± 2 Ma). At the boundary between the Yaminué and Nahuel Niyeu blocks, K-Ar muscovite ages of 188 ± 3 and 193 ± 5 Ma were calculated for the Flores Granite, whereas the Early Permian Navarrete granodiorite, located in the Nahuel Niyeu block, yielded a K-Ar biotite age of 274 ± 4 Ma. The Jurassic thermal history is not regionally uniform. In the supracrustal exposures of the Nahuel Niyeu block, the Early Permian granitoids of its western sector as well as other Permian plutons and Ordovician leucogranites located further east show no evidence of cooling age reset since mica ages suggest cooling in the wake of crystallization of these intrusive rocks. In contrast, deeper crustal levels are inferred for Permian-Early Triassic granitoids in the Yaminué block since cooling ages for these rocks are of Jurassic age (198-182 Ma). Jurassic resetting is contemporaneous with the massive Lower Jurassic Flores Granite, and the Marifil and Chon Aike volcanic provinces. This intraplate deformational pulse that affected northeastern

  3. A Survey on Web-based AR Applications

    CERN Document Server

    Parhizkar, Behrang; Lashkari, Arash Habibi; Bartaripou, Mohammad Mehdi; Babae, Hossein Reza


    Due to the increase of interest in Augmented Reality (AR), the potential uses of AR are increasing also. It can benefit the user in various fields such as education, business, medicine, and other. Augmented Reality supports the real environment with synthetic environment to give more details and meaning to the objects in the real word. AR refers to a situation in which the goal is to supplement a user's perception of the real-world through the addition of virtual objects. This paper is an attempt to make a survey of web-based Augmented Reality applications and make a comparison among them.

  4. A Survey on Web-based AR Applications

    Directory of Open Access Journals (Sweden)

    Behrang Parhizkar


    Full Text Available Due to the increase of interest in Augmented Reality (AR, the potential uses of AR are increasing also. It can benefit the user in various fields such as education, business, medicine, and other. Augmented Reality supports the real environment with synthetic environment to give more details and meaning to the objects in the real word. AR refers to a situation in which the goal is to supplement a user's perception of the real-world through the addition of virtual objects. This paper is an attempt to make a survey of web-based Augmented Reality applications and make a comparison among them.

  5. Mass Spectrometric and Langmuir Probe Measurements in Inductively Coupled Plasmas in Ar, CHF3/Ar and CHF3/Ar/O2 Mixtures (United States)

    Kim, J. S.; Rao, M. V. V. S.; Cappelli, M. A.; Sharma, S. P.; Meyyappan, M.; Arnold, Jim (Technical Monitor)


    Absolute fluxes and energy distributions of ions in inductively coupled plasmas of Ar, CHF3/Ar, and CHF3/Ar/O2 have been measured. These plasmas were generated in a Gaseous Electronics Conference (GEC) cell modified for inductive coupling at pressures 10-50 mTorr and 100-300 W of 13.56 MHz radio frequency (RF) power in various feedgas mixtures. In pure Ar plasmas, the Ar(+) flux increases linearly with pressure as well as RF-power. Total ion flux in CHF3 mixtures decreases with increase in pressure and also CHF3 concentration. Relative ion fluxes observed in the present studies are analyzed with the help of available cross sections for electron impact ionization and charge-exchange ion-molecule reactions. Measurements of plasma potential, electron and ion number densities, electron energy distribution function, and mean electron energy have also been made in the center of the plasma with a RF compensated Langmuir probe. Plasma potential values are compared with the mean ion energies determined from the measured ion energy distributions and are consistent. Electron temperature, plasma potential, and mean ion energy vary inversely with pressure, but increase with CHF3 content in the mixture.

  6. (40)Ar/(39)Ar Age of Hornblende-Bearing R Chondrite LAP 04840 (United States)

    Righter, K.; Cosca, M.


    Chondrites have a complex chronology due to several variables affecting and operating on chondritic parent bodies such as radiogenic heating, pressure and temperature variation with depth, aqueous alteration, and shock or impact heating. Unbrecciated chondrites can record ages from 4.56 to 4.4 Ga that represent cooling in small parent bodies. Some brecciated chondrites exhibit younger ages (much less than 4 to 4.4 Ga) that may reflect the age of brecciation, disturbance, or shock and impact events (much less than 4 Ga). A unique R chondrite was recently found in the LaPaz Icefield of Antarctica - LAP 04840. This chondrite contains approximately 15% hornblende and trace amounts of biotite, making it the first of its kind. Studies have revealed an equigranular texture, mineral equilibria yielding equilibration near 650-700 C and 250-500 bars, hornblende that is dominantly OH-bearing (very little Cl or F), and high D/H ratios. To help gain a better understanding of the origin of this unique sample, we have measured the (40)Ar/(39)Ar age (LAP 04840 split 39).

  7. 40Ar/39Ar dating of Pleistocene tuffs: an accurate age for the Matuyama-Brunhes geomagnetic reversal (MBGR) (United States)

    Mark, D. F.; Renne, P. R.; Morgan, L. E.; Deino, A.; Smith, V. C.; Ellis, B. S.; Pearce, N. J.


    Recent recalibrations of the 40Ar/39Ar system [1,2] reveal inconsistencies with some previous ages inferred for the MBGR. An Ar/Ar age [3] for the Bishop Tuff (BT) (which post-dates the MBGR by at least 15.3 ± 2.2 ka [3]) recalculated [2] yields an age of 778.0 ± 3.8 ka (1σ, full systematic uncertainty). The age is c. 10 ka older than the BT zircon ID-TIMS U-Pb age [4] and places the MBGR at c. 793 ka, c. 13 and 20 ka older than astronomical ages for the MBGR of 780 ka [5] and 773 ka [6], respectively. To determine an accurate age for the MBGR, we have made a series of 40Ar/39Ar age determinations for Pleistocene tuffs from both Indonesia and North America that have direct relationships to the MBGR. Blind analyses were conducted at SUERC and BGC. We observed excellent inter-laboratory agreement and no systematic offset in data. Ar/Ar ages are reported relative to [2] (1σ, full systematic uncertainty). Drill cores from ODP Site 758 show the precise location of the MBGR. Below the MBGR are two distal tephra horizons that we have identified as products of two temporally distinct Old Toba Tuff (OTT) eruptions (layer d OTT1 and layer D OTT2). Continuous sedimentation between OTT1 (802.8 ± 0.7 ka, n = 100, MSWD 1.2) and OTT2 (796.2 ± 0.8 ka, n = 62, MSWD 1.3) allows for calculation of an accurate sedimentation rate and for extrapolation of an age from OTT2 to the MBGR. Data define an age for the MBGR of 795.2 ± 0.9 ka. Using tephra above the MBGR boundary, the Middle Toba Tuff (layer C) and Young Toba Tuff (layer A), extrapolation down core supports a MBGR age of c. 795 ka. Recent age data for BT sanidine reported relative to FCs at 28.172 Ma (767.4 ± 1.1 Ma) [7] oddly yielded an Ar/Ar age that was indistinguishable from the BT zircon U-Pb age [4], which is consistent with previous 40Ar/39Ar age measurements made relative to FCs at 28.02 Ma [3]. Thus we made a series of 40Ar/39Ar measurements on the exact same sample as used by Rivera et al. [7] and observed

  8. 40Ar/39Ar and U-Th-Pb dating of separated clasts from the Abee E4 chondrite (United States)

    Bogard, D.D.; Unruh, D.M.; Tatsumoto, M.


    Determinations of 40Ar/39Ar and U-Th-Pb are reported for three clasts from the Abee (E4) enstatite chondrite, which has been the object of extensive consortium investigations. The clasts give 40Ar/39Ar plateau ages and/or maximum ages of 4.5 Gy, whereas two of the clasts give average ages of 4.4 Gy. Within the range of 4.4-4.5 Gy these data do not resolve any possible age differences among the three clasts. 206Pb measured in these clasts is only ???1.5-2.5% radiogenic, which leads to relatively large uncertainties in the Pb isochron age and in the 207Pb/206Pb model ages. The Pb data indicate that the initial 207Pb/206Pb was no more than 0.08??0.07% higher than this ratio in Can??on Diablo troilite. The U-Th-Pb data are consistent with the interpretation that initial formation of these clasts occurred 4.58 Gy ago and that the clasts have since remained closed systems, but are contaminated with terrestrial Pb. The 40Ar/39Ar ages could be gas retention ages after clast formation or impact degassing ages. The thermal history of Abee deduced from Ar data appears consistent with that deduced from magnetic data, and suggests that various Abee components experienced separate histories until brecciation no later than 4.4 Gy ago, and experienced no appreciable subsequent heating. ?? 1983.

  9. The Thermo Scientific HELIX-SFT noble gas mass spectrometer: (preliminary) performance for 40Ar/39Ar geochronology (United States)

    Barfod, D. N.; Mark, D. F.; Morgan, L. E.; Tomkinson, T.; Stuart, F.; Imlach, J.; Hamilton, D.


    The Thermo Scientific HELIX-platform Split Flight Tube (HELIX-SFT) noble gas mass spectrometer is specifically designed for simultaneous collection of helium isotopes. The high mass spur houses a switchable 1011 - 1012 Ω resistor Faraday cup and the low mass spur a digital pulse-counting secondary electron multiplier (SEM). We have acquired the HELIX-SFT with the specific intention to measure argon isotopes for 40Ar/39Ar geochronology. This contribution will discuss preliminary performance (resolution, reproducibility, precision etc.) with respect to measuring argon isotope ratios for 40Ar/39Ar dating of geological materials. We anticipate the greatest impact for 40Ar/39Ar dating will be increased accuracy and precision, especially as we approach the techniques younger limit. Working with Thermo Scientific we have subtly modified the source, alpha and collector slits of the HELIX-SFT mass spectrometer to improve its resolution for resolving isobaric interferences at masses 36 to 40. The enhanced performance will allow for accurate and precise measurement of argon isotopes. Preliminary investigations show that we can obtain a valley resolution of >700 and >1300 (compared to standard HELIX-SFT specifications of >400 and >700) for the high and low mass spurs, respectively. The improvement allows for full resolution of hydrocarbons (C3+) at masses 37 - 40 and almost full resolution at mass 36. The HELIX-SFT will collect data in dual collection mode with 40Ar+ ion beams measured using the switchable 1011 - 1012 Ω resistor Faraday cup and 39Ar through 36Ar measured using the SEM. The HELIX-SFT requires Faraday-SEM inter-calibration but negates the necessity to inter-calibrate multiple electron multipliers. We will further present preliminary data from the dating of mineral standards: Alder Creek sanidine, Fish Canyon sanidine and Mount Dromedary biotite (GA1550).

  10. Single-crystal 40Ar/39Ar incremental heating reveals bimodal sanidine ages in the Bishop Tuff (United States)

    Andersen, N. L.; Jicha, B. R.; Singer, B. S.


    The 650 km3 Bishop Tuff (BT) is among the most studied volcanic deposits because it is an extensive marker bed deposited just after the Matuyama-Brunhes boundary. Reconstructions of the vast BT magma reservoir from which high-silica rhyolite erupted have long influenced thinking about how large silicic magma systems are assembled, crystallized, and mixed. Yet, the longevity of the high silica rhyolitic melt and exact timing of the eruption remain controversial due to recent conflicting 40Ar/39Ar sanidine vs. SIMS and ID-TIMS U-Pb zircon dates. We have undertaken 21 40Ar/39Ar incremental heating ages on 2 mm BT sanidine crystals from pumice in 3 widely separated outcrops of early-erupted fall and flow units. Plateau ages yield a bimodal distribution: a younger group has a mean of 766 ka and an older group gives a range between 772 and 782 ka. The younger population is concordant with the youngest ID-TIMS and SIMS U-Pb zircon ages recently published, as well as the astronomical age of BT in marine sediment. Of 21 crystals, 17 yield older, non-plateau, steps likely affected by excess Ar that would bias traditional 40Ar/39Ar total crystal fusion ages. The small spread in older sanidine ages, together with 25+ kyr of pre-eruptive zircon growth, suggest that the older sanidines are not partially outgassed xenocrysts. A bimodal 40Ar/39Ar age distribution implies that some fraction of rhyolitic melt cooled below the Ar closure temperature at least 10 ky prior to eruption. We propose that rapid "thawing" of a crystalline mush layer released older crystals into rhyolitic melt from which sanidine also nucleated and grew immediately prior to the eruption. High precision 40Ar/39Ar dating can thus provide essential information on thermo-physical processes at the millenial time scale that are critical to interpreting U-Pb zircon age distributions that are complicated by large uncertainties associated with zircon-melt U-Th systematics.

  11. RadNet Air Data From Little Rock, AR (United States)

    This page presents radiation air monitoring and air filter analysis data for Little Rock, AR from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  12. H- Beam Stripping Loss at Background Partial Pressure of Ar

    Institute of Scientific and Technical Information of China (English)

    Hu Chundong; Wang Shaohu; Hu Liqun


    It has been observed that H- current could be improved by adding Ar to H2 plasma.But due to a slower pumping speed for Ar with the existing pumping scheme, the tank pressure will increase quickly during the length of a beam pulse. Since H- stripping loss depends on the tank pressure and gas species, part of the H- beam can be converted to H0 and then H0 can be converted into H+ with background H2 and Ar gas thickness. Therefore, the H- beam current,measured by a Faraday cup, situated at a distance L from GG (ground grid), will decrease because it will be converted into a H+ current. This gives a ratio of the Faraday cup net current to the H- beam current before stripping at background partial pressure of Ar.

  13. AR Ser: photometric observations of a Blazhko star (United States)

    Bonnardeau, Michel; Hambsch, Franz-Josef


    Photometric observations in 2010-2014 of the RR Lyrae star AR Serpentis are presented and analysed. Two Blazhko modulations of comparable amplitude are detected, with the periods 89 and 108 days, and with evidence for irregularities.

  14. The emission spectra of Ar, Kr and Xe + TEA (United States)

    Suzuki, Masayo; Strock, Pierre; Sauli, Fabio; Charpak, Georges


    The emission spectra of Ar, Kr and Xe + 6% TEA gas mixtures are measured by using a single wire proportional counter as the emission source. Asymmetric emission bands are observed in the range of 270 to 350 nm, which can be attributed to the radiative deexcitation of excited TEA molecules. For the practical application of optical readout of avalanche chambers, the Ar + 2.0% TEA + 20% isobutane gas mixture is also examined, and nearly the same emission band is observed.

  15. Detrital mica 40Ar/39Ar dating approach for provenance and exhumation of the Eastern Alps. (United States)

    Gemignani, Lorenzo; Sun, Xilin; Van Gerve, Thomas; Braun, Jean; Wijbrans, Jan Robert


    The use of thermochronological techniques on detrital minerals, such as (U-Th)/He on apatite and zircon, zircon fission-tracks and Ar-dating on mica and microcline, can be used to constrain the lateral variation of the exhumation rate and the sediment provenance of large sectors of an actively deforming mountain belt. Analysis of modern river sands yields an inventory of ages of rocks currently cropping out and eroding in the hinterland of a river drainage basin. So far, only few studies have focused on testing the consistency of the detrital mineral age distributions and the surface bed-rock thermochronology. We present here new detrital 40Ar/39Ar biotite and muscovite age distributions for nineteen modern river sands from rivers draining the Eastern Alps north of the Periadriatic line. The ages, interpreted to reflect cooling of the source rock under the closure temperature of muscovite and biotite respectively, were compared with the in-situ ages for the bedrock in the hinterland from literature. The results were generally comparable with the bedrocks ages for both the target minerals and represent three main clusters of ages that record the main exhumation pulses in this sector of the Alps. We have applied two numerical methods to the cooling ages to a) quantify the rates of exhumation of the Tauern Window during Paleocene-Miocene period of the Alpine orogeny, b) linearly compute the spatial variability of the present-day exhumation rates of a set of 4 detrital mineral sample drainage basins along the Inn river stream. Our results suggest a 0.17-0.52 mm/yr range in exhumation rates for the Tauern Window since the Miocene. The results from modelling constrained the downstream evolution of the detrital signal in the Inn river and realistically predicts higher erosion rates in the downstream basin where young cooling ages from the Penninic units of the Tauern are drained into the system, forming a characteristic peak. Our data define more inclusive trends in

  16. Ars Moriendi: Coping with death in the Late Middle Ages. (United States)

    Espi Forcén, Fernando; Espi Forcén, Carlos


    The Ars moriendi was a book written in the early 15th century with the goal of assisting friars in their work of helping the dying. The aim of our study was to review the current literature on the Ars Moriendi concerning the field of medicine, to analyze the psychological mechanisms for coping with death anxiety within Ars Moriendi, and to explore parallels between the strategies used in the medieval book and in contemporary literature about death and dying. A review of literature using Pubmed, EMBASE, JSTOR, Project MUSE, and the New York Public Library was undertaken first. The primary source was then interpreted from a medical/psychological point of view. Seven articles were selected by literature review. These works comment on the importance of the Ars Moriendi in its historical context and explore the possibility of retrieving the principles of the text in contemporary society. The original text of Ars Moriendi, the primary source, presents death as a relief from the sufferings of earthly life and a gateway to eternal glory. According to the author, a good death implied the triumph over five demonic temptations in agonizing people: a lack of faith, despair, impatience, pride and greed. Analyzed from a modern psychiatric perspective, the Ars Moriendi offers descriptions of behavioral manifestations compatible with delirium, mood and anxiety disorders that characterize people with terminal illnesses. Moreover, we also explored parallels between the strategies used to cope with death anxiety in the Late Middle Ages and in contemporary society.

  17. Chemical studies of L chondrites. III - Mobile trace elements and Ar-40/Ar-39 ages (United States)

    Huston, T. J.; Lipschutz, M. E.


    Radiochemical neutron activation analysis has been used to determine the content of the mobile trace elements Ag, Au, Bi, Cd, Co, Cs, Ga, In, Rb, Se, Te, Tl, and Zn, in L4-6 chondrites with undisturbed Ar-40 release patterns or patterns showing some 4.4-4.6 Gyr plateau disturbance that indicates some shock-induced loss. The mean concentrations are significantly lower in 16 chondrites with disturbed patterns than in 4 with undisturbed ones, consistent with shock-induced mobilization. Significantly lower mean concentrations of nearly all trace elements in 26 strongly shocked chondrites than in 14 mildly shocked ones indicate loss in shock-formed FeS-Fe eutectic and/or by means of vaporization during cooling of shock-heated collisional debris.

  18. /sup 40/Ar-/sup 39/Ar dating of melt rock from impact craters

    Energy Technology Data Exchange (ETDEWEB)

    Bottomley, R.J.


    Meteorite impacts produce large volumes of shocked and brecciated rocks near the impact site. If the impact is large enough, target rocks will be fused to form melt rock which often pools on the crater floor. This melt rock will typically have a fine grained matrix enclosing heated but unmelted clasts of broken country rock. A suite of melt rocks from fifteen craters along with shocked rock from one crater and three tektites were analyzed by 40Ar-39Ar dating to study the argon systematics of melted and shocked rocks and to determine the time of impact which formed the craters. The age spectra from most of the melt rock samples turned out to be more complex than expected. The spectra could be classified into four families: 1) good plateaux; 2) structured plateaux; 3) stepwise rising spectra; and 4) snail shape spectra. In most cases an age based on one or both of these factors could be made of the non-plateau spectra. However the meaning of the resulting age is less certain than in the good plateaux cases. On the basis of their age, either of two Canadian craters, Wanapitei or Mistastin, could be comtemporaneous with the formation of the bediasites, raising the possibility that more than one impact was responsible for North American tektite strewnfield. In addition, there appears to be evidence that there was a higher than average incidence of impacts about 35 m.y. ago. During sample fusion, melt rocks release a greater proportion of their argon below 800/sup 0/C than do most terrestrial whole rocks.

  19. Non-Adiabatic Dynamics of ICN-(Ar)n and BrCN-(Ar)n (United States)

    Opoku-Agyeman, Bernice; McCoy, Anne B.


    We investigate the dynamics of the photodissociation of ICN-(Ar)n and BrCN-(Ar)n following electronic excitation to states that dissociate into X- + CN and X* + CN- (X = I or Br) using classical dynamics approaches. Observations made from previous experiments and calculations of these anions demonstrated that non-adiabatic effects are important in the photodissociation process and are reflected in the branching ratios of the photoproducts. The addition of an argon atom is expected to shift the relative energies of these excited states, thereby altering the product branching. Interestingly, experimental studies show that electronically exciting ICN- solvated with even a single argon atom leads to a small fraction of the products recombine to form ICN-.a In this study, the dynamics are carried out using classical mechanics, treating the non-adiabatic effect with a surface hopping algorithm. We assess the accuracy of this approach by first calculating the branching ratios for the bare anions and comparing the results to those from quantum dynamics calculations.a,b Once the results from both the quantum and classical dynamics are shown to be consistent, the classical dynamics simulations are extended to the argon solvated anions. S. Case, E. M. Miller, J. P. Martin, Y. J. Lu, L. Sheps, A. B. McCoy, and W. C. Lineberger, Angew. Chem., Int. Ed. 51, 2651 (2012). B. Opoku-Agyeman, A. S. Case, J. H. Lehman, W. Carl Lineberger and A. B. McCoy, J. Chem Phys. 141, 084305 (2014). J. C. Tully, J. Chem Phys. 93, 1061 (1990).

  20. Ar-Ar Analysis of Chelyabinsk: Evidence for a Recent Impact (United States)

    Beard, S. P.; Kring, D. A.; Isachsen, C. E.; Lapen, T. J.; Zolensky, M. E.; Swindle, T. D.


    The Chelyabinsk meteorite is an LL5 ordinary chondrite that fell as a spectacular fireball on February 15th, 2013, over the Ural region in Russia. The meteoroid exploded at an altitude of 25-30 km, producing shockwaves that broke windowpanes in Chelyabinsk and surrounding areas, injuring some 1500 people. Analyses of the samples show that the meteorite underwent moderate shock metamorphism (stage S4; 25-35 GPa) [1]. Most of the samples have a fusion crust ranging from 0.1-1mm thick, and roughly a third of the samples were composed of a dark fine-grained impact melt with chondrule fragments which were targeted for chronometry. A Pb-Pb age obtained by [2] of a shock-darkened and potentially melted sample of Chelyabinsk is reported as 4538.3 +/- 2.1 Ma, while a U-Pb study [3] gave an upper concordia intercept of 4454 +/- 67 Ma and a lower intercept of 585 +/- 390. Galimov et al. 2013 [1] suggest the Sm-Nd system records a recent impact event [290 Ma] that may represent separation from the parent body, while the Rb-Sr isotopic system is disturbed and does not give any definitive isochron. In order to better understand its history, we have performed 40Ar-39Ar analysis on multiple splits of two Chelyabinsk samples; clast- rich MB020f,2 and melt-rich MB020f,5. The term "clast-rich" lithology is meant to indicate a mechanical mixture of highly shock-darkened and less shocked components, both with some shock melt veining.

  1. Combined U-Th/He and 40Ar/39Ar geochronology of post-shield lavas from the Mauna Kea and Kohala volcanoes, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Aciego, S.M.; Jourdan, F.; DePaolo, D.J.; Kennedy, B.M.; Renne, P.R.; Sims, K.W.W.


    Late Quaternary, post-shield lavas from the Mauna Kea and Kohala volcanoes on the Big Island of Hawaii have been dated using the {sup 40}Ar/{sup 39}Ar and U-Th/He methods. The objective of the study is to compare the recently demonstrated U-Th/He age method, which uses basaltic olivine phenocrysts, with {sup 40}Ar/{sup 39}Ar ages measured on groundmass from the same samples. As a corollary, the age data also increase the precision of the chronology of volcanism on the Big Island. For the U-Th/He ages, U, Th and He concentrations and isotopes were measured to account for U-series disequilibrium and initial He. Single analyses U-Th/He ages for Hamakua lavas from Mauna Kea are 87 {+-} 40 ka to 119 {+-} 23 ka (2{sigma} uncertainties), which are in general equal to or younger than {sup 40}Ar/{sup 39}Ar ages. Basalt from the Polulu sequence on Kohala gives a U-Th/He age of 354 {+-} 54 ka and a {sup 40}Ar/{sup 39}Ar age of 450 {+-} 40 ka. All of the U-Th/He ages, and all but one spurious {sup 40}Ar/{sup 39}Ar ages conform to the previously proposed stratigraphy and published {sup 14}C and K-Ar ages. The ages also compare favorably to U-Th whole rock-olivine ages calculated from {sup 238}U - {sup 230}Th disequilibria. The U-Th/He and {sup 40}Ar/{sup 39}Ar results agree best where there is a relatively large amount of radiogenic {sup 40}Ar (>10%), and where the {sup 40}Ar/{sup 36}Ar intercept calculated from the Ar isochron diagram is close to the atmospheric value. In two cases, it is not clear why U-Th/He and {sup 40}Ar/{sup 39}Ar ages do not agree within uncertainty. U-Th/He and {sup 40}Ar/{sup 39}Ar results diverge the most on a low-K transitional tholeiitic basalt with abundant olivine. For the most alkalic basalts with negligible olivine phenocrysts, U-Th/He ages were unattainable while {sup 40}Ar/{sup 39}Ar results provide good precision even on ages as low as 19 {+-} 4 ka. Hence, the strengths and weaknesses of the U-Th/He and {sup 40}Ar/{sup 39}Ar methods are

  2. Combined U-Th/He and 40Ar/ 39Ar geochronology of post-shield lavas from the Mauna Kea and Kohala volcanoes, Hawaii (United States)

    Aciego, S. M.; Jourdan, F.; DePaolo, D. J.; Kennedy, B. M.; Renne, P. R.; Sims, K. W. W.


    Late Quaternary, post-shield lavas from the Mauna Kea and Kohala volcanoes on the Big Island of Hawaii have been dated using the 40Ar/ 39Ar and U-Th/He methods. The objective of the study is to compare the recently demonstrated U-Th/He age method, which uses basaltic olivine phenocrysts, with 40Ar/ 39Ar ages measured on groundmass from the same samples. As a corollary, the age data also increase the precision of the chronology of volcanism on the Big Island. For the U-Th/He ages, U, Th and He concentrations and isotopes were measured to account for U-series disequilibrium and initial He. Single analyses U-Th/He ages for Hamakua lavas from Mauna Kea are 87 ± 40 to 119 ± 23 ka (2 σ uncertainties), which are in general equal to or younger than 40Ar/ 39Ar ages. Basalt from the Polulu sequence on Kohala gives a U-Th/He age of 354 ± 54 ka and a 40Ar/ 39Ar age of 450 ± 40 ka. All of the U-Th/He ages, and all but one spurious 40Ar/ 39Ar ages conform to the previously proposed stratigraphy and published 14C and K-Ar ages. The ages also compare favorably to U-Th whole rock-olivine ages calculated from 238U- 230Th disequilibria. The U-Th/He and 40Ar/ 39Ar results agree best where there is a relatively large amount of radiogenic 40Ar (>10%), and where the 40Ar/ 36Ar intercept calculated from the Ar isochron diagram is close to the atmospheric value. In two cases, it is not clear why U-Th/He and 40Ar/ 39Ar ages do not agree within uncertainty. U-Th/He and 40Ar/ 39Ar results diverge the most on a low-K transitional tholeiitic basalt with abundant olivine. For the most alkalic basalts with negligible olivine phenocrysts, U-Th/He ages were unattainable while 40Ar/ 39Ar results provide good precision even on ages as low as 19 ± 4 ka. Hence, the strengths and weaknesses of the U-Th/He and 40Ar/ 39Ar methods are complimentary for basalts with ages of order 100-500 ka.

  3. 40Ar-39Ar age of a lava flow from the Bhimashankar Formation, Giravali Ghat, Deccan Traps

    Indian Academy of Sciences (India)

    Kanchan Pande; S K Pattanayak; K V Subbarao; P Navaneethakrishnan; T R Venkatesan


    We report here a 40Ar-39Ar age of 66.0 ± 0.9Ma (2 ) for a reversely magnetised tholeiitic lava flow from the Bhimashankar Formation (Fm.), Giravali Ghat, western Deccan province, India. This age is consistent with the view that the 1.8–2km thick bottom part of the exposed basalt flow sequence in the Western Ghats was extruded very close to 67.4 Ma.

  4. Exhumation history of the NW Indian Himalaya revealed by fission track and 40Ar/39Ar ages (United States)

    Schlup, M.; Steck, A.; Carter, A.; Cosca, M.; Epard, J.-L.; Hunziker, J.


    New fission track and Ar/Ar geochronological data provide time constraints on the exhumation history of the Himalayan nappes in the Mandi (Beas valley) - Tso Morari transect of the NW Indian Himalaya. Results from this and previous studies suggest that the SW-directed North Himalayan nappes were emplaced by detachment from the underthrusted upper Indian crust by 55. Ma and metamorphosed by ca. 48-40. Ma. The nappe stack was subsequently exhumed to shallow upper crustal depths (Elsevier Ltd.

  5. Exhumation history of the NW Indian Himalaya revealed by fission track and 40Ar/39Ar ages (United States)

    Schlup, Micha; Steck, Albrecht; Carter, Andrew; Cosca, Michael; Epard, Jean-Luc; Hunziker, Johannes


    New fission track and Ar/Ar geochronological data provide time constraints on the exhumation history of the Himalayan nappes in the Mandi (Beas valley) — Tso Morari transect of the NW Indian Himalaya. Results from this and previous studies suggest that the SW-directed North Himalayan nappes were emplaced by detachment from the underthrusted upper Indian crust by 55 Ma and metamorphosed by ca. 48–40 Ma. The nappe stack was subsequently exhumed to shallow upper crustal depths (

  6. The mass of sup 3 sup 2 Ar and sup 3 sup 3 Ar for fundamental tests

    CERN Document Server

    Blaum, K; Beck, D; Bollen, G; Herfurth, F; Kellerbauer, A G; Kluge, H J; Sauvan, E; Schwarz, S


    Masses of the short-lived radionuclides sup 3 sup 2 Ar (T sub 1 sub / sub 2 = 98 ms) sup 3 sup 3 Ar (T sub 1 sub / sub 2 = 173 ms) have been determined with the Penning trap mass spectrometer ISOLTRAP. Relative uncertainties of 6.0 x 10 sup - sup 8 (delta m = 1.8 keV) and 1.4 x 10 sup - sup 8 (delta m = 0.44 keV), respectively, have been achieved. At present, these new mass data serve as the most stringent test of the quadratic form of the isobaricmultiplet mass equation IMME. Furthermore, the improved accuracy for the mass of sup 3 sup 2 Ar yields a better constraint on scalar contributions to the weak interaction. New mass values have also been measured for sup 4 sup 4 Ar and sup 4 sup 5 Ar, and a 20 sigma deviation for sup 4 sup 4 Ar from the literature value was found and interpreted.

  7. Ar-40/Ar-39 Ages for Maskelynites and K-Rich Melt from Olivine-Rich Lithology in (Kanagawa) Zagami (United States)

    Park, J.; Herzog, G. F.; Nyquist, L. E.; Lindsay, F.; Turrin, B.; Swisher, C. C., III; Delaney, J. S.; Shih, C.-Y.; Niihara, T.; Misawa, K.


    We report Ar/Ar release patterns for small maskelynite grains and samples of a K-rich phase separated from the basaltic shergottite Zagami. The purpose of the work is to investigate the well-known discrepancy between published Ar/Ar ages of Zagami, >200 Ma, and its age of approx. 170 Ma as determined by other methods [1-6]. Niihara et al. [7] divide less abundant darker material present in Zagami into an olivine-rich lithology (ORL), from which most of our samples came, and a pyroxene-rich one (Dark Mottled-Lithology: DML) [8, 9]. ORL consists of vermicular fayalitic olivine, coarse-grained pyroxene, maskelynite, and a glassy phase exceptionally rich in K (up to 8.5 wt%), Al, and Si, but poor in Fe and Mg. The elemental composition suggests a late-stage melt, i.e., residual material that solidified late in a fractional crystallization sequence. Below we refer to it as "K-rich melt." The K-rich melt contains laths of captured olivine, Ca-rich pyroxene, plagioclase, and opaques. It seemed to offer an especially promising target for Ar-40/Ar-39 dating.

  8. Acoustic Resonance Spectroscopy (ARS) Munition Classification System enhancements. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vela, O.A.; Huggard, J.C.


    Acoustic Resonance Spectroscopy (ARS) is a non-destructive evaluation technology developed at the Los Alamos National Laboratory (LANL). This technology has resulted in three generations of instrumentation, funded by the Defense Special Weapons Agency (DSWA), specifically designed for field identification of chemical weapon (CW) munitions. Each generation of ARS instrumentation was developed with a specific user in mind. The ARS1OO was built for use by the U.N. Inspection Teams going into Iraq immediately after the Persian Gulf War. The ARS200 was built for use in the US-Russia Bilateral Chemical Weapons Treaty (the primary users for this system are the US Onsite Inspection Agency (OSIA) and their Russian counterparts). The ARS300 was built with the requirements of the Organization for the Prohibition of Chemical Weapons (OPCW) in mind. Each successive system is an improved version of the previous system based on learning the weaknesses of each and, coincidentally, on the fact that more time was available to do a requirements analysis and the necessary engineering development. The ARS300 is at a level of development that warrants transferring the technology to a commercial vendor. Since LANL will supply the computer software to the selected vendor, it is possible for LANL to continue to improve the decision algorithms, add features where necessary, and adjust the user interface before the final transfer occurs. This paper describes the current system, ARS system enhancements, and software enhancements. Appendices contain the Operations Manual (software Version 3.01), and two earlier reports on enhancements.

  9. Optical Emission Spectroscopic Studies of ICP Ar Plasma

    Institute of Scientific and Technical Information of China (English)

    QI Xuelian; REN Chunsheng; ZHANG Jian; MA Tengcai


    The ion line of 434.8 nm and atom line of 419.8 nm of Ar plasma produced by an inductively coupled plasma (ICP) were measured by optical emission spectroscopy and the influences from the working gas pressure, radio-frequency (RF) power and different positions in the discharge chamber on the line intensities were investigated in this study. It was found that the intensity of Ar atom line increased firstly and then saturated with the increase of the pressure. The line intensity of Ar+, on the other hand, reached a maximum value and then decreased along with the pressure. The intensity of the line in an RF discharge also demonstrated a jumping mode and a hysteresis phenomenon with the RF power. When the RF power increased to 400 W, the discharge jumped from the E-mode to the H-mode where the line intensity of Ar atom demonstrated a sudden increase, while the intensity of Ar+ ion only changed slightly. If the RF power decreased from a high value, e.g., 1000 W, the discharge would jump from the H-mode back to the E-mode at a power of 300 W. At this time the intensities of Ar and Ar+ lines would also decrease sharply. It was also noticed in this paper that the intensity of the ion line depended on the detective location in the chamber, namely at the bottom of the chamber the line was more intense than that in the middle of the chamber, but less intense than at the top, which is considered to be related to the capacitance coupling ability of the ICP plasma in different discharge areas.

  10. 40Ar/39Ar dating of the Honghuaqiao Formation in SE China (United States)

    Chang, S.; Zhang, H.; Hemming, S. R.; Mesko, G. T.; Fang, Y.


    The Jehol Biota, defined as the characteristic Eosestheria-Ephemeropsis-Lycoptera assemblage (Grabau, 1923, Bulletin of the Geological Survey of China), is widely distributed in eastern and central Asia (Li et al., 1982, Acta Geologica Sinica; Chen, 1988, Acta Palaeontologica Sinica). Abundant and varied fossils of the terrestrial Jehol Biota, including plants, insects, dinosaurs, birds, mammals, and freshwater invertebrates, have been discovered from the Dabeigou, the Yixian and the Jiufotang Formations (or their correlative strata) in northeast China from the Liaoning and Hebei Provinces and Inner Mongolia (Chen and Jin, 1999, Acta Palaeontologica Sinica). In addition, strata that may be correlative with the classic Jehol fossil-bearing formations have been identified extensively in central and eastern China, the Korean Peninsula, Mongolia, and Siberia. In the past three decades mollusk, conchostracan, ostracod, insect, fish, and plant fossils from localities in southeastern China, interpreted as related to the Jehol biota of the northeast, have been found (Mateer and Chen, 1986, Cretaceous Research; Li, 2003, Chinese Science Bulletin; Chen, Li and Batten, 2007, Geological Journal). However, a detailed correlation between the classic Jehol outcrops and the more recently found localities to the South and West has yet to emerge. Volcanic rocks from the Honghuaqiao fossil-bearing Formation in Tuzhou City of eastern Anhui Province, southeastern China provide an excellent opportunity to rectify this situation. Preliminary results of a pilot study suggest that the Honghuaqiao Formation is equivalent to the Longwanshan Formation of Anhui Province, southeastern China and the Yixian Formation, northeastern China (Chang et al., 2009, AGU abstract). Initial 40Ar/39Ar results indicate that conchostracans from the upper Honghuaqiao Formation are approximately 130 Ma. Our ongoing work aims to establish a high-resolution chronostratigraphy for Tuzhou City in Anhui Province

  11. {sup 40}Ar-{sup 39}Ar dating of terrestrial and exterrestrial materials. Basalts from the Japan Sea floor, Deccan Plateau and meteorites from Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Kaneoka, Ichiro [Tokyo Univ. (Japan). Earthquake Research Inst.; Takigami, Yutaka


    Through a series of {sup 40}Ar-{sup 39}Ar dating for terrestrial and exterrestrial samples, the results for basalts from the Japan Sea floor, Deccan Plateau and for meteorites from Antarctica give significant information concerning their formation histories. {sup 40}Ar-{sup 39}Ar ages of basalts from the Japan Sea floor give a constraint that the Japan Sea floor was formed at least 20 Ma. {sup 40}Ar-{sup 39}Ar ages for dyke samples from the Deccan Plateau indicate a possibility for the occurrence of a little younger ages than that of the main plateau formations by a few million years. Meteorites collected from Antarctica show some variable {sup 40}Ar-{sup 39}Ar ages reflecting their different thermal histories. (author).

  12. Multinucleon transfer reactions in the 40Ar+208Pb system (United States)

    Mijatović, T.; Szilner, S.; Corradi, L.; Montanari, D.; Pollarolo, G.; Fioretto, E.; Gadea, A.; Goasduff, A.; Malenica, D. Jelavić; Mǎrginean, N.; Milin, M.; Montagnoli, G.; Scarlassara, F.; Soić, N.; Stefanini, A. M.; Ur, C. A.; Valiente-Dobón, J. J.


    We measured multinucleon transfer reactions in the 40Ar+208Pb system at an energy close to the Coulomb barrier, by employing the PRISMA magnetic spectrometer. We extracted differential and total cross sections of the different transfer channels, with a careful investigation of the total kinetic energy loss distributions. Comparisons between different systems having the same 208Pb target and with projectiles going from neutron-poor to neutron-rich nuclei, i.e., 40Ca, 58Ni, and 40Ar, as well as between the data and GRAZING calculations have been carried out. The neutron-rich (stable) 40Ar beam allowed us to get access to the channels involving proton pickup, whose behavior in connection with the production of neutron-rich heavy partner has been outlined.

  13. Analysis of Intensity Fluctuations of SASE using the AR Model

    CERN Document Server

    Kato, Ryukou; Isoyama, Goro; Kashiwagi, Shigeru; Okamoto, C; Suemine, Shoji; Yamamoto, Tamotsu


    We are conducting experimental study on Self-Amplified Spontaneous Emission (SASE) in the far-infrared region using the L-band linac at the Institute of Scientific and Industrial Research (ISIR), Osaka University. The intensity of SASE fluctuates intrinsically because the number of coherent optical pulses generated in an electron bunch is limited. In the actual system, however, another factor producing intensity fluctuations also shows up, which is instability of the linac. Generally speaking, it is difficult to distinguish contributions of these two factors in measured intensity fluctuations. We have applied the autoregressive (AR) model, which is one of the techniques of statistical analysis, to exclude contributions of linac instability from measured data. In the AR model, the present data can be expressed with a linear combination of the past data plus white noise. In the analysis, contributions of the linac instability are identified with the AR model and can be subtracted from the measured data of SASE,...

  14. Effects of AR Antagonist on Myocardial α1-AR Density and VERP-D after Myocardial Infarction

    Institute of Scientific and Technical Information of China (English)

    Zhang Jingmin; Wu Wei; Fang Chang; Zhang Yan; Wang Jingfeng


    Objectives To investigate the effects of adrenergic receptor antagonist ( metoprolol or prazosin) on myocardial α1-AR density and the changes of ventricular effective refractory period dispersion (VERP-D) in rabbits after myocardial infarction.Methods twenty-four adult male New Zealand rabbits were divided into four groups at random: control group ( n = 6 ); MI with placebo group ( n = 6 ); MI with metoprolol group (n = 6 ) ; MI with prazosin group (n = 6 ). The rabbits received corresponding drugs for seven days, beginning at the first day after MI and myocardial α1-AR density were measured and meanwhile, myocardial β-AR was also measured.Results In the placebo group, the density of ventricular α1-AR was increased in comparison with control group ( α1 -AR in normal region 36.9 ± 0.2 vs 27.3 ±0.9 fmol mg-1 Pro-1 ,p <0.01; α1-AR in ischemic region 33.0±0.9 vs 26.6 ±0.4 fmol mg-1 pro-1 P <0.01). In the metoprolol group, it was also increased in comparison with control group( α1-AR in normal region 44.7 ±1.5 vs 27.3 ±0.9 fmol mg-1 pro-1 ,P <0.01; α1-AR in ischemic region 33.6 ± 0.5 vs 26.6 ± 0.4 fmol mg-1pro-1 , P < 0.01 ). Meanwhile the density of ventricular α1-AR in normal region in the metoprolol group was increased in comparison with placebo group (44.7 ±1.5 vs 36.9 ±0.2 fmol mg-1 pro-1,P<0.01). While it decreased in the prazosin group in comparison with control group ( α1-AR in normal region 22.5 ± 0.6 vs27.3 ±0.9 fmol mg-1pro-1 ,P <0.01; α1-AR in ischemic region 20.9 ±0.4 vs 26.6 ±0.4 fmol mg-1 pro-1,P <0.01 ). VERP-D was increased after MI(P <0.01 ).After treatment with metoprolol or prazosin, VERP-D was decreased ( P < 0.01 ). Conclusions After acute MI, α1-AR of ventricular myocardium was upregulated, which may be accompanied by its activitation.The density of myocardial α1-AR became upregulated more dramatically treated with metoprolol and downregulated with prazosin. When treated with metoprolol or prazosin

  15. A model for meteoritic and lunar 40Ar/39Ar age spectra: Addressing the conundrum of multi-activation energies (United States)

    Boehnke, P.; Harrison, T. Mark; Heizler, M. T.; Warren, P. H.


    Results of whole-rock 40Ar/39Ar step-heating analyses of extra-terrestrial materials have been used to constrain the timing of impacts in the inner solar system, solidification of the lunar magma ocean, and development of planetary magnetic fields. Despite the importance of understanding these events, the samples we have in hand are non-ideal due to mixed provenance, isotopic disturbances from potentially multiple heating episodes, and laboratory artifacts such as nuclear recoil. Although models to quantitatively assess multi-domain, diffusive 40Ar* loss have long been applied to terrestrial samples, their use on extra-terrestrial materials has been limited. Here we introduce a multi-activation energy, multi-diffusion domain model and apply it to 40Ar/39Ar temperature-cycling, step-heating data for meteoritic and lunar samples. We show that age spectra of extra-terrestrial materials, the Jilin chondrite (K-4) and Apollo 16 lunar breccia (67514 , 43), yielding seemingly non-ideal behavior commonly interpreted as either laboratory artifacts or localized shock heating of pyroxene, are meaningful and can be understood in context of the presence of multi-diffusion domains containing multiple activation energies. Internally consistent results from both the meteoritic and lunar samples reveal high-temperature/short duration thermal episodes we interpret as due to moderate shock heating.

  16. A Knock-in Reporter for a Novel AR-Targeted Therapy (United States)


    MK, Gursoy-Yuzugullu O, Xu C, Xu Y, Price BD. DNA double-strand breaks promote methylation of histone H3 on lysine 9 and transient formation of...carrying FLuc in the AR gene locus and thereby bicistronically co-expressing the reporter gene with AR under the control of the endogenous AR promoter and...AR gene under the control of the endogenous AR promoter and enhancer. Such a knock-in reporter can faithfully reproduce chemical responses of the

  17. Development of a low-level Ar-37 calibration standard

    CERN Document Server

    Williams, R M; Bowyer, T W; Day, A R; Fuller, E S; Haas, D A; Hayes, J C; Hoppe, E W; Humble, P H; Keillor, M E; LaFerriere, B D; Mace, E K; McIntyre, J I; Miley, H S; Myers, A W; Orrell, J L; Overman, C T; Panisko, M E; Seifert, A


    Argon-37 is an environmental signature of an underground nuclear explosion. Producing and quantifying low-level Ar-37 standards is an important step in the development of sensitive field measurement instruments. This paper describes progress at Pacific Northwest National Laboratory in developing a process to generate and quantify low-level Ar-37 standards, which can be used to calibrate sensitive field systems at activities consistent with soil background levels. This paper presents a discussion of the measurement analysis, along with assumptions and uncertainty estimates.

  18. Adsorption of Ar on a nonuniform MgO surface (United States)

    Hinman, D. C.; Halsey, G. D.


    Data are presented for the adsorption of Ar and N2 on a strongly heterogeneous MgO surface at 84 K and for Ar at a range of temperatures between 130 and 250 K. The high-temperature data are analyzed according to a model which separates the contributions to the potential into bulk and surface terms, providing a method for the determination of the surface area from parameters characteristic of the bulk material. A solid-gas energy parameter and parameters indicating the strength of the impurity sites are also evaluated.

  19. Interatomic scattering in energy dependent photoelectron spectra of Ar clusters

    Energy Technology Data Exchange (ETDEWEB)

    Patanen, M.; Benkoula, S.; Nicolas, C.; Goel, A. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Antonsson, E. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Physikalische und Theoretische Chemie Institut für Chemie und Biochemie, Fachbereich Biologie, Chemie, Pharmazie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin (Germany); Neville, J. J. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Department of Chemistry, University of New Brunswick, Fredericton, New Brunswick E3B 6E2 (Canada); Miron, C., E-mail: [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Extreme Light Infrastructure - Nuclear Physics (ELI-NP), ‘Horia Hulubei’ National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125 Măgurele, Jud. Ilfov (Romania)


    Soft X-ray photoelectron spectra of Ar 2p levels of atomic argon and argon clusters are recorded over an extended range of photon energies. The Ar 2p intensity ratios between atomic argon and clusters’ surface and bulk components reveal oscillations similar to photoelectron extended X-ray absorption fine structure signal (PEXAFS). We demonstrate here that this technique allows us to analyze separately the PEXAFS signals from surface and bulk sites of free-standing, neutral clusters, revealing a bond contraction at the surface.

  20. Axenfeld-Rieger syndrome (ARS): A review and case report.

    LENUS (Irish Health Repository)

    Waldron, Jennie M


    Axenfeld-Rieger syndrome (ARS) is a rare, autosomal dominant condition characterized by ocular, craniofacial, dental, and periumbilical abnormalities. Relatively little information exists on this syndrome within the dental literature despite the fact that midface hypoplasia and maxillary hypodontia are classical presenting features of this syndrome. This is a case report of a 7-year-old Caucasian female with ARS who presented with significant ocular and dental anomalies. She was also found to have osteopenia. Her dental condition is described, her immediate treatment is shown, and her long-term treatment needs are discussed.

  1. β-delayed Multi-particle Emission From 31Ar

    Institute of Scientific and Technical Information of China (English)

    A. A. Ciemny; J. Du´enas-Daz; V. Dunin; J. M. Espino; A. Estrade; F. Farinon; A. Fomichev; H. Geisse; A. Gorshkov; G. Kami´nski; O. Kiselev; C. Mazzocchi; R. Kn¨obe; S. Krupko; M. Kuich; Yu. A. Litvinov; G. Marquinez-Dur´an; I. Martel; I. Mukha; C. Nociforo; A. K. Ord´uz; S. Pietri; W. Dominik; A. Prochazka; A. M. S´anchez-Ben´ıtez; H. Simon; B. Sitar; R. Slepnev; M. Stanoiu; P. Strmen; I. Szarka; M. Takechi; Y. Tanaka; Z. Janas; H. Weick; J. S. Winfield; M. Pf¨utzner; M. Pomorski; L. Acosta; S. Baraeva; E. Casarejos


    The β+ decay of 31Ar was investigated in an experiment at the GSI-FRS spectrometer. The ions of interest have been produced in the fragmentation of a 36Ar beam at 880 MeV/nucleon and implanted in a time projection chamber with optical readout. In addition to β-delayed one and two proton emission, for the first time the emission ofβ-delayed 3 protons has been observed. The branching ratio for this decay mode is found to be (0.07 ± 0.02)%.

  2. 39Ar-40Ar Dating of Eucrites and Howardites and the Early Bombardment of the HED Parent Body (United States)

    Bogard, D. D.; Garrison, D. H.


    Eucrite and howardite meteorites are impact breccias from the HED parent body, which may have been the 520 km diameter asteroid 4 Vesta [1]. Using textural and compositional information on pyroxenes from individual clasts, [2] proposed a classification scheme based on the degree of thermal metamorphism exhibited by nearly all eucrites. In the highest grade, chemical zoning of pyroxenes has been erased and areas of impact melt sometimes have been produced. Thus, HED meteorites appear to be products of an early bombardment history of the inner portion of the main asteroid belt, just as most lunar highland rocks are products of early impact bombardment of the Moon. To determine the time period for major impacts on the HED parent body, we have measured ^39Ar-^40Ar ages for a large number of eucritic clasts from eucrites and howardites. All of these samples indicate partial to complete K-Ar chronometer resetting by several different impact events much more recent than eucrite crystallization times of ~4.45-4.55 Ga. For example, the ^39Ar- ^40Ar ages of paired eucrites Y-791186 and Y-792510 were essentially entirely reset 3.45 +- 0.05 Ga ago. A clast from Millbillillie gave a slightly older ^39Ar-^40Ar resetting age of 3.55 +- 0.02 Ga. (A similar degassing age of 3.5 +- 0.1 Ga was recently reported for Stannern [3]). Clast EET87531,21 gave a degassing age of 3.83 +- 0.05 Ga; clast EET82600 suggests an age of 3.89 +- 0.07 Ga; a clast from LEW85300 suggests a similar age to these. Several eucritic clasts gave ^39Ar-^40Ar degassing ages near 4.0 Ga. These include two clasts from EET87509 (,71 at 4.00 +- 0.05 Ga and ,74 at 3.93 +- 0.06 Ga), EET87509,24 (4.07 +- 0.02 Ga), Y-792769,68 (3.99 +- 0.04 Ga), and Y-790020,5 (4.03 +- 0.03 Ga). Clast and matrix samples from Y-75011 gave slightly different ages of 3.98 +- 0.03 Ga and 3.94 +- 0.04 Ga. Analyses of several additional eucritic clasts gave less well-defined ^39Ar-^40Ar release spectra that are consistent with this range in

  3. Transcriptional and posttranscriptional regulation of Bacillus sp. CDB3 arsenic-resistance operon ars1

    Directory of Open Access Journals (Sweden)

    Xuefei Yu


    Full Text Available Bacillus sp. CDB3 possesses a novel eight-gene ars cluster (ars1, arsRYCDATorf7orf8 with some unusual features in regard to expression regulation. This study demonstrated that the cluster is a single operon but can also produce a short three-gene arsRYC transcript. A hairpin structure formed by internal inverted repeats between arsC and arsD was shown to diminish the expression of the full operon, thereby probably acting as a transcription attenuator. A degradation product of the arsRYC transcript was also identified. Electrophoretic mobility shift analysis demonstrated that ArsR interacts with the ars1 promoter forming a protein-DNA complex that could be impaired by arsenite. However, no interaction was detected between ArsD and the ars1 promoter, suggesting that the CDB3 ArsD protein may not play a regulatory role. Compared to other ars gene clusters, regulation of the Bacillus sp. CDB3 ars1 operon is more complex. It represents another example of specific mRNA degradation in the transporter gene region and possibly the first case of attenuator-mediated regulation of ars operons.

  4. Thermal plasma properties for Ar-Al, Ar-Fe and Ar-Cu mixtures used in welding plasmas processes: I. Net emission coefficients at atmospheric pressure (United States)

    Cressault, Y.; Gleizes, A.


