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Sample records for hurston dawn latta

  1. A Feminist Reading of a Regional Novel: Zora Neale Hurston's ...

    African Journals Online (AJOL)

    Hurston makes use of her African-American dialect as is evident both in the lexical ... into all African-Americans so that they might become proud of their culture. ... to liberating the African-Americans from the American social legislative system ...

  2. Folklore in Zora Neale Hurston's "Their Eyes Were Watching God." [Lesson Plan].

    Science.gov (United States)

    2002

    Zora Neale Hurston's work is lively, lyrical, funny, and poignant, but this consummate literary craftsperson was also a first-rate ethnographer, conducting field work for Franz Boas and for the Works Progress Administration (WPA). "Their Eyes Were Watching God," often acclaimed as Hurston's masterpiece, is perhaps the richest beneficiary…

  3. Celebrating the Black Female Self: Zora Neale Hurston's American Classic (Reclaiming the Canon).

    Science.gov (United States)

    Roemer, Julie

    1989-01-01

    Outlines Zora Neale Hurston's "Their Eyes Were Watching God," focusing on the structure of the novel as a classic hero's quest. Notes that this story of a Black woman's journey toward self-definition can stretch students' own horizons of possibility. (MM)

  4. Domestic Violence in Zora Neale Hurston's Their Eyes Were Watching God: A Feminist Reading

    Directory of Open Access Journals (Sweden)

    Parmis Tasharofi

    2014-07-01

    Full Text Available Zora Neale Hurston's Their Eyes Were Watching God is one of the acclaimed boldly feminist novels of the 20th century. In general, this article draws on feminism and what looms large in feminism which is called sexism. In particular it focuses on domestic violence as a major sexist oppression. Domestic violence aroused by jealousy, anger, coercion, humiliation, threatening is manifest in verbal and physical abusing of women. Hurston skillfully depicts her heroine's undergoing of domestic violence by her husbands, each in different ways. This article aims to show that how the black heroine's battling with this violence purports to feminism and self-discovery of women. Keywords: Patriarchy, Domestic household, Domestic violence, Sexism, Feminism

  5. The Significance of the Body in Zora Neale Hurston's Their Eyes Were Watching God: A Cixousian Reading

    Directory of Open Access Journals (Sweden)

    Iran Zamani

    2013-05-01

    Full Text Available The purpose of the current paper is studying Zora Neale Hurston's masterpiece in the light of the post-structuralist feminist theories of the French philosopher, writer and critic Hélène Cixous. The article aims at scrutinizing the concept of body which is an integral part of écriture féminine. In order to accomplish this investigation, the researcher attempts to present manifestations of corporeality through the course of the selected novel which is Their Eyes Were Watching God. The fact that Hurston's involvement in adapting the notion of corporeality is evident to the point that some scholars approve of her obsession with the mentioned issue may serve as a proof of the fruitfulness of this research. The present article encompasses examining Hurston's attitude toward the selected concept, working with the selected text and taking the female characters and their deeds under consideration in order to grasp the desirable result.

  6. "Different by Degree": Ella Cara Deloria, Zora Neale Hurston, and Franz Boas Contend with Race and Ethnicity.

    Science.gov (United States)

    Hoefel, Roseanne

    2001-01-01

    American Indian ethnographer and linguist Ella Cara Deloria and African American folklorist and writer Zora Neale Hurston did fieldwork for Franz Boas, the father of modern anthropology. Both were shocked by how American racism empowered white people's historical actions. By correcting stereotypes through their work, they reasserted the role of…

  7. Study on "double dawn

    Institute of Scientific and Technical Information of China (English)

    刘次沅; 李建科; 周晓陆

    1999-01-01

    The ancient record, "During the first year of King Yi, the day dawned twice at Zheng", has provided important clues to early Chinese chronicles. The astronomical conditions and visible area distributions related to such a "double dawn" event are discussed, and the precision and current problems in the calculations of ancient astronomical phenomena are shown. On such a basis, all the solar eclipses from 1000 BC to 840 BC are calculated and their associated "double dawn" features investigated. The conclusion that the "double dawn" was a solar eclipse occurring on April 21st, 899 BC is corfirmed to be the most reasonable.

  8. Mapping the Cosmic Dawn

    Science.gov (United States)

    Furlanetto, Steven

    The following sections are included: * A Brief History of Our Universe: From Soup to Galaxies * The Hidden Cosmic Dawn * The Solution: Flipping Spins * The Spin-Flip Transition as an Astronomical Tool * Foiled!: Early Cosmology with the Spin-Flip Transition * Spin-Flip Radiation Holds the Key to Observing the Cosmic Dawn * The Spin-Flip Background: The First Stars * The Spin-Flip Background: The First Black Holes * The Spin-Flip Background: The Epoch of Reionization * FM Radio Antennae as Cosmic Observatories * Piles and Tiles of Antennae: Mapping the Spin-Flip Background * Mountains to Scale: Challenges to Observing the Spin-Flip Background * Sound and Fury, Signifying Statistics * An Explosion of Telescopes * Dreams for the Future * An Unfinished Story

  9. Interview with Dawn Raffel

    Directory of Open Access Journals (Sweden)

    Monica Manolescu-Oancea

    2011-04-01

    Full Text Available Dawn Raffel was born in Wisconsin and graduated from Brown University. She has published three books: In the Year of Long Division, a collection of short fiction (Knopf, 1994, Carrying the Body, a novel (Scribner, 2002 and Further Adventures in the Restless Universe, a collection of stories (Dzanc Books, 2010. She was the guest of Marc Chénetier and the Observatoire de littérature américaine at the Université Paris 7-Denis Diderot in March 2007.Monica Manolescu: At the opening of the confe...

  10. Cosmic Dawn Intensity Mapper

    CERN Document Server

    Cooray, Asantha; Burgarella, Denis; Chary, Ranga; Chang, Tzu-Ching; Doré, Olivier; Fazio, Giovanni; Ferrara, Andrea; Gong, Yan; Santos, Mario; Silva, Marta; Zemcov, Michael

    2016-01-01

    Cosmic Dawn Intensity Mapper is a "Probe Class" mission concept for reionization studies of the universe. It will be capable of spectroscopic imaging observations between 0.7 to 6-7 microns in the near-Infrared. The primary observational objective is pioneering observations of spectral emission lines of interest throughout the cosmic history, but especially from the first generation of distant, faint galaxies when the universe was less than 800 million years old. With spectro-imaging capabilities, using a set of linear variable filters (LVFs), CDIM will produce a three-dimensional tomographic view of the epoch of reionization (EoR). CDIM will also study galaxy formation over more than 90% of the cosmic history and will move the astronomical community from broad-band astronomical imaging to low-resolution (R=200-300) spectro-imaging of the universe.

  11. Dawn at Ceres

    Science.gov (United States)

    Toplis, Michael J.; De Sanctis, Maria Cristina; Dawn Science Team

    2016-10-01

    Dawn arrived at Ceres in 2015, after a 7.5-year journey. It had orbited and mapped the basaltic asteroid Vesta before arriving at its final target, the innermost dwarf planet [1]. Dawn found a very dark, cratered surface punctuated by small extremely bright spots, including the large bright area in the Occator crater. Ceres' surface has many craters but it is missing the largest expected craters and it is gravitationally relaxed at lowest orders, implying a mechanically strong thick crust with a weaker deep interior [2-4]. Ceres' surface composition is dominated by dark carbon-rich minerals, phyllosilicates, ammoniated clays, and carbonates [5]. The distribution of the observed species across the surface indicates that Ceres underwent widespread aqueous alteration [6]. Water ice has also been observed in fresh craters [7] and elemental composition is consistent with an increasing H content toward high latitudes [8], indicating an increasing content of water ice in the immediate subsurface towards the poles. The composition of the bright area in Occator is mostly consistent with a large amount of carbonate, implying recent hydrothermal activity [9]. Several lines of morphological evidence, like flat crater floors, flows of material across the surface and isolated mountains, point to the importance of volatile-driven activity on Ceres that may involve brine-driven cryovolcanism. References[1] Russell, et al., ISBN: 978-1-4614-4902-7, 2011.[2] Russell, et al., Science, 2016.[3] Marchi et al., Nat Comm., 2016 [4] Park et al. Nature, 2016. [5] De Sanctis et al., Nature, 2015, [6] Ammannito et al., Science, 2016.[7] Combe et al., Science 2016. [8] Prettyman et al., this meeting [9] De Sanctis et al., Nature, 2016

  12. The dawn of freudism

    Directory of Open Access Journals (Sweden)

    Renato Barilli

    2013-02-01

    Full Text Available The author is a follower of the so called cultural materialism, which invites us to put the incoming of a new technology at the origin of each cultural age. A big rupture  arrived at the end of the 18th century, when scientists (as Galvani and Volta realized the first discoveries concerning electromagnetism. Such discoveries led to establish that matter is mainly energy, so opening a path which had to reach  the audacious conclusions due to Einstein’s relativism. But at the same time some writers and visual artists (Blake, Goethe, Alfieri, Foscolo, Leopardi discovered that a corresponding energy exists also into each of us. By this way they anticipated on a psychological level the intuitions  which should come from  Freud and his psychoanalisis. So we may conclude that at the end of i8th century there was a kind  of dawn both of technetronic era  and  of psychoanalysis.

  13. Poets of Taller Dawn Break

    Directory of Open Access Journals (Sweden)

    Juan Pascual Gay

    2016-04-01

    Full Text Available Dawn is a source of Mexican literature particularly the group of poets is called Workshop that tested the neopopularista trend driven by the Spanish poets of the generation of 27. This text provides an account of how the " Dawn " was a term he cohered as a group from 1931-1938 , when printing out the magazine Taller ( 1938-1941 of which were named.  These pages serve the years (1931-1938 they begin to relate to constitute itself as a group from that magazine.

  14. Pre-Dawn Martian Sky

    Science.gov (United States)

    1997-01-01

    On Sol 39 there were wispy blue clouds in the pre-dawn sky of Mars, as seen by the Imager for Mars Pathfinder (IMP). The color image was made by taking blue, green, and red images and then combining them into a single color image. The clouds appear to have a bluish side and a greenish side because they moved (in the wind from the northeast) between images. This picture was made an hour and twenty minutes before sunrise -- the sun is not shining directly on the water ice clouds, but they are illuminated by the dawn twilight.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  15. Quest of Archetype in Zora Neale Hurston's Works%佐拉·尼尔·赫斯顿作品的追寻原型

    Institute of Scientific and Technical Information of China (English)

    陈莹莹

    2012-01-01

    赫斯顿在众多作品中刻画了黑人从无知懵懂到成熟的坎坷追寻历程,显示出追寻的原型主题。作品中诸多主人公的追寻过程则显示了作者对黑人文化传统的认同和对黑人女性的关注,反映了赫斯顿颂扬黑人文化的独特角度。%This article analyzes Zora Neale Hurston's works with Joseph Campbell's theory of the Hero's journey and points out that the quest of archetype is embodied in her stories concerning black people's struggles in the white world. The unique quests of black people under her pen show her affirmation of black culture and her great concern for black women, which demonstrates her unique way of celebrating black culture.

  16. Drug Abuse Warning Network (DAWN-2008)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  17. Drug Abuse Warning Network (DAWN-2010)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  18. Drug Abuse Warning Network (DAWN-2011)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  19. Drug Abuse Warning Network (DAWN-2004)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  20. Drug Abuse Warning Network (DAWN-2009)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  1. Drug Abuse Warning Network (DAWN-2007)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  2. Drug Abuse Warning Network (DAWN-2006)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  3. Drug Abuse Warning Network (DAWN-2005)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that has monitored drug related emergency department (ED)...

  4. Dawn at Vesta: An overview after the Dawn mission

    Science.gov (United States)

    Zambon, Francesca

    2016-07-01

    Vesta, the second largest object in the main asteroid belt of our Solar System, was explored by the Dawn mission for over a year [1, 2]. Dawn is equipped with the Framing Camera (FC) [3], which provides geological and compositional analysis, the Visible and InfraRed (VIR) mapping spectrometer [4], which allowed a comprehensive mineralogical mapping of the surface, and the Gamma Ray and Neutron Detector (GRaND) [5], which reveals the elemental composition. A wealth of data acquired by these three instruments allowed for improving the knowledge on the surface and near-surface properties of Vesta. Dawn covered a large fraction of Vesta' surface. Dawn's mission at Vesta has been divided into four different phases based on the spacecraft altitude [1], which resulted in a variety of pixel resolutions, reaching down to ~70 m/pixel for VIR and ~25 m/pixel for the FC. Pyroxene absorptions are the most prominent visible-to-near infrared spectral features of Vesta [6]. The overall mineralogy is consistent with howardite-eucrite-diogenite (HED) meteorites [7, 8]. More specifically, VIR spectra, acquired in the overall range 0.25-5.1 μm at spatial scales ranging from tens of meters to tens of kilometers, are consistent with a surface covered by a howardite-like regolith containing various proportions of eucrite and diogenite at different locations [9, 10]. Diogenite shows up in localized regions and mostly occurs in the southern polar region within the Rheasilvia impact basin [10]. Lithologies other than HEDs were indeed revealed by VIR spectra at the local scale. Olivine-rich deposits have been detected in Bellicia and Arruntia craters as well as in a limited number of other sites [11, 12, 13], while a large number of bright [14] and dark units [15, 16, 17] overlay Vesta'surface. Spectrally distinct, eucrite-rich ejecta have been observed in the Oppia and Octavia ejecta, interpreted to be glassy impact melt [18, 19]. VIR spectral analysis highlights a shallow 2.8-μm band

  5. The Dynamical Environment of Dawn at Vesta

    CERN Document Server

    Tricarico, Pasquale

    2010-01-01

    Dawn is the first NASA mission to operate in the vicinity of the two most massive asteroids in the main belt, Ceres and Vesta. This double-rendezvous mission is enabled by the use of low-thrust solar electric propulsion. Dawn will arrive at Vesta in 2011 and will operate in its vicinity for approximately one year. Vesta's mass and non-spherical shape, coupled with its rotational period, presents very interesting challenges to a spacecraft that depends principally upon low-thrust propulsion for trajectory-changing maneuvers. The details of Vesta's high-order gravitational terms will not be determined until after Dawn's arrival at Vesta, but it is clear that their effect on Dawn operations creates the most complex operational environment for a NASA mission to date. Gravitational perturbations give rise to oscillations in Dawn's orbital radius, and it is found that trapping of the spacecraft is possible near the 1:1 resonance between Dawn's orbital period and Vesta's rotational period, located approximately betw...

  6. Dawn at Vesta: testing the protoplanetary paradigm

    Science.gov (United States)

    Russell, C.T.; Raymond, C.A.; Coradini, A.; McSween, H.Y.; Zuber, M.T.; Nathues, A.; DeSanctis, Maria-Cristina; Jaumann, R.; Konopliv, A.S.; Preusker, F.; Asmar, S.W.; Park, R.S.; Gaskell, R.; Keller, H.U.; Mottola, S.; Roatsch, T.; Scully, J.E.C.; Smith, D.E.; Tricarico, P.; Toplis, M.J.; Christensen, U.R.; Feldman, W.C.; Lawrence, D.J.; McCoy, T.J.; Prettyman, T.H.; Reedy, R.C.; Sykes, M.E.; Titus, T.N.

    2012-01-01

    The Dawn spacecraft targeted 4 Vesta, believed to be a remnant intact protoplanet from the earliest epoch of solar system formation, based on analyses of howardite-eucrite-diogenite (HED) meteorites that indicate a differentiated parent body. Dawn observations reveal a giant basin at Vesta's south pole, whose excavation was sufficient to produce Vesta-family asteroids (Vestoids) and HED meteorites. The spatially resolved mineralogy of the surface reflects the composition of the HED meteorites, confirming the formation of Vesta's crust by melting of a chondritic parent body. Vesta's mass, volume, and gravitational field are consistent with a core having an average radius of 107 to 113 kilometers, indicating sufficient internal melting to segregate iron. Dawn's results confirm predictions that Vesta differentiated and support its identification as the parent body of the HEDs.

  7. Sherry Red Owl, Stands at Dawn Woman

    Science.gov (United States)

    Crazy Bull, Cheryl

    2014-01-01

    This article introduces Sherry Red Owl, also known as "Stands at Dawn Woman," because she greets each day as a new opportunity and has spent her life working at new things. She worked at Sinte Gleska University (SGU) during its founding years, taught at an elementary school when few Native teachers were employed in the school systems,…

  8. Escrevivências na Diáspora:escritoras negras, produção editorial e suas escolhas afetivas, uma leitura de Carolina Maria de Jesus, Conceição Evaristo, Maya Angelou e Zora Neale Hurston

    OpenAIRE

    Fernanda Felisberto da Silva

    2011-01-01

    A pesquisa apresenta um inventário das obras literárias produzidas por romancistas negras afro-americanas e afro-brasileiras, publicadas no mercado editorial brasileiro. Investiga como autoras afro-americanas Maya Angelou e Zora Neale Hurston e as afro-brasileiras Carolina Maria de Jesus e Conceição Evaristo, representam em suas obras as suas escolhas afetivas. Examina as experiências individuais das autoras, analisa como o tema da afetividade é tratado em suas produções usando como eixo cent...

  9. Data Analysis WorkbeNch (DAWN)

    Science.gov (United States)

    Basham, Mark; Filik, Jacob; Wharmby, Michael T.; Chang, Peter C. Y.; El Kassaby, Baha; Gerring, Matthew; Aishima, Jun; Levik, Karl; Pulford, Bill C. A.; Sikharulidze, Irakli; Sneddon, Duncan; Webber, Matthew; Dhesi, Sarnjeet S.; Maccherozzi, Francesco; Svensson, Olof; Brockhauser, Sandor; Náray, Gabor; Ashton, Alun W.

    2015-01-01

    Synchrotron light source facilities worldwide generate terabytes of data in numerous incompatible data formats from a wide range of experiment types. The Data Analysis WorkbeNch (DAWN) was developed to address the challenge of providing a single visualization and analysis platform for data from any synchrotron experiment (including single-crystal and powder diffraction, tomography and spectroscopy), whilst also being sufficiently extensible for new specific use case analysis environments to be incorporated (e.g. ARPES, PEEM). In this work, the history and current state of DAWN are presented, with two case studies to demonstrate specific functionality. The first is an example of a data processing and reduction problem using the generic tools, whilst the second shows how these tools can be targeted to a specific scientific area. PMID:25931106

  10. Dawn Maps the Surface Composition of Vesta

    Science.gov (United States)

    Prettyman, T.; Palmer, E.; Reedy, R.; Sykes, M.; Yingst, R.; McSween, H.; DeSanctis, M. C.; Capaccinoni, F.; Capria, M. T.; Filacchione, G.; Magni, G.; Ammannito, E.; Carraro, F.; Coradini, A.; Fonte, S.; Noschese, R.; Tosi, F.; Blewett, D.; Denevi, B.; Lawrence, D.; Buratti, B.; Raymond, C. A.; Combe, J. P.; McCord, T.; Forni, O.

    2011-01-01

    By 7-October-2011, the Dawn mission will have completed Survey orbit and commenced high altitude mapping of 4-Vesta. We present a preliminary analysis of data acquired by Dawn's Framing Camera (FC) and the Visual and InfraRed Spectrometer (VIR) to map mineralogy and surface temperature, and to detect and quantify surficial OH. The radiometric calibration of VIR and FC is described. Background counting data acquired by GRaND are used to determine elemental detection limits from measurements at low altitude, which will commence in November. Geochemical models used in the interpretation of the data are described. Thermal properties, mineral-, and geochemical-data are combined to provide constraints on Vesta s formation and thermal evolution, the delivery of exogenic materials, space weathering processes, and the origin of the howardite, eucrite, and diogenite (HED) meteorites.

  11. Dawn Raffel–A Family Portrait

    Directory of Open Access Journals (Sweden)

    Monica Manolescu-Oancea

    2011-04-01

    Full Text Available This article wishes to examine the literary genealogy of Dawn Raffel and to explore the notion of intertextuality as well, together with the critical debate surrounding it. A tentative family portrait will be drawn through the study of the short story collection In the Year of Long Divsion (1994, with references to the novel Carrying the Body (2002.Cet article se propose d’examiner la généalogie littéraire de l’écrivain contemporain Dawn Raffel et d’explorer également la notion d’intertextualité et le débat critique qu’elle suscite. Il s’agira d’esquisser un portrait de famille à travers l’étude des nouvelles du recueil In the Year of Long Division (1994, avec des références au roman Carrying the Body (2002.

  12. Data Analysis WorkbeNch (DAWN)

    Energy Technology Data Exchange (ETDEWEB)

    Basham, Mark; Filik, Jacob; Wharmby, Michael T.; Chang, Peter C. Y.; El Kassaby, Baha; Gerring, Matthew; Aishima, Jun; Levik, Karl; Pulford, Bill C. A.; Sikharulidze, Irakli; Sneddon, Duncan; Webber, Matthew; Dhesi, Sarnjeet S.; Maccherozzi, Francesco [Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Svensson, Olof [European Synchrotron Radiation Facility (ESRF), 71 Rue des Martyrs, Grenoble 38000 (France); Brockhauser, Sandor; Náray, Gabor [European Molecular Biology Laboratory (EMBL), 6 Rue Jules Horowitz, Grenoble 38042 (France); Ashton, Alun W., E-mail: scientificsoftware@diamond.ac.uk [Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2015-04-02

    DAWN is a generic data analysis software platform that has been developed for use at synchrotron beamlines for data visualization and analysis. Its generic design makes it suitable for use in a range of scientific and engineering applications. Synchrotron light source facilities worldwide generate terabytes of data in numerous incompatible data formats from a wide range of experiment types. The Data Analysis WorkbeNch (DAWN) was developed to address the challenge of providing a single visualization and analysis platform for data from any synchrotron experiment (including single-crystal and powder diffraction, tomography and spectroscopy), whilst also being sufficiently extensible for new specific use case analysis environments to be incorporated (e.g. ARPES, PEEM). In this work, the history and current state of DAWN are presented, with two case studies to demonstrate specific functionality. The first is an example of a data processing and reduction problem using the generic tools, whilst the second shows how these tools can be targeted to a specific scientific area.

  13. Vesta in the Light of Dawn, But Without HEDS?

    Science.gov (United States)

    McSween, H. Y.; Mittlefehldt, D. W.

    2014-01-01

    The derivation of HEDs from Vesta is strongly supported by Dawn data [1], and these meterorites have made interpretations of Dawn spectra much more rigorous. Compared to the Moon, where samples became available after geologic mapping, the exploration of Vesta has been backwards. But what if HEDs had not been available or identified as vestan samples? What petrologic and geochemical predictions would have been possible using Dawn data, without the benefit of HEDs?

  14. Early Mission Power Assessment of the Dawn Solar Array

    Science.gov (United States)

    Stella, Paul M.; DiStefano, Salvatore; Rayman, Marc D.; Ulloa-Severino, Antonio

    2009-01-01

    NASA's Discovery Mission Dawn was launched in September 2007. Dawn will be the first to orbit two asteroids on a single voyage. The solar array for the Dawn mission will provide power under greatly varying illumination and temperature conditions. Dawn's ion propulsion system (IPS) will provide the spacecraft with enough thrust to reach Vesta and Ceres and orbit both. The demanding mission would be impossible without ion propulsion -- a mission only to the asteroid Vesta (and not including Ceres) would require a much more massive spacecraft and, a much larger launch vehicle.

  15. Early Mission Power Assessment of the Dawn Solar Array

    Science.gov (United States)

    Stella, Paul M.; DiStefano, Salvatore; Rayman, Marc D.; Ulloa-Severino, Antonio

    2009-01-01

    NASA's Discovery Mission Dawn was launched in September 2007. Dawn will be the first to orbit two asteroids on a single voyage. The solar array for the Dawn mission will provide power under greatly varying illumination and temperature conditions. Dawn's ion propulsion system (IPS) will provide the spacecraft with enough thrust to reach Vesta and Ceres and orbit both. The demanding mission would be impossible without ion propulsion -- a mission only to the asteroid Vesta (and not including Ceres) would require a much more massive spacecraft and, a much larger launch vehicle.

  16. Dawning4000A high performance computer

    Institute of Scientific and Technical Information of China (English)

    SUN Ninghui; MENG Dan

    2007-01-01

    Dawning4000A is an AMD Opteron-based Linux Cluster with 11.2Tflops peak performance and 8.06Tflops Linpack performance.It was developed for the Shanghai Supercomputer Center (SSC)as one of the computing power stations of the China National Grid (CNGrid)project.The Massively Cluster Computer (MCC)architecture is proposed to put added-value on the industry standard system.Several grid-enabling components are developed to support the running environment of the CNGrid.It is an achievement for a high performance computer with the low-cost approach.

  17. Ceres' Geophysical Evolution Inferred from Dawn Data

    Science.gov (United States)

    Castillo-Rogez, Julie; Bowling, Timothy; Ermakov, Anton I.; Fu, Roger; Park, Ryan; Raymond, Carol; De Sanctis, Maria Cristina; Ammannito, Eleonora; Ruesch, Ottaviano; Prettyman, Thomas H.; Y McSween, Harry; Toplis, Michael J.; Russell, Christopher T.; Dawn Team

    2016-10-01

    If Ceres formed as an ice-rich body, as suggested by its low density and the detection of ammoniated phyllosilicates [1], then it should have differentiated an ice-dominated shell, analogous to large icy satellites [2]. Instead, Dawn observations revealed an enrichment of Ceres' shell in strong materials, either a rocky component and/or salts and gas hydrates [3, 4, 5, 6]. We have explored several scenarios for the emplacement of Ceres' surface. Endogenic processes cannot account for its overall homogeneity. Instead we suggest that Ceres differentiated an icy shell upon freezing of its early ocean that was removed as a consequence of frequent exposure by impacting after the dwarf planet migrated from a cold accretional environment to the warmer outer main belt (or when the solar nebula dissipated, if Ceres formed in situ). This scenario implies that Ceres' current surface represents the interface between the original ice shell and the top of the frozen ocean, a region that is extremely rich chemistry-wise, as illustrated by the mineralogical observations returned by Dawn [7]. Thermal modeling shows that the shell could remain warm over the long term and offer a setting for the generation of brines that may be responsible for the emplacement of Ahuna Mons [8] and Occator's bright spots [7] on an otherwise homogeneous surface [9]. An important implication is that Ceres' surface offers an analog for better understanding the deep interior and chemical evolution of large ice-rich bodies.References: [1] De Sanctis et al., Nature, 2015; [2] McCord and Sotin, Journal of Geophysical Research, 2005; [3] Park et al., Nature, 2016 (in press); [4] Hiesinger et al., Science (submitted); [5] Bland et al., Nature Geoscience, 2016 (in press); [6] Fu et al., AGU Fall Meeting, 2015 [7] De Sanctis et al., Nature, 2016 (in press); [8] Ruesch et al., Science, in revision; [9] Ammannito et al., Science, 2016 (accepted).Acknowledgements: Part of this work is being carried out at the Jet

  18. Paradigms and Paradoxes: Dawn at Vesta

    Science.gov (United States)

    Raymond, C. A.; Russell, C. T.; Mittlefehldt, D. W.

    2014-01-01

    While confirming the popular paradigm of Vesta as the parent body of the HED meteorites, Dawn measurements have discovered many unexpected aspects of the vestan surface. First, an olivine layer was not found in the bottom of the large basin near the south pole of Vesta. In fact, while patches of olivine have been found in the north, it is rare on the surface. Secondly, while Vesta has little gravity and appears to have completely differentiated, it is not completely dry evidence for transient flows and pits resulting from devolatization have been found, implying a substantial amount of accessible water. Thirdly, transport of material to the surface of Vesta from elsewhere in the asteroid belt appears as dark material buried near the top of the crust to Vesta. This may have arrived in a single large impact and been spread around the surface and buried, later to be re-excavated. However, it is not certain that this is the only scenario possible for the source of this material. In short, Dawn's observations of Vesta have been both reassuring but unsettling at the same time.

  19. Energetic electrons in Jupiter's dawn magnetodisc

    Science.gov (United States)

    Van Allen, J. A.

    1979-01-01

    The paper presents and analyzes absolute energy density data on electrons from the University of Iowa instrument on Pioneer 10 for one example of a plasma sheet traversal in Jupiter's dawn magnetodisk on 6-7 December 1973. The absolute integral omnidirectional intensity spectrum of electrons is based on a full and accurate reduction of the counting rate data. The main finding is that electrons of energy greater than 0.060 MeV provide only about 3% of the charged particle pressure required to explain the observed depression in the magnetic field at the center of the plasma sheet, in spite of the fact that the intensity of such electrons is well correlated with the depression of the magnetic pressure throughout the sheet.

  20. Dawn Spacecraft Reaction Control System Flight Experience

    Science.gov (United States)

    Mizukami, Masashi; Nakazono, Barry

    2014-01-01

    The NASA Dawn spacecraft mission is studying conditions and processes of the solar system's earliest epoch by investigating two protoplanets remaining intact since their formations, Ceres and Vesta. Launch was in 2007. Ion propulsion is used to fly to and enter orbit around Vesta, depart Vesta and fly to Ceres, and enter orbit around Ceres. A conventional blowdown hydrazine reaction control system (RCS) is used to provide external torques for attitude control. Reaction wheel assemblies were intended to provide attitude control in most cases. However, the spacecraft experienced one, then two apparent failures of reaction wheels. Also, similar thrusters experienced degradation in a long life application on another spacecraft. Those factors led to RCS being operated in ways completely different than anticipated prior to launch. Numerous mitigations and developments needed to be implemented. The Vesta mission was fully successful. Even with the compromises necessary due to those anomalies, the Ceres mission is also projected to be feasible.

  1. The dawn of gravitational wave astronomy

    CERN Document Server

    CERN. Geneva

    2016-01-01

    On Sep 14 2015, gravitational waves were for the first time detected directly. This observation by the LIGO interferometric detectors marks the dawn of a new era in our observational study of the cosmos as a qualitatively new window to its exploration has been opened. This talk reviews some of the fundamental concepts of gravitational waves and the methodology employed for their observation. The first event, dubbed GW150914, and the properties of its source, as inferred from the observation, will be discussed. The talk concludes with a selected set of the most important topics where we expect gravitational-wave observations to deepen and either challenge or confirm our present understanding of the laws and the history of our universe.

  2. Vesta and Ceres as Seen by Dawn

    Science.gov (United States)

    Russell, C. T.; Nathues, A.; De Sanctis, M. C.; Prettyman, T. H.; Konopliv, A. S.; Park, R. S.; Jaumann, R.; McSween, H. Y., Jr.; Raymond, C. A.; Pieters, C. M.; McCord, T. B.; Marchi, S.; Schenk, P.; Buczkowski, D.

    2015-12-01

    Ceres and Vesta are the most massive bodies in the main asteroid belt. They have witnessed 4.6 Ga of solar system history. Dawn's objective is to interview these two witnesses. These bodies are relatively simple protoplanets, with a modest amount of thermal evolution and geochemical alteration. They are our best archetypes of the early building blocks of the terrestrial planets. In particular siderophile elements in the Earth's core were probably first segregated in Vesta-like bodies, and its water was likely first condensed in Ceres-like bodies. Vesta has provided copious meteorites for geochemical analysis. This knowledge was used to infer the constitution of the parent body. Dawn verified that Vesta was consistent with being that body, confirming the geochemical inferences from these samples on the formation and evolution of the solar system. Ceres has not revealed itself with a meteoritic record nor an asteroid family. While the surface is scarred with craters, it is probable that the ejecta from the crater-forming events created little competent material from the icy crust and any such ejected material that reached Earth might have disintegrated upon entry into the Earth's atmosphere. Ceres' surface differs greatly from Vesta's. Plastic or fluidized mass wasting is apparent as are many irregularly shaped craters, including many polygonal crater forms. There are many central-pit craters possibly caused by volatilization of the crust in the center of the impact. There are many central-peak craters but are these due to rebound or pingo-like formation processes? Bright spots, possibly salt deposits, dot the landscape, evidence of fluvial processes beneath the crust. Observations of the largest region of bright spots may suggest sublimation from the surface of the bright area, consistent with Herschel water vapor observations. Ceres is not only the most massive body in the asteroid belt but also possibly the most active occupant of the main belt.

  3. Drug Abuse Warning Network US (DAWN-NS-1997)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) survey is designed to capture data on emergency department (ED) episodes that are induced by or related to the use of an...

  4. Drug Abuse Warning Network US (DAWN-NS-1994)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) survey is designed to capture data on emergency department (ED) episodes that are induced by or related to the use of an...

  5. 2004 through 2010 Drug Abuse Warning Network (DAWN)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Abuse Warning Network (DAWN) is a nationally representative public health surveillance system that continuously monitors drug-related visits to hospital...

  6. Pre-Dawn Temperatures on Ganymede

    Science.gov (United States)

    1997-01-01

    This infrared image of Jupiter's moon Ganymede, showing heat radiation from its surface at a wavelength of 27 microns (millionths of a meter), provides the best view yet of pre-dawn temperatures on Ganymede. Temperatures, derived from the brightness of the infrared radiation, can be determined from the colors by reference to the scale at the bottom of the image.The image, taken by NASA's Galileo spacecraft, shows half of Ganymede's disk as seen by the approaching spacecraft. Longitudes covered range from 340 on the right of the image, through longitude zero (the direction facing Jupiter) to longitude 60 near Ganymede's limb on the left. The morning terminator, near longitude 15, curves through the middle of the image, separating areas experiencing the last hours of the long (3.5 Earth day) Ganymede night, on the left, from areas that are warming up in the morning sunshine, on the right. Ganymede's north pole is in the upper right corner of the image, and the south pole is in the lower right. Ganymede rotates from left to right.Nighttime temperatures, shown in blue and purple colors, are in the range 85 - 100 Kelvin (-306 to -279 F). The surface cools steadily during the night, so the warmest nighttime temperatures are on the left side of the disk, and temperatures drop towards the dawn terminator on the right, before warming rapidly once the sun rises (the red, yellow and white areas on the far right). Study of the rate of nighttime cooling and the rate of post-sunrise warming, will provide information about Ganymede's surface properties.The image was taken with Galileo's PPR (Photopolarimeter-Radiometer) instrument on the spacecraft's seventh orbit around Jupiter, from a range of about 190,000 kilometers (118,060 miles). Surface temperatures derived from the strength of infrared radiation, as was done here, are called 'brightness temperatures', and may be slightly in error.The PPR instrument builds up an image by slowly scanning across the target over a period of

  7. Ceres: Dawn visits a Warm Wet Planet

    Science.gov (United States)

    McCord, T. B.; Combe, J. P.

    2014-12-01

    Ceres likely contains considerable water, has differentiated, and formed a hydrated silicate core and water mantle. There were major dimensional, thermal and chemical changes over its history, making it more a planet than an asteroid. These factors created the present day body, which the Dawn misson will visit next March. I will summarize our current understanding of Ceres and suggest what Dawn will find. A major uncertainty is how processes, such as aqueous mineralization, impact and cratering, infall of external material, mixing, and viscous relaxation of surface features have altered the formation materials and surface, hiding Ceres' secrets. Ceres' bulk density of 2100 kg/m3, suggest major water content. Modeling of Ceres' thermodynamic evolution for different times of accretion, assuming several radioactive heating scenarios, produces results ranging from a dry Vestal-like object (earlier, hotter formation) to retention and melting of the ice and differentiation of silicates from liquid water. Mixing of liquid water and silicates leads to exothermic hydration reactions, formation of a core and a liquid mantle. Large dimensional changes are associated. A crust stays frozen but founders at times due to gravitational instability, dimensional changes and impacts. The liquid mantle freezes from top, down, but a layer of salty liquid water probably exists today near the core. Hydrated silicates from the initial differentiation would likely dehydrate near the core center due to temperature and pressure. From observations, only subdued spatial albedo and color variations are observed at UV and IR wavelengths on Ceres' surface at the scale possible from Earth (~50-100 km) and an oblate spheroid shape is found, consistent with a differentiated body. Compositional evidence includes the long known similarity of Ceres' albedo and visual-IR reflectance spectrum to those for carbonaceous chondrite meteorites. Thus, the surface is likely made of carbon-bearing, hydroxolated

  8. Vesta Mineralogy after Dawn Global Observations

    Science.gov (United States)

    ChristinaDeSanctis, Maria; Ammannito, E.; Capaccioni, F.; Cparia, M. T.; Carraro, F.; Fonte, S.; Frigeri, A.; Longobardo, A.; Marchi, S.; Palomba, E.; hide

    2012-01-01

    The Dawn mission has completed its mapping phases at Vesta and millions of spectra have been acquired by the Visible and InfraRed Mapping Spectrometer, VIR(1). VIR characterizes and maps the mineral distribution on Vesta -strengthening the Vesta HED linkage- and provides new insights into Vesta s formation and evolution(2,3). VIR spectra are dominated by pyroxene absorptions near 0.9 and 2.0 m and large thermal emission beyond 3.5 m. Although almost all surface materials exhibit howardite-like spectra, some large regions can be interpreted to be richer in eucritic (basaltic) material and others richer in diogenititic (Mg-orthopyroxenitic) material. The Rheasilvia basin contains Mg-pyroxene-rich terrains for example. Vesta' s surface shows considerable diversity at local scales. Many bright and dark areas(3,4) are associated with various geological features and show remarkably different morphology. Moreover, VIR detected statistically significant, but weak, variations at 2.8 m that have been interpreted as indicating the presence of OH-bearing phases on the surface(5). The OH distribution is uneven with large regions lacking this absorption feature. Associations of 2.8 m band with morphological structures indicate complex process responsible for OH. Vesta exhibits large spectral variations that often correlate with geological structures, indicating a complex geological and evolutionary history, more similar to that of the terrestrial planets than to other asteroids visited by spacecrafts.

  9. Artifacts reduction in VIR/Dawn data

    Science.gov (United States)

    Carrozzo, F. G.; Raponi, A.; De Sanctis, M. C.; Ammannito, E.; Giardino, M.; D'Aversa, E.; Fonte, S.; Tosi, F.

    2016-12-01

    Remote sensing images are generally affected by different types of noise that degrade the quality of the spectral data (i.e., stripes and spikes). Hyperspectral images returned by a Visible and InfraRed (VIR) spectrometer onboard the NASA Dawn mission exhibit residual systematic artifacts. VIR is an imaging spectrometer coupling high spectral and spatial resolutions in the visible and infrared spectral domain (0.25-5.0 μm). VIR data present one type of noise that may mask or distort real features (i.e., spikes and stripes), which may lead to misinterpretation of the surface composition. This paper presents a technique for the minimization of artifacts in VIR data that include a new instrument response function combining ground and in-flight radiometric measurements, correction of spectral spikes, odd-even band effects, systematic vertical stripes, high-frequency noise, and comparison with ground telescopic spectra of Vesta and Ceres. We developed a correction of artifacts in a two steps process: creation of the artifacts matrix and application of the same matrix to the VIR dataset. In the approach presented here, a polynomial function is used to fit the high frequency variations. After applying these corrections, the resulting spectra show improvements of the quality of the data. The new calibrated data enhance the significance of results from the spectral analysis of Vesta and Ceres.

  10. Dawn Mission Education and Public Outreach: Science as Human Endeavor

    Science.gov (United States)

    Cobb, W. H.; Wise, J.; Schmidt, B. E.; Ristvey, J.

    2012-12-01

    Dawn Education and Public Outreach strives to reach diverse learners using multi-disciplinary approaches. In-depth professional development workshops in collaboration with NASA's Discovery Program, MESSENGER and Stardust-NExT missions focusing on STEM initiatives that integrate the arts have met the needs of diverse audiences and received excellent evaluations. Another collaboration on NASA ROSES grant, Small Bodies, Big Concepts, has helped bridge the learning sequence between the upper elementary and middle school, and the middle and high school Dawn curriculum modules. Leveraging the Small Bodies, Big Concepts model, educators experience diverse and developmentally appropriate NASA activities that tell the Dawn story, with teachers' pedagogical skills enriched by strategies drawn from NSTA's Designing Effective Science Instruction. Dawn mission members enrich workshops by offering science presentations to highlight events and emerging data. Teachers' awareness of the process of learning new content is heightened, and they use that experience to deepen their science teaching practice. Activities are sequenced to enhance conceptual understanding of big ideas in space science and Vesta and Ceres and the Dawn Mission 's place within that body of knowledge Other media add depth to Dawn's resources for reaching students. Instrument and ion engine interactives developed with the respective science team leads help audiences engage with the mission payload and the data each instrument collects. The Dawn Dictionary, an offering in both audio as well as written formats, makes key vocabulary accessible to a broader range of students and the interested public. Further, as Dawn E/PO has invited the public to learn about mission objectives as the mission explored asteroid Vesta, new inroads into public presentations such as the Dawn MissionCast tell the story of this extraordinary mission. Asteroid Mapper is the latest, exciting citizen science endeavor designed to invite the

  11. Moon Search Algorithms for NASA's Dawn Mission to Asteroid Vesta

    CERN Document Server

    Memarsadeghi, Nargess; Skillman, David; McLean, Brian; Mutchler, Max; Carsenty, Uri; Palmer, Eric E; 10.1117/12.915564

    2013-01-01

    A moon or natural satellite is a celestial body that orbits a planetary body such as a planet, dwarf planet, or an asteroid. Scientists seek understanding the origin and evolution of our solar system by studying moons of these bodies. Additionally, searches for satellites of planetary bodies can be important to protect the safety of a spacecraft as it approaches or orbits a planetary body. If a satellite of a celestial body is found, the mass of that body can also be calculated once its orbit is determined. Ensuring the Dawn spacecraft's safety on its mission to the asteroid (4) Vesta primarily motivated the work of Dawn's Satellite Working Group (SWG) in summer of 2011. Dawn mission scientists and engineers utilized various computational tools and techniques for Vesta's satellite search. The objectives of this paper are to 1) introduce the natural satellite search problem, 2) present the computational challenges, approaches, and tools used when addressing this problem, and 3) describe applications of various...

  12. Diabetes Attitudes Wishes and Needs 2 (DAWN2)

    DEFF Research Database (Denmark)

    Peyrot, Mark; Burns, Katharina Kovacs; Davies, Melanie J

    2013-01-01

    AIMS: The Diabetes Attitudes Wishes and Needs 2 (DAWN2) study aims to provide a holistic assessment of diabetes care and management among people with diabetes (PWD), family members (FM), and healthcare professionals (HCPs) and explores potential drivers leading to active management. METHODS: DAWN2...... (2001), as well as psychometrically validated instruments and novel questions developed for this study to assess self-management, attitudes/beliefs, disease impact/burden, psychosocial distress, health-related quality of life, healthcare provision/receipt, social support and priorities for improvement...

  13. Dawn Vesta Raw Gravity Science V1.0

    Science.gov (United States)

    Buccino, D. R.; Konopliv, A. S.; Park, R. S.; Asmar, S. W.

    2014-10-01

    This data set contains archival raw, partially processed, and ancillary/supporting gravity science data acquired during the Dawn mission while the spacecraft was in orbit around the asteroid Vesta. The radio observations were carried out using the Dawn spacecraft and Earth-based receiving stations of the NASA Deep Space Network (DSN). The data set was designed primarily to support generation of high-resolution gravity field models for Vesta. Of most interest are likely to be the Orbit Data Files in the ODF directory, which provided the raw input to gravity investigations, as well as the ionospheric and tropospheric media calibration files in the ION and TRO directories, respectively.

  14. ORIGIN: Metal Creation and Evolution from the Cosmic Dawn

    DEFF Research Database (Denmark)

    Herder, J. W. den; Piro, L.; Ohashi, T.

    2011-01-01

    ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to identify the physical conditions of all abundant elements between C and Ni to red-shifts of z=10, a...

  15. ORIGIN: metal creation and evolution from the cosmic dawn

    NARCIS (Netherlands)

    den Herder, J.W.; Piro, L.; Ohashi, T.; Kouveliotou, C.; Hartmann, D.H.; Kaastra, J.S.; Amati, L.; Andersen, M.I.; Arnaud, M.; Atteia, J.-L.; Bandler, S.; Barbera, M.; Barcons, X.; Barthelmy, S.; Basa, S.; Basso, S.; de Boer, M.; Branchini, E.; Branduardi-Raymont, G.; Borgani, S.; Boyarsky, A.; Brunetti, G.; Budtz-Jorgensen, C.; Burrows, D.; Butler, N.; Campana, S.; Caroli, E.; Ceballos, M.; Christensen, F.; Churazov, E.; Comastri, A.; Colasanti, L.; Cole, R.; Content, R.; Corsi, A.; Costantini, E.; Conconi, P.; Cusumano, G.; de Plaa, J.; De Rosa, A.; Del Santo, M.; Di Cosimo, S.; De Pasquale, M.; Doriese, R.; Ettori, S.; Evans, P.; Ezoe, Y.; Ferrari, L.; Finger, H.; Figueroa-Feliciano, T.; Friedrich, P.; Fujimoto, R.; Furuzawa, A.; Fynbo, J.; Gatti, F.; Galeazzi, M.; Gehrels, N.; Gendre, B.; Ghirlanda, G.; Ghisellini, G.; Gilfanov, M.; Giommi, P.; Girardi, M.; Grindlay, J.; Cocchi, M.; Godet, O.; Guedel, M.; Haardt, F.; Hartog, R.; Hepburn, I.; Hermsen, W.; Hjorth, J.; Hoekstra, H.; Holland, A.; Hornstrup, A.; van der Horst, A.; Hoshino, A.; in 't Zand, J.; Irwin, K.; Ishisaki, Y.; Jonker, P.; Kitayama, T.; Kawahara, H.; Kawai, N.; Kelley, R.; Kilbourne, C.; de Korte, P.; Kusenko, A.; Kuvvetli, I.; Labanti, M.; Macculi, C.; Maiolino, R.; Mas Hesse, M.; Matsushita, K.; Mazzotta, P.; McCammon, D.; Méndez, M.; Mignani, R.; Mineo, T.; Mitsuda, K.; Mushotzky, R.; Molendi, S.; Moscardini, L.; Natalucci, L.; Nicastro, F.; O'Brien, P.; Osborne, J.; Paerels, F.; Page, M.; Paltani, S.; Pedersen, K.; Perinati, E.; Ponman, T.; Pointecouteau, E.; Predehl, P.; Porter, S.; Rasmussen, A.; Rauw, G.; Röttgering, H.; Roncarelli, M.; Rosati, P.; Quadrini, E.; Ruchayskiy, O.; Salvaterra, R.; Sasaki, S.; Sato, K.; Savaglio, S.; Schaye, J.; Sciortino, S.; Shaposhnikov, M.; Sharples, R.; Shinozaki, K.; Spiga, D.; Sunyaev, R.; Suto, Y.; Takei, Y.; Tanvir, N.; Tashiro, M.; Tamura, T.; Tawara, Y.; Troja, E.; Tsujimoto, M.; Tsuru, T.; Ubertini, P.; Ullom, J.; Ursino, E.; Verbunt, F.; van de Voort, F.; Viel, M.; Wachter, S.; Watson, D.; Weisskopf, M.; Werner, N.; White, N.; Willingale, R.; Wijers, R.; Yamasaki, N.; Yoshikawa, K.; Zane, S.

    2012-01-01

    ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to identify the physical conditions of all abundant elements between C and Ni to red-shifts of z = 10, an

  16. ORIGIN : Metal creation and evolution from the cosmic dawn

    NARCIS (Netherlands)

    den Herder, Jan-Willem; Piro, Luigi; Ohashi, Takaya; Kouveliotou, Chryssa; Hartmann, Dieter H.; Kaastra, Jelle S.; Amati, L.; Andersen, M. I.; Arnaud, M.; Attéia, J.-L.; Bandler, S.; Barbera, M.; Barcons, X.; Barthelmy, S.; Basa, S.; Basso, S.; Boer, M.; Branchini, E.; Branduardi-Raymont, G.; Borgani, S.; Boyarsky, A.; Brunetti, G.; Budtz-Jorgensen, C.; Burrows, D.; Butler, N.; Campana, S.; Caroli, E.; Ceballos, M.; Christensen, F.; Churazov, E.; Comastri, A.; Colasanti, L.; Cole, R.; Content, R.; Corsi, A.; Costantini, E.; Conconi, P.; Cusumano, G.; de Plaa, J.; De Rosa, A.; Del Santo, M.; Di Cosimo, S.; De Pasquale, M.; Doriese, R.; Ettori, S.; Evans, P.; Ezoe, Y.; Ferrari, L.; Finger, H.; Figueroa-Feliciano, T.; Friedrich, P.; Fujimoto, R.; Furuzawa, A.; Fynbo, J.; Gatti, F.; Galeazzi, M.; Gehrels, N.; Gendre, B.; Ghirlanda, G.; Ghisellini, G.; Gilfanov, M.; Giommi, P.; Girardi, M.; Grindlay, J.; Cocchi, M.; Godet, O.; Guedel, M.; Haardt, F.; den Hartog, R.; Hepburn, I.; Hermsen, W.; Hjorth, J.; Hoekstra, H.; Holland, A.; Hornstrup, A.; van der Horst, A.; Hoshino, A.; in't Zand, J.; Irwin, K.; Ishisaki, Y.; Jonker, P.; Kitayama, T.; Kawahara, H.; Kawai, N.; Kelley, R.; Kilbourne, C.; de Korte, P.; Kusenko, A.; Kuvvetli, I.; Labanti, M.; Macculi, C.; Maiolino, R.; Hesse, M. Mas; Matsushita, K.; Mazzotta, P.; McCammon, D.; Méndez, M.; Mignani, R.; Mineo, T.; Mitsuda, K.; Mushotzky, R.; Molendi, S.; Moscardini, L.; Natalucci, L.; Nicastro, F.; O'Brien, P.; Osborne, J.; Paerels, F.; Page, M.; Paltani, S.; Pedersen, K.; Perinati, E.; Ponman, T.; Pointecouteau, E.; Predehl, P.; Porter, S.; Rasmussen, A.; Rauw, G.; Röttgering, H.; Roncarelli, M.; Rosati, P.; Quadrini, E.; Ruchayskiy, O.; Salvaterra, R.; Sasaki, S.; Sato, K.; Savaglio, S.; Schaye, J.; Sciortino, S.; Shaposhnikov, M.; Sharples, R.; Shinozaki, K.; Spiga, D.; Sunyaev, R.; Suto, Y.; Takei, Y.; Tanvir, N.; Tashiro, M.; Tamura, T.; Tawara, Y.; Troja, E.; Tsujimoto, M.; Tsuru, T.; Ubertini, P.; Ullom, J.; Ursino, E.; Verbunt, F.; van de Voort, F.; Viel, M.; Wachter, S.; Watson, D.; Weisskopf, M.; Werner, N.; White, N.; Willingale, R.; Wijers, R.; Yamasaki, N.; Yoshikawa, K.; Zane, S.

    2012-01-01

    ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to identify the physical conditions of all abundant elements between C and Ni to red-shifts of z = 10, an

  17. ORIGIN: metal creation and evolution from the cosmic dawn

    NARCIS (Netherlands)

    den Herder, J.W.A.; Piro, L.; Ohashi, T.; Kouveliotou, C.; Hartmann, D.H.; Kaastra, J.S.; Amati, L.

    2011-01-01

    ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to identify the physical conditions of all abundant elements between C and Ni to red-shifts of z = 10, an

  18. Moon Search Algorithms for NASA's Dawn Mission to Asteroid Vesta

    Science.gov (United States)

    Memarsadeghi, Nargess; Mcfadden, Lucy A.; Skillman, David R.; McLean, Brian; Mutchler, Max; Carsenty, Uri; Palmer, Eric E.

    2012-01-01

    A moon or natural satellite is a celestial body that orbits a planetary body such as a planet, dwarf planet, or an asteroid. Scientists seek understanding the origin and evolution of our solar system by studying moons of these bodies. Additionally, searches for satellites of planetary bodies can be important to protect the safety of a spacecraft as it approaches or orbits a planetary body. If a satellite of a celestial body is found, the mass of that body can also be calculated once its orbit is determined. Ensuring the Dawn spacecraft's safety on its mission to the asteroid Vesta primarily motivated the work of Dawn's Satellite Working Group (SWG) in summer of 2011. Dawn mission scientists and engineers utilized various computational tools and techniques for Vesta's satellite search. The objectives of this paper are to 1) introduce the natural satellite search problem, 2) present the computational challenges, approaches, and tools used when addressing this problem, and 3) describe applications of various image processing and computational algorithms for performing satellite searches to the electronic imaging and computer science community. Furthermore, we hope that this communication would enable Dawn mission scientists to improve their satellite search algorithms and tools and be better prepared for performing the same investigation in 2015, when the spacecraft is scheduled to approach and orbit the dwarf planet Ceres.

  19. Dawn Arrives at Ceres: Results of the Survey Orbit

    Science.gov (United States)

    Russell, C. T.; Raymond, C. A.; Nathues, A.; Hoffman, M.; DeSanctis, M. C.; Ammannito, E.; Prettyman, T. H.; Konopliv, A. S.; Park, R. S.; McSween, H. Y.; Pieters, C. M.; Jaumann, R.; Toplis, M. J.; Joy, S. P.; Polanskey, C. A.; Rayman, M. D.

    2015-10-01

    In September 2012 the Dawn spacecraft left Vesta the second most massive body in the asteroid main belt and set sail for Ceres the most massive. On March 6, 2015 Dawn settled into orbit around Ceres becoming the first spacecraft to orbit separately two distant solar orbiting bodies and establishing a new era in space exploration. Unlike Vesta, Ceres has remained hidden from our geochemical eyes into the origin of the asteroid belt, the analysis of meteorites. Ceres has no known associated meteorites nor a family of asteroids. The observations at Ceres return totally new information. Dawn is equipped with a framing camera with one clear and seven color filters, a visible and infrared mapping spectrometer, a gamma ray and neutron spectrometer and radiometric tracking for gravity determination. The approach trajectory is shown in Figure 1. A distant pass over the daylight surface was followed by a distant looping orbit over the dark side. Then in late April Dawn settled into a high altitude orbit known as Rotational Characterization (RC3). On the approach to RC3 the spacecraft found a pair of bright spots on the surface at about 240ºE longitude and 20ºN latitude shown in Figure 2. These two spots were not resolved at the distances flown during approach.

  20. Ceres' evolution before and after Dawn: Where are we now?

    Science.gov (United States)

    McCord, Thomas B.; Castillo-Rogez, Julie C.

    2016-10-01

    Observations of Ceres before Dawn indicated that it contains ~25 wt% water, and thermodynamic modeling indicated Ceres probably had experienced the same process of differentiation due to melting of the original ice after accretion as experienced by large icy moons. Consistent with that was a surface of altered mineralogy like clays suggesting aqueous alteration of the original chondritic silicates. Dawn has revealed some concentration of mass toward the center, specific aqueously altered mineralogies, a stiff surface with weaker material beneath, and extrusions and protrusions suggesting recent subsurface activity, including exposures of water ice that must be very recent. This wealth of new information from Dawn enables selection of more specific evolution models that best match the vastly improved Dawn observations. In this new study we propose one possibility is that Ceres accreted as an ice and silicate mixture after short-lived radionuclides in CAIs had significantly decayed, i.e. nearer 5 my after CAIs, and thus differentiated less completely than for hotter models. On the other hand, the presence of heavily aqueously altered mineralogies, including probably salts, suggests extensive mixing of water and silicates, which might normally be associated with more complete differentiation. Geologically recent activity, perhaps even to the present time, seems evident from several young landforms, including protrusions consistent with diapirism and recent exposures of water ice. This suggests recent flexing of the subsurface and rising of less dense interior material, including salts and ice. The presence of ammoniated minerals and what appear to be salt deposits suggest a major lowering of subsurface water ice melting temperature, enhancing the duration of water-silicate contact, and perhaps accelerating the mineralization processes and slowing or halting differentiation of water and silicates. Thus, Ceres is becoming known as the first body outward from the Sun

  1. On the Mother-Daughter Relationships under the Pen of Hurston and Morrison%论赫斯顿和莫里森笔下的母女关系

    Institute of Scientific and Technical Information of China (English)

    郭巍

    2014-01-01

    Two renowned black female writers Zora Neale Hurston and Toni Morrison have portrayed the enduring images of the black women respectively in their novels Their Eyes were Watching God and Sula. The feminist psychoanalyst Nancy Chodorow’s theory of the reproduction of mothering is applied to analyze the complicated relations between the three heroines and their mothers living under the fetters of racism, sexism and classism - maternal bonds could be cruel separation or restriction of one’s selfhood or unbreakable attachment for the heroines -in order to shed light on the mothers’ restrictive or empowering influence on the formations of their daughters’ personality, self-awareness and their identity as a black female in the society.%佐拉·尼尔·赫斯顿和托尼·莫里森分别在《他们眼望上苍》和《秀拉》中塑造了不朽的黑人女性形象。借用心理分析学家南茜·乔多萝的客体关系理论,从女性主义的视角,对比分析在种族、性别和阶层的桎梏下寻求独立的女主人公们与她们母亲间错综复杂的关系:母爱对女主人公来说或是分离的残酷现实,或是对自我成长的限制,或是难以摆脱的依恋,母亲的影响对女性性格的塑造、自我意识的发掘和女性身份的认同起到限制或推动性的作用。

  2. Exploiting the Capabilities of the Interconnection Network on Dawning-1000

    Institute of Scientific and Technical Information of China (English)

    XIAO Limin; ZHU Mingfa

    1999-01-01

    On Dawning-1000, the two-dimension mesh interconnection network enables low-latency, high-bandwidth communication, however, these capabilities have not been realized because of the high processing overhead imposed by existing communication software. Active Messages provide an efficient communication mechanism with small overhead, which may expose the raw capabilities of the underlying hardware. In addition, one of the most promising techniques, user-level communication, is often used to improve the performance of the traditional protocols such as TCP and UDP, andis also adopted in implementing the novel abstractions like Active Messages. Thus a user-level Active Messages model is designed and implemented on Dawning-1000. Preliminary experiments show that the combination of Active Messages mechanism and user-level communication technique is quite efficient in reducing software overhead associated with sending and receiving messages, and in exploiting the capabilitiesof the interconnection network.

  3. "Double dawn" eclipse and the rotational variation of the earth

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A record of "double dawn'' at State Zheng in the first year of the reign of King Yi in Western Zhou Dynasty in the chronicle "Bamboo Annals" (Zhushu Jinian) is discussed. We think that it may be a record of an annular solar eclipse happening in 899 BC. The record and the △T, which describes the secular variation of the earth's rotation, are analyzed and discussed.

  4. Diabetes Attitudes, Wishes and Needs second study (DAWN2™)

    DEFF Research Database (Denmark)

    Kovacs Burns, K; Nicolucci, Antonio; Holt, Richard I G

    2013-01-01

    AIMS: The second Diabetes Attitudes, Wishes and Needs (DAWN2) study examined the experiences of family members of people with diabetes for benchmarking and identifying unmet needs or areas for improvement to assist family members and those with diabetes to effectively self-manage. METHODS: In total...... indicators of family members' psychosocial needs that will help identify the support required for, and from, them to improve the lives of people with diabetes and their families....

  5. DAWN Mission Bus and Waveguide Venting Analysis Review

    Science.gov (United States)

    Cragg, Clinton H.; Kichak, Robert A.; Sutter, James K.; Holder, Donald; Jeng, Frank; Ruitberg, Arthur; Sank, Victor

    2007-01-01

    A concern was raised regarding the time after launch when the DAWN Mission Communications Subsystem, which contains a 100 Watt X-Band Traveling Wave Tube Amplifier (TWTA) with a high voltage ((approximately 7 Kilo Volt (KV)) Electronic Power Converter (EPC), will be powered on for the first post-launch downlink. This activation is planned to be approximately one hour after launch. Orbital Sciences (the DAWN Mission spacecraft contractor) typically requires a 24-hour wait period prior to high voltage initiation for Earth-orbiting Science and GEO spacecraft. The concern relates to the issue of corona and/or radio frequency (RF) breakdown of the TWTA ((high voltage direct current (DC) and RF)), and of the microwave components (high voltage RF) in the presence of partial atmospheric pressures or outgassing constituents. In particular, generally the diplexer and circulator are susceptible to RF breakdown in the corona region due to the presence of small physical gaps (( 2.5 millimeter (mm)) between conductors that carry an RF voltage. The NESC concurred the DAWN Mission communication system is safe for activation.

  6. The dawn and dusk electrojet response to substorm onset

    Directory of Open Access Journals (Sweden)

    E. Borälv

    Full Text Available We have investigated the time delay between substorm onset and related reactions in the dawn and dusk ionospheric electrojets, clearly separated from the nightside located substorm current wedge by several hours in MLT. We looked for substorm onsets occurring over Greenland, where the onset was identified by a LANL satellite and DMI magnetometers located on Greenland. With this setup the MARIA magnetometer network was located at dusk, monitoring the eastward electrojet, and the IMAGE chain at dawn, for the westward jet. In the first few minutes following substorm onset, sudden enhancements of the electrojets were identified by looking for rapid changes in magnetograms. These results show that the speed of information transfer between the region of onset and the dawn and dusk ionosphere is very high. A number of events where the reaction seemed to preceed the onset were explained by either unfavorable instrument locations, preventing proper onset timing, or by the inner magnetosphere's reaction to the Earthward fast flows from the near-Earth neutral line model. Case studies with ionospheric coherent (SuperDARN and incoherent (EISCAT radars have been performed to see whether a convection-induced electric field or enhanced conductivity is the main agent for the reactions in the electrojets. The results indicate an imposed electric field enhancement.

    Key words: Ionosphere (auroral ionosphere; electric fields and currents - Magnetospheric physics (storms and substorms

  7. High resolution Ceres HAMO atlas derived from Dawn FC images

    Science.gov (United States)

    Roatsch, Thomas; Kersten, Elke; Matz, Klaus-Dieter; Preusker, Frank; Scholten, Frank; Jaumann, Ralf; Raymond, Carol A.; Russell, Chris T.

    2016-04-01

    Introduction: NASA's Dawn spacecraft entered the orbit of dwarf planet Ceres in March 2015, and will characterize the geology, elemental and mineralogical composition, topography, shape, and internal structure of Ceres. One of the major goals of the mission is a global mapping of Ceres. Data: The Dawn mission was mapping Ceres in HAMO (High Altitude Mapping Orbit, 1475 km altitude) between August and October 2015. The framing camera took about 2,600 clear filter images with a resolution of about 140 m/pixel during these cycles. The images were taken with different viewing angles and different illumination conditions. We selected images from one cycle (cycle #1) for the mosaicking process to have similar viewing and illumination conditions. Very minor gaps in the coverage were filled with a few images from cycle #2. Data Processing: The first step of the processing chain towards the cartographic products is to ortho-rectify the images to the proper scale and map projec-tion type. This process requires detailed information of the Dawn orbit and attitude data and of the topography of the targets. Both, improved orientation and a high-resolution shape model, are provided by stereo processing (bundle block adjustment) of the HAMO stereo image dataset [3]. Ceres's HAMO shape model was used for the calculation of the ray intersection points while the map projection itself was done onto the reference sphere of Ceres with a radius of 470 km. The final step is the controlled mosaicking) of all images to a global mosaic of Ceres, the so-called basemap. Ceres map tiles: The Ceres atlas was produced in a scale of 1:750,000 and consists of 15 tiles that conform to the quadrangle scheme proposed by Greeley and Batson [4]. A map scale of 1:750,000 guarantees a mapping at the highest available Dawn resolution in HAMO. The individual tiles were extracted from the global mosaic and reprojected. Nomenclature: The Dawn team proposed 81 names for geological features. By international

  8. Diabetes Attitudes, Wishes and Needs second study (DAWN2™)

    DEFF Research Database (Denmark)

    Holt, Richard I G; Nicolucci, Antonio; Kovacs Burns, K

    2013-01-01

    AIMS: The second Diabetes Attitudes, Wishes and Needs (DAWN2) study sought cross-national comparisons of perceptions on healthcare provision for benchmarking and sharing of clinical practices to improve diabetes care. METHODS: In total, 4785 healthcare professionals caring for people with diabetes...... between team members and people with diabetes [56.1% (22.3-85.4%)], specialist nurse availability [63.8% (27.9-90.7%)] and psychological support [62.7% (40.6-79.6%)]. In some countries, up to one third of healthcare professionals reported not having received any formal diabetes training. Societal...

  9. Chatty, Dawn: Displacement and Dispossession in the Modern Middle East

    DEFF Research Database (Denmark)

    Mohns, Erik

    2011-01-01

    Dawn Chatty studies the kaleidoscopic diversity of Levantine societies by starting out with an examination of the regional processes of dispossession, dispersal, and forced migration in the 19th and 20th centuries. By combining a regional social history of dispersion, forced migration...... and resettlement with an anthropological account of life experiences of individual members of dispersed communities, Chatty allows the reader to inspect “how various peoples, forced to migrate into or within the Middle East, have survived, founded new communities, integrated, and generally exhibited remarkable...

  10. Attenuation Distance of Low Frequency Waves Upstream of the Pre-Dawn Bow Shock: GEOTAIL snd ISEE-3 Comparison

    Science.gov (United States)

    Sugiyama, T.; Terasawa, T.; Kawano, H.; Yamamoto, T.; Kokubun, S.; Frank, L.; Ackerson, K.; Tsurutani, B.

    1994-01-01

    This paper presents a statistical study of the spatial distribution of low frequency waves in the region upstream of the pre-dawn to dawn side bow shock using both GEOTAIL and ISEE-3 magnetometer data.

  11. Natural entrainment without dawn and dusk : The case of the European ground squirrel (Spermophilus citellus)

    NARCIS (Netherlands)

    Hut, RA; van Oort, BEH; Daan, S; Oort, Bob E.H. van

    Observational data collected in the field and in enclosures show that diurnal, burrow-dwelling European ground squirrels (Spermophilus citellus) never were above ground during twilight at dawn or at dusk. The animals emerged on average 4.02 h (SD = 0.45) after civil twilight at dawn and retreated in

  12. Natural entrainment without dawn and dusk : The case of the European ground squirrel (Spermophilus citellus)

    NARCIS (Netherlands)

    Hut, RA; van Oort, BEH; Daan, S; Oort, Bob E.H. van

    1999-01-01

    Observational data collected in the field and in enclosures show that diurnal, burrow-dwelling European ground squirrels (Spermophilus citellus) never were above ground during twilight at dawn or at dusk. The animals emerged on average 4.02 h (SD = 0.45) after civil twilight at dawn and retreated in

  13. Effect of simulated dawn on quality of sleep – a community-based trial

    Directory of Open Access Journals (Sweden)

    Haukka Jari

    2003-10-01

    Full Text Available Abstract Background Morning light exposure administered as simulated dawn looks a promising method to treat Seasonal Affective Disorder, but it may moreover help with resetting the inaccurate organisation of body clock functions relative to sleep occurring in winter among people in general. Disturbances in sleep patterns are common and may compromise wellbeing even in the short term. Our hypothesis was that simulated dawn could improve the subjective quality of sleep during winter. Methods A community-based trial with 100 volunteer subjects provided with dawn simulators. Study period lasted for eight weeks, and subjects used the dawn simulators for two weeks at a time, each subject acting as his own control (ABAB-design. Main outcome measure was subjective quality of sleep recorded each morning with Groningen Sleep Quality Scale. Results 77 subjects completed the trial. Quality of sleep improved while subjects were using dawn simulator-devices (p = 0.001. The treatment became beneficial after six days' use of dawn simulator, but the effect did not last after the use was ceased. Conclusion Dawn simulation may help to improve the subjective quality of sleep, but the benefits are modest. Further research is needed to verify these findings and to elucidate the mechanism by which dawn simulation acts on the sleep-wake pattern.

  14. Nature of the "Orange" Material on Vesta From Dawn

    Science.gov (United States)

    LeCorre, L.; Reddy, V.; Schmedemann, N.; Becker, K. J.; OBrien, D. P.; Yamashita, N.; Peplowski, P. N.; Prettyman, T. H.; Li, J.-Y.; Coultis, E. A.; hide

    2014-01-01

    From ground-based observations of Vesta, it is well-known that the vestan surface has a large variation in albedo. Analysis of images acquired by the Hubble Space Telescope allowed production of the first color maps of Vesta and showed a diverse surface in terms of reflectance. Thanks to images collected by the Dawn spacecraft at Vesta, it became obvious that these specific units observed previously can be linked to geological features. The presence of the darkest material mostly around impact craters and scattered in the Western hemisphere has been associated with carbonaceous chondrite contamination [4]; whereas the brightest materials are believed to result from exposure of unaltered material from the subsurface of Vesta (in fresh looking impact crater rims and in Rheasilvia's ejecta and rim remants). Here we focus on a distinct material characterized by a steep slope in the near-IR relative to all other kinds of materials found on Vesta. It was first detected when combining Dawn Framing Camera (FC) color images in Clementine false-color composites [5] during the Approach phase of the mission (100000 to 5200 km from Vesta). We investigate the mineralogical and elemental composition of this material and its relationship with the HEDs (Howardite-Eucrite- Diogenite group of meteorites).

  15. Offshore Wind Measurements Using Doppler Aerosol Wind Lidar (DAWN) at NASA Langley Research Center

    Science.gov (United States)

    Beyon, Jeffrey Y.; Koch, Grady J.; Kavaya, Michael J.

