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Sample records for primordial learning richard

  1. Richard III

    DEFF Research Database (Denmark)

    Lauridsen, Palle Schantz

    2017-01-01

    Kort analyse af Shakespeares Richard III med fokus på, hvordan denne skurk fremstilles, så tilskuere (og læsere) langt henad vejen kan føle sympati med ham. Med paralleller til Netflix-serien "House of Cards"......Kort analyse af Shakespeares Richard III med fokus på, hvordan denne skurk fremstilles, så tilskuere (og læsere) langt henad vejen kan føle sympati med ham. Med paralleller til Netflix-serien "House of Cards"...

  2. Primordial Dwarfism

    Science.gov (United States)

    ... Topics Gait & Motion Analysis Genetic Disorders Limb Length Discrepancy Orthopedics Orthotics Primordial Dwarfism Locations & Doctors About Primordial ... Sign-In » Patient-Family Resources Insurance We Accept Pay My Bill Financial Assistance Medical Records Support Services ...

  3. In Conversation with Paul Richards

    Science.gov (United States)

    Holman, Andrew

    2013-01-01

    Paul Richards is one of those individuals who make a difference and is as far from institutional as one can be. The author met up with him at the Learning Disability Today conference in London to talk more about his work and life. Paul coordinates the service user involvement across Southdown Housing Association, based in Sussex.

  4. Primordial nucleosynthesis.

    Science.gov (United States)

    Schramm, D N

    1998-01-06

    With the advent of the new extragalactic deuterium observations, Big Bang nucleosynthesis (BBN) is on the verge of undergoing a transformation. In the past, the emphasis has been on demonstrating the concordance of the BBN model with the abundances of the light isotopes extrapolated back to their primordial values by using stellar and galactic evolution theories. As a direct measure of primordial deuterium is converged upon, the nature of the field will shift to using the much more precise primordial D/H to constrain the more flexible stellar and galactic evolution models (although the question of potential systematic error in 4He abundance determinations remains open). The remarkable success of the theory to date in establishing the concordance has led to the very robust conclusion of BBN regarding the baryon density. This robustness remains even through major model variations such as an assumed first-order quark-hadron phase transition. The BBN constraints on the cosmological baryon density are reviewed and demonstrate that the bulk of the baryons are dark and also that the bulk of the matter in the universe is nonbaryonic. Comparison of baryonic density arguments from Lyman-alpha clouds, x-ray gas in clusters, and the microwave anisotropy are made.

  5. Primordial Nucleosynthesis

    International Nuclear Information System (INIS)

    Coc, Alain

    2013-01-01

    Primordial nucleosynthesis, or Big Bang Nucleosynthesis (BBN), is one of the three evidences for the Big-Bang model, together with the expansion of the Universe and the Cosmic Microwave Background. There is a good global agreement over a range of nine orders of magnitude between abundances of 4 He, D, 3 He and 7 Li deduced from observations, and calculated in primordial nucleosynthesis. This comparison was used to determine the baryonic density of the Universe. For this purpose, it is now superseded by the analysis of the Cosmic Microwave Background (CMB) radiation anisotropies. However, there remain, a yet unexplained, discrepancy of a factor 3-5, between the calculated and observed lithium primordial abundances, that has not been reduced, neither by recent nuclear physics experiments, nor by new observations. We review here the nuclear physics aspects of BBN for the production of 4 He, D, 3 He and 7 Li, but also 6 Li, 9 Be, 11 B and up to CNO isotopes. These are, for instance, important for the initial composition of the matter at the origin of the first stars. Big-Bang nucleosynthesis, that has been used, to first constrain the baryonic density, and the number of neutrino families, remains, a valuable tool to probe the physics of the early Universe, like variation of ''constants'' or alternative theories of gravity.

  6. Primordial Nucleosynthesis

    Science.gov (United States)

    Coc, Alain

    Primordial or big bang nucleosynthesis (BBN) is now a parameter free theory whose predictions are in good overall agreement with observations. However, the 7Li calculated abundance is significantly higher than the one deduced from spectroscopic observations. Most solutions to this lithium problem involve a source of extra neutrons that inevitably leads to an increase of the deuterium abundance. This seems now to be excluded by recent deuterium observations that have drastically reduced the uncertainty on D/H and also calls for improved precision on thermonuclear reaction rates.

  7. Primordial nuclei

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The recent detection of intergalactic helium by NASA's Astro-2 mission backs up two earlier measurements by ESA and the University of California, San Diego, using instruments aboard the Hubble Space Telescope. Taken together, these results give strong evidence that this helium is primordial, confirming a key prediction of the Big Bang theory. The amount of helium the results imply could also account for some of the Universe's invisible dark matter - material which affects galactic motion but is otherwise undetectable. According to theory, helium nuclei formed at around 100 seconds after the Big Bang, but the amount of helium depended on even earlier events. Initially, protons turned into neutrons with the same probability that neutrons turned into protons. But after about one second, the Universe had cooled down enough for the weak interaction to freeze out. Neutrons continued to decay into the slightly lighter protons, whilst the opposite reaction became much more scarce. At around 100 seconds, thermonuclear fusion reactions could begin, and all the neutrons that were left became absorbed into helium nuclei, leaving the remaining protons locked up in hydrogen. The ratio of helium to hydrogen was therefore determined by events occurring when the Universe was just one second old. Standard models of primordial nucleosynthesis fix this ratio at slightly less than 2 5% by mass. All heavier elements were cooked up much later in the stars, and amount to less than 1 % of the Universe's mass. These predictions have been borne out remarkably well by observation, although proof of the primordial origins of hydrogen and helium has remained elusive until now. Big Bang nucleosynthesis goes on to estimate that primordial baryonic matter in the form of light nuclei could account for around 10% of the Universe's dark matter. All three recent measurements used the same technique of looking at distant quasars, some of the most luminous objects in the Universe, to

  8. Professor Richard Feynman colloquium

    CERN Multimedia

    1965-01-01

    Richard P. Feynman received the Nobel Prize for physics in 1965. Following the ceremony in Stockholm, Feynman gave the colloquium "Development of the space-time view of quantum electrodynamics" at CERN on 17th December.

  9. Primordial Spirituality

    Directory of Open Access Journals (Sweden)

    Kees Waaijman

    2010-11-01

    Full Text Available This article explores the primordial spirituality of the Bible, as expressed in names, narratives and prayers. It looks at the nomadic families of Abraham and Sarah, Isaac and Rebecca, Jacob, Lea and Rachel, moving around from Mesopotamia via Canaan into Egypt and vice versa (see Gn 11:31–32; 12:4–5; 27:43; 28:10; 29:4; Gn 24 and 29–31. It analyses their experiences, covering the span between birth and death and listens to their parental concerns about education as survival. It also follows their journeys along the margins of the deserts. It shares their community life as it takes shape in mutual solidarity, mercy and compassion.

  10. Primordial nucleosynthesis

    International Nuclear Information System (INIS)

    Gustavino, C.; Anders, M.; Bemmerer, D.; Elekes, Z.; Trezzi, D.

    2016-01-01

    Big Bang nucleosynthesis (BBN) describes the production of light nuclei in the early phases of the Universe. For this, precise knowledge of the cosmological parameters, such as the baryon density, as well as the cross section of the fusion reactions involved are needed. In general, the energies of interest for BBN are so low (E < 1 MeV) that nuclear cross section measurements are practically unfeasible at the Earth's surface. As of today, LUNA (Laboratory for Underground Nuclear Astrophysics) has been the only facility in the world available to perform direct measurements of small cross section in a very low background radiation. Owing to the background suppression provided by about 1400 meters of rock at the Laboratori Nazionali del Gran Sasso (LNGS), Italy, and to the high current offered by the LUNA accelerator, it has been possible to investigate cross sections at energies of interest for Big Bang nucleosynthesis using protons, 3 He and alpha particles as projectiles. The main reaction studied in the past at LUNA is the 2 H( 4 He, γ) 6 Li. Its cross section was measured directly, for the first time, in the BBN energy range. Other processes like 2 H(p, γ) 3 He, 3 He( 2 H, p) 4 He and 3 He( 4 He, γ) 7 Be were also studied at LUNA, thus enabling to reduce the uncertainty on the overall reaction rate and consequently on the determination of primordial abundances. The improvements on BBN due to the LUNA experimental data will be discussed and a perspective of future measurements will be outlined. (orig.)

  11. Richard Halliburton's Bearded Tales

    Science.gov (United States)

    Morris, Charles E., III

    2009-01-01

    Fusing the concept of "the beard" with the genre of the tall tale to theorize bearded tales deepens our understanding of closet eloquence, or rhetorical repertories of sexual passing in U.S. history. An examination of adventurer-writer-lecturer Richard Halliburton's sexual provenance and bestselling travel tale, "The Royal Road to Romance" (1925),…

  12. Richards Bay effluent pipeline

    CSIR Research Space (South Africa)

    Lord, DA

    1986-07-01

    Full Text Available of major concern identified in the effluent are the large volume of byproduct calcium sulphate (phosphogypsum) which would smother marine life, high concentrations of fluoride highly toxic to marine life, heavy metals, chlorinated organic material... ........................ 9 THE RICHARDS BAY PIPELINE ........................................ 16 Environmental considerations ................................... 16 - Phosphogypsum disposal ................................... 16 - Effects of fluoride on locally occurring...

  13. Richard von Volkmann

    Science.gov (United States)

    Willy, Christian; Schneider, Peter; Engelhardt, Michael; Hargens, Alan R.

    2008-01-01

    Richard von Volkmann (1830–1889), one of the most important surgeons of the 19th century, is regarded as one of the fathers of orthopaedic surgery. He was a contemporary of Langenbeck, Esmarch, Lister, Billroth, Kocher, and Trendelenburg. He was head of the Department of Surgery at the University of Halle, Germany (1867–1889). His popularity attracted doctors and patients from all over the world. He was the lead physician for the German military during two wars. From this experience, he compared the mortality of civilian and war injuries and investigated the general poor hygienic conditions in civilian hospitals. This led him to introduce the “antiseptic technique” to Germany that was developed by Lister. His powers of observation and creativity led him to findings and achievements that to this day bear his name: Volkmann’s contracture and the Hueter-Volkmann law. Additionally, he was a gifted writer; he published not only scientific literature but also books of children’s fairy tales and poems under the pen name of Richard Leander, assuring him a permanent place in the world of literature as well as orthopaedics. PMID:18196438

  14. The primordial nucleosynthesis

    International Nuclear Information System (INIS)

    Audouze, J.

    1984-01-01

    This review of the primordial nucleosynthesis is divided in three chapters. In the first the author attempts to determine the primordial abundances of the lightest elements which can be formed by the Big Bang nucleosynthesis. The second is a summary of the Standard Big Bang nucleosynthesis. This simple and attractive model might be found in difficulty in the case of a primordial abundance of He <= 0.24 and/or in the case of models of galactic evolution allowing infall of external matter having a primordial composition. Finally, in the third, two alternative proposals to the Standard Big Bang nucleosynthesis are summarized. (Auth.)

  15. Richard Lavenham on Future Contingents

    DEFF Research Database (Denmark)

    Øhrstrøm, Peter

    1983-01-01

    Richard Lavenham on Future Contingents’, Cahiers de l’Institut du Moyen-âge Grec et Latin, 44 (1983), p.180-186.......‘Richard Lavenham on Future Contingents’, Cahiers de l’Institut du Moyen-âge Grec et Latin, 44 (1983), p.180-186....

  16. Primordial chemistry: an overview

    International Nuclear Information System (INIS)

    Signore, Monique; Puy, Denis

    1999-01-01

    In the standard Big Bang model, the light elements in the cosmos -hydrogen and helium but also deuterium and lithium- were created in the very early Universe. The main problem is to connect what we can actually observe to day with the standard Big Bang nucleosynthesis predictions essentially because of uncertainties in modeling their evolution since the Big Bang. After a brief review of the primordial nucleosynthesis -predictions and observations of the primordial abundances- we present the preliminary studies of the primordial chemistry: molecular formation and evolution in the early Universe

  17. Primordial dwarfism: an update.

    Science.gov (United States)

    Alkuraya, Fowzan S

    2015-02-01

    To review the recent advances in the clinical and molecular characterization of primordial dwarfism, an extreme growth deficiency disorder that has its onset during embryonic development and persists throughout life. The last decade has witnessed an unprecedented acceleration in the discovery of genes mutated in primordial dwarfism, from one gene to more than a dozen genes. These genetic discoveries have confirmed the notion that primordial dwarfism is caused by defects in basic cellular processes, most notably centriolar biology and DNA damage response. Fortunately, the increasing number of reported clinical primordial dwarfism subtypes has been accompanied by more accurate molecular classification. Qualitative defects of centrioles with resulting abnormal mitosis dynamics, reduced proliferation, and increased apoptosis represent the predominant molecular pathogenic mechanism in primordial dwarfism. Impaired DNA damage response is another important mechanism, which we now know is not mutually exclusive to abnormal centrioles. Molecular characterization of primordial dwarfism is helping families by enabling more reproductive choices and may pave the way for the future development of therapeutics.

  18. An appreciation of Richard Threlkeld Cox

    Science.gov (United States)

    Tribus, Myron

    2002-05-01

    Richard T. Cox's contributions to the foundations of probability theory and inductive logic are not generally appreciated or understood. This paper reviews his life and accomplishments, especially those in his book The Algebra of Probable Inference and his final publication Inference and Inquiry which, in this author's opinion, has the potential to influence in a significant way the design and analysis of self organizing systems which learn from experience. A simple application to the simulation of a neuron is presented as an example of the power of Cox's contribution.

  19. Richard Peters and Valuing Authenticity

    Science.gov (United States)

    Degenhardt, M. A. B.

    2009-01-01

    Richard Peters has been praised for the authenticity of his philosophy, and inquiry into aspects of the development of his philosophy reveals a profound authenticity. Yet authenticity is something he seems not to favour. The apparent paradox is resolved by observing historical changes in the understanding of authenticity as an important value.…

  20. Obituary: Dr. Richard Roland Baker

    Directory of Open Access Journals (Sweden)

    Thornton R

    2014-12-01

    Full Text Available Richard Baker died at Easter 2007 after a very short illness. It is sad that he died so soon after his retirement from the British American Tobacco Company at the end of 2005, and just as he was beginning to enjoy his new life, even though tobacco science still had a part to play.

  1. Before primordial inflation

    Science.gov (United States)

    Nanopoulos, D. V.; Srednicki, M.

    1983-12-01

    We show that, before the onset of primordial inflation, there is plenty of time for fields with very flat potentials and very weak couplings (such as the local supersymmetry breaking field and the axion field) to roll to the global minima of their potentials. Thus there is no energy stored in these fields today and hence no constraint (such as faxion USA.

  2. Photinos and primordial nucleosynthesis

    International Nuclear Information System (INIS)

    Salati, P.

    1986-07-01

    Photinos are among the most interesting particles predicted by supersymmetric theories. If they exist they should influence in many ways the results of the primordial nucleosynthesis i.e. the predicted primordial abundances of D, 3 He, 4 He (and 7 Li). If photinos are stable, cosmological constraints restrict their possible mass to be either very light (M∼ γ γ > a few GeV), depending on the slepton and squark masses. In the case where photinos are unstable, they could create high energy photons able to photodisintegrate the light elements. The comparison between the predicted and the observed abundances allows to restrict significantly the photino mass-lifetime range: roughly speaking photinos of relatively high mass (M∼ γ > 150 MeV) and low time scale ( 3 sec) are compatible with these abundances

  3. The Primordial Inflation Explorer

    Science.gov (United States)

    Kogut, Alan J.

    2012-01-01

    The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10(exp -3) at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy. I describe the PIXIE instrument and mission architecture needed to detect the inflationary signature using only 4 semiconductor bolometers.

  4. Corrections to primordial nucleosynthesis

    International Nuclear Information System (INIS)

    Dicus, D.A.; Kolb, E.W.; Gleeson, A.M.; Sudarshan, E.C.G.; Teplitz, V.L.; Turner, M.S.

    1982-01-01

    The changes in primordial nucleosynthesis resulting from small corrections to rates for weak processes that connect neutrons and protons are discussed. The weak rates are corrected by improved treatment of Coulomb and radiative corrections, and by inclusion of plasma effects. The calculations lead to a systematic decrease in the predicted 4 He abundance of about ΔY = 0.0025. The relative changes in other primoridal abundances are also 1 to 2%

  5. Richard Mattessich: vida y obra

    OpenAIRE

    Daniel Carrasco Díaz

    2006-01-01

    El texto que se ofrece a continuación constituye el discurso pronunciado por el profesor Daniel Carrasco Díaz, catedrático de Economía Financiera y Contabilidad como padrino del homenajeado, en el solemne acto de investidura del Prof. Dr. Richard Mattessich, profesor emérito de la Sauder School of Commerce, de la University of British Columbia, Vancouver (Canadá), como Doctor honoris causa por la Universidad de Málaga, celebrado el 18 de mayo de 2006.

  6. J. Richard Hackman (1940-2013)

    OpenAIRE

    Wageman, Ruth; Amabile, Teresa M.

    2013-01-01

    When J. Richard Hackman died in Cambridge, Massachusetts, on January 8, 2013, psychology lost a giant. Six and a half feet tall, with an outsize personality to match, Richard was the leading scholar in two distinct areas: work design and team effectiveness. In both domains, his work is foundational. Throughout his career, Richard applied rigorous methods to problems of great social importance, tirelessly championing multi-level analyses of problems that matter. His impact on our field has bee...

  7. Richard's back: death, scoliosis and myth making.

    Science.gov (United States)

    Lund, Mary Ann

    2015-12-01

    The body of a mediaeval monarch was always under scrutiny, and Richard III's was no exception. In death, however, his body became subject to new forms of examination and interpretation: stripped naked after the battle of Bosworth, his corpse was carried to Leicester and exhibited before being buried. In 2012, it was rediscovered. The revelation that Richard suffered from scoliosis prompts this article to re-evaluate the historical sources about Richard's physique and his posthumous reputation. This article argues that Richard's death and his myth as 'crookback' are inextricably linked and traces attitudes to spinal curvature in the early modern period. It also considers how Shakespeare represented Richard as deformed, and aspects of performance history which suggest physical vulnerability. It then considers Richard's scoliosis from the perspective of medical history, reviewing classical accounts of scoliosis and arguing that Richard was probably treated with a mixture of axial traction and pressure. It demonstrates from the evidence of Richard's medical household that he was well placed to receive hands-on therapies and considers in particular the role of his physician and surgeon, William Hobbes. Finally, it shows how the case of Richard III demonstrates the close relationship between politics and medicine in the period and the contorted process of historical myth making. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  8. Accretion, primordial black holes and standard cosmology

    Indian Academy of Sciences (India)

    Primordial black holes evaporate due to Hawking radiation. We find that the evaporation times of primordial black holes increase when accretion of radiation is included. Thus, depending on accretion efficiency, more primordial black holes are existing today, which strengthens the conjecture that the primordial black holes ...

  9. Richard Nixon, 1972-2016 Obituary

    OpenAIRE

    Tom, Brian Dermot; Thompson, Simon Gregory; Duffy, SW; Sweeting, Michael John; Ohlssen, DI

    2017-01-01

    After a year-long journey with cancer, Dr Richard Nixon died on August 26th, 2016, aged only 43 years. He leaves behind his wife of 5 years, Valda, and their 1-year-old baby daughter, Kyra. Richard, a Yorkshireman, was born on September 8th, 1972. He attended Ilkley Grammar School, studied mathematics at Durham University (1991–1994) and was awarded the Diploma in Mathematical Statistics from the University of Cambridge in 1995. Richard then took a career break for a couple of years to...

  10. Theodore William Richards and the Periodic Table

    Science.gov (United States)

    Conant, James B.

    1970-01-01

    Discusses the contribution of Theodore Richards to the accurate determination of atomic weights of copper and other elements; his major contribution was to the building of the definitive periodic table of the elements. (BR)

  11. Primordial germ cells and amnion development in the avian embryo

    NARCIS (Netherlands)

    De Melo Bernardo, Ana

    2016-01-01

    Primordial germ cells (PGCs) are the progenitors of the gametes, responsible for transmitting genetic information from generation to generation. Although there is a long history of gamete biology research, there is still a lot to be learned about many of the mechanisms underlying germ cell

  12. Richards Barrier LA Reference Design Feature Evaluation

    International Nuclear Information System (INIS)

    N.E. Kramer

    1999-01-01

    The Richards Barrier is one of the design features of the repository to be considered for the License Application (LA), Richards was a soil scientist who first described the diversion of moisture between two materials with different hydrologic properties. In this report, a Richards Barrier is a special type of backfill with a fine-grained material (such as sand) overlaying a coarse-grained material (such as gravel). Water that enters an emplacement drift will first encounter the fine-grained material and be transported around the coarse-grained material covering the waste package, thus protecting the waste package from contact with most of the groundwater. The objective of this report is to discuss the benefits and liabilities to the repository by the inclusion of a Richards Barrier type backfill in emplacement drifts. The Richards Barrier can act as a barrier to water flow, can reduce the waste package material dissolution rate, limit mobilization of the radionuclides, and can provide structural protection for the waste package. The scope of this report is to: (1) Analyze the behavior of barrier materials following the intrusion of groundwater for influxes of 1 to 300 mm per year. The report will demonstrate diversion of groundwater intrusions into the barrier over an extended time period when seismic activity and consolidation may cause the potential for liquefaction and settlement of the Richards Barrier. (2) Review the thermal effects of the Richards Barrier on material behavior. (3) Analyze the effect of rockfall on the performance of the Richards Barrier and the depth of the barrier required to protect waste packages under the barrier. (4) Review radiological and heating conditions on placement of multiple layers of the barrier. Subsurface Nuclear Safety personnel will perform calculations to determine the radiation reduction-time relationship and shielding capacity of the barrier. (5) Evaluate the effects of ventilation on cooling of emplacement drifts and

  13. In conversation with: Professor Richard James

    Directory of Open Access Journals (Sweden)

    John Clarke

    2014-03-01

    Full Text Available In 2011, Richard James wrote in the Foreword to Nelson, Clarke, Kift, and Creagh’s (2012 monograph on Australasian literature on the First Year Experience that:The trend towards universal participation will usher in dramatic changes in the character of the first year in higher education. … (p. iiiIn an interview at the University of Melbourne, Australia in July 2013 between Richard James and John Clarke, Co-editor of the International Journal of the First Year in Higher Education, these and related issues were explored.  The interview picks up where the Foreword left off:  focussing on universal participation.

  14. Quantum Man: Richard Feynman's Life in Science

    CERN Document Server

    CERN. Geneva

    2011-01-01

    It took a man who was willing to break all the rules to tame a theory that breaks all the rules. This talk will be based on my new book Quantum Man: Richard Feynman's life in science. I will try and present a scientific overview of the contributions of Richard Feynman, as seen through the arc of his fascinating life. From Quantum Mechanics to Antiparticles, from Rio de Janeiro to Los Alamos, a whirlwind tour will provide insights into the character, life and accomplishments of one of the 20th centuries most important scientists, and provide an object lesson in scientific integrity.

  15. Searching for Primordial Antimatter

    Science.gov (United States)

    2008-10-01

    Scientists are on the hunt for evidence of antimatter - matter's arch nemesis - leftover from the very early Universe. New results using data from NASA's Chandra X-ray Observatory and Compton Gamma Ray Observatory suggest the search may have just become even more difficult. Antimatter is made up of elementary particles, each of which has the same mass as their corresponding matter counterparts --protons, neutrons and electrons -- but the opposite charges and magnetic properties. When matter and antimatter particles collide, they annihilate each other and produce energy according to Einstein's famous equation, E=mc2. According to the Big Bang model, the Universe was awash in particles of both matter and antimatter shortly after the Big Bang. Most of this material annihilated, but because there was slightly more matter than antimatter - less than one part per billion - only matter was left behind, at least in the local Universe. Trace amounts of antimatter are believed to be produced by powerful phenomena such as relativistic jets powered by black holes and pulsars, but no evidence has yet been found for antimatter remaining from the infant Universe. How could any primordial antimatter have survived? Just after the Big Bang there was believed to be an extraordinary period, called inflation, when the Universe expanded exponentially in just a fraction of a second. "If clumps of matter and antimatter existed next to each other before inflation, they may now be separated by more than the scale of the observable Universe, so we would never see them meet," said Gary Steigman of The Ohio State University, who conducted the study. "But, they might be separated on smaller scales, such as those of superclusters or clusters, which is a much more interesting possibility." X-rayChandra X-ray Image In that case, collisions between two galaxy clusters, the largest gravitationally-bound structures in the Universe, might show evidence for antimatter. X-ray emission shows how much hot

  16. Obituary: Richard Joseph Elston, 1960-2004

    Science.gov (United States)

    Jannuzi, Buell Tomasson; Bechtold, Jill

    2004-12-01

    Richard Joseph Elston, known for his development of innovative astronomical instrumentation, died on 26 January 2004 in Gainesville, Florida, after a four-year battle with Hodgkin's lymphoma. A professor of astronomy at the University of Florida, Richard had an unusually broad range of interests and skills, and a willingness to share his passion for astronomy with others, which made him a highly valued member of the astronomical community. Born 1 July 1960, in Albuquerque, New Mexico, Richard was the son of a geologist father and journalist mother. His childhood interest in astronomy and instrumentation matured as he majored in physics and astronomy at the University of New Mexico (BS, 1983) under the mentorship of Michael Zeilik. Richard pursued his PhD in astronomy at the University of Arizona and earned his degree in 1988. He pioneered the use of IR arrays for deep imaging surveys of the sky to study galaxy formation, and completed his thesis Search for Rapidly Forming Galaxies at High Redshift under the direction of George Rieke. Richard's graduate work included the first detection of galaxies at intermediate redshifts with evolved populations too red to have been identifiable from optical imaging surveys alone. In the Astrophysical Journal Letters in 1988, he, George Rieke, and Marcia Rieke reported the discovery of this new class of galaxies, now known as EROs (Extremely Red Objects), important as the possible progenitors of present day elliptical galaxies. Following post-doctoral positions at Kitt Peak National Observatory from 1988 to 1991 and at the Observatories of the Carnegie Institution of Washington from 1991 to 1992, Richard joined the scientific staff of Cerro Tololo Inter-American Observatory in Chile, part of the NSF's National Optical Astronomy Observatory. By 1994, he had become head of CTIO's IR instrumentation program and was leading the development of new instruments for the US astronomical community. In 1996, Richard married astronomer

  17. Richard W. Ziolkowski Receives Honorary Doctorate

    DEFF Research Database (Denmark)

    Breinbjerg, Olav

    2012-01-01

    At the annual Commemoration of the Technical University of Denmark (DTU) on April 27, 2012, Prof. Richard W. Ziolkowski, University of Arizona (UoA), received DTU's highest academic degree, the Honorary Doctor degree: Doctor Technices Honoris Causa (Figure 1). Prof. Ziolkowski has been a close...

  18. Potshemu medved rõtshit / Richard Pipes

    Index Scriptorium Estoniae

    Pipes, Richard

    2006-01-01

    Harvardi ülikooli ajalooprofessor Richard Pipes arutleb, miks Venemaa viimase aja käitumises väljendub soovimatus koostööks, sageli ka vaenulikkus. Venemaa võimetus rahvusvahelises kontekstis oma kohta leida, selle ajaloolised juured

  19. Richard A. Werners forskning i pengeskabelse

    DEFF Research Database (Denmark)

    2016-01-01

    Hvilken rolle spiller penge i samfundsøkonomien og hvilken rolle burde penge spille i den økonomiske videnskab? Det forsker Richard Werner i. Han er professor i økonomi ved Southampton University i England, og her præsenteres fire dele af hans forskning i penge: (1) Hvad foregår der egentlig i en...

  20. Recensie "The Great Reset" : Richard Florida

    NARCIS (Netherlands)

    Roy van Dalm

    2010-01-01

    Like the Great Depression and the Long Depression before it, experts have viewed prolonged economic downturns as crises. In The Great Reset , bestselling author Richard Florida argues that we should instead see the recent recession as an opportunity to create entirely new ways of working and living

  1. Richard Florida : loovsektor on majanduskasvu mootor / Richard Florida ; interv. Argo Ideon

    Index Scriptorium Estoniae

    Florida, Richard

    2008-01-01

    USA majandus- ja ühiskonnateadlane Richard Florida loovklassi teooriast, selle osast majanduskasvu tagamisel, seosest ühiskonna tolerantsuse ja ühiskonna majandusliku edukuse vahel, sotsiaalse sidususe takistavast rollist loovuse motiveerimisel

  2. Late baryogenesis faces primordial nucleosynthesis

    International Nuclear Information System (INIS)

    Delbourgo-Salvador, P.; Audouze, J.; Salati, P.

    1991-11-01

    Since the sphalleron mechanism present in the standard theory of electro-weak interactions violates B+L, models have been suggested where baryogenesis takes place at late epochs and is concomitant with primordial nucleosynthesis. The possibility for the baryon asymmetry to be generated was numerically investigated at the same time as the light elements are cooked. The primordial yields of D, 3 He, 4 He and 7 Li were shown to exceed the upper limits inferred from observation, unless baryogenesis is anterior to the freeze-out of the weak interactions. This implies strong constraints on scenarios where the baryon asymmetry originates from the late decay of massive gravitinos. (author) 18 refs., 6 figs

  3. Primordial Kaluza-Klein inflation

    International Nuclear Information System (INIS)

    Gonzalez-Diaz, P.F.

    1986-01-01

    In a higher-dimensional version of the gravitational action with higher-derivative terms and logarithmic dependence on the curvature scalar, in addition to the four-dimensional gravitational action integral, the non-gravitational Coleman-Weinberg effective potential that governs primordial inflation is obtained. Also, it is obtained that the length scale for the internal space decreases monotonously during the inflationary era, at a similar rate as the three spacelike dimensions grow. (orig.)

  4. Method of lines solution of Richards` equation

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, C.T.; Miller, C.T.; Tocci, M.D.

    1996-12-31

    We consider the method of lines solution of Richard`s equation, which models flow through porous media, as an example of a situation in which the method can give incorrect results because of premature termination of the nonlinear corrector iteration. This premature termination arises when the solution has a sharp moving front and the Jacobian is ill-conditioned. While this problem can be solved by tightening the tolerances provided to the ODE or DAE solver used for the temporal integration, it is more efficient to modify the termination criteria of the nonlinear solver and/or recompute the Jacobian more frequently. In this paper we continue previous work on this topic by analyzing the modifications in more detail and giving a strategy on how the modifications can be turned on and off in response to changes in the character of the solution.

  5. Richard Weaver's Untraditional Case for Federalism

    OpenAIRE

    Jeremy David Bailey

    2004-01-01

    Although Richard M. Weaver's political writings do not offer a systematic examination of federalism, they include a defense of federalist arrangements. Because Weaver's federalism is central to his conservatism, and because his argument for federalism differs from more common conservative defenses of federalism offered in the twentieth century, his writings allow students of federalism to examine possible connections between federalism and conservative political thought. Copyright 2004, Oxfor...

  6. Richard Wollheim 1923-2003 / Marek Volt

    Index Scriptorium Estoniae

    Volt, Marek

    2004-01-01

    Järelehüüe anglo-ameerika filosoofile Richard Wollheimile (5. V 1923-4. XI 2003), kes huvitus maalist ja psühhoanalüüsist ning kuulub XX sajandi analüütilist kunstifilosoofiat enim kujundanud filosoofide hulka. Tema peamised tööd: "Art and Its Objects" (1968), "Painting As an Art" (1987), "On Painting and the Self" (1992). Ilmunud ka raamatus: Volt, Marek. Esteetikast. Tallinn : Sirp, 2006

  7. Primordial inflation and the monopole problem

    International Nuclear Information System (INIS)

    Olive, K.A.; Seckel, D.

    1984-01-01

    This chapter discusses the cosmological abundance of magnetic monopoles in locally supersymmetry grand unified theories (GUTs) and primordial inflation. It is shown how the magnetic monopole problem can be solved in variants of broken N=1 supergravity primordial inflation. The monopole problem and its solution in inflationary models is reviewed. It is demonstrated that the monopole problem can be solved by coupling primordial inflation to supersymmetric SU(5) breaking

  8. Neutron oscillations and the primordial magnetic field

    International Nuclear Information System (INIS)

    Sarkar, S.

    1988-01-01

    It has been claimed that a primordial magnetic field must exist in order to suppress possible oscillations of neutrons into antineutrons which would otherwise affect the cosmological synthesis of helium. We demonstrate that such oscillations, even if they do occur, have a negligible effect on primordial nucleosynthesis, thus refuting the above claim. Hence the possible existence of a primordial magnetic field, relevant to current speculations concerning superconducting 'cosmic strings', remains an open question. (author)

  9. QCD pairing in primordial nuggets

    Science.gov (United States)

    Lugones, G.; Horvath, J. E.

    2003-08-01

    We analyze the problem of boiling and surface evaporation of quark nuggets in the cosmological quark-hadron transition. Recently, it has been shown that QCD pairing modifies the stability properties of strange quark matter. More specifically, strange quark matter in a color-flavor locked state was found to be absolutely stable for a much wider range of the parameters than ordinary unpaired strange quark matter (G. Lugones and J. E. Horvath, Phys. Rev. D, 66, 074017 (2002)). Assuming that primordial quark nuggets are actually formed we analyze the consequences of pairing on the rates of boiling and surface evaporation in order to determine whether they could have survived.

  10. Resonant primordial gravitational waves amplification

    Directory of Open Access Journals (Sweden)

    Chunshan Lin

    2016-01-01

    Full Text Available We propose a mechanism to evade the Lyth bound in models of inflation. We minimally extend the conventional single-field inflation model in general relativity (GR to a theory with non-vanishing graviton mass in the very early universe. The modification primarily affects the tensor perturbation, while the scalar and vector perturbations are the same as the ones in GR with a single scalar field at least at the level of linear perturbation theory. During the reheating stage, the graviton mass oscillates coherently and leads to resonant amplification of the primordial tensor perturbation. After reheating the graviton mass vanishes and we recover GR.

  11. Primordial gravitational waves and cosmology.

    Science.gov (United States)

    Krauss, Lawrence M; Dodelson, Scott; Meyer, Stephan

    2010-05-21

    The observation of primordial gravitational waves could provide a new and unique window on the earliest moments in the history of the universe and on possible new physics at energies many orders of magnitude beyond those accessible at particle accelerators. Such waves might be detectable soon, in current or planned satellite experiments that will probe for characteristic imprints in the polarization of the cosmic microwave background, or later with direct space-based interferometers. A positive detection could provide definitive evidence for inflation in the early universe and would constrain new physics from the grand unification scale to the Planck scale.

  12. Cosmology with primordial black holes

    International Nuclear Information System (INIS)

    Lindley, D.

    1981-09-01

    Cosmologies containing a substantial amount of matter in the form of evaporating primordial black holes are investigated. A review of constraints on the numbers of such black holes, including an analysis of a new limit found by looking at the destruction of deuterium by high energy photons, shows that there must be a negligible population of small black holes from the era of cosmological nucleosynthesis onwards, but that there are no strong constraints before this time. The major part of the work is based on the construction of detailed, self-consistent cosmological models in which black holes are continually forming and evaporating The interest in these models centres on the question of baryon generation, which occurs via the asymmetric decay of a new type of particle which appears as a consequence of the recently developed Grand Unified Theories of elementary particles. Unfortunately, there is so much uncertainty in the models that firm conclusions are difficult to reach; however, it seems feasible in principle that primordial black holes could be responsible for a significant part of the present matter density of the Universe. (author)

  13. The Primordial Inflation Explorer (PIXIE)

    Science.gov (United States)

    Kogut, Alan; Chluba, Jens; Fixsen, Dale J.; Meyer, Stephan; Spergel, David

    2016-01-01

    The Primordial Inflation Explorer is an Explorer-class mission to open new windows on the early universe through measurements of the polarization and absolute frequency spectrum of the cosmic microwave background. PIXIE will measure the gravitational-wave signature of primordial inflation through its distinctive imprint in linear polarization, and characterize the thermal history of the universe through precision measurements of distortions in the blackbody spectrum. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning over 7 octaves in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). Multi-moded non-imaging optics feed a polarizing Fourier Transform Spectrometer to produce a set of interference fringes, proportional to the difference spectrum between orthogonal linear polarizations from the two input beams. Multiple levels of symmetry and signal modulation combine to reduce systematic errors to negligible levels. PIXIE will map the full sky in Stokes I, Q, and U parameters with angular resolution 2.6 degrees and sensitivity 70 nK per 1degree square pixel. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r inflation to the nature of the first stars and the physical conditions within the interstellar medium of the Galaxy. We describe the PIXIE instrument and mission architecture required to measure the CMB to the limits imposed by astrophysical foregrounds.