    This article is devoted to the calculation of the net emission coefficient (NEC) of Ar-Al, Ar-Fe and Ar-Cu mixtures at atmospheric pressure for arc welding processes. The results are given in data tables for temperatures between 3 kK and 30 kK, for five plasma thicknesses (0, 0.5, 1, 2, 5 mm) and ten concentrations of metallic vapours (pure gas, 0.01%, 0.1%, 1%, 5%, 10%, 25%, 50%, 75% and pure metal vapours in mass proportions). The results are in good agreement with most of the works published on the subject for such mixtures. They highlight the influence of three parameters on the radiation of the plasma: the NEC is directly related to temperature and inversely related to plasma radius and is highly sensitive to the presence of metal vapours. Finally, numerical data are supplied in tables in order to develop accurate computational modelling of welding arc and to estimate both qualitatively and quantitatively the influence of each metallic vapour on the size and on the shape of the weld pool.

  5. Alignment of Ar+ Ions Produced After Resonant Auger Decay of Ar* 2p5 3d Resonances (United States)

    Meyer, M.; Marquette, A.; Grum-Grzhimailo, A.; Flesch, R.; Rühl, E.

    Fluorescence spectra have been recorded in the wavelength region 300 nm fluo) 3d excitation of atomic Ar using monochromatic synchrotron light. The radiative emission is characterized by strong transitions from Ar+ 3p4 (1S, 1D, 3P) nl ionic states. It is mainly assigned to processes of the type 3p4 4d --> 3p4 4p and 3p4 4p --> 3p4 4s. In addition, we have analyzed the degree of polarization of the fluorescence lines and we have determined the alignment of the Ar+ ions, which are produced after the resonant Auger decay. In comparison to investigations based on photoelectron spectroscopy, the spectral analysis of the fluorescence provides complementary information about the electronic relaxation during the resonant Auger process and, in particular, it allows one to examine directly the remaining ion.

  6. Additional 40Ar- 39Ar dating of the basement and the alkaline volcanism of Gorringe Bank (Atlantic Ocean) (United States)

    Féraud, Gilbert; York, Derek; Mével, Catherine; Cornen, Guy; Hall, Chris M.; Auzende, Jean-Marie


    40Ar/ 39Ar step heating analyses are reported for a variety of samples from Gorringe Bank (Atlantic Ocean). Flat age spectra for two primary, igneous hornblendes of Gorringe (corresponding to an age of 143 Ma) show that the K-Ar ages obtained on these samples by Prichard and Mitchell [4] are evidently crystallization and not hybrid ages. This sustains the concept of an initiation age of 140 Ma [4] for Gorringe Bank. No support is found for Carpena's suggestion [7] that the formation of Gorringe Bank began 200 Ma ago. Secondary hornblendes from Ormonde seamount rocks appear to have formed shortly after the initiation of the Bank. Precise plateau ages on samples of two alkaline volcanics from Ormonde correspond to the older limit of the alkaline volcanism suggested by Féraud et al. [3,5].

  7. Characterization of the ars Gene Cluster from Extremely Arsenic-Resistant Microbacterium sp. Strain A33▿ † (United States)

    Achour-Rokbani, Asma; Cordi, Audrey; Poupin, Pascal; Bauda, Pascale; Billard, Patrick


    The arsenic resistance gene cluster of Microbacterium sp. A33 contains a novel pair of genes (arsTX) encoding a thioredoxin system that are cotranscribed with an unusual arsRC2 fusion gene, ACR3, and arsC1 in an operon divergent from arsC3. The whole ars gene cluster is required to complement an Escherichia coli ars mutant. ArsRC2 negatively regulates the expression of the pentacistronic operon. ArsC1 and ArsC3 are related to thioredoxin-dependent arsenate reductases; however, ArsC3 lacks the two distal catalytic cysteine residues of this class of enzymes. PMID:19966021

  8. Thermal History of the Felsite Unit, Geysers Geothermal Field, From Thermal Modeling of 40Ar/39Ar Incremental Heating Data

    Energy Technology Data Exchange (ETDEWEB)

    T. M. Harrison (U of California); G. B. Dalrymple (Oregon State U); J. B. Hulen (U of Utah); M. A. Lanphere; M. Grove; O. M. Lovera


    An Ar-40/Ar-39 and U-Pb study was performed of the Geysers plutonic complex of the Geysers Geothermal Field in California. Sixty-nine ion microprobe spot analyses of zircons from four granite samples from the plutonic complex that underlies the Geysers geothermal field yielded Pb-207/Pb-206 vs. U-238/Pb-206 concordia ages ranging from 1.13 {+-} 0.04 Ma to 1.25 {+-} 0.04 Ma. The U-Pb ages coincide closely with Ar-40/Ar-39 age spectrum plateau and ''terminal'' ages from coexisting K-feldspars and with the eruption ages of overlying volcanic rocks. The data indicate that the granite crystallized at 1.18 Ma and had cooled below 350 C by {approximately}0.9-1.0 Ma. Interpretation of the feldspar Ar-40/Ar-39 age data using multi-diffusion domain theory indicates that post-emplacement rapid cooling was succeeded either by slower cooling from 350-300 C between 1.0 and 0.4 Ma or transitory reheating to 300-350 C at about 0.4-0.6 Ma. Heat flow calculations constrained with K-feldspar thermal histories and the pre sent elevated regional heal flow anomaly demonstrate that appreciable heat input from sources external to the known Geysers plutonic complex is required to maintain the geothermal system. This requirement is satisfied by either a large, underlying, convecting magma chamber (now solidified) emplaced at 1.2 Ma or episodic intrusion of smaller bodies from 1.2-0.6 Ma.

  9. Late Paleozoic deformation and exhumation in the Sierras Pampeanas (Argentina): 40Ar/39Ar-feldspar dating constraints (United States)

    Löbens, Stefan; Oriolo, Sebastián; Benowitz, Jeff; Wemmer, Klaus; Layer, Paul; Siegesmund, Siegfried


    Systematic 40Ar/39Ar feldspar data obtained from the Sierras Pampeanas are presented, filling the gap between available high- (>~300 °C) and low-temperature (Pie de Palo regions, whereas the Sierras de San Luis and the Sierra de Comechingones regions record exhumation during the Carboniferous. Comparison between new and available data points to a Carboniferous tectonic event in the Sierras Pampeanas, which represents a key period to constrain the early evolution of the proto-Andean margin of Gondwana. This event was probably transtensional and played a major role during the evolution of the Paganzo Basin as well as during the emplacement of alkaline magmatism in the retroarc.

  10. Shock tube study of the reaction H plus O2 plus Ar yields HO2 plus Ar (United States)

    Jachimowski, C. J.; Houghton, W. M.


    Rate coefficient data for the recombination reaction H + 02 + Ar yields H02 + Ar have been determined from studies of lean hydrogen-oxygen mixtures behind incident shock waves over the temperature range of 948 to 1125 K. Hydroxyl radical concentration profiles were measured by ultraviolet absorption spectroscopy, and rate data were obtained through analysis of induction time and exponential growth parameter data. Analysis of the data yielded a rate coefficient which was generally lower than most of the more recent values obtained from shock tube studies. The effect of boundary layer formation on the conditions behind the shock was also examined and found to be negligible.

  11. Vector Magnetic Field Measurement of NOAA AR 10197

    Institute of Scientific and Technical Information of China (English)

    Hong-Fei Liang; Hai-Juan Zhao; Fu-Yuan Xiang


    A set of two-dimensional Stokes spectral data of NOAA AR 10197 obtained by the Solar Stokes Spectral Telescope (S3T) at the Yunnan Observatory are qualitatively analyzed.The three components of the vector magnetic field, the strength H, inclination γ and azimuth x, are derived. Based on the three components, we contour the distributions of the longitudinal magnetic field and transverse magnetic field. The active region (AR) has two different magnetic polarities apparent in the longitudinal magnetic map due to projection effect. There is a basic agreement on the longitudinal magnetic fields between the S3T and SOHO/MDI magnetograms, with a correlation coefficient ρBl = 0.911. The transverse magnetic field of the AR has a radial distribution from a center located in the southwest of the AR. It is also found that the transverse magnetic fields obtained by Huairou Solar Observing Station (HRSOS) have a similar radial distribution. The distributions of transverse magnetic field obtained by S3T and HRSOS have correlation coefficients, ρAzimu = 0.86 and ρBt = 0.883,in regard to the azimuthal angle and intensity.

  12. Pulsed electric field (PEF)research at USDA, ARS, ERRC (United States)

    This article summarizes the effects of pulsed electric fields on the microbiological safety and quality aspects of various liquid food matrices, obtained at USDA, ARS, Eastern Regional Research Center under CRIS Project No. 1935-41420-013-00D, Processing Intervention Technologies for Enhancing the S...

  13. Analizando las intenciones profundas del "Ars poetica" de Horacio

    Directory of Open Access Journals (Sweden)

    Óscar Velásquez


    Full Text Available El "Arte Poética" de Horacio ha sido interpretada muy diversamente, pero es conveniente tener en cuenta su estilo epistolar, que la distancia a la vez del tratado de tipo filosófico y de la libertad de la sátira. Se propone en este estudio que de todos modos el AP es una obra que se articula en base a una idea fundamental, a saber, la de "forma", de la que surgen los conceptos de 'materia temática' y 'acción', especialmente la épica y el drama. El amplio espacio, por otra parte, concedido al arte, como sería natural en una poética,se debería explicar por el hecho de que el "ars" es de un cierto modo la "forma" que da realidad al verdadero poeta. (Horace's "Ars Poetica" has been interpreted in many ways, but it is important to consider its epistolary style, which sets it apart from the philosophical essay and from the free-style satyre. This study proposes that "Ars Poetica" is articulated upon a fundamental notion, that of "form", from which the concepts of 'thematic matter' and 'action' emerge, especially epic and drama. The relevance given to art, on the other hand, is explained by the fact that "ars" is somehow the "form" that shapes the real poet.


    NARCIS (Netherlands)



    A canonical form for AR 2-D systems representations is introduced. This yields a method for computing the system trajectories by means of a line-by-line recursion, and displays some relevant information about the system structure such as the choice of inputs and initial conditions.

  15. Interacting with Visual Poems through AR-Based Digital Artwork (United States)

    Lin, Hao-Chiang Koong; Hsieh, Min-Chai; Liu, Eric Zhi-Feng; Chuang, Tsung-Yen


    In this study, an AR-based digital artwork called "Mind Log" was designed and evaluated. The augmented reality technique was employed to create digital artwork that would present interactive poems. A digital poem was generated via the interplay between a video film and a text-based poem. This artwork was created following a rigorous design flow,…

  16. Global properties of the white dwarf pulsar AR Scorpii

    CERN Document Server

    Franzon, B


    In view of the new recent observation and measurement of the fast-rotating and highly-magnetized white dwarf AR Sco \\cite{Marsh:2016uhc}, we determine bounds for its radius, magnetic fields, moment of inertia and gravitational wave (GW) emission by using observations of the luminosity, as well the rotation frequency $\

  17. Big data computing: Building a vision for ARS information management (United States)

    Improvements are needed within the ARS to increase scientific capacity and keep pace with new developments in computer technologies that support data acquisition and analysis. Enhancements in computing power and IT infrastructure are needed to provide scientists better access to high performance com...

  18. Professor Oberth and Dr. von Braun at ARS Banquet (United States)


    Dr. Wernher von Braun holds the coveted Hermarn Oberth award presented to him by Professor Oberth during the banquet hosted by the Alabama Section of the American Rocket Society (ARS), on October 19, 1961. The Oberth award was given for outstanding technical contributions to the field of astronautics or for the promotion and advancement of astronautical sciences.

  19. Electron Scattering by Ar Atoms in a Laser Field

    Institute of Scientific and Technical Information of China (English)

    ZHANG Sheng-Hai; QIAN Xing-Zhong; JIANG Yu-Hai; SUN Jin-Feng


    The differentialcross sections of electron-Ar atom scattering for free-free transition with one and two photons absorption in the presence of CO2 laser field is obtained by the second Born approximation, the direction of laser polarization being perpendicular to the change of electron momentum. Compared with the more recent available experimental data, the present results are very good.

  20. Mälestusi "Ars Fennica'st" / Eha Komissarov

    Index Scriptorium Estoniae

    Komissarov, Eha, 1947-


    Ars Fennica 2008. aasta nominentide Tea Mäkipää, Seppo Renvalli, Maria Dunckeri, Katrīna Neiburga (Läti) ja Mark Raidpere näitus Kumu Kunstimuuseumis 26. aprillini. Preemiaga pärjati Mark Raidpere ekspositsioon

  1. Ars Fennica - isikliku ja poliitilise vahel / Janar Ala

    Index Scriptorium Estoniae

    Ala, Janar, 1979-


    2008. aasta Ars Fennica kunstiauhinna kandidaatide tööde näitus Kumu Kunstimuuseumis kuni 26. aprillini. Läti kunstniku Katrina Neiburga, soomlaste Seppo Renvalli, Maria Dunckeri ja Tea Mäkipää ning Mark Raidpere näitusel eksponeeritud töödest

  2. Mälestusi "Ars Fennica'st" / Eha Komissarov

    Index Scriptorium Estoniae

    Komissarov, Eha, 1947-


    Ars Fennica 2008. aasta nominentide Tea Mäkipää, Seppo Renvalli, Maria Dunckeri, Katrīna Neiburga (Läti) ja Mark Raidpere näitus Kumu Kunstimuuseumis 26. aprillini. Preemiaga pärjati Mark Raidpere ekspositsioon

  3. Near-contact Binaries IZ Monocerotis and AR Draconis (United States)

    Yang, Yuan-Gui; Dai, Hai-Feng; Zhou, Zheng; Li, Qun


    We present multi-color photometric observations for two neglected near-contact binaries, IZ Mon (P=0\\_\\_AMP\\_\\_fd;77980) and AR Dra (P=0\\_\\_AMP\\_\\_fd;67584). By the aid of the updated W-D analysis code, the photometric solutions were deduced from the multi-color light curves (LCs). IZ Mon is a semi-detached binary with a mass ratio of q=0.388(+/- 0.002), while AR Dra is a detached star with a mass ratio of q=0.652(+/- 0.002). The asymmetric LCs of IZ Mon were modeled by a hot spot on the secondary’s surface, which may be attributed to mass transfer from the primary. Based on all collected eclipse times for two systems, we constructed their timing residual curves. The orbital period for IZ Mon may be continuously decreasing at a rate of {dP}/{dt}=-2.06(+/- 0.04) {days} {{yr}}-1, which may result from mass and angular momentum loss from the central system. For AR Dra, there exists a cyclic variation with a period of {P}3=104.9(+/- 2.9) {yr} due to light-time orbit effect via the presence of the third body, whose mass is more than 0.28(+/- 0.02) {M}⊙ . Finally, two near-contact binaries, IZ Mon and AR Dra, will evolve into contact binaries.

  4. Multi-particle emission in the decay of $^{31}$Ar

    CERN Document Server

    Koldste, G T; Borge, M.J.G.; Briz, J.A.; Carmona-Gallardo, M.; Fraile, L.M.; Fynbo, H.O.U.; Giovinazzo, J.; Grann, B.D.; Johansen, J.G.; Jokinen, A.; Jonson, B.; Kurturkian-Nieto, T.; Kusk, J.H.; Nilsson, T.; Perea, A.; Pesudo, V.; Picado, E.; Riisager, K.; Saastamoinen, A.; Tengblad, O.; Thomas, J.C.; Van de Walle, J.


    A multi-hit capacity setup was used to study the decay of the dripline nucleus 31Ar, produced at the ISOLDE facility at CERN. A spectroscopic analysis of the beta-delayed three-proton decay of 31Ar is presented for the first time together with a quantitative analysis of the beta-delayed two-proton-gamma-decay. A new method for determination of the spin of low-lying levels in the beta-proton-daughter 30S using proton-proton angular correlations is presented and used for the level at 5.2 MeV, which is found to be either a 3+ or 4+ level, with the data pointing towards the 3+. The half-life of 31Ar is found to be 15.1(3) ms. An improved analysis of the Fermi beta-strength gives a total measured branching for the beta-3p-decay of 3.60(44) %, which is lower than the theoretical value found to be 4.24(43) %. Finally the strongest gamma-transitions in the decay of 33Ar are shown including a line at 4734(3) keV associated to the decay of the IAS, which has not previously been identified.

  5. The ARS Culture Collection and Developments in Biotechnology (United States)

    The ARS Culture Collection (NRRL) has played a prominent role in the development of biotechnology since its founding in 1940 when the Northern Regional Research Laboratory opened. Early discoveries included selection of production strains for penicillin, dextran blood extender, xanthan gum and the v...

  6. Atom trap trace analysis of {sup 39}Ar

    Energy Technology Data Exchange (ETDEWEB)

    Welte, Joachim


    Detection of {sup 39}Ar in natural water samples can be employed for radiometric dating on a timescale of 50 to 1000 years before present. This experimental work comprises the setup of an atomic beam and trap apparatus that captures and detects {sup 39}Ar atoms by the laser-cooling technique ''Atom Trap Trace Analysis''. With this approach, the limitations of low-level counting, regarding sample size and measurement time, could be overcome. In the course of this work, the hyperfine structure spectrum of the cooling transition 1s{sub 5}-2p{sub 9} has been experimentally determined. A high intensity, optically collimated beam of slow metastable argon atoms has been set up and fluorescence detection of individual {sup 39}Ar atoms in a magneto-optical trap is realized. {sup 39}Ar count rates of 1 atom in about 4 hours have been achieved for atmospheric argon. Recent improvements further suggest that even higher count rates of 1 atom/hour are within reach.

  7. Loopedia, a Database for Loop Integrals arXiv

    CERN Document Server

    Bogner, C.; Hahn, T.; Heinrich, G.; Jones, S.P.; Kerner, M.; von Manteuffel, A.; Michel, M.; Panzer, E.; Papara, V.

    Loopedia is a new database at for information on Feynman integrals, intended to provide both bibliographic information as well as results made available by the community. Its bibliometry is complementary to that of SPIRES or arXiv in the sense that it admits searching for integrals by graph-theoretical objects, e.g. its topology.

  8. He-, Ne-, and Ar-phosgene intermolecular potential energy surfaces

    DEFF Research Database (Denmark)

    Munteanu, Cristian R.; Henriksen, Christian; Felker, Peter M.


    Using the CCSD(T) model, we evaluated the intermolecular potential energy surfaces of the He-, Ne-, and Ar-phosgene complexes. We considered a representative number of intermolecular geometries for which we calculated the corresponding interaction energies with the augmented (He complex) and double...

  9. Ars Fennica - isikliku ja poliitilise vahel / Janar Ala

    Index Scriptorium Estoniae

    Ala, Janar, 1979-


    2008. aasta Ars Fennica kunstiauhinna kandidaatide tööde näitus Kumu Kunstimuuseumis kuni 26. aprillini. Läti kunstniku Katrina Neiburga, soomlaste Seppo Renvalli, Maria Dunckeri ja Tea Mäkipää ning Mark Raidpere näitusel eksponeeritud töödest

  10. Electron impact ionization of Ar/sup 8 +/

    Energy Technology Data Exchange (ETDEWEB)

    Defrance, P.; Rachafi, S.; Jureta, J.; Meyer, F.; Chantrenne, S.


    Absolute electron impact ionization cross-sections have been measured for the Neon-like Ar/sup 8 +/ in the energy range from below the threshold for the metastable state to 2500 eV. No contribution of metastable states is observed. The results are well reproduced by the Distorted Wave Born Approximation. 12 refs., 1 fig.

  11. Behaviour of AR glass fibre for building structural applications

    Directory of Open Access Journals (Sweden)

    Miravete, A.


    Full Text Available The AR glass reinforcement fibres were designed to resist the alkalis from the concrete. This is the main reason for its utilisation as a short-fibre-reinforcement of mortar and concrete for the last decades. Originally, the AR glass fibre sizing was not compatible with synthetic resins, so that this type of reinforcement was applied exclusively to mortar and concrete matrices. Recently, due to the developments of sizing, which are compatible with synthetic resins, the AR- glass fibres may be used as reinforcement of organic matrix composite materials, broadening the range of structural applications. The mechanical properties of AR glass fibre and organic matrix composite materials will be studied in this paper. First, the behaviour of this material under stress corrosion will be analysed. Their mass loss will be compared to E, C, and boron free glass fibres. Second, an experimental study dealing with 3P test bending and short beam ofAR glass fibre/polyester will de described with the goal of obtaining their Young modulus and tensile and interlaminar shear strengths. Finally, these experimental results will be compared to E glass fibre/polyester and several conclusions about their structural applications will be drawn.

    El vidrio AR y su presentación en forma de fibras de refuerzo, fue diseñado para ser inerte a los álcalis de los cementos. Por este motivo se viene utilizando desde hace varias décadas como refuerzo de morteros y hormigones en forma de fibra corta. El ensimaje que estas fibras de vidrio de refuerzo A R presentaba en su origen no era compatible con resinas de tipo sintéticas, por lo que el refuerzo era exclusivo para cementos y hormigones fuera cual fuera la aplicación, formato o proceso productivo. Recientemente, gracias al desarrollo específico de ensimajes especiales acordes a las fibras de vidrio AR ha aparecido la misma tipología de vidrio AR como refuerzo en forma de fibra continua compatible con resinas sint

  12. Ar40/Ar39计时及西藏南部喜马拉雅期几个黑云母年龄的测定

    Institute of Scientific and Technical Information of China (English)

    戴橙谟; 洪阿实


    Five biotites of Himalayan Period from southern Xizang platean have been irradiated and determined using reactor No. 901 in Qinghua University as fast neutron source(neutron flux 1.17× 1013n/cm2·s, fast neutron - 25%, duration of irradiation 18 hours) and MMhb-1 hornblende from USA as standard. Most of the samples were also determined by Ar36 isotope dilation method, and good agreement has been obtained for the results between the two approaches. This shows that Ar40/Ar39 dating is capable to distinguish clearly the order of intrusion among the multiphase intrnsions with respect to the young granites of Himalayan Period. Powder sample of CaF2 and K2SO4 were irradiated and ratios of (Ar36/Ar37)Ca. and(Ar39/Ar37)Ca and (Ar40/Ar39)x have been measured, which are of the same magnitutc of order as reported from other reac-tors in the world. For the ZBH-2506 biotite standard of China, Ar40/Ar39 age (130.9--131.9my)agrees with the age of 131±2.6 my as determined by dilution method. Plateau age obtained by step-wise heating (131±0.8my) is similar with the data obtained from total fusion and dilution methods.

  13. Precision angle-resolved autoionization resonances in Ar and Ne

    Energy Technology Data Exchange (ETDEWEB)

    Berrah, N.; Langer, B.; Gorczyca, T.W. [Western Michigan Univ., Kalamazoo, MI (United States)] [and others


    Theoretical work has shown that the electron angular distribution and the shape of the autoionization resonances are crucial to the understanding of certain types of electron-electron correlation. Autoionization resonances in Ne (Ar) result from the decay of the excited discrete state Ne{sup *} 2s2p{sup 6} np (Ar{sup *} 3s3p{sup 6} np) into the continuum state Ne{sup +} 2s{sup 2}2p{sup 5} + e{sup {minus}} (ks,kd) (Ar{sup +} 3s{sup 2}3p{sup 5} + e{sup {minus}} (ks,kd)). Since the continuum can also be reached by direct photoionization, both paths add coherently, giving rise to interferences that produce the characteristic Beutler-Fano line shape. In this work, the authors report on quantitative angle-resolved electron spectrometry studies of (a) the Ne 2s{sup 2}2p{sup 6} {r_arrow} 2s2p{sup 6} np (n=3-5) autoionizing resonances and the 2s{sup 2}2p{sup 6} {r_arrow} 2p{sup 4}3s3p doubly excited resonance, (b) the Ar 3s{sup 2}3p{sup 6} {r_arrow} 3s3p{sup 6} np (n=4-9) autoionization resonances and extended R-matrix calculations of the angular-distribution parameters for both Ne and Ar measurements. Their results are compared with previous theoretical work by Taylor.

  14. The AR Sandbox: Augmented Reality in Geoscience Education (United States)

    Kreylos, O.; Kellogg, L. H.; Reed, S.; Hsi, S.; Yikilmaz, M. B.; Schladow, G.; Segale, H.; Chan, L.


    The AR Sandbox is a combination of a physical box full of sand, a 3D (depth) camera such as a Microsoft Kinect, a data projector, and a computer running open-source software, creating a responsive and interactive system to teach geoscience concepts in formal or informal contexts. As one or more users shape the sand surface to create planes, hills, or valleys, the 3D camera scans the surface in real-time, the software creates a dynamic topographic map including elevation color maps and contour lines, and the projector projects that map back onto the sand surface such that real and projected features match exactly. In addition, users can add virtual water to the sandbox, which realistically flows over the real surface driven by a real-time fluid flow simulation. The AR Sandbox can teach basic geographic and hydrologic skills and concepts such as reading topographic maps, interpreting contour lines, formation of watersheds, flooding, or surface wave propagation in a hands-on and explorative manner. AR Sandbox installations in more than 150 institutions have shown high audience engagement and long dwell times of often 20 minutes and more. In a more formal context, the AR Sandbox can be used in field trip preparation, and can teach advanced geoscience skills such as extrapolating 3D sub-surface shapes from surface expression, via advanced software features such as the ability to load digital models of real landscapes and guiding users towards recreating them in the sandbox. Blueprints, installation instructions, and the open-source AR Sandbox software package are available at .

  15. 40Ar/39Ar geochronological constraints on syn-orogenic strike-slip movement of Tan-Lu fault zone

    Institute of Scientific and Technical Information of China (English)

    ZHU Guang; LIU Guosheng; W. J. Dunlap; C. Teyssier; WANG Yongsheng; NIU Manlan


    Two phases of sinistral strike-slip ductile shear belts occur on the eastern margin of the Dabie orogenic belt.A muscovite 40Ar/39Ar plateau age of 128 Ma was obtained from mylonite in the later ductile shear zone. Three muscovite samples separated from mylonites of 3 localities in the earlier ductile shear belts yield 40Ar/39Ar plateau ages of 192.5±0.7 Ma, 189.7±0.6 Ma and 188.7±0.7 Ma, respectively. They are interpreted as cooling ages of the earlier sinistrai strike-slip deformation. It is suggested that left-lateral displacement of the Tan-Lu fault zone started in a late stage of the collision orogeny in the Dabie-Sulu orogenic belt between the North and South China plates. Therefore, the earlier Tan-Lu fault zone was syn-orogenic strike-slip tectonics.The fault zone was used again for sinistral displacement during tectonic activities of peri-Pacific regime in Early Cretaceous. It is proposed that the fault zone occurred as a transform fault during the orogenic process.

  16. ISEA reversed event in the Cretaceous Normal Superchron (CNS):40Ar/39Ar dating and paleomagnetic results

    Institute of Scientific and Technical Information of China (English)

    SHI Ruiping; HE Huaiyu; ZHU Rixiang; PAN Yongxin


    In order to provide the age for the ISEA (one reversed event in the CNS) a combined rock magnetic, paleomagnetic and geochronologic study has been conducted on two Cretaceous andesitic basalt lava flows from Sanbaoying, Liaoning Province of northeastern China. Rock magnetic investigations show that pseudo-single domain (PSD) titanomagnetite with poor-Ti content is the dominant magnetic mineral in Sanbaoying lava flows. Detailed systematic thermal demagnetization allowed us to isolate two remanence components after removing a low temperature component at 100℃/150℃; an intermediate temperature component with normal polarity at 150℃/200℃-380℃/400℃ and the characteristic remanence component (ChRM) with reversed polarity above 400℃/450℃. 40Ar/39Ar dating results show that Sanbaoying rocks were erupted at 116.0±0.3 Ma. Combination of paleomagnetic results and 40Ar/39Ar dating indicates that the reversed event recorded in Sanbaoying lavas corresponds to the ISEA event in the CNS. Our age determination for ISEA reversed event provides chronological evidence to study the relevance between global geological events that occurred in the CNS and geodynamo processes.

  17. Ar-Ar geochronology of Late Mesozoic volcanic rocks from the Yanji area,NE China and tectonic implications

    Institute of Scientific and Technical Information of China (English)

    LI ChaoWen; GUO Feng; FAN WeiMing; GAO XiaoFeng


    Ar-Ar dating results of late Mesozoic-Cenozoic volcanic rocks from the Yanji area, NE China provide a new volcano-sedimentary stratigraphic framework. The previously defined "Triassic-Jurassic" volcanic rocks(including those from Sanxianling, Tuntianying, Tianqiaoling and Jingouling Fms.)were erupted during 118-106Ma,corresponding to Early Cretaceous. The new eruption age span is slightly younger than the main stage(130-120 Ma)of the extensive magmatism in the eastern Central Asian Orogenic Belt and its adjacent regions. Subduction-related adakites occurring in the previously defined Quanshuicun Fm. Were extruded at ca.55 Ma. Based on these new Ar-Ar ages, the late Mesozoic to Palaeocene volcano-sedimentary sequences is rebuilt as:Tuopangou Fm., Sanxianling/Tuntianying Fm.(118-115 Ma),Malugou/Tianqiaoling Fm.(K1),Huoshanyan/Jingouling Fm.(108-106 Ma),Changcai Fm.(K2),Quanshuicun Fm.(~55 Ma)and Dalazi Fm. Our results suggest that subduction of the Palaeo-Pacific Ocean beneath the East Asian continental margin occurred during 106to 55 Ma. Consistent with the paleomagnetic observations and magmatic records which indicated that the Izanagi-Farallon ridge subduction beneath the southwestern Japan took place during 95-65 Ma.

  18. Ar-Ar geochronology of Late Mesozoic volcanic rocks from the Yanji area, NE China and tectonic implications

    Institute of Scientific and Technical Information of China (English)


    Ar-Ar dating results of late Mesozoic-Cenozoic volcanic rocks from the Yanji area, NE China provide a new volcano-sedimentary stratigraphic framework. The previously defined “Triassic-Jurassic” volcanic rocks (including those from Sanxianling, Tuntianying, Tianqiaoling and Jingouling Fms.) were erupted during 118―106 Ma, corresponding to Early Cretaceous. The new eruption age span is slightly younger than the main stage (130―120 Ma) of the extensive magmatism in the eastern Central Asian Orogenic Belt and its adjacent regions. Subduction-related adakites occurring in the previously defined Quanshuicun Fm. were extruded at ca. 55 Ma. Based on these new Ar-Ar ages, the late Mesozoic to Palaeocene volcano-sedimentary sequences is rebuilt as: Tuopangou Fm., Sanxianling/Tuntianying Fm. (118―115 Ma), Malugou/Tianqiaoling Fm. (K1), Huoshanyan/Jingouling Fm. (108―106 Ma), Changcai Fm. (K2), Quanshuicun Fm. (~55 Ma) and Dalazi Fm. Our results suggest that subduction of the Pa- laeo-Pacific Ocean beneath the East Asian continental margin occurred during 106 to 55 Ma, consistent with the paleomagnetic observations and magmatic records which indicated that the Izanagi-Farallon ridge subduction beneath the southwestern Japan took place during 95―65 Ma.

  19. 40Ar 39Ar Ages and tectonic setting of ophiolite from the Neyriz area, southeast Zagros Range, Iran (United States)

    Lanphere, M.A.; Pamic, J.


    An ophiolite, considered to be an allochthonous fragment of Tethyan oceanic crust and mantle, crops out near Neyriz in the Zagros Range, Iran. 40Ar 39Ar ages ranging from 76.8 ?? 23.8 Ma to 105 ?? 23.3 Ma were measured on hornblende from five samples of plagiogranite and diabase from the ophiolite. The most precise ages are 85.9 ?? 3.8 Ma for a diabase and 83.6 ?? 8.4 Ma for a plagiogranite. The weighted mean age of hornblende from the five samples is 87.5 ?? 7.2 Ma which indicates that the igneous part of the Neyriz ophiolite formed during the early part of the Late Cretaceous. Pargasite from amphibolite below peridotite of the Neyriz ophiolite has a 40Ar 39Ar age of 94.9 ?? 7.6 Ma. The pargasite age agrees within analytical uncertainty with the ages measured on diabase and plagiogranite. Comparable ages have been measured on igneous rocks from the Samail ophiolite of Oman and on amphibolite below peridotite of the Samail ophiolite. ?? 1983.

  20. Geochemistry and 40Ar/39Ar age of Early Carboniferous dolerite sills in the southern Baltic Sea

    Directory of Open Access Journals (Sweden)

    Gediminas Motuza


    Full Text Available The Early Carboniferous magmatic event in the southern Baltic Sea is manifested by dolerite intrusions. The presumable area in which the dolerite intrusions occur ranges from 30 to 60 km in east–west direction, and is about 100 km in north–south direction. The dolerites were sampled in well D1-1 and investigated by applying chemical analysis and 40Ar/39Ar step-heating dating. Dolerites are classified as alkali and sodic, characterized by high TiO2 (3.92, 3.99 wt% and P2O5 (1.67, 1.77 wt% and low MgO (4.89, 4.91 wt% concentrations, enriched in light rare earth elements, originated from an enriched mantle magma source and emplaced in a continental rift tectonic setting. The 351 ± 11 Ma 40Ar/39Ar plateau age for groundmass plagioclase indicates a considerable age gap with the 310–250 Ma magmatism in southern Scandinavia and northern Germany. The magmatic rocks in the Baltic Sedimentary Basin are coeval with alkaline intrusions of NE Poland. Both magmatic provinces lie in the northwestward prolongation of the Pripyat–Dnieper–Donetsk Rift (370–359 Ma and may constitute a later phase of magmatic activity of this propagating rift system.

  1. 40Ar/ 39Ar mineral ages from the Oki metamorphic complex, Oki-Dogo, southwest Japan: implications for regional correlations (United States)

    Dallmeyer, R. D.; Takasu, A.


    The Oki metamorphic complex exposed in the Oki-Dogo islands consists predominantly of psammitic and pelitic gneisses with subordinate amphibolite and rare calcareous gneiss. The Oki gneisses were regionally metamorphosed to general amphibolite facies conditions, with local development of granulite facies assemblages. Peak metamorphic conditions of c. 800°C have been suggested. Hornblende concentrates from amphibolites collected within the Oki metamorphic complex record 40Ar/ 39Ar isotope correlation ages of 199-192 Ma. These are interpreted to date the post metamorphic cooling through temperatures required for intracrystalline retention of argon (c. 500°C). Muscovite concentrates record 40Ar/ 39Ar plateau ages of 167-168 Ma. These are interpreted to date post metamorphic cooling through appropriate closure temperature of muscovite (c. 400-375°C). Combined with the previously reported geochronological data, the Oki metamorphic complex appears to have experienced peak metamorphic conditions at c. 250 Ma. Subsequently, it cooled and was exhumed at the earth's surface at c. 90 Ma with cooling rate of c. 5°C/Ma. The Oki metamorphic complex records a similar prograde metamorphic event as the Hida metamorphic complex exposed in central Japan. The cooling and exhumation rates of the Hida metamorphic complex were significantly more rapid compared with the Oki metamorphic complex, and they were exhumed with extensively intruded Jurassic granites (Funatsu granites).

  2. 40Ar/ 39Ar ages for the alkaline volcanism and the basement of Gorringe Bank, North Atlantic ocean (United States)

    Féraud, Gilbert; Gastaud, Janine; Auzende, Jean-Marie; Olivet, Jean-Louis; Cornen, Guy


    Gorringe Bank is situated on the Europe-Africa plate boundary at the eastern end of the Azores-Gibraltar fracture zone. It has two summits, Gettysburg Bank to the Southwest and Ormonde Bank to the northeast. We applied the 40Ar/ 39Ar stepwise heating method to date six samples of the alkaline volcanic rocks, two gabbros from the Ormonde Bank and a dolerite from the Gettysburg Bank. The results that the alkaline volcanism lasted probably for less than 6 Ma(66-60 Ma). Although the nature of this volcanism precludes any subduction feature during its setting, the alkaline volcanism of Ormonde is probably linked to Upper Cretaceous/Eocene compressive tectonic events. The basement rocks of Gorringe Bank reveal distrubed 40Ar/ 39Ar age spectra. One plagioclase and one biotite from a gabbro give evidence for a thermic event whose age is tentatively estimated at about 75 Ma, and related to a variation in the direction of the relative movement between Europe and Africa. The more probable age given by a plagioclase of another gabbro and by a dolerite (110 Ma) corresponds to tilting northeastward of the Gorringe massif.

  3. Langmuir Probe Measurements of Inductively Coupled CHF3/Ar and Ar/CHF3/O2 Plasmas (United States)

    Sharma, S. P.; Rao, M. V. V. S.; Meyyappan, M.


    Plasma parameters, such as, electron number density (ne), electron temperature (Te), y electron energy distribution function (EEDF), mean electron energy (Ee), ion number density (ni), and plasma potential (Vp), have been measured by using Langmuir probe in low-pressure (10-50 mTorr) inductively coupled CHF3/Ar and CHF3/Ar/O2 plasmas generated in the GEC cell. The measurements were made at the center of the plasma, keeping the lower electrode grounded, for various CHF3/Ar and Ar/CHF3/O2 mixtures operating at 10-50 mTorr pressures and two input RF power levels, 200 and 300 W. EEDF data show a strong Druyvesteyn distribution with relatively lower number of low energy electrons as compared to a Maxwell distribution and a large electron population with energies higher than the plasma potential. The results further show that at low CHF3 concentrations (less than 50%) the electron number density remains nearly constant with increase in pressure. At higher CHF3 concentrations, however, it decreases with increase in pressure. Plasma potential and electron temperature increase with decrease in pressure and with increase in CHF3 concentration. An analysis of the above observations and mechanisms will be presented.

  4. Yolcu Gemisi Pis Su Arıtım Standartları ve Arıtma Sistemleri

    Directory of Open Access Journals (Sweden)

    Volkan Şahin


    Full Text Available Yolcu gemisi sektörü, dünya turizminde payı en yüksek olan sektörlerden bir tanesidir. Hızla büyüyen bu sektör, yolcu gemilerini yüzer şehirler haline dönüştürmüştür. Dev yolcu gemileri gerek binlerce yolcusunun ürettiği gerekse de operasyonu sırasında oluşturduğu atıklar bakımından denizlerimiz için ciddi bir tehdit haline gelmiştir. 3000 – 4000 yolcu kapasiteli bu yüzer şehirlerin diğer yük gemileriyle karşılaştırıldıklarında önemli miktarda pis su boşaltımı yaptıkları görülmektedir. Oluşan pis suyun arıtım ve boşaltım prosedürleri MARPOL ve EPA gibi önemli kuruluşlar tarafından düzenlenmekte ve denetlenmektedir. Bu çalışmada pis su arıtım sistemlerinin tipleri, çalışma prensipleri, arıtılmış atığın ulusal ve uluslararası kuruluşlar tarafından belirlenen standartlara uygunluğu ve denetim kuruluşlarının boşaltım standartları incelenerek karşılaştırılmıştır. Pis su arıtımında özellikle yolcu gemilerinde kullanılan MSDs (Klasik Arıtma Sistemleri ve AWTs (Gelişmiş Atık Su Arıtma Sistemleri sistemlerinin pis su içeriğinde bulunan patojen, nütrient, kimyasal bileşenler ve ağır metal gibi zararlı bileşenleri arıtma yöntemleri hakkında bilgiler verilmiştir. Bu sistemlerin verimleri birbirleriyle karşılaştırılarak, uluslararası pis su boşaltım kurallarına uygunluğu incelenmiştir. MSD ve AWT sistemleri, arıtım prosedürleri ve arıttıkları atık suyun konsantrasyonları açısından karşılaştırıldıklarında, AWT sistemlerinin, MSD sistemlerine göre daha yüksek ve kaliteli şekilde arıtım yaptığı görülmüştür. Özellikle Alaska sularına yapılan boşaltımları denetleyen EPA’nın, diğer uluslararası kurallara göre daha sıkı olan standartları, özellikle yolcu gemilerinde MSD sisteminden, AWT sistemine geçişi kaçınılmaz hale getirmiştir.

  5. Crater Retention Ages from (4) Vesta Matching Independent Ar-Ar Ages of HED Meteorites (United States)

    Schmedemann, Nico; Kneissl, Thomas; Ivanov, Boris A.; Michael, Gregory G.; Neukum, Gerhard; Nathues, Andreas; Sierks, Holger; Wagner, Roland; Krohn, Katrin; Le Corre, Lucille; Reddy, Vishnu; Ruesch, Ottaviano; Hiesinger, Harald; Jaumann, Ralf; Raymond, Carol A.; Russell, Christopher T.


    .054/-0.087) Ga and 3.63 (+0.058/-0.096) Ga. We also find seismic (miniscule ejecta blanket from Rheasilvia) resurfacing events in the time frame of ~3.56 to ~3.59 Ga at several areas in the northern hemisphere, indicative for a major seismic activity probably connected to the Rheasilvia formation. An antipodal activity is also suggested by hydrocode modeling [9]. By summation of age probability curves of measurements we link to the Rheasilvia formation, we find 3.58 (+0.07/-0.12) Ga. Using a similar attempt we find 3.75 (+0.05/-0.21) Ga for the Veneneia formation. Both crater retention ages correspond within the error bars with prominent peaks of independent Ar-Ar ages of Vesta related HED meteorites [10]. Acknowledgement: This work has been supported by the German Space Agency (DLR) on behalf of the Federal Ministry of Economics and Technology, grants 50OW1101(NS,TK), 50QM1001 (GM) and 50OW1102 (OR,HH). References: [1] Russell et al. (2007): Advances in Space Research 40(2): pp193-201, 2007. [2] Neukum and Ivanov: In: Gehrels T (ed) "Hazards due to comets and asteroids". University of Arizona Press, Tucson, 359-416, 1994. [3] O'Brien and Greenberg (2005): Icarus 178(1): 179-212. [4] Nesvorny et al. (2009): Icarus 200(2): 698-701. [5] Ivanov (2001): Chronology and Evolution of Mars 96, 87-104, 2001. [6] Schmedemann et al. (2012): 43.LPSC, The Woodlands, #1659. [7] Morbidelli et al. (2003): Icarus 162, 328-336. [8] Marchi et al. (2012): Science 336, 690. [9] Bowling et al. (2012): 75th Annual Meeting of the Meteoritical Society, 2012, Cairns, Australia. Meteoritics and Planetary Science Supplement, id.5256. [10] Bogard, D. D. (2011): Chemie der Erde - Geochemistry, vol. 71, issue 3: 207-226.

  6. 40Ar/39Ar geochronology, paleomagnetism, and evolution of the Boring volcanic field, Oregon and Washington, USA (United States)

    Fleck, Robert J.; Hagstrum, Jonathan T.; Calvert, Andrew T.; Evarts, Russell C.; Conrey, Richard M.


    The 40Ar/39Ar investigations of a large suite of fine-grained basaltic rocks of the Boring volcanic field (BVF), Oregon and Washington (USA), yielded two primary results. (1) Using age control from paleomagnetic polarity, stratigraphy, and available plateau ages, 40Ar/39Ar recoil model ages are defined that provide reliable age results in the absence of an age plateau, even in cases of significant Ar redistribution. (2) Grouping of eruptive ages either by period of activity or by composition defines a broadly northward progression of BVF volcanism during latest Pliocene and Pleistocene time that reflects rates consistent with regional plate movements. Based on the frequency distribution of measured ages, periods of greatest volcanic activity within the BVF occurred 2.7–2.2 Ma, 1.7–0.5 Ma, and 350–50 ka. Grouped by eruptive episode, geographic distributions of samples define a series of northeast-southwest–trending strips whose centers migrate from south-southeast to north-northwest at an average rate of 9.3 ± 1.6 mm/yr. Volcanic activity in the western part of the BVF migrated more rapidly than that to the east, causing trends of eruptive episodes to progress in an irregular, clockwise sense. The K2O and CaO values of dated samples exhibit well-defined temporal trends, decreasing and increasing, respectively, with age of eruption. Divided into two groups by K2O, the centers of these two distributions define a northward migration rate similar to that determined from eruptive age groups. This age and compositional migration rate of Boring volcanism is similar to the clockwise rotation rate of the Oregon Coast Range with respect to North America, and might reflect localized extension on the trailing edge of that rotating crustal block.

  7. Huntingtin-associated protein 1 (HAP1) interacts with androgen receptor (AR) and suppresses SBMA-mutant-AR-induced apoptosis. (United States)

    Takeshita, Yukio; Fujinaga, Ryutaro; Zhao, Changjiu; Yanai, Akie; Shinoda, Koh


    Huntingtin-associated protein 1 (HAP1), an interactor of huntingtin, has been known as an essential component of the stigmoid body (STB) and recently reported to play a protective role against neurodegeneration in Huntington's disease (HD). In the present study, subcellular association between HAP1 and androgen receptor (AR) with a long polyglutamine tract (polyQ) derived from spinal-and-bulbar-muscular-atrophy (SBMA) was examined using HEp-2 cells cotransfected with HAP1 and/or normal ARQ25, SBMA-mutant ARQ65 or deletion-mutant AR cDNAs. The results provided the first clear evidence that HAP1 interacts with AR through its ligand-binding domain in a polyQ-length-dependent manner and forms prominent inclusions sequestering polyQ-AR, and that addition of dihydrotestosterone reduces the association strength of HAP1 with ARQ25 more dramatically than that with ARQ65. Furthermore, SBMA-mutant-ARQ65-induced apoptosis was suppressed by cotransfection with HAP1. Our findings strongly suggest that HAP1/STB is relevant to polyQ-length-dependent modification on subcellular AR functions and critically involved in pathogenesis of not only HD but also SBMA as an important intrinsic neuroprotectant determining the threshold for cellular vulnerability to apoptosis. Taking together with previous reports that HAP1/STB is selectively expressed in the brain regions spared from degenerative targets in HD and SBMA, the current study might explain the region-specific occurrence of neurodegeneration in both diseases, shedding light on common aspects of their molecular pathological mechanism and yet-to-be-uncovered diagnostic or therapeutic applications for HD and SBMA patients.

  8. Development of a Low-Level Ar-37 Calibration Standard

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Richard M.; Aalseth, Craig E.; Bowyer, Ted W.; Day, Anthony R.; Fuller, Erin S.; Haas, Derek A.; Hayes, James C.; Hoppe, Eric W.; Humble, Paul H.; Keillor, Martin E.; LaFerriere, Brian D.; Mace, Emily K.; McIntyre, Justin I.; Miley, Harry S.; Myers, Allan W.; Orrell, John L.; Overman, Cory T.; Panisko, Mark E.; Seifert, Allen


    Argon-37 is an important environmental signature of an underground nuclear explosion. Producing and quantifying low-level 37Ar standards is an important step in the development of sensitive field measurement instruments for use during an On-Site Inspection, a key provision of the Comprehensive Nuclear-Test-Ban Treaty. This paper describes progress at Pacific Northwest National Laboratory (PNNL) in the development of a process to generate and quantify low-level 37Ar standard material, which can then be used to calibrate sensitive field systems at activities consistent with soil background levels. The 37Ar used for our work was generated using a laboratory-scale, high-energy neutron source to irradiate powdered samples of calcium carbonate. Small aliquots of 37Ar were then extracted from the head space of the irradiated samples. The specific activity of the head space samples, mixed with P10 (90% stable argon:10% methane by mole fraction) count gas, is then derived using the accepted Length-Compensated Internal-Source Proportional Counting method. Due to the low activity of the samples, a set of three Ultra-Low Background Proportional-Counters designed and fabricated at PNNL from radio-pure electroformed copper was used to make the measurements in PNNL’s shallow underground counting laboratory. Very low background levels (<10 counts/day) have been observed in the spectral region near the 37Ar emission feature at 2.8 keV. Two separate samples from the same irradiation were measured. The first sample was counted for 12 days beginning 28 days after irradiation, the second sample was counted for 24 days beginning 70 days after irradiation (the half-life of 37Ar is 35.0 days). Both sets of measurements were analyzed and yielded very similar results for the starting activity (~0.1 Bq) and activity concentration (0.15 mBq/ccSTP argon) after P10 count gas was added. A detailed uncertainty model was developed based on the ISO Guide to the Expression of Uncertainty in

  9. Deciphering the Paleoproterozoic cooling history of the northeastern Trans-Hudson Orogen, Baffin Island (Canada), using 40Ar/39Ar step-heating and UV laser thermochronology (United States)

    Skipton, D. R.; Schneider, D. A.; Kellett, D. A.; Joyce, N. L.


    The previously unstudied cooling and exhumation history of mid-crustal rocks exposed on southeastern Baffin Island (Canada) provides new insights into the post-orogenic evolution of the Paleoproterozoic Trans-Hudson Orogen (THO). New 40Ar/39Ar step-heat analyses of biotite, muscovite and phlogopite and core-to-rim intra-grain 40Ar/39Ar analyses of muscovite have a range of apparent ages compatible with slow regional cooling following peak metamorphism. Twenty-nine amphibolite- to granulite-facies rocks were dated using the 40Ar/39Ar step-heating laser (CO2) method. 40Ar/39Ar spot analyses were performed across muscovite grains from three samples using an ultraviolet (UV) laser to investigate intra-grain 40Ar/39Ar age variations. Step-heating apparent ages range from ca. 1788-1622 Ma for biotite, 1720-1630 Ma for phlogopite and 1729-1657 Ma for muscovite. UV spot 40Ar/39Ar analyses in the three muscovite grains range from ca. 1661-1640 Ma, 1675-1645 Ma and 1680-1652 Ma, with core-to-rim apparent age gradients of 20-30 Myr. Previous studies resolved peak metamorphism in this region to between ca. 1860 and 1820 Ma and identified late- to post-THO zircon and monazite populations at ca. 1800-1750 Ma. Numerical diffusion models for Ar in muscovite were conducted to test different Proterozoic cooling and exhumation scenarios. Comparisons with our 40Ar/39Ar ages attest to cooling rates of 1-2 °C/Myr following peak metamorphism and 1.5-2.5 °C/Myr after ca. 1740 Ma. Anomalously old apparent 40Ar/39Ar ages, in cases equivalent to U-Pb zircon rim and monazite ages, likely result from incorporation of excess Ar. The results suggest that mid-crustal rocks on southeastern Baffin Island remained hotter than 420-450 °C for 150-200 Myr after peak metamorphism, with subsequent slow cooling and denudation rates that are typical of Proterozoic orogens. The apparent absence of orogenic collapse implies that, despite high temperatures and estimated maximum crustal thicknesses

  10. Evidence for pre-Cretaceous history and partial Neogene (19-9 Ma) reequilibration in the Karakorum (NW Himalayan Syntaxis) from 40Ar- 39Ar amphibole dating (United States)

    Rolland, Yann; Villa, Igor M.; Guillot, Stéphane; Mahéo, Gweltaz; Pêcher, Arnaud


    Amphiboles and a biotite from amphibolites and amphibolitic gneisses of the Karakorum Metamorphic Complex (KMC, NW Himalaya), were dated using the 40Ar/ 39Ar method. Isotope correlations were compared to electron-microprobe analyses. Both Al IV and Al VI contents of amphibole increase from the south near the Shyok Suture Zone to the Dassu-Askole Area in the north, with an increase in metamorphic grade (from anchizone to upper amphibolite facies). In the lower metamorphic zone, discordant age spectra were obtained. They are related to epidote-amphibolite overgrowth of amphibole rims on older (Precambrian to Mesozoic) magmatic cores. In the Shyok Suture Zone Ar/Ar ages of 38-62 Ma are contemporaneous with the emplacement of the Ladakh Batholith granodiorites, while middle Cretaceous magmatic Ar/Ar ages (˜ 120 Ma) are locally preserved in tschermakite relics. In the Southern Karakorum basement, a minimum Ar/Ar age of 651 Ma was preserved, while an age of 208.5±2 Ma was preserved in Panjal Trap-like diorites. At the margin of the domes zone, more recent metamorphism resulted in mineral growth at 20-5 Ma. In the domes zone, amphibole Ar/Ar ages of 17 Ma (Askole) and bimodal age spectra of 15-17 and 9-13 Ma (Dassu) extend towards the east the zone of Neogene amphibolite to granulite facies metamorphism known in the Nanga Parbat Syntaxis.

  11. Quantifying interference of krypton produced from neutron irradiation of inclusion-hosted and lattice-coordinated bromine with 40Ar/39Ar geochronology (United States)

    Rutte, Daniel; Becker, Tim A.; Renne, Paul R.


    Various interfering reactions producing Ar isotopes during neutron irradiation from Cl, Ar, K, and Ca have been previously detailed with the significant ones being routinely corrected for in 40Ar/39Ar geochronology. Interference of double charged 80Kr (80Kr++) with 40Ar has not yet been considered. Significant amounts of 80Kr are produced during neutron irradiation through the reaction 79Br(n,β-)80Kr. While previous workers reported a computed fission spectrum averaged cross section of ∼48 mb-compared to ∼113 mb for 39K(n,p)39Ar-we determined a ∼33-fold higher production rate of 80Kr from Br compared to 39Ar from K in the CLICIT facility of the OSU reactor. Low-K, high-Br phases, e.g., some amphiboles, and fluid or melt inclusion rich samples are prone to 80Kr++ interference biasing 40Ar/39Ar dates in the ‰ to % range. 80Kr++ resembles excess 40Ar in step-heating experiments. The interference can be corrected for by using the parallel reaction 81Br(n,β-)82Kr.