    2014-01-01

    The latest flight demonstration of Doppler Aerosol Wind Lidar (DAWN) at NASA Langley Research Center (LaRC) is presented. The goal of the campaign was to demonstrate the improvement of DAWN system since the previous flight campaign in 2012 and the capabilities of DAWN and the latest airborne wind profiling algorithm APOLO (Airborne Wind Profiling Algorithm for Doppler Wind Lidar) developed at LaRC. The comparisons of APOLO and another algorithm are discussed utilizing two and five line-of-sights (LOSs), respectively. Wind parameters from DAWN were compared with ground-based radar measurements for validation purposes. The campaign period was June - July in 2013 and the flight altitude was 8 km in inland toward Charlotte, NC, and offshores in Virginia Beach, VA and Ocean City, MD. The DAWN system was integrated into a UC12B with two operators onboard during the campaign.

  16. The effect of mate removal on dawn singing behaviour in male pied bush chats

    Institute of Scientific and Technical Information of China (English)

    Vinaya Kumar SETHI; Dinesh BHATT; Amit KUMAR

    2011-01-01

    To determine the influence of pairing status on dawn singing behaviour in pied bush chats Saxicola caprata, we conducted mate removal experiments across eight territories. The experiment was divided into three stages: pre-removal (pairs were present on theit respective territories), removal (females were experimentally removed), and returned (females were released into the focal pairs' territories). Dawn bout length, song rate, song complexity, percentage performance time, song perch height, and distance of singing location to territory boundary were measured for each male during each experimental stage. We did not find an effect of mate removal on any dawn song characteristics of male pied bush chats suggesting that the presence or absence of a mate does not influence male dawn singing behaviour. Our findings further suggest that males use dawn chorus to mediate social relationships with neighbouring males to proclaim an established territory.

  17. Offshore wind measurements using Doppler aerosol wind lidar (DAWN) at NASA Langley Research Center

    Science.gov (United States)

    Beyon, Jeffrey Y.; Koch, Grady J.; Kavaya, Michael J.

    2014-06-01

    The latest flight demonstration of Doppler Aerosol Wind Lidar (DAWN) at NASA Langley Research Center (LaRC) is presented. The goal of the campaign was to demonstrate the improvement of DAWN system since the previous flight campaign in 2012 and the capabilities of DAWN and the latest airborne wind profiling algorithm APOLO (Airborne Wind Profiling Algorithm for Doppler Wind Lidar) developed at LaRC. The comparisons of APOLO and another algorithm are discussed utilizing two and five line-of-sights (LOSs), respectively. Wind parameters from DAWN were compared with ground-based radar measurements for validation purposes. The campaign period was June - July in 2013 and the flight altitude was 8 km in inland toward Charlotte, NC, and offshores in Virginia Beach, VA and Ocean City, MD. The DAWN system was integrated into a UC12B with two operators onboard during the campaign.

  18. Before the dawn recovering the lost history of our ancestors

    CERN Document Server

    Wade, Nicholas

    2007-01-01

    Nicholas Wade’s articles are a major reason why the science section has become the most popular, nationwide, in the New York Times. In his groundbreaking Before the Dawn, Wade reveals humanity’s origins as never before—a journey made possible only recently by genetic science, whose incredible findings have answered such questions as: What was the first human language like? How large were the first societies, and how warlike were they? When did our ancestors first leave Africa, and by what route did they leave? By eloquently solving these and numerous other mysteries, Wade offers nothing less than a uniquely complete retelling of a story that began 500 centuries ago.

  19. Diabetes Attitudes, Wishes and Needs second study (DAWN2™)

    DEFF Research Database (Denmark)

    Nicolucci, Antonio; Kovacs Burns, K; Holt, Richard I G

    2013-01-01

    AIMS: The second Diabetes Attitudes, Wishes and Needs (DAWN2) study aimed to assess psychosocial outcomes in people with diabetes across countries for benchmarking. METHODS: Surveys included new and adapted questions from validated questionnaires that assess health-related quality of life, self......-management, attitudes/beliefs, social support and priorities for improving diabetes care. Questionnaires were conducted online, by telephone or in person. RESULTS: Participants were 8596 adults with diabetes across 17 countries. There were significant between-country differences for all benchmarking indicators; no one...... country's outcomes were consistently better or worse than others. The proportion with likely depression [WHO-5 Well-Being Index (WHO-5) score ≤ 28] was 13.8% (country range 6.5-24.1%). Diabetes-related distress [Problem Areas in Diabetes Scale 5 (PAID-5) score ≥ 40] was reported by 44.6% of participants...

  20. [Cholera update at the dawn of the millenium].

    Science.gov (United States)

    Boutin, J P; Pages, F; Migliani, R; Chaignat, C L; Ivanoff, B

    2001-01-01

    Cholera is an ancestral disease belonging to the mythology of numerous societies. In the last two centuries, seven pandemias have been recorded, in which the spatial and temporal modalities of disease transmission are related to the major technical revolutions of the period. The now ongoing seventh pandemia is by far the longest and most widespread with specific features that raise new challenges and hopes. The authors present the situation at the dawn of the third millennium based on a review of current epidemiological, clinical, therapeutic, diagnostic and vaccinal data. This update shows that the field is progressing and may indeed be standing on the verge of significant breakthroughs for management of the disease and vibrion endemicity.

  1. First observations of Ceres by VIR on Dawn mission

    Science.gov (United States)

    De Sanctis, M. Cristina; Ammannito, Eleonora; Fonte, Sergio; Magni, Gianfranco; Capaccioni, Fabrizio; Capria, M. Teresa; Raymond, Carol. A.; Russell, Christopher T.

    2015-04-01

    The Dawn spacecraft [1] is now approaching Ceres, the second of its targets. Ceres represents the key to understand some important points relative to the role of the protoplanet size and the water content in the evolution of these bodies. Ceres is thought to be differentiated, and hydrated minerals were proposed to exist on its surface [2,3,4]. Its low density [3] associated with the presence of transient water vapour, suggests a high content of ice inside the body and on its surface. Ceres seems to have been subject to differentiation and hydrothermal activity, and might host a liquid subsurface layer even today. Dawn is equipped with a Visible and InfraRed Mapping Spectrometer (VIR-MS) [5]. VIR-MS is an imaging spectrometer coupling high spectral and spatial resolution in the VIS (0.25-1 micron) and IR (0.95-5 micron) spectral ranges. The surface composition of Ceres is poorly understood through its nearly featureless visible spectrum. Its visible reflectance spectrum has a steep UV absorption edge that begins at a relatively short wavelength, around 0.4 micron, unlike many C-type asteroids where the UV drop-off begins around 0.6 to 0.7 micron[6]. The near-IR spectrum has a strong absorption band centered at about 3-micron. The absorption features in the 3-micron region were attributed to structural water in clay minerals [7,8] but could also be ammoniated clays [9]. [10] reported the discovery of carbonates and iron-rich clays from measurements of weak 3-micron features, and the results are consistent with the mid-IR spectra of clay minerals. On approach to Ceres, Dawn will obtain images and hyperspectral . VIR data, with resolution larger than Hubble images will reveal the first details of the Ceres' surface composition. Here we report about the first data obtained by VIR during its approach to Ceres. Acknowledgments VIR is funded by the Italian Space Agency-ASI and was developed under the leadership of INAF-Istituto di Astrofisica e Planetologia Spaziali, Rome

  2. Dawn FC2 Derived Ceres Mosaics V1.0

    Science.gov (United States)

    Roatsch, T.; Kersten, E.; Matz, K.-D.; Preusker, F.; Scholten, F.; Elgner, S.; Schroeder, S. E.; Jaumann, R.; Raymond, C. A.; Russell, C. T.

    2016-10-01

    This accumulating data set includes Ceres global mosaics and quadrangles derived from images acquired by the Framing Camera 2 (FC2) on the NASA Dawn spacecraft. Global mosaics are provided in cylindrical and polar stereographic projections. The quadrangle mosaics use Mercator (equatorial), Lambert conformal (mid-latitude) and stereographic projections. Global color filter mosaics are provided for data acquired during the high altitude mapping orbit (HAMO) on volume DWNCHFFC2_2. Global mapping in all filters at low altitude was not possible due to time and downlink limitations. Attempts were made to acquire color imaging of selected Ceres targets but with only limited success because of issues related to ephemeris predictability. Clear filter global mosaics and quadrangle maps are provided for both HAMO (DWNCHCFC2_2) and the low altitude mapping orbit (LAMO, DWNCLCFC2_2) science phases.

  3. Dawn Grand Map Vesta Neutron Absorption V1.0

    Science.gov (United States)

    Prettyman, T. H.

    2014-06-01

    A global map of a unitless compositional parameter, delta-C_perpendicular (DCP), and propagated 1-sigma uncertainties is provided. DCP varies linearly with the macroscopic thermal neutron absorption cross section of Vesta's regolith. An equation for converting tabulated DCP values to absorption units is provided in this document. DCP was determined from thermal and epithermal neutron counting rates measured by the NASA Dawn mission's Gamma Ray and Neutron Detector (GRaND) while in low altitude mapping orbit, about 210 km from Vesta's surface. The measurements are representative of Vesta's bulk regolith composition to depths of a few decimeters with a spatial resolution of about 300-km full-width-at-half-maximum of arc length on the surface. The methods used to determine neutron absorption are described by PRETTYMANETAL2013.

  4. The collisional history of dwarf planet Ceres revealed by Dawn

    Science.gov (United States)

    Marchi, S.; Williams, D. A.; Mest, S. C.; Schenk, P.; O'Brien, D. P.; De Sanctis, M. C.; Ermakov, A.; Castillo, J. C.; Jaumann, R.; Neesemann, A.; Hiesinger, H.; Park, R. S.; Kneissl, T.; Schmedemann, N.; Raymond, C. A.; Russell, C. T.

    2015-12-01

    Impact craters are a ubiquitous feature of solid surfaces of celestial objects. Craters are oftentimes used to constrain the past evolution of their host objects, as well as to assess their crustal structures. The Dawn spacecraft, currently in orbit around the dwarf planet Ceres, has revealed a surface peppered with impact craters. Two important facts emerge from their global spatial distribution: i) significant longitudinal and latitudinal asymmetries in the crater areal density, ii) and the lack of well-preserved craters larger than 400 km in imaging data. Interestingly, most of the low crater density terrains are found in the vicinity of the three largest, well-preserved impact craters ranging from ~160 to ~290 km in diameter. These low crater areal density terrains expand over a greater distance than observed for large craters on rocky bodies and icy satellites, which typically are confined within one crater radius from the rim. To assess the collisional history of Ceres we developed a Monte Carlo model that tracks the timing, size and number of collisions throughout the history of the solar system. The model shows that Ceres' collisional evolution should have resulted typically in a factor of 10 more craters than observed, with some ~10 craters larger than 400 km expected to have formed over the last 4.5 Gyr ago. While small craters may have reached an equilibrium level, which does not allow then to further increase in number, the lack of evident large craters is a puzzle. A possibility is that the scars of large craters have been obliterated by topography relaxation due to an ice-rich crust. Here we will present an overview of the Ceres' crater spatial distribution and compare it to other siblings (such as the asteroid Vesta), and collisional evolution models. We will also discuss how these results pose important constraints on the internal structure of the dwarf planet in conjunction with surface composition and gravity data acquired by Dawn.

  5. A new DAWN: Improving the psychosocial management of diabetes

    Directory of Open Access Journals (Sweden)

    Richard I. G. Holt

    2013-01-01

    Full Text Available Aims: The second Diabetes Attitudes, Wishes and Needs (DAWN-2 study assessed psychosocial issues and health-care provision of people with diabetes, their family members and health-care professionals. Materials and Methods: Participants completed an online, telephone or in-person survey designed to assess health-related quality-of-life, self-management, attitudes/beliefs, social support and priorities for improving diabetes care as well as health-care provision and the impact of diabetes on family life. Results: A total of 8596 adults with diabetes, 2057 family members of people with diabetes and 4785 health-care professionals across 17 countries completed the survey. There were significant between country differences, but no one country′s outcomes were consistently better or worse than others. A high proportion of people with diabetes reported likely depression (13.8% and poor quality-of-life (12.2%. Diabetes had a negative impact on many aspects of life, including relationships with family/friends and physical health. A third of family members did not know how to help the person with diabetes, but wanted to be more involved in their care. Many health-care professionals indicated that major improvements were needed across a range of areas including health-care organization, resources for diabetes prevention, earlier diagnosis and treatment and psychological support. Conclusions: DAWN-2 is a multinational, multidisciplinary systematic study that compared unmet needs of people with diabetes and those who care for them in 17 countries across four continents. Its findings should facilitate innovative efforts to improve self-management and psychosocial support in diabetes, with the aim of reducing the burden of disease. The implications for India are discussed.

  6. Analysis of Temperature Maps of Selected Dawn Data Over the Surface of Vesta

    Science.gov (United States)

    Tosi, F.; Capria, M. T.; DeSanctis, M. C.; Palomba, E.; Grassi, D.; Capaccioni, F.; Ammannito, E.; Combe, J.-Ph.; Sunshine, J. M.; McCord, T. B.; Li, Y.-Y.; Titus, T. N.; Russell, C. T.; Raymond, C. A.; Mittlefehldt, D. W.; Toplis, M. J.; Forni, O.; Sykes, M. V.

    2012-01-01

    The thermal behavior of areas of unusual albedo at the surface of Vesta can be related to physical properties that may provide some information about the origin of those materials. Dawn s Visible and Infrared Mapping Spectrometer (VIR) [1] hyperspectral cubes can be used to retrieve surface temperatures. Due to instrumental constraints, high accuracy is obtained only if temperatures are greater than 180 K. Bright and dark surface materials on Vesta are currently investigated by the Dawn team [e.g., 2 and 3 respectively]. Here we present temperature maps of several local-scale features that were observed by Dawn under different illumination conditions and different local solar times.

  7. Comparing Dawn, Hubble Space Telescope, and Ground-Based Interpretations of (4) Vesta

    CERN Document Server

    Reddy, Vishnu; Corre, Lucille Le; Scully, Jennifer E C; Gaskell, Robert; Russell, Christopher T; Park, Ryan S; Nathues, Andreas; Raymond, Carol; Gaffey, Michael J; Sierks, Holger; Becker, Kris J; McFadden, Lucy A

    2013-01-01

    Observations of asteroid 4 Vesta by NASA's Dawn spacecraft are interesting because its surface has the largest range of albedo, color and composition of any other asteroid visited by spacecraft to date. These hemispherical and rotational variations in surface brightness and composition have been attributed to impact processes since Vesta's formation. Prior to Dawn's arrival at Vesta, its surface properties were the focus of intense telescopic investigations for nearly a hundred years. Ground-based photometric and spectroscopic observations first revealed these variations followed later by those using Hubble Space Telescope. Here we compare interpretations of Vesta's rotation period, pole, albedo, topographic, color, and compositional properties from ground-based telescopes and HST with those from Dawn. Rotational spectral variations observed from ground-based studies are also consistent with those observed by Dawn. While the interpretation of some of these features was tenuous from past data, the interpretati...

  8. Simulation of the dawn-dusk magnetosheath asymmetry under quasi-steady states

    Institute of Scientific and Technical Information of China (English)

    GUO Jiuling; LIU Zhenxing

    2005-01-01

    The dawn-dusk asymmetry of the magnetosheath under quasi-steady states has been studied by using a newly developed 3D MHD magnetosphere simulation model. The results show that the dawn-dusk asymmetry is substantial because of the Parker spiral IMF. It is found that the dawn-dusk magnetosheath thickness asymmetry is the effect of different shock conditions. The plasma density and flux asymmetry are mainly caused by the different thickness of the dawn-dusk magnetosheath, and the magnetic reconnection on the magnetopause has no significant effects. It is also showed that the Plasma Depletion Layer in front of the dayside magnetopause can cause duskward plasma flow, and the total plasma flux on the dusk side will be higher.

  9. Understanding Spacecraft Agility for Orbit Transfers on the Dawn Low-thrust Mission

    Science.gov (United States)

    Smith, Brett A.; Vanelli, C. Anthony; Lee, Allan Y.

    2012-01-01

    Conventional maneuver design processes were inadequate. Long thrusting durations with the small force of SEP. Increased coupling between ACS and NAV teams. Definition of quantifiable constraints proved impractical. Specifically for the Dawn mission, because of the attitude steering algorithm. A time-efficient simulation tool, qSTAT, was developed and allowed fast verification of candidate thrust profile designs. This approach allowed Dawn to overcome the complications of low-thrust orbit transfers.

  10. The dawn of the third renaissance in surgery.

    Science.gov (United States)

    Hackam, David J

    2015-08-01

    In this presidential address, I will share my belief that our proud and noble field stands at the dawn of a great renaissance. I further believe that this is the third such renaissance that has occurred in surgery. As described herein, the first renaissance in surgery occurred during the 1600s, which involved a transformation in operative care unlike anything that had been seen since Roman times. This first renaissance was triggered by tumultuous world events but was spurred on by the invention of the printing press. The second renaissance occurred during the 1980s and was triggered by the invention of the computer, which is of equal significance to the printing press 240 years earlier. I believe that this third renaissance shares with the earlier renaissances its transformative nature and its reaction to turmoil, both in the medical and nonmedical worlds. This is a renaissance driven by science, by creativity, and by innovation—resources that are never in short supply within our great profession. Copyright © 2015. Published by Elsevier Inc.

  11. Technologies for Low Frequency Radio Observations of the Cosmic Dawn

    Science.gov (United States)

    Jones, Dayton L.

    2014-01-01

    The Jet Propulsion Laboratory (JPL) is developing concepts and technologies for low frequency radio astronomy space missions aimed at observing highly redshifted neutral Hydrogen from the Dark Ages. This is the period of cosmic history between the recombination epoch when the microwave background radiation was produced and the re-ionization of the intergalactic medium by the first generation of stars (Cosmic Dawn). This period, at redshifts greater than about 20, is a critical epoch for the formation and evolution of large-scale structure in the universe. The 21-cm spectral line of Hydrogen provides the most promising method for directly studying the Dark Ages, but the corresponding frequencies at such large redshifts are only tens of MHz and thus require space-based observations to avoid terrestrial RFI and ionospheric absorption and refraction. This paper reports on the status of several low frequency technology development activities at JPL, including deployable bi-conical dipoles for a planned lunar-orbiting mission, and both rover-deployed and inflation-deployed long dipole antennas for use on the lunar surface.

  12. ORIGIN: Metal Creation and Evolution from the Cosmic Dawn

    CERN Document Server

    den Herder, J.W.; Ohashi, T.; Kouveliotou, C.; Hartmann, D.H.; Kaastra, J.S.; Amati, L.; Andersen, M.; Arnaud, M.; Atteia, J-L.; Bandler, S.; Barbera, M.; Barcons, X.; Barthelmy, S.; Basa, S.; Basso, S.; Boer, M.; Branchini, E.; Branduardi-Raymont, G.; Borgani, S.; Boyarski, O.; Brunetti, G.; Budtz-Jorgensen, C.; Burrows, D.; Butler, N.; Campana, S.; Caroli, E.; Ceballos, M.; Christensen, F.; Churazov, E.; Comastri, A.; Colasanti, L.; Cole, R.; Content, R.; Corsi, A.; Costantini, E.; Conconi, P.; Cusumano, G.; de Plaa, J.; De Rosa, A.; Del Santo, M.; Di Cosimo, S.; De Pasquale, M.; Doriese, R.; Ettori, S.; Evans, P.; Ezoe, Y.; Ferrari, L.; Finger, H.; Figueroa-Feliciano, T.; Friedrich, P.; Fujimoto, R.; Furuzawa, A.; Fynbo, J.; Gatti, F.; Galeazzi, M.; Gehrels, N.; Gendre, B.; Ghirlanda, G.; Ghisellini, G.; Gilfanov, M.; Giommi, P.; Girardi, M.; Grindlay, J.; Cocchi, M.; Godet, O.; Guedel, M.; Haardt, F.; Hartog, R.den; Hepburn, I.; Hermsen, W.; Hjorth, J.; Hoekstra, H.; Holland, A.; Hornstrup, A.; van der Horst, A.; Hoshino, A.; Zand, J.in 't; Irwin, K.; Ishisaki, Y.; Jonker, P.; Kitayama, T.; Kawahara, H.; Kawai, N.; Kelley, R.; Kilbourne, C.; de Korte, P.; Kusenko, A.; Kuvvetli, I.; Labanti, M.; Macculi, C.; Maiolino, R.; Hesse, M.Mas; Matsushita, K.; Mazzotta, P.; McCammon, D.; Mendez, M.; Mignani, R.; Mineo, T.; Mitsuda, K.; Mushotzky, R.; Molendi, S.; Moscardini, L.; Natalucci, L.; Nicastro, F.; O'Brien, P.; Osborne, J.; Paerels, F.; Page, M.; Paltani, S.; de Pasquale, M.; Pedersen, K.; Perinati, E.; Ponman, T.; Pointecouteau, E.; Predehl, P.; Porter, S.; Rasmussen, A.; Rauw, G.; Rottgering, H.; Roncarelli, M.; Rosati, P.; Quadrini, E.; Ruchayskiy, O.; Salvaterra, R.; Sasaki, S.; Sato, K.; Savaglio, S.; Schaye, J.; Sciortino, S.; Shaposhnikov, M.; Sharples, R.; Shinozaki, K.; Spiga, D.; Sunyaev, R.; Suto, Y.; Takei, Y.; Tanvir, N.; Tashiro, M.; Tamura, T.; Tawara, Y.; Troja, E.; Tsujimoto, M.; Tsuru, T.; Ubertini, P.; Ullom, J.; Ursino, E.; Verbunt, F.; van de Voort, F.; Viel, M.; Wachter, S.; Watson, D.; Weisskopf, M.; Werner, N.; White, N.; Willingale, R.; Wijers, R.; Yamasaki, N.; Yoshikawa, K.; Zane, S.

    2011-01-01

    ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to identify the physical conditions of all abundant elements between C and Ni to red-shifts of z=10, and beyond. The mission will answer questions such as: When were the first metals created? How does the cosmic metal content evolve? Where do most of the metals reside in the Universe? What is the role of metals in structure formation and evolution? To reach out to the early Universe ORIGIN will use Gamma-Ray Bursts (GRBs) to study their local environments in their host galaxies. This requires the capability to slew the satellite in less than a minute to the GRB location. By studying the chemical composition and properties of clusters of galaxies we can extend the range of exploration to lower redshifts (z ~ 0.2). For this task we need a high-resolution spectral imaging instrument with a large field of view. Using the ...

  13. Bacterial targeted tumour therapy-dawn of a new era.

    Science.gov (United States)

    Wei, Ming Q; Mengesha, Asferd; Good, David; Anné, Jozef

    2008-01-18

    Original observation of patients' spontaneous recovery from advanced tumours after an infection or a "fever" inspired extensive research. As a result, Coley's toxin for the therapy of sarcomas and live Bacillus Calmette-Guerin (BCG) for bladder cancer were born. In addition, three genera of anaerobic bacteria have been shown to specifically and preferentially target solid tumours and cause significant tumour lyses. Initial research had focused on determining the best tumour colonizing bacteria, and assessing the therapeutic efficacy of different strategies either as a single or combination treatment modalities. However, although clinical trials were carried out as early as the 1960s, lack of complete tumour lyses with injection of Clostridial spores had limited their further use. Recent progress in the field has highlighted the rapid development of new tools for genetic manipulation of Clostridia which have otherwise been a hurdle for a long time, such as plasmid transformation using electroporation that bore the problems of inefficiency, instability and plasmid loss. A new Clostridium strain, C. novyi-NT made apathogenic by genetic modification, is under clinical trials. New genetic engineering tools, such as the group II intron has shown promise for genetic manipulation of bacteria and forecast the dawn of a new era for a tumour-targeted bacterial vector system for gene therapy of solid tumours. In this review we will discuss the potential of genetically manipulated bacteria that will usher in the new era of bacterial therapy for solid tumours, and highlight strategies and tools used to improve the bacterial oncolytic capability.

  14. DAWN'S Operations in Cruise from Vesta to Ceres

    Science.gov (United States)

    Rayman, Marc D.; Mase, Robert A.

    2013-01-01

    On 5 September 2012, Dawn concluded its successful exploration of Vesta, the second most massive object in the main asteroid belt. The spacecraft departed after 14 months in orbit and is now using its ion propulsion system to travel to dwarf planet Ceres, the most massive main-belt asteroid. The principal activity now is thrusting with the ion propulsion system to provide the 3.4 km/s required to rendezvous with Ceres early in 2015. Because two of the four reaction wheels have experienced faults and are likely unrecoverable, a substantial effort has been invested in preparing for Ceres operations with alternate attitude control methods. The project has engaged in an intensive campaign to reduce hydrazine expenditures, which has resulted in a significant increase in the hydrazine expected to be available for Ceres. Based on this work, studies provide good confidence that the required activities at Ceres can be completed. This paper describes post-Vesta operations, including measures taken to conserve hydrazine as well as other preparations for Ceres.

  15. Does Vesta Have Moons?: Dawn's Search for Satellites

    Science.gov (United States)

    McFadden, L. A.; Sykes, M. V.; Tricarico, P.; Carsenty, U.; Gutierrez-Marques, P.; Jacobson, R. A.; Joy, S.; Keller, H. U.; Li, J.-Y.; McLean, B.; Memarsadeghi, N.; Mottola, S.; Mutchler, M.; Nathues, A.; OBrien, D.; Palmer, E.; Polanskey, C.; Sierks, H.; Rayman, M. D.; Raymond, C. A.; Russell, C. T.; Schroeder, S.; Skillman, D.; Weinstein-Weiss, S.

    2011-01-01

    Upon approach to asteroid 4 Vesta, the Dawn mission included a dedicated satellite search observation of the operational sphere of the spacecraft around Vesta. Discovery of moons of Vesta would constrain theories of satellite f()rmation. The sequence using the framing camera and clear filter includes three mosaics of six stations acquired on July 9-10. 2011. Each station consists of four sets with three different exposures, 1.5,20 and 270 s. We also processed and scanned the optical navigation sequences until Vesta filled the field of view. Analysis of images involves looking for moving objects in the mosaics and identifying catalogued stars, subtracting them from the image and examining residual objects for evidence of bodies in orbit around Vesta. Celestial coordinates were determined using Astrometry.net, an astrometry calibration service (http://astrometry.net/use.html). We processed the images by subtracting dark and bias fields and dividing by a Hatfield. Images were further filtered subtracting a box car filter (9x9 average) to remove effects of scattered light from Vesta itself. Images were scanned by eye for evidence of motion in directions different from the background stars. All objects were compared with Hubble Space Telescope's Guide Star Catalogue and US Naval Observatory's UCAC3 catalog. We report findings from these observations and analysis, including limits of magnitude, size and motion of objects in orbit around Vesta. We gratefully acknowledge modifications made to Astrometrica http://www.astrometrica.at/ for purposes of this effort.

  16. Red Dawn – the final episode of the Cold war

    Directory of Open Access Journals (Sweden)

    Ivan Kovačević

    2016-02-01

    Full Text Available In the period of renewal of the Cold war, after 1980, movies which abandon the idea of the dentate appear, and they represent the response to Soviet expansion taking place under the auspices of diminished military confrontation. Of course, the Hollywood reaction to the real expansion of communism was not at adequate response, but it is a part of the wider restructuring of American politics regarding the Soviet Union, which was evidenced by strengthening defenses through the Strategic Defense Initiative (SDI, forcible intervention in Grenada, helping anti-communist movements around the world etc. In opposition to part of the US political scene which shut down attempts to stop the spread of communism across the world, action through popular culture, especially film, created a new climate in which multifaceted pressures on the socialist block were prepared. The movie Red Dawn can be considered part of the reaction of US politics on the particularistic view of the dentate as a shield for military and political spread of the USSR in Africa and other parts of the world. This pressure played on the inherent weaknesses of Soviet society in the 1980’s, a society which, after a brief period of failed transformation fell apart at the start of the final decade of the 20th century.

  17. Energetic particles in the pre-dawn magnetotail of Jupiter

    Science.gov (United States)

    Schardt, A. W.; Mcdonald, F. B.; Trainor, J. H.

    1980-01-01

    A detailed account is given of the energetic electron and proton populations as observed with Voyagers 1 and 2 during their passes through the dawn magnetotail of Jupiter. The region between 20 and 150 R sub J is dominated by a thin plasma sheet, where trapped energetic electron and proton fluxes reach their maximum. Proton spectra can be represented by an exponential in rigidity with a characteristic energy of approximately 50 keV. Proton anisotropies were consistent with corotation even at 100 R sub J. A major proton acceleration event as well as several cases of field aligned proton streaming were observed. The flux of 0.4 MeV protons decreases by three orders of magnitude between 30 and 90 R sub J and then remains relatively constant to the magnetopause. Fine structure in the data indicate longitudinal asymmetries with respect to the dipole orientation. Electron spectra in the magnetosheath and interplanetary space are modulated by the Jovian longitude relative to the subsolar point.

  18. Evolution of asteroid (4) Vesta in the light of Dawn

    Science.gov (United States)

    Thangjam, Guneshwar; Mengel, Kurt; Nathues, Andreas; Schmidt, Kai H.; Hoffmann, Martin

    2016-04-01

    Asteroid (4) Vesta has been visited by the NASA Dawn spacecraft in 2011/12. The combination of compositional/elemental information from the three onboard instruments with mineralogical information from the howardite-eucrite-diogenite (HED) clan of stony achondrites has shed new light on the surface lithologic heterogeneity and the early evolution. Although petrologic/chemical models have tried to unravel the evolutionary processes, inconsistencies exist for some chemical major element/phase [e.g., 1, 2]. A revised evolutionary model is presented here [3]. The three oxygen isotope signature of HEDs and, thus, of proto-Vesta is best met by a mixture of 80% ordinary plus 20 % CV chondrites. Assuming a 27Al-triggered magma ocean within the first MA after accretion and taking into account the reliable major element data of the silicate fraction of the chondritic mixture results a crystallization sequence that differs from the earlier models [1, 2, 3]. The crystallized phase obtained by 'MELTS' software [4] starts with olivine and continues with minor olivine plus orthopyroxene until the liquid reaches a Kd value (partition coefficient) of 0.31 where the fractionated melt is in equilibrium with the residual liquid [5]. The abundance of minerals and rocks formed in this model are converted in volume proportions assuming a spherical shape of early Vesta (262 km radius) with a core (FeNi, FeNiS) radius of 110 km [6]. Two scenarios are considered to describe the early bulk silicate Vesta. First, the early-crystallized olivine accumulated at the base of the silicate shell is accounted for a dunitic lower mantle having a thickness of 46 km while the later crystallized phases form an orthopyroxenitic upper mantle and a crust of thickness 84 and 22 km, respectively. Second, an olivine-rich lower mantle that gradually changes to orthopyroxene-rich upper mantle is expected having an overall shell thickness of 137 km, with a 15 km thick crust. An important result is that the deep

  19. Cluster observations of surface waves on the dawn flank magnetopause

    Directory of Open Access Journals (Sweden)

    C. J. Owen

    2004-03-01

    Full Text Available On 14 June 2001 the four Cluster spacecraft recorded multiple encounters of the dawn-side flank magnetopause. The characteristics of the observed electron populations varied between a cold, dense magnetosheath population and warmer, more rarified boundary layer population on a quasi-periodic basis. The demarcation between these two populations can be readily identified by gradients in the scalar temperature of the electrons. An analysis of the differences in the observed timings of the boundary at each spacecraft indicates that these magnetopause crossings are consistent with a surface wave moving across the flank magnetopause. When compared to the orientation of the magnetopause expected from models, we find that the leading edges of these waves are approximately 45° steeper than the trailing edges, consistent with the Kelvin-Helmholtz (KH driving mechanism. A stability analysis of this interval suggests that the magnetopause is marginally stable to this mechanism during this event. Periods in which the analysis predicts that the magnetopause is unstable correspond to observations of greater wave steepening. Analysis of the pulses suggests that the waves have an average wavelength of approximately 3.4 RE and move at an average speed of ~65km s-1 in an anti-sunward and northward direction, despite the spacecraft location somewhat south of the GSE Z=0 plane. This wave propagation direction lies close to perpendicular to the average magnetic field direction in the external magnetosheath, suggesting that these waves may preferentially propagate in the direction that requires no bending of these external field lines

    Key words. Magnetospheric physics (magnetospheric configuration and dynamics; MHD waves and unstabilities; solar wind-magnetosphere interactions

  20. Ceres' Yellow Spots - Observations with Dawn Framing Camera

    Science.gov (United States)

    Schäfer, Michael; Schäfer, Tanja; Cloutis, Edward A.; Izawa, Matthew R. M.; Platz, Thomas; Castillo-Rogez, Julie C.; Hoffmann, Martin; Thangjam, Guneshwar S.; Kneissl, Thomas; Nathues, Andreas; Mengel, Kurt; Williams, David A.; Kallisch, Jan; Ripken, Joachim; Russell, Christopher T.

    2016-04-01

    The Framing Camera (FC) onboard the Dawn spacecraft acquired several spectral data sets of (1) Ceres with increasing spatial resolution (up to 135 m/pixel with nearly global coverage). The FC is equipped with seven color filters (0.4-1.0 μm) plus one panchromatic ('clear') filter [1]. We produced spectral mosaics using photometrically corrected FC color filter images as described in [2]. Even early FC color mosaics obtained during Dawn's approach unexpectedly exhibited quite a diversity of surface materials on Ceres. Besides the ordinary cerean surface material, potentially composed of ammoniated phyllosilicates [3] or some other alteration product of carbonaceous chondrites [4], a large number of bright spots were found on Ceres [5]. These spots are substantially brighter than the average surface (exceeding its triple standard deviation), with the spots within Occator crater being the brightest and most prominent examples (reflectance more than 10 times the average of Ceres). We observed bright spots which are different by their obvious yellow color. This yellow color appears both in a 'true color' RGB display (R=0.65, G=0.55, B=0.44 μm) as well as in a false color display (R=0.97, G=0.75, B=0.44 μm) using a linear 2% stretch. Their spectra show a steep red slope between 0.44 and 0.55 μm (UV drop-off). On the contrary to these yellow spots, the vast majority of bright spots appears white in the aforementioned color displays and exhibit blue sloped spectra, except for a shallow UV drop-off. Thus, yellow spots are easily distinguishable from white spots and the remaining cerean surface by their high values in the ratio 0.55/0.44 μm. We found 8 occurrences of yellow spots on Ceres. Most of them (>70 individual spots) occur both inside and outside crater Dantu, where white spots are also found in the immediate vicinity. Besides Dantu, further occurrences with only a few yellow spots were found at craters Ikapati and Gaue. Less definite occurrences are found at 97

  1. Orbit Transfers for Dawn's Vesta Operations : Navigation and Mission Design Experience

    Science.gov (United States)

    Han, Dongsuk

    2012-01-01

    Dawn, a mission belonging to NASA's Discovery Program, was launched on September 27, 2007 to explore main belt asteroids in order to yield insights into important questions about the formation and evolution of the solar system. From July of 2011 to August of 2012, the Dawn spacecraft successfully returned valuable science data, collected during the four planned mapping orbits at its first target asteroid, Vesta. Each mapping orbit was designed to enable a different set of scientific observations. Such a mission would have been impossible without the low thrust ion propulsion system (IPS). Maneuvering a spacecraft using only the IPS for the transfers between the mapping orbits posed many technical challenges to Dawn's flight team at NASA's Jet Propulsion Laboratory. Each transfer needs a robust plan that accounts for uncertainties in maneuver execution, orbit determination, and physical characteristics of Vesta. This paper discusses the mission design and navigational experience during Dawn's Vesta operations. Topics include requirements and constraints from Dawn's science and spacecraft teams, orbit determination and maneuver design and building process for transfers, developing timelines for thrust sequence build cycles, and the process of scheduling very demanding coverage with ground antennae at NASA's Deep Space Network.

  2. Dawn Orbit Determination Team: Trajectory and Gravity Prediction Performance During Vesta Science Phases

    Science.gov (United States)

    Kennedy, Brian; Abrahamson, Matt; Ardito, Alessandro; Han, Dongsuk; Haw, Robert; Mastrodemos, Nicholas; Nandi, Sumita; Park, Ryan; Rush, Brian; Vaughan, Andrew

    2013-01-01

    The Dawn spacecraft was launched on September 27th, 2007. Its mission is to consecutively rendezvous with and observe the two largest bodies in the asteroid belt, Vesta and Ceres. It has already completed over a year's worth of direct observations of Vesta (spanning from early 2011 through late 2012) and is currently on a cruise trajectory to Ceres, where it will begin scientific observations in mid-2015. Achieving this data collection required careful planning and execution from all spacecraft teams. Dawn's Orbit Determination (OD) team was tasked with accurately predicting the trajectory of the Dawn spacecraft during the Vesta science phases, and also determining the parameters of Vesta to support future science orbit design. The future orbits included the upcoming science phase orbits as well as the transfer orbits between science phases. In all, five science phases were executed at Vesta, and this paper will describe some of the OD team contributions to the planning and execution of those phases.

  3. High-resolution Ceres High Altitude Mapping Orbit atlas derived from Dawn Framing Camera images

    Science.gov (United States)

    Roatsch, Th.; Kersten, E.; Matz, K.-D.; Preusker, F.; Scholten, F.; Jaumann, R.; Raymond, C. A.; Russell, C. T.

    2016-09-01

    The Dawn spacecraft Framing Camera (FC) acquired over 2400 clear filter images of Ceres with a resolution of about 140 m/pixel during the six cycles in the High Altitude Mapping Orbit (HAMO) phase between August 18 and October 21, 2015. We ortho-rectified the images from the first cycle and produced a global, high-resolution, controlled photomosaic of Ceres. This global mosaic is the basis for a high-resolution Ceres atlas that consists of 15 tiles mapped at a scale of 1:750,000. The nomenclature used in this atlas was proposed by the Dawn team and was approved by the International Astronomical Union (IAU). The full atlas is available to the public through the Dawn Geographical Information System (GIS) web page

  4. Singing in the moonlight: dawn song performance of a diurnal bird varies with lunar phase

    Science.gov (United States)

    York, Jennifer E.; Young, Andrew J.; Radford, Andrew N.

    2014-01-01

    It is well established that the lunar cycle can affect the behaviour of nocturnal animals, but its potential to have a similar influence on diurnal species has received less research attention. Here, we demonstrate that the dawn song of a cooperative songbird, the white-browed sparrow weaver (Plocepasser mahali), varies with moon phase. When the moon was above the horizon at dawn, males began singing on average 10 min earlier, if there was a full moon compared with a new moon, resulting in a 67% mean increase in performance period and greater total song output. The lack of a difference between full and new moon dawns when the moon was below the horizon suggests that the observed effects were driven by light intensity, rather than driven by other factors associated with moon phase. Effects of the lunar cycle on twilight signalling behaviour have implications for both pure and applied animal communication research. PMID:24429683

  5. Dawn Orbit Determination Team: Trajectory and Gravity Prediction Performance During Vesta Science Phases

    Science.gov (United States)

    Kennedy, Brian; Abrahamson, Matt; Ardito, Alessandro; Han, Dongsuk; Haw, Robert; Mastrodemos, Nicholas; Nandi, Sumita; Park, Ryan; Rush, Brian; Vaughan, Andrew

    2013-01-01

    The Dawn spacecraft was launched on September 27th, 2007. Its mission is to consecutively rendezvous with and observe the two largest bodies in the asteroid belt, Vesta and Ceres. It has already completed over a year's worth of direct observations of Vesta (spanning from early 2011 through late 2012) and is currently on a cruise trajectory to Ceres, where it will begin scientific observations in mid-2015. Achieving this data collection required careful planning and execution from all spacecraft teams. Dawn's Orbit Determination (OD) team was tasked with accurately predicting the trajectory of the Dawn spacecraft during the Vesta science phases, and also determining the parameters of Vesta to support future science orbit design. The future orbits included the upcoming science phase orbits as well as the transfer orbits between science phases. In all, five science phases were executed at Vesta, and this paper will describe some of the OD team contributions to the planning and execution of those phases.

  6. Dawning Nebulae: A PetaFLOPS Supercomputer with a Heterogeneous Structure

    Institute of Scientific and Technical Information of China (English)

    Ning-Hui Sun; Jing Xing; Zhi-Gang Huo; Guang-Ming Tan; Jin Xiong; Bo Li; Can Ma

    2011-01-01

    Dawning Nebulae is a heterogeneous system composed of 9280 multi-core x86 CPUs and 4640 NVIDIA Fermi GPUs. With a Linpack performance of 1.271 petaFLOPS, it was ranked the second in the TOP500 List released in June 2010. In this paper, key issues in the system design of Dawning Nebulae are introduced. System tuning methodologies aiming at petaFLOPS Linpack result are presented, including algorithmic optimization and communication improvement. The design of its file I/O subsystem, including HVFS and the underlying DCFS3, is also described. Performance evaluations show that the Linpack efficiency of each node reaches 69.89%, and 1024-node aggregate read and write bandwidths exceed 100 GB/s and 70 GB/s respectively. The success of Dawning Nebulae has demonstrated the viability of CPU/GPU heterogeneous structure for future designs of supercomputers.

  7. The correlation of dawn phenomenon with glycemic variability parameters in type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Roman Gabriela

    2016-03-01

    Full Text Available Introduction. Dawn phenomenon could have deleterious effect on overall glycemic control. Glycemic variability may be an independent risk factor for the development of diabetes chronic complications. The study aimed to evaluate any correlations between the dawn phenomenon and parameters of glycemic variability in a cohort of type 2 diabetes patients (T2DM. Material and methods. This retrospective observational study included 131 T2DM patients. Continuous glucose monitoring (CGM has been performed. Data from the first 24h of full recording were used for analysis of glycemic variability indices: mean level of 24h interstitial glucose value and standard deviation; % coefficient of variation; J index; mean amplitude of glycemic excursion - MAGE; continuous overall net glycemic action (CONGA at 1, 2, 4 and 6 hours; mean of daily differences (MODD index. Results. Mean age was 56.04 ± 9.91 years, 35.9% women, 17.6% on diet, 53.4% on oral therapy and 29% on insulin. Dawn phenomenon was more frequent in patients below 60 years (70% and in oral therapy group (72.85%. Significant correlations between the dawn phenomenon and j-index, MAGE, CONGA-4 and CONGA-6 have been found in T2DM patients on diet therapy alone. The amplitude of dawn phenomenon was 46.10 ± 24.40 mg/dl and significantly correlated (p<0.05 after adjustment for age, gender and treatment with % CV, MAGE, CONGA-1, CONGA-2, CONGA-4, CONGA-6 and MODD. Conclusions. The dawn phenomenon significantly increases the glycemic variability parameters in drug-naive T2DM patients, with no impact in T2DM on oral or insulin therapy.

  8. Dawn chorus variation in East-Asian tropical montane forest birds and its ecological and morphological correlates

    NARCIS (Netherlands)

    Chen, W.-M.; Lee, Y.-F.; Tsai, C.-F.; Yao, C.-T.; Chen, Y.-H.; Li, S.-H.; Kuo, Y.-M.

    2015-01-01

    Many birds in breeding seasons engage in vigorous dawn singing that often turns to a prominent chorus. We examined dawn chorus variation of avian assemblages in a tropical montane forest in Taiwan and tested the hypothesis that onset sequence is affected by eye sizes, foraging heights, and diet of b

  9. ISIS Cartographic Tools for the Dawn Framing Camera and Visual and Infrared Spectrometer

    Science.gov (United States)

    Anderson, J.; Becker, K. J.; Titus, T. N.; De sanctis, M.; Nathues, A.; Tosi, F.; Schroeder, S.; Le Corre, L.; Kelley, M. S.; Raymond, C. A.; Russell, C. T.

    2011-12-01

    Launched in September 2007, the Dawn spacecraft houses two imaging instruments: the framing camera (FC) and the Visual and Infrared Spectrometer (VIR) [1]. The spacecraft began orbiting asteroid 4 Vesta in July 2011 and over the course of one year will systematically map the body with both instruments. Camera model software and Dawn FC and VIR readers have been developed in the USGS Integrated Software for Imager and Spectrometers (ISIS) [2]. The readers, "dawnfc2isis" and "dawnvir2isis", convert both Planetary Data System (PDS) raw Experiment Data Records (EDRs) and calibrated Reduced Data Records (RDRs) into the native ISIS3 cube format. The ISIS camera models allow for orthorectification of the Vesta FC and VIR cubes to a variety of cartographic map projections using the long-standing "cam2map" application. Other standard tools such as "qview" for visualization and photometric processing applications (e.g.,"photomet" and "phocube") are available for use because of the integration of the new readers and camera models into ISIS [3]. These tools for Dawn cartographic and scientific analysis of Dawn data will be available for download in the October 2011 release of ISIS. The software release is timely as the Dawn image EDR data will be publicly released to the science community by the PDS within 90 days after each acquisition phase. Therefore, raw Vesta approach images will be available in November 2011. Raw images for other acquisition phases including survey, high altitude (HAMO) and low altitude (LAMO) mapping orbits will be delivered throughout 2012 [4]. Currently, there are no plans to include radiometric processing software for FC or VIR into ISIS. However, radiometrically calibrated PDS images (RDRs) will be publicly released six months after Vesta departure. [1] Russell, C.T., et al. (2007) Exploring the asteroid belt with ion propulsion: Dawn mission history, status and plans, Advances in Space Research, Volume 40, Issue 2, pages 193-201. [2] Anderson, J

  10. In-Flight Operation of the Dawn Ion Propulsion System - The First Nine Months

    Science.gov (United States)

    Garner, Charles E.; Brophy, John R.; Mikes, Steven C.; Raymond, Marc D.

    2008-01-01

    The Dawn mission, part of NASA's Discovery Program, has as its goal the scientific exploration of the two most massive main-belt asteroids, Vesta and Ceres. The Dawn spacecraft was launched from Cape Canaveral Air Force Station on September 27, 2007 on a Delta-II 7925H-9.5 (Delta-II Heavy) rocket that placed the 1218 kg spacecraft into an Earth-escape trajectory. On-board the spacecraft is an ion propulsion system (IPS) which will provide most of the delta-V needed for heliocentric transfer to Vesta, orbit capture at Vesta, transfer to Vesta science orbits, departure and escape from Vesta, heliocentric transfer to Ceres, orbit capture at Ceres, and transfer to Ceres science orbits. The Dawn ion engine design is based on the design validated on NASA's Deep Space 1 mission. However, because of the very substantial (11 km/s) delta-V requirements for this mission Dawn requires two engines to complete its mission objectives. The power processor units (PPU), digital control and interface units (DCIU) slice boards and the xenon control assembly (XCA) are also based on the DS1 design. The DCIUs and thrust gimbal assemblies (TGA) were developed at the Jet Propulsion Laboratory. The spacecraft was provided by Orbital Sciences Corporation, Sterling, Virginia, and the mission is managed by and operated from the Jet Propulsion Laboratory. Dawn partnered with Germany, Italy and Los Alamos National Laboratory for the science instruments. The mission is led by the principal investigator, Dr. Christopher Russell, from the University of California, Los Angeles. The first 80 days after launch were dedicated to the initial checkout of the spacecraft prior to the initiation of long-term thrusting for the heliocentric transfer to Vesta. The IPS hardware, consisting of three ion thrusters and TGAs, two PPUs and DCIUs, xenon feed system, and spacecraft control software, was investigated extensively. Thrust measurements, roll torque measurements, pointing capabilities, control

  11. Frequency and Severity of the Dawn Phenomenon in Type 2 Diabetes

    Science.gov (United States)

    Monnier, Louis; Colette, Claude; Sardinoux, Mathieu; Baptista, Gregory; Regnier-Zerbib, Alyne; Owens, David

    2012-01-01

    OBJECTIVE To know whether age has an independent effect on the dawn phenomenon in noninsulin-using type 2 diabetes. RESEARCH DESIGN AND METHODS Eighty-one individuals with type 2 diabetes were matched for HbA1c and divided by age into three subgroups of 27 individuals (1: ≥70 years; 2: 60–69 years; and 3: ≤59 years). All underwent ambulatory continuous glucose monitoring for quantifying the dawn phenomenon (i.e., the absolute [∂G, mg/dL] or relative [∂G%] increments from nocturnal nadirs to prebreakfast time points). RESULTS HbA1c levels and 24-h glycemic profiles were similar across the three groups. Glucose increments (mean ± SEM) were identical in the three groups: ∂G (mg/dL), 22.0 ± 4.7 (1), 21.3 ± 3.6 (2), and 18.0 ± 3.6 (3) and δG (%), 19.9 ± 4.9 (1), 21.6 ± 4.4 (2), and 17.6 ± 4.2 (3). Using the most common definition (∂G >10 mg/dL), the prevalence of the dawn phenomenon was 52, 70, and 59% in groups 1, 2, and 3, respectively. CONCLUSIONS The dawn phenomenon is present in the elderly. PMID:22991448

  12. Dawn-dusk asymmetries in rotating magnetospheres: Lessons from modeling Saturn

    Science.gov (United States)

    Jia, Xianzhe; Kivelson, Margaret G.

    2016-02-01

    Spacecraft measurements reveal perplexing dawn-dusk asymmetries of field and plasma properties in the magnetospheres of Saturn and Jupiter. Here we describe a previously unrecognized source of dawn-dusk asymmetry in a rapidly rotating magnetosphere. We analyze two magnetohydrodynamic simulations, focusing on how flows along and across the field vary with local time in Saturn's dayside magnetosphere. As plasma rotates from dawn to noon on a dipolarizing flux tube, it flows away from the equator along the flux tube at roughly half of the sound speed (Cs), the maximum speed at which a bulk plasma can flow along a flux tube into a lower pressure region. As plasma rotates from noon to dusk on a stretching flux tube, the field-aligned component of its centripetal acceleration decreases and it flows back toward the equator at speeds typically smaller than 1/2 Cs. Correspondingly, the plasma sheet remains far thicker and the field less stretched in the afternoon than in the morning. Different radial force balance in the morning and afternoon sectors produce asymmetry in the plasma sheet thickness and a net dusk-to-dawn flow inside of L = 15 or equivalently, a large-scale electric field (E) oriented from postnoon to premidnight, as reported from observations. Morning-afternoon asymmetry analogous to that found at Saturn has been observed at Jupiter, and a noon-midnight component of E cannot be ruled out.

  13. 4 Vesta in Color: High Resolution Mapping from Dawn Framing Camera Images

    Science.gov (United States)

    Reddy, V.; LeCorre, L.; Nathues, A.; Sierks, H.; Christensen, U.; Hoffmann, M.; Schroeder, S. E.; Vincent, J. B.; McSween, H. Y.; Denevi, B. W.; Li, J.-Y.; Pieters, C. M.; Gaffey, M.; Mittlefehldt, D.; Buratti, B.; Hicks, M.; McCord, T.; Combe, J.-P.; DeSantis, M. C.; Russell, C. T.; Raymond, C. A.; Marques, P. Gutierrez; Maue, T.; Hall, I.

    2011-01-01

    Rotational surface variations on asteroid 4 Vesta have been known from ground-based and HST observations, and they have been interpreted as evidence of compositional diversity. NASA s Dawn mission entered orbit around Vesta on July 16, 2011 for a year-long global characterization. The framing cameras (FC) onboard the Dawn spacecraft will image the asteroid in one clear (broad) and seven narrow band filters covering the wavelength range between 0.4-1.0 microns. We present color mapping results from the Dawn FC observations of Vesta obtained during Survey orbit (approx.3000 km) and High-Altitude Mapping Orbit (HAMO) (approx.950 km). Our aim is to create global color maps of Vesta using multi spectral FC images to identify the spatial extent of compositional units and link them with other available data sets to extract the basic mineralogy. While the VIR spectrometer onboard Dawn has higher spectral resolution (864 channels) allowing precise mineralogical assessment of Vesta s surface, the FC has three times higher spatial resolution in any given orbital phase. In an effort to extract maximum information from FC data we have developed algorithms using laboratory spectra of pyroxenes and HED meteorites to derive parameters associated with the 1-micron absorption band wing. These parameters will help map the global distribution of compositionally related units on Vesta s surface. Interpretation of these units will involve the integration of FC and VIR data.

  14. Effects of artificial dawn on sleep inertia, skin temperature, and the awakening cortisol response

    NARCIS (Netherlands)

    van de Werken, Maan; Gimenez, Marina C.; de Vries, Bonnie; Beersma, Domien G. M.; van Someren, Eus J. W.; Gordijn, Marijke C. M.

    P>The effect of artificial dawn during the last 30 min of sleep on subsequent dissipation of sleep inertia was investigated, including possible involvement of cortisol and thermoregulatory processes. Sixteen healthy subjects who reported difficulty with waking up participated in random order in a

  15. A re-investigation of the 'double dawn' event recorded in the Bamboo Annals

    Science.gov (United States)

    Stephenson, F. R.

    1992-06-01

    An allusion to a 'double dawn' phenomenon in an ancient Chinese chronicle, which has been identified as caused by a sunrise eclipse occurring in 899 BC, is discussed. This event has been regarded as of considerable importance in the investigation of earth's past rotation. It is shown that an eclipse interpretation is implausible, not least because the eclipse in question was only annular.

  16. Analytical and numerical study of the ground-track resonances of Dawn orbiting Vesta

    CERN Document Server

    Delsate, N

    2012-01-01

    The aim of Dawn mission is the acquisition of data from orbits around two bodies, (4)Vesta and (1)Ceres, the two most massive asteroids. Due to the low thrust propulsion, Dawn will slowly cross and transit through ground-track resonances, where the perturbations on Dawn orbit may be significant. In this context, to safety go the Dawn mission from the approach orbit to the lowest science orbit, it is essential to know the properties of the crossed resonances. This paper analytically investigates the properties of the major ground-track resonances (1:1, 1:2, 2:3 and 3:2) appearing for Vesta orbiters: location of the equilibria, aperture of the resonances and period at the stable equilibria. We develop a general method using an averaged Hamiltonian formulation with a spherical harmonic approximation of the gravity field. If the values of the gravity field coefficient change, our method stays correct and applicable. We also discuss the effect of one uncertainty on the C20 and C22 coefficients on the properties of...

  17. Orbital bistatic radar observations of asteroid Vesta by the Dawn mission.

    Science.gov (United States)

    Palmer, Elizabeth M; Heggy, Essam; Kofman, Wlodek

    2017-09-12

    We present orbital bistatic radar observations of a small-body, acquired during occultation by the Dawn spacecraft at asteroid Vesta. The radar forward-scattering properties of different reflection sites are used to assess the textural properties of Vesta's surface at centimeter-to-decimeter scales and are compared to subsurface hydrogen concentrations observed by Dawn's Gamma Ray and Neutron Detector to assess potential volatile occurrence in the surface and shallow subsurface. We observe significant differences in surface radar reflectivity, implying substantial spatial variations in centimeter-to-decimeter-scale surface roughness. Our results suggest that unlike the Moon, Vesta's surface roughness variations cannot be explained by cratering processes only. In particular, the occurrence of heightened hydrogen concentrations within large smoother terrains (over hundreds of square kilometers) suggests that potential ground-ice presence may have contributed to the formation of Vesta's current surface texture. Our observations are consistent with geomorphological evidence of transient water flow from Dawn Framing Camera images.The Dawn spacecraft has provided orbital bistatic radar observations of a small body in the solar system. Here, the authors present results from Vesta suggesting that smooth terrains with heightened hydrogen concentrations indicate that ground-ice presence potentially helped shape Vesta's current surface texture.

  18. Books, Not Bombs: Teaching Peace since the Dawn of the Republic. Peace Education

    Science.gov (United States)

    Howlett, Charles; Harris, Ian,

    2010-01-01

    "Books Not Bombs: Teaching Peace Since the Dawn of the Republic" is an important work relevant to peace scholars, practitioners, and students. This incisive book offers an exciting and comprehensive historical analysis of the origins and development of peace education from the creation of the New Republic at the end of the Eighteenth Century to…

  19. Dawn-dusk asymmetry in ionospheric return flows: relationship between flows and Birkeland currents

    Science.gov (United States)

    Larson, R.; Anderson, B. J.; Korth, H.; Bodurtha, K. E.; Wilson, G.

    2008-12-01

    Intense duskside ionospheric flows occurring equatorward of the discrete auroral precipitation zone have been attributed to large electric fields resulting from partial ring current injections. In this picture the driver is the ion injection that feeds the Region 2 currents which in turn cause the electric field. Alternatively, one may take the view that the return flow at dusk is favored energetically by the coupled magnetosphere-ionosphere system. In this energetics view, the upward Region 2 at dawn corresponds to discrete aurora and enhanced conductance on closed field lines on the dawn side, whereas the downward Region 2 at dusk does not contribute as substantially to enhancing the duskside conductance. The energy dissipation associated with a given flow is proportional to the conductance. Thus, it is energetically more favorable for the coupled system to send more return flow to the dayside at dusk than at dawn. In this paper we assess whether there is a persistent dawn dusk asymmetry in the return flow relative to the Birkeland current location and intensity. Birkeland currents derived from the Iridium Satellite constellation, augmented with DMSP F13 magnetic field data are used to place DMSP F13 drift meter data in the context of both the global and local Birkeland currents. Using events from the Iridium stable currents database of Anderson et al. (2008), we identified 59 events with high quality drift observations during southward IMF. The events are divided into two ranges of IMF intensity and five IMF clock angle bins. We order the data in latitude relative to the peak Region 1 current density. There is a persistent suppression of the dawn return flows relative to those at dusk regardless of IMF By or IMF intensity. This result indicates that the return flow predominantly occurs through the evening closed field line region, consistent with the above energetics picture of return flow in the coupled system.

  20. Comparing Vesta's Surface Roughness to the Moon Using Bistatic Radar Observations by the Dawn Mission

    Science.gov (United States)

    Palmer, E. M.; Heggy, E.; Kofman, W. W.; Moghaddam, M.

    2015-12-01

    The first orbital bistatic radar (BSR) observations of a small body have been conducted opportunistically by NASA's Dawn spacecraft at Asteroid Vesta using the telecommunications antenna aboard Dawn to transmit and the Deep Space Network 70-meter antennas on Earth to receive. Dawn's high-gain communications antenna continuously transmitted right-hand circularly polarized radio waves (4-cm wavelength), and due to the opportunistic nature of the experiment, remained in a fixed orientation pointed toward Earth throughout each BSR observation. As a consequence, Dawn's transmitted radio waves scattered from Vesta's surface just before and after each occultation of the Dawn spacecraft behind Vesta, resulting in surface echoes at highly oblique incidence angles of greater than 85 degrees, and a small Doppler shift of ~2 Hz between the carrier signal and surface echoes from Vesta. We analyze the power and Doppler spreading of Vesta's surface echoes to assess surface roughness, and find that Vesta's area-normalized radar cross section ranges from -8 to -17 dB, which is notably much stronger than backscatter radar cross section values reported for the Moon's limbs (-20 to -35 dB). However, our measurements correspond to the forward scattering regime--such that at high incidence, radar waves are expected to scatter more weakly from a rough surface in the backscatter direction than that which is scattered forward. Using scattering models of rough surfaces observed at high incidence, we report on the relative roughness of Vesta's surface as compared to the Moon and icy Galilean satellites. Through this, we assess the dominant processes that have influenced Vesta's surface roughness at centimeter and decimeter scales, which are in turn applicable to assisting future landing, sampling and orbital missions of other small bodies.

  1. Reevaluating Surface Composition of Asteroid (4) Vesta by Comparing HED Spectral Data with Dawn Framing Camera (FC) Observations

    Science.gov (United States)

    Giebner, T.; Jaumann, R.; Schröder, S.

    2016-08-01

    This master's thesis project tries to reevaluate previous findings on asteroid (4) Vesta's surface composition by using DAWN FC Filter image ratios in a new way in order to identify HED (howardite, eucrite, diogenite) lithologies on the surface.

  2. DAWNING Information Industry Co.,Ltd, Beijing%曙光信息产业(北京)有限公司

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The notion,theories and methods of overall quality management in Dawning have penetrated throughout the corporation. We attend Top100 evaluation activity with a focus to digest and assimilate the outstanding quality management theories and measures.

  3. Particles upstream of the pre-dawn bow shock - ISEE-3 observations

    Energy Technology Data Exchange (ETDEWEB)

    Terasawa, T.; Scholer, M.; Hovestadt, D.; Klecker, B.; Ipavich, F.M.; Gloeckler, G.; Sanderson, T.R.; Wenzel, K.P.; Smith, E.J.

    1985-06-01

    The first observations of energetic ions (equal to or greater than 30 keV) in the region upstream of the pre-dawn bow shock (X between 0 and -60 Re inclusively) are presented. The intensity in this region is controlled by the direction of the interplanetary magnetic field (IMF) and is maximized when the IMF is around the spiral direction. The particle distributions are highly anisotropic with the anisotropy directed perpendicular to the magnetic field. In the E x B frame this perpendicular anisotropy is conserved and it is argued that the distribution is pancake-like. This indicates that the energetic particles in the pre-dawn upstream region have their origin in the near-earth upstream region, from where they are convected by the solar wind perpendicular to the magnetic field. It is therefore concluded that acceleration occurs mainly near the nose of the bow shock, and particle acceleration at the distant bow shock is weak. 15 references.

  4. Photometric Properties of Ceres from Telescopic Observations using Dawn Framing Camera Color Filters

    CERN Document Server

    Reddy, Vishnu; Gary, Bruce L; Sanchez, Juan A; Stephens, Robert D; Megna, Ralph; Coley, Daniel; Nathues, Andreas; Corre, Lucille Le; Hoffmann, Martin

    2015-01-01

    The dwarf planet Ceres is likely differentiated similar to the terrestrial planets but with a water/ice dominated mantle and an aqueously altered crust. Detailed modeling of Ceres' phase function has never been performed to understand its surface properties. The Dawn spacecraft began orbital science operations at the dwarf planet in April 2015. We observed Ceres with flight spares of the seven Dawn Framing Camera color filters mounted on ground-based telescopes over the course of three years to model its phase function versus wavelength. Our analysis shows that the modeled geometric albedos derived from both the IAU HG model and the Hapke model are consistent with a flat and featureless spectrum of Ceres, although the values are ~10% higher than previous measurements. Our models also suggest a wavelength dependence of Ceres' phase function. The IAU G-parameter and the Hapke single-particle phase function parameter, g, are both consistent with decreasing (shallower) phase slope with increasing wavelength. Such...

  5. Implications of conspecific background noise for features of blue tit, Cyanistes caeruleus , communication networks at dawn

    DEFF Research Database (Denmark)

    Poesel, Angelika; Dabelsteen, Torben; Pedersen, Simon Boel

    2007-01-01

    Abstract  Communication among animals often comprises several signallers and receivers within the signal's transmission range. In such communication networks, individuals can extract information about differences in relative performance of conspecifics by eavesdropping on their signalling...... interactions. In songbirds, information can be encoded in the timing of signals, which either alternate or overlap, and both male and female receivers may utilise this information when engaging in territorial interactions or making reproductive decisions, respectively. We investigated how conspecific...... background noise at dawn may overlay and possibly constrain the perception of such singing patterns. We simulated a small communication network of blue tits, Cyanistes caeruleus, at dawn in spring. Two loudspeakers simulated a singing interaction which was recorded from four different receiver positions...

  6. The far-ultraviolet main auroral emission at Jupiter. Pt. 1. Dawn-dusk brightness asymmetries

    Energy Technology Data Exchange (ETDEWEB)

    Bonfond, B.; Gustin, J.; Gerard, J.C.; Grodent, D.; Radioti, A. [Liege Univ. (Belgium). Lab. de Physique Atmospherique et Planetaire; Palmaerts, B. [Liege Univ. (Belgium). Lab. de Physique Atmospherique et Planetaire; Max-Planck-Institut fuer Sonnensystemforschung, Goettingen (Germany); Badman, S.V. [Lancaster Univ. (United Kingdom). Dept. of Physics; Khurana, K.K. [California Univ., Los Angeles, CA (United States); Tao, C. [Institut de Recherche en Astrophysique et Planetologie, Toulouse (France)

    2015-07-01

    The main auroral emission at Jupiter generally appears as a quasi-closed curtain centered around the magnetic pole. This auroral feature, which accounts for approximately half of the total power emitted by the aurorae in the ultraviolet range, is related to corotation enforcement currents in the middle magnetosphere. Early models for these currents assumed axisymmetry, but significant local time variability is obvious on any image of the Jovian aurorae. Here we use far-UV images from the Hubble Space Telescope to further characterize these variations on a statistical basis. We show that the dusk side sector is ∝ 3 times brighter than the dawn side in the southern hemisphere and ∝ 1:1 brighter in the northern hemisphere, where the magnetic anomaly complicates the interpretation of the measurements.We suggest that such an asymmetry between the dawn and the dusk sectors could be the result of a partial ring current in the nightside magnetosphere.

  7. Origin of Dark Material on VESTA from DAWN FC Data: Remnant Carbonaceous Chondrite Impators

    Science.gov (United States)

    Reddy, V.; LeCorre, L.; Nathues, A.; Mittlefehldt, David W.; Cloutis, E. A.; OBrien, D. P.; Durda, D. D.; Bottke, W. F.; Buczkowski, D.; Scully, J. E. C.; Palmer, E. M.; Sierks, H.; Mann, P. J.; Becker, K. J.; Beck, A. W.; Li, Y-Y.; Gaskell, R.; Russell, C. T.; Gaffey, M. J.; McSween, H. Y.; McCord, T. B.; Combe, J.-P.; Blewett, D.

    2012-01-01

    NASA's Dawn spacecraft entered orbit around asteroid (4) Vesta in July 2011 for a yearlong mapping orbit. The surface of Vesta as imaged by the Dawn Framing Camera (FC) revealed a surface that is unlike any asteroid we have visited so far with a spacecraft. Albedo and color variations on Vesta are the most diverse in the asteroid belt with a majority of these linked to distinct compositional units on the asteroid s surface. FC discovered dark material on Vesta. These low albedo surface features were first observed during Rotational Characterization 3 phase at a resolution of approx. 487 m/pixel. Here we explore the composition and possible meteoritical analogs for the dark material on Vesta.

  8. Dawn-dusk asymmetry in the Kelvin-Helmholtz instability at Mercury.

    Science.gov (United States)

    Paral, Jan; Rankin, Robert

    2013-01-01

    The NASA MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) spacecraft entered orbital phase around Mercury on 18 March 2011. A surprising consistent feature in the data returned is large-scale vortices that form exclusively on the dusk side of the magnetosphere. Here we present global kinetic hybrid simulations that explain these observations. It is shown that vortices are excited by a Kelvin-Helmholtz instability near the subsolar point, which grows convectively along the dusk-side magnetopause. Virtual time series along a track approximating a flyby of the MESSENGER show correspondence with the satellite data; the data contain sawtooth oscillations in plasma density, flow and magnetic field, and exhibit the observed dawn-dusk asymmetry. It is shown that asymmetry between dawn and dusk at Mercury is controlled by the finite gyroradius of ions and by convection electric fields. Mercury's magnetosphere offers a natural laboratory for studying plasma regimes not present in other planetary magnetospheres or the laboratory.

  9. The role of PDF neurons in setting the preferred temperature before dawn in Drosophila.

    Science.gov (United States)

    Tang, Xin; Roessingh, Sanne; Hayley, Sean E; Chu, Michelle L; Tanaka, Nobuaki K; Wolfgang, Werner; Song, Seongho; Stanewsky, Ralf; Hamada, Fumika N

    2017-05-02

    Animals have sophisticated homeostatic controls. While mammalian body temperature fluctuates throughout the day, small ectotherms, such as Drosophila achieve a body temperature rhythm (BTR) through their preference of environmental temperature. Here, we demonstrate that pigment dispersing factor (PDF) neurons play an important role in setting preferred temperature before dawn. We show that small lateral ventral neurons (sLNvs), a subset of PDF neurons, activate the dorsal neurons 2 (DN2s), the main circadian clock cells that regulate temperature preference rhythm (TPR). The number of temporal contacts between sLNvs and DN2s peak before dawn. Our data suggest that the thermosensory anterior cells (ACs) likely contact sLNvs via serotonin signaling. Together, the ACs-sLNs-DN2s neural circuit regulates the proper setting of temperature preference before dawn. Given that sLNvs are important for sleep and that BTR and sleep have a close temporal relationship, our data highlight a possible neuronal interaction between body temperature and sleep regulation.