  14. EDITORIAL: Richard Palmer: celebrating 37 years with Journal of Physics: Condensed Matter Richard Palmer: celebrating 37 years with Journal of Physics: Condensed Matter

    Science.gov (United States)

    Ferry, David

    2009-01-01

    in Materials Science and Engineering. Under the new structure, journal development became an increasingly important part of his job. At about the same time, Richard was also asked to take over running Reports on Progress in Physics, which up to then had been done by the head of the IOP Journals Department, Kurt Paulus. In 1989, Journal of Physics C: Solid State Physics and Journal of Physics F: Metal Physics remerged to form JPCM. Since then, Richard has gradually shed his other journal responsibilities, except for Reports on Progress in Physics, to build up JPCM. He has worked closely with four Editors-in-Chief of Journal of Physics C: Solid State Physics, five of JPCM, five of Reports on Progress in Physics and about ten of other journals, and attended approximately 300 Editorial Board meetings. I should say that he has made my own tenure at Editor-in-Chief an easy task to learn and take on, and has been a major guiding light in the development of the journal. In 2006, Richard was honoured by the award of a Member of the British Empire (MBE) for services to science publishing. Those of us on the board were particularly pleased about this, as one is not always recognized for the effort they expend, and this award was certainly due for Richard. We are going to miss Richard a great deal, but are happy that he will remain on a part time basis to help our new Publisher, Dr Lucy Smith, and the rest of us through the transition. His retirement leaves us with a huge hole that we will have to work extremely hard to fill. Speaking for the various boards, and especially the executive board, I want to wish Richard the very best in his retirement.

  15. Fluctuations in models with primordial inflation

    International Nuclear Information System (INIS)

    Kahn, R.; Brandenberger, R.

    1984-01-01

    The recently proposed general framework for calculating the growth of primordial energy density fluctuations in cosmological models is applied to two models of phenomenological interest in which the cosmological evolution differs crucially from that in new inflationary universe models. Both in a model of primordial supersymmetric inflation and in Linde's proposal of chaotic inflation we verify the conjectured results. (orig.)

  16. Illustrated & Dissected: Professor Richard Sawdon Smith.

    Science.gov (United States)

    2015-06-01

    This Alternative Gallery feature introduces the photographic artist Professor Richard Sawdon Smith. Professor Sawdon Smith's work stems around a fascination with representations of anatomy that have been fuelled by his experience as a hospital patient. The work has allowed him to explore ideas through the use of medical illustrations which include early anatomical drawings, personal medical photography and facial modelling. The work highlights how such imagery can be used in the context of a patient seeking understanding and acceptance of ill health and disease using the body as a canvas on which to translate the experience.

  17. Richard Bright and his neurological studies.

    Science.gov (United States)

    Pearce, J M S

    2009-01-01

    Richard Bright was one of the famous triumvirate of Guy's Hospital physicians in the Victorian era. Remembered for his account of glomerulonephritis (Bright's disease) he also made many important and original contributions to medicine and neurology. These included his work on cortical epileptogenesis, descriptions of simple partial (Jacksonian) seizures, infantile convulsions, and a variety of nervous diseases. Most notable were his reports of neurological studies including papers on traumatic tetanus, syringomyelia, arteries of the brain, contractures of spinal origin, tumours of the base of the brain, and narcolepsy. His career and these contributions are outlined. Copyright 2009 S. Karger AG, Basel.

  18. Richard Feynman a life in science

    CERN Document Server

    Gribbin, John

    1998-01-01

    This text is a portrayal of one of the greatest scientists of the late 20th-century, which also provides a picture of the significant physics of the period. It combines personal anecdotes, writings and recollections with narrative. Richard Feynman's career included: war-time work on the atomic bomb at Los Alamos; a theory of quantum mechanics for which he won the Nobel prize; and major contributions to the sciences of gravity, nuclear physics and particle theory. In 1986, he was able to show that the Challenger disaster was due to the effect of cold on the booster rocket rubber sealings.

  19. Richard Feynman Quarks, Bombs, and Bongos

    CERN Document Server

    Henderson, Harry

    2010-01-01

    Described by his peers as the "finest physicist of his generation," Richard Feynman defied scientist stereotypes. This brash New York-born American physicist startled the more conservative giants of European physics with his endless ability to improvise. Indeed, later in life, Feynman became an accomplished bongo player. Feynman's legacy to physics was his ability to simplify complex equations and clarify fundamental principles through the use of graphs. He developed the theory of quantum electrodynamics, which illustrates the behavior of electrically charged particles, such as elect

  20. Richard von Volkmann: surgeon and Renaissance man.

    Science.gov (United States)

    Willy, Christian; Schneider, Peter; Engelhardt, Michael; Hargens, Alan R; Mubarak, Scott J

    2008-02-01

    Richard von Volkmann (1830-1889), one of the most important surgeons of the 19(th) century, is regarded as one of the fathers of orthopaedic surgery. He was a contemporary of Langenbeck, Esmarch, Lister, Billroth, Kocher, and Trendelenburg. He was head of the Department of Surgery at the University of Halle, Germany (1867-1889). His popularity attracted doctors and patients from all over the world. He was the lead physician for the German military during two wars. From this experience, he compared the mortality of civilian and war injuries and investigated the general poor hygienic conditions in civilian hospitals. This led him to introduce the "antiseptic technique" to Germany that was developed by Lister. His powers of observation and creativity led him to findings and achievements that to this day bear his name: Volkmann's contracture and the Hueter-Volkmann law. Additionally, he was a gifted writer; he published not only scientific literature but also books of children's fairy tales and poems under the pen name of Richard Leander, assuring him a permanent place in the world of literature as well as orthopaedics.

  1. Seeing Scale: Richard Dunn’s Structuralism

    Directory of Open Access Journals (Sweden)

    Keith Broadfoot

    2012-11-01

    Full Text Available Writing on the occasion of a retrospective of Richard Dunn’s work, Terence Maloon argued that ‘structuralism had an important bearing on virtually all of Richard Dunn’s mature works’, with ‘his modular, “crossed” formats’ being the most obvious manifestation of this. In this article I wish to reconsider this relation, withdrawing from a broad consideration of the framework of structuralism to focus on some of the quite particular ideas that Lacan proposed in response to structuralism. Beginning from a pivotal painting in the 1960s that developed out of Dunn’s experience of viewing the work of Barnett Newman, I wish to suggest a relation between the ongoing exploration of the thematic of scale in Dunn’s work and the idea of the symbolic that Lacan derives from structuralist thought. This relation, I argue, opens up a different way of understanding the art historical transition from Minimalism to Conceptual art.

  2. Primordial nucleosynthesis: Beyond the standard model

    International Nuclear Information System (INIS)

    Malaney, R.A.

    1991-01-01

    Non-standard primordial nucleosynthesis merits continued study for several reasons. First and foremost are the important implications determined from primordial nucleosynthesis regarding the composition of the matter in the universe. Second, the production and the subsequent observation of the primordial isotopes is the most direct experimental link with the early (t approx-lt 1 sec) universe. Third, studies of primordial nucleosynthesis allow for important, and otherwise unattainable, constraints on many aspects of particle physics. Finally, there is tentative evidence which suggests that the Standard Big Bang (SBB) model is incorrect in that it cannot reproduce the inferred primordial abundances for a single value of the baryon-to-photon ratio. Reviewed here are some aspects of non-standard primordial nucleosynthesis which mostly overlap with the authors own personal interest. He begins with a short discussion of the SBB nucleosynthesis theory, high-lighting some recent related developments. Next he discusses how recent observations of helium and lithium abundances may indicate looming problems for the SBB model. He then discusses how the QCD phase transition, neutrinos, and cosmic strings can influence primordial nucleosynthesis. He concludes with a short discussion of the multitude of other non-standard nucleosynthesis models found in the literature, and make some comments on possible progress in the future. 58 refs., 7 figs., 2 tabs

  3. Primordial black holes from fifth forces

    Science.gov (United States)

    Amendola, Luca; Rubio, Javier; Wetterich, Christof

    2018-04-01

    Primordial black holes can be produced by a long-range attractive fifth force stronger than gravity, mediated by a light scalar field interacting with nonrelativistic "heavy" particles. As soon as the energy fraction of heavy particles reaches a threshold, the fluctuations rapidly become nonlinear. The overdensities collapse into black holes or similar screened objects, without the need for any particular feature in the spectrum of primordial density fluctuations generated during inflation. We discuss whether such primordial black holes can constitute the total dark matter component in the Universe.

  4. Conoscenza e etica in Richard Rorty

    Directory of Open Access Journals (Sweden)

    Emilia Romano

    2011-12-01

    Full Text Available The era in which we live, characterized by multiculturalism and complexity, it is a time when it is clear the difficulty of man to orient and to choose their own way. It’s the time of the fall of every certainty, is the era of “post”, after the tradition, after metaphysics, after the truth, and that requires more effort than any other constant reflection. The neopragmatismo seems to be an effective investigative tool for conducting this reflection and a vantage point to carry on a conversation around the issues of education. In particular, the author intended to refer to the work of Richard Rorty, the author who more than others reflected on the encounter between two important pragmatist tradition: that of classical pragmatism and the “continental” or responsible for the development of a new European concept of truth, understood as a critical and interpretative.

  5. El vocabulario sechurano de Richard Spruce

    Directory of Open Access Journals (Sweden)

    Matthias Urban

    2015-12-01

    Full Text Available This paper makes accesible a new transcription of Richard Spruce’s vocabulary of the Sechura language. Collected in the mid-19th century by the British botanist, it constitutes one of only two sources of data for this language of northernmost Peru. A comparison of the original with previously published versions shows serious errors in transcription, in particular in those of Otto von Buchwald and Jacinto Jijón y Camaaño. The article also discusses the probable circumstances of data collection and the publication history of the hitherto known version, and concludes with some first observations on the significance of Spruce’s wordlist for elucidating the linguistic history of the region, in particular with regard to the question of the linguistic situation at Olmos.

  6. Has Richard Rorty a moral philosophy?

    Directory of Open Access Journals (Sweden)

    Mohammad Asghari

    2015-06-01

    Full Text Available I try to show that Richard Rorty, although is not a moral philosopher like Kant, nerveless, has moral philosophy that must be taken seriously. Rorty was not engaged with moral philosophy in the systematic manner common among leading modern and contemporary moral philosophers. This paper has two parts: first part, in brief, is concerned with principles of his philosophy such as anti-essentialism, Darwinism, Freudism, and historicism. Second part which be long and detailed, considers many moral themes in Rorty's thought such as critique of Kantian morality, solidarity, moral progress, cruelty and concept of other, etc. Subsequently, I will try to answer the research question of the article namely, has Rorty a moral philosophy?

  7. The Primordial Inflation Explorer (PIXIE)

    Science.gov (United States)

    Kogut, Alan; Chluba, Jens; Fixsen, Dale J.; Meyer, Stephan; Spergel, David

    2016-07-01

    The Primordial Inflation Explorer is an Explorer-class mission to open new windows on the early universe through measurements of the polarization and absolute frequency spectrum of the cosmic microwave background. PIXIE will measure the gravitational-wave signature of primordial inflation through its distinctive imprint in linear polarization, and characterize the thermal history of the universe through precision measurements of distortions in the blackbody spectrum. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning over 7 octaves in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). Multi-moded non-imaging optics feed a polarizing Fourier Transform Spectrometer to produce a set of interference fringes, proportional to the difference spectrum between orthogonal linear polarizations from the two input beams. Multiple levels of symmetry and signal modulation combine to reduce systematic errors to negligible levels. PIXIE will map the full sky in Stokes I, Q, and U parameters with angular resolution 2.6° and sensitivity 70 nK per 1° square pixel. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r complements anticipated ground-based polarization measurements such as CMB- S4, providing a cosmic-variance-limited determination of the large-scale E-mode signal to measure the optical depth, constrain models of reionization, and provide a firm detection of the neutrino mass (the last unknown parameter in the Standard Model of particle physics). In addition, PIXIE will measure the absolute frequency spectrum to characterize deviations from a blackbody with sensitivity 3 orders of magnitude beyond the seminal COBE/FIRAS limits. The sky cannot be black at this level; the expected results will constrain physical processes ranging from inflation to the nature of the first stars and the

  8. Running of featureful primordial power spectra

    Science.gov (United States)

    Gariazzo, Stefano; Mena, Olga; Miralles, Victor; Ramírez, Héctor; Boubekeur, Lotfi

    2017-06-01

    Current measurements of the temperature and polarization anisotropy power spectra of the cosmic microwave background (CMB) seem to indicate that the naive expectation for the slow-roll hierarchy within the most simple inflationary paradigm may not be respected in nature. We show that a primordial power spectrum with localized features could in principle give rise to the observed slow-roll anarchy when fitted to a featureless power spectrum. From a model comparison perspective, and assuming that nature has chosen a featureless primordial power spectrum, we find that, while with mock Planck data there is only weak evidence against a model with localized features, upcoming CMB missions may provide compelling evidence against such a nonstandard primordial power spectrum. This evidence could be reinforced if a featureless primordial power spectrum is independently confirmed from bispectrum and/or galaxy clustering measurements.

  9. Microcephalic osteodysplastic primordial dwarfism (MOPD) type I ...

    African Journals Online (AJOL)

    Rabah M. Shawky

    2017-05-02

    May 2, 2017 ... Seckel syndrome, microcephalic osteodysplastic primordial dwarf- ism (MOPD) type ... tures of elbow and knee joints, thin dry skin with marked decreased ... lashes and eyebrows, protruding eyes, prominent nose with a flat.

  10. Primordial gravitational waves, BICEP2 and beyond

    Indian Academy of Sciences (India)

    2016-01-07

    Jan 7, 2016 ... Observations of the imprints of primordial gravitational waves on the ... the cosmic microwave background can provide us with unambiguous clues to the ... by the stress–energy tensor) can be classified, for instance, based on ...

  11. 77 FR 21555 - Manning, Richard W.; Notice of Filing

    Science.gov (United States)

    2012-04-10

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ID-6835-001] Manning, Richard W.; Notice of Filing Take notice that on April 2, 2012, Richard W. Manning submitted for filing... not serve to make protestants parties to the proceeding. Any person wishing to become a party must...

  12. Richard Avedon ja Annie Leibovitz laulsid kaanonit / Marika Alver

    Index Scriptorium Estoniae

    Alver, Marika

    2008-01-01

    Richard Avedoni (1923-2004) retrospektiivnäitusest (fotod aastatest 1946-2004) kuraator Helle Crenzien (Lousiana Kaasaegse Kunsti muuseum Taanis), millega kaasnes ka Helen Whitney film "Richard Avedon : darkness and light" ja Annie Leibovitzi (1949) suurprojektist "A photographer's life 1990-2005" Pariisis

  13. Obituary: Richard D. Schwartz (1941-2011)

    Science.gov (United States)

    Wilking, Bruce

    2011-12-01

    Richard D. Schwartz, Professor Emeritus of Astronomy, died at his home in Sequim, WA, after a nearly 3 year battle against pancreatic cancer. Richard was born in Pretty Prairie, Kansas. He was active in sports and band and graduated in 1959. After completing a BS at Kansas State, and a Master's degree in Divinity at Union Seminary in NY, he further studied astrophysics, receiving his doctorate from University of Washington in 1973. When Dick arrived at the University of Missouri-St. Louis in 1975, he was the only astronomer in the Department of Physics. He built the astronomy program and initiated the B.S. in physics with an astrophysics option that the majority of physics majors choose. Dick was a wonderful teacher and provided outstanding leadership to the campus. He designed and provided oversight on the construction of the campus observatory that was completed in 1981. Since that time the observatory has served as both a teaching and research facility. It is also used for monthly public open houses that draw hundreds of people annually to the campus to view the moon, stars, and planets. Upon his retirement in 2003, the Board of Curators approved naming the campus observatory the "Richard D. Schwartz Observatory" in honor of his distinctive service to the University of Missouri-St. Louis. Just as important as Dick's service to promote public interest in astronomy was his effort to make the campus observatory a research facility. Dick equipped and maintained the observatory with state-of-art detectors that allowed students to get their first taste of scientific research. From 1991-2003, he managed the campus program for the NASA/Missouri Space Grant Consortium and mentored over 30 research students in projects at the observatory. Some of the results have been published in astronomical journals. Many of those students went on to graduate schools and several have achieved tenure and distinction at major universities. In addition to Dick's service to the University

  14. Richard Murphy: a life in writing

    Directory of Open Access Journals (Sweden)

    E. Meihuizen

    2006-07-01

    Full Text Available The Irish poet Richard Murphy published his autobiography “The kick: a life among writers” in 2003. From a slightly different perspective the subtitle of this work could be rewritten as “A life in writing” since it is an account of the agencies that moulded a life devoted to creative writing which forms the book’s essential impetus. The memoir is based on notebooks which Murphy kept throughout his life “to hold the scraps of verse, elusive images, dreams, desires and revelations” to be developed into poetry. Apart from contextualising his poetry by registering the relationships, circumstances and landscapes from which it germinated, Murphy also tells of the creative process itself and the personal poetics underlying this process. This article explores what is regarded as the central determining feature of Murphy’s identity as poet, namely the relationship between the creative self and a particular place, where the concept of “place” is seen as a cultural palimpsest which represents not only physical qualities, but also the shaping and development of the landscape through time according to a certain way of life.

  15. Richard Murphy: Autobiography and the Connemara landscape

    Directory of Open Access Journals (Sweden)

    Elsa Meihuizen

    2015-08-01

    Full Text Available It could be argued that an important feature of Richard Murphy’s work, and of his identity as a poet is the relationship between the creative self and a particular place, where ‘place’ should be understood as referring not just to physical qualities of the natural environment, but in a broader sense to denote an environment in which everything is interrelated and connected, and in which there is no sharp division between the natural and the human. The landscape providing inspiration for Murphy’s poetic imagination is the landscapes and seascapes of Connemara in north-west Ireland. In 1959 he settled in this environment which was to be his base for the next 20 years and from this period and this location emanated the bulk of his poetic oeuvre. For Murphy committing to a life of writing poetry necessarily means being in the Connemara landscape. Returning to this environment in adulthood represents a quest for recovering childhood feelings, of belonging and love, as connected to particular places. Murphy’s Connemara poems could be read as an account of this process of re-placement, as a type of autobiographical text in which the artist creates a ‘double portrait’: in writing about the landscape he also writes about himself, creating a place-portrait which is, at the same time, a self-portrait.

  16. Richard Swedberg, The Art of Social Theory

    DEFF Research Database (Denmark)

    Carleheden, Mikael

    2015-01-01

    to systematic consideration. Swedberg attributes this strange absence to what he sees as the miserable state of contemporary social theory. We must, he claims, avoid two misconceptions: ‘empiricism’ and ‘abstract theory’. In the first case, theory is reduced to the task of summarizing the outcome of empirical......It is a rare event when a new general field of research opens up within sociology. However, with this book, Richard Swedberg intends to do just that. It is not just another book on social theory. It is a book on ‘theorizing’. And that makes all the difference. Swedberg has chosen the term ‘art......’, but also ‘craft’, to emphasize the practical side of doing theory. This topic has been strangely absent, not just in sociology but in the social sciences in general. In order to see this absence, we should ask ourselves how education in sociology is conventionally organized. The answer is by a taken...

  17. Galaxy bias and primordial non-Gaussianity

    Energy Technology Data Exchange (ETDEWEB)

    Assassi, Valentin; Baumann, Daniel [DAMTP, Cambridge University, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Schmidt, Fabian, E-mail: assassi@ias.edu, E-mail: D.D.Baumann@uva.nl, E-mail: fabians@MPA-Garching.MPG.DE [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany)

    2015-12-01

    We present a systematic study of galaxy biasing in the presence of primordial non-Gaussianity. For a large class of non-Gaussian initial conditions, we define a general bias expansion and prove that it is closed under renormalization, thereby showing that the basis of operators in the expansion is complete. We then study the effects of primordial non-Gaussianity on the statistics of galaxies. We show that the equivalence principle enforces a relation between the scale-dependent bias in the galaxy power spectrum and that in the dipolar part of the bispectrum. This provides a powerful consistency check to confirm the primordial origin of any observed scale-dependent bias. Finally, we also discuss the imprints of anisotropic non-Gaussianity as motivated by recent studies of higher-spin fields during inflation.

  18. Galaxy bias and primordial non-Gaussianity

    International Nuclear Information System (INIS)

    Assassi, Valentin; Baumann, Daniel; Schmidt, Fabian

    2015-01-01

    We present a systematic study of galaxy biasing in the presence of primordial non-Gaussianity. For a large class of non-Gaussian initial conditions, we define a general bias expansion and prove that it is closed under renormalization, thereby showing that the basis of operators in the expansion is complete. We then study the effects of primordial non-Gaussianity on the statistics of galaxies. We show that the equivalence principle enforces a relation between the scale-dependent bias in the galaxy power spectrum and that in the dipolar part of the bispectrum. This provides a powerful consistency check to confirm the primordial origin of any observed scale-dependent bias. Finally, we also discuss the imprints of anisotropic non-Gaussianity as motivated by recent studies of higher-spin fields during inflation

  19. Primordial Black Holes from First Principles (Overview)

    Science.gov (United States)

    Lam, Casey; Bloomfield, Jolyon; Moss, Zander; Russell, Megan; Face, Stephen; Guth, Alan

    2017-01-01

    Given a power spectrum from inflation, our goal is to calculate, from first principles, the number density and mass spectrum of primordial black holes that form in the early universe. Previously, these have been calculated using the Press- Schechter formalism and some demonstrably dubious rules of thumb regarding predictions of black hole collapse. Instead, we use Monte Carlo integration methods to sample field configurations from a power spectrum combined with numerical relativity simulations to obtain a more accurate picture of primordial black hole formation. We demonstrate how this can be applied for both Gaussian perturbations and the more interesting (for primordial black holes) theory of hybrid inflation. One of the tools that we employ is a variant of the BBKS formalism for computing the statistics of density peaks in the early universe. We discuss the issue of overcounting due to subpeaks that can arise from this approach (the ``cloud-in-cloud'' problem). MIT UROP Office- Paul E. Gray (1954) Endowed Fund.

  20. Primordial nucleosynthesis: A cosmological point of view

    International Nuclear Information System (INIS)

    Mathews, G. J.; Kajino, T.; Yamazaki, D.; Kusakabe, M.; Cheoun, M.-K.

    2014-01-01

    Primordial nucleosynthesis remains as one of the pillars of modern cosmology. It is the test-ing ground upon which all cosmological models must ultimately rest. It is our only probe of the universe during the first few minutes of cosmic expansion and in particular during the important radiation-dominated epoch. These lectures review the basic equations of space-time, cosmology, and big bang nucleosynthesis. We will then review the current state of observational constraints on primordial abundances along with the key nuclear reactions and their uncertainties. We summarize which nuclear measure-ments are most crucial during the big bang. We also review various cosmological models and their constraints. In particular, we summarize the constraints that big bang nucleosynthesis places upon the possible time variation of fundamental constants, along with constraints on the nature and origin of dark matter and dark energy, long-lived supersymmetric particles, gravity waves, and the primordial magnetic field

  1. Kuues väljasuremine / Richard Leakey, Roger Lewin

    Index Scriptorium Estoniae

    Leakey, Richard

    2002-01-01

    Inimtegevuse hävitavast toimest looduslikule mitmekesisusele, mis tingib loodusliku energiatootmise järsu kahanemise, millest omakorda sõltub inimese enda ellujäämine. Lühidalt Richard Leakey'st

  2. Loop corrections to primordial non-Gaussianity

    Science.gov (United States)

    Boran, Sibel; Kahya, E. O.

    2018-02-01

    We discuss quantum gravitational loop effects to observable quantities such as curvature power spectrum and primordial non-Gaussianity of cosmic microwave background (CMB) radiation. We first review the previously shown case where one gets a time dependence for zeta-zeta correlator due to loop corrections. Then we investigate the effect of loop corrections to primordial non-Gaussianity of CMB. We conclude that, even with a single scalar inflaton, one might get a huge value for non-Gaussianity which would exceed the observed value by at least 30 orders of magnitude. Finally we discuss the consequences of this result for scalar driven inflationary models.

  3. Swearing Used in Richard Wright’s Black Boy

    OpenAIRE

    Giyatmi Giyatmi; Ratih WIjayava; Nunun Tri Widarwati

    2017-01-01

    This research aims at finding the types of swearing expressions and linguistic forms of English swearing used in Richard Wright's Black Boy. This is a descriptive qualitative research since it describes the phenomena of swearing used in the novel. The data of the research are all the conversations or sentences used swearing in the novel written by Richard Wright namely Black Boy as the main data source. The method of collecting data in this research is observation and teknik lanjut catat. Aft...

  4. BHDD: Primordial black hole binaries code

    Science.gov (United States)

    Kavanagh, Bradley J.; Gaggero, Daniele; Bertone, Gianfranco

    2018-06-01

    BHDD (BlackHolesDarkDress) simulates primordial black hole (PBH) binaries that are clothed in dark matter (DM) halos. The software uses N-body simulations and analytical estimates to follow the evolution of PBH binaries formed in the early Universe.

  5. Primordial spectra from sudden turning trajectory

    Science.gov (United States)

    Noumi, Toshifumi; Yamaguchi, Masahide

    2013-12-01

    Effects of heavy fields on primordial spectra of curvature perturbations are discussed in inflationary models with a sudden turning trajectory. When heavy fields are excited after the sudden turn and oscillate around the bottom of the potential, the following two effects are generically induced: deformation of the inflationary background spacetime and conversion interactions between adiabatic and isocurvature perturbations, both of which can affect the primordial density perturbations. In this paper, we calculate primordial spectra in inflationary models with sudden turning potentials taking into account both of the two effects appropriately. We find that there are some non-trivial correlations between the two effects in the power spectrum and, as a consequence, the primordial scalar power spectrum has a peak around the scale exiting the horizon at the turn. Though both effects can induce parametric resonance amplifications, they are shown to be canceled out for the case with the canonical kinetic terms. The peak feature and the scale dependence of bispectra are also discussed.

  6. Primordial Prevention of Cardiometabolic Risk in Childhood.

    Science.gov (United States)

    Tanrikulu, Meryem A; Agirbasli, Mehmet; Berenson, Gerald

    2017-01-01

    Fetal life and childhood are important in the development of cardiometabolic risk and later clinical disease of atherosclerosis, hypertension and diabetes mellitus. Molecular and environmental conditions leading to cardiometabolic risk in early life bring us a challenge to develop effective prevention and intervention strategies to reduce cardiovascular (CV) risk in children and later disease. It is important that prevention strategies begin at an early age to reduce future CV morbidity and mortality. Pioneering work from longitudinal studies such as Bogalusa Heart Study (BHS), the Finnish Youth Study and other programs provide an awareness of the need for public and health services to begin primordial prevention. The impending CV risk beginning in childhood has a significant socioeconomic burden. Directions to achieve primordial prevention of cardiometabolic risk in children have been developed by prior longitudinal studies. Based on those studies that show risk factors in childhood as precursors of adult CV risk, implementation of primordial prevention will have effects at broad levels. Considering the epidemic of obesity, the high prevalence of hypertension and cardiometabolic risk, prevention early in life is valuable. Comprehensive health education, such as 'Health Ahead/Heart Smart', for all elementary school age children is one approach to begin primordial prevention and can be included in public education beginning in kindergarten along with the traditional education subject matter.

  7. Primordial braneworld black holes: significant enhancement of ...

    Indian Academy of Sciences (India)

    Abstract. The Randall-Sundrum (RS-II) braneworld cosmological model with a frac- tion of the total energy density in primordial black holes is considered. Due to their 5d geometry, these black holes undergo modified Hawking evaporation. It is shown that dur- ing the high-energy regime, accretion from the surrounding ...

  8. Primordial tensor modes from quantum corrected inflation

    DEFF Research Database (Denmark)

    Joergensen, Jakob; Sannino, Francesco; Svendsen, Ole

    2014-01-01

    . Finally we confront these theories with the Planck and BICEP2 data. We demonstrate that the discovery of primordial tensor modes by BICEP2 require the presence of sizable quantum departures from the $\\phi^4$-Inflaton model for the non-minimally coupled scenario which we parametrize and quantify. We...

  9. Obituary: Richard B. Dunn, 1927-2005

    Science.gov (United States)

    Keil, Stephen L.; Dooling, David

    2007-12-01

    Dr. Richard B. Dunn, astronomer emeritus at the National Solar Observatory, died of a heart attack on September 29, 2005. He was recognized as one of the foremost experimental solar physicists. His innovative designs for telescopes and instruments led to many important discoveries in solar physics. Born in Baltimore, Maryland, in 1927 and raised in Minneapolis, Minnesota, Dick's parents were Dr. Halbert L. Dunn and Katherine Brandner. Halbert (MD, Ph.D., F.A.P.H.A.) was an physician who became Chief of the National Office of Vital Statistics, Public Health Service. He published a paper "High Level Wellness for Man and Society" that became the founding paper of the field of wellness health care. After their divorce in 1942, Katherine moved to New York and became a social worker. Dick had two older brothers who died before him, Halbert (born in 1921, who became a civil engineer) and Robert (born in 1924, who became an architect). Dick earned a BS in mechanical engineering and an MS in astronomy at the University of Minnesota. At the end of World War II he served in the United States Army in Japan. For his master's degree, Dick undertook the design and construction of a Lyot-type birefringent filter for observations of solar prominences. This early work led to his acceptance at Harvard, where Professor Donald Menzel encouraged him to continue his work with the 15-inch Cambridge telescope. In 1951 he conducted part of his doctoral thesis work at the fledgling Sacramento Peak Observatory in southern New Mexico. The observatory director, Dr. John Evans, was impressed with Dick's outstanding instrumental talents and invited him to join as one of the first scientific staff members. During his first few years at Sac Peak, Dick developed two more birefringent filter systems including one with an integrated coronagraph. With this system, he produced the best prominence and spicule observations ever obtained. Dick's career was dedicated to obtaining solar observations of the

  10. Are cometary nuclei primordial rubble piles?

    Science.gov (United States)

    Weissman, P. R.

    1986-01-01

    Whipple's icy conglomerate model for the cometary nucleus has had considerable sucess in explaining a variety of cometary phenomena such as gas production rates and nongravitational forces. However, as discussed here, both observational evidence and theoretical considerations suggest that the cometary nucleus may not be a well-consolidated single body, but may instead be a loosely bound agglomeration of smaller fragments, weakly bonded and subject to occasional or even frequent disruptive events. The proposed model is analogous to the 'rubble pile' model suggested for the larger main-belt asteroids, although the larger cometary fragments are expected to be primordial condensations rather than collisionally derived debris as in the asteroid case. The concept of cometary nuclei as primordial rubble piles is proposed as a modification of the basic Whipple model, not as a replacement for it.

  11. Shapes and features of the primordial bispectrum

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Jinn-Ouk [Asia Pacific Center for Theoretical Physics, Cheongam-ro 67, Pohang, 37673 (Korea, Republic of); Palma, Gonzalo A.; Sypsas, Spyros, E-mail: jinn-ouk.gong@apctp.org, E-mail: gpalmaquilod@ing.uchile.cl, E-mail: s.sypsas@gmail.com [Departamento de Física, FCFM, Universidad de Chile, Blanco Encalada 2008, Santiago, 837.0415 Chile (Chile)

    2017-05-01

    If time-dependent disruptions from slow-roll occur during inflation, the correlation functions of the primordial curvature perturbation should have scale-dependent features, a case which is marginally supported from the cosmic microwave background (CMB) data. We offer a new approach to analyze the appearance of such features in the primordial bispectrum that yields new consistency relations and justifies the search of oscillating patterns modulated by orthogonal and local templates. Under the assumption of sharp features, we find that the cubic couplings of the curvature perturbation can be expressed in terms of the bispectrum in two specific momentum configurations, for example local and equilateral. This allows us to derive consistency relations among different bispectrum shapes, which in principle could be tested in future CMB surveys. Furthermore, based on the form of the consistency relations, we construct new two-parameter templates for features that include all the known shapes.

  12. Inflating Kahler moduli and primordial magnetic fields

    Directory of Open Access Journals (Sweden)

    Luis Aparicio

    2017-05-01

    Full Text Available We study the production of primordial magnetic fields in inflationary models in type IIB string theory where the role of the inflaton is played by a Kahler modulus. We consider various possibilities to realise the Standard Model degrees of freedom in this setting and explicitly determine the time dependence of the inflaton coupling to the Maxwell term in the models. Using this we determine the strength and scale dependence of the magnetic fields generated during inflation. The usual “strong coupling problem” for primordial magnetogenesis manifests itself by cycle sizes approaching the string scale; this appears in a certain class of fibre inflation models where the standard model is realised by wrapping D7-branes on cycles in the geometric regime.

  13. Inflating Kahler moduli and primordial magnetic fields

    International Nuclear Information System (INIS)

    Aparicio, Luis; Maharana, Anshuman

    2017-01-01

    We study the production of primordial magnetic fields in inflationary models in type IIB string theory where the role of the inflaton is played by a Kahler modulus. We consider various possibilities to realise the Standard Model degrees of freedom in this setting and explicitly determine the time dependence of the inflaton coupling to the Maxwell term in the models. Using this we determine the strength and scale dependence of the magnetic fields generated during inflation. The usual “strong coupling problem” for primordial magnetogenesis manifests itself by cycle sizes approaching the string scale; this appears in a certain class of fibre inflation models where the standard model is realised by wrapping D7-branes on cycles in the geometric regime.

  14. Inflating Kahler moduli and primordial magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Aparicio, Luis, E-mail: laparici@ictp.it [Abdus Salam ICTP, Strada Costiera 11, Trieste 34014 (Italy); Maharana, Anshuman, E-mail: anshumanmaharana@hri.res.in [Harish Chandra Research Institute, HBNI, Chattnag Road, Jhunsi, Allahabad 211019 (India)

    2017-05-10

    We study the production of primordial magnetic fields in inflationary models in type IIB string theory where the role of the inflaton is played by a Kahler modulus. We consider various possibilities to realise the Standard Model degrees of freedom in this setting and explicitly determine the time dependence of the inflaton coupling to the Maxwell term in the models. Using this we determine the strength and scale dependence of the magnetic fields generated during inflation. The usual “strong coupling problem” for primordial magnetogenesis manifests itself by cycle sizes approaching the string scale; this appears in a certain class of fibre inflation models where the standard model is realised by wrapping D7-branes on cycles in the geometric regime.

  15. Finite temperature effects in primordial inflation

    Science.gov (United States)

    Gelmini, G. B.; Nanopoulos, D. V.; Olive, K. A.

    1983-11-01

    We present a detailed study of a recently proposed model for primordial inflation based on an N=1 locally supersymmetric potential. For a large class of parameters with which all cosmological constraints are satisfied, the temperature corrections can be neglected during the inflation period. At higher temperatures, the minimum is not at the origin, but very close to it. Address after July 1, 1983: Theory Group, Fermilab, PO Box 500, Batavia, IL 60510, USA.

  16. Primordial Inflation Polarization Explorer: Status and Plans

    Science.gov (United States)

    Kogut, Alan

    2009-01-01

    The Primordial Inflation Polarization Explorer is a balloon-borne instrument to measure the polarization of the cosmic microwave background in order to detect the characteristic signature of gravity waves created during an inflationary epoch in the early universe. PIPER combines cold /I.G K\\ optics, 5120 bolometric detectors, and rapid polarization modulation using VPM grids to achieve both high sensitivity and excellent control of systematic errors. I will discuss the current status and plans for the PIPER instrument.