  12. Medidas da umidade relativa do ar em um ambiente fechado

    Directory of Open Access Journals (Sweden)

    Costa Eden V.


    Full Text Available Umidade do ar e o vapor d'água presente na atmosfera. Neste trabalho medimos a umidade relativa do ar em um ambiente fechado onde a temperatura foi mantida constante. Nestas condições, a umidade cresce até o vapor d'água tornar-se saturado. Neste instante, a umidade é máxima. O aparato experimental utilizado consiste de recipiente fechado de vidro, higrômetro, termômetro e relógio. Trata-se, portanto, de um experimento simples, possível de ser realizado em um laboratório didático e capaz de preencher a lacuna dos livros de texto de física, que, em geral, negligenciam este tópico.

  13. Simulation of Carbon Nanotube Welding through Ar bombardment

    CERN Document Server

    Kucukkal, Mustafa U


    Single-walled carbon nanotubes show promise as nanoscale transistors, for nanocomputing applications. This use will require appropriate methods for creating electrical connections between distinct nanotubes, analogous to welding of metallic wires at larger length scales, but methods for performing nanoscale chemical welding are not yet sufficiently understood. This study examined the effect of Ar bombardment on the junction of two crossed single-walled carbon nanotubes, to understand the value and limitations of this method for generating connections between nanotubes. A geometric criterion was used to assess the quality of the junctions formed, with the goal of identifying the most productive conditions for experimental ion bombardment. In particular, the effects of nanotube chirality, Ar impact kinetic energy, impact particle flux and fluence, and annealing temperature were considered. The most productive bombardment conditions, leading to the most crosslinking of the tubes with the smallest loss of graphit...

  14. Ryoji Ikeda, Data Artist - Prix Ars Electronica Collide@CERN

    CERN Document Server

    CERN. Geneva; Koek, Ariane; Heuer, Rolf; Ikeda, Ryoji; Mr. Horst, Hoertner


    at the CERN Globe of Science and Innovation, CERN. You are very warmly invited to the opening presentation of Data Artist, Ryoji Ikeda’s residency at CERN. Ryoji Ikeda, one of the world’s leading electronic composers and visual artists, is the new Prix Ars Electronica Collide@CERN award winner. Ryoji Ikeda and his science inspiration partner, Theoretical Physicist, Dr. Tom Melia will talk about their work in arts and science. They are at the beginning of their creative journey together at CERN. A little about Ryoji Ikeda – the new Prix Ars Electronica Collide@CERN artist in residence. Ryoji Ikeda focuses on the essential characteristics of sound itself and that of visuals as light by means of both mathematical precision and mathematical aesthetics. Ikeda has gained a reputation as one of the few international artists working convincingly across both visual ...

  15. Discurso y ejemplaridad en Ovidio, Ars 1.101-134


    Schniebs, Alicia


    RÉSUMÉ Sur la base d’une analyse concernant l’intertextualité, l’intratextualité ainsi que lês rapports avec d’autres discours symboliques du contexte de production, le travail se propose d’étudier l’excursus de l’enlèvement des Sabines chez Ovide Ars 1.101- 134. Cette étude a pour but de déterminer la construction du lien exemplaire Romulus-Auguste impliqué dans le texte et sa relation avec cette même exemplaritélà dans le régime du principat. Mots-clés: exemplarité, Ovide, Ars amatoria, Rom...

  16. Progreso y retos de la geocronología 40Ar/39Ar en Costa Rica y Nicaragua Progress and Challenges Using 40Ar/39Ar Geochronology in Costa Rica and Nicaragua

    Directory of Open Access Journals (Sweden)

    Ian Saginor¹


    Full Text Available Con el principal objetivo de realizar mejores cálculos de la producción volcánica, en el Arco Volcánico de América Central, realizamos 61 dataciones 40Ar/39Ar en tefras y lavas en localidades de frente volcánico de Costa Rica y Nicaragua por medio de varias campañas de campo y análisis de laboratorio (preparación de muestras, envió al reactor nuclear, espectroscopía de masas de las muestras radiactivas, al laboratorio de gases nobles del Departamento de Ciencias de la Tierra y Planetarias de la Universidad Rutgers del 2002-2008. En este artículo presentamos diferentes observaciones que resultaron de este estudio donde se describe la precisión, exactitud y la confiabilidad de las edades 40Ar/39Ar. El primer resultado muestra las limitaciones de esta técnica en muestras baja en K2O con edades To better estimate the extrusive flux of the Central American Arc, from 2002-2008, we obtained sixty one high precision 40Ar/39Ar ages on geographically well-situated lavas and tephra from Costa Rica and Nicaragua. Here, we describe a number of observations encountered during this study using four examples that well document the precision, accuracy and general reliability of the 40Ar/39Ar ages. First, low K2O values, particularly in samples from Nicaragua, is a major limitation in or attempts to obtain reliable dates on samples under 1 My. Second, extensive weathering of samples due to the tropical climate of Central America has resulted in various levels of argon loss even when the hand sample appeared unaltered. Third, our field and geochronological data lead us to conclude that eruptive rates have not been constant over the past 15 to 20 My, but rather appears punctuated by gaps of up to several million years. We attempted to address the temporal gaps in several ways. First, geochemical analyses were used to identify samples that may have erupted during time periods without known volcanism. For example, U/Th values in the active Central

  17. Dielectric behavior of Ar{sup +} implanted CR-39 polymer

    Energy Technology Data Exchange (ETDEWEB)

    Shekhawat, Nidhi; Sharma, Annu; Aggarwal, Sanjeev; Deshpande, S. K.; Nair, K. G. M. [Department of Physics, Kurukshetra University Kurukshetra-136119 (India); UGC-DAE Consortium for Scientific Research, Mumbai Centre, BARC, Mumbai 400085 (India); Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)


    The frequency dependent dielectric response of Ar{sup +} implanted CR-39 specimens has been studied. Samples were implanted with 130 keV Ar{sup +} ions to various doses ranging from 5x10{sup 14} to 1x10{sup 16} cm{sup -2}. The frequency response of dielectric constant (e) and dielectric loss has been studied both in the pristine and argon ion implanted samples of CR-39 polymer in the frequency range 10{sup 4} to 10{sup 8} Hz. Structural changes produced in CR-39 specimens due to implantation have been studied using Attenuated total reflectance (ATR) Fourier transform infrared spectroscopic technique. Results of dielectric analysis indicate the lowering in dielectric constant ({epsilon}') and similar behavior of dielectric loss with increase in ion fluence. An attempt has been made to correlate these changes produced in the dielectric properties of implanted specimens with the structural changes produced due to implantation.

  18. Constraining the alteration history of a Late Cretaceous Patagonian volcaniclastic bentonite-ash-mudstone sequence using K-Ar and 40Ar/39Ar isotopes (United States)

    Warr, L. N.; Hofmann, H.; van der Pluijm, B. A.


    Smectite is typically considered unsuitable for radiometric dating, as argon (40Ar) produced from decay of exchangeable potassium (40K) located in the interlayer sites can be lost during fluid-rock interaction and/or during wet sample preparation in the laboratory. However, age analysis of Late Cretaceous Argentinian bentonites and associated volcaniclastic rocks from Lago Pellegrini, Northern Patagonia, indicates that, in the case of these very low-permeability rocks, the radioactive 40Ar was retained and thus can provide information on smectite age and the timing of rock alteration. This study presents isotopic results that indicate the ash-to-bentonite conversion and alteration of the overlying tuffaceous mudstones in Northern Patagonia was complete 13-17 my after middle Campanian sedimentation when the system isotopically closed. The general absence of illite in these smectite-rich lithologies reflects the low activity of K and the low temperature (<60 °C) of the formation waters that altered the parent ash.

  19. Infrared absorption spectroscopy of CO 2-Ar complexes (United States)

    Sharpe, S. W.; Sheeks, R.; Wittig, C.; Beaudet, R. A.


    The ν 4 rovibrational band of CO 2-Ar near 2350 cm -1 (i.e. CO 2 asymmetric stretch) has been recorded in absorption at 8 K using a tunable diode laser. Rotational constants for both ν 4=0 and 1 are very similar, and indicate a T-shaped geometry. It was not possible to detect this species mass spectrometrically (18-70 eV electrons), indicating extensive fragmentation.


    Directory of Open Access Journals (Sweden)

    Fernando Fantoni Bencke


    business: the significant taxes, lack of incentives and credit available and the opportunity to “make a little extra” through informal sales. AR Consultoria’s entry to the market was marked by these and other difficulties. This case aims at presenting a real situation that can be found in some organizational sectors areas, which demands readers to take a decision and an ethical stance when faced with moral challenges.

  1. arXiv in the classical Russian literature

    CERN Document Server

    Silagadze, Z K


    The creation of arXiv, a highly democratic open access repository of research papers in high-energy physics more than twenty years ago was undoubtedly the most spectacular and landmark event for the high-energy physics community. However, we report a curious observation which indicates that the general cultural significance of this event extends far beyond the boundaries assumed at the beginning.

  2. Secondary scintillation in Ar-CF$_4$ mixtures

    CERN Document Server

    Beschi, Andrea


    In order to build a optical time projection chamber that can be used as a tracking detector, it is necessary to study the scintillation proprieties of gases in order to optimize the light emission. A detailed study of the scintillation of Ar-CF$_4$ mixtures at different concentrations has been performed to study the light emission of the gas in a triple GEM detector.

  3. Konsep Pemikiran Harun ar-Rasyid dalam Pendidikan Karakter


    Ahmad Afnan Anshori


    CHARACTER BUILDING IN HARUN AR-RASYID THOUGH. Ampant cases of violence in society, political instability, as well as the moral degradation of the nation as a whole raises awareness of the importance of good character development at the level of the family as an institution forming the smallest nation to the character development of the nation at large. In addition to the family, the environment and education institutions also have a role no less important in the formation of national characte...

  4. Selective AR Modulators that Distinguish Proliferative from Differentiative Gene Promoters (United States)


    dependent compound screen, aided by the University of Michigan Center for Chemical Genomics . Differential AR activation in transfected cells was assessed...WR, Parker JS, Lee MX, Kass EM, Spratt DE, Iaquinta PJ, Arora VK, Yen WF, Cai L, Zheng D, Carver BS, Chen Y, Watson PA, Shah NP, Fujisawa S, Goglia...for known genes and genome -wide by ChIP-seq. Results will strengthen our overall hypothesis that genes with similar function (i.e

  5. Immune epitope database analysis resource (IEDB-AR)

    DEFF Research Database (Denmark)

    Zhang, Qing; Wang, Peng; Kim, Yohan;


    We present a new release of the immune epitope database analysis resource (IEDB-AR,, a repository of web-based tools for the prediction and analysis of immune epitopes. New functionalities have been added to most of the previously implemented tools, and a total...... of eight new tools were added, including two B-cell epitope prediction tools, four T-cell epitope prediction tools and two analysis tools....

  6. Electrical properties and dielectric spectroscopy of Ar+ implanted polycarbonate (United States)

    Chawla, Mahak; Shekhawat, Nidhi; Aggarwal, Sanjeev; Sharma, Annu; Nair, K. G. M.


    The aim of the present paper is to study the effect of argon ion implantation on electrical and dielectric properties of polycarbonate. Specimens were implanted with 130 keV Ar+ ions in the fluence ranging from 1×1014 to 1×1016 ions cm-2. The beam current used was ˜0.40 µA cm-2. The electrical conduction behaviour of virgin and Ar+ implanted polycarbonate specimens have been studied through current-voltage (I-V characteristic) measurements. It has been observed that after implantation conductivity increases with increasing ion fluence. The dielectric spectroscopy of these specimens has been done in the frequency range of 100 kHz-100 MHz. Relaxation processes were studied by Cole-Cole plot of complex permittivity (real part of complex permittivity, ɛ' vs. imaginary part of complex permittivity, ɛ″). The Cole-Cole plots have also been used to determine static dielectric constant (ɛs), optical dielectric constant (ɛ∞), spreading factor (α), average relaxation time (τ0) and molecular relaxation time (τ). The dielectric behaviour has been found to be significantly affected due to Ar+ implantation. The possible correlation between this behaviour and the changes induced by the implantation has been discussed.

  7. 37 Ar Calibration of the Large Underground Xenon Experiment (United States)

    Boulton, Elizabeth; LUX Collaboration Collaboration


    The LUX collaboration released its 332 live-day WIMP search result in June 2016. Besides WIMPs, there are several other rare particles to search for using two-phase xenon detectors, such as axion-like pseudoscalars, axions, and electrophilic dark matter. All of these proposed particles interact with xenon via electron recoils at low energy. Also, the neutrino magnetic moment can be searched for by examining the rates of neutrino-electron scattering at low energy. Therefore, understanding xenon's response in this low-energy regime is vitally important. 37Ar is an ideal source for calibrating a detector at these low energies, because it decays via electron capture (EC) and releases x-rays at two energies: 2.8 keV due to EC from the K-shell and 0.27 keV due to EC from the L-shell. Additionally, 37Ar can be used to precisely study recombination fluctuations at a specific energy in the WIMP region of interest. Recombination fluctuations limit electron recoil discrimination efficiency, so understanding how these fluctuations change with electric drift field is important to all LUX analysis. This talk will explain the motivation, creation, deployment, and results of the 37Ar source in LUX over a wide range of drift fields.

  8. Production of Ar metastables in a dielectric barrier discharge (United States)

    Mikheyev, Pavel A.; Han, Jiande; Clark, Amanda; Sanderson, Carl; Heaven, Michael C.


    The results of experiments with a dielectric barrier discharge (DBD) are presented, where the production of metastable argon atoms was studied. The recently proposed optically pumped all-rare-gas laser (OPRGL) utilizes metastable atoms of heavier rare gases as lasing species. The required number density of metastables for efficient laser operation is 1012÷1013 cm-3 in an atmospheric pressure of He buffer gas. Recent experiments had shown that such densities are easily produced in a nanosecond pulsed discharge, even at pressures larger than atmospheric, but problems appear when one is trying to produce them in a CW regime. The reason for difficulties in the CW production of metastables at an atmospheric pressure seems to be the low value of the E/N parameter (DBD in 2-5% Ar mixture with He at an atmospheric pressure was studied. [Ar(1s5)] number density of the order of 1012 cm-3 was readily achieved. Temporal behavior of [Ar(1s5)] throughout the DBD cycle was obtained. The results demonstrate the feasibility of DBDs for OPRGL development.

  9. Konsep Pemikiran Harun ar-Rasyid dalam Pendidikan Karakter

    Directory of Open Access Journals (Sweden)

    Ahmad Afnan Anshori


    Full Text Available CHARACTER BUILDING IN HARUN AR-RASYID THOUGH. Ampant cases of violence in society, political instability, as well as the moral degradation of the nation as a whole raises awareness of the importance of good character development at the level of the family as an institution forming the smallest nation to the character development of the nation at large. In addition to the family, the environment and education institutions also have a role no less important in the formation of national character, it’s because the institution is spearheading the development of the nation in the realm of formal education. Education as a process that helps mature, directing and developing the potential in man is regarded as an appropriate means in the formation of one’s character. One of the concepts of character education is found in the will written by Harun ar-Rashid to al-Ahmar the teacher who is appointed by the Caliph to educate the crown prince, later known as al-Amin. In this testament, there are several character education concepts, including role models of teachers, obedience, respect for family, teaching the Qur’an and Sunnah as well as many others. The concept of character education promoted by Harun ar-Rashid was not different from the concept of character education offered by modern education experts, this proves that the concept of character education contained in the will of Harun al -Rashid is universal without any limitation of space and time.

  10. Transfer ionization of the isocharge sequence ion and Ar collisions

    Institute of Scientific and Technical Information of China (English)

    Cai Xiao-Hong; Yu De-Yang; Cao Zhu-Rong; Lu Rong-Chun; Yang Wei; Shao Cao-Jie; Chen Xi-Meng


    The ratios of transfer ionization to single capture for isocharge Cq+, Nq+, Oq+, Neq+ ions on Ar atoms are measured by using position-sensitive and time-of-flight techniques. It is found that the ratio R1 increases with nuclear charge Z in a q=4 sequence, and the ratio R1 sequences have the minimum values at Z=7 and Z=8 in q=5 and q=6 sequences, respectively, and the ratio R1 decreases with the increase in the nuclear charge Z in a q=7 sequence. The results may be explained within the frame of the statistical model. It may be concluded that the transfer ionization depends remarkably upon the electronic structure of the projectile. The projectiles used in this study have the same charge state and velocity, but different electronic structures. The dependence of the ratio R1 on q is studied for Neq+-Ar collisions. The ratio R1 is found to increase as q increases for Neq+-Ar collisions. The measured dependence of the ratio R1 on q is compared with the calculation using the molecular Coulomb over-barrier model.

  11. Thermal neutron induced (n,p) and (n,alpha) reactions on Ar-37

    NARCIS (Netherlands)

    Bieber, R; Wagemans, C; Goeminne, G; Wagemans, J; Denecke, B; Loiselet, M; Gaelens, M; Geltenbort, P; Oberhummer, H


    The Ar-37(n(th),alpha)S-34 and Ar-37(n(th),p)Cl-37 reactions were studied at the high flux reactor of the ILL in Grenoble, For the Ar-37(n(th),alpha(0))S-34 and Ar-37(n(th),p)Cl-37 reaction cross sections, values of (1070 +/- 80) b and (37 +/- 4) b, respectively, were obtained. Both values are about

  12. Ar-40/Ar-39 age spectra of Apollo 15 impact melt rocks by laser step-heating and their bearing on the history of lunar basin formation (United States)

    Dalrymple, G. B.; Ryder, Graham


    Results are reported on 26 high-resolution (16-51 steps) Ar-40/Ar-39 age spectra obtained on 12 Apollo-15 melt rocks of different composition using a continuous laser system on submg fragments of recrystallized melt and single-crystal plagioclase clasts from impact melt rocks collected at the Apennine Front where the Imbrium and Serenitatis basins intersect. A table is presented with the summary of the Ar-40/Ar-39 spectrum data, which represent 891 individual temperature step analyses. Also presented are 20 of the 26 age spectra along with their respective K/Ca plots. Melt rock fragments and plagioclase clasts from seven of the 12 samples analyzed yielded reproducible, intermediate-T Ar-40/Ar-39 age spectrum plateaus, which were interpreted as crystallization ages that represent the times of impact of bolides onto the lunar surface.

  13. File list: Oth.Prs.10.AR.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Prs.10.AR.AllCell hg19 TFs and others AR Prostate SRX595676,SRX595671,SRX595675...,SRX315149,SRX315147,SRX315153,SRX022568,SRX736053,SRX315152,SRX882952,SRX022566,SRX283757 ...

  14. 75 FR 29656 - Amendment of Class E Airspace; Mountain View, AR (United States)


    ... Federal Aviation Administration 14 CFR Part 71 Amendment of Class E Airspace; Mountain View, AR AGENCY... airspace for Mountain View, AR. Decommissioning of the Wilcox non-directional beacon (NDB) at Mountain View Wilcox Memorial Field Airport, Mountain View, AR, has made this action necessary to enhance the...

  15. File list: Oth.Unc.50.AR.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Unc.50.AR.AllCell hg19 TFs and others AR Unclassified SRX334244,SRX334252,SRX33...334249,SRX334248 ...

  16. File list: Oth.ALL.20.AR.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.20.AR.AllCell hg19 TFs and others AR All cell types SRX595676,SRX595671,SRX...736053,SRX502068,SRX092448,SRX092447,SRX861678,SRX147604,SRX1033268 ...

  17. File list: Oth.Brs.05.AR.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Brs.05.AR.AllCell hg19 TFs and others AR Breast SRX1339020,SRX1339018,SRX250092...,SRX1339019,SRX1339016,SRX1339017,SRX1339015 ...

  18. 75 FR 30750 - Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR (United States)


    ..., Little Rock, AR AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking. SUMMARY: The Coast Guard... Waterway at mile 119.6 at Little Rock, AR, so that vessel operators will contact the remote drawbridge... the Baring Cross Railroad Drawbridge, mile 119.6, at Little Rock, AR is maintained in the...

  19. Chromosomal context and replication properties of ARS plasmids in Schizosaccharomyces pombe

    Indian Academy of Sciences (India)

    Aditya S Pratihar; Vishnu P Tripathi; Mukesh P Yadav; Dharani D Dubey


    Short, specific DNA sequences called as Autonomously Replicating Sequence (ARS) elements function as plasmid as well as chromosomal replication origins in yeasts. As compared to ARSs, different chromosomal origins vary greatly in their efficiency and timing of replication probably due to their wider chromosomal context. The two Schizosaccharomyces pombe ARS elements, ars727 and ars2OO4, represent two extremities in their chromosomal origin activity - ars727 is inactive and late replicating, while ars2OO4 is a highly active, early-firing origin. To determine the effect of chromosomal context on the activity of these ARS elements, we have cloned them with their extended chromosomal context as well as in the context of each other in both orientations and analysed their replication efficiency by ARS and plasmid stability assays. We found that these ARS elements retain their origin activity in their extended/altered context. However, deletion of a 133-bp region of the previously reported ars727-associated late replication enforcing element (LRE) caused advancement in replication timing of the resulting plasmid. These results confirm the role of LRE in directing plasmid replication timing and suggest that the plasmid origin efficiency of ars2OO4 or ars727 remains unaltered by the extended chromosomal context.

  20. Measuring the Perceived Quality of an AR-Based Learning Application: A Multidimensional Model (United States)

    Pribeanu, Costin; Balog, Alexandru; Iordache, Dragos Daniel


    Augmented reality (AR) technologies could enhance learning in several ways. The quality of an AR-based educational platform is a combination of key features that manifests in usability, usefulness, and enjoyment for the learner. In this paper, we present a multidimensional model to measure the quality of an AR-based application as perceived by…

  1. Multiple target ionization in collisions between highly charged ions and Ar

    NARCIS (Netherlands)

    deNijs, G; Hoekstra, R; Morgenstern, R


    We have performed measurements on charge-state distributions of target ions produced in collisions of C6+, N6+, O6+, Ne6+, Ar6+ and Kr6+ on Ar. Charge states of Ar target ions higher than the initial projectile charge state are observed for C6+, N6+ and O6+. This intriguing observation seems to

  2. 40Ar/39Ar dating of shear deformation of the Xianshuihe fault zone in west Sichuan and its tectonic significance

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Yueqiao; CHEN; Wen; YANG; Nong


    Based on field geological survey, structural measurements and classical 40Ar/39Ar dating of mica, biotite and K-feldspar, we obtain cooling ages for Miocene left-lateral shear along the Xianshuihe fault zone. The results document two thermal events during the sinistral shear.The early event (12-10 Ma) corresponds to rapid cooling of the Zheduoshan granitic massif from above 700℃ to below 350℃. The late event (5-3.5 Ma) corresponds to cooling of granites intruded along the eastern side of the fault zone. These dating results provide important thermochronological constraint on the timing of late Cenozoic eastward extrusion of the Chuan-Dian Block in the SE Tibetan margin.

  3. Charge-exchange, ionization and excitation in low-energy Li$^{+}-$ Ar, K$^{+}-$ Ar, and Na$^{+}-$He collisions

    CERN Document Server

    Lomsadze, Ramaz A; Kezerashvili, RomanYa; Schulz, Michael


    Absolute cross sections are measured for charge-exchange, ionization, and excitation within the same experimental setup for the Li$^{+}-$Ar, K$^{+}-$ Ar, and Na$^{+}-$ He collisions in the ion energy range $0.5-10$ keV. Results of our measurements along with existing experimental data and the schematic correlation diagrams are used to analyze and determine the mechanisms for these processes. The experimental results show that the charge-exchange processes are realized with high probabilities and electrons are predominately captured in ground states. The cross section ratio for charge exchange, ionization and excitation processes roughly attains the value $10:2:1$, respectively. The contributions of various partial inelastic channels to the total ionization cross sections are estimated and a primary mechanism for the process is defined. The energy-loss spectrum, in addition, is applied to estimate the relative contribution of different inelastic channels and to determine the mechanisms for the ionization and f...

  4. Emplacement of Amba Dongar Carbonatite-alkaline Complex at Cretaceous/Tertiary Boundary: Evidence from 40Ar-39Ar Chronology

    Indian Academy of Sciences (India)

    Jyotiranjan S Ray; Kanchan Pande; T R Venkatesan


    40Ar-39Ar analyses of three fresh alkaline rock samples and a phlogopite separate from a carbonatite from Amba Dongar carbonatite-alkaline complex of the Deccan Flood Basalt Province, India, yield indistinguishable precise plateau ages of 64.8 ± 0.6, 64.7 ± 0.5, 65.5 ± 0.8 and 65.3 ± 0.6 Ma, giving a mean plateau age of 65.0 ± 0.3 Ma, which is the age of emplacement of this complex. This age implies contemporaneity of Amba Dongar with several other carbonatite-alkaline activities of Chhota Udaipur subprovince and is consistent with their Reunion-Deccan plume origin hypothesis. The emplacement of these complexes at 65 Ma makes them very significant in the ongoing debate on the K/T extinctions owing to their capacity to rapidly inject a substantial amount of CO2 and SO2 into the atmosphere.

  5. Late Paleozoic deformation and exhumation in the Sierras Pampeanas (Argentina): 40Ar/39Ar-feldspar dating constraints (United States)

    Löbens, Stefan; Oriolo, Sebastián; Benowitz, Jeff; Wemmer, Klaus; Layer, Paul; Siegesmund, Siegfried


    Systematic 40Ar/39Ar feldspar data obtained from the Sierras Pampeanas are presented, filling the gap between available high- (> 300 °C) and low-temperature (< 150 °C) thermochronological data. Results show Silurian-Devonian exhumation related to the late stages of the Famatinian/Ocloyic Orogeny for the Sierra de Pocho and the Sierra de Pie de Palo regions, whereas the Sierras de San Luis and the Sierra de Comechingones regions record exhumation during the Carboniferous. Comparison between new and available data points to a Carboniferous tectonic event in the Sierras Pampeanas, which represents a key period to constrain the early evolution of the proto-Andean margin of Gondwana. This event was probably transtensional and played a major role during the evolution of the Paganzo Basin as well as during the emplacement of alkaline magmatism in the retroarc.

  6. Age of the youngest volcanism at Eagle Lake, northeastern California—40Ar/39Ar and paleomagnetic results (United States)

    Clynne, Michael A.; Calvert, Andrew T.; Champion, Duane E.; Muffler, L.J.P.; Sawlan, Michael G.; Downs, Drew T.


    The age of the youngest volcanism at Eagle Lake, California, was investigated using stratigraphic, paleomagnetic, and 40Ar/39Ar techniques. The three youngest volcanic lava flows at Eagle Lake yielded ages of 130.0±5.1, 127.5±3.2 and 123.6±18.7 ka, and are statistically indistinguishable. Paleomagnetic results demonstrate that two of the lava flows are very closely spaced in time, whereas the third is different by centuries to at most a few millennia. These results indicate that the basalt lava flows at Eagle Lake are not Holocene in age, and were erupted during an episode of volcanism at about 130–125 ka that is unlikely to have spanned more than a few thousand years. Thus, the short-term potential for subsequent volcanism at Eagle Lake is considered low. 

  7. 40Ar/39Ar Dating of Zn-Pb-Ag Mineralization in the Northern Brooks Range, Alaska (United States)

    Werdon, Melanie B.; Layer, Paul W.; Newberry, Rainer J.


    The 40Ar/39Ar laser step-heating method potentially can be used to provide absolute ages for a number of formerly undatable, low-temperature ore deposits. This study demonstrates the use of this method by determining absolute ages for Zn-Pb-Ag sediment-hosted massive sulfide deposits and vein-breccia occurrences found throughout a 300-km-long, east-west-trending belt in the northern Brooks Range, Alaska. Massive sulfide deposits are hosted by Mississippian to Pennsylvanian(?) black carbonaceous shale, siliceous mudstone, and lesser chert and carbonate turbidites of the Kuna Formation (e.g., Red Dog, Anarraaq, Lik (Su), and Drenchwater). The vein-breccia occurrences (e.g., Husky, Story Creek, West Kivliktort Mountain, Vidlee, and Kady) are hosted by a deformed but only weakly metamorphosed package of Upper Devonian to Lower Mississippian mixed continental and marine clastic rocks (the Endicott Group) that stratigraphically underlie the Kuna Formation. The vein-breccias are mineralogically similar to, but not spatially associated with, known massive sulfide deposits. The region's largest shale-hosted massive sulfide deposit is Red Dog; it has reserves of 148 Mt grading 16.6 percent zinc, 4.5 percent lead, and 77 g of silver per tonne. Hydrothermally produced white mica in a whole-rock sample from a sulfide-bearing igneous sill within the Red Dog deposit yielded a plateau age of 314.5 Ma. The plateau age of this whole-rock sample records the time at which temperatures cooled below the argon closure temperature of the white mica and is interpreted to represent the minimum age limit for massive sulfide-related hydrothermal activity in the Red Dog deposit. Sulfide-bearing quartz veins at Drenchwater crosscut a hypabyssal intrusion with a maximum biotite age of 337.0 Ma. Despite relatively low sulfide deposition temperatures in the vein-breccia occurrences (162°-251°C), detrital white mica in sandstone immediately adjacent to large vein-breccia zones was partially to

  8. Detailed 40Ar/39Ar dating of geologic events associated with the Mantos Blancos copper deposit, northern Chile (United States)

    Oliveros, Verónica; Féraud, Gilbert; Aguirre, Luis; Ramírez, Luis; Fornari, Michel; Palacios, Carlos; Parada, Miguel


    The 40Ar/39Ar geochronological method was applied to date magmatic and hydrothermal alteration events in the Mantos Blancos mining district in the Coastal Cordillera of northern Chile, allowing the distinction of two separate mineralization events. The Late Jurassic Mantos Blancos orebody, hosted in Jurassic volcanic rocks, is a magmatic-hydrothermal breccia-style Cu deposit. Two superimposed mineralization events have been recently proposed. The first event is accompanied by a phyllic hydrothermal alteration affecting a rhyolitic dome. The second mineralization event is related to the intrusion of bimodal stocks and sills inside the deposit. Because of the superposition of several magmatic and hydrothermal events, the obtained 40Ar/39Ar age data are complex; however, with a careful interpretation of the age spectra, it is possible to detect complex histories of successive emplacement, alteration, mineralization, and thermal resetting. The extrusion of Jurassic basic to intermediate volcanic rocks of the La Negra Formation is dated at 156.3 ± 1.4 Ma (2 σ) using plagioclase from an andesitic lava flow. The first mineralization event and associated phyllic alteration affecting the rhyolitic dome occurred around 155-156 Ma. A younger bimodal intrusive event, supposed to be equivalent to the bimodal stock and sill system inside the deposit, is probably responsible for the second mineralization event dated at ca. 142 Ma. Other low-temperature alteration events have been dated on sericitized plagioclase at ca. 145-146, 125, and 101 Ma. This is the first time that two distinct mineralization events have been documented from radiometric data for a copper deposit in the metallogenic belt of the Coastal Cordillera of northern Chile.

  9. Geochemical and 40Ar/39Ar constraints on the evolution of volcanism in the Woodlark Rift, Papua New Guinea (United States)

    Catalano, Joseph P.

    The tectonic mechanisms producing Pliocene to active volcanism in eastern Papua New Guinea (PNG) have been debated for decades. In order to assess mechanisms that produce volcanism in the Woodlark Rift, we evaluate the evolution of volcanism in eastern PNG using 40Ar/39Ar thermochronology and whole rock geochemistry. Active volcanism in southeastern Papua New Guinea occurs on the Papuan Peninsula (Mt. Lamington, Mt. Victory and Waiwa), in the Woodlark Rift (Dobu Island, SE Goodenough Island, and Western Fergusson Island), and in the Woodlark Basin. In the Woodlark Basin, seafloor spreading is active and decompression melting of the upper mantle is producing basaltic magmatism. However, the cause of Pliocene and younger volcanism in the Woodlark Rift is controversial. Two hypotheses for the tectonic setting have been proposed to explain Pliocene and younger volcanism in the Woodlark Rift: (1) southward subduction of Solomon Sea lithosphere beneath eastern PNG at the Trobriand Tough and (2) decompression melting of mantle, previously modified by subduction, as the lithosphere undergoes extension associated with the opening of the Woodlark Basin. A comparison of 40Ar/39Ar ages with high field strength element (HFSE) concentrations in primary magmas indicates that HFSE concentrations correlate with age in the Woodlark rift. These data support the hypothesis that Pliocene to active volcanism in the Woodlark Rise and D'Entrecasteaux Islands results from decompression melting of a relict mantle wedge. The subduction zone geochemical signatures (negative HFSE anomalies) in Woodlark Rift lavas younger than 4 m.y. are a relict from older subduction beneath eastern Papua, likely in the middle Miocene. As the lithosphere is extended ahead of the tip of the westward propagating seafloor spreading center in the Woodlark Basin, the composition of volcanism is inherited from prior arc magmatism (via flux melting) and through time evolves toward magmatism associated with a rifting

  10. Episodic Holocene eruption of the Salton Buttes rhyolites, California, from paleomagnetic, U-Th, and Ar/Ar dating (United States)

    Wright, Heather M.; Vazquez, Jorge A.; Champion, Duane E.; Calvert, Andrew T.; Mangan, Margaret T.; Stelten, Mark; Cooper, Kari M.; Herzig, Charles; Schriener, Alexander


    In the Salton Trough, CA, five rhyolite domes form the Salton Buttes: Mullet Island, Obsidian Butte, Rock Hill, North and South Red Hill, from oldest to youngest. Results presented here include 40Ar/39Ar anorthoclase ages, 238U-230Th zircon crystallization ages, and comparison of remanent paleomagnetic directions with the secular variation curve, which indicate that all domes are Holocene. 238U-230Th zircon crystallization ages are more precise than but within uncertainty of 40Ar/39Ar anorthoclase ages, suggesting that zircon crystallization proceeded until shortly before eruption in all cases except one. Remanent paleomagnetic directions require three eruption periods: (1) Mullet Island, (2) Obsidian Butte, and (3) Rock Hill, North Red Hill, and South Red Hill. Borehole cuttings logs document up to two shallow tephra layers. North and South Red Hills likely erupted within 100 years of each other, with a combined 238U-230Th zircon isochron age of: 2.83 ± 0.60 ka (2 sigma); paleomagnetic evidence suggests this age predates eruption by hundreds of years (1800 cal BP). Rock Hill erupted closely in time to these eruptions. The Obsidian Butte 238U-230Th isochron age (2.86 ± 0.96 ka) is nearly identical to the combined Red Hill age, but its Virtual Geomagnetic Pole position suggests a slightly older age. The age of aphyric Mullet Island dome is the least well constrained: zircon crystals are resorbed and the paleomagnetic direction is most distinct; possible Mullet Island ages include ca. 2300, 5900, 6900, and 7700 cal BP. Our results constrain the duration of Salton Buttes volcanism to between ca. 5900 and 500 years.

  11. Paleozoic accretionary orogenesis in the eastern Beishan orogen: constraints from zircon U-Pb and 40Ar/39Ar geochronology (United States)

    Ao, Songjian; Xiao, Wenjiao; Windley, Brian; Mao, Qigui


    The continental growth mechanism of the Altaids in Central Asia is still in controversy between models of continuous subduction-accretion versus punctuated accretion by closure of multiple oceanic basins. The Beishan orogenic belt, located in the southern Altaids, is a natural laboratory to address this controversy. Key questions that are heavily debated are: the closure time and subduction polarity of former oceans, the emplacement time of ophiolites, and the styles of accretion and collision. This paper reports new structural data, zircon ages and Ar-Ar dates from the eastern Beishan Orogen that provide information on the accretion process and tectonic affiliation of various terranes. Our geochronological and structural results show that the younging direction of accretion was northwards and the subduction zone dipped southwards under the northern margin of the Shuangyingshan micro-continent. This long-lived and continuous accretion process formed the Hanshan accretionary prism. Our field investigations show that the emplacement of the Xiaohuangshan ophiolite was controlled by oceanic crust subduction beneath the forearc accretionary prism of the Shuangyingshan-Mazongshan composite arc to the south. Moreover, we address the age and terrane affiliation of lithologies in the eastern Beishan orogen through detrital zircon geochronology of meta-sedimentary rocks. We provide new information on the ages, subduction polarities, and affiliation of constituent structural units, as well as a new model of tectonic evolution of the eastern Beishan orogen. The accretionary processes and crustal growth of Central Asia were the result of multiple sequences of accretion and collision of manifold terranes. Reference: Ao, S.J., Xiao, W., Windley, B.F., Mao, Q., Han, C., Zhang, J.e., Yang, L., Geng, J., Paleozoic accretionary orogenesis in the eastern Beishan orogen: Constraints from zircon U-Pb and 40Ar/39Ar geochronology. Gondwana Research, doi:

  12. Mars Atmospheric History Derived from Upper-Atmospheric Structure of 38Ar/36Ar Measured From MAVEN (United States)

    Jakosky, Bruce; Slipski, Marek; Benna, Mehdi; Mahaffy, Paul; Elrod, Meredith K.; Yelle, Roger; Stone, Shane; Alsaeed, Noora


    Measurements of the structure of the Martian upper atmosphere made from MAVEN observations allow us to derive homopause and exobase altitudes in the Mars upper atmosphere and to determine the isotopic fractionation that occurs between them. Fractionation in the ratio of 38Ar/36Ar occurs between the homopause and exobase due to diffusive separation. This fractionation, combined with measurements of the bulk atmospheric ratio, is used to determine the total amount of argon lost to space by pick-up-ion sputtering. Our analysis is based on Rayleigh distillation, modified by replenishment of gas to the atmosphere by outgassing, impact, and crustal weathering. Approximately 80 % of the 36Ar that was ever in the atmosphere has been removed through time. This high value requires that a major fraction of Mars atmospheric gas has been lost to space. It points strongly to loss to space as having been the dominant mechanism driving the transition in Martian climate from an early, warm, wet environment to today's cold, dry, thin atmosphere.

  13. Evaluation of sintering effects on SiC-incorporated UO2 kernels under Ar and Ar-4%H2 environments (United States)

    Silva, Chinthaka M.; Lindemer, Terrence B.; Hunt, Rodney D.; Collins, Jack L.; Terrani, Kurt A.; Snead, Lance L.


    Silicon carbide (SiC) is suggested as an oxygen getter in UO2 kernels used for tristructural isotropic (TRISO) particle fuels and to prevent kernel migration during irradiation. Scanning electron microscopy and X-ray diffractometry analyses performed on sintered kernels verified that an internal gelation process can be used to incorporate SiC in UO2 fuel kernels. Even though the presence of UC in either argon (Ar) or Ar-4%H2 sintered samples suggested a lowering of the SiC up to 3.5-1.4 mol%, respectively, the presence of other silicon-related chemical phases indicates the preservation of silicon in the kernels during sintering process. UC formation was presumed to occur by two reactions. The first was by the reaction of SiC with its protective SiO2 oxide layer on SiC grains to produce volatile SiO and free carbon that subsequently reacted with UO2 to form UC. The second process was direct UO2 reaction with SiC grains to form SiO, CO, and UC. A slightly higher density and UC content were observed in the sample sintered in Ar-4%H2, but both atmospheres produced kernels with ˜95% of theoretical density. It is suggested that incorporating CO in the sintering gas could prevent UC formation and preserve the initial SiC content.

  14. WA1ms: A ∼2.61 Ga muscovite standard for 40Ar/39Ar dating (United States)

    Jourdan, Fred; Frew, Adam; Joly, Aurore; Mayers, Celia; Evans, Noreen J.


    The 40Ar/39Ar dating technique requires the use of neutron fluence monitors (standards) to allow calculation of the age of a sample. Precise calibration of these standards is crucial to obtaining accurate ages and decreasing the uncertainties associated with 40Ar/39Ar dates. Few fully intercalibrated 40Ar/39Ar standards with a sufficient total fusion grain-to-grain reproducibility are currently in use in the argon community. For Precambrian samples, only Hb3gr hornblende (∼1.08 Ga) yields sufficient grain-to-grain reproducibility and has an appropriate age for acceptable argon isotopic ratio measurements. Here, we present chemical and intercalibration results for a new ∼2.61 Ga standard. WA1ms is a muscovite extracted from an Archaean shear zone in the Lake Johnston greenstone belt, Western Australia. In situ trace element analysis by ELA-ICPMS revealed consistent K contents, subtle zonation and intra-grain and grain-to-grain heterogeneities in Rb, Sr, Ti, and Fe but a lack of mineral inclusions.WA1ms has been investigated over 3 irradiations ranging from 25 to 40 h, in two reactors, with several disc positions and three grains sizes and has been calibrated against FCs and GA1550, and Hb3gr. Overall, we carried out 48 total fusion and 4 step-heating experiments of WA1ms crystals. Flat age spectra and average F-value (40Ar∗/39ArK) relative standard deviations ranging from of 0.43% to 0.60% (P = 0.15-0.83) for 47/48 analyses demonstrate the reproducibility of WA1ms and its suitability as a reliable 40Ar/39Ar standard. We calculated R[WA1ms/FCs] = 205.59 ± 0.25, R[WA1ms/GA1550] = 57.25 ± 0.06 and R[WA1ms/Hb3gr] = 3.9713 ± 0.014 (all with P > 0.14) allowing direct comparison between WA1ms and any standards in used in the community, provided that they have been calibrated against any of the three standards used in the calibration and regardless of the age adopted for each of these standards. The recently revised decay constant values and standard ages proposed

  15. Pneumatically sprayed Cu2ZnSnS4 films under Ar and Ar-H2 atmosphere (United States)

    Espindola Rodriguez, M.; Sylla, D.; Sanchez, Y.; López-Marino, S.; Fontané, X.; López-García, J.; Placidi, M.; Pérez-Rodríguez, A.; Vigil-Galán, O.; Saucedo, E.


    Cu2ZnSnS4 (CZTS) thin films have been deposited by pneumatic spray pyrolysis onto soda-lime glass and Mo-coated glass substrates by using a special reactor designed for working under controlled atmospheres. The films were grown using both Ar and Ar-H2 as the carrier gas and atmosphere, aiming to eliminate the oxygen-containing atmosphere from the classical spray pyrolysis configuration that uses air as the carrier gas. Thin films with different compositions were prepared and thermally annealed to investigate its compositional and physical properties and its performance as absorber layers in solar cells. To know the impact of the thermal annealing, two different annealing temperatures were used: 550 and 580 °C, both for 30 min. The last temperature showed a great improvement in the crystallinity and allowed a better incorporation of Sn into the films. The optical band gap of the annealed films was found to be around 1.45 eV. Cu-S and ZnO were found as contaminant phases in the as-grown Ar-sprayed samples, but were effectively transformed after annealing. ZnS was detected in both the as-grown and annealed films as the main secondary phase. Solar cells free of scarce elements were fabricated showing an improved conversion efficiency of 1.4%, evidencing the higher potential of this approach for the synthesis of device-grade films.

  16. 40Ar* loss in experimentally deformed muscovite and biotite with implications for 40Ar/39Ar geochronology of naturally deformed rocks (United States)

    Cosca, Michael; Stunitz, Holger; Bourgiex, Anne-Lise; Lee, John P.


    The effects of deformation on radiogenic argon (40Ar*) retentivity in mica are described from high pressure experiments performed on rock samples of peraluminous granite containing euhedral muscovite and biotite. Cylindrical cores, ~15 mm in length and 6.25 mm in diameter, were drilled from granite collected from the South Armorican Massif in northwestern France, loaded into gold capsules, and weld-sealed in the presence of excess water. The samples were deformed at a pressure of 10 kb and a temperature of 600 degrees C over a period 29 of hours within a solid medium assembly in a Griggs-type triaxial hydraulic deformation apparatus. Overall shortening in the experiments was approximately 10%. Transmitted light and secondary and backscattered electron imaging of the deformed granite samples reveals evidence of induced defects and for significant physical grain size reduction by kinking, cracking, and grain segmentation of the micas.

  17. Androgen receptor (AR) expression in AR-negative prostate cancer cells results in differential effects of DHT and IGF-I on proliferation and AR activity between localized and metastatic tumors. (United States)

    Plymate, Stephen R; Tennant, Marie K; Culp, Stephen H; Woodke, Lillie; Marcelli, Marco; Colman, Ilsa; Nelson, Peter S; Carroll, Julie M; Roberts, Charles T; Ware, Joy L


    Two features of the progression from organ-confined to metastatic prostate cancer are dysregulation of the androgen receptor (AR) and a decrease in insulin-like growth factor-type-I receptor (IGF-IR) expression. The purpose of this study was to determine the effect of changes in IGF-IR expression on AR activity. M12 human prostate cells were stably transfected with an AR expression construct to produce the M12-AR parental (PAR) cell line. PAR cells were implanted orthotopically into nude mice and M12-AR primary (PRI) cell lines were derived from intraprostatic tumors and metastatic cell lines (MET) were derived from PRI tumors that had metastasized to diaphragm or lung. Tumor formation in the prostate by PAR cells was decreased significantly compared to M12 controls. PAR, PRI, and MET cells expressed equivalent amounts of AR protein; however, IGF-IR expression was increased significantly in PAR and PRI cells. IGF-IR expression decreased in MET lines to the levels seen in M12 control cells. IGF-I significantly enhanced dihydrotestosterone (DHT)-stimulated, but not basal, AR transcriptional activity in PRI cells. In MET cells, IGF-I significantly suppressed DHT-stimulated transcriptional activity. In MET cells in which the IGF-IR was re-expressed from a retroviral vector, the effects of DHT and IGF-I on AR activity were similar to those seen in PRI cells. This study demonstrates that the changes in IGF-IR expression exhibited by this model of metastatic progression cause significant alterations in AR signaling and suggest that this interaction may be an important aspect of the changes seen in AR function in disease progression in vivo. 2004 Wiley-Liss, Inc.

  18. Audit, Control and Monitoring Design Patterns (ACMDP for Autonomous Robust Systems (ARS

    Directory of Open Access Journals (Sweden)

    C. Trad


    Full Text Available This paper proposes the Audit, Control and Monitoring Design Patterns (ACMDP for building Autonomous and Robust Systems (ARS such as Mobile Robot Systems (MRS. These patterns are also applicable to other Mission Critical and Complex Systems (MCCS. This paper presents a proposal which will help ARS project managers and engineers design, build and estimate the probability that an ARS will succeed or fail. Furthermore, this proposal offers the possibility to ARS problems with the help of audit, monitoring and controlling components, adjust the project management pathways, and define the problem sources as well as their possible solutions, in order to deliver an ARS or an MRS.

  19. High-Energy Ions Emitted from Ar Clusters Irradiated by Intense Femtosecond Laser Pulses

    Institute of Scientific and Technical Information of China (English)

    LI Zhong; LEI An-Le; NI Guo-Quan; XU Zhi-Zhan


    We have experimentally studied the energy spectra of Ar ions emitted from Ar clusters irradiated by intense femtosecond laser pulses. The Ar clusters were produced in the adiabatic expansion of Ar gas into vacuum at high backing pressures. The laser peak intensity was about 2×106 W/cm2 with a pulse duration of 45 fs. The maximum and the average energies of Ar ions are 0.2 MeV and 15kev at a backing pressure of 2. S MPa, respectively. They are almost independent of the backing pressures in the range of 0.6 to 4.5 MPa.

  20. Comparative Genomic Analysis Reveals Organization, Function and Evolution of ars Genes in Pantoea spp.


    Wang, Liying; Wang, Jin; Jing, Chuanyong


    Numerous genes are involved in various strategies to resist toxic arsenic (As). However, the As resistance strategy in genus Pantoea is poorly understood. In this study, a comparative genome analysis of 23 Pantoea genomes was conducted. Two vertical genetic arsC-like genes without any contribution to As resistance were found to exist in the 23 Pantoea strains. Besides the two arsC-like genes, As resistance gene clusters arsRBC or arsRBCH were found in 15 Pantoea genomes. These ars clusters we...

  1. Identification of a new androgen receptor (AR) co-regulator BUD31 and related peptides to suppress wild-type and mutated AR-mediated prostate cancer growth via peptide screening and X-ray structure analysis. (United States)

    Hsu, Cheng-Lung; Liu, Jai-Shin; Wu, Po-Long; Guan, Hong-Hsiang; Chen, Yuh-Ling; Lin, An-Chi; Ting, Huei-Ju; Pang, See-Tong; Yeh, Shauh-Der; Ma, Wen-Lung; Chen, Chung-Jung; Wu, Wen-Guey; Chang, Chawnshang


    Treatment with individual anti-androgens is associated with the development of hot-spot mutations in the androgen receptor (AR). Here, we found that anti-androgens-mt-ARs have similar binary structure to the 5α-dihydrotestosterone-wt-AR. Phage display revealed that these ARs bound to similar peptides, including BUD31, containing an Fxx(F/H/L/W/Y)Y motif cluster with Tyr in the +5 position. Structural analyses of the AR-LBD-BUD31 complex revealed formation of an extra hydrogen bond between the Tyr+5 residue of the peptide and the AR. Functional studies showed that BUD31-related peptides suppressed AR transactivation, interrupted AR N-C interaction, and suppressed AR-mediated cell growth. Combination of peptide screening and X-ray structure analysis may serve as a new strategy for developing anti-ARs that simultaneously suppress both wt and mutated AR function.

  2. Production and release rate of (37)Ar from the UT TRIGA Mark-II research reactor. (United States)

    Johnson, Christine; Biegalski, Steven R; Artnak, Edward J; Moll, Ethan; Haas, Derek A; Lowrey, Justin D; Aalseth, Craig E; Seifert, Allen; Mace, Emily K; Woods, Vincent T; Humble, Paul


    Air samples were taken at various locations around The University of Texas at Austin's TRIGA Mark II research reactor and analyzed to determine the concentrations of (37)Ar, (41)Ar, and (133)Xe present. The measured ratio of (37)Ar/(41)Ar and historical records of (41)Ar releases were then utilized to estimate an annual average release rate of (37)Ar from the reactor facility. Using the calculated release rate, atmospheric transport modeling was performed in order to determine the potential impact of research reactor operations on nearby treaty verification activities. Results suggest that small research reactors (∼1 MWt) do not release (37)Ar in concentrations measurable by currently proposed OSI detection equipment.

  3. Estudio del sistema simbiótico AR Pavonis (United States)

    Quiroga, C.; Brandi, E.; Ferrer, O.; García, L.; Barbá, R.

    Se presenta un estudio espectroscópico y polarimétrico de la binaria eclipsante AR Pavonis a partir de observaciones obtenidas con el telescopio de 2.15 m. del CASLEO (San Juan). El estudio de la naturaleza del sistema se realizó a través del análisis de algunos espectros reunidos entre los años 1990 y 1995 y de datos polarimétricos correspondientes al intervalo 1995 y 1997. El análisis espectroscópico indica que AR Pav está compuesta por una gigante roja M3.7 y una componente caliente compacta, con una temperatura mayor a 90000 K y una luminosidad del orden de 500Lsolar. A lo largo del período orbital, las variaciones observadas en flujo y en velocidades radiales, reflejan que las emisiones permitidas se forman en una región que rodea la componente caliente. El estudio de la polarización lineal de AR Pav indica que además de una componente interestelar, existe una componente intrínseca del sistema que varía temporalmente y con la longitud de onda de la luz polarizada. El distinto comportamiento del grado de polarización y del ángulo de posición observado en fases diferentes, sugiere que distintos mecanismos pueden estar actuando, dependiendo de la región de scattering observado a lo largo de la línea de la visual.

  4. Rotational Spectrum of Ar...PROPARGYL Alcohol Complex (United States)

    Mani, Devendra; Shahi, Abhishek; Arunan, E.


    Pure rotational spectrum for Ar...Propargyl alcohol complex has been observed and fitted. Fitted rotational constants for the complex are : A=4346.17307(90) MHz, B=1617.15317(19)MHz and C= 1245.42065(15) MHz. These rotational constants are very close to the ab-initio rotational constants for the geometry, in which propargyl alcohol exists in gauche conformation and Ar interacts with both, the hydroxyl group and the acetylenic group of propargyl alcohol. Rotational spectrum of deuterated isotopologue (-OD) of the complex further confirms the existence of the above mentioned geometry. In previous studies tunneling frequency corresponding to -OH tunneling motion in propargyl alocohol monomer was determined to be 652.4 GHz and for -OD tunneling motion in mono-deuterated species, it was 213.5 GHz. In Ar...Propargyl alcohol complex also, a-type and c-dipole transitions show tunneling splitting. In the parent complex, for a-type transitions, tunneling splitting was 10 KHz and for c-type transitions (c-dipole of the complex is in the same direction as in propargyl alcohol monomer, and it is antisymmetric with respect to OH tunneling motion in both monomer and the complex), it was 2.59 MHz. In deuterated complex (OD) splitting was not resolvable for a-type transitions while for c-type it reduces to 900 KHz. Search for C-13 isotopologues is in progress. Moreover, propargyl alcohol offers several possibilities for H-bonding and we are planning to study its complexes with water in near future. Results will be presented in the talk. E. Hirota,J. Mol. Spectrosc. 26 (1968) 335-350. J.C. Pearson, B.J. Drouin, J. Mol. Spectrosc. 234 (2005) 149-156.