  10. Light pollution alters the phenology of dawn and dusk singing in common European songbirds

    Science.gov (United States)

    Da Silva, Arnaud; Valcu, Mihai; Kempenaers, Bart

    2015-01-01

    Artificial night lighting is expanding globally, but its ecological consequences remain little understood. Animals often use changes in day length as a cue to time seasonal behaviour. Artificial night lighting may influence the perception of day length, and may thus affect both circadian and circannual rhythms. Over a 3.5 month period, from winter to breeding, we recorded daily singing activity of six common songbird species in 12 woodland sites, half of which were affected by street lighting. We previously reported on analyses suggesting that artificial night lighting affects the daily timing of singing in five species. The main aim of this study was to investigate whether the presence of artificial night lighting is also associated with the seasonal occurrence of dawn and dusk singing. We found that in four species dawn and dusk singing developed earlier in the year at sites exposed to light pollution. We also examined the effects of weather conditions and found that rain and low temperatures negatively affected the occurrence of dawn and dusk singing. Our results support the hypothesis that artificial night lighting alters natural seasonal rhythms, independently of other effects of urbanization. The fitness consequences of the observed changes in seasonal timing of behaviour remain unknown. PMID:25780238

  11. The highest-ranking rooster has priority to announce the break of dawn.

    Science.gov (United States)

    Shimmura, Tsuyoshi; Ohashi, Shosei; Yoshimura, Takashi

    2015-07-23

    The "cock-a-doodle-doo" crowing of roosters, which symbolizes the break of dawn in many cultures, is controlled by the circadian clock. When one rooster announces the break of dawn, others in the vicinity immediately follow. Chickens are highly social animals, and they develop a linear and fixed hierarchy in small groups. We found that when chickens were housed in small groups, the top-ranking rooster determined the timing of predawn crowing. Specifically, the top-ranking rooster always started to crow first, followed by its subordinates, in descending order of social rank. When the top-ranking rooster was physically removed from a group, the second-ranking rooster initiated crowing. The presence of a dominant rooster significantly reduced the number of predawn crows in subordinates. However, the number of crows induced by external stimuli was independent of social rank, confirming that subordinates have the ability to crow. Although the timing of subordinates' predawn crowing was strongly dependent on that of the top-ranking rooster, free-running periods of body temperature rhythms differed among individuals, and crowing rhythm did not entrain to a crowing sound stimulus. These results indicate that in a group situation, the top-ranking rooster has priority to announce the break of dawn, and that subordinate roosters are patient enough to wait for the top-ranking rooster's first crow every morning and thus compromise their circadian clock for social reasons.

  12. Behavior and Stability of Ground Ice on Ceres: Initial Clues from Dawn

    Science.gov (United States)

    Byrne, S.; Landis, M. E.; Schorghofer, N.; Schmidt, B. E.; Raymond, C. A.; Russell, C. T.

    2015-12-01

    Models of the historical evolution of Ceres [1] and recent observations of surface geomorphology by the Dawn spacecraft [2] suggest a crust with a substantial fraction of water ice. However, clear spectral detections of ice are absent indicating that the uppermost material is dry. Further constraints on near surface ice come from detections of water vapor around Ceres by the Herschel telescope [3], which indicate production rates of 1026molecules per second. Here we build on the pioneering work of [4] and examine ground ice stability with the benefit of these new observations as well as accurate pole-vector determinations by Dawn. We model surface and subsurface temperatures on Ceres by balancing surface insolation, thermal emission and conduction to the subsurface. We estimate ice loss rates for both surface ice and ice covered with a low-thermal-inertia sublimation lag. Dawn observations show no large high-albedo regions indicating pure surface ice. In the case where pore-filling ice (50% ice by volume) extends to the surface, average loss rates range from almost zero (mm/Gyr) at the poles to several decimeters per year at the equator. These loss rates are suppressed by 2-3 orders of magnitude when this pore-filling ice is covered by even a few centimeters of dry sublimation lag, which is expected to form on geologically short timescales. Assuming negligible internal heat flux, we estimate the outgassing of water molecules expected from buried ice at all latitudes and in combination with previous work [5,6] find that the observations of [3] cannot be due to global sublimation of buried ice. Dawn observations also show the presence of small-scale high-albedo spots. Our models show that, if icy, the most prominent of these (in Occator crater) loses ~2cm/yr. Suggestively, the area and sublimation rates of the Occator bright spots match the observed vapor production rates of [3]. However, these high loss rates are difficult to reconcile with long-term spot

  13. PHASE ANGLE EFFECTS ON 3 μm ABSORPTION BAND ON CERES: IMPLICATIONS FOR DAWN MISSION

    Energy Technology Data Exchange (ETDEWEB)

    Takir, D.; Reddy, V.; Sanchez, J. A.; Corre, L. Le [Planetary Science Institute, 1700 E Fort Lowell Road, Suite 106, Tucson, AZ 85719 (United States); Hardersen, P. S. [Department of Space Studies, University of North Dakota, Grand Forks, ND 58202 (United States); Nathues, A., E-mail: dtakir@psi.edu [Max-Planck-Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)

    2015-05-01

    Phase angle-induced spectral effects are important to characterize since they affect spectral band parameters such as band depth and band center, and therefore skew mineralogical interpretations of planetary bodies via reflectance spectroscopy. Dwarf planet (1) Ceres is the next target of NASA’s Dawn mission, which is expected to arrive in 2015 March. The visible and near-infrared mapping spectrometer (VIR) on board Dawn has the spatial and spectral range to characterize the surface between 0.25–5.0 μm. Ceres has an absorption feature at 3.0 μm due to hydroxyl- and/or water-bearing minerals. We analyzed phase angle-induced spectral effects on the 3 μm absorption band on Ceres using spectra measured with the long-wavelength cross-dispersed (LXD: 1.9–4.2 μm) mode of the SpeX spectrograph/imager at the NASA Infrared Telescope Facility. Ceres LXD spectra were measured at different phase angles ranging from 0.°7 to 22°. We found that the band center slightly increases from 3.06 μm at lower phase angles (0.°7 and 6°) to 3.07 μm at higher phase angles (11° and 22°), the band depth decreases by ∼20% from lower phase angles to higher phase angles, and the band area decreases by ∼25% from lower phase angles to higher phase angles. Our results will have implications for constraining the abundance of OH on the surface of Ceres from VIR spectral data, which will be acquired by Dawn starting spring 2015.

  14. Probing Individual Sources during Reionization and Cosmic Dawn using Square Kilometre Array HI 21-cm Observations

    Indian Academy of Sciences (India)

    Kanan K. Datta; Raghunath Ghara; Suman Majumdar; T. Roy Choudhury; Somnath Bharadwaj; Himadri Roy; Abhirup Datta

    2016-12-01

    Detection of individual luminous sources during the reionization epoch and cosmic dawn through their signatures in the HI 21-cm signal is one of the direct approaches to probe the epoch. Here, we summarize our previous works on this and present preliminary results on the prospects of detecting such sources using the SKA1-low experiment. We first discuss the expected HI 21-cm signal around luminous sources at different stages of reionization and cosmic dawn. We then introduce two visibility based estimators for detecting such signals: one based on the matched filtering technique and the other relies on simply combing the visibility signal from different baselines and frequency channels. We find that the SKA1-low should be able to detect ionized bubbles of radius $R_{\\mathrm {b}} \\gtrsim 10$ Mpc with $\\sim100 \\rm h$ of observations at redshift $z\\sim8$ provided that the mean outside neutral hydrogen fraction $\\mathrm {x}_{\\text {HI}} \\gtrsim 0.5$. We also investigate the possibility of detecting HII regions around known bright QSOs such as around ULASJ1120+0641 discovered by Mortlock et al. (Nature 474, 7353 (2011)). We find that a $5σ$ detection is possible with 600 h of SKA1-low observations if the QSO age and the outside $\\mathrm {x}_{\\text {HI}}$ are at least $\\sim2 \\times 10^7$ Myr and $\\sim0.2$ respectively. Finally, we investigate the possibility of detecting the very first X-ray and Ly- α sources during the cosmic dawn. We consider mini-QSOs like sources which emits in X-ray frequency band. We find that with a total $\\sim 1000 \\rm h$ of observations, SKA1-low should be able to detect those sources individually with a $∼ 9σ$ significance at redshift z=15. We summarize how the SNR changes with various parameters related to the source properties.

  15. High-resolution Ceres LAMO atlas derived from Dawn FC images

    Science.gov (United States)

    Roatsch, T.; Kersten, E.; Matz, K. D.; Preusker, F.; Scholten, F.; Jaumann, R.; Raymond, C. A.; Russell, C.

    2016-12-01

    Introduction: NASA's Dawn spacecraft has been orbiting the dwarf planet Ceres since December 2015 in LAMO (High Altitude Mapping Orbit) with an altitude of about 400 km to characterize for instance the geology, topography, and shape of Ceres. One of the major goals of this mission phase is the global high-resolution mapping of Ceres. Data: The Dawn mission is equipped with a fram-ing camera (FC). The framing camera took until the time of writing about 27,500 clear filter images in LAMO with a resolution of about 30 m/pixel and dif-ferent viewing angles and different illumination condi-tions. Data Processing: The first step of the processing chain towards the cartographic products is to ortho-rectify the images to the proper scale and map projec-tion type. This process requires detailed information of the Dawn orbit and attitude data and of the topography of the target. A high-resolution shape model was provided by stereo processing of the HAMO dataset, orbit and attitude data are available as reconstructed SPICE data. Ceres' HAMO shape model is used for the calculation of the ray intersection points while the map projection itself was done onto a reference sphere of Ceres. The final step is the controlled mosaicking of all nadir images to a global mosaic of Ceres, the so called basemap. Ceres map tiles: The Ceres atlas will be produced in a scale of 1:250,000 and will consist of 62 tiles that conforms to the quadrangle schema for Venus at 1:5,000,000. A map scale of 1:250,000 is a compro-mise between the very high resolution in LAMO and a proper map sheet size of the single tiles. Nomenclature: The Dawn team proposed to the International Astronomical Union (IAU) to use the names of gods and goddesses of agriculture and vege-tation from world mythology as names for the craters and to use names of agricultural festivals of the world for other geological features. This proposal was ac-cepted by the IAU and the team proposed 92 names for geological features to the IAU

  16. Bayesian constraints on the global 21-cm signal from the Cosmic Dawn

    CERN Document Server

    Bernardi, G; Price, D; Greenhill, L J; Mesinger, A; Dowell, J; Eftekhari, T; Ellingson, S W; Kocz, J; Schinzel, F

    2016-01-01

    The birth of the first luminous sources and the ensuing epoch of reionization are best studied via the redshifted 21-cm emission line, the signature of the first two imprinting the last. In this work we present a fully-Bayesian method, \\textsc{hibayes}, for extracting the faint, global (sky-averaged) 21-cm signal from the much brighter foreground emission. We show that a simplified (but plausible), Gaussian model of the 21-cm emission from the Cosmic Dawn epoch ($15 \\lesssim z \\lesssim 30$), parameterized by an amplitude $A_{\\rm HI}$, a frequency peak $\

  17. A new dawn for plant mitochondrial NAD(P)H dehydrogenases

    DEFF Research Database (Denmark)

    Møller, I.M.

    2002-01-01

    The expression of complex I and two homologues of bacterial and yeast NADH dehydrogenases, NDA and NDB, have been studied in potato leaf mitochondria. The mRNA level of NDA is completely light dependent and shows a diurnal rhythm with a sharp maximum just after dawn. NDA protein quantity and inte...... and internal rotenone-insensitive NADH dehydrogenase activity are also light dependent. These findings suggest that NDA has a role in photorespiration and might be identical to the previously unidentified internal rotenone-insensitive NADH dehydrogenase....

  18. In-Flight Operation of the Dawn Ion Propulsion System Through Orbit Capture at Vesta

    Science.gov (United States)

    Garner, Charles E.; Rayman, Marc D.; Brophy, John R.; Mikes, Steven C.

    2011-01-01

    The Dawn mission, part of NASA's Discovery Program, has as its goal the scientific exploration of the two most massive main-belt asteroids, Vesta and Ceres. The Dawn spacecraft was launched from Cape Canaveral Air Force Station on September 27, 2007 on a Delta -II 7925H-9.5 (Delta-II Heavy) rocket that placed the 1218 kg spacecraft into an Earth-escape trajectory. Onboard the spacecraft is an ion propulsion system (IPS) developed at the Jet Propulsion Laboratory which will provide most of the ?V needed for heliocentric transfer to Vesta, orbit capture at Vesta, transfer among Vesta science orbits, departure and escape from Vesta, heliocentric transfer to Ceres, orbit capture at Ceres, and transfer among Ceres science orbits. The first 80 days after launch were dedicated to the initial checkout of the spacecraft which was followed by about ten months of full-power thrusting leading to a Mars gravity assist in February 2009 that provided 1 km/s of heliocentric energy increase and is the only part of the mission following launch in which a needed velocity change is not accomplished by the IPS. Deterministic thrusting for heliocentric transfer to Vesta resumed in June 2009 and was concluded with orbit capture at Vesta in July 2011. IPS was operated for approximately 23,400 hours, consumed approximately 250 kg of xenon, and provided a delta-V of approximately 6.7 km/s to achieve orbit capture at Vesta. IPS performance characteristics are very close to the expected performance characteristics based on analysis performed pre-launch. The only significant problem to have occurred over the almost four years of IPS operations in flight was the temporary failure of a valve driver board in DCIU-1, resulting in a loss of thrust of approximately 29 hours. Thrusting operations resumed after switching to DCIU-2, and power cycling conducted after orbit capture indicates DCIU-1 is completely operational. After about three weeks of survey operations IPS will be used to maneuver the

  19. Understanding Volatile Occurrence on Vesta Using Bistatic Radar and GRaND Observations by the Dawn Mission

    Science.gov (United States)

    Palmer, E. M.; Heggy, E.; Kofman, W. W.

    2016-12-01

    The first orbital bistatic radar experiment was conducted by Dawn at Asteroid Vesta, where Dawn's HGA was used to transmit X-band radio waves and Earth's Deep Space Network (DSN) 70-meter antennas were used to receive. Due to the opportunistic nature of the experiment, the HGA remained in a fixed orientation toward the Earth such that surface radar reflections occurred at grazing incidence angles of 89° just before and after Dawn's occultation behind Vesta. Among the 16 observed echo sites, we find that σ0ranges from -12 dB to -20 dB and has corresponding RMS slopes ranging from 1°- 8°. To assess potential volatile presence, we compare the distribution of RMS slopes to subsurface hydrogen concentrations observed by Dawn's Gamma Ray and Neutron Detector (GRaND) to 1 m depth. While Vesta's surface is thought to have been largely depleted of volatiles during its differentiation, observations by Dawn'sGRaND and VIR instruments suggest the potential introduction of hydrated material through meteoritic impacts. We identify seven sites of potential volatile occurrence—where low roughness (overlap Divalia Fossae, Marcia crater ejecta and Octavia crater, respectively—and exit orbit numbers 377, 406, 407 and 720—overlapping northern cratered trough terrain, dark material near Aruntia crater and the cratered highlands. Toward comparing volatile occurrence on other small bodies, Dawn'sBSR experiment at Asteroid Ceres raises new questions. How does the range of decimeter-scale RMS slopes compare with Vesta's surface? How well does the distribution of RMS slopes correlate with GRaND's map of subsurface hydrogen concentration? In addition to optimizing future missions' landing and surface trafficability, characterizing small body surface roughness using BSR will enable further investigation into the relationship between volatile presence and decimeter-scale surface roughness.

  20. First detection of global dawn-dusk ionospheric current intensities using Ampere's integral law on Orsted orbits

    DEFF Research Database (Denmark)

    Stauning, P.; Primdahl, Fritz

    2000-01-01

    The magnetic measurements by the Orsted satellite in noon-midnight orbits have enabled the derivation of the global dawn-dusk oriented ionospheric currents from an Ampere's law closed loop line integral of the geomagnetic vector field along the satellite track. The globally integrated dawn......-to-dusk ionospheric current is found to be proportional to the gee-effective solar wind electric field and is around 1 million ampere for a typical solar wind electric field of 2 mV/m. Dividing the Ampere integral into semi-orbit parts has enabled us to show that the hemispherical total current intensities depend...

  1. Line of sight anisotropies in the Cosmic Dawn and EoR 21-cm power spectrum

    CERN Document Server

    Majumdar, Suman; Ghara, Raghunath; Mondal, Rajesh; Choudhury, T Roy; Bharadwaj, Somnath; Ali, Sk Saiyad; Datta, Abhirup

    2016-01-01

    The line of sight direction in the redshifted 21-cm signal coming from the cosmic dawn and the epoch of reionization is quite unique in many ways compared to any other cosmological signal. Different unique effects, such as the evolution history of the signal, non-linear peculiar velocities of the matter etc will imprint their signature along the line of sight axis of the observed signal. One of the major goals of the future SKA-LOW radio interferometer is to observe the cosmic dawn and the epoch of reionization through this 21-cm signal. It is thus important to understand how these various effects affect the signal for it's actual detection and proper interpretation. For more than one and half decades, various groups in India have been actively trying to understand and quantify the different line of sight effects that are present in this signal through analytical models and simulations. In many ways the importance of this sub-field under 21-cm cosmology have been identified, highlighted and pushed forward by ...

  2. Probing individual sources during reionization and cosmic dawn using SKA HI 21-cm observations

    CERN Document Server

    Datta, Kanan K; Majumdar, Suman; Choudhury, T Roy; Bharadwaj, Somnath; Roy, Himadri; Datta, Abhirup

    2016-01-01

    Detection of individual luminous sources during the reionization epoch and cosmic dawn through their signatures in the HI 21-cm signal is one of the direct approaches to probe the epoch. Here, we summarize our previous works on this and present preliminary results on the prospects of detecting such sources using the SKA1-low experiment. We first discuss the expected HI 21-cm signal around luminous sources at different stages of reionization and cosmic dawn. We then introduce two visibility based estimators for detecting such signal: one based on the matched filtering technique and the other relies on simply combing the visibility signal from different baselines and frequency channels. We find that that the SKA1-low should be able to detect ionized bubbles of radius $R_b \\gtrsim 10$ Mpc with $\\sim 100$ hr of observations at redshift $z \\sim 8$ provided that the mean outside neutral Hydrogen fraction $ x_{\\rm HI} \\gtrsim 0.5$. We also investigate the possibility of detecting HII regions around known bright QSOs...

  3. The Metaphor of the Dawn of the Space Age in the Contemporary Social Sciences and Humanities

    Directory of Open Access Journals (Sweden)

    Natalija Majsova

    2015-05-01

    Full Text Available The dawn of the space age in the early 1960s first provoked unabashed awe. Then, it inspired numerous attempts to explain (away the evental status of the first examples of manned spaceflight accounts that mainly interpreted Yuri Garagin’s flight (1961 and the Moon landing (1969 as logical consequences of technological progress, a certain constellation of political circumstances, and a pinch of ‘imagination’ to begin with. Curiously enough, conclusions of the vast majority of such accounts cannot but resort to ‘terrestrial’ metaphors in order to explain why these endeavours were worth undertaking in the first place. In the 21st century, reflections on outer space seem to have settled within three conceptually designed research fields within the social sciences and humanities: astrosociology, noocosmology and cultural studies of outer space. The text analyses conceptualisations and accounts of the dawn of the space age exhibited by the core texts and methodologies of these research fields to demonstrate how they actually hinge on variant epistemologies, and interpret the role of metaphor in world-formation in radically differing ways.

  4. Spectral analysis of Ahuna Mons from Dawn mission's visible-infrared spectrometer

    Science.gov (United States)

    Zambon, F.; Raponi, A.; Tosi, F.; De Sanctis, M. C.; McFadden, L. A.; Carrozzo, F. G.; Longobardo, A.; Ciarniello, M.; Krohn, K.; Stephan, K.; Palomba, E.; Pieters, C. M.; Ammannito, E.; Russell, C. T.; Raymond, C. A.

    2017-01-01

    Ahuna Mons is the highest mountain on Ceres. A unique complex in terms of size, shape, and morphology, Ahuna is bordered by flanks of the talus around its summit. Recent work by Ruesch et al. based on Dawn's Framing Camera images shed light on the possible origin of Ahuna Mons. According to Ruesch et al. (2016), Ahuna Mons is formed by a volcanic process involving the ascent of cryomagma and extrusion onto the surface followed by dome development and subsequent spreading. Here we analyzed in detail the composition of Ahuna Mons, using data acquired by the visible and infrared spectrometer aboard Dawn. The spectral analysis reveals a relatively high abundance of carbonates and a nonhomogeneous variation in carbonate composition and abundance along Ahuna's flanks, associated with a lower amount of the Ceres's ubiquitous NH4-phyllosilicates over a large portion of the flanks. The grain size is coarser on the flanks than in the surrounding regions, suggesting the presence of fresher material, also compatible with a larger abundance of carbonates. Thermal variations are seen in Ahuna, supporting the evidence of different compactness of the surface regolith in specific locations. Results of the spectral analysis are consistent with a possible cryovolcanic origin which exposed fresher material that slid down on the flanks.

  5. Phase Angle Effects on 3-micron Absorption Band on Ceres: Implications for Dawn Mission

    CERN Document Server

    Takir, Driss; Sanchez, Juan A; Corre, Lucille Le; Hardersen, Paul S; Nathues, Andreas

    2015-01-01

    Phase angle-induced spectral effects are important to characterize since they affect spectral band parameters such as band depth and band center, and therefore skew mineralogical interpretations of planetary bodies via reflectance spectroscopy. Dwarf planet (1) Ceres is the next target of NASA's Dawn mission, which is expected to arrive in March 2015. The visible and near-infrared mapping spectrometer (VIR) onboard Dawn has the spatial and spectral range to characterize the surface between 0.25-5.0 microns. Ceres has an absorption feature at 3.0 microns due to hydroxyl- and/or water-bearing minerals (e.g. Lebofsky et al. 1981, Rivkin et al. 2003). We analyzed phase angle-induced spectral effects on the 3-micron absorption band on Ceres using spectra measured with the long-wavelength cross-dispersed (LXD: 1.9-4.2 microns) mode of the SpeX spectrograph/imager at the NASA Infrared Telescope Facility (IRTF). Ceres LXD spectra were measured at different phase angles ranging from 0.7o to 22o. We found that the band...

  6. Case study : Dawn simulation as maintenance treatment in a nine-year-old patient with seasonal affective disorder

    NARCIS (Netherlands)

    Meesters, Y

    After four winter seasons of successful treatment with tight boxes. a g-year-old patient with seasonal affective disorder refused to make further use of the light box. instead he was treated with dawn simulation (a dim light administered just before waking up and gradually increased in intensity).

  7. Intruders: New Neighbors in "Dawn of the Planet of the Apes" and "The Hundred-Foot Journey"

    Science.gov (United States)

    Beck, Bernard

    2015-01-01

    Conflicts over territory are about the power to establish dominant cultures in territories and are often accompanied by cultural claims to legitimacy by each side. The cultural claims, or ideologies, are often expressed in terms of "homeland" dwellers versus "intruders." Two recent movies, "Dawn of the Planet of the…

  8. High-Resolution Ceres HAMO Color Mosaics derived from Dawn FC Images

    Science.gov (United States)

    Matz, K. D.; Schroeder, S.; Roatsch, T.; Kersten, E.; Preusker, F.; Scholten, F.; Jaumann, R.; Raymond, C. A.; Russell, C.

    2016-12-01

    Introduction: NASA's Dawn spacecraft orbited the dwarf planet Ceres from August to October 2015 in HAMO (High Altitude Mapping Orbit) with an altitude of about 1,500 km to characterize, among others, the geology, topography, and shape of Ceres. Data: The Dawn mission is equipped with a framing camera (FC) which has one broad band clear filter and seven narrow band color filters. The FC took about 4300 color filter images in HAMO with a resolution of about 140 m/pixel. Data Processing: The first steps of the processing chain towards the mosaics are: radiometric calibration and photometric correction of the images followed by ortho-rectification to the proper scale and map projection type. These steps require detailed information of the Dawn orbit, the orientation of the spacecraft, and of the topography of the target. Both, improved orientation and a high-resolution shape model, are provided by the stereo processing of the HAMO clear filter dataset. Ceres' HAMO shape model is used for the calculation of the ray intersection points and the orientation of the surface normals, while the map projection itself is done onto a reference sphere for Ceres. The final step is the controlled mosaicking of all color images to seven global mosaics of Ceres. True color: True color was achieved by scaling FC images acquired through the red, green, and blue filters (effective wavelength 653, 555, and 438 nm) to RGB values calculated from the CIE color matching functions and a Ceres reflectance spectrum. Color ratios: Color ratio image mosaics were calculated using the images of four different narrow band filters; Red channel: 965/749 nanometers (nm); Green channel: 555/749 nm; Blue channel: 438/749 nm. The color ratio image serves to cancel out the dominant brightness variations of the scene (caused by albedo variations and topographic shading) and enhances color differences related to soil mineralogy and, possibly, maturity. Download: All color mosaics will become available to the

  9. Dawn: A Simulation Model for Evaluating Costs and Tradeoffs of Big Data Science Architectures

    Science.gov (United States)

    Cinquini, L.; Crichton, D. J.; Braverman, A. J.; Kyo, L.; Fuchs, T.; Turmon, M.

    2014-12-01

    In many scientific disciplines, scientists and data managers are bracing for an upcoming deluge of big data volumes, which will increase the size of current data archives by a factor of 10-100 times. For example, the next Climate Model Inter-comparison Project (CMIP6) will generate a global archive of model output of approximately 10-20 Peta-bytes, while the upcoming next generation of NASA decadal Earth Observing instruments are expected to collect tens of Giga-bytes/day. In radio-astronomy, the Square Kilometre Array (SKA) will collect data in the Exa-bytes/day range, of which (after reduction and processing) around 1.5 Exa-bytes/year will be stored. The effective and timely processing of these enormous data streams will require the design of new data reduction and processing algorithms, new system architectures, and new techniques for evaluating computation uncertainty. Yet at present no general software tool or framework exists that will allow system architects to model their expected data processing workflow, and determine the network, computational and storage resources needed to prepare their data for scientific analysis. In order to fill this gap, at NASA/JPL we have been developing a preliminary model named DAWN (Distributed Analytics, Workflows and Numerics) for simulating arbitrary complex workflows composed of any number of data processing and movement tasks. The model can be configured with a representation of the problem at hand (the data volumes, the processing algorithms, the available computing and network resources), and is able to evaluate tradeoffs between different possible workflows based on several estimators: overall elapsed time, separate computation and transfer times, resulting uncertainty, and others. So far, we have been applying DAWN to analyze architectural solutions for 4 different use cases from distinct science disciplines: climate science, astronomy, hydrology and a generic cloud computing use case. This talk will present

  10. Dawn-dusk asymmetry in particles of solar wind origin within the magnetosphere

    Directory of Open Access Journals (Sweden)

    T. J. Stubbs

    Full Text Available Solar wind/magnetosheath plasma in the magnetosphere can be identified using a component that has a higher charge state, lower density and, at least soon after their entry into the magnetosphere, lower energy than plasma from a terrestrial source. We survey here observations taken over 3 years of He2+ ions made by the Magnetospheric Ion Composition Sensor (MICS of the Charge and Mass Magnetospheric Ion Composition Experiment (CAMMICE instrument aboard POLAR. The occurrence probability of these solar wind ions is then plotted as a function of Magnetic Local Time (MLT and invariant latitude (7 for various energy ranges. For all energies observed by MICS (1.8–21.4 keV and all solar wind conditions, the occurrence probabilities peaked around the cusp region and along the dawn flank. The solar wind conditions were filtered to see if this dawnward asymmetry is controlled by the Svalgaard-Mansurov effect (and so depends on the BY component of the interplanetary magnetic field, IMF or by Fermi acceleration of He2+ at the bow shock (and so depends on the IMF ratio BX /BY . It is shown that the asymmetry remained persistently on the dawn flank, suggesting it was not due to effects associated with direct entry into the magnetosphere. This asymmetry, with enhanced fluxes on the dawn flank, persisted for lower energy ions (below a "cross-over" energy of about 23 keV but reversed sense to give higher fluxes on the dusk flank at higher energies. This can be explained by the competing effects of gradient/curvature drifts and the convection electric field on ions that are convecting sunward on re-closed field lines. The lower-energy He2+ ions E × B drift dawnwards as they move earthward, whereas the higher energy ions curvature/ gradient drift towards dusk. The convection electric field in the tail is weaker for

  11. Iron oxide minerals in dust of the Red Dawn event in eastern Australia, September 2009

    Science.gov (United States)

    Reynolds, Richard L.; Cattle, Stephen R.; Moskowitz, Bruce M.; Goldstein, Harland L.; Yauk, Kimberly; Flagg, Cody B.; Berquó, Thelma S.; Kokaly, Raymond F.; Morman, Suzette; Breit, George N.

    2014-12-01

    Iron oxide minerals typically compose only a few weight percent of bulk atmospheric dust but are important for potential roles in forcing climate, affecting cloud properties, influencing rates of snow and ice melt, and fertilizing marine phytoplankton. Dust samples collected from locations across eastern Australia (Lake Cowal, Orange, Hornsby, and Sydney) following the spectacular "Red Dawn" dust storm on 23 September 2009 enabled study of the dust iron oxide assemblage using a combination of magnetic measurements, Mössbauer spectroscopy, reflectance spectroscopy, and scanning electron microscopy. Red Dawn was the worst dust storm to have hit the city of Sydney in more than 60 years, and it also deposited dust into the Tasman Sea and onto snow cover in New Zealand. Magnetization measurements from 20 to 400 K reveal that hematite, goethite, and trace amounts of magnetite are present in all samples. Magnetite concentrations (as much as 0.29 wt%) were much higher in eastern, urban sites than in western, agricultural sites in central New South Wales (0.01 wt%), strongly suggesting addition of magnetite from local urban sources. Variable temperature Mössbauer spectroscopy (300 and 4.2 K) indicates that goethite and hematite compose approximately 25-45% of the Fe-bearing phases in samples from the inland sites of Orange and Lake Cowal. Hematite was observed at both temperatures but goethite only at 4.2 K, thereby revealing the presence of nanogoethite (less than about 20 nm). Similarly, hematite particulate matter is very small (some of it d < 100 nm) on the basis of magnetic results and Mössbauer spectra. The degree to which ferric oxide in these samples might absorb solar radiation is estimated by comparing reflectance values with a magnetic parameter (hard isothermal remanent magnetization, HIRM) for ferric oxide abundance. Average visible reflectance and HIRM are correlated as a group (r2 = 0.24), indicating that Red Dawn ferric oxides have capacity to absorb

  12. The geological evolution of asteroid Vesta from Dawn orbital observations and meteorite analogs

    Science.gov (United States)

    Ruesch, Ottaviano

    2015-11-01

    Asteroid Vesta is a survivor protoplanet and the knowledge it yields is essential to understand the early stages of planet formation. To support mineralogical characterization of its surface, mineralogical and near-IR (0.7-2.5 µm) analyses of 24 howardite-eucrite-diogenite meteorites were performed (Ruesch et al., 2015). The range of observation geometries within which the compositional variations can be distinguished from geometry effects were determined, and empirical calibrations relating the position of absorption bands to average pyroxene compositions were established. Next, the empirical calibrations were applied to reflectance spectra of Vesta from the Dawn's near-IR spectrometer (VIR) revealing that Vesta´s iron-poor terrains have a Fs30Wo5 pyroxene, whereas iron-rich terrains have an average Fs47Wo14 (Ruesch et al. 2015). This confirms that, despite a homogeneous regolith, different terrains are preserved, and formed during an early magmatic period. To further characterize Vesta’s igneous processes, a search for olivine's near-IR signature was performed. Concentrations of olivine-enriched areas were found in the northern hemisphere (Ruesch et al. 2014a), corroborating other studies. As such location was unexpected, the geology of the northern was characterized with the Dawn Framing Camera observations (Ruesch et al., 2014b). The hemisphere is composed of an ancient (pre-Veneneian epoch), densely cratered terrain, partly disrupted by a subdued tectonic system (Veneneian epoch). Olivine-enriched materials are exposed recently (Marcian epoch) by impacts and mass wasting, but most of their parent lithologies are probably the result of shallow magmatic activity during the pre-Veneneian. The presence of olivine-enriched material in this context and not as exposure of an olivine-rich mantle, partly contradicts many pre-Dawn concepts of Vestan differentiation. As an alternative to the HED parent body model, few scenarios exist for Vesta's early evolution, and

  13. Spectral modeling of Ceres VIR data from Dawn: Method and Result

    Science.gov (United States)

    Raponi, Andrea; De Sanctis, M. C.; Ciarniello, M.; Carrozzo, F. G.; Ammannito, E.; Capaccioni, F.; Capria, M. T.; Frigeri, A.; Fonte, S.; Giardino, M.; Longobardo, A.; Magni, G.; Marchi, S.; Palomba, E.; Pieters, C. M.; Tosi, F.; Turrini, D.; Zambon, F.; Raymond, C. A.; Russell, C. T.

    2015-11-01

    The Dawn spacecraft [1] is at Ceres, the closest of the IAU-defined dwarf planets to the Sun. This work focuses on the interpretation of Ceres’ surface composition based on the data from the VIR instrument [2] onboard Dawn. The Visible InfraRed (VIR) mapping spectrometer combines high spectral and spatial resolution in the VIS (0.25-1mm) and IR (1-5mm) spectral ranges. VIR will provide a very good coverage of the surface during its orbital mission at Ceres.In order to model the measured spectra, we have utilized Hapke's radiative transfer model [3], which allows estimation of the mineral composition, the relative abundances of the spectral end-members, and the grain size. Optical constants of the spectral end-members are approximated by applying the methodology described in [4] to IR spectra reflectance obtained from the RELAB database.The observed spectra of Ceres surface are affected by a thermal emission component that prevents direct comparison with laboratory data at longer wavelengths. Thus to model the whole wavelength range measured by VIR, the thermal emission is modeled together with the reflectance. Calibrated spectra are first cleaned by removing artefacts. A best fit is obtained with a least square optimization algorithm. For further details on the method, see reference [5].The range 2.5 - 2.9 μm is severely hindered by Earth's atmosphere, but it contains a strong absorption band that dominates the IR Ceres’ spectrum. Thanks to the VIR instrument we can obtain a compositional model for the whole IR range [6]. We used several different combinations of materials hypothesized to be representative of the Ceres’ surface including phyllosilicates, ices, carbonaceous chondrites and salts. The results will be discussed.Acknowledgements This work is supported by the Italian Space Agencies and NASA. Enabling contributions from the Dawn Instrument, Operations, and Science Teams are gratefully acknowledged.Reference[1] Russell et al., Space Sci. Rev., 163

  14. Bulk Composition of Vesta as Constrained by the Dawn Mission and the HED Meteorites

    Science.gov (United States)

    Toplis, M. J.; Mizzon, H.; Forni, O.; Monnereau, H.; Prettyman, T. H.; McSween, H. Y.; McCoy, T. J.; Mittlefehldt, D. W.; DeSactis, M. C.; Raymond, C. T.; Russell, C. T.

    2014-01-01

    Of the objects in the main asteroid belt, Vesta is of particular interest as it is large enough to have experienced internal differentiation (520 km diameter), and it is known to have a basaltic surface dominated by FeO-bearing pyroxenes. Furthermore, visible-IR spectra of Vesta and associated Vestoids are remarkably similar to laboratory spectra of Howardite-Eucrite-Diogenite (HED) meteorites, leading to the paradigm that the HEDs ultimately came from Vesta. Geochemical and petrological studies of the HEDs confirm the differentiated nature of the near-surface region of their parent body, and imply that crust extraction occurred well within the first 10 Ma of solar system history Vesta is therefore a prime target for studies that aim to constrain the earliest stages of planet building, and it is within this context that the NASA Dawn spacecraft orbited Vesta from July 2011 to September 2012. The results of the Dawn mission so far have significantly reinforced the HED-Vesta connection, confirming a significant degree of internal differentiation, a surface mineralogy compatible with that of the HEDs, and near-surface ratios of Fe/O and Fe/Si consistent with HED lithologies. The combination of data from the HED meteorites and the Dawn mission thus presents an unprecedented opportunity to use Vesta as a natural laboratory of early differentiation processes in the early solar system. However, the bulk composition of Vesta remains a significant unknown parameter, but one that plays a key role on the physical and chemical properties of the internal and surface reservoirs (core, mantle, crust). Several attempts have been made to constrain the bulk composition of the eucrite parent body, early endeavours relying on petrological or cosmochemical constraints. More recently, individual chondrite class compositions, or mixtures thereof, have been considered, constrained by considerations such as O-isotopes, trace-element ratios and siderophile element concentrations of the

  15. Gas supermarket: Dawn pipeline junction rises as a trading hub on a continental scale in southwestern Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Faulkner, P.

    1999-11-01

    Dawn, Ontario, a small farming community near Sarnia's famed chemical valley is the site of the Union Gas Dawn Operations Centre. The region's capacity to store gas in geological formations beneath fertile fertile farm land will be used more and more with the completion of pipelines that will transmit more Alberta natural gas to markets in the eastern United States through Ontario. Its central location, a growing Ontario-Quebec market and prospects of more incoming gas appear to have conferred upon Dawn the status of a premier trading hub in Canada and maybe in North America, spurred on by regulatory regimes on both sides of the border that favour free trade in natural gas and the growing demand in the previously under-served northeastern United States materialize. The Dawn center trades gas for more than 100 energy companies, several of them electricity providers, that have been recently allowed to step into the market territory formerly occupied by Ontario Hydro. Natural gas is replacing coal burning power stations and to some extent, nuclear power in Ontario; the trend is also strong in the New England states, hence future demand for natural gas is likely to increase. It is this reasoning that underlies the construction of new pipelines, such as the Alliance Project, which will move gas from Alberta into the United States, back to Canada at Dawn, then back again into New York. If all goes according to plan, another new route called Millennium will run east from Dawn than travel under Lake Erie to join the Columbia Gas System that feeds New York City. Another line -- Vector -- that will geographically diversify west-east trading capabilities, also received FERC and NEB approval early in 1999. Yet another line by TriState, initially denied a US permit, recently received preliminary FERC approval, conditional upon approval by NEB. It is easy to see that with the spread of deregulation and competition, Dawn's role as a trading hub and as a storage

  16. Exploring Vesta's Surface Roughness and Dielectric Properties Using VIR Spectrometer and Bistatic Radar Observations by the Dawn Mission

    Science.gov (United States)

    Palmer, E. M.; Heggy, E.; Capria, M. T.; Tosi, F.; Kofman, W. W.; Russell, C. T.

    2014-12-01

    Multiple lines of evidence from NASA's Dawn mission suggest transient volatile presence at the surface of asteroid Vesta. Radar remote sensing is a useful technique for the investigation of volatile content at the surface and shallow subsurface, but requires the use of accurate dielectric and topographic models in order to deconvolve the effect of surface roughness from the total observed radar backscatter. Toward this end, we construct a dielectric model for the dry, volatile-poor case of Vesta's surface to represent average surface conditions, and to assess the expected average range of dielectric properties due to known variations in mineralogy, temperature, and density as inferred from Dawn VIR data. We employ dielectric studies of lunar samples to serve as a suitable analog to the Vestan regolith, and in the case of 10-wavelength penetration depth of X-band frequency radar observations, our model yields ɛ' from 2.5 to 2.6 from the night to dayside of Vesta, and tan δ from 0.011 to 0.014. Our estimation of ɛ' corresponds to specular surface reflectivity of ~0.05. In addition to modeling, we have also conducted an opportunistic bistatic radar (BSR) experiment at Vesta using the communications antennas aboard Dawn and on Earth. In this configuration, Dawn transmits a continuous radar signal toward the Earth while orbiting Vesta. As the Dawn spacecraft passes behind Vesta (entering an occultation), the line of sight between Dawn and Earth intersects Vesta's surface, resulting in a reflection of radar waves from the surface and shallow subsurface, which are then received on Earth for analysis. The geometry of the Dawn BSR experiment results in high incidence angles on Vesta's surface, and leads to a differential Doppler shift of only a few 10s of Hz between the direct signal and the surface echo. As a consequence, this introduces ambiguity in the measurement of bandwidth and peak power of each surface echo. We report our interpretations of each surface echo in

  17. Global variations in regolith properties on asteroid Vesta from Dawn's low-altitude mapping orbit

    Science.gov (United States)

    Denevi, Brett W.; Beck, Andrew W.; Coman, Ecaterina I.; Thomson, Bradley J.; Ammannito, Eleonora; Blewett, David T.; Sunshine, Jessica M.; de Sanctis, Maria Cristina; Li, Jian-Yang; Marchi, Simone; Mittlefehldt, David W.; Petro, Noah E.; Raymond, Carol A.; Russell, Christopher T.

    2016-12-01

    We investigate the depth, variability, and history of regolith on asteroid Vesta using data from the Dawn spacecraft. High-resolution (15-20 m pixel-1) Framing Camera images are used to assess the presence of morphologic indicators of a shallow regolith, including the presence of blocks in crater ejecta, spur-and-gully-type features in crater walls, and the retention of small (chondrite material. The presence of a thick regolith in this area supports the idea that this is an ancient terrain that has accumulated a larger component of exogenic debris. We find evidence for the gardening of crater ejecta toward more howarditic compositions, consistent with regolith mixing being the dominant form of "weathering" on Vesta.

  18. Geological Mapping of the Ac-H-14 Yalode Quadrangle of Ceres from NASA's Dawn Mission

    Science.gov (United States)

    Crown, David; Yingst, Aileen; Mest, Scott; Platz, Thomas; Sizemore, Hanna; Berman, Daniel; Williams, David; Roatsch, Thomas; Preusker, Frank; Nathues, Andreas; Hoffman, Martin; Schäfer, Michael; Raymond, Carol; Russell, Christopher

    2016-04-01

    The Dawn Science Team is conducting a geologic mapping campaign for Ceres that includes production of a Survey- and High Altitude Mapping Orbit (HAMO)-based global map and a series of 15 Low Altitude Mapping Orbit (LAMO)-based quadrangle maps. In this abstract we discuss the surface geology and geologic evolution of the Ac-H-14 Yalode Quadrangle (21-66°S, 270-360°E). The current geologic map was produced using ArcGIS software based on HAMO images (140 m/pixel) for surface morphology and stratigraphic relationships, Survey (400 m/pixel) digital terrain models for topographic information, and Dawn Framing Camera (FC) color images as context for map unit identification. The map will be updated through analysis of LAMO images (35 m/pixel) that are just becoming available. The Yalode Quadrangle is dominated by the 260-km diameter impact basin Yalode (42.3°S, 293.6°E) and includes rugged and smooth terrains to the east. Preliminary geologic mapping defined two regional units (cratered terrain and smooth material), which dominate the quadrangle, as well as a series of impact crater material units. Mapped geologic features include crater rims, graben, ridges, troughs, scarp, lineaments, and impact crater chains. Geologic contacts are typically not distinct in Survey and HAMO images. Impact craters in Yalode Quadrangle display a range of preservation states. Degraded features, including Yalode basin and numerous smaller craters, exhibit subdued rims, lack discrete ejecta deposits, and have infilled interiors. More pristine features (including Mondamin, Besua, Lono and craters on the Yalode basin floor) have well-defined, quasi-circular forms with prominent rims and in some cases discernible ejecta. Some of these craters have bowl-shaped interiors, and others contain hills or mounds on their floors that are interpreted as central peaks. Yalode basin has a variably preserved rim, which is continuous and sharply defined to the north/northwest and is irregular or degraded

  19. Modelling the 21 cm Signal From the Epoch of Reionization and Cosmic Dawn

    CERN Document Server

    Choudhury, T Roy; Majumdar, Suman; Ghara, Raghunath; Paranjape, Aseem; Mondal, Rajesh; Bharadwaj, Somnath; Samui, Saumyadip

    2016-01-01

    Studying the cosmic dawn and the epoch of reionization through the redshifted 21 cm line are among the major science goals of the SKA1. Their significance lies in the fact that they are closely related to the very first stars in the universe. Interpreting the upcoming data would require detailed modelling of the relevant physical processes. In this article, we focus on the theoretical models of reionization that have been worked out by various groups working in India with the upcoming SKA in mind. These models include purely analytical and semi-numerical calculations as well as fully numerical radiative transfer simulations. The predictions of the 21 cm signal from these models would be useful in constraining the properties of the early galaxies using the SKA data.

  20. Modelling the 21-cm Signal from the Epoch of Reionization and Cosmic Dawn

    Indian Academy of Sciences (India)

    T. Roy Choudhury; Kanan Datta; Suman Majumdar; Raghunath Ghara; Aseem Paranjape; Rajesh Mondal; Somnath Bharadwaj; Saumyadip Samui

    2016-12-01

    Studying the cosmic dawn and the epoch of reionization through the redshifted 21-cm line are among the major science goals of the SKA1. Their significance lies in the fact that they are closely related to the very first stars in the Universe. Interpreting the upcoming data would require detailed modelling of the relevant physical processes. In this article, we focus on the theoretical models of reionization that have been worked out by various groups working in India with the upcoming SKA in mind. These models include purely analytical and semi-numerical calculations as well as fully numerical radiative transfer simulations. The predictions of the 21-cm signal from these models would be useful in constraining the properties of the early galaxies using the SKA data.

  1. A Review Essay "Lise Meitner and the Dawn of the Nuclear Age", by Patricia Rife

    CERN Document Server

    Goldstein, G R

    2000-01-01

    The recently published book, ``Lise Meitner and the Dawn of the Nuclear Age'', by Patricia Rife (Boston: Birkh\\"{a}user, 1999) is reviewed in an essay for the lay audience. Meitner was a leading nuclear physicist at the time that the nucleus was the most exciting frontier of science. To establish her career, she had to overcome daunting prejudices against women in science and academia. Being of Jewish origin in Germany in the 1930's, she narrowly escaped certain disaster. Meitner was a crucial participant in the discovery of nuclear fission, yet did not share in the Nobel Prize that her collaborator, Otto Hahn, received in 1945. How these events came about, how they were intertwined with contemporary history and how they fit into the evolution of Meitner's social conscience and her abhorrence of war are some of the fascinating subjects discussed in the book and reviewed in this essay.

  2. Lithologic Mapping of HED Terrains on Vesta using Dawn Framing Camera Color Data

    CERN Document Server

    Thangjam, Guneshwar Singh; Corre, Lucille Le; Nathues, Andreas; Sierks, Holger; Hiesinger, Harald; Li, Jian-Yang; Sanchez, Juan A; Russell, Christopher T; Gaskell, Robert; Raymond, Carol

    2013-01-01

    The surface composition of Vesta, the most massive intact basaltic object in the asteroid belt, is interesting because it provides us with an insight into magmatic differentiation of planetesimals that eventually coalesced to form the terrestrial planets. The distribution of lithologic and compositional units on the surface of Vesta provides important constraints on its petrologic evolution, impact history and its relationship with Vestoids and howardite-eucrite-diogenite (HED) meteorites. Using color parameters (band tilt and band curvature) originally developed for analyzing lunar data, we have identified and mapped HED terrains on Vesta in Dawn Framing Camera (FC) color data. The average color spectrum of Vesta is identical to that of howardite regions, suggesting an extensive mixing of surface regolith due to impact gardening over the course of solar system history. Our results confirm the hemispherical dichotomy (east-west and north-south) in albedo/color/composition that has been observed by earlier stu...

  3. Mineralogy and Geology of asteroid (4) Vesta from Dawn Framing Camera

    CERN Document Server

    Thangjam, Guneshwar

    2016-01-01

    This thesis presents insights into the surface compositional heterogeneity and geology of asteroid Vesta. Lithologic mapping using Framing Camera onboard the NASA Dawn spacecraft revealed that the majority of the surface is howarditic in composition (Thangjam et al. 2013). An important outcome of this thesis is identification of olivine-rich exposures for the first time using FC color data (Thangjam et al., 2014). Another significant contribution from this thesis is an innovative three-dimensional approach of spectral analysis that could be used to study surface compositional heterogeneity of Vesta (Thangjam et al., 2016). The three band parameter space with defined polyhedrons is more advanced and robust compared to the generally used two-dimensional spectral analysis i.e., two band parameter space. A revised petrologic evolution model is presented to explain the ongoing problem of missing olivine-rich mantle of Vesta and also the petrogenesis of HED meteorites (howardite, eucrite, diogenite clan of stony ac...

  4. Dawn arrives at Ceres: Exploration of a small, volatile-rich world

    Science.gov (United States)

    Russell, C. T.; Raymond, C. A.; Ammannito, E.; Buczkowski, D. L.; De Sanctis, M. C.; Hiesinger, H.; Jaumann, R.; Konopliv, A. S.; McSween, H. Y.; Nathues, A.; Park, R. S.; Pieters, C. M.; Prettyman, T. H.; McCord, T. B.; McFadden, L. A.; Mottola, S.; Zuber, M. T.; Joy, S. P.; Polanskey, C.; Rayman, M. D.; Castillo-Rogez, J. C.; Chi, P. J.; Combe, J. P.; Ermakov, A.; Fu, R. R.; Hoffmann, M.; Jia, Y. D.; King, S. D.; Lawrence, D. J.; Li, J.-Y.; Marchi, S.; Preusker, F.; Roatsch, T.; Ruesch, O.; Schenk, P.; Villarreal, M. N.; Yamashita, N.

    2016-09-01

    On 6 March 2015, Dawn arrived at Ceres to find a dark, desiccated surface punctuated by small, bright areas. Parts of Ceres’ surface are heavily cratered, but the largest expected craters are absent. Ceres appears gravitationally relaxed at only the longest wavelengths, implying a mechanically strong lithosphere with a weaker deep interior. Ceres’ dry exterior displays hydroxylated silicates, including ammoniated clays of endogenous origin. The possibility of abundant volatiles at depth is supported by geomorphologic features such as flat crater floors with pits, lobate flows of materials, and a singular mountain that appears to be an extrusive cryovolcanic dome. On one occasion, Ceres temporarily interacted with the solar wind, producing a bow shock accelerating electrons to energies of tens of kilovolts.

  5. Reconciling the Dawn-Dusk Asymmetry in Mercury’s Exosphere with the Micrometeoroid Impact Directionality

    Science.gov (United States)

    Pokorný, Petr; Sarantos, Menelaos; Janches, Diego

    2017-06-01

    Combining dynamical models of dust from Jupiter-family comets and Halley-type comets, we demonstrate that the seasonal variation of the dust/meteoroid environment at Mercury is responsible for producing the dawn-dusk asymmetry in Mercury’s exosphere observed by the MESSENGER spacecraft. Our latest models, calibrated recently from ground-based and space-borne measurements, provide unprecedented statistics that enable us to study the longitudinal and latitudinal distribution of meteoroids impacting Mercury’s surface. We predict that the micrometeoroid impact vaporization source is expected to undergo significant motion on Mercury’s surface toward the nightside during Mercury’s approach to aphelion and toward the dayside when the planet is approaching the Sun.

  6. [Public health in Quebec at the dawn of the 21st century].

    Science.gov (United States)

    Colin, C

    2004-06-01

    This paper summarises the status of public health in Quebec at the dawn of the 21st century. After introducing the current definition, the author lays out five basic functions of public health in Quebec: knowledge and surveillance of populations health and wellbeing, health protection; prevention of disease, trauma and social problems that influence health; health and wellbeing promotion; and service organization and evaluation. The organization of public health services is then described at the local level (CLSC), regional level (Public health units) and national level (Ministry, Public health directorate and National Institute of Public Health). Finally, the trends and priorities elaborated over the last ten years, as well as the National Public Health Program to be implemented over the next ten years are described.

  7. Naked eye determination of the dawn for Sinai and Assiut of Egypt

    Directory of Open Access Journals (Sweden)

    A.H. Hassan

    2016-06-01

    Full Text Available Twilight observations were carried out by naked eye in the period (2010–2012 for north Sinai (Lat. 31°4′N, Long. 32°52′E where the background is desert, and for Assiut (Lat. 27°10′N, Long. 31°10′E in the period (2012–2014 where the background is agricultural land. The purpose of these observations is to calculate the depression of the sun below the horizon at which the normal eye can discriminate the dawn (morning white thread for two sites. The results indicated that this discrimination takes place at vertical sun depression angles, Do = 14.61° and 13.665° at Sinai and Assiut respectively.

  8. Dielectric Properties of Vesta's Surface as Constrained by Dawn VIR Observations

    CERN Document Server

    Palmer, Elizabeth M; Capria, Maria Teresa; Tosi, Federico

    2015-01-01

    Earth and orbital based radar observations of asteroids provide a unique opportunity to characterize surface roughness and the dielectric properties of their surfaces, as well as potentially explore some of their shallow subsurface physical properties. If the dielectric and topographic properties of asteroid's surfaces are defined, we can constrain their textural characteristics as well as potential subsurface volatile enrichment using the observed radar backscatter. To achieve this objective, we establish the first dielectric model of asteroid Vesta for the case of a dry, volatile-poor regolith -- employing an analogy to the dielectric properties of lunar regolith, and adjusted for the surface densities and temperatures deduced from Dawn's Visible and InfraRed mapping spectrometer (VIR). Our model suggests that the dielectric constant at the surface of Vesta is relatively constant, ranging from 2.0 to 2.1 from the night- to day-side of Vesta, while the loss tangent shows slight variation as a function of diu...

  9. Dawn Mission’s Search for satellites at Ceres: Upper limits on size of orbital objects

    Science.gov (United States)

    McFadden, Lucy-Ann A.; Skillman, David R.; Memarsadeghi, Nargess; Carsenty, Uri; Schroeder, Stefan E.; Li, Jian-Yang Y.; Rayman, Marc D.

    2015-11-01

    Hundreds of asteroids have small secondary satellites or are double, or even multiple body systems; yet dwarf planet Ceres doesn’t and isn’t. Ground-based and space-based telescopic searches have placed upper limits on the size of any secondary bodies gravitationally bound to Ceres of 1-2 km (Gehrels et al 1987, Bieryla et al. 2011). The Dawn project’s satellite working group designed and conducted a search during approach to Ceres and during high orbit concentrating its search close to Ceres’ limb where previous searches could not reach. Over 2000 images for both science and optical navigation were searched. In addition, a dedicated satellite search was conducted during two commanded off-nadir pointings. The acquired images extend 5.5° x 5.5° on either side of Ceres, at a range of ~ 145,000 km and solar phase angle at Ceres of 18°. No moving objects associated with Ceres were detected. The search extended down to Ceres’ limb (previous searches went to 500 km above the limb) and extended the upper limit for the non-detection to 30 +/- 6 and 45 +/-9 meter radius for effective exposure times of 114s and 19s respectively. An additional small search was conducted using the spacecraft's star tracker from which no objects were found. The Dawn mission’s search reduced the previous detection limit from Hubble Space Telescope images by two orders of magnitude. Why some asteroids have satellites and others don’t is a matter for dynamical speculation.

  10. The GIS data model of the Visible and Infrared mapping spectrometer (VIR) onboard NASA/Dawn

    Science.gov (United States)

    Frigeri, Alessandro; De Sanctis, Maria Cristina; Ammannito, Eleonora; Capaccioni, Fabrizio; VIR Team

    2016-10-01

    The spectrometer onboard Dawn mission to Vesta and Ceres (Russell et al., Earth Moon Planet (2007) 101:65-91) is a hyperspectral spectrometer with imaging capability which returns data useful for the determination of the mineral composition of surface materials in their geologic context. The VIR Spectrometer—covering the range from the near UV (0.25 μm) to the near IR (5.0 μm) and having moderate to high spectral resolution and imaging capabilities—is the appropriate instrument for the determination of Vesta's and Ceres' global and local properties (De Sanctis et al., SSR 2011). VIR combines two data channels in one compact instrument. The visible channel covers 0.25-1.05 μm and the infrared channel covers 1-5.0 μm. VIR is inherited from the VIRTIS mapping spectrometer (Coradini et al. in Planet. Space Sci. 46:1291-1304, 1998; Reininger et al. in Proc. SPIE 2819:66-77, 1996) on board the ESA Rosetta mission.Since the beginning of the scientific campaign, VIR calibrated data have been converted into a Geographic Information System (GIS) compatible format. Here we present the GIS data model we developed for VIR, which presents some unique peculiarities due to the specific NASA/Dawn mission design. The model has been developed starting from an object oriented modeling. This object oriented design gives the flexibility which is necessary to face, time to time, the unexpected aspects of remote sensing over planetary surfaces unobserved before with this kind of instruments.

  11. Fire and ice: GRaND observations of Vesta and Ceres by Dawn

    Science.gov (United States)

    Prettyman, Thomas H.; Yamashita, Naoyuki; Toplis, Michael J.; Y McSween, Harry; Schorghofer, Norbert; Marchi, Simone; Feldman, William C.; Castillo-Rogez, Julie; Raymond, Carol; Russell, Christopher T.; Dawn Science Team

    2016-10-01

    In June of 2016, Dawn completed its primary mission to explore the asteroid (4) Vesta and the dwarf planet (1) Ceres, the largest bodies in the main belt. At both targets, Dawn's Gamma Ray and Neutron Detector (GRaND) acquired several months of global elemental mapping data. Gamma ray and neutron spectra were analyzed to determine the bulk elemental composition of the uppermost meter of the regolith within broad surface regions. Measurements of global Fe/Si, Fe/O, and K/Th ratios buttress the connection between Vesta and the Howardite, Eucrite and Diogenite (HED) meteorites. Their parent body underwent igneous differentiation to form an iron-rich core, ultramafic mantle, and basaltic crust. In some regions, GRaND measurements show that hydrogen is concentrated in Vesta's otherwise anhydrous, basaltic regolith. Multiple lines of evidence support exogenic delivery of hydrogen by the infall of carbonaceous chondrites. In comparison, the regolith of Ceres contains orders of magnitude more hydrogen, which must have originated from within. Near Ceres' equator, the elemental composition of the regolith resembles the aqueously altered CI/CM chondrites (based on H, Fe, K, C and compositional parameters). Increased concentrations of hydrogen observed by GRaND at high latitudes likely result from the presence of extensive near-surface water ice, as anticipated by Fanale and Salvail (1989). GRaND data provide evidence that the action of water altered Ceres on a global scale, resulting in widespread hydrated minerals and residual water ice that has survived to the present day. We describe how GRaND elemental measurements constrain chemical and physical processes that shaped Ceres and discuss implications for the origins of Ceres and similar main belt objects.Fanale, F. P. and J. R. Salvail (1989), The water regime of asteroid (1) Ceres, Icarus, Vol. 82, Issue 1, pp. 97-110, doi:10.1016/0019-1035(89)90026-2.

  12. More diversity for volcanism: Ceres' Ahuna Mons from Dawn's Framing Camera data

    Science.gov (United States)

    Ruesch, Ottaviano; Platz, Thomas; Schenk, Paul M.; McFadden, Lucy Ann; Castillo-Rogez, Julie; Quick, Lynnae C.; Byrne, Shane; Preusker, Frank; O'Brien, David P.; Schmedemann, Nico; Williams, David A.; Li, Jian-Yang; Bland, Michael T.; Hiesinger, Harald; Kneissl, Thomas; Neesemann, Adrian; Schaefer, Michael; Pasckert, Jan Hendrik; Schmidt, Britney E.; Buczkowski, Debra; Sykes, Mark V.; Nathues, Andreas; Roatsch, Thomas; Hoffmann, Martin; Raymond, Carol; Russell, Christopher T.

    2016-10-01

    In the last decades, the exploration of planets and moons by spacecraft revealed a variety of volcanic expressions. The recent visit to dwarf planet Ceres by the Dawn spacecraft is shedding light on a possible new, compositionally different volcanism falling into the cryovolcanism field. The dwarf planet's properties, i.e., low bulk density, low internal temperatures and volatile-rich composition relative to terrestrial planets, would only generate melts composed of brines. On the other hand, Ceres' carbonate- and clay-rich surface mineralogy suggests a cryovolcanism different from that of water-ice dominated icy satellites.The Dawn Framing Camera (FC) provides a complete global dataset for photo-geological investigations of Ceres, including a 35 m/pixel visible coverage, a 135 m/pixel multi-spectral coverage, and a 135 m/pixel global digital elevation model from stereo-photogrammetry. Domical landforms up to a few kilometers in elevation and tens of kilometers in diameter (referred to as tholi and montes) are found scattered across Ceres' surface. Ahuna Mons is a 4-km topographic high distinct in its shape and morphology from other topographic features on Ceres. The mountain consists of two morphological units: a flank unit of unconsolidated material and a fractured (i.e., consolidated) summit unit. Steep slopes at the angle of repose characterize the flank unit, whereas the summit unit has a convex shape. The flank and summit morphologies and the morphometry of the mountain can be explained by the formation of a cryovolcanic dome, analogous to a silicic volcanic dome found on terrestrial planets. Albedo and crater size-frequency distribution measurements from FC imagery reveal geologically-recent activity on Ahuna Mons, occurring sometime within the last few hundreds Myr. The characteristics of and implications for this possible cryomagma for Ceres thermal and chemical evolution will be discussed.

  13. Geological Mapping of the Ac-H-12 Toharu Quadrangle of Ceres from NASA Dawn Mission

    Science.gov (United States)

    Mest, Scott; Williams, David; Crown, David; Yingst, Aileen; Buczkowski, Debra; Scully, Jennifer; Jaumann, Ralf; Roatsch, Thomas; Preusker, Frank; Nathues, Andres; Hoffmann, Martin; Schaefer, Michael; Raymond, Carol; Russell, Christopher

    2016-04-01

    The Dawn Science Team is conducting a geologic mapping campaign for Ceres similar to that done for Vesta [1,2], including production of a Survey- and High Altitude Mapping Orbit (HAMO)-based global map and a series of 15 Low Altitude Mapping Orbit (LAMO)-based quadrangle maps. In this abstract we discuss the surface geology and geologic evolution of the Ac-H-12 Toharu Quadrangle (21-66°S, 90-180°E). At the time of this writing LAMO images (35 m/pixel) are just becoming available. The current geologic map of Ac-H-12 was produced using ArcGIS software, and is based on HAMO images (140 m/pixel) and Survey (400 m/pixel) digital terrain models (for topographic information). Dawn Framing Camera (FC) color images were also used to provide context for map unit identification. The map (to be presented as a poster) will be updated from analyses of LAMO images. The Toharu Quadrangle is named after crater Toharu (86 km diameter; 48.3°S, 156°E), and is dominated by smooth terrain in the north, and more heavily cratered terrain in the south. The quad exhibits ~9 km of relief, with the highest elevations (~3.5-4.6 km) found among the western plateau and eastern crater rims, and the lowest elevation found on the floor of crater Chaminuka. Preliminary geologic mapping has defined three regional units (smooth material, smooth Kerwan floor material, and cratered terrain) that dominate the quadrangle, as well as a series of impact crater material units. Smooth materials form nearly flat-lying plains in the northwest part of the quad, and overlies hummocky materials in some areas. These smooth materials extend over a much broader area outside of the quad, and appear to contain some of the lowest crater densities on Ceres. Cratered terrain forms much of the map area and contains rugged surfaces formed largely by the structures and deposits of impact features. In addition to geologic units, a number of geologic features - including crater rims, furrows, scarps, troughs, and impact

  14. Geological Mapping of the Ac-H-5 Fejokoo Quadrangle of Ceres from NASA's Dawn Mission

    Science.gov (United States)

    Hughson, Kynan; Russell, Christopher; Williams, David; Buczkowski, Debra; Mest, Scott; Scully, Jennifer; Kneissl, Thomas; Ruesch, Ottaviano; Frigeri, Alessandro; Combe, Jean-Philippe; Jaumann, Ralf; Roatsch, Thomas; Preusker, Frank; Platz, Thomas; Nathues, Andreas; Hoffmann, Martin; Schaefer, Michael; Park, Ryan; Marchi, Simone; Raymond, Carol

    2016-04-01

    NASA's Dawn spacecraft arrived at Ceres on March 6, 2015, and has been studying the dwarf planet through a series of successively lower orbits, obtaining morphological & topographical image, mineralogical, elemental abundance, and gravity data. Ceres is the largest object in the asteroid belt with a mean diameter of ~950 km. The Dawn Science Team is conducting a geologic mapping campaign for Ceres similar to that done for the asteroid Vesta [1, 2], including production of a Survey- and High Altitude Mapping Orbit (HAMO)-based global map, and a series of 15 Low Altitude Mapping Orbit (LAMO)-based quadrangle maps. In this abstract we present the LAMO-based geologic map of the Ac-H-5 Fejokoo quadrangle (21-66 °N and 270-360 °E) and discuss its geologic evolution. At the time of this writing LAMO images (35 m/pixel) are just becoming available. Thus, our geologic maps are based on HAMO images (~140 m/pixel) and Survey (~400 m/pixel) digital terrain models (for topographic information) [3, 4]. Dawn Framing Camera (FC) color images are also used to provide context for map unit identification. The maps to be presented as posters will be updated from analyses of LAMO images (~35 m/pixel). The Fejokoo quadrangle hosts six primary geologic features: (1) the centrally located, ~80 km diameter, distinctly hexagonal impact crater Fejokoo; (2) Victa crater with its large exterior dark lobate flow feature, and interior lobate and furrowed deposits; (3) Abellio crater, which exhibits a well formed ejecta blanket and has an arcuately textured infilled floor whose morphology is similar to those of homologously sized craters on some of the icy Saturnian satellites [5]; (4) Cozobi crater, whose floor is filled with an unusually bulbous and smooth deposit, thin sheeted multi-lobed flow-like features that are reminiscent of fluidized ejecta as seen on Mars are also observed to be emanating outwards from the N and S rims of this crater [6]; (5) the peculiar Oxo crater on the eastern

  15. Ceres composition as inferred by the VIR-Dawn imaging spectrometer

    Science.gov (United States)

    Longobardo, Andrea

    2016-07-01

    The NASA's Dawn spacecraft [1] is orbiting around Ceres since early 2015. The Dawn mission to Ceres is divided in five stages, characterized by different altitudes above the Ceres mean surface. These five stages correspond with the different phases of the mission,, i.e. Approach, Rotational Characterization, Survey, High Altitude Mapping Orbit (HAMO) and Low Altitude Mapping Orbit (LAMO). Each phase is characterized by an increasing spatial resolution linked with the spacecraft altitude. The VIR imaging spectrometer [2] on board the Dawn spacecraft is providing a huge amount of data and giving an essential contribution to understand the Ceres composition and to give constraint about its evolution. VIR observations revealed that Ceres is a dark body, with an average albedo of 0.08 measured at 1.2 mm [3]. However, specific features seen at the local scale may show substantially higher albedo (i.e. greater than 0.2), especially in Occator, Haulani and Oxo craters [4]. VIR data reveal that the Ceres visible and near-infrared spectra (wavelength range from 0.25 to 5 mm) are mainly characterized by the following absorptions: - 2.7 mm band, ascribed to OH-bearing materials [5] and distributed across the Ceres surface; - 3.05 mm band, ascribed to NH4-bearing materials [5] and also ubiquitous on the Ceres surface; - 3.3-3.5 mm complex and 3.9 mm band, ascribed to carbonates [4] and observed only at some locations [6]. The presence of these features, in particular the 3.05 mm band, indicate widespread occurrence of ammoniated phyllosilicates [5], which could be mixed with carbonates in specific regions. The phyllosilicates composition is basically homogeneous across the Ceres surface, as suggested by the low variation of 2.7 mm and 3.05 mm band centers [7]. The presence of ammonia suggests the presence of outer Solar System materials, which could have been brought in the Main Asteroid Belt and accreted during the Ceres formation [8]. Alternatively, Ceres itself could have

  16. Attenuation distance of low frequency waves upstream of the pre-dawn bow shock: GEOTAIL and ISEE 3 comparison

    Science.gov (United States)

    Sugiyama, T.; Terasawa, T.; Kawano, H.; Yamamoto, T.; Kokubun, S.; Frank, L. A.; Ackerson, K.; Tsurutani, B. T.

    1995-01-01

    We have made a statistical study of the spatial distribution of low frequency waves (approx. 0.01-0.1 Hz) in the region upstream of the pre-dawn to dawn side bow shock (-50 Re less than X less than 15 Re) using both GEOTAIL and international sun earth explorer 3 (ISEE-3) magnetometer data. We have found that the wave amplitude dependence on D and X(sub s), where D is the distance from the bow shock and X(sub s) the x-coordinate position of shock foot point of the IMF, can be described by a functional form of A exp (X(sub s)/L(sub X)-D/L(sub D), with the characteristic attenuation distances, L(sub X) = 62 +/- 12 Re and L(sub D) = 59 +/- 38 Re.

  17. Attenuation distance of low frequency waves upstream of the pre-dawn bow shock: GEOTAIL and ISEE comparison

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, T.; Terasawa, T.; Kawano, H. [Univ. of Tokoyo (Japan)] [and others

    1995-01-15

    The authors have made a statistical study of the spatial distribution of low frequency waves ({approximately}0.01-0.1 Hz) in the region upstream of the pre-dawn to dawn side bow shock ({minus}50 Re

  18. In-Flight Operation of the Dawn Ion Propulsion System: Status at One Year from the Vesta Rendezvous

    Science.gov (United States)

    Garner, Charles E.; Rayman, Marc D.

    2010-01-01

    The Dawn mission, part of NASA's Discovery Program, has as its goal the scientific exploration of the two most massive main-belt asteroids, Vesta and Ceres. The Dawn spacecraft was launched from Cape Canaveral Air Force Station on September 27, 2007 on a Delta-II 7925H-9.5 (Delta-II Heavy) rocket that placed the 1218 kg spacecraft into an Earth-escape trajectory. On-board the spacecraft is an ion propulsion system (IPS) developed at the Jet Propulsion Laboratory which will provide most of the delta V needed for heliocentric transfer to Vesta, orbit capture at Vesta, transfer among Vesta science orbits, departure and escape from Vesta, heliocentric transfer to Ceres, orbit capture at Ceres, and transfer among Ceres science orbits. The Dawn ion thruster [I thought we only called it a thruster. Both terms are used in the paper, but I think a replacement of every occurrence of "engine" with "thruster" would be clearer.] design is based on the design validated on NASA's Deep Space 1 (DS1) mission. However, because of the very substantial (11 km/s) delta V requirements for this mission Dawn requires two engines to complete its mission objectives. The power processor units (PPU), digital control and interface units (DCIU) slice boards and the xenon control assembly (XCA) are derivatives of the components used on DS1. The DCIUs and thrust gimbal assemblies (TGA) were developed at the Jet Propulsion Laboratory. The spacecraft was provided by Orbital Sciences Corporation, Sterling, Virginia, and the mission is managed by and operated from the Jet Propulsion Laboratory. Dawn partnered with Germany, Italy and Los Alamos National Laboratory for the science instruments. The mission is led by the principal investigator, Dr. Christopher Russell, from the University of California, Los Angeles. The first 80 days after launch were dedicated to the initial checkout of the spacecraft followed by cruise to Mars. Cruise thrusting leading to a Mars gravity assist began on December 17

  19. In-Flight Operation of the Dawn Ion Propulsion System Through Start of the Vesta Cruise Phase

    Science.gov (United States)

    Garner, Charles E.; Rayman, Marc D.; Brophy, John R.