  17. Primordial anisotropies in gauged hybrid inflation

    Science.gov (United States)

    Akbar Abolhasani, Ali; Emami, Razieh; Firouzjahi, Hassan

    2014-05-01

    We study primordial anisotropies generated in the model of gauged hybrid inflation in which the complex waterfall field is charged under a U(1)gauge field. Primordial anisotropies are generated either actively during inflation or from inhomogeneities modulating the surface of end of inflation during waterfall transition. We present a consistent δN mechanism to calculate the anisotropic power spectrum and bispectrum. We show that the primordial anisotropies generated at the surface of end of inflation do not depend on the number of e-folds and therefore do not produce dangerously large anisotropies associated with the IR modes. Furthermore, one can find the parameter space that the anisotropies generated from the surface of end of inflation cancel the anisotropies generated during inflation, therefore relaxing the constrains on model parameters imposed from IR anisotropies. We also show that the gauge field fluctuations induce a red-tilted power spectrum so the averaged power spectrum from the gauge field can change the total power spectrum from blue to red. Therefore, hybrid inflation, once gauged under a U(1) field, can be consistent with the cosmological observations.

  18. Primordial anisotropies in gauged hybrid inflation

    International Nuclear Information System (INIS)

    Abolhasani, Ali Akbar; Emami, Razieh; Firouzjahi, Hassan

    2014-01-01

    We study primordial anisotropies generated in the model of gauged hybrid inflation in which the complex waterfall field is charged under a U(1)gauge field. Primordial anisotropies are generated either actively during inflation or from inhomogeneities modulating the surface of end of inflation during waterfall transition. We present a consistent δN mechanism to calculate the anisotropic power spectrum and bispectrum. We show that the primordial anisotropies generated at the surface of end of inflation do not depend on the number of e-folds and therefore do not produce dangerously large anisotropies associated with the IR modes. Furthermore, one can find the parameter space that the anisotropies generated from the surface of end of inflation cancel the anisotropies generated during inflation, therefore relaxing the constrains on model parameters imposed from IR anisotropies. We also show that the gauge field fluctuations induce a red-tilted power spectrum so the averaged power spectrum from the gauge field can change the total power spectrum from blue to red. Therefore, hybrid inflation, once gauged under a U(1) field, can be consistent with the cosmological observations

  19. Nuclear reaction rates and primordial 6Li

    International Nuclear Information System (INIS)

    Nollett, K.M.; Schramm, D.N.; Lemoine, M.; Schramm, D.N.; Lemoine, M.; Schramm, D.N.

    1997-01-01

    We examine the possibility that big-bang nucleosynthesis (BBN) may produce nontrivial amounts of 6 Li. If a primordial component of this isotope could be observed, it would provide a new fundamental test of big-bang cosmology, as well as new constraints on the baryon density of the universe. At present, however, theoretical predictions of the primordial 6 Li abundance are extremely uncertain due to difficulties in both theoretical estimates and experimental determinations of the 2 H(α,γ) 6 Li radiative capture reaction cross section. We also argue that present observational capabilities do not yet allow the detection of primeval 6 Li in very metal-poor stars of the galactic halo. However, if the critical cross section is very high in its plausible range and the baryon density is relatively low, then improvements in 6 Li detection capabilities may allow the establishment of 6 Li as another product of BBN. It is also noted that a primordial 6 Li detection could help resolve current concerns about the extragalactic D/H determination. copyright 1997 The American Physical Society

  20. Quantum inflaton, primordial perturbations, and CMB fluctuations

    International Nuclear Information System (INIS)

    Cao, F.J.; Vega, H.J. de; Sanchez, N.G.

    2004-01-01

    We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the dynamics of the (classical) cosmological metric. For chaotic inflation, the quantum treatment avoids the unnatural requirements of an initial state with all the energy in the zero mode. For new inflation it allows a consistent treatment of the explosive particle production due to spinodal instabilities. Quantum field inflation (under conditions that are the quantum analog of slow-roll) leads, upon evolution, to the formation of a condensate starting a regime of effective classical inflation. We compute the primordial perturbations taking the dominant quantum effects into account. The results for the scalar, vector and tensor primordial perturbations are expressed in terms of the classical inflation results. For a N-component field in a O(N) symmetric model, adiabatic fluctuations dominate while isocurvature or entropy fluctuations are negligible. The results agree with the current Wilkinson Microwave Anisotropy Probe observations and predict corrections to the power spectrum in classical inflation. Such corrections are estimated to be of the order of (m 2 /NH 2 ), where m is the inflaton mass and H the Hubble constant at the moment of horizon crossing. An upper estimate turns to be about 4% for the cosmologically relevant scales. This quantum field treatment of inflation provides the foundations to the classical inflation and permits to compute quantum corrections to it

  1. Primordial nucleosynthesis revisited via Trojan Horse Results

    Directory of Open Access Journals (Sweden)

    Pizzone R.G.

    2016-01-01

    Full Text Available Big Bang Nucleosynthesis (BBN requires several nuclear physics inputs and nuclear reaction rates. An up-to-date compilation of direct cross sections of d(d,pt, d(d,n3He and 3He(d,p4He reactions is given, being these ones among the most uncertain bare-nucleus cross sections. An intense experimental effort has been carried on in the last decade to apply the Trojan Horse Method (THM to study reactions of relevance for the BBN and measure their astrophysical S(E-factor. The reaction rates and the relative error for the four reactions of interest are then numerically calculated in the temperature ranges of relevance for BBN (0.01primordial nucleosynthesis calculations in order to evaluate their impact on the calculated primordial abundances of D, 3,4He and 7Li. These were compared with the observational primordial abundance estimates in different astrophysical sites. A comparison was also performed with calculations using other reaction rates compilations available in literature.

  2. The primordial helium abundance from updated emissivities

    International Nuclear Information System (INIS)

    Aver, Erik; Olive, Keith A.; Skillman, Evan D.; Porter, R.L.

    2013-01-01

    Observations of metal-poor extragalactic H II regions allow the determination of the primordial helium abundance, Y p . The He I emissivities are the foundation of the model of the H II region's emission. Porter, Ferland, Storey, and Detisch (2012) have recently published updated He I emissivities based on improved photoionization cross-sections. We incorporate these new atomic data and update our recent Markov Chain Monte Carlo analysis of the dataset published by Izotov, Thuan, and Stasi'nska (2007). As before, cuts are made to promote quality and reliability, and only solutions which fit the data within 95% confidence level are used to determine the primordial He abundance. The previously qualifying dataset is almost entirely retained and with strong concordance between the physical parameters. Overall, an upward bias from the new emissivities leads to a decrease in Y p . In addition, we find a general trend to larger uncertainties in individual objects (due to changes in the emissivities) and an increased variance (due to additional objects included). From a regression to zero metallicity, we determine Y p = 0.2465 ± 0.0097, in good agreement with the BBN result, Y p = 0.2485 ± 0.0002, based on the Planck determination of the baryon density. In the future, a better understanding of why a large fraction of spectra are not well fit by the model will be crucial to achieving an increase in the precision of the primordial helium abundance determination

  3. Success: Richard Dyer on Diana Ross [and Beyond

    NARCIS (Netherlands)

    Kooijman, J.

    2016-01-01

    In June 1982, film scholar Richard Dyer published a two-page essay on African-American star Diana Ross in the journal Marxism Today. Part of Dyer’s essay focuses on the American conception of success and specifically on how Ross is one of the few black artists who has been "allowed" to be such a

  4. Reading 'blackface': A (narrative) introduction to Richard Kearney's ...

    African Journals Online (AJOL)

    Prominent Irish philosopher Richard Kearney's notion of 'carnal hermeneutics' is introduced by applying it to a case study of a recent event that took place at one of South Africa's university campuses. The narrative assists in illuminating some of the core principles of carnal hermeneutics and illustrates the applicability of ...

  5. To Have Been a Student of Richard Feynman

    Indian Academy of Sciences (India)

    Excerpt from Most of the Good Stuff: Memories of Richard Feynman, 1993, ... of Feynman, but while it inspired us to try for originality after we left Cornell, it also lowered our productivity to a point that at times was dangerous to our academic careers. In truth .... (However, my actual thesis topic turned out to be a different one.).

  6. Koht, kust tagasi ei tulda / Mark Jenkins ; fotod Cory Richards

    Index Scriptorium Estoniae

    Jenkins, Mark

    2015-01-01

    National Geographicu ekspeditsiooni, mille koosseisu kuulusid Renan Ozturk, Mark Jenkins, Cory Richards, Emily Harrington ja Kilaree O'Neill, püüdlustest tõusta Kagu-Aasia kõrgeima mäe Hkakabo Razi tippu ning mõõta selle täpset kõrgust GPS-i abil

  7. Whatever Happened to Richard Reid's List of First Programming Languages?

    Science.gov (United States)

    Siegfried, Robert M.; Greco, Daniel M.; Miceli, Nicholas G.; Siegfried, Jason P.

    2012-01-01

    Throughout the 1990s, Richard Reid of Michigan State University maintained a list showing the first programming language used in introductory programming courses taken by computer science and information systems majors; it was updated for several years afterwards by Frances Van Scoy of West Virginia University. However, it has been 5 years since…

  8. In memoriam: Richard (Rick) G. Harrison—benefactor for ...

    Indian Academy of Sciences (India)

    Professor Richard Harrison (1946–2016), a most influential evolutionary biologist of ... were profoundly important in my development as a scientist and a person. ... observations to infer his love of family, but I am going to risk correction by those ...

  9. Chiral primordial gravitational waves from a Lifshitz point.

    Science.gov (United States)

    Takahashi, Tomohiro; Soda, Jiro

    2009-06-12

    We study primordial gravitational waves produced during inflation in quantum gravity at a Lifshitz point proposed by Horava. Assuming power-counting renormalizability, foliation-preserving diffeomorphism invariance, and the condition of detailed balance, we show that primordial gravitational waves are circularly polarized due to parity violation. The chirality of primordial gravitational waves is a quite robust prediction of quantum gravity at a Lifshitz point which can be tested through observations of cosmic microwave background radiation and stochastic gravitational waves.

  10. Fingerprints of primordial universe paradigms as features in density perturbations

    International Nuclear Information System (INIS)

    Chen Xingang

    2011-01-01

    Experimentally distinguishing different primordial universe paradigms that lead to the Big Bang model is an outstanding challenge in modern cosmology and astrophysics. We show that a generic type of signals that exist in primordial universe models can be used for such purpose. These signals are induced by tiny oscillations of massive fields and manifest as features in primordial density perturbations. They are capable of recording the time-dependence of the scale factor of the primordial universe, and therefore provide direct evidence for specific paradigm. These signals present special opportunities and challenges for experiments and data analyses.

  11. Primordial black holes from passive density fluctuations

    International Nuclear Information System (INIS)

    Lin, Chia-Min; Ng, Kin-Wang

    2013-01-01

    In this Letter, we show that if passive fluctuations are considered, primordial black holes (PBHs) can be easily produced in the framework of single-field, slow-roll inflation models. The formation of PBHs is due to the blue spectrum of passive fluctuations and an enhancement of the spectral range which exits horizon near the end of inflation. Therefore the PBHs are light with masses ≲10 15 g depending on the number of e-folds when the scale of our observable universe leaves horizon. These PBHs are likely to have evaporated and cannot be a candidate for dark matter but they may still affect the early universe.

  12. Primordial black holes from passive density fluctuations

    OpenAIRE

    Lin, Chia-Min; Ng, Kin-Wang

    2013-01-01

    In this paper, we show that if passive fluctuations are considered, primordial black holes (PBHs) can be easily produced in the framework of single-field, slow-roll inflation models. The formation of PBHs is due to the blue spectrum of passive fluctuations and an enhancement of the spectral range which exits horizon near the end of inflation. Therefore the PBHs are light with masses $\\lesssim 10^{15}g$ depending on the number of e-folds when the scale of our observable universe leaves horizon...

  13. Identifying the inflaton with primordial gravitational waves.

    Science.gov (United States)

    Easson, Damien A; Powell, Brian A

    2011-05-13

    We explore the ability of experimental physics to uncover the underlying structure of the gravitational Lagrangian describing inflation. While the observable degeneracy of the inflationary parameter space is large, future measurements of observables beyond the adiabatic and tensor two-point functions, such as non-gaussianity or isocurvature modes, might reduce this degeneracy. We show that, even in the absence of such observables, the range of possible inflaton potentials can be reduced with a precision measurement of the tensor spectral index, as might be possible with a direct detection of primordial gravitational waves.

  14. Primordial hadrosynthesis in the Little Bang

    CERN Document Server

    Heinz, Ulrich W

    1999-01-01

    The present status of soft hadron production in high energy heavy-ion collisions is summarized. In spite of strong evidence for extensive dynamical evolution and collective expansion of the fireball before freeze-out I argue that its chemical composition is hardly changed by hadronic final state interactions. The measured hadron yields thus reflect the primordial conditions at hadronization. The observed production pattern is consistent with statistical hadronization at the Hagedorn temperature from a state of uncorrelated, color deconfined quarks and antiquarks, but requires non-trivial chemical evolution of the fireball in a prehadronic (presumably QGP) stage before hadron formation.

  15. Resolving primordial physics through correlated signatures

    OpenAIRE

    Enqvist, Kari; Mulryne, David J.; Nurmi, Sami

    2014-01-01

    We discuss correlations among spectral observables as a new tool for differentiating between models for the primordial perturbation. We show that if generated in the isocurvature sector, a running of the scalar spectral index is correlated with the statistical properties of non-Gaussianities. In particular, we find a large running will inevitably be accompanied by a large running of $f_{\\rm NL}$ and enhanced $g_{\\rm NL}$, with $g_{\\rm NL}\\gg f_{\\rm NL}^2$. If the tensor to scalar ratio is lar...

  16. Gravitational waves from primordial black hole mergers

    Energy Technology Data Exchange (ETDEWEB)

    Raidal, Martti; Vaskonen, Ville; Veermäe, Hardi, E-mail: martti.raidal@cern.ch, E-mail: ville.vaskonen@kbfi.ee, E-mail: hardi.veermae@cern.ch [NICPB, Rävala 10, 10143 Tallinn (Estonia)

    2017-09-01

    We study the production of primordial black hole (PBH) binaries and the resulting merger rate, accounting for an extended PBH mass function and the possibility of a clustered spatial distribution. Under the hypothesis that the gravitational wave events observed by LIGO were caused by PBH mergers, we show that it is possible to satisfy all present constraints on the PBH abundance, and find the viable parameter range for the lognormal PBH mass function. The non-observation of a gravitational wave background allows us to derive constraints on the fraction of dark matter in PBHs, which are stronger than any other current constraint in the PBH mass range 0.5−30 M {sub ⊙}. We show that the predicted gravitational wave background can be observed by the coming runs of LIGO, and its non-observation would indicate that the observed events are not of primordial origin. As the PBH mergers convert matter into radiation, they may have interesting cosmological implications, for example in the context of relieving the tension between high and low redshift measurements of the Hubble constant. However, we find that these effects are suppressed as, after recombination, no more that 1% of dark matter can be converted into gravitational waves.

  17. Jupiter's evolution with primordial composition gradients

    Science.gov (United States)

    Vazan, Allona; Helled, Ravit; Guillot, Tristan

    2018-02-01

    Recent formation and structure models of Jupiter suggest that the planet can have composition gradients and not be fully convective (adiabatic). This possibility directly affects our understanding of Jupiter's bulk composition and origin. In this Letter we present Jupiter's evolution with a primordial structure consisting of a relatively steep heavy-element gradient of 40 M⊕. We show that for a primordial structure with composition gradients, most of the mixing occurs in the outer part of the gradient during the early evolution (several 107 yr), leading to an adiabatic outer envelope (60% of Jupiter's mass). We find that the composition gradient in the deep interior persists, suggesting that 40% of Jupiter's mass can be non-adiabatic with a higher temperature than the one derived from Jupiter's atmospheric properties. The region that can potentially develop layered convection in Jupiter today is estimated to be limited to 10% of the mass. Movies associated to Figs. 1-3 are available at http://https://www.aanda.org

  18. The statistical clustering of primordial black holes

    International Nuclear Information System (INIS)

    Carr, B.J.

    1977-01-01

    It is shown that Meszaros theory of galaxy formation, in which galaxies form from the density perturbations associated with the statistical fluctuation in the number density of primordial black holes, must be modified if the black holes are initially surrounded by regions of lower radiation density than average (as is most likely). However, even in this situation, the sort of effect Meszaros envisages does occur and could in principle cause galactic mass-scales to bind at the conventional time. In fact, the requirement that galaxies should not form prematurely implies that black holes could not have a critical density in the mass range above 10 5 M(sun). If the mass spectrum of primordial black holes falls off more slowly than m -3 (as expected), then the biggest black holes have the largest clustering effect. In this case the black hole clustering theory of galaxy formation reduces to the black hole seed theory of galaxy formation, in which each galaxy becomes bound under the gravitational influence of a single black hole nucleus. The seed theory could be viable only if the early Universe had a soft equation of state until a time exceeding 10 -4 s or if something prevented black hole formation before 1 s. (orig.) [de

  19. Summary of Recent Developments in Primordial Nucleosynthesis.

    Science.gov (United States)

    Schramm, D N

    1993-06-01

    This paper summarizes the recent observational and theoretical results on Big Bang Nucleosynthesis. In particular, it is shown that the new Pop II (6)Li results strongly support the argument that the Spite Plateau lithium is a good estimate of the primordial value. The (6)Li is consistent with the Be and Be found in Pop II stars, assuming those elements are cosmic ray produced. The HST (2)D value tightens the (2)D arguments and the observation of the (3)He in planetary nebula strengthens the (3)He +(2)D argument as a lower bound on Ωb. The new low metalicity (4)He determinations slightly raise the best primordial (4)He number and thus make a better fit and avoid a potential problem. The quark-hadron inspired inhomogeneous calculations now unanimously agree that only relatively small variations in Ωb are possible vis-à-vis the homogeneous model; hence, the robustness of Ωb∼ 0.05 is now apparent. A comparison with the ROSAT cluster data is also shown to be consistent with the standard BBN model. Ωb∼ 1 seems to be definitely excluded, so, if Ω= 1, as some recent observations may hint, then non-baryonic dark matter is required.

  20. Inflation and dark matter primordial black holes

    International Nuclear Information System (INIS)

    Erfani, Encieh

    2012-09-01

    In this thesis a broad range of single field models of inflation are analyzed in light of all relevant recent cosmological data, checking whether they can lead to the formation of long-lived Primordial Black Holes (PBHs) to serve as candidates for Dark Matter. To that end we calculate the spectral index of the power spectrum of primordial perturbations as well as its first and second derivatives. PBH formation is possible only if the spectral index increases significantly at small scales, i.e. large wave number k. Since current data indicate that the first derivative α S of the spectral index n S (k pivot ) is negative at the pivot scale k pivot , PBH formation is only possible in the presence of a sizable and positive second derivative (''running of the running'') β S . Among the three small-field and five large-field inflation models we analyze, only one small-field model, the ''running-mass'' model, allows PBH formation, for a narrow range of parameters. We also note that none of the models we analyze can accord for a large and negative value of α S , which is weakly preferred by current data. Similarly, proving conclusively that the second derivative of the spectral index is positive would exclude all the large-field models we investigated.

  1. Inflation and dark matter primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Erfani, Encieh

    2012-09-15

    In this thesis a broad range of single field models of inflation are analyzed in light of all relevant recent cosmological data, checking whether they can lead to the formation of long-lived Primordial Black Holes (PBHs) to serve as candidates for Dark Matter. To that end we calculate the spectral index of the power spectrum of primordial perturbations as well as its first and second derivatives. PBH formation is possible only if the spectral index increases significantly at small scales, i.e. large wave number k. Since current data indicate that the first derivative {alpha}{sub S} of the spectral index n{sub S}(k{sub pivot}) is negative at the pivot scale k{sub pivot}, PBH formation is only possible in the presence of a sizable and positive second derivative (''running of the running'') {beta}{sub S}. Among the three small-field and five large-field inflation models we analyze, only one small-field model, the ''running-mass'' model, allows PBH formation, for a narrow range of parameters. We also note that none of the models we analyze can accord for a large and negative value of {alpha}{sub S}, which is weakly preferred by current data. Similarly, proving conclusively that the second derivative of the spectral index is positive would exclude all the large-field models we investigated.

  2. Cosmological implications of primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Luis Bernal, José; Bellomo, Nicola; Raccanelli, Alvise; Verde, Licia, E-mail: joseluis.bernal@icc.ub.edu, E-mail: nicola.bellomo@icc.ub.edu, E-mail: alvise@icc.ub.edu, E-mail: liciaverde@icc.ub.edu [ICC, University of Barcelona, IEEC-UB, Martí i Franquès, 1, E08028 Barcelona (Spain)

    2017-10-01

    The possibility that a relevant fraction of the dark matter might be comprised of Primordial Black Holes (PBHs) has been seriously reconsidered after LIGO's detection of a ∼ 30 M {sub ⊙} binary black holes merger. Despite the strong interest in the model, there is a lack of studies on possible cosmological implications and effects on cosmological parameters inference. We investigate correlations with the other standard cosmological parameters using cosmic microwave background observations, finding significant degeneracies, especially with the tilt of the primordial power spectrum and the sound horizon at radiation drag. However, these degeneracies can be greatly reduced with the inclusion of small scale polarization data. We also explore if PBHs as dark matter in simple extensions of the standard ΛCDM cosmological model induces extra degeneracies, especially between the additional parameters and the PBH's ones. Finally, we present cosmic microwave background constraints on the fraction of dark matter in PBHs, not only for monochromatic PBH mass distributions but also for popular extended mass distributions. Our results show that extended mass distribution's constraints are tighter, but also that a considerable amount of constraining power comes from the high-ℓ polarization data. Moreover, we constrain the shape of such mass distributions in terms of the correspondent constraints on the PBH mass fraction.

  3. Statistical clustering of primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Carr, B J [Cambridge Univ. (UK). Inst. of Astronomy

    1977-04-01

    It is shown that Meszaros theory of galaxy formation, in which galaxies form from the density perturbations associated with the statistical fluctuation in the number density of primordial black holes, must be modified if the black holes are initially surrounded by regions of lower radiation density than average (as is most likely). However, even in this situation, the sort of effect Meszaros envisages does occur and could in principle cause galactic mass-scales to bind at the conventional time. In fact, the requirement that galaxies should not form prematurely implies that black holes could not have a critical density in the mass range above 10/sup 5/ M(sun). If the mass spectrum of primordial black holes falls off more slowly than m/sup -3/ (as expected), then the biggest black holes have the largest clustering effect. In this case the black hole clustering theory of galaxy formation reduces to the black hole seed theory of galaxy formation, in which each galaxy becomes bound under the gravitational influence of a single black hole nucleus. The seed theory could be viable only if the early Universe had a soft equation of state until a time exceeding 10/sup -4/ s or if something prevented black hole formation before 1 s.

  4. Astronomical fire: Richard Carrington and the solar flare of 1859.

    Science.gov (United States)

    Clark, Stuart

    2007-09-01

    An explosion on the Sun in 1859, serendipitously witnessed by amateur astronomer Richard Carrington, plunged telegraphic communications into chaos and bathed two thirds of the Earth's skies in aurorae. Explaining what happened to the Sun and how it could affect Earth, 93 million miles away, helped change the direction of astronomy. From being concerned principally with charting the stars to aid navigation, astronomers became increasingly concerned with what the celestial objects were, how they behaved and how they might affect life on Earth.

  5. Drawings of fossils by Robert Hooke and Richard Waller

    Science.gov (United States)

    Kusukawa, Sachiko

    2013-01-01

    The drawings of fossils by Robert Hooke and Richard Waller that were the basis of the engravings in Hooke's Posthumous works (1705) are published here for the first time. The drawings show that both Hooke and Waller were proficient draftsmen with a keen eye for the details of petrified objects. These drawings provided Hooke with a polemic edge in making the case for the organic origins of ‘figured stones’.

  6. Richard Carwardine and Jay Sexton, eds., The Global Lincoln.

    Directory of Open Access Journals (Sweden)

    Hans Krabbendam

    2012-06-01

    Full Text Available Most countries have their export heroes that transcend their national origin: India has its Ghandi, South Africa its Mandela, England its Churchill, and the US has Abraham Lincoln. While particularly known for his role in the American Civil War, he has developed into an international beacon for liberalism and democracy, especially for nationals deprived of this liberties.This collection of essays, edited by Corpus Christi College (Oxford, UK colleagues Richard Carwardine and Jay Sexton, puts...

  7. When Richard Branson wants to build his own facility

    International Nuclear Information System (INIS)

    Cosnard, D.

    2005-01-01

    The capacity of petroleum refineries is today insufficient to meet the demand. In front of this shortage, Sir Richard Branson, the owner of Virgin Atlantic Airways, has decided to invest in the building of a refinery in Europe or in Canada. His new company, Virgin Oil, is already launched. However, the setting up of a new facility is very expensive and raises important problems of permits and public contestation which remain to be solved. Short paper. (J.S.)

  8. Historical Investigations of the Richard B. Russell Multiple Resource Area.

    Science.gov (United States)

    1981-11-01

    period of this project as a contemporary c~lebration and a reiteration of an ancient folk construction, Stonehenge . Appropriately, as this document goes to...55, 56m, 59m, 64m, 65-68, 71- Stonehenge 216 72, 75-76, 79-84, 84m, 91, 94- Sutch, Richard 20 95, 100, lOlm, 102, 103, 121m, Swift, James Y. 195 126

  9. Response to Richard Widdess: Music, Meaning and Culture

    Directory of Open Access Journals (Sweden)

    Jerome Lewis

    2012-09-01

    Full Text Available This commentary discusses the anthropological implications of Richard Widess’ paper by summarizing some anthropological approaches to music, especially focusing on the way musical participation inculcates and transmits an aesthetic orientation that guides action across cultural domains such as politics, economics and religion. The paper ends by suggesting that the heart of human culture is more likely to be an aesthetic orientation than a script or set of rules, and traces out some reasons why music does this so well.

  10. Richard Wright, Toni Morrison, and United States book clubs

    Directory of Open Access Journals (Sweden)

    Mark Madigan

    2004-12-01

    Full Text Available This essay focuses on the influence of commercial book clubs in the United States. It will examine the country's oldest commercial book club, the Book-of-the-Month Club (BOMC, Oprah's Book Club (OBC, which bears the name of its founder, television personality Oprah Winfrey, and their roles in the careers of two African-American authors, Richard Wright and Toni Morrison.

  11. Bridging the Knowledge Gaps between Richards' Equation and Budyko Equation

    Science.gov (United States)

    Wang, D.

    2017-12-01

    The empirical Budyko equation represents the partitioning of mean annual precipitation into evaporation and runoff. Richards' equation, based on Darcy's law, represents the movement of water in unsaturated soils. The linkage between Richards' equation and Budyko equation is presented by invoking the empirical Soil Conservation Service curve number (SCS-CN) model for computing surface runoff at the event-scale. The basis of the SCS-CN method is the proportionality relationship, i.e., the ratio of continuing abstraction to its potential is equal to the ratio of surface runoff to its potential value. The proportionality relationship can be derived from the Richards' equation for computing infiltration excess and saturation excess models at the catchment scale. Meanwhile, the generalized proportionality relationship is demonstrated as the common basis of SCS-CN method, monthly "abcd" model, and Budyko equation. Therefore, the linkage between Darcy's law and the emergent pattern of mean annual water balance at the catchment scale is presented through the proportionality relationship.

  12. When Richard Branson wants to build his own facility; Quand Richard Branson veut construire son propre complexe

    Energy Technology Data Exchange (ETDEWEB)

    Cosnard, D

    2005-10-01

    The capacity of petroleum refineries is today insufficient to meet the demand. In front of this shortage, Sir Richard Branson, the owner of Virgin Atlantic Airways, has decided to invest in the building of a refinery in Europe or in Canada. His new company, Virgin Oil, is already launched. However, the setting up of a new facility is very expensive and raises important problems of permits and public contestation which remain to be solved. Short paper. (J.S.)

  13. Electroweak baryogenesis with primordial hypermagnetic fields

    International Nuclear Information System (INIS)

    Ayala, Alejandro; Pallares, Gabriel; Besprosvany, Jaime; Piccinelli, Gabriella

    2002-01-01

    Primordial magnetic fields, independently of their origin, could have had a significant influence over several physical processes that took place during the evolution of the early universe, in particular baryogenesis. Recall that for temperatures above the electroweak phase transition (T > 100 GeV), the symmetry of the standard model corresponded to the U(1)y hypercharge group, instead of the U(1)em electromagnetic group and are therefore properly called hypermagnetic fields. In this work, we show that during a first order electroweak phase transition, the presence of hypermagnetic fields produces an axial charge segregation in the reflection and transmission of fermions off the true vacuum bubbles. We also comment on the possible consequences that these processes have for the generation of baryon number during the phase transition

  14. Schwinger-Keldysh diagrammatics for primordial perturbations

    Science.gov (United States)

    Chen, Xingang; Wang, Yi; Xianyu, Zhong-Zhi

    2017-12-01

    We present a systematic introduction to the diagrammatic method for practical calculations in inflationary cosmology, based on Schwinger-Keldysh path integral formalism. We show in particular that the diagrammatic rules can be derived directly from a classical Lagrangian even in the presence of derivative couplings. Furthermore, we use a quasi-single-field inflation model as an example to show how this formalism, combined with the trick of mixed propagator, can significantly simplify the calculation of some in-in correlation functions. The resulting bispectrum includes the lighter scalar case (mcase (m>3H/2) that has not been explicitly computed for this model. The latter provides a concrete example of quantum primordial standard clocks, in which the clock signals can be observably large.

  15. Primordial Evolution in the Finitary Process Soup

    Science.gov (United States)

    Görnerup, Olof; Crutchfield, James P.

    A general and basic model of primordial evolution—a soup of reacting finitary and discrete processes—is employed to identify and analyze fundamental mechanisms that generate and maintain complex structures in prebiotic systems. The processes—ɛ-machines as defined in computational mechanics—and their interaction networks both provide well defined notions of structure. This enables us to quantitatively demonstrate hierarchical self-organization in the soup in terms of complexity. We found that replicating processes evolve the strategy of successively building higher levels of organization by autocatalysis. Moreover, this is facilitated by local components that have low structural complexity, but high generality. In effect, the finitary process soup spontaneously evolves a selection pressure that favors such components. In light of the finitary process soup's generality, these results suggest a fundamental law of hierarchical systems: global complexity requires local simplicity.

  16. The Search for Primordial Molecular Cloud Matter

    DEFF Research Database (Denmark)

    van Kooten, Elishevah M M E

    evolution. Some of the least altered, most primitive meteorites can give us clues to the original make-up of the interstellar molecular cloud from which the Sun and its surrounding planets formed, thus, permitting us to trace Solar System formation from its most early conditions. Using state......Our Solar System today presents a somewhat static picture compared to the turbulent start of its existence. Meteorites are the left-over building blocks of planet formation and allow us to probe the chemical and physical processes that occurred during the first few million years of Solar System...... prebiotic species such as amino acids, determining the formation pathways of this organic matter is of utmost importance to understanding the habitability of Earth as well as exoplanetary systems. Hence, further detailed analyses of organic matter in some of the meteorites with primordial signatures have...

  17. Microcephalic osteodysplastic primordial dwarfism type 1.

    Science.gov (United States)

    Ferrell, Steven; Johnson, Aaron; Pearson, Waylon

    2016-06-16

    Microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1) is an uncommon cause of microcephaly and intrauterine growth retardation in a newborn. Early identifying features include but are not limited to sloping forehead, micrognathia, sparse hair, including of eyebrows and short limbs. Immediate radiological findings may include partial or complete agenesis of the corpus callosum, interhemispheric cyst and shallow acetabula leading to dislocation. Genetic testing displaying a mutation in RNU4ATAC gene is necessary for definitive diagnosis. Early identification is important as MOPD1 is an autosomal recessive condition and could present in subsequent pregnancies. The purpose of this case is to both identify and describe some common physical findings related to MOPD1. We present a case of MOPD1 in a girl born to non-consanguineous parents that was distinct for subglottic stenosis and laryngeal cleft. 2016 BMJ Publishing Group Ltd.

  18. Spectrum evolution of primordial cosmic turbulence

    International Nuclear Information System (INIS)

    Futamase, T.; Matsuda, T.

    1980-01-01

    The evolution of primordial cosmic turbulence prior to the epoch of plasma recombination is investigated numerically using the Wiener-Hermite expansion technique which gives reasonable results for laboratory turbulence. It is found that the Kolmogorov spectrum is established only within a narrow range of wavenumber space for reasonable parameter sets, because the expansion of the Universe has a tendency to suppress an energy cascade from larger eddies to smaller ones. The present result does not agree with that obtained by Kurskov and Ozernoi, who computed the decay of turbulence in a fictitious non-expanding frame using the Heisenberg closure hypothesis, while it was done in a physical frame in the present work. (author)

  19. Primordial beryllium as a big bang calorimeter.

    Science.gov (United States)

    Pospelov, Maxim; Pradler, Josef

    2011-03-25

    Many models of new physics including variants of supersymmetry predict metastable long-lived particles that can decay during or after primordial nucleosynthesis, releasing significant amounts of nonthermal energy. The hadronic energy injection in these decays leads to the formation of ⁹Be via the chain of nonequilibrium transformations: Energy(h)→T, ³He→⁶He, ⁶Li→⁹Be. We calculate the efficiency of this transformation and show that if the injection happens at cosmic times of a few hours the release of O(10 MeV) per baryon can be sufficient for obtaining a sizable ⁹Be abundance. The absence of a plateau structure in the ⁹Be/H abundance down to a O(10⁻¹⁴) level allows one to use beryllium as a robust constraint on new physics models with decaying or annihilating particles.

  20. Primordial nucleosynthesis in the new cosmology

    International Nuclear Information System (INIS)

    Cyburt, R.H.

    2003-01-01

    Big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies independently predict the universal baryon density. Comparing their predictions will provide a fundamental test on cosmology. Using BBN and the CMB together, we will be able to constrain particle physics, and predict the primordial, light element abundances. These future analyses hinge on new experimental and observational data. New experimental data on nuclear cross sections will help reduce theoretical uncertainties in BBN's predictions. New observations of light element abundances will further sharpen BBN's probe of the baryon density. Observations from the MAP and PLANCK satellites will measure the fluctuations in the CMB to unprecedented accuracy, allowing the precise determination of the baryon density. When combined, this data will present us with the opportunity to perform precision cosmology

  1. Grand unification scale primordial black holes: consequences and constraints.

    Science.gov (United States)

    Anantua, Richard; Easther, Richard; Giblin, John T

    2009-09-11

    A population of very light primordial black holes which evaporate before nucleosynthesis begins is unconstrained unless the decaying black holes leave stable relics. We show that gravitons Hawking radiated from these black holes would source a substantial stochastic background of high frequency gravititational waves (10(12) Hz or more) in the present Universe. These black holes may lead to a transient period of matter-dominated expansion. In this case the primordial Universe could be temporarily dominated by large clusters of "Hawking stars" and the resulting gravitational wave spectrum is independent of the initial number density of primordial black holes.

  2. Review of Richard Bausch, Hello to the Cannibals

    Directory of Open Access Journals (Sweden)

    Géraldine Chouard

    2006-03-01

    Full Text Available Richard Bausch is credited with five collections of short stories and nine novels that have received various awards in the United States. His latest work, Hello to the Cannibals, blends a historical epic and a more intimate tale. Watch out‑this is a voracious novel.Other CarnageAn ethnologist investigating cannibalistic rites in Africa asks the head of the tribe : « Do you still have cannibals in your tribe ? » « No, we ate the last one yesterday, » answers the head of the tribe. Undoubtedly,...

  3. Richard H. Thaler: Wirtschaftsnobelpreisträger 2017

    OpenAIRE

    Bruttel, Lisa Verena; Stolley, Florian

    2017-01-01

    Der diesjährige Nobelpreisträger Richard H. Thaler ist einer breiteren Öffentlichkeit vor allem durch sein mit Cass R. Sunstein gemeinsam verfasstes Buch zum Nudging bekannt geworden. Tatsächlich hat er in den vergangenen 40 Jahren die Entwicklung der Verhaltensökonomie entscheidend mitgeprägt und vorangebracht. Thaler hat die Annahmen hinter dem Modell des Homo oeconomicus untersucht und die Abweichungen menschlichen Verhaltens von den Rationalitätsannahmen auf zwei wesentliche Ursachen zurü...