  5. Multi-particle Emission from ${^{31}}$Ar at ISOLDE

    CERN Document Server

    Marroquin, I; Ciemny, A A; de Witte, H; Fraile, L M; Fynbo, H O U; Garzón-Camacho, A; Howard, A; Johansson, H; Jonson, B; Kirsebom, O S; Koldste, G T; Lica, R; Lund, M V; Madurga, M; Mazzocchi, C; Mihai, C; Munch, M; Nae, S A; Nacher, E; Negret, A; Nilsson, T; Perea, A; Refsgaard, J; Riisager, K; Rapisarda, E; Sotty, C; Stanoiu, M; Tengblad, O; Turturica, A E; Vedia, M V


    A multi-particle decay experiment was successfully performed at the ISOLDE Decay Station. In this new permanent station, devoted to\\break $\\beta$-decay studies, the novel MAGISOL Si-Plugin Chamber was installed to study the exotic decay modes of the proton drip-line nucleus ${^{31}}$Ar. The motivation was to search for $\\beta3p$ and $\\beta3p\\gamma$ channels, as well as to provide information on resonances in ${^{30}}$S and ${^{29}}$P relevant for the astrophysical\\break rp-process. Description of the experimental set-up and preliminary results are presented.

  6. Adsorption of Ar on individual carbon nanotubes, graphene, and graphite (United States)

    Dzyubenko, Boris; Kahn, Joshua; Vilches, Oscar; Cobden, David


    We compare and contrast results of adsorption measurements of Ar on single-walled carbon nanotubes, graphene, and graphite. Adsorption isotherms on individual suspended nanotubes were obtained using both the mechanical resonance frequency shift (sensitive to mass adsorption) and the electrical conductance. Isotherms on graphene mounted on hexagonal boron nitride were obtained using only the conductance. New volumetric adsorption isotherms on bulk exfoliated graphite were also obtained, paying special attention to the very low coverage region (less than 2% of a monolayer). This allowed us to compare the degree of heterogeneity on the three substrate types, the binding energies, and the van der Waals 2D parameters. Research supported by NSF DMR 1206208.

  7. AR-based Algorithms for Short Term Load Forecast

    Directory of Open Access Journals (Sweden)

    Zuhairi Baharudin


    Full Text Available Short-term load forecast plays an important role in planning and operation of power systems. The accuracy of the forecast value is necessary for economically efficient operation and effective control of the plant. This study describes the methods of Autoregressive (AR Burg’s and Modified Covariance (MCOV in solving the short term load forecast. Both algorithms are tested with power load data from Malaysian grid and New South Wales, Australia. The forecast accuracy is assessed in terms of their errors. For the comparison the algorithms are tested and benchmark with the previous successful proposed methods.

  8. Tissue Characterization on Common Carotid Artery using AR Model (United States)

    Koya, Yoshiharu; Mizoshiri, Isao

    This study uses one image with a echocardiography and detects arteriosclerosis on the common carotid artery by tissue characterization. The conventional methods are measurement of thickness on the vessel wall or stiffness on the common carotid artery. However, they need frames of several beats and great calculation times. But, we detect the arteriosclerosis with only one image. Our method estimate the grade of arteriosclerosis by AR model parameters fitted to the texture on the lumen-intima wall. Experimental results show the validity of the proposed method.

  9. Predication of Crane Condition Parameters Based on SVM and AR (United States)

    Xiuzhong, Xu; Xiong, Hu; Congxiao, Zhou


    Through statistic analysis of vibration signals of motor on the container crane hoisting mechanism in a port, the feature vectors with vibration are obtained. Through data preprocessing and training data, Training models of condition parameters based on support vector machine (SVM) are established. The testing data of condition monitoring parameters can be predicted by the training models. During training the models, the penalty parameter and kernel function of model are optimized by cross validation. In order to analysis the accurate of SVM model, autoregressive model is used to predict the trend of vibration. The research showed the predicted results of model using SVM are better than the results by autoregressive (AR) modeling.

  10. Energy Levels of Highly Ionized Ar ⅩⅣ

    Institute of Scientific and Technical Information of China (English)

    CHENG Zhang; LI Ping; DENG Xiao-Hui


    With the Breit interaction and quantum electrodynamics corrections considered, relativistic configuration interaction calculations have been carried out in the extended optimal level scheme using multi-configuration Dirac-Fock wave functions on the 204 energy levels and electric dipole transitions of Ar ⅩⅣ. The results of electric dipole transitions are in good agreement with experiments. Among the energy levels calculated, the lowest 125 levels are in good agreement with available experimental and other theoretical ones, and the other 79 levels are new ones obtained by the present work. This wide range of atomic energy levels is useful in astrophysics and plasma physics.

  11. X-ray calculations for a NLTE Ar plasma

    Institute of Scientific and Technical Information of China (English)

    WU Ze-qing; PANG Jin-qiao; HAN Guo-xing


    A model is developed to calculate emission spectrum of non-local thermodynamic equilibrium(NLTE) plasmas. The Collisional-Radiative model is adopted for non-LTE population calculations. Configuration-averaged rate coefficients that needed in the rate equations are obtained based on the first order perturbation theory. The Hatree-Fock-Slater self-consistent-field method is used to calculate electron wave functions. The present model is applied to the calculation of emissivity from a Ar plasma. The features of the spectra are in good agreement with those calculated by other theoretical models, but the data of the integrated emissivity differ by a factor 2~8.

  12. The readout system for the ArTeMis camera (United States)

    Doumayrou, E.; Lortholary, M.; Dumaye, L.; Hamon, G.


    During ArTeMiS observations at the APEX telescope (Chajnantor, Chile), 5760 bolometric pixels from 20 arrays at 300mK, corresponding to 3 submillimeter focal planes at 450μm, 350μm and 200μm, have to be read out simultaneously at 40Hz. The read out system, made of electronics and software, is the full chain from the cryostat to the telescope. The readout electronics consists of cryogenic buffers at 4K (NABU), based on CMOS technology, and of warm electronic acquisition systems called BOLERO. The bolometric signal given by each pixel has to be amplified, sampled, converted, time stamped and formatted in data packets by the BOLERO electronics. The time stamping is obtained by the decoding of an IRIG-B signal given by APEX and is key to ensure the synchronization of the data with the telescope. Specifically developed for ArTeMiS, BOLERO is an assembly of analogue and digital FPGA boards connected directly on the top of the cryostat. Two detectors arrays (18*16 pixels), one NABU and one BOLERO interconnected by ribbon cables constitute the unit of the electronic architecture of ArTeMiS. In total, the 20 detectors for the tree focal planes are read by 10 BOLEROs. The software is working on a Linux operating system, it runs on 2 back-end computers (called BEAR) which are small and robust PCs with solid state disks. They gather the 10 BOLEROs data fluxes, and reconstruct the focal planes images. When the telescope scans the sky, the acquisitions are triggered thanks to a specific network protocol. This interface with APEX enables to synchronize the acquisition with the observations on sky: the time stamped data packets are sent during the scans to the APEX software that builds the observation FITS files. A graphical user interface enables the setting of the camera and the real time display of the focal plane images, which is essential in laboratory and commissioning phases. The software is a set of C++, Labview and Python, the qualities of which are respectively used

  13. Eruption of the Continental Flood Basalts at ~259 Ma in the Emeishan Large Igneous Province, SW China: Evidence from Laser Microprobe 40Ar/39Ar Dating

    Institute of Scientific and Technical Information of China (English)

    HOU Zengqian; CHEN Wen; LU Jiren


    A suite of continental flood basalts sampled over a vast exposure and stratigraphic thickness in the Emeishan large igneous province (LLP), SW China was investigated for laser microprobe 40Ar/39Ar dating. There are two 40Ar/39Ar age groups for these basalts, corresponding to 259-246 Ma and 177-137 Ma, respectively. A well-defined isochron gives an eruption age of huge quantities of mafic magmas at 258.9±3.4 Ma, which is identical to previous dating and paleontological data. Much younger 40Ar/39Ar ages for some basalts with low-greenschist metamorphic facies probably recorded a late thermo-tectonic event caused by collision between the Yangtze and Qiangtang continental blocks during the Mesozoic, which resulted in the reset of argon isotope system. The 40Ar/39Ar age data, we present here, combined with previous dating and paleontological data, suggest relatively short duration (about 3 Ma) of mafic volcanism, which have important implication on mantle plume genesis of the Emeishan continental flood basalts in the LIP.

  14. Jauno vecāku apmierinātības ar attiecībām saistība ar vecāku stresu.


    Strangate, Ilze


    Bakalaura darba mērķis ir izpētīt apmierinātības ar pāra attiecībām saistību ar vecāku stresu, un atbildēt uz jautājumiem - Vai pastāv saistība starp jauno vecāku apmierinātību ar attiecībām un vecāku stresu? Vai pastāv apmierinātības ar attiecībām un vecāku stresa saistības atšķirības jaunajām mātēm un tēviem? Vai atšķiras apmierinātība ar attiecībām un vecāku stress jaunajiem vecākiem ar dažādu kopdzīves veidu? Vai kopdzīves ilgums ir saistīts ar apmierinātību ar attiecībām un vecāku stresu...

  15. Time and Spectrally Resolved Fluorescence of Cl*2 and ArCl* in Cl2 Doped Ar Under State Selective Pulsed Photoexcitation with Synchrotron Radiation (United States)

    Möller, T.; Jordan, B.; Zimmerer, G.; Haaks, D.; Le Calvé, J.; Castex, M.-C.


    Synchrotron Radiation is used to selectively excite chlorine and Cl2 doped argon in the VUV region. Stationary fluorescence and excitation spectra of the 11Σ{/u +}, 21Σ{/u +} and 23Π g Cl{2/*} states and of the ArCl*( B-X) transition are obtained. The excitation threshold of ArCl*( B) in Ar/Cl2 system is found to be 1,285±5 Å and that of ArCl( C) at ˜1,260 Å. The formation of ArCl* and Cl*2(23Π g) is discussed in terms of recent potential curves data. A detailed time resolved study is reported which allows us to determine precisely the radiative lifetime of ArCl*( B) state (5.2 ns) and numerous kinetic parameters of this system, to estimate the C state energy and to discuss the relaxation and mixing process of the ArCl*( B) and ( C) states. A two ladder multilevel kinetic model is described which accounts for the experimental results and shows the difficulty of studying this particular ArCl* system as compared to the closely related XeCl* and KrCl* ones.

  16. Sedimentary cycles and volcanic ash beds in the Lower Pliocene lacustrine succession of Ptolemais (NW Greece): discrepancy between 40 Ar/39 Ar and astronomical ages

    NARCIS (Netherlands)

    Steenbrink, J.; Vugt, N. van; Hilgen, F.J.; Wijbrans, J.R.; Meulenkamp, J.E.


    A high-resolution cyclostratigraphy for the rhythmically bedded lignite-marl sequences of the Lower Pliocene Ptole-mais Formation is combined with 40 Ar= 39 Ar dating results of intercalated volcanic ash beds. Detailed field reconnaissance in three open-pit lignite mines reveals three end-member sed

  17. Surface modification and biocompatible improvement of polystyrene film by Ar, O{sub 2} and Ar + O{sub 2} plasma

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yashao, E-mail: [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, School of Chemistry and Chemical Engineering, Xi' an 710062 (China); Gao Qiang; Wan Haiyan; Yi Jinhong; Wei Yanlin [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, School of Chemistry and Chemical Engineering, Xi' an 710062 (China); Liu Peng [Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing 400044 (China)


    Highlights: Black-Right-Pointing-Pointer NVP is successfully grafted onto the different discharge gases (Ar, O{sub 2}, and Ar + O{sub 2}) plasma-treated PS film surface by Ar plasma induced graft polymerization. Black-Right-Pointing-Pointer Compare with Ar and O{sub 2} plasma, the Ar + O{sub 2} plasma-treated film surface introduced large amounts of NVP, as known from ATR-FTIR and XPS results. Black-Right-Pointing-Pointer According to SEM, the surface roughness increased at different levels after plasma treatment. Contact angle reveal that the hydrophilicity of the PS film surface was greatly improved. Black-Right-Pointing-Pointer Cellular compatibility tests indicate that Ar + O{sub 2} plasma is more capable of increasing cell adhesion and proliferation. - Abstract: This paper reports the surface modification of different discharge gases (Ar, O{sub 2}, and Ar + O{sub 2}) plasma-treated polystyrene (PS) film by Ar plasma induced graft polymerization, with biocompatible monomer N-vinyl-2-pyrrolidone (NVP) is carried out to improve biocompatibility. The films are characterized by attenuated total reflectance Fourier transfer infrared (ATR-FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Water contact angle measurement demonstrates the modified films possess a relatively hydrophilic surface. Furthermore, the films are also examined cell attachment and proliferation in vitro using mouse fibroblasts (L929 cells). The modified film surface shows a better cell distribution and growth than that of the pristine PS surface. From cell culture experiments, it is also observed that Ar + O{sub 2} plasma is more capable of increasing cell adhesion and proliferation. This method will provide a potential and effective solution for grafting useful component in future tissue-engineering applications.

  18. Dating fault-generated pseudotachylytes: comparison of 40Ar/39Ar stepwise-heating, laser-ablation and Rb-Sr microsampling analyses (United States)

    Müller, Wolfgang; Kelley, Simon; Villa, Igor


    Three different geochronological techniques (stepwise-heating, laser-ablation 40Ar/39Ar, Rb-Sr microsampling) have been evaluated for dating fault-generated pseudotachylytes sampled along the Periadriatic Fault System (PAF) of the Alps. Because pseudotachylytes are whole-rock systems composed of melt, clast and alteration phases, chemical control from both Ar isotopes (Cl/K, Ca/K ratios) and EMPA analyses is crucial for their discrimination. When applied to stepwise-heating 40Ar/39Ar analyses, this approach yields accurate melt-related ages, even for complex age spectra. The spatial resolution of laser-ablation 40Ar/39Ar analyses is capable of contrasting melt, clast and alteration phases in situ, provided the clasts are not too fine grained, the latter of which results in integrated "mixed" ages without geological information. Elevated Cl/K and Ca/K ratios were found to be an invaluable indicator for the presence of clast admixture or inherited 40Ar. Due to incomplete isotopic resetting during frictional melting, Rb-Sr microsampling dating did not furnish geologically meaningful ages. On the basis of isotopic disequilibria among pseudotachylyte matrix phases, and independent Rb-Sr microsampling dating of cogenetic (ultra)mylonites, the concordant 40Ar/39Ar pseudotachylyte ages are interpreted as formation ages. The investigated pseudotachylytes altogether reveal a Cretaceous to Miocene history for the entire PAF, consistent with independent geological evidence. Individual faults, however, consistently reveal narrower intervals of enhanced activity lasting a few million years. Electronic supplementary material to this paper can be obtained by using the Springer LINK server at

  19. Scientia sexualis versus ars erotica: Foucault, van Gulik, Needham. (United States)

    Rocha, Leon Antonio


    This paper begins with a discussion of the scientia sexualis/ars erotica distinction, which Foucault first advances in History of Sexuality Vol. 1, and which has been employed by many scholars to do a variety of analytical work. Though Foucault has expressed his doubts regarding his conceptualization of the differences between Western and Eastern discourses of desire, he never entirely disowns the distinction. In fact, Foucault remains convinced that China must have an ars erotica. I will explore Foucault's sources of authority. To this end, I introduce the work of famous Dutch sinologist Robert Hans van Gulik, who published the tremendously influential Sexual Life in Ancient China in 1961, and also explore Joseph Needham's view on Chinese sex. I argue that, Foucault, in his fierce polemic against the "Repressive Hypothesis", himself imagined a utopian Other where pleasure and desire were organised differently. I end on a discuss on Orientalism and the project of "Sinography" of comparative literature scholars Haun Saussy, Eric Hayot and others.

  20. An industrial approach to design compelling VR and AR experience (United States)

    Richir, Simon; Fuchs, Philippe; Lourdeaux, Domitile; Buche, Cédric; Querrec, Ronan


    The convergence of technologies currently observed in the field of VR, AR, robotics and consumer electronic reinforces the trend of new applications appearing every day. But when transferring knowledge acquired from research to businesses, research laboratories are often at a loss because of a lack of knowledge of the design and integration processes in creating an industrial scale product. In fact, the innovation approaches that take a good idea from the laboratory to a successful industrial product are often little known to researchers. The objective of this paper is to present the results of the work of several research teams that have finalized a working method for researchers and manufacturers that allow them to design virtual or augmented reality systems and enable their users to enjoy "a compelling VR experience". That approach, called "the I2I method", present 11 phases from "Establishing technological and competitive intelligence and industrial property" to "Improvements" through the "Definition of the Behavioral Interface, Virtual Environment and Behavioral Software Assistance". As a result of the experience gained by various research teams, this design approach benefits from contributions from current VR and AR research. Our objective is to validate and continuously move such multidisciplinary design team methods forward.

  1. Re-measurement of $^{32}$Ar to test the IMME

    CERN Multimedia

    The Isobaric Multiplet Mass Equation (IMME) has been subject to extensive studies in the low-mass region. Especially at the A = 32 quintet, the predicted quadratic form could not be confirmed, possible explanations being the insufficient accuracy of input parameters or higher-order interactions within the nucleon. For this quintet, the uncertainty on the mass-excess values of four of the five T = 2 multiplet members is extremely low: 0.6 keV for $^{32}$Cl, 0.3 keV for $^{32}$S, 0.2 keV for $^{32}$P, and 0.7 keV for $^{32}$Si. In the case of $^{32}$Ar, however, the uncertainty is as large as 1.8 keV. State-of-the-art high-precision Penning-trap mass spectrometry makes it possible to decrease this uncertainty. We propose to remeasure the mass of $^{32}$Ar at the Penning-trap mass spectrometer ISOLTRAP thus decreasing the uncertainty by a factor of 3-5. The proposed measurement is part of an experimental collaboration with JYFLTRAP, where the remaining masses of the T = 2 isospin quintet at A = 32 will be remeas...

  2. archAR: an archaeological augmented reality experience (United States)

    Wiley, Bridgette; Schulze, Jürgen P.


    We present an application for Android phones or tablets called "archAR" that uses augmented reality as an alternative, portable way of viewing archaeological information from UCSD's Levantine Archaeology Laboratory. archAR provides a unique experience of flying through an archaeological dig site in the Levantine area and exploring the artifacts uncovered there. Using a Google Nexus tablet and Qualcomm's Vuforia API, we use an image target as a map and overlay a three-dimensional model of the dig site onto it, augmenting reality such that we are able to interact with the plotted artifacts. The user can physically move the Android device around the image target and see the dig site model from any perspective. The user can also move the device closer to the model in order to "zoom" into the view of a particular section of the model and its associated artifacts. This is especially useful, as the dig site model and the collection of artifacts are very detailed. The artifacts are plotted as points, colored by type. The user can touch the virtual points to trigger a popup information window that contains details of the artifact, such as photographs, material descriptions, and more.

  3. Synthesis and characterization of Ar-annealed zinc oxide nanostructures

    Directory of Open Access Journals (Sweden)

    Narayanan Kuthirummal


    Full Text Available Nanostructured zinc oxide samples were synthesized through CVD and annealed in argon. The samples were investigated using SEM, TEM, XRD, and UV/VIS/FTIR photoacoustic spectroscopy. The SEM/TEM images show relatively spherical particles that form elongated, connected domains post-anneal. XRD measurements indicate a typical wurtzite structure and reveal an increase in average grain size from 16.3 nm to 21.2 nm in Ar-annealed samples over pristine samples. Visible photoacoustic spectra reveal the contribution of defect levels on the absorption edge of the fundamental gap of zinc oxide. The steepness parameter of the absorption edge, which is inversely proportional to the width of the absorption edge, decreased from 0.1582 (pristine to 0.1539 (annealed for 90 minutes revealing increased density of defect states upon annealing. The FTIR photoacoustic spectra show an intense peak at 412 cm-1 and a shoulder at 504 cm-1 corresponding to the two transverse optical stretching modes of ZnO. These results may indicate a self-assembly mechanism upon anneal under Ar atmosphere leading to early-stage nanorod growth.

  4. 40 Ar/39 Ar Ages of Auriferous Quartz Veins from the Fengyang and Zhangbaling Regions and Their Geological Significance

    Institute of Scientific and Technical Information of China (English)

    应汉龙; 赵利清


    Geotectonically the Fengyang and Zhangbaling regions belong to the North China craton and the Dabie-Sulu orogene, respectively. Neo-Archean gneiss and amphibolite and metamor-phosed sea-facies sodic volcanic rocks are the main outcrops in the two regions, respectively. The Zhangbaling terrane strike-skipped along the Tancheng-Lujiang fault zone in Mesozoic and Cenozo-ic eras and got close to the Fengyang terrane. Mesozoic Yanshanian intrusions occur broadly in the two regions. Gold-bearing quartz veins occur in the metamorphic rocks in the Fengyang region and in the granodiorite and metamorphosed sea-facies sodic volcanic rocks in the Zhangbaling region.Generally, the formation of the auriferous quartz veins involved three stages. At the first stage, gold-poor sulfide quartz veins were formed; at the second stage gold-rich quartz sulfide veins were formed; and at the third stage gold-poor barite and/or carbonate veins were formed. The 40Ar/39Ar step-heating plateau ages of the first-stage and the second-stage quartz aggregates from the Zhuding, Maoshan and Shangcheng gold deposits range between 116.1 + 0.6 Ma and 118.3 + 0.5 Ma and are pretty close to their least apparent ages and isochronal ages, respectively. All plat-eau, least apparent and isochronal ages range between 113.4 ± 0.4 Ma and 118.3 ± 0.5 Ma,which are considered as the formation age range of the quartz. It is reasonable and reliable to take the 40Ar/39Ar age range of the quartz as the formation age range of gold-bearing quartz veins on the basis of spatial relationship between gold-bearing quartz veins and their country rocks. The gold deposits in the two regions were formed in Aptian, Cretaceous, when the Tancheng-Lujiang fault zone moved as a normal fault with slightly right-lateral strike-skip, was extensional and expe-rienced very strong magmatic process. It is shown that the magmatic hydrothermal fluid is a very important part of the gold ore-forming hydrothermal fluid in the Fengyang and

  5. Multiplicity fluctuations in Ar+Sc collisions at the CERN SPS from NA61/SHINE arXiv

    CERN Document Server

    Seryakov, Andrey

    Multiplicity fluctuations were investigated in Ar+Sc collisions at 13A, 19A, 30A, 40A, 75A, 150A GeV/c using the NA61/SHINE detector at the SPS. Centrality selection is based on the nucleon-spectator energy in the forward hemisphere as measured by the Projectile spectator detector. Preliminary results on the scaled variance {\\omega} and the strongly intensive measure {\\Omega} were obtained for the multiplicity distribution of all, negatively and positively charged hadrons. Results are discussed and compared with p+p results and Pb+Pb data of NA49 and EPOS 1.99 simulations.

  6. Aurora A regulates expression of AR-V7 in models of castrate resistant prostate cancer (United States)

    Jones, Dominic; Noble, Martin; Wedge, Steve R.; Robson, Craig N.; Gaughan, Luke


    Androgen receptor variants (AR-Vs) provide a mechanism of therapy evasion in castrate-resistant prostate cancer (CRPC), yet mechanisms of regulation remain largely unknown. Here we investigate the role of Aurora A kinase on AR-Vs in models of CRPC and show depletion of Aurora A reduces AR-V target gene expression. Importantly, knockdown of Aurora A reconfigures splicing of AR pre-mRNA to discriminately down-regulate synthesis of AR-V transcripts, including AR-V7, without effecting full-length AR mRNA; and as a consequence, AR-V-driven proliferation and survival of CRPC cells is markedly reduced. Critically, these effects are reproduced by Aurora A inhibition. We show that Aurora A levels increase in advanced disease and AURKA is an AR-V target gene demonstrating a positive feedback mechanism of androgenic signalling in CRPC. In all, our data suggests that Aurora A plays a pivotal role in regulation of AR-V7 expression and represents a new therapeutic target in CRPC. PMID:28205582

  7. Acetalated dextran encapsulated AR-12 as a host-directed therapy to control Salmonella infection. (United States)

    Hoang, Ky V; Borteh, Hassan M; Rajaram, Murugesan V S; Peine, Kevin J; Curry, Heather; Collier, Michael A; Homsy, Michael L; Bachelder, Eric M; Gunn, John S; Schlesinger, Larry S; Ainslie, Kristy M


    AR-12 has been evaluated in clinical trials as an anti-cancer agent but also has demonstrated host-directed, broad-spectrum clearance of bacteria. We have previously shown that AR-12 has activity in vitro against Salmonella enterica serovar Typhimurium and Francisella species by inducing autophagy and other host immune pathways. AR-12 treatment of S. Typhimurium-infected mice resulted in a 10-fold reduction in bacterial load in the liver and spleen and an increased survival time. However, AR-12 treatment did not protect mice from death, likely due poor formulation. In the current study, AR-12 was encapsulated in a microparticulate carrier formulated from the novel degradable biopolymer acetalated dextran (Ace-DEX) and subsequently evaluated for its activity in human monocyte-derived macrophages (hMDMs). Our results show that hMDMs efficiently internalized Ace-DEX microparticles (MPs), and that encapsulation significantly reduced host cell cytotoxicity compared to unencapsulated AR-12. Efficient macrophage internalization of AR-12 loaded MPs (AR-12/MPs) was further demonstrated by autophagosome formation that was comparable to free AR-12 and resulted in enhanced clearance of intracellular Salmonella. Taken together, these studies provide support that Ace-DEX encapsulated AR-12 may be a promising new therapeutic agent to control intracellular bacterial pathogens of macrophages by targeting delivery and reducing drug toxicity.

  8. A novel MAs(III)-selective ArsR transcriptional repressor. (United States)

    Chen, Jian; Nadar, Venkadesh Sarkarai; Rosen, Barry P


    Microbial expression of genes for resistance to heavy metals and metalloids is usually transcriptionally regulated by the toxic ions themselves. Arsenic is a ubiquitous, naturally occurring toxic metalloid widely distributed in soil and groundwater. Microbes biotransform both arsenate (As(V)) and arsenite (As(III)) into more toxic methylated metabolites methylarsenite (MAs(III)) and dimethylarsenite (DMAs(III)). Environmental arsenic is sensed by members of the ArsR/SmtB family. The arsR gene is autoregulated and is typically part of an operon that contains other ars genes involved in arsenic detoxification. To date every identified ArsR is regulated by inorganic As(III). Here we described a novel ArsR from Shewanella putrefaciens selective for MAs(III). SpArsR orthologs control expression of two MAs(III) resistance genes, arsP that encodes the ArsP MAs(III) efflux permease, and arsH encoding the ArsH MAs(III) oxidase. SpArsR has two conserved cysteine residues, Cys101 and Cys102. Mutation of either resulted in loss of MAs(III) binding, indicating that they form an MAs(III) binding site. SpArsR can be converted into an As(III)-responsive repressor by introduction of an additional cysteine that allows for three-coordinate As(III) binding. Our results indicate that SpArsR evolved selectivity for MAs(III) over As(III) in order to control expression of genes for MAs(III) detoxification. © 2017 John Wiley & Sons Ltd.

  9. ID4 promotes AR expression and blocks tumorigenicity of PC3 prostate cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Komaragiri, Shravan Kumar; Bostanthirige, Dhanushka H.; Morton, Derrick J.; Patel, Divya; Joshi, Jugal; Upadhyay, Sunil; Chaudhary, Jaideep, E-mail:


    Deregulation of tumor suppressor genes is associated with tumorigenesis and the development of cancer. In prostate cancer, ID4 is epigenetically silenced and acts as a tumor suppressor. In normal prostate epithelial cells, ID4 collaborates with androgen receptor (AR) and p53 to exert its tumor suppressor activity. Previous studies have shown that ID4 promotes tumor suppressive function of AR whereas loss of ID4 results in tumor promoter activity of AR. Previous study from our lab showed that ectopic ID4 expression in DU145 attenuates proliferation and promotes AR expression suggesting that ID4 dependent AR activity is tumor suppressive. In this study, we examined the effect of ectopic expression of ID4 on highly malignant prostate cancer cell, PC3. Here we show that stable overexpression of ID4 in PC3 cells leads to increased apoptosis and decreased cell proliferation and migration. In addition, in vivo studies showed a decrease in tumor size and volume of ID4 overexpressing PC3 cells, in nude mice. At the molecular level, these changes were associated with increased androgen receptor (AR), p21, and AR dependent FKBP51 expression. At the mechanistic level, ID4 may regulate the expression or function of AR through specific but yet unknown AR co-regulators that may determine the final outcome of AR function. - Highlights: • ID4 expression induces AR expression in PC3 cells, which generally lack AR. • ID4 expression increased apoptosis and decreased cell proliferation and invasion. • Overexpression of ID4 reduces tumor growth of subcutaneous xenografts in vivo. • ID4 induces p21 and FKBP51 expression- co-factors of AR tumor suppressor activity.

  10. Geology, geochemistry and Ar Ar geochronology of the Nangimali ruby deposit, Nanga Parbat Himalaya (Azad Kashmir, Pakistan) (United States)

    Pêcher, A.; Giuliani, G.; Garnier, V.; Maluski, H.; Kausar, A. B.; Malik, R. H.; Muntaz, H. R.


    The Nangimali ruby deposit in the southern part of the Nanga Parbat Himalaya, has been investigated through field work, geochemistry, stable and radiogenic isotopes. It outcrops in the Shontar valley in a large north-vergent syncline consisting of high-grade metamorphic gneisses capped by a metasedimentary series dominated by marbles and amphibolites. The ore-body is stratiform. Ruby is found within 0.1-2 cm thick shear-veinlets and gash veins cutting dolomitic marbles and carbonate-bearing bands. The marbles of the Nangimali Formation display restricted ranges in δ18O (from 23.6 to 27.6‰ relative to SMOW) and in δ13C (from -1.9 to 2.6‰ relative to PDB). Fluid infiltration along the shear-zone in the marble has no effect on the isotopic signatures of the carbonates. Fluids are metamorphic and CO 2 is derived from the decarbonation of marbles. Mass-balance and geochemical analyses suggest that the mobilisation by the fluids of aluminium and chromium in the marbles is sufficient to enable the formation of ruby in the shear-zone. Rubies have been indirectly dated using a stepwise 40Ar- 39Ar laser heating technique on syngenetic phlogopites. The Miocene age records a Neogene cooling in the South of the Nanga Parbat massif and a minimum formation age for ruby of 16 Ma.

  11. Potash-rich volcanic rocks and lamprophyres in western Shandong Province: 40Ar39Ar dating and source tracing

    Institute of Scientific and Technical Information of China (English)


    Highly precise 40Ar39Ar dating results demonstrate that the ages of potash-rich volcanic rocks in western Shandong Province are 114.7-124.3 Ma, and that of the lamprophyres is 119.6 Ma. The potash-rich volcanic rocks have relatively high (87Sr/86Sr)i ratios ( 0.708715-0.711418)and distinctly negative εNd values ( -11.47 - -17.54), and are enriched in radiogenic lead (206Pb/204pb=17.341-17.622,207pb/204Pb=15.525-15.538, 208Pb/204pb = 37.563-37.684).Similarly, the lamprophyres also have quite low εNd values ( -11.57 - -19.64). Based on the fact that the Sr, Nd and Pb isotopic compositions of potash-rich volcanic rocks are very consistent with that of the clinopyroxene separates, and by integrating comprehensive analyses of their tectonic settings,and extensive comparisons of the Sr, Nd isotopic compositions with that of the related simultaneous rocks, it is concluded that the potash-rich volcanic rocks and lamprophyres in western Shandong Province were most possibly derived from the partial melting of enriched mantle which was caused by source contamination and metasomatism of subducted continental crustal materials.``

  12. High resolution mapping of Dense spike-ar ( to the genetic centromere of barley chromosome 7H. (United States)

    Shahinnia, Fahimeh; Druka, Arnis; Franckowiak, Jerome; Morgante, Michele; Waugh, Robbie; Stein, Nils


    Spike density in barley is under the control of several major genes, as documented previously by genetic analysis of a number of morphological mutants. One such class of mutants affects the rachis internode length leading to dense or compact spikes and the underlying genes were designated dense spike (dsp). We previously delimited two introgressed genomic segments on chromosome 3H (21 SNP loci, 35.5 cM) and 7H (17 SNP loci, 20.34 cM) in BW265, a BC(7)F(3) nearly isogenic line (NIL) of cv. Bowman as potentially containing the dense spike mutant locus, by genotyping 1,536 single nucleotide polymorphism (SNP) markers in both BW265 and its recurrent parent. Here, the gene was allocated by high-resolution bi-parental mapping to a 0.37 cM interval between markers SC57808 (Hv_SPL14)-CAPSK06413 residing on the short and long arm at the genetic centromere of chromosome 7H, respectively. This region putatively contains more than 800 genes as deduced by comparison with the collinear regions of barley, rice, sorghum and Brachypodium, Classical map-based isolation of the gene thus will be complicated due to the infavorable relationship of genetic to physical distances at the target locus.

  13. 40Ar-39Ar Age Constraints on Volcanism and Tectonism in the Terror Rift of the Ross Sea, Antarctica (United States)


    Volcanic sills and dikes inferred from seismic reflection profiles and geophysical studies of the Ross Sea are thought to be related to the rift basins in the region, and their emplacement to be coeval with extension. However, lack of precise geochronology in the Terror Rift of the Ross Sea region has left these inferred relationships poorly constrained and has hindered neotectonic studies, because of the large temporal gaps between seismic reflectors of known ages. New 40Ar/39Ar geochronology presented here for submarine volcanic rocks provides better age constraints for neotectonic interpretations within the Terror Rift. Several samples from seamounts yielded young ages between 156 ± 21 and 122 ± 26 Ka. These ages support interpretations that extension within the Terror Rift was active at least through the Pleistocene. Three evenly spaced samples from the lowermost 100 m of Franklin Island range in age from 3.28 ± 0.04 to 3.73 ± 0.05 Ma. These age determinations demonstrate that construction of a small volcanic edifice such as Franklin Island took at least several hundred thousand years, and therefore that much larger ones in the Erebus Volcanic Province are likely to have taken considerably longer than previously inferred. This warrants caution in applying a limited number of age determinations to define the absolute ages of events in the Ross Sea region

  14. 40Ar-39Ar Age and Geological Significance of the Sawur Gold Belt in Northern Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    SHEN Ping; SHEN Yuanchao; ZENG Qingdong; LIU Tiebing; LI Guangming


    The 40Ar-39Ar age method is employed in this work to analyze fluid inclusions of quartz in the ore bodies from the Kuo'erzhenkuola and Bu'erkesidai gold deposits in the Sawur gold belt, northern Xinjiang. The results show that the main mineralization occurred in 332.05±2.02-332.59±0.51 Ma and 335.53±0.32 Ma-336.78±0.50 Ma for the Kuo'erzhenkuola and Bu'erkesidai gold deposits respectively, indicating that the two deposits are formed almost at the same time, and the metallogenic time of the two deposits are close to those of the hosting rocks formed by volcanic activity of the Sawur gold belt. This geochronological study supplies new evidence for determining the timing of gold mineralization, the geneses of gold deposits, and identifies that in the Hercynian period, the Altay area developed a tectonic-magmatic-hydrothermal mineralization of the Early Carboniferous period, except the two known mineralization periods including the tectonic-magmatic-hydrothermal mineralization of the Devonian period and Late CarboniferousPermian period.

  15. SEM and ESR measurements on HOPG surfaces irradiated with Ar{sup 11+} and Ar{sup 1+}

    Energy Technology Data Exchange (ETDEWEB)

    Liu Shengjin; Sakurai, Makoto; Zhang Weimin; Asakura, Ken; Iida, Naoyuki; Sakurai, Takahiro; Ohta, Hitoshi [Department of Physics, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan); Tona, Masahide [Department of Chemistry, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan); Terui, Toshifumi, E-mail: [National Institute of Information and Communications Technology, Iwaoka, Kobe 651-2492 (Japan)


    Highly oriented pyrolytic graphite (HOPG) samples were irradiated with a highly charged ion (HCI) Ar{sup 11+} at a fluence of 10{sup 14} cm{sup -2}. After irradiation, scanning electron microscopy (SEM) was used to observe the irradiated trace. During SEM measurement, an electron acceleration voltage of 0.5, 1 and 5 kV was applied to measure the samples, respectively. The irradiated contrast can be observed in the Si surface at 0.5 kV, which could not be found at 1 kV or higher. The irradiated area becomes brighter than that of the unirradiated area. When Ar{sup 1+} was used to bombard the solid surface, the fluence should become of the order of 10{sup 15} cm{sup -2}. In this case, the irradiated contrast could be observed. It means HCI is able to enhance more effectively the surface modification. Furthermore, electron spin resonance was used to measure the surface of highly oriented pyrolytic graphite (HOPG). A clear resonant peak appears in the irradiated sample, which cannot be found in the pristine sample. The phenomenon could be related to defects induced by the HCI impact.

  16. Carbon isotope stratigraphy, magnetostratigraphy, and 40Ar/39Ar age of the Cretaceous South Atlantic coast, Namibe Basin, Angola (United States)

    Strganac, Christopher; Salminen, Johanna; Jacobs, Louis L.; Polcyn, Michael J.; Ferguson, Kurt M.; Mateus, Octávio; Schulp, Anne S.; Morais, Maria Luísa; Tavares, Tatiana da Silva; Gonçalves, António Olímpio


    We present the δ13C and paleomagnetic stratigraphy for marine strata at the coast of southern Angola, anchored by an intercalated basalt with a whole rock 40Ar/39Ar radiometric age of 84.6 ± 1.5 Ma, being consistent with both invertebrate and vertebrate biostratigraphy. This is the first African stable carbon isotope record correlated to significant events in the global carbon record spanning the Late Cenomanian to Early Maastrichtian. A positive ∼3‰ excursion seen in bivalve shells below the basalt indicates the Cenomanian-Turonian Boundary Event at 93.9 Ma, during Oceanic Anoxic Event 2. Additional excursions above the basalt are correlated to patterns globally, including a negative ∼3‰ excursion near the top of the section interpreted as part of the Campanian-Maastrichtian Boundary Events. The age of the basalt ties the studied Bentiaba section to a pulse of Late Cretaceous magmatic activity around the South Atlantic and significant tectonic activity, including rotation, of the African continent.

  17. 40Ar/39Ar geochronology and geochemical reconnaissance of the Eocene Lowland Creek volcanic field, west-central Montana (United States)

    Dudas, F.O.; Ispolatov, V.O.; Harlan, S.S.; Snee, L.W.


    We report geochronological and geochemical data for the calc-alkalic Lowland Creek volcanic field (LCVF) in westcentral Montana. 40Ar/ 39Ar age determinations show that the LCVF was active from 52.9 to 48.6 Ma, with tuff-forming eruptions at 52.9 ?? 0.14 and 51.8 ?? 0.14 Ma. These dates span the age range of vigorous Eocene igneous activity in the Kamloops-Absaroka-Challis belt. The LCVF evolved upward from basal rhyolites (SiO 2>71 wt%) to dacites and andesites (SiO 2 > 62 wt%). Compositional change parallels a transition from early explosive volcanism to late effusive activity. Four geochemical components can be detected in the rocks. A component with 206Pb/204Pb nd epsilon;Nd near-15 is predominant in anhydrous, two-pyroxene dacites; hydrous rhyolites, rhyodacites, and dacites with epsilon;Nd below-10 are dominated by a second component; hydrous rocks with 206Pb/ 204Pb > 18.3 and epsilon;Nd>-9 contain a third component; and an andesite with low Nd content and epsilon;Nd near-9 probably contains a fourth component. The first three components probably derive from the lower and middle crust, whereas the fourth is probably from the lithospheric mantle. ?? 2010 by The University of Chicago.

  18. A combined noble gas and {sup 40}Ar-{sup 39}Ar study of Salt Lake Crater xenolith SL322 from Oahu, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Trieloff, M. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Rocholl, A. [Heidelberg Univ. (Germany). Mineralogisch-Petrographisches Inst.; Jessberger, E.K. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)]|[Muenster Univ. (Germany). Inst. fuer Planetologie


    The microdistribution of noble gases in a garnet pyroxenite nodule from Salt Lake Crater (SLC), Oahu, Hawaii, was investigated by a detailed step-heating and -crushing analysis and a {sup 40}Ar-{sup 39}Ar-study. A noble gas component with MORB type argon, helium and neon resides in CO{sub 2}-rich fluid inclusions trapped in <30 km depth. This component was most probably derived from the nephelinitic SLC host magma and confirms the dominance of MORB type noble gases in the late post-erosional magmatic stages of Hawaiian volcanism, as suggested previsouly (Kurz et al., 1983; Valbracht et al., 1996). A second previously detected (Rocholl et al., 1996) low {sup 40}Ar/{sup 36}Ar ({proportional_to}5000) component turned out to be associated with two different reservoirs. The larger reservoir is most probably related to garnet, the other one is associated with low retentive sites containing few K and Cl and could not yet be adequately identified. The low {sup 40}Ar/{sup 36}Ar ({proportional_to}5000) component hosted by garnet can be interpreted as a mixture of MORB and plume type noble gas components with specific {sup 4}He/{sup 40}Ar ratios. The results demonstrate the complexity of the microdistribution of noble gases in ultramafic nodules and allow insight into plume induced metasomatism of the Hawaiian lithosphere. (orig.)

  19. The transcriptional programme of the androgen receptor (AR) in prostate cancer. (United States)

    Lamb, Alastair D; Massie, Charlie E; Neal, David E


    The androgen receptor (AR) is essential for normal prostate and prostate cancer cell growth. AR transcriptional activity is almost always maintained even in hormone relapsed prostate cancer (HRPC) in the absence of normal levels of circulating testosterone. Current molecular techniques, such as chromatin-immunoprecipitation sequencing (ChIP-seq), have permitted identification of direct AR-binding sites in cell lines and human tissue with a distinct coordinate network evident in HRPC. The effectiveness of novel agents, such as abiraterone acetate (suppresses adrenal androgens) or enzalutamide (MDV3100, potent AR antagonist), in treating advanced prostate cancer underlines the on-going critical role of the AR throughout all stages of the disease. Persistent AR activity in advanced disease regulates cell cycle activity, steroid biosynthesis and anabolic metabolism in conjunction with regulatory co-factors, such as the E2F family, c-Myc and signal transducer and activator of transcription (STAT) transcription factors. Further treatment approaches must target these other factors.

  20. Further support for a Cretaceous age for the feathered-dinosaur beds of Liaoning,China:New 40Ar/39Ar dating of the Yixian and Tuchengzi Formations

    Institute of Scientific and Technical Information of China (English)


    We report new 40Ar/39Ar dating results obtained from total fusion and incremental-heating analyses of sanidine and biotite from three tuffs found interbedded within the fossil-bearing deposits of Liaoning, northeast China. The first is a new sample of the Bed 6 Sihetun tuff from the Yixian Formation, previously dated by our team as middle Early Cretaceous, and recently considered by Lo et al., partially reset due to metamorphism from a nearby basaltic sill. The second is the Yixian Bed 9 tuff from Hengdaozi considered by Lo et al. to be unaffected by metamorphism and whose age, based on total fusion 40Ar/39Ar dating of biotite, argues for a Jurassic age for the Yixian Formation.The third tuff is a previously undated tuff from the upper part of the underlying Tuchengzi Formation. Single crystal total fusion 40Ar/39Ar analyses of the Sihetun sanidine showed homogeneous radiogenic Ar, Ca/K ratios, excellent reproducibility and gave a mean age of 125.0 ± 0.18 (1SD) ±0.04 (SE) Ma. Single sanidine crystal total fusion 40Ar/39Aranalyses of the Hengdaozi tuff gave a mean age of 125.0 +0.19 (1SD) ± 0.04 (SE) Ma, which is indistinguishable from the Sihetun tuff. The Tuchengzi Formation tuff gave a mean age of 139.4 ± 0.19 (1SD) ± 0.05 (SE) Ma. Detailed laser incremental-heating analyses of biotite from Sihetun, Hengdaozi, and Tuchengzi tuffs show disturbed Ar release patterns and evidence of trapped argon components. We conclude from these analyses that the total fusion dates on biotite by Lo et al. are erroneously old and isotopic dating of both biotite and sanidine from tuffs of the Yixian Formation point to a middle Early Cretaceous age. The upper part of the Tuchengzi Formation can be referred to the Early Cretaceous.``

  1. Palaeomagnetism and K-Ar and 40Ar/39Ar ages in the Ali Sabieh area (Republic of Djibouti and Ethiopia): constraints on the mechanism of Aden ridge propagation into southeastern Afar during the last 10 Myr (United States)

    Audin, L.; Quidelleur, X.; Coulié, E.; Courtillot, V.; Gilder, S.; Manighetti, I.; Gillot, P.-Y.; Tapponnier, P.; Kidane, T.


    A new detailed palaeomagnetic study of Tertiary volcanics, including extensive K-Ar and 40Ar/39Ar dating, helps constrain the deformation mechanisms related to the opening processes of the Afar depression (Ethiopia and Djibouti). Much of the Afar depression is bounded by 30 Myr old flood basalts and floored by the ca 2 Myr old Stratoid basalts, and evidence for pre-2 Ma deformation processes is accessible only on its borders. K-Ar and 40Ar/39Ar dating of several mineral phases from rhyolitic samples from the Ali Sabieh block shows indistinguishable ages around 20 Myr. These ages can be linked to separation of this block in relation to continental breakup. Different amounts of rotation are found to the north and south of the Holhol fault zone, which cuts across the northern part of the Ali Sabieh block. The southern domain did not record any rotation for the last 8 Myr, whereas the northern domain experienced approximately 12 +/- 9° of clockwise rotation. We propose to link this rotation to the counter-clockwise rotation observed in the Danakil block since 7 Ma. This provides new constraints on the early phases of rifting and opening of the southern Afar depression in connection with the propagation of the Aden ridge. A kinematic model of propagation and transfer of extension within southern Afar is proposed, with particular emphasis on the previously poorly-known period from 10 to 4 Ma.

  2. Microanalysis of Ar and He bombarded biomedical polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Manso Silvan, M. [Departamento de Fisica Aplicada C-XII, Universidad Autonoma de Madrid, 28049 Madrid (Spain)]. E-mail:; Gago, R. [Departamento de Fisica Aplicada C-XII, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Centro de Microanalisis de Materiales, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Valsesia, A. [European Commission, Institute for Health and Consumer Protection, Via Enrico Fermi, 21020 Ispra (Italy); Climent Font, A. [Departamento de Fisica Aplicada C-XII, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Centro de Microanalisis de Materiales, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Duart, J.M. Martinez [Departamento de Fisica Aplicada C-XII, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Rossi, F. [European Commission, Institute for Health and Consumer Protection, Via Enrico Fermi, 21020 Ispra (Italy)


    Implantations onto polyethyleneglycol, polycaprolactone and polymethylmethacrylate, carried out with Ar and He ions at 25 and 100 KeV with fluences of 5 x 10{sup 13} cm{sup -2}, have been made with identical ion currents (20 {mu}A) but different sweep areas in order to take into account the effect of the ion flux on the composition and structure of these biopolymers. Vibrational (Fourier transformed infrared spectroscopy), microanalytical (Rutherford backscattering and energy recoil detection) and microscopic techniques (atomic force microscopy) confirm that, even in this low fluence regime, the ion flux effect is responsible of scaled modifications. More interestingly, these techniques indicate that the damage seems to be higher for He. All these factors suggest that He could be preferentially used to engineer biomedical polymers exploiting the tailoring opportunities offered by ion flux effects.

  3. Vibrational predissociation of ArH2O (United States)

    Bissonnette, C.; Clary, D. C.


    Accurate close-coupling calculations are used to investigate the vibrational predissociation of ArH2O as a function of the overall rotation J of the van der Waals complex. A full vibrational and rotational basis of H2O states is used in the calculation. The potential energy surface is of a form due to Cohen and Saykally and derived from far-infrared spectra, with an additional term to introduce the dependence on the vibrations of H2O. The linewidths calculated in this work show a maximum at J=6 and it is found that Fermi resonances affect dramatically the magnitude of the calculated linewidths. Good agreement with experimentally measured linewidths of Nesbitt and Lascola is achieved and the calculations provide a simple picture for the J dependence of the linewidths.

  4. Neon reduction program on Cymer ArF light sources (United States)

    Kanawade, Dinesh; Roman, Yzzer; Cacouris, Ted; Thornes, Josh; O'Brien, Kevin


    In response to significant neon supply constraints, Cymer has responded with a multi-part plan to support its customers. Cymer's primary objective is to ensure that reliable system performance is maintained while minimizing gas consumption. Gas algorithms were optimized to ensure stable performance across all operating conditions. The Cymer neon support plan contains four elements: 1. Gas reduction program to reduce neon by >50% while maintaining existing performance levels and availability; 2. short-term containment solutions for immediate relief. 3. qualification of additional gas suppliers; and 4. long-term recycling/reclaim opportunity. The Cymer neon reduction program has shown excellent results as demonstrated through the comparison on standard gas use versus the new >50% reduced neon performance for ArF immersion light sources. Testing included stressful conditions such as repetition rate, duty cycle and energy target changes. No performance degradation has been observed over typical gas lives.

  5. Spectroscopic properties of alkali atoms embedded in Ar matrix. (United States)

    Jacquet, E; Zanuttini, D; Douady, J; Giglio, E; Gervais, B


    We present a theoretical investigation of visible absorption and related luminescence of alkali atoms (Li, Na, and K) embedded in Ar matrix. We used a model based on core polarization pseudopotentials, which allows us to determine accurately the gas-to-matrix shifts of various trapping sites. The remarkable agreement between our calculated results and the experimental spectra recorded by several authors allows us to establish a clear assignment of the observed spectra, which are made of contributions from crystalline sites on the one hand, and of grain boundary sites on the other hand. Our study reveals remarkably large Stokes shifts, up to 9000 cm(-1), which could be observed experimentally to identify definitely the trapping sites.

  6. A Model of White Dwarf Pulsar AR Scorpii

    CERN Document Server

    Geng, Jin-Jun; Huang, Yong-Feng


    A 3.56-hour white dwarf (WD) - M dwarf (MD) close binary system, AR Scorpii, was recently reported to show pulsating emission in radio, IR, optical, and UV, with a 1.97-minute period, which suggests the existence of a WD with a rotation period of 1.95 minutes. We propose a model to explain the temporal and spectral characteristics of the system. The WD is a nearly perpendicular rotator, with both open field line beams sweeping the MD stellar wind periodically. A bow shock propagating into the stellar wind accelerates electrons in the wind. Synchrotron radiation of these shocked electrons can naturally account for the broad-band (from radio to X-rays) spectral energy distribution of the system.

  7. Mean pion multiplicities in Ar+Sc collisions

    CERN Document Server

    Naskręt, Michał


    Preliminary results for mean negatively charged pion multiplicities $\\langle \\pi^- \\rangle$ using the $h^-$ method are presented for central Ar+Sc collisions at 13, 19, 30, 40, 75 and 150\\textit{A} GeV/c beam momentum. The data were recorded by the NA61/SHINE detector at the CERN SPS. Starting with rapidity distributions ${dn}/{dy}$ the procedure of obtaining total multiplicities is presented. The mean number of wounded nucleons $\\langle W\\rangle$ extracted from the Glissando MC model is used to calculate the ratio $\\langle \\pi^- \\rangle/\\langle W\\rangle.$ The results are compared to those from other experiments and their dependence on colliding systems and collision energy is discussed.

  8. Ar-rahnu as a Source of Financial Sustainability for Women Micro-Entrepreneurs in Malaysia


    Nik Hadiyan Nik Azman; Salina Hj. Kassim


    Muslims in Malaysia had practiced ar-rahnu for fulfilling their financial need, especially for emergency purposes since early 1990s. The pioneer of ar-rahnu in Malaysia is Muassasah Gadaian Islam Terengganu (MGIT) in January 1992, followed by the Kelantan Capitalization Berhad (PKB) in March 1992. Both of these Islamic pawn centres are among the earliest exponents to the Islamic pawn scheme in Malaysia. Ar-rahnu is an increasingly popular financing option among micro-entrepreneurs in Malaysia...