    2009-01-01

    The Dawn mission, part of NASA's Discovery Program, has as its goal the scientific exploration of the two most massive main-belt asteroids, Vesta and Ceres. The Dawn spacecraft was launched from Cape Canaveral Air Force Station on September 27, 2007 on a Delta-II 7925H-9.5 (Delta-II Heavy) rocket that placed the 1218 kg spacecraft into an Earth-escape trajectory. On-board the spacecraft is an ion propulsion system (IPS) which will provide most of the delta V needed for heliocentric transfer to Vesta, orbit capture at Vesta, transfer to Vesta science orbits, departure and escape from Vesta, heliocentric transfer to Ceres, orbit capture at Ceres, and transfer to Ceres science orbits. The Dawn ion design is based on the design validated on NASA's Deep Space 1 (DS1) mission. However, because of the very substantial (11 km/s) delta V requirements for this mission Dawn requires two engines to complete its mission objectives. The power processor units (PPU), digital control and interface units (DCIU) slice boards and the xenon control assembly (XCA) are derivatives of the components used on DS1. The DCIUs and thrust gimbal assemblies (TGA) were developed at the Jet Propulsion Laboratory. The spacecraft was provided by Orbital Sciences Corporation, Sterling, Virginia, and the mission is managed by and operated from the Jet Propulsion Laboratory. Dawn partnered with Germany, Italy and Los Alamos National Laboratory for the science instruments. The mission is led by the principal investigator, Dr. Christopher Russell, from the University of California, Los Angeles. The first 80 days after launch were dedicated to the initial checkout of the spacecraft followed by cruise to Mars. Cruise thrusting leading to a Mars gravity assist began on December 17, 2007 and was successfully concluded as planned on October 31, 2008. During this time period the Dawn IPS was operated mostly at full power for approximately 6500 hours, consumed 71.7 kg of xenon and delivered approximately 1.8 km

  20. It's Always Darkest Before the Cosmic Dawn: Early Results from Novel Tools and Telescopes for 21 cm Cosmology

    CERN Document Server

    Dillon, Joshua S

    2015-01-01

    21 cm cosmology, the statistical observation of the high redshift universe using the hyperfine transition of neutral hydrogen, has the potential to revolutionize our understanding of cosmology and the astrophysical processes that underlie the formation of the first stars, galaxies, and black holes during the "Cosmic Dawn." By making tomographic maps with low frequency radio interferometers, we can study the evolution of the 21 cm signal with time and spatial scale and use it to understand the density, temperature, and ionization evolution of the intergalactic medium over this dramatic period in the history of the universe. For my Ph.D. thesis, I explore a number of advancements toward detecting and characterizing the 21 cm signal from the Cosmic Dawn, especially during its final stage, the epoch of reionization. In seven different previously published papers, I explore new techniques for the statistical analysis of interferometric measurements, apply them to data from current generation telescopes like the Mu...

  1. Comparison of the onset of dawn chorus of bulbuls and house sparrows in two different geographical locations: effect of climate, noise and light pollution

    Directory of Open Access Journals (Sweden)

    Nail M. Hasan

    2011-04-01

    Full Text Available The onset of dawn chorus was studied for a period of fourteen months for bulbuls (Pycnonotidae and house sparrows (Passer domesticus in two different geographical locations. One is very quiet and semi lit place in the suburbs of the small Mediterranean city of Tulkarem/Palestinian Authority. The other location is comparatively noisy and very well lit place in the Ar-Rayyan urban district of the city of Riyadh/ Saudi Arabia where desert climate prevails. This study is the first of its kind and clearly shows that the timing of dawn chorus is similar for autumn and winter seasons in both locations but major differences were observed from February until September between the two locations. It can be concluded that very early timing of dawn chorus during spring / summer for the Riyadh location cannot only be attributed to breeding season and is temperature dependent (strong positive correlation, r>0.6. The similarities for autumn and early winter between the two locations is very interesting in that it is not in agreement with the notion that big cities (urbanization influence the timing of dawn chorus due to noise and light pollution. This emphasizes that dawn chorus is a complex process and that change in the onset and pattern of dawn chorus can not merely be attributed to one variable such as noise or light pollution alone.

  2. Geological Mapping of the Ac-H-13 Urvara Quadrangle of Ceres from NASA's Dawn Mission

    Science.gov (United States)

    Sizemore, Hanna; Williams, David; Platz, Thomas; Mest, Scott; Yingst, Aileen; Crown, David; O'Brien, David; Buczkowski, Debra; Schenk, Paul; Scully, Jennifer; Jaumann, Ralf; Roatsch, Thomas; Preusker, Frank; Nathues, Andreas; De Sanctis, Maria Cristina; Russell, Christopher; Raymond, Carol

    2016-04-01

    The Dawn Science Team is conducting a geologic mapping campaign for Ceres similar to that done for Vesta [1,2], including production of a Survey- and High Altitude Mapping Orbit (HAMO)-based global map, and a series of 15 Low Altitude Mapping Orbit (LAMO)-based quadrangle maps. In this abstract we discuss the geologic evolution of the Ac-H-13 Urvara Quadrangle. At the time of this writing LAMO images (35 m/pixel) are just becoming available. Thus, our geologic maps are based on HAMO images (140 m/pixel) and Survey (400 m/pixel) digital ter-rain models (for topographic information). Dawn Framing Camera (FC) color images are also used to provide context for map unit identification. The maps to be presented as posters will be updated from analyses of LAMO images. The Urvara Quadrangle is dominated by the 170-km diameter impact basin Urvara (46.4°S, 248.6°E) and includes cratered terrain to the west. Named features include the impact craters Meanderi (40.9°S, 193.7°E, 103 km diameter), Sekhet (66.4°S, 254.9°E, 41 km diameter), and Fluusa (31.5°S, 277.9°E), as well as the crater chains Gerber Catena (38.1°S, 214.8°E) and Sam-hain Catena (19.6°S, 210.3°E). Based on preliminary geologic mapping [3,4], we interpret the two prominent catenae as pit craters associated with large scale tectonism rather than secondary impacts. We interpret two large curvilinear depressions near the eastern quadrangle boundary as secondary crater chains resulting from the Urvara impact. Textural and morphological asymme-tries in crater materials within the quadrangle indicate heterogeneities in subsurface composition and volatile content. Features on the Urvara basin floor are consistent with impact fluidization of target materials; post impact extrusion of volatile rich material may have also played a minor role. References: [1] Williams D.A. et al. (2014) Icarus, 244, 1-12. [2] Yingst R.A. et al. (2014) PSS, 103, 2-23. [3] Sizemore et al. (2015) GSA Abstracts with Program

  3. Line-of-Sight Anisotropies in the Cosmic Dawn and Epoch of Reionization 21-cm Power Spectrum

    Indian Academy of Sciences (India)

    Suman Majumdar; Kanan K. Datta; Raghunath Ghara; Rajesh Mondal; T. Roy Choudhury; Somnath Bharadwaj; Sk. Saiyad Ali; Abhirup Datta

    2016-12-01

    The line-of-sight direction in the redshifted 21-cm signal coming from the cosmic dawn and the epoch of reionization is quite unique in many ways compared to any other cosmological signal. Different unique effects, such as the evolution history of the signal, non-linear peculiar velocities of the matter etc. will imprint their signature along the line-of-sight axis of the observed signal. One of the major goals of the future SKA-LOW radio interferometer is to observe the cosmic dawn and the epoch of reionization through this 21-cm signal. It is thus important to understand how these various effects affect the signal for its actual detection and proper interpretation. For more than one and half decades, various groups in India have been actively trying to understand and quantify the different line-of-sight effects that are present in this signal through analytical models and simulations. In many ways the importance of this sub-field under 21-cm cosmology have been identified, highlighted and pushed forward by the Indian community. In this article, we briefly describe their contribution and implication of these effects in the context of the future surveys of the cosmic dawn and the epoch of reionization that will be conducted by the SKA-LOW.

  4. The location of the open-closed magnetic field line boundary in the dawn sector auroral ionosphere

    Directory of Open Access Journals (Sweden)

    J. A. Wild

    2004-11-01

    Full Text Available As a measure of the degree of coupling between the solar wind-magnetosphere-ionosphere systems, the rate at which the size of the polar cap (the region corresponding to ionospheric termini of open magnetic flux tubes varies is of prime importance. However, a reliable technique by which the extent of the polar cap might be routinely monitored has yet to be developed. Current techniques provide particularly ambiguous indications of the polar cap boundary in the dawn sector. We present a case study of space- and ground-based observations of the dawn-sector auroral zone and attempt to determine the location of the polar cap boundary using multi-wavelength observations of the ultraviolet aurora (made by the IMAGE FUV imager, precipitating particle measurements (recorded by the FAST, DMSP, and Cluster 1 and 3 satellites, and SuperDARN HF radar observations of the ionospheric Doppler spectral width boundary. We conclude that in the dawn sector, during the interval presented, neither the poleward edge of the wideband auroral UV emission (140-180nm nor the Doppler spectral width boundary were trustworthy indicators of the polar cap boundary location, while narrow band UV emissions in the range 130-140nm appear to be much more reliable.

  5. A filament of energetic particles near the high-latitude dawn magnetopause

    Science.gov (United States)

    Lui, A. T. Y.; Williams, D. J.; Mcentire, R. W.; Christon, S. P.; Jacquey, C.; Angelopoulos, V.; Yamamoto, T.; Kokubun, S.; Frank, L. A.; Ackerson, K. L.

    1994-01-01

    The Geotail satelite detected a filament of tailward-streaming energetic particles spatially separated from the boundary layer of energetic particles at the high-latitude dawn magnetopause at a downstream distance of approximately 80 R(sub E) on October 27, 1992. During this event, the composition and charge states of energetic ions at energies above approximately 10 keV show significant intermix of ions from solar wind and ionospheric sources. Detailed analysis leads to the deduction that the filament was moving southward towards the neutral sheet at an average speed of approximately 80 km/s, implying an average duskward electric field of approximately 1 mV/m. Its north-south dimension was approximately 1 R(sub E) and it was associated with an earthward directed field-aligned current of approximately 5 mA/m. The filament was separated from the energetic particle boundary layer straddling the magnetopause by approximately 0.8 R(sub E) and was inferred to be detached from the boundary layer at downstream distance beyond approximately 70 R(sub E) in the distant tail.

  6. Dusk to dawn activity patterns of anopheline mosquitoes in West Timor and Java, Indonesia.

    Science.gov (United States)

    Ndoen, Ermi; Wild, Clyde; Dale, Pat; Sipe, Neil; Dale, Mike

    2011-05-01

    Malaria is a serious health issue in Indonesia. We investigated the dusk to dawn anopheline mosquito activity patterns, host-seeking and resting locations in coastal plain, hilly and highland areas in West Timor and Java. Adult mosquitoes were captured landing on humans or resting in houses or animal barns. Data analyzed were: mosquito night-time activities; period of peak activity; night-time activity in specific periods of time and for mosquito resting locations. Eleven species were recorded; data were sparse for some species therefore detailed analyses were performed for four species only. In Java Anopheles vagus was common, with a bimodal pattern of high activity. In West Timor, its activity peaked around midnight. Other species with peak activity around the middle of the night were An. barbirostris and An. subpictus. Most species showed no biting and resting preference for indoors or outdoors, although An. barbirostris preferred indoors in West Timor, but outdoors in Java. An. aconitus and An. annularis preferred resting in human dwellings; An. subpictus and An. vagus preferred resting in animal barns. An. barbirostris preferred resting in human dwellings in West Timor and in animal barns in Java. The information is useful for planning the mosquito control aspect of malaria management. For example, where mosquito species have peak activity at night indoors, bednets and indoor residual spraying should reduce malaria risk, but where mosquitoes are most active outdoors, other options may be more effective.

  7. 21 cm Fluctuations of the Cosmic Dawn with the Owens Valley Long Wavelength Array

    Science.gov (United States)

    Eastwood, Michael; Hallinan, Gregg; Owens Valley LWA Collaboration

    2016-01-01

    The Owens Valley Long Wavelength Array (OVRO LWA) is a 288-antenna interferometer covering 30 to 80 MHz located at the Owens Valley Radio Observatory (OVRO) near Big Pine, California. I am leading the effort to detect spatial fluctuations of the 21 cm transition from the cosmic dawn (z~20) with the OVRO LWA. These spatial fluctuations are primarily sourced by inhomogeneous X-ray heating from early star formation. The spectral hardness of early X-ray sources, stellar feedback mechanisms, and baryon streaming therefore all play a role in shaping the power spectrum. I will present the application of m-mode analysis (Shaw et al. 2014, Shaw et al. 2015) to OVRO LWA data to: 1. compress the data set, 2. create maps of the northern sky that can be fed back into the calibration pipeline, and 3. filter foreground emission. Finally I will present the current status and future prospects of the OVRO LWA for detecting the 21 cm power spectrum at z~20.

  8. Introducing CoDa (Cosmic Dawn): Radiation-Hydrodynamics of Galaxy Formation in the Early Universe

    Science.gov (United States)

    Ocvirk, Pierre; Gillet, Nicolas; Shapiro, Paul; Aubert, Dominique; Iliev, Ilian; Romain, Teyssier; Yepes, Gustavo; Choi, Jun-hwan; Sullivan, David; Knebe, Alexander; Gottloeber, Stefan; D'Aloisio, Anson; Park, Hyunbae; Hoffman, Yehuda

    2015-08-01

    CoDa (Cosmic Dawn) is the largest fully coupled radiation hydrodynamics simulation of the reionization of the local Universe to date. It was performed using RAMSES-CUDATON running on 8192 nodes (i.e. 8192 GPUs) on the titan supercomputer at Oak Ridge National Laboratory to simulate a 64 h-1Mpc side box down to z=4.23. In this simulation, reionization proceeds self-consistently, driven by stellar radiation. We compare the simulation's reionization history, ionizing flux density, the cosmic star formation history and the CMB Thompson scattering optical depth with their observational values. Luminosity functions are also in rather good agreement with high redshift observations, although very bright objects (MAB1600 gas filaments present a sheathed structure, with a hot envelope surrounding a cooler core. They are however not able to self-shield, while regions denser than 10^-4.5 H atoms per comoving h^-3cm^3 are. Haloes below M ˜ 3.10^9 M⊙ are severely affected by the expanding, rising UV background: their ISM is quickly photo-heated to temperatures above our star formation threshold and therefore stop forming stars after local reionization has occured. Overall, the haloes between 10^(10-11) M⊙ dominate the star formation budget of the box for most of the Epoch of Reionization. Several additional studies will follow, looking for instance at environmental effects on galaxy properties, and the regimes of accretion.

  9. Performance of High-Efficiency Advanced Triple-Junction Solar Panels for the LILT Mission Dawn

    Science.gov (United States)

    Fatemi, Navid S.; Sharma, Surya; Buitrago, Oscar; Sharps, Paul R.; Blok, Ron; Kroon, Martin; Jalink, Cees; Harris, Robin; Stella, Paul; Distefano, Sal

    2005-01-01

    NASA's Discovery Mission Dawn is designed to (LILT) conditions. operate within the solar system's Asteroid belt, where the large distance from the sun creates a low-intensity, low-temperature (LILT) condition. To meet the mission power requirements under LlLT conditions, very high-efficiency multi-junction solar cells were selected to power the spacecraft to be built by Orbital Sciences Corporation (OSC) under contract with JPL. Emcore's InGaP/InGaAs/Ge advanced triple-junction (ATJ) solar cells, exhibiting an average air mass zero (AMO) efficiency of greater than 27.6% (one-sun, 28 C), were used to populate the solar panels [1]. The two solar array wings, to be built by Dutch Space, with 5 large- area panels each (total area of 36.4 sq. meters) are projected to produce between 10.3 kWe and 1.3 kWe of end-of life (EOL) power in the 1.0 to 3.0 AU range, respectively. The details of the solar panel design, testing and power analysis are presented.

  10. Extremely metal-poor stars from the cosmic dawn in the bulge of the Milky Way

    CERN Document Server

    Howes, L M; Asplund, M; Keller, S C; Yong, D; Nataf, D M; Poleski, R; Lind, K; Kobayashi, C; Owen, C I; Ness, M; Bessell, M S; Da Costa, G S; Schmidt, B P; Tisserand, P; Udalski, A; Szymański, M K; Soszyński, I; Pietrzyński, G; Ulaczyk, K; Wyrzykowski, Ł; Pietrukowicz, P; Skowron, J; Kozłowski, S; Mróz, P

    2015-01-01

    The first stars are predicted to have formed within 200 million years after the Big Bang, initiating the cosmic dawn. A true first star has not yet been discovered, although stars with tiny amounts of elements heavier than helium ('metals') have been found in the outer regions ('halo') of the Milky Way. The first stars and their immediate successors should, however, preferentially be found today in the central regions ('bulges') of galaxies, because they formed in the largest over-densities that grew gravitationally with time. The Milky Way bulge underwent a rapid chemical enrichment during the first 1-2 billion years, leading to a dearth of early, metal-poor stars. Here we report observations of extremely metal-poor stars in the Milky Way bulge, including one star with an iron abundance about 10,000 times lower than the solar value without noticeable carbon enhancement. We confirm that the most metal-poor bulge stars are on tight orbits around the Galactic Centre, rather than being halo stars passing through...

  11. Olivine or Impact Melt: Nature of the "Orange" Material on Vesta from Dawn

    CERN Document Server

    Corre, Lucille Le; Schmedemann, Nico; Becker, Kris J; O'Brien, David P; Yamashita, Naoyuki; Peplowski, Patrick N; Prettyman, Thomas H; Li, Jian-Yang; Cloutis, Edward A; Denevi, Brett W; Kneissl, Thomas; Palmer, Eric; Gaskell, Robert W; Nathues, Andreas; Gaffey, Michael J; Mittlefehldt, David W; Garry, William B; Sierks, Holger; Russell, Christopher T; Raymond, Carol A

    2013-01-01

    NASA's Dawn mission observed a great variety of colored terrains on asteroid (4) Vesta during its survey with the Framing Camera (FC). Here we present a detailed study of the orange material on Vesta, which was first observed in color ratio images obtained by the FC and presents a red spectral slope. The orange material deposits can be classified into three types, a) diffuse ejecta deposited by recent medium-size impact craters (such as Oppia), b) lobate patches with well-defined edges, and c) ejecta rays from fresh-looking impact craters. The location of the orange diffuse ejecta from Oppia corresponds to the olivine spot nicknamed "Leslie feature" first identified by Gaffey (1997) from ground-based spectral observations. The distribution of the orange material in the FC mosaic is concentrated on the equatorial region and almost exclusively outside the Rheasilvia basin. Our in-depth analysis of the composition of this material uses complementary observations from FC, the visible and infrared spectrometer (VI...

  12. Internal lecture: The dawn of the Standard Model's revolution | 6 June | Main Auditorium

    CERN Multimedia

    2014-01-01

    "The dawn of the Standard Model's revolution", by Luigi di Lella and Alvaro de Rujula.   Alvaro de Rujula. 15:30 - 16:20: Lecture by Alvaro de Rujula (followed by 20 minutes of questions) Abstract In the few years around November 1974, particle physics changed very significantly and at a frantic pace. Practitioners began to get accustomed to the successful predictions of the Standard Model, which did not have many believers at that time. I shall recall the main experimental and theoretical advances, concerning in particular quarks as partons, the asymptotic freedom of QCD, charmonia and the first openly charmed particles. Career Alvaro de Rújula was at Harvard University during the Standard Model revolution. Before and after, amongst many other places, he worked at CERN.   16:40 - 17:00: Coffee break   Luigi di Lella. 17:00 - 17:50: Lecture by Luigi di Lella: Experiments at CERN in the decade 1964-1974 (followed by 20 minut...

  13. Olivine-rich exposures at Bellicia and Arruntia craters on (4) Vesta from Dawn FC

    CERN Document Server

    Thangjam, Guneshwar; Mengel, Kurt; Hoffmann, Martin; Schäfer, Michael; Reddy, Vishnu; Cloutis, Edward A; Christensen, Ulrich; Sierks, Holger; Corre, Lucille Le; Vincent, Jean-Baptiste; Russell, Christopher T

    2014-01-01

    We present an analysis of the olivine-rich exposures at Bellicia and Arruntia craters using Dawn Framing Camera (FC) color data. Our results confirm the existence of olivine-rich materials at these localities as described by Ammannito et al. (2013a) using Visual Infrared Spectrometer (VIR) data. Analyzing laboratory spectra of various Howardite-Eucrite-Diogenite meteorites, high-Ca pyroxenes, olivines and olivine-orthopyroxene mixtures, we derive three FC spectral band parameters that are indicators of olivine-rich materials. Combining the three band parameters allows us, for the first time, to reliably identify sites showing modal olivine contents >40%. The olivine-rich exposures at Bellicia and Arruntia are mapped using higher spatial resolution FC data. The exposures are located on the slopes of outer/inner crater walls, on the floor of Arruntia, in the ejecta, as well as in nearby fresh small impact craters. The spatial extent of the exposures ranges from a few hundred meters to few kilometers. The olivin...

  14. Performance of High-Efficiency Advanced Triple-Junction Solar Panels for the LILT Mission Dawn

    Science.gov (United States)

    Fatemi, Navid S.; Sharma, Surya; Buitrago, Oscar; Sharps, Paul R.; Blok, Ron; Kroon, Martin; Jalink, Cees; Harris, Robin; Stella, Paul; Distefano, Sal

    2005-01-01

    NASA's Discovery Mission Dawn is designed to (LILT) conditions. operate within the solar system's Asteroid belt, where the large distance from the sun creates a low-intensity, low-temperature (LILT) condition. To meet the mission power requirements under LlLT conditions, very high-efficiency multi-junction solar cells were selected to power the spacecraft to be built by Orbital Sciences Corporation (OSC) under contract with JPL. Emcore's InGaP/InGaAs/Ge advanced triple-junction (ATJ) solar cells, exhibiting an average air mass zero (AMO) efficiency of greater than 27.6% (one-sun, 28 C), were used to populate the solar panels [1]. The two solar array wings, to be built by Dutch Space, with 5 large- area panels each (total area of 36.4 sq. meters) are projected to produce between 10.3 kWe and 1.3 kWe of end-of life (EOL) power in the 1.0 to 3.0 AU range, respectively. The details of the solar panel design, testing and power analysis are presented.

  15. Simulating the Impact of X-ray Heating during the Cosmic Dawn

    CERN Document Server

    Ross, Hannah E; Iliev, Ilian T; Mellema, Garrelt

    2016-01-01

    Upcoming observations of the 21-cm signal from the Epoch of Reionization will soon provide us with the first direct detection of this era. This signal is influenced by many astrophysical effects, including long range X-ray heating of the intergalactic gas. During the preceding Cosmic Dawn era the impact of this heating on the 21-cm signal is particularly prominent, especially before spin temperature saturation. We present the largest-volume (244~$h^{-1}$Mpc=349\\,Mpc comoving) full numerical radiative transfer simulations to date of this epoch, including the effects of helium and multi-frequency heating, both with and without X-ray sources. We show that X-ray sources can contribute significantly to early heating of the neutral intergalactic medium and, hence, to the corresponding 21-cm signal. The inclusion of hard, energetic radiation yields an earlier, extended transition from absorption to emission compared to the stellar-only case. The presence of X-ray sources decreases the absolute value of the mean 21-c...

  16. Extremely metal-poor stars from the cosmic dawn in the bulge of the Milky Way.

    Science.gov (United States)

    Howes, L M; Casey, A R; Asplund, M; Keller, S C; Yong, D; Nataf, D M; Poleski, R; Lind, K; Kobayashi, C; Owen, C I; Ness, M; Bessell, M S; Da Costa, G S; Schmidt, B P; Tisserand, P; Udalski, A; Szymański, M K; Soszyński, I; Pietrzyński, G; Ulaczyk, K; Wyrzykowski, Ł; Pietrukowicz, P; Skowron, J; Kozłowski, S; Mróz, P

    2015-11-26

    The first stars are predicted to have formed within 200 million years after the Big Bang, initiating the cosmic dawn. A true first star has not yet been discovered, although stars with tiny amounts of elements heavier than helium ('metals') have been found in the outer regions ('halo') of the Milky Way. The first stars and their immediate successors should, however, preferentially be found today in the central regions ('bulges') of galaxies, because they formed in the largest over-densities that grew gravitationally with time. The Milky Way bulge underwent a rapid chemical enrichment during the first 1-2 billion years, leading to a dearth of early, metal-poor stars. Here we report observations of extremely metal-poor stars in the Milky Way bulge, including one star with an iron abundance about 10,000 times lower than the solar value without noticeable carbon enhancement. We confirm that most of the metal-poor bulge stars are on tight orbits around the Galactic Centre, rather than being halo stars passing through the bulge, as expected for stars formed at redshifts greater than 15. Their chemical compositions are in general similar to typical halo stars of the same metallicity although intriguing differences exist, including lower abundances of carbon.

  17. Observations and Theory of Mirror-Mode Structures in the Dawn-Side Magnetosphere

    Science.gov (United States)

    Rae, I. J.; Mann, I. R.; Watt, C. E. J.; Kistler, L. M.

    There are a number of mechanisms by which ULF oscillations can be excited in the magnetosphere both externally i e solar wind or internally e g via resonance with energetic particle sources One mechanism that is not traditionally considered observed is the mirror instability mode The mirror mode is a compressible slow mode typically excited in high-beta plasmas where there is significant pressure anisotropy and grows if the free energy of the pressure anisotropy is sufficiently large and must be dissipated Observational evidence of these mirror modes are rare but mainly concentrated in the dayside magnetosheath where the necessary temperature anisotropies can develop and increase as the magnetopause is approached However it is possible to generate the mirror instability inside the magnetosphere though as yet there are few observational examples We present an interval on the 19 th March 1998 when the Equator-S spacecraft is traversing the dawn-side magnetosphere above the ecliptic plane at radial distances of up to L sim 11 and encounters quasi-monochromatic perturbations in the magnetic field ion number density temperatures and velocities The magnetic field strength and number density oscillations are anti-correlated and the plasma and magnetic field pressure variations are in anti-phase also which are all consistent with the mirror instability hypothesis We calculate the classic mirror instability criterion Hasegawa 1969 and find that the condition for mirror-mode waves to grow is strongly met throughout the interval

  18. The prehistory of potyviruses: their initial radiation was during the dawn of agriculture.

    Directory of Open Access Journals (Sweden)

    Adrian J Gibbs

    Full Text Available BACKGROUND: Potyviruses are found world wide, are spread by probing aphids and cause considerable crop damage. Potyvirus is one of the two largest plant virus genera and contains about 15% of all named plant virus species. When and why did the potyviruses become so numerous? Here we answer the first question and discuss the other. METHODS AND FINDINGS: We have inferred the phylogenies of the partial coat protein gene sequences of about 50 potyviruses, and studied in detail the phylogenies of some using various methods and evolutionary models. Their phylogenies have been calibrated using historical isolation and outbreak events: the plum pox virus epidemic which swept through Europe in the 20th century, incursions of potyviruses into Australia after agriculture was established by European colonists, the likely transport of cowpea aphid-borne mosaic virus in cowpea seed from Africa to the Americas with the 16th century slave trade and the similar transport of papaya ringspot virus from India to the Americas. CONCLUSIONS/SIGNIFICANCE: Our studies indicate that the partial coat protein genes of potyviruses have an evolutionary rate of about 1.15x10(-4 nucleotide substitutions/site/year, and the initial radiation of the potyviruses occurred only about 6,600 years ago, and hence coincided with the dawn of agriculture. We discuss the ways in which agriculture may have triggered the prehistoric emergence of potyviruses and fostered their speciation.

  19. Quality of Life, Wishes, and Needs in Women with Gestational Diabetes: Italian DAWN Pregnancy Study

    Directory of Open Access Journals (Sweden)

    A. Lapolla

    2012-01-01

    Full Text Available The DAWN (Diabetes Attitudes, Wishes and Needs study is a survey promoted by the International Diabetes Federation to recognize the perceptions and attitudes of people suffering from diabetes mellitus. In this context, we evaluated the quality of life of Italian and immigrant women with gestational diabetes mellitus (GDM. Information was gathered using a structured questionnaire for patients’ self-compilation. In a 3-month period, a 51-item questionnaire was submitted to 198 Italians and 88 immigrants (from 27 different foreign nationalities. Italian women were older and had higher education than the immigrants. 60% of the Italians and 38% of the immigrants had a family history of diabetes mellitus. In both groups, the diagnosis of GDM caused anxiety; one-third of women feared their child could contract diabetes at delivery and/or have congenital malformations. Some women had trouble in following treatment regimens: the major concern being dietary advice and blood glucose testing. Most women were satisfied (34% or highly satisfied (60% with the quality of care, although the degree of cooperation between diabetes specialists and gynaecologists was considered sometimes unsatisfactory. In order to optimize maternal and foetal outcomes, educational projects and improved communication between patients and the healthcare provider team are recommended.

  20. The remarkable surface homogeneity of the Dawn mission target (1) Ceres

    CERN Document Server

    Carry, Benoit; Dumas, Christophe; Merline, William J; Mousis, Olivier; Rousselot, Philippe; Jehin, Emmanuel; Manfroid, Jean; Fulchignoni, Marcello; Zucconi, Jean-Marc

    2011-01-01

    Dwarf-planet (1) Ceres is one of the two targets, along with (4) Vesta, that will be studied by the NASA Dawn spacecraft via imaging, visible and near-infrared spectroscopy, and gamma-ray and neutron spectroscopy. While Ceres' visible and near-infrared disk-integrated spectra have been well characterized, little has been done about quantifying spectral variations over the surface. Any spectral variation would give us insights on the geographical variation of the composition and/or the surface age. The only work so far was that of Rivkin & Volquardsen (2010, Icarus 206, 327) who reported rotationally-resolved spectroscopic (disk-integrated) observations in the 2.2-4.0 {\\mu}m range; their observations showed evidence for a relatively uniform surface. Here, we report disk-resolved observations of Ceres with SINFONI (ESO VLT) in the 1.17-1.32 {\\mu}m and 1.45-2.35 {\\mu}m wavelength ranges. The observations were made under excellent seeing conditions (0.6"), allowing us to reach a spatial resolution of ~75 km o...

  1. The Cosmic Dawn and Epoch of Reionization with the Square Kilometre Array

    CERN Document Server

    Koopmans, L V E; Mellema, G; Abdalla, F; Aguirre, J; Ahn, K; Barkana, R; van Bemmel, I; Bernardi, G; Bonaldi, A; Briggs, F; de Bruyn, A G; Chang, T C; Chapman, E; Chen, X; Ciardi, B; Datta, K K; Dayal, P; Ferrara, A; Fialkov, A; Fiore, F; Ichiki, K; Illiev, I T; Inoue, S; Jelić, V; Jones, M; Lazio, J; Maio, U; Majumdar, S; Mack, K J; Mesinger, A; Morales, M F; Parsons, A; Pen, U -L; Santos, M; Schneider, R; Semelin, B; de Souza, R S; Subrahmanyan, R; Takeuchi, T; Trott, C; Vedantham, H; Wagg, J; Webster, R; Wyithe, S

    2015-01-01

    Concerted effort is currently ongoing to open up the Epoch of Reionization (EoR) ($z\\sim$15-6) for studies with IR and radio telescopes. Whereas IR detections have been made of sources (Lyman-$\\alpha$ emitters, quasars and drop-outs) in this redshift regime in relatively small fields of view, no direct detection of neutral hydrogen, via the redshifted 21-cm line, has yet been established. Such a direct detection is expected in the coming years, with ongoing surveys, and could open up the entire universe from $z\\sim$6-200 for astrophysical and cosmological studies, opening not only the EoR, but also its preceding Cosmic Dawn ($z\\sim$30-15) and possibly even the later phases of the Dark Ages ($z\\sim$200-30). All currently ongoing experiments attempt statistical detections of the 21-cm signal during the EoR, with limited signal-to-noise. Direct imaging, except maybe on the largest (degree) scales at lower redshifts, as well as higher redshifts will remain out of reach. The Square Kilometre Array(SKA) will revolu...

  2. Bayesian constraints on the global 21-cm signal from the Cosmic Dawn

    Science.gov (United States)

    Bernardi, G.; Zwart, J. T. L.; Price, D.; Greenhill, L. J.; Mesinger, A.; Dowell, J.; Eftekhari, T.; Ellingson, S. W.; Kocz, J.; Schinzel, F.

    2016-09-01

    The birth of the first luminous sources and the ensuing epoch of reionization are best studied via the redshifted 21-cm emission line, the signature of the first two imprinting the last. In this work, we present a fully Bayesian method, HIBAYES, for extracting the faint, global (sky-averaged) 21-cm signal from the much brighter foreground emission. We show that a simplified (but plausible) Gaussian model of the 21-cm emission from the Cosmic Dawn epoch (15 ≲ z ≲ 30), parametrized by an amplitude A_{H I}, a frequency peak ν _{H I} and a width σ _{H I}, can be extracted even in the presence of a structured foreground frequency spectrum (parametrized as a seventh-order polynomial), provided sufficient signal-to-noise (400 h of observation with a single dipole). We apply our method to an early, 19-min-long observation from the Large aperture Experiment to detect the Dark Ages, constraining the 21-cm signal amplitude and width to be -890 6.5 MHz (corresponding to Δz > 1.9 at redshift z ≃ 20) respectively at the 95-per cent confidence level in the range 13.2 ν > 50 MHz).

  3. Japanese Cosmic Dawn/Epoch of Reionization Science with the Square Kilometre Array

    CERN Document Server

    Hasegawa, Kenji; Ichiki, Kiyotomo; Inoue, Akio K; Inoue, Susumu; Ishiyama, Tomoaki; Shimabukuro, Hayato; Takahashi, Keitaro; Tashiro, Hiroyuki; Yajima, Hidenobu; Yokoyama, Shu-ichiro; Yoshikawa, Kohji; Yoshiura, Shintaro

    2016-01-01

    Cosmic reionization is known to be a major phase transition of the gas in the Universe. Since astronomical objects formed in the early Universe, such as the first stars, galaxies and black holes, are expected to have caused cosmic reionization, the formation history and properties of such objects are closely related to the reionization process. In spite of the importance of exploring reionization, our understandings regarding reionization is not sufficient yet. Square Kilometre Array (SKA) is a next-generation large telescope that will be operated in the next decade. Although several programs of next-generation telescopes are currently scheduled, the SKA will be the unique telescope with a potential to directly observe neutral hydrogen up to z~30, and provide us with valuable information on the Cosmic Dawn (CD) and the Epoch of Reionization (EoR). The early science with the SKA will start in a few years; it is thus the time for us to elaborate a strategy for CD/EoR Science with the SKA. The purpose of this do...

  4. Spectrophotometric properties of dwarf planet Ceres from VIR onboard Dawn mission

    CERN Document Server

    Ciarniello, M; Ammannito, E; Raponi, A; Longobardo, A; Palomba, E; Carrozzo, F G; Tosi, F; Li, J -Y; Schröder, S; Zambon, F; Frigeri, A; Fonte, S; Giardino, M; Pieters, C M; Raymond, C A; Russell, C T

    2016-01-01

    We study the spectrophotometric properties of dwarf planet Ceres in the VIS-IR spectral range by means of hyper-spectral images acquired by the VIR instrument onboard NASA Dawn mission. Observations with phase angle within the $7.3^{\\circ}<\\alpha<131^{\\circ}$ interval have been used to characterize Ceres' phase curve in the 0.465-4.05 $\\mu m$ spectral range. Hapke's model has been applied to perform the photometric correction of the dataset, allowing us to produce albedo and color maps of the surface. The $V$ band magnitude phase function of Ceres has been fitted with both the classical linear model and HG formalism. The single scattering albedo and the asymmetry parameter at 0.55 $\\mu m$ are respectively $w=0.14 \\pm 0.02$ and $\\xi=-0.11 \\pm0.08$ (two lobes Henyey-Greenstein phase function); the modeled geometric albedo is $0.094\\pm0.007$; the roughness parameter is $\\bar{\\theta}=29^{\\circ} \\pm 6^{\\circ}$. Albedo maps indicate small variability at global scale with average reflectance $0.034 \\pm 0.003$....

  5. Global Photometric Properties of Asteroid (4) Vesta Observed with Dawn Framing Camera

    CERN Document Server

    Li, Jian-Yang; Schröder, Stefan E; Reddy, Vishnu; Denevi, Brett W; Buratti, Bonnie J; Mottola, Stefano; Hoffmann, Martin; Gutierrez-Marques, Pablo; Nathues, Andreas; Russell, Christopher T; Raymond, Carol A

    2013-01-01

    Dawn spacecraft orbited Vesta for more than one year and collected a huge volume of multispectral, high-resolution data in the visible wavelengths with the Framing Camera. We present a detailed disk-integrated and disk-resolved photometric analysis using the Framing Camera images with the Minnaert model and the Hapke model, and report our results about the global photometric properties of Vesta. The photometric properties of Vesta show weak or no dependence on wavelengths, except for the albedo. At 554 nm, the global average geometric albedo of Vesta is 0.38+/-0.04, and the Bond albedo range is 0.20+/-0.02. The bolometric Bond albedo is 0.18+/-0.01. The phase function of Vesta is similar to those of S-type asteroids. Vesta's surface shows a single-peaked albedo distribution with a full-width-half-max ~17% relative to the global average. This width is much smaller than the full range of albedos (from ~0.55x to >2x global average) in localized bright and dark areas of a few tens of km in sizes, and is probably ...

  6. At the dawn of the Anthropocene, a "crude look at the whole"

    Science.gov (United States)

    Revkin, Andrew

    2016-04-01

    This lecture provides an informed lay reflection on evidence that, for the first time in planetary history, a species is both a planet-scale force and slowly becoming aware of that potency. The presenter, a veteran science journalist who is also a member of the Anthropocene Working Group, will argue for the value of a rough overview by alluding to Nobelist Murray Gell-mann's stragey for finding meaning in complex systems by taking a "crude look at the whole." The debate around the dawn of the Anthropocene, whether it is accepted as a geological epoch or remains an informal construct, is really a debate about the burdens that come with increased knowledge. Human beings are essentially in a three-pronged race -- between their environmental potency; their awareness of the expressed and potential ramifications of impacts on Earth's operating systems; and growing awareness of the deeply embedded perceptual and behavioral traits that shape how our species does, or doesn't, address certain kinds of risks. The outcome of this race remains an open question, this lecture will argue, and whether the outcome can be judged good or bad is not just a function of more science. The talk will focus on the role of communication innovation in tipping the odds in a positive direction.

  7. 21-cm signal from cosmic dawn - II: Imprints of the light-cone effects

    CERN Document Server

    Ghara, Raghunath; Choudhury, T Roy

    2015-01-01

    Details of various unknown physical processes during the cosmic dawn and the epoch of reionization can be extracted from observations of the redshifted 21-cm signal. These observations, however, will be affected by the evolution of the signal along the line-of-sight which is known as the "light-cone effect". We model this effect by post-processing a dark matter $N-$body simulation with a 1-D radiative transfer code. We find that the effect is much stronger and dramatic in presence of inhomogeneous heating and Ly$\\alpha$ coupling compared to the case where these processes are not accounted for. One finds increase (decrease) in the coeval spherically averaged power spectrum up to a factor of 3 (0.6) at large scales ($k \\sim 0.05\\, \\rm Mpc^{-1}$), though these numbers are highly dependent on the source model. Consequently, the peak and trough-like features seen in the evolution of the large-scale power spectrum can be smoothed out to a large extent if the width of the frequency bands used in the experiment is la...

  8. Colors and Photometry of Bright Materials on Vesta as Seen by the Dawn Framing Camera

    Science.gov (United States)

    Schroeder, S. E.; Li, J.-Y.; Mittlefehldt, D. W.; Pieters, C. M.; De Sanctis, M. C.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.; Keller, H. U.; Nathues, A.

    2012-01-01

    The Dawn spacecraft has been in orbit around the asteroid Vesta since July, 2011. The on-board Framing Camera has acquired thousands of high-resolution images of the regolith-covered surface through one clear and seven narrow-band filters in the visible and near-IR wavelength range. It has observed bright and dark materials that have a range of reflectance that is unusually wide for an asteroid. Material brighter than average is predominantly found on crater walls, and in ejecta surrounding caters in the southern hemisphere. Most likely, the brightest material identified on the Vesta surface so far is located on the inside of a crater at 64.27deg S, 1.54deg . The apparent brightness of a regolith is influenced by factors such as particle size, mineralogical composition, and viewing geometry. As such, the presence of bright material can indicate differences in lithology and/or degree of space weathering. We retrieve the spectral and photometric properties of various bright terrains from false-color images acquired in the High Altitude Mapping Orbit (HAMO). We find that most bright material has a deeper 1-m pyroxene band than average. However, the aforementioned brightest material appears to have a 1-m band that is actually less deep, a result that awaits confirmation by the on-board VIR spectrometer. This site may harbor a class of material unique for Vesta. We discuss the implications of our spectral findings for the origin of bright materials.

  9. One Year of Observations of Dawn at Ceres: Composition as seen by VIR

    Science.gov (United States)

    De Sanctis, M. Cristina; Ammannito, Eleonora; Ciarniello, Mauro; Raponi, Andrea; Carrozzo, F. Giacomo; Frigeri, Alessandro; Longobardo, Andrea; Palomba, Ernesto; Tosi, Federico; Zambon, Francesca; Fonte, Sergio; Formisano, Michelangelo; Giardino, Marco; Magni, Gianfranco; Capaccioni, Fabrizio; Capria, M. Teresa; Marchi, Simone; Pieters, Carle M.; Ehlmann, Bethany; McCord, Tom

    2016-04-01

    NASA's Dawn spacecraft [1] arrived at Ceres on March 5, 2015, and has been studying the dwarf planet. The Dawn mission is observing Ceres' surface with its suite of instruments [1] including a Visible and InfraRed Mapping Spectrometer (VIR-MS) [2]. VIR-MS is an imaging spectrometer coupling high spectral and spatial resolution in the VIS (0.25-1-micron) and IR (0.95-5-micron) spectral ranges. Ceres' surface is very dark, but small localized areas exhibit unexpectedly bright materials. Since the first approach data, near infrared spectra revealed a dark surface, with a strong and complex absorption band in the spectral region around 3 microns [3]. Near-infrared spectroscopic analyses confirmed previous observation of bands at 3.1, 3.3-3.5, 3.9 micron but have clearly identified a band at 2.72 micron. This characteristic narrow feature is distinctive for OH-bearing minerals, while H2O-bearing phases, show a much broader absorption band that is a poor match for the Ceres spectrum. Water ice does not fit the observed spectrum. The 3.05-3.1 μm band is also visible in Ceres' ground-based spectra, and has been previously attributed to different phases including water ice, hydrated or NH4-bearing clays and brucite [4,5,6]. We find here that the best fit is obtained with ammoniated phyllosilicate added to a dark material (likely magnetite), antigorite and carbonate [7]. These different components, including ammoniated phases, occur everywhere across the surface although with different relative abundances [8]. Particularly interesting are the bright materials present in some craters like Occator, Haulani and Oxo that show different proportions of the components of the mixture [8]. However, the distribution of the band depths are not always linked to morphological structures. The retrieved mineralogy and composition indicates pervasive aqueous alteration of the surface, processes that are expected to be favored on large bodies like Ceres [9]. Furthermore, Ceres' low density

  10. The Dawn Mission & Asteroid Mappers: The Impact of Crowd-Sourced Crater Counting

    Science.gov (United States)

    Schmidt, B. E.; Scully, J. E.; Hart, R.; Russell, C. T.; Wise, J.; Cobb, W. H.; Ristvey, J.; Counley, J.; Hess, N.

    2012-12-01

    While the driving principle for a science investigation may be the pursuit of knowledge, the process of acquiring that knowledge that matters as much as the result. This process is known to many as the scientific method, a concept regularly taught in schools but that remains in many cases poorly tied to science outreach. But with the growth of the Citizen Science movement, we have entered a new era for both science and science outreach marked by the accessibility of tools that allow the public to experience science first hand in a manner previously unimagined. Gone are the days when a launch and a landing are all that are seen of a mission. Now, it's time to let the public in on the fun, and of course, all the work. In a time of large data returns and dwindling science budgets, citizen science may help scientists and educators with two fundamental problems: (1) increasing awareness and (2) accomplishing the key science investigations. The Dawn Mission has long been on the path towards involving the public in the process of science, and with the advent of the new Asteroid Mappers project, joint with CosmoQuest, the long-term goal of presenting the data to the public in a meaningful manner will be achieved. And in the long run, the public may also prove key to accomplishing mission science. Vesta is a unique body in the solar system, a likely a witness to the earliest stages of solar system formation and the environment within the main asteroid belt. Its impact history will be critical not only to understanding the initial population of the asteroid belt and thus impact hazards on the early Earth, but also the production of Vesta's impact family and the samples of Vesta, the HED meteorites, we have on Earth. Thus determining the impact crater population and distribution is a critical mission goal. Because craters are easily recognized and relatively straightforward to measure, a careful member of the public may be able to perform the same basic tasks as a scientist

  11. Geological Mapping of the Ac-H-3 Dantu Quadrangle of Ceres from NASA's Dawn Mission.

    Science.gov (United States)

    Kneissl, Thomas; Schmedemann, Nico; Neesemann, Adrian; Williams, David A.; Crown, David A.; Mest, Scott C.; Buczkowski, Debra L.; Scully, Jennifer E. C.; Frigeri, Allessandro; Ruesch, Ottaviano; Hiesinger, Harald; Walter, Sebastian H. G.; Jaumann, Ralf; Roatsch, Thomas; Preusker, Frank; Kersten, Elke; Naß, Andrea; Nathues, Andreas; Platz, Thomas; Russell, Chistopher T.

    2016-04-01

    The Dawn Science Team is conducting a geologic mapping campaign for Ceres similar to that done for Vesta [1,2], including production of a Survey- and High Altitude Mapping Orbit (HAMO)-based global map and a series of 15 Low Altitude Mapping Orbit (LAMO)-based quadrangle maps. In this abstract we discuss the geologic evolution of the Ac-H-3 Dantu Quadrangle. The current map is based on a Framing Camera (FC) clear-filter image mosaic from HAMO data (~140 m/px) as well as a digital terrain model (DTM) derived from imagery of the Survey phase [3]. Albedo variations were identified and mapped using a mosaic of photometrically corrected HAMO images provided by DLR. FC color images provided further context for map unit identification. LAMO images (35m/pixel), which have just become available at the time of writing, will be used to update the map to be presented as a poster. The quadrangle is located between 21-66°N and 90-180°E in a large-scale depression north of the impact basin Kerwan. The northern and southeastern parts of the quadrangle are characterized by cratered terrain while the south and southwest are dominated by the partially smooth ejecta blankets of craters Dantu and Gaue. East-west oriented pit/crater chains in the southern half of the quadrangle might be related to tectonic processes [4,5]. Dantu crater (d=~126 km) is a complex impact crater showing slump terraces and a partially smooth crater floor with concentric and radial fractures. Furthermore, Dantu shows a central pit structure with pitted terrain on its floor as well as several bright spots in the interior and exterior of the crater. High-resolution measurements of crater size-frequency distributions (CSFDs) superposed on Dantu indicate a formation/modification age of ~200 - 700 Ma. Most of the ejecta appear to be relatively bright and correspond to parts of the #2 high albedo region observed with the Hubble Space Telescope [6]. However, the southwestern portion of the ejecta blanket is

  12. Geological Mapping of the Ac-H-4 Ezinu Quadrangle of Ceres from NASA's Dawn Misssion

    Science.gov (United States)

    Scully, Jennifer E. C.; Raymond, Carol A.; Williams, David A.; Buczkowski, Debra L.; Mest, Scott C.; Hughson, Kynan H. G.; Russell, Christopher T.; Kneissl, Thomas; Ruesch, Ottaviano; Frigeri, Alessandro; Combe, Jean-Philippe; Jaumann, Ralf; Roatsch, Thomas; Preusker, Frank; Platz, Thomas; Nathues, Andreas; Hoffmann, Martin; Schaefer, Michael; Park, Ryan

    2016-04-01

    NASA's Dawn spacecraft is currently orbiting Ceres, a dwarf planet and the largest object in the asteroid belt (diameter of ~940 km). Ceres science data are primarily acquired during three orbits of decreasing altitude: Survey, High Altitude Mapping Orbit (HAMO) and Low Altitude Mapping Orbit (LAMO). The Dawn Science Team is conducting a geologic mapping campaign for Ceres similar to that undertaken at Vesta [1]. Thus, Ceres' surface is divided into fifteen quadrangles to facilitate systematic HAMO-based and LAMO-based geological mapping. Here we present the LAMO-based geologic map of Ezinu quadrangle (21-66 °N, 180-270 °E). Acquisition of Survey and HAMO data was completed by the submission of this abstract, along with the collection of initial LAMO data. Thus, the current geologic map is based on HAMO (~140 m/pixel) and Survey (~400 m/pixel) mosaics of clear filter Framing Camera images [2]. Framing Camera color images and topography data, derived from the Framing Camera images, are also used to inform the geologic mapping. Updated mapping will be undertaken before the conference, using ~35 m/pixel LAMO Framing Camera mosaics. The key geologic features in Ezinu quadrangle are: linear features, Occator crater, Ezinu crater, Datan and Geshtin craters, and Erntedank Planum. We propose that linear features radial to impact craters (e.g. Occator) are ejecta ray systems, which commonly form as secondary material is ejected during impact crater formation. There is also a prominent set of grooves and chains of pits/craters that are centered near Erntedank Planum (topographically high region) and are cross-cut by ejecta from Occator crater. We interpret these grooves and chains of pits/craters as the surface expression of sub-surface fractures [3, 4]. Occator is a geologically fresh impact crater, and contains the brightest bright spots on Ceres [5], along with bright lobate material, undivided lobate material, hummocky crater floor material, smooth material and smooth

  13. Distinct thermal appearances on Vesta as inferred from the Dawn/VIR data

    Science.gov (United States)

    Tosi, F.; Capria, M.; De Sanctis, M.; Zambon, F.; Ammannito, E.; Buczkowski, D.; Capaccioni, F.; Denevi, B.; Scully, J.; Russell, C.; Raymond, C.

    2014-07-01

    In this paper, we review some of the peculiar thermal appearances that the Dawn spacecraft has observed on Vesta at the local scale: pitted terrains, with an emphasis on the Marcia crater, olivine-rich sites, and diogenite-rich howardite craters. The information derived by the thermal infrared measured by the Visible and InfraRed mapping spectrometer [1] onboard Dawn is fully complementary to mineralogical information inferred by the same instrument at shorter wavelengths, and to geologic and topographic information derived on the basis of optical images acquired by the onboard camera. In particular, the thermal information is crucial to identify local concentrations of coherent material, and thus allow a better understanding of the observed structures. Pitted terrains were found in a few sites on Vesta [2], and display distinct thermal properties compared to other terrains. They show a reduced thermal emission at infrared wavelengths greater than 4 μ m and have distinct margins in the temperature images, being cooler than nearby terrains observed under similar solar illumination conditions. Pitted terrains can be >10 K cooler than the surroundings [3], and even cooler than bright material units found on Vesta, despite their lower albedo [4]. The Marcia crater is the largest location of pitted terrains [2]. The pitted floor of Marcia is distinct in color and albedo from its surroundings, with lower reflectance at visual wavelengths and shallower pyroxene band depths. A prominent difference in temperature is found between the pitted floor (cooler at ˜230 K) and the regions of curvilinear systems in the crater walls (hotter at ˜240--260 K). The lower temperatures of Marcia's pitted floor, as well as of other pitted sites on Vesta, suggest a higher thermal inertia, i.e., a slower thermal response to changing insolation. This is consistent with an increased local density or a higher thermal conductivity (or both), following an impact [4]: local cavities at

  14. Resolved Spectrophotometric Properties of the Ceres Surface from Dawn Framing Camera Images

    Science.gov (United States)

    Schroeder, Stefan; Mottola, Stefano; Carsenty, Uri; Jaumann, Ralf; Li, Jian-Yang; Palmer, Eric; Pieters, Carle; Preusker, Frank; Stephan, Katrin; Raymond, Carol; Russell, Christopher T.

    2016-10-01

    We present a global spectrophotometric characterization of the Ceres surface using Dawn Framing Camera images. We identify the photometric model that yields the best results for photometrically correcting images. Corrected images acquired on approach to Ceres were assembled into global maps of albedo and color. The albedo map is dominated by a large, circular, bright basin-like feature, known from HST images, and dotted by smaller bright features mostly associated with fresh-looking craters. The dominant color variation over the surface is represented by the presence of "blue" material in and around such craters, which has a negative spectral slope when compared to average terrain. We also mapped variations of the phase curve by employing an exponential photometric model, a technique previously applied to asteroid Vesta. The surface of Ceres scatters light differently from Vesta in the sense that the ejecta of several fresh-looking craters appear to be physically smooth rather than rough. Albedo, blue color, and physical smoothness all appear to be indicators of youth. The physical smoothness of some blue terrains is consistent with an initially liquid condition, perhaps as a consequence of impact melting of subsurface water ice. We propose that the color of blue ejecta derives from an originally ice-rich condition, which implies the presence of sub-surface deposits of water ice. Space weathering may be responsible for the fading of the blue color over time. The large positive albedo feature of which the Dantu crater forms the northern part may be an ancient impact basin, or palimpsest, whose relief has mostly disappeared. Its visible color and phase curve are similar to those of Ceres average. Occator crater has several bright spots. The center spot is the brightest with a visual normal albedo of six times Ceres average and has a red color. Its scattering properties are consistent with those of a particulate surface deposit of high albedo. The less

  15. Hall effect control of magnetotail dawn-dusk asymmetry: A three-dimensional global hybrid simulation

    Science.gov (United States)

    Lu, San; Lin, Y.; Angelopoulos, V.; Artemyev, A. V.; Pritchett, P. L.; Lu, Quanming; Wang, X. Y.

    2016-12-01

    Magnetotail reconnection and related phenomena (e.g., flux ropes, dipolarizing flux bundles, flow bursts, and particle injections) occur more frequently on the duskside than on the dawnside. Because this asymmetry can directly result in dawn-dusk asymmetric space weather effects, uncovering its physical origin is important for better understanding, modeling, and prediction of the space weather phenomena. However, the cause of this pervasive asymmetry is unclear. Using three-dimensional global hybrid simulations, we demonstrate that the Hall physics in the magnetotail current sheet is responsible for the asymmetry. The current sheet thins progressively under enhanced global convection; when its thickness reaches ion kinetic scales, some ions are decoupled from the magnetized electrons (the Hall effect). The resultant Hall electric field Ez is directed toward the neutral plane. The Hall effect is stronger (grows faster) on the duskside; i.e., more ions become unmagnetized there and do not comove with the magnetized dawnward Ez × Bx drifting electrons, thus creating a larger additional cross-tail current intensity jy (in addition to the diamagnetic current) on the duskside, compared to the dawnside. The stronger Hall effect strength on the duskside is controlled by the higher ion temperature, thinner current sheet, and smaller normal magnetic field Bz there. These asymmetric current sheet properties are in turn controlled by two competing processes that correspond to the Hall effect: (1) the dawnward E × B drift of the magnetic flux and magnetized ions and electrons and (2) the transient motion of the unmagnetized ions which do not execute E × B drift.

  16. Observations of Mirror-Mode Structures in the Dawn-Side Magnetosphere

    Science.gov (United States)

    Rae, I. J.; Mann, I. R.; Watt, C. E.; Kistler, L. M.

    2005-12-01

    There are a number of mechanisms by which ULF oscillations can be excited in the magnetosphere, both externally (i.e. solar wind) or internally (e.g. via resonance with energetic particle sources). One mechanism that is not traditionally considered/observed is the mirror instability/mode. The mirror mode is a fundamental plasma instability and described as a compressible slow mode typically excited in high-beta plasmas where there is significant pressure anisotropy and grows if the free energy of the pressure anisotropy is sufficiently large and must be dissipated. Observational evidence of these mirror modes are rare, but mainly concentrated in the dayside magnetosheath, where the necessary temperature anisotropies can develop, and increase as the magnetopause is approached. However, it is possible to generate the mirror instability inside the magnetosphere, though as yet there are few examples. We present an interval on the 19th March 1998 when the Equator-S spacecraft is traversing the dawn-side magnetosphere above the ecliptic plane at radial distances of up to L ~ 11, and encounters quasi-monochromatic magnetic field fluctuations, and also similar variations in ion number density, temperatures and velocities. The magnetic field strength and number densities are anti-correlated, and the plasma and magnetic field pressures are in anti-phase also, which are all consistent with the mirror instability hypothesis. We calculate the mirror instability criterion (Hasegawa, 1969) and find that the condition for mirror-mode waves to grow is strongly met throughout the interval. We believe that this is a rare observation of a fundamental plasma instability in a natural environment at high temporal resolution. Observations such as these provide an invaluable natural tool in which to test current plasma theory.

  17. Dawn and Dusk Set States of the Circadian Oscillator in Sprouting Barley (Hordeum vulgare Seedlings.

    Directory of Open Access Journals (Sweden)

    Weiwei Deng

    Full Text Available The plant circadian clock is an internal timekeeper that coordinates biological processes with daily changes in the external environment. The transcript levels of clock genes, which oscillate to control circadian outputs, were examined during early seedling development in barley (Hordeum vulgare, a model for temperate cereal crops. Oscillations of clock gene transcript levels do not occur in barley seedlings grown in darkness or constant light but were observed with day-night cycles. A dark-to-light transition influenced transcript levels of some clock genes but triggered only weak oscillations of gene expression, whereas a light-to-dark transition triggered robust oscillations. Single light pulses of 6, 12 or 18 hours induced robust oscillations. The light-to-dark transition was the primary determinant of the timing of subsequent peaks of clock gene expression. After the light-to-dark transition the timing of peak transcript levels of clock gene also varied depending on the length of the preceding light pulse. Thus, a single photoperiod can trigger initiation of photoperiod-dependent circadian rhythms in barley seedlings. Photoperiod-specific rhythms of clock gene expression were observed in two week old barley plants. Changing the timing of dusk altered clock gene expression patterns within a single day, showing that alteration of circadian oscillator behaviour is amongst the most rapid molecular responses to changing photoperiod in barley. A barley EARLY FLOWERING3 mutant, which exhibits rapid photoperiod-insensitive flowering behaviour, does not establish clock rhythms in response to a single photoperiod. The data presented show that dawn and dusk cues are important signals for setting the state of the circadian oscillator during early development of barley and that the circadian oscillator of barley exhibits photoperiod-dependent oscillation states.

  18. Evidence from glycine transfer RNA of a frozen accident at the dawn of the genetic code

    Directory of Open Access Journals (Sweden)

    Tate Warren P

    2008-12-01

    Full Text Available Abstract Background Transfer RNA (tRNA is the means by which the cell translates DNA sequence into protein according to the rules of the genetic code. A credible proposition is that tRNA was formed from the duplication of an RNA hairpin half the length of the contemporary tRNA molecule, with the point at which the hairpins were joined marked by the canonical intron insertion position found today within tRNA genes. If these hairpins possessed a 3'-CCA terminus with different combinations of stem nucleotides (the ancestral operational RNA code, specific aminoacylation and perhaps participation in some form of noncoded protein synthesis might have occurred. However, the identity of the first tRNA and the initial steps in the origin of the genetic code remain elusive. Results Here we show evidence that glycine tRNA was the first tRNA, as revealed by a vestigial imprint in the anticodon loop sequences of contemporary descendents. This provides a plausible mechanism for the missing first step in the origin of the genetic code. In 448 of 466 glycine tRNA gene sequences from bacteria, archaea and eukaryote cytoplasm analyzed, CCA occurs immediately upstream of the canonical intron insertion position, suggesting the first anticodon (NCC for glycine has been captured from the 3'-terminal CCA of one of the interacting hairpins as a result of an ancestral ligation. Conclusion That this imprint (including the second and third nucleotides of the glycine tRNA anticodon has been retained through billions of years of evolution suggests Crick's 'frozen accident' hypothesis has validity for at least this very first step at the dawn of the genetic code. Reviewers This article was reviewed by Dr Eugene V. Koonin, Dr Rob Knight and Dr David H Ardell.

  19. An MCMC approach to extracting the global 21-cm signal during the cosmic dawn from sky-averaged radio observations

    CERN Document Server

    Harker, Geraint J A; Burns, Jack O; Bowman, Judd D

    2011-01-01

    Efforts are being made to observe the 21-cm signal from the 'cosmic dawn' using sky-averaged observations with individual radio dipoles. In this paper, we develop a model of the observations accounting for the 21-cm signal, foregrounds, and several major instrumental effects. Given this model, we apply Markov Chain Monte Carlo techniques to demonstrate the ability of these instruments to separate the 21-cm signal from foregrounds and quantify their ability to constrain properties of the first galaxies. For concreteness, we investigate observations between 40 and 120 MHz with the proposed DARE mission in lunar orbit, showing its potential for science return.

  20. Spiraling Away from Vesta: Design of the Transfer from the Low to High Altitude Dawn Mapping Orbits

    Science.gov (United States)

    Smith, John C.; Parcher, Daniel W.; Whiffen, Gregory J.

    2013-01-01

    Dawn has successfully completed its orbital mission at Vesta and is currently en route to an orbital rendezvous with Ceres in 2015. The longest duration and most complex portion of the Vesta departure trajectory was the transfer from the low to high altitude science orbit. This paper describes the design of this low-thrust trajectory optimized assuming a minimum-propellant mass objective. The transfer utilized solar-electric ion propulsion applied over 139 spacecraft revolutions about Vesta. Science drivers, operational constraints, and robustness to statistical uncertainties are addressed. The 45-day transfer trajectory was successfully implemented in early 2012.

  1. The Dawn of Information Industry Recovery Emerging%信息产业绽放复兴曙光

    Institute of Scientific and Technical Information of China (English)

    本刊战略研究部

    2003-01-01

    The flexuous development of global information industry in recent three years tells us again that the depression is unavoidable in any development. After the great change some questions may come into our minds: in which stage is the present development of information industry in the whole, and what about its future? After lucubrating and analyzing, the Network Trend Research Institute of PPTNA, together with Strategy Study Center of CTC, reaches the conclusion that the general trend of informatization never changes despite of the temporary frustration, and the development of internet is beginning. After three years'' adjusting and regulating, the dawn of informatLon industry recovery is emerging.

  2. Factors associated to the career choice of family medicine among Japanese physicians: the dawn of a new era.

    Science.gov (United States)

    Ie, Kenya; Tahara, Masao; Murata, Akiko; Komiyama, Manabu; Onishi, Hirotaka

    2014-01-01

    Despite recent developments in post-graduate family medicine training in Japan, the numbers of junior doctors entering family medicine residencies are still limited. The objective of this qualitative study was to investigate the possible factors associated to the career choice of family medicine, especially in the context of the newly established family medicine programs in Japan. From December 2010 to January 2011, we distributed a semi-structured questionnaire about career choice to 58 physician members of the Japan Primary Care Association, and 41 of them responded. Four researchers used the Modified Grounded Theory Approach (Kinoshita, 2003) for three-stage conceptualization. We extracted a conceptual model of the choice of newly established family medicine as a career in Japan, consisting of six categories and 77 subordinate concepts from 330 variations. The subcategories of personal background affecting the family-medicine career choice were characteristics ("self-reliance," "pioneering spirit"), career direction ("community/rural-orientedness," "multifaceted orientation") and experience (e.g., "discomfort with fragmented care"). We divided the influencing factors that were identified for career choice into supporters (e.g., "role model"), conflict of career choice (e.g., "anxiety about diverse/broad practice"), and the dawn of a new era in family medicine in Japan (e.g., "lack of social recognition," "concern about livelihood," and "too few role models"). Although the dawn of a new era seemed a rather negative influencer, it was unique to our study that the dawn itself could attract those with a "pioneering spirit" and an "attitude of self-training." Unlike previous studies, the positive factors such as lifestyle and the short residency program were not shown to be part of family medicine's attractiveness. In contrast, "concern about livelihood" was specific among our respondents and was related to career choice in the dawn period. "Community

  3. Early birds are sexy: male age, dawn song and extrapair paternity in blue tits, Cyanistes (formerly Parus) caeruleus

    DEFF Research Database (Denmark)

    Poesel, Angelika; Kunc, H.P.; Foerster, K.

    2006-01-01

    Sexual selection theory predicts that signals reflecting the relative quality of individuals should be used in mate choice. Females could base their choice of copulation partners on male secondary sexual traits that honestly signal male age, as predicted by the age-based indicator mechanism...... SY males. This difference in the onset of dawn singing was due to age-related changes in individual performance rather than differential survival of individuals with varying expression of the trait. Males that began to sing earlier at dawn had more mating partners, and were more likely to gain...... extrapair paternity. Our findings suggest that the onset of dawn song can provide a simple mechanism for females to assess the relative quality of their mate and of neighbouring males. We propose that females use the onset of singing as a cue for their choice of extrapair partners....

  4. Field-aligned currents in Saturn's magnetosphere: Local time dependence of southern summer currents in the dawn sector between midnight and noon

    Science.gov (United States)

    Hunt, G. J.; Cowley, S. W. H.; Provan, G.; Bunce, E. J.; Belenkaya, E. S.; Alexeev, I. I.; Kalegaev, V. V.; Dougherty, M. K.; Coates, A. J.

    2016-12-01

    We examine and compare the magnetic field perturbations associated with field-aligned ionosphere-magnetosphere coupling currents at Saturn, observed by the Cassini spacecraft during two sequences of highly inclined orbits in 2006/7 and 2008 under late southern summer conditions. These sequences explore the southern currents in the dawn-noon and midnight sectors, respectively. This allows investigation of possible origins of the local time (LT) asymmetry in auroral Saturn kilometric radiation (SKR) emissions, which peak in power at 8 h LT in the dawn-noon sector. We first show that the dawn-noon field data generally have the same four-sheet current structure as found previously in the midnight data, and that both are similarly modulated by "planetary period oscillation" (PPO) currents, these being associated with the 10.7 h magnetic field oscillations observed throughout Saturn's magnetosphere. We then separate the averaged PPO-independent (e.g., subcorotation) and PPO-related currents for both LT sectors using the latter current system symmetry properties. Surprisingly, we find that the PPO-independent currents are essentially identical within uncertainties in the dawn-dusk and midnight sectors, thus providing no explanation for the LT dependence of the SKR emissions. The main PPO-related currents are, however, found to be slightly stronger and narrower in latitudinal width at dawn-noon than at midnight, leading to estimated precipitating electron powers, and hence emissions, that are on average a factor of 1.3 larger at dawn-noon than at midnight, inadequate to account for the observed LT asymmetry in SKR power by a factor of 2.7. Some other factor must also be involved, such as a LT asymmetry in the hot magnetospheric auroral source electron population.

  5. Geological Mapping of the Ac-H-11 Sintana Quadrangle of Ceres from NASA's Dawn Mission.

    Science.gov (United States)

    Schulzeck, Franziska; Krohn, Katrin; Jaumann, Ralf; Williams, David A.; Buczkowski, Debra L.; Mest, Scott C.; Scully, Jennifer E. C.; Gathen, Isabel v. d.; Kersten, Elke; Matz, Klaus-Dieter; Naß, Andrea; Otto, Katharina; Pieters, Carle M.; Preusker, Frank; Roatsch, Thomas; De Sanctis, Maria C.; Schenk, Paul; Schröder, Stefanus; Stephan, Katrin; Wagner, Roland

    2016-04-01

    In December 2015, the Dawn spacecraft delivered the first images of the Low Altitude Mapping Orbit (LAMO) of the dwarf planet Ceres at a resolution of 35 m/pixel. This data will be used to finish the geological mapping of Ceres' surface in order to identify composition and surface forming processes. Mapping was already done using Survey Orbit and High Altitude Mapping Orbit (HAMO) data. With the new images, an updated map will be presented. To this point, the data material consists of a HAMO clear-filter mosaic (140 m/pixel) [1], a digital elevation model (DTM) [2] derived from Survey orbit (415 m/pixel) data, color-filter ratios and photometrically corrected images. Ceres' surface has been divided into 15 mapping quadrangles. The Ac-H-11 Sintana quadrangle is located in the southern hemisphere of Ceres between 21 66°S and 0 90°E. Geological units identified so far are cratered terrain, which covers most of the area, and a younger unit of relatively smooth material. The latter is characterized by a low crater density. Material of the same unit was found in adjacent quadrangles as well. Interest is taken in the diversity of crater shapes. Many craters show different forms of asymmetries. One and the same crater for instance displays different stages of rim degradation and some crater walls are partly terraced and their slopes' steepness is varying alongside the crater rim. Several mass wasting features, which partly cause the observed asymmetries, have been identified. Next to the multiple collapsed rims, landslides due to later cratering on the primary crater rim are observed. Whereas collapse structures are mostly blocky, single landslides are characterized by lobate margins. Occurrence and type of mass wasting feature might hint to subsurface differences. Further, there is a diversity of inner crater structures, like relaxed crater floors, ridges, central peaks, mounds and smooth plains. Processes like mass wasting and relaxation have modified many craters

  6. Regional and Local Temperature Maps of Dwarf Planet Ceres from Dawn/VIR

    Science.gov (United States)

    Tosi, F.; Zambon, F.; Capria, M. T.; Carrozzo, F. G.; Ciarniello, M.; De Sanctis, M. C.; Longobardo, A.; Raponi, A.; Ammannito, E.; Combe, J. P.; Hiesinger, H.; Li, J. Y.; McFadden, L. A.; Schorghofer, N.; Schroeder, S.; Stephan, K.; Rayman, M.; Raymond, C. A.; Russell, C. T.