  4. [Sir William Richard Gowers: author of the "bible of neurology"].

    Science.gov (United States)

    Hirose, Genjiro

    2014-11-01

    William Richard Gowers is one of the great pioneers in neurology and the author of the well-known neurology textbook, "A Manual of Diseases of the Nervous System." His concepts of neurology are based on meticulously and carefully accumulated knowledge of history, observations, and neurological examinations of patients with various neurological diseases. He is not only a great neurologist but also a great teacher who loves teaching students and physicians through well-prepared lectures. We can glean the essence of the field of neurology through his life story and numerous writings concerning neurological diseases.

  5. "Symposium" by Richard Dawkins, Gerard 't Hooft, Alain Connes

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    Richard Dawkins will speak on biology, Gerard ‘t Hooft will focus on physics, and Alain Connes will discuss mathematics. CERN scientists probe ever-deeper levels of matter and their interactions, but can we say that the patterns they see are truly fundamental? Does the universe obey the same laws throughout? Since mathematical constructions can be true in the absence of any relation to the physical world, is mathematics more fundamental than physics? Extraterrestrial life would probably look much different from that on Earth, but natural selection still be fundamental to their evolution?

  6. Richard Wollheim über die Metapher in der Malerei

    OpenAIRE

    Heinrich, Richard

    1993-01-01

    Es handelt sich um den Text eines Vortrages, den ich Jänner 1993 im Rahmen einer Vortragsreihe am Institut für Kunstgeschichte der Universität Wien gehalten habe. Er ist bisher unpubliziert und nicht redigiert. Das worüber ich spreche ist ein Artikel von Richard Wollheim mit dem Titel "Die Metapher in der Malerei". Diesen Artikel habe ich herausgegeben, gemeinsam mit meinem Kollegen Helmuth Vetter, 1991 in dem Band "Bilder der Philosophie". Ursprünglich handelt es sich um einen Vortrag, d...

  7. Richard Rorty, o la posibilidad de un etnocentrismo universal

    Directory of Open Access Journals (Sweden)

    Isabel Gamero Cabrera

    2010-04-01

    Full Text Available En el presente artículo intentaremos comprender y analizar las implicaciones actuales de dos tesis del filósofo estadounidense Richard Rorty en relación con su etnocentrismo: La expansión global del sistema democrático liberal como horizonte de su teoría política y la restricción de las creencias de importancia última a la esfera privada. Compararemos esta teoría con las aportaciones de otros dos autores: una interpretación antropológica de los juegos de lenguaje de Wittgenstein y la democracia radical de Mouffe.

  8. Free as in Freedom Richard Stallman's Crusade for Free Software

    CERN Document Server

    Williams, Sam

    2011-01-01

    Free as in Freedom interweaves biographical snapshots of GNU project founder Richard Stallman with the political, social and economic history of the free software movement. It examines Stallman's unique personality and how that personality has been at turns a driving force and a drawback in terms of the movement's overall success. Free as in Freedom examines one man's 20-year attempt to codify and communicate the ethics of 1970s era "hacking" culture in such a way that later generations might easily share and build upon the knowledge of their computing forebears. The book documents Stallman'

  9. Primordial Noble Gases from Earth's Core

    Science.gov (United States)

    Wang, K.; Lu, X.; Brodholt, J. P.

    2016-12-01

    Recent partitioning experiment suggests helium is more compatible in iron melt than in molten silicates at high pressures (> 10 GPa) (1), thus provide the possibility of the core as being the primordial noble gases warehouse that is responsible for the high primordial/radiogenic noble gas isotopic ratios observed in plume-related basalts. However, the possible transportation mechanism of the noble gases from the core to the overlying mantle is still ambiguous, understanding how this process would affect the noble gas isotopic characteristics of the mantle is critical to validate this core reservoir model. As diffusion is a dominant mass transport process that plays an important role in chemical exchange at the core-mantle boundary (CMB), we have determined the diffusion coefficients of helium, neon and argon in major lower mantle minerals, i.e. periclase (MgO), bridgemanite (MgSiO3-Pv) and post-perovskite (MgSiO3-PPv), by first-principles calculation based on density functional theory (DFT). As expected, the diffusion rate of helium is the fastest at the CMB, which is in the range of 3 × 10-10 to 1 × 10-8 m2/s. The neon diffusion is slightly slower, from 5 × 10-10 to 5 × 10-9 m2/s. Argon diffuses slowest at the rate from 1 × 10-10 to 2 × 10-10 m2/s. We have further simulated the evolution of noble gas isotopic ratios in the mantle near the CMB. Considering its close relationship with the mantle plumes and very likely to be the direct source of "hot-spot" basalts, we took a close investigation on the large low-shear-velocity provinces (LLSVPs). Under reasonable assumptions based on our diffusion parameters, the modelling results indicate that LLSVP is capable of generating all the noble gas isotope signals, e.g., 3He/4He = 55 Ra, 3He/22Ne = 3.1, 3He/36Ar = 0.82, 40Ar/36Ar = 9500, that are in good agreement with the observed values in "hot-spot" basalts (2). Therefore, this core-reservior hypothesis is a self-consistent model that can fits in multiple noble gas

  10. The Paradox of the Public Realm in Richard Rorty

    Directory of Open Access Journals (Sweden)

    Martha Palacio Avendaño

    2008-12-01

    Full Text Available The concepto of the public sphere in Richard Rorty's philosophy, inherited of liberal tradition, allows be treated as a part of a game of language called democratic liberalism. One of the rules for validating a move in this game consists in taking for granted the distinction between the public and the private spheres. Richard Rorty thought that democratic liberalism did not need any foundation beyond the way to play it; its only criteria would be the game's practices, according an utopia which would allow us to make more movements in the game. That is, democratic liberalism does not require foundations, but just practices for achieving a social hioe inspired on freedom and pluralism. This kind of utopia, based upon the non-cruelty principle, would make possible an inclusive society where everyone would have a place for their own private vocabulary. In this way, Rorty would have linked freedom and solidarity. However, this language-game reveals the paradox of the link which implies the meaning of the public shere. Herein, freedom is not a sufficient condition of solidarity; hence, there is no place for social inclusion in Rorty's language game.

  11. Argument from Design in Richard Baxter's Natural Theology

    Directory of Open Access Journals (Sweden)

    Igor Koshelev

    2017-12-01

    Full Text Available The article deals with the teleological argument, or argument from design, as expounded by a famous English Protestant theologian Richard Baxter, one of the leading 17-th century English Puritans, in his work “The Reasons of the Christian Religion”. Natural theology, providing arguments for the existence of God based on reason and without appeal to the Revelation, has always played a vital role throughout the entire history of theological thought. The most popular was the so called teleological argument, or the argument from design, which stands out among all rational arguments for the existence of the Creator. It is mostly known from the “Fifth Way” of the medieval Scholastic philosopher Thomas Aquinas and a famous work “Natural Theology” by an English 19-th century theologian William Paley. The foundation for the modern research in the area was laid during the age of the Scientific Revolution of the 17th century English nature philosophers and theologians, especially Robert Boyle, who believed the teleological argument to be the key element of Natural Theology. His friend and confessor, Richard Baxter, a prominent representative of the Puritan Natural Theology, mostly known by his theological works, paved the way for Natural Theology both in his own time and the following centuries. His work was thought to be the best collection of the evidences for Christianity.

  12. Prof. Richard Mattessich at 95. His Research Methodology

    Directory of Open Access Journals (Sweden)

    Giuseppe Galassi

    2017-12-01

    Full Text Available This paper is presented as a tribute to prof. Richard Mattessich. It is written “through the eyes” of a researcher who has worked closely with him over a period of 42 years, starting attending his courses of “Income Determination Theory” and “Research Methodology” at the University of British Columbia in 1975. Among his huge scientific research and publications, I intend to underline these three major contributions: (i Accounting metrics and other mathematical instruments which anticipated computer spreadsheet by 30 years; (ii. The preparation of accountants for information economics by means of analytical methods; and (iii The proposition of the “onion model of reality” to distinguish different Kind of reality. Este trabajo se presenta como un tributo al profesor Richard Mattessich. Está escrito “con los ojos” de un investigador que ha trabajado estrechamente con él durante un período de 42 años, comenzando a asistir a sus cursos de " Income Determination Theory" y "Research Methodology" en la Universidad de British Columbia en 1975. Entre su investigación y publicaciones, más importantes pretendo subrayar estas tres contribuciones principales: (i Accounting metrics and other mathematical instruments which anticipated computer spreadsheet by 30 years; (ii The preparation of accountants for information economics by means of analytical methods; y (iii The proposition of the “onion model of reality” to distinguish different Kind of reality.

  13. Swearing Used in Richard Wright’s Black Boy

    Directory of Open Access Journals (Sweden)

    Giyatmi Giyatmi

    2017-07-01

    Full Text Available This research aims at finding the types of swearing expressions and linguistic forms of English swearing used in Richard Wright’s Black Boy. This is a descriptive qualitative research since it describes the phenomena of swearing used in the novel. The data of the research are all the conversations or sentences used swearing in the novel written by Richard Wright namely Black Boy as the main data source. The method of collecting data in this research is observation and teknik lanjut catat. After all the data had been collected then they are coded using the coding system such as data number/title of novel/chapter/page/data. There is no data reduction since all the data are analyzed in this research. This research used theory triangulation. Kind of swearing expressions found in this novel dealing with God and religion terms, name of  animals and plants, part of body, racial terms, stupidity terms, name of occupation, sexual terms, family terms. The linguistic forms of English swearing used in this novel are word, phrase, and clause. The swearing in the form of words consists of (1 noun referring to place, person, occupation, animal, and idea (2 verb and (3 adjective. Phrase consists of (1 noun phrase with swearing functioning as headword, modifier, and both headword and modifier, (2 adjective phrase with swearing functioning as modifier. Swearing expression is also found in the form of sentence.

  14. Review: Lyn Richards (2005. Handling Qualitative Data: A Practical Guide

    Directory of Open Access Journals (Sweden)

    Robert L. Miller

    2006-03-01

    Full Text Available Handling Qualitative Data: A Practical Guide is an introductory textbook covering all stages of qualitative research from the initial conceptualisation of a project, through data collection and analysis, to writing up. The author, Lyn RICHARDS, is a well-known developer of two key qualitative software analysis packages, NUD*IST and NVivo. While RICHARDS clearly advocates the use of qualitative analysis software, the text is "generic" and could be used in tandem with any qualitative software package. The book concentrates on practical advice about the use of software to manage and analyse qualitative data, and provides insights in these areas. The consideration of issues around team-based qualitative research is another strong point. However, due in part to its short length, the overall coverage of topics tends to be superficial. In itself, the book does not provide sufficient detailed support for a student who would like to use it as her/his main source of guidance for carrying out a qualitative research project. URN: urn:nbn:de:0114-fqs0602244

  15. Cosmic microwave background constraints on primordial black hole dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Aloni, Daniel; Blum, Kfir [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Herzl 234, Rehovot (Israel); Flauger, Raphael, E-mail: daniel.aloni@weizmann.ac.il, E-mail: kfir.blum@weizmann.ac.il, E-mail: flauger@physics.ucsd.edu [University of California, 9500 Gilman Drive 0319, La Jolla, San Diego, CA, 92093 (United States)

    2017-05-01

    We revisit cosmic microwave background (CMB) constraints on primordial black hole dark matter. Spectral distortion limits from COBE/FIRAS do not impose a relevant constraint. Planck CMB anisotropy power spectra imply that primordial black holes with m {sub BH}∼> 5 M {sub ⊙} are disfavored. However, this is susceptible to sizeable uncertainties due to the treatment of the black hole accretion process. These constraints are weaker than those quoted in earlier literature for the same observables.

  16. Primordial black holes survive SN lensing constraints

    Science.gov (United States)

    García-Bellido, Juan; Clesse, Sébastien; Fleury, Pierre

    2018-06-01

    It has been claimed in [arxiv:1712.02240] that massive primordial black holes (PBH) cannot constitute all of the dark matter (DM), because their gravitational-lensing imprint on the Hubble diagram of type Ia supernovae (SN) would be incompatible with present observations. In this note, we critically review those constraints and find several caveats on the analysis. First of all, the constraints on the fraction α of PBH in matter seem to be driven by a very restrictive choice of priors on the cosmological parameters. In particular, the degeneracy between Ωm and α was ignored and thus, by fixing Ωm, transferred the constraining power of SN magnitudes to α. Furthermore, by considering more realistic physical sizes for the type-Ia supernovae, we find an effect on the SN lensing magnification distribution that leads to significantly looser constraints. Moreover, considering a wide mass spectrum of PBH, such as a lognormal distribution, further softens the constraints from SN lensing. Finally, we find that the fraction of PBH that could constitute DM today is bounded by fPBH < 1 . 09(1 . 38) , for JLA (Union 2.1) catalogs, and thus it is perfectly compatible with an all-PBH dark matter scenario in the LIGO band.

  17. Primordial non-Gaussianity from LAMOST surveys

    International Nuclear Information System (INIS)

    Gong Yan; Wang Xin; Chen Xuelei; Zheng Zheng

    2010-01-01

    The primordial non-Gaussianity (PNG) in the matter density perturbation is a very powerful probe of the physics of the very early Universe. The local PNG can induce a distinct scale-dependent bias on the large scale structure distribution of galaxies and quasars, which could be used for constraining it. We study the detection limits of PNG from the surveys of the LAMOST telescope. The cases of the main galaxy survey, the luminous red galaxy (LRG) survey, and the quasar survey of different magnitude limits are considered. We find that the Main1 sample (i.e. the main galaxy survey which is one magnitude deeper than the SDSS main galaxy survey, or r NL are |f NL | NL | NL | is between 50 and 103, depending on the magnitude limit of the survey. With Planck-like priors on cosmological parameters, the quasar survey with g NL | < 43 (2σ). We also discuss the possibility of further tightening the constraint by using the relative bias method proposed by Seljak.

  18. Super-horizon primordial black holes

    International Nuclear Information System (INIS)

    Harada, Tomohiro; Carr, B.J.

    2005-01-01

    We discuss a new class of solutions to the Einstein equations which describe a primordial black hole (PBH) in a flat Friedmann background. Such solutions arise if a Schwarzschild black hole is patched onto a Friedmann background via a transition region. They are possible providing the black hole event horizon is larger than the cosmological apparent horizon. Such solutions have a number of strange features. In particular, one has to define the black hole and cosmological horizons carefully and one then finds that the mass contained within the black hole event horizon decreases when the black hole is larger than the Friedmann cosmological apparent horizon, although its area always increases. These solutions involve two distinct future null infinities and are interpreted as the conversion of a white hole into a black hole. Although such solutions may not form from gravitational collapse in the same way as standard PBHs, there is nothing unphysical about them, since all energy and causality conditions are satisfied. Their conformal diagram is a natural amalgamation of the Kruskal diagram for the extended Schwarzschild solution and the conformal diagram for a black hole in a flat Friedmann background. In this paper, such solutions are obtained numerically for a spherically symmetric universe containing a massless scalar field, but it is likely that they exist for more general matter fields and less symmetric systems

  19. Primordial black hole detection through diffractive microlensing

    Science.gov (United States)

    Naderi, T.; Mehrabi, A.; Rahvar, S.

    2018-05-01

    Recent observations of gravitational waves motivate investigations for the existence of primordial black holes (PBHs). We propose the observation of gravitational microlensing of distant quasars for the range of infrared to the submillimeter wavelengths by sublunar PBHs as lenses. The advantage of observations in the longer wavelengths, comparable to the Schwarzschild radius of the lens (i.e., Rsch≃λ ) is the detection of the wave optics features of the gravitational microlensing. The observation of diffraction pattern in the microlensing light curve of a quasar can break the degeneracy between the lens parameters and determine directly the lens mass as well as the distance of the lens from the observer. We estimate the wave optics optical-depth, also calculate the rate of ˜0.1 to ˜0.3 event per year per a quasar, assuming that hundred percent of dark matter is made of sublunar PBHs. Also, we propose a long-term survey of quasars with the cadence of almost one hour to few days to resolve the wave optics features of the light curves to discover PBHs and determine the fraction of dark matter made of sublunar PBHs as well as their mass function.

  20. The Primordial Inflation Explorer (PIXIE) Mission

    Science.gov (United States)

    Kogut, Alan J.; Chuss, David T.; Dotson, Jessie L.; Fixsen, Dale J.; Halpern, Mark; Hinshaw, Gary F.; Meyer, Stephan M.; Moseley, S. Harvey; Seiffert, Michael D.; Spergel, David N.; hide

    2011-01-01

    The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission to map the absolute intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from frequencies 30 GHz to 6 THz (I cm to 50 I-tm wavelength). PIXIE uses a polarizing Michelson interferometer with 2.7 K optics to measure the difference spectrum between two orthogonal linear polarizations from two co-aligned beams. Either input can view either the sky or a temperature-controlled absolute reference blackbody calibrator. The multimoded optics and high etendu provide sensitivity comparable to kilo-pixel focal plane arrays, but with greatly expanded frequency coverage while using only 4 detectors total. PIXIE builds on the highly successful COBEIFIRAS design by adding large-area polarization-sensitive detectors whose fully symmetric optics are maintained in thermal equilibrium with the CMB. The highly symmetric nulled design provides redundant rejection of major sources of systematic uncertainty. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much less than 10(exp -3). PIXIE will also return a rich data set constraining physical processes ranging from Big Bang cosmology, reionization, and large-scale structure to the local interstellar medium. Keywords: cosmic microwave background, polarization, FTS, bolometer

  1. The origin, evolution and signatures of primordial magnetic fields.

    Science.gov (United States)

    Subramanian, Kandaswamy

    2016-07-01

    The universe is magnetized on all scales probed so far. On the largest scales, galaxies and galaxy clusters host magnetic fields at the micro Gauss level coherent on scales up to ten kpc. Recent observational evidence suggests that even the intergalactic medium in voids could host a weak  ∼  10(-16) Gauss magnetic field, coherent on Mpc scales. An intriguing possibility is that these observed magnetic fields are a relic from the early universe, albeit one which has been subsequently amplified and maintained by a dynamo in collapsed objects. We review here the origin, evolution and signatures of primordial magnetic fields. After a brief summary of magnetohydrodynamics in the expanding universe, we turn to magnetic field generation during inflation and phase transitions. We trace the linear and nonlinear evolution of the generated primordial fields through the radiation era, including viscous effects. Sensitive observational signatures of primordial magnetic fields on the cosmic microwave background, including current constraints from Planck, are discussed. After recombination, primordial magnetic fields could strongly influence structure formation, especially on dwarf galaxy scales. The resulting signatures on reionization, the redshifted 21 cm line, weak lensing and the Lyman-α forest are outlined. Constraints from radio and γ-ray astronomy are summarized. Astrophysical batteries and the role of dynamos in reshaping the primordial field are briefly considered. The review ends with some final thoughts on primordial magnetic fields.

  2. Naturalismo e existencialismo na teoria moral de Richard Hare

    Directory of Open Access Journals (Sweden)

    Marco Antônio Oliveira de Azevedo

    2009-08-01

    Full Text Available http://dx.doi.org/10.5007/1677-2954.2009v8n2p247 Em um artigo de 1966, Amartya Sen procurou mostrar que mesmo Richard Hare, um devoto explícitodo antinaturalismo em ética, ainda que inadvertidamente, incorreu num tipo de naturalismo que Senintitulou de existencial. Neste breve artigo, traço um resumo dessa crítica à teoria de Hare, em especial,da chamada “Lei de Hume”, a qual Sen preferiu apropriadamente intitular “Regra de Hare”. Pretendomostrar como esse tipo peculiar de “existencialismo” nos conduz, ainda que sob o possível protesto deHare e seus seguidores, a conclusões subjetivistas e relativistas sobre a moralidade.

  3. RICHARD WAGNER E O ROMANTISMO ALEMÃO

    Directory of Open Access Journals (Sweden)

    Rainer Câmara Patriota

    2015-07-01

    Full Text Available A cultura musical romântica encontra em Richard Wagner– em sua obra musical e teórica – um de seus maiores protagonistas.A rejeição da Aufklärung e a exaltação da supremacia germânica –elementos constituidores da Weltanschauung romântica alemã –caracterizam fortemente o pensamento e a atitude de Wagner frenteà vida, assumindo conotações ainda mais radicais através de seucontumaz antissemitismo. De modo que pensar Wagner por ocasiãode seu bicentenário também significa retomar uma discussão crucialsobre o romantismo alemão e suas implicações políticas eideológicas.

  4. La paradoja de lo público en Richard Rorty

    Directory of Open Access Journals (Sweden)

    Martha Palacio Avendaño

    2008-01-01

    Full Text Available El concepto de lo público en Richard Rorty, heredero de la tradición liberal, admite ser tratado como parte de un juego del lenguaje denominado liberalismo democrático. En ese sentido, una de las reglas de este juego para saber si una jugada es válida consiste en asumir la distinción entre esfera pública y privada. Richard Rorty pensó que este juego no requería fundamentación más allá de la forma de jugarlo, que el criterio en que se apoyaría estaba en las prácticas que tienen lugar dentro del mismo con arreglo a sostener una utopía que permitiera hacer cada vez más jugadas. Esto es, el liberalismo democrático no requería basarse en algo más allá de las prácticas conducentes a lograr una esperanza social alentada por la libertad en defensa del pluralismo. Su utopía liberal, guiada por el principio de la no-crueldad, haría posible una sociedad inclusiva en la que todos tuvieran espacio para su léxico privado. De este modo, Rorty habría vinculado libertad y solidaridad, pero su juego del lenguaje permite advertir la paradoja del vínculo que implicaría el sentido de lo público. Aquí, la libertad no es condición suficiente de la solidaridad, de modo que la inclusión social no tiene cabida en su juego del lenguaje.

  5. The Formation of Primordial Luminous Objects

    International Nuclear Information System (INIS)

    Ripamonti, Emanuele; Kapteyn Astron. Inst., Groningen; Abel, Tom; KIPAC, Menlo Park

    2005-01-01

    The scientific belief that the universe evolves in time is one of the legacies of the theory of the Big Bang. The concept that the universe has an history started to attract the interest of cosmologists soon after the first formulation of the theory: already Gamow (1948; 1949) investigated how and when galaxies could have been formed in the context of the expanding Universe. However, the specific topic of the formation (and of the fate) of the first objects dates to two decades later, when no objects with metallicities as low as those predicted by primordial nucleosynthesis (Z ∼ -10 ∼ 10 -8 Z # circle d ot#) were found. Such concerns were addressed in two seminal papers by Peebles and Dicke (1968; hereafter PD68) and by Doroshkevich, Zel'Dovich and Novikov (1967; hereafter DZN67), introducing the idea that some objects could have formed before the stars we presently observe. (1) Both PD68 and DZN67 suggest a mass of ∼ 10 5 M # circle d ot# for the first generation of bound systems, based on the considerations on the cosmological Jeans length (Gamow 1948; Peebles 1965) and the possible shape of the power spectrum. (2) They point out the role of thermal instabilities in the formation of the proto-galactic bound object, and of the cooling of the gas inside it; in particular, PD68 introduces H 2 cooling and chemistry in the calculations about the contraction of the gas. (3) Even if they do not specifically address the occurrence of fragmentation, these papers make two very different assumptions: PD68 assumes that the gas will fragment into ''normal'' stars to form globular clusters, while DZN67 assumes that fragmentation does not occur, and that a single ''super-star'' forms. (4) Finally, some feedback effects as considered (e.g. Peebles and Dicke considered the effects of supernovae). Today most of the research focuses on the issues when fragmentation may occur, what objects are formed and how they influence subsequent structure formation. In these notes we will

  6. Primordial power spectrum features and consequences

    Science.gov (United States)

    Goswami, G.

    2014-03-01

    The present Cosmic Microwave Background (CMB) temperature and polarization anisotropy data is consistent with not only a power law scalar primordial power spectrum (PPS) with a small running but also with the scalar PPS having very sharp features. This has motivated inflationary models with such sharp features. Recently, even the possibility of having nulls in the power spectrum (at certain scales) has been considered. The existence of these nulls has been shown in linear perturbation theory. What shall be the effect of higher order corrections on such nulls? Inspired by this question, we have attempted to calculate quantum radiative corrections to the Fourier transform of the 2-point function in a toy field theory and address the issue of how these corrections to the power spectrum behave in models in which the tree-level power spectrum has a sharp dip (but not a null). In particular, we have considered the possibility of the relative enhancement of radiative corrections in a model in which the tree-level spectrum goes through a dip in power at a certain scale. The mode functions of the field (whose power spectrum is to be evaluated) are chosen such that they undergo the kind of dynamics that leads to a sharp dip in the tree level power spectrum. Next, we have considered the situation in which this field has quartic self interactions, and found one loop correction in a suitably chosen renormalization scheme. Thus, we have attempted to answer the following key question in the context of this toy model (which is as important in the realistic case): In the chosen renormalization scheme, can quantum radiative corrections be enhanced relative to tree-level power spectrum at scales, at which sharp dips appear in the tree-level spectrum?

  7. The Primordial Inflation Polarization Explorer (PIPER)

    Science.gov (United States)

    Lazear, Justin Scott; Ade, Peter A.; Benford, Dominic J.; Bennett, Charles L.; Chuss, David T.; Dotson, Jessie L.; Eimer, Joseph R.; Fixsen, Dale J.; Halpern, Mark; Hinderks, James; hide

    2014-01-01

    The Primordial Inflation Polarization ExploreR (Piper) is a balloon-borne cosmic microwave background (CMB) polarimeter designed to search for evidence of inflation by measuring the large-angular scale CMB polarization signal. Bicep2 recently reported a detection of B-mode power corresponding to the tensor-to-scalar ratio r = 0.2 on approximately 2 degree scales. If the Bicep2 signal is caused by inflationary gravitational waves (IGWs), then there should be a corresponding increase in B-mode power on angular scales larger than 18 degrees. Piper is currently the only suborbital instrument capable of fully testing and extending the Bicep2 results by measuring the B-mode power spectrum on angular scales theta ? = approximately 0.6 deg to 90 deg, covering both the reionization bump and recombination peak, with sensitivity to measure the tensor-to-scalar ratio down to r = 0.007, and four frequency bands to distinguish foregrounds. Piper will accomplish this by mapping 85% of the sky in four frequency bands (200, 270, 350, 600 GHz) over a series of 8 conventional balloon flights from the northern and southern hemispheres. The instrument has background-limited sensitivity provided by fully cryogenic (1.5 K) optics focusing the sky signal onto four 32×40-pixel arrays of time-domain multiplexed Transition-Edge Sensor (TES) bolometers held at 140 milli-Kelvin. Polarization sensitivity and systematic control are provided by front-end Variabledelay Polarization Modulators (VPMs), which rapidly modulate only the polarized sky signal at 3 Hz and allow Piper to instantaneously measure the full Stokes vector (I,Q,U,0V) for each pointing. We describe the Piper instrument and progress towards its first flight.

  8. Some cosmological consequences of primordial black-hole evaporations

    International Nuclear Information System (INIS)

    Carr, B.J.

    1976-01-01

    According to Hawking, primordial black holes of less than 10 15 g would have evaporated by now. This paper examines the way in which small primordial black holes could thereby have contributed to the background density of photons, nucleons, neutrinos, electrons, and gravitons in the universe. Any photons emitted late enough should maintain their emission temperature apart from a redshift effect: it is shown that the biggest contribution should come from primordial black holes of about 10 15 g, which evaporate in the present era, and it is argued that observations of the γ-ray background indicate that primordial black holes of this size must have a mean density less than 10 -8 times the critical density. Photons which were emitted sufficiently early to be thermalized could, in principle, have generated the 3 K background in an initially cold universe, but only if the density fluctuations in the early universe had a particular form and did not extend up to a mass scale of 10 15 g. Primordial black holes of less than 10 14 g should emit nucleons: it is shown that such nucleons could not contribute appreciably to the cosmic-ray background. However, nucleon emission could have generated the observed number density of baryons in an initially baryon-symmetric universe, provided some CP-violating process operates in black hole evaporations such that more baryons are always produced than antibaryons. We predict the spectrum of neutrinos, electrons, and gravitons which should result from primordial black-hole evaporations and show that the observational limits on the background electron flux might place a stronger limitation on the number of 10 15 g primordial black holes than the γ-ray observations. Finally, we examine the limits that various observations place on the strength of any long-range baryonic field whose existence might be hypothesized as a means of preserving baryon number in black-hole evaporations

  9. 78 FR 43093 - Richard C. Theuer; Filing of Food Additive Petition and Citizen Petition

    Science.gov (United States)

    2013-07-19

    ... [Docket Nos. FDA-2013-F-0700 and FDA-2013-P-0472] Richard C. Theuer; Filing of Food Additive Petition and... proposing that the food additive regulations be amended to prohibit the use of carrageenan and salts of... that Richard C. Theuer, Ph.D., 7904 Sutterton Ct., Raleigh, NC 27615, has filed a food additive...

  10. 76 FR 10936 - Culturally Significant Objects Imported for Exhibition Determinations: “Richard Serra Drawing: A...

    Science.gov (United States)

    2011-02-28

    ... DEPARTMENT OF STATE [Public Notice: 7348] Culturally Significant Objects Imported for Exhibition Determinations: ``Richard Serra Drawing: A Retrospective'' SUMMARY: Notice is hereby given of the following... objects to be included in the exhibition ``Richard Serra Drawing: A Retrospective,'' imported from abroad...

  11. Travelling wave solutions for the Richards equation incorporating non-equilibrium effects in the capillarity pressure

    NARCIS (Netherlands)

    van Duijn, C. J.; Mitra, K.; Pop, I. S.

    2018-01-01

    The Richards equation is a mathematical model for unsaturated flow through porous media. This paper considers an extension of the Richards equation, where non-equilibrium effects like hysteresis and dynamic capillarity are incorporated in the relationship that relates the water pressure and the

  12. H.E. Mr Richard J. Fredericks, Ambassador of the United States of America to Switzerland

    CERN Document Server

    Patrice Loïez

    2001-01-01

    Photo 01 : Prof. L. Maiani, CERN Director-General, gives a piece of LHC super conducting wire to H.E. Mr. Richard J. Fredericks; Photo 02 : Prof. L. Maiani, CERN Director-General, Mr. Jan van der Boon, CERN Director of Administration and H.E. Mr. J. Richard Fredericks

  13. W. Richard Scott, Institutions and Organizations: Ideas, Interests, and Identities

    DEFF Research Database (Denmark)

    Jakobsen, Michael

    2014-01-01

    Book review of: W. Richard Scott: Institutions and Organizations: Ideas, Interests, and Identities. 4th edition. Thousand Oaks, CA: SAGE Publications, 2014. xiii, 345 pp.......Book review of: W. Richard Scott: Institutions and Organizations: Ideas, Interests, and Identities. 4th edition. Thousand Oaks, CA: SAGE Publications, 2014. xiii, 345 pp....

  14. Morphological anomaly of primordial follicle in {gamma}-irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Lee, Chang Joo; Lee, Young Dal [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1999-08-01

    Ovarian follicles are faced with one of two fates, atresia or development. Up to 99% of follicles become degenerated rather than ovulated in female life span. Thus, atresia occurs at all stages of follicle development in mammalian ovaries. In the present experiment, the effect of {gamma}-radiation on primordial follicles was morphologically analyzed in a mouse ovary. Thirty-seven percent of the primordial follicles in the non-irradiated control mice ovaries were abnormal. At day 8 post irradiation, most of primordial follicles became atretic. They lost their integrity of architecture in the follicular shape. Then, all the oocytes disappeared from the follicles. And only 3 to 4 granulosa cells lay down onto the basement membrane. Disappearance of granulosa cells or oocytes resulted from the radiation-induced apoptotic process. It is definitely clear that {gamma}-radiation induces rapid apoptotic degeneration of the primordial follicles. The morphological degeneration induced by radiation in the primordial follicles can be used as an experimental model to draw out a deeper insight for radioprotectant researches. (author). 22 refs., 4 figs.

  15. Mechanisms and pathways of growth failure in primordial dwarfism.

    Science.gov (United States)

    Klingseisen, Anna; Jackson, Andrew P

    2011-10-01

    The greatest difference between species is size; however, the developmental mechanisms determining organism growth remain poorly understood. Primordial dwarfism is a group of human single-gene disorders with extreme global growth failure (which includes Seckel syndrome, microcephalic osteodysplastic primordial dwarfism I [MOPD] types I and II, and Meier-Gorlin syndrome). Ten genes have now been identified for microcephalic primordial dwarfism, encoding proteins involved in fundamental cellular processes including genome replication (ORC1 [origin recognition complex 1], ORC4, ORC6, CDT1, and CDC6), DNA damage response (ATR [ataxia-telangiectasia and Rad3-related]), mRNA splicing (U4atac), and centrosome function (CEP152, PCNT, and CPAP). Here, we review the cellular and developmental mechanisms underlying the pathogenesis of these conditions and address whether further study of these genes could provide novel insight into the physiological regulation of organism growth.

  16. [Persistence of the primordial vitreous body and buphthalmos].

    Science.gov (United States)

    Cernea, P; Simionescu, C; Bosun, I

    1995-01-01

    Persistence of the hyperplasic primordial vitreous body is determined by a deletion of embryonal development of the vitreous body and of the hyaloid vascular system. Infant aged 3.5 years presents persistence of primordial vitreous body with crystalline dislocation in the camera aquosa and secondary buphthalmos of the left eye and microphthalmos with dislocation of the crystalline in the vitreous body of the right eye. At the back of the right eye we noticed a whitish mass, richly vascularized with vestiges from the hyaloid artery, but the posterior half of the vitreous cavity is filled with microscopic blood; the fibrovascular membrane is made of conjunctive tissue set in parallel layers and vessels with macrolipophagic degeneration. Microscopic investigation of retina reveals glial hyperplasia zones in the neighbourhood of the vitreous body. In the present paper the authors show the persistence of the primordial vitreous body in the left eye and bilateral dislocation of the crystalline, revealing multiple ocular malformations.

  17. Direct search for features in the primordial bispectrum

    Directory of Open Access Journals (Sweden)

    Stephen Appleby

    2016-09-01

    Full Text Available We study features in the bispectrum of the primordial curvature perturbation correlated with the reconstructed primordial power spectrum from the observed cosmic microwave background temperature data. We first show how the bispectrum can be completely specified in terms of the power spectrum and its first two derivatives, valid for any configuration of interest. Then using a model-independent reconstruction of the primordial power spectrum from the Planck angular power spectrum of temperature anisotropies, we compute the bispectrum in different triangular configurations. We find that in the squeezed limit at k∼0.06 Mpc−1 and k∼0.014 Mpc−1 there are marginal 2σ deviations from the standard featureless bispectrum, which meanwhile is consistent with the reconstructed bispectrum in the equilateral configuration.

  18. Standard Clock in primordial density perturbations and cosmic microwave background

    International Nuclear Information System (INIS)

    Chen, Xingang; Namjoo, Mohammad Hossein

    2014-01-01

    Standard Clocks in the primordial epoch leave a special type of features in the primordial perturbations, which can be used to directly measure the scale factor of the primordial universe as a function of time a(t), thus discriminating between inflation and alternatives. We have started to search for such signals in the Planck 2013 data using the key predictions of the Standard Clock. In this Letter, we summarize the key predictions of the Standard Clock and present an interesting candidate example in Planck 2013 data. Motivated by this candidate, we construct and compute full Standard Clock models and use the more complete prediction to make more extensive comparison with data. Although this candidate is not yet statistically significant, we use it to illustrate how Standard Clocks appear in Cosmic Microwave Background (CMB) and how they can be further tested by future data. We also use it to motivate more detailed theoretical model building

  19. Astrochemistry: From primordial gas to present-day clouds

    OpenAIRE

    Schleicher, Dominik R. G.; Bovino, Stefano; Körtgen, Bastian; Grassi, Tommaso; Banerjee, Robi

    2017-01-01

    Astrochemistry plays a central role during the process of star formation, both in the primordial regime as well as in the present-day Universe. We revisit here the chemistry in both regimes, focusing first on the chemistry under close to primordial conditions, as observed in the so-called Caffau star SDSS J102915+172927, and subsequently discuss deuteration processes in present-day star-forming cores. In models of the high-redshift Universe, the chemistry is particularly relevant to determine...