  9. The Contribution of ArsB to Arsenic Resistance in Campylobacter jejuni


    Zhangqi Shen; Jing Han; Yang Wang; Orhan Sahin; Qijing Zhang


    Arsenic, a toxic metalloid, exists in the natural environment and its organic form is approved for use as a feed additive for animal production. As a major foodborne pathogen of animal origin, Campylobacter is exposed to arsenic selection pressure in the food animal production environments. Previous studies showed that Campylobacter isolates from poultry were highly resistant to arsenic compounds and a 4-gene operon (containing arsP, arsR, arsC, and acr3) was associated with arsenic resistanc...

  10. Testing coeffcients of AR and bilinear time series models by a graphical approach

    Institute of Scientific and Technical Information of China (English)

    IP; WaiCheung


    AR and bilinear time series models are expressed as time series chain graphical models, based on which, it is shown that the coefficients of AR and bilinear models are the conditional correlation coefficients conditioned on the other components of the time series. Then a graphically based procedure is proposed to test the significance of the coeffcients of AR and bilinear time series. Simulations show that our procedure performs well both in sizes and powers.

  11. Tracking the timing of subduction and exhumation using 40Ar/39Ar phengite ages in blueschist- and eclogite-facies rocks (Sivrihisar, Turkey) (United States)

    Fornash, Katherine F.; Cosca, Michael A.; Whitney, Donna L.


    Geochronologic studies of high-pressure/low-temperature rocks can be used to determine the timing and rates of burial and exhumation in subduction zones by dating different stages of the pressure–temperature history. In this study, we present new in situ UV laser ablation 40Ar/39Ar phengite ages from a suite of lawsonite blueschist- and eclogite-facies rocks representing different protoliths (metabasalt, metasediment), different structural levels (within and outside of a high-strain zone), and different textural positions (eclogite pod core vs. margin) to understand the timing of these events in an exhumed Neo-Tethyan subduction zone (Sivrihisar Massif, Tavşanlı Zone, Turkey). Weighted mean in situ 40Ar/39Ar ages of phengite from the cores of lawsonite eclogite pods (90–93 Ma) are distinctly older than phengite from retrogressed, epidote eclogite (82 ± 2 Ma). These ages are interpreted as the age of peak and retrograde metamorphism, respectively. Eclogite records the narrowest range of ages (10–14 m.y.) of any rock type analyzed. Transitional eclogite- and blueschist-facies assemblages and glaucophane-rimmed lawsonite + garnet + phengite veins from eclogite pod margins record a much wider age range of 40Ar/39Ar ages (~20 m.y.) with weighted mean ages of ~91 Ma. Blueschists and quartzites record more variable 40Ar/39Ar ages that may in part be related to structural position: samples within a high-strain zone at the tectonic contact of the HP rocks with a meta-ultramafic unit have in situ UV laser ablation 40Ar/39Ar ages of 84.0 ± 1.3–103.7 ± 3.1 Ma, whereas samples outside this zone range to older ages (84.6 ± 2.4–116.7 ± 2.7 Ma) and record a greater age range (22–38 m.y.). The phengite ages can be correlated with the preservation of HP mineral assemblages and fabrics as well as the effects of deformation. Collectively, these results show that high-spatial resolution UV laser ablation 40Ar/39Ar phengite data, when considered

  12. Planktic foraminifer census data from Northwind Ridge cores PI-88-AP P3, PI-88-AR P7 and PI-88-AR P9, Arctic Ocean (United States)

    Foley, Kevin M.; Poore, Richard Z.


    The U.S. Geological Survey recovered 9 piston cores from the Northwind Ridge in the Canada Basin of the Arctic Ocean from a cruise of the USCGC Polar Star during 1988. Preliminary analysis of the cores suggests sediments deposited on Northwind Ridge preserve a detailed record of glacial and interglacial cycles for the last few hundred-thousand to one million years. This report includes quantitative data on foraminifers and selected sediment size-fraction data in 98 samples from Northwind Ridge core PI-88AR P3, 51 samples from core PI-88-AR P7 and 117 samples from core PI-88-AR P9.

  13. Tracking the timing of subduction and exhumation using 40Ar/39Ar phengite ages in blueschist- and eclogite-facies rocks (Sivrihisar, Turkey) (United States)

    Fornash, Katherine F.; Cosca, Michael A.; Whitney, Donna L.


    Geochronologic studies of high-pressure/low-temperature rocks can be used to determine the timing and rates of burial and exhumation in subduction zones by dating different stages of the pressure-temperature history. In this study, we present new in situ UV laser ablation 40Ar/39Ar phengite ages from a suite of lawsonite blueschist- and eclogite-facies rocks representing different protoliths (metabasalt, metasediment), different structural levels (within and outside of a high-strain zone), and different textural positions (eclogite pod core vs. margin) to understand the timing of these events in an exhumed Neo-Tethyan subduction zone (Sivrihisar Massif, Tavşanlı Zone, Turkey). Weighted mean in situ 40Ar/39Ar ages of phengite from the cores of lawsonite eclogite pods (90-93 Ma) are distinctly older than phengite from retrogressed, epidote eclogite (82 ± 2 Ma). These ages are interpreted as the age of peak and retrograde metamorphism, respectively. Eclogite records the narrowest range of ages (10-14 m.y.) of any rock type analyzed. Transitional eclogite- and blueschist-facies assemblages and glaucophane-rimmed lawsonite + garnet + phengite veins from eclogite pod margins record a much wider age range of 40Ar/39Ar ages (~20 m.y.) with weighted mean ages of ~91 Ma. Blueschists and quartzites record more variable 40Ar/39Ar ages that may in part be related to structural position: samples within a high-strain zone at the tectonic contact of the HP rocks with a meta-ultramafic unit have in situ UV laser ablation 40Ar/39Ar ages of 84.0 ± 1.3-103.7 ± 3.1 Ma, whereas samples outside this zone range to older ages (84.6 ± 2.4-116.7 ± 2.7 Ma) and record a greater age range (22-38 m.y.). The phengite ages can be correlated with the preservation of HP mineral assemblages and fabrics as well as the effects of deformation. Collectively, these results show that high-spatial resolution UV laser ablation 40Ar/39Ar phengite data, when considered in a petrologic and structural

  14. ArsAB, a novel enzyme from Sporomusa ovata activates phenolic bases for adenosylcobamide biosynthesis. (United States)

    Chan, Chi Ho; Escalante-Semerena, Jorge C


    In the homoacetogenic bacterium Sporomusa ovata, phenol and p-cresol are converted into α-ribotides, which are incorporated into biologically active cobamides (Cbas) whose lower ligand bases do not form axial co-ordination bonds with the cobalt ion of the corrin ring. Here we report the identity of two S. ovata genes that encode an enzyme that transfers the phosphoribosyl group of nicotinate mononucleotide (NaMN) to phenol or p-cresol, yielding α-O-glycosidic ribotides. The alluded genes were named arsA and arsB (for alpha-ribotide synthesis), arsA and arsB were isolated from a genomic DNA library of S. ovata. A positive selection strategy using an Escherichia coli strain devoid of NaMN:5,6-dimethylbenzimidazole (DMB) phosphoribosyltransferase (CobT) activity was used to isolate a fragment of S. ovata DNA that contained arsA and arsB, whose nucleotide sequences overlapped by 8 bp. SoArsAB was isolated to homogeneity, shown to be functional as a heterodimer, and to have highest activity at pH 9. SoArsAB also activated DMB to its α-N-glycosidic ribotide. Previously characterized CobT-like enzymes activate DMB but do not activate phenolics. NMR spectroscopy was used to confirm the incorporation of phenol into the cobamide, and mass spectrometry was used to identify SoArsAB reaction products. © 2011 Blackwell Publishing Ltd.

  15. Natural ³⁷Ar concentrations in soil air: implications for monitoring underground nuclear explosions. (United States)

    Riedmann, Robin A; Purtschert, Roland


    For on-site inspections (OSI) under the Comprehensive Nuclear-Test-Ban Treaty (CTBT) measurement of the noble gas ³⁷Ar is considered an important technique. ³⁷Ar is produced underground by neutron activation of Calcium by the reaction ⁴⁰Ca(n,α)³⁷Ar. The naturally occurring equilibrium ³⁷Ar concentration balance in soil air is a function of an exponentially decreasing production rate from cosmic ray neutrons with increasing soil depth, diffusive transport in the soil air, and radioactive decay (T(1/2): 35 days). In this paper for the first time, measurements of natural ³⁷Ar activities in soil air are presented. The highest activities of ~100 mBq m⁻³ air are 2 orders of magnitude larger than in the atmosphere and are found in 1.5-2.5 m depth. At depths > 8 m ³⁷Ar activities are < 20 mBq m⁻³ air. After identifying the main ³⁷Ar production and gas transport factors the expected global activity range distribution of ³⁷Ar in shallow subsoil (0.7 m below the surface) was estimated. In high altitude soils, with large amounts of Calcium and with low gas permeability, ³⁷Ar activities may reach values up to 1 Bq m⁻³.

  16. The Correlation Between PARP1 and BRCA1 in AR Positive Triple-negative Breast Cancer. (United States)

    Luo, Jiayan; Jin, Juan; Yang, Fang; Sun, Zijia; Zhang, Wenwen; Shi, Yaqin; Xu, Jing; Guan, Xiaoxiang


    Triple-negative breast cancer (TNBC) lacks estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER-2) expression and thus cannot benefit from conventional hormonal or anti-HER2 targeted therapies. Anti-androgen therapy has shown a certain effect on androgen receptor (AR) positive TNBC. The emerging researches have proved that poly (ADP-ribose) polymerase (PARP) inhibitor is effective in BRCA1-deficient breast cancers. We demonstrated that combination of AR antagonist (bicalutamide) and PARP inhibitor (ABT-888) could inhibit cell viability and induce cell apoptosis significantly whatever in vitro or in vivo setting in AR-positive TNBC. Previous studies have proved that both BRCA1 and PARP1 have close connections with AR in prostate cancer. We explored the correlation among AR, PARP1 and BRCA1 in TNBC for the first time. After BRCA1 overexpression, the expression of AR and PARP1 were decreased in mRNA and protein levels. Additionally, AR positively regulated PARP1 while PARP1 also up-regulated AR expression in vitro. We also confirmed BRCA1 expression was negatively correlated with AR and PARP1 in TNBC patients using a tissue microarray with TNBC patient samples. These results suggest that the combination of bicalutamide and PARP inhibitor may be a potential strategy for TNBC patients and merits further evaluation.

  17. Alteration of natural (37)Ar activity concentration in the subsurface by gas transport and water infiltration. (United States)

    Guillon, Sophie; Sun, Yunwei; Purtschert, Roland; Raghoo, Lauren; Pili, Eric; Carrigan, Charles R


    High (37)Ar activity concentration in soil gas is proposed as a key evidence for the detection of underground nuclear explosion by the Comprehensive Nuclear Test-Ban Treaty. However, such a detection is challenged by the natural background of (37)Ar in the subsurface, mainly due to Ca activation by cosmic rays. A better understanding and improved capability to predict (37)Ar activity concentration in the subsurface and its spatial and temporal variability is thus required. A numerical model integrating (37)Ar production and transport in the subsurface is developed, including variable soil water content and water infiltration at the surface. A parameterized equation for (37)Ar production in the first 15 m below the surface is studied, taking into account the major production reactions and the moderation effect of soil water content. Using sensitivity analysis and uncertainty quantification, a realistic and comprehensive probability distribution of natural (37)Ar activity concentrations in soil gas is proposed, including the effects of water infiltration. Site location and soil composition are identified as the parameters allowing for a most effective reduction of the possible range of (37)Ar activity concentrations. The influence of soil water content on (37)Ar production is shown to be negligible to first order, while (37)Ar activity concentration in soil gas and its temporal variability appear to be strongly influenced by transient water infiltration events. These results will be used as a basis for practical CTBTO concepts of operation during an OSI.

  18. Atmospheric Ar and Ne returned from mantle depths to the Earth's surface by forearc recycling. (United States)

    Baldwin, Suzanne L; Das, J P


    In subduction zones, sediments, hydrothermally altered lithosphere, fluids, and atmospheric gases are transported into the mantle, where ultrahigh-pressure (UHP) metamorphism takes place. However, the extent to which atmospheric noble gases are trapped in minerals crystallized during UHP metamorphism is unknown. We measured Ar and Ne trapped in phengite and omphacite from the youngest known UHP terrane on Earth to determine the composition of Ar and Ne returned from mantle depths to the surface by forearc recycling. An (40)Ar/(39)Ar age [7.93 ± 0.10 My (1σ)] for phengite is interpreted as the timing of crystallization at mantle depths and indicates that (40)Ar/(39)Ar phengite ages reliably record the timing of UHP metamorphism. Both phengite and omphacite yielded atmospheric (38)Ar/(36)Ar and (20)Ne/(22)Ne. Our study provides the first documentation, to our knowledge, of entrapment of atmospheric Ar and Ne in phengite and omphacite. Results indicate that a subduction barrier for atmospheric-derived noble gases does not exist at mantle depths associated with UHP metamorphism. We show that the crystallization age together with the isotopic composition of nonradiogenic noble gases trapped in minerals formed during subsolidus crystallization at mantle depths can be used to unambiguously assess forearc recycling of atmospheric noble gases. The flux of atmospheric noble gas entering the deep Earth through subduction and returning to the surface cannot be fully realized until the abundances of atmospheric noble gases trapped in exhumed UHP rocks are known.

  19. Development of a Control and Vision Interface for an AR.Drone


    Cheema Prasad; Luo Simon; Gibbens Peter


    The AR.Drone is a remote controlled quadcopter which is low cost, and readily available for consumers. Therefore it represents a simple test-bed on which control and vision research may be conducted. However, interfacing with the AR.Drone can be a challenge for new researchers as the AR.Drone's application programming interface (API) is built on low-level, bit-wise, C instructions. Therefore, this paper will demonstrate the use of an additional layer of abstraction on the AR.Drone’s API via t...

  20. Double excitation of Ar{sup 16+} projectiles in the intermediate velocity regime

    Energy Technology Data Exchange (ETDEWEB)

    Adoui, L.; Chetioui, A.; Despiney, I.; L`hoir, A.; Rozet, J.P.; Schmaus, D.; Touati, A.; Vernhet, D.; Wohrer, K. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique des Solides; Cassimi, A.; Grandin, J.P.; Ramillon, J.M. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Stephan, C. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire


    The double excitation of Ar{sup 16+} projectiles is observed at GANIL with Ar{sup 16+} projectiles of 13.6 MeV/u (v=23 a.u.) by looking at the radiative decay of the double excited states, thus avoiding the interference effect. Moreover, double excitation together with single excitation in very similar systems (Ar{sup 16+} {yields} He, N{sub 2}, Ne, Ar, Kr, Xe) have been studied, thus allowing to a real test of the two-electron mechanism. 1 fig., 4 refs.

  1. Development and validation of a chromatographic method for determining Clematichinenoside AR and related impurities

    Directory of Open Access Journals (Sweden)

    Zhou Yang


    Full Text Available Abstract Background Clematichinenoside AR is a promising lead compound for the treatment of rheumatoid arthritis. A systematic research for the related impurities in AR bulk samples is still lacking. For the safe use of this natural product in future clinical practice, the structure and content of each constituent, including the main ingredient as well as the impurities in AR bulk sample must be characterized in detail. Results A simple and stability indicating RP-HPLC method was developed and validated for determining the purity of clematichinenoside AR (AR, a natural product from the roots of Clematis manshurica Rupr. (Ranunculaceae with the potential of treating rheumatoid arthritis. Five impurities were characterized, and impurity 2 (Clematomandshurica saponin F is a new triterpenoid saponin isolated from this product. Optimum separation for clematichinenoside AR and five related impurities was carried out on an Agilent octadecylsilane bonded silica gel column (TC-C18, 4.6 mm ×150 mm, 5 μm using a gradient HPLC method. The validation results showed good sensitivity, specificity, linearity(r2>0.9992 precision(RSD Conclusion Five related impurities of clematichinenoside AR were characterized, including a new triterpenoid saponins firstly found in clematichinenoside AR bulk samples. In the simple chromatographic method for determining clematichinenoside AR and its related impurities in bulk samples, the correction factor was better for the quality control in the relative stable concentrations.

  2. The Correlation Between PARP1 and BRCA1 in AR Positive Triple-negative Breast Cancer (United States)

    Luo, Jiayan; Jin, Juan; Yang, Fang; Sun, Zijia; Zhang, Wenwen; Shi, Yaqin; Xu, Jing; Guan, Xiaoxiang


    Triple-negative breast cancer (TNBC) lacks estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER-2) expression and thus cannot benefit from conventional hormonal or anti-HER2 targeted therapies. Anti-androgen therapy has shown a certain effect on androgen receptor (AR) positive TNBC. The emerging researches have proved that poly (ADP-ribose) polymerase (PARP) inhibitor is effective in BRCA1-deficient breast cancers. We demonstrated that combination of AR antagonist (bicalutamide) and PARP inhibitor (ABT-888) could inhibit cell viability and induce cell apoptosis significantly whatever in vitro or in vivo setting in AR-positive TNBC. Previous studies have proved that both BRCA1 and PARP1 have close connections with AR in prostate cancer. We explored the correlation among AR, PARP1 and BRCA1 in TNBC for the first time. After BRCA1 overexpression, the expression of AR and PARP1 were decreased in mRNA and protein levels. Additionally, AR positively regulated PARP1 while PARP1 also up-regulated AR expression in vitro. We also confirmed BRCA1 expression was negatively correlated with AR and PARP1 in TNBC patients using a tissue microarray with TNBC patient samples. These results suggest that the combination of bicalutamide and PARP inhibitor may be a potential strategy for TNBC patients and merits further evaluation. PMID:27994514

  3. Defining the Tristan-Gough Hotspot: High-Resolution 40Ar/39Ar Dating of Volcanism at Tristan da Cunha (United States)

    Schnur, S.; Koppers, A. A. P.


    Explaining the spatial distribution of intra-plate volcanism is an important geologic problem. The Walvis Ridge is a uniquely-shaped hotspot trail in the South Atlantic that is not fully explained by the prevailing mantle plume paradigm. About halfway through its 130 Myr history, Walvis shows a morphological shift from a continuous ridge to a diffuse region of guyots arranged in two volcanic tracks. Recent volcanism at both Tristan da Cunha and Gough Island suggests these tracks are produced by two hotspots sourced from a single plume. However, the islands are located more than 400 km apart, which does not conform to our understanding of plumes as narrow, semi-stationary upwellings. It remains unclear which of the two islands better represents the current plume position. New ages from previously unstudied seamounts show that Tristan is younger than surrounding volcanism, whereas Gough appears to fit the local age progression (Schnur et al. 2014). Modern radiometric ages suggest the main island of Tristan may have been active for up to 1.3 ± 0.2 Myr (O'Connor and le Roex 1992). However, the seemingly older Inaccessible, Nightingale and Middle islands have yet to be reliably dated and could be up to 18 ± 4 Ma based on K-Ar ages (Miller in Baker et al. 1964). In order to confidently delineate the duration of volcanism at Tristan, we present the results of 29 new 40Ar/39Ar step-heating experiments on biotite, hornblende, plagioclase and groundmass separates from rocks collected on Inaccessible, Nightingale and Middle islands. Our results show that volcanism on all three islands is young, in most cases Middle islands are therefore too old and should be ignored in interpretations of plume dynamics. These results also show that magma was being supplied simultaneously to both Tristan and Gough over recent geologic time. Two possible explanations for this are that (1) there is a broad plume underlying the area, with focus points at Tristan and Gough or (2) hotspot magma

  4. Weathering and denudation history of the western continental margin of India constrained by combined Ar-Ar dating and paleomagnetism (United States)

    Jean, Amandine; Mathé, Pierre-Etienne; Beauvais, Anicet; Chardon, Dominique; Demory, François; Janwari, Shazia


    The western continental passive margin of Peninsular India is fringed by an escarpment, the Western Ghats escarpment (WGE), which separates a narrow coastal lowland plain drained to the west from a highland plateau drained to the east. Since Deccan Traps emplacement, the combined effects of chemical alteration and mechanical erosion led to the formation and dissection of lateritic landscapes whose relicts are preserved both sides of the WGE. Ar-Ar ages of K-rich manganese oxides (cryptomelane) sampled in the lateritic profile of each paleolandscape element have documented the weathering history and put constraints on the paleoclimatic and denudation history of Peninsular India [1,2]. The results have documented intense lateritic weathering during the Eocene (ca. 53-45 Ma) on either sides of the escarpment. Here, we present new independent constraints on the age of that weathering based on paleomagnetism of ferricretes included in thick lateritic weathering mantles of the coastal lowland plain. Our method is based on the paleomagnetic properties of Fe-oxy-hydroxides crystallized in situ in the lateritic weathering profile. The major magnetic minerals, hematite and goethite, have been analyzed by combining hysteresis and remanent magnetizations together with magnetic susceptibility measurements including thermomagnetic curves (KT curves). The main carrier of Natural Remanent Magnetization (NRM) at low temperature is a well-crystallized goethite of first generation characterized by sharp Neel temperature, Tn, at 85°C on KT curves; late goethite generations with distributed Tn below diurnal temperatures (primary and neoformed hematite mimics the primary goethite component. The derived paleopole fits the APWP of India at paleolatitude of 62.3° (with alpha95=5.2°) suggesting an age of ca. 52 Ma [3]. The reverse polarity systematically observed may be ascribed to Chron 23 [4] that refines the paleomagnetic age of the primary goethite to 51.9 - 52.2 Ma. This new age is

  5. 40Ar-39Ar thermochronology of two ductile shear zones from Yiwulüshan, West Liaoning Region: Age constraints on the Mesozoic tectonic events

    Institute of Scientific and Technical Information of China (English)


    Two ductile shear zones trending EW and NNE respectively not only controlled the tectonic framework of the northern North China, but also constrained the geodynamic background for gold mineralization in this region. Field observations and microstructural analyses reveal that the EW trending ductile shear zones are mainly contributed to dextral compressional deformation resulting from top-to- the-southeast oblique thrust shearing, whereas the NNE trending ones are genetically related to sinistral strike-slip and extensional faulting. One sample from the former yielded an 40Ar-39Ar plateau age of (219±4) Ma (Bi) and two samples from the latter gave 40Ar-39Ar plateau ages of (116±2) Ma (Bi) and (127±3) Ma (Bi). These ages provide constraints on the top-to-the-southeast oblique thrusting event occurring in Late Triassic and the sinistral extensional and strike-slip faulting event which occurred in Early Cretaceous.

  6. 40Ar-39Ar Dating of Quartz from Ore in the Baiyangping Cu-Co Polymetallic Ore-Concentrated Area, Lanping Basin, Yunnan

    Institute of Scientific and Technical Information of China (English)

    何明勤; 刘家军; 李朝阳; 李志明; 刘玉平; 杨爱平; 桑海清


    40Ar-39Ar fast neutron activation age spectrum of quartz in ore collected from the Baiyangping Cu-Co polymetallic ore-concentrated area, Lanping Basin, is saddle-shaped. The plateau age, minimum appearance age and isochron age shown on the spectra are 56.53±0.43 Ma, 55.52±1.78 Ma and 55.90±0.29 Ma respectively. The age data are consistent with each other within 1σ uncertainties. Because the given initial 40Ar/36Ar value of 294.7±1.14 is very close to Nier's value (295.5±5), both plateau and isochron ages may be considered as the forming time of quartz. So the age of 55.90-56.53 Ma represents the forming age of ore deposits. It is obvious that the ore deposits were formed during the Early Himalayan period.

  7. New palynology-based astronomical and revised 40Ar/39Ar ages for the Eocene maar lake of Messel (Germany) (United States)

    Lenz, Olaf K.; Wilde, Volker; Mertz, Dieter F.; Riegel, Walter


    The annually laminated oil shale from the Eocene maar lake at Messel (Federal State of Hessen, Germany) provides unique paleoenvironmental data for a time interval of ~640 ka during the Paleogene greenhouse phase. As a consequence of orbitally controlled changes in the vegetation in the vicinity of the lake, the lacustrine laminites can now be astronomically tuned. Dating is based on the short eccentricity amplitude modulations of the regional pollen rain and their correlation to the astronomical La2010a/La2010d solutions in combination with a revised 40Ar/39Ar age of a basalt fragment from a lapilli tuff section below the first lacustrine sediments. Depending on different newly suggested ages for the Fish Canyon sanidine used as monitor for neutron irradiation, the age for the eruption at Messel is between 48.27 ± 0.22 and 48.11 ± 0.22 Ma. This allows for the first time the exact correlation of a Paleogene lacustrine sequence to the marine record in Central Europe. The Messel oil shale becomes now slightly older than previously assumed and includes the Ypresian/Lutetian boundary that moves the base of the European Land Mammal Age Geiseltalian (MP 11) into the Lower Eocene. This opens a window for establishing an independent chronostratigraphic framework for Paleogene terrestrial records and their correlation to the marine realm. Furthermore, the study reveals that higher amounts of pollen from "wet" and thermophilous plants indicate less seasonal and more balanced precipitation and slightly higher temperatures during a well-expressed eccentricity minimum.

  8. Provenance of Greenland Ice Sheet icebergs constrained by Ar-Ar radioisotope data from late glacial-early Holocene records (United States)

    Knutz, P. C.; Storey, M.; Kuijpers, A.


    Radiogenic Ar-Ar dating of hornblende has been used to constrain the sources of ice-rafted detritus on the southwest Greenland margin and central Davis Strait. Single hornblende grains (total of 248) were picked from sand-size fractions of two marine cores, DA04-31P and TTR462G, covering the early Holocene to late glacial interval including Heinrich events (HE) 1-3. Paleoceanographic analyses of DA04-31P have indicated that the last deglaciation of the southern Greenland Ice Sheet occurred in multiple steps during the early deglacial/HE1, Allerød and early Holocene intervals (Knutz et al., in review). Each of these collapse stages were preceded by upper ocean warming related to enhanced Irminger Current activity. Pre-HE1, Allerød and Holocene hornblende samples show a bimodal signature of late Archean (2.5-3.0 Ga) and early Proterozoic (1.6-2.2 Ga) ages consistent with southern Greenland bedrock sources. In contrast hornblende grains from detrital carbonate HE layers and within the Younger Dryas interval show a dominant early Proterozoic spectrum that is similar to results obtained from the central North Atlantic IRD belt. The early Proterozoic age of Younger Dryas samples from the Davis Strait site and the high amounts of basalt in this core, presumably derived from the Disko-Nussuaq province, suggests that icebergs carrying Archean material from southern Greenland did not enter the Baffin Bay or at least not for this specific time interval. The conclusion of our study is that the Greenland Ice Sheet appears to have been a much larger contributor to non-Heinrich IRD in the North Atlantic than thought previously. P. C. Knutz, H. Ebbesen, S. Christiansen, M.-A. Sicre and A. Kuijpers. Multiple deglaciation steps of the southern Greenland Ice Sheet driven by vigorous Irminger Current: Significance for the Younger Dryas cooling. Submitted to Quaternary Science Reviews.

  9. Sm-Nd and Ar-Ar Studies of DHO 908 and 489: Implications for Lunar Crustal History (United States)

    Nyquist, L. E.; Shih, C. Y.; Reese, Y. D.; Park, J.; Bogard, D. D.; Garrison, D. H.; Yamaguchi, A.


    It is widely assumed that ferroan anorthosites (FANs) formed as flotation cumulates on a global lunar magma ocean (LMO). A corollary is that all FANs are approximately contemporaneous and formed with the same initial Nd-143/Nd-144 ratio. Indeed, a whole rock isochron for selected FANs (and An93 anorthosite) yields an isochron age of 4.42 +/- 0.13 Ga and initial Nd-143/Nd-144, expressed in epsilon-units, of epsilon(sub Nd,CHUR) = 0.3+/-0.3 relative to the CHondritic Uniform Reservoir , or epsilon(sub Nd,HEDPB)=-0.6+/-0.3 relative to the HED Parent Body. These values are in good agreement with the age (T) = 4.47+/-0.07 Ga, and epsilon(sub Nd,HEDPB) =-0.6 +/- 0.5 for FAN 67075. We also have studied anorthositic clasts in the Dhofar 908 and 489 lunar highland meteorites containing clasts of magnesian anorthosites (MAN) with Mg# approximately 75. Because of their relatively high Mg#, magnesian anorthosites should have preceded most FANs in crystallization from the LMO if both are LMO products. Thus, it is important to determine whether the Nd-isotopic data of MAN and FAN are consistent with a co-magmatic origin. We previously reported Sm-Nd data for white clast Dho 908 WC. Mafic minerals in this clast were too small to be physically separated for an isochron. However, we estimated initial Nd-143/Nd-144 for the clast by combining its bulk ("whole rock") Sm-Nd data with an Ar-39-Ar-40 age of 4.42+/-.04 Ga. Here we report additional Sm-Nd data for bulk samples of Dho 908 and its pair Dho 489.

  10. XRD-based 40Ar/39Ar age correction for fine-grained illite, with application to folded carbonates in the Monterrey Salient (northern Mexico) (United States)

    Fitz-Díaz, Elisa; Hall, Chris M.; van der Pluijm, Ben A.


    Due to their minute size, 40Ar/39Ar analysis of illite faces significant analytical challenges, including mineral characterization and, especially, effects of grain size and crystallography on 39Ar recoil. Quantifying the effects of 39Ar recoil requires the use of sample vacuum encapsulation during irradiation, which permits the measurement of the fraction of recoiled 39Ar as well as the 39Ar and 40Ar∗ retained within illite crystals that are released during step heating. Total-Gas Ages (TGA) are calculated by using both recoiled and retained argon, which is functionally equivalent to K-Ar ages, while Retention Ages (RA) only involve retained Ar in the crystal. Natural applications have shown that TGA fits stratigraphic constraints of geological processes when the average illite crystallite thickness (ICT) is smaller than 10 nm, and that RA matches these constraints for ICTs larger than 50 nm. We propose a new age correction method that takes into account the average ICT and corresponding recoiled 39Ar for a sample, with X-ray Corrected Ages (XCA) lying between Total-Gas and Retention Ages depending on ICT. This correction is particularly useful in samples containing authigenic illite formed in the anchizone, with typical ICT values between 10 and 50 nm. In three samples containing authigenic illite from Cretaceous carbonates in the Monterrey Salient in northern Mexico, there is a range in TGAs among the different size-fractions of 46-49, 36-43 and 40-52 Ma, while RAs range from 54-64, 47-52 and 53-54 Ma, respectively. XCA calculations produce tighter age ranges for these samples of 52.5-56, 45.5-48.5 and 49-52.5 Ma, respectively. In an apparent age vs ICT or %2M 1illite plot, authigenic illite grains show a slope that is in general slightly positive for TGA, slightly negative for RA, but close to zero for XCA, with thinner crystallites showing more dispersion than thicker ones. In order to test if dispersion is due to a different formation history or the result

  11. Noninvasive Detection of AR-FL/AR-V7 as a Predictive Biomarker for Therapeutic Resistance in Men with Metastatic Castration-Resistant Prostate Cancer (United States)


    Accomplishments 4 4. Impact 9 5. Changes /Problems 11 6. Products 12 7. Participants & Other Collaborating Organizations 15 8. Special Reporting...AWARD NUMBER: W81XWH-15-2-0052 TITLE: Noninvasive Detection of AR-FL/AR-V7 as a Predictive Biomarker for Therapeutic Resistance in Men with...Metastatic Castration- Resistant Prostate Cancer PRINCIPAL INVESTIGATOR: Stephen Plymate RECIPIENT: University of Washington Seattle, WA 98195

  12. The effect of thermal resetting and recrystallisation on white mica 40Ar/39Ar ages during retrograde metamorphism on Syros, Greece (United States)

    Uunk, Bertram; Wijbrans, Jan; Brouwer, Fraukje


    White mica 40Ar/39Ar dating is a proven powerful tool for constraining timing of metamorphism, deformation and exhumation. However, in high-pressure metamorphic rocks, dating often results in wide age ranges which are not in agreement with constraints from other isotopic systems, indicating that geological and chemical processes complicate straightforward 40Ar/39Ar dating. In this research project, white mica ages from rocks of the Cycladic Blueschist Unit on Syros, Greece with contrasting rheology and strain mechanisms are compared, in order to better understand the role of deformation, recrystallization and fluid flow on 40Ar/39Ar ages of white mica during retrograde metamorphism. Resulting ages vary along different sections on the island, inconsistent with other isotopic constraints on eclogite-blueschist metamorphism (55-50 Ma) and greenschist overprinting (41-30 Ma). Two end-member models are possible: 1) Results represent continuous crystallization of white mica while moving from blueschist to greenschist conditions in the metamorphic P-T loop, or 2) white mica equilibrated in eclogite-blueschist conditions and their diffusion systematics were progressively perturbed during greenschist overprinting. The single grain fusion analyses yielded contrasting age distributions, which indicate contrasts in degree of re-equilibration during retrograde metamorphism. Step wise heating of larger grain populations resulted in flat plateau shapes, providing no evidence for partial resetting. Electron microprobe measurements of Si per formula unit, as a proxy for pressure during crystallisation, do not explain age variation within sections or on the island scale. The previously unreported north-south age trend and age ranges per sample, as shown only in the 40Ar/39Ar system of the metapelitic and marble lithologies, contains key information that will allow us to test between different scenarios for age formation. Excess argon infiltration at this stage seems to have been of

  13. Application of K-Ar Dating to the Chronology of Young Volcanic Centers (United States)

    Lanphere, M. A.


    K-Ar dating and a derivative technique, 40Ar/39Ar dating, are methods of high-precision chronology applicable to young volcanic centers. Cascade volcanoes studied in detail by several USGS volcanologists, Duane Champion paleomagetist, and me include Mt. Baker, WA; Mt. Rainier, WA; Mt. Adams, WA; Mt. Hood, OR; Crater Lake, OR; and Medicine Lake, CA. For Mt. Adams using detailed geologic mapping by Hildreth and Fierstein and 74 K-Ar ages for 63 mapped units, Hildreth and Lanphere established a detailed chronology for the stratovolcano. Good agreement has been achieved for K-Ar ages and 40Ar/39Ar ages of rocks from Mt. Adams as young as 36 ka. A similar detailed chronology has been established for other Cascade volcanoes using andesites, in particular. These chronologies often take 10 years or more to develop. Major advantages of the 40Ar/39Ar technique are the ability to work with small sample sizes and the possibility to push the technique to very young ages. The Campanian Ignimbrite erupted from the Campi Flegrei crater near Naples, Italy is an example of the use of small samples. Nine incremental-heating ages were determined on samples of sanidine ranging in size from 47 mg to 67 mg. These samples yielded ages for the Campanian Ignimbrite ranging from 37.1 +/- 0.75 ka to 39.5 +/- 0.62 ka and averaging 38.1 +/- 0.8 ka. Other workers have proposed 40Ar/39Ar ages for the Campanian Ignimbrite of 37.1 +/- 0.4 ka and 39.3 +/- 0.1 ka. An example of the use of 40Ar/39Ar dating of very young samples is the Christian Era (CE) age of the Vesuvius eruption of year 79. Eight packets of sanidine weighing 213-296 mg from two localities, Casti Amanti in Pompeii and Villa Poppea in nearby Oplontis, yielded a weighted-mean incremental-heating age of 1924 +/- 66 years. The known age for the CE 79 eruption of Vesuvius is 1924 years. Earlier studies of Vesuvius by other workers yielded an 40Ar/39Ar age for the Villa Poppea locality of 1922 +/- 72 years.

  14. Characterization of Key Helicobacter pylori Regulators Identifies a Role for ArsRS in Biofilm Formation. (United States)

    Servetas, Stephanie L; Carpenter, Beth M; Haley, Kathryn P; Gilbreath, Jeremy J; Gaddy, Jennifer A; Merrell, D Scott


    Helicobacter pylori must be able to rapidly respond to fluctuating conditions within the stomach. Despite this need for constant adaptation, H. pylori encodes few regulatory proteins. Of the identified regulators, the ferric uptake regulator (Fur), the nickel response regulator (NikR), and the two-component acid response system (ArsRS) are each paramount to the success of this pathogen. While numerous studies have individually examined these regulatory proteins, little is known about their combined effect. Therefore, we constructed a series of isogenic mutant strains that contained all possible single, double, and triple regulatory mutations in Fur, NikR, and ArsS. A growth curve analysis revealed minor variation in growth kinetics across the strains; these were most pronounced in the triple mutant and in strains lacking ArsS. Visual analysis showed that strains lacking ArsS formed large aggregates and a biofilm-like matrix at the air-liquid interface. Biofilm quantification using crystal violet assays and visualization via scanning electron microscopy (SEM) showed that all strains lacking ArsS or containing a nonphosphorylatable form of ArsR (ArsR-D52N mutant) formed significantly more biofilm than the wild-type strain. Molecular characterization of biofilm formation showed that strains containing mutations in the ArsRS pathway displayed increased levels of cell aggregation and adherence, both of which are key to biofilm development. Furthermore, SEM analysis revealed prevalent coccoid cells and extracellular matrix formation in the ArsR-D52N, ΔnikR ΔarsS, and Δfur ΔnikR ΔarsS mutant strains, suggesting that these strains may have an exacerbated stress response that further contributes to biofilm formation. Thus, H. pylori ArsRS has a previously unrecognized role in biofilm formation. Despite a paucity of regulatory proteins, adaptation is key to the survival of H. pylori within the stomach. While prior studies have focused on individual regulatory proteins

  15. Steroidogenic acute regulatory protein (StAR), a novel mitochondrial cholesterol transporter. (United States)

    Miller, Walter L


    Cholesterol is a vital component of cellular membranes, and is the substrate for biosynthesis of steroids, oxysterols and bile acids. The mechanisms directing the intracellular trafficking of this nearly insoluble molecule have received increased attention through the discovery of the steroidogenic acute regulatory protein (StAR) and similar proteins containing StAR-related lipid transfer (START) domains. StAR can transfer cholesterol between synthetic liposomes in vitro, an activity which appears to correspond to the trans-cytoplasmic transport of cholesterol to mitochondria. However, trans-cytoplasmic cholesterol transport in vivo appears to involve the recently-described protein StarD4, which is expressed in most cells. Steroidogenic cells must also move large amounts of cholesterol from the outer mitochondrial membrane to the first steroidogenic enzyme, which lies on the matrix side of the inner membrane; this action requires StAR. Congenital lipoid adrenal hyperplasia, a rare and severe disorder of human steroidogenesis, results from mutations in StAR, providing a StAR knockout of nature that has provided key insights into its activity. Cell biology experiments show that StAR moves large amounts of cholesterol from the outer to inner mitochondrial membrane, but acts exclusively on the outer membrane. Biophysical data show that only the carboxyl-terminal alpha-helix of StAR interacts with the outer membrane. Spectroscopic data and molecular dynamics simulations show that StAR's interactions with protonated phospholipid head groups on the outer mitochondrial membrane induce a conformational change (molten globule transition) needed for StAR's activity. StAR appears to act in concert with the peripheral benzodiazepine receptor, but the precise itinerary of a cholesterol molecule entering the mitochondrion remains unclear.

  16. Bacillus sp.CDB3 isolated from cattle dip-sites possesses two ars gene clusters

    Institute of Scientific and Technical Information of China (English)

    Somanath Bhat; Xi Luo; Zhiqiang Xu; Lixia Liu; Ren Zhang


    Contamination of soil and water by arsenic is a global problem.In Australia, the dipping of cattle in arsenic-containing solution to control cattle ticks in last centenary has left many sites heavily contaminated with arsenic and other toxicants.We had previously isolated five soil bacterial strains (CDB1-5) highly resistant to arsenic.To understand the resistance mechanism, molecular studies have been carried out.Two chromosome-encoded arsenic resistance (ars) gene clusters have been cloned from CDB3 (Bacillus sp.).They both function in Escherichia coli and cluster 1 exerts a much higher resistance to the toxic metalloid.Cluster 2 is smaller possessing four open reading frames (ORFs) arsRorf2BC, similar to that identified in Bacillus subtilis Skin element.Among the eight ORFs in cluster 1 five are analogs of common ars genes found in other bacteria, however, organized in a unique order arsRBCDA instead of arsRDABC.Three other putative genes are located directly downstream and designated as arsTIP based on the homologies of their theoretical translation sequences respectively to thioredoxin reductases, iron-sulphur cluster proteins and protein phosphatases.The latter two are novel of any known ars operons.The arsD gene from Bacillus species was cloned for the first time and the predict protein differs from the well studied E.coli ArsD by lacking two pairs of C-terrninal cysteine residues.Its functional involvement in arsenic resistance has been confirmed by a deletion experiment.There exists also an inverted repeat in the intergenic region between arsC and arsD implying some unknown transcription regulation.

  17. An Ediacaran–Cambrian thermal imprint in Rajasthan, western India: Evidence from 40Ar-39Ar geochronology of the Sindreth volcanics

    Indian Academy of Sciences (India)

    Archisman Sen; Kanchan Pande; Hetu C Sheth; Kamal Kant Sharma; Shraboni Sarkar; A M Dayal; Harish Mistry


    The Sindreth Group exposed near Sirohi in southern Rajasthan, western India, is a volcanosedimentary sequence. Zircons from Sindreth rhyolite lavas and tuffs have yielded U–Pb crystallization ages of ∼768–761 Ma, suggesting that the Sindreth Group is a part of the Malani magmatic event. Earlier 40Ar-39Ar studies of other Malani volcanic and plutonic rocks yielded disturbed argon release spectra, ascribed to a ∼550 Ma thermal event possibly related to the Pan-African orogeny. To test and confirm this possibility, we dated two whole-rock and three feldspar separate samples of the Sindreth volcanics by the 40Ar-39Ar method. All samples yield disturbed argon release spectra suggesting radiogenic argon loss and with plateau segments at 550 Ma or 490 Ma. We interpret these as events of argon loss at 550–490 Ma related to an Ediacaran–Cambrian thermal event, possibly related to the Malagasy orogeny. The combined older and new 40Ar-39Ar results are significant in showing that whereas Ediacaran–Cambrian magmatic and metamorphic events are well known from many parts of India, they left thermal imprints in much of Trans-Aravalli Rajasthan as well. The overall evidence is consistent with a model of multiphase assembly of Gondwanaland from separate continental landmasses.

  18. Coeval 40Ar/39Ar Ages of 65.0 Million Years Ago from Chicxulub Crater Melt Rock and Cretaceous-Tertiary Boundary Tektites. (United States)

    Swisher, C C; Grajales-Nishimura, J M; Montanari, A; Margolis, S V; Claeys, P; Alvarez, W; Renne, P; Cedillo-Pardoa, E; Maurrasse, F J; Curtis, G H; Smit, J; McWilliams, M O


    (40)Ar/(39)Ar dating of drill core samples of a glassy melt rock recovered from beneath a massive impact breccia contained within the 180-kilometer subsurface Chicxulub crater in Yucatán, Mexico, has yielded well-behaved incremental heating spectra with a mean plateau age of 64.98 +/- 0.05 million years ago (Ma). The glassy melt rock of andesitic composition was obtained from core 9 (1390 to 1393 meters) in the Chicxulub 1 well. The age of the melt rock is virtually indistinguishable from (40)Ar/(39)Ar ages obtained on tektite glass from Beloc, Haiti, and Arroyo el Mimbral, northeastern Mexico, of 65.01 +/- 0.08 Ma (mean plateau age for Beloc) and 65.07 +/- 0.10 Ma (mean total fusion age for both sites). The (40)Ar/(39)Ar ages, in conjunction with geochemical and petrological similarities, strengthen the recent suggestion that the Chicxulub structure is the source for the Haitian and Mexican tektites and is a viable candidate for the Cretaceous-Tertiary boundary impact site.

  19. Coeval Ar-40/Ar-39 ages of 65.0 million years ago from Chicxulub crater melt rock and Cretaceous-Tertiary boundary tektites (United States)

    Swisher, Carl C., III; Grajales-Nishimura, Jose M.; Montanari, Alessandro; Margolis, Stanley V.; Claeys, Philippe; Alvarez, Walter; Renne, Paul; Cedillo-Pardo, Esteban; Maurrasse, Florentin J.-M. R.; Curtis, Garniss H.


    Ar-40/Ar-39 dating of drill-core samples of a glassy melt rock recovered from beneath a massive impact breccia contained with the 180-kilometer subsurface Chicxulub crater yields well-behaved incremental heating spectra with a mean plateau age of 64.98 +/- 0.05 million years ago (Ma). The glassy melt rock of andesitic composition was obtained from core 9 (1390 to 1393 meters) in the Chicxulub 1 well. The age of the melt rock is virtually indistinguishable from Ar-40/Ar-39 ages obtained on tektite glass from Beloc, Haiti, and Arroyo el Mimbral, northeastern Mexico, of 65.01 +/- 0.08 Ma (mean plateau age for Beloc) and 65.07 +/- 0.10 Ma (mean total fusion age for both sites). The Ar-40/Ar-39 ages, in conjunction with geochemical and petrological similarities, strengthen the suggestion that the Chicxulub structure is the source for the Haitian and Mexican tektites and is a viable candidate for the Cretaceous-Tertiary boundary impact site.

  20. The Ar-Ar age and petrology of Miller Range 05029: Evidence for a large impact in the very early solar system (United States)

    Weirich, J. R.; Wittmann, A.; Isachsen, C. E.; Rumble, D.; Swindle, T. D.; Kring, D. A.


    Miller Range (MIL) 05029 is a slowly cooled melt rock with metal/sulfide depletion and an Ar-Ar age of 4517 ± 11 Ma. Oxygen isotopes and mineral composition indicate that it is an L chondrite impact melt, and a well-equilibrated igneous rock texture with a lack of clasts favors a melt pool over a melt dike as its probable depositional setting. A metallographic cooling rate of approximately 14 °C Ma-1 indicates that the impact occurred at least approximately 20 Ma before the Ar-Ar closure age of 4517 Ma, possibly even shortly after accretion of its parent body. A metal grain with a Widmanstätten-like pattern further substantiates slow cooling. The formation age of MIL 05029 is at least as old as the Ar-Ar age of unshocked L and H chondrites, indicating that endogenous metamorphism on the parent asteroid was still ongoing at the time of impact. Its metallographic cooling rate of approximately 14 °C Ma-1 is similar to that typical for L6 chondrites, suggesting a collisional event on the L chondrite asteroid that produced impact melt at a minimum depth of 5-12 km. The inferred minimum crater diameter of 25-60 km may have shattered the 100-200 km diameter L chondrite asteroid. Therefore, MIL 05029 could record the timing and petrogenetic setting for the observed lack of correlation of cooling rates with metamorphic grades in many L chondrites.

  1. Fremtidens lydværker på Venedig Biennalen og Ars Electronica

    DEFF Research Database (Denmark)

    Vandsø, Anette


    Diskussion af lydkunstens status på baggrund af den aktuelle Lydkunst på Venedig Biennalen og Ars Electronica......Diskussion af lydkunstens status på baggrund af den aktuelle Lydkunst på Venedig Biennalen og Ars Electronica...

  2. Research, demonstration, and extension: the ARS area-wide ecologically based invasive plant management project (United States)

    The Area-wide project is a collaborative five year effort funded in 2008 by USDA-ARS that has brought together scientists with the USDA-ARS, universities, land managers, and policy makers throughout the Great Basin. A primary goal of the project is to develop and implement a comprehensive, regional...

  3. Establishment and Usability Evaluation of an Interactive AR Learning System on Conservation of Fish (United States)

    Lin, Hao-Chiang Koong; Hsieh, Min-Chai; Wang, Cheng-Hung; Sie, Zong-Yuan; Chang, Shei-Hsi


    In this study, we develop an interactive AR Learning System based on Augmented Reality and interactive touch-screen. The learning content knowledge is about conservation of fish in Taiwan. The system combines the game by the concept of AR book which allows children to learn about the importance of conservation of fish. A mechanism is designed to…

  4. 75 FR 66306 - Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR (United States)


    ..., Little Rock, AR AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY: Drawbridge operations for the Baring Cross Railroad Drawbridge across the Arkansas Waterway at Mile 119.6 at Little Rock, Arkansas... (NPRM) entitled Drawbridge Operation Regulation; Arkansas Waterway, Little ] Rock, AR in the...

  5. Learning Protein Structure with Peers in an AR-Enhanced Learning Environment (United States)

    Chen, Yu-Chien


    Augmented reality (AR) is an interactive system that allows users to interact with virtual objects and the real world at the same time. The purpose of this dissertation was to explore how AR, as a new visualization tool, that can demonstrate spatial relationships by representing three dimensional objects and animations, facilitates students to…

  6. Applying an AR Technique to Enhance Situated Heritage Learning in a Ubiquitous Learning Environment (United States)

    Chang, Yi Hsing; Liu, Jen-ch'iang


    Since AR can display 3D materials and learner motivation is enhanced in a situated learning environment, this study explores the learning effectiveness of learners when combining AR technology and the situation learning theory. Based on the concept of embedding the characteristics of augmented reality and situated learning into a real situation to…

  7. Tail behavior and OLS based robust inference in AR-GARCH models

    DEFF Research Database (Denmark)

    Lange, T


    The scope of this paper is twofold. We first describe the tail behavior for general AR-GARCH processes and hence extend the results of Basrak, Davis, and Mikosch (2002b) to another empirical relevant model class. Second, and primarily, we study properties for the OLS estimator in general AR-GARCH...

  8. A DNA polymerase mutation that suppresses the segregation bias of an ARS plasmid in Saccharomyces cerevisiae. (United States)

    Houtteman, S W; Elder, R T


    Yeast autonomously replicating sequence (ARS) plasmids exhibit an unusual segregation pattern during mitosis. While the nucleus divides equally into mother and daughter cells, all copies of the ARS plasmid will often remain in the mother cell. A screen was designed to isolate mutations that suppress this segregation bias. A plasmid with a weak ARS (wARS) that displayed an extremely high segregation bias was constructed. When cells were grown under selection for the wARS plasmid, the resulting colonies grew slowly and had abnormal morphology. A spontaneous recessive mutation that restored normal colony morphology was identified. This mutation suppressed plasmid segregation bias, as indicated by the increased stability of the wARS plasmid in the mutant cells even though the plasmid was present at a lower copy number. An ARS1 plasmid was also more stable in mutant cells than in wild-type cells. The wild-type allele for this mutant gene was cloned and identified as POL delta (CDC2). This gene encodes DNA polymerase delta, which is essential for DNA replication. These results indicate that DNA polymerase delta plays some role in causing the segregation bias of ARS plasmids.

  9. Data of evolutionary structure change: 1AR5A-1UNFX [Confc[Archive

    Lifescience Database Archive (English)



    ETV testing of the ARS CFU-50 APC Electroflocculation and Filtration Water Treatment System (ARS CFU-50 APC) for arsenic removal was conducted at the Town of Bernalillo Well #3 site from April 18 through May 2, 2006. The source water was chlorinated groundwater from two supply w...

  11. Membrane lipid composition of pancreatic AR42J cells: modification by exposure to different fatty acids. (United States)

    Audi, Nama'a; Mesa, María D; Martínez, María A; Martínez-Victoria, Emilio; Mañas, Mariano; Yago, María D


    Dietary fat type influences fatty acids in rat pancreatic membranes, in association with modulation of secretory activity and cell signalling in viable acini. We aimed to confirm whether AR42J cells are a valid model to study the interactions between lipids and pancreatic acinar cell function. For this purpose we have (i) compared the baseline fatty acid composition of AR42J cells with that of pancreatic membranes from rats fed a standard chow; (ii) investigated if fatty acids in AR42J membranes can be modified in culture; and (iii) studied if similar compositional variations that can be evoked in rats when dietary fat type is altered occur in AR42J cells. Weaning Wistar rats were fed for 8 weeks either a commercial chow (C) or semi-purified diets containing virgin olive oil (VOO) or sunflower oil (SO) as fat source. AR42J cells were incubated for 72 hrs in medium containing unmodified fetal calf serum (FCS, AR42J-C cells), FCS enriched with 18:1 n-9 (AR42J-O cells), or FCS enriched with 18:2 n-6 (AR42J-L cells). Fatty acids in crude membranes from rat pancreas and AR42J cells were determined by gas-liquid chromatography. Differences in membrane fatty acids between C rats and AR42J-C cells can be explained in part by variations in the amount of fatty acids in the extracellular environment. Supplementation of FCS with 18:1 n-9 or 18:2 n-6 changed the fatty acid spectrum of AR42J cells in a manner that resembles the pattern found, respectively, in VOO and SO rats, although AR42J-L cells were unable to accumulate 20:4 n-6. The AR42J cell line can be a useful tool to assess the effect of membrane compositional changes on acinar cell function. However, differences in baseline characteristics, and perhaps fatty acid metabolism, indicate that results obtained in AR42J cells should be confirmed with experiments in the whole animal.