    2015-12-01

    Since the beginning of 2015, the Visible InfraRed (VIR) mapping spectrometer onboard the NASA Dawn mission has obtained hyperspectral images of Ceres, with improving spatial resolution. VIR operates in the overall spectral range 0.25-5.1 μm, with the main goal of inferring the surface composition of the target in its uppermost layer, as thick as tens of microns. Taking advantage of the wavelength range longward of 3 μm, VIR can be used as a thermal mapper, i.e. as a tool to derive thermal images and spatially-resolved temperature maps. To do this, the VIR team uses a Bayesian approach to nonlinear inversion that was extensively applied to the Vesta dataset earlier. Already in February 2015, VIR had the chance to acquire data with a spatial resolution of ~11 km/px. Those temperature images revealed that a spot of high-albedo (bright) material, highlighted by the Hubble Space Telescope (HST) earlier and recently associated with the crater Haulani, was cooler than sorrounding regions seen under similar solar illumination, whereas the brightest spots on Ceres, in the crater Occator, did not display any thermal contrast. The following Survey phase yielded hyperspectral coverage of Ceres at ~1.3 km/px, and the High Altitude Mapping Orbit (HAMO) phase starting in mid-August 2015 is expected to provide VIR data with a resolution of ~0.4 km/px. These datasets allow derivation of regional and local temperature maps as well as the study of thermal anomalies at those spatial scales. Due to the low overall thermal inertia of Ceres, the surface temperature is essentially dominated by the instantaneous value of the solar incidence angle. Small values of this angle result in high surface temperatures, and, unlike Vesta, the low obliquity of Ceres (~4°) does not result in observable seasonal effects for a given location on the surface. However, different responses to insolation as observed at the local scale may be indicative of differences in density/porosity and thermal

  7. Geochemistry of Vesta and Ceres: In-flight calibration of Dawn

    Science.gov (United States)

    Prettyman, T. H.; Feldman, W. C.; McSween, H. Y.

    2009-04-01

    The purpose of the Dawn mission is to investigate processes that contributed to the formation and early evolution of solid bodies in the solar system by exploring Vesta and Ceres, which are the two largest bodies in the main astreroid belt. Because they were formed at different heliocentric distances, Vesta and Ceres incorporated different amounts of water and other volatiles, which strongly influenced their thermal evolution. Vesta, which is thought to be the source of the basaltic, Howardite, Eucrite, and Diogenite (HED) meteorites, is dry and underwent igneous differentiation. In contrast, low-temperature, aqueous processing must have played an important role in the evolution of Ceres, which is rich in water and other volatiles, and may still contain subsurface liquid water. By exploring both Vesta and Ceres, the gradient in the composition of the solar nebula and role of water in planetary evolution can be investigated. The Dawn payload includes redundant framing cameras (FC), a visible and infrared spectrometer (VIR), and a gamma ray and neutron detector (GRaND), which, along with radio science, will measure surface geomorphology, composition, and mineralogy, and provide constraints on the internal structure of Vesta and Ceres. For both Vesta and Ceres, global mapping data will be acquired from circular polar orbits. In low altitude orbits, GRaND will map the elemental composition of Vesta and Ceres to depths less than one meter, including major rock forming elements and light elements (such as H, C, and N), which are the primary constituents of ices. GRaND consists of 21 radiation sensors, which measure the spectrum of neutrons and gamma rays originating from interactions between galactic cosmic rays and the material constituents of the asteroids and, separately, backgrounds from spacecraft materials. GRaND uses a bismuth germanate (BGO) scintillator for gamma ray spectroscopy, which has high efficiency, enabling the measurement of gamma rays up to 10 Me

  8. Structure of the auroral precipitation region in the dawn sector: relationship to convection reversal boundaries and field-aligned currents

    Directory of Open Access Journals (Sweden)

    Y. I. Feldstein

    electrons and isotropic ion precipitation (AO is mapped to the dawn periphery of the Central Plasma Sheet (CPS; the soft small scale structured precipitation (SSSL is mapped to the outer magnetosphere close to the magnetopause, i.e. the Low Latitude Boundary Layer (LLBL. In the near-noon sector, earthward fluxes of soft electrons, which cause the Diffuse Red Aurora (DRA, are observed. The ion energies decrease with increasing latitude. The plasma spectra of the DRA regime are analogous to the spectra of the Plasma Mantle (PM. In the dawn sector, the large-scale field-aligned currents flow into the ionosphere at the SSSL latitudes (Region 1 and flow out at the AO or DAZ latitudes (Region 2. In the dawn and dusk sectors, the large-scale Region 1 and Region 2 FAC generation occurs in different plasma domains of the distant magnetosphere. The dawn and dusk FAC connection to the traditional Region 1 and Region 2 has only formal character, as FAC generating in various magnetospheric plasma domains integrate in the same region (Region 1 or Region 2. In the SSSL, there is anti-sunward convection; in the DAZ and the AO, there is the sunward convection. At PM latitudes, the convection is controlled by the azimuthal IMF component (By . It is suggested to extend the notation of the plasma pattern boundaries, as proposed by Newell et al. (1996, for the nightside sector of the auroral oval to the dawn sector.

    Key words. Magnetospheric physics (current systems; magnetospheric configuration and dynamics; plasma convection

  9. Geological Mapping of the Ac-H-9 Occator Quadrangle of Ceres from NASA Dawn Mission

    Science.gov (United States)

    Buczkowski, Debra; Williams, David; Scully, Jennifer; Mest, Scott; Crown, David; Aileen Yingst, R.; Schenk, Paul; Jaumann, Ralf; Roatsch, Thomas; Preusker, Frank; Platz, Thomas; Nathues, Andreas; Hoffmann, Martin; Schaefer, Michael; Marchi, Simone; De Sanctis, M. Cristina; Raymond, Carol; Russell, Chris

    2016-04-01

    As was done at Vesta [1], the Dawn Science Team is conducting a geological mapping cam-paign at Ceres during the nominal mission, including iterative mapping using data obtained dur-ing each orbital phase. We are using geological mapping as a method to identify the geologic processes that have modified the surface of dwarf planet Ceres. We here present the geology of the Ac-H-9 Occator quadrangle, located between 22°S-22°N and 216-288°E. The Ac-H-9 map area is completely within the topographically high region on Ceres named Erntedank Planum. It is one of two longitudinally distinct regions where ESA Herschel space telescope data suggested a release of water vapor [2]. The quadrangle includes several other notable features, including those discussed below. Occator is the 92 km diameter crater that hosts the "Bright Spot 5" that was identified in Hubble Space Telescope data [3], which is actually comprised of multiple bright spots on the crater floor. The floor of Occator is cut by linear fractures, while circumferential fractures are found in the ejecta and on the crater walls. The bright spots are noticeably associated with the floor fractures, although the brightest spot is associated with a central pit [4]. Multiple lobate flows are observed on the crater floor; these appear to be sourced from the center of the crater. The crater has a scalloped rim that is cut by regional linear structures, displaying a cross-section of one structure in the crater wall. Color data show that the Occator ejecta have multiple colors, generally related to changes in morphology. Azacca is a 50 km diameter crater that has a central peak and bright spots on its floor and within its ejecta. Like Occator, Azacca has both floor fractures and circumferential fractures in its ejecta and crater walls. Also like Occator, the Azacca ejecta is multi-colored with variable morphology. Linear structures - including grooves, pit crater chains, fractures and troughs - cross much of the eastern

  10. The Relevance Concept of Dawn and Twilight in the Book of Al-Qanun al-Mas’udi for Determine Isya’ and Subuh Pray Time

    Directory of Open Access Journals (Sweden)

    Nugroho Eko Atmanto

    2012-06-01

    Full Text Available Morning dawn and phenomenon twilight phenomenon are interesting for the sci- entists not only for weather forecast and navigation but also setting time prayer times for muslims. The concept of the morning dawn and evening twilight were introduced by al-Biruni in the book Al-Qanun al-Mas’udi. Al-Biruni described the scene at morning dawn and evening twilight in the book Al-Qanun al-Mas’udi and concluded that the twilight occur when the position of the sun is at an altitude of -18°. The concept of al-Biruni is recognized by modern science, astronomy, and the prophetic tradition for its conformity. Besides, the discovery of al-Biruni on the height of the sun is so far used by several religious organizations in some coun- tries to set the time for isha and fajr prayers. By using content analysis, this study discussed the relevance of the concept of morning dawn and evening twilight in the book Al-Qanun al-Mas’udi for determining maghrib prayer time, the praying time for isha and fajr as well.

  11. Experimental illumination of a forest: no effects of lights of different colours on the onset of the dawn chorus in songbirds

    NARCIS (Netherlands)

    Da Silva, Arnaud; de Jong, Maaike; van Grunsven, Roy H. A.; Visser, Marcel E.; Kempenaers, Bart; Spoelstra, Kamiel

    2017-01-01

    Light pollution is increasing exponentially, but its impact on animal behaviour is still poorly understood. For songbirds, the most repeatable finding is that artificial night lighting leads to an earlier daily onset of dawn singing. Most of these studies are, however, correlational and cannot entir

  12. Experimental illumination of a forest: no effects of lights of different colours on the onset of the dawn chorus in songbirds

    NARCIS (Netherlands)

    Silva, Da Arnaud; Jong, de Maaike; Grunsven, van R.H.A.; Visser, M.E.; Kempenaers, Bart; Spoelstra, Kamiel

    2017-01-01

    Light pollution is increasing exponentially, but its impact on
    animal behaviour is still poorly understood. For songbirds, the
    most repeatable finding is that artificial night lighting leads to
    an earlier daily onset of dawn singing. Most of these studies are,
    however, correlational

  13. Experimental illumination of a forest: no effects of lights of different colours on the onset of the dawn chorus in songbirds

    NARCIS (Netherlands)

    Silva, Da Arnaud; Jong, de Maaike; Grunsven, van R.H.A.; Visser, M.E.; Kempenaers, Bart; Spoelstra, Kamiel

    2017-01-01

    Light pollution is increasing exponentially, but its impact on
    animal behaviour is still poorly understood. For songbirds, the
    most repeatable finding is that artificial night lighting leads to
    an earlier daily onset of dawn singing. Most of these studies are,
    however, correlational

  14. Correlates and outcomes of worries about hypoglycemia in family members of adults with diabetes : The second Diabetes Attitudes, Wishes and Needs (DAWN2) study

    NARCIS (Netherlands)

    Nefs, G.M.; Pouwer, F.; Holt, R.I.; Skovlund, S.; Hermanns, N.; Nicolucci, A.; Peyrot, M.

    2016-01-01

    Objective We examined (a) the demographic and clinical correlates of worries about hypoglycemia in adult family members of adults with diabetes, and (b) the association of these worries with measures of diabetes support. Methods The second multinational Diabetes Attitudes, Wishes and Needs (DAWN2)

  15. From Sociosemiotic Perspective to Study the Repro-duction of Referential Meaning in“Dawn Blossoms Plucked at Dusk”by the Yangs

    Institute of Scientific and Technical Information of China (English)

    张蝉

    2013-01-01

    Sociosemiotic provides a comprehensive system to analyze language signs. Using sociosemiotic concept can help us to deeply understand the social function of translation and effectively find ways to over-come cultural barriers. This thesis based on sociosemiotic theory, discussing the referential meaning in“Dawn Blossoms Plucked at Dusk”.

  16. Exposed H2O-rich areas detected on Ceres with Dawn Visible and Infrared Mapping Spectrometer

    Science.gov (United States)

    Combe, Jean-Philippe; Raponi, Andrea; De Sanctis, Maria Cristina; Tosi, Federico; Ammannito, Eleonora; Byrne, Shane; Giacomo Carrozzo, Filippo; Hayne, Paul O.; Hughson, Kynan Horace; Johnson, Katherine Ellen; Landis, Margaret E.; Mazarico, Erwan; McCord, Thomas B.; Pieters, Carle; Ruesch, Ottaviano; Singh, Sandeep; Raymond, Carol; Russell, Christopher T.; VIR Team

    2016-10-01

    H2O-rich materials are exposed at the surface of Ceres as discovered from VIR spectra [1] of the Dawn mission [2]. Oxo crater exhibits the most diagnostic absorption bands of the H2O molecule at 1.65 and 1.28 µm [3]. These features exist in at least four other locations, and they are consistent with H2O ice mixed with low-albedo components [3,4]. Spectra of mineral hydrates such as salts are also characterized by H2O absorption overtones, however they do not fit VIR observations as well as H2O ice spectra. In order to further constrain the composition, the thermophysical and chemical stability of exposed H2O-rich compounds on Ceres and results from chemical models of Ceres interior are being investigated. One meter of pure H2O ice exposed to direct sunlight would sublimate within a few tens of years [5-7].The sublimation of a H2O ice-cemented regolith would leave a low-albedo lag deposit that would also decrease detectability over time [8]. All the reported H2O exposures occur at latitudes higher than 30°N in fresh craters near rim shadows, have surface area < 3 km2, and relatively high albedo.The exposed H2O ice observed by VIR is likely due to a recent impact or a landslide. In some occurrences, high-albedo materials observed within these shadows by the Framing Camera (FC) are contiguous to the observed H2O several of them could be in Permanently Shadowed Regions. The surface shape model and history of illumination will allow us to determine whether these areas could be cold traps where H2O ice could be preserved from sublimation [9].AcknowledgementsThe funding for this research was provided under the NASA Dawn mission through a subcontract 2090-S-MB516 from the University of California, Los Angeles and the Dawn Guest Investigator Program. The VIR instrument and VIR team are funded by ASI (Italian Space Agency) and INAF (Istituto Nazionale di Astrofisica).References1. De Sanctis M.C. et al.,2011, SSR 1632. Russell C. T. et al., 2011, SSR 1633. Combe J-Ph. et al

  17. The Surface and Interior Evolution of Ceres Revealed by Analysis of Fractures and Secondary Crater Chains Using Dawn Data

    Science.gov (United States)

    Scully, J. E. C.; Buczkowski, D.; King, S. D.; Castillo, J. C.; Schmedemann, N.; Raymond, C. A.; O'Brien, D. P.; Marchi, S.; Russell, C. T.; Mitri, G.; Bland, M. T.

    2016-12-01

    Dawn is the first spacecraft to visit and orbit Ceres, a dwarf planet and the largest body in the asteroid belt (radius 470 km) (Russell et al., 2016). Previously, telescopic observations and thermal evolution modeling indicated Ceres was at least partially differentiated, with a density of 2,100 kg/m3 (e.g. Drummond et al., 2014; Castillo-Rogez & McCord, 2010). Moreover, models of crater retention predicted that pervasive viscous relaxation in a water-ice-rich outer layer could erase most surface features (Bland, 2013). However, a full understanding of Ceres' surface and interior evolution remained elusive until Dawn explored Ceres. Here we present a global geologic map of Ceres' ≥1 km wide linear features, which we interpret as: 1) the surface expression of subsurface fractures, and 2) secondary crater chains formed when material ejected during impact-crater formation impacts and scours the surface. The formation and preservation of these linear features indicate Ceres' outer layer is relatively strong, and not dominated by viscous relaxation as predicted (Buczkowski et al., 2016). The fractures (called the Samhain Catenae) give us insights into the interior. Based on a fracture spacing to fractured layer thickness ratio of 1 (Bai & Pollard, 2000), the spacing of the Samhain Catenae indicates that the outer, fractured layer is 88 km thick. Moreover, consistent with geodynamic modeling (King et al., 2016), we interpret the Samhain Catenae formed because of uplift and extension induced by an upwelling region. Unlike many cerean secondary crater chains, the Junina Catenae secondary crater chains are not radial to their source impact crater(s). On account of Ceres' fast rotation (period of 9 hours) and relatively small radius, modeling indicates that the Junina Catenae originated from the Urvara/Yalode impact craters, which are located in a different hemisphere. Our results show Ceres has different surface and interior characteristics than predicted, and underwent

  18. Dawn of the electronic age electrical technologies in the shaping of the modern world 1914 to 1945

    CERN Document Server

    Nebeker, Frederik

    2009-01-01

    Much of the infrastructure of today's industrialized world arose in the period from the outbreak of World War I to the conclusion of World War II. It was during these years that the capabilities of traditional electrical engineering became ubiquitous. Even more importantly, it was during this time that a new type of electrical engineering--electronics--emerged. Because of its applications in communications, entertainment, industry, science and medicine, and the military, the electronics industry became a major part of the economy. Dawn of the Electronic Age explores how this engineering knowledge and its main applications developed in various scientific, economic, and social contexts, and explains how each was profoundly affected by electrical technologies. It takes an international perspective and a narrative approach, unfolding the story chronologically. --from publisher description.

  19. Cosmic Dawn (CoDa): the First Radiation-Hydrodynamics Simulation of Reionization and Galaxy Formation in the Local Universe

    CERN Document Server

    Ocvirk, Pierre; Shapiro, Paul R; Aubert, Dominique; Iliev, Ilian T; Teyssier, Romain; Yepes, Gustavo; Choi, Jun-Hwan; Sullivan, David; Knebe, Alexander; Gottloeber, Stefan; D'Aloisio, Anson; Park, Hyunbae; Hoffman, Yehuda; Stranex, Timothy

    2015-01-01

    Cosmic reionization by starlight from early galaxies affected their evolution, thereby impacting reionization, itself. Star formation suppression, for example, may explain the observed underabundance of Local Group dwarfs relative to N-body predictions for Cold Dark Matter. Reionization modelling requires simulating volumes large enough ~(100 Mpc)^3 to sample reionization "patchiness", while resolving millions of galaxy sources above ~10^8 Msun, combining gravitational and gas dynamics with radiative transfer. Modelling the Local Group requires initial cosmological density fluctuations pre-selected to form the well-known structures of the local universe today. Cosmic Dawn ("CoDa") is the first such fully-coupled, radiation-hydrodynamics simulation of reionization of the local universe. Our new hybrid CPU-GPU code, RAMSES-CUDATON, performs hundreds of radiative transfer and ionization rate-solver timesteps on the GPUs for each hydro-gravity timestep on the CPUs. CoDa simulated (91 Mpc)^3 with 4096^3 particles ...

  20. Modeling the Radio Foreground for detection of CMB spectral distortions from Cosmic Dawn and Epoch of Reionization

    CERN Document Server

    Rao, Mayuri Sathyanarayana; Shankar, N Udaya; Chluba, Jens

    2016-01-01

    Cosmic baryon evolution during Cosmic Dawn and Cosmological Reionization results in spectral distortions in the cosmic microwave background (CMB) owing to redshifted 21-cm absorption and emission. These spectral features from redshifts $30 \\lesssim z \\lesssim 6$ appear at meter wavelengths ($\\lesssim200$ MHz) as a tiny CMB distortion component in addition to the Galactic and extragalactic radio sky spectrum, which is orders of magnitude brighter. These spectral distortions encode information about the thermal history of baryons and the nature and timing of the first collapsed objects. However detecting them requires methods for precise modeling of foregrounds. Here we present an improvement over previous efforts to simulate foregrounds. We adopt GMOSS, a physically motivated sky model that represents sky spectra using radiative processes to simulate realistic expectation of sky spectra over 40--200 MHz. From mock observations resulting plausible spectral shapes we demonstrate that a polynomial of at least ord...

  1. Updates in the IR responsivity of VIR, the spectrometer of the Dawn mission.

    Science.gov (United States)

    Ammannito, Eleonora; Mc Cord, Thomas B.; De Sanctis, Maria Cristina.; Combe, Jean-Philippe

    VIR-MS (Visual and Infrared Mapping Spectrometer) is the imaging spectrometer of the Dawn mission (1,2). Here, first we describe the computation of a new instrument responsivity based on the internal calibration data acquired during the operations at Vesta, and then we describe its effect on the dataset and on the results published so far. VIR-MS was built in Italy by a scientific-industrial (IAPS/INAF in Rome (Italy) and Selex ES in Campi Bisenzio (Fi, Italy)) consortium financially supported by the Italian Space Agency. VIR-MS is an high spatial resolution spectrometer (FOV of 64mrad, IFOV of 250 µrad) in the 0.25-5 µm range with an IFOV of 250 µrad and a spectral sampling of about 2 nm in the visible range and 10 nm in the IR range. The results of the on-ground calibration held in the Selex calibration facility in September 2005 were already presented and discussed in a paper (2). This version has been used to calibrate the data available on the Planetary Data System (PDS) Small Bodies Node, dataset used in all the papers published so far. However, after the operations at the asteroid Vesta, we have identified some artifacts in the instrument responsivity in the 2.5-3.5 µm region, which is where several absorption bands of OH and H2O occur. Those artifacts were systematic, and therefore they did not prevent the detection of relative spectral variations associated to OH and H2O. Actually, the only paper published in which are discussed spectra in this range (3) used a different calibration method described in the paper itself. This method used a simple correction of the response function based on an empirical calibration correction that is appropriate to recover the signal in that specific range. However, the absolute absorption band depth of OH and H2O could not be calculated. To compute a new instrument responsivity we used the internal lamp of the spectrometer. This lamp, made of a tungsten filament, is characterized by a blackbody-like emission at about

  2. Dynamics and local boundary properties of the dawn-side magnetopause under conditions observed by Equator-S

    Directory of Open Access Journals (Sweden)

    M. W. Dunlop

    Full Text Available Magnetic field measurements, taken by the magnetometer experiment (MAM on board the German Equator-S spacecraft, have been used to identify and categorise 131 crossings of the dawn-side magnetopause at low latitude, providing unusual, long duration coverage of the adjacent magnetospheric regions and near magnetosheath. The crossings occurred on 31 orbits, providing unbiased coverage over the full range of local magnetic shear from 06:00 to 10:40 LT. Apogee extent places the spacecraft in conditions associated with intermediate, rather than low, solar wind dynamic pressure, as it processes into the flank region. The apogee of the spacecraft remains close to the magnetopause for mean solar wind pressure. The occurrence of the magnetopause encounters are summarised and are found to compare well with predicted boundary location, where solar wind conditions are known. Most scale with solar wind pressure. Magnetopause shape is also documented and we find that the magnetopause orientation is consistently sunward of a model boundary and is not accounted for by IMF or local magnetic shear conditions. A number of well-established crossings, particularly those at high magnetic shear, or exhibiting unusually high-pressure states, were observed and have been analysed for their boundary characteristics and some details of their boundary and near magnetosheath properties are discussed. Of particular note are the occurrence of mirror-like signatures in the adjacent magnetosheath during a significant fraction of the encounters and a high number of multiple crossings over a long time period. The latter is facilitated by the spacecraft orbit which is designed to remain in the near magnetosheath for average solar wind pressure. For most encounters, a well-ordered, tangential (draped magnetosheath field is observed and there is little evidence of large deviations in local boundary orientations. Two passes corresponding to close conjunctions of the Geotail spacecraft

  3. Sleep architecture of consolidated and split sleep due to the dawn (Fajr) prayer among Muslims and its impact on daytime sleepiness

    OpenAIRE

    BaHammam, Ahmed S.; Sharif, Munir M.; D Warren Spence; Pandi-Perumal, Seithikurippu R.

    2012-01-01

    Background: Muslims are required to wake up early to pray (Fajr) at dawn (approximately one and one-half hours before sunrise). Some Muslims wake up to pray Fajr and then sleep until it is time to work (split sleep), whereas others sleep continuously (consolidated sleep) until work time and pray Fajr upon awakening. Aim: To objectively assess sleep architecture and daytime sleepiness in consolidated and split sleep due to the Fajr prayer. Setting and Design: A cross-sectional, single-...

  4. Experimental illumination of a forest: no effects of lights of different colours on the onset of the dawn chorus in songbirds

    Science.gov (United States)

    de Jong, Maaike; van Grunsven, Roy H. A.; Visser, Marcel E.; Kempenaers, Bart; Spoelstra, Kamiel

    2017-01-01

    Light pollution is increasing exponentially, but its impact on animal behaviour is still poorly understood. For songbirds, the most repeatable finding is that artificial night lighting leads to an earlier daily onset of dawn singing. Most of these studies are, however, correlational and cannot entirely dissociate effects of light pollution from other effects of urbanization. In addition, there are no studies in which the effects of different light colours on singing have been tested. Here, we investigated whether the timing of dawn singing in wild songbirds is influenced by artificial light using an experimental set-up with conventional street lights. We illuminated eight previously dark forest edges with white, green, red or no light, and recorded daily onset of dawn singing during the breeding season. Based on earlier work, we predicted that onset of singing would be earlier in the lighted treatments, with the strongest effects in the early-singing species. However, we found no significant effect of the experimental night lighting (of any colour) in the 14 species for which we obtained sufficient data. Confounding effects of urbanization in previous studies may explain these results, but we also suggest that the experimental night lighting may not have been strong enough to have an effect on singing. PMID:28280562

  5. Modeling the Radio Foreground for Detection of CMB Spectral Distortions from the Cosmic Dawn and the Epoch of Reionization

    Science.gov (United States)

    Sathyanarayana Rao, Mayuri; Subrahmanyan, Ravi; Udaya Shankar, N.; Chluba, Jens

    2017-05-01

    Cosmic baryon evolution during the Cosmic Dawn and Reionization results in redshifted 21-cm spectral distortions in the cosmic microwave background (CMB). These encode information about the nature and timing of first sources over redshifts 30-6 and appear at meter wavelengths as a tiny CMB distortion along with the Galactic and extragalactic radio sky, which is orders of magnitude brighter. Therefore, detection requires precise methods to model foregrounds. We present a method of foreground fitting using maximally smooth (MS) functions. We demonstrate the usefulness of MS functions over traditionally used polynomials to separate foregrounds from the Epoch of Reionization (EoR) signal. We also examine the level of spectral complexity in plausible foregrounds using GMOSS, a physically motivated model of the radio sky, and find that they are indeed smooth and can be modeled by MS functions to levels sufficient to discern the vanilla model of the EoR signal. We show that MS functions are loss resistant and robustly preserve EoR signal strength and turning points in the residuals. Finally, we demonstrate that in using a well-calibrated spectral radiometer and modeling foregrounds with MS functions, the global EoR signal can be detected with a Bayesian approach with 90% confidence in 10 minutes’ integration.

  6. The Geology of the Marcia Quadrangle of Asteroid 4Vesta: An Integrated Mapping Study Using Dawn Spacecraft Data

    Science.gov (United States)

    Williams, David A.; Denevi, B. W.; Mittlefehldt, D. W.; Mest, S. C.; Schenk, P. M.; Jaumann, R.; DeSanctis, M. C.; Buczkowski, D. L.; Ammannito, E.; Prettyman, T. H.; Buczkowski, D. L.

    2012-01-01

    We used geologic mapping applied to Dawn data as a tool to understand the geologic history of the Marcia quadrangle of Vesta. This region hosts a set of relatively fresh craters and surrounding ejecta field, an unusual dark hill named Arisia Tholus, and a orange (false color) diffuse material surrounding the crater Octavia. Stratigraphically, from oldest to youngest, three increasingly larger impact craters named Minucia, Calpurnia, and Marcia make up a snowmanlike feature, which is surrounded by a zone of dark material interpreted to consist of impact ejecta and possibly impact melts. The floor of Marcia contains a pitted terrain thought to be related to release of volatiles (1). The dark ejecta field has an enhanced signature of H, possibly derived from carbonaceous chondritic material that accumulated in Vesta s crust (2,3). The dark ejecta has a spectrally distinctive behavior with shallow pyroxenes band depths. Outside the ejecta field this quadrangle contains various cratered terrains, with increasing crater abundance moving south to north away from the Rheasilvia basin. Arisia Tholus, originally suggested as an ancient volcano, appears to be an impact-sculpted basin rim fragment with a superposed darkrayed impact crater. There remains no unequivocal evidence of volcanic features on Vesta s surface, likely because basaltic material of the HED meteorite suite demonstrates magmatism ended very early on Vesta (4). Ongoing work includes application of crater statistical techniques to obtain model ages of surface units, and more detailed estimates of the compositional variations among the surface units.

  7. DETECTION OF WIDESPREAD HYDRATED MATERIALS ON VESTA BY THE VIR IMAGING SPECTROMETER ON BOARD THE DAWN MISSION

    Energy Technology Data Exchange (ETDEWEB)

    De Sanctis, M. C.; Ammannito, E.; Palomba, E.; Longobardo, A.; Capaccioni, F.; Capria, M. T.; Tosi, F.; Zambon, F.; Carraro, F.; Fonte, S.; Frigeri, A.; Magni, G. [Istituto di Astrofisica e Planetologia Spaziali, INAF, Rome (Italy); Combe, J.-Ph.; McCord, T. B. [Bear Fight Institute, Winthrop, WA (United States); Marchi, S. [NASA Lunar Science Institute, Boulder, CO (United States); Mittlefehldt, D. W. [NASA Johnson Space Center, Houston, TX (United States); Pieters, C. M. [Department of Geological Sciences, Brown University, Providence, RI (United States); Sunshine, J. [Department of Astronomy, University of Maryland, Maryland (United States); Raymond, C. A. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States); Russell, C. T., E-mail: mariacristina.desanctis@iaps.inaf.it [Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA (United States); and others

    2012-10-20

    Water plays a key role in the evolution of terrestrial planets, and notably in the occurrence of Earth's oceans. However, the mechanism by which water has been incorporated into these bodies-including Earth-is still extensively debated. Here we report the detection of widespread 2.8 {mu}m OH absorption bands on the surface of the asteroid Vesta by the VIR imaging spectrometer on board Dawn. These observations are surprising as Vesta is fully differentiated with a basaltic surface. The 2.8 {mu}m OH absorption is distributed across Vesta's surface and shows areas enriched and depleted in hydrated materials. The uneven distribution of hydrated mineral phases is unexpected and indicates ancient processes that differ from those believed to be responsible for OH on other airless bodies, like the Moon. The origin of Vestan OH provides new insight into the delivery of hydrous materials in the main belt and may offer new scenarios on the delivery of hydrous minerals in the inner solar system, suggesting processes that may have played a role in the formation of terrestrial planets.

  8. The Evolution of 21-cm Structure (EOS): public, large-scale simulations of Cosmic Dawn and Reionization

    CERN Document Server

    Mesinger, Andrei; Sobacchi, Emanuele

    2016-01-01

    We introduce the Evolution of 21-cm Structure (EOS) project: providing periodic, public releases of the latest cosmological 21-cm simulations. 21-cm interferometry is set to revolutionize studies of the Cosmic Dawn (CD) and epoch of reionization (EoR), eventually resulting in 3D maps of the first billion years of our Universe. Progress will depend on sophisticated data analysis pipelines, which are in turn tested on large-scale mock observations. Here we present the 2016 EOS data release, consisting of the largest (1.6 Gpc on side with a 1024^3 grid), public 21-cm simulations of the CD and EoR. We include calibrated, sub-grid prescriptions for inhomogeneous recombinations and photo-heating suppression of star formation in small mass galaxies. We present two simulation runs that approximately bracket the contribution from faint unseen galaxies. From these two extremes, we predict that the duration of reionization (defined as a change in the mean neutral fraction from 0.9 to 0.1) should be between 2.7 < Delt...

  9. Imaging the redshifted 21-cm pattern around the first sources during the cosmic dawn using the SKA

    CERN Document Server

    Ghara, Raghunath; Datta, Kanan K; Choudhuri, Samir

    2016-01-01

    Understanding properties of the first sources in the Universe using the redshifted \\HI ~21-cm signal is one of the major aims of present and upcoming low-frequency experiments. We investigate the possibility of imaging the redshifted 21-cm pattern around the first sources during the cosmic dawn using the SKA1-low. We model the \\HI ~21-cm image maps, appropriate for the SKA1-low, around the first sources consisting of stars and X-ray sources within galaxies. In addition to the system noise, we account also for the astrophysical foregrounds by adding them to the signal maps. We find that after subtracting the foregrounds using a polynomial fit and suppressing the noise by smoothing the maps over $10^{'} - 30^{'}$ angular scale, the isolated sources at $z \\sim 15$ are detectable with $\\sim 4 - 9 \\, \\sigma$ confidence level in 2000 h of observation with the SKA1-low. Although the 21-cm profiles around the sources get altered because of the Gaussian smoothing, the images can still be used to extract some of the so...

  10. Dawn-dusk asymmetries and sub-Alfvénic flow in the high and low latitude magnetosheath

    Directory of Open Access Journals (Sweden)

    M. Longmore

    2005-11-01

    Full Text Available We present the results of a statistical survey of the magnetosheath using four years of Cluster orbital coverage. Moments of the plasma distribution obtained from the electron and ion instruments together with magnetic field data are used to characterise the flow and density in the magnetosheath. We note two important differences between our survey and the gasdynamic model predictions: a deceleration of the flow at higher latitudes close to the magnetopause, resulting in sub-Alfvénic flow near the cusp, and a dawn-dusk asymmetry with higher velocity magnitudes and lower densities measured on the dusk side of the magnetosheath in the Northern Hemisphere. The latter observation is in agreement with studies carried out by Paularena et al. (2001, Němeček et al. (2000, and Šafránková et al. (2004. In equations of hydrodynamics for a single-component additon to this we observe a reverse of this asymmetry for the Southern Hemisphere. High-latitude sub-Alfvénic flow is thought to be a necessary condition for steady state reconnection pole-ward of the cusp.

  11. Three-dimensional spectral analysis of compositional heterogeneity at Arruntia crater on (4) Vesta using Dawn FC

    CERN Document Server

    Thangjam, Guneshwar; Mengel, Kurt; Schäfer, Michael; Hoffmann, Martin; Cloutis, Edward A; Mann, Paul; Müller, Christian; Platz, Thomas; Schäfer, Tanja

    2015-01-01

    We introduce an innovative three-dimensional spectral approach (three band parameter space with polyhedrons) that can be used for both qualitative and quantitative analyses improving the characterization of surface heterogeneity of (4) Vesta. It is an advanced and more robust methodology compared to the standard two-dimensional spectral approach (two band parameter space). The Dawn Framing Camera (FC) color data obtained during High Altitude Mapping Orbit (resolution ~ 60 m/pixel) is used. The main focus is on the howardite-eucrite-diogenite (HED) lithologies containing carbonaceous chondritic material, olivine, and impact-melt. The archived spectra of HEDs and their mixtures, from RELAB, HOSERLab and USGS databases as well as our laboratory-measured spectra are used for this study. Three-dimensional convex polyhedrons are defined using computed band parameter values of laboratory spectra. Polyhedrons based on the parameters of Band Tilt (R0.92{\\mu}m/R0.96{\\mu}m), Mid Ratio ((R0.75{\\mu}m/R0.83{\\mu}m)/(R0.83{\\...

  12. An analysis of United States K-12 stem education versus STEM workforce at the dawn of the digital revolution

    Science.gov (United States)

    Cataldo, Franca

    The world is at the dawn of a third industrial revolution, the digital revolution, that brings great changes the world over. Today, computing devices, the Internet, and the World Wide Web are vital technology tools that affect every aspect of everyday life and success. While computing technologies offer enormous benefits, there are equally enormous safety and security risks that have been growing exponentially since they became widely available to the public in 1994. Cybercriminals are increasingly implementing sophisticated and serious hack attacks and breaches upon our nation's government, financial institutions, organizations, communities, and private citizens. There is a great need for computer scientists to carry America's innovation and economic growth forward and for cybersecurity professionals to keep our nation safe from criminal hacking. In this digital age, computer science and cybersecurity are essential foundational ingredients of technological innovation, economic growth, and cybersecurity that span all industries. Yet, America's K-12 education institutions are not teaching the computer science and cybersecurity skills required to produce a technologically-savvy 21st century workforce. Education is the key to preparing students to enter the workforce and, therefore, American K-12 STEM education must be reformed to accommodate the teachings required in the digital age. Keywords: Cybersecurity Education, Cybersecurity Education Initiatives, Computer Science Education, Computer Science Education Initiatives, 21 st Century K-12 STEM Education Reform, 21st Century Digital Literacies, High-Tech Innovative Problem-Solving Skills, 21st Century Digital Workforce, Standardized Testing, Foreign Language and Culture Studies, Utica College, Professor Chris Riddell.

  13. Cosmic Dawn (CoDa): the First Radiation-Hydrodynamics Simulation of Reionization and Galaxy Formation in the Local Universe

    Science.gov (United States)

    Ocvirk, Pierre; Gillet, Nicolas; Shapiro, Paul R.; Aubert, Dominique; Iliev, Ilian T.; Teyssier, Romain; Yepes, Gustavo; Choi, Jun-Hwan; Sullivan, David; Knebe, Alexander; Gottlöber, Stefan; D'Aloisio, Anson; Park, Hyunbae; Hoffman, Yehuda; Stranex, Timothy

    2016-12-01

    Cosmic reionization by starlight from early galaxies affected their evolution, thereby impacting reionization itself. Star formation suppression, for example, may explain the observed underabundance of Local Group dwarfs relative to N-body predictions for cold dark matter. Reionization modelling requires simulating volumes large enough [˜ (100 Mpc)3] to sample reionization `patchiness', while resolving millions of galaxy sources above ˜108 M⊙ combining gravitational and gas dynamics with radiative transfer. Modelling the Local Group requires initial cosmological density fluctuations pre-selected to form the well-known structures of the Local Universe today. Cosmic Dawn (`CoDa') is the first such fully coupled, radiation-hydrodynamics simulation of reionization of the Local Universe. Our new hybrid CPU-GPU code, RAMSES-CUDATON, performs hundreds of radiative transfer and ionization rate-solver timesteps on the GPUs for each hydro-gravity timestep on the CPUs. CoDa simulated (91Mpc)3 with 40963 particles and cells, to redshift 4.23, on ORNL supercomputer Titan, utilizing 8192 cores and 8192 GPUs. Global reionization ended slightly later than observed. However, a simple temporal rescaling which brings the evolution of ionized fraction into agreement with observations also reconciles ionizing flux density, cosmic star formation history, CMB electron scattering optical depth and galaxy UV luminosity function with their observed values. Photoionization heating suppressed the star formation of haloes below ˜2 × 109 M⊙, decreasing the abundance of faint galaxies around MAB1600 = [-10, -12]. For most of reionization, star formation was dominated by haloes between 1010-1011 M⊙ , so low-mass halo suppression was not reflected by a distinct feature in the global star formation history. Intergalactic filaments display sheathed structures, with hot envelopes surrounding cooler cores, but do not self-shield, unlike regions denser than 100 .

  14. A Vortical Dawn Flank Boundary Layer for Near-Radial IMF: Wind Observations on 24 October 2001

    Science.gov (United States)

    Farrugia, C. J.; Gratton, F. T.; Gnavi, G.; Torbert, R. B.; Wilson, Lynn B., III

    2014-01-01

    We present an example of a boundary layer tailward of the dawn terminator which is entirely populated by rolled-up flow vortices. Observations were made by Wind on 24 October 2001 as the spacecraft moved across the region at the X plane approximately equal to -13 Earth radii. Interplanetary conditions were steady with a near-radial interplanetary magnetic field (IMF). Approximately 15 vortices were observed over the 1.5 hours duration of Wind's crossing, each lasting approximately 5 min. The rolling up is inferred from the presence of a hot tenuous plasma being accelerated to speeds higher than in the adjoining magnetosheath, a circumstance which has been shown to be a reliable signature of this in single-spacecraft observations. A blob of cold dense plasma was entrained in each vortex, at whose leading edge abrupt polarity changes of field and velocity components at current sheets were regularly observed. In the frame of the average boundary layer velocity, the dense blobs were moving predominantly sunward and their scale size along the X plane was approximately 7.4 Earth radii. Inquiring into the generation mechanism of the vortices, we analyze the stability of the boundary layer to sheared flows using compressible magnetohydrodynamic Kelvin-Helmholtz theory with continuous profiles for the physical quantities. We input parameters from (i) the exact theory of magnetosheath flow under aligned solar wind field and flow vectors near the terminator and (ii) the Wind data. It is shown that the configuration is indeed Kelvin-Helmholtz (KH) unstable. This is the first reported example of KH-unstable waves at the magnetopause under a radial IMF.

  15. Cosmic Dawn (CoDa): the First Radiation-Hydrodynamics Simulation of Reionization and Galaxy Formation in the Local Universe

    Science.gov (United States)

    Ocvirk, Pierre; Gillet, Nicolas; Shapiro, Paul R.; Aubert, Dominique; Iliev, Ilian T.; Teyssier, Romain; Yepes, Gustavo; Choi, Jun-Hwan; Sullivan, David; Knebe, Alexander; Gottlöber, Stefan; D'Aloisio, Anson; Park, Hyunbae; Hoffman, Yehuda; Stranex, Timothy

    2016-08-01

    Cosmic reionization by starlight from early galaxies affected their evolution, thereby impacting reionization, itself. Star formation suppression, for example, may explain the observed underabundance of Local Group dwarfs relative to N-body predictions for Cold Dark Matter. Reionization modelling requires simulating volumes large enough [ ˜ (100 Mpc)3] to sample reionization "patchiness", while resolving millions of galaxy sources above ˜108 M⊙ , combining gravitational and gas dynamics with radiative transfer. Modelling the Local Group requires initial cosmological density fluctuations pre-selected to form the well-known structures of the local universe today. Cosmic Dawn ("CoDa") is the first such fully-coupled, radiation-hydrodynamics simulation of reionization of the local universe. Our new hybrid CPU-GPU code, RAMSES-CUDATON, performs hundreds of radiative transfer and ionization rate-solver timesteps on the GPUs for each hydro-gravity timestep on the CPUs. CoDa simulated (91Mpc)3 with 40963 particles and cells, to redshift 4.23, on ORNL supercomputer Titan, utilizing 8192 cores and 8192 GPUs. Global reionization ended slightly later than observed. However, a simple temporal rescaling which brings the evolution of ionized fraction into agreement with observations also reconciles ionizing flux density, cosmic star formation history, CMB electron scattering optical depth and galaxy UV luminosity function with their observed values. Photoionization heating suppressed the star formation of haloes below ˜2 × 109 M⊙ , For most of reionization, star formation was dominated by haloes between 1010 - 1011 M⊙ , so low-mass halo suppression was not reflected by a distinct feature in the global star formation history. Intergalactic filaments display sheathed structures, with hot envelopes surrounding cooler cores, but do not self-shield, unlike regions denser than 100 .

  16. The fiction of Zora Neale Hurston: an assertion of black womanhood* The fiction of Zora Neale Hurston: an assertion of black womanhood*

    Directory of Open Access Journals (Sweden)

    Rita Terezinha Schmidt

    2008-04-01

    Full Text Available Contrary to what oficial historical records show, recentstudies convincingly prove that women have been writing forcenturies, in a variety of literary modes and genres. However,an historical examination of the role of woman as writer revealsthat she has suffered from the persistent cultural ideal ofwoman's silence, an invisibility which has rendered her worksmarginal to what the guardians of the great tradition call 'theserious enterprise of art.' Denied legitimacy for so long by atraditional canon which has prescribed standards of literaryexcellence on the basis of pre-existing social bias, womenwriters are just beginning to be reviewed in major literarypublications, included in literary histories and universitycurricula as a result of the efforts geared to the body ofstudies in literature which has emerged as an important part ofthe post-60's upsurge of work in woman's studies, especially inthe United States. Certain ideas, perpetuated in the theory andpractice of literature, (such as the domain of the male creatorthrough whose agency and power man acquired the Word, becomingthe sacer vates, or the exclusively male transcendental images of creativity as opposed to earth-bound images of female nature, which have invested all significance in the experience, ideasand discourse of men, are now being called to question.Retrieving woman's texts and the literary expression of thefemale experience is a sign of basic changes in the consciousness of western art and society and a task in which weall should join as professionais concerned with the relationshipbetween women and literature. Contrary to what oficial historical records show, recentstudies convincingly prove that women have been writing orcenturies, in a variety of literary modes and genres. However,an historical examination of the role of woman as writer revealsthat she has suffered from the persistent cultural ideal ofwoman's silence, an invisibility which has rendered her worksmarginal to what the guardians of the great tradition call 'theserious enterprise of art.' Denied legitimacy for so long by atraditional canon which has prescribed standards of literaryexcellence on the basis of pre-existing social bias, womenwriters are just beginning to be reviewed in major literarypublications, included in literary histories and universitycurricula as a result of the efforts geared to the body ofstudies in literature which has emerged as an important part ofthe post-60's upsurge of work in woman's studies, especially inthe United States. Certain ideas, perpetuated in the theory andpractice of literature, (such as the domain of the male creatorthrough whose agency and power man acquired the Word, becomingthe sacer vates, or the exclusively male transcendental images of creativity as opposed to earth-bound images of female nature, which have invested all significance in the experience, ideasand discourse of men, are now being called to question.Retrieving woman's texts and the literary expression of thefemale experience is a sign of basic changes in the consciousness of western art and society and a task in which weall should join as professionais concerned with the relationshipbetween women and literature.

  17. The fiction of zora neale hurston: an assertion of black womanhood The fiction of zora neale hurston: an assertion of black womanhood

    Directory of Open Access Journals (Sweden)

    Rita Terezinha Schmidt

    2008-04-01

    Full Text Available Contrary to what official historical records show, recent studies convincingly prove that women have been writing for centuries, in a variety of literary modes and genres. However, an historical examination of the role of woman as writer reveals that she has suffered from the persistent cultural ideal of woman's silence, an invisibility which has rendered her works marginal to what the guardians of the great tradition call 'the serious enterprise of art.' Denied legitimacy for so long by a traditional canon which has prescribed standards of literary excellence on the basis of pre-existing social bias, women writers are just beginning to be reviewed in major literary publications, included in literary histories and university curricula as a result of the efforts geared to the body of studies in literature which has emerged as an important part of the post-60's upsurge of work in woman's studies, especially in the United States. Contrary to what official historical records show, recent studies convincingly prove that women have been writing for centuries, in a variety of literary modes and genres. However, an historical examination of the role of woman as writer reveals that she has suffered from the persistent cultural ideal of woman's silence, an invisibility which has rendered her works marginal to what the guardians of the great tradition call 'the serious enterprise of art.' Denied legitimacy for so long by a traditional canon which has prescribed standards of literary excellence on the basis of pre-existing social bias, women writers are just beginning to be reviewed in major literary publications, included in literary histories and university curricula as a result of the efforts geared to the body of studies in literature which has emerged as an important part of the post-60's upsurge of work in woman's studies, especially in the United States.

  18. Preliminary Geological Map of the Ac-H-9 Occator Quadrangle of Ceres: An Integrated Mapping Study Using Dawn Spacecraft Data

    Science.gov (United States)

    Buczkowski, D.; Yingst, R. A.; Williams, D. A.; Mest, S. C.; Scully, J. E. C.; Crown, D. A.; Schenk, P.; Jaumann, R.; Roatsch, T.; Preusker, F.; Platz, T.; Nathues, A.; Hoffmann, M.; Schäfer, M.; Marchi, S.; De Sanctis, M. C.; Raymond, C. A.; Russell, C. T.

    2015-12-01

    We used geologic mapping applied to Dawn spacecraft data as a tool to understand the geologic history of the Ac-H-9 Occator quadrangle of dwarf planet Ceres. This region, located between 22˚S-22˚N and 216-288˚E, is one of two longitudinally distinct regions on Ceres where ESA Herschel space telescope data suggested a release of water vapor [1] and hosts: 1) the 92 km diameter impact crater Occator in the NW of the quadrangle, whose rim is scalloped and whose interior encompasses Hubble "Bright Spot 5"; 2) the 115 km diameter crater Kirnis, a degraded crater that contains a large dome-like feature on the western half of its floor; and 3) regional linear structures, that both cut crater rims (including Occator and Kirnis) and affect crater shapes. Key goals of the ongoing mapping are to 1) determine the source of the bright spots in Occator; 2) determine if the dome-like feature in Kirnis resulted from a mass-wasting or is a product of uplift; and 3) assess the relationships between linear structural features and impact craters, including the effects of surface stress regimes on crater formation and modification. At the time of this writing geologic mapping was performed on Framing Camera (FC) mosaics from late Approach (1.3 km/px) and Survey (415 m/px) orbits, including clear filter and color images and digital terrain models derived from stereo images. In Fall 2015 images from the High Altitude Mapping Orbit (140 m/px) will be used to refine the mapping, followed by Low Altitude Mapping Orbit (35 m/px) images starting in December 2015. Support of the Dawn Instrument, Operations, and Science Teams is acknowledged. This work is supported by grants from NASA through the Dawn project, and from the German and Italian Space Agencies. Reference: [1] Küppers, M., et al. (2014). Nature, v. 505, 525-527.

  19. PARALLELIZATION OF THE MM4 NUMERICAL MODEL ON DAWNING-1000%MM4数值模式在曙光1000机上的并行化

    Institute of Scientific and Technical Information of China (English)

    李国杰; 李柏; 翟武全; 赵建勇; 陈国良; 刘清; 石春娥

    2001-01-01

    In the light of the function and characteristics of the Dawning-1000 paral lel computer made in China, we designed the parallel calculation scheme of the MM4 mesoscale numerical model. Because of the technological processing and meticulously remaking of the data organization and program flow of the sequential program, it reaches reliable calculation results and the SPEEDUP ratio rises obviously at last. When sixteen processing nodes are used, the SPEEDUP ratio reaches 1:6.7. In finite region, the model needs only less than 30 minutes to integrate 36 hours, and the operational parallel calculation environment for application of MM4 mesoscale model is preliminarily set up.

  20. The INTERBALL-Tail ELECTRON experiment: initial results on the low-latitude boundary layer of the dawn magnetosphere

    Directory of Open Access Journals (Sweden)

    J.-A. Sauvaud

    Full Text Available The Toulouse electron spectrometer flown on the Russian project INTERBALL-Tail performs electron measurements from 10 to 26 000 eV over a 4 solid angle in a satellite rotation period. The INTERBALL-Tail probe was launched on 3 August 1995 together with a subsatellite into a 65° inclination orbit with an apogee of about 30 RE. The INTERBALL mission also includes a polar spacecraft launched in August 1996 for correlated studies of the outer magnetosphere and of the auroral regions. We present new observations concerning the low-latitude boundary layers (LLBL of the magnetosphere obtained near the dawn magnetic meridian. LLBL are encountered at the interface between two plasma regimes, the magnetosheath and the dayside extension of the plasma sheet. Unexpectedly, the radial extent of the region where LLBL electrons can be sporadically detected as plasma clouds can reach up to 5 RE inside the magnetopause. The LLBL core electrons have an average energy of the order of 100 eV and are systematically field-aligned and counterstreaming. As a trend, the temperature of the LLBL electrons increases with decreasing distance to Earth. Along the satellite orbit, the apparent time of occurrence of LLBL electrons can vary from about 5 to 20 min from one pass to another. An initial first comparison between electron- and magnetic-field measurements indicates that the LLBL clouds coincide with a strong increase in the magnetic field (by up to a factor of 2. The resulting strong magnetic field gradient can explain why the plasma-sheet electron flux in the keV range is strongly depressed in LLBL occurrence regions (up to a factor of sim10. We also show that LLBL electron encounters are related to field-aligned current structures and that wide LLBL correspond to northward interplanetary magnetic field. Evidence for LLBL/plasma-sheet electron leakage into the magnetosheath during southward IMF is also presented.

  1. Preliminary Geological Map of the Ac-H-13 Urvara Quadrangle of Ceres: An Integrated Mapping Study Using Dawn Spacecraft Data

    Science.gov (United States)

    Williams, D. A.; Sizemore, H. G.; Platz, T.; O'Brien, D. P.; Mest, S. C.; Yingst, R. A.; Crown, D. A.; Buczkowski, D.; Schenk, P.; Scully, J. E. C.; Jaumann, R.; Roatsch, T.; Preusker, F.; Nathues, A.; De Sanctis, M. C.; Russell, C. T.; Raymond, C. A.

    2015-12-01

    We used geologic mapping applied to Dawn spacecraft data as a tool to understand the geologic history of the Ac-H-13 Urvara Quadrangle of dwarf planet Ceres. This region, located between 21˚S-66˚S and 180-270˚E, is dominated by the Urvara basin in the east and cratered plains in the west. The elevation of the cratered plains is intermediate between the identified "highland" and "lowland" units of Ceres. Plains in the SW corner of the quadrangle are hummocky and heavily cratered, while the NW corner is smoother and less densely cratered. Features of note include 1) the 200 km diameter Urvara basin, which includes a degraded northern rim and smooth interior and exterior material that hosts a significantly lower impact crater density than most of the rest of Ceres' surface; 2) semi-radial curvilinear structures extending to the east and west of Urvara; 3) two large-scale dome structures 10s of km in diameter exterior to Urvara; and 4) numerous small-scale domical structures (digital terrain models derived from stereo images. In Fall 2015 images from the High Altitude Mapping Orbit (140 m/px) will be used to refine the mapping, followed by Low Altitude Mapping Orbit (35 m/px) images starting in December 2015. Support of the Dawn Instrument, Operations, and Science Teams is acknowledged. This work is supported by grants from NASA, the Max Planck Society and from the German and Italian Space Agencies.

  2. The Dawn of Peace?

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The recent memorandum of understanding between the Israelis and the Palestinians has restarted the Middle East Peace talks,but is the road to lasting peace in sight? Peace talks between Israel and Palestine during the past several years have not been as crucial as other Middle East issues such as the Iranian nuclear issue and the war in Iraq.During this time,the peace process has not made any progress and the situation in the region has not improved.But in late November,the world was surprised to see lsraeli and Palestinian leaders meeting in

  3. Earthquake at Dawn

    Institute of Scientific and Technical Information of China (English)

    张江云

    1996-01-01

    The earth is covered by continent-size slabs of rock that are in endlessslow motion-tectonic plates afloat on a sea of semimolten rock. Smashingand grinding against each other, they create a labyrinth of cracks, or faultlines, in the earth’s crust.

  4. Dawn of Cavity Spintronics

    OpenAIRE

    Hu, Can-Ming

    2015-01-01

    Merging the progress of spintronics with the advancement in cavity quantum electrodynamics and cavity polaritons, a new field of Cavity Spintronics is forming, which connects some of the most exciting modern physics, such as quantum information and quantum optics, with one of the oldest science on the earth, the magnetism.

  5. Undermining Patriarchal Ideology in African Literature: A Study of Ngozi Chuma-Udeh’s Echoes of a New Dawn

    Directory of Open Access Journals (Sweden)

    Ujowundu Cornel O.

    2013-11-01

    s sexual passion; and worst of all, not consulted in the decision making processes in their communities. The women as wives are expected to be submissive, obedient, unquestioning and servile while any challenge to these attributes attracts social disfavour. So the clearly defined roles for women are passed on to the girl-child as she grows. As soon as she is able to do things for herself, she starts assuming the roles society has mapped out for her: learning how to cook, care for the home, helping with everything else the mother does, and preparing for womanhood and matrimony. This paper, therefore, takes a critical look into Ngozi Chuma-Udeh’s novel that advocates a new dawn for the women. The novelist wants the men to reconsider their negative notions about women and to also appreciate their contributions in the well-being of their societies, their families and the upbringing of the children. Keywords: Patriarchy, Ideology, Feminism, Emancipation, Marriage, Humiliation, Ignorance

  6. MPI ALGORITHM OF MULTILEVEL PRECONDITIONER FOR PLATE PROBLEM ON DAWN 1000+%板问题预条件子在曙光D1000+上的MPI实现

    Institute of Scientific and Technical Information of China (English)

    陈文斌; 王岚

    2000-01-01

    An optimal multilevel preconditioner for plate problem was constructedin [7]. In this paper, the matrix presentation of the preconditioner isgiven and EBE technology is used to realize the saving and computing ofglobal stiff matrix, interpolation matrix and transport matrix. An MPIalgorithm is also given on Dawn 1000+.

  7. Spectral modeling of water ice-rich areas on Ceres' surface from Dawn-VIR data analysis: abundance and grain size retrieval

    Science.gov (United States)

    Raponi, Andrea; De Sanctis, Maria Cristina; Ciarniello, Mauro; Tosi, Federico; Combe, Jean-Philippe; Frigeri, Alessandro; Zambon, Francesca; Ammannito, Eleonora; Giacomo Carrozzo, Filippo; Magni, Gianfranco; Capria, Maria Teresa; Formisano, Michelangelo; Longobardo, Andrea; Palomba, Ernesto; Pieters, Carle; Russell, Christopher T.; Raymond, Carol; Dawn/VIR Team

    2016-10-01

    Dawn spacecraft orbits around Ceres since early 2015 acquiring a huge amount of data at different spatial resolutions during the several phases of the mission. VIR, the visible and InfraRed spectrometer onboard Dawn [1] allowed to detect the principal mineralogical phases present on Ceres: a large abundance of dark component, NH4-phillosilicates and carbonates.Water has been detected in small areas on Ceres' surface by the Dawn-VIR instrument. The most obvious finding is located in Oxo crater [2]. Further detections of water have been made during the Survey observation phase (1.1 km/pixel) and High-Altitude Mapping Orbit (400 m/px) [3]. During the LAMO phase (Low Altitude Mapping Orbit), the data with increased spatial resolution (100 m/px) coming from both regions have improved the detection of water, highlighting clear diagnostic water ice absorption features. In this study, we focused on spectral modeling of VIR spectra of Oxo and another crater (lon = 227°, lat 57°), near Messor crater.The Hapke radiative transfer model [4] has been applied in order to retrieve the water ice properties. We consider two types of mixtures: areal and intimate mixing. In areal mixing, the surface is modelled as patches of pure water ice, with each photon scattered within one patch. In intimate mixing, the particles of water ice are in contact with particles of the dark terrain, and both are involved in the scattering of a single photon. The best fit with the measured spectra has been derived with the areal mixture. The water ice abundance obtained is up to 15-20% within the field of view, and the grain size retrieved is of the order of 100-200 μm. Phyllosilicates and carbonates, which are ubiquitous on Ceres surface [5], have been also detected and modeled in correspondence with the icy regions. The water ice is typically located near and within the shadows projected by the crater rims. Further analysis is required to study the thermal state of the ice and its origin

  8. Preliminary Geological Maps of the Ac-H-10 Rongo and Ac-H-15 Zadeni Quadrangles: An integrated Mapping Study Using Dawn Spacecraft Data

    Science.gov (United States)

    Platz, T.; Nathues, A.; Crown, D. A.; Mest, S. C.; Williams, D. A.; Hoffmann, M.; Schäfer, M.; Sizemore, H. G.; Yingst, R. A.; Ruesch, O.; Buczkowski, D.; Kneissl, T.; Schmedemann, N.; Hughson, K.; Preusker, F.; Russell, C. T.

    2015-12-01

    We used geologic mapping applied to Dawn spacecraft data as a tool to understand the geologic history of the Ac-H-10 Rongo and Ac-H-15 Zadeni quadrangles of dwarf planet Ceres. These regions, Rongo and Zadeni, are located between 22°S-22°N and 288°-360°E and 65-90°S and 0°-360°E, respectively. The Rongo Quadrangle hosts a number of features: 1) the southwest portion is dissected by curvilinear structures likely caused by Yalode basin formation; 2) the central part is marked by dome-like constructs up to 100 km across; 3) a peculiar bright, c.4 km tall, conical structure informally known as the 'pyramid'; 4) impact craters of various diameters appear moderately to highly degraded or are partially buried; and 5) bright material is primarily exposed in the central portion and often associated with craters. Rongo crater (68 km across) exhibits a central peak and scalloped walls indicative of its degraded appearance. The Zadeni Quadrangle is characterised by impact craters up to 130 km in diameter of which Zadeni crater is the largest. Impact craters across all sizes exhibit fresh to highly degraded morphologies or are partially buried. Many craters developed central peaks. Inter-crater plains are generally hummocky with isolated regions of smooth-textured surfaces. The south pole area (85-90°S) is poorly illuminated and may host a large impact structure. At the time of this writing geologic mapping was performed on Framing Camera (FC) mosaics from Approach (1.3 km/px) and Survey (415 m/px) orbits, including clear filter and colour images and digital terrain models derived from stereo images. In Fall 2015 images from the High Altitude Mapping Orbit (140 m/px) will be used to refine the mapping, followed by Low Altitude Mapping Orbit (35 m/px) starting in December 2015. Support of the Dawn Instrument, Operations, and Science Teams is acknowledged. This work is supported by grants from NASA through the Dawn project, and from the German and Italian Space Agencies.

  9. Research and Design on Dawning Parallel File System%曙光并行文件系统DPFS的研究与设计

    Institute of Scientific and Technical Information of China (English)

    曹立强; 马捷

    2005-01-01

    并行文件系统是高性能计算系统中的快速I/O库.它的目的是为并行计算应用提供快速Input/Output的手段.文章总结了并行应用程序的读写特点,其中的关键问题和在并行文件系统的通常使用的技术,并以此为基础设计了面向曙光高性能服务器的曙光并行文件系统(Dawning Parallel File System,DPFS).

  10. Evidence of sub-optimal sleep in adolescent Middle Eastern academy soccer players which is exacerbated by sleep intermission proximal to dawn.

    Science.gov (United States)

    Fowler, Peter M; Paul, Darren J; Tomazoli, Gustavo; Farooq, Abdulaziz; Akenhead, Richard; Taylor, Lee

    2017-10-01

    The purpose was to assess sleep patterns, quantity and quality in adolescent (16.2 ± 1.2 yr) Middle Eastern academy soccer players (n = 20) and the influence of an intermission upon these characteristics. On a 17-day training camp (located one time zone west of home) including three discrete matches, sleep was assessed pre- (PRE) and post-match (POST) via wrist actigraphy. Retrospective actigraphy analysis identified sleep characteristics, including if players experienced a sleep intermission (YES) or not (NO) proximal to dawn, and bedtime (hh:mm), get-up time (hh:mm), time in bed (h), sleep duration (h) and sleep efficiency (%). Within YES two bouts were identified (BOUT1 and BOUT2). No differences were seen between PRE and POST, nor between BOUT1 and BOUT2 (p > .05). Overall players did not meet National Sleep Foundation (NSF) guidelines (7:04 ± 1:16 h vs. recommended 8-10 h for 14-17 yr). Sleep duration was significantly reduced (∼ -13% or -1:06) in YES compared to NO (6:33 ± 1:05 vs. 7:29 ± 1:17, p sleep durations relative to NSF guidelines, with decrements increased by an intermission proximal to dawn. High inter- and intra-individual variance in the players sleep characteristics indicates the need for individualized sleep education strategies and interventions to promote appropriate sleep.

  11. Chondritic Models of 4 Vesta: Comparison of Data from the Dawn Mission with Predicted Internal Structure and Surface Composition/Mineralogy

    Science.gov (United States)

    Toplis, M. J.; Mizzon, H.; Forni, O.; Monnereau, M.; Barrat, J-A.; Prettyman, T. H.; McSween, H. Y.; McCoy, T. J.; Mittlefehldt, D. W.; De Sanctis, M. C.; Raymond, C. A.; Russell, C. T.

    2012-01-01

    While the HEDs provide an extremely useful basis for interpreting data from the Dawn mission, there is no guarantee that they provide a complete vision of all possible crustal (and possibly mantle) lithologies that are exposed at the surface of Vesta. With this in mind, an alternative approach is to identify plausible bulk compositions and use mass-balance and geochemical modelling to predict possible internal structures and crust/mantle compositions and mineralogies. While such models must be consistent with known HED samples, this approach has the potential to extend predictions to thermodynamically plausible rock types that are not necessarily present in the HED collection. Nine chondritic bulk compositions are considered (CI, CV, CO, CM, H, L, LL, EH, EL). For each, relative proportions and densities of the core, mantle, and crust are quantified. This calculation is complicated by the fact that iron may occur in metallic form (in the core) and/or in oxidized form (in the mantle and crust). However, considering that the basaltic crust has the composition of Juvinas and assuming that this crust is in thermodynamic equilibrium with the residual mantle, it is possible to calculate a single solution to this problem for a given bulk composition. Of the nine bulk compositions tested, solutions corresponding to CI and LL groups predicted a negative metal fraction and were not considered further. Solutions for enstatite chondrites imply significant oxidation relative to the starting materials and these solutions too are considered unlikely. For the remaining bulk compositions, the relative proportion of crust to bulk silicate is typically in the range 15 to 20% corresponding to crustal thicknesses of 15 to 20 km for a porosity-free Vesta-sized body. The mantle is predicted to be largely dominated by olivine (greater than 85%) for carbonaceous chondrites, but to be a roughly equal mixture of olivine and pyroxene for ordinary chondrite precursors. All bulk compositions

  12. Effects Of The Ionosphere On Ground-Based Detection Of The Global 21 CM Signal From The Cosmic Dawn And The Dark Ages

    CERN Document Server

    Datta, Abhirup; Burns, Jack O; Harker, Geraint; Komjathy, Attila; Lazio, T Joseph W

    2014-01-01

    Detection of global HI 21 cm signal from the Cosmic Dawn and the Epoch of Reionization is the key science driver for several ongoing ground-based and future ground/space based experiments. The crucial spectral features in the global 21cm signal (turning points) occurs at low radio frequencies < 100 MHz. In addition to the human-generated RFI (Radio Frequency Interference), Earth's ionosphere drastically corrupts low-frequency radio observations from the ground. In this paper, we examine the effects of time-varying ionospheric refraction, absorption and thermal emission at these low radio frequencies and their combined effect on any ground-based global 21cm experiment. It should be noted that this is the first study of the effect of a dynamic ionosphere on global 21cm experiments. Our results indicate that the spectral features in the global 21cm signal below 100 MHz cannot be detected from the ground under even "quiet" night-time ionospheric conditions. Any attempt to calibrate the ionospheric effect will ...

  13. Chondritic Models of 4 Vesta: Comparison of Predicted Internal Structure and Surface Composition/Mineralogy with Data from the Dawn Mission

    Science.gov (United States)

    Toplis, M. J.; Mizzon, H.; Forni, O.; Monnereau, M.; Barrat, J-A.; Prettyman, T. H.; McSween, H. Y.; McCoy, T. J.; Mittlefehldt, D. W.; De Sanctis, M. C.; Raymond, C. A.; Russell, C. T.

    2012-01-01

    Understanding the physical and chemical processes which led to the formation of the terrestrial planets remains one of the principal challenges of the Earth and planetary science communities. However, direct traces of the earliest stages of planet building have generally been wiped out on larger bodies such as the Earth or Mars, obscuring our view of how that process occurred. On the other hand, the planet building process would appear to have been arrested prematurely in the region between Mars and Jupiter, now populated by several hundred thousand compositionally diverse objects that escaped accretion into larger planets. Of these, the asteroid 4 Vesta is of particular interest as it is large (520 km diameter), and known to have a basaltic surface dominated by pyroxenes [1, 2]. Furthermore, visible-IR spectra of Vesta obtained by ground and space-based telescopes are remarkably similar to laboratory spectra measured on meteorites of the Howardite-Eucrite-Diogenite clan (HED), leading to the paradigm that the HEDs came from Vesta [2]. Geochemical and petrological studies of the HEDs confirm the differentiated nature of the near-surface region of their parent body, and imply that crust extraction occurred well within the first 10Ma of solar system history [3]. Vesta is therefore a prime target for studies that aim to constrain the earliest stages of planet building, and for that reason it is currently the subject of the Dawn mission [4].

  14. [Entering the Dawn of a New Life: A Discussion of Life for Survivors of the Formosa Fun Coast Water Park Explosion].

    Science.gov (United States)

    Wen, Hui-Min

    2016-02-01

    A dust explosion at the Formosa Fun Coast water park in Taiwan caused nearly 500 burn injury cases. One hundred of these cases involved burns over more than 20% of the total body surface area. This tragedy inundated hospitals across northern Taiwan with an unprecedented number of burn patients. Significant manpower and medical resources were targeted on related resuscitation and treatment efforts, with support and assistance provided by agencies and organizations nationwide. Most of the burn patients were young people in their teens and twenties, whose severe burns posed the greatest threat and challenge to their lives so far. Furthermore, their experience presented major psychosocial and physical health challenges. Patients received an array of clinical treatments such as debridement, skin grafting, dressing, and rehabilitation. Debilitating pain, skin damage, changes to body image, physical disabilities, helplessness, sadness, and anxiety have not only deeply affected the patients physically and psychologically but also created significant life stresses for their family members / companions, which requires counseling in order to facilitate emotional healing. Although burn patients gradually recover as they pass through the acute, recovery, and rehabilitation phases, they will face the challenges of lifelong rehabilitation after discharge. I hope that these young victims will take courage and be brave and strong in dealing with the difficulties and challenges of daily life and will embrace the future with hope as they enter the dawn of their new life.