  20. Chirality oscillation of primordial gravitational waves during inflation

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yong; Wang, Yu-Tong [School of Physics, University of Chinese Academy of Sciences,Beijing 100049 (China); Piao, Yun-Song [School of Physics, University of Chinese Academy of Sciences,Beijing 100049 (China); Institute of Theoretical Physics, Chinese Academy of Sciences,P.O. Box 2735, Beijing 100190 (China)

    2017-03-06

    We show that if the gravitational Chern-Simons term couples to a massive scalar field (m>H), the primordial gravitational waves (GWs) will show itself the chirality oscillation, i.e., the amplitudes of the left- and right-handed GWs modes will convert into each other and oscillate in their propagations. This oscillation will eventually develop a permanent difference of the amplitudes of both modes, which leads to nearly opposite oscillating shapes in the power spectra of the left- and right-handed primordial GWs. We discuss its implication to the CMB B-mode polarization.

  1. Primordial lithium and the standard model(s)

    International Nuclear Information System (INIS)

    Deliyannis, C.P.; Demarque, P.; Kawaler, S.D.; Krauss, L.M.; Romanelli, P.

    1989-01-01

    We present the results of new theoretical work on surface 7 Li and 6 Li evolution in the oldest halo stars along with a new and refined analysis of the predicted primordial lithium abundance resulting from big-bang nucleosynthesis. This allows us to determine the constraints which can be imposed upon cosmology by a consideration of primordial lithium using both standard big-bang and standard stellar-evolution models. Such considerations lead to a constraint on the baryon density today of 0.0044 2 <0.025 (where the Hubble constant is 100h Km sec/sup -1/ Mpc /sup -1/), and impose limitations on alternative nucleosynthesis scenarios

  2. Transcendence, Taxis, Trust: Richard Kearney and Jacques Derrida

    Directory of Open Access Journals (Sweden)

    Ulrich Schmiedel

    2017-03-01

    Full Text Available Whatever else it takes to drive a taxi, it takes trust. Day after day, the driver has to decide whether the other is or is not trustworthy. I take the taxi as a test case to analyze and assess Richard Kearney’s diacritical hermeneutics of the other. I argue that Kearney functionalizes the concept of transcendence in order to connect the transcendence of the finite other to the transcendence of the infinite other. However, in his central critique of the deconstructionists following Jacques Derrida, Kearney counters his connection. While Kearney’s critique of Derrida’s account of absolute alterity is correct and compelling, I argue that Derrida’s critique of a distinction between the trustworthy other and the non-trustworthy other might be more crucial than Kearney contends. Insisting on openness to the other’s otherness, Derrida provokes any hermeneutic of the other to trust in transcendence. The taxi is taken as a test to illustrate the implications which diacritical and deconstructive drivers might have for evaluating the entanglement of ethics and eschatology—inside and outside the taxi.

  3. Forjando nuestras democracias: entre Richard Rorty y Vladimiro Montesinos

    Directory of Open Access Journals (Sweden)

    Miguel Giusti

    2001-07-01

    Full Text Available This article aims at explaining the recent history of Peru, in an exercise in which it is possible to extract lessons about the way Latin American democracies have been(or have not been forged. The text draws a parallel between the ideas developed by Richard Rorty in his recently published book, Forjar nuestro país. El pensamiento de izquierdas en los Estados Unidos del siglo XX, and the events in Fugimori's and Montesinos' Peru. If, according to what Rorty believes, "national pride is for the countries what self esteem is for individuals ... " how would it be possible to narrate a history in which there are few motives to be proud of? Trying to escape fatalism and sarcasm, the text tries to show that Montesino's political course is, symbolically, a summary of the decomposition process of Peruvian democracy. Secondly, the text analyses the movements of the political left wing and deals with the support the regimen received from inside and outside the country, a support that was largely based on the illusion of political stability. Finally, it states, as Rorty does, that in order to forge democracies it is necessary for us to be deeply committed to the defense of the State of Right.

  4. Juvenile Cosmology; Or Richard Powers’ Post-Global Doughnut

    Directory of Open Access Journals (Sweden)

    Judith Roof

    2010-02-01

    Full Text Available Le roman de Richard Powers, Operation Wandering Soul (1993, présente le lien subtil qui associe un mondialisme déjà usé et vieillissant à l’enfant perçu comme catégorie dominante. Comme les faces serpentines d’un ruban de Möbius lové autour de l’illimité et de l’intemporel, le texte, tendu entre ses deux infinis – l’univers et l’enfant – révise la portée, la conception, la structure et le style du genre romanesque. Délaissant Aristote pour Einstein, Operation Wandering Soul se place sur le terrain de la cosmologie. Le récit, qui rassemble la kyrielle des grands ralliements juvéniles et leurs vains pèlerinages, concentre l’espace-temps dans une présentation qui évoque la « somme des histoires » de Richard Feynman. La contraction de l’espace-temps opérée par le roman ne fait pas de celui-ci un hymne simpliste au global (catégorie déjà aussi datée que celle des malheureux vétérans du Vietnam, mais capte au contraire la conscience grandissante d’une existence sans origine qui s’étend à perte de vue au-delà de ses coordonnées supposées. Le roman s’enroule sur lui-même tout en s’épanchant au dehors, boucle ses cadres et ses détours tout en desserrant leur emprise. Il fait tourner la roue de ses récits comme des planètes en rotation, la ronde d’un système solaire, le tourbillon d’une galaxie. La conscience que présente Operation Wandering Soul ne se résume donc pas au seul point de vue de l’âme errante qu’est le personnage de Kraft, mais consiste en la somme de tous les temps et de tous les lieux, de leurs strates accumulées comme une conscience en acte, complexe et tissée de réseaux, qui n’appartient à personne et est partagée par tous. Cette accumulation organise le jeu des perspectives multiples qui instaurent l’acte de lecture et sont instaurées par lui. À cet égard, lire constitue ici une physique des oubliés.Richard Powers’ novel Operation Wandering

  5. PolyRES: A polygon-based Richards equation solver

    International Nuclear Information System (INIS)

    Hills, R.G.

    1995-12-01

    This document describes the theory, implementation, and use of a software package designed to solve the transient, two-dimensional, Richards equation for water flow in unsaturated-saturated soils. This package was specifically designed to model complex geometries with minimal input from the user and to simulate groundwater flow related to assessment of low-level radioactive waste disposal sites and engineered facilities. The spatial variation of the hydraulic properties can be defined across individual polygon-shaped subdomains, called objects. These objects combine to form a polygon-shaped model domain. Each object can have its own distribution of hydraulic parameters. The resulting model domain and polygon-shaped internal objects are mapped onto a rectangular, finite-volume, computational grid by a preprocessor. This allows the user to specify model geometry independently of the underlying grid and greatly simplifies user input for complex geometries. In addition, this approach significantly reduces the computational requirements since complex geometries are actually modeled on a rectangular grid. This results in well-structured, finite difference-like systems of equations that require minimal storage and are very efficient to solve. The documentation for this software package includes a user's manual, a detailed description of the underlying theory, and a detailed discussion of program flow. Several example problems are presented that show the use and features of the software package. The water flow predictions for several of these example problems are compared to those of another algorithm to test for prediction equivalency

  6. [Richard Koch's life in national socialism and in Soviet emigration].

    Science.gov (United States)

    Boltres, Daniela; Töpfer, Frank; Wiesing, Urban

    2006-01-01

    The Jewish historian and theorist of medicine, Richard Koch, teaching in Frankfurt/Main, fled in 1936 from National Socialist Germany to the USSR where he lived in the Caucasian spa Essentuki until his death in 1949. Here he worked as a doctor and continued his scientific work, especially on the foundations of medicine in natural philosophy. None of his works of this time were published. Koch was a scientific outsider in the USSR, and he was aware of this. However, he tried to make his views compatible with official doctrines. In 1947 he lost his employment at the medical clinic of Essentuki, and his material situation grew worse. It is still an open question whether this development was related to an increasingly anti-Jewish atmosphere in the USSR that was linked with the Stalinist "purges", as Koch himself appeared to believe. Before his flight from Germany Koch did not show any tendency towards communism or the political left at all. His attitude towards Soviet society and Stalin was mixed: cautious criticism was accompanied by strong expressions of commitment to Stalin and Koch's new Socialist home. The question to what extent Koch's comments showed his true convictions must remain without a definite answer. At least in part they can be understood as precautions in threatening circumstances. The opportunity of a remigration to Germany after 1945, however, was turned down by Koch.

  7. Perception of Leitmotives in Richard Wagner's Der Ring des Nibelungen

    Directory of Open Access Journals (Sweden)

    David J. Baker

    2017-05-01

    Full Text Available The music of Richard Wagner tends to generate very diverse judgments indicative of the complex relationship between listeners and the sophisticated musical structures in Wagner's music. This paper presents findings from two listening experiments using the music from Wagner's Der Ring des Nibelungen that explores musical as well as individual listener parameters to better understand how listeners are able to hear leitmotives, a compositional device closely associated with Wagner's music. Results confirm findings from a previous experiment showing that specific expertise with Wagner's music can account for a greater portion of the variance in an individual's ability to recognize and remember musical material compared to measures of generic musical training. Results also explore how acoustical distance of the leitmotives affects memory recognition using a chroma similarity measure. In addition, we show how characteristics of the compositional structure of the leitmotives contributes to their salience and memorability. A final model is then presented that accounts for the aforementioned individual differences factors, as well as parameters of musical surface and structure. Our results suggest that that future work in music perception may consider both individual differences variables beyond musical training, as well as symbolic features and audio commonly used in music information retrieval in order to build robust models of musical perception and cognition.

  8. Failed Mothers, Monster Sons. Reading Shakespeare’S Richard Iii as a Fairy Tale

    Directory of Open Access Journals (Sweden)

    Percec Dana

    2014-03-01

    Full Text Available The paper looks at Shakespeare’s historical play Richard III and its fairy tale-like character given by the configuration of the main character as an arch-villain and the presence of motifs and patterns typically associated with the fairy tale genre. More specifically, it considers the mother-son relationship between the Duchess of York and Richard in the light of the motif of monstrous birth. It is not a coincidence that the emergence of such motifs coincides with the historical contexts of the early modern period. Reading Richard III in this key is related to the revisionist approach to chronicle plays.

  9. Molecular mechanisms governing primordial germ cell migration in zebrafish

    NARCIS (Netherlands)

    Doitsidou, M.

    2005-01-01

    In most sexually reproducing organisms primordial germ cells (pGCs) are specified early in development in places that are distinct from the region where the somatic part of the gonad develops. From their places of specification they have to migrate towards the site where they associate with somatic

  10. Lifting Primordial Non-Gaussianity Above the Noise

    NARCIS (Netherlands)

    Welling, Yvette; Woude, Drian van der; Pajer, Enrico

    2016-01-01

    Primordial non-Gaussianity (PNG) in Large Scale Structures is obfuscated by the many additional sources of non-linearity. Within the Effective Field Theory approach to Standard Perturbation Theory, we show that matter non-linearities in the bispectrum can be modeled sufficiently well to strengthen

  11. Mutations in the pericentrin (PCNT) gene cause primordial dwarfism

    NARCIS (Netherlands)

    Rauch, Anita; Thiel, Christian T.; Schindler, Detlev; Wick, Ursula; Crow, Yanick J.; Ekici, Arif B.; van Essen, Anthonie J.; Goecke, Timm O.; Al-Gazali, Lihadh; Chrzanowska, Krystyna H.; Zweier, Christiane; Brunner, Han G.; Becker, Kristin; Curry, Cynthia J.; Dallapiccola, Bruno; Devriendt, Koenraad; Dörfler, Arnd; Kinning, Esther; Megarbane, André; Meinecke, Peter; Semple, Robert K.; Spranger, Stephanie; Toutain, Annick; Trembath, Richard C.; Voss, Egbert; Wilson, Louise; Hennekam, Raoul; de Zegher, Francis; Dörr, Helmuth-Günther; Reis, André

    2008-01-01

    Fundamental processes influencing human growth can be revealed by studying extreme short stature. Using genetic linkage analysis, we find that biallelic loss-of-function mutations in the centrosomal pericentrin (PCNT) gene on chromosome 21q22.3 cause microcephalic osteodysplastic primordial dwarfism

  12. Mutations in the pericentrin (PCNT) gene cause primordial dwarfism

    NARCIS (Netherlands)

    Rauch, Anita; Thiel, Christian T.; Schindler, Detlev; Wick, Ursula; Crow, Yanick J.; Ekici, Arif B.; van Essen, Anthonie J.; Goecke, Timm O.; Al-Gazali, Lihadh; Chrzanowska, Krystyna H.; Zweier, Christiane; Brunner, Han G.; Becker, Kristin; Curry, Cynthia J.; Dallapiccola, Bruno; Devriendt, Koenraad; Doerfler, Arnd; Kinning, Esther; Megarbane, Andre; Meinecke, Peter; Semple, Robert K.; Spranger, Stephanie; Toutain, Annick; Trembath, Richard C.; Voss, Egbert; Wilson, Louise; Hennekam, Raoul; de Zegher, Francis; Doerr, Helmuth-Guenther; Reis, Andre

    2008-01-01

    Fundamental processes influencing human growth can be revealed by studying extreme short stature. Using genetic linkage analysis, we find that biallelic loss- of- function mutations in the centrosomal pericentrin ( PCNT) gene on chromosome 21q22.3 cause microcephalic osteodysplastic primordial

  13. Rewarming the Primordial Soup: Revisitations and Rediscoveries in Prebiotic Chemistry.

    Science.gov (United States)

    Saladino, Raffaele; Šponer, Judit E; Šponer, Jiří; Di Mauro, Ernesto

    2018-01-04

    A short history of Campbell's primordial soup: In this essay we try to disclose some of the historical connections between the studies that have contributed to our current understanding of the emergence of catalytic RNA molecules and their components from an inanimate matter. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  14. Planck 2013 Results. XXIV. Constraints on primordial non-Gaussianity

    DEFF Research Database (Denmark)

    Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.

    2013-01-01

    The Planck nominal mission cosmic microwave background (CMB) maps yield unprecedented constraints on primordial non-Gaussianity (NG).Using three optimal bispectrum estimators, separable template-fitting (KSW), binned, and modal, we obtain consistent values for the primordiallocal, equilateral, an...

  15. Cosmic microwave background trispectrum and primordial magnetic field limits.

    Science.gov (United States)

    Trivedi, Pranjal; Seshadri, T R; Subramanian, Kandaswamy

    2012-06-08

    Primordial magnetic fields will generate non-gaussian signals in the cosmic microwave background (CMB) as magnetic stresses and the temperature anisotropy they induce depend quadratically on the magnetic field. We compute a new measure of magnetic non-gaussianity, the CMB trispectrum, on large angular scales, sourced via the Sachs-Wolfe effect. The trispectra induced by magnetic energy density and by magnetic scalar anisotropic stress are found to have typical magnitudes of approximately a few times 10(-29) and 10(-19), respectively. Observational limits on CMB non-gaussianity from WMAP data allow us to conservatively set upper limits of a nG, and plausibly sub-nG, on the present value of the primordial cosmic magnetic field. This represents the tightest limit so far on the strength of primordial magnetic fields, on Mpc scales, and is better than limits from the CMB bispectrum and all modes in the CMB power spectrum. Thus, the CMB trispectrum is a new and more sensitive probe of primordial magnetic fields on large scales.

  16. The ISS flight of Richard Garriott: a template for medicine and science investigation on future spaceflight participant missions.

    Science.gov (United States)

    Jennings, Richard T; Garriott, Owen K; Bogomolov, Valery V; Pochuev, Vladimir I; Morgun, Valery V; Garriott, Richard A

    2010-02-01

    A total of eight commercial spaceflight participants have launched to the International Space Station (ISS) on Soyuz vehicles. Based on an older mean age compared to career astronauts and an increased prevalence of medical conditions, spaceflight participants have provided the opportunity to learn about the effect of space travel on crewmembers with medical problems. The 12-d Soyuz TMA-13/12 ISS flight of spaceflight participant Richard Garriott included medical factors that required preflight intervention, risk mitigation strategies, and provided the opportunity for medical study on-orbit. Equally important, Mr. Garriott conducted extensive medical, scientific, and educational payload operations during the flight. These included 7 medical experiments and a total of 15 scientific projects such as protein crystal growth, Earth observations/photography, educational projects with schools, and amateur radio. The medical studies included the effect of microgravity on immune function, sleep, bone loss, corneal refractive surgery, low back pain, motion perception, and intraocular pressure. The overall mission success resulted from non-bureaucratic agility in mission planning, cooperation with investigators from NASA, ISS, International Partners, and the Korean Aerospace Research Institute, in-flight support and leadership from a team with spaceflight and Capcom experience, and overall mission support from the ISS program. This article focuses on science opportunities that suborbital and orbital spaceflight participant flights offer and suggests that the science program on Richard Garriott's flight be considered a model for future orbital and suborbital missions. The medical challenges are presented in a companion article.

  17. Stand diameter distribution modelling and prediction based on Richards function.

    Directory of Open Access Journals (Sweden)

    Ai-guo Duan

    Full Text Available The objective of this study was to introduce application of the Richards equation on modelling and prediction of stand diameter distribution. The long-term repeated measurement data sets, consisted of 309 diameter frequency distributions from Chinese fir (Cunninghamia lanceolata plantations in the southern China, were used. Also, 150 stands were used as fitting data, the other 159 stands were used for testing. Nonlinear regression method (NRM or maximum likelihood estimates method (MLEM were applied to estimate the parameters of models, and the parameter prediction method (PPM and parameter recovery method (PRM were used to predict the diameter distributions of unknown stands. Four main conclusions were obtained: (1 R distribution presented a more accurate simulation than three-parametric Weibull function; (2 the parameters p, q and r of R distribution proved to be its scale, location and shape parameters, and have a deep relationship with stand characteristics, which means the parameters of R distribution have good theoretical interpretation; (3 the ordinate of inflection point of R distribution has significant relativity with its skewness and kurtosis, and the fitted main distribution range for the cumulative diameter distribution of Chinese fir plantations was 0.4∼0.6; (4 the goodness-of-fit test showed diameter distributions of unknown stands can be well estimated by applying R distribution based on PRM or the combination of PPM and PRM under the condition that only quadratic mean DBH or plus stand age are known, and the non-rejection rates were near 80%, which are higher than the 72.33% non-rejection rate of three-parametric Weibull function based on the combination of PPM and PRM.

  18. AD-1 with research pilot Richard E. Gray

    Science.gov (United States)

    1982-01-01

    Standing in front of the AD-1 Oblique Wing research aircraft is research pilot Richard E. Gray. Richard E. Gray joined National Aeronautics and Space Administration's Johnson Space Center, Houston, Texas, in November 1978, as an aerospace research pilot. In November 1981, Dick joined the NASA's Ames-Dryden Flight Research Facility, Edwards, California, as a research pilot. Dick was a former Co-op at the NASA Flight Research Center (a previous name of the Ames-Dryden Flight Research Facility), serving as an Operations Engineer. At Ames-Dryden, Dick was a pilot for the F-14 Aileron Rudder Interconnect Program, AD-1 Oblique Wing Research Aircraft, F-8 Digital Fly-By-Wire and Pilot Induced Oscillations investigations. He also flew the F-104, T-37, and the F-15. On November 8, 1982, Gray was fatally injured in a T-37 jet aircraft while making a pilot proficiency flight. Dick graduated with a Bachelors degree in Aeronautical Engineering from San Jose State University in 1969. He joined the U.S. Navy in July 1969, becoming a Naval Aviator in January 1971, when he was assigned to F-4 Phantoms at Naval Air Station (NAS) Miramar, California. In 1972, he flew 48 combat missions in Vietnam in F-4s with VF-111 aboard the USS Coral Sea. After making a second cruise in 1973, Dick was assigned to Air Test and Evaluation Squadron Four (VX-4) at NAS Point Mugu, California, as a project pilot on various operational test and evaluation programs. In November 1978, Dick retired from the Navy and joined NASA's Johnson Space Center. At JSC Gray served as chief project pilot on the WB-57F high-altitude research projects and as the prime television chase pilot in a T-38 for the landing portion of the Space Shuttle orbital flight tests. Dick had over 3,000 hours in more than 30 types of aircraft, an airline transport rating, and 252 carrier arrested landings. He was a member of the Society of Experimental Test Pilots serving on the Board of Directors as Southwest Section Technical Adviser in

  19. Chameleon-photon mixing in a primordial magnetic field

    International Nuclear Information System (INIS)

    Schelpe, Camilla A. O.

    2010-01-01

    The existence of a sizable, O(10 -10 -10 -9 G), cosmological magnetic field in the early Universe has been postulated as a necessary step in certain formation scenarios for the large-scale O(μG) magnetic fields found in galaxies and galaxy clusters. If this field exists then it may induce significant mixing between photons and axion-like particles (ALPs) in the early Universe. The resonant conversion of photons into ALPs in a primordial magnetic field has been studied elsewhere by Mirizzi, Redondo and Sigl (2009). Here we consider the nonresonant mixing between photons and scalar ALPs with masses much less than the plasma frequency along the path, with specific reference to the chameleon scalar field model. The mixing would alter the intensity and polarization state of the cosmic microwave background (CMB) radiation. We find that the average modification to the CMB polarization modes is negligible. However the average modification to the CMB intensity spectrum is more significant and we compare this to high-precision measurements of the CMB monopole made by the far infrared absolute spectrophotometer on board the COBE satellite. The resulting 95% confidence limit on the scalar-photon conversion probability in the primordial field (at 100 GHz) is P γ↔φ -2 . This corresponds to a degenerate constraint on the photon-scalar coupling strength, g eff , and the magnitude of the primordial magnetic field. Taking the upper bound on the strength of the primordial magnetic field derived from the CMB power spectra, B λ ≤5.0x10 -9 G, this would imply an upper bound on the photon-scalar coupling strength in the range g eff -13 GeV -1 to g eff -14 GeV -1 , depending on the power spectrum of the primordial magnetic field.

  20. Selections from 2016: Primordial Black Holes as Dark Matter

    Science.gov (United States)

    Kohler, Susanna

    2016-12-01

    Editors note:In these last two weeks of 2016, well be looking at a few selections that we havent yet discussed on AAS Nova from among the most-downloaded paperspublished in AAS journals this year. The usual posting schedule will resume after the AAS winter meeting.LIGO Gravitational Wave Detection, Primordial Black Holes, and the Near-IR Cosmic Infrared Background AnisotropiesPublished May2016Main takeaway:A study by Alexander Kashlinsky (NASA Goddard SFC) proposes that the cold dark matter that makes up the majority of the universes matter may be made of black holes. These black holes, Kashlinsky suggests, are primordial: they collapsed directly from dense regions of the universe soon after the Big Bang.Why its interesting:This model would simultaneously explain several observations. In particular, we see similarities in patterns between the cosmic infrared and X-ray backgrounds. This would make sense if accretion onto primordial black holes in halos produced the X-ray background in the same regions where the first stars also formed, producing the infrared background.What this means for current events:In Kashlinskys model, primordial black holes would occasionally form binary pairs and eventually spiral in and merge. The release of energy from such an event would then be observable by gravitational-wave detectors. Could the gravitational-wave signal that LIGO detected last year have been two primordial black holes merging? More observations will be needed to find out.CitationA. Kashlinsky 2016 ApJL 823 L25. doi:10.3847/2041-8205/823/2/L25

  1. Lendab nagu kotkas üle maailmas kogutud tarkuse / Richard Aroksaar ; intervjueerinud Ene Riet

    Index Scriptorium Estoniae

    Aroksaar, Richard

    2014-01-01

    Intervjuu eestlase Richard Aroksaarega, kes õppinud psühholoogiat ja raamatukogundust, töötab USA Rahvusparkide Ühenduse raamatukogus (National Park Service Library, NPS) süsteemi raamatukoguhoidja ja administraatorina

  2. Richard Kelly: Pioneirismo na iluminação da arquitetura moderna

    Directory of Open Access Journals (Sweden)

    Fernanda Brito Bandeira

    2018-04-01

    Full Text Available Livros resenhado: NEUMANN, Dietrich; STERN, Robert A. M. The structure of light: Richard Kelly and the illumination of modern architecture. New York: Yale University Press, 2010, 214 p. ISBN: 978-0-300-16370-4

  3. Obituary: Richard L. (Dick) Walker, Jr., 1938-2005

    Science.gov (United States)

    Pier, Jeffrey R.; Mason, Brian

    2005-12-01

    Koch Center for Science, Math, and Technology at Deerfield Academy in Massachusetts. He also consulted with James Turrell, providing astronomical position information for the design of the Roden Crater Project outside of Flagstaff. While he will be remembered for his significant scientific contributions to the field of astronomy, those who knew Dick, both scientists and non-scientists alike, will probably remember him best for his humility, his humanity, and his loyal and abiding friendship. He was a man with a terrific sense of humor and an infectious laugh. It was always an honor and pleasure to be in his company. Richard L. Walker, Jr. is survived by his wife, Patricia, two daughters from his first marriage: Brenda Walker of Las Vegas, NV, and Pamela Hepburn of Holland, OH, as well as four children from Patricia's first marriage: Doug Browning of Lake Havasu City, AZ, Michael Browning of Kingman, AZ, Kim Bructo of Orient, OH, and Jennifer Brown of Lake Havasu City, AZ. He is also survived by ten grandchildren and three great-grandchildren. He was preceded in death by his father Richard, mother Mary, and daughter, Paula Jean Elizabeth Stone.

  4. Primordial statistical anisotropy generated at the end of inflation

    International Nuclear Information System (INIS)

    Yokoyama, Shuichiro; Soda, Jiro

    2008-01-01

    We present a new mechanism for generating primordial statistical anisotropy of curvature perturbations. We introduce a vector field which has a non-minimal kinetic term and couples with a waterfall field in a hybrid inflation model. In such a system, the vector field gives fluctuations of the end of inflation and hence induces a subcomponent of curvature perturbations. Since the vector has a preferred direction, the statistical anisotropy could appear in the fluctuations. We present the explicit formula for the statistical anisotropy in the primordial power spectrum and the bispectrum of curvature perturbations. Interestingly, there is the possibility that the statistical anisotropy does not appear in the power spectrum but does appear in the bispectrum. We also find that the statistical anisotropy provides the shape dependence to the bispectrum

  5. Primordial statistical anisotropy generated at the end of inflation

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Shuichiro [Department of Physics and Astrophysics, Nagoya University, Aichi 464-8602 (Japan); Soda, Jiro, E-mail: shu@a.phys.nagoya-u.ac.jp, E-mail: jiro@tap.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, Kyoto 606-8501 (Japan)

    2008-08-15

    We present a new mechanism for generating primordial statistical anisotropy of curvature perturbations. We introduce a vector field which has a non-minimal kinetic term and couples with a waterfall field in a hybrid inflation model. In such a system, the vector field gives fluctuations of the end of inflation and hence induces a subcomponent of curvature perturbations. Since the vector has a preferred direction, the statistical anisotropy could appear in the fluctuations. We present the explicit formula for the statistical anisotropy in the primordial power spectrum and the bispectrum of curvature perturbations. Interestingly, there is the possibility that the statistical anisotropy does not appear in the power spectrum but does appear in the bispectrum. We also find that the statistical anisotropy provides the shape dependence to the bispectrum.

  6. Mutations in XRCC4 cause primordial dwarfism without causing immunodeficiency.

    Science.gov (United States)

    Saito, Shinta; Kurosawa, Aya; Adachi, Noritaka

    2016-08-01

    In successive reports from 2014 to 2015, X-ray repair cross-complementing protein 4 (XRCC4) has been identified as a novel causative gene of primordial dwarfism. XRCC4 is indispensable for non-homologous end joining (NHEJ), the major pathway for repairing DNA double-strand breaks. As NHEJ is essential for V(D)J recombination during lymphocyte development, it is generally believed that abnormalities in XRCC4 cause severe combined immunodeficiency. Contrary to expectations, however, no overt immunodeficiency has been observed in patients with primordial dwarfism harboring XRCC4 mutations. Here, we describe the various XRCC4 mutations that lead to disease and discuss their impact on NHEJ and V(D)J recombination.

  7. Constraints on amplitudes of curvature perturbations from primordial black holes

    International Nuclear Information System (INIS)

    Bugaev, Edgar; Klimai, Peter

    2009-01-01

    We calculate the primordial black hole (PBH) mass spectrum produced from a collapse of the primordial density fluctuations in the early Universe using, as an input, several theoretical models giving the curvature perturbation power spectra P R (k) with large (∼10 -2 -10 -1 ) values at some scale of comoving wave numbers k. In the calculation we take into account the explicit dependence of gravitational (Bardeen) potential on time. Using the PBH mass spectra, we further calculate the neutrino and photon energy spectra in extragalactic space from evaporation of light PBHs, and the energy density fraction contained in PBHs today (for heavier PBHs). We obtain the constraints on the model parameters using available experimental data (including data on neutrino and photon cosmic backgrounds). We briefly discuss the possibility that the observed 511 keV line from the Galactic center is produced by annihilation of positrons evaporated by PBHs.

  8. Microcephalic Osteodysplastic Primordial Dwarfism, Type II: a Clinical Review.

    Science.gov (United States)

    Bober, Michael B; Jackson, Andrew P

    2017-04-01

    This review will provide an overview of the microcephalic primordial dwarfism (MPD) class of disorders and provide the reader comprehensive clinical review with suggested care guidelines for patients with microcephalic osteodysplastic primordial dwarfism, type II (MOPDII). Over the last 15 years, significant strides have been made in the diagnosis, natural history, and management of MOPDII. MOPDII is the most common and well described form of MPD. The classic features of the MPD group are severe pre- and postnatal growth retardation, with marked microcephaly. In addition to these features, individuals with MOPDII have characteristic facies, skeletal dysplasia, abnormal dentition, and an increased risk for cerebrovascular disease and insulin resistance. Biallelic loss-of-function mutations in the pericentrin gene cause MOPDII, which is inherited in an autosomal recessive manner.

  9. Primordial helium abundance determination using sulphur as metallicity tracer

    Science.gov (United States)

    Fernández, Vital; Terlevich, Elena; Díaz, Angeles I.; Terlevich, Roberto; Rosales-Ortega, F. F.

    2018-05-01

    The primordial helium abundance YP is calculated using sulphur as metallicity tracer in the classical methodology (with YP as an extrapolation of Y to zero metals). The calculated value, YP, S = 0.244 ± 0.006, is in good agreement with the estimate from the Planck experiment, as well as, determinations in the literature using oxygen as the metallicity tracer. The chemical analysis includes the sustraction of the nebular continuum and of the stellar continuum computed from simple stellar population synthesis grids. The S+2 content is measured from the near infrared [SIII]λλ9069Å, 9532Å lines, while an ICF(S3 +) is proposed based on the Ar3 +/Ar2 + fraction. Finally, we apply a multivariable linear regression using simultaneously oxygen, nitrogen and sulphur abundances for the same sample to determine the primordial helium abundance resulting in YP - O, N, S = 0.245 ± 0.007.

  10. Cosmological lepton asymmetry, primordial nucleosynthesis and sterile neutrinos

    Science.gov (United States)

    Abazajian, Kevork; Bell, Nicole F.; Fuller, George M.; Wong, Yvonne Y. Y.

    2005-09-01

    We study post weak decoupling coherent active-sterile and active-active matter-enhanced neutrino flavor transformation in the early Universe. We show that flavor conversion efficiency at Mikheyev-Smirnov-Wolfenstein resonances is likely to be high (adiabatic evolution) for relevant neutrino parameters and energies. However, we point out that these resonances cannot sweep smoothly and continuously with the expansion of the Universe. We show how neutrino flavor conversion in this way can leave both the active and sterile neutrinos with nonthermal energy spectra, and how, in turn, these distorted energy spectra can affect the neutron-to-proton ratio, primordial nucleosynthesis, and cosmological mass/closure constraints on sterile neutrinos. We demonstrate that the existence of a light sterile neutrino which mixes with active neutrinos can change fundamentally the relationship between the cosmological lepton numbers and the primordial nucleosynthesis He4 yield.

  11. Inflation, Reionization, and All That: The Primordial Inflation Explorer

    Science.gov (United States)

    Kogut, Alan J.

    2012-01-01

    The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10(exp -3) at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy. I describe the PIXIE instrument and mission architecture needed to detect the inflationary signature using only 4 semiconductor bolometers.

  12. Testing the Standard Model with the Primordial Inflation Explorer

    Science.gov (United States)

    Kogut, Alan J.

    2011-01-01

    The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10A{-3) at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy. I describe the PIXIE instrument and mission architecture needed to detect the inflationary signature using only 4 semiconductor bolometers.

  13. On the evolution of the primordial cosmic turbulence

    International Nuclear Information System (INIS)

    Tanabe, Kenji.

    1980-09-01

    The evolution of the primordial cosmic turbulence in the big-bang universe is studied by numerical integration of the spectral equation derived by Nariai and closed by Heisenberg's hypothesis. In order to examine whether the turbulence can survive by the epoch of the plasma recombination, the equation is dealt with by taking full account of the viscosity effect. The main conclusion is that the resulting spectrum survived against the viscous decay depends on the initial spectral shape which is assumed at the epoch t sub(eq) when the density of matter is equal to that of radiation. The Taylor's micro-scale is also calculated which is available to determine the fate of the primordial cosmic turbulence. (author)

  14. Primordial non-Gaussian features from DBI Galileon inflation

    International Nuclear Information System (INIS)

    Choudhury, Sayantan; Pal, Supratik

    2015-01-01

    We have studied primordial non-Gaussian features of a model of potential-driven single field DBI Galileon inflation. We have computed the bispectrum from the three-point correlation function considering all possible cross correlations between the scalar and tensor modes of the proposed setup. Further, we have computed the trispectrum from a four-point correlation function considering the contribution from contact interaction, and scalar and graviton exchange diagrams in the in-in picture. Finally we have obtained the non-Gaussian consistency conditions from the four-point correlator, which results in partial violation of the Suyama-Yamaguchi four-point consistency relation. This further leads to the conclusion that sufficient primordial non-Gaussianities can be obtained from DBI Galileon inflation. (orig.)

  15. Primordial Regular Black Holes: Thermodynamics and Dark Matter

    Directory of Open Access Journals (Sweden)

    José Antonio de Freitas Pacheco

    2018-05-01

    Full Text Available The possibility that dark matter particles could be constituted by extreme regular primordial black holes is discussed. Extreme black holes have zero surface temperature, and are not subjected to the Hawking evaporation process. Assuming that the common horizon radius of these black holes is fixed by the minimum distance that is derived from the Riemann invariant computed from loop quantum gravity, the masses of these non-singular stable black holes are of the order of the Planck mass. However, if they are formed just after inflation, during reheating, their initial masses are about six orders of magnitude higher. After a short period of growth by the accretion of relativistic matter, they evaporate until reaching the extreme solution. Only a fraction of 3.8 × 10−22 of relativistic matter is required to be converted into primordial black holes (PBHs in order to explain the present abundance of dark matter particles.