  12. CERN inspires 2011 edition of the ARS Electronica Digital Arts Festival

    CERN Multimedia

    Jordan Juras


    This year’s annual ARS Electronica Digital Arts Festival featured CERN as the springboard for its theme, ORIGIN – How it All Begins. The prestigious digital arts festival also served as the perfect venue to launch the Collide@CERN project.   Colours and Lights at the ARS Electronica Digital Arts Festival in Linz (Austria). (Photo by Claudia Marcelloni) The CERN cultural policy project, announced at the beginning of 2011 has started to gain momentum. Ariane Koek, art specialist for the Communication Group, received confirmation in May that ARS Electronica had chosen her proposal to use CERN as the primary source of inspiration for their annual ARS Electronica Festival. This marks the first of the cultural policy’s arts partnerships. The world-renowned celebration for the digital arts is held annually in Linz, Austria, where, amongst the incredible collection of displays and productions, the Prix ARS Electronica – the Oscars of the digital arts world -&...

  13. myADS-arXiv: A fully customized, open access virtual journal (United States)

    Kurtz, Michael; Eichhorn, Guenther; Henneken, Edwin; Accomazzi, Alberto; Grant, Carolyn; Thompson, Donna; Bohlen, Elizabeth; Murray, Stephen


    myADS-arXiv is a collaboration of the Astrophysics Data System group at the Smithsonian Astrophysical Observatory and the arXiv group at Cornell University. The myADS-arXiv service provides a listing of those articles in physics or astronomy which have been posted in the last week which are of most interest to you. In essence myADS-arXiv is a free, weekly, fully customized (for each individual user) open access virtual journal which covers the most important, most recent papers in physics and astronomy. myADS-arXiv follows the same format as the existing myADS-Astronomy and myADS-Physics notification services. These services provide access to the most interesting (to you) recent journal articles in physics and astronomy. These are done in collaboration with nearly every publisher of physics or astronomy journals, including APS, AIP, AAS, RAS, IoP, EDP, World Scientific, Wiley, Springer, and Elsevier.

  14. AR-V7 and prostate cancer: The watershed for treatment selection? (United States)

    Ciccarese, Chiara; Santoni, Matteo; Brunelli, Matteo; Buti, Sebastiano; Modena, Alessandra; Nabissi, Massimo; Artibani, Walter; Martignoni, Guido; Montironi, Rodolfo; Tortora, Giampaolo; Massari, Francesco


    The androgen receptor (AR) plays a key role in progression to metastatic castration-resistant prostate cancer (mCRPC). Despite the recent progress in targeting persistent AR activity with the next-generation hormonal therapies (abiraterone acetate and enzalutamide), resistance to these agents limits therapeutic efficacy for many patients. Several explanations for response and/or resistance to abiraterone acetate and enzalutamide are emerging, but growing interest is focusing on importance of AR splice variants (AR-Vs) and in particular of AR-V7. Increasing evidences highlight the concept that variant expression could be used as a potential predictive biomarker and a therapeutic target in advanced prostate cancer. Therefore, understanding the mechanisms of treatment resistance or sensitivity can help to achieve a more effective management of mCRPC, increasing clinical outcomes and representing a promising and engaging area of prostate cancer research.

  15. AR-aging as a new approach for enhanced results (United States)

    Hays, C.; Stemmler, R. P.


    MAR-aging steels have earned a niche in the metal market arena, especially where aerospace and outerspace applications are concerned. MAR-aging steels owe their high strength, excellent fracture toughness, and good ductility to a precipitation-hardening (aging) mechanism that has been debated by scientists for several years. Because of today’s trend toward more demanding design requirements and a continuing need to better understand the MAR-aging family of materials, six different alloys (C-200, C-250, C-300, C-350, T-250, and T-300) were selected for study using a singular processing treatment: a hot-wall zone-gradient furnace. These alloys were evaluated for the effects of a specific thermal gradient (°C/cm) from 1231 °C (2250 °F) at the hot-wall limit to about 260 °C (500 °F) at the opposite end, the cold wall. All six alloys were evaluated in terms of their microstructure, microhardness, composition, and associated properties as a result of this specific thermal processing method. In this paper, detailed observations on the C-350 alloy are presented, and the results are interpreted in terms of a new heat treatment cycle called AR-aging.

  16. Infrared absorption spectroscopy of the COAr complex (United States)

    McKellar, A. R. W.; Zeng, Y. P.; Sharpe, S. W.; Wittig, C.; Beaudet, R. A.


    The rotation-vibration spectrum of the weakly bound complex COAr has been studied in the 2140 cm -1 region of the fundamental band of CO. Data were obtained from two different experiments: first, a pulsed slit-jet supersonic expansion and a tunable diode laser source; and second a long-path low-temperature static gas cell and a Fourier transform spectrometer. The low rotational temperature and narrow line width of the jet expansion data were complementary to the higher J-values and broad coverage of the static cell data. The observed spectrum was approximately that of a T-shaped near-prolate asymmetric rotor molecule. About 370 transitions were assigned to 6 perpendicular subbands with K = 3-2, 2-1, 1-0, 0-1, 1-2, and 2-3. No parallel (Δ K = 0) subbands were observed. The observed B rotational constant of the complex in its ground state, 0.0691 cm -1, corresponds to an effective intermolecular separation of about 3.850 Å. The observed A rotational constant of about 2.47 cm -1 is not too far from the overlineB value of the CO monomer, 1.92 cm -1, as expected for the approximately T-shaped effective geometry of the complex.

  17. The Structure of the DoAr 25 Circumstellar Disk

    CERN Document Server

    Andrews, Sean M; Wilner, D J; Qi, Chunhua


    We present high spatial resolution (< 0.3" = 40$ AU) Submillimeter Array observations of the 865 micron continuum emission from the circumstellar disk around the young star DoAr 25. Despite its bright millimeter emission, this source exhibits only a comparatively small infrared excess and low accretion rate, suggesting that the material and structural properties of the inner disk may be in an advanced state of evolution. A simple model of the physical conditions in the disk is derived from the submillimeter visibilities and the complete spectral energy distribution using a Monte Carlo radiative transfer code. For the standard assumption of a homogeneous grain size distribution at all disk radii, the results indicate a shallow surface density profile, $\\Sigma \\propto r^{-p}$ with p = 0.34, significantly less steep than a steady-state accretion disk (p = 1) or the often adopted minimum mass solar nebula (p = 1.5). Even though the total mass of material is large (M_d = 0.10 M_sun), the densities inferred in t...

  18. Cartografar é traçar um plano comum

    Directory of Open Access Journals (Sweden)

    Virgínia Kastrup


    Full Text Available A pesquisa de campo sobre produção da subjetividade enfrenta o problema de construir conhecimento envolvendo pesquisadores e pesquisados, com territórios e semióticas singulares. Surgem questões relativas ao protagonismo dos participantes e a como traçar com eles um plano comum, garantindo o caráter participativo da pesquisa. No contexto do método da cartografia, o artigo tem como objetivo tratar do tema do comum num duplo aspecto. Num primeiro, discute o acesso ao plano comum. Com base em Gilles Deleuze e Felix Guattari, tal plano não é dito homogêneo nem reúne atores que manteriam entre si relações de identidade, mas opera comunicação entre singularidades, sendo pré-individual e coletivo. Num segundo aspecto, aponta que, enquanto pesquisa-intervenção, a cartografia se compromete com a criação de um mundo comum e heterogêneo. O artigo mostra que o traçado do comum tem como diretriz metodológica a tranversalidade e examina os procedimentos de participação, inclusão e tradução.

  19. Ars vitae in Iamblichus and in the Stoic Seneca

    Directory of Open Access Journals (Sweden)

    Eliopoulos, Panos


    Full Text Available Seneca expounds a theory of therapy and teaching with the ultimate goal of self knowledge and wisdom. Some of his techniques are based on Pythagorean principles or derive ideas from them, among them the focused and constant ascesis of self control. Iamblichus in De Vita Pythagorica exhibits great interest on the fact that man’s inherent abilities along with the aid of proper education suffice for his attainment of wisdom. For both thinkers, knowledge through practice is considered to be one of the major philosophical demands in the perspective of an “ars vitae”. The human being has to canalize himself into the modeling of a new way of living, an “art of living” which will contribute decisively to the fulfillment of his teleology, to his perpetual eudaimonia (bene vivere. The admittance of individual differences in people’s ability to reform themselves only signifies the more intense effort of the teacher towards a purification of their intellect and greater engagement of the individuals’ volition but not their inability for correction.

  20. An alternative method for smartphone input using AR markers

    Directory of Open Access Journals (Sweden)

    Yuna Kang


    Full Text Available As smartphones came into wide use recently, it has become increasingly popular not only among young people, but among middle-aged people as well. Most smartphones adopt capacitive full touch screen, so touch commands are made by fingers unlike the PDAs in the past that use touch pens. In this case, a significant portion of the smartphone’s screen is blocked by the finger so it is impossible to see the screens around the finger touching the screen; this causes difficulties in making precise inputs. To solve this problem, this research proposes a method of using simple AR markers to improve the interface of smartphones. A marker is placed in front of the smartphone camera. Then, the camera image of the marker is analyzed to determine the position of the marker as the position of the mouse cursor. This method can enable click, double-click, drag-and-drop used in PCs as well as touch, slide, long-touch-input in smartphones. Through this research, smartphone inputs can be made more precise and simple, and show the possibility of the application of a new concept of smartphone interface.

  1. Consumo de arsénico y riesgo cardiovascular

    Directory of Open Access Journals (Sweden)

    Lachiner Saborío Morales


    Full Text Available El arsénico (As es un elemento considerado como ubicuo, cuyas fuentes pueden ser naturales o productos de la actividad humana. La exposición a este elemento ocurre principalmente por la vía oral. Las presentaciones inorgánicas del As son consideradas como las más tóxicas. La absorción del As ocurre en el intestino delgado y por medio de acuaporinas ingresa a los hepatocitos, en casos de ingesta crónica el As tiende acumularse en hígado, riñones, corazón, sistema nervioso, pulmones, músculo, tracto gastrointestinal y bazo. El consumo crónico de agua con concentraciones de As por encima del valor de referencia dado por la Organización Mundial de la Salud (OMS ha demostrado un aumento del riesgo de accidentes vasculares cerebrales (AVC, hipertensión arterial (HTA, aterosclerosis carotidea, enfermedades arteriales periféricas, mortalidad por infarto agudo del miocardio (IAM, aumento en enfermedades cardiovasculares en la población pediátrica y diabetes mellitus tipo II.

  2. Ionization satellites of the ArHe dimer

    Energy Technology Data Exchange (ETDEWEB)

    Miteva, Tsveta; Klaiman, Shachar; Gokhberg, Kirill [Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany); Gromov, Evgeniy V., E-mail: [Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany); Laboratory of Quantum Chemistry, Computer Center, Irkutsk State University, K. Marks 1, 664003 Irkutsk (Russian Federation)


    Ionization satellites are key ingredients in the control of post ionization processes such as molecular dissociation and interatomic Coulombic decay. Here, using the high-level ab initio method of multi-reference configuration interaction up to triple excitations, we study the potential energy curves (PECs) of the ionization satellites of the ArHe dimer. With this model system, we demonstrate that the simple model used in alkaline earth metal and rare gas complexes to describe the satellites as a Rydberg electron moving on top of a dicationic core does not fully hold for the rare gas clusters. The more complex valence structure in the rare gas atom leads to the mixing of different electronic configurations of the dimer. This prevents one from assigning a single dicationic parent state to some of the ionization satellites. We further analyze the structure of the different PECs, demonstrating how the density of the Rydberg electron is reflected in the structure of the PEC wherever the simple model is applicable.

  3. A Study of Compound Solar Eruption in NOAA AR11429 (United States)

    Zhang, Jie; Dhakal, Suman Kumar


    We analyze and report a compound eruption process associated with an M8.4 flare occurred on March 10, 2012 in NOAA AR 11429. In the main phase of the flare, there were two major peaks in GOES X-ray at ~17:20 UT and ~ 17:40 UT respectively. We found that the two flare peaks, separated by about 20 minutes, corresponded to two individual erupting magnetic flux bundles from the same active region and along the same magnetic polarity inversion line. The erupting features were seen as a hot channel-like structure of a temperature of ~ 10 MK in coronal images obtained from SDO AIA 131 A passband. We believe that each erupting feature is originated from an individual magnetic flux bundle. Prior to the onset of the eruption, the magnetic structure of the source region likely contains a double decker configuration, i.e., a coherent flux bundle lies above another coherent flux bundle. The upper bundle became unstable and started to erupt. Shortly after, the lower bundle started to accelerate and merged with the upper bundle, forming a single CME as seen in coronagraph images. This study demonstrates that complex magnetic configuration could form in the corona and result in a compound solar eruption that involves energy release in different magnetic structures. We will discuss the physical processes that inter-connect multiple magnetic structure in an active region.

  4. AR based ornament design system for 3D printing

    Directory of Open Access Journals (Sweden)

    Hiroshi Aoki


    Full Text Available In recent years, 3D printers have become popular as a means of outputting geometries designed on CAD or 3D graphics systems. However, the complex user interfaces of standard 3D software can make it difficult for ordinary consumers to design their own objects. Furthermore, models designed on 3D graphics software often have geometrical problems that make them impossible to output on a 3D printer. We propose a novel AR (augmented reality 3D modeling system with an air-spray like interface. We also propose a new data structure (octet voxel for representing designed models in such a way that the model is guaranteed to be a complete solid. The target shape is based on a regular polyhedron, and the octet voxel representation is suitable for designing geometrical objects having the same symmetries as the base regular polyhedron. Finally, we conducted a user test and confirmed that users can intuitively design their own ornaments in a short time with a simple user interface.

  5. Teaching Children Musical Perception with MUSIC-AR

    Directory of Open Access Journals (Sweden)

    Valéria Farinazzo Martins


    Full Text Available Unfortunately in Brazil there is a non compulsory musical education in schools that leads to loss of sound/musical perception of Brazilian children. This fact, associated with the lack of software for the teaching of musical perception, inspired the creation of Music-AR, a set of software that uses Augmented Reality technology for the teaching of sound properties, such as timbre, pitch and sound intensity. There were four small applications for that: the first one allows the child to manipulate virtual objects linked to sounds, this way, the child can loosen and stretch virtual objects relating them to the (bass and treble sound pitch; the second focus on the concept of sound intensity, associating it to virtual animals been far or near to the children; the third is related to duration of the sound (short or long, and the last is about timbre – the personality of the sound. Tests were applied and the results are presented in this work.

  6. Shockwave compression of Ar gas at several initial densities (United States)

    Dattelbaum, Dana M.; Goodwin, Peter M.; Garcia, Daniel B.; Gustavsen, Richard L.; Lang, John M.; Aslam, Tariq D.; Sheffield, Stephen A.; Gibson, Lloyd L.; Morris, John S.


    Experimental data of the principal Hugoniot locus of variable density gas-phase noble and molecular gases are rare. The majority of shock Hugoniot data is either from shock tube experiments on low-pressure gases or from plate impact experiments on cryogenic, liquefied gases. In both cases, physics regarding shock compressibility, thresholds for the on-set of shock-driven ionization, and even dissociation chemistry are difficult to infer for gases at intermediate densities. We have developed an experimental target design for gas gun-driven plate impact experiments on noble gases at initial pressures between 200-1000 psi. Using optical velocimetry, we are able to directly determine both the shock and particle velocities of the gas on the principal Hugoniot locus, as well as clearly differentiate ionization thresholds. The target design also results in multiply shocking the gas in a quasi-isentropic fashion yielding off-Hugoniot compression data. We describe the results of a series of plate impact experiments on Ar with starting densities between 0.02-0.05 g/cm3 at room temperature. Furthermore, by coupling optical fibers to the targets, we have measured the time-resolved optical emission from the shocked gas using a spectrometer coupled to an optical streak camera to spectrally-resolve the emission, and with a 5-color optical pyrometer for temperature determination.

  7. Improvement of two-dimension AR model and application in simulation on surface profiles of steel plates

    Institute of Scientific and Technical Information of China (English)

    汪家道; 陈大融; 孔宪梅


    The order and parameter estimation is always difficult in two-dimension AR model because the two-dimension Yule-Walker equation does not have the property of uniqueness and identifiability as the one-dimension AR model.This paper provides an AR order estimation method for a two-dimension AR model, and an AR model parameter estimation method on the basis of an autocorrelation function. A simulation example on surface profiles of some kinds of steel plates is given using this improved AR model with positive results.

  8. ars1, an Arabidopsis mutant exhibiting increased tolerance to arsenate and increased phosphate uptake. (United States)

    Lee, David A; Chen, Alice; Schroeder, Julian I


    Arsenic is one of the most toxic pollutants at contaminated sites, yet little is known about the mechanisms by which certain plants survive exposure to high arsenic levels. To gain insight into the mechanisms of arsenic tolerance in plants, we developed a genetic screen to isolate Arabidopsis thaliana mutants with altered tolerance to arsenic. We report here on the isolation of a mutant arsenic resisant 1 (ars1) with increased tolerance to arsenate. ars1 germinates and develops under conditions that completely inhibit growth of wild-type plants and shows a semi-dominant arsenic resistance phenotype. ars1 accumulates levels of arsenic similar to that accumulated by wild-type plants, suggesting that ars1 plants have an increased ability to detoxify arsenate. However, ars1 plants produce phytochelatin levels similar to levels produced by the wild type, and the enhanced resistance of ars1 is not abolished by the gamma-glutamylcysteine synthetase inhibitor l-buthionine sulfoxime (BSO). Furthermore, ars1 plants do not show resistance to arsenite or other toxic metals such as cadmium and chromium. However, ars1 plants do show a higher rate of phosphate uptake than that shown by wild-type plants, and wild-type plants grown with an excess of phosphate show increased tolerance to arsenate. Traditional models of arsenate tolerance in plants are based on the suppression of phosphate uptake pathways and consequently on the reduced uptake of arsenate. Our data suggest that arsenate tolerance in ars1 could be due to a new mechanism mediated by increased phosphate uptake in ars1. Models discussing how increased phosphate uptake could contribute to arsenate tolerance are discussed.

  9. Arsenate reduction and expression of multiple chromosomal ars operons in Geobacillus kaustophilus A1. (United States)

    Cuebas, Mariola; Villafane, Aramis; McBride, Michelle; Yee, Nathan; Bini, Elisabetta


    Geobacillus kaustophilus strain A1 was previously isolated from a geothermal environment for its ability to grow in the presence of high arsenate levels. In this study, the molecular mechanisms of arsenate resistance of the strain were investigated. As(V) was reduced to As(III), as shown by HPLC analysis. Consistent with the observation that the micro-organism is not capable of anaerobic growth, no respiratory arsenate reductases were identified. Using specific PCR primers based on the genome sequence of G. kaustophilus HTA426, three unlinked genes encoding detoxifying arsenate reductases were detected in strain A1. These genes were designated arsC1, arsC2 and arsC3. While arsC3 is a monocistronic locus, sequencing of the regions flanking arsC1 and arsC2 revealed the presence of additional genes encoding a putative arsenite transporter and an ArsR-like regulator upstream of each arsenate reductase, indicating the presence of sequences with putative roles in As(V) reduction, As(III) export and arsenic-responsive regulation. RT-PCR demonstrated that both sets of genes were co-transcribed. Furthermore, arsC1 and arsC2, monitored by quantitative real-time RT-PCR, were upregulated in response to As(V), while arsC3 was constitutively expressed at a low level. A mechanism for regulation of As(V) detoxification by Geobacillus that is both consistent with our findings and relevant to the biogeochemical cycle of arsenic and its mobility in the environment is proposed.

  10. Biogeochemical cyclic activity of bacterial arsB in arsenic-contaminated mines

    Institute of Scientific and Technical Information of China (English)

    CHANG Jin-Soo; PEN Xianghao; KIM Kyoung-Woong


    Biogeochemical cyclic activity of the ars (arsenic resistance system) operon is arsB influx/efflux encoded by the ecological of Pseudomonas putida. This suggests that studying arsenite-oxidizing bacteria may lead to a better understanding of molecular geomicrobiology, which can be applied to the bioremediation of arsenic-contaminated mines. This is the first report in which multiple arsB-binding mechanisms have been used on indigenous bacteria. In ArsB (swains OS-5; ABB83931; OS-19; ABB04282 and RW-28;ABB88574), there are ten putative enzyme, Histidine (His) 131, His 133, His 137, Arginine (Arg) 135, Arg 137, Arg 161, Trptohan (Trp) 142, Trp 164, Trp 166, and Trp 171, which are each located in different regions of the partial sequence. The adenosine triphosphate (ATP)-binding cassette transports, binding affinities and associating ratable constants show that As-binding is comparatively insensitive to the location of the residues within the moderately stable a-helical structure. The α-helical structures in ArsB-permease and anion permease arsB have been shown to import/export arsenic in P. putida. We proposed that arsB residues, His 131, His 133, His 137, Arg 135, Arg 137, Arg 161, Trp 142, Trp 164, Trp 166, and Trp 171 are required for arsenic binding and activation ofarsA/arsB or arsAB.This arsB influx/efflux pum-ping is important, and the effect in arsenic species change and mobility in mine soil has got a significantly ecological role because it allows arsenic oxidizing/reducing bacteria to control biogeochemical cycle of abandoned mines.

  11. Decisive factors affecting plasma resistance and roughness formation in ArF photoresist

    Energy Technology Data Exchange (ETDEWEB)

    Jinnai, Butsurin; Uesugi, Takuji; Koyama, Koji; Samukawa, Seiji [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Kato, Keisuke; Yasuda, Atsushi; Maeda, Shinichi [Yokohama Research Laboratories, Mitsubishi Rayon Co., Ltd, 10-1 Daikoku-cho, Tsurumi-ku, Yokohama 230-0053 (Japan); Momose, Hikaru, E-mail: [Corporate Research Laboratories, Mitsubishi Rayon Co., Ltd, 2-1 Miyuki-cho, Otake, Hiroshima 739-0693 (Japan)


    Low plasma resistance and roughness formation in an ArF photoresist are serious issues in plasma processes. To resolve these issues, we investigated several factors that affect the roughness formation and plasma resistance in an ArF photoresist. We used our neutral beam process to categorize the effects of species from the plasma on the ArF photoresist into physical bombardment, chemical reactions and ultraviolet/vacuum ultraviolet (UV/VUV) radiation. The UV/VUV radiation drastically increased the etching rates of the ArF photoresist films, and, in contrast, chemical reactions increased the formation of surface roughness. FTIR analysis indicated that the UV/VUV radiation preferentially dissociates C-H bonds in the ArF photoresist, rather than C=O bonds, because of the dissociation energies of the bonds. This indicated that the etching rates of the ArF photoresist are determined by the UV/VUV radiation because this radiation can break C-H bonds, which account for the majority of structures in the ArF photoresist. In contrast, FTIR analysis showed that chemical species such as radicals and ions were likely to react with C=O bonds, in particular C=O bonds in the lactone groups of the ArF photoresist, due to the structural and electronic effects of the lactone groups. As a result, the etching rates of the ArF photoresist can vary in different bond structures, leading to increased surface roughness in the ArF photoresist.

  12. Paleomagnetism, magnetic fabric, and 40Ar/39Ar dating of Pliocene and Quaternary ignimbrites in the Arequipa area, southern Peru (United States)

    Paquereau-Lebti, Perrine; Fornari, Michel; Roperch, Pierrick; Thouret, Jean-Claude; Macedo, Orlando


    40Ar/39Ar ages and paleomagnetic correlations using characteristic remanent magnetizations (ChRM) show that two main ignimbrite sheets were deposited at 4.86 ± 0.07 Ma (La Joya Ignimbrite: LJI) and at 1.63 ± 0.07 Ma (Arequipa Airport Ignimbrite: AAI) in the Arequipa area, southern Peru. The AAI is a 20-100 m-thick ignimbrite that fills in the Arequipa depression to the west of the city of Arequipa. The AAI is made up of two cooling units: an underlying white unit and an overlying weakly consolidated pink unit. Radiometric data provide the same age for the two units. As both units record exactly the same well-defined paleomagnetic direction (16 sites in the white unit of AAI: Dec = 173.7; Inc = 31.2; α95 = 0.7; k = 2749; and 10 sites in the pink unit of AAI; Dec = 173.6; Inc = 30.3; α95 = 1.2; k = 1634), showing no evidence of secular variation, the time gap between emplacement of the two units is unlikely to exceed a few years. The >50 m thick well-consolidated white underlying unit of the Arequipa airport ignimbrite provides a very specific magnetic zonation with low magnetic susceptibilities, high coercivities and unblocking temperatures of NRM above 580°C indicating a Ti-poor titanohematite signature. The Anisotropy of Magnetic Susceptibility (AMS) is strongly enhanced in this layer with anisotropy values up to 1.25. The fabric delineated by AMS was not recognized neither in the field nor in thin sections, because most of the AAI consists in a massive and isotrope deposit with no visible textural fabric. Pumices deformation due to welding is only observed at the base of the thickest sections. AMS within the AAI ignimbrite show a very well defined pattern of apparent imbrications correlated to the paleotopography, with planes of foliation and lineation dipping often at more than 20° toward the expected vent, buried beneath the Nevado Chachani volcanic complex. In contrast with the relatively small extent of the thick AAI, the La Joya ignimbrite covers large

  13. 40Ar/39Ar geochronology of the Faku tectonites: Implications for the tectonothermal evolution of the Faku block, northern Liaoning

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Xiaohui; WANG; Hui; LI; Tiesheng


    For lack of reliable isotopic chronological data, the metamorphic rock series in the Faku region of northern Liaoning has long been regarded as the platform basement. Recent studies reveal that these deformed and metamorphosed rocks, with a variety of protoliths of plutonic intrusions and supracrustal volcanic and sedimentary rocks, were genetically related to later ductile shearing events, and they, together with the syntectonic intrusions, constituted the large-scale Faku tectonites. In this paper, we report new 40Ar/39Ar data on hornblende, biotite, and K-feldspar from typical granitic mylonites in this suite of tectonites. The plateau age 256 Ma of FK53 hornblende and the high-temperature plateau age 262 Ma of Fk51-1 biotite should represent the cooling ages when the granites, formed as a result of Paleozoic oceanic crustal subduction beneath the continental crust or collision of multiple micro-continental blocks, were exhumed into shallow crustal levels. The plateau age 231 Ma of FK51-1 boitite and the apparent age 227 Ma of Fk51-2 K-feldspar are interpreted to record the time of ductile deformation occurring under greenschist facies conditions, i.e. the formation age of the Faku tectonites, while the age gradient from 197 Ma to 220 Ma of Fk51-2 K-feldspar probably record the subsequent stable uplift-cooling process. The tectonic exhumation event indicated by the plateau age 180 Ma of Fk51-2 K-feldspar may be associated with the onset of paleo-Pacific subduction beneath the North China plate. In addition, the U-Pb dating of FK54 zircon from later-intruded granite yields the age of crystallization of this super-unit intrusion at 159 Ma, thus establishing an upper limit for the formation age of the Faku tectonites, while the plateau age 125 Ma of Fk54 K-feldspar most likely corresponds to the rapid cooling and tectonic denudation event associated with the final collision between the Siberian plate and the North China plate. These isotopic ages provide important

  14. K-Ar、40Ar/39Ar定年中尼尔值和初始氩比值%Nier value and initial argon isotope ratio of K-Ar、40Ar/39Ar dating technique

    Institute of Scientific and Technical Information of China (English)

    权伍勋; 季建清; 周晶


    K-Ar、4Ar/ 39Ar定年中,用以计算囚禁40Ar绝对量的40Ar/36Ar,称为初始氩比值.现代大气中的初始氩比值叫尼尔值,为295.5.K-Ar、40Ar/ 39Ar定年的表观年龄都是在假设初始氩比值与现代大气中的尼尔值一致的基础上得到的.事实证明,地球样品的初始氩比值不总是尼尔值,因此这种假定不可靠,尤其在对年轻样品进行K-Ar、40Ar/39Ar定年时,会带来错误的表观年龄结果.对于K-Ar、40Ar/ 39Ar精细年代学,特别对于年轻样品和低钾含量样品,只有初始氩比值才对定年研究有意义,而初始氩比值只能通过40Ar/39Ar等时线法求得.所以严格地讲,只有等时线年龄才是可靠的.结合实验流程,本文分析了40Ar/39Ar定年中为什么大多数等时线获取的初始氩比值接近尼尔值,一是因为常规40Ar/39Ar坪年龄的计算方法,二是因为吸附氩的干扰.初始氩比值的一致性,被用来证明样品同位素同源和封闭特性,对年龄数据的精度及可靠性有非常大的影响,尤其是年轻样品.因此,在40Ar/39Ar定年中要选取氩同位素初始比值一致的同源样品,并在实验流程中尽量克服样品吸附气体.本文对传统400Ar/39Ar方法中坪年龄、年龄坪的意义提出了质疑,对提高40Ar/39Ar定年的精度具有重要意义,并使之能够应用到极年轻的火山岩定年中.

  15. Androgen receptor (AR) in osteocytes is important for the maintenance of male skeletal integrity: evidence from targeted AR disruption in mouse osteocytes. (United States)

    Sinnesael, Mieke; Claessens, Frank; Laurent, Michaël; Dubois, Vanessa; Boonen, Steven; Deboel, Ludo; Vanderschueren, Dirk


    Androgens play a key role in the maintenance of male skeletal integrity. The regulation of this integrity by androgen receptor (AR) signaling has been mainly attributed to osteoblasts. Although osteocytes have emerged as key regulators of bone remodeling, the influence of sex steroids on these cells has been poorly studied. We aimed to investigate the role of AR signaling, specifically in osteocytes using the Cre/LoxP system in male mice (driven by dentin matrix protein 1 [ocy-ARKOs]). Osteocyte fractions of control (AR(ex2)/Y) and ocy-ARKO (ARflox(ex2)/Y; DMP1-cre) mice isolated through sequential collagenase digestion showed increasing AR expression toward the mature osteocyte fraction of control males compared with the more immature fractions, whereas this was reduced by >80% in ocy-ARKO osteocytes. The skeletal phenotype of mutant mice was further assessed by histomorphometry and quantitative micro-computed tomography at 12 and 32 weeks of age. Ocy-ARKOs had significantly lower trabecular bone volume and number in femora and tibias at 32 weeks as well as decreased trabecular number in the L(5) vertebra at 12 weeks. Biomechanical testing showed that ocy-ARKO femora were also stiffer and required a lower ultimate force to induce failure at 32 weeks. However, femoral cortical structure was not significantly different at any time point. The absence of AR in osteocyte also did not appear to affect trabecular bone formation nor its response to mechanical loading. In conclusion, selective inactivation of the AR in osteocytes of male mice accelerates age-related deterioration of skeletal integrity. These findings provide evidence for a direct role of androgens in the maintenance of trabecular bone through actions of the AR in osteocytes.


    Energy Technology Data Exchange (ETDEWEB)

    Cueto, M.; Herrero, V. J.; Tanarro, I.; Doménech, J. L. [Molecular Physics Department, Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, E-28006 Madrid (Spain); Cernicharo, J. [Department of Astrophysics, CAB. INTA-CSIC. Crta Torrejón-Ajalvir Km 4, E-28850 Torrejón de Ardoz, Madrid (Spain); Barlow, M. J.; Swinyard, B. M., E-mail: [Department of Physics and Astronomy, University College London. Gower Street, London WC1E 6BT (United Kingdom)


    The protonated argon ion, {sup 36}ArH{sup +}, was recently identified in the Crab Nebula from Herschel spectra. Given the atmospheric opacity at the frequency of its J = 1-0 and J = 2-1 rotational transitions (617.5 and 1234.6 GHz, respectively), and the current lack of appropriate space observatories after the recent end of the Herschel mission, future studies on this molecule will rely on mid-infrared observations. We report on accurate wavenumber measurements of {sup 36}ArH{sup +} and {sup 38}ArH{sup +} rotation-vibration transitions in the v = 1-0 band in the range 4.1-3.7 μm (2450-2715 cm{sup –1}). The wavenumbers of the R(0) transitions of the v = 1-0 band are 2612.50135 ± 0.00033 and 2610.70177 ± 0.00042 cm{sup –1} (±3σ) for {sup 36}ArH{sup +} and {sup 38}ArH{sup +}, respectively. The calculated opacity for a gas thermalized at a temperature of 100 K and with a linewidth of 1 km s{sup –1} of the R(0) line is 1.6 × 10{sup –15} × N({sup 36}ArH{sup +}). For column densities of {sup 36}ArH{sup +} larger than 1 × 10{sup 13} cm{sup –2}, significant absorption by the R(0) line can be expected against bright mid-IR sources.

  17. Polychronous (Early Cretaceous to Palaeogene) emplacement of the Mundwara alkaline complex, Rajasthan, India: 40Ar/39Ar geochronology, petrochemistry and geodynamics (United States)

    Pande, Kanchan; Cucciniello, Ciro; Sheth, Hetu; Vijayan, Anjali; Sharma, Kamal Kant; Purohit, Ritesh; Jagadeesan, K. C.; Shinde, Sapna


    The Mundwara alkaline plutonic complex (Rajasthan, north-western India) is considered a part of the Late Cretaceous-Palaeogene Deccan Traps flood basalt province, based on geochronological data (mainly 40Ar/39Ar, on whole rocks, biotite and hornblende). We have studied the petrology and mineral chemistry of some Mundwara mafic rocks containing mica and amphibole. Geothermobarometry indicates emplacement of the complex at middle to upper crustal levels. We have obtained new 40Ar/39Ar ages of 80-84 Ma on biotite separates from mafic rocks and 102-110 Ma on whole-rock nepheline syenites. There is no evidence for excess 40Ar. The combined results show that some of the constituent intrusions of the Mundwara complex are of Deccan age, but others are older and unrelated to the Deccan Traps. The Mundwara alkaline complex is thus polychronous and similar to many alkaline complexes around the world that show recurrent magmatism, sometimes over hundreds of millions of years. The primary biotite and amphibole in Mundwara mafic rocks indicate hydrous parental magmas, derived from hydrated mantle peridotite at relatively low temperatures, thus ruling out a mantle plume. This hydration and metasomatism of the Rajasthan lithospheric mantle may have occurred during Jurassic subduction under Gondwanaland, or Precambrian subduction events. Low-degree decompression melting of this old, enriched lithospheric mantle, due to periodic diffuse lithospheric extension, gradually built the Mundwara complex from the Early Cretaceous to Palaeogene time.

  18. Ar+注入对UHMWPE摩擦学性能的影响%Effects of Ar+ ion implantation on tribological behaviour of UHMWPE

    Institute of Scientific and Technical Information of China (English)

    施雯; 曾招钦; 陈智勇; 徐润翔



  19. Comparison of Estimation Procedures for Multilevel AR(1 Models

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    Tanja eKrone


    Full Text Available To estimate a time series model for multiple individuals, a multilevel model may be used.In this paper we compare two estimation methods for the autocorrelation in Multilevel AR(1 models, namely Maximum Likelihood Estimation (MLE and Bayesian Markov Chain Monte Carlo.Furthermore, we examine the difference between modeling fixed and random individual parameters.To this end, we perform a simulation study with a fully crossed design, in which we vary the length of the time series (10 or 25, the number of individuals per sample (10 or 25, the mean of the autocorrelation (-0.6 to 0.6 inclusive, in steps of 0.3 and the standard deviation of the autocorrelation (0.25 or 0.40.We found that the random estimators of the population autocorrelation show less bias and higher power, compared to the fixed estimators. As expected, the random estimators profit strongly from a higher number of individuals, while this effect is small for the fixed estimators.The fixed estimators profit slightly more from a higher number of time points than the random estimators.When possible, random estimation is preferred to fixed estimation.The difference between MLE and Bayesian estimation is nearly negligible. The Bayesian estimation shows a smaller bias, but MLE shows a smaller variability (i.e., standard deviation of the parameter estimates.Finally, better results are found for a higher number of individuals and time points, and for a lower individual variability of the autocorrelation. The effect of the size of the autocorrelation differs between outcome measures.

  20. A carbon cycle science update since IPCC AR-4. (United States)

    Dolman, A J; van der Werf, G R; van der Molen, M K; Ganssen, G; Erisman, J-W; Strengers, B


    We review important advances in our understanding of the global carbon cycle since the publication of the IPCC AR4. We conclude that: the anthropogenic emissions of CO2 due to fossil fuel burning have increased up through 2008 at a rate near to the high end of the IPCC emission scenarios; there are contradictory analyses whether an increase in atmospheric fraction, that might indicate a declining sink strength of ocean and/or land, exists; methane emissions are increasing, possibly through enhanced natural emission from northern wetland, methane emissions from dry plants are negligible; old-growth forest take up more carbon than expected from ecological equilibrium reasoning; tropical forest also take up more carbon than previously thought, however, for the global budget to balance, this would imply a smaller uptake in the northern forest; the exchange fluxes between the atmosphere and ocean are increasingly better understood and bottom up and observation-based top down estimates are getting closer to each other; the North Atlantic and Southern ocean take up less CO2, but it is unclear whether this is part of the 'natural' decadal scale variability; large-scale fires and droughts, for instance in Amazonia, but also at Northern latitudes, have lead to significant decreases in carbon uptake on annual timescales; the extra uptake of CO2 stimulated by increased N-deposition is, from a greenhouse gas forcing perspective, counterbalanced by the related additional N2O emissions; the amount of carbon stored in permafrost areas appears much (two times) larger than previously thought; preservation of existing marine ecosystems could require a CO2 stabilization as low as 450 ppm; Dynamic Vegetation Models show a wide divergence for future carbon trajectories, uncertainty in the process description, lack of understanding of the CO2 fertilization effect and nitrogen-carbon interaction are major uncertainties.

  1. Cerebral artery alpha-1 AR subtypes: high altitude long-term acclimatization responses.

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    Ravi Goyal

    Full Text Available In response to hypoxia and other stress, the sympathetic (adrenergic nervous system regulates arterial contractility and blood flow, partly through differential activities of the alpha1 (α1 - adrenergic receptor (AR subtypes (α1A-, α1B-, and α1D-AR. Thus, we tested the hypothesis that with acclimatization to long-term hypoxia (LTH, contractility of middle cerebral arteries (MCA is regulated by changes in expression and activation of the specific α1-AR subtypes. We conducted experiments in MCA from adult normoxic sheep maintained near sea level (300 m and those exposed to LTH (110 days at 3801 m. Following acclimatization to LTH, ovine MCA showed a 20% reduction (n = 5; P<0.05 in the maximum tension achieved by 10-5 M phenylephrine (PHE. LTH-acclimatized cerebral arteries also demonstrated a statistically significant (P<0.05 inhibition of PHE-induced contractility in the presence of specific α1-AR subtype antagonists. Importantly, compared to normoxic vessels, there was significantly greater (P<0.05 α1B-AR subtype mRNA and protein levels in LTH acclimatized MCA. Also, our results demonstrate that extracellular regulated kinase 1 and 2 (ERK1/2-mediated negative feedback regulation of PHE-induced contractility is modulated by α1B-AR subtype. Overall, in ovine MCA, LTH produces profound effects on α1-AR subtype expression and function.

  2. Direct interaction between AR and PAK6 in androgen-stimulated PAK6 activation. (United States)

    Liu, Xia; Busby, Jennifer; John, Ciny; Wei, Jianning; Yuan, Xin; Lu, Michael L


    A p21-activated kinase 6 (PAK6) was previously identified to be an androgen receptor (AR) interacting protein through a yeast two-hybrid screening. We used hormone responsive prostate cancer LAPC4 and LNCap cell lines as models to study the signaling events associated with androgen stimulation and PAK6. An androgen-stimulated PAK6 kinase activation was observed in LAPC4 cells expressing endogenous PAK6 and in LNCap cells ectopically expressing a wild type PAK6. This activation was likely mediated through a direct interaction between AR and PAK6 since siRNA knock-down of AR in LAPC4 cells downregulated androgen-stimulated PAK6 activation. In addition, LNCap cells expressing a non-AR-interacting PAK6 mutant exhibited dampened androgen-stimulated kinase activation. As a consequence of androgen-stimulated activation, PAK6 was phosphorylated at multiple serine/threonine residues including the AR-interacting domain of PAK6. Furthermore, androgen-stimulation promoted prostate cancer cell motility and invasion were demonstrated in LNCap cells ectopically expressing PAK6-WT. In contrast, LNCap expressing non-AR-interacting mutant PAK6 did not respond to androgen stimulation with increased cell motility and invasion. Our results demonstrate that androgen-stimulated PAK6 activation is mediated through a direct interaction between AR and PAK6 and PAK6 activation promotes prostate cancer cells motility and invasion.

  3. Direct interaction between AR and PAK6 in androgen-stimulated PAK6 activation.

    Directory of Open Access Journals (Sweden)

    Xia Liu

    Full Text Available A p21-activated kinase 6 (PAK6 was previously identified to be an androgen receptor (AR interacting protein through a yeast two-hybrid screening. We used hormone responsive prostate cancer LAPC4 and LNCap cell lines as models to study the signaling events associated with androgen stimulation and PAK6. An androgen-stimulated PAK6 kinase activation was observed in LAPC4 cells expressing endogenous PAK6 and in LNCap cells ectopically expressing a wild type PAK6. This activation was likely mediated through a direct interaction between AR and PAK6 since siRNA knock-down of AR in LAPC4 cells downregulated androgen-stimulated PAK6 activation. In addition, LNCap cells expressing a non-AR-interacting PAK6 mutant exhibited dampened androgen-stimulated kinase activation. As a consequence of androgen-stimulated activation, PAK6 was phosphorylated at multiple serine/threonine residues including the AR-interacting domain of PAK6. Furthermore, androgen-stimulation promoted prostate cancer cell motility and invasion were demonstrated in LNCap cells ectopically expressing PAK6-WT. In contrast, LNCap expressing non-AR-interacting mutant PAK6 did not respond to androgen stimulation with increased cell motility and invasion. Our results demonstrate that androgen-stimulated PAK6 activation is mediated through a direct interaction between AR and PAK6 and PAK6 activation promotes prostate cancer cells motility and invasion.

  4. Speed of CMEs and the Magnetic Non-Potentiality of Their Source ARs (United States)

    Tiwari, Sanjiv K.; Falconer, David A.; Moore, Ronald L.; Venkatakrishnan, P.


    Most fast coronal mass ejections (CMEs) originate from solar active regions (ARs). Non-potentiality of ARs is expected to determine the speed and size of CMEs in the outer corona. Several other unexplored parameters might be important as well. To find out the correlation between the initial speed of CMEs and the non-potentiality of source ARs, we associated over a hundred of CMEs with source ARs via their co-produced flares. The speed of the CMEs are collected from the SOHO LASCO CME catalog. We have used vector magnetograms obtained mainly with HMI/SDO, also with Hinode (SOT/SP) when available within an hour of a CME occurrence, to evaluate various magnetic non-potentiality parameters, e.g. magnetic free-energy proxies, computed magnetic free energy, twist, shear angle, signed shear angle etc. We have also included several other parameters e.g. total unsigned flux, net current, magnetic area of ARs, area of sunspots, to investigate their correlation, if any, with the initial speeds of CMEs. Our preliminary results show that the ARs with larger non-potentiality and area mostly produce fast CMEs but they can also produce slower ones. The ARs with lesser non-potentiality and area generally produce only slower CMEs, however, there are a few exceptions. The total unsigned flux correlate with the non-potentiality parameters and area of ARs but some ARs with large unsigned flux are also found to be least non-potential. A more detailed analysis is underway.

  5. Hepatic glucose intolerance precedes hepatic steatosis in the male aromatase knockout (ArKO mouse.

    Directory of Open Access Journals (Sweden)

    Michelle L Van Sinderen

    Full Text Available Estrogens are known to play a role in modulating metabolic processes within the body. The Aromatase knockout (ArKO mice have been shown to harbor factors of Metabolic syndrome with central adiposity, hyperinsulinemia and male-specific hepatic steatosis. To determine the effects of estrogen ablation and subsequent replacement in males on whole body glucose metabolism, three- and six-month-old male ArKO mice were subjected to whole body glucose, insulin and pyruvate tolerance tests and analyzed for ensuing metabolic changes in liver, adipose tissue, and skeletal muscle. Estrogen-deficient male ArKO mice showed increased gonadal adiposity which was significantly reduced upon 17β-estradiol (E2 treatment. Concurrently, elevated ArKO serum leptin levels were significantly reduced upon E2 treatment and lowered serum adiponectin levels were restored to wild type levels. Three-month-old male ArKO mice were hyperglycemic, and both glucose and pyruvate intolerant. These phenotypes continued through to 6 months of age, highlighting a loss of glycemic control. ArKO livers displayed changes in gluconeogenic enzyme expression, and in insulin signaling pathways upon E2 treatment. Liver triglycerides were increased in the ArKO males only after 6 months of age, which could be reversed by E2 treatment. No differences were observed in insulin-stimulated ex vivo muscle glucose uptake nor changes in ArKO adipose tissue and muscle insulin signaling pathways. Therefore, we conclude that male ArKO mice develop hepatic glucose intolerance by the age of 3 months which precedes the sex-specific development of hepatic steatosis. This can be reversed upon the administration of exogenous E2.

  6. Normal phenotype in conditional androgen receptor (AR) exon 3-floxed neomycin-negative male mice. (United States)

    Rana, Kesha; Clarke, Michele V; Zajac, Jeffrey D; Davey, Rachel A; MacLean, Helen E


    Androgens (testosterone and dihydrotestosterone) acting via the androgen receptor (AR) are required for male sexual differentiation, and also regulate the development of many other tissues including muscle, fat and bone. We previously generated an AR(lox) mouse line with exon 3 of the AR gene targeted by loxP sites. The deletion of exon 3 is in-frame, so only the DNA binding-dependent actions of the AR are deleted, but non-DNA binding-dependent actions are retained. This line also contained an antibiotic resistance selection cassette, neomycin (neo) in intron 3, which was also flanked by loxP sites. Hemizygous AR(lox) male mice demonstrated a phenotype of hyperandrogenization, with increased mass of androgen-dependent tissues. We hypothesized that this hyperandrogenization was likely to be due to the presence of the neo cassette. In this study, we have generated an AR(lox) neo-negative mouse line, using the EIIa-cre deleter mouse line to remove the neo cassette. Hemizygous AR(lox) neo-negative male mice have a normal phenotype, with normal body mass and normal mass of androgen-dependent tissues including the testis, seminal vesicles, kidney, spleen, heart and retroperitoneal fat. This neo-negative exon 3-targeted mouse line is the only floxed AR mouse line available to study the DNA binding-dependent actions of the AR in a tissue-specific manner, and is suitable for investigation in all tissues. This study demonstrates the importance of removing the selection cassette, which can potentially alter the phenotype of floxed mouse lines even in the absence of detectable effects on target gene expression.

  7. CYP3A5 regulates prostate cancer cell growth by facilitating nuclear translocation of AR. (United States)

    Mitra, Ranjana; Goodman, Oscar B


    The central role of androgen receptor (AR) signaling is established in prostate cancer growth and progression. We propose CYP3A5 is part of a feedback loop that modulates the sensitivity of AR to androgen exposure. The purpose of this study is to elucidate the mechanism of regulation of AR expression by CYP3A5. To identify the role of CYP3A5 in regulating AR signaling, CYP3A5 protein expression was inhibited using CYP3A5 siRNA and azamulin. Both cell fractionation and immunocytochemical approaches in combination with dihydrotestosterone (DHT) and R1881 treatment were used to evaluate changes in AR nuclear translocation. CYP3A5 siRNA blocked growth of LNCaP and C4-2 cells by 30-60% (P ≤ 0.005). Azamulin, a CYP3A pharmacologic inhibitor, reduced the growth of LNCaP, C4-2 and 22RV1 lines by ∼ 40% (P ≤ 0.005). CYP3A5 siRNA inhibited growth in response to DHT and R1881 treatment in LNCaP and C4-2 by decreasing nuclear AR localization and resulting in diminished PSA and TMPRSS2 expression. Decreased AR nuclear localization resulting from CYP3A5 inhibition resulted in growth inhibition comparable to IC60 and IC40 of bicalutamide in LNCaP and C4-2 cell lines. Conversely, the CYP3A inducer rifampicin enhanced AR nuclear localization. As CYP3A5 regulates the nuclear translocation of AR; co-targeting CYP3A5 may provide a novel strategy for enhancing the efficacy of androgen deprivation therapy. Consequentially, these data suggest that concomitant medications may impact androgen deprivation therapy's efficacy. © 2015 Wiley Periodicals, Inc.

  8. Glandular epithelial AR inactivation enhances PTEN deletion-induced uterine pathology. (United States)

    Choi, Jaesung Peter; Zheng, Yu; Handelsman, David J; Simanainen, Ulla


    Phosphatase and tensin homolog (PTEN) deletion induces uterine pathology, whereas androgen actions via androgen receptor (AR) support uterine growth and therefore may modify uterine cancer risk. We hypothesized that the androgen actions mediated via uterine glandular epithelial AR could modify PTEN deletion-induced uterine pathology. To test our hypothesis, we developed uterine glandular epithelium-specific PTEN and/or AR knockout mouse models comparing the uterine pathology among wild-type (WT), glandular epithelium-specific AR inactivation (ugeARKO), PTEN deletion (ugePTENKO), and the combined PTEN and AR knockout (ugePTENARKO) female mice. The double knockout restricted to glandular epithelium showed that AR inactivation enhanced PTEN deletion-induced uterine pathology with development of intraepithelial neoplasia by 20 weeks of age. In ugePTENARKO, 6/10 (60%) developed intraepithelial neoplasia, whereas 3/10 (30%) developed only glandular hyperplasia in ugePTENKO uterus. No uterine pathology was observed in WT (n=8) and ugeARKO (n=7) uteri. Uterine weight was significantly (P=0.002) increased in ugePTENARKO (374±97 mg (mean±s.e.)) compared with WT (97±6 mg), ugeARKO (94±12 mg), and ugePTENKO (205±33 mg). Estrogen receptor alpha (ERα) and P-AKT expression was modified by uterine pathology but did not differ between ugePTENKO and ugePTENARKO, suggesting that its expressions are not directly affected by androgens. However, progesterone receptor (PR) expression was reduced in ugePTENARKO compared to ugePTENKO uterus, suggesting that PR expression could be regulated by glandular epithelial AR inactivation. In conclusion, glandular epithelial AR inactivation (with persistent stromal AR action) enhanced PTEN deletion-induced uterine pathology possibly by downregulating PR expression in the uterus.

  9. Inhibition of SGK1 enhances mAR-induced apoptosis in MCF-7 breast cancer cells. (United States)

    Liu, Guilai; Honisch, Sabina; Liu, Guoxing; Schmidt, Sebastian; Pantelakos, Stavros; Alkahtani, Saad; Toulany, Mahmoud; Lang, Florian; Stournaras, Christos


    Functional membrane androgen receptors (mAR) have previously been described in MCF-7 breast cancer cells. Their stimulation by specific testosterone albumin conjugates (TAC) activate rapidly non-genomic FAK/PI3K/Rac1/Cdc42 signaling, trigger actin reorganization and inhibit cell motility. PI3K stimulates serum and glucocorticoid inducible kinase SGK1, which in turn regulates the function of mAR. In the present study we addressed the role of SGK1 in mAR-induced apoptosis. TAC-stimulated mAR activation elicited apoptosis of MCF-7 cells, an effect significantly potentiated by concomitant incubation of the cells with TAC and the specific SGK1 inhibitors EMD638683 and GSK650394. In line with this, TAC and EMD638683 activated caspase-3. These effects were insensitive to the classical androgen receptor (iAR) antagonist flutamide, pointing to iAR-independent, mAR-induced responses. mAR activation and SGK1 inhibition further considerably augmented the radiation-induced apoptosis of MCF-7 cells. Moreover, TAC- and EMD638683 triggered early actin polymerization in MCF-7 cells. Blocking actin restructuring with cytochalasin B abrogated the TAC- and EMD638683-induced pro-apoptotic responses. Further analysis of the molecular signaling revealed late de-phosphorylation of FAK and Akt. Our results demonstrate that mAR activation triggers pro-apoptotic responses in breast tumor cells, an effect significantly enhanced by SGK1 inhibition, involving actin reorganization and paralleled by down-regulation of FAK/Akt signaling.