  15. Sleep architecture of consolidated and split sleep due to the dawn (Fajr prayer among Muslims and its impact on daytime sleepiness

    Directory of Open Access Journals (Sweden)

    Ahmed S BaHammam

    2012-01-01

    Full Text Available Background: Muslims are required to wake up early to pray (Fajr at dawn (approximately one and one-half hours before sunrise. Some Muslims wake up to pray Fajr and then sleep until it is time to work (split sleep, whereas others sleep continuously (consolidated sleep until work time and pray Fajr upon awakening. Aim: To objectively assess sleep architecture and daytime sleepiness in consolidated and split sleep due to the Fajr prayer. Setting and Design: A cross-sectional, single-center observational study in eight healthy male subjects with a mean age of 32.0 ± 2.4 years. Methods: The participants spent three nights in the Sleep Disorders Center (SDC at King Khalid University Hospital, where they participated in the study, which included (1 a medical checkup and an adaptation night, (2 a consolidated sleep night, and (3 a split-sleep night. Polysomnography (PSG was conducted in the SDC following the standard protocol. Participants went to bed at 11:30 PM and woke up at 7:00 AM in the consolidated sleep protocol. In the split-sleep protocol, participants went to bed at 11:30 PM, woke up at 3:30 AM for 45 minutes, went back to bed at 4:15 AM, and finally woke up at 7:45 AM. PSG was followed by a multiple sleep latency test to assess the daytime sleepiness of the participants. Results: There were no differences in sleep efficiency, the distribution of sleep stages, or daytime sleepiness between the two protocols. Conclusion: No differences were detected in sleep architecture or daytime sleepiness in the consolidated and split-sleep schedules when the total sleep duration was maintained.

  16. The Effects of the Ionosphere on Ground-based Detection of the Global 21 cm Signal from the Cosmic Dawn and the Dark Ages

    Science.gov (United States)

    Datta, Abhirup; Bradley, Richard; Burns, Jack O.; Harker, Geraint; Komjathy, Attila; Lazio, T. Joseph W.

    2016-11-01

    Detection of the global H i 21 cm signal from the Cosmic Dawn and the Epoch of Reionization is the key science driver for several ongoing ground-based and future ground-/space-based experiments. The crucial spectral features in the global 21 cm signal (turning points) occur at low radio frequencies ≲ 100 {{MHz}}. In addition to the human-generated radio frequency interference, Earth’s ionosphere drastically corrupts low-frequency radio observations from the ground. In this paper, we examine the effects of time-varying ionospheric refraction, absorption, and thermal emission at these low radio frequencies and their combined effect on any ground-based global 21 cm experiment. It should be noted that this is the first study of the effect of a dynamic ionosphere on global 21 cm experiments. The fluctuations in the ionosphere are influenced by solar activity with flicker noise characteristics. The same characteristics are reflected in the ionospheric corruption to any radio signal passing through the ionosphere. As a result, any ground-based observations of the faint global 21 cm signal are corrupted by flicker noise (or 1/f noise, where f is the dynamical frequency) which scales as {ν }-2 (where ν is the frequency of radio observation) in the presence of a bright galactic foreground (\\propto {ν }-s, where s is the radio spectral index). Hence, the calibration of the ionosphere for any such experiment is critical. Any attempt to calibrate the ionospheric effects will be subject to the inaccuracies in the current ionospheric measurements using Global Positioning System (GPS) ionospheric measurements, riometer measurements, ionospheric soundings, etc. Even considering an optimistic improvement in the accuracy of GPS-total electron content measurements, we conclude that Earth’s ionosphere poses a significant challenge in the absolute detection of the global 21 cm signal below 100 MHz.

  17. Correlates and outcomes of worries about hypoglycemia in family members of adults with diabetes: The second Diabetes Attitudes, Wishes and Needs (DAWN2) study.

    Science.gov (United States)

    Nefs, Giesje; Pouwer, François; Holt, Richard I G; Skovlund, Søren; Hermanns, Norbert; Nicolucci, Antonio; Peyrot, Mark

    2016-10-01

    We examined (a) the demographic and clinical correlates of worries about hypoglycemia in adult family members of adults with diabetes, and (b) the association of these worries with measures of diabetes support. The second multinational Diabetes Attitudes, Wishes and Needs (DAWN2) study cross-sectionally surveyed 2057 family members from 17 countries. Participants completed questions about demographics, diabetes, and psychosocial functioning, including worry about overall and nocturnal hypoglycemia. Analyses included hierarchical ordinal and linear regression. Eighty-five percent of family members (n=1661) were at least occasionally very worried about the risk of hypoglycemic events overall. Correlates of worries about hypoglycemia included female gender, higher age and lower education in the family member, younger age of the person with diabetes and this person being a parent or another adult (versus spouse or partner), insulin or non-insulin injectable treatment, severe or non-severe hypoglycemia in the past 12months, and family member recognition of hypoglycemia. Elevated worries about hypoglycemia had a significant independent association with increased odds of diabetes-related family arguments and family member frustration in providing helpful support (OR range 1.60-3.72). High levels of worries about hypoglycemia were associated with increased odds of attending diabetes-related health-care visits. Worries about hypoglycemia were not associated with family member involvement in diabetes care. Similar results were found for worries about nocturnal events. Worries about hypoglycemia were common in family members and were associated with suboptimal diabetes support. This issue therefore deserves increased clinician attention. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. A preliminary study of pathogenesis of dawn phenomenon in patients with type 2 diabetes mellitus%2型糖尿病患者黎明现象发生机制的初步研究

    Institute of Scientific and Technical Information of China (English)

    任惠珠; 陈莉明; 郑妙艳; 单春艳; 杨菊红; 徐延光; 王颖; 常宝成

    2015-01-01

    Objective To study the preliminary pathogenesis of dawn phenomenon in patients with type 2 diabetes mellitus. Methods Two-hundred and sixty-four patients with type 2 diabetes had performed continuous glucose monitoring since Jan 2012 to July 2014. They were divided into two groups: patients without dawn phenomenon and patients with dawn phenomenon. Biochemical indicators including liver and kidney function, blood lipids, HbA1C , fructosamine(FMN), adrenocorticotropic hormone and cortisol were detected in the two groups. Oral glucose tolerance test, insulin releasing test and glucagon releasing test were performed. The differences in biochemical indicators, glucose level and α-cell and β-cell function after fasting and glucose-load were compared. The correlation and regression analysis were performed between dawn phenomenon and other indicators. Results The level of adrenocorticotropic hormone, cortisol, HbA1C , FMN, the increment of fasting glucose and nocturnal nadir glucose (BG1 ), the glucose increment before and after breakfast(BG2 ), 24-hour mean glucose, duration above high limit, and HOMA-IR were significantly higher in patients with dawn phenomenon compared to those in patients without dawn phenomenon[(6. 6 ± 2. 4) vs(4. 8 ± 1. 9) pmol/ L, (523. 8 ± 84. 2) vs (448. 2 ± 76. 9) nmol/ L, (8. 1 ± 2. 0)% vs (7. 5 ± 1. 8)% ,(0. 32 ± 0. 09) vs(0. 29 ± 0. 08) mmol/ L, (26. 2 ± 5. 8) vs (18. 0 ± 4. 9) mg/ dl, (39. 6 ± 8. 3) vs (28. 8 ± 7. 4) mg/ dl,(188. 5 ± 36. 2) vs(164. 5 ± 31. 2) mg/ dl, 29 : 31(41% ) vs 20 : 10(28% ), 4. 18 ± 0. 94 vs 3. 82 ± 0. 82](all P<0. 05). ISI and AUCG / AUCI were lower in patients with dawn phenomenon than those in patients without dawn phenomenon(-4. 28±0. 62 vs -4. 04±0. 54, -0. 74±0. 48 vs -0. 63±0. 30) (all P<0. 05). The level of glucagon at each time point and area under curve of glucagon were significantly higher in patients with dawn phenomenon than those in patients without. 0, 60, 180 min glucagon

  19. The dawn of mathematical biology

    CERN Document Server

    Hoffmann, Daniel Sander

    2015-01-01

    In this paper I describe the early development of the so-called mathematical biophysics, as conceived by Nicolas Rashevsky back in the 1920's, as well as his latter idealization of a "relational biology". I also underline that the creation of the journal "The Bulletin of Mathematical Biophysics" was instrumental in legitimating the efforts of Rashevsky and his students, and I finally argue that his pioneering efforts, while still largely unacknowledged, were vital for the development of important scientific contributions, most notably the McCulloch-Pitts model of neural networks.

  20. At the Dawn of Science

    Science.gov (United States)

    Lopez, Claude-Anne

    2003-04-01

    This talk will provide a snap shot of the scientific life of Benjamin Franklin from the perspective, not of Franklin's science, but of his social interactions with other great scientists of the enlightenment. We will find that the pursuit of science was cross-disciplinary -- indeed, the disciplinary boundaries as we know them today were not so well-defined -- and characterized by conviviality. I will focus in particular on Franklin's relationship with Lavoisier, based on the extensive documentary evidence drawn from Franklin's correspondence.

  1. By the Dawn's Early Light.

    Science.gov (United States)

    Wolf, Milton T.

    1999-01-01

    Discusses the need for cooperative collection development among libraries on a worldwide scale. Considers the relationship between knowledge and power; information needs and telecommunications technologies; economic and political issues; digital libraries; publishing industry; and laws of intellectual property. (LRW)

  2. At the dawn of geodesy

    Science.gov (United States)

    Fischer, Irene K.

    1981-06-01

    The first land surveyors were rope stretchers and rope knotters, remembered in ancient documents and tomb paintings and also in some terminology. The L-shaped carpenter’s square, one of the earliest and most versatile basic tools, represents the observed direction of the plumb line versus the water level and appears as the shadow-casting gnomon and also as the geometrical gnomon in magically-restricted enlargements of altars. The related “Pythagorean” theorem was known in antiquity centuries before Pythagoras, with algebraic proofs in Babylonia and China. The spherical shape of the earth, deduced from the observation of circumpolar stars, was part of a complete equatorial astronomical system in ancient China. But although shadow measurements were generally used to establish north-south distances, only the Greeks derived from them the size of the earth. The striking difference between the abstract, geometric approach of Greece and the concrete, algebraic approach of Babylonia and China represents not a difference in talents but a difference in culture-bound interests.

  3. A New Dawn for Doha?

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    China is being urged to exert its efforts to get the stalled Doha Round of trade negotiations moving again The Doha Round of global trade talks was suspended in July, but that is not the end of the story. While there have been a lot of fingers pointing over the causes of the breakdown, debates on different aspects of the World

  4. Dawn of e-government

    DEFF Research Database (Denmark)

    Henriksen, Helle Zinner; Damsgaard, Jan

    2007-01-01

    Danish initiative implemented to stimulate e-government adoption. The e-Day initiative simply yet powerfully states that 'one governmental authority has the right to demand that its communication with another authority must be in electronic format' which is expected to create ripple effects both...... internally and externally. The e-Day initiative represents a drastic change in the former policy statements concerning IT adoption and diffusion in Danish government. The policy statements had previously been based on voluntary adoption focusing on visions and pedagogical intervention in governmental......Most countries have defined strategies for e-government. The objectives for implementing e-government are often defined but the means for fuelling the adoption and diffusion of e-government are typically less well clear in the policy statements. The present study assesses the impact of latest...

  5. Dawn of the Social Cyborg

    Science.gov (United States)

    Campbell, Joe; Finegan, William

    2011-01-01

    Corporate learning environments have undergone disruptive changes over the last 20 years due to the explosion of information technology, globalization of the workforce, and shrinking travel and training budgets. Those disruptions are accelerating with the introduction of new technologies such as social media. Potentially the most disruptive change…

  6. A new dawn for CMS

    CERN Multimedia

    2007-01-01

    Supported by a gigantic crane and a factory-size room full of enthusiasm, the central barrel of CMS made its final journey underground on 28 February. The central section of the CMS detector starts its dramatic 10-hour descent underground.Several hours (and 100 metres) later, the massive barrel rests on the cavern floor. CMS scientists, journalists, photographers and members of the transport crew basked in the final rays of the 'solenoid-set' on 28 February as the central barrel of the CMS detector sinks below the horizon and began its ten-hour descent into the cavern 100 metres below. Thirteen metres long and weighing as much as five jumbo jets (1920 tonnes), the barrel is the largest of the 15 chunks of CMS detector that are being lowered one by one into the cavern. 'This is a challenging feat of engineering, as there are just 20 cm of leeway between the detector and the walls of the shaft,' said Austin Ball, Technical Coordinator of CMS. The section of the detector, which contains the solenoid of the magne...

  7. La predicación dominicana del Rosario. El Rosario de la aurora de Zafra en el siglo XVIII (Dominican preaching of the rosary: The dawn rosary of Zafra in 18 th Century

    Directory of Open Access Journals (Sweden)

    Carlos José Romero Mensaque

    2016-01-01

    Full Text Available Resumen: El Rosario, signo de identidad misional de la Orden de Predicadores, desborda los cauces conventuales ya desde el siglo XVI al universalizarse el rezo y devoción. Los dominicos predican el Rosario en sendas misiones y fundan numerosas hermandades adscritas a la Orden en parroquias e iglesias diocesanas, pero ya en el siglo XVII el rezo avemariano rebasa incluso los espacios sagrados para ser predicado en las calles. El proceso culmina en el siglo XVIII con un protagonismo del pueblo en la predicación del rosario, asumiendo en gran parte la responsabilidad de la misión que comenzaran los dominicos. En el extremo de la Provincia Bética, Zafra se convierte en escenario de esta Misión Popular con el Rosario de la Aurora y su hermandad, una corporación claramente misional y asistencial, que no duda en dar mayoría de edad a la mujer en su gobierno.Abstract: The rosary is an important sign of missionary identity for the Dominican Order, whose use has not been limited to the convent since the 16th century when preach and devotion became universal. Dominic monks preach the rosary in all their missions and found several brotherhoods affiliated with the Order in parishes and diocesans churches, but in the 17th century the Hail Mary can be found outside sacred places, it is preached even in the streets. This process end up in the 18th century when common people take a bigger responsibility and continue with the mission started by Dominic monks. Zafra, situated at the limit of the Baetica Province, becomes the stage of this Popular Mission thanks to the dawn rosary and its brotherhood, which clearly was a corporation dedicated to the mission and the assistant of people in need. This brotherhood does not hesitate before giving majority of age to the women in their government, even though they faced a strong social exclusion.

  8. 2型糖尿病患者睡眠障碍与黎明现象的关系%Association between sleep disorders and dawn phenomenon in patients with type 2 diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    任惠珠; 陈莉明; 单春艳; 杨菊红; 郑妙艳; 王颖; 徐延光; 杨艳辉; 常宝成

    2015-01-01

    目的 探讨2型糖尿病患者睡眠障碍与黎明现象的关系.方法 应用匹兹堡睡眠质量指数将2011年7月至2014年7月天津医科大学代谢病医院收治的316例行动态血糖监测、资料完整的2型糖尿病患者分为无睡眠障碍组(186例)和睡眠障碍组(130例),测定肝肾功能、血脂、糖化血红蛋白(HbA1c)、果糖胺等生化指标,行口服葡萄糖耐量试验及胰岛素、胰高糖素释放试验,比较两组血糖水平、空腹和糖负荷后胰岛α和β细胞功能变化,对睡眠障碍行相关及回归分析.结果 睡眠障碍组HbA1c、果糖胺、空腹血糖与夜间最低点血糖净增值、早餐后与早餐前血糖净增值、24 h平均血糖、空腹胰岛素、稳态模型-胰岛素抵抗指数(HOMA-IR)、胰岛素曲线下面积均显著高于无睡眠障碍组[(8.2±2.0)%比(7.4±1.7)%,(0.33±0.10)比(0.29 ±0.07) mmol/L,(1.511 ±0.294)比(0.889±0.233) mmol/L,(2.144±0.400)比(1.522±0.378) mmol/L,(9.917±1.800)比(8.694±1.622) mmol/L,(13.49±4.68)比(12.16±4.56) mU/L,4.98±0.90比3.82±0.82,8.47 ±0.59比8.25 ±0.54](均P<0.05).睡眠障碍组胰岛素敏感指数显著低于无睡眠障碍组(-4.28 ±0.62比-4.03 ±0.52),各时间点胰高糖素水平及胰高糖素曲线下面积均显著高于无睡眠障碍组,0、30、180 min胰高糖素/胰岛素比值及胰高糖素/血糖比值也均显著高于无睡眠障碍组(均P<0.05).睡眠障碍与HOMA-IR、胰高糖素/胰岛素比值、空腹血糖与夜间最低点血糖净增值、黎明现象均呈正相关,与胰岛素敏感指数呈负相关(均P<0.05).结论 睡眠障碍与黎明现象相关,改善睡眠障碍可能有助于改善黎明现象,从而优化整体血糖控制.%Objective To explore the association between sleep disorders and dawn phenomenon in patients with type 2 diabetes mellitus (T2DM).Methods From July 2011 to July 2014 at Metabolic Disease Hospital,Tianjin Medical University,316 T2DM patients on

  9. 2型糖尿病患者黎明现象与胰岛α和β细胞功能的关系%Association between dawn phenomenon and islet α-cell andβ-cell function in patients with type 2 diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    任惠珠; 陈莉明; 郑妙艳; 单春艳; 杨菊红; 徐延光; 王颖; 常宝成

    2015-01-01

    Objective To investigate the association between dawn phenomenon and islet α⁃cell and β⁃cell function in patients with type 2 diabetes. Methods Two hundred and eighteen patients with type 2 diabetes who performed continuous glucose monitoring from January 2012 to January 2014 were divided into two groups: patients without dawn phenomenon and patients with dawn phenomenon. Biochemical indicators were detected in two groups. Oral glucose tolerance test, insulin releasing test and glucagon releasing test were performed to investigate the differences of α⁃cell andβ⁃cell function between groups after fasting and glucose⁃load. The correlation and regression analysis were performed between dawn phenomenon and other indicators. Results The level of HbA1c,the increment of fasting glucose and nocturnal nadir glucose(BG1),the glucose increment before and after breakfast(BG2),24 hours mean blood glucose(24 hMG) and HOMA⁃IR were significantly higher in patients with dawn phenomenon compared to those in patients without dawn phenomenon((8.3%±2.2%) vs (7.7%±1.9%), (1.41±0.33) vs (0.96±0.26)mmol/L, (2.40±0.48) vs (1.90±0.42)mmol/L,(10.69±2.25) vs (9.36±1.82)mmol/L,(4.3±0.9) vs (3.4±0.8), t=2.1282, 10.9955,all P<0.05). Insulin sensitivity index(ISI) was lower in patients with dawn phenomenon than those in patients without dawn phenomenon(t=2.1328, P<0.05).The level of glucagon, glucagon/insulin ratio, glucagon/glucose ratio and area under curve of glucagon were significantly higher in patients with dawn phenomenon than those in patients without(t=2.000-10.2190,P<0.05). Logistic regression analysis showed that dawn phenomenon was positively related to HOMA⁃IR, glucagon/insulin ratio, BG2 and BG1(all P<0.05), and negatively related to ISI (P<0.05). Conclusions Dawn phenomenon is associated with the dysfunction of isletα⁃cell andβ⁃cell.Improving islet function may help to improve the dawn phenomenon and optimize glycemic control.%目的:研究2

  10. 贝多芬《黎明奏鸣曲》中弱音记号的功能及表现手段%STUDY ON THE FUNCTION AND PERFORMANCE MEANS OF WEAK SOUND MARK IN BEETHOVEN′S "DAWN SONATA"

    Institute of Scientific and Technical Information of China (English)

    朱晓敏

    2012-01-01

    dawn sonata is Beethoven piano sonatas of the classics,it on a grand scale,luxuriant skills and surging passion praises of the vigorous vitality,the nature of the pure and fresh breath and lyrical ShiCu,vividly reflected the Beethoven′s view of nature and humane view.This paper attempts illustrate the important function and performance means of the mark of weak sound in Beethoven′s sonata dawn.%《黎明奏鸣曲》是贝多芬钢琴奏鸣曲中的经典之作,它以宏大的规模、华丽的技巧以及澎湃的热情讴歌了大自然朝气蓬勃的活力、清新的气息和抒情的诗趣,鲜明地反映了贝多芬的自然观和人文观。本文试图通过对贝多芬黎明奏鸣曲的分析来阐述弱音记号的重要功能及表现手段。

  11. Mapping the dawn of nanoecotoxicological research.

    Science.gov (United States)

    Kahru, Anne; Ivask, Angela

    2013-03-19

    Some researchers consider nanotechnology the next industrial revolution, and consumer products and a variety of industries increasingly use synthetic nanoparticles. In this Account, we review the initial accomplishments of nanoecotoxicology, a discipline that is just a decade old. This new subdiscipline of ecotoxicology faces two important and challenging problems: the analysis of the safety of nanotechnologies in the natural environment and the promotion of sustainable development while mitigating the potential pitfalls of innovative nanotechnologies. In this Account, we provide a snapshot of the publicly available scientific information regarding the ecotoxicity of engineered nanoparticles. We pay special attention to information relevant to aquatic freshwater species commonly used for risk assessment and regulation. Just as the development of ecotoxicology has lagged behind that of toxicology, nanoecotoxicological research has developed much more slowly than nanotoxicology. Although the first nanotoxicolology papers were published in 1990s, the first nanoecotoxicology papers came out in 2006. A meta-analysis of scientific publications covering different environmental impacts of nanomaterials showed that the importance of research into the environmental impact of nanotechnology has gradually increased since 2005. Now the most frequently cited papers in the environmental disciplines are often those that focus on synthetic nanoparticles. The first nanoecotoxicology studies focused on adverse effects of nanoparticles on fish, algae and daphnids, which are ecotoxicological model organisms for classification and labeling of chemicals (these model organisms are also used in the EU chemical safety policy adopted in 2007: Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH)). Based on our experience, we propose a multitrophic battery of nanoecotoxicological testing that includes particle-feeding and a priori particle-"proof" prokaryotic and eukaryotic organisms at different food-chain levels. Using this battery of selected test organisms, we demonstrated that TiO₂ nanoparticles were toxic to algae and that ZnO and CuO nanoparticles were toxic to several aquatic invertebrate test species. Thus, one single biotest cannot predict the ecotoxicological effects of chemicals/nanoparticles, and researchers should use several tests instead. Moreover, produced nanoparticles usually vary in features such as size, shape, and coating; therefore, a single nanoparticle species may actually include many entities with different physicochemical properties. An ecotoxicity analysis of all these variants would require a huge number of laboratory tests. To address these issues, high throughput bioassays and computational (QSAR) models that serve as powerful alternatives to conventional (eco)toxicity testing must be implemented to handle both the diversity of nanomaterials and the complexity of ecosystems.

  12. The Dawn of Multi-Messenger Astronomy

    CERN Document Server

    Santander, Marcos

    2016-01-01

    The recent discoveries of high-energy astrophysical neutrinos and gravitational waves have opened new windows of exploration to the Universe. Combining neutrino observations with measurements of electromagnetic radiation and cosmic rays promises to unveil the sources responsible for the neutrino emission and to help solve long-standing problems in astrophysics such as the origin of cosmic rays. Neutrino observations may also help localize gravitational-wave sources, and enable the study of their astrophysical progenitors. In this work we review the current status and future plans for multi-messenger searches of neutrino sources.

  13. Boganmeldelse: Dawn Langan Teele, red. (2014)

    DEFF Research Database (Denmark)

    Hansen, Jonas Hedegaard

    2015-01-01

    Universitetsforskere og organisationer anvender i stigende grad felteksperimenter – i nogle kredse også kaldet »Randomized Controlled Trials« – som metode, når de ønsker at undersøge spørgsmål om årsager og effekter. Flere vestlige regeringer har oprettet kontorer, der skal sikre, at felteksperim...

  14. The dawn of X‐ray spectroscopy

    DEFF Research Database (Denmark)

    Gerward, Leif

    2013-01-01

    This paper describes a few episodes from the early days of X‐ray spectroscopy. It relies on contemporary publications, especially those by Barkla, Moseley, Siegbahn, and Compton. The paper addresses the subject from the vantage point of physics and should be of interest to the X‐ray spectroscopist...

  15. At the Dawn of Radio Communications

    Directory of Open Access Journals (Sweden)

    V. P. Samokhin

    2017-01-01

    Full Text Available A brief review of the history of radio communications, which were used before the advent of humanity tubes, in the context of the essays in the series "At the root of media", published in the "History of Technical Progress" section of the supplement to our journal "Science and Education". The review covers the main stages of the development of spark radio-telegraph systems, the creation of the first powerful arc and electric machine generators of non-stopping oscillations of the carrier frequency for radiotelephony and the detection features. The first experiments of Mahlon Loomis, scientific and technical achievements of James Maxwell, Henry Hertz, Eduard Branly, Alexander Popov, Oliver Lodge, Jagadish Bosch, Karl Brown, Lee de Forest, Louis Austin, Herman Simon, William Duddel, Valdemar Paulsen, Ernst Alexander, Valentin Vologdin, Semyon Eisenstein and other creators of the nascent radio engineering. Particular attention is paid to the intersections of their work with the work of Thomas Edison, Nikola Tesla, Guglielmo Marconi, Reginald Fessenden and other heroes of our essays.

  16. Optics at the dawn of the Renaissance

    Science.gov (United States)

    Hockney, David; Falco, Charles M.

    2003-10-01

    Recently, one of us (DH) observed that certain drawings and paintings from as early as the Renaissance seemed almost "photographic" in detail. An extensive visual investigation of western art of the past 1000 years resulted in the revolutionary claim that artists even of the prominence of van Eyck and Bellini must have used optical aids. However, art historians insisted there was no supporting evidence for such a remarkable assertion. This paper presents some of the optical evidence we subsequently discovered that convincingly demonstrates optical instruments were in use - by artists, not scientists - nearly 200 years earlier than widely thought possible, and that accounts for the remarkable transformation in the reality of portraits that occurred early in the 15th century.

  17. The dawn of fungal pathogen genomics.

    Science.gov (United States)

    Xu, Jin-Rong; Peng, You-Liang; Dickman, Martin B; Sharon, Amir

    2006-01-01

    Recent advances in sequencing technologies have led to a remarkable increase in the number of sequenced fungal genomes. Several important plant pathogenic fungi are among those that have been sequenced or are being sequenced. Additional fungal pathogens are likely to be sequenced in the near future. Analysis of the available genomes has provided useful information about genes that may be important for plant infection and colonization. Genome features, such as repetitive sequences, telomeres, conserved syntenic blocks, and expansion of pathogenicity-related genes, are discussed in detail with Magnaporthe oryzae (M. grisea) and Fusarium graminearum as examples. Functional and comparative genomic studies in plant pathogenic fungi, although still in the early stages and limited to a few pathogens, have enormous potential to improve our understanding of the molecular mechanisms involved in host-pathogen interactions. Development of advanced genomics tools and infrastructure is critical for efficient utilization of the vast wealth of available genome sequence information and will form a solid foundation for systems biology studies of plant pathogenic fungi.

  18. Intergalactic Magnetogenesis at Cosmic Dawn by Photoionization

    CERN Document Server

    Durrive, Jean-Baptiste

    2015-01-01

    We present a detailed analysis of an astrophysical mechanism that generates cosmological magnetic fields during the Epoch of Reionization. It is based on the photoionization of the Intergalactic Medium by the first sources formed in the Universe. First the induction equation is derived, then the characteristic length and time scales of the mechanism are identified, and finally numerical applications are carried out for first stars, primordial galaxies and distant powerful quasars. In these simple examples, the strength of the generated magnetic fields varies between the order of $10^{-23}$ G on hundreds of kiloparsecs to $10^{-19}$ G on hundreds of parsecs in the neutral Intergalactic Medium between the Str\\"omgren spheres of the sources. Thus this mechanism contributes to the premagnetization of the whole Universe before large scale structures are in place. It operates with any ionizing source, at any time during the Epoch of Reionization. Finally, the generated fields possess a characteristic spatial config...

  19. Oil Companies at Dawn of Competition

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ China has recently released the "Regulation of Crude Oil Market Management"and the "Regulation of Refined Oil Market Management" in an effort to further open China's petroleum market to the outside world and promote market-orientated reform in oil distribution. This is set in the context of China's WTO transitional period having drawn to an end. The regulations indicate that the government is serious about fulfilling China's WTO obligations.

  20. DAWN: Dynamic Ad-hoc Wireless Network

    Science.gov (United States)

    2016-06-19

    Wireless Networks, , ( ): . doi: Ning Li, Jennifer C. Hou. Localized Topology Control Algorithms for Heterogeneous Wireless Networks, IEEE ...Multi-User Diversity in Single-Radio OFDMA AdHoc Networks Based on Gibbs Sampling, IEEE Milcom . 03-NOV-10, . : , TOTAL: 1 Number of Peer-Reviewed...Networks, ( ) Hui Xu, , Xianren Wu, , Hamid R. Sadjadpour, , J.J. Garcia-Luna-Aceves, . A Unified Analysis of Routing Protocols inMANETs, IEEE

  1. The dawn of hedgehog inhibitors: Vismodegib

    Directory of Open Access Journals (Sweden)

    Selvarajan Sandhiya

    2013-01-01

    Full Text Available Cancer, one of the leading causes of death worldwide is estimated to increase to approximately 13.1 million by 2030. This has amplified the research in oncology towards the exploration of novel targets. Recently there has been lots of interest regarding the hedgehog (Hh pathway, which plays a significant role in the development of organs and tissues during embryonic and postnatal periods. In a normal person, the Hh signaling pathway is under inhibition and gets activated upon the binding of Hh ligand to a transmembrane receptor called Patched (PTCH1 thus allowing the transmembrane protein, smoothened (SMO to transfer signals through various proteins. One of the newer drugs namely vismodegib involves the inhibition of Hh pathway and has shown promising results in the treatment of advanced basal-cell carcinoma as well as medulloblastoma. It has been granted approval by US Food and Drug Administration′s (US FDA priority review program on January 30, 2012 for the treatment of advanced basal-cell carcinoma. The drug is also being evaluated in malignancies like medulloblastoma, pancreatic cancer, multiple myeloma, chondrosarcoma and prostate cancer. Moreover various Hh inhibitors namely LDE 225, saridegib, BMS 833923, LEQ 506, PF- 04449913 and TAK-441 are also undergoing phase I and II trials for different neoplasms. Hence this review will describe briefly the Hh pathway and the novel drug vismodegib.

  2. O alvorecer da anestesia inalatória: uma perspectiva histórica El alborear de la anestesia inhaladora: una perspectiva histórica Dawning of inhalational anesthesia: a historical perspective

    Directory of Open Access Journals (Sweden)

    R icardo Jakson de Freitas Maia

    2002-11-01

    , is not something unchangeable and limited to the past. It is adapted according to conveniences of one or other ruling social class. Deliberately or accidentally hidden information, when unveiled may change current concepts, so far taken for granted. So, history, as any other science, is not totally impartial; it suffers influences and interferences of political, religious, economic and cultural thinking. The same is true for anesthesia. Some questions remain unanswered: Why did it take so long for the civilization to control pain? Who did in fact discover Anesthesia? How was the world when Anesthesia was officially discovered? To discuss such questions it is necessary to go back to the History of Anesthesia. CONTENTS: This paper addresses the surgical act, pain and anesthesia from the Hellenic culture to the first officially recognized anesthesia, often emphasizing forgotten names and historical peculiarities which have benefited or harmed one or other discoverer. It also focuses on values, culture and scientific developments of the 19th century, correlating them to events that marked the dawning of anesthesia. CONCLUSIONS: It would be unfair to attribute the merit of discovering anesthesia to a single person. Historical peculiarities that benefited or harmed one or other researcher cannot be forgotten. Morton was undoubtedly the most favored by the circumstances. He lived in a privileged time and place and has met the most adequate people to his intent. However there is still a question. After all, who is the most important: the father of the idea or who disclosed it? The answer will certainly remain in the field of subjectivity.

  3. Utilizing Organizational Culture to Predict Responses to Planned Change in a Public School: A Test of the OC[superscript 3] Model

    Science.gov (United States)

    Sandberg, Eric Christian

    2012-01-01

    The primary purpose of this research was to test the capability of the Organizational Change in Cultural Context (OC[superscript 3]) Model (Latta, 2009, 2011) to predict responses to change. According to Latta, predictions of resistance to or facilitation of change can be predicted by utilizing organizational culture and its alignment with the…

  4. Implied Audience: Video Program Interpretation from the Perspectives of Narratology and Receptional Aesthetics --Before Dawn as a Case in Point%“隐含观众”:叙事学和接受美学照观下的影视作品解读——以《黎明之前》为例

    Institute of Scientific and Technical Information of China (English)

    陈莲洁

    2012-01-01

    本文以《黎明之前》为例,将布斯叙事学中的隐合作者和伊瑟尔接受美学的隐含读者概念联系起来,把影视作品创作和欣赏视为一个连续完整的过程,以此考察文艺批评理论在现代影视传媒语境下的拓展和应用。本文首先介绍了“隐含编剧”、“隐含导演”、“隐含演员和“隐含观众”的理念,以此揭示从静态文本到动态影视作品的形成过程中,编剧、导演、演员“第一自我”和“第二自我”的融合和分离。作者详细分析了由于观众的艺术素养和审.美需求差异,尤其是受时代的政治和文化理念影响,以及他们在影视欣赏中不同的移情程度,而导致的对影视作品中“空白”的不同解读效果。%Taking Before Dawn as an example, this paper tries to combine implied author in Buth 's Narratology with implied reader in Iser's Reception Aesthetics. It treats the composition and interpretation of a video program as a continuous process, so as to extend the application of literary critical theories in the context of modem audio - visual mass media. Starting with an introduction of implied playwright, implied director, implied actor, as well as implied audience, it shows that converting a static text into a dynamic video program entails various degrees of merging and diversion of First Self and Second Self. The author then analyzes in detail that, due to different artistic dispositions and aesthetic needs in different audience communities, and especially due to different political and cultural principles in different historical contexts, and mostly, due to their different degrees of empathy and efforts in video program interpretation, any blank in a video program may actually bring about numerous interpretation results.

  5. The second Jurassic dinosaur rush and the dawn of dinomania.

    Science.gov (United States)

    Brinkman, Paul D

    2010-09-01

    During the second Jurassic dinosaur rush museum paleontologists raced to display the world's first mounted sauropod dinosaur. The American Museum of Natural History triumphed in 1905 when its Brontosaurus debuted before an admiring crowd of wealthy New Yorkers. The Carnegie Museum of Natural History in Pittsburgh, the Field Columbian Museum in Chicago and other institutions were quick to follow with their own sauropod displays. Thereafter, dinomania spread far and wide, and big, showpiece dinosaurs became a museum staple. This brief but intensely competitive period of acquisitiveness fostered important Jurassic dinosaur revisions and crucial innovations in paleontological field and lab techniques.

  6. The Cosmic Dawn and Epoch of Reionisation with SKA

    NARCIS (Netherlands)

    Koopmans, L.; Pritchard, J.; Mellema, G.; Aguirre, J.; Ahn, K.; Barkana, R.; van Bemmel, I.; Bernardi, G.; Bonaldi, A.; Briggs, F.; de Bruyn, A. G.; Chang, T. C.; Chapman, E.; Chen, X.; Ciardi, B.; Dayal, P.; Ferrara, A.; Fialkov, A.; Fiore, F.; Ichiki, K.; Illiev, I. T.; Inoue, S.; Jelic, V.; Jones, M.; Lazio, J.; Maio, U.; Majumdar, S.; Mack, K. J.; Mesinger, A.; Morales, M. F.; Parsons, A.; Pen, U. L.; Santos, M.; Schneider, R.; Semelin, B.; de Souza, R. S.; Subrahmanyan, R.; Takeuchi, T.; Vedantham, H.; Wagg, J.; Webster, R.; Wyithe, S.; Datta, K. K.; Trott, C.

    2014-01-01

    Concerted effort is currently ongoing to open up the Epoch of Reionization (EoR) ($z\\sim$15-6) for studies with IR and radio telescopes. Whereas IR detections have been made of sources (Lyman-$\\alpha$ emitters, quasars and drop-outs) in this redshift regime in relatively small fields of view, no dir

  7. The Cosmic Dawn and Epoch of Reionisation with SKA

    NARCIS (Netherlands)

    Koopmans, L.; Pritchard, J.; Mellema, G.; Aguirre, J.; Ahn, K.; Barkana, R.; van Bemmel, I.; Bernardi, G.; Bonaldi, A.; Briggs, F.; de Bruyn, A. G.; Chang, T. C.; Chapman, E.; Chen, X.; Ciardi, B.; Dayal, P.; Ferrara, A.; Fialkov, A.; Fiore, F.; Ichiki, K.; Illiev, I. T.; Inoue, S.; Jelic, V.; Jones, M.; Lazio, J.; Maio, U.; Majumdar, S.; Mack, K. J.; Mesinger, A.; Morales, M. F.; Parsons, A.; Pen, U. L.; Santos, M.; Schneider, R.; Semelin, B.; de Souza, R. S.; Subrahmanyan, R.; Takeuchi, T.; Vedantham, H.; Wagg, J.; Webster, R.; Wyithe, S.; Datta, K. K.; Trott, C.

    2015-01-01

    Concerted effort is currently ongoing to open up the Epoch of Reionization (EoR) ($z\\sim$15-6) for studies with IR and radio telescopes. Whereas IR detections have been made of sources (Lyman-$\\alpha$ emitters, quasars and drop-outs) in this redshift regime in relatively small fields of view, no dir

  8. Dawning Dependence: Processes underlying smoking cessation in adolescence

    NARCIS (Netherlands)

    M. Kleinjan (Marloes)

    2009-01-01

    textabstractDuring adolescence young people are known to try out a range of risk behaviours, including smoking. Even though the detrimental health consequences of smoking are well known, the prevalence of smoking among Dutch adolescents remains high. Until today, efforts to control adolescent smokin

  9. Dark Ages Radio Explorer Mission: Probing the Cosmic Dawn

    CERN Document Server

    Jones, Dayton L; Burns, Jack O

    2014-01-01

    The period between the creation of the cosmic microwave background at a redshift of ~1000 and the formation of the first stars and black holes that re-ionize the intergalactic medium at redshifts of 10-20 is currently unobservable. The baryonic component of the universe during this period is almost entirely neutral hydrogen, which falls into local regions of higher dark matter density. This seeds the formation of large-scale structures including the cosmic web that we see today in the filamentary distribution of galaxies and clusters of galaxies. The only detectable signal from these dark ages is the 21-cm spectral line of hydrogen, redshifted down to frequencies of approximately 10-100 MHz. Space-based observations of this signal will allow us to determine the formation epoch and physics of the first sources of ionizing radiation, and potentially detect evidence for the decay of dark matter particles. JPL is developing deployable low frequency antenna and receiver prototypes to enable both all-sky spectral m...

  10. When Consciousness Dawns: Confronting Homophobia with Turkish High School Students

    Science.gov (United States)

    Michell, Michael J.

    2009-01-01

    Turkey, like many Mediterranean and Middle Eastern cultures, is homosocial. Profoundly intimate, though nonsexual, relationships between members of the same gender predominate. In such cultures it is expected that male friends kiss one another on the cheek when greeting or saying goodbye, and it is common to see men walk arm-in-arm together, hold…

  11. Red, black or white? The dawn of colour symbolism

    Directory of Open Access Journals (Sweden)

    Simona Petru

    2006-12-01

    Full Text Available In this paper the use of the pigments in the Paleolithic is presented, and some ideas of the symbolic meaning of colours are suggested. The colour red might have been a symbol of transformation, and as such, it was used in burials and for painting the Venus figurines. In the Slovenian Paleolithic, there is scant evidence of importance of colour and only a few finds of stones used for the grinding of the red pigment have been found.

  12. Operation Odyssey Dawn and Lessons for the Future

    Science.gov (United States)

    2013-02-14

    future for Libya with Qaddafi in power.൚ Late in June, Obama stated more clearly, interestingly in a joint interview with German Chancellor Angela ... Merkel , that Qaddafi must step down, hand over power to the Libyan people, and "the pressure will only continue to increase until he does.൛

  13. Representing Something Out of Nothing: The Dawning of Zero.

    Science.gov (United States)

    Nieder, Andreas

    2016-11-01

    Zero stands for emptiness, for nothing, and yet it is considered to be one of the greatest achievements of humankind. This review first recapitulates the discovery of the number zero in human history, then follows its progression in human development, traces its evolution in the animal kingdom, and finally elucidates how the brain transforms 'nothing' into an abstract zero category. It is argued that the emergence of zero passes through four corresponding representations in all of these interrelated realms: first, sensory 'nothing'; then categorical 'something'; then quantitative empty sets; and finally the number zero. The concept of zero shows how the brain, originally evolved to represent stimuli ('something'), detaches from empirical properties to achieve ultimate abstract thinking. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Communicating with Light: A New Dawn in the Information Age

    Science.gov (United States)

    Raible, Daniel

    2016-01-01

    You and I are living in a very special time; the age of Solar System exploration. Our Solar System is a complex masterpiece of which we knew so little from our ground-based observations. But within the span of a single lifetime, NASA has sent spacecraft to every planet and several moons, our first eyes to set upon undiscovered lands. Before we endeavored on this journey everything we knew of Pluto could have fit on a single file card, and now we downlink new data every day.

  15. Brazilian studies in Canada: dawn of a new era?

    Directory of Open Access Journals (Sweden)

    W. E. (Ted Hewitt

    2005-01-01

    Full Text Available Desde os dias sombrios do Bombardier - Embraer e do boicote da carne de gado brasileira no final dos anos 90, as relações entre Canadá e Brazil tiveram uma significante melhora. Isto pode ser verificado em vários setores, do acadêmico (como pode ser testemunhado pelo estabelecimento de uma cadeira como visitante de pesquisa em estudos Brasileiros,ao político (no crescente número de delegações de parlamentares brasileiras visitando o Canadá, ao econômico (evidenciado pela recente ascensão do investimento bilateral, especialmente em cimento, bebidas e aço e ao cultural (demonstrado no gosto canadense pela música, cerveja e comida brasileiras. Neste trabalho, nós examinamos se e como tais desenvolvimentos têm sido acompanhados por um aumento na pesquisa acadêmica canadense sobre o Brasil nos últimos anos, especialmente em setores de investigação menos tradicionais, tais como o da política e da economia. Concluímos o trabalho com uma avaliação das futuras necessidades e capacidades na área de Estudos Brasileiros neste país.

  16. Solar water heaters in China: A new day dawning

    NARCIS (Netherlands)

    Han, Jingyi; Mol, A.P.J.; Lu, Y.

    2010-01-01

    Solar thermal utilization, especially the application of solar water heater technology, has developed rapidly in China in recent decades. Manufacturing and marketing developments have been especially strong in provinces such as Zhejiang, Shandong and Jiangsu. This paper takes Zhejiang, a relatively

  17. The dawn of bilaterian animals: the case of acoelomorph flatworms.

    Science.gov (United States)

    Baguñà, Jaume; Riutort, Marta

    2004-10-01

    The origin of the bilaterian metazoans from radial ancestors is one of the biggest puzzles in animal evolution. A way to solve it is to identify the nature and main features of the last common ancestor of the bilaterians (LCB). Recent progress in molecular phylogeny has shown that many platyhelminth flatworms, regarded for a long time as basal bilaterians, now belong to the lophotrochozoan protostomates. In contrast, the LCB is now considered a complex organism bearing several features of modern bilaterians. Here we discuss an alternative view, in which acoelomorph (Acoela + Nemertodermatida) flatworms, which do not belong to the Platyhelminthes, represent the earliest extant bilaterian clade. Sequences from ribosomal and other nuclear genes, Hox cluster genes, and reinterpretation of some morphological features strongly support the basal position of acoelomorphs arguing against a complex LCB. This reconstruction backs the old planuloid-acoeloid hypothesis and may help our understanding of the evolution of body axes, Hox genes and the Cambrian explosion.

  18. ARTIFICIAL INTELLIGENCE IN SPORTS BIOMECHANICS: NEW DAWN OR FALSE HOPE?

    Directory of Open Access Journals (Sweden)

    Roger Bartlett

    2006-12-01

    Full Text Available This article reviews developments in the use of Artificial Intelligence (AI in sports biomechanics over the last decade. It outlines possible uses of Expert Systems as diagnostic tools for evaluating faults in sports movements ('techniques' and presents some example knowledge rules for such an expert system. It then compares the analysis of sports techniques, in which Expert Systems have found little place to date, with gait analysis, in which they are routinely used. Consideration is then given to the use of Artificial Neural Networks (ANNs in sports biomechanics, focusing on Kohonen self-organizing maps, which have been the most widely used in technique analysis, and multi-layer networks, which have been far more widely used in biomechanics in general. Examples of the use of ANNs in sports biomechanics are presented for javelin and discus throwing, shot putting and football kicking. I also present an example of the use of Evolutionary Computation in movement optimization in the soccer throw in, which predicted an optimal technique close to that in the coaching literature. After briefly overviewing the use of AI in both sports science and biomechanics in general, the article concludes with some speculations about future uses of AI in sports biomechanics.

  19. The Dawn Of Gender Justice Against Discrimination - A Legal Paradigm

    Directory of Open Access Journals (Sweden)

    Sindhu Vijaya Kumar

    2011-06-01

    Full Text Available The Socio-economic rights are a vital aspect of human rights agenda for women. The slowstudy process and radical change in recognizing the rights of women to a greater extend has helped tobuild her own identity and withstand her rights against all discrimination. The feminist movementquestioned several discriminatory practices against women. However there was a need for revolutionto debar the discriminatory practice of status on the ground of gender. And revolution was created byfeminist movement. These Movements largely contributed by feminist writing recognized the need tosubdue the discriminatory practice of status. Feminist theory emerged from these feministmovements includes general theories and theories about the origins of inequality, economic injusticeand in some cases, about the social construction of sex and gender, in a variety of disciplines.Feminist activists have campaigned for women's rights as such, in contract, property, and voting,while also promoting women's rights from human right perspective. They have opposed domesticviolence sexual harassment and sexual assault, in economics they have advocated for workplacerights, including equal pay and opportunities for careers and to start businesses. Interventions ofnational and international legal instrument have added grace and recognized women’s right. All thisresulted in increase participation of women both in formal and informal job sector. However thejourney to heed her right did not end here; it was the beginning, the beginning to fight for hersurvival.

  20. Paul Flory and the Dawn of Polymers as a Science

    Indian Academy of Sciences (India)

    S Sivaram

    2017-04-01

    If Wallace Carothers was the designer, Flory was the architectand builder of the edifice of polymer science. If Carotherswas the composer, Flory was the man who wrote the notes forthe music. Carothers and Flory represent the quintessentialqualities that are needed to make great science – intuition andrationality, experiment and theory, flights of imagination anddiligent reduction to practice, exuberance and rigour.

  1. A basin redox transect at the dawn of animal life

    Science.gov (United States)

    Sperling, Erik A.; Halverson, Galen P.; Knoll, Andrew H.; Macdonald, Francis A.; Johnston, David T.

    2013-06-01

    Multiple eukaryotic clades make their first appearance in the fossil record between ~810 and 715 Ma. Molecular clock studies suggest that the origin of animal multicellularity may have been part of this broader eukaryotic radiation. Animals require oxygen to fuel their metabolism, and low oxygen levels have been hypothesized to account for the temporal lag between metazoan origins and the Cambrian radiation of large, ecologically diverse animals. Here, paleoredox conditions were investigated in the Fifteenmile Group, Ogilvie Mountains, Yukon, Canada, which hosts an 811 Ma ash horizon and spans the temporal window that captures the inferred origin and early evolution of animals. Iron-based redox proxies, redox-sensitive trace elements, organic carbon percentages and pyrite sulfur isotopes were analyzed in seven stratigraphic sections along two parallel basin transects. These data suggest that for this basin, oxygenated shelf waters overlay generally anoxic deeper waters. The anoxic water column was dominantly ferruginous, but brief periods of euxinia likely occurred. These oscillations coincide with changes in total organic carbon, suggesting euxinia was primarily driven by increased organic carbon loading. Overall, these data are consistent with proposed quantitative constraints on Proterozoic atmospheric oxygen being greater than 1% of modern levels, but less than present levels. Comparing these oxygen levels against the likely oxygen requirements of the earliest animals, both theoretical considerations and the ecology of modern oxygen-deficient settings suggest that the inferred oxygen levels in the mixed layer would not have been prohibitive to the presence of sponges, eumetazoans or bilaterians. Thus the evolution of the earliest animals was probably not limited by the low absolute oxygen levels that may have characterized Neoproterozoic oceans, although these inferred levels would constrain animals to very small sizes and low metabolic rates.

  2. The new Liberal Party from dawn to downfall 1906 - 1924

    Directory of Open Access Journals (Sweden)

    Kenneth O. Morgan

    2011-09-01

    Full Text Available From 1906 to 1914The Liberal Party and Liberal government, particularly from 1906, is a very important period of British history, often compared with the Labour government after 1945, another great phase of reform. But there is of course one big difference: the Liberal government of 1906 was pre-war, the Attlee government post-war. The Labour government in 1945 set the tone for post-war British development, politically and socially, down, perhaps, to the regime of Mrs Thatcher in the 1980s. B...

  3. Green stone beads at the dawn of agriculture.

    Science.gov (United States)

    Bar-Yosef Mayer, Daniella E; Porat, Naomi

    2008-06-24

    The use of beads and other personal ornaments is a trait of modern human behavior. During the Middle and Upper Paleolithic periods, beads were made out of shell, bone, ivory, egg shell, and occasionally of minerals. During the transition to agriculture in the Near East, stone, in particular green stone, was used for the first time to make beads and pendants. We observed that a large variety of minerals of green colors were sought, including apatite, several copper-bearing minerals, amazonite and serpentinite. There seems to be an increase with time of distance from which the green minerals were sought. Because beads in white, red, yellow, brown, and black colors had been used previously, we suggest that the occurrence of green beads is directly related to the onset of agriculture. Green beads and bead blanks were used as amulets to ward off the evil eye and as fertility charms.

  4. Questing the "Land of the Taffeta Dawn" through Basal Readers.

    Science.gov (United States)

    Carlson, Ruth Kearney

    This paper presents some ways of helping young children to extend their imaginative powers through an interpretative recreation of literary selections and some techniques for reading various literary genres imaginatively. Various teachers' guides and manuals that suggest ways to read literature in a critical and imaginative manner are discussed.…

  5. Viruses and cells intertwined since the dawn of evolution.

    Science.gov (United States)

    Durzyńska, Julia; Goździcka-Józefiak, Anna

    2015-10-16

    Many attempts have been made to define nature of viruses and to uncover their origin. Our aim within this work was to show that there are different perceptions of viruses and many concepts to explain their emergence: the virus-first concept (also called co-evolution), the escape and the reduction theories. Moreover, a relatively new concept of polyphyletic virus origin called "three RNA cells, three DNA viruses" proposed by Forterre is described herein. In this paper, not only is each thesis supported by a body of evidence but also counter-argued in the light of various findings to give more insightful considerations to the readers. As the origin of viruses and that of living cells are most probably interdependent, we decided to reveal ideas concerning nature of cellular last universal common ancestor (LUCA). Furthermore, we discuss monophyletic ancestry of cellular domains and their relationships at the molecular level of membrane lipids and replication strategies of these three types of cells. In this review, we also present the emergence of DNA viruses requiring an evolutionary transition from RNA to DNA and recently discovered giant DNA viruses possibly involved in eukaryogenesis. In the course of evolution viruses emerged many times. They have always played a key role through horizontal gene transfer in evolutionary events and in formation of the tree of life or netlike routes of evolution providing a great deal of genetic diversity. In our opinion, future findings are crucial to better understand past relations between viruses and cells and the origin of both.

  6. New York City at the dawn of neurological surgery.

    Science.gov (United States)

    Solomon, Robert A

    2016-11-01

    Although there are many cities that can claim to have been the incubator of modern neurological surgery, the rise of this surgical subspecialty in New York City in the late 19th and early 20th century mirrors what was occurring around the world. The first confirmed brain tumor operation in the US was performed there in 1887. The author describes the role of several pioneers in the development of neurological surgery. Charles Elsberg was the first dedicated neurological surgeon in New York City and was instrumental in the development of the Neurological Institute and the careers of several other notable neurosurgeons.

  7. The dawn of symbiosis between plants and fungi

    Science.gov (United States)

    Bidartondo, Martin I.; Read, David J.; Trappe, James M.; Merckx, Vincent; Ligrone, Roberto; Duckett, Jeffrey G.

    2011-01-01

    The colonization of land by plants relied on fundamental biological innovations, among which was symbiosis with fungi to enhance nutrient uptake. Here we present evidence that several species representing the earliest groups of land plants are symbiotic with fungi of the Mucoromycotina. This finding brings up the possibility that terrestrialization was facilitated by these fungi rather than, as conventionally proposed, by members of the Glomeromycota. Since the 1970s it has been assumed, largely from the observation that vascular plant fossils of the early Devonian (400 Ma) show arbuscule-like structures, that fungi of the Glomeromycota were the earliest to form mycorrhizas, and evolutionary trees have, until now, placed Glomeromycota as the oldest known lineage of endomycorrhizal fungi. Our observation that Endogone-like fungi are widely associated with the earliest branching land plants, and give way to glomeromycotan fungi in later lineages, raises the new hypothesis that members of the Mucoromycotina rather than the Glomeromycota enabled the establishment and growth of early land colonists. PMID:21389014

  8. Light Dawns on Dark Gamma-ray Bursts

    Science.gov (United States)

    2010-12-01

    Gamma-ray bursts are among the most energetic events in the Universe, but some appear curiously faint in visible light. The biggest study to date of these so-called dark gamma-ray bursts, using the GROND instrument on the 2.2-metre MPG/ESO telescope at La Silla in Chile, has found that these gigantic explosions don't require exotic explanations. Their faintness is now fully explained by a combination of causes, the most important of which is the presence of dust between the Earth and the explosion. Gamma-ray bursts (GRBs), fleeting events that last from less than a second to several minutes, are detected by orbiting observatories that can pick up their high energy radiation. Thirteen years ago, however, astronomers discovered a longer-lasting stream of less energetic radiation coming from these violent outbursts, which can last for weeks or even years after the initial explosion. Astronomers call this the burst's afterglow. While all gamma-ray bursts [1] have afterglows that give off X-rays, only about half of them were found to give off visible light, with the rest remaining mysteriously dark. Some astronomers suspected that these dark afterglows could be examples of a whole new class of gamma-ray bursts, while others thought that they might all be at very great distances. Previous studies had suggested that obscuring dust between the burst and us might also explain why they were so dim. "Studying afterglows is vital to further our understanding of the objects that become gamma-ray bursts and what they tell us about star formation in the early Universe," says the study's lead author Jochen Greiner from the Max-Planck Institute for Extraterrestrial Physics in Garching bei München, Germany. NASA launched the Swift satellite at the end of 2004. From its orbit above the Earth's atmosphere it can detect gamma-ray bursts and immediately relay their positions to other observatories so that the afterglows could be studied. In the new study, astronomers combined Swift data with new observations made using GROND [2] - a dedicated gamma-ray burst follow-up observation instrument, which is attached to the 2.2-metre MPG/ESO telescope at La Silla in Chile. In doing so, astronomers have conclusively solved the puzzle of the missing optical afterglow. What makes GROND exciting for the study of afterglows is its very fast response time - it can observe a burst within minutes of an alert coming from Swift using a special system called the Rapid Response Mode - and its ability to observe simultaneously through seven filters covering both the visible and near-infrared parts of the spectrum. By combining GROND data taken through these seven filters with Swift observations, astronomers were able to accurately determine the amount of light emitted by the afterglow at widely differing wavelengths, all the way from high energy X-rays to the near-infrared. The astronomers used this information to directly measure the amount of obscuring dust that the light passed through en route to Earth. Previously, astronomers had to rely on rough estimates of the dust content [3]. The team used a range of data, including their own measurements from GROND, in addition to observations made by other large telescopes including the ESO Very Large Telescope, to estimate the distances to nearly all of the bursts in their sample. While they found that a significant proportion of bursts are dimmed to about 60-80 percent of the original intensity by obscuring dust, this effect is exaggerated for the very distant bursts, letting the observer see only 30-50 percent of the light [4]. The astronomers conclude that most dark gamma-ray bursts are therefore simply those that have had their small amount of visible light completely stripped away before it reaches us. "Compared to many instruments on large telescopes, GROND is a low cost and relatively simple instrument, yet it has been able to conclusively resolve the mystery surrounding dark gamma-ray bursts," says Greiner. Notes [1] Gamma-ray bursts lasting longer than two seconds are referred to as long bursts and those with a shorter duration are known as short bursts. Long bursts, which were observed in this study, are associated with the supernova explosions of massive young stars in star-forming galaxies. Short bursts are not well understood, but are thought to originate from the merger of two compact objects such as neutron stars. [2] The Gamma-Ray burst Optical and Near-infrared Detector (GROND) was designed and built at the Max-Planck Institute for Extraterrestrial Physics in collaboration with the Tautenburg Observatory, and has been fully operational since August 2007. [3] Other studies relating to dark gamma-ray bursts have been released. Early this year, astronomers used the Subaru Telescope to observe a single gamma-ray burst, from which they hypothesised that dark gamma-ray bursts may indeed be a separate sub-class that form through a different mechanism, such as the merger of binary stars. In another study published last year using the Keck Telescope, astronomers studied the host galaxies of 14 dark GRBs, and based on the derived low redshifts they infer dust as the likely mechanism to create the dark bursts. In the new work reported here, 39 GRBs were studied, including nearly 20 dark bursts, and it is the only study in which no prior assumptions have been made and the amount of dust has been directly measured. [4] Because the afterglow light of very distant bursts is redshifted due to the expansion of the Universe, the light that left the object was originally bluer than the light we detect when it gets to Earth. Since the reduction of light intensity by dust is greater for blue and ultraviolet light than for red, this means that the overall dimming effect of dust is greater for the more distant gamma-ray bursts. This is why GROND's ability to observe near-infrared radiation makes such a difference. More information This research is presented in a paper to appear in the journal Astronomy & Astrophysics on 16 December 2010 The team is composed of: J. Greiner (Max-Planck-Institut für extraterrestrische Physik [MPE], Germany), T. Krühler (MPE, Universe Cluster, Technische Universität München), S. Klose (Thüringer Landessternwarte, Germany), P. Afonso (MPE), C. Clemens (MPE), R. Filgas (MPE), D.H. Hartmann (Clemson University, USA), A. Küpcü Yoldaş¸ (University of Cambridge, UK), M. Nardini (MPE), F. Olivares E. (MPE), A. Rau (MPE), A. Rossi (Thüringer Landessternwarte, Germany), P. Schady (MPE), and A. Updike (Clemson University, USA) ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

  9. Cosmic dawn the search for the first stars and galaxies

    CERN Document Server

    Rhee, George

    2013-01-01

    The visible universe consists of stars and galaxies. One of the challenges of astronomy is to understand how galaxies and stars first came into existence over thirteen billion years ago. This book tells the story of our quest to solve this problem. Four hundred years after Galileo used his telescope to discover the  moons of Jupiter, we are using new telescopes and instruments to search for the first galaxies to form after the Big Bang. This book brings the reader to the current frontier of this subject and lays out some of the exciting developments we can expect in the years to come.

  10. CHINA AND AFRICA: THE DAWN OF AN EXCITING ERA

    Institute of Scientific and Technical Information of China (English)

    Adama Gaye

    2008-01-01

    <正>As the world’s oldest-centralised nation-state, and now hosting more than 1.3 billion people, China is definitely not an ordinary nation. The powerful dragon, it has come to symbolise, is drawing attention, raising eyebrows, and generating mixed reactions.

  11. Laboratory tests of headache disorders - dawn of a new era?

    DEFF Research Database (Denmark)

    Schytz, Henrik Winther; Olesen, Jes

    2017-01-01

    and some secondary headaches. BACKGROUND: In this narrative review we present and discuss published tests that might be useful in phenotyping and/or diagnosis of long-lasting headache disorders such as migraine, tension-type headache, trigeminal autonomic cephalalgias, trigeminal neuralgia and persisting...... secondary headaches. AIM: The palpometer test, quantitative sensory testing, nociceptive blink reflex and autonomic tests may be valuable to phenotype and/or diagnose subforms of migraine, tension-type headache, cluster headache, trigeminal neuralgia and medication-overuse headache. Provocation tests...

  12. The Dawning of the Stream of Aquarius in RAVE

    NARCIS (Netherlands)

    Williams, M. E. K.; Steinmetz, M.; Sharma, S.; Bland-Hawthorn, J.; de Jong, R. S.; Seabroke, G. M.; Helmi, A.; Freeman, K. C.; Binney, J.; Minchev, I.; Bienayme, O.; Campbell, R.; Fulbright, J. P.; Gibson, B. K.; Gilmore, G. F.; Grebel, E. K.; Munari, U.; Navarro, J. F.; Parker, Q. A.; Reid, W.; Siebert, A.; Siviero, A.; Watson, F. G.; Wyse, R. F. G.; Zwitter, T.

    2011-01-01

    We identify a new, nearby (0.5 kpc less than or similar to d less than or similar to 10 kpc) stream in data from the RAdial Velocity Experiment (RAVE). As the majority of stars in the stream lie in the constellation of Aquarius, we name it the Aquarius Stream. We identify 15 members of the stream ly

  13. Short GRBs at the dawn of the gravitational wave era

    CERN Document Server

    Ghirlanda, G; Pescalli, A; Ghisellini, G; Salvaterra, R; Chassande-Mottin, E; Colpi, M; Nappo, F; D'Avanzo, P; Melandri, A; Bernardini, M G; Branchesi, M; Campana, S; Ciolfi, R; Covino, S; Gotz, D; Vergani, S D; Zennaro, M; Tagliaferri, G

    2016-01-01

    We derive the luminosity function and redshift distribution of short Gamma Ray Bursts (SGRBs) using (i) all the available observer-frame constraints (i.e. peak flux, fluence, peak energy and duration distributions) of the large population of Fermi SGRBs and (ii) the rest-frame properties of a complete sample of Swift SGRBs. We show that a steep $\\phi(L)\\propto L^{-a}$ with a>2.0 is excluded if the full set of constraints is considered. We implement a Monte Carlo Markov Chain method to derive the $\\phi(L)$ and $\\psi(z)$ functions assuming intrinsic Ep-Liso and Ep-Eiso correlations or independent distributions of intrinsic peak energy, luminosity and duration. To make our results independent from assumptions on the progenitor (NS-NS binary mergers or other channels) and from uncertainties on the star formation history, we assume a parametric form for the redshift distribution of SGRBs. We find that a relatively flat luminosity function with slope ~0.5 below a characteristic break luminosity ~3$\\times10^{52}$ er...

  14. Gentle Like the Dawn: A Dying Woman's Healing.

    Science.gov (United States)

    Ingersoll, R. Elliott

    2000-01-01

    This article recounts the author's counseling relationship with a client who was a nursing home resident. The article describes the client's spiritual experiences and their impact on the client and the counselor. (Author)

  15. Dawn of small worlds dwarf planets, asteroids, comets

    CERN Document Server

    Moltenbrey, Michael

    2016-01-01

    This book gives a detailed introduction to the thousands and thousands of smaller bodies in the solar system. Written for interested laymen, amateur astronomers and students it describes the nature and origin of asteroids, dwarf planets and comets, and gives detailed information about their role in the solar system. The author nicely reviews the history of small-world-exploration and describes past, current and future space craft missions studying small worlds, and presents their results. Readers will learn that small solar system worlds have a dramatically different nature and appearance than the planets. Even though research activity on small worlds has increased in the recent past many of their properties are still in the dark and need further research.

  16. The dawn of the e-lance economy.

    Science.gov (United States)

    Malone, T W; Laubacher, R J

    1998-01-01

    Will the large industrial corporation dominate the twenty-first century as it did the twentieth? Maybe not. Drawing on their research at MIT's Initiative on Inventing the Organizations of the 21st Century, Thomas Malone and Robert Laubacher postulate a world in which business is not controlled through a stable chain of management in a large, permanent company. Rather, it is carried out autonomously by independent contractors connected through personal computers and electronic networks. These electronically connected free-lancers-e-lancers-would join together into fluid and temporary networks to produce and sell goods and services. When the job is done--after a day, a month, a year--the network would dissolve and its members would again become independent agents. Far from being a wild hypothesis, the e-lance economy is, in many ways, already upon us. We see it in the rise of outsourcing and telecommuting, in the increasing importance within corporations of ad-hoc project teams, and in the evolution of the Internet. Most of the necessary building blocks of this type of business organization--efficient networks, data interchange standards, groupware, electronic currency, venture capital micromarkets--are either in place or under development. What is lagging behind is our imagination. But, the authors contend, it is important to consider sooner rather than later the profound implications of how such an e-lance economy might work. They examine the opportunities, and the problems, that may arise and anticipate how the role of managers may change fundamentally--or possibly even disappear altogether.

  17. The dawn of symbiosis between plants and fungi.

    Science.gov (United States)

    Bidartondo, Martin I; Read, David J; Trappe, James M; Merckx, Vincent; Ligrone, Roberto; Duckett, Jeffrey G

    2011-08-23

    The colonization of land by plants relied on fundamental biological innovations, among which was symbiosis with fungi to enhance nutrient uptake. Here we present evidence that several species representing the earliest groups of land plants are symbiotic with fungi of the Mucoromycotina. This finding brings up the possibility that terrestrialization was facilitated by these fungi rather than, as conventionally proposed, by members of the Glomeromycota. Since the 1970s it has been assumed, largely from the observation that vascular plant fossils of the early Devonian (400 Ma) show arbuscule-like structures, that fungi of the Glomeromycota were the earliest to form mycorrhizas, and evolutionary trees have, until now, placed Glomeromycota as the oldest known lineage of endomycorrhizal fungi. Our observation that Endogone-like fungi are widely associated with the earliest branching land plants, and give way to glomeromycotan fungi in later lineages, raises the new hypothesis that members of the Mucoromycotina rather than the Glomeromycota enabled the establishment and growth of early land colonists.

  18. Molecular epigenetics: dawn of a new era of biomedical research

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    At about the same time in 1940s when Erwin Schrdinger published his famous little book What Is Life, which sparked the birth of molecular biology, the term epigenetics was coined by the English biologist Conrad Waddington. The concept of epi-inheritance can be traced back to French naturalist Jean-Baptiste Lamarck’s idea of "inheritance of

  19. Stellar black holes at the dawn of the universe

    CERN Document Server

    Mirabel, I F; Laurent, P; Loeb, A; Pritchard, J R

    2011-01-01

    It is well established that between 380000 and 1 billion years after the Big Bang the Inter Galactic Medium (IGM) underwent a "phase transformation" from cold and fully neutral to warm (~10^4 K) and ionized. Whether this phase transformation was fully driven and completed by photoionization by young hot stars is a question of topical interest in cosmology. AIMS. We propose here that besides the ultraviolet radiation from massive stars, feedback from accreting black holes in high-mass X-ray binaries (BH-HMXBs) was an additional, important source of heating and reionization of the IGM in regions of low gas density at large distances from star-forming galaxies. METHODS. We use current theoretical models on the formation and evolution of primitive massive stars of low metallicity, and the observations of compact stellar remnants in the near and distant universe, to infer that a significant fraction of the first generations of massive stars end up as BH-HMXBs. The total number of energetic ionizing photons from an...

  20. The Dawn of physics beyond the standard model

    CERN Multimedia

    Kane, Gordon

    2003-01-01

    "The Standard Model of particle physics is at a pivotal moment in its history: it is both at the height of its success and on the verge of being surpassed [...] A new era in particle physics could soon be heralded by the detection of supersymmetric particles at the Tevatron collider at Fermi National Accelerator Laboratory in Batavia, Ill." (8 pages)

  1. Mary E. Hall: Dawn of the Professional School Librarian

    Science.gov (United States)

    Alto, Teresa

    2012-01-01

    A century ago, a woman named Mary E. Hall convinced school leaders of the need for the professional school librarian--a librarian who cultivated a love of reading, academic achievement, and independent learning skills. After graduating from New York City's Pratt Institute Library School in 1895, Hall developed her vision for the high school…

  2. Urban policy under new labour: a new dawn?

    Directory of Open Access Journals (Sweden)

    Susan Ball-Petsimeris

    2004-01-01

    Full Text Available British urban policies can be collectively characterised as a series of experiments introducedby successive newly elected governments keen to put their own ideological twist onpolicy for the inner cities and peripheral. The aim of this paper is to examine whether ornot, or to what extent, New Labour’s urban policy marks a change in policy direction. Followinga presentation of the legacy of urban policy left by the outgoing New Right government,the paper will go on to outline New Labour’s ideological standpoint. This discussionwill provide the context for an examination of the urban policies introduced by theBlair administration.

  3. When Consciousness Dawns: Confronting Homophobia with Turkish High School Students

    Science.gov (United States)

    Michell, Michael J.