  16. RTTN Mutations Cause Primary Microcephaly and Primordial Dwarfism in Humans.

    Science.gov (United States)

    Shamseldin, Hanan; Alazami, Anas M; Manning, Melanie; Hashem, Amal; Caluseiu, Oana; Tabarki, Brahim; Esplin, Edward; Schelley, Susan; Innes, A Micheil; Parboosingh, Jillian S; Lamont, Ryan; Majewski, Jacek; Bernier, Francois P; Alkuraya, Fowzan S

    2015-12-03

    Primary microcephaly is a developmental brain anomaly that results from defective proliferation of neuroprogenitors in the germinal periventricular zone. More than a dozen genes are known to be mutated in autosomal-recessive primary microcephaly in isolation or in association with a more generalized growth deficiency (microcephalic primordial dwarfism), but the genetic heterogeneity is probably more extensive. In a research protocol involving autozygome mapping and exome sequencing, we recruited a multiplex consanguineous family who is affected by severe microcephalic primordial dwarfism and tested negative on clinical exome sequencing. Two candidate autozygous intervals were identified, and the second round of exome sequencing revealed a single intronic variant therein (c.2885+8A>G [p.Ser963(∗)] in RTTN exon 23). RT-PCR confirmed that this change creates a cryptic splice donor and thus causes retention of the intervening 7 bp of the intron and leads to premature truncation. On the basis of this finding, we reanalyzed the exome file of a second consanguineous family affected by a similar phenotype and identified another homozygous change in RTTN as the likely causal mutation. Combined linkage analysis of the two families confirmed that RTTN maps to the only significant linkage peak. Finally, through international collaboration, a Canadian multiplex family affected by microcephalic primordial dwarfism and biallelic mutation of RTTN was identified. Our results expand the phenotype of RTTN-related disorders, hitherto limited to polymicrogyria, to include microcephalic primordial dwarfism with a complex brain phenotype involving simplified gyration. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  17. Primordial large-scale electromagnetic fields from gravitoelectromagnetic inflation

    Energy Technology Data Exchange (ETDEWEB)

    Membiela, Federico Agustin [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, (7600) Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)], E-mail: membiela@mdp.edu.ar; Bellini, Mauricio [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, (7600) Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)], E-mail: mbellini@mdp.edu.ar

    2009-04-20

    We investigate the origin and evolution of primordial electric and magnetic fields in the early universe, when the expansion is governed by a cosmological constant {lambda}{sub 0}. Using the gravitoelectromagnetic inflationary formalism with A{sub 0}=0, we obtain the power of spectrums for large-scale magnetic fields and the inflaton field fluctuations during inflation. A very important fact is that our formalism is naturally non-conformally invariant.

  18. Primordial large-scale electromagnetic fields from gravitoelectromagnetic inflation

    Science.gov (United States)

    Membiela, Federico Agustín; Bellini, Mauricio

    2009-04-01

    We investigate the origin and evolution of primordial electric and magnetic fields in the early universe, when the expansion is governed by a cosmological constant Λ0. Using the gravitoelectromagnetic inflationary formalism with A0 = 0, we obtain the power of spectrums for large-scale magnetic fields and the inflaton field fluctuations during inflation. A very important fact is that our formalism is naturally non-conformally invariant.

  19. Primordial large-scale electromagnetic fields from gravitoelectromagnetic inflation

    International Nuclear Information System (INIS)

    Membiela, Federico Agustin; Bellini, Mauricio

    2009-01-01

    We investigate the origin and evolution of primordial electric and magnetic fields in the early universe, when the expansion is governed by a cosmological constant Λ 0 . Using the gravitoelectromagnetic inflationary formalism with A 0 =0, we obtain the power of spectrums for large-scale magnetic fields and the inflaton field fluctuations during inflation. A very important fact is that our formalism is naturally non-conformally invariant.

  20. Tracing primordial black holes in nonsingular bouncing cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jie-Wen, E-mail: chjw@mail.ustc.edu.cn [CAS Key Laboratory for Researches in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China); Liu, Junyu, E-mail: junyu@mail.ustc.edu.cn [CAS Key Laboratory for Researches in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China); Department of Physics, California Institute of Technology, Pasadena, California 91125 (United States); Xu, Hao-Lan, E-mail: xhl1995@mail.ustc.edu.cn [CAS Key Laboratory for Researches in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China); Institut d' Astrophysique de Paris, UMR 7095-CNRS, Université Pierre et Marie Curie, 98 bis boulevard Arago, 75014 Paris (France); Cai, Yi-Fu, E-mail: yifucai@ustc.edu.cn [CAS Key Laboratory for Researches in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2017-06-10

    We in this paper investigate the formation and evolution of primordial black holes (PBHs) in nonsingular bouncing cosmologies. We discuss the formation of PBH in the contracting phase and calculate the PBH abundance as a function of the sound speed and Hubble parameter. Afterwards, by taking into account the subsequent PBH evolution during the bouncing phase, we derive the density of PBHs and their Hawking radiation. Our analysis shows that nonsingular bounce models can be constrained from the backreaction of PBHs.

  1. Dark energy and dark matter from primordial QGP

    Energy Technology Data Exchange (ETDEWEB)

    Vaidya, Vaishali, E-mail: vaidvavaishali24@gmail.com; Upadhyaya, G. K., E-mail: gopalujiain@yahoo.co.in [School of Studies in Physics, Vikram University Ujjain (India)

    2015-07-31

    Coloured relics servived after hadronization might have given birth to dark matter and dark energy. Theoretical ideas to solve mystery of cosmic acceleration, its origin and its status with reference to recent past are of much interest and are being proposed by many workers. In the present paper, we present a critical review of work done to understand the earliest appearance of dark matter and dark energy in the scenario of primordial quark gluon plasma (QGP) phase after Big Bang.

  2. Calculating the mass fraction of primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Young, Sam; Byrnes, Christian T. [Department of Physics and Astronomy, University of Sussex, North-South Road, Brighton (United Kingdom); Sasaki, Misao, E-mail: sy81@sussex.ac.uk, E-mail: ctb22@sussex.ac.uk, E-mail: misao@yukawa.kyoto-u.ac.jp [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

    2014-07-01

    We reinspect the calculation for the mass fraction of primordial black holes (PBHs) which are formed from primordial perturbations, finding that performing the calculation using the comoving curvature perturbation R{sub c} in the standard way vastly overestimates the number of PBHs, by many orders of magnitude. This is because PBHs form shortly after horizon entry, meaning modes significantly larger than the PBH are unobservable and should not affect whether a PBH forms or not—this important effect is not taken into account by smoothing the distribution in the standard fashion. We discuss alternative methods and argue that the density contrast, Δ, should be used instead as super-horizon modes are damped by a factor k{sup 2}. We make a comparison between using a Press-Schechter approach and peaks theory, finding that the two are in close agreement in the region of interest. We also investigate the effect of varying the spectral index, and the running of the spectral index, on the abundance of primordial black holes.

  3. Calculating the mass fraction of primordial black holes

    International Nuclear Information System (INIS)

    Young, Sam; Byrnes, Christian T.; Sasaki, Misao

    2014-01-01

    We reinspect the calculation for the mass fraction of primordial black holes (PBHs) which are formed from primordial perturbations, finding that performing the calculation using the comoving curvature perturbation R c in the standard way vastly overestimates the number of PBHs, by many orders of magnitude. This is because PBHs form shortly after horizon entry, meaning modes significantly larger than the PBH are unobservable and should not affect whether a PBH forms or not—this important effect is not taken into account by smoothing the distribution in the standard fashion. We discuss alternative methods and argue that the density contrast, Δ, should be used instead as super-horizon modes are damped by a factor k 2 . We make a comparison between using a Press-Schechter approach and peaks theory, finding that the two are in close agreement in the region of interest. We also investigate the effect of varying the spectral index, and the running of the spectral index, on the abundance of primordial black holes

  4. Assumptions of the primordial spectrum and cosmological parameter estimation

    International Nuclear Information System (INIS)

    Shafieloo, Arman; Souradeep, Tarun

    2011-01-01

    The observables of the perturbed universe, cosmic microwave background (CMB) anisotropy and large structures depend on a set of cosmological parameters, as well as the assumed nature of primordial perturbations. In particular, the shape of the primordial power spectrum (PPS) is, at best, a well-motivated assumption. It is known that the assumed functional form of the PPS in cosmological parameter estimation can affect the best-fit-parameters and their relative confidence limits. In this paper, we demonstrate that a specific assumed form actually drives the best-fit parameters into distinct basins of likelihood in the space of cosmological parameters where the likelihood resists improvement via modifications to the PPS. The regions where considerably better likelihoods are obtained allowing free-form PPS lie outside these basins. In the absence of a preferred model of inflation, this raises a concern that current cosmological parameter estimates are strongly prejudiced by the assumed form of PPS. Our results strongly motivate approaches toward simultaneous estimation of the cosmological parameters and the shape of the primordial spectrum from upcoming cosmological data. It is equally important for theorists to keep an open mind towards early universe scenarios that produce features in the PPS. (paper)

  5. Galaxy bispectrum, primordial non-Gaussianity and redshift space distortions

    Energy Technology Data Exchange (ETDEWEB)

    Tellarini, Matteo; Ross, Ashley J.; Wands, David [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth, PO1 3FX (United Kingdom); Tasinato, Gianmassimo, E-mail: matteo.tellarini@port.ac.uk, E-mail: ross.1333@osu.edu, E-mail: g.tasinato@swansea.ac.uk, E-mail: david.wands@port.ac.uk [Department of Physics, Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom)

    2016-06-01

    Measurements of the non-Gaussianity of the primordial density field have the power to considerably improve our understanding of the physics of inflation. Indeed, if we can increase the precision of current measurements by an order of magnitude, a null-detection would rule out many classes of scenarios for generating primordial fluctuations. Large-scale galaxy redshift surveys represent experiments that hold the promise to realise this goal. Thus, we model the galaxy bispectrum and forecast the accuracy with which it will probe the parameter f {sub NL}, which represents the degree of primordial local-type non Gaussianity. Specifically, we address the problem of modelling redshift space distortions (RSD) in the tree-level galaxy bispectrum including f {sub NL}. We find novel contributions associated with RSD, with the characteristic large scale amplification induced by local-type non-Gaussianity. These RSD effects must be properly accounted for in order to obtain un-biased measurements of f {sub NL} from the galaxy bispectrum. We propose an analytic template for the monopole which can be used to fit against data on large scales, extending models used in the recent measurements. Finally, we perform idealised forecasts on σ {sub f} {sub N{sub L}}—the accuracy of the determination of local non-linear parameter f {sub NL}—from measurements of the galaxy bispectrum. Our findings suggest that current surveys can in principle provide f {sub NL} constraints competitive with Planck , and future surveys could improve them further.

  6. Galaxy bispectrum, primordial non-Gaussianity and redshift space distortions

    International Nuclear Information System (INIS)

    Tellarini, Matteo; Ross, Ashley J.; Wands, David; Tasinato, Gianmassimo

    2016-01-01

    Measurements of the non-Gaussianity of the primordial density field have the power to considerably improve our understanding of the physics of inflation. Indeed, if we can increase the precision of current measurements by an order of magnitude, a null-detection would rule out many classes of scenarios for generating primordial fluctuations. Large-scale galaxy redshift surveys represent experiments that hold the promise to realise this goal. Thus, we model the galaxy bispectrum and forecast the accuracy with which it will probe the parameter f NL , which represents the degree of primordial local-type non Gaussianity. Specifically, we address the problem of modelling redshift space distortions (RSD) in the tree-level galaxy bispectrum including f NL . We find novel contributions associated with RSD, with the characteristic large scale amplification induced by local-type non-Gaussianity. These RSD effects must be properly accounted for in order to obtain un-biased measurements of f NL from the galaxy bispectrum. We propose an analytic template for the monopole which can be used to fit against data on large scales, extending models used in the recent measurements. Finally, we perform idealised forecasts on σ f NL —the accuracy of the determination of local non-linear parameter f NL —from measurements of the galaxy bispectrum. Our findings suggest that current surveys can in principle provide f NL constraints competitive with Planck , and future surveys could improve them further.

  7. Quantum inflaton, primordial metric perturbations and CMB fluctuations

    International Nuclear Information System (INIS)

    Cao, F J

    2007-01-01

    We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the dynamics of the (classical) cosmological metric. For chaotic inflation, the quantum treatment avoids the unnatural requirements of an initial state with all the energy in the zero mode. For new inflation it allows a consistent treatment of the explosive particle production due to spinodal instabilities. Quantum field inflation (under conditions that are the quantum analog of slow roll) leads, upon evolution, to the formation of a condensate starting a regime of effective classical inflation. We compute the primordial perturbations taking the dominant quantum effects into account. The results for the scalar, vector and tensor primordial perturbations are expressed in terms of the classical inflation results. For a N-component field in a O(N) symmetric model, adiabatic fluctuations dominate while isocurvature or entropy fluctuations are negligible. The results agree with the current WMAP observations and predict corrections to the power spectrum in classical inflation. Such corrections are estimated to be of the order of m 2 /[NH 2 ] where m is the inflaton mass and H the Hubble constant at horizon crossing. This turns to be about 4% for the cosmologically relevant scales. This quantum field treatment of inflation provides the foundations to the classical inflation and permits to compute quantum corrections to it

  8. Reconstructing the size distribution of the primordial Main Belt

    Science.gov (United States)

    Tsirvoulis, G.; Morbidelli, A.; Delbo, M.; Tsiganis, K.

    2018-04-01

    In this work we aim to constrain the slope of the size distribution of main-belt asteroids, at their primordial state. To do so we turn out attention to the part of the main asteroid belt between 2.82 and 2.96 AU, the so-called "pristine zone", which has a low number density of asteroids and few, well separated asteroid families. Exploiting these unique characteristics, and using a modified version of the hierarchical clustering method we are able to remove the majority of asteroid family members from the region. The remaining, background asteroids should be of primordial origin, as the strong 5/2 and 7/3 mean-motion resonances with Jupiter inhibit transfer of asteroids to and from the neighboring regions. The size-frequency distribution of asteroids in the size range 17 size distribution slope q = - 1.43 . In addition, applying the same 'family extraction' method to the neighboring regions, i.e. the middle and outer belts, and comparing the size distributions of the respective background populations, we find statistical evidence that no large asteroid families of primordial origin had formed in the middle or pristine zones.

  9. Morrow, Reiff, Receive 2013 Space Physics and Aeronomy Richard Carrington Awards: Response

    Science.gov (United States)

    Reiff, Patricia H.

    2014-08-01

    It is a special privilege to receive this award honoring Richard Carrington's discovery of what we now call space weather. It is particularly appropriate that this award also recognizes Cherilynn Morrow, who 20 years ago made a presentation to the Space Science Advisory Committee on Jeff Rosendhal's idea of mission-based E/PO. We worked together, bringing that idea to the successful, but threatened, network it is today. For me, learning and teaching go hand in hand—as we publish our findings for our peers, we should also repay the public investment in our research with accurate, understandable results. My interest in space science was sparked by a father-daughter course in astronomy sponsored by the Brownies at the Oklahoma City Planetarium and kindled by the Bell Labs production The Strange Case of the Cosmic Rays directed by Frank Capra. Knowing that planetarium shows and educational movies can change lives, I have devoted a large portion of my last 25 years to creating software, shows, and portable planetariums to inspire and engage youth. This has not been a one-person effort, of course. My work Cherilynn Ann Morrow would have been impossible without the collaboration of Carolyn Sumners, vice president of the Houston Museum of Natural Science. Our museum kiosk and planetarium control software would not have happened without the skill and perseverance of my chief programmer, Colin Law. Jim Burch has been first a mentor and then a colleague on both the research and outreach sides of my career. I share this honor with a long line of highly talented students and postdocs who have contributed science content and outreach efforts. Most importantly, without the support of my husband, Tom Hill, I would not have had the time and freedom to build an educational network while continuing research and raising a family. I thank AGU for bestowing this honor.

  10. Observational constraints on the primordial curvature power spectrum

    Science.gov (United States)

    Emami, Razieh; Smoot, George F.

    2018-01-01

    CMB temperature fluctuation observations provide a precise measurement of the primordial power spectrum on large scales, corresponding to wavenumbers 10‑3 Mpc‑1 lesssim k lesssim 0.1 Mpc‑1, [1-7, 11]. Luminous red galaxies and galaxy clusters probe the matter power spectrum on overlapping scales (0.02 Mpc‑1 lesssim k lesssim 0.7 Mpc‑1 [10, 12-20]), while the Lyman-alpha forest reaches slightly smaller scales (0.3 Mpc‑1 lesssim k lesssim 3 Mpc‑1 [22]). These observations indicate that the primordial power spectrum is nearly scale-invariant with an amplitude close to 2 × 10‑9, [5, 23-28]. These observations strongly support Inflation and motivate us to obtain observations and constraints reaching to smaller scales on the primordial curvature power spectrum and by implication on Inflation. We are able to obtain limits to much higher values of k lesssim 105 Mpc‑1 and with less sensitivity even higher k lesssim 1019‑ 1023 Mpc‑1 using limits from CMB spectral distortions and other limits on ultracompact minihalo objects (UCMHs) and Primordial Black Holes (PBHs). PBHs are one of the known candidates for the Dark Matter (DM). Due to their very early formation, they could give us valuable information about the primordial curvature perturbations. These are complementary to other cosmological bounds on the amplitude of the primordial fluctuations. In this paper, we revisit and collect all the published constraints on both PBHs and UCMHs. We show that unless one uses the CMB spectral distortion, PBHs give us a very relaxed bounds on the primordial curvature perturbations. UCMHs, on the other hand, are very informative over a reasonable k range (3 lesssim k lesssim 106 Mpc‑1) and lead to significant upper-bounds on the curvature spectrum. We review the conditions under which the tighter constraints on the UCMHs could imply extremely strong bounds on the fraction of DM that could be PBHs in reasonable models. Failure to satisfy these conditions would

  11. Effect of vacuum energy on evolution of primordial black holes in Einstein gravity

    International Nuclear Information System (INIS)

    Nayak, Bibekananda; Jamil, Mubasher

    2012-01-01

    We study the evolution of primordial black holes by considering present universe is no more matter dominated rather vacuum energy dominated. We also consider the accretion of radiation, matter and vacuum energy during respective dominance period. In this scenario, we found that radiation accretion efficiency should be less than 0.366 and accretion rate is much larger than previous analysis by Nayak et al. (2009) . Thus here primordial black holes live longer than previous works Nayak and Singh (2011). Again matter accretion slightly increases the mass and lifetime of primordial black holes. However, the vacuum energy accretion is slightly complicated one, where accretion is possible only up to a critical time. If a primordial black hole lives beyond critical time, then its' lifespan increases due to vacuum energy accretion. But for presently evaporating primordial black holes, critical time comes much later than their evaporating time and thus vacuum energy could not affect those primordial black holes.

  12. Trochanteric fractures. Classification and mechanical stability in McLaughlin, Ender and Richard osteosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Herrlin, K.; Stroemberg, T.; Lidgren, L.; Walloee, A.; Pettersson, H.

    Four hundred and thirty trochanteric factures operated upon with McLaughlin, Ender or Richard's osteosynthesis were divided into 6 different types based on their radiographic appearance before and immediately after reposition with special reference to the medial cortical support. A significant correlation was found between the fracture type and subsequent mechanical complications where types 1 and 2 gave less, and types 4 and 5 more complications. A comparison of the various osteosyntheses showed that Richard's had significantly fewer complications than either the Ender or McLaughlin types. For Richard's osteosynthesis alone no correlation to fracture type could be made because of the small number of complications in this group.

  13. The Cosmochemistry of Pluto: A Primordial Origin of Volatiles?

    Science.gov (United States)

    Glein, C. R.; Waite, J. H., Jr.

    2017-12-01

    Pluto is a wonderland of volatiles. Nitrogen, methane, and carbon monoxide are the principal volatiles that maintain its tenuous atmosphere, and they have also created a mesmerizing landscape of icy geological features, including Pluto's iconic "heart". Recent data, particularly those returned by the New Horizons mission [1-3], allow us to begin testing hypotheses for the cosmochemical origins of these world-shaping species on Pluto. Here, we investigate if Pluto's volatiles could have been accreted in its building blocks. We take both bottom-up and top-down approaches in testing this hypothesis in terms of mass balance. We estimate Pluto's primordial inventory of volatiles by scaling a range of cometary abundances up to the ice mass fraction of Pluto. We also make estimates of the present and lost inventories of volatiles based on surface observations and interpretations, as well as different scenarios of atmospheric photochemistry and escape. We find that, if primordial Pluto resembled a giant comet with respect to volatile abundances, then the initial volatile inventory would have been sufficient to account for the estimated present and lost inventories. This consistency supports a primordial origin for Pluto's volatiles. However, the observed ratio of CO/N2 in Pluto's atmosphere [4] is several orders of magnitude lower than the nominal cometary value. We are currently using phase equilibrium and rate models to explore if volatile layering in Sputnik Planitia, or the destruction of CO in a past or present subsurface ocean of liquid water could explain the apparent depletion of CO on Pluto. References: [1] Moore et al. (2016) Science 351, 1284. [2] Grundy et al. (2016) Science 351, aad9189. [3] Gladstone et al. (2016) Science 351, aad8866. [4] Lellouch et al. (2017) Icarus 286, 289.

  14. The statistics of maxima in primordial density perturbations

    International Nuclear Information System (INIS)

    Peacock, J.A.; Heavens, A.F.

    1985-01-01

    An investigation has been made of the hypothesis that protogalaxies/protoclusters form at the sites of maxima in a primordial field of normally distributed density perturbations. Using a mixture of analytic and numerical techniques, the properties of the maxima, have been studied. The results provide a natural mechanism for biased galaxy formation in which galaxies do not necessarily follow the large-scale density. Methods for obtained the true autocorrelation function of the density field and implications for Microwave Background studies are discussed. (author)

  15. Bicycling to Work and Primordial Prevention of Cardiovascular Risk

    DEFF Research Database (Denmark)

    Grøntved, Anders; Koivula, Robert W; Johansson, Ingegerd

    2016-01-01

    of incident obesity, hypertension, hypertriglyceridemia, and impaired glucose tolerance, comparing individuals who commuted to work by bicycle with those who used passive modes of transportation. We also examined the relationship of change in commuting mode with incidence of these clinical risk factors......% CI 0.74-0.91) compared with participants not cycling to work at both times points or who switched from cycling to other modes of transport during follow-up. CONCLUSIONS: These data suggest that commuting by bicycle to work is an important strategy for primordial prevention of clinical cardiovascular...... risk factors among middle-aged men and women....

  16. Les Houches 1999 Summer School, Session 71 : The Primordial Universe

    CERN Document Server

    Schäffer, R; Silk, J; David, F

    2000-01-01

    This book reviews the interconnection of cosmology and particle physics over the last decade. It provides introductory courses in supersymmetry, superstring and M-theory, responding to an increasing interest to evaluate the cosmological consequences of these theories. Based on a series of extended courses providing an introduction to the physics of the very early universe, in the light of the most recent advances in our understanding of the fundamental interactions, it reviews all the classical issues (inflation, primordial fluctuations, dark matter, baryogenesis), but also introduces the most

  17. Primordial gravitational waves measurements and anisotropies of CMB polarization rotation

    Directory of Open Access Journals (Sweden)

    Si-Yu Li

    2015-12-01

    Full Text Available Searching for the signal of primordial gravitational waves in the B-modes (BB power spectrum is one of the key scientific aims of the cosmic microwave background (CMB polarization experiments. However, this could be easily contaminated by several foreground issues, such as the interstellar dust grains and the galactic cyclotron electrons. In this paper we study another mechanism, the cosmic birefringence, which can be introduced by a CPT-violating interaction between CMB photons and an external scalar field. Such kind of interaction could give rise to the rotation of the linear polarization state of CMB photons, and consequently induce the CMB BB power spectrum, which could mimic the signal of primordial gravitational waves at large scales. With the recently released polarization data of BICEP2 and the joint analysis data of BICEP2/Keck Array and Planck, we perform a global fitting analysis on constraining the tensor-to-scalar ratio r by considering the polarization rotation angle [α(nˆ] which can be separated into a background isotropic part [α¯] and a small anisotropic part [Δα(nˆ]. Since the data of BICEP2 and Keck Array experiments have already been corrected by using the “self-calibration” method, here we mainly focus on the effects from the anisotropies of CMB polarization rotation angle. We find that including Δα(nˆ in the analysis could slightly weaken the constraints on the tensor-to-scalar ratio r, when using current CMB polarization measurements. We also simulate the mock CMB data with the BICEP3-like sensitivity. Very interestingly, we find that if the effects of the anisotropic polarization rotation angle could not be taken into account properly in the analysis, the constraints on r will be dramatically biased. This implies that we need to break the degeneracy between the anisotropies of the CMB polarization rotation angle and the CMB primordial tensor perturbations, in order to measure the signal of primordial

  18. The quark-hadron phase transition and primordial nucleosynthesis

    Science.gov (United States)

    Hogan, Craig J.

    1987-01-01

    After presenting the current view of the processes taking place during the cosmological transition from 'quark soup' to normal hadron matter, attention is given to what happens to cosmological nucleosynthesis in the presence of small-scale baryon inhomogeneities. The QCD phase transition is among the plausible sources of this inhomogeneity. It is concluded that the formation of primordial 'quark nuggets' and other cold exotica requires very low entropy regions at the outset, and that even the more modest nonlinearities perturbing nucleosynthesis probably require some ingredient in addition to a quiescent, mildly supercooled transition.

  19. Cosmic gamma radiation of ultra high energy of primordial origin

    International Nuclear Information System (INIS)

    Aquino Filho, F.G. de.

    1984-01-01

    The quantum mechanical effects near a collapsing black hole as shown by Stephen W.Hawking in 1974 to produce streaming particles through tunneling effect was explored in the context of cosmic gamma ray production. In this thesis, we show the possible production of gamma rays of high energies (ν approx 10 41 Hz) in the initial stages of the formation of the Universe by the explosion of primordial mini black holes. These mini black hole explosions happening at 10 -43 s to 10 -37 s after the start perhaps may account for the existing universal cosmic background radiation of 2.7 0 K. (Author) [pt

  20. Baryogenesis in extended inflation. II. Baryogenesis via primordial black holes

    International Nuclear Information System (INIS)

    Barrow, J.D.; Copeland, E.J.; Kolb, E.W.; Liddle, A.R.

    1991-01-01

    This is the second of two papers devoted to the study of baryogenesis at the end of extended inflation. Extended inflation is brought to an end by the collisions of bubble walls surrounding regions of true vacuum, a process which produces particles well out of thermal equilibrium. In the first paper we considered baryogenesis via direct production and subsequent decay of baryon-number-violating bosons. In this paper we consider the further possibility that the wall collisions may provide a significant density of primordial black holes and examine their possible role in generating a baryon asymmetry

  1. Quasi-constitutional change without intent : A response to Richard Albert

    NARCIS (Netherlands)

    Passchier, Reijer

    2017-01-01

    Recently, Buffalo Law Review published Richard Albert’s article on “quasi-constitutional amendments.” These are, in Albert’s words, “sub-constitutional changes that do not possess the same legal status as a constitutional amendment, that are formally susceptible to statutory repeal or revision, but

  2. Ripples from a Passing Ship: Memories; and a Legacy of Richard Peters

    Science.gov (United States)

    Harris, Kevin

    2013-01-01

    This paper outlines aspects and dimensions of my "relationship" with Richard Peters from 1966 onward. The underlying suggestion is that, while Peters' contribution to philosophy of education was undeniably of major proportions, both that contribution and his legacy are institutional rather than substantive. (Contains 15 notes.)

  3. Racial Shame and the Pleasure of Transformation: Richard Rodriguez's Queer Aesthetics of Assimilation

    Science.gov (United States)

    Beltran, Cristina

    2012-01-01

    This essay analyzes Latino conservative thought by rethinking the logics of assimilation through a simultaneous exploration of aesthetic possibility and negative affect. Focusing on the writings of Richard Rodriguez, the essay considers how creative forms of self-individuation and political agency cannot easily be decoupled from negative forms of…

  4. Richard Rorty's Conception of Philosophy of Education Revisited

    Science.gov (United States)

    Noaparast, Khosrow Bagheri

    2014-01-01

    In this essay Khosrow Bagheri Noaparast argues that, by focusing on acculturation and edification, Richard Rorty has provided a promising view for education because without acculturation, education turns into a destructive endeavor, and without edification, education risks the danger of being repetitive and reproductive. However, Rorty's view…

  5. Richard Wright's Thematic Treatment of Women in "Uncle Tom's Children,""Black Boy," and "Native Son."

    Science.gov (United States)

    Brewton, Butler E.

    Richard Wright's literary work emphasizes a contrast between black women and white women. Although both are "givers" to black boys, the nature of what they give is different. The black woman gives physical life, feeds it, and protects it at the expense of spiritual or creative vitality. Her goal is to survive bodily, to breathe, to have…

  6. Understanding Richard Wright's "Black Boy": A Student Casebook to Issues, Sources, and Historical Documents.

    Science.gov (United States)

    Felgar, Robert

    In "Black Boy," Richard Wright triumphs over an ugly, racist world by fashioning an inspiring, powerful, beautiful, and fictionalized autobiography. To help students understand and appreciate his story in the cultural, political, racial, social, and literary contexts of its time, this casebook provides primary historical documents,…

  7. Süütuse kaotamine / Richard Branson ; intervjueerinud Peter Fisk ; tõlkinud Endrik Randoja

    Index Scriptorium Estoniae

    Branson, Richard

    2009-01-01

    Turunduskirjanik Peter Fiski intervjuu Suurbritannia ärimagnaadi Sir Richard Bransoniga, milles arutletakse ettevõtja suurimate saavutuste ja suurimate pettuste üle, uuritakse Bransoni võimet juhtida oma 450 ettevõtet, tema suhtumist konkurentsi ning uutesse äriideedesse, samuti tema ajakasutust

  8. Transforming Faith: H. Richard Niebuhr and Paulo Freire on Moral Education

    Science.gov (United States)

    Daniel, Joshua Leonard

    2013-01-01

    Through a contextual comparison of the theological ethics of H. Richard Niebuhr and the educational theory of Paulo Freire, I argue that socialization, while an essential task of moral education, is an insufficient aim. The proper aim of moral education is individual development. The intention of my argument is address tendencies towards…

  9. Resisting Biopolitics through “Diaphanous Wonder”: Richard Flanagan's Gould's Book of Fish

    NARCIS (Netherlands)

    Wiese, Doro|info:eu-repo/dai/nl/304842699

    2014-01-01

    In Gould's Book of Fish (2003), author Richard Flanagan manages to invent a format in which content and style account for historical events on Sarah Island, Tasmania in the 1820s, yet he does so in a manner that is not in the least objective, disinterested or fact-orientated. The perspective of

  10. Somaesthetic Training, Aesthetics, Ethics, and the Politics of Difference in Richard Shusterman's "Body Consciousness"

    Science.gov (United States)

    Powell, Kimberly

    2010-01-01

    In this essay, the author first addresses the theme of disciplined somatic training and its relationship to self-awareness and transformation. Her attention is focused specifically on the chapter on Ludwig Wittgenstein, in which Richard Shusterman presents and then elaborates upon the philosopher's connections between conscious bodily feelings and…

  11. Astronaut Richard H. Truly in training session RMS for STS-2 bldg 9A

    Science.gov (United States)

    1981-01-01

    Astronaut Richard H. Truly in training session with the Remote Manipulator System (RMS) for STS-2 bldg 9A. Views show Truly working at the command console while watching out the windows. Karen Ehlers, an RMS procedures specialist, can be seen at left side of frame (34314); view from behind Truly as he trains at the RMS console (34315).

  12. Strauss, Richard. Ariane a Naxos: opera seulement, integrale. Miliza Korjus / Michel Parouty

    Index Scriptorium Estoniae

    Parouty, Michel

    1995-01-01

    Uuest heliplaadist "Strauss, Richard. Ariane a Naxos: opera seulement, integrale. Miliza Korjus (Najade). Orchestre de l'Opea l'Efat de Vienne" Arlecchino ARL 14-16, distribution Dante (3 CD: 390 F). 1935, 1944. TT: 3h 46'17"

  13. Fluid flow in porous media using image-based modelling to parametrize Richards' equation.

    Science.gov (United States)

    Cooper, L J; Daly, K R; Hallett, P D; Naveed, M; Koebernick, N; Bengough, A G; George, T S; Roose, T

    2017-11-01

    The parameters in Richards' equation are usually calculated from experimentally measured values of the soil-water characteristic curve and saturated hydraulic conductivity. The complex pore structures that often occur in porous media complicate such parametrization due to hysteresis between wetting and drying and the effects of tortuosity. Rather than estimate the parameters in Richards' equation from these indirect measurements, image-based modelling is used to investigate the relationship between the pore structure and the parameters. A three-dimensional, X-ray computed tomography image stack of a soil sample with voxel resolution of 6 μm has been used to create a computational mesh. The Cahn-Hilliard-Stokes equations for two-fluid flow, in this case water and air, were applied to this mesh and solved using the finite-element method in COMSOL Multiphysics. The upscaled parameters in Richards' equation are then obtained via homogenization. The effect on the soil-water retention curve due to three different contact angles, 0°, 20° and 60°, was also investigated. The results show that the pore structure affects the properties of the flow on the large scale, and different contact angles can change the parameters for Richards' equation.

  14. Making the Road While Walking It: A Conversation with Richard Simpson

    Science.gov (United States)

    Zabel, Robert H.; Kaff, Marilyn; Teagarden, James

    2016-01-01

    Richard Simpson is professor of special education at the University of Kansas (KU). Dr. Simpson's duties at KU have included roles of staff psychologist, teaching associate, assistant professor, project director, associate professor, professor, and chairperson for the Department of Special Education. He has directed numerous University of Kansas…

  15. Non-standard primordial fluctuations and nongaussianity in string inflation

    International Nuclear Information System (INIS)

    Burgess, C.P.; Cicoli, M.; Gomez-Reino, M.; Tasinato, G.; Zavala, I.

    2010-05-01

    Inflationary scenarios in string theory often involve a large number of light scalar fields, whose presence can enrich the post-inflationary evolution of primordial fluctuations generated during the inflationary epoch. We provide a simple example of such post-inflationary processing within an explicit string-inflationary construction, using a Kaehler modulus as the inflaton within the framework of LARGE Volume Type-IIB string flux compactifications. We argue that inflationary models within this broad category often have a selection of scalars that are light enough to be cosmologically relevant, whose contributions to the primordial fluctuation spectrum can compete with those generated in the standard way by the inflaton. These models consequently often predict nongaussianity at a level, f NL ≅O(10), potentially observable by the Planck satellite, with a bi-spectrum maximized by triangles with squeezed shape in a string realization of the curvaton scenario. We argue that the observation of such a signal would robustly prefer string cosmologies such as these that predict a multi-field dynamics during the very early universe. (orig.)

  16. Non-Standard Primordial Fluctuations and Nongaussianity in String Inflation

    International Nuclear Information System (INIS)

    Burgess, C.P.; Cicoli, M.; Gomez-Reino, M.; Quevedo, F.; Tasinato, G.; Zavala, I.

    2010-05-01

    Inflationary scenarios in string theory often involve a large number of light scalar fields, whose presence can enrich the post-inflationary evolution of primordial fluctuations generated during the inflationary epoch. We provide a simple example of such post-inflationary processing within an explicit string-inflationary construction, using a Kaehler modulus as the inflaton within the framework of LARGE Volume Type-IIB string flux compactifications. We argue that inflationary models within this broad category often have a selection of scalars that are light enough to be cosmologically relevant, whose contributions to the primordial fluctuation spectrum can compete with those generated in the standard way by the inflaton. These models consequently often predict nongaussianity at a level, f NL ≅ O(10), potentially observable by the Planck satellite, with a bi-spectrum maximized by triangles with squeezed shape in a string realization of the curvaton scenario. We argue that the observation of such a signal would robustly prefer string cosmologies such as these that predict a multi-field dynamics during the very early universe. (author)

  17. Primordial linkage of β2-microglobulin to the MHC.

    Science.gov (United States)

    Ohta, Yuko; Shiina, Takashi; Lohr, Rebecca L; Hosomichi, Kazuyoshi; Pollin, Toni I; Heist, Edward J; Suzuki, Shingo; Inoko, Hidetoshi; Flajnik, Martin F

    2011-03-15

    β2-Microglobulin (β2M) is believed to have arisen in a basal jawed vertebrate (gnathostome) and is the essential L chain that associates with most MHC class I molecules. It contains a distinctive molecular structure called a constant-1 Ig superfamily domain, which is shared with other adaptive immune molecules including MHC class I and class II. Despite its structural similarity to class I and class II and its conserved function, β2M is encoded outside the MHC in all examined species from bony fish to mammals, but it is assumed to have translocated from its original location within the MHC early in gnathostome evolution. We screened a nurse shark bacterial artificial chromosome library and isolated clones containing β2M genes. A gene present in the MHC of all other vertebrates (ring3) was found in the bacterial artificial chromosome clone, and the close linkage of ring3 and β2M to MHC class I and class II genes was determined by single-strand conformational polymorphism and allele-specific PCR. This study satisfies the long-held conjecture that β2M was linked to the primordial MHC (Ur MHC); furthermore, the apparent stability of the shark genome may yield other genes predicted to have had a primordial association with the MHC specifically and with immunity in general.