  10. Phylogenetic analysis of bacterial and archaeal arsC gene sequences suggests an ancient, common origin for arsenate reductase

    Directory of Open Access Journals (Sweden)

    Dugas Sandra L


    Full Text Available Abstract Background The ars gene system provides arsenic resistance for a variety of microorganisms and can be chromosomal or plasmid-borne. The arsC gene, which codes for an arsenate reductase is essential for arsenate resistance and transforms arsenate into arsenite, which is extruded from the cell. A survey of GenBank shows that arsC appears to be phylogenetically widespread both in organisms with known arsenic resistance and those organisms that have been sequenced as part of whole genome projects. Results Phylogenetic analysis of aligned arsC sequences shows broad similarities to the established 16S rRNA phylogeny, with separation of bacterial, archaeal, and subsequently eukaryotic arsC genes. However, inconsistencies between arsC and 16S rRNA are apparent for some taxa. Cyanobacteria and some of the γ-Proteobacteria appear to possess arsC genes that are similar to those of Low GC Gram-positive Bacteria, and other isolated taxa possess arsC genes that would not be expected based on known evolutionary relationships. There is no clear separation of plasmid-borne and chromosomal arsC genes, although a number of the Enterobacteriales (γ-Proteobacteria possess similar plasmid-encoded arsC sequences. Conclusion The overall phylogeny of the arsenate reductases suggests a single, early origin of the arsC gene and subsequent sequence divergence to give the distinct arsC classes that exist today. Discrepancies between 16S rRNA and arsC phylogenies support the role of horizontal gene transfer (HGT in the evolution of arsenate reductases, with a number of instances of HGT early in bacterial arsC evolution. Plasmid-borne arsC genes are not monophyletic suggesting multiple cases of chromosomal-plasmid exchange and subsequent HGT. Overall, arsC phylogeny is complex and is likely the result of a number of evolutionary mechanisms.

  11. KioskAR: An Augmented Reality Game as a New Business Model to Present Artworks

    Directory of Open Access Journals (Sweden)

    Yoones A. Sekhavat


    Full Text Available This paper presents the architecture of KioskAR, which is a pervasive game implemented using augmented reality (AR. This game introduces a new business model that makes it possible for players to present their artworks in virtual kiosks using augmented reality, while they are having fun playing the game. In addition to competition between the players in the game, this game requires social interaction between players to earn more points. A user study is conducted to evaluate the sense of presence and the usability of the application. The results of experiments show that KioskAR can achieve a high level of usability as well as sense of presence.

  12. Purification and Detection of 39Ar in Groundwater Samples via Low-Level Counting (United States)

    Mace, E. K.; Aalseth, C.; Brandenberger, J. M.; Humble, P.; Panisko, M.; Seifert, A.; Williams, R. M.


    Argon-39 can be used as a radiotracer to age-date groundwater aquifers to study recharge rates and to better understand the mean residence time, or age distributions, of groundwater. Argon-39 (with a half-life of 269 years) is created in the atmosphere by cosmic rays interacting with argon in the air (primarily 40Ar). The use of 39Ar as a radiotracer fills a gap in the age dating range which is currently covered by 3H/3He or 85Kr (1000 years); 39Ar fills the intermediate time scale range from 50-1000 years where the previously established radiotracers are not adequate. We will introduce the process for purifying and detecting 39Ar in ground water using ultra-low-background proportional counters (ULBPCs) at the shallow underground laboratory at Pacific Northwest National Laboratory. Argon-39 is detected through direct beta counting using ULBPCs loaded with a mixture of geologic argon (extracted from a carbon dioxide well with no measureable 39Ar activity) and methane, which enhances the sensitivity for 39Ar measurements. The ULBPCs have been shown to have a background count rate of 148 counts per day (cpd) in the energy range 3-400 keV when filled with 10 atm of P-10 counting gas (90% geologic Ar, 10% CH4). Initial demonstration samples were collected from groundwater aquifers in Fresno, California supported by the United States Geological Survey (USGS). A discussion of the sampling technique to degas the water from these wells and to then purify it for counting will be presented. In order to quantify the 39Ar contribution in the groundwater samples, the ULBPCs were characterized to determine two components: 1) the detector efficiency to modern levels of 39Ar, and 2) the remaining detector background (using geologic sourced argon which is free from 39Ar - no measureable 39Ar activity). These characterization results will be presented along with a discussion of the quantification of the 39Ar age of the demonstration measurements.

  13. Electron transport in Ar{sup +}-irradiated single wall carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Skakalova, V.; Woo, Y.S.; Roth, S. [Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart (Germany); Osvath, Z.; Biro, L.P. [Research Institute for Technical Physics and Materials Science, Hungarian Academy of Sciences MFA, P.O. Box 49, 1525 Budapest (Hungary)


    We study the effect of Ar{sup +}-irradiation on electrical transport in an individual single wall carbon nanotube (SWNT), a thin SWNT network and a thick SWNT film. The damage to SWNT structure induced by Ar{sup +}-irradiation is characterized by Raman spectroscopy. The electrical conductance both in an individual SWNT and in a thin SWNT network is strongly reduced by highly energetic Ar{sup +} ions. On contrary, a thick SWNT film exhibits an increase of its conductivity as well as of its Young modulus after irradiation. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. A Study of the Residual 39Ar Content in Argon from Underground Sources

    CERN Document Server

    Xu, J; Galbiati, C; Goretti, A; Guray, G; Hohman, T; Holtz, D; Ianni, A; Laubenstein, M; Loer, B; Love, C; Martoff, C J; Montanari, D; Mukhopadhyay, S; Nelson, A; Rountree, S D; Vogelaar, R B; Wright, A


    The discovery of argon from underground sources with significantly less 39Ar than atmospheric argon was an important step in the development of direct-detection dark matter experiments using argon as the active target. We report on the design and operation of a low background detector with a single phase liquid argon target that was built to study the 39Ar content of the underground argon. Underground argon from the Kinder Morgan CO2 plant in Cortez, Colorado was determined to have less than 0.65% of the 39Ar activity in atmospheric argon.

  15. The R- and AR-indices: Complementing the h-index


    JIN, BIHUI; Liang, Liming; Rousseau, Ronald; Egghe, Leo


    Based on the foundation laid by the h-index we introduce and study the R- and AR-indices. These new indices eliminate some of the disadvantages of the h-index, especially when they are used in combination with the h-index. The R-index measures the h-core’s citation intensity, while AR goes one step further and takes the age of publications into account. This allows for an index that can actually increase and decrease over time. We propose the pair (h, AR) as a meaningful indicator for researc...

  16. Interference effects in K vacancy transfer of hydrogen-like S ions colliding with Ar

    Energy Technology Data Exchange (ETDEWEB)

    Schuch, R.; Justiniano, E.; Schulz, M.; Ziegler, F.; Ingwersen, H.; Schmidt-Boecking, H.


    The impact-parameter-dependent K-shell to K-shell vacancy transfer probability has been investigated for 4.7, 7.9, 16, 32 and 90 MeV S/sup 15 +/-Ar collisions by measuring S and Ar K x-ray particle coincidences. With low-energy H-like S beams, oscillating Ar K vacancy probabilities as a function of impact parameter were measured. The interference maxima and minima could be related to values of the phase integral over the 2psigma-1ssigma energy difference from which information about this energy difference could be obtained.

  17. Biodisponibilidad y especiación de arsénico en las algas marinas


    García Sartal, Cristina


    Las algas, desde un punto de vista alimenticio, constituyen una fuente de proteínas, aminoácidos esenciales, vitaminas, lípidos y minerales. Sin embargo, las algas también pueden acumular elementos no esenciales procedentes del agua marina circundante, entre ellos, el arsénico, elemento ampliamente reconocido por su toxicidad. La toxicidad del arsénico depende fundamentalmente de su especiación, resultando más toxicas las especies inorgánicas de arsénico que sus correspondie...

  18. The R- and AR-indices: Complementing the h-index

    Institute of Scientific and Technical Information of China (English)

    JIN BiHui; LIANG LiMing; Ronald ROUSSEAU; Leo EGGHE


    Based on the foundation laid by the h-index we introduce and study the R- and AR-indices. These new indices eliminate some of the disadvantages of the h-index, especially when they are used in combination with the h-index. The R-index measures the h-core's citation intensity, while AR goes one step further and takes the age of publications into account. This allows for an index that can actually increase and decrease over time. We propose the pair (h, AR) as a meaningful indicator for research evaluation. We further prove a relation characterizing the h-index in the power law model.

  19. Evolution of the Ar isotopic chain: the N=28 shell gap south of {sup 48}Ca

    Energy Technology Data Exchange (ETDEWEB)

    Mengoni, D., E-mail: [Dipartimento di Fisica dell' Universita and INFN Sezione di Padova, Padova (Italy); Valiente-Dobon, J.J. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro (Italy); Gadea, A. [Instituto de Fisica Corpuscular, CSIC-Universidad de Valencia (Spain); Lenzi, S.M.; Lunardi, S. [Dipartimento di Fisica dell' Universita and INFN Sezione di Padova, Padova (Italy); Broda, R. [Institute of Nuclear Physics, Polish Academy of Sciences, Cracow (Poland); Dewald, A.; Pissulla, T. [Institut fuer Kernphysik der Universtaet zu Koeln, Koeln (Germany); Angus, L. [School of Engineering and Science, University of Paisley, Paisley, Scotland (United Kingdom); Aydin, S.; Bazzacco, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Padova (Italy); Benzoni, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano (Italy); Bizzeti, P.G.; Bizzeti-Sona, A.M. [Dipartimento di Fisica dell' Universita and INFN Sezione di Firenze, Firenze (Italy); Corradi, L. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro (Italy); Crespi, F. [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano (Italy); Angelis, G. de [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro (Italy); Farnea, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Padova (Italy); Fioretto, E. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro (Italy); Goergen, A. [CEA Saclay, Daphnia/SphN, Gif-sur-Yvette Cedex (France)


    The lifetimes of the first excited states of the Z = 18 {sup 44}Ar and {sup 46}Ar isotopes have been determined using a novel technique that combines the Recoil Distance Doppler Shift method with the CLARA-PRISMA spectrometers for Multinucleon Transfer Reactions. The B(E2) values extracted for the 2{sup +}->0{sup +} transitions in both nuclei, as well as for higher excites states in {sup 44}Ar, are discussed and compared with the available experimental results and with the new large-scale shell-model calculations.

  20. Rotational energy transfer in collisions between CO and Ar at temperatures from 293 to 30 K (United States)

    Mertens, Laura A.; Labiad, Hamza; Denis-Alpizar, Otoniel; Fournier, Martin; Carty, David; Le Picard, Sébastien D.; Stoecklin, Thierry; Sims, Ian R.


    Experimental measurements and theoretical calculations are reported for rotational energy transfer in the Ar-CO system. Experiments were performed in cold uniform supersonic flows of Ar, using an infrared - vacuum ultraviolet double resonance technique to measure absolute state-to-state rate constants and total relaxation cross sections for rotational energy transfer within the (v = 2) vibrational state of CO in collision with Ar at temperatures from 30.5 to 293 K. Close-coupling calculations were also performed using a recent potential energy surface (Sumiyoshi and Endo, 2015). Very good agreement is obtained between measured and calculated values.

  1. Presencia de arsénico en pozos y en cultivos en Oaxaca, México


    Pablo Ubaldo Caballero-Guti\\u00E9rrez; Jos\\u00E9 Cruz Carrillo-Rodriguez; Rosa Mar\\u00EDa Gomez-Ugalde; Martha Patricia Jerez-Salas


    Presencia de arsénico en pozos y en cultivos en Oaxaca, México. El objetivo de este trabajo fue determinar la presencia de arsénico en agua de pozos y en cultivos. Se muestrearon pozos noria y semip rofundos, y diferentes cultivos (tomate, lechuga, frijol y maíz), pertenecie ntes al paraje "Flor de Guayabal", en Tlacolula, Oaxaca, México, durante un periodo de 10 meses (julio 2006 a abril 2007).Hubo dos fases: la primera fue el diagnóstico que se obtuvo de la determinación mensual del arsénic...

  2. Additional /sup 40/Ar-/sup 39/Ar dating of the basement and the alkaline volcanism of Gorringe Bank (Atlantic Ocean)

    Energy Technology Data Exchange (ETDEWEB)

    Feraud, G.; York, D.; Mevel, C.; Cornen, G.; Hall, C.M.; Auzende, J.M.


    /sup 40/Ar//sup 39/Ar step heating analyses are reported for a variety of samples from Gorringe Bank (Atlantic Ocean). Flat age spectra for two primary, igneous hornblendes of Gorringe (corresponding to an age of 143 Ma) show that the K-Ar ages obtained on these samples by Prichard and Mitchell are evidently crystallization and not hybrid ages. This sustains the concept of an initiation age of 140 Ma for Gorringe Bank. No support is found for Carpena's suggestion that the formation of Gorringe Bank began 200 Ma ago. Secondary hornblendes from Ormonde seamount rocks appear to have formed shortly after the initiation of the Bank. Precise plateau ages on samples of two alkaline volcanics from Ormonde correspond to the older limit of the alkaline volcanism suggested by Feraud et al.

  3. Mound Facility activities in chemical and physical research: July--December 1977. [Kr-Xe and Kr-Ar diffusion; Ne-Ar thermal diffusion

    Energy Technology Data Exchange (ETDEWEB)


    Isotope separation of Ar, C, /sup 3/He, Kr, Ne, O, and Xe isotopes is reported. TiFeH/sub x/, TiCoH/sub x/, TiCuH/sub x/, and VH/sub x/ were studied using NMR (proton relaxation times). VD/sub x/ and VT/sub x/ were synthesized. The problem of calculating the valence state of Pu is discussed. A series solution to the plutonium (N,H) characteristic equation is suggested. Shipments of /sup 231/Pa, /sup 230/Th, and /sup 229/Th are reported. Separation and processing of /sup 234/U are also reported. Theoretical methods were developed to calculate temperature distributions as functions of water flow rate in liquid thermal diffusion columns. Diffusion coefficients were measured from 300 to 1200/sup 0/K for Kr-Xe and Kr-Ar. New thermal diffusion factors are submitted for Ne-Ar.

  4. Comparison of Structures and Properties between Wool and Ramie Fibers Treated by Atmospheric Pressure Ar and Ar/O2 Plasma

    Institute of Scientific and Technical Information of China (English)

    WANG Yue-ping; XU Xiang-yu; WANG Shou-guo; ZHANG Xiao-dan; ZHAO Ling-li; SHI Li-min; GAO Xu-shan


    The technique of atmospheric pressure plasma is of value in textile industry. In this paper, argon (Ar) and argon/oxygen (Ar/O2) atmospheric pressure plasma were used to treat wool and ramie fibers. The structures and properties of treated fibers were investigated by means of SEM, XPS, single fiber tensile tester and so on.The results proved that the effects of plasma treatments depended on structural characteristics of fibers to a great extent, besides conditions of plasma treatment. By atmospheric pressure plasma treatment, wool fiber had significant changes in morphology structure, surface chemical component, mechanic properties and dyeability, while ramie fiber just showed a little change. In additional, Ar/Q2 plasma showed more effective action than argon. And at the beginning of treatment, plasma brought about remarkable effects, which did not increase with prolonging of treat time.

  5. Cadomian vs. Variscan evolution of the Ossa-Morena zone (SW Iberia): field and 40Ar/ 39Ar mineral age constraints (United States)

    Dallmeyer, R. D.; Quesada, C.


    Six hornblende and ten muscovite concentrates have been dated from three contrasting tectonic units exposed within the Ossa-Morena zone of the Iberian Massif. These include: (1) the Obejo-Valsequillo domain (north of the Badajoz-Córdoba shear zone); (2) the Sierra Albarrana structural unit (immediately south of the Badajoz-Córdoba shear zone); and (3) the thermal some exposed within the Olivenza-Monesterio antiform (Zafra-Monesterio domain). Hornblende from foliated amphibolite in the Obejo-Valsequillo domain (Siera Negra unit) displays internally discordant 40Ar/ 39Ar age spectra as a result of both intracrystalline contamination with extraneous argon and slight rejuvenation. 36Ar/ 40Ar vs. 39Ar/ 40Ar isotope-correlations are generally well-defined and yield ages of c. 550-560 Ma. These are interpreted to date cooling following late Precambrian-early Paleozoic (Cadomian) tectonothermal activity. This was followed by slight Variscan rejuvenation at c. 375-400 Ma. Muscovite from this unit displays internally discordant age spectra which reflect more extensive Variscan rejuvenation of intracrystalline argon systems which had initially cooled below appropriate blocking temperatures at c. 560 Ma. Hornblende and muscovite from the Sierra Albarrana domain (Sierra Albarrana Group) record 40Ar/ 39Ar plateau and isotope-correlation ages which range between c. 392 Ma and 351 Ma. These results indicate that complete Variscan rejuvenation was followed by relatively rapid post-metamorphic cooling. Hornblende separated from various lithologie elements exposed in the Olivenza-Monesterio Antiform yield variable results. Hornblende within a mafic xenolith in the Monesterio Granodiorite records an isotope-correlation age of c. 553 Ma which is interpreted to date the last cooling through appropriate argon retention temperatures. Hornblende within amphibolite of the Montemolin Series (lower Serie Negra) records internally discordant age spectra which reflect extensive Variscan (c

  6. Ar and Kr concentrations in nitrogen as a measure of the 39Ar and 85Kr activities in connection with the solar neutrino experiment BOREXINO. (United States)

    Zuzel, G; Simgen, H; Heusser, G


    Among other radionuclides, 39Ar and 85Kr are potential background sources in the solar neutrino detector BOREXINO. The expected low event rate requires that the nitrogen used in the experiment needs to have lower concentrations than 0.5 microBq/m3 for 39Ar and 0.2 microBq/m3 for 85Kr, corresponding to volume concentrations in N2 of 0.4 x 10(-6)m3/m3 for Ar and 0.2 x 10(-12)m3/m3 for Kr. Applying gas mass spectrometry and special care in the sampling technique we succeeded in finding the required purity. In addition, we studied the possibility to purify nitrogen from Kr by the adsorption method.

  7. A high-resolution 40Ar/39Ar lava chronology and edifice construction history for Ruapehu volcano, New Zealand (United States)

    Conway, Chris E.; Leonard, Graham S.; Townsend, Dougal B.; Calvert, Andrew T.; Wilson, Colin J. N.; Gamble, John A.; Eaves, Shaun R.


    Ruapehu is an active 150 km3 andesite-dacite composite volcano located at the southern end of the Taupo Volcanic Zone, New Zealand. The growth of the present-day edifice has occurred throughout coeval eruptive and glacial histories since 200 ka. We present high-precision 40Ar/39Ar eruption ages for 46 samples and whole-rock major element geochemical data for 238 samples from lava flows. These new and existing data are interpreted in the context of geomorphologic and geologic mapping, volcano-ice interaction processes and glacier reconstructions to present an improved chronostratigraphic framework and new edifice evolution history for Ruapehu. Sub-glacial to ice-marginal effusive eruption of medium-K basaltic-andesites and andesites constructed the northern portion of the exposed edifice between 200 and 150 ka, and a wide southeast planèze as well as parts of the northern, eastern and western flanks between 160 and 80 ka. None of the dated lava flows have ages in the range of 80-50 ka, which may reflect an eruptive hiatus. Alternatively the lack of ages may be the result of erosion and burial of lavas and syn-eruptive glacial conveyance of lava flows to the ring-plain during glacial advance at 70-60 ka. From 50-15 ka edifice growth occurred via effusive eruptions onto the glaciated flanks of the volcano, resulting in construction of ice-bounded planèzes and ridges. The distribution of dated ice-marginal lavas indicates a general decrease in glacier thicknesses over this time, except for a short-lived period centred at 31 ka when peak ice cover was reached. The compositional ranges of medium- to high-K andesite and dacite lava flows within 50-35 ka eruptive packages define broadly bimodal high- and low-MgO trends. Lavas erupted at 35-22 ka have compositions that fill a transitional geochemical field between older dacites and younger andesites. Large-scale retreat of flank glaciers since 15 ka has resulted in intra-valley lava flow emplacement at elevations below

  8. New 40Ar/ 39Ar dating results from the Shanwang Basin, eastern China: Constraints on the age of the Shanwang Formation and associated biota (United States)

    He, Huaiyu; Deng, Chenglong; Pan, Yongxin; Deng, Tao; Luo, Zhaohua; Sun, Jimin; Zhu, Rixiang


    The fluvio-lacustrine sequence of the Shanwang Basin, eastern China, preserves a rich and important terrestrial fossil fauna and flora; the exceptional preservation of these fossils reveals the dynamics of ancient mammalian ecosystems and plant biology. However, the timing of this sedimentary sequence has been the subject of debate for decades. Here we contribute to this debate by presenting the detailed results of 40Ar/ 39Ar analysis of the basalts above, below, and within the Shanwang Formation. These dates place stringent constraints on the age of Shanwang Formation and associated biota. 40Ar/ 39Ar ages obtained from basalts of the Niushan and Yaoshan Formations, which underlie and overlie the Shanwang Formation, are 21.0 ± 2.5 Ma (2σ, full external error) and 17.3 ± 1.5 Ma (2σ, full external error), respectively. The 40Ar/ 39Ar age of the basalt in the Shanwang Formation is 17-18 Ma. Given the age constraints of the basalts of the Yaoshan and Shanwang Formations, the age of the Shanwang biota is estimated to be ca. 17 Ma, late Burdigalian of the Early Miocene, indicating that the deposition of this fauna coincided with the onset of the mid-Miocene Climatic Optimum. The results provide new age constraints on the Shanwang mammal fauna, and independently support interpretations that this fauna can be assigned to chronozone MN4, and correlated with middle Orleanian of the European Land Mammal Age, and to late Hemingfordian of the North American Land Mammal Age. Biological diversity of the Shanwang Formation could reflect the global-scale mid-Miocene Climatic Optimum.

  9. Constraints on the thermal history of the Blue Ridge in northernmost Virginia: [sup 40]Ar/[sup 39]Ar age dating results

    Energy Technology Data Exchange (ETDEWEB)

    Kunk, M.J.; Lyttle, P.T.; Schindler, S.J.; Burton, W.C. (Geological Survey, Reston, VA (United States))


    [sup 40]Ar/[sup 39]Ar age dating techniques have been used to analyze hornblende, phlogopite, white mica, biotite, and K-feldspar mineral separates from Middle and Late Proterozoic crystalline basement and from Late Proterozoic-Early Cambrian cover rocks in the Blue Ridge anticlinorium. Regionally, both cover and basement rocks contain a variably developed overprint fabric, the Blue Ridge-South Mountain cleavage, commonly defined by white mica. Petrographic analysis indicates a maximum metamorphic overprint of lower greenschist facies that locally produces biotite. [sup 40]Ar/[sup 39]Ar age spectra of hornblende from crystalline basement units suggest ages ranging from about 1 Ga to about 920 Ma. [sup 40]Ar/[sup 39]Ar age spectra of most cleavage-defining white mica are sigmoidal in shape suggesting the presence of multiple generations of white mica, the last of which probably grew below the blocking temperature for retention of argon in muscovite ([approximately]350 C). Interpretation of these complex spectra suggest that most of the cleavage-defining white mica may have formed below [approximately]350 C during the Late Paleozoic Alleghanian orogeny. However, these complex age spectra, together with age spectra from cleavage-defining phlogopite from a marble in the Fauquier Formation and biotite in the Late Proterozoic Robertson River Igneous Suite suggest the existence of an earlier episode of white mica growth of Middle Paleozoic age that has not been thermally reset or totally recrystallized. High temperature release steps can be interpreted to represent times of cooling through closure during the Middle Paleozoic. Low-temperature steps of these same age spectra suggest final closure or partial resetting of the samples at about 200 Ma or less and are interpreted to represent the effects of Mesozoic rifting.

  10. Contribution of the 40Ar/39Ar method to improve Middle-Pleistocene archaeological/palaeontological sites from the Italian Peninsula (United States)

    Nomade, Sebastien, ,, Dr.; Pereira, MSc. Alison; voinchet, Pierre, ,, Dr.; Bahain, Jean-Jacques, ,, Dr.; Aureli, Daniele, ,, Dr.; Arzarello, Marta, ,, Dr.; Anzidei, Anna-Paola, ,, Dr.; Biddittu, Italo, ,, Dr.; Bulgarelli, Maria-Grazia, ,, Dr.; Falguères, Christophe, ,, Dr.; Giaccio, Biagio, ,, Dr.; Guillou, Hervé, ,, Dr.; Manzi, Gorgio, ,, Dr.; Moncel, Marie-Hélène, ,, Dr.; Nicoud, Elisa, ,, Dr.; Pagli, Maria, ,, Dr.; Parenti, Fabio, ,, Dr.; Peretto, Carlo, ,, Dr.; Piperno, Marcello, ,, Dr.; Rocca, Roxane, ,, Dr.


    European Middle-Pleistocene archaeological and/or paleontological sites lack a unified and precise chronological framework. Despite recent efforts mostly focused on methods such as OSL, ESR/U-series or cosmogenic nuclides, the age of numerous sites from this period fundamentally still relies on qualitative and speculative palaeoenvironmental and/or palaeontological/palaeoanthropological considerations. The lack of robust chronologies, along with the scarcity of human fossils, prevent coherent correlations between European sites which in turn limits our understanding of human diffusion dynamics, understand techno-cultural evolution or correlate archaeological sites with palaeoclimatic and environmental records. With the goal of providing an accurate and precise chronological framework based on a multi-method approach, a research network including geochronologists, archaeologist and paleoanthropologists from various French and Italian institutions launched in 2010 a wide study of Middle-Pleistocene archaeological sites of central and southern Italy. This study combining the 39Ar/40Ar method with palaeo-dosimetric methods applied to European sites in the age range of 700 ka to 300 ka is unprecedented. In parallel, a large effort has been done to improve the regional Middle-Pleistocene tephrostratigraphic database through a massive application of both high-precision 40Ar/39Ar geochronological and geochemical investigations. We illustrate our approach and results in addressing several key-sites such as Notarchirico, Valle Giumentina; Ceprano-Campogrande and La Polledrara di Cecanibbio. The accurate and precise chronological framework we built permits us to replace all the investigated archaeological and palaeontological records into a coherent climatic and environmental context. Furthermore, our work provides the opportunity to compare lithic industries from a technical and evolutionary point of view within a homogeneous temporal frame. These preliminary results border

  11. Chemical and physical erosion rhythms of the West African Cenozoic morphogenesis: The 39Ar-40Ar dating of supergene K-Mn oxides (United States)

    Beauvais, Anicet; Ruffet, Gilles; HéNocque, Olivier; Colin, Fabrice


    Chemical weathering and mechanical erosion are first-order processes of long-term tropical morphogenesis, which is still poorly deciphered for lack of time constraints. We address this issue by laser probe 39Ar-40Ar dating of generations of cryptomelane [K1-2Mn8O16, nH2O] from the manganese ore deposit of Tambao in northern Burkina Faso. This Mn deposit results from the supergene weathering of carbonate and silicate Mn protores underneath lateritic palaeolandsurfaces. It consists of an upper cryptomelane-rich domain and a lower domain where pyrolusite (β-MnO2) is the dominant Mn oxide. The oldest 39Ar-40Ar ages (59-45 Ma) are obtained on surface outcrops while the youngest ones characterize deep oxidation fronts (3.4-2.9 Ma). Apparent correlations of 39Ar-40Ar age groups with δ18O and eustatic curves allow definition of the different stages of morphogenesis. Paleocene-Eocene ages (59-45 Ma) bracket a greenhouse period propitious to bauxitic weathering. The lack of significant ages between ˜45 and 29 Ma characterizes a period dominated by mechanical erosion, during which detrital sediments, including lateritic materials, were accumulated in intracratonic basins allowing the exhumation of a new lateritic landsurface. Two major weathering periods separated by a second erosion episode (24-18 Ma) are also depicted at the end of Oligocene (29-24 Ma) and lower to mid-Miocene (18-11.5 Ma) in the upper domain, during which newly shaped land surfaces conspicuously weathered. The shorter-weathering and erosion episodes recorded in the lower domain from ˜18 to ˜2.9 Ma led to the final geomorphic changes that were conducive to the formation of glacis. The preservation of old cryptomelane (59-45 Ma) in the upper part of the ore deposit indicates a Cenozoic denudation limited to the erosion of previous bauxites, and partly, of ferricretes.

  12. Exploring AR-NFkappaB/p52-Targeted Inhibitors as Novel Therapy Against Castration-Resistant Prostate Cancer Progression (United States)


    SUPPLEMENTARY NOTES 14. ABSTRACT The goal of this research was to verify the specificity of the inhibition of androgen receptor (AR) – NFkB / these cells as the mutations in AR rendered AR inactive and not responding to androgen treatment until later time point (72h). We also looked at

  13. Preoptimised VB: a fast method for the ground and excited states of ionic clusters I. Localised preoptimisation for (ArCO) +, (ArN 2) + and N 4+ (United States)

    Langenberg, J. H.; Bucur, I. B.; Archirel, P.


    We show that in the simple case of van der Waals ionic clusters, the optimisation of orbitals within VB can be easily simulated with the help of pseudopotentials. The procedure yields the ground and the first excited states of the cluster simultaneously. This makes the calculation of potential energy surfaces for tri- and tetraatomic clusters possible, with very acceptable computation times. We give potential curves for (ArCO) +, (ArN 2) + and N 4+. An application to the simulation of the SCF method is shown for Na +H 2O.

  14. 31+/-17 ka 40Ar/39Ar Plateau Age on the Very Low-Potassium Hat Creek Basalt Fits Stratigraphic and Geochronologic Constraints of Contiguous Units (United States)

    Clynne, M. A.; Turrin, B. D.; Champion, D. E.; Muffler, L. P.


    The Hat Creek Basalt is a late Pleistocene low-K olivine tholeiite that floors much of the Hat Creek Valley, north of the Lassen volcanic highland in NE California. The flow erupted from a fissure trending N 10° W located 0.5 to 4.0 km SSE of Old Station and flowed north nearly 30 km, mainly through lava tubes. Paleomagnetic data indicate that the Hat Creek Basalt is a single eruptive unit with an inclination of 64.3° and a declination of 1.0° . The Hat Creek Basalt is overlain by gravel related to the last major glaciation, which ended about 15 to 17 ky ago. The Hat Creek Basalt overlies numerous andesite and basaltic andesite lava flows that are closely related geographically, stratigraphically, petrographically and geochemically and probably represent the same eruptive episode (although not necessarily the same year or century). Three of these flows have been dated by the 40Ar/39Ar method and yield concordant plateau, integrated (total fusion), and isochron ages: Little Potato Butte (1.42% K2O; 67+/-4 ka), Sugarloaf (1.85% K2O; 55+/-7 ka), and Big Potato Butte (1.62% K2O; 73+/-14 ka). The Hat Creek Basalt also overlies the basaltic andesite of Cinder Butte (1.65% K2O) with a 40Ar/39Ar plateau age of 38+/-7 ka. Given that the age of the Hat Creek Basalt is thus firmly bracketed between ˜15 ka and 38+/-7 ka, we attempted to date this low-potassium tholeiitic basalt directly. One sample produced 40Ar/39Ar data that cannot be interpreted, but a second sample (0.17% K2O) yielded concordant plateau, integrated (total fusion), and isochron ages of 31+/-17 ka, 30+/-20 ka, and 24+/-6 ka; within the time bracket determined by stratigraphic relations. These data indicate that samples of latest Pleistocene tholeiitic basalt with very low K2O can give useful 40Ar/39Ar ages. As with all isotopically determined ages, the confidence of the results are significantly enhanced when additional constraints imposed by other isotopic ages within a stratigraphic context are taken

  15. Study of the {sup 40}Ar + {sup 208}Pb reaction using the {sup 40}Ar Piave-ALPI test beam and the Prisma-Clara set-up

    Energy Technology Data Exchange (ETDEWEB)

    Stefanini, A.M.; Marginean, N.; Corradi, L. [INFN, Laboratori Nazionali di Legnaro Padova (Italy)] (and others)


    The study of few- and multi-nucleon transfer reactions in the system {sup 40}Ar + {sup 208}Pb may offer interesting results, also in the comparison with what we obtained in the recent study of {sup 40}Ca + {sup 208}Pb where clear evidences of simultaneous nucleon pair transfer have been found. Moreover, the case of {sup 40}Ar + {sup 208}Pb is attractive from the point of view of the possibility of populating neutron-rich nuclei in the sulphur-silicon region with non-negligible cross sections, for nuclear structure studies.

  16. New U-Pb zircon and 40Ar/39Ar muscovite age constraints on the emplacement of the Lizio syn-tectonic granite (Armorican Massif, France)


    Tartese, Romain; Poujol, Marc; Ruffet, Gilles; Boulvais, Philippe; Yamato, Philippe; Kosler, Jan


    International audience; LA-ICP-MS U-Pb analyses performed on zircon grains from the Lizio granite yielded an emplacement age of 316 6 Ma. Typical S-C structures show that the Lizio granite was emplaced contemporaneously with dextral shearing along the northern branch of the South Armorican Shear Zone and that it was therefore active at that time. 40Ar/39Ar analyses performed on muscovite grains yielded plateau dates ranging between 311.5 and 308.2 Ma. Muscovite chemistry is typical of primary...

  17. Using high-precision 40Ar/39Ar geochronology to understand volcanic hazards within the Rio Grande rift and along the Jemez lineament, New Mexico (United States)

    Zimmerer, M. J.; McIntosh, W. C.; Heizler, M. T.; Lafferty, J.


    High-precision Ar/Ar ages were generated for late Quaternary volcanic fields in the Rio Grande rift and along the Jemez Lineament, New Mexico, to assess the time-space patterns of volcanism and begin quantifying volcanic hazards for the region. The published chronology of most late Quaternary volcanic centers in the region is not sufficiently precise, accurate, or complete for a comprehensive volcanic hazard assessment. Ar/Ar ages generated as part of this study were determined using the high-sensitivity, multi-collector ARGUS VI mass spectrometer, which provides about an order of magnitude more precise isotopic measurements compared to older generation, single-detector mass spectrometers. Ar/Ar ages suggest an apparent increase in eruption frequency during the late Quaternary within the Raton-Clayton volcanic field, northeastern NM. Only four volcanoes erupted between 426±8 and 97±3 ka. Contrastingly, four volcanoes erupted between 55±2 and 32±5 ka. This last eruptive phase displays a west to east migration of volcanism, has repose periods of 0 to 17 ka, and an average recurrence rate of 1 eruption per 5750 ka. The Zuni-Bandera volcanic field, west-central NM, is composed of the ~100 late Quaternary basaltic vents. Preliminary results suggest that most of the Chain of Craters, the largest and oldest part of the Zuni-Bandera field, erupted between ~100 and 250 ka. Volcanism then migrated to the east, where published ages indicate at least seven eruptions between 50 and 3 ka. Both volcanic fields display a west to east migration of volcanism during the last ~500 ka, although the pattern is more pronounced in the Zuni-Bandera field. A reassessment of low-precision published ages for other late Quaternary volcanic fields in region indicates that most fields display a similar west to east migration of volcanism during the last ~500 ka. One possible mechanism to explain the observed patterns of volcanism is the westward migration of the North American plate relative

  18. The 40Ar/39Ar age record of formation and uplift of the blueschists and eclogites in the western Tianshan Mountains

    Institute of Scientific and Technical Information of China (English)


    The 40Ar/39Ar ages indicate that the eclogite facies rocks of the Hasiate slice in the western Tianshan Mountains were formed at the early stage of Devonian (401 Ma) and had been uplifted to the greenschist facies tectonic level in the middle stage of Devonian (381 Ma). The formation and uplift of the blueschists of the Akesayi slice are constrained to the late stage of Devonian (370─364 Ma). The different tectonic slices in the high-pressure metamorphic belt have experienced the different uplift history.

  19. Exploring the Role of BET Bromodomain Proteins in AR Transcriptional Regulation: A Perpetuating Cycle of JQ1 Resistance in CRPC Therapy (United States)


    the N-terminal BET bromodomain of BRD4 to disrupt its interaction with AR and prevent expression of DHT dependent AR target genes. Ironically, while...with AR and prevent expression of DHT dependent AR target genes such as prostate-specific antigen (PSA) and ERG by inhibiting transcription (1...androgen and JQ1 treated prostate cancer cells and assess its correlation with AR mRNA expression. To determine whether DHT mediated AR activation

  20. Ar + induced interfacial mixing and phase formation in the Al/Cr system (United States)

    Kim, H. K.; Kim, S. O.; Song, J. H.; Kim, K. W.; Woo, J. J.; Whang, C. N.; Smith, R. J.


    Evaporated Al/Cr bilayer thin films were irradiated by 80 keV Ar + at doses in the range from 1 × 10 15 to 2 × 10 16 Ar +/cm 2 at room temperature in order to investigate the Ar + induced interfacial mixing behavior and the phase formation and transition by Ar + bombardment. Ion bombardment induces intermixing across the Al/Cr interface and mixing variance increases with increasing ion dose. Cascade and thermal spike models are found to be not adequate for the ion beam mixing mechanism at room temperature in this system. The Al 13Cr 2 phase is formed as an initial phase by ion beam mixing and then transforms into the Al 11Cr 2 or Al 4Cr phases at subsequent ion bombardment. This result is discussed in terms of the enhanced atomic mobility and the thermodynamical driving force by introducing the concept of an effective heat of formation.

  1. Speech and regulation of behavior: the works of LS Vygosty and AR Luria

    National Research Council Canada - National Science Library

    Derouesné, Christian


    The role of speech in the regulation of behavior was described in child psychology by LS Vygotsky and AR Luria in the Soviet Union during the twenties, and extended to neuropsychology by Luria after the World War II...

  2. Complete Genome Sequence of Mayaro Virus (Togaviridae, Alphavirus) Strain BeAr 20290 from Brazil. (United States)

    Espósito, Danillo Lucas Alves; da Fonseca, Benedito Antônio Lopes


    We report here the complete genome sequence of Mayaro virus strain BeAr 20290 isolated from Haemagogus mosquitoes in 1960. The sequence presented here includes all nonstructural and structural proteins and the 5'- and 3'-untranslated (UTR) regions.

  3. Microscopic structure and gas-gas critical line of the Ar-water system

    Energy Technology Data Exchange (ETDEWEB)

    Ricci, M.A. [Dipartimento di Fisica ' E. Amaldi' , Universita degli Studi ' Roma Tre' , Via della Vasca Navale 84, 00146 Rome (Italy)]. E-mail:; Mancinelli, R. [Dipartimento di Fisica ' E. Amaldi' , Universita degli Studi ' Roma Tre' , Via della Vasca Navale 84, 00146 Rome (Italy); Lu Russo, M. [ESRF, European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, 38043 Grenoble (France); Botti, A. [Dipartimento di Fisica ' E. Amaldi' , Universita degli Studi ' Roma Tre' , Via della Vasca Navale 84, 00146 Rome (Italy); Bruni, F. [Dipartimento di Fisica ' E. Amaldi' , Universita degli Studi ' Roma Tre' , Via della Vasca Navale 84, 00146 Rome (Italy); Soper, A.K. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX (United Kingdom)


    The dependence of the derivative of the gas-gas critical temperature on the microscopic structure of a mixture is analyzed using neutron diffraction on the Ar-water system at two solute concentrations. At low Ar concentration the critical line departs from the critical point of the solvent with negative derivative: at a microscopic level this corresponds to a repulsive solute-solvent interaction, keeping Ar atoms outside the first water-water neighboring shell. As the solute concentration increases at constant temperature and pressure, the critical temperature goes through a minimum and eventually Ar atoms enter the first neighbor water shell. At this point, no H-bonding between water molecules is visible.

  4. Anti-Cancer Effect of Lambertianic Acid by Inhibiting the AR in LNCaP Cells

    Directory of Open Access Journals (Sweden)

    Myoung-Sun Lee


    Full Text Available Lambertianic acid (LA is known to have anti-allergic and antibacterial effects. However, the anticancer activities and mechanism of action of LA have not been investigated. Therefore, the anticancer effects and mechanism of LA are investigated in this study. LA decreased not only AR protein levels, but also cellular and secretory levels of PSA. Furthermore, LA inhibited nuclear translocation of the AR induced by mibolerone. LA suppressed cell proliferation by inducing G1 arrest, downregulating CDK4/6 and cyclin D1 and activating p53 and its downstream molecules, p21 and p27. LA induced apoptosis and the expression of related proteins, including cleaved caspase-9 and -3, c-PARP and BAX, and inhibited BCl-2. The role of AR in LA-induced apoptosis was assessed by using siRNA. Collectively, these findings suggest that LA exerts the anticancer effect by inhibiting AR and is a valuable therapeutic agent in prostate cancer treatment.

  5. 77 FR 51064 - Huntington Foam LLC, Fort Smith, AR; Notice of Affirmative Determination Regarding Application... (United States)


    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employment and Training Administration Huntington Foam LLC, Fort Smith, AR; Notice of Affirmative Determination Regarding Application for Reconsideration By application dated May 21, 2012, the State...

  6. 78 FR 5202 - Notice of Inventory Completion: Arkansas State University Museum, Jonesboro, AR (United States)


    ... National Park Service Notice of Inventory Completion: Arkansas State University Museum, Jonesboro, AR AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: The Arkansas State University Museum... culturally affiliated with the human remains may contact the Arkansas State University Museum....

  7. 78 FR 5199 - Notice of Inventory Completion: Arkansas State University Museum, Jonesboro, AR (United States)


    ... National Park Service Notice of Inventory Completion: Arkansas State University Museum, Jonesboro, AR AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: The Arkansas State University Museum... associated funerary objects may contact the Arkansas State University Museum. Repatriation of the...

  8. Degradation Assessment and Fault Diagnosis for Roller Bearing Based on AR Model and Fuzzy Cluster Analysis

    Directory of Open Access Journals (Sweden)

    Lingli Jiang


    Full Text Available This paper proposes a new approach combining autoregressive (AR model and fuzzy cluster analysis for bearing fault diagnosis and degradation assessment. AR model is an effective approach to extract the fault feature, and is generally applied to stationary signals. However, the fault vibration signals of a roller bearing are non-stationary and non-Gaussian. Aiming at this problem, the set of parameters of the AR model is estimated based on higher-order cumulants. Consequently, the AR parameters are taken as the feature vectors, and fuzzy cluster analysis is applied to perform classification and pattern recognition. Experiments analysis results show that the proposed method can be used to identify various types and severities of fault bearings. This study is significant for non-stationary and non-Gaussian signal analysis, fault diagnosis and degradation assessment.

  9. Downregulated StAR gene and male reproductive dysfunction caused by nifedipine and ethosuximide

    Directory of Open Access Journals (Sweden)

    Rasha A. Ebiya


    Conclusions: Both nifedipine and ethosuximide significantly increase chromosome abnormalities, decrease sperm function, and down regulate StAR-mRNA expression. All these side effects may lead to irreversible male sterility.

  10. USDA‐ARS Riesel Watersheds, Riesel, Texas, USA: Water quality research database

    National Research Council Canada - National Science Library

    Harmel, R. Daren; Haney, Richard L; Smith, Douglas R; White, Michael; King, Kevin W


    ... ( ). In addition, water quality data including dissolved inorganic N and P compounds measured from more than 1000 storm runoff events, 1300 base flow sampling events...

  11. USDA-ARS Riesel Watersheds, Riesel, Texas, USA: Water quality research database

    National Research Council Canada - National Science Library

    R Daren Harmel; Richard L Haney; Douglas R Smith; Michael White; Kevin W King


    ... ( In addition, water quality data including dissolved inorganic N and P compounds measured from more than 1000 storm runoff events, 1300 base flow sampling events...

  12. Optimization of Coding of AR Sources for Transmission Across Channels with Loss

    DEFF Research Database (Denmark)

    Arildsen, Thomas

    , and quantization. On this background we propose a new algorithm for optimization of predictive coding of AR sources for transmission across channels with loss. The optimization algorithm takes as its starting point a re-thinking of the source coding operation as an operation producing linear measurements....... Channel coding is usually applied in combination with source coding to ensure reliable transmission of the (source coded) information at the maximal rate across a channel given the properties of this channel. In this thesis, we consider the coding of auto-regressive (AR) sources which are sources that can...... be modeled as auto-regressive processes. The coding of AR sources lends itself to linear predictive coding. We address the problem of joint source/channel coding in the setting of linear predictive coding of AR sources. We consider channels in which individual source coded signal samples can be lost during...

  13. Assessment of cerebral blood flow autoregulation (CBF AR) with rheoencephalography (REG): studies in animals (United States)

    Popovic, Djordje; Bodo, Michael; Pearce, Frederick; van Albert, Stephen; Garcia, Alison; Settle, Tim; Armonda, Rocco


    The ability of cerebral vasculature to regulate cerebral blood flow (CBF) in the face of changes in arterial blood pressure (SAP) or intracranial pressure (ICP) is an important guard against secondary ischemia in acute brain injuries, and official guidelines recommend that therapeutic decisions be guided by continuous monitoring of CBF autoregulation (AR). The common method for CBF AR monitoring, which rests on real-time derivation of the correlation coefficient (PRx) between slow oscillations in SAP and ICP is, however, rarely used in clinical practice because it requires invasive ICP measurements. This study investigated whether the correlation coefficient between SAP and the pulsatile component of the non-invasive transcranial bioimpedance signal (rheoencephalography, REG) could be used to assess the state and lower limit of CBF AR. The results from pigs and rhesus macaques affirm the utility of REG; however, additional animal and clinical studies are warranted to assess selectivity of automatic REG-based evaluation of CBF AR.

  14. Phosphorylation dependent and independent regulation of Helicobacter pylori acid acclimation by the ArsRS two-component system (United States)

    Marcus, Elizabeth A.; Sachs, George; Wen, Yi; Scott, David R.


    Background The pH sensitive Helicobacter pylori ArsRS two-component system (TCS) aids survival of this neutralophile in the gastric environment by directly sensing and responding to environmental acidity. ArsS is required for acid-induced trafficking of urease and its accessory proteins to the inner membrane, allowing rapid, urea-dependent cytoplasmic and periplasmic buffering. Expression of ArsR, but not its phosphorylation, is essential for bacterial viability. The aim of this study is to characterize the roles of ArsS and ArsR in the response of H. pylori to acid. Materials and Methods Wildtype H. pylori and an arsR(D52N) phosphorylation deficient strain were incubated at acidic or neutral pH. Gene and protein expression, survival, membrane trafficking of urease proteins, urease activity, and internal pH were studied. Results Phosphorylation of ArsR is not required for acid survival. ArsS-driven trafficking of urease proteins to the membrane in acid, required for recovery of internal pH, is independent of ArsR phosphorylation. ArsR phosphorylation increases expression of the urease gene cluster, and the loss of negative feedback in a phosphorylation deficient mutant leads to an increase in total urease activity. Conclusions ArsRS has a dual function in acid acclimation: regulation of urease trafficking to UreI at the cytoplasmic membrane, driven by ArsS, and regulation of urease gene cluster expression, driven by phosphorylation of ArsR. ArsS and ArsR work through phosphorylation dependent and independent regulatory mechanisms to impact acid acclimation and allow gastric colonization. Furthering understanding of the intricacies of acid acclimation will impact the future development of targeted, non-antibiotic treatment regimens. PMID:25997502

  15. Enduring Rivalry in the Philippines and the Application of Amnesty, Reintegration and Reconciliation (AR2) (United States)


    Enduring Rivalry in the Philippines and the Application of Amnesty, Reintegration and Reconciliation (AR2) A Monograph by MAJ Gary J Morea...NUMBER 4. TITLE AND SUBTITLE Enduring Rivalry in the Philippines and the Application of Amnesty, Reintegration and Reconciliation (AR2) 5c...of force, diplomacy and economic programs that are necessary in initiating and sustaining peace. While the elements of amnesty, reintegration and

  16. Plasma Reactors and Plasma Thrusters Modeling by Ar Complete Global Models

    Directory of Open Access Journals (Sweden)

    Chloe Berenguer


    Full Text Available A complete global model for argon was developed and adapted to plasma reactor and plasma thruster modeling. It takes into consideration ground level and excited Ar and Ar+ species and the reactor and thruster form factors. The electronic temperature, the species densities, and the ionization percentage, depending mainly on the pressure and the absorbed power, have been obtained and commented for various physical conditions.

  17. Lifetime measurements in sd-shell nuclei : (I). Mean lives of 38Ar levels

    NARCIS (Netherlands)

    Engelbertink, G.A.P.; Middelkoop, G. van


    The 41K(p,αγ) and 35CI(α, pγ) reactions were used to populate levels in 38Ar. The mean lives of the lowest six excited states in 38Ar were measured with the Doppler shift attenuation method. Gamma rays were detected at 90°, in coincidence with particles observed at angles θ = 100° and −100° or 110°

  18. Resonant photoionization spectroscopy of refractory metal-rare gas complexes: AlAr (United States)

    Gardner, John M.; Lester, Marsha I.


    Mass-resolved resonance-enhanced multiphoton ionization is used to probe AlAr complexes in the spectral region about the Al 2S 1/2- 2P 1/2 transition. Analysis of a vibrational progression in the AlAr 2Σ +state provides lower limits for binding energies in the X 2Π 1/2and B 2Σ + states of 133 and 373 cm -1, respectively.

  19. [Calcium transport in sarcoplasmic reticulum in the presence of AR-L 115 BS]. (United States)

    Hasselbach, W


    2-[(2-Methoxy-4-methylsulfinyl)phenyl]-1H-imidazo[4,5-b]pyridine (AR-L 115 BS) is a substance with positive inotropic activity which does not influence the activity of the sarcoplasmic calcium pump. It can, therefore, be expected that AR-L 115 BS does not interfere with the distribution and movement of calcium in the resting and active muscle.


    Institute of Scientific and Technical Information of China (English)

    刘应安; 韦博成


    This paper constructs a set of confidence regions of parameters in terms of statistical curvatures for AR(q) nonlinear regression models. The geometric frameworks are proposed for the model. Then several confidence regions for parameters and parameter subsets in terms of statistical curvatures are given based on the likelihood ratio statistics and score statistics. Several previous results, such as [1] and [2] are extended to AR(q)nonlinear regression models.

  1. Analytic model of nanoparticle formation and growth in a SiH4-Ar plasma (United States)

    Gordiets, B. F.; Bertran, E.


    A kinetic model of formation and growth of nanoparticles in a low-pressure plasma-chemical reactor with an rf capacitive discharge in a SiH4-Ar mixture is presented. Analytic formulas are derived for calculating the concentration of monomers, as well as the concentration and average size of nanoparticles. The results are compared with the results of numerical calculations and experimental data for nanoparticles in a SiH4-Ar plasma.

  2. The science case for 37Ar as a monitor for underground nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Haas, Derek A.; Orrell, John L.; Bowyer, Ted W.; McIntyre, Justin I.; Miley, Harry S.; Aalseth, Craig E.; Hayes, James C.


    A new calculation of the production of 37Ar from nuclear explosion neutron interactions on 40Ca in a suite of common sub-surface materials (rock, etc) is presented. Even in mineral structures that are relatively low in Ca, the resulting 37Ar signature is large enough for detection in cases of venting or gaseous diffusion driven by barometric pumping. Field and laboratory detection strategies and projected sensitivities are presented.

  3. First-Principles Calculations of Scanning-Tunnelling-Microscopy Images of Ar Atoms Adsorbed on a Graphite Sheet

    Institute of Scientific and Technical Information of China (English)

    白玉林; 周晓林; 陈向荣; 芶清泉


    Local density approximation within the framework of the density functional theory is applied to calculate the scanning tunnelling microscopy(STM)images of Ar atoms adsorbed on a graphite sheet(Ar/graphite system).It is found that the optimal site of adsorbed Ar atom is at the top of the centre of the carbon hexagon and its equilibrium distance from the graphite surface is about 3.20A.We demonstrate that it is the hybridization of the C 2 p electronic states with the Ar 3 p and 4 s electronic states,which renders Ar atoms visible in the STM experiment.

  4. Experimental measurements of the hollow cathode DC glow discharge parameters in Ar and He plasmas (United States)

    Omrani, M.; Amrollahi, R.; Iraji, D.


    In this article, we focus on some of the fundamental parameters of SS316L hollow cathode glow discharge. Four SS316L samples are placed at different locations on the cathode surface and the current passed through them is measured in Ar and He glow discharge plasmas. The wall current densities of Ar and He are in the range of 8-25 µA cm-2 and 8-35 µA cm-2, respectively. Results also show that with decreasing working pressure, the ion flux and current density distribution on the wall surface becomes more uniform. The ion flux of the Ar and He is in the range of 1013 to 1014 ~\\text{ion} \\text{c}{{\\text{m}}-2} . Total energy losses of Ar and He are measured at the pressure range of 1.4-5.5  ×  10-2 torr and 3.2-7.1  ×  10-1, respectively. In both Ar and He, total energy losses decreased with increasing pressure. The secondary electron emission coefficients of Ar and He, which are evaluated for the hallow cathode configuration, are about 0.42 and 0.26, respectively, and are higher in comparison with the plate cathode configuration.