    2009-01-01

    Turkey, like many Mediterranean and Middle Eastern cultures, is homosocial. Profoundly intimate, though nonsexual, relationships between members of the same gender predominate. In such cultures it is expected that male friends kiss one another on the cheek when greeting or saying goodbye, and it is common to see men walk arm-in-arm together, hold…

  4. The Dawning of the Stream of Aquarius in RAVE

    CERN Document Server

    Williams, Mary E K; Sharma, Sanjib; Bland-Hawthorn, Joss; de Jong, Roelof S; Seabroke, George M; Helmi, Amina; Freeman, Kenneth C; Binney, James; Minchev, Ivan; Bienaymé, Olivier; Campbell, Rachel; Fulbright, Jon P; Gibson, Brad K; Gilmore, Gerard F; Grebel, Eva K; Munari, Ulisse; Navarro, Julio F; Parker, Quentin A; Reid, Warren; Siebert, Arnaud; Siviero, Alessandro; Watson, Fred G; Wyse, Rosemary F G; Zwitter, Tomaz

    2010-01-01

    We identify a new, nearby (0.5 < d < 10 kpc) stream in data from the RAdial Velocity Experiment (RAVE). As the majority of stars in the stream lie in the constellation of Aquarius we name it the Aquarius Stream. We identify 15 members of the stream lying between 30 < l < 75 and -70< b <-50, with heliocentric line-of-sight velocities V_los~-200 km/s. The members are outliers in the radial velocity distribution, and the overdensity is statistically significant when compared to mock samples created with both the Besan\\c{c}on Galaxy model and newly-developed code Galaxia. The metallicity distribution function and isochrone fit in the log g - T_eff plane suggest the stream consists of a 10 Gyr old population with [m/H]~-1.0. We explore relations to other streams and substructures, finding the stream cannot be identified with known structures: it is a new, nearby substructure in the Galaxy's halo. Using a simple dynamical model of a dissolving satellite galaxy we account for the localization of th...

  5. At the dawn of a new revolution in life sciences

    Institute of Scientific and Technical Information of China (English)

    Frantiek; Baluka; Guenther; Witzany

    2013-01-01

    In a recently published article Sydney Brenner argued that the most relevant scientific revolution in biology at his time was the breakthrough of the role of "information" in biology.The fundamental concept that integrates this new biological "information" with matter and energy is the universal Turing machine and von Neumann’s self-reproducing machines.In this article we demonstrate that in contrast to Turing/von Neumann machines living cells can really reproduce themselves.Additionally current knowledge on the roles of noncoding RNAs indicates a radical violation of the central dogma of molecular biology and opens the way to a new revolution in life sciences.

  6. Specialized myrmecophily at the ecological dawn of modern ants.

    Science.gov (United States)

    Parker, Joseph; Grimaldi, David A

    2014-10-20

    Myrmecophiles--species that depend on ant societies--include some of the most morphologically and behaviorally specialized animals known. Remarkable adaptive characters enable these creatures to bypass fortress-like security, integrate into colony life, and exploit abundant resources and protection inside ant nests. Such innovations must result from intimate coevolution with hosts, but a scarcity of definitive fossil myrmecophiles obscures when and how this lifestyle arose. Here, we report the earliest known morphologically specialized and apparently obligate myrmecophile, in Early Eocene (∼ 52 million years old) Cambay amber from India. Protoclaviger trichodens gen. et sp. nov. is a stem-group member of Clavigeritae, a speciose supertribe of pselaphine rove beetles (Coleoptera: Staphylinidae) heavily modified for myrmecophily via reduced mouthparts for trophallaxis with worker ants, brush-like trichomes that exude appeasement compounds, and fusions of many body and antennal segments. Protoclaviger captures a transitional stage in the evolutionary development of this novel body plan, most evident in its still-distinct abdominal tergites. The Cambay paleobiota marks one of the first occurrences in the fossil record of a significant presence of modern ants. Protoclaviger reveals that sophisticated social parasites were nest intruders throughout, and probably before, the ascent of ants to ecological dominance, with ancient groups such as Clavigeritae primed to radiate as their hosts became increasingly ubiquitous.

  7. Learning disabilities at the dawn of the XXI century

    Directory of Open Access Journals (Sweden)

    Goikoetxea, Edurne

    2012-01-01

    Full Text Available The purpose of this article is to inform to the reader the current debate on learning disabilities area. The language barrier imposed by the scientific literature in English makes professionals and college to miss the exciting progress on this diagnostic category so controversial from its formal beginning. We first analyze the definitions of specific learning disabilities that have been in force until the first decade of this century, then make the new definitions formulated to now and discuss characteristics of the history of definitions in this field. We conclude with the demands that we face because of the new definitions.

  8. Homeotic shift at the dawn of the turtle evolution

    Science.gov (United States)

    Szczygielski, Tomasz

    2017-04-01

    All derived turtles are characterized by one of the strongest reductions of the dorsal elements among Amniota, and have only 10 dorsal and eight cervical vertebrae. I demonstrate that the Late Triassic turtles, which represent successive stages of the shell evolution, indicate that the shift of the boundary between the cervical and dorsal sections of the vertebral column occurred over the course of several million years after the formation of complete carapace. The more generalized reptilian formula of at most seven cervicals and at least 11 dorsals is thus plesiomorphic for Testudinata. The morphological modifications associated with an anterior homeotic change of the first dorsal vertebra towards the last cervical vertebra in the Triassic turtles are partially recapitulated by the reduction of the first dorsal vertebra in crown-group Testudines, and they resemble the morphologies observed under laboratory conditions resulting from the experimental changes of Hox gene expression patterns. This homeotic shift hypothesis is supported by the, unique to turtles, restriction of Hox-5 expression domains, somitic precursors of scapula, and brachial plexus branches to the cervical region, by the number of the marginal scute-forming placodes, which was larger in the Triassic than in modern turtles, and by phylogenetic analyses.

  9. Dawning Dependence: Processes underlying smoking cessation in adolescence

    NARCIS (Netherlands)

    M. Kleinjan (Marloes)

    2009-01-01

    textabstractDuring adolescence young people are known to try out a range of risk behaviours, including smoking. Even though the detrimental health consequences of smoking are well known, the prevalence of smoking among Dutch adolescents remains high. Until today, efforts to control adolescent

  10. The Marin Lab at the Dawn of Cognitive Neuropsychology.

    Science.gov (United States)

    Schwartz, Myrna F

    2015-09-01

    This essay discusses the intellectual developments in psychology, linguistics, and behavioral neurology that shaped Oscar Marin's approach to disorders of high cortical function. As Chief of Neurology at Baltimore City Hospitals in the 1970s, Dr Marin teamed with biopsychologist Eleanor Saffran and the author in seminal studies of acquired language disorders (aphasia) centering on core processes of syntax and semantics, and rejecting premature reductionism. The philosophical and methodological principles that motivated these studies are traced through the author's personal recollections and the published writings of the Marin lab. These principles came to be associated with the cognitive neuropsychology school of research and have important linkages to contemporary work in the neuroscience of aphasia and related cognitive disorders.

  11. The Russian Armed Forces at the Dawn of the Millennium

    Science.gov (United States)

    2000-12-01

    weakening of health in the young generation of Russians. People are consuming less meat, milk and eggs, and the diet is vitamin-deficient. Hypotrophy or...particularly relevant to our analysis. The first is the depletion of power resources, particularly the military muscle needed to maintain a hegemonic

  12. Genome engineering at the dawn of the golden age.

    Science.gov (United States)

    Segal, David J; Meckler, Joshua F

    2013-01-01

    Genome engineering--the ability to precisely alter the DNA information in living cells--is beginning to transform human genetics and genomics. Advances in tools and methods have enabled genetic modifications ranging from the "scarless" correction of a single base pair to the deletion of entire chromosomes. Targetable nucleases are leading the advances in this field, providing the tools to modify any gene in seemingly any organism with high efficiency. Targeted gene alterations have now been reported in more than 30 diverse species, ending the reign of mice as the exclusive model of mammalian genetics, and targetable nucleases have been used to modify more than 150 human genes and loci. A nuclease has also already entered clinical trials, signaling the beginning of genome engineering as therapy. The recent dramatic increase in the number of investigators using these techniques signifies a transition away from methods development toward a new age of exciting applications.

  13. By Dawn's Early Light: CMB Polarization Impact on Cosmological Constraints

    OpenAIRE

    Das, Sudeep; Linder, Eric V.

    2012-01-01

    Cosmic microwave background polarization encodes information not only on the early universe but also dark energy, neutrino mass, and gravity in the late universe through CMB lensing. Ground based surveys such as ACTpol, PolarBear, SPTpol significantly complement cosmological constraints from the Planck satellite, strengthening the CMB dark energy figure of merit and neutrino mass constraints by factors of 3-4. This changes the dark energy probe landscape. We evaluate the state of knowledge in...

  14. By Dawn's Early Light: CMB Polarization Impact on Cosmological Constraints

    CERN Document Server

    Das, Sudeep

    2012-01-01

    Cosmic microwave background polarization encodes information not only on the early universe but also dark energy, neutrino mass, and gravity in the late universe through CMB lensing. Ground based surveys such as ACTpol, PolarBear, SPTpol significantly complement cosmological constraints from the Planck satellite, strengthening the CMB dark energy figure of merit and neutrino mass constraints by factors of 3-4. This changes the dark energy probe landscape. We evaluate the state of knowledge in 2017 from ongoing experiments including dark energy surveys (supernovae, weak lensing, galaxy clustering), fitting for dynamical dark energy, neutrino mass, and a modified gravitational growth index. Adding a modest strong lensing time delay survey improves those dark energy constraints by a further 32%, and an enhanced low redshift supernova program improves them by 26%.

  15. Pathfinder aircraft prepared for flight at dawn on lakebed

    Science.gov (United States)

    1996-01-01

    The Pathfinder solar-powered research aircraft is silhouetted by the morning sun on the bed of Rogers Dry Lake as technicians prepare it for flight. The unique remotely piloted flying wing flew for two hours under control of a ground-based pilot on Nov. 19, 1996, at NASA's Dryden Flight Research Center, Edwards, California, while engineers checked out various aircraft systems. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

  16. An Interpretation of Style in Their Eyes Were Watching God

    Institute of Scientific and Technical Information of China (English)

    冯彦

    2016-01-01

    Zora Neale Hurston is an important writers in Harlem Renaissance. Meanwhile, her unique writing styles influence African American literature. Especially, after Their Eyes Were Watching God (1934) were published, Hurston aroused various reflections. This paper analyzes the writing features in this work which differ from others.

  17. Dawn of a New Space Age: Developing a Global Exploration Strategy.

    Science.gov (United States)

    Volosin, Jeff

    2006-01-01

    Jeff Volosin is an aerospace engineer with over 20 years of experience in the design, development, and operations of both robotic and crewed spacecraft. Mr. Volosin is currently leading the NASA effort to develop and integrate a global exploration strategy which reflects the lunar exploration interests of international space agencies, academia and commercial stakeholders. Prior to joining NASA as a member of the Exploration Systems Mission Directorate in 2004, Jeff was an aerospace contractor, serving in a number of leadership positions including: Operations Manager for the NASA Communications Network and Flight Operations Manager for the Advanced Composition Explorer, Tropical Rainfall Measuring Mission, and the NOAA Polar and Geostationary satellite constellations. Earlier in his career, Jeff spent 4 years as a system engineer supporting the Space Exploration Initiative studies on human voyages to the Moon and Mars and also supported the Space Station program as an advanced life support engineer.

  18. Disks, Jets and the dawn of planets, Proceedings of the 2nd JEDI meeting

    CERN Document Server

    Alcala', J M; Biazzo, K; Bacciotti, F; Bianchi, E; Bonito, R; Codella, C; Fedele, D; Fontani, F; Frasca, A; Giannini, T; Manara, C; Nisini, B; Podio, L; Rigliaco, E; Tazzari, M

    2015-01-01

    This booklet contains a collection of contributions to the meeting of the JEts and Disks at INAF (JEDI) group, which took place at the Capodimonte Observatory during 9-10 April 2015. Scope of the meeting was to bring together the JEDI researchers of the Italian Istituto Nazionale di Astrofisica (INAF) working in the field of circumstellar disks and jets in young stars, to discuss together the different agents affecting the structure and the evolution of disks, namely accretion, jets and winds. More information on the JEDI group and its activities can be found at \\texttt{http://www.oa-roma.inaf.it/irgroup/JEDI}.

  19. A basal dinosaur from the dawn of the dinosaur era in southwestern Pangaea.

    Science.gov (United States)

    Martinez, Ricardo N; Sereno, Paul C; Alcober, Oscar A; Colombi, Carina E; Renne, Paul R; Montañez, Isabel P; Currie, Brian S

    2011-01-14

    Upper Triassic rocks in northwestern Argentina preserve the most complete record of dinosaurs before their rise to dominance in the Early Jurassic. Here, we describe a previously unidentified basal theropod, reassess its contemporary Eoraptor as a basal sauropodomorph, divide the faunal record of the Ischigualasto Formation with biozones, and bracket the formation with (40)Ar/(39)Ar ages. Some 230 million years ago in the Late Triassic (mid Carnian), the earliest dinosaurs were the dominant terrestrial carnivores and small herbivores in southwestern Pangaea. The extinction of nondinosaurian herbivores is sequential and is not linked to an increase in dinosaurian diversity, which weakens the predominant scenario for dinosaurian ascendancy as opportunistic replacement.

  20. The households of Serbia at the dawn of third millennium: Socio-demographical analysis

    Directory of Open Access Journals (Sweden)

    Bobić Mirjana

    2004-01-01

    Full Text Available Side by side with tumultuous social processes in the end of XXth century great demographical changes have been taking place in Serbia, such as: the decline of nuptiality and fertility, postponement of family formation into older ages of life course of individuals, the rise of: extramarital births as well as adolescent pregnancies and live births, the spread of one-parent households, particularly of lone mothers, and divorces. Besides that, the main feature of the demographic development of Serbia has been increased mobility of population, namely migrations of highly educated professionals to the West ("brain drain" and forced migration of refugees and internally displaced persons to Serbia, as a consequence of armed conflicts in its surroundings and at Kosovo and Metohija. All the above-mentioned demographical changes caused the precomposition of households, as profound associations of population, where its biological and socio-economical reproductions take place. The information of last census of population of Serbia in 2002 indicate that according to the features of family and households, Serbia has approached the countries of Central and Eastern Europe, that are forerunning in the process of post-socialistic transformation and European integrations. Common characteristics of all those countries are: decrease of universality and popularity of marriage delay of childbearing, continuation of earlier demographic tendencies: of low natality, depopulation and aging of population. All those processes have contributed to the transformation of prevailing forms of households, i.e. decline of nuclear family units and the rise of single person households households of aged persons, as well as single-parent ones. As to the Serbia the demographic differences between its separate parts: Vojvodina and central Serbia, have been fading for the first time in its history, owing to previous socio-demographic developments starting from the beginning of XXth century, as well as to the above actual ones, in the period between last two censuses.

  1. Ultrafast, laser-based, x-ray science: the dawn of atomic-scale cinematography

    Energy Technology Data Exchange (ETDEWEB)

    Barty, C.P.J. [University of California, Department of Applied Mechanics and Engineering Science, Urey Hall, Mali Code 0339, San Diego, La Jolla, CA (United States)

    2000-03-01

    The characteristics of ultrafast chirped pulse amplification systems are reviewed. Application of ultrafast chirped pulse amplification to the generation of femtosecond, incoherent, 8-keV line radiation is outlined and the use of femtosecond laser-based, x-rays for novel time-resolved diffraction studies of crystalline dynamics with sub-picosecond temporal resolution and sub-picometer spatial resolution is reviewed in detail. Possible extensions of laser-based, x-ray technology and evaluation of alternative x-ray approaches for time-resolved studies of the atomic scale dynamics are given. (author)

  2. Characteristics of the near-tail dawn magnetopause and boundary layer

    Directory of Open Access Journals (Sweden)

    G. Paschmann

    2005-06-01

    Full Text Available The paper discusses properties of the near-tail dawnside and boundary layer, as obtained from Cluster plasma and magnetic field measurements during a single skimming orbit on 4 and 5 July 2001 that included 24 well-defined crossings by all four spacecraft. As a result of variations of the interplanetary magnetic field, the magnetic shear across the local varied between ~0° and ~180°. Using an improved method, which takes into account acceleration and thickness variation, we have determined the orientation, speed, thickness and current for the 96 individual crossings. The orientations show clear evidence of surface waves. Magnetopause thicknesses range from ~100 to ~2500km, with an average of 753km. The speeds range from less than 10up to more than 300, with an average of 48. Both results are consistent with earlier ISEE and AMPTE results obtained for the dayside magnetopause. Importantly, scaling the thicknesses to the ion gyro radius or the ion inertial length did not reduce the large dynamic range. There is also no significant dependence of thickness on magnetic shear. Current densities range from ~0.01 up to ~0.3uA, with an average value of 0.05 . By including some extra crossings that did not involve all four spacecraft, we were able to apply the Walén test to a total of 60 by Cluster 1 and 3, and have classified 19 cases as rotational discontinuities (RDs, of which 12 and 7 were sunward and tailward of an X-line, respectively. Of these 60 crossings, 26 show no trace of a boundary layer. The only with substantial boundary layers are into the plasma mantle. Of the 26 without a boundary layer, 8 were identified as RDs. Since reconnection produces wedge-shaped boundary layers emanating from the X-line, RDs without may be considered close to the X-line, in which case the observed magnetic shear and Alfvén Mach number should be representative of the conditions at the X-line itself. It is therefore important that four of the eight cases had shear angles ≤100, i.e. the reconnecting fields were far from being anti-parallel, and that all eight cases had Alfvén Mach numbers MA>1 in the adjoining magnetosheath. Another important conclusion can be drawn from the without a that were tangential discontinuities (TDs. To observe TDs with no at such large distances from the subsolar point appears to rule out diffusion over large portions of the as an effective means for plasma transport across the magnetopause.

  3. Pasteur, Pastorians, and the dawn of immunology: the importance of specificity.

    Science.gov (United States)

    Silverstein, A M

    2000-01-01

    Throughout his career, the problems that attracted Louis Pasteur almost invariably involved considerations of specificity of structure and/or of action. Thus, his work on asymmetric crystals showed that chemical form not only specifies crystalline structure, but affects the affinity of ferments as well. In his studies of diseases of silkworms, of beer, and of wine, he could unerringly distinguish with the microscope the specific agents of disease. From this emerged his concept of the specificity of species and against the nonspecificity of spontaneous generation, whence the germ theory of disease. It was in the new field of immunology, however, where the manifestations of an exquisite specificity were most clearly seen. Here, Pasteur's vaccines worked because he chose the specific pathogen in order to induce a specific immunity, and he succeeded each time. But the two most prominent Pastorian successors in immunology, Elie Metchnikoff and Jules Bordet, were not equally successful. Although each contributed significantly to the birth of immunology, each advanced a theory that neglected the principle of specificity and paid a price in consequence. Metchnikoff's phagocytic theory of immunity could not survive the demonstrable specificity of humoral antibodies, while Bordet's physical adsorptive concept of the antibody-cell interaction quickly fell to Paul Ehrlich's demonstration of the stereochemical determination of immunological specificity.

  4. High-efficient transgenic hairy roots induction in chicory: re-dawn of a traditional herb

    Directory of Open Access Journals (Sweden)

    Sara Kabirnataj

    2016-10-01

    Full Text Available Plant roots can be manipulated by Agrobacterium rhizogenes to stimulate the production of heterologous proteins for pharmaceutical applications as green cell-factories. During the present study, four bacterial strains (A4, ATCC15834, ATCC11325 and A13 in combination with three co-cultivation media (MS, B5, LS were examined to establish an efficient and reliable transformation system for chicory (Cichorium intybus L. using A. rhizogenes. The maximum chicory hairy roots induction was achieved using A13 strain. The observation confirmed that MS medium was more effective on hairy root growth. Dried biomass accumulation of hairy roots infected by A13 strain was 1.10 g l-1 in MS medium which was significantly higher than those grown in LS and B5 medium (0.88 and 0.72 g l-1, respectively. Beta-glucuronidase (GUS gene was introduced by A13 strain carrying the pCAMBIA1304 binary vector. The results showed that the highest frequency of transformation (63.15 % was achieved using A13 strain and MS cultivation medium. Detection of GUS and hptII genes by PCR and GUS histochemical localization confirmed the integrative transformation in hairy roots. In conclusion, the whole process was successfully optimized as a pre-step to manipulate the chicory hairy root cells to improve the unique potential of secondary metabolite production.

  5. HIV-1/AIDS vaccine development: are we in the darkness before the dawn?

    Institute of Scientific and Technical Information of China (English)

    QIU Chao; XU Jian-qing

    2008-01-01

    @@ The pandemic of human immunodeficiency virus type 1 (HIV-1) has been devastating for the last two decades in a number of developing countries and constituting a grand challenge to the public health.WHO/UNAIDS estimates that approximately 33.2million people were living with HIV-1 infection by the end of 2007 and almost 2.5 million new infections occurred in 2007. An unprecedented scientifc challenge for the AIDS vaccine community is how to develop an effective HIV vaccine that can block HIV transmission and consequently stop the continuing spread of HIV-1.The recent failure of Merck Phase Ⅱ B trial alerted the HIV vaccine community that new vaccine strategies need to be more exclusively explored. In this review, we outline the basics of HIV vaccine and retrospect the history of the road to HIV vaccine in last two decades,and highlight the challenges we are currently facing and new strategies to develop HIV vaccines in this field.The Institute of Biomedical Sciences, Fudan University, Shanghai

  6. Mathematical Models of Pluripotent Stem Cells: At the Dawn of Predictive Regenerative Medicine.

    Science.gov (United States)

    Pir, Pınar; Le Novère, Nicolas

    2016-01-01

    Regenerative medicine, ranging from stem cell therapy to organ regeneration, is promising to revolutionize treatments of diseases and aging. These approaches require a perfect understanding of cell reprogramming and differentiation. Predictive modeling of cellular systems has the potential to provide insights about the dynamics of cellular processes, and guide their control. Moreover in many cases, it provides alternative to experimental tests, difficult to perform for practical or ethical reasons. The variety and accuracy of biological processes represented in mathematical models grew in-line with the discovery of underlying molecular mechanisms. High-throughput data generation led to the development of models based on data analysis, as an alternative to more established modeling based on prior mechanistic knowledge. In this chapter, we give an overview of existing mathematical models of pluripotency and cell fate, to illustrate the variety of methods and questions. We conclude that current approaches are yet to overcome a number of limitations: Most of the computational models have so far focused solely on understanding the regulation of pluripotency, and the differentiation of selected cell lineages. In addition, models generally interrogate only a few biological processes. However, a better understanding of the reprogramming process leading to ESCs and iPSCs is required to improve stem-cell therapies. One also needs to understand the links between signaling, metabolism, regulation of gene expression, and the epigenetics machinery.

  7. Metropolitan architecture & cinematography: Modern psychotechnologies at the dawn of the 20th century

    OpenAIRE

    Ginosatis, Dimitris

    2009-01-01

    International audience; Αντλώντας επιλεκτικά από ένα ευρύ φάσμα θεωριών, το παρόν κείμενο επιχειρεί να δείξει ότι, πολύ περισσότερο από απλές αισθητικές μορφές, η Μητρόπολη και το τεχνικό μέσο του Κινηματογράφου, στην εποχή του μοντερνισμού, συνιστούν πρωτίστως σύνθετες πολιτισμικές τεχνολογίες με πολύπλοκες δομές και επιπτώσεις. Η μοντέρνα μητρόπολη είναι κάτι παραπάνω από αυτό που υπονοεί: δηλαδή τον αρχιτεκτονικά διευθετημένο φυσικό χώρο της πόλης. Ομοίως, η κινηματογραφία είναι κάτι παραπ...

  8. Star formation and dust obscuration at z~2: galaxies at the dawn of downsizing

    CERN Document Server

    Pannella, M; Daddi, E; Cracken, H J Mc; Owen, F N; Renzini, A; Strazzullo, V; Civano, F; Koekemoer, A M; Schinnerer, E; Scoville, N; Smolcic, V; Taniguchi, Y; Aussel, H; Kneib, J P; Ilbert, O; Mellier, Y; Salvato, M; Thompson, D; Willott, C J

    2009-01-01

    We present first results of a study aimed to constrain the star formation rate and dust content of galaxies at z~2. We use a sample of BzK-selected star-forming galaxies, drawn from the COSMOS survey, to perform a stacking analysis of their 1.4 GHz radio continuum as a function of different stellar population properties, after removing AGN contaminants from the sample. Dust unbiased star formation rates are derived from radio fluxes assuming the local radio-IR correlation. The main results of this work are: i) specific star formation rates are constant over about 1 dex in stellar mass and up to the highest stellar mass probed; ii) the dust attenuation is a strong function of galaxy stellar mass with more massive galaxies being more obscured than lower mass objects; iii) a single value of the UV extinction applied to all galaxies would lead to grossly underestimate the SFR in massive galaxies; iv) correcting the observed UV luminosities for dust attenuation based on the Calzetti recipe provide results in very ...

  9. From improvement towards enhancement : A regenesis of environmental law at the dawn of the anthropocene

    NARCIS (Netherlands)

    Somsen, Han; Brownsword, Roger; Young, Karen; Scotford, Eloise

    2016-01-01

    This paper discusses a host of what mostly are still isolated ad hoc technology-driven initiatives, usually in support of human (rights) imperatives, which effectively endeavour to engineer and re-engineer living and non-living environments in ways that have no natural, legal or historical

  10. From improvement towards enhancement : A regenesis of environmental law at the dawn of the anthropocene

    NARCIS (Netherlands)

    Somsen, Han; Brownsword, Roger; Young, Karen; Scotford, Eloise

    2016-01-01

    This paper discusses a host of what mostly are still isolated ad hoc technology-driven initiatives, usually in support of human (rights) imperatives, which effectively endeavour to engineer and re-engineer living and non-living environments in ways that have no natural, legal or historical precedent

  11. The Dawns of the Spanish Geo technic; Los albores de la Geotecnia espanola

    Energy Technology Data Exchange (ETDEWEB)

    Serrano Gonzalez, A.

    2013-06-01

    From a personal perspective, there are analyzed the first steps of the spanish Geotechnical Engineering history understood as an academic discipline but also linked in a very directly way the profession. This evolution is not foreign to the own history of the Geneticist in other countries of our cultural or geographical environment. The contributions discover that our predecessors transmitted important achievements to the international community. The direct presence in the international congresses of that time of the spanish geo technicians is analysed. Three consecutive stages are distinguished, personalizing in each of them the participation of celebrated spanish Civil Engineers. (Author)

  12. Do Mesosiderites Reside on 4 VESTA? an Assessment Based on Dawn Grand Data

    Science.gov (United States)

    Mittlefehldt, D. W.; Prettyman, T. H.; Reedy, R. C.; Beck, A. W.; Blewett, D. T.; Gaffey, M. J.; Lawrence, D. J.; McCoy, T. J.; McSween, H. Y., Jr.; Toplis, J. J.

    2012-01-01

    Almost a century ago, simple petrographic observations were used to suggest a close genetic link between eucrites and the silicates in mesosiderites [1]. Mesosiderites are composed of roughly equal proportions of silicates that are very similar in mineralogy and texture to howardites, and Fe, Ni metal (Fig. 1) [2]. This similarity has led some to conclude that mesosiderites come from the howardite, eucrite and diogenite (HED) parent asteroid [3, 4]. Subsequent petrologic study demonstrated a number of differences between mesosiderite silicates and HEDs that are more plausibly explained as requiring separate parent asteroids [5]. However, HEDs and mesosiderites are identical in oxygen isotopic composition, and this has been used to argue for a common parent 4 Vesta [6].

  13. Publishing Children's Literature at the Dawn of the 21st Century.

    Science.gov (United States)

    Taxel, Joel; Ward, Holly M.

    2000-01-01

    Presents a critique of recent trends and changes within the children's book publishing industry, especially nonliterary factors, tensions between commerce and culture, and the impact of mergers. Suggests that changes are dramatically altering the underlying culture of the publishing industry and radically altering the publishing people have come…

  14. Mega sporting events: A poisoned chalice or a new dawn for low- and middle-income

    Directory of Open Access Journals (Sweden)

    Mark Tomlinson

    2011-06-01

    Full Text Available Mega sporting events in South Africa, which has the largest number of HIV-positive people in the world, and India, with 1.8 million deaths of children under 5 each year and 52 million stunted children, raise questions about the effective and, as importantly, the moral imperative of spending billions of dollars to host a sporting event. From a health perspective, selling alcohol and debt tarnishes further the notion of any intangible benefits of mega events to low- and middle-income countries.

  15. From improvement towards enhancement : A regenesis of environmental law at the dawn of the anthropocene

    NARCIS (Netherlands)

    Somsen, Han; Brownsword, Roger; Young, Karen; Scotford, Eloise

    2016-01-01

    This paper discusses a host of what mostly are still isolated ad hoc technology-driven initiatives, usually in support of human (rights) imperatives, which effectively endeavour to engineer and re-engineer living and non-living environments in ways that have no natural, legal or historical precedent

  16. Renewed Support Dawns in Europe: An Action to Develop Space Weather Products and Services

    Science.gov (United States)

    Belehaki, Anna; Watermann, Jurgen; Lilensten, Jean; Glover, Alexi; Hapgood, Mike; Messerotti, Mauro; van der Linden, Ronald; Lundstedt, Henrik

    2009-03-01

    The effects of space weather span a range of sectors. They can cause radio communications problems; can disrupt synthetic aperture radar systems, the Global Positioning System (GPS), and the future European Galileo systems; and can increase radiation risks for aircraft crew and passengers. Electric power network disturbances and enhanced corrosion effects observed in long-distance fuel supply pipelines are other well-known effects of unfavorable space weather. In severe cases, large-scale power outages have also been traced to space weather phenomena (Figure 1).

  17. The Methodian mission on the Polish lands until the dawn of 11th century

    Directory of Open Access Journals (Sweden)

    Antoni Mironowicz

    2014-12-01

    Full Text Available The process of Conversion of the Slavs was commenced with the contact of the Slavic people and the Byzantine culturewhich was initiated by the mission of Sts. Cyril and Methodius. Apart from the exceptional role of Bulgaria and GreatMoravia in the development of the Cyrillo-Methodian legacy the Russian lands became the heir of this great religious andcultural tradition. Before we move on to the problem of the presence of the Methodian rite on the Polish lands it is worthrecalling the basic facts of the activity of Sts. Cyril and Methodius in the area of Great Moravia.The presented influence of the Methodian rite on the Polish lands had a significant influence in the shaping of thereligious tradition in the local Orthodox Church. In the land of the Piasts and Jagiellons the named tradition rooted in thecult of Bulgarian and Greek saints of the Church-Slavonic liturgy, rituals and culture. The awareness of the role of Cyriland Methodius in the introduction of Christianity in Poland shall be especially cultivated in the Eastern Church. Theevangelization of the Great Moravia, Czech and Poland shall be attributed to the Slavonic Apostles.

  18. The receptor binding domain of MERS-CoV: the dawn of vaccine and treatment development.

    Science.gov (United States)

    Zhou, Nan; Zhang, Yun; Zhang, Jin-Chun; Feng, Ling; Bao, Jin-Ku

    2014-03-01

    The newly emerged Middle East respiratory syndrome coronavirus (MERS-CoV) is becoming another "SARS-like" threat to the world. It has an extremely high death rate (∼50%) as there is no vaccine or efficient therapeutics. The identification of the structures of both the MERS-CoV receptor binding domain (RBD) and its complex with dipeptidyl peptidase 4 (DPP4), raises the hope of alleviating this currently severe situation. In this review, we examined the molecular basis of the RBD-receptor interaction to outline why/how could we use MERS-CoV RBD to develop vaccines and antiviral drugs.

  19. Twilight ascents by common swifts, Apus apus, at dawn and dusk: acquisition of orientation cues?

    NARCIS (Netherlands)

    A.M. Dokter; S. Akesson; H. Beekhuis; W. Bouten; L.S. Buurma; H. van Gasteren; I. Holleman

    2013-01-01

    Common swifts are specialist flyers spending most of their life aloft, including night-time periods when this species roosts on the wing. Nocturnal roosting is preceded by a vertical ascent in twilight conditions towards altitudes of up to 2.5 km, behaviour previously explained as flight altitude se

  20. Bayesian approaches to infer the physical properties of star-forming galaxies at cosmic dawn

    Science.gov (United States)

    Salmon, Brett Weston Killebrew

    In this thesis, I seek to advance our understanding of galaxy formation and evolution in the early universe. Using the largest single project ever conducted by the Hubble Space Telescope (the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, CANDELS) I use deep and wide broadband photometric imaging to infer the physical properties of galaxies from z=8.5 to z=1.5. First, I will present a study that extends the relationship between the star-formation rates (SFRs) and stellar masses (M⋆) of galaxies to 3.5attenuated in galaxies. I calculate the Bayesian evidence for galaxies under different assumptions of their underlying dust-attenuation law. By modeling galaxy ultraviolet-to-near-IR broadband CANDELS data I produce Bayesian evidence towards the dust law in individual galaxies that is confirmed by their observed IR luminosities. Moreover, I find a tight correlation between the strength of attenuation in galaxies and their dust law, a relation reinforced by the results from radiative transfer simulations. Finally, I use the Bayesian methods developed in this thesis to study the number density of SFR in galaxies from z=8 to z=4, and resolve the current disconnect between its evolution and that of the stellar mass function. In doing so, I place the first constraints on the dust law of z>4 galaxies, finding it obeys a similar relation as found at z˜2. I find a clear excess in number density at high SFRs. This new SFR function is in better agreement with the observed stellar mass functions, the few to-date infrared detections at high redshifts, and the connection to the observed distribution of lower redshift infrared sources. Together, these studies greatly improve our understanding of the galaxy star-formation histories, the nature of their dust attenuation, and the distribution of SFR among some of the most distant galaxies in the universe.

  1. Music Audiences 3.0: Concert-Goers’ Psychological Motivations at the Dawn of Virtual Reality

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Charron

    2017-05-01

    Full Text Available Reviewing consumers’ motivations to attend performances in a continuously evolving social and technological context is essential because live concerts generate an important and growing share of revenues for the music industry. Evolving fans’ preferences and technological innovations constantly alter the way music is distributed and consumed. In a marketing 3.0 era, what consumers do with music is becoming more significant than simply owning or listening to a song. These changes are not only blurring the lines between production and consumption (i.e., co-creation, but also distorting the concept of live attendance altogether. Although mediated performances typically lack presence and authenticity, recent advances in immersive technologies, such as spherical videos and virtual reality goggles, could represent a new form of experiencing live music.

  2. Music Audiences 3.0: Concert-Goers’ Psychological Motivations at the Dawn of Virtual Reality

    National Research Council Canada - National Science Library

    Jean-Philippe Charron

    2017-01-01

    ... an important and growing share of revenues for the music industry. Evolving fans’ preferences and technological innovations constantly alter the way music is distributed and consumed. In a marketing...

  3. Music Audiences 3.0: Concert-Goers' Psychological Motivations at the Dawn of Virtual Reality.

    Science.gov (United States)

    Charron, Jean-Philippe

    2017-01-01

    Reviewing consumers' motivations to attend performances in a continuously evolving social and technological context is essential because live concerts generate an important and growing share of revenues for the music industry. Evolving fans' preferences and technological innovations constantly alter the way music is distributed and consumed. In a marketing 3.0 era, what consumers do with music is becoming more significant than simply owning or listening to a song. These changes are not only blurring the lines between production and consumption (i.e., co-creation), but also distorting the concept of live attendance altogether. Although mediated performances typically lack presence and authenticity, recent advances in immersive technologies, such as spherical videos and virtual reality goggles, could represent a new form of experiencing live music.

  4. A pulse of mid-Pleistocene rift volcanism in Ethiopia at the dawn of modern humans

    Science.gov (United States)

    Hutchison, William; Fusillo, Raffaella; Pyle, David M.; Mather, Tamsin A.; Blundy, Jon D.; Biggs, Juliet; Yirgu, Gezahegn; Cohen, Benjamin E.; Brooker, Richard A.; Barfod, Dan N.; Calvert, Andrew T.

    2016-10-01

    The Ethiopian Rift Valley hosts the longest record of human co-existence with volcanoes on Earth, however, current understanding of the magnitude and timing of large explosive eruptions in this region is poor. Detailed records of volcanism are essential for interpreting the palaeoenvironments occupied by our hominin ancestors; and also for evaluating the volcanic hazards posed to the 10 million people currently living within this active rift zone. Here we use new geochronological evidence to suggest that a 200 km-long segment of rift experienced a major pulse of explosive volcanic activity between 320 and 170 ka. During this period, at least four distinct volcanic centres underwent large-volume (>10 km3) caldera-forming eruptions, and eruptive fluxes were elevated five times above the average eruption rate for the past 700 ka. We propose that such pulses of episodic silicic volcanism would have drastically remodelled landscapes and ecosystems occupied by early hominin populations.

  5. Operations Odyssey Dawn and Unified Protector: Another Win for Warden s Theory

    Science.gov (United States)

    2014-12-04

    the aircraft aimed at armoured vehicles just outside Benghazi. At night, US Navy ships and Royal Navy submarine HMS Triumph launched 112 Tomahawk...affect air superiority: materiel, personnel, and position. Materiel includes aircraft, supplies , and infrastructure for direct support.37 Personnel...warning is that interdiction missions should not be attempted without air superiority, except under unusual circumstances. A possible compromise is

  6. Offshore Outsourcing and the Dawn of the Post-Colonial Era of Western Engineering Education

    Science.gov (United States)

    Oberst, Bethany S.; Jones, Russel C.

    2006-01-01

    This paper summarizes the phenomenon of offshore outsourcing and relates it to the history and current state of engineering education and the engineering profession in Europe and the USA. In order to assess the climate affecting employment decisions by and about engineers we have used as sources mostly the serious press, with an emphasis on…

  7. Cone Beam Computed Tomography-Dawn of A New Imaging Modality in Orthodontics

    Science.gov (United States)

    Mamatha, J; Chaitra, K R; Paul, Renji K; George, Merin; Anitha, J; Khanna, Bharti

    2015-01-01

    Today, we are in a world of innovations, and there are various diagnostics aids that help to take a decision regarding treatment in a well-planned way. Cone beam computed tomography (CBCT) has been a vital tool for imaging diagnostic tool in orthodontics. This article reviews case reports during orthodontic treatment and importance of CBCT during the treatment evaluation. PMID:26225116

  8. The dawn of a new era in onco-cardiology: The Kumamoto Classification.

    Science.gov (United States)

    Sueta, Daisuke; Tabata, Noriaki; Akasaka, Tomonori; Yamashita, Takayoshi; Ikemoto, Tomokazu; Hokimoto, Seiji

    2016-10-01

    The term "onco-cardiology" has been used in reference to cardiotoxicity in the treatment of malignant disease. In actual clinical situations, however, cardiovascular disease (CVD) associated with malignant disease and the concurrence of atherosclerotic disease with malignant disease are commonly observed, complicating the course of treatment. Patients with malignant disease associated with coronary artery disease often die from the cardiovascular disease, so it is essential to classify these disease states. Additionally, the prevalence of these classifications makes it easy to manage patients with malignant disease and coronary artery disease. We divided the broad field of onco-cardiology into 4 classifications based on clinical scenarios (CSs): CS1 represents the so-called paraneoplastic syndrome. CS2 represents cardiotoxicity during treatment of malignant diseases. CS3 represents the concurrence of atherosclerotic disease with malignant disease, and CS4 represents cardiovascular disease with benign tumors. This classification facilitates the management of patients with malignant disease and coronary artery disease by promoting not only the primary but also the secondary prevention of CVD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Echinococcus granulosus genomics: a new dawn for improved diagnosis, treatment, and control of echinococcosis.

    Science.gov (United States)

    Zhang, Wenbao; Wang, Shengyue; McManus, Donald P

    2014-01-01

    Cystic echinococcosis (CE) is a cosmopolitan disease caused by the dog tapeworm Echinococcus granulosus. The disease is difficult to diagnose, treat, and control and is responsible for considerable human morbidity and mortality globally. There is an urgent need for new diagnostic tests and new drugs for treatment of CE and the development of a vaccine against adult worms of E. granulosus in dogs. We recently presented a draft genomic sequence for the worm comprising 151.6 Mb encoding 11,325 proteins. We undertook an extensive comparative analysis of the E. granulosus transcriptome using representative life stages (protoscoleces, cyst germinal cells and membranes, adult worms, and oncospheres) to explore different aspects of tapeworm biology and parasitism. The genome and transcriptome of E. granulosus provide a unique platform for post-genomic research and to facilitate the development of new, effective treatments and interventions for echinococcosis control.

  10. Standards for Quantitative Assessment of Lung Structure: The Dawn of Stereopneumology

    Directory of Open Access Journals (Sweden)

    Georgios T. Stathopoulos

    2010-01-01

    Full Text Available SUMMARY. The lungs are complex 3D structuresstudied in the clinic and the laboratory using histologic or imaging sections. Although such 2D analyses of lung structure are considered “gold standards”, the information conveyed is often insufficient and does not represent the whole organ. Stereology, the mathematical approach to the analysis of 3D structures via 2D sampling and morphometry, the practical application of stereology, provide solutions to this problem, but had until recently not been systematically adoptedin pneumology. In an effort of minimizing the above-mentioned methodological problems and of standardizing the quantitative assessment of lung structure, the American Thoracic Society and European Respiratory Society formed a task force, which recently published its findings. The task force aimed at comprehensively reviewing current stereologic methods for lung morphometry, formulating practical guidelines for using unbiased methods for basic and translational research of lung structure, and examining the extensions of stereologic methods on non-invasive imaging of lung architecture. In the statement of the task force are included useful directives with important application in the laboratory and the clinic, the most pertinent of which are discussed in the present mini-review. Pneumon 2010, 23(2:141-152.

  11. Nuclear dawn F. E. Simon and the race for atomic weapons in World War II

    CERN Document Server

    McRae, Kenneth D

    2014-01-01

    This book provides a rounded biography of Franz (later Sir Francis) Simon, his early life in Germany, his move to Oxford in 1933, and his experimental contributions to low temperature physics approximating absolute zero. After 1939 he switched his research to nuclear physics, and is credited with solving the problem of uranium isotope separation by gaseous diffusion for the British nuclear programme Tube Alloys. The volume is distinctive for its inclusion of source materials not available to previous researchers, such as Simon's diary and his correspondence with his wife, and for a fresh, well-informed insider voice on the five-power nuclear rivalry of the war years. The work also draws on a relatively mature nuclear literature to attempt a comparison and evaluation of the five nuclear rivals in wider political and military context, and to identify the factors, or groups of factors, that can explain the results.

  12. Dawn of the dead: protein pseudokinases signal new adventures in cell biology.

    Science.gov (United States)

    Eyers, Patrick A; Murphy, James M

    2013-08-01

    Recent studies of proteins containing kinase-like domains that lack catalytic residue(s) classically required for phosphotransfer, termed pseudokinases, have uncovered important roles in cell signalling across the kingdoms of life. Additionally, mutations within pseudokinase domains are known to underlie human diseases, suggesting that these proteins may represent new and unexplored therapeutic targets. To date, few pseudokinases have been studied in intricate detail, but as described in the present article and in the subsequent papers in this issue of Biochemical Society Transactions, several new studies have provided an advanced template and an improved framework for interrogating the roles of pseudokinases in signal transduction. In the present article, we review landmarks in the establishment of this field of study, highlight some experimental challenges and propose a simple scheme for definition of these domains based on their primary sequences, rather than experimentally defined nucleotide-binding or catalytic activities.

  13. The dawn of computer-assisted robotic osteotomy with ytterbium-doped fiber laser.

    Science.gov (United States)

    Sotsuka, Yohei; Nishimoto, Soh; Tsumano, Tomoko; Kawai, Kenichiro; Ishise, Hisako; Kakibuchi, Masao; Shimokita, Ryo; Yamauchi, Taisuke; Okihara, Shin-ichiro

    2014-05-01

    Currently, laser radiation is used routinely in medical applications. For infrared lasers, bone ablation and the healing process have been reported, but no laser systems are established and applied in clinical bone surgery. Furthermore, industrial laser applications utilize computer and robot assistance; medical laser radiations are still mostly conducted manually nowadays. The purpose of this study was to compare the histological appearance of bone ablation and healing response in rabbit radial bone osteotomy created by surgical saw and ytterbium-doped fiber laser controlled by a computer with use of nitrogen surface cooling spray. An Ytterbium (Yb)-doped fiber laser at a wavelength of 1,070 nm was guided by a computer-aided robotic system, with a spot size of 100 μm at a distance of approximately 80 mm from the surface. The output power of the laser was 60 W at the scanning speed of 20 mm/s scan using continuous wave system with nitrogen spray level 0.5 MPa (energy density, 3.8 × 10(4) W/cm(2)). Rabbits radial bone osteotomy was performed by an Yb-doped fiber laser and a surgical saw. Additionally, histological analyses of the osteotomy site were performed on day 0 and day 21. Yb-doped fiber laser osteotomy revealed a remarkable cutting efficiency. There were little signs of tissue damage to the muscle. Lased specimens have shown no delayed healing compared with the saw osteotomies. Computer-assisted robotic osteotomy with Yb-doped fiber laser was able to perform. In rabbit model, laser-induced osteotomy defects, compared to those by surgical saw, exhibited no delayed healing response.

  14. The classical KAM theory at the dawn of the twenty-first century

    CERN Document Server

    Sevryuk, M B

    2002-01-01

    We survey several recent achievements in the KAM theory. The achievements chosen pertain to Hamiltonian systems only and are closely connected with the content of Kolmogorov's original theorem of 1954. They include the weak nondegeneracy conditions, Gevrey smoothness of families of perturbed invariant tori, the ``exponential condensation'' of perturbed tori, destruction mechanisms of the resonant unperturbed tori, the excitation of the elliptic normal modes of the unperturbed tori, and ``atropic'' invariant tori (i.e., tori that are neither isotropic nor coisotropic). The exposition is informal and nontechnical, and, as a rule, the methods of proofs are not discussed. The paper contains 152 references.

  15. [The dawn of a smoke-free leisure industry in The Nederlands].

    Science.gov (United States)

    Verheugt, F W A; Zaat, J O M; de Leeuw, P W

    2008-06-28

    From the 1st of July 2008 the Dutch smoking ban for public spaces will be extended to hotels, restaurants and bars. The ban is a result of a 2003 Health Council report in which it was concluded that the annual incidence of deaths due to passive smoking is considerable. Based on these numbers, smoking in public spaces is prohibited since 2004. In a society where smoking in public spaces is prohibited, the harm of passive smoking will decrease. In this issue of The Nederlands Tijdschrit voor Geneeskunde (Dutch Journal of Medicine) a number of articles are dedicated to the subject of smoking.

  16. Health at the dawn of development: the thought of Abraham Horwitz.

    Science.gov (United States)

    Pires-Alves, Fernando A; Maio, Marcos Chor

    2015-01-01

    The article explores the ideas of Pan American Health Organization director Abraham Horwitz on the relations between health and development at the time the Alliance for Progress was established, in 1961. Taking development discourse as a public philosophy of international cooperation, the discussion centers on how Horwitz worked to mediate between health and development. Horwitz endeavored to establish arguments that highlighted the importance of social policy, especially in health; he also strove to reach different audiences and drew connections between elements like health, illness, and labor productivity, without ignoring the humanistic considerations so dear to the public health tradition.

  17. Health at the dawn of development: the thought of Abraham Horwitz

    National Research Council Canada - National Science Library

    Pires-Alves, Fernando A; Maio, Marcos Chor

    2015-01-01

    The article explores the ideas of Pan American Health Organization director Abraham Horwitz on the relations between health and development at the time the Alliance for Progress was established, in 1961...

  18. From Emigration to Immigration: New Dawn for an Intercultural 21st Century Ireland

    Science.gov (United States)

    Mutwarasibo, Fidele

    2005-01-01

    Within the course of a decade Ireland has emerged from being a country of emigration to a country of immigration. Since the mid-1990s, Ireland has undergone rapid economic expansion with the recent economic growth resulting in approximately 252,000 migrants entering Ireland over the last 6 years, according to the Irish Times (2003). While a large…

  19. The universal machine from the dawn of computing to digital consciousness

    CERN Document Server

    Watson, Ian

    2012-01-01

    In less than a human lifetime, computers are transforming economies and societies like no other human invention. This book looks past technology to introduce comuputing pioneers: Babbage, Turing, Wozniak and Jobs, Bill Gates, Tim Berners-Lee, Mark Zuckerberg.

  20. Solar disks and solar cycles : spindle whorls and the dawn of solar art in postclassic Mexico

    OpenAIRE

    Brumfiel, Elisabeth

    2007-01-01

    Sun disks are a common motif in spindle whorl decorations at Xaltocan, Mexico. These and other forms of symbolism on domestic artifacts suggest that women participated in the solar cosmologies of Postclassic Central Mexico. These symbols and their cosmologies precede and anticipate the principles of Aztec state religion. Thus, the spindle whorls with solar symbolism suggest that rulers appropriated the symbolism of household units in their efforts to establish the legitimacy of their states. ...

  1. From dusk till dawn: nocturnal and diurnal pollination in the epiphyte Tillandsia heterophylla (Bromeliaceae).

    Science.gov (United States)

    Aguilar-Rodríguez, P A; Krömer, T; García-Franco, J G; MacSwiney G, M C

    2016-01-01

    In order to compare the effectiveness of diurnal and nocturnal pollinators, we studied the reproductive biology and pollinators of Tillandsia heterophylla E. Morren, an epiphytic tank bromeliad endemic to southeastern Mexico. Since anthesis in T. heterophylla is predominantly nocturnal but lasts until the following day, we hypothesised that this bromeliad would receive visits from both diurnal and nocturnal visitors, but that nocturnal visitors would be the most effective pollinators, since they arrive first to the receptive flower, and that bats would be the most frequent nocturnal visitors, given the characteristics of the nectar. Flowering of T. heterophylla began in May and lasted until July. The species is fully self-compatible, with an anthesis that lasts for ca. 15-16 h. Mean volume of nectar produced per flower was 82.21 μl, with a mean sugar concentration of 6.33%. The highest volume and concentration of nectar were found at 20:00 h, with a subsequent decline in both to almost zero over the following 12-h period. T. heterophylla has a generalist pollination system, since at least four different morphospecies of visitors pollinate its flowers: bats, moths, hummingbirds and bees. Most of the pollinating visits corresponded to bats and took place in the early evening, when stigma receptivity had already begun; making bats the probable pollinator on most occasions. However, diurnal pollinators may be important as a 'fail-safe' system by which to guarantee the pollination of T. heterophylla.

  2. MUSE tells the story of NGC 4371: The dawning of secular evolution

    CERN Document Server

    Gadotti, Dimitri A; Sanchez-Blazquez, Patricia; Falcon-Barroso, Jesus; Husemann, Bernd; Coelho, Paula; Perez, Isabel

    2015-01-01

    We use data from the Multi-Unit Spectroscopic Explorer (MUSE), recently commissioned at the Very Large Telescope (VLT), to study the kinematics and stellar population content of NGC 4371, an early-type massive barred galaxy in the core of the Virgo cluster. We integrate this study with a detailed structural analysis using imaging data from the Hubble and Spitzer space telescopes, which allows us to perform a thorough investigation of the physical properties of the galaxy. We show that the rotationally supported inner components in NGC 4371, an inner disc and a nuclear ring - which, according to the predominant scenario, are built with stars formed from gas brought to the inner region by the bar - are vastly dominated by stars older than 10 Gyr. Our results thus indicate that the formation of the bar occurred at a redshift of about $z=1.8^{+0.5}_{-0.4}$ (error bars are derived from 100 Monte Carlo realisations). NGC 4371 thus testifies to the robustness of bars. In addition, the mean stellar age of the fractio...

  3. Pathogenesis of Dengue: Dawn of a New Era [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Scott B. Halstead

    2015-11-01

    Full Text Available Dengue virus (DENV infections of humans were long thought to be self-limited and of low mortality. Beginning in the 1950s, at the time when four different DENVs were discovered, a lethal variant of dengue emerged. Dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS initially observed in Southeast Asia now has spread throughout the world. Two risk factors for DHF/DSS are well-established: severe disease occurs during a second heterotypic DENV infection or during a first DENV infection in infants born to dengue-immune mothers. A large number of hypotheses have been proposed to explain severe dengue disease. As discussed, few of them attempt to explain why severe disease occurs under the two different immunological settings. New experimental evidence has demonstrated that DENV non-structural protein 1 (NS1 is toll-receptor 4 agonist that stimulates primary human myeloid cells to produce the same cytokines observed during the course of severe dengue disease. In addition, NS1 directly damages endothelial cells. These observations have been repeated and extended to an in vivo mouse model. The well-established phenomenon, antibody-dependent enhancement of DENV infection in Fc-receptor-bearing cells, should similarly enhance the production of DENV NS1 in humans, providing a unitary mechanism for severe disease in both immunological settings

  4. A dawning demand for a new cannabis policy: A study of Swedish online drug discussions.

    Science.gov (United States)

    Månsson, Josefin

    2014-07-01

    This study examines how online discussions on drug policy are formulating an oppositional cannabis discourse in an otherwise prohibitionist country like Sweden. The focus of the paper is to identify demands for an alternative cannabis policy as well as analysing how these demands are linked to governance. The empirical material is 56 discussion-threads from the online message-board Flashback Forum that were active during the first eight months of 2012. Discourse theory was used to locate the discourse, and governmentality theory was used to locate the political belonging of the discourse. On Flashback Forum demands for a new cannabis policy are articulated in opposition to Swedish prohibitionist discourse. The oppositional discourse is constructed around the nodal points cannabis, harm, state and freedom that fill legalisation/decriminalisation/liberalisation with meaning. The nodal points are surrounded by policy demands that get their meaning through the particular nodal. These demands originate from neo-liberal and welfarist political rationalities. Neo-liberal and welfarist demands are mixed, and participants are simultaneously asking for state and individual approaches to handle the cannabis issue. Swedish online discourse on cannabis widens the scope beyond the confines of drug policy to broader demands such as social justice, individual choice and increased welfare. These demands are not essentially linked together and many are politically contradictory. This is also significant for the discourse; it is not hegemonised by a political ideology. The discourse is negotiated between the neo-liberal version of an alternative policy demanding individual freedom, and the welfarist version demanding social responsibility. This implies the influence of the heritage from the social-democratic discourse, centred on state responsibility, which have been dominating Swedish politics in modern times. Consequently, this study refutes that the demand for a new cannabis policy is strictly neo-liberal. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Work motivation theory and research at the dawn of the twenty-first century.

    Science.gov (United States)

    Latham, Gary P; Pinder, Craig C

    2005-01-01

    In the first Annual Review of Psychology chapter since 1977 devoted exclusively to work motivation, we examine progress made in theory and research on needs, traits, values, cognition, and affect as well as three bodies of literature dealing with the context of motivation: national culture, job design, and models of person-environment fit. We focus primarily on work reported between 1993 and 2003, concluding that goal-setting, social cognitive, and organizational justice theories are the three most important approaches to work motivation to appear in the last 30 years. We reach 10 generally positive conclusions regarding predicting, understanding, and influencing work motivation in the new millennium.

  6. The dawn of Aurora kinase research: from fly genetics to the clinic.

    Directory of Open Access Journals (Sweden)

    Mar eCarmena

    2015-11-01

    Full Text Available Aurora kinases comprise a family of highly conserved serine-threonine protein kinases that play a pivotal role in the regulation of cell cycle. Aurora kinases are not only involved in the control of multiple processes during cell division but also coordinate chromosomal and cytoskeletal events, contributing to the regulation of checkpoints and ensuring the smooth progression of the cell cycle.Because of their fundamental contribution to cell cycle regulation, Aurora kinases were originally identified in independent genetic screens designed to find genes involved in the regulation of cell division. The first aurora mutant was part of a collection of mutants isolated in C. Nusslein-Volhard’s laboratory. This collection was screened in D. M. Glover’s laboratory in search for mutations disrupting the centrosome cycle in embryos derived from homozygous mutant mothers. The mutants identified were given names related to the polar regions, and included not only aurora but also the equally famous polo. Ipl1, the only Aurora in yeast, was identified in a genetic screen looking for mutations that caused chromosome segregation defects. The discovery of a second Aurora-like kinase in mammals opened a new chapter in the research of Aurora kinases. The rat kinase AIM was found to be highly homologous to the fly and yeast proteins, but localised at the midzone and midbody and was proposed to have a role in cytokinesis. Homologs of the equatorial Aurora (Aurora B were identified in metazoans ranging from flies to humans. Xenopus Aurora B was found to be in a complex with the chromosomal passenger INCENP, and both proteins were shown to be essential in flies for chromosome structure, segregation, central spindle formation and cytokinesis. Fifteen years on, Aurora kinase research is an active field of research. After the successful introduction of the first anti-mitotic agents in cancer therapy, both Auroras have become the focus of attention as targets for the development of new anti-cancer drugs. In this review we will aim to give a historical overview of the research on Aurora kinases, highlighting the most relevant milestones in the advance of the field.

  7. Health at the dawn of development: the thought of Abraham Horwitz

    Directory of Open Access Journals (Sweden)

    Fernando A. Pires-Alves

    2015-03-01

    Full Text Available The article explores the ideas of Pan American Health Organization director Abraham Horwitz on the relations between health and development at the time the Alliance for Progress was established, in 1961. Taking development discourse as a public philosophy of international cooperation, the discussion centers on how Horwitz worked to mediate between health and development. Horwitz endeavored to establish arguments that highlighted the importance of social policy, especially in health; he also strove to reach different audiences and drew connections between elements like health, illness, and labor productivity, without ignoring the humanistic considerations so dear to the public health tradition

  8. Medical tourism and reproductive outsourcing: the dawning of a new paradigm for healthcare.

    Science.gov (United States)

    Jones, C A; Keith, L G

    2006-01-01

    Medical tourism, a term that also can be used to describe medical outsourcing, is characterized by travel away from one's home region to procure treatment in another. It may take one of two forms: obligatory or elective. The former occurs when necessary treatments are unavailable or illegal in the place of origin. The latter includes elective and medically indicated procedures that, although available at the place of origin, may be delivered more quickly or in a more cost-effective manner in another location. Reproductive outsourcing is a special form of medical tourism that has quickly become an important area of present-day medicine because the changes of the last four decades have left all but the most advanced fertility centers breathless as they try to adjust their treatment protocols in effective and ethical manners. Legal and policy limitations have created a global environment where, in a rising number of instances, individuals and couples must travel elsewhere to procure fertility procedures that are unavailable back home. With low cost airfares to and from America, a growing number of "medical cartographers" have set out to map which places are the "best" (in terms of cost, effectiveness and timeliness), for what procedures, and for whom. On the other hand, physicians, legal experts and policy makers have only begun to shape how government and health care agencies should formally guide or regulate medical tourism. In doing so, a number of factors may challenge the limits of ethics, policy and legality in this most important trend in modern medicine.

  9. Cone Beam Computed Tomography-Dawn of A New Imaging Modality in Orthodontics

    OpenAIRE

    Mamatha, J; Chaitra, K R; Paul, Renji K; George, Merin; J. Anitha; Khanna, Bharti

    2015-01-01

    Today, we are in a world of innovations, and there are various diagnostics aids that help to take a decision regarding treatment in a well-planned way. Cone beam computed tomography (CBCT) has been a vital tool for imaging diagnostic tool in orthodontics. This article reviews case reports during orthodontic treatment and importance of CBCT during the treatment evaluation.

  10. Cone Beam Computed Tomography-Dawn of A New Imaging Modality in Orthodontics.

    Science.gov (United States)

    Mamatha, J; Chaitra, K R; Paul, Renji K; George, Merin; Anitha, J; Khanna, Bharti

    2015-01-01

    Today, we are in a world of innovations, and there are various diagnostics aids that help to take a decision regarding treatment in a well-planned way. Cone beam computed tomography (CBCT) has been a vital tool for imaging diagnostic tool in orthodontics. This article reviews case reports during orthodontic treatment and importance of CBCT during the treatment evaluation.

  11. Extracorporeal Organ Support following Trauma: The Dawn of a New Era in Combat Casualty Critical Care

    Science.gov (United States)

    2013-01-01

    hemofiltration uses ultrafiltration with subsequent replacement fluid (convection). As discussed later, the convective clearance obtained through J...training in extracorporeal organ support (Fig. 5). Advances in nanotechnology are allowing the creation of complex filters with multiple functions...continuous renal replacement therapy at various dialy- sate and ultrafiltration flow rates. Am J Kidney Dis. 1999;34:486Y492. 61. Davenport A. Management of

  12. Dawn of the digital diagnosis assisting system, can it open a new age for pathology?

    Science.gov (United States)

    Saito, Akira; Cosatto, Eric; Kiyuna, Tomoharu; Sakamoto, Michiie

    2013-03-01

    Digital pathology is developing based on the improvement and popularization of WSI (whole slide imaging) scanners. WSI scanners are widely expected to be used as the next generation microscope for diagnosis; however, their usage is currently mostly limited to education and archiving. Indeed, there are still many hindrances in using WSI scanners for diagnosis (not research purpose), two of the main reasons being the perceived high cost and small gain in productivity obtained by switching from the microscope to a WSI system and the lack of WSI standardization. We believe that a key factor for advancing digital pathology is the creation of computer assisted diagnosis systems (CAD). Such systems require high-resolution digitization of slides and provide a clear added value to the often costly conversion to WSI. We (NEC Corporation) are creating a CAD system, named e-Pathologist ®. This system is currently used at independent pathology labs for quality control (QC/QA), double-checking pathologists diagnosis and preventing missed cancers. At the end of 2012, about 80,000 slides, 200,000 tissues of gastric and colorectal samples will have been analyzed by e-Pathologist ®. Through the development of e-Pathologist ®, it has become clear that a computer program should be inspired by the pathologist diagnosis process, yet it should not be a mere copy or simulation of it. Indeed pathologists often approach the diagnosis of slides in a "holistic" manner, examining them at various magnifications, panning and zooming in a seemingly haphazard way that they often have a hard time to precisely describe. Hence there has been no clear recipe emerging from numerous interviews with pathologists on how to exactly computer code a diagnosis expert system. Instead, we focused on extracting a small set of histopathological features that were consistently indicated as important by the pathologists and then let the computer figure out how to interpret in a quantitative way the presence or absence of these features over the entire slide. Using the overall pathologists diagnosis (into a class of disease), we train the computer system using advanced machine learning techniques to predict the disease based on the extracted features. By considering the diagnosis of several expert pathologists during the training phase, we insure that the machine is learning a "gold standard" that will be applied consistently and objectively for all subsequent diagnosis, making them more predictable and reliable. Considering the future of digital pathology, it is essential for a CAD system to produce effective and accurate clinical data. To this effect, there remain many hurdles, including standardization as well as more research into seeking clinical evidences from "computer-friendly" objective measurements of histological images. Currently the most commonly used staining method is H&E (Hematoxylin and Eosin), but it is extremely difficult to standardize the H&E staining process. Current pathology criteria, category, definitions, and thresholds are all on based pathologists subjective observations. Digital pathology is an emerging field and researchers should bear responsibility not only for developing new algorithms, but also for understanding the meaning of measured quantitative data.

  13. Dawn of ocular gene therapy: implications for molecular diagnosis in retinal disease

    Science.gov (United States)

    Jacques, ZANEVELD; Feng, WANG; Xia, WANG; Rui, CHEN

    2013-01-01

    Personalized medicine aims to utilize genomic information about patients to tailor treatment. Gene replacement therapy for rare genetic disorders is perhaps the most extreme form of personalized medicine, in that the patients’ genome wholly determines their treatment regimen. Gene therapy for retinal disorders is poised to become a clinical reality. The eye is an optimal site for gene therapy due to the relative ease of precise vector delivery, immune system isolation, and availability for monitoring of any potential damage or side effects. Due to these advantages, clinical trials for gene therapy of retinal diseases are currently underway. A necessary precursor to such gene therapies is accurate molecular diagnosis of the mutation(s) underlying disease. In this review, we discuss the application of Next Generation Sequencing (NGS) to obtain such a diagnosis and identify disease causing genes, using retinal disorders as a case study. After reviewing ocular gene therapy, we discuss the application of NGS to the identification of novel Mendelian disease genes. We then compare current, array based mutation detection methods against next NGS-based methods in three retinal diseases: Leber’s Congenital Amaurosis, Retinitis Pigmentosa, and Stargardt’s disease. We conclude that next-generation sequencing based diagnosis offers several advantages over array based methods, including a higher rate of successful diagnosis and the ability to more deeply and efficiently assay a broad spectrum of mutations. However, the relative difficulty of interpreting sequence results and the development of standardized, reliable bioinformatic tools remain outstanding concerns. In this review, recent advances NGS based molecular diagnoses are discussed, as well as their implications for the development of personalized medicine. PMID:23393028

  14. Acoustic resonance at the dawn of life: musical fundamentals of the psychoanalytic relationship.

    Science.gov (United States)

    Pickering, Judith

    2015-11-01

    This paper uses a case vignette to show how musical elements of speech are a crucial source of information regarding the patient's emotional states and associated memory systems that are activated at a given moment in the analytic field. There are specific psychoacoustic markers associated with different memory systems which indicate whether a patient is immersed in a state of creative intersubjective relatedness related to autobiographical memory, or has been triggered into a traumatic memory system. When a patient feels immersed in an atmosphere of intersubjective mutuality, dialogue features a rhythmical and tuneful form of speech featuring improvized reciprocal imitation, theme and variation. When the patient is catapulted into a traumatic memory system, speech becomes monotone and disjointed. Awareness of such acoustic features of the traumatic memory system helps to alert the analyst that such a shift has taken place informing appropriate responses and interventions. Communicative musicality (Malloch & Trevarthen 2009) originates in the earliest non-verbal vocal communication between infant and care-giver, states of primary intersubjectivity. Such musicality continues to be the primary vehicle for transmitting emotional meaning and for integrating right and left hemispheres. This enables communication that expresses emotional significance, personal value as well as conceptual reasoning. © 2015, The Society of Analytical Psychology.

  15. Los poetas de Taller quiebran albores / Poets of Taller Dawn Break

    OpenAIRE

    Juan Pascual Gay

    2016-01-01

    El alba es un motivo de la literatura mexicana particularmente del grupo de poetas que se denomina de Taller que ensayaron la tendencia neopopularista impulsada por los poetas españoles de la generación del 27. Este texto quiere dar cuenta de cómo el “alba” fue un término que los cohesionó como grupo desde 1931 hasta 1938, año en que sale de imprenta la revista Taller (1938-1941) de la que recibieron el nombre. Estas páginas atienden a los años (1931-1938) en que comienzan a relacionarse hast...

  16. Circadian entrainment by different daylengths : The roles of dawn and dusk

    NARCIS (Netherlands)

    Daan, S.; Comas, M.; Spoelstra, K.; Hut, R.; Beersma, D.

    2009-01-01

    In the early days of circadian rhythms research there were two competing views on entrainment by light: through parametric action on the velocity of the endogenous cycle (Aschoff) versus non-parametric discrete phase shifts elicited by the lights-on and –off transitions (Pittendrigh). Although the

  17. Star-Forming Galaxies at the Cosmic Dawn = Stervormende sterrenstelsels tijdens het kosmische ochtendgloren

    NARCIS (Netherlands)

    Smit, Renske

    2015-01-01

    The question of how the first stars formed and assembled into galaxies lies at the frontier of modern astrophysics. The study of these first sources of cosmic illumination was transformed by the installation of new instrumentation aboard the Hubble Space Telescope during one of the final Space Shutt

  18. Nietzsche’s New Dawn : Educating students to strive for better in a dynamic professional world

    NARCIS (Netherlands)

    H. Joosten (Henriëtta)

    2015-01-01

    markdownabstractAbstract Professional higher education is expected to educate large numbers of students to become innovative professionals within a time frame of three or four years. A mission impossible? Not necessarily, according to Henriëtta Joosten who is a philosopher as well as a teacher. S

  19. Editoral: Molecular epigenetics: dawn of a new era of biomedical research

    Institute of Scientific and Technical Information of China (English)

    XU RuiMing

    2009-01-01

    @@ At about the same time in 1940s when Erwin Schrǒdinger published his famous little book What Is Life, which sparked the birth of molecular biology, the term epigenetics was coined by the English biologist Conrad Waddington.The concept of epi-inheritance can be traced back to French naturalist Jean-Baptiste Lamarck's idea of "inheritance of acquired traits". Nevertheless, epigenetics as an experimental science owes much credit to Barbara McCiintock's pio-neering work on transposable elements in maize. In early 1950s, she put forward a theory that alteration in chromatin structure is responsible for the peculiar non-Mendelian rules of inheritance - a concept nowadays widely accepted as the comer stone of modem epigenetics.

  20. The Life Story of Hydrogen Peroxide III: Chirality and Physical Effects at the Dawn of Life

    Science.gov (United States)

    Ball, Rowena; Brindley, John

    2016-03-01

    It is a remarkable observed fact that all life on Earth is homochiral, its biology using exclusively the D-enantiomer of ribose, the sugar moiety of the ribonucleic acids, and the L-enantiomers of the chiral amino acids. Motivated by concurrent work that elaborates further the role of hydrogen peroxide in providing an oscillatory drive for the RNA world (Ball & Brindley 2015a, J. R. Soc. Interface 12, 20150366, and Ball & Brindley 2015b, this journal, in press), we reappraise the structure and physical properties of this small molecule within this context. Hydrogen peroxide is the smallest, simplest molecule to exist as a pair of non-superimposable mirror images, or enantiomers, a fact which leads us to develop the hypothesis that its enantiospecific interactions with ribonucleic acids led to enantioselective outcomes. We propose a mechanism by which these chiral interactions may have led to amplification of D-ribonucleic acids and extinction of L-ribonucleic acids.