  18. Single field double inflation and primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Kannike, K.; Marzola, L.; Raidal, M.; Veermäe, H., E-mail: kristjan.kannike@cern.ch, E-mail: luca.marzola@cern.ch, E-mail: martti.raidal@cern.ch, E-mail: hardi.veermae@cern.ch [National Institute of Chemical Physics and Biophysics, Rävala 10, 10143 Tallinn (Estonia)

    2017-09-01

    Within the framework of scalar-tensor theories, we study the conditions that allow single field inflation dynamics on small cosmological scales to significantly differ from that of the large scales probed by the observations of cosmic microwave background. The resulting single field double inflation scenario is characterised by two consequent inflation eras, usually separated by a period where the slow-roll approximation fails. At large field values the dynamics of the inflaton is dominated by the interplay between its non-minimal coupling to gravity and the radiative corrections to the inflaton self-coupling. For small field values the potential is, instead, dominated by a polynomial that results in a hilltop inflation. Without relying on the slow-roll approximation, which is invalidated by the appearance of the intermediate stage, we propose a concrete model that matches the current measurements of inflationary observables and employs the freedom granted by the framework on small cosmological scales to give rise to a sizeable population of primordial black holes generated by large curvature fluctuations. We find that these features generally require a potential with a local minimum. We show that the associated primordial black hole mass function is only approximately lognormal.

  19. Primordial Molecular Cloud Material in Metal-Rich Carbonaceous Chondrites

    Science.gov (United States)

    Taylor, G. J.

    2016-03-01

    The menagerie of objects that make up our Solar System reflects the composition of the huge molecular cloud in which the Sun formed, a late addition of short-lived isotopes from an exploding supernova or stellar winds from a neighboring massive star, heating and/or alteration by water in growing planetesimals that modified and segregated the primordial components, and mixing throughout the Solar System. Outer Solar System objects, such as comets, have always been cold, hence minimizing the changes experienced by more processed objects. They are thought to preserve information about the molecular cloud. Elishevah Van Kooten (Natural History Museum of Denmark and the University of Copenhagen) and co-authors in Denmark and at the University of Hawai'i, measured the isotopic compositions of magnesium and chromium in metal-rich carbonaceous chondrites. They found that the meteorites preserve an isotopic signature of primordial molecular cloud materials, providing a potentially detailed record of the molecular cloud's composition and of materials that formed in the outer Solar System.

  20. Planck 2013 Results. XXIV. Constraints on primordial non-Gaussianity

    CERN Document Server

    Ade, P.A.R.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Bartlett, J.G.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoit, A.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R.C.; Cardoso, J.F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, L.Y.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.M.; Desert, F.X.; Diego, J.M.; Dole, H.; Donzelli, S.; Dore, O.; Douspis, M.; Ducout, A.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Ensslin, T.A.; Eriksen, H.K.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giraud-Heraud, Y.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F.K.; Hanson, D.; Harrison, D.; Heavens, A.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Jaffe, T.R.; Jaffe, A.H.; Jones, W.C.; Juvela, M.; Keihanen, E.; Keskitalo, R.; Kisner, T.S.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lacasa, F.; Lagache, G.; Lahteenmaki, A.; Lamarre, J.M.; Lasenby, A.; Laureijs, R.J.; Lawrence, C.R.; Leahy, J.P.; Leonardi, R.; Lesgourgues, J.; Lewis, A.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Maffei, B.; Maino, D.; Mandolesi, N.; Mangilli, A.; Marinucci, D.; Maris, M.; Marshall, D.J.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschenes, M.A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Naselsky, P.; Natoli, P.; Netterfield, C.B.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Peiris, H.V.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G.W.; Prezeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Racine, B.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rubino-Martin, J.A.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Smith, K.; Spencer, L.D.; Starck, J.L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Varis, J.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L.A.; Wandelt, B.D.; White, M.; White, S.D.M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-01-01

    The Planck nominal mission cosmic microwave background (CMB) maps yield unprecedented constraints on primordial non-Gaussianity (NG). Using three optimal bispectrum estimators, separable template-fitting (KSW), binned, and modal, we obtain consistent values for the primordial local, equilateral, and orthogonal bispectrum amplitudes, quoting as our final result fNL^local= 2.7+/-5.8, fNL^equil= -42+/-75, and fNL^ortho= -25+\\-39 (68% CL statistical). NG is detected in the data; using skew-C_l statistics we find a nonzero bispectrum from residual point sources, and the ISW-lensing bispectrum at a level expected in the LambdaCDM scenario. The results are based on comprehensive cross-validation of these estimators on Gaussian and non-Gaussian simulations, are stable across component separation techniques, pass an extensive suite of tests, and are confirmed by skew-C_l, wavelet bispectrum and Minkowski functional estimators. Beyond estimates of individual shape amplitudes, we present model-independent, 3-dimensional...

  1. Constraining the primordial power spectrum from SNIa lensing dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Dayan, Ido [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kalaydzhyan, Tigran [State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics and Astronomy

    2013-09-15

    The (absence of detecting) lensing dispersion of Supernovae type Ia (SNIa) can be used as a novel and extremely efficient probe of cosmology. In this preliminary example we analyze its consequences for the primordial power spectrum. The main setback is the knowledge of the power spectrum in the non-linear regime, 1 Mpc{sup -1}primordial power spectrum. The probe extends our handle on the spectrum to a total of 12-15 inflation e-folds. These constraints are so strong that they are already ruling out a large portion of the parameter space allowed by PLANCK for running {alpha}{identical_to}dn{sub s}/d ln k and running of running {beta}{identical_to}d{sup 2}n{sub s}/d ln k{sup 2}. The bounds follow a linear relation to a very good accuracy. A conservative bound disfavours any enhancement above the line {beta}(k{sub 0})=0.032-0.41{alpha}(k{sub 0}) and a realistic estimate disfavours any enhancement above the line {beta}(k{sub 0})=0.019-0.45{alpha}(k{sub 0}).

  2. Towards Forming a Primordial Protostar in a Cosmological AMR Simulation

    Science.gov (United States)

    Turk, Matthew J.; Abel, Tom; O'Shea, Brian W.

    2008-03-01

    Modeling the formation of the first stars in the universe is a well-posed problem and ideally suited for computational investigation.We have conducted high-resolution numerical studies of the formation of primordial stars. Beginning with primordial initial conditions appropriate for a ΛCDM model, we used the Eulerian adaptive mesh refinement code (Enzo) to achieve unprecedented numerical resolution, resolving cosmological scales as well as sub-stellar scales simultaneously. Building on the work of Abel, Bryan and Norman (2002), we followed the evolution of the first collapsing cloud until molecular hydrogen is optically thick to cooling radiation. In addition, the calculations account for the process of collision-induced emission (CIE) and add approximations to the optical depth in both molecular hydrogen roto-vibrational cooling and CIE. Also considered are the effects of chemical heating/cooling from the formation/destruction of molecular hydrogen. We present the results of these simulations, showing the formation of a 10 Jupiter-mass protostellar core bounded by a strongly aspherical accretion shock. Accretion rates are found to be as high as one solar mass per year.

  3. Primordial-like enzymes from bacteria with reduced genomes.

    Science.gov (United States)

    Ferla, Matteo P; Brewster, Jodi L; Hall, Kelsi R; Evans, Gary B; Patrick, Wayne M

    2017-08-01

    The first cells probably possessed rudimentary metabolic networks, built using a handful of multifunctional enzymes. The promiscuous activities of modern enzymes are often assumed to be relics of this primordial era; however, by definition these activities are no longer physiological. There are many fewer examples of enzymes using a single active site to catalyze multiple physiologically-relevant reactions. Previously, we characterized the promiscuous alanine racemase (ALR) activity of Escherichia coli cystathionine β-lyase (CBL). Now we have discovered that several bacteria with reduced genomes lack alr, but contain metC (encoding CBL). We characterized the CBL enzymes from three of these: Pelagibacter ubique, the Wolbachia endosymbiont of Drosophila melanogaster (wMel) and Thermotoga maritima. Each is a multifunctional CBL/ALR. However, we also show that CBL activity is no longer required in these bacteria. Instead, the wMel and T. maritima enzymes are physiologically bi-functional alanine/glutamate racemases. They are not highly active, but they are clearly sufficient. Given the abundance of the microorganisms using them, we suggest that much of the planet's biochemistry is carried out by enzymes that are quite different from the highly-active exemplars usually found in textbooks. Instead, primordial-like enzymes may be an essential part of the adaptive strategy associated with streamlining. © 2017 The Authors. Molecular Microbiology Published by John Wiley & Sons Ltd.

  4. 75 FR 53730 - Culturally Significant Objects Imported for Exhibition Determinations: “Richard Hawkins-Third Mind”

    Science.gov (United States)

    2010-09-01

    ... DEPARTMENT OF STATE [Public Notice 7148] Culturally Significant Objects Imported for Exhibition Determinations: ``Richard Hawkins--Third Mind'' SUMMARY: Notice is hereby given of the following determinations... the exhibition ``Richard Hawkins--Third Mind,'' imported from abroad for temporary exhibition within...

  5. Technical realization of a closure concept for a chamber-system in the underground Richard repository in the Czech Republic

    International Nuclear Information System (INIS)

    Kucerka, Miroslav

    2006-01-01

    The Phare project CZ 632.02.04 'Realization of closure of a chamber in the Richard repository as input for establishing a safety case' is a follow up implementation phase of the Phare project, CZ 01.14.03 'Solution for closure of a chamber in the Richard repository'. Main objective of both projects is to propose and realize a disposal system in selected chambers of the Richard repository, which will eliminate burden from the past practices in waste management during the first phase of the Richard repository operation (1965 - 1980) and which will improve its overall long term safety. This objective will be assured by realization of the concept of so called 'hydraulic cage', which technical solution was developed by DBE Technology within the Phare project CZ 01.14.03. The solution is described in the previous presentation 'Hydraulic Cage Concept for Waste Chambers and its Technical Implementation for the Underground Richard Repository, Litomerice, Czech Republic'. (author)

  6. Issues on generating primordial anisotropies at the end of inflation

    Energy Technology Data Exchange (ETDEWEB)

    Emami, Razieh; Firouzjahi, Hassan, E-mail: emami@mail.ipm.ir, E-mail: firouz@mail.ipm.ir [School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2012-01-01

    We revisit the idea of generating primordial anisotropies at the end of inflation in models of inflation with gauge fields. To be specific we consider the charged hybrid inflation model where the waterfall field is charged under a U(1) gauge field so the surface of end of inflation is controlled both by inflaton and the gauge fields. Using δN formalism properly we find that the anisotropies generated at the end of inflation from the gauge field fluctuations are exponentially suppressed on cosmological scales. This is because the gauge field evolves exponentially during inflation while in order to generate appreciable anisotropies at the end of inflation the spectator gauge field has to be frozen. We argue that this is a generic feature, that is, one can not generate observable anisotropies at the end of inflation within an FRW background.

  7. Issues on generating primordial anisotropies at the end of inflation

    International Nuclear Information System (INIS)

    Emami, Razieh; Firouzjahi, Hassan

    2012-01-01

    We revisit the idea of generating primordial anisotropies at the end of inflation in models of inflation with gauge fields. To be specific we consider the charged hybrid inflation model where the waterfall field is charged under a U(1) gauge field so the surface of end of inflation is controlled both by inflaton and the gauge fields. Using δN formalism properly we find that the anisotropies generated at the end of inflation from the gauge field fluctuations are exponentially suppressed on cosmological scales. This is because the gauge field evolves exponentially during inflation while in order to generate appreciable anisotropies at the end of inflation the spectator gauge field has to be frozen. We argue that this is a generic feature, that is, one can not generate observable anisotropies at the end of inflation within an FRW background

  8. Sterile neutrinos, lepton asymmetries, primordial elements: How much of each?

    International Nuclear Information System (INIS)

    Chu Yizen; Cirelli, Marco

    2006-01-01

    We investigate quantitatively the extent to which having a primordial leptonic asymmetry (n ν ≠n ν ) relaxes the bounds on light sterile neutrinos imposed by BBN and LSS. We adopt a few assumptions that allow us to solve the neutrino evolution equations over a broad range of mixing parameters and asymmetries. For the general cases of sterile mixing with the electron or muon neutrino, we identify the regions that can be reopened. For the particular case of a LSND-like sterile neutrino, soon to be rejected or confirmed by MiniBooNE, we find that an asymmetry of the order of 10 -4 is needed to lift the conflicts with cosmology

  9. Primordial and Stellar Nucleosynthesis Chemical Evolution of Galaxies

    International Nuclear Information System (INIS)

    Chiosi, Cesare

    2010-01-01

    Following a brief introduction to early Universe cosmology, we present in some detail the results of primordial nucleosynthesis. Then we summarize the basic theory of nuclear reactions in stars and sketch the general rules of stellar evolution. We shortly review the subject of supernova explosions both by core collapse in massive stars (Type II) and carbon-deflagration in binary systems when one of the components is a White Dwarf accreting mass from the companion (Type Ia). We conclude the part dedicated to nucleosynthesis with elementary notions on the s- and r-process. Finally, we shortly address the topic of galactic chemical evolution and highlight some simple solutions aimed at understanding the main observational data on abundances and abundance ratios.

  10. Running-mass inflation model and primordial black holes

    International Nuclear Information System (INIS)

    Drees, Manuel; Erfani, Encieh

    2011-01-01

    We revisit the question whether the running-mass inflation model allows the formation of Primordial Black Holes (PBHs) that are sufficiently long-lived to serve as candidates for Dark Matter. We incorporate recent cosmological data, including the WMAP 7-year results. Moreover, we include ''the running of the running'' of the spectral index of the power spectrum, as well as the renormalization group ''running of the running'' of the inflaton mass term. Our analysis indicates that formation of sufficiently heavy, and hence long-lived, PBHs still remains possible in this scenario. As a by-product, we show that the additional term in the inflaton potential still does not allow significant negative running of the spectral index

  11. Lifting primordial non-Gaussianity above the noise

    International Nuclear Information System (INIS)

    Welling, Yvette; Woude, Drian van der; Pajer, Enrico

    2016-01-01

    Primordial non-Gaussianity (PNG) in Large Scale Structures is obfuscated by the many additional sources of non-linearity. Within the Effective Field Theory approach to Standard Perturbation Theory, we show that matter non-linearities in the bispectrum can be modeled sufficiently well to strengthen current bounds with near future surveys, such as Euclid. We find that the EFT corrections are crucial to this improvement in sensitivity. Yet, our understanding of non-linearities is still insufficient to reach important theoretical benchmarks for equilateral PNG, while, for local PNG, our forecast is more optimistic. We consistently account for the theoretical error intrinsic to the perturbative approach and discuss the details of its implementation in Fisher forecasts.

  12. The Primordial Role of Stories in Human Self-Creation

    Directory of Open Access Journals (Sweden)

    Arran Gare

    2007-08-01

    Full Text Available We now have a paradoxical situation where the place and status of stories is in decline within the humanities, while scientists are increasingly recognizing their importance. Here the attitude towards narratives of these scientists is defended. It is argued that stories play a primordial role in human self-creation, underpinning more abstract discourses such as mathematics, logic and science. To uphold the consistency of this claim, this thesis is defended by telling a story of the evolution of European culture from Ancient Greece to the present, including an account of the rise of the notion of culture and its relation to the development of history, thereby showing how stories function to justify beliefs, situate people as agents within history and orient them to create the future.

  13. The standard and degenerate primordial nucleosynthesis versus recent experimental data

    International Nuclear Information System (INIS)

    Esposito, S.; Mangano, G.; Miele, G.; Pisanti, O.

    2000-01-01

    We report the results on Big Bang Nucleosynthesis (BBN) based on an updated code, with accuracy of the order of 0.1% on He4 abundance, compared with the predictions of other recent similar analysis. We discuss the compatibility of the theoretical results, for vanishing neutrino chemical potentials, with the observational data. Bounds on the number of relativistic neutrinos and baryon abundance are obtained by a likelihood analysis. We also analyze the effect of large neutrino chemical potentials on primordial nucleosynthesis, motivated by the recent results on the Cosmic Microwave Background Radiation spectrum. The BBN exclusion plots for electron neutrino chemical potential and the effective number of relativistic neutrinos are reported. We find that the standard BBN seems to be only marginally in agreement with the recent BOOMERANG and MAXIMA-1 results, while the agreement is much better for degenerate BBN scenarios for large effective number of neutrinos, N ν ∼ 10. (author)

  14. Primordial Pb, radiogenic Pb and lunar soil maturity

    International Nuclear Information System (INIS)

    Reed, G.W. Jr.; Jovanovic, S.

    1978-01-01

    The soil maturity index I/sub s//FeO does not apply to either 204 Pb/sub r/ or C/sub hyd/; both are directly correlated with the submicron Fe 0 (I/sub s/) content. They act as an index of soil maturity which is independent of soil composition. In contrast to primordial Pb, radiogenic Pb is lost during soil maturation. Radiogenic Pb is present in mineral grains and may be lost by solar wind sputtering (or volatilization) and not resupplied. 204 Pb coating grain surfaces acts as a reservoir to provide the 204 Pb being extracted in the Fe 0 formation process. Venting or some other volatile source may replenish the surface 204 Pb. 1 figure

  15. Globular cluster seeding by primordial black hole population

    Energy Technology Data Exchange (ETDEWEB)

    Dolgov, A. [ITEP, Bol. Cheremushkinsaya ul., 25, 117218 Moscow (Russian Federation); Postnov, K., E-mail: dolgov@fe.infn.it, E-mail: kpostnov@gmail.com [Sternberg Astronomical Institute, Moscow M.V. Lomonosov State University, Universitetskij pr., 13, Moscow 119234 (Russian Federation)

    2017-04-01

    Primordial black holes (PBHs) that form in the early Universe in the modified Affleck-Dine (AD) mechanism of baryogenesis should have intrinsic log-normal mass distribution of PBHs. We show that the parameters of this distribution adjusted to provide the required spatial density of massive seeds (≥ 10{sup 4} M {sub ⊙}) for early galaxy formation and not violating the dark matter density constraints, predict the existence of the population of intermediate-mass PBHs with a number density of 0∼ 100 Mpc{sup −3}. We argue that the population of intermediate-mass AD PBHs can also seed the formation of globular clusters in galaxies. In this scenario, each globular cluster should host an intermediate-mass black hole with a mass of a few thousand solar masses, and should not obligatorily be immersed in a massive dark matter halo.

  16. Nonthermal production of dark matter from primordial black holes

    Science.gov (United States)

    Allahverdi, Rouzbeh; Dent, James; Osinski, Jacek

    2018-03-01

    We present a scenario for nonthermal production of dark matter from evaporation of primordial black holes. A period of very early matter domination leads to formation of black holes with a maximum mass of ≃2 ×108 g , whose subsequent evaporation prior to big bang nucleosynthesis can produce all of the dark matter in the Universe. We show that the correct relic abundance can be obtained in this way for thermally underproduced dark matter in the 100 GeV-10 TeV mass range. To achieve this, the scalar power spectrum at small scales relevant for black hole formation should be enhanced by a factor of O (105) relative to the scales accessible by the cosmic microwave background experiments.

  17. Nuclear Physics Solutions to the Primordial Lithium Problem

    Directory of Open Access Journals (Sweden)

    Williams E.

    2012-10-01

    Full Text Available The primordial lithium problem is one of the major outstanding issues in the standard model of the Big Bang. Measurements of the baryon to photon ratio in the cosmic microwave background constrain model predictions, giving abundances of 7Li two to four times larger than observed via spectroscopic measurements of metal-poor stars. In an attempt to reconcile this discrepancy, significant effort has been directed at measuring reaction cross sections of light nuclei at astrophysically relevant energies. However, there remain reaction cross sections with large uncertainties, and some that have not yet been measured. Particularly relevant are those involving the destruction of 7Be, a progenitor of 7Li. Key issues that can be improved by nuclear physics input will be highlighted, and the applicability of detectors and event reconstruction techniques recently developed at the ANU will be discussed.

  18. Lensing of 21-cm fluctuations by primordial gravitational waves.

    Science.gov (United States)

    Book, Laura; Kamionkowski, Marc; Schmidt, Fabian

    2012-05-25

    Weak-gravitational-lensing distortions to the intensity pattern of 21-cm radiation from the dark ages can be decomposed geometrically into curl and curl-free components. Lensing by primordial gravitational waves induces a curl component, while the contribution from lensing by density fluctuations is strongly suppressed. Angular fluctuations in the 21-cm background extend to very small angular scales, and measurements at different frequencies probe different shells in redshift space. There is thus a huge trove of information with which to reconstruct the curl component of the lensing field, allowing tensor-to-scalar ratios conceivably as small as r~10(-9)-far smaller than those currently accessible-to be probed.

  19. Effect of nuclear reaction rates on primordial abundances

    International Nuclear Information System (INIS)

    Mishra, Abhishek; Basu, D.N.

    2011-01-01

    The theoretical predictions of the primordial abundances of elements in the big-bang nucleosynthesis (BBN) are dominated by uncertainties in the input nuclear reaction rates. The effect of modifying these reaction rates on light element abundance yields in BBN by replacing the thirty-five reaction rates out of the existing eighty-eight has been investigated. Also the study have been taken of these yields as functions of evolution time or temperature. Here it has been found that using these new reaction rates results in only a little increase in helium mass fraction over that obtained previously in BBN calculations. This allows insights into the role of the nuclear reaction rates in the setting of the neutron-to-proton ratio during the BBN epoch. We observe that most of these nuclear reactions have minimal effect on the standard BBN abundance yields of 6 Li and 7 Li

  20. Primordial Black Holes from Supersymmetry in the Early Universe.

    Science.gov (United States)

    Cotner, Eric; Kusenko, Alexander

    2017-07-21

    Supersymmetric extensions of the standard model generically predict that in the early Universe a scalar condensate can form and fragment into Q balls before decaying. If the Q balls dominate the energy density for some period of time, the relatively large fluctuations in their number density can lead to formation of primordial black holes (PBH). Other scalar fields, unrelated to supersymmetry, can play a similar role. For a general charged scalar field, this robust mechanism can generate black holes over the entire mass range allowed by observational constraints, with a sufficient abundance to account for all dark matter in some parameter ranges. In the case of supersymmetry the mass range is limited from above by 10^{23}  g. We also comment on the role that topological defects can play for PBH formation in a similar fashion.

  1. One Percent Determination of the Primordial Deuterium Abundance

    Science.gov (United States)

    Cooke, Ryan J.; Pettini, Max; Steidel, Charles C.

    2018-03-01

    We report a reanalysis of a near-pristine absorption system, located at a redshift {z}abs}=2.52564 toward the quasar Q1243+307, based on the combination of archival and new data obtained with the HIRES echelle spectrograph on the Keck telescope. This absorption system, which has an oxygen abundance [O/H] = ‑2.769 ± 0.028 (≃1/600 of the solar abundance), is among the lowest metallicity systems currently known where a precise measurement of the deuterium abundance is afforded. Our detailed analysis of this system concludes, on the basis of eight D I absorption lines, that the deuterium abundance of this gas cloud is {log}}10({{D}}/{{H}})=-4.622+/- 0.015, which is in very good agreement with the results previously reported by Kirkman et al., but with an improvement on the precision of this single measurement by a factor of ∼3.5. Combining this new estimate with our previous sample of six high precision and homogeneously analyzed D/H measurements, we deduce that the primordial deuterium abundance is {log}}10{({{D}}/{{H}})}{{P}}=-4.5974+/- 0.0052 or, expressed as a linear quantity, {10}5{({{D}}/{{H}})}{{P}}=2.527+/- 0.030; this value corresponds to a one percent determination of the primordial deuterium abundance. Combining our result with a big bang nucleosynthesis (BBN) calculation that uses the latest nuclear physics input, we find that the baryon density derived from BBN agrees to within 2σ of the latest results from the Planck cosmic microwave background data. Based on observations collected at the W.M. Keck Observatory which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  2. Primordial dwarfism: overview of clinical and genetic aspects.

    Science.gov (United States)

    Khetarpal, Preeti; Das, Satrupa; Panigrahi, Inusha; Munshi, Anjana

    2016-02-01

    Primordial dwarfism is a group of genetic disorders which include Seckel Syndrome, Silver-Russell Syndrome, Microcephalic Osteodysplastic Primordial Dwarfism types I/III, II and Meier-Gorlin Syndrome. This genetic disorder group is characterized by intra-uterine growth retardation and post-natal growth abnormalities which occur as a result of disorganized molecular and genomic changes in embryonic stage and, thus, it represents a unique area to study growth and developmental abnormalities. Lot of research has been carried out on different aspects; however, a consolidated review that discusses an overall spectrum of this disorder is not accessible. Recent research in this area points toward important molecular and cellular mechanisms in human body that regulate the complexity of growth process. Studies have emerged that have clearly associated with a number of abnormal chromosomal, genetic and epigenetic alterations that can predispose an embryo to develop PD-associated developmental defects. Finding and associating such fundamental changes to its subtypes will help in re-examination of alleged functions at both cellular and developmental levels and thus reveal the intrinsic mechanism that leads to a balanced growth. Although such findings have unraveled a subtle understanding of growth process, we further require active research in terms of identification of reliable biomarkers for different subtypes as an immediate requirement for clinical utilization. It is hoped that further study will advance the understanding of basic mechanisms regulating growth relevant to human health. Therefore, this review has been written with an aim to present an overview of chromosomal, molecular and epigenetic modifications reported to be associated with different subtypes of this heterogenous disorder. Further, latest findings with respect to clinical and molecular genetics research have been summarized to aid the medical fraternity in their clinical utility, for diagnosing disorders

  3. Cosmological cosmic rays: Sharpening the primordial lithium problem

    International Nuclear Information System (INIS)

    Prodanovic, Tijana; Fields, Brian D.

    2007-01-01

    Cosmic structure formation leads to large-scale shocked baryonic flows which are expected to produce a cosmological population of structure-formation cosmic rays (SFCRs). Interactions between SFCRs and ambient baryons will produce lithium isotopes via α+α→ 6,7 Li. This pre-galactic (but nonprimordial) lithium should contribute to the primordial 7 Li measured in halo stars and must be subtracted in order to arrive to the true observed primordial lithium abundance. In this paper we point out that the recent halo star 6 Li measurements can be used to place a strong constraint to the level of such contamination, because the exclusive astrophysical production of 6 Li is from cosmic-ray interactions. We find that the putative 6 Li plateau, if due to pre-galactic cosmic-ray interactions, implies that SFCR-produced lithium represents Li SFCR /Li plateau ≅15% of the observed elemental Li plateau. Taking the remaining plateau Li to be cosmological 7 Li, we find a revised (and slightly worsened) discrepancy between the Li observations and big bang nucleosynthesis predictions by a factor of 7 Li BBN / 7 Li plateau ≅3.7. Moreover, SFCRs would also contribute to the extragalactic gamma-ray background (EGRB) through neutral pion production. This gamma-ray production is tightly related to the amount of lithium produced by the same cosmic rays; the 6 Li plateau limits the pre-galactic (high-redshift) SFCR contribution to be at the level of I γ π SFCR /I EGRB < or approx. 5% of the currently observed EGRB

  4. Primordial nucleosynthesis as a probe of particle physics and cosmology

    International Nuclear Information System (INIS)

    Walker, T.P.

    1987-01-01

    In this dissertation, the author uses the success of the standard model of big-bang nucleosynthesis to examine the effects of interacting particle species and the effect of varying coupling constants, predicted by theories set in extra dimensions, on primordial nucleosynthesis. A review is given of the standard model and of the abundances of the light elements expected to be produced in the early Universe. The weakest piece of the concordance between the standard model of big-bang nucleosynthesis and observation is the production and primordial abundance of 7 Li. Therefore he discusses the production of 7 Li in astrophysical environments other than the early Universe and shows that the predictions of big-bang nucleosynthesis, when supplemented by those due to astrophysical sources, are in good agreement with observation. He then shows that the effect on big-bang nucleosynthesis of an additional particle species which remains coupled to either photons or light neutrinos can be quite different from that predicted by the equivalent number of neutrino species parameterization, which does work for decoupled additional species. In particular he considers the case of an additional axion-like particle and shows that its effect is to decrease the amount of 4 He produced in the big-bang. In addition, he considers the effects of varying coupling constants on 4 He production in the big-bang and shows that constraining Y p = 0.24 ± 0.01 leads to a constraint on the time variation of the fine-structure constant of |dln α/dt| ≤ x 10 -14

  5. Magnification bias as a novel probe for primordial magnetic fields

    International Nuclear Information System (INIS)

    Camera, S.; Fedeli, C.; Moscardini, L.

    2014-01-01

    In this paper we investigate magnetic fields generated in the early Universe. These fields are important candidates at explaining the origin of astrophysical magnetism observed in galaxies and galaxy clusters, whose genesis is still by and large unclear. Compared to the standard inflationary power spectrum, intermediate to small scales would experience further substantial matter clustering, were a cosmological magnetic field present prior to recombination. As a consequence, the bias and redshift distribution of galaxies would also be modified. Hitherto, primordial magnetic fields (PMFs) have been tested and constrained with a number of cosmological observables, e.g. the cosmic microwave background radiation, galaxy clustering and, more recently, weak gravitational lensing. Here, we explore the constraining potential of the density fluctuation bias induced by gravitational lensing magnification onto the galaxy-galaxy angular power spectrum. Such an effect is known as magnification bias. Compared to the usual galaxy clustering approach, magnification bias helps in lifting the pathological degeneracy present amongst power spectrum normalisation and galaxy bias. This is because magnification bias cross-correlates galaxy number density fluctuations of nearby objects with weak lensing distortions of high-redshift sources. Thus, it takes advantage of the gravitational deflection of light, which is insensitive to galaxy bias but powerful in constraining the density fluctuation amplitude. To scrutinise the potentiality of this method, we adopt a deep and wide-field spectroscopic galaxy survey. We show that magnification bias does contain important information on primordial magnetism, which will be useful in combination with galaxy clustering and shear. We find we shall be able to rule out at 95.4% CL amplitudes of PMFs larger than 5 × 10 −4 nG for values of the PMF power spectral index n B ∼ 0

  6. Richard III in Russian Theatre at the Twilight of the "Thaw"

    OpenAIRE

    Sokolyansky, Mark

    2007-01-01

    Richard III was very rarely staged in Russian theatre in tsarist and Stalin’s times, because the story of inhuman tyranny provoked associations with Russian political reality. In the period of the so-called “Thaw” (1954ß1964) the play became very popular in the USSR and several scenic productions of it were real events in Russian (and Soviet) theatrical life. In the essay three most original and successful performances (in Kujbyshev, Gorkij and Erevan) are discussed and compare...

  7. Missing Kettles and Too Few Toasters: The Forecasting Methodology at Morphy Richards

    OpenAIRE

    Lane, D; Hughes, D

    2002-01-01

    Faced with problems in forecasting at Morphy Richards, this research represents an investigation into their forecasting methodology following the hypothesis that the current forecasting system was no longer sufficient to ensure guaranteed supply to customers, or to enable forward planning.\\ud \\ud The purpose of the research was to identify any requirements for change within the forecasting system and to identify the ‘best practice’ within the industry. Primary research was carried out using a...

  8. Richard J. Bernstein on Ethics and Philosophy between the Linguistic and the Pragmatic Turn

    OpenAIRE

    Marchetti, Sarin

    2017-01-01

    1. In his compelling article American Pragmatism: The Conflict of Narratives, Richard Bernstein quotes a perceptive line by Alasdair MacIntyre that goes [A] tradition not only embodies the narrative of an argument, but is only recovered by an argumentative retelling of that narrative which will itself be in conflict with other argumentative retellings. Bernstein, in the essay mentioned, works through MacIntyre’s passage in order to “engage in the ‘argumentative retelling’ of a metanarrative –...

  9. Il concetto di medium artistico: Richard Wollheim interprete di Ludwig Wittgenstein

    OpenAIRE

    Maistrello, Andrea

    2016-01-01

    The aim of the dissertation is twofold: (i) analyzing the notion (well known by aestheticians, but not so intensively studied) of artistic medium; (ii) showing the relevance of such notion for aesthetics through the examination of some relevant aspects of Richard Wollheim’s philosophy of art, maybe the main figure in Anglo-American philosophy as for considering artistic medium central in art-theorizing. Artistic media, according to Wollheim, can develop only if properly connected to a cultura...

  10. Selfish memes: An update of Richard Dawkins’ bibliometric analysis of key papers in sociobiology

    OpenAIRE

    Aaen-Stockdale, Craig

    2017-01-01

    This is an Open Access journal available from http://www.mdpi.com/ In the second edition of The Selfish Gene, Richard Dawkins included a short bibliometric analysis of key papers instrumental to the sociobiological revolution, the intention of which was to support his proposal that ideas spread within a population in an epidemiological manner. In his analysis, Dawkins primarily discussed the influence of an article by British evolutionary biologist William Donald Hamilton which had introdu...

  11. Metaforos populiarojo mokslo literatūroje: Richard Dawkins knygos analizė

    OpenAIRE

    Urbanavičiūtė, Dovilė

    2017-01-01

    The following paper discusses metaphor usage in the genre of popular science. The object of this analysis is a chapter called ‘Immortal coils’ taken from Richard Dawkins’ book The Selfish Gene. The study discusses the impact of creative conceptual metaphors on the construction of the overall meaning of the text, as well as the significance of their linguistic manifestations and context. In focusing on the genre of popular science, it also makes an attempt at defining potential difficulties of...

  12. Pimping climate change: Richard Branson, global warming, and the performance of green capitalism

    OpenAIRE

    Scott Prudham

    2009-01-01

    On 21 September 2006 UK über-entrepreneur and Virgin Group Chairman Richard Branson pledged approximately £1.6 billion, the equivalent of all the profits from Virgin Atlantic and Virgin Trains for the next ten years, to fighting climate change. Since then, Branson has restated his commitment to action on global warming, including investment in technologies for sequestering carbon dioxide from the atmosphere. In this paper, I critically examine and engage with Branson’s announcements as a spec...

  13. Primordial blackholes and gravitational waves for an inflection-point model of inflation

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, Sayantan [Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 B.T. Road, Kolkata 700 108 (India); Mazumdar, Anupam [Consortium for Fundamental Physics, Physics Department, Lancaster University, LA1 4YB (United Kingdom)

    2014-06-02

    In this article we provide a new closed relationship between cosmic abundance of primordial gravitational waves and primordial blackholes that originated from initial inflationary perturbations for inflection-point models of inflation where inflation occurs below the Planck scale. The current Planck constraint on tensor-to-scalar ratio, running of the spectral tilt, and from the abundance of dark matter content in the universe, we can deduce a strict bound on the current abundance of primordial blackholes to be within a range, 9.99712×10{sup −3}<Ω{sub PBH}h{sup 2}<9.99736×10{sup −3}.

  14. Impact of stochastic primordial magnetic fields on the scalar contribution to cosmic microwave background anisotropies

    International Nuclear Information System (INIS)

    Finelli, Fabio; Paci, Francesco; Paoletti, Daniela

    2008-01-01

    We study the impact of a stochastic background of primordial magnetic fields on the scalar contribution of cosmic microwave background (CMB) anisotropies and on the matter power spectrum. We give the correct initial conditions for cosmological perturbations and the exact expressions for the energy density and Lorentz force associated to the stochastic background of primordial magnetic fields, given a power-law for their spectra cut at a damping scale. The dependence of the CMB temperature and polarization spectra on the relevant parameters of the primordial magnetic fields is illustrated.

  15. Primordial gravitational waves induced by magnetic fields in an ekpyrotic scenario

    Directory of Open Access Journals (Sweden)

    Asuka Ito

    2017-08-01

    Full Text Available Both inflationary and ekpyrotic scenarios can account for the origin of the large scale structure of the universe. It is often said that detecting primordial gravitational waves is the key to distinguish both scenarios. We show that this is not true if the gauge kinetic function is present in the ekpyrotic scenario. In fact, primordial gravitational waves sourced by the gauge field can be produced in an ekpyrotic universe. We also study scalar fluctuations sourced by the gauge field and show that it is negligible compared to primordial gravitational waves. This comes from the fact that the fast roll condition holds in ekpyrotic models.