  5. Stability of Ar(H2)2 to 358 GPa. (United States)

    Ji, Cheng; Goncharov, Alexander F; Shukla, Vivekanand; Jena, Naresh K; Popov, Dmitry; Li, Bing; Wang, Junyue; Meng, Yue; Prakapenka, Vitali B; Smith, Jesse S; Ahuja, Rajeev; Yang, Wenge; Mao, Ho-Kwang


    "Chemical precompression" through introducing impurity atoms into hydrogen has been proposed as a method to facilitate metallization of hydrogen under external pressure. Here we selected Ar(H2)2, a hydrogen-rich compound with molecular hydrogen, to explore the effect of "doping" on the intermolecular interaction of H2 molecules and metallization at ultrahigh pressure. Ar(H2)2 was studied experimentally by synchrotron X-ray diffraction to 265 GPa, by Raman and optical absorption spectroscopy to 358 GPa, and theoretically using the density-functional theory. Our measurements of the optical bandgap and the vibron frequency show that Ar(H2)2 retains 2-eV bandgap and H2 molecular units up to 358 GPa. This is attributed to reduced intermolecular interactions between H2 molecules in Ar(H2)2 compared with that in solid H2 A splitting of the molecular vibron mode above 216 GPa suggests an orientational ordering transition, which is not accompanied by a change in lattice symmetry. The experimental and theoretical equations of state of Ar(H2)2 provide direct insight into the structure and bonding of this hydrogen-rich system, suggesting a negative chemical pressure on H2 molecules brought about by doping of Ar.

  6. Use of 41Ar production to measure ablator areal density in NIF beryllium implosions (United States)

    Wilson, D. C.; Cassata, W. B.; Sepke, S. M.; Velsko, C. A.; Huang, H.; Yeamans, C. B.; Kline, J. L.; Yi, A.; Simakov, A. N.; Haan, S. W.; Batha, S. H.; Dewald, E. L.; Rygg, J. R.; Tommasini, R.; Xu, H.; Kong, C.; Bae, J.; Rice, N.


    For the first time, 41Ar produced by the (n,ϒ) reaction from 40Ar in the beryllium shell of a DT filled Inertial Confinement Fusion capsule has been measured. Ar is co-deposited with beryllium in the sputter deposition of the capsule shell. Combined with a measurement of the neutron yield, the radioactive 41Ar then quantifies the areal density of beryllium during the DT neutron production. The measured 1.15 ± 0.17 × 10+8 atoms of 41Ar are 2.5 times that from the best post-shot calculation, suggesting that the Ar and Be areal densities are correspondingly higher than those calculated. Possible explanations are that (1) the beryllium shell is compressed more than calculated, (2) beryllium has mixed into the cold DT ice, or more likely (3) less beryllium is ablated than calculated. Since only one DT filled beryllium capsule has been fielded at NIF, these results can be confirmed and expanded in the future.

  7. Ar-rahnu as a Source of Financial Sustainability for Women Micro-Entrepreneurs in Malaysia

    Directory of Open Access Journals (Sweden)

    Nik Hadiyan Nik Azman


    Full Text Available Muslims in Malaysia had practiced ar-rahnu for fulfilling their financial need, especially for emergency purposes since early 1990s. The pioneer of ar-rahnu in Malaysia is Muassasah Gadaian Islam Terengganu (MGIT in January 1992, followed by the Kelantan Capitalization Berhad (PKB in March 1992. Both of these Islamic pawn centres are among the earliest exponents to the Islamic pawn scheme in Malaysia. Ar-rahnu is an increasingly popular financing option among micro-entrepreneurs in Malaysia, particularly women micro-entrepreneurs. Women micro-entrepreneurs play a vital role in the Malaysian economy and could be considered as the backbone of the industrial development in Malaysia. This study examines the role of ar-rahnu as a source of financial stability for women micro-entrepreneurs. 600 questionnaires were distributed at three states in Malaysia which are Kelantan, Terengganu and Kedah. Then, this study used SPSS and SEM Amos to analyses the data for 600 respondents (women micro-entrepreneurs in Malaysia. In essence, this study finds that shariah compliancy, locality, service charges, collateral and customer satisfaction has positive and significant impact towards the use of ar-rahnu. The study also found use of ar-rahnu has significant impact towards financial self-sufficiency for women micro-entrepreneurs.

  8. Immersive realities: articulating the shift from VR to mobile AR through artistic practice (United States)

    Margolis, Todd; Cornish, Tracy; Berry, Rodney; DeFanti, Thomas A.


    Our contemporary imaginings of technological engagement with digital environments has transitioned from flying through Virtual Reality to mobile interactions with the physical world through personal media devices. Experiences technologically mediated through social interactivity within physical environments are now being preferenced over isolated environments such as CAVEs or HMDs. Examples of this trend can be seen in early tele-collaborative artworks which strove to use advanced networking to join multiple participants in shared virtual environments. Recent developments in mobile AR allow untethered access to such shared realities in places far removed from labs and home entertainment environments, and without the bulky and expensive technologies attached to our bodies that accompany most VR. This paper addresses the emerging trend favoring socially immersive artworks via mobile Augmented Reality rather than sensorially immersive Virtual Reality installations. With particular focus on AR as a mobile, locative technology, we will discuss how concepts of immersion and interactivity are evolving with this new medium. Immersion in context of mobile AR can be redefined to describe socially interactive experiences. Having distinctly different sensory, spatial and situational properties, mobile AR offers a new form for remixing elements from traditional virtual reality with physically based social experiences. This type of immersion offers a wide array of potential for mobile AR art forms. We are beginning to see examples of how artists can use mobile AR to create social immersive and interactive experiences.

  9. Comparative Genomic Analysis Reveals Organization, Function and Evolution of ars Genes in Pantoea spp. (United States)

    Wang, Liying; Wang, Jin; Jing, Chuanyong


    Numerous genes are involved in various strategies to resist toxic arsenic (As). However, the As resistance strategy in genus Pantoea is poorly understood. In this study, a comparative genome analysis of 23 Pantoea genomes was conducted. Two vertical genetic arsC-like genes without any contribution to As resistance were found to exist in the 23 Pantoea strains. Besides the two arsC-like genes, As resistance gene clusters arsRBC or arsRBCH were found in 15 Pantoea genomes. These ars clusters were found to be acquired by horizontal gene transfer (HGT) from sources related to Franconibacter helveticus, Serratia marcescens, and Citrobacter freundii. During the history of evolution, the ars clusters were acquired more than once in some species, and were lost in some strains, producing strains without As resistance capability. This study revealed the organization, distribution and the complex evolutionary history of As resistance genes in Pantoea spp.. The insights gained in this study improved our understanding on the As resistance strategy of Pantoea spp. and its roles in the biogeochemical cycling of As. PMID:28377759

  10. Comparative Genomic Analysis Reveals Organization, Function and Evolution of ars Genes in Pantoea spp. (United States)

    Wang, Liying; Wang, Jin; Jing, Chuanyong


    Numerous genes are involved in various strategies to resist toxic arsenic (As). However, the As resistance strategy in genus Pantoea is poorly understood. In this study, a comparative genome analysis of 23 Pantoea genomes was conducted. Two vertical genetic arsC-like genes without any contribution to As resistance were found to exist in the 23 Pantoea strains. Besides the two arsC-like genes, As resistance gene clusters arsRBC or arsRBCH were found in 15 Pantoea genomes. These ars clusters were found to be acquired by horizontal gene transfer (HGT) from sources related to Franconibacter helveticus, Serratia marcescens, and Citrobacter freundii. During the history of evolution, the ars clusters were acquired more than once in some species, and were lost in some strains, producing strains without As resistance capability. This study revealed the organization, distribution and the complex evolutionary history of As resistance genes in Pantoea spp.. The insights gained in this study improved our understanding on the As resistance strategy of Pantoea spp. and its roles in the biogeochemical cycling of As.

  11. Postcollision interactions in the Auger decay of the Ar L-shell

    Energy Technology Data Exchange (ETDEWEB)

    Samson, J.A.R.; Stolte, W.C.; He, Z.X. [Univ. of Nebraska, Lincoln, NE (United States)] [and others


    The photoionization cross sections for Ar{sup +} through Ar{sup 4+}, produced by the Auger decay of an inner shell 2p hole, have been measured between 242 eV and 253 eV on beamline 9.0.1 and 6.3.2. In this study the authors are interested in near threshold phenomenon involving postcollision interactions (PCI), which are related to the Auger decay of a vacancy in the Ar L-shell. During an Auger decay a postcollision interaction can occur causing the out-going photoelectron to be retarded thus losing a certain amount of energy. If the retardation is sufficiently large the photoelectron will not escape. This result produces a singly charged ion, which normally would not be present. Such evidence of electron capture by the PCI effect was first shown clearly by Eberhardt et al. and, with higher resolution, in the present work. However, capture of the photoelectron is expected to be 100% exactly at the L{sub 2,3} thresholds. Thus, from the authors results they would have expected the Ar{sup 2+} signal to be zero at threshold, but it was not? The authors can explain this anomoly on the basis that during the Auger decay the photoelectrons are captured into high lying excited states of Ar{sup +}, which subsequently decay through autoionization yielding Ar{sup 2+}. Future work in this area will seek experimental evidence to verify this prediction.

  12. AR-AODV routing algorithm based on acknowledgement refused tactic%一种基于拒绝应答的路由协议算法AR-AODV

    Institute of Scientific and Technical Information of China (English)

    田杰; 戴晨铖; 周胶; 王钰


    针对AODV协议进行了研究,并在此基础上进行改进.通过更改路由请求包和路由回复包的结构,增加负载因子项,给出了一种拒绝应答策略的AR-AODV算法以适应重负载网络,并平衡节点能量消耗.通过NS2环境进行仿真实验,结果表明AR-AODV协议比AODV协议拥有更低的端到端时延和路由开销,可缓解网络中心节点的负载并提高网络的性能.%This paper proposed an AR-AODV routing algorithm by changing the structure of route request and reply packet,and increasing a loadfactor term,which accommodated the heavy load network and balanced the node energy consumption by acknowledgement refused tactic.The results of simulation show that the AR-AODV protocol has a lower end-to-end delay and routing spengding than AODV protocol,and it can alleviate the load of the network center nodes and effectively improve the network performance.

  13. Emplacement age for the mafic-ultramafic plutons in the northern Dabie Mts. (Hubei): Zircon U-Pb, Sm-Nd and 40Ar/39Ar dating

    Institute of Scientific and Technical Information of China (English)


    The protoliths of mafic-ultramafic plutons in the northern Dabie Mts. (NDM) (Hubei) include pyroxenite and gabbro. The zircon U-Pb dating for a gabbro suggests that emplacement of mafic magma took place in the post-collisional setting at the age of 122.9(0.6 Ma. It is difficult to obtain a reliable Sm-Nd isochron age, due to disequilibrium of the Sm-Nd isotopic system. Two hornblende 40Ar/39Ar ages of 116.1(1.1 Ma and 106.6(0.8 Ma may record cooling of metamorphism in the mafic-ultramafic plutons in Hubei below 500(C. The hornblende 40Ar/39Ar ages for the mafic-ultramafic rocks in Hubei are evidently 15-25 Ma younger than those for the same rocks in Anhui, indicating that there is a diversity of the cooling rates for the mafic-ultramafic rocks in Hubei and Anhui. The difference in their cooling rates may be controlled by the north-dipping normal faults in the NDM. The intense metamorphism occurring in the mafic-ultramafic rocks in Hubei may result from the Yanshanian magmatic reheating and thermal fluid action induced by the Cretaceous migmatization. The geochemical similarity of these mafic-ultramafic rocks wherever in Hubei and Anhui may be attributed to the same tectonic setting via an identical genetic mechanism.

  14. 40Ar/39Ar dating of tuff vents in the Campi Flegrei caldera (southern Italy): Toward a new chronostratigraphic reconstruction of the Holocene volcanic activity (United States)

    Fedele, L.; Insinga, D.D.; Calvert, A.T.; Morra, V.; Perrotta, A.; Scarpati, C.


    The Campi Flegrei hosts numerous monogenetic vents inferred to be younger than the 15 ka Neapolitan Yellow Tuff. Sanidine crystals from the three young Campi Flegrei vents of Fondi di Baia, Bacoli and Nisida were dated using 40Ar/39Ar geochronology. These vents, together with several other young edifices, occur roughly along the inner border of the Campi Flegrei caldera, suggesting that the volcanic conduits are controlled by caldera-bounding faults. Plateau ages of ∼9.6 ka (Fondi di Baia), ∼8.6 ka (Bacoli) and ∼3.9 ka (Nisida) indicate eruptive activity during intervals previously interpreted as quiescent. A critical revision, involving calendar age correction of literature 14C data and available 40Ar/39Ar age data, is presented. A new reference chronostratigraphic framework for Holocene Phlegrean activity, which significantly differs from the previously adopted ones, is proposed. This has important implications for understanding the Campi Flegrei eruptive history and, ultimately, for the evaluation of related volcanic risk and hazard, for which the inferred history of its recent activity is generally taken into account.

  15. Pre-Himalayan tectono-magmatic imprints in the Darjeeling-Sikkim Himalaya (DSH) constrained by 40Ar/39Ar dating of muscovite (United States)

    Acharyya, Subhrangsu K.; Ghosh, Subhajit; Mandal, Nibir; Bose, Santanu; Pande, Kanchan


    The Lower Lesser Himalayan Sequence (L-LHS) in Darjeeling-Sikkim Himalaya (DSH) displays intensely deformed, low-grade meta-sedimentary rocks, frequently intervened by granite intrusives of varied scales. The principal motivation of our present study is to constrain the timing of this granitic event. Using 40Ar/39Ar geochronology, we dated muscovite from pegmatites emplaced along the earliest fabric in the low grade Daling phyllite, and obtained ∼1850 Ma Ar-Ar muscovite cooling age, which is broadly coeval with crystallization ages of Lingtse granite protolith (e.g., 1800-1850 Ma U-Pb zircon ages) reported from the L-LHS. We present here field observations to show the imprints (tectonic fabrics) of multiple ductile deformation episodes in the LHS terrain. The earliest penetrative fabric, axial planar to N-S trending reclined folds, suggest a regional tectonic event in the DSH prior to the active phase of Indo-Asia collision. Based on the age of granitic bodies and their structural correlation with the earliest fabric, we propose that the L-LHS as a distinct convergent tectono-magmatic belt, delineating the northern margin of Indian craton in the framework of the ∼1850 Ma Columbia supercontinent assembly.

  16. Paleoclimate change in the Nakuru basin, Kenya, at 119 - 109 ka derived from δ18Odiatom and diatom assemblages and 40Ar/39Ar geochronology (United States)

    Bergner, Andreas; Deino, Alan; Leng, Melanie; Gasse, Francoise


    A 4.5m-thick diatomite bed deposited during the cold interval of the penultimate interglacial at ~119 - 109 ka documents a period in which a deep freshwater lake filled the Nakuru basin in the Central Kenya Rift (CKR), East Africa. Palaeohydrological conditions of the basin are reconstructed for the paleolake highstand using δ18Odiatom and characterization of diatom assemblages. The age of the diatomite deposit is established by precise 40Ar/39Ar-dating of intercalated pumice tuffs. The paleolake experienced multiple hydrological fluctuations on sub-orbital (~1,500 to 2,000 years) time scales. The magnitude of the δ18Odiatom change (+/- 3‰) and significant changes in the plankton-littoral ratio of the diatom assemblage (+/- 25%) suggest that the paleolake record can be interpreted in the context of long-term climatic change in East Africa. Using 40Ar/39Ar age control and nominal diatomite-sedimentation rates we establish a simplified age model of paleohydrological vs. climatic change, from which we conclude that more humid conditions prevailed in equatorial East Africa during the late Pleistocene over a relatively long time interval of several thousands years. Then, extreme insolation at eccentricity maximum and weakened zonal air-pressure gradients in the tropics favored intensified ITCZ-like convection over East Africa and deep-freshwater lake conditions.

  17. The Interaction of Child-Parent Shared Reading with an Augmented Reality (AR) Picture Book and Parents' Conceptions of AR Learning (United States)

    Cheng, Kun-Hung; Tsai, Chin-Chung


    Following a previous study (Cheng & Tsai, 2014. "Computers & Education"), this study aimed to probe the interaction of child-parent shared reading with the augmented reality (AR) picture book in more depth. A series of sequential analyses were thus conducted to infer the behavioral transition diagrams and visualize the continuity…

  18. Inelastic processes in Na$^{+}-$Ne, Ar and Ne$^{+},$ Ar$^{+}-$Na collisions in energy range $0.5-14$ keV

    CERN Document Server

    Lomsadze, R A; Kezerashvili, R Ya


    Absolute cross sections for charge-exchange, ionization and excitation in Na$% ^{+}-$Ne and Na$^{+}-$Ar collisions were measured in the ion energy range $% 0.5-10$ keV using a refined version of a capacitor method, and collision and optical spectroscopy methods simultaneously in the same experimental set-up. Ionization cross sections for Ne$^{+}-$Na and Ar$^{+}-$Na collisions are measured at the energies of $2-14$ keV using a crossed-beam spectroscopy method. The experimental data and the schematic correlation diagrams are used to analyze and determine the mechanisms for these processes. For the charge-exchange process in Na$^{+}$ $-$Ar collisions two nonadiabatic regions are revealed and mechanisms responsible for these regions are explained. Structural peculiarity on the excitation function for the resonance lines of argon atoms in Na$^{+}$ $-$Ar collisions are observed and the possible mechanisms of this phenomenon are explored. The measured ionization cross sections for Na$^{+}-$Ne and Ne$^{+}-$Na collisi...

  19. Inelastic processes in Na+-Ne, Na+-Ar, Ne+-Na, and Ar+-Na collisions in the energy range 0.5-14 keV (United States)

    Lomsadze, R. A.; Gochitashvili, M. R.; Kezerashvili, R. Ya.


    Absolute cross sections for charge-exchange, ionization, and excitation in Na+-Ne and Na+-Ar collisions were measured in the ion energy range 0.5 -10 keV using a refined version of a capacitor method and collision and optical spectroscopy methods simultaneously in the same experimental setup. Ionization cross sections for Ne+-Na and Ar+-Na collisions are measured at energies of 2 -14 keV using a crossed-beam spectroscopy method. The experimental data and the schematic correlation diagrams are used to analyze and determine the mechanisms for these processes. For the charge-exchange process in Na+-Ar collisions two nonadiabatic regions are revealed and mechanisms responsible for these regions are explained. Structural peculiarity on the excitation function for the resonance lines of argon atoms in Na+-Ar collisions are observed and the possible mechanisms of this phenomenon are explored. The measured ionization cross sections for Na+-Ne and Ne+-Na collisions in conjunction with the Landau-Zener formula are used to determine the coupling matrix element and transition probability in a region of pseudocrossing of the potential curves.

  20. 40Ar/39Ar ages of seamount trachytes from the South China Sea and implications for the evolution of the northwestern sub-basin

    Institute of Scientific and Technical Information of China (English)

    Xiaohu Li; Jiabiao Li; Xing Yu; Chunsheng Wang; Fred Jourdan


    A chronological study of seamount rocks in the South China Sea basin provides a great opportunity to understand the expansion and evolution history of the sea basin. In this paper, we analyzed the 40Ar/39Ar age of trachytic samples collected from the Shuangfeng seamounts in the northwestern sub-basin of the South China Sea. The two samples yielded plateau ages of 23.80 ? 0.18 and 23.29 ? 0.22 Ma, respectively, which indicate magmatic activity in late Oligocene which helpful constraints the expansion time of the northwest sub-basin. Previous studies suggested that the northwestern sub-basin and southwestern sub-basin have experienced a relatively consistent expansion in the NWeSE direction followed by a late expansion of the eastern sub-basin. We concluded that the expansion of the northwestern sub-basin began prior to ca. 24 Ma, which also implicated magmatic events of a late or stop expansion of the northwestern sub-basin combined with our results of 40Ar/39Ar age data and previous geophysical data.

  1. 40Ar/39Ar ages of seamount trachytes from the South China Sea and implications for the evolution of the northwestern sub-basin

    Directory of Open Access Journals (Sweden)

    Xiaohu Li


    Full Text Available A chronological study of seamount rocks in the South China Sea basin provides a great opportunity to understand the expansion and evolution history of the sea basin. In this paper, we analyzed the 40Ar/39Ar age of trachytic samples collected from the Shuangfeng seamounts in the northwestern sub-basin of the South China Sea. The two samples yielded plateau ages of 23.80 ± 0.18 and 23.29 ± 0.22 Ma, respectively, which indicate magmatic activity in late Oligocene which helpful constraints the expansion time of the northwest sub-basin. Previous studies suggested that the northwestern sub-basin and southwestern sub-basin have experienced a relatively consistent expansion in the NW–SE direction followed by a late expansion of the eastern sub-basin. We concluded that the expansion of the northwestern sub-basin began prior to ca. 24 Ma, which also implicated magmatic events of a late or stop expansion of the northwestern sub-basin combined with our results of 40Ar/39Ar age data and previous geophysical data.

  2. 40Ar/39Ar dating of Quaternary volcanic ashes by multi-collection noble gas mass spectrometry: protocols, precision and intercalibration

    DEFF Research Database (Denmark)

    Storey, Michael; Rivera, Tiffany; Flude, Stephanie

    where potassium-bearing phenocrysts may contain relatively small amounts of radiogenic 40Ar. In 2005, the Quaternary Dating Laboratory, Roskilde University, installed a Nu-Instruments multi-collector Noblesse noble gas mass spectrometer, which is configured with a Faraday detector and three ion...

  3. 40Ar/(39)Ar dating of Chemeron Formation strata encompassing the site of hominid KNM-BC 1, Tugen Hills, Kenya. (United States)

    Deino, Alan L; Hill, Andrew


    A fossil hominid temporal bone (KNM-BC 1) from surface exposures at Baringo Paleontological Research Project site BPRP#2 in the Chemeron Formation outcropping in a tributary drainage of the Kapthurin River west of Lake Baringo, Kenya has been attributed to Homo sp. indet. K-feldspar phenocrysts from lapilli tuffs bracketing the inferred fossiliferous horizon yield single-crystal(40)Ar/(39)Ar ages of 2.456+/-0.006 and 2.393+/-0.013 Ma. These age determinations are supported by stratigraphically consistent ages on higher tuff horizons and from nearby sections. In addition, new(40)Ar/(39)Ar ages on tuffaceous units near the base and top of the formation along the Kapthurin River yield 3.19+/-0.03 and 1.60+/-0.05 Ma respectively. The base of the formation along the Kapthurin River is thus approximately 0.5 Ma younger than the uppermost Chemeron Formation strata exposed at Tabarin, 23 km to the north-northwest. The upper half of the formation along the Kapthurin River was deposited at an average rate of approximately 11 cm/ka, compared to 21-23 cm/ka at Tabarin.

  4. 40Ar-39Ar dating and tectonic implications of volcanic rocks recovered at IODP Hole U1342A and D on Bowers Ridge, Bering Sea (United States)

    Sato, Keiko; Kawabata, Hiroshi; W. Scholl, David; Hyodo, Hironobu; Takahashi, Kozo; Suzuki, Katsuhiko; Kumagai, Hidenori


    During the Integrated Ocean Drilling Program (IODP), a total of 41.54 m of basement rock, consolidated volcaniclastic sediment, was recovered beneath a thin sediment cover. The drilled site is at the eastern end of the crestal area of Bowers Ridge, a north and westward sweeping offshoot of the Aleutian Arc into the Bering Sea. The volcanic sequence recovered from Holes U1342A and U1342D was divided into six major lithologic units. We used the single grain 40Ar-39Ar dating method performed by step-wise heated laser fusion technique to date andesites of Unit 1. Thereby two ages of Oligocene volcanism (34-32 Ma, 28-26 Ma) were distinguished each other according to our 40Ar-39Ar data. These ages refute a hypothesized Cretaceous origin in the North Pacific as an exotic arc massif or sector of the Hawaiian-Emperor chain and indicate that the Bowers Ridge is a Bering-Sea formed arc or remnant arc that ceased forming in the latest Oligocene to the earliest Miocene time.

  5. The novel HDAC inhibitor AR-42-induced anti-colon cancer cell activity is associated with ceramide production

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Weihong; Xu, Bin; Yao, Yiting; Yu, Xiaoling [Department of Clinical Laboratory, Tongren Hospital, Shanghai (China); Shen, Jie, E-mail: [Department of Administrative, Tongren Hospital, No. 786 Yuyuan Road, Changning District, Shanghai (China)


    In the current study, we investigated the potential activity of AR-42, a novel histone deacetylase (HDAC) inhibitor, against colon cancer cells. Our in vitro results showed that AR-42 induced ceramide production, exerted potent anti-proliferative and pro-apoptotic activities in established (SW-620 and HCT-116 lines) and primary human colon cancer cells. Exogenously-added sphingosine 1-phosphate (S1P) suppressed AR-42-induced activity, yet a cell-permeable ceramide (C4) facilitated AR-42-induced cytotoxicity against colon cancer cells. In addition, AR-42-induced ceramide production and anti-colon cancer cell activity were inhibited by the ceramide synthase inhibitor fumonisin B1, but were exacerbated by PDMP, which is a ceramide glucosylation inhibitor. In vivo, oral administration of a single dose of AR-42 dramatically inhibited SW-620 xenograft growth in severe combined immunodeficient (SCID) mice, without inducing overt toxicities. Together, these results show that AR-42 dramatically inhibits colon cancer cell proliferation in vitro and in vivo, and ceramide production might be the key mechanism responsible for its actions. - Highlights: • AR-42 is anti-proliferative against primary/established colon cancer cells. • AR-42 induces significant apoptotic death in primary/established colon cancer cells. • Ceramide production mediates AR-42-induced cytotoxicity in colon cancer cells. • AR-42 oral administration potently inhibits SW-620 xenograft growth in SCID mice.

  6. Chronology and shock history of the Bencubbin meteorite: A nitrogen, noble gas, and Ar-Ar investigation of silicates, metal and fluid inclusions (United States)

    Marty, Bernard; Kelley, Simon; Turner, Grenville


    We have investigated the distribution and isotopic composition of nitrogen and noble gases, and the Ar-Ar chronology of the Bencubbin meteorite. Gases were extracted from different lithologies by both stepwise heating and vacuum crushing. Significant amounts of gases were found to be trapped within vesicles present in silicate clasts. Results indicate a global redistribution of volatile elements during a shock event caused by an impactor that collided with a planetary regolith. A transient atmosphere was created that interacted with partially or totally melted silicates and metal clasts. This atmosphere contained 15N-rich nitrogen with a pressure ⩾3 × 10 5 hPa, noble gases, and probably, although not analyzed here, other volatile species. Nitrogen and noble gases were re-distributed among bubbles, metal, and partly or totally melted silicates, according to their partition coefficients among these different phases. The occurrence of N 2 trapped in vesicles and dissolved in silicates indicates that the oxygen fugacity ( fO2) was greater than the iron-wüstite buffer during the shock event. Ar-Ar dating of Bencubbin glass gives an age of 4.20 ± 0.05 Ga, which probably dates this impact event. The cosmic-ray exposure age is estimated at ˜40 Ma with two different methods. Noble gases present isotopic signatures similar to those of "phase Q" (the major host of noble gases trapped in chondrites) but elemental patterns enriched in light noble gases (He, Ne and Ar) relative to Kr and Xe, normalized to the phase Q composition. Nitrogen isotopic data together with 40Ar/ 36Ar ratios indicate mixing between a 15N-rich component (δ 15N = +1000‰), terrestrial N, and an isotopically normal, chondritic N. Bencubbin and related 15N-rich meteorites of the CR clan do not show stable isotope (H and C) anomalies, precluding contribution of a nucleosynthetic component as the source of 15N enrichments. This leaves two possibilities, trapping of an ancient, highly fractionated

  7. Androgen-Sensitized Apoptosis of HPr-1AR Human Prostate Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Congcong Chen

    Full Text Available Androgen receptor (AR signaling is crucial to the development and homeostasis of the prostate gland, and its dysregulation mediates common prostate pathologies. The mechanisms whereby AR regulates growth suppression and differentiation of luminal epithelial cells in the prostate gland and proliferation of malignant versions of these cells have been investigated in human and rodent adult prostate. However, the cellular stress response of human prostate epithelial cells is not well understood, though it is central to prostate health and pathology. Here, we report that androgen sensitizes HPr-1AR and RWPE-AR human prostate epithelial cells to cell stress agents and apoptotic cell death. Although 5α-dihydrotestosterone (DHT treatment alone did not induce cell death, co-treatment of HPr-1AR cells with DHT and an apoptosis inducer, such as staurosporine (STS, TNFt, or hydrogen peroxide, synergistically increased cell death in comparison to treatment with each apoptosis inducer by itself. We found that the synergy between DHT and apoptosis inducer led to activation of the intrinsic/mitochondrial apoptotic pathway, which is supported by robust cleavage activation of caspase-9 and caspase-3. Further, the dramatic depolarization of the mitochondrial membrane potential that we observed upon co-treatment with DHT and STS is consistent with increased mitochondrial outer membrane permeabilization (MOMP in the pro-apoptotic mechanism. Interestingly, the synergy between DHT and apoptosis inducer was abolished by AR antagonists and inhibitors of transcription and protein synthesis, suggesting that AR mediates pro-apoptotic synergy through transcriptional regulation of MOMP genes. Expression analysis revealed that pro-apoptotic genes (BCL2L11/BIM and AIFM2 were DHT-induced, whereas pro-survival genes (BCL2L1/BCL-XL and MCL1 were DHT-repressed. Hence, we propose that the net effect of these AR-mediated expression changes shifts the balance of BCL2-family proteins

  8. Investigation of Deep Ocean Circulation and Mixing Using Ar-39 (Invited) (United States)

    Smethie, W. M.; Schlosser, P.


    Ar-39 is a radioactive noble gas that forms in the atmosphere by cosmic ray interaction with Ar-40. It has a half-life of 269 years and its production rate in the atmosphere has varied no more than 7% during the past 1000 years. It enters the surface ocean with an average equilibration time of about one month and thus the entire surface ocean, except for ice covered regions at high latitudes, is in quasi-equilibrium with the atmospheric Ar-39:Ar ratio. The well known input to the ocean, radioactive decay constant and chemical inertness make Ar-39 an ideal tracer of circulation and mixing in the deep ocean, where anthropogenic transient tracers such as CFCs and tritium have not yet penetrated. However, due to the difficult measurement, only about 125 oceanic Ar-39 samples have been measured to date. This was done by counting the decays of Ar-39 atoms and required a half liter of argon gas per sample, extracted from about 1500 liters of water. The 125 samples that have been measured provide a glimpse of the information that can be gained from Ar-39 observations. In the Pacific Ocean three vertical profiles show a decrease in Ar-39 from the surface mixed layer through the thermocline to a minimum at intermediate depths and an increase from there to the bottom. This reflects formation of bottom water around the Antarctic continent, spreading of this water northward and upwelling and mixing into intermediate depths. The lowest concentration was 6×4% modern which is equivalent to a 900-1600 year isolation time from the surface. In the Atlantic Ocean newly formed North Atlantic Deep Water has an Ar-39 concentration of about 85% modern compared to 55% modern for newly formed Antarctic Bottom Water and reach values as low as about 40% modern in the interior reflecting the more rapid ventilation of the deep Atlantic Ocean relative to the deep Pacific Ocean. In the Arctic Ocean the mean residence time of deep water in the Nansen, Amundsen and Makarov Basins based on Ar-39

  9. Androgen receptor (AR) pathophysiological roles in androgen-related diseases in skin, bone/muscle, metabolic syndrome and neuron/immune systems: lessons learned from mice lacking AR in specific cells. (United States)

    Chang, Chawnshang; Yeh, Shuyuan; Lee, Soo Ok; Chang, Ta-Min


    The androgen receptor (AR) is expressed ubiquitously and plays a variety of roles in a vast number of physiological and pathophysiological processes. Recent studies of AR knockout (ARKO) mouse models, particularly the cell type- or tissue-specific ARKO models, have uncovered many AR cell type- or tissue-specific pathophysiological roles in mice, which otherwise would not be delineated from conventional castration and androgen insensitivity syndrome studies. Thus, the AR in various specific cell types plays pivotal roles in production and maturation of immune cells, bone mineralization, and muscle growth. In metabolism, the ARs in brain, particularly in the hypothalamus, and the liver appear to participate in regulation of insulin sensitivity and glucose homeostasis. The AR also plays key roles in cutaneous wound healing and cardiovascular diseases, including atherosclerosis and abdominal aortic aneurysm. This article will discuss the results obtained from the total, cell type-, or tissue-specific ARKO models. The understanding of AR cell type- or tissue-specific physiological and pathophysiological roles using these in vivo mouse models will provide useful information in uncovering AR roles in humans and eventually help us to develop better therapies via targeting the AR or its downstream signaling molecules to combat androgen/AR-related diseases.

  10. Differential Contributions of the Complement Anaphylotoxin Receptors C5aR1 and C5aR2 to the Early Innate Immune Response against Staphylococcus aureus Infection

    Directory of Open Access Journals (Sweden)

    Sarah A. Horst


    Full Text Available The complement anaphylatoxin C5a contributes to host defense against Staphylococcus aureus. In this study, we investigated the functional role of the two known C5a receptors, C5aR1 and C5aR2, in the host response to S. aureus. We found that C5aR1−/− mice exhibited greater susceptibility to S. aureus bloodstream infection than wild type and C5aR2−/− mice, as demonstrated by the significantly higher bacterial loads in the kidneys and heart at 24 h of infection, and by the higher levels of inflammatory IL-6 in serum. Histological and immunohistochemistry investigation of infected kidneys at 24 h after bacterial inoculation revealed a discrete infiltration of neutrophils in wild type mice but already well-developed abscesses consisting of bacterial clusters surrounded by a large number of neutrophils in both C5aR1−/− and C5aR2−/− mice. Furthermore, blood neutrophils from C5aR1−/− mice were less efficient than those from wild type or C5aR2−/− mice at killing S. aureus. The requirement of C5aR1 for efficient killing of S. aureus was also demonstrated in human blood after disrupting C5a-C5aR1 signaling using specific inhibitors. These results demonstrated a role for C5aR1 in S. aureus clearance as well as a role for both C5aR1 and C5aR2 in the orchestration of the inflammatory response during infection.

  11. Theoretical study of Al{sub n}V{sup +} clusters and their interaction with Ar

    Energy Technology Data Exchange (ETDEWEB)

    Fernández, Eva María, E-mail: [Departamento de Física Fundamental, Facultad de Ciencias, UNED, 28040 Madrid (Spain); Vega, Andrés; Balbás, Luis Carlos [Departamento de Física Teórica, Universidad de Valladolid, 47011 Valladolid (Spain)


    Recently, it has been experimentally elucidated whether a V impurity in Al{sub n}V{sup +} clusters occupies an external or an internal site by studying their interaction with argon as a function of cluster size [S. M. Lang, P. Claes, S. Neukermans, and E. Janssens, J. Am. Soc. Mass Spectrom. 22, 1508 (2011)]. In the work presented here we studied, by means of density functional theoretic calculations, the structural and electronic properties of Al{sub n}V{sup +} clusters with n = 14–21 atoms, as well as the adsorption of a single Ar atom on them. For n < 17 the lowest energy structure of Al{sub n}V{sup +} is related to that of the pure Al {sub n+1}{sup +} cluster with the V atom substituting a surface Al atom. For n ⩾ 17 the V impurity becomes embedded in the cluster, in agreement with the experimental results, and the clusters adopt a fcc-like structure instead of the icosahedral-like skeleton of pure Al {sub n+1}{sup +}. We have studied the binding energy per atom, the second energy difference, and the V and Al atom separation energies, in comparison with those of pure Al {sub n+1}{sup +}. We also studied the adsorption of atomic Ar on endohedral and exohedral V doped clusters. The optimized Ar adsorption geometries are formed with Ar on top of a surface atom (V for n < 17, and Al for n ⩾ 17) without noticeable structural distortion of the host cluster. At the critical size (n = 17) of the exohedral-endohedral transition, the calculated Ar adsorption energy exhibits a drop and the Ar-cluster distance increases drastically, indicating that Ar becomes physisorbed rather than chemisorbed. All these results confirm the assumptions made by the experimentalists when interpreting their measurements.

  12. Cerebral A{sub 1} adenosine receptors (A{sub 1}AR) in liver cirrhosis

    Energy Technology Data Exchange (ETDEWEB)

    Boy, Christian [Research Centre Juelich, Brain Imaging Centre West, Institute of Medicine, Juelich (Germany); University Hospital Essen, Department of Nuclear Medicine, Essen (Germany); Meyer, Philipp T. [Research Centre Juelich, Brain Imaging Centre West, Institute of Medicine, Juelich (Germany); University Hospital Aachen, Department of Nuclear Medicine, Aachen (Germany); Kircheis, Gerald; Haussinger, Dieter [University of Duesseldorf, Clinic for Gastroenterology, Hepatology and Infectiology, Duesseldorf (Germany); Holschbach, Marcus H.; Coenen, Heinz H. [Research Centre Juelich, Institute of Nuclear Chemistry, Juelich (Germany); Herzog, Hans; Elmenhorst, David [Research Centre Juelich, Brain Imaging Centre West, Institute of Medicine, Juelich (Germany); Kaiser, Hans J. [University Hospital Aachen, Department of Nuclear Medicine, Aachen (Germany); Zilles, Karl [Research Centre Juelich, Brain Imaging Centre West, Institute of Medicine, Juelich (Germany); C. and O. Vogt Institute of Brain Research, Duesseldorf (Germany); Bauer, Andreas [Research Centre Juelich, Brain Imaging Centre West, Institute of Medicine, Juelich (Germany); University of Duesseldorf, Department of Neurology, Duesseldorf (Germany)


    The cerebral mechanisms underlying hepatic encephalopathy (HE) are poorly understood. Adenosine, a neuromodulator that pre- and postsynaptically modulates neuronal excitability and release of classical neurotransmitters via A{sub 1} adenosine receptors (A{sub 1}AR), is likely to be involved. The present study investigates changes of cerebral A{sub 1}AR binding in cirrhotic patients by means of positron emission tomography (PET) and [{sup 18}F]CPFPX, a novel selective A{sub 1}AR antagonist. PET was performed in cirrhotic patients (n = 10) and healthy volunteers (n = 10). Quantification of in vivo receptor density was done by Logan's non-invasive graphical analysis (pons as reference region). The outcome parameter was the apparent binding potential (aBP, proportional to B{sub max}/K{sub D}). Cortical and subcortical regions showed lower A{sub 1}AR binding in cirrhotic patients than in controls. The aBP changes reached statistical significance vs healthy controls (p < 0.05, U test with Bonferroni-Holm adjustment for multiple comparisons) in cingulate cortex (-50.0%), precentral gyrus (-40.9%), postcentral gyrus (-38.6%), insular cortex (-38.6%), thalamus (-32.9%), parietal cortex (-31.7%), frontal cortex (-28.6), lateral temporal cortex (-28.2%), orbitofrontal cortex (-27.9%), occipital cortex (-24.6), putamen (-22.7%) and mesial temporal lobe (-22.4%). Regional cerebral adenosinergic neuromodulation is heterogeneously altered in cirrhotic patients. The decrease of cerebral A{sub 1}AR binding may further aggravate neurotransmitter imbalance at the synaptic cleft in cirrhosis and hepatic encephalopathy. Different pathomechanisms may account for these alterations including decrease of A{sub 1}AR density or affinity, as well as blockade of the A{sub 1}AR by endogenous adenosine or exogenous xanthines. (orig.)

  13. C3a Enhances the Formation of Intestinal Organoids through C3aR1

    Directory of Open Access Journals (Sweden)

    Naoya Matsumoto


    Full Text Available C3a is important in the regulation of the immune response as well as in the development of organ inflammation and injury. Furthermore, C3a contributes to liver regeneration but its role in intestinal stem cell function has not been studied. We hypothesized that C3a is important for intestinal repair and regeneration. Intestinal organoid formation, a measure of stem cell capacity, was significantly limited in C3-deficient and C3a receptor (C3aR 1-deficient mice while C3a promoted the growth of organoids from normal mice by supporting Wnt-signaling but not from C3aR1-deficient mice. Similarly, the presence of C3a in media enhanced the expression of the intestinal stem cell marker leucine-rich repeat G-protein-coupled receptor 5 (Lgr5 and of the cell proliferation marker Ki67 in organoids formed from C3-deficient but not from C3aR1-deficient mice. Using Lgr5.egfp mice we showed significant expression of C3 in Lgr5+ intestinal stem cells whereas C3aR1 was expressed on the surface of various intestinal cells. C3 and C3aR1 expression was induced in intestinal crypts in response to ischemia/reperfusion injury. Finally, C3aR1-deficient mice displayed ischemia/reperfusion injury comparable to control mice. These data suggest that C3a through interaction with C3aR1 enhances stem cell expansion and organoid formation and as such may have a role in intestinal regeneration.

  14. The burden of allergic rhinitis (AR in Canada: perspectives of physicians and patients

    Directory of Open Access Journals (Sweden)

    Keith Paul K


    Full Text Available Abstract Background Allergic rhinitis (AR is a common problem and we sought to examine the burden of disease and its management in Canada from the perspectives of patients and physicians. Methods Two parallel, Canadawide structured telephone interviews surveyed 1,001 AR patients and 160 physicians in July 2006. Results 44% of patients had experienced nasal symptoms unrelated to a cold and 20% had a physician diagnosis of AR. At screening 27% reported asthma, 15% chronic or recurrent sinusitis and 5% nasal polyps. With attacks nasal congestion and runny nose were the most bothersome symptoms. Other problems experienced were fatigue (46%, poor concentration (32%, and reduced productivity (23%. Most (77% had not seen a physician in the past year. Physicians estimated they prescribed intranasal cortico steroids (INCS to most AR patients (77% consistent with guidelines but only 19% of patients had used one in the last month. Only 48% of patients were very satisfied with their current INCS. 41% of AR patients reported discontinuing their INCS with the most common reason being a perceived lack of long-lasting symptom relief (44%. 52% of patients felt that their current INCS lost effectiveness over 24 h. The most common INCS side effects included dripping down the throat, bad taste, and dryness. Most AR patients reported lifestyle limitations despite treatment (66%. 61% of patients felt that their symptoms were only somewhat controlled or poorly/not controlled during their worst month in the past year. Conclusions AR symptoms are common and many patients experience inadequate control. Physicians report they commonly prescribe intranasal corticosteroids, but patient’s perceived loss of efficacy and side effects lead to their discontinuation. Persistent relief of allergic rhinitis symptoms remains a major unmet need. Better treatments and education are required.

  15. Discordant K-Ar and young exposure dates for the Windjana sandstone, Kimberley, Gale Crater, Mars (United States)

    Vasconcelos, P. M.; Farley, K. A.; Malespin, C. A.; Mahaffy, P.; Ming, D.; McLennan, S. M.; Hurowitz, J. A.; Rice, Melissa S.


    K-Ar and noble gas surface exposure age measurements were carried out on the Windjana sandstone, Kimberley region, Gale Crater, Mars, by using the Sample Analysis at Mars instrument on the Curiosity rover. The sandstone is unusually rich in sanidine, as determined by CheMin X-ray diffraction, contributing to the high K2O concentration of 3.09 ± 0.20 wt % measured by Alpha-Particle X-ray Spectrometer analysis. A sandstone aliquot heated to 915°C yielded a K-Ar age of 627 ± 50 Ma. Reheating this aliquot yielded no additional Ar. A second aliquot heated in the same way yielded a much higher K-Ar age of 1710 ± 110 Ma. These data suggest incomplete Ar extraction from a rock with a K-Ar age older than 1710 Ma. Incomplete extraction at 900°C is not surprising for a rock with a large fraction of K carried by Ar-retentive K-feldspar. Likely, variability in the exact temperature achieved by the sample from run to run, uncertainties in sample mass estimation, and possible mineral fractionation during transport and storage prior to analysis may contribute to these discrepant data. Cosmic ray exposure ages from 3He and 21Ne in the two aliquots are minimum values given the possibility of incomplete extraction. However, the general similarity between the 3He (57 ± 49 and 18 ± 32 Ma, mean 30 Ma) and 21Ne (2 ± 32 and 83 ± 24 Ma, mean 54 Ma) exposure ages provides no evidence for underextraction. The implied erosion rate at the Kimberley location is similar to that reported at the nearby Yellowknife Bay outcrop.

  16. Monazite and allanite U-Th-Pb vs mica 39Ar-40Ar ages in equilibrated metasediments: closure behavior and closure temperatures (United States)

    Allaz, J.; Engi, M.; Berger, A.; Janots, E.; Villa, I. M.


    The art of geochronology implies identification of processes, so as to correctly interpret an isotopic age as (1) crystallization, (2) cooling, or (3) meaningless owing to inheritance and/or late mineral recrystallization. We address here a field calibration of 39Ar-40Ar ages against U-Th-Pb ages. We demonstrate that detailed petrological, micro-textural and micro-chemical investigations are a necessary prerequisite for meaningful geochronology. The Barrovian metamorphism in the Alps results from the collision of Europe and Apulia and reaches its thermal maximum (upper amphibolite facies) in the Central Alps. Age estimates for the Alpine orogeny have long been controversial, despite a multitude of studies. Based on the resetting of Rb-Sr and K-Ar ages in muscovite from polymetamorphic gneisses, Jäger [1] had proposed an age of 38±2 Ma for the Barrovian metamorphism, corresponding to a “closure temperature TC” (following [2]) of 350 °C for K-Ar in muscovite. However, a uniform Eocene age for the metamorphism in the Central Alps was in conflict already with early monazite and xenotime U-Pb ages from the same area, namely 30 Ma in the southern, and ~20 Ma in the northern part (e.g. [3]). A recent study [4] both confirmed the young monazite ages in the north (SHRIMP U-Pb of 18-19 Ma near Tmax = 570 °C), and demonstrated that ca. 30 Ma ago this part of the belt was still heating up, as allanite grew prograde near 440 °C. These results once more prove isotopic inheritance, and therefore underestimation of mica K-Ar TC, in Jäger’s [1] samples. To avoid isotopic inheritance problems we selected only Mesozoic metasediments from the northern Central Alps. We screened all samples by PTAX: many had undergone a variety of retrogression reactions and calculations show petrological disequilibrium; we favored those in near-ideal petrological equilibrium. 39Ar-40Ar ages for mica separates from equilibrium samples yield ages between 18.93±0.83 and 15.79±0.11 Ma for

  17. ArF准分子激光系统的能量效率特性∗%Energy efficiency analysis of ArF excimer laser system

    Institute of Scientific and Technical Information of China (English)

    王倩; 赵江山; 罗时文; 左都罗; 周翊


    为深入理解ArF准分子激光系统的运转机制,进而获得优化ArF准分子激光系统设计的理论及方向性指导,利用一维流体模型,以气体高压放电等离子体深紫外激光辐射过程为主要对象,研究了放电抽运ArF准分子激光系统的动力学特性,梳理了ArF准分子激光系统的能量传递过程,深入研究了等离子体放电机理,从能量沉积效率、ArF∗粒子形成过程、激光输出三个方面,分析了动力学过程中影响能量效率的主要因素,提出了相应的改进优化措施。仿真结果表明,氟气及相关粒子在系统运转过程中有重要作用,工作气体中氟气的组分比例对能量效率影响较大,偏离最佳点会导致激光系统能量效率的下降。相关结论为ArF准分子激光系统的优化设计和稳定可靠运转提供了重要的理论参考依据。%The reliable functioning and continual optimizing of ArF excimer laser system is of importance when it comes to productization into the market from a laboratory test machine. The analysis of dynamic characteristics of the system is vital to understanding its operating mechanism and optimizing the design theoretically. In this article, one-dimensional fluid model is used to analyze the excimer laser discharge mechanism, and the content ratio of fluorine gas, argon gas, and neon gas, which constitute a gas mixture, is studied in a simulated ArF excimer laser system. Particles are treated as a fluid, which significantly reduces the computing cost in fluid model, and therefore is suitable for high-pressure situation. Four equations are included in one-dimensional fluid model, i.e., Boltzmann equation that describes electron energy distribution, ion continue equation that illustrates ion number density, Poisson’s equation that shows the distribution of electric field, and photon rate equation that demonstrates laser outputting process. By combining these four equations, high

  18. Studies on 40Ar/39Ar thermochronology of strike-slip time of the Tan-Lu fault zone and their tectonic implications

    Institute of Scientific and Technical Information of China (English)

    ZHU; Guang


    deposition onshore China, Marine and Petroleum Geology, 1987, (4): 205-225.[12]Okay. A. I.. Sengor, A. M. C., Evidence for intracontinental thrust related exhumation of the ultra-high-pressure rocks in China, Geology, 1992, 20:411-414.[13]Fossen, H., Dunlap, W. J,, Timing and kinematics of Caledonian thrusting and extensional collapse, southern Norway: Evidence from 40Ar/39Ar thermochronology, Journal of Structural Geology, 1998, 20(6): 765-78 l.[14]Wang. Z. H., Lu, H. F., 40Ar/39Ar thermochronological studies on the Changle-Nanao ductile shear zone, Science in China, Ser. D., 1997, 40(6): 641-647.[15]Lee. J., Incremental 40Ar/39Ar thermochronology of mylonitic rocks from the northern Snake Range, Nevada, Tectonics, 1991. 10(l): 77-100.[16]Maluski, H., Rajlich, P., Matte, P., 40Ar39Ar dating of the inner Carpathians Variscan basement and Alpine mylonitic overprinting, Tectonophysics, 1993, 223:313-337.[17]Van Camp, S. G., Fullagar, E D., Rb-Sr whole-rock ages of mylonites from the Blue Ridge and Brevard zone of North Carolina. Geol. Soc. Amer. Abs. With. Prog., 1982, 14: 92-93.[18]Leak, B. E., Tanner, P. W., Singh, D. et al., Major southward thrusting of the Dalradian rocks of Connemara, western Ireland, Nature, 1983, 305: 210-213.[19]Adams, M. G.. Su, Q., The nature and timing of deformation in the Beech Mountain Thrust Sheet between the Grandfather Mountain and Mountain City Windows in the Blue Ridge of northwestern north Carolina, The Journal of Geology, 1996,104: 197-213.[20]Dallmeyer, R. D., Takasu, A., 40Ar/39Ar ages of detrital muscovite and whole-rock slate/phyllite, Naragansett Basin: linplications for rejuvenation during very low-grade metamorphism, Contributions to Mineralogy and Petrology, 1992, 110:515-527.[21]Little, T. A.. McWilliams, M. O., Holcombe, R. J., 40Ar/39Ar thermochronology of epidote blueschists from the North D'Aguilar block, Queensland, Australia: Timing and kinematics of subduction complex unroofing, Geol

  19. Analysis of protein expression regulated by the Helicobacter pylori ArsRS two-component signal transduction system. (United States)

    Loh, John T; Gupta, Shobhana S; Friedman, David B; Krezel, Andrzej M; Cover, Timothy L


    Previous studies have shown that the Helicobacter pylori ArsRS two-component signal transduction system contributes to acid-responsive gene expression. To identify additional members of the ArsRS regulon and further investigate the regulatory role of the ArsRS system, we analyzed protein expression in wild-type and arsS null mutant strains. Numerous proteins were differentially expressed in an arsS mutant strain compared to a wild-type strain when the bacteria were cultured at pH 5.0 and also when they were cultured at pH 7.0. Genes encoding 14 of these proteins were directly regulated by the ArsRS system, based on observed binding of ArsR to the relevant promoter regions. The ArsRS-regulated proteins identified in this study contribute to acid resistance (urease and amidase), acetone metabolism (acetone carboxylase), resistance to oxidative stress (thioredoxin reductase), quorum sensing (Pfs), and several other functions. These results provide further definition of the ArsRS regulon and underscore the importance of the ArsRS system in regulating expression of H. pylori proteins during bacterial growth at both neutral pH and acidic pH.

  20. Bacterial Expression and Purification of an Active ω-Atracotoxin-Ar1b from Spider Atrax robustus

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-qin; WANG Jue; LI Jian; LIU Qiang; HUANG Shi-di; WANG Dun


    The ω-atracotoxin-Ar1b toxin(ω-ACTX-Ar1b)is one of the arthropod-selective peptide neurotoxins from the venom of Australian funnel-web spider Atrax robustus.The gene of Ar1b was synthesized and cloned into pET-32a(+)vector to allow expression of Ar1b as a fusion protein with thioredoxin and the His-tag(rTrx-Ar1b)in E.coli BL21(DE3).The optimal condition for inducing the expression of rTrx-Ar1b was 1.0 mmol L-1 IPTG for 6 h at 28℃.The fusion protein rTrx-Ar1b was expressed in soluble form and was purified effectively by His Trap HP affinity column and rpHLPC and a final yield of purified rTrx-Ar1b was 95 mg from 1000 mL E.coli culture.The LD50 values for Mythimna separate and Tenebrio molitor were 111.66 and 11.04 μg g-1 determined by injection of the purified rTrx-Ar1b.The results indicated that the recombinant Ar1b protein was successfully expressed in E.coli and it was high toxicity against tested insects.