  1. Lost Soul or New Dawn? Lifelong Learning Lessons and Prospects from East Asia

    Science.gov (United States)

    Duke, Chris

    2015-01-01

    Most learning takes place in communities, neighbourhoods and workplaces. Here practical solutions to big problems work or fall down. We may call this the iron law of social learning, recognised in "community development", "community capacity-building", "workplace", "work-based" and…

  2. Exploiting the compromised spindle assembly checkpoint function of tumor cells: dawn on the horizon?

    NARCIS (Netherlands)

    Schmidt, M.; Medema, R.H.

    2006-01-01

    Aneuploidy is a frequent property of cancer cells that arises as a consequence of chromosomal instability (CIN). A major safeguard mechanism protecting cells from CIN is the spindle assembly checkpoint. This checkpoint surveys proper attachment of chromosomes to the mitotic spindle and effectively s

  3. The dawn of chelonian research: turtles between comparative anatomy and embryology in the 19th century.

    Science.gov (United States)

    MacCord, Kate; Caniglia, Guido; Moustakas-Verho, Jacqueline E; Burke, Ann C

    2015-05-01

    Many evo-devo studies of the turtle's shell draw hypotheses and support from historical sources. The groundbreaking works of Cuvier, Geoffroy St. Hilaire, Carus, Rathke, Owen, and others are being revived in modern research, and their centuries-old understanding of the turtle's shell reconsidered. In the works of these eminent biologists of the 19th century, comparative anatomy and embryology of turtle morphology set the stage for future studies in developmental biology, histology, and paleontology. Given the impact that these works still make on modern research, it is important to develop a thorough appreciation of previous authors, regarding how they arrived at their conclusions (i.e., what counted as evidence?), whether there was debate amongst these authors about shell development (i.e., what counted as an adequate explanation?), and even why these men, some of the most powerful and influential thinkers and anatomists of their day, were concerned with turtles. By tracing and exposing the context and content of turtle shell studies in history, our aim is to inform modern debates about the evolution and development of the turtle's shell. © 2014 Wiley Periodicals, Inc.

  4. The ethics of natural environment at the dawn of a post-natural era

    OpenAIRE

    Petrović, Ružica

    2012-01-01

    This paper discusses the issue of the development of the relationship between nature and ethics in a world that exhibits the features of a post-natural epoch. The discussion includes the character of: pragmatic ethics, shaped by economic and material reasons, philosophical ethics, based on anthropological and axiological principles, and environmental ethics as the field of the value abstractions of the biosphere. The author traces the development of the relationship between man and nature, fr...

  5. The Darkest Hour Before Dawn: Contributions to Cosmic Reionisation from Dark Matter Annihilation and Decay

    CERN Document Server

    Liu, Hongwan; Zavala, Jesús

    2016-01-01

    Dark matter annihilation or decay could have a significant impact on the ionisation and thermal history of the universe. In this paper, we study the potential contribution of dark matter annihilation ($s$-wave- or $p$-wave-dominated) or decay to cosmic reionisation, via the production of electrons, positrons and photons. We map out the possible perturbations to the ionisation and thermal histories of the universe due to dark matter processes, over a broad range of velocity-averaged annihilation cross-sections/decay lifetimes and dark matter masses. We have employed recent numerical studies of the efficiency with which annihilation/decay products induce heating and ionization in the intergalactic medium, and in this work extended them down to a redshift of $1+z = 4$ for two different reionisation scenarios. We also improve on earlier studies by using the results of detailed structure formation models of dark matter haloes and subhaloes that are consistent with up-to-date $N$-body simulations, with estimates on...

  6. The owl of Minerva from dusk till dawn, or, two shades of gray

    Directory of Open Access Journals (Sweden)

    Dolar Mladen

    2015-01-01

    Full Text Available The paper takes as its starting point the figure of the owl as the emblem of philosophy, it looks at its history and takes up its most significant philosophical use, the notorious passage where Hegel uses the owl as the indication of philosophy’s necessary belatedness. This is the passage which is usually taken as the point of indictment of Hegel’s position and the role he ascribed to philosophy. Hegel’s adage ‘What is rational is actual, and what is actual is rational’ is scrutinized in its various aspects, particularly in view of its other version, ‘what is rational must happen’. The tension between the ‘is’ and the ‘ought’ is perhaps the clue to understanding this adage, where Hegel doesn’t opt for the one or the other, but aims at the paradoxical intersection of the two. Hegel’s adage is put in contrast with Marx’s Thesis Eleven. The paper considers the concepts of the rational, the actual, the belatedness/retroaction, the grayness and finally the owl (and the part that bestiary plays in philosophy, thus trying to circumscribe the task that should be assigned to philosophy.

  7. Lost Soul or New Dawn? Lifelong Learning Lessons and Prospects from East Asia

    Science.gov (United States)

    Duke, Chris

    2015-01-01

    Most learning takes place in communities, neighbourhoods and workplaces. Here practical solutions to big problems work or fall down. We may call this the iron law of social learning, recognised in "community development", "community capacity-building", "workplace", "work-based" and…

  8. Parsec-scale structure of quasars: dawn of the golden age?

    CERN Document Server

    Ojha, Roopesh

    2013-01-01

    Half a century after their discovery, the study of quasars remains one of the most fascinating intellectual challenges in astronomy. Quasars are laboratories for everything from relativity to magnetohydrodynamics and are perhaps the best available probes for cosmology. A tremendous amount has been learned about quasars and yet many of the most fundamental questions about their physics remain open. Parsec-scale observations have played an indispensable role in building up our current understanding of quasars; virtually everything we know about quasars depends on such observations. However, the finest hour for parsec scale observations may be just beginning. This is partly due to the development of highly reliable VLBI networks (which is continuing) but mostly due to the unprecedented availability of multiepoch, simultaneous, broadband observations that have long been the `holy grail' for quasar researchers.

  9. Patient and provider perceptions of care for diabetes: results of the cross-national DAWN Study

    DEFF Research Database (Denmark)

    Peyrol, Mark; Rubin, Richard R.; Lauritzen, Torsten

    2006-01-01

    Aims/hypothesis We assessed country-level and individual-level patterns in patient and provider perceptions of diabetes care. Methods The study used a cross-sectional design with face-to-face or telephone interviews of diabetic patients and healthcare providers in 13 countries from Asia, Australia......, Europe and North America. Participants were randomly selected adults with type 1 or type 2 diabetes (n=5,104), and randomly selected diabetes-care providers, including primary-care physicians (n=2,070), diabetes specialist physicians (n=635) and nurses (n=1,122). Multivariate analysis was used to examine...... the relationships between outcomes and both country and respondent characteristics, and the interaction between these two factors. Results Providers rated chronic-care systems and remuneration for chronic care as mediocre. Patients reported that ease of access to care was high, but not without financial barriers...

  10. Music Audiences 3.0: Concert-Goers’ Psychological Motivations at the Dawn of Virtual Reality

    Science.gov (United States)

    Charron, Jean-Philippe

    2017-01-01

    Reviewing consumers’ motivations to attend performances in a continuously evolving social and technological context is essential because live concerts generate an important and growing share of revenues for the music industry. Evolving fans’ preferences and technological innovations constantly alter the way music is distributed and consumed. In a marketing 3.0 era, what consumers do with music is becoming more significant than simply owning or listening to a song. These changes are not only blurring the lines between production and consumption (i.e., co-creation), but also distorting the concept of live attendance altogether. Although mediated performances typically lack presence and authenticity, recent advances in immersive technologies, such as spherical videos and virtual reality goggles, could represent a new form of experiencing live music. PMID:28588528

  11. Bothe's 1925 heuristic assumption in the dawn of quantum field theory

    Science.gov (United States)

    Fick, D.

    2013-01-01

    In an unpublished manuscript filed at the Archive of the Max-Planck Society in Berlin, Walther Bothe (1891-1957) put, with one heuristic assumption, the spontaneous and induced transitions of light quanta, on an equal footing, probably as early as 1925. In modern terms, he assumed that the probability for the creation of a light quantum in a phase space cell already containing s light quanta is proportional to s + 1 and not, as assumed at that time, proportional to s; that is proportional to the fraction of the total radiation density which belongs to s light quanta. For Bothe, the added +1 somehow replaced the spontaneous decay and allowed him to treat empty phase space cells in a black body as thermodynamically consistent. We describe in some detail Bothe's route to this heuristic trick. Finally we discuss why, both Bose's and Bothe's heuristic assumptions lead to an identical distribution law for light quanta in a black body and thus to Planck's law and Einstein's fluctuation formula.

  12. Clinical pharmacokinetics of nabumetone. The dawn of selective cyclo-oxygenase-2 inhibition?

    Science.gov (United States)

    Davies, N M

    1997-12-01

    Nabumetone is a nonsteroidal anti-inflammatory drug (NSAID) of the 2,6-disubstituted naphthyl-alkanone class. Nabumetone is metabolised to an active metabolite 6-methoxy-2-napthylacetic acid (6-MNA) which is a relatively selective cyclo-oxygenase-2 inhibitor that has anti-inflammatory and analgesic properties. Nabumetone and its metabolites bind extensively to plasma albumin. Nabumetone is eliminated following biotransformation to 6-MNA, which does not undergo enterohepatic circulation and the respective glucoroconjugated metabolites are excreted in urine. Substantial concentrations of 6-MNA are attained in synovial fluid, which is he proposed site of action in chronic inflammatory arthropathies. A smaller area under the plasma concentration-time curve (AUC) is evident at steady state as compared with a single dose; this is possibly due to an increase in the volume of distribution and saturation of protein binding. Relationships between 6-MNA concentrations and the therapeutic and toxicological effects have yet to be elucidated for this NSAID. Renal failure significantly reduces 6-MNA elimination but steady-state concentrations of 6-MNA are not increased, possibly because of nonlinear protein binding. Elderly patients with osteoarthritis demonstrate decreased elimination and increased plasma concentrations of nabumetone as compared with young healthy volunteers. Rheumatic disease activity also influences 6-MNA plasma concentrations, as patients with more active disease and lower serum albumin concentrations demonstrate a lower area under the plasma concentration versus time curve. A reduced bioavailability of 6-MNA in patients with severe hepatic impairment is also evident. Dosage adjustment may be required in the elderly, patients with active rheumatic disease and those with hepatic impairment, but not in patients with mild-to-moderate renal failure.

  13. DAWN (Design Assistant Workstation) for advanced physical-chemical life support systems

    Science.gov (United States)

    Rudokas, Mary R.; Cantwell, Elizabeth R.; Robinson, Peter I.; Shenk, Timothy W.

    1989-01-01

    This paper reports the results of a project supported by the National Aeronautics and Space Administration, Office of Aeronautics and Space Technology (NASA-OAST) under the Advanced Life Support Development Program. It is an initial attempt to integrate artificial intelligence techniques (via expert systems) with conventional quantitative modeling tools for advanced physical-chemical life support systems. The addition of artificial intelligence techniques will assist the designer in the definition and simulation of loosely/well-defined life support processes/problems as well as assist in the capture of design knowledge, both quantitative and qualitative. Expert system and conventional modeling tools are integrated to provide a design workstation that assists the engineer/scientist in creating, evaluating, documenting and optimizing physical-chemical life support systems for short-term and extended duration missions.

  14. Ten Propositions Regarding Space Power: The Dawn of a Space Force

    Science.gov (United States)

    2006-01-01

    The answer is yes. Space Power: What fundamenta strengths best characterize Historical Background the potentia of military space power? What are space...p1yiasenhrwlrfgh’Ie itiphysical strength , or will to fight."’ The United The key for space power to support all levels States is more space dependent than any...aviatwon will beUSFre c a a xdiarj and the equite US Space Force: amount omo , a compared with the other No Longer a Question e wben ect to theof a deci i0

  15. Educational Reconstruction "By the Dawn's Early Light": Violent Political Conflict and American Overseas Education Reform

    Science.gov (United States)

    Sobe, Noah W.

    2009-01-01

    Using a historical approach, Sobe examines the myths and ideals that have underlain U.S. educational initiatives in postconflict nations abroad. Building on its tradition of modern schooling designed to advance civic and social order, America has sought to extend its political and cultural values overseas through educational reforms in…

  16. Causality at the dawn of the 'omics' era in medicine and in nephrology.

    Science.gov (United States)

    Zoccali, Carmine; Brancaccio, Diego; Nathan, Marco J

    2016-09-01

    Causality is a core concept in medicine. The quantitative determinacy characterizing today's biomedical science is unprecedented. The assessment of causal relations in human diseases is evolving, and it is therefore fundamental to keep up with the steady pace of theoretical and technological advancements. The exact specification of all causes of pathologies at the individual level, precision medicine, is expected to allow the complete eradication of disease. In this article, we discuss the various conceptualizations of causation that are at play in the context of randomized clinical trials and observational studies. Genomics, proteomics, metabolomics and epigenetics can now produce the precise knowledge we need for 21st century medicine. New conceptions of causality are needed to form the basis of the new precision medicine.

  17. The Neoclassical Advent: American Economics at the Dawn of the 20th Century

    OpenAIRE

    Joseph Persky

    2000-01-01

    For the U.S. economy, the last quarter of the 19th century brought the closing of the Western frontier, agricultural hardship in the South, the rise of large corporations and trusts, and the emergence of a serious labor movement. The fledgling American economics profession struggled to document and prescribe for the confounding mix of industrialization, urbanization, and rural crisis. In 1900, the relatively small community of serious economic researchers focused on applied issues in public p...

  18. False Dawns, Bleak Sunset: The Coalition Government's Policies on Career Guidance

    Science.gov (United States)

    Watts, A. G.

    2013-01-01

    The Coalition Government's policies on career guidance are analysed. Its rhetorical concern for career guidance provision is based largely on its support for social mobility, and its recognition of the role of career guidance in moving towards a demand-led skills system. Initial policy statements affirmed its intention to establish an all-age…

  19. The rise of homosexuality and the dawn of communism in Hong Kong film: 1993-1998.

    Science.gov (United States)

    Grossman, A

    2000-01-01

    I have designed this essay as a general overview of the self-evident trend towards queer subject matter in the past decade in Hong Kong film, a trend that not only coincides historically with the 1997 handover to the Mainland but also frequently comes equipped with parent-child relationships that can be read as allegories for the colony's future as the "child" to its mother country. Queerness in HK films has both alternated between and combined indigenous forms of queerness and the imported Western variety; by charting courses through internationalized concepts of homosexuality, HK films have posited their queerness not only as an existential allegory of (post)colonialism but also as a claim (or hope) for a utopian sexuality cum utopian international politics.

  20. The New Dawn of Virtual Reality in Health Care: Medical Simulation and Experiential Interface.

    Science.gov (United States)

    Riva, Giuseppe; Wiederhold, Brenda K

    2015-01-01

    The 90s and 00s saw great hopes that virtual reality was poised to sweep health care and change everything. But it didn't. Though researchers could immerse themselves in more complex virtual environments, the chasm between that digital experience and the complexity of real life - using a VR system in an hospital without a dedicated technician was a real challenge - just was too great. Now the situation is changing quickly. The rise of Oculus Rift and the shift of virtual reality from PC to mobile phones thanks to both the Oculus designed Gear VR headsets for Samsung phones and the Google Cardboard project are going to transform health care tools and experiences.

  1. Therapeutic plasma exchange-A new dawn in the treatment of pemphigus vulgaris

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar

    2015-01-01

    Full Text Available Pemphigus vulgaris is an autoimmune disorder that involves intraepithelial blistering and sores of skin and mucous membrane. It generally correlates with the levels of circulating autoantibodies; their removal seems a reasonable therapeutic approach. Therapeutic plasma exchange is hypothesized to remove pathogenic autoantibodies and has been used in refractory or severe cases. It may be considered for rapid control of severe or recalcitrant pemphigus vulgaris and should be combined with use of concomitant immuno-suppressive.

  2. From the Dawn of Nuclear Physics to the First Atomic Bombs

    Science.gov (United States)

    Woolbright, Stephen; Schumacher, Jacob; Michonova-Alexova, Ekaterina

    2014-03-01

    This work gives a fresh look at the major discoveries leading to nuclear fission within the historical perspective. The focus is on the main contributors to the discoveries in nuclear physics, leading to the idea of fission and its application to the creation of the atomic bombs used at the end of the World War II. The present work is a more complete review on the history of the nuclear physics discoveries and their application to the atomic bomb. In addition to the traditional approach to the topic, focusing mainly on the fundamental physics discoveries in Europe and on the Manhattan Project in the United States, the nuclear research in Japan is also emphasized. Along with that, a review of the existing credible scholar publications, providing evidence for possible atomic bomb research in Japan, is provided. Proper credit is given to the women physicists, whose contributions had not always been recognized. Considering the historical and political situation at the time of the scientific discoveries, thought-provoking questions about decision-making, morality, and responsibility are also addressed. The work refers to the contributions of over 20 Nobel Prize winners. EM-A is grateful to Prof. Walter Grunden and to Prof. Emeritus Shadahiko Kano, Prof. Emeritus Monitori Hoshi for sharing their own notes, documents, and references, and to CCCU for sponsoring her participation in the 2013 Nuclear Weapons Seminar in Japan.

  3. SPIRAL2 at GANIL: At the Dawn of a New Era

    Science.gov (United States)

    Gales, S.

    2010-04-01

    The exploration of unknown region of the nuclear mass chart, in particular, the neutron rich side, raised new and challenging physics issues in the understanding of nuclei far from stability. The physics of weakly bound systems, the appearance of shell quenching, the interface with astrophysical problems prompted the study of new generation of "Rad ioactive Beam Facilities" with high luminosity and the development of associated new experimental tools. GANIL presently offers unique opportunities in nuclear physics and many other fields. With the construction of SPIRAL2 over the next few years, GANIL is in a good position to retain its world-leading capability even though it faces strong competition from new and upgraded ISOL and fragmentation facilities. As selected by the ESFRI committee, the next generation of ISOL facility in Europe is represented by the SPIRAL2 project to be built at GANIL (Caen, France). SPIRAL2 is based on a high power, CW, superconducting LINAC, delivering 5 mA of deuteron beams at 40 MeV (200 KW) directed on a C converter+ Uranium target and producing therefore more 1013 fissions/s. The expected radioactive beams intensities in the mass range from A = 60 to A = 140, will surpass by two order of magnitude any existing facilities in the world. These unstable atoms will be available at energies between few KeV/n to 15 MeV/n. The same driver will accelerate high intensity (100* A to 1 mA), heavier ions (Ar up to Xe) at maximum energy of 14 MeV/n. In applied areas SPIRAL2 is considered as a powerful variable energy neutron source. The Neutrons For Science collaboration (NFS) is proposing a physics program on fission induced by fast neutrons as well as fusion studies on materials. Under the 7FP program of European Union called*Preparatory phase*, the SPIRAL2 project has been granted a budget of about 4 M€ to build up an international consortium around this new venture. Regarding the future physics program a call for Letter of intents has been launched in Oct 2006 and 8 large International collaborations has been built up around new instruments for SPIRAL2. The status of the construction of SPIRAL2 accelerator and technical R&D programs for physics instrumentation (detectors, spectrometers) in collaboration with EU and International partners will be presented.

  4. 麦德林城的新曙光%A new dawn for Medellin

    Institute of Scientific and Technical Information of China (English)

    张媛媛

    2011-01-01

    城市世界:麦德林拥有早期的工业化、交通运输网络和教育中心,直以来都是一座一线城市.麦德林还积极参与了“百城行动”(100 Cities Initiative).麦德林作为21 世纪全球的领跑者,有什么突出之处呢?萨拉萨尔:麦德林在本世纪一直在努力改善教育和知识的民主化,这是保证社会公平和竞争的一项长期政策.随之而来的是一个更具包容性的人类重新排序和工人阶级街区的转型,通过创造一个更有意义的社区结构来促进发展.反过来,又促使人们有了自豪感和认同感.所有这些策略都是一种方法的一部分,就是为了用一项更加平等的社会政策创造一个更具包容性的社会.

  5. Circadian timed wakefulness at dawn opposes compensatory sleep responses after sleep deprivation in Octodon degus

    NARCIS (Netherlands)

    Kas, M J; Edgar, D M

    1999-01-01

    The circadian timing system in mammals is thought to promote wakefulness and oppose sleep drive that accumulates across the activity phase in diurnal and nocturnal species. Whether the circadian system actively opposes compensatory sleep responses in mammals with episodes of alertness consolidated a

  6. Pulmonary tuberculosis in Romania at the dawn of the millennium--a major public health issue.

    Science.gov (United States)

    Marica, C

    2009-01-01

    TB incidence in our country is still quite high compared to the average of the European Union countries (1st place among EU countries and 3rd place among WHO European Region countries), which means that a national coordinated response against this disease needs to become the priority of the current health care policy. The multi-factorial conditioning, which includes the social and economic dimensions of TB spreading, requires a multi-disciplinary and inter-sectorial approach to this pathology, going beyond healthcare services. The National Tuberculosis Control Strategy is a part of Romania's Country Strategy based on the guidelines set out in WHO's 2006-2015 Global Plan to Stop Tuberculosis (MDGs 2015) and it provides the necessary framework for refining and harmonizing the national legislation and regulations with the European laws after Romania's integration in the EU.

  7. [Slaves and citizens on Ilha Grande: the dawning of the Republic came slowly].

    Science.gov (United States)

    Schnoor, Eduardo Cavalcanti

    2012-12-01

    The article introduces Ilha Grande, a district in the municipality of Angra dos Reis, and describes its role within the subsistence market economy and the memory of slavery as found in the Angra dos Reis Civil Records. According to the Almanaque Laemmert, this district had the largest number of slaves in the municipality as of the 1870s. Most owners had few slaves, and the majority of landholdings were small. The Angra dos Reis Civil Records did not forget slavery after May 1888. A number of birth and death notifications describe the persons in question as former slaves. Even in the twentieth century, clerks continued to describe various republican citizens as ex-slaves.

  8. Radiation Backgrounds at Cosmic Dawn: X-Rays from Compact Binaries

    CERN Document Server

    Madau, Piero

    2016-01-01

    We compute the expected X-ray diffuse background and radiative feedback on the intergalactic medium (IGM) from X-ray binaries prior and during the epoch of reionization. The cosmic evolution of compact binaries is followed using a population synthesis technique that treats separately neutron stars and black hole binaries in different spectral states and is calibrated to reproduce the observed X-ray properties of galaxies at z6. Radiative transfer effects modulate the background spectrum, which shows a characteristic peak between 1 and 2 keV. While the filtering of X-ray radiation through the IGM slightly increases the mean excess energy per photoionization, it also weakens the radiation intensity below 1 keV, lowering the mean photoionization and heating rates. Numerical integration of the rate and energy equations shows that the contribution of X-ray binaries to the ionization of the bulk IGM is negligible, with the electron fraction never exceeding 1%. Direct HeI photoionizations are the main source of IGM ...

  9. NCBI nr-aa BLAST: CBRC-HSAP-15-0019 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-HSAP-15-0019 ref|NP_001028103.1| cholinergic receptor, muscarinic 5 [Macaca mu...latta] sp|P56490|ACM5_MACMU Muscarinic acetylcholine receptor M5 gb|AAB95159.1| muscarinic receptor [Macaca mulatta] NP_001028103.1 0.0 95% ...

  10. Perceived Discrimination and Women's Psychological Distress: The Roles of Collective and Personal Self-Esteem

    Science.gov (United States)

    Fischer, Ann R.; Holz, Kenna Bolton

    2007-01-01

    In the spirit of counseling psychology's social justice mission (e.g., L. A. Goodman, B. Liang, J. E. Helms, R. E. Latta, E. Sparks, & S. R. Weintraub, 2004), the authors examined perceptions of discrimination against women as related to women's views of the group women, their views of themselves as individuals, and their psychological…

  11. NCBI nr-aa BLAST: CBRC-FCAT-01-0943 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-FCAT-01-0943 ref|NP_001028103.1| cholinergic receptor, muscarinic 5 [Macaca mu...latta] sp|P56490|ACM5_MACMU Muscarinic acetylcholine receptor M5 gb|AAB95159.1| muscarinic receptor [Macaca mulatta] NP_001028103.1 1e-53 92% ...

  12. NCBI nr-aa BLAST: CBRC-DRER-17-0002 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-17-0002 ref|NP_001028103.1| cholinergic receptor, muscarinic 5 [Macaca mu...latta] sp|P56490|ACM5_MACMU Muscarinic acetylcholine receptor M5 gb|AAB95159.1| muscarinic receptor [Macaca mulatta] NP_001028103.1 1e-166 60% ...

  13. NCBI nr-aa BLAST: CBRC-DNOV-01-2458 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DNOV-01-2458 ref|NP_001028103.1| cholinergic receptor, muscarinic 5 [Macaca mu...latta] sp|P56490|ACM5_MACMU Muscarinic acetylcholine receptor M5 gb|AAB95159.1| muscarinic receptor [Macaca mulatta] NP_001028103.1 0.0 90% ...

  14. NCBI nr-aa BLAST: CBRC-MMUS-02-0383 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-MMUS-02-0383 ref|NP_001028103.1| cholinergic receptor, muscarinic 5 [Macaca mu...latta] sp|P56490|ACM5_MACMU Muscarinic acetylcholine receptor M5 gb|AAB95159.1| muscarinic receptor [Macaca mulatta] NP_001028103.1 0.0 87% ...

  15. NCBI nr-aa BLAST: CBRC-DNOV-01-1759 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DNOV-01-1759 ref|NP_001028103.1| cholinergic receptor, muscarinic 5 [Macaca mu...latta] sp|P56490|ACM5_MACMU Muscarinic acetylcholine receptor M5 gb|AAB95159.1| muscarinic receptor [Macaca mulatta] NP_001028103.1 5e-68 92% ...

  16. NCBI nr-aa BLAST: CBRC-EEUR-01-0450 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-EEUR-01-0450 ref|NP_001028103.1| cholinergic receptor, muscarinic 5 [Macaca mu...latta] sp|P56490|ACM5_MACMU Muscarinic acetylcholine receptor M5 gb|AAB95159.1| muscarinic receptor [Macaca mulatta] NP_001028103.1 1e-117 86% ...

  17. NCBI nr-aa BLAST: CBRC-SARA-01-1348 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-SARA-01-1348 ref|NP_001028103.1| cholinergic receptor, muscarinic 5 [Macaca mu...latta] sp|P56490|ACM5_MACMU Muscarinic acetylcholine receptor M5 gb|AAB95159.1| muscarinic receptor [Macaca mulatta] NP_001028103.1 0.0 88% ...

  18. NCBI nr-aa BLAST: CBRC-CJAC-01-0745 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CJAC-01-0745 ref|NP_001028103.1| cholinergic receptor, muscarinic 5 [Macaca mu...latta] sp|P56490|ACM5_MACMU Muscarinic acetylcholine receptor M5 gb|AAB95159.1| muscarinic receptor [Macaca mulatta] NP_001028103.1 0.0 93% ...

  19. NCBI nr-aa BLAST: CBRC-OGAR-01-1059 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OGAR-01-1059 ref|NP_001028103.1| cholinergic receptor, muscarinic 5 [Macaca mu...latta] sp|P56490|ACM5_MACMU Muscarinic acetylcholine receptor M5 gb|AAB95159.1| muscarinic receptor [Macaca mulatta] NP_001028103.1 0.0 90% ...

  20. Perceived Discrimination and Women's Psychological Distress: The Roles of Collective and Personal Self-Esteem

    Science.gov (United States)

    Fischer, Ann R.; Holz, Kenna Bolton

    2007-01-01

    In the spirit of counseling psychology's social justice mission (e.g., L. A. Goodman, B. Liang, J. E. Helms, R. E. Latta, E. Sparks, & S. R. Weintraub, 2004), the authors examined perceptions of discrimination against women as related to women's views of the group women, their views of themselves as individuals, and their psychological…

  1. Did the ancient crenarchaeal viruses from the dawn of life survive exceptionally well the eons of meteorite bombardment?

    Science.gov (United States)

    Jalasvuori, Matti; Bamford, Jaana K H

    2009-01-01

    The viruses of Crenarchaeota are unexpectedly diverse in their morphologies, and most have no, or few, genes related to bacterial, eukaryal, euryarchaeal, or other crenarchaeal viruses. Though several different virus morphotypes have been discovered in enrichment cultures of microbial communities collected from geothermally heated environments around the world, the origins of such differences are unknown. We present a model that combines consideration of Earth's geological history, the early emergence of hyperthermophiles, and the early formation of viruses from primordial genes with the intent to explain this vast diversity of crenarchaeal viruses. Several meteorite- or flood basalt-induced extinction events in the past resulted in a reduction in the numbers of cellular organisms. Acidophilic hyperthermophiles survived the global thermal rises and, therefore, still host a wide variety of ancient virus morphotypes. In contrast, other, more "recent" cellular lineages have lost the majority of their original viruses, as they have been separated geologically and genetically, and have gone through several near-extinction-level episodes of decimation. This view suggests that, among crenarchaeal viruses, the direct descendants of very early genetic elements are well preserved; thus, their examination would improve our understanding as to how life actually evolved from its origins to the complex cellular systems we see today. We also present a hypothesis that describes the role of viral armadas and extinctions during evolution, as extinctions may have episodically eliminated most of the abusive parasites.

  2. Climatic Crisis: Place, Taste and Race in Hardy Wilson’s 'Dawn of a New Civilization' (1929

    Directory of Open Access Journals (Sweden)

    Deborah van der Plaat

    2013-10-01

    Full Text Available In 1929, the Australian architect and author William Hardy Wilson (1881–1950 identified architectural practice within Australia as degenerate and in decline. He attributed this regression not to changing tastes or styles but to the increasing number of native-born architects and their long-term exposure to a subtropical or tropical climate. Wilson believed that Australia’s warmer climates negatively affected the nation’s future capacity for innovation and invention and the development of national style. Central to Wilson’s thesis was the proposition that climate was the primary determinant of artistic agency. The importance of this idea was twofold. First, it enabled Wilson to develop a critique of the White Australia policies which were introduced in 1901 and which grew in influence in the early decades of twentieth-century Australia. Second, it helped Wilson to locate Australian architectural practice within a global theory of civilisation. In documenting the crisis that Wilson saw within the architecture of Australia, the paper considers this aspect of his work in detail for the first time.

  3. False Dawn of a Solar Age: A History of Solar Heating and Power During the Energy Crisis, 1973-1986

    Science.gov (United States)

    Scavo, Jordan Michael

    The unfolding of the energy crisis in the early 1970s brought solar to the fore as a topic for national discussion. National dialogues about solar power and national energy policy were one way that Americans interpreted their present and envisioned their nation's future. Yet, policy makers and the general public considered alternative energies, including solar, largely based on the economic conditions of their eras, considerations that, at least until the Reagan era, often transcended political ideologies and parties. Energy prices and the emerging political expediency of replacing fossil fuels were the primary drivers in shaping federal energy policies and public interest during this era. Enthusiasm for solar power often corresponded to the market price of petroleum. By the late 1970s, a lot of people believed the same. Amid growing public enthusiasm, President Carter eventually came out strongly in favor of solar energy, mounting solar panels on the White House and unveiling a plan to procure 20% of the nation's energy from the sun by the year 2000. During the 1960s and 1970s, Americans changed their energy values in response to concerns over environmentalism and the antinuclear movement. Pollution, environmental disasters, and energy crises during the 1960s and 1970s brought terms like "clean energy" and "renewable energy" into the national lexicon, and solar often served as the most prominent symbol of those ideas. At the same time, advocates presented solar as a stark contrast to nuclear: solar energy made life on earth possible; nuclear energy made it perilous. Science fiction and futurism shaped the American popular imagination through its presentation of solar technology. Each genre suffused the other and ingrained in the American national consciousness a sense of grandiose wonderment about the potential for solar energy, a potential that often did not match the contemporary applications for solar technology. The emergence of solar industries alarmed oil corporations and utilities. Several of these companies embarked on a concerted public misinformation campaign designed to downplay the potential of solar energy, and these actions undermined the development of the nascent solar industries. Solar heating equipment relied on federal stimulus to compete in the market. Yet, federal support for research and development, commercialization, and market facilitation withered under the Reagan administration. Solar occupied a point of convergence for several of Reagan's targets: solar represented Carter, represented big government intervention in the market, and represented environmentalism. Reagan's administration reduced solar funding, redirected and reorganized solar agencies, and repressed solar information. By the early 1980s, Carter's 20% solar goal was dead, and, as a result, the nation's efforts toward developing solar energy were set back decades.

  4. Geologic Mapping of the Ac-H-6 Quadrangle of Ceres from Nasa's Dawn Mission: Compositional Changes

    Science.gov (United States)

    Krohn, Katrin; Jaumann, Ralf; Tosi, Federico; Nass, Andrea; Otto, Katharina A.; Schulzeck, Franziska; Stephan, Katrin; Wagner, Roland J.; Williams, David A.; Buczkowski, Debra L.; Mest, Scott C.; Scully, Jennifer E. C.; von der Gathen, Isabel; Kersten, Elke; Matz, Klaus-Dieter; Pieters, Carle M.; Preusker, Frank; Roatsch, Thomas; De Sanctis, Maria Cristina; Zambon, Francesca

    2016-04-01

    Cereś surface is affected by numerous impact craters and some of them show features such as channels or multiple flow events forming a smooth, less cratered surface, indicating possible post-impact resurfacing [1,2]. Flow features occur on several craters on Ceres such as Haulani, Ikapati, Occator, Jarimba and Kondos in combination with smooth crater floors [3,4], appearing as extended plains, ponded material, lobate flow fronts and in the case of Haulani lobate flows originating from the crest of the central ridge [3] partly overwhelming the mass wasting deposits from the rim. Haulanís crater flanks are also affected by multiple flow events radiating out from the crater and partly forming breakages. Flows occur as fine-grained lobes with well-defined margins and as smooth undifferentiated streaky flows covering the adjacent surface. Thus, adjacent craters are covered by flow material. Occator also exhibits multiple flows but in contrast to Haulani, the flows originating from the center overwhelm the mass wasting deposits from the rim [4]. The flows have a "bluish" signature in the FC color filters ratio. Channels occur at relatively fresh craters. They also show the "bluish" signature like the flows and plains. Only few channels occur at older "reddish" craters. They are relatively fresh incised into flow features or crater ejecta. Most are small, narrow and have lobated lobes with predominant distinctive flow margins. The widths vary between a few tens of meters to about 3 km. The channels are found on crater flanks as well as on the crater floors. The occurrence of flow features indicates viscous material on the surface. Those features could be formed by impact melt. However, impact melt is produced during the impact, assuming similar material properties as the ejecta it is expected to have nearly the same age as the impact itself, but the flows and plains are almost free of craters, thus, they seem to be much younger than the impact itself. In addition, the source of impact melt flows is diffusely distributed but many of the observed flows originate from district sources in the crater interior and the flows, however, are well defined. The compositional differences derived from the color ratio and possible time variable effects related to cryo-processes either volcanic or glacial [1,2]. Furthermore, the suggestion of an occurrence ice within the Cerean crust [5] as well as possible salts incorporated into a regolith layer [4,5,6] indicates similar geological processes as seen on other icy bodies. Some lobate flow-like deposits on Ganymede such as at Sippar Sulcus are suggested to be formed by volcanic eruptions creating a channel and flow, and cutting down into the surface forming a depression. Thus, an endogenic formation process cannot be excluded. References: [1] Jaumann R. et al. (2015) EPSC X, Abstract #2015-83. [2] Jaumann R. et al. (2015) AGU, Abstract #P42A-05. [3] Krohn K. et al. (2016) LPSC XLVII, this issue. [4] Jaumann R. et al. (2016) LPSC XLVII, this issue. [5] McCord T.B. and Sotin C. (2005) J. Geophys. Res., 110, E05009. [6] Castillo-Rogez J.C. and McCord T.B. (2010) Icarus 203, 443-459.

  5. Probing the Dawn of Galaxies at z~9-12: New Constraints from HUDF12/XDF and CANDELS Data

    CERN Document Server

    Oesch, P A; Illingworth, G D; Labbe, I; Franx, M; van Dokkum, P G; Trenti, M; Stiavelli, M; Gonzalez, V; Magee, D

    2013-01-01

    We present a comprehensive analysis of z>8 galaxies based on ultra-deep WFC3/IR data. We constrain the evolution of the UV luminosity function (LF) and luminosity densities from z~11 to z~8 by exploiting all the WFC3/IR data over the Hubble Ultra-Deep Field from the HUDF09 and the new HUDF12 program, in addition to the HUDF09 parallel field data, as well as wider area WFC3/IR imaging over GOODS-South. Galaxies are selected based on the Lyman Break Technique in three samples centered around z~9, z~10 and z~11, with seven z~9 galaxy candidates, and one each at z~10 and z~11. We confirm a new z~10 candidate (with z=9.8+-0.6) that was not convincingly identified in our first z~10 sample. The deeper data over the HUDF confirms all our previous z>~7.5 candidates as genuine high-redshift candidates, and extends our samples to higher redshift and fainter limits (H_160~29.8 mag). We perform one of the first estimates of the z~9 UV LF and improve our previous constraints at z~10. Extrapolating the lower redshift UV LF ...

  6. Alvorecer de uma nova ciência: a medicina tropicalista baiana The dawning of a new science

    Directory of Open Access Journals (Sweden)

    Pedro Motta de Barros

    1997-11-01

    Full Text Available No século XIX, o saber e o ensino médico e a assistência clínica, de caráter especulativo e elitista, entram em choque, no Brasil, com novas teorias da doença e do cuidado médico baseadas na parasitologia, bacteriologia e anatomopatologia e numa clínica experimental orientada para enfermidades tropicais dos pobres. O novo referencial teórico e social, que influi na política pública de saúde, entra em decadência quando é apropriado pela ideologia da inferioridade racial e cultural da população de origem africana. Duas novas disciplinas - antropologia física criminal e medicina legal - geram conhecimentos inéditos nos meios intelectuais e, ao mesmo tempo, são funcionais à ordem dominante, dando curso forçado a princípios e dispositivos de que a mesma elite usa para se perpetuar no poder. Essa construção híbrida é o legado de barbárie à civilização atual.Medicine in 19th-century Brazil was a scientific field where traditional knowledge, academic teaching, and clinical care found themselves clashing with new theories of illness and medical care underpinned by pioneer disciplines like parasitology, bacteriology, and anatomopatbology and an experimental clinical practice focused on tropical diseases which afflict the poor. This new set of theoretical and social references which affected public health-care policy saw its decadence when it was appropriated by an ideology that argued that the Afro-Brazilian population was racially and culturally inferior. Two new disciplines- criminal physical anthropology and legal medicine- contributed to the development of specialized knowledge within intellectual circles. At the same time, they were placed at the service of the ruling order, reinforcing principles and devices that the elite utilized to keep itself in power. This hybrid structure constitutes the legacy of barbarianism which is sundering today's civilization.

  7. Provisioning the Ritual Neolithic Site of Kfar HaHoresh, Israel at the Dawn of Animal Management

    Science.gov (United States)

    Goring-Morris, A. Nigel; Munro, Natalie D.

    2016-01-01

    It is widely agreed that a pivotal shift from wild animal hunting to herd animal management, at least of goats, began in the southern Levant by the Middle Pre-Pottery Neolithic B period (10,000–9,500 cal. BP) when evidence of ritual activities flourished in the region. As our knowledge of this critical change grows, sites that represent different functions and multiple time periods are needed to refine the timing, pace and character of changing human-animal relationships within the geographically variable southern Levant. In particular, we investigate how a ritual site was provisioned with animals at the time when herd management first began in the region. We utilize fauna from the 2010–2012 excavations at the mortuary site of Kfar HaHoresh—the longest continuous Pre-Pottery Neolithic B faunal sequence in the south Levantine Mediterranean Hills (Early–Late periods, 10,600–8,700 cal. BP). We investigate the trade-off between wild and domestic progenitor taxa and classic demographic indicators of management to detect changes in hunted animal selection and control over herd animal movement and reproduction. We find that ungulate selection at Kfar HaHoresh differs from neighboring sites, although changes in dietary breadth, herd demographics and body-size data fit the regional pattern of emerging management. Notably, wild ungulates including aurochs and gazelle are preferentially selected to provision Kfar HaHoresh in the PPNB, despite evidence that goat management was underway in the Mediterranean Hills. The preference for wild animals at this important site likely reflects their symbolic significance in ritual and mortuary practice. PMID:27902736

  8. Version 2000: the new beta-lactamases of Gram-negative bacteria at the dawn of the new millennium.

    Science.gov (United States)

    Thomson, K S; Smith Moland, E

    2000-08-01

    beta-lactamases of Gram-negative bacteria are evolving dynamically. New developments include the production of enzymes with novel substrate profiles, reduced susceptibility to beta-lactamase inhibitors, and the simultaneous production of multiple types of beta-lactamases. The changes represent evolutionary upgrades which provide modern pathogens with a greater potential to resist beta-lactam antibiotics and cause formidable therapeutic, infection control, and diagnostic challenges. This review is a clinically oriented outline of recent developments in the beta-lactamase production of Gram-negative bacteria.

  9. The Dawn And Inheritance of the Moral Criminology%道德犯罪学的启蒙和传承

    Institute of Scientific and Technical Information of China (English)

    封志晔

    2003-01-01

    加罗法罗的"自然犯罪观"是道德犯罪学的启蒙.他从基本道德出发构建犯罪概念、犯罪原因论和犯罪对策论,对西方犯罪理论产生了重要影响.重新解读加罗法罗,对中国"以德治国,以法治国"有着重要的启示意义.

  10. Du crépuscule à l’aube From dusk to dawn: Finding compromises in nurses’ night shifts

    Directory of Open Access Journals (Sweden)

    Cathy Toupin

    2009-07-01

    Full Text Available Parmi les caractéristiques du travail susceptibles d’influencer les processus de régulation en lien avec l’âge et l’expérience, les questions d’horaires sont peu abordées. Nous pensons cependant qu’une composante importante, dans la construction et la mobilisation de l’expérience, s’élabore en relation avec le type d’horaire. L’objectif de cette recherche est de caractériser, au travers d’une étude menée auprès d’infirmières d’un service de pneumologie français, les stratégies mises en œuvre par les personnels de nuit ; et de proposer une approche dynamique de l’articulation entre horaires et activité de travail, en repérant comment cette articulation s’est forgée au cours du parcours professionnel avec l’expérience, comment ce processus est « lisible » dans l’activité d’aujourd’hui. Les infirmières se « prescrivent » des buts d’actions, élaborent une acception nocturne de leur tâche compte tenu de l’état des patients (par exemple, but visant à respecter le sommeil des patients, à apaiser leurs angoisses, de l’environnement désert des services (par exemple, but visant à consolider sa connaissance de l’état des patients, et de leur état psychophysiologique (par exemple, but visant à maintenir la vigilance. L’expérience du travail de nuit va leur permettre, d’une part de reconnaître ces buts, et d’identifier les contradictions pouvant en émerger ; d’autre part de compenser les difficultés et perturbations provoquées par ces tensions, via l’élaboration de compromis.Among the work characteristics that are likely to influence age and experience related adjustment processes, the issue of work schedules remains largely unexplored. We believe however that work schedules or shifts play an important part in building and mobilizing experience. This paper aims at characterizing the specific strategies implemented by night shift personnel based on a study conducted with nurses in a hospital department of pulmonary diseases. It also suggests a dynamic approach regarding the links between work shifts and the work activity, pointing out how such links evolve over the course of a career as a result of experience, and how such a process is “visible” in their activity at present. Nurses in the pulmonary disease department “assign” themselves goals; they devise a “night interpretation” of their task, taking into account the condition of their patients (goals aimed at protecting their sleep and calming their anxiety, the absence of health care staff resulting in a deserted environment (goals aimed at ensuring they are always well informed on the state of each patient, and their own psycho-physiological state (goal aimed at remaining alert. Their experience of night work allows them, on the one hand to recognize the aims of such actions, and identify the contradictions that may arise from them; and on the other hand to compensate for the difficulties and disturbances caused by such “tensions” by finding ways to compromise.

  11. Quantum-Dot Light-Emitting Diodes for Large-Area Displays: Towards the Dawn of Commercialization.

    Science.gov (United States)

    Dai, Xingliang; Deng, Yunzhou; Peng, Xiaogang; Jin, Yizheng

    2017-04-01

    Quantum dots are a unique class of emitters with size-tunable emission wavelengths, saturated emission colors, near-unity luminance efficiency, inherent photo- and thermal- stability and excellent solution processability. Quantum dots have been used as down-converters for back-lighting in liquid-crystal displays to improve color gamut, leading to the booming of quantum-dot televisions in consumer market. In the past few years, efficiency and lifetime of electroluminescence devices based on quantum dots achieved tremendous progress. These encouraging facts foreshadow the commercialization of quantum-dot light-emitting diodes (QLEDs), which promises an unprecedented generation of cost-effective, large-area, energy-saving, wide-color-gamut, ultra-thin and flexible displays. Here we provide a Progress Report, covering interdisciplinary aspects including material chemistry of quantum dots and charge-transporting layers, optimization and mechanism studies of prototype devices and processing techniques to produce large-area and high-resolution red-green-blue pixel arrays. We also identify a few key challenges facing the development of active-matrix QLED displays. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Dawning dependence: Processes underlying smoking cessation in adolescence = Opkomende afhankelijkheid: Onderliggende processen van stoppen met roken in de adolescentie

    NARCIS (Netherlands)

    Kleinjan, M.

    2009-01-01

    During adolescence young people are known to try out a range of risk behaviours, including smoking. Even though the detrimental health consequences of smoking are well known, the prevalence of smoking among Dutch adolescents remains high. Until today, efforts to control adolescent smoking are mainly

  13. Efficacy and Safety of Sofosbuvir in the Treatment of Chronic Hepatitis C: The Dawn of a New Era.

    Science.gov (United States)

    Gentile, Ivan; Borgia, Federico; Zappulo, Emanuela; Buonomo, Antonio Riccardo; Spera, Anna Maria; Castaldo, Giuseppe; Borgia, Guglielmo

    2014-01-01

    Hepatitis C virus (HCV) infection affects about 160 million people worldwide. Currently, it is treated with pegylated interferon (PEG-IFN) plus ribavirin, associated with a protease inhibitor in case of genotype 1 infection. However, this combination is often contraindicated and associated with severe adverse events that limit its use in clinical practice. Several drugs active against HCV are in an advanced phase of clinical development. Among these, sofosbuvir appears one of the most promising candidates for use in association with both interferon and interferon-free combinations. This review focuses on the results of several sofosbuvir-based phase III trials that have very recently become available. These studies show that the co-administration of sofosbuvir, PEG-IFN and ribavirin for 12 weeks is associated with a very high rate of sustained virological responses (SVR) (about 90%) in naïve patients with genotypes 1, 4, 5 or 6. In patients infected by genotypes 2 or 3, the interferon-free combination of sofosbuvir and ribavirin administered for 12 weeks is associated with a SVR of 97% and 56% in naïve patients, and of 86% and 30% in experienced genotype 2 or 3 patients, respectively. The safety and tolerability profile is optimal and consistent with that of the other drugs administered in the combination (ribavirin and/or interferon). In conclusion, the recent phase III trials of sofosbuvir confirm the excellent results of phase II studies in terms of efficacy and safety and will probably open a new era in the fight against HCV.

  14. The Dawn of the Red: Star formation histories of group galaxies over the past 5 billion years

    CERN Document Server

    McGee, Sean L; Wilman, David J; Bower, Richard G; Mulchaey, John S; Parker, Laura C; Oemler, Augustus

    2010-01-01

    We examine the star formation properties of group and field galaxies in two surveys, the Sloan Digital Sky Survey (SDSS; at z ~ 0.08) and the Group Environment and Evolution Collaboration (GEEC; at z ~ 0.4). Using UV imaging from the GALEX space telescope, along with optical and, for GEEC, near infrared photometry, we compare the observed spectral energy distributions to large suites of stellar population synthesis models. This allows us to accurately determine star formation rates and stellar masses. We find that star forming galaxies of all environments undergo a systematic lowering of their star formation rate between z=0.4 and z=0.08 regardless of mass. Nonetheless, the fraction of passive galaxies is higher in groups than the field at both redshifts. Moreover, the difference between the group and field grows with time and is mass-dependent, in the sense the the difference is larger at low masses. However, the star formation properties of star forming galaxies, as measured by their average specific star f...

  15. Portraying Science as Humanism--A Historical Case Study of Cultural Boundary Work from the Dawn of the "Atomic Age"

    Science.gov (United States)

    Lynning, Kristine Hays

    2007-01-01

    In the late 1950s, when a new curriculum for the Danish upper secondary school was under construction, the reform debates on science were strongly concerned with the scarcity of technologically and scientifically educated labour, and thus relations between science, technology and welfare were stressed. Simultaneously however, the relationship…

  16. Socio-demographic and psychological determinants of political (intolerance: Hungary at the dawn of the 21st century

    Directory of Open Access Journals (Sweden)

    Todosijević Bojan

    2015-01-01

    Full Text Available The paper presents a socio-psychological causal model of political intolerance in Hungary, on the basis of a national random sample survey data (N=1002. The research improves on the existing models in two directions: by constructing a more complete model through inclusion of a wider set of potentially relevant variables, and by using more reliable operationalisation of the examined concepts. The results indicate that political tolerance in Hungary, as defined by the 'content free' method, can only weakly be explained by an extensive set of socio-demographic, psychological and political variables. Contrary to the commonly reported results, socio-economic status variables displayed a rather complex and often direct pattern of influence on political tolerance, while psychological variables proved to be relatively weak predictors. In Hungary, psychological factors have a relatively strong role in determining the choice of target groups and socio-demographic variables have a stronger role in determining the degree of intolerance. In general, the findings suggest that intolerance of different groups is not uniformly related to social and psychological explanatory variables.

  17. The comings and goings of MHC class I molecules herald a new dawn in cross-presentation.

    Science.gov (United States)

    Blander, J Magarian

    2016-07-01

    MHC class I (MHC-I) molecules are the centerpieces of cross-presentation. They are loaded with peptides derived from exogenous sources and displayed on the plasma membrane to communicate with CD8 T cells, relaying a message of tolerance or attack. The study of cross-presentation has been focused on the relative contributions of the vacuolar versus cytosolic pathways of antigen processing and the location where MHC-I molecules are loaded. While vacuolar processing generates peptides loaded onto vacuolar MHC-I molecules, how and where exogenous peptides generated by the proteasome and transported by TAP meet MHC-I molecules for loading has been a matter of debate. The source and trafficking of MHC-I molecules in dendritic cells have largely been ignored under the expectation that these molecules came from the Endoplasmic reticulum (ER) or the plasma membrane. New studies reveal a concentrated pool of MHC-I molecules in the endocytic recycling compartment (ERC). These pools are rapidly mobilized to phagosomes carrying microbial antigens, and in a signal-dependent manner under the control of Toll-like receptors. The phagosome becomes a dynamic hub receiving traffic from multiple sources, the ER-Golgi intermediate compartment for delivering the peptide-loading machinery and the ERC for deploying MHC-I molecules that alert CD8 T cells of infection.

  18. In vivo evidence for a controlled offset of melatonin synthesis at dawn by the suprachiasmatic nucleus in the rat.

    NARCIS (Netherlands)

    Perreau-Lenz, S; Kalsbeek, A.; Vliet, J. van der; Pevet, P.; Buijs, R.M.

    2005-01-01

    The daily rhythm of melatonin synthesis in the rat pineal gland is controlled by the central biological clock, located in the suprachiasmatic nucleus (SCN), via a multi-synaptic pathway involving, successively, neurones of the paraventricular nucleus of the hypothalamus (PVN), sympathetic preganglio

  19. "Dawn of a New Day for Europe? The Merkel-Sarkozy Promise to End the Eurozone Crisis"

    OpenAIRE

    C. J. Polychroniou

    2011-01-01

    Failure on the part of EU leaders to address the eurozone crisis is in large part due to the fact that Germany and France are at opposite poles—politically, economically, and culturally. In this context, the announcement by Germany's Angela Merkel and French President Nicolas Sarkozy that they've agreed to a comprehensive package of proposals to solve the eurozone debt crisis is definitely a positive development. It indicates that they have set aside their disagreements—surely no small feat, ...

  20. New dawn for electricity? EU policy and the changing decision space for electricity production in Sweden; a CANES Working Paper

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Maans

    2009-11-15

    The European Union has taken an increasing interest in governing the energy sector in its Member States. However, EU still competes with national-level policies as well as sectoral organizational fields with sticky institutions, norms and knowledge. Therefore, despite its high ambitions in the energy field, for instance in the promotion of renewables and market reform, it is not clear whether the EU really exerts a strong influence, and if there is such an influence, the processes of influence and 'filtering' through to national political and industrial structures are not well understood. This paper examines a recent strategic change amongst national actors in Sweden in the energy sector; the decision space for investment in electricity. It examines the influence of European policy change, national political and policy change and organizational field-level developments on this decision space. It finds that European policy has rarely been very coercive, partly because Sweden has been a forerunner both on electricity market reform and renewable energy promotion, but that its influence is notable both directly through its emissions trading directive and more indirectly through signalling its intentions and long-term goals. Still, it appears that domestic developments, both cognitive and normative structures in the organizational field, and national policy change remain more instrumental determinants of the changed decision space. (Author)

  1. Space Educational Opportunities and Outreach Activities at the Dawn of the 21st Century. A European Students Perspective

    Science.gov (United States)

    Ferretti, S.; Robinson, D.; Manfletti, C.; Amadori, K.; Boccalatte, A.; Alessandrini, M.; Bedogna, P.; Corradi, P.; Marcuccio, M.

    2002-01-01

    Taking part in space activities and participating in the development and growth of space project has now become an undeniable reality. Thanks to academic institutions and outreach activities space enthusiasts can engage in numerous and diverse yet unique opportunities. The ESA Outreach Office sees students of every background taking part in its activities. This unique mixture of students of diverse nationalities enthusiastically co-operating ensures the program's interdisciplinarity. The added value of such an environment to the programs is significant and must not be forgotten. The friendship that blossom, and lose with which cultural and language barriers are overcome during the time spent working on the projects offered to university student and young professionals are invaluable. The purpose of this abstract is to give our perspective to the space community and to the general public on the importance of developing a space culture. The academic value of the space research projects mainly in which the authors have participated, the importance of such projects for the future of European relations and personal and social development through experience of international teams are topics that will be addressed. The activities discussed are : Attending sessions of congresses around the world, making contacts of major companies and players in the space sector, dealing of topics such as space engineering, policy and law, life sciences, business and finance, satellite applications, the exhilaration of floating in zero-g, the interdisciplinary, international and intercultural approach, the chance of quickly learning about many new concepts are just some of the marvellous experiences and opportunities that these programs offer. Reaching out to the general public is the second purpose of these unique activities.Images, photos and reports can seep into every house thanks to the great instrument that is the media, thus informing almost everyone about the activities and projects growing in the space arena. Newspapers, magazines and scientific publications are extra ordinarily powerful tools that can spread space news. Internet gives everyone the possibility of accessing an immense range of information regarding space flights, space stations, discoveries and new and old projects. Public events and congresses are also effective in approaching the general public and increasing its involvement in the space world. These media contacts are encouraged by the ESA Outreach Office, Euravia association and ISU, and students involve the respective countries as much as possible. This paper aims to show how these media have been used and have lead to the creation of a strong network bringing European universities and organisations together. The experiences have been life changing for the authors. They have succeeded in bringing culturally different young scientists together from across Europe (East Europe and Russia) to strive for a common goal and to better understand space sciences and the next generation technology. It is these experiences that have allowed a deeper understanding of those interpersonal interactions occurring within diverse European teams. Young professionals will no longer work in a country alone but in an European arena and this change makes such understanding essential for the future of Space industry.

  2. Policies of inclusion: immigrants, disease, dependency, and American immigration policy at the dawn and dusk of the 20th century.

    Science.gov (United States)

    Fairchild, Amy L

    2004-04-01

    The racial politics of immigration have punctuated national discussions about immigration at different periods in US history, particularly when concerns about losing an American way of life or American population have coincided with concerns about infectious diseases. Nevertheless, the main theme running through American immigration policy is one of inclusion. The United States has historically been a nation reliant on immigrant labor and, accordingly, the most consequential public policies regarding immigration have responded to disease and its economic burdens by seeking to control the behavior of immigrants within our borders rather than excluding immigrants at our borders.

  3. Excavating abiotic stress-related gene resources of terrestrial macroscopic cyanobacteria for crop genetic engineering: dawn and challenge.

    Science.gov (United States)

    Ye, Shuifeng; Gao, Xiang

    2015-01-01

    Genetically engineered (GE) crops with resistance to environmental stresses are one of the most important solutions for future food security. Numerous genes associated to plant stress resistance have been identified and characterized. However, the current reality is that only a few transgenic crops expressing prokaryotic genes are successfully applied in field conditions. These few prokaryotic genes include Agrobacterium strain CP4 EPSPS gene, Bacillus thuringiensis Cry1Ab gene and a bacterial chaperonin gene. Thus, the excavation of potentially critical genes still remains an arduous task for crop engineering. Terrestrial macroscopic cyanobacteria, Nostoc commune and Nostoc flagelliforme, which exhibit extreme resistance to desiccation stress, may serve as new prokaryotic bioresources for excavating critical genes. Recently, their marker gene wspA was heterologously expressed in Arabidopsis plant and the transgenics exhibited more flourishing root systems than wild-type plants under osmotic stress condition. In addition, some new genes associated with drought response and adaptation in N. flagelliforme are being uncovered by our ongoing RNA-seq analysis. Although the relevant work about the terrestrial macroscopic cyanobacteria is still underway, we believe that the prospect of excavating their critical genes for application in GE crops is quite optimistic.

  4. Portraying Science as Humanism--A Historical Case Study of Cultural Boundary Work from the Dawn of the "Atomic Age"

    Science.gov (United States)

    Lynning, Kristine Hays

    2007-01-01

    In the late 1950s, when a new curriculum for the Danish upper secondary school was under construction, the reform debates on science were strongly concerned with the scarcity of technologically and scientifically educated labour, and thus relations between science, technology and welfare were stressed. Simultaneously however, the relationship…

  5. The Dawn of Criminal Law, Regulation of Punitive Power in the Sumerian, Akk adian and Semite Codes

    Directory of Open Access Journals (Sweden)

    Ramiro J. García Falconí

    2016-06-01

    Full Text Available General and special Law, the regulation of the punitive power appeared since the first codings known in the history of mankind, being clear their religious character, their sacrifice logic, and the violence element that permeate to it. This punitive matrix is found in both Sumerian and Akkadian Codes, as in the later Jewish legislation, in which violence and sacredness fuse. The Talion Law already makes its appearance, as well as the structures on which the Inquisitorial System will be later built, and some traits that survive until today.

  6. Silicon for prevention, cure and care: A technology toolbox of wearables at the dawn of a new health system

    NARCIS (Netherlands)

    Hoof, C. van; Brand, J. van den; Smet, J. de; Grieten, L.; De Francisco, R.

    2016-01-01

    Our increasing life expectancy also implies that many of us will be suffering from one or more chronic illnesses during a larger part of our lives. Medical-grade wearables have the grand promise and the largely untapped potential to become a cornerstone technology in the care cycle. For chronic pati

  7. Artificial night lighting rather than traffic noise affects the daily timing of dawn and dusk singing in common European songbirds

    NARCIS (Netherlands)

    Da Silva, Arnaud; Samplonius, Jelmer Menno; Schlicht, Emmi; Valcu, Mihai; Kempenaers, Bart

    2014-01-01

    It is well established that artificial night lighting can influence animal orientation, but there is less information about its effects on other behaviors. Previous work suggested that light pollution can affect both seasonal and daily patterns of behavior. The aim of our study was to investigate

  8. The theory of international relations at the dawn of the twentieth-first century: dialogue, dissidence, approaches

    Directory of Open Access Journals (Sweden)

    Mónica Salomón González

    2001-12-01

    Full Text Available The article considers three main trends in current theorizing on international relations. The first is the dialogue that has been going on among neoliberal (or institutionalist and neorealist authors for the last decade over possibilities for international cooperation. The second is the call for dissidence and/or restructuring of the discipline from “reflectivist” approaches: critical theory, postmodernisms, and feminisms. The third is the attempt to achieve a synthesis of the traditional and reflectivist approaches, an attempt made from both the standpoint of a new constructivist theory as well as from a classical point of view of international society.

  9. Twilight of dawn or of evening? A century of research methods in the Journal of Applied Psychology.

    Science.gov (United States)

    Cortina, Jose M; Aguinis, Herman; DeShon, Richard P

    2017-03-01

    We offer a critical review and synthesis of research methods in the first century of the Journal of Applied Psychology. We divide the chronology into 6 periods. The first emphasizes the first few issues of the journal, which, in many ways, set us on a methodological course that we sail to this day, and then takes us through the mid-1920s. The second is the period through World War II, in which we see the roots of modern methodological concepts and techniques, including a transition from a discovery orientation to a hypotheticodeductive model orientation. The third takes us through roughly 1970, a period in which many of our modern-day practices were formed, such as reliance on null hypothesis significance testing. The fourth, from 1970 through 1989, sees an emphasis on the development of measures of critical constructs. The fifth takes us into the present, which is marked by greater plurality regarding data-analytic approaches. Finally, we offer a glimpse of possible and, from our perspective, desirable futures regarding research methods. Specifically, we highlight the need to conduct replications; study the exceptional and not just the average; improve the quality of the review process, particularly regarding methodological issues; emphasize design and measurement issues; and build and test more specific theories. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  10. Long noncoding RNAs (LncRNAs) - The dawning of a new treatment for cardiac hypertrophy and heart failure.

    Science.gov (United States)

    Han, Dong; Gao, Quansheng; Cao, Feng

    2017-08-01

    Long noncoding RNAs (lncRNAs) represent a category of noncoding RNAs with the potential for genetic and epigenetic regulations. As important regulators of gene expression, increasing evidence has proven that lncRNAs play a significant regulatory role in various cardiovascular pathologies. In particular, lncRNAs have been proved to be participating in gene regulatory mechanisms involved in heart growth and development that can be exploited to repair the injured adult heart. Furthermore, lncRNAs have been revealed as possible therapeutic targets for heart failure with different causes and in different stages. In the journey from a healthy heart to heart failure, lncRNAs have been shown to participate in almost every landmark of heart failure pathogenesis including ischemic injury, cardiac hypertrophy, and cardiac fibrosis. Furthermore, the manipulation of lncRNAs palliates the progression of heart failure by attenuating ischemic heart injury, cardiac hypertrophy and cardiac fibrosis, as well as facilitating heart regeneration and therapeutic angiogenesis. This review will highlight recent updates regarding the involvement of lncRNAs in cardiac hypertrophy and heart failure and their potential as novel therapeutic targets. This article is part of a Special Issue entitled: Genetic and epigenetic control of heart failure - edited by Jun Ren & Megan Yingmei Zhang. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Sloan Digital Sky Survey Standard Star Catalog for Stripe 82: The Dawn of Industrial 1% Optical Photometry

    Science.gov (United States)

    2007-09-01

    Thiswidespread use of the ugriz photometric system motivates the construction of a large standard star catalog with 1% accuracy. As part of its im- aging...6 Department of Astronomy, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan. 7 Institute for Cosmic Ray...perpendicular to the blue part of the locus in the g r vs. u g plane; w, perpendicular to the blue part in the r i vs. g r plane; x, perpendicular to

  12. Dawning dependence: Processes underlying smoking cessation in adolescence = Opkomende afhankelijkheid: Onderliggende processen van stoppen met roken in de adolescentie

    NARCIS (Netherlands)

    Kleinjan, M.

    2009-01-01

    During adolescence young people are known to try out a range of risk behaviours, including smoking. Even though the detrimental health consequences of smoking are well known, the prevalence of smoking among Dutch adolescents remains high. Until today, efforts to control adolescent smoking are mainly

  13. A Visit to the Hmong of Asia: Globalization and Ethnicity at the Dawn of the 21st Century

    Directory of Open Access Journals (Sweden)

    Kou Yang

    2009-01-01

    Full Text Available This paper consists of observations made from my two and a half month visit to the Hmong in Thailand, Laos, Vietnam and China.1 As such, it contains two parts. The first part is my observation of the Hmong in Asia and their common issues. The second part is a photo essay of the visit to the Hmong in Asia, covering issues discussed in the paper. Although I did visit other subgroups of the Miao, such as the Hmu in Guizhou and Qo Xiong in Hunan, this paper covers only the Hmong, whom I hope will be better presented and discussed as a result of my work. Moreover, the Hmong live in all the above mentioned countries, whereas other sub-groups of the Miao live only in China. This paper highlights the socio-economic conditions and educational experiences of the Hmong in the above mentioned countries. It also covers my observations of Hmong civic engagement and other aspects of their social and political lives in the respective countries.

  14. PENGARUH PRODUCT PLACEMENT VOLVO DI DALAM FILM TWILIGHT SAGA: BREAKING DAWN PART 1 & PART 2 TERHADAP BRAND RECALL

    Directory of Open Access Journals (Sweden)

    Ghygha Yunus Widya Prasetya

    2013-07-01

    Full Text Available Movie scenes have become attractive means for many industries to present their products without enforced impression. Through careful designed product placement strategy, Twilight movie became the perfect promotional media for Volvo in promoting their products. Volvo is one of the premium automotive brands under the auspices of Indomobil. This well-known brand always put and positions their product merely for the target premium. Product placement is an example of a hybrid message or an attempt to influence audience at an affordable cost. Some benefits in advertising through product placement are a lot of audiences see the products so that the brand awareness and the products’ credibility would significantly increase. In conclusion, consumer’s behavior in recognizing and remembering a product might be affected by their vision, hearing, and admiration.

  15. China Dawn - The Story of a Technology and Business Revolution- David Sheff. 1. ed. San Francisco, Harper Business, 2002

    Directory of Open Access Journals (Sweden)

    Michelle Ong Yu

    2006-06-01

    Full Text Available O que aconteceu há mais de uma década, no Vale do Silício, na Califórnia, agora varre a China, com implicações muito mais dramáticas.O autor nos descreve, em crônicas de extraordinária competência jornalística, o estilo capitalista chinês que sobrevive e se desenvolve de modo incrível. Como disse, o senhor Lee Kuan Yew, Senior Minister of Singapore: "China is not just another player. Its is the biggest player in the history of man". O capitalismo de risco faz um papel incansável para desenvolver empresas de tecnologia da informação no país.

  16. Dual-action Hybrid Compounds - A New Dawn in the Discovery of Multi-target Drugs: Lead Generation Approaches.

    Science.gov (United States)

    Abdolmalekia, Azizeh; Ghasemi, Jahan B

    2016-09-27

    Finding high quality beginning compounds is a critical job at the start of the lead generation stage for multi-target drug discovery (MTDD). Designing hybrid compounds as a selective multi-target chemical entity is a challenge, opportunity, and new idea to better act against specific multiple targets. One hybrid molecule is formed by two (or more) pharmacophore group's participation. So, these new compounds often exhibit two or more activities going about as multi-target drugs (mt-drugs) and may have superior safety or efficacy. Application of integrating a range of information and sophisticated new in silico, bioinformatics, structural biology, pharmacogenomics methods may be useful to discover/design, and synthesis of the new hybrid molecules. In this regard, many rational and screening approaches have followed by medicinal chemists for the lead generation in MTDD. Here, we review some popular lead generation approaches that have been used for designing multiple ligands (DMLs). This paper focuses on dual- acting chemical entities that incorporate a part of two drugs or bioactive compounds to compose hybrid molecules. Also, it presents some of key concepts and limitations/strengths of lead generation methods by comparing combination framework method with screening approaches. Besides, a number of examples to represent applications of hybrid molecules in the drug discovery are included.

  17. I Yam What I Am: Examining Qualitative Research through the Ethnographic Self, the Literary "Other" and the Academy.

    Science.gov (United States)

    Jeffries, Rhonda Baynes

    The conduct and use of qualitative research and the role of fiction as a way of examining the experiences of an African American woman are explored. The paper uses an alternative qualitative model to examine issues of power, equity, and race in the particular context of the African American woman. It discusses the writings of Zora Neale Hurston as…

  18. Bookworms: Great Writers and Readers Celebrate Reading.

    Science.gov (United States)

    Furman, Laura, Ed.; Standard, Elinore, Ed.

    The voices in this anthology, i.e., Zora Neale Hurston, Eudora Welty, Anthony Trollope, E.M. Forster, Franz Kafka, Frederick Douglass, Emily Post, Virginia Woolf, Bernard Malamud, and many others, describe the excitement of first learning to read and remind everyone of the unique companionship offered throughout life by books. The anthology…

  19. Bookworms: Great Writers and Readers Celebrate Reading.

    Science.gov (United States)

    Furman, Laura, Ed.; Standard, Elinore, Ed.

    The voices in this anthology, i.e., Zora Neale Hurston, Eudora Welty, Anthony Trollope, E.M. Forster, Franz Kafka, Frederick Douglass, Emily Post, Virginia Woolf, Bernard Malamud, and many others, describe the excitement of first learning to read and remind everyone of the unique companionship offered throughout life by books. The anthology…

  20. An Argument for an Integrated Approach to Teaching Southern Literature

    Science.gov (United States)

    Ellis, Grace

    1978-01-01

    In addition to such writers as William Faulkner, Flannery O'Connor, Carson McCullers, and Eudora Welty, a good course in modern Southern fiction should include black writers such as Zora Hurston, Nella Larsen, Jean Toomer, Richard Wright, Maya Angelou, and Alice Walker. (MKM)