  16. Ruth Colvin Clark - Richard E. Mayer. e-Learning and the Science of Instruction

    Directory of Open Access Journals (Sweden)

    De Giusti, Laura Cristina

    2016-06-01

    Full Text Available En este libro se abordarán cuestiones fundamentales tales como: ¿Qué tipos de gráficos ayuda para aprender? ¿Qué audiencias más se benefician de gráficos? ¿Cuándo y cómo utilizar mejor las animaciones? Situaciones en las que es mejor es utilizar el audio para describir gráficos. Situaciones en las que es mejor es utilizar el texto para describir gráficos. Cómo colocar texto en la pantalla para maximizar el aprendizaje ¿Cómo evitar la sobrecarga mental causado por el uso inadecuado de los gráficos, texto y audio Los beneficios de la personalización de las lecciones a través de un lenguaje informal y en la pantalla avatares. Formas de aumentar la presencia social en los eventos virtuales de aprendizaje y asíncronos.

  17. Richard Watson.

    Science.gov (United States)

    Wright, Ian; Bevin, William

    2017-11-25

    An inspirational equine veterinary surgeon with a keen interest in racing, to whom horses were a way of life. He took much pride in the success of his homebred racehorses. British Veterinary Association.

  18. Richard Rorty

    DEFF Research Database (Denmark)

    Hjermitslev, Hans Henrik

    2016-01-01

    dekonstruktion forlod han Princeton og blev han i 1982 udnævnt til professor i humaniora ved University of Virginia. Her skrev han i 1989 sit andet hovedværk Contingency, Irony, and Solidarity, der med originale læsninger af Heidegger, Derrida, Orwell, Nabokov, Freud og andre blev modtaget med stor interesse...

  19. Book Review of Relational Patterns, Therapeutic Presence: Concepts and practice of Integrative Psychotherapy by Richard G. Erskine

    Directory of Open Access Journals (Sweden)

    Marye O'Reilly-Knapp

    2015-12-01

    Full Text Available Book Review of Relational Patterns, Therapeutic Presence: Concepts and practice of Integrative Psychotherapy by Richard G. Erskine. Published by Karnac Books: London, 2015 Paperback, Pages 366, ISBN 13: 978-1-78220-190-8

  20. Book Review of Relational Patterns, Therapeutic Presence: Concepts and practice of Integrative Psychotherapy by Richard G. Erskine

    OpenAIRE

    Marye O'Reilly-Knapp

    2015-01-01

    Book Review of Relational Patterns, Therapeutic Presence: Concepts and practice of Integrative Psychotherapy by Richard G. Erskine. Published by Karnac Books: London, 2015 Paperback, Pages 366, ISBN 13: 978-1-78220-190-8

  1. An MCMC determination of the primordial helium abundance

    Science.gov (United States)

    Aver, Erik; Olive, Keith A.; Skillman, Evan D.

    2012-04-01

    Spectroscopic observations of the chemical abundances in metal-poor H II regions provide an independent method for estimating the primordial helium abundance. H II regions are described by several physical parameters such as electron density, electron temperature, and reddening, in addition to y, the ratio of helium to hydrogen. It had been customary to estimate or determine self-consistently these parameters to calculate y. Frequentist analyses of the parameter space have been shown to be successful in these parameter determinations, and Markov Chain Monte Carlo (MCMC) techniques have proven to be very efficient in sampling this parameter space. Nevertheless, accurate determination of the primordial helium abundance from observations of H II regions is constrained by both systematic and statistical uncertainties. In an attempt to better reduce the latter, and continue to better characterize the former, we apply MCMC methods to the large dataset recently compiled by Izotov, Thuan, & Stasińska (2007). To improve the reliability of the determination, a high quality dataset is needed. In pursuit of this, a variety of cuts are explored. The efficacy of the He I λ4026 emission line as a constraint on the solutions is first examined, revealing the introduction of systematic bias through its absence. As a clear measure of the quality of the physical solution, a χ2 analysis proves instrumental in the selection of data compatible with the theoretical model. Nearly two-thirds of the observations fall outside a standard 95% confidence level cut, which highlights the care necessary in selecting systems and warrants further investigation into potential deficiencies of the model or data. In addition, the method also allows us to exclude systems for which parameter estimations are statistical outliers. As a result, the final selected dataset gains in reliability and exhibits improved consistency. Regression to zero metallicity yields Yp = 0.2534 ± 0.0083, in broad agreement

  2. An MCMC determination of the primordial helium abundance

    International Nuclear Information System (INIS)

    Aver, Erik; Olive, Keith A.; Skillman, Evan D.

    2012-01-01

    Spectroscopic observations of the chemical abundances in metal-poor H II regions provide an independent method for estimating the primordial helium abundance. H II regions are described by several physical parameters such as electron density, electron temperature, and reddening, in addition to y, the ratio of helium to hydrogen. It had been customary to estimate or determine self-consistently these parameters to calculate y. Frequentist analyses of the parameter space have been shown to be successful in these parameter determinations, and Markov Chain Monte Carlo (MCMC) techniques have proven to be very efficient in sampling this parameter space. Nevertheless, accurate determination of the primordial helium abundance from observations of H II regions is constrained by both systematic and statistical uncertainties. In an attempt to better reduce the latter, and continue to better characterize the former, we apply MCMC methods to the large dataset recently compiled by Izotov, Thuan, and Stasińska (2007). To improve the reliability of the determination, a high quality dataset is needed. In pursuit of this, a variety of cuts are explored. The efficacy of the He I λ4026 emission line as a constraint on the solutions is first examined, revealing the introduction of systematic bias through its absence. As a clear measure of the quality of the physical solution, a χ 2 analysis proves instrumental in the selection of data compatible with the theoretical model. Nearly two-thirds of the observations fall outside a standard 95% confidence level cut, which highlights the care necessary in selecting systems and warrants further investigation into potential deficiencies of the model or data. In addition, the method also allows us to exclude systems for which parameter estimations are statistical outliers. As a result, the final selected dataset gains in reliability and exhibits improved consistency. Regression to zero metallicity yields Y p = 0.2534 ± 0.0083, in broad

  3. Production of high stellar-mass primordial black holes in trapped inflation

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Shu-Lin; Lee, Wolung [Department of Physics, National Taiwan Normal University,Taipei 11677, Taiwan (China); Ng, Kin-Wang [Institute of Physics, Academia Sinica,Taipei 11529, Taiwan (China); Institute of Astronomy and Astrophysics, Academia Sinica,Taipei 11529, Taiwan (China)

    2017-02-01

    Trapped inflation has been proposed to provide a successful inflation with a steep potential. We discuss the formation of primordial black holes in the trapped inflationary scenario. We show that primordial black holes are naturally produced during inflation with a steep trapping potential. In particular, we have given a recipe for an inflaton potential with which particle production can induce large non-Gaussian curvature perturbation that leads to the formation of high stellar-mass primordial black holes. These primordial black holes could be dark matter observed by the LIGO detectors through a binary black-hole merger. At the end, we have given an attempt to realize the required inflaton potential in the axion monodromy inflation, and discussed the gravitational waves sourced by the particle production.

  4. Follistatin288 Regulates Germ Cell Cyst Breakdown and Primordial Follicle Assembly in the Mouse Ovary.

    Directory of Open Access Journals (Sweden)

    Zhengpin Wang

    Full Text Available In mammals, the primordial follicle pool represents the entire reproductive potential of a female. The transforming growth factor-β (TGF-β family member activin (ACT contributes to folliculogenesis, although the exact mechanism is not known. The role of FST288, the strongest ACT-neutralizing isoform of follistatin (FST, during cyst breakdown and primordial follicle formation in the fetal mice ovary was assessed using an in vitro culture system. FST was continuously expressed in the oocytes as well as the cuboidal granulosa cells of growing follicles in perinatal mouse ovaries. Treatment with FST288 delayed germ cell nest breakdown, particularly near the periphery of the ovary, and dramatically decreased the percentage of primordial follicles. In addition, there was a dramatic decrease in proliferation of granulosa cells and somatic cell expression of Notch signaling was impaired. In conclusion, FST288 impacts germ cell nest breakdown and primordial follicle assembly by inhibiting somatic cell proliferation.

  5. The Effect of Aqueous Alteration on Primordial Noble Gases in CM Chondrites

    Science.gov (United States)

    Weimer, D.; Busemann, H.; Alexander, C. M. O'D.; Maden, C.

    2017-07-01

    We have analyzed 32 CM chondrites for their noble gas contents and isotopic compositions and calculated CRE ages. Correlated effects of parent body aqueous alteration with primordial noble gas contents were detected.

  6. Expanding the phenotypic and mutational spectrum in microcephalic osteodysplastic primordial dwarfism type I.

    Science.gov (United States)

    Abdel-Salam, Ghada M H; Abdel-Hamid, Mohamed S; Issa, Mahmoud; Magdy, Ahmed; El-Kotoury, Ahmed; Amr, Khalda

    2012-06-01

    Mutations in the RNU4ATAC gene cause microcephalic osteodysplastic primordial dwarfism type I. It encodes U4atac, a small nuclear RNA that is a component of the minor spliceosome. Six distinct mutations in 30 patients diagnosed as microcephalic osteodysplastic primordial dwarfism type I have been described. We report on three additional patients from two unrelated families presenting with a milder phenotype of microcephalic osteodysplastic primordial dwarfism type I and metopic synostosis. Patient 1 had two novel heterozygous mutations in the 3' prime stem-loop, g.66G > C and g.124G > A while Patients 2 and 3 had a homozygous mutation g.55G > A in the 5' prime stem-loop. Although they manifested the known spectrum of clinical features of microcephalic osteodysplastic primordial dwarfism type I, they lacked evidence of severe developmental delay and neurological symptoms. These findings expand the mutational and phenotypic spectrum of this syndrome. Copyright © 2012 Wiley Periodicals, Inc.

  7. "Ocular moyamoya" syndrome in a patient with features of microcephalic osteodysplastic primordial dwarfism type II.

    Science.gov (United States)

    Bang, Genie M; Kirmani, Salman; Patton, Alice; Pulido, Jose S; Brodsky, Michael C

    2013-02-01

    Primordial dwarfism refers to severely impaired growth beginning early in fetal life. There are many genetic causes of primordial dwarfism, including disorders classified as microcephalic osteodysplastic primordial dwarfism. Microcephalic osteodysplastic primordial dwarfism type II is an autosomal-recessive disease characterized by small stature, bone and dental anomalies, and characteristic facies. Affected patients have a high risk of stroke secondary to progressive cerebral vascular anomalies, which often are classified as moyamoya disease. We present the case of a boy with features suggestive of MOPD II with unilateral moyamoya cerebrovascular changes and correlative moyamoya collaterals involving the iris of the ipsilateral eye. Copyright © 2013 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

  8. Ultrastructure of Sheep Primordial Follicles Cultured in the Presence of Indol Acetic Acid, EGF, and FSH

    Directory of Open Access Journals (Sweden)

    Evelyn Rabelo Andrade

    2011-01-01

    Full Text Available The aim of this study was to investigate the ultrastructural characteristics of primordial follicles after culturing of sheep ovarian cortical slices in the presence of indol acetic acid (IAA, Epidermal Growth Factor (EGF, and FSH. To evaluate ultrastructure of primordial follicles cultured in MEM (control or in MEM containing IAA, EGF, and FSH, fragments of cultured tissue were processes for transmission electron microscopy. Except in the control, primordial follicles cultured in supplemented media for 6 d were ultrastructurally normal. They had oocyte with intact nucleus and the cytoplasm contained heterogeneous-sized lipid droplets and numerous round or elongated mitochondria with intact parallel cristae were observed. Rough endoplasmic reticulum (RER was rarely found. The granulosa cells cytoplasm contained a great number of mitochondria and abundant RER. In conclusion, the presence of IAA, EGF, and FSH helped to maintain ultrastructural integrity of sheep primordial follicles cultured in vitro.

  9. MAJEWSKI OSTEODYSPLASTIC PRIMORDIAL DWARFISM TYPE II: CLINICAL FINDINGS AND DENTAL MANAGEMENT OF A CHILD PATIENT

    OpenAIRE

    Terlemez, Arslan; Altunsoy, Mustafa; Çelebi, Hakkı

    2015-01-01

    Majewski osteodysplastic primordial dwarfism type II (MOPD II) is an unusual autosomal recessive inherited form of primordial dwarfism, which is characterized by a small head diameter at birth, but which also progresses to severe microcephaly, progressive bony dysplasia, and characteristic facies and personality. This report presents a case of a five-year-old girl with MOPD II syndrome. The patient was referred to our clinic with the complaint of severe tooth pain at the left mandibular prima...

  10. Primordial nucleosynthesis in inhomogeneous cosmologies: Ω = 1 with baryonic dark matter

    International Nuclear Information System (INIS)

    Mathews, G.J.; Sale, K.E.

    1986-09-01

    We consider the constraints on Ω from primordial nucleosynthesis in inhomogeneous cosmologies. We find that allowance for isothermal fluctuations significantly weakens the upper bound on the average value of Ω derived from the standard big bang. Under the plausible additional assumption that regions of high baryon density are preferentially absorbed into cold dark matter, the constraints from primordial nucleosynthesis can be satisfied for large values of Ω, including Ω = 1. 22 refs., 2 figs

  11. Pregnancy in a woman with proportionate (primordial) dwarfism: a case report and literature review

    OpenAIRE

    Vance, C E; Desmond, M; Robinson, A; Johns, J; Zacharin, M; Savarirayan, R; König, K; Warrillow, S; Walker, S P

    2012-01-01

    Primordial dwarfism is a rare form of severe proportionate dwarfism which poses significant challenges in pregnancy. A 27-year-old with primordial dwarfism (height 97 cm, weight 22 kg) and coexisting morbidities of familial hypercholesterolaemia and hypertension presented to our unit. Early pregnancy was complicated by difficult blood pressure control, sinus tachycardia, biochemical hyperthyroidism and insulin-requiring gestational diabetes. Delivery was indicated at 24 weeks with uncontrolla...

  12. Primordial lithium: New reaction rates, new abundances, new constraints

    International Nuclear Information System (INIS)

    Kawano, L.; Schramm, D.; Steigman, G.

    1986-12-01

    Newly measured nuclear reaction rates for 3 H(α,γ) 7 Li (higher than previous values) and 7 Li(p,α) 4 He (lower than previous values) are shown to increase the 7 Li yield from big bang nucleosynthesis for lower baryon to photon ratio (eta ≤ 4 x 10 -10 ); the yield for higher eta is not affected. New, independent determinations of Li abundances in extreme Pop II stars are in excellent agreement with the earlier work of the Spites and give continued confidence in the use of 7 Li in big bang baryon density determinations. The new 7 Li constraints imply a lower limit on eta of 2 x 10 -10 and an upper limit of 5 x 10 -10 . This lower limit to eta is concordant with that obtained from considerations of D + 3 He. The upper limit is consistent with, but even more restrictive than, the D bound. With the new rates, any observed primordial Li/H ratio below 10 -10 would be inexplicable by the standard big bang nucleosynthesis. A review is made of the strengths and possible weaknesses of utilizing conclusions drawn from big bang lithium considerations. An appendix discusses the null effect of a factor of 32 increase in the experimental rate for the D(d,γ) 4 He reaction. 28 refs., 1 fig

  13. Primordial black holes from single field models of inflation

    CERN Document Server

    Garcia-Bellido, Juan

    Primordial black holes (PBH) have been shown to arise from high peaks in the matter power spectra of multi-field models of inflation. Here we show, with a simple toy model, that it is also possible to generate a peak in the curvature power spectrum of single-field inflation. We assume that the effective dynamics of the inflaton field presents a near-inflection point which slows down the field right before the end of inflation and gives rise to a prominent spike in the fluctuation power spectrum at scales much smaller than those probed by Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) observations. This peak will give rise, upon reentry during the radiation era, to PBH via gravitational collapse. The mass and abundance of these PBH is such that they could constitute the totality of the Dark Matter today. We satisfy all CMB and LSS constraints and predict a very broad range of PBH masses. Some of these PBH are light enough that they will evaporate before structure formation, leaving behind a ...

  14. Gravitational wave bursts from Primordial Black Hole hyperbolic encounters

    CERN Document Server

    Garcia-Bellido, Juan

    2017-01-01

    We propose that Gravitational Wave (GW) bursts with millisecond durations can be explained by the GW emission from the hyperbolic encounters of Primordial Black Holes in dense clusters. These bursts are single events, with the bulk of the released energy happening during the closest approach, and emitted in frequencies within the AdvLIGO sensitivity range. We provide expressions for the shape of the GW emission in terms of the peak frequency and amplitude, and estimate the rates of these events for a variety of mass and velocity configurations. We study the regions of parameter space that will allow detection by both AdvLIGO and, in the future, LISA. We find for realistic configurations, with total mass M∼60 M⊙, relative velocities v∼0.01c, and impact parameters b∼10−3 AU, for AdvLIGO an expected event rate is O(10) events/yr/Gpc^3 with millisecond durations. For LISA, the typical duration is in the range of minutes to hours and the event-rate is O(10^3) events/yr/Gpc^3 for both 10^3 M⊙ IMBH and 1...

  15. Curvature profiles as initial conditions for primordial black hole formation

    International Nuclear Information System (INIS)

    Polnarev, Alexander G; Musco, Ilia

    2007-01-01

    This work is part of an ongoing research programme to study possible primordial black hole (PBH) formation during the radiation-dominated era of the early universe. Working within spherical symmetry, we specify an initial configuration in terms of a curvature profile, which represents initial conditions for the large amplitude metric perturbations, away from the homogeneous Friedmann-Robertson-Walker model, which are required for PBH formation. Using an asymptotic quasi-homogeneous solution, we relate the curvature profile with the density and velocity fields, which at an early enough time, when the length scale of the configuration is much larger than the cosmological horizon, can be treated as small perturbations of the background values. We present general analytic solutions for the density and velocity profiles. These solutions enable us to consider in a self-consistent way the formation of PBHs in a wide variety of cosmological situations with the cosmological fluid being treated as an arbitrary mixture of different components with different equations of state. We obtain the analytical solutions for the density and velocity profiles as functions of the initial time. We then use two different parametrizations for the curvature profile and follow numerically the evolution of initial configurations

  16. Primordial black holes formation from particle production during inflation

    International Nuclear Information System (INIS)

    Erfani, Encieh

    2016-01-01

    We study the possibility that particle production during inflation can source the required power spectrum for dark matter (DM) primordial black holes (PBH) formation. We consider the scalar and the gauge quanta production in inflation models, where in the latter case, we focus in two sectors: inflaton coupled i) directly and ii) gravitationally to a U(1) gauge field. We do not assume any specific potential for the inflaton field. Hence, in the gauge production case, in a model independent way we show that the non-production of DM PBHs puts stronger upper bound on the particle production parameter. Our analysis show that this bound is more stringent than the bounds from the bispectrum and the tensor-to-scalar ratio derived by gauge production in these models. In the scenario where the inflaton field coupled to a scalar field, we put an upper bound on the amplitude of the generated scalar power spectrum by non-production of PBHs. As a by-product we also show that the required scalar power spectrum for PBHs formation is lower when the density perturbations are non-Gaussian in comparison to the Gaussian density perturbations

  17. Microcephalic primordial dwarfism in an Emirati patient with PNKP mutation.

    Science.gov (United States)

    Nair, Pratibha; Hamzeh, Abdul Rezzak; Mohamed, Madiha; Saif, Fatima; Tawfiq, Nafisa; El Halik, Majdi; Al-Ali, Mahmoud Taleb; Bastaki, Fatma

    2016-08-01

    Microcephaly is a rare neurological condition, both in isolation and when it occurs as part of a syndrome. One of the syndromic forms of microcephaly is microcephaly, seizures and developmental delay (MCSZ) (OMIM #613402), a rare autosomal recessive neurodevelopmental disorder with a range of phenotypic severity, and known to be caused by mutations in the polynucleotide kinase 3' phosphatase (PNKP) gene. The PNK protein is a key enzyme involved in the repair of single and double stranded DNA breaks, a process which is particularly important in the nervous system. We describe an Emirati patient who presented with microcephaly, short stature, uncontrollable tonic-clonic seizures, facial dysmorphism, and developmental delay, while at the same time showing evidence of brain atrophy and agenesis of the corpus callosum. We used whole exome sequencing to identify homozygosity for a missense c.1385G > C (p.Arg462Pro) mutation in PNKP in the patient and heterozygosity for this mutation in her consanguineous parents. The Arg 462 residue forms a part of the lid subdomain helix of the P-loop Kinase domain. Although our patient's phenotype resembled that of MCSZ, the short stature and evidence of brain atrophy distinguished it from other classic cases of the condition. The report raises the question of whether to consider this case as an atypical variant of MCSZ or as a novel form of microcephalic primordial dwarfism. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. Quantum diffusion during inflation and primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Pattison, Chris; Assadullahi, Hooshyar; Wands, David [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Vennin, Vincent, E-mail: hooshyar.assadullahi@port.ac.uk, E-mail: christopher.pattison@port.ac.uk, E-mail: vincent.vennin@port.ac.uk, E-mail: david.wands@port.ac.uk [Laboratoire Astroparticule et Cosmologie, Université Denis Diderot Paris 7, 75013 Paris (France)

    2017-10-01

    We calculate the full probability density function (PDF) of inflationary curvature perturbations, even in the presence of large quantum backreaction. Making use of the stochastic-δ N formalism, two complementary methods are developed, one based on solving an ordinary differential equation for the characteristic function of the PDF, and the other based on solving a heat equation for the PDF directly. In the classical limit where quantum diffusion is small, we develop an expansion scheme that not only recovers the standard Gaussian PDF at leading order, but also allows us to calculate the first non-Gaussian corrections to the usual result. In the opposite limit where quantum diffusion is large, we find that the PDF is given by an elliptic theta function, which is fully characterised by the ratio between the squared width and height (in Planck mass units) of the region where stochastic effects dominate. We then apply these results to the calculation of the mass fraction of primordial black holes from inflation, and show that no more than ∼ 1 e -fold can be spent in regions of the potential dominated by quantum diffusion. We explain how this requirement constrains inflationary potentials with two examples.

  19. Primordial Terrestrial Xe from the Viewpoint of CFF-Xe

    Science.gov (United States)

    Meshik, A. P.; Shukolyukov, Yu. A.; Jessberger, E. K.

    1995-09-01

    We have already reported [7, 23] on the non-linear isotope mass-fractionation of fission Xe by migration of the precursors I, Te, Sn, and Sb and simultaneous fission of heavy nuclei. Xe with anomalous isotopic pattern was found in a number of meteorites and terrestrial materials and was named CFF-Xe (Chemically Fractionated Fission Xe). It is characterized by an up eightfold ^132Xe and ^131Xe excesses coupled with smaller ^134Xe and ^129Xe excesses. The present work is aimed to estimate the role of CFF-Xe in the terrestrial lithosphere and specifically deals with the problem of the isotopic composition of primordial terrestrial Xe. Due to variations of the migration conditions the isotopic structure of CFF-Xe is not well established and is even not reproducible in the same rock [2]. Nevertheless, we have tried to estimate the composition of CFF-Xe by investigating all available isotopic data of Xe of presumable mantle origin. This is Xe in MORB [29, 1, 12] and ocean island glasses [1, 28], in diamonds [17], in volcanic rocks [29, 8, 9, 21], in volcanic glasses from pillow basalts [16, 6], continental igneous rocks [1, 24, 10, 22], carbonatites and granitoids [1] as well as Xe in natural gases [3, 24, 11, 4, 15]. All data are plotted Fig. 1 where we also suggest end members of the observed scattering. Optimized slopes of CFF-lines are shown as well as the position of the initial points which we regard as primordial terrestrial Xe (Xe0). The isotopic composition of CFF-Xe and Xe0 are given in Tab. 1. The abundances of ^124Xe and ^126Xe in mantle derived samples are very uncertain, but since ^128Xe/^130Xe in Xea and Xe0 is very similar we propose the same ^124Xe/^130Xe and ^126Xe/^130Xe ratios for both Xea and Xe0. If so, AVCC-Xe is simply Xe0 with an admixture of L-Xe, and atmospheric xenon Xea consists of Xe0, CFF-Xe and a small amount of fission Xe (92.5%Xe0 + 5.3%CFF-Xe + 2.2%XeF). Thus, a number of old problems in xenology are removed. The hypothetic components U

  20. Primordial Black Holes and r-Process Nucleosynthesis.

    Science.gov (United States)

    Fuller, George M; Kusenko, Alexander; Takhistov, Volodymyr

    2017-08-11

    We show that some or all of the inventory of r-process nucleosynthesis can be produced in interactions of primordial black holes (PBHs) with neutron stars (NSs) if PBHs with masses 10^{-14}  M_{⊙}

  1. Primordial black holes from polynomial potentials in single field inflation

    Science.gov (United States)

    Hertzberg, Mark P.; Yamada, Masaki

    2018-04-01

    Within canonical single field inflation models, we provide a method to reverse engineer and reconstruct the inflaton potential from a given power spectrum. This is not only a useful tool to find a potential from observational constraints, but also gives insight into how to generate a large amplitude spike in density perturbations, especially those that may lead to primordial black holes (PBHs). In accord with other works, we find that the usual slow-roll conditions need to be violated in order to generate a significant spike in the spectrum. We find that a way to achieve a very large amplitude spike in single field models is for the classical roll of the inflaton to overshoot a local minimum during inflation. We provide an example of a quintic polynomial potential that implements this idea and leads to the observed spectral index, observed amplitude of fluctuations on large scales, significant PBH formation on small scales, and is compatible with other observational constraints. We quantify how much fine-tuning is required to achieve this in a family of random polynomial potentials, which may be useful to estimate the probability of PBH formation in the string landscape.

  2. Primordial Black Holes as Generators of Cosmic Structures

    Science.gov (United States)

    Carr, Bernard; Silk, Joseph

    2018-05-01

    Primordial black holes (PBHs) could provide the dark matter in various mass windows below 102M⊙ and those of 30M⊙ might explain the LIGO events. PBHs much larger than this might have important consequences even if they provide only a small fraction of the dark matter. In particular, they could generate cosmological structure either individually through the `seed' effect or collectively through the `Poisson' effect, thereby alleviating some problems associated with the standard CDM scenario. If the PBHs all have a similar mass and make a small contribution to the dark matter, then the seed effect dominates on small scales, in which case PBHs could generate the supermassive black holes in galactic nuclei or even galaxies themselves. If they have a similar mass and provide the dark matter, the Poisson effect dominates on all scales and the first bound clouds would form earlier than in the usual scenario, with interesting observational consequences. If the PBHs have an extended mass spectrum, which is more likely, they could fulfill all three roles - providing the dark matter, binding the first bound clouds and generating galaxies. In this case, the galactic mass function naturally has the observed form, with the galaxy mass being simply related to the black hole mass. The stochastic gravitational wave background from the PBHs in this scenario would extend continuously from the LIGO frequency to the LISA frequency, offering a potential goal for future surveys.

  3. Testing for new physics: neutrinos and the primordial power spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Canac, Nicolas; Abazajian, Kevork N. [Department of Physics, University of California at Irvine, Irvine, CA 92697 (United States); Aslanyan, Grigor [Berkeley Center for Cosmological Physics, University of California, Berkeley, CA 94720 (United States); Easther, Richard [Department of Physics, University of Auckland, Private Bag 92019, Auckland (New Zealand); Price, Layne C., E-mail: ncanac@uci.edu, E-mail: aslanyan@berkeley.edu, E-mail: kevork@uci.edu, E-mail: r.easther@auckland.ac.nz, E-mail: laynep@andrew.cmu.edu [McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States)

    2016-09-01

    We test the sensitivity of neutrino parameter constraints from combinations of CMB and LSS data sets to the assumed form of the primordial power spectrum (PPS) using Bayesian model selection. Significantly, none of the tested combinations, including recent high-precision local measurements of H{sub 0} and cluster abundances, indicate a signal for massive neutrinos or extra relativistic degrees of freedom. For PPS models with a large, but fixed number of degrees of freedom, neutrino parameter constraints do not change significantly if the location of any features in the PPS are allowed to vary, although neutrino constraints are more sensitive to PPS features if they are known a priori to exist at fixed intervals in log k . Although there is no support for a non-standard neutrino sector from constraints on both neutrino mass and relativistic energy density, we see surprisingly strong evidence for features in the PPS when it is constrained with data from Planck 2015, SZ cluster counts, and recent high-precision local measurements of H{sub 0}. Conversely combining Planck with matter power spectrum and BAO measurements yields a much weaker constraint. Given that this result is sensitive to the choice of data this tension between SZ cluster counts, Planck and H{sub 0} measurements is likely an indication of unmodeled systematic bias that mimics PPS features, rather than new physics in the PPS or neutrino sector.

  4. A pilgrim's progress: Seeking meaning in primordial germ cell migration.

    Science.gov (United States)

    Cantú, Andrea V; Laird, Diana J

    2017-10-01

    Comparative studies of primordial germ cell (PGC) development across organisms in many phyla reveal surprising diversity in the route of migration, timing and underlying molecular mechanisms, suggesting that the process of migration itself is conserved. However, beyond the perfunctory transport of cellular precursors to their later arising home of the gonads, does PGC migration serve a function? Here we propose that the process of migration plays an additional role in quality control, by eliminating PGCs incapable of completing migration as well as through mechanisms that favor PGCs capable of responding appropriately to migration cues. Focusing on PGCs in mice, we explore evidence for a selective capacity of migration, considering the tandem regulation of proliferation and migration, cell-intrinsic and extrinsic control, the potential for tumors derived from failed PGC migrants, the potential mechanisms by which migratory PGCs vary in their cellular behaviors, and corresponding effects on development. We discuss the implications of a selective role of PGC migration for in vitro gametogenesis. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Genomic analysis of primordial dwarfism reveals novel disease genes.

    Science.gov (United States)

    Shaheen, Ranad; Faqeih, Eissa; Ansari, Shinu; Abdel-Salam, Ghada; Al-Hassnan, Zuhair N; Al-Shidi, Tarfa; Alomar, Rana; Sogaty, Sameera; Alkuraya, Fowzan S

    2014-02-01

    Primordial dwarfism (PD) is a disease in which severely impaired fetal growth persists throughout postnatal development and results in stunted adult size. The condition is highly heterogeneous clinically, but the use of certain phenotypic aspects such as head circumference and facial appearance has proven helpful in defining clinical subgroups. In this study, we present the results of clinical and genomic characterization of 16 new patients in whom a broad definition of PD was used (e.g., 3M syndrome was included). We report a novel PD syndrome with distinct facies in two unrelated patients, each with a different homozygous truncating mutation in CRIPT. Our analysis also reveals, in addition to mutations in known PD disease genes, the first instance of biallelic truncating BRCA2 mutation causing PD with normal bone marrow analysis. In addition, we have identified a novel locus for Seckel syndrome based on a consanguineous multiplex family and identified a homozygous truncating mutation in DNA2 as the likely cause. An additional novel PD disease candidate gene XRCC4 was identified by autozygome/exome analysis, and the knockout mouse phenotype is highly compatible with PD. Thus, we add a number of novel genes to the growing list of PD-linked genes, including one which we show to be linked to a novel PD syndrome with a distinct facial appearance. PD is extremely heterogeneous genetically and clinically, and genomic tools are often required to reach a molecular diagnosis.

  6. Primordial black hole formation during the QCD epoch

    International Nuclear Information System (INIS)

    Jedamzik, K.

    1997-01-01

    We consider the formation of horizon-size primordial black holes (PBH close-quote s) from pre-existing density fluctuations during cosmic phase transitions. It is pointed out that the formation of PBH close-quote s should be particularly efficient during the QCD epoch due to a substantial reduction of pressure forces during adiabatic collapse, or equivalently, a significant decrease in the effective speed of sound during the color-confinement transition. Our considerations imply that for generic initial density perturbation spectra PBH mass functions are expected to exhibit a pronounced peak on the QCD-horizon mass scale ∼1M circle-dot . This mass scale is roughly coincident with the estimated masses for compact objects recently observed in our galactic halo by the MACHO Collaboration. Black holes formed during the QCD epoch may offer an attractive explanation for the origin of halo dark matter evading possibly problematic nucleosynthesis and luminosity bounds on baryonic halo dark matter. copyright 1997 The American Physical Society

  7. Reduced bispectrum seeded by helical primordial magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Hortúa, Héctor Javier [Universidad Nacional de Colombia-Bogotá, Facultad de Ciencias, Departamento de Física, Carrera 30 Calle 45-03, C.P. 111321 Bogotá (Colombia); Castañeda, Leonardo, E-mail: hjhortuao@unal.edu.co, E-mail: lcastanedac@unal.edu.co [Grupo de Gravitación y Cosmología, Observatorio Astronómico Nacional, Universidad Nacional de Colombia, cra 45 No 26-85, Edificio Uriel Gutierréz, Bogotá, D.C. (Colombia)

    2017-06-01

    In this paper, we investigate the effects of helical primordial magnetic fields (PMFs) on the cosmic microwave background (CMB) reduced bispectrum. We derive the full three-point statistics of helical magnetic fields and numerically calculate the even contribution in the collinear configuration. We then numerically compute the CMB reduced bispectrum induced by passive and compensated PMF modes on large angular scales. There is a negative signal on the bispectrum due to the helical terms of the fields and we also observe that the biggest contribution to the bispectrum comes from the non-zero IR cut-off for causal fields, unlike the two-point correlation case. For negative spectral indices, the reduced bispectrum is enhanced by the passive modes. This gives a lower value of the upper limit for the mean amplitude of the magnetic field on a given characteristic scale. However, high values of IR cut-off in the bispectrum, and the helical terms of the magnetic field relaxes this bound. This demonstrates the importance of the IR cut-off and helicity in the study of the nature of PMFs from CMB observations.

  8. New cosmic microwave background constraint to primordial gravitational waves.

    Science.gov (United States)

    Smith, Tristan L; Pierpaoli, Elena; Kamionkowski, Marc

    2006-07-14

    Primordial gravitational waves (GWs) with frequencies > or approximately equal to 10(-15) Hz contribute to the radiation density of the Universe at the time of decoupling of the cosmic microwave background (CMB). This affects the CMB and matter power spectra in a manner identical to massless neutrinos, unless the initial density perturbation for the GWs is nonadiabatic, as may occur if such GWs are produced during inflation or some post-inflation phase transition. In either case, current observations provide a constraint to the GW amplitude that competes with that from big-bang nucleosynthesis (BBN), although it extends to much lower frequencies (approximately 10(-15) Hz rather than the approximately 10(-10) Hz from BBN): at 95% confidence level, omega(gw)h(2)

  9. Nuclear Reprogramming in Mouse Primordial Germ Cells: Epigenetic Contribution

    Directory of Open Access Journals (Sweden)

    Massimo De Felici

    2011-01-01

    Full Text Available The unique capability of germ cells to give rise to a new organism, allowing the transmission of primary genetic information from generation to generation, depends on their epigenetic reprogramming ability and underlying genomic totipotency. Recent studies have shown that genome-wide epigenetic modifications, referred to as “epigenetic reprogramming”, occur during the development of the gamete precursors termed primordial germ cells (PGCs in the embryo. This reprogramming is likely to be critical for the germ line development itself and necessary to erase the parental imprinting and setting the base for totipotency intrinsic to this cell lineage. The status of genome acquired during reprogramming and the associated expression of key pluripotency genes render PGCs susceptible to transform into pluripotent stem cells. This may occur in vivo under still undefined condition, and it is likely at the origin of the formation of germ cell tumors. The phenomenon appears to be reproduced under partly defined in vitro culture conditions, when PGCs are transformed into embryonic germ (EG cells. In the present paper, I will try to summarize the contribution that epigenetic modifications give to nuclear reprogramming in mouse PGCs.

  10. Quantum origin of the primordial fluctuation spectrum and its statistics

    Science.gov (United States)

    Landau, Susana; León, Gabriel; Sudarsky, Daniel

    2013-07-01

    The usual account for the origin of cosmic structure during inflation is not fully satisfactory, as it lacks a physical mechanism capable of generating the inhomogeneity and anisotropy of our Universe, from an exactly homogeneous and isotropic initial state associated with the early inflationary regime. The proposal in [A. Perez, H. Sahlmann, and D. Sudarsky, Classical Quantum Gravity 23, 2317 (2006)] considers the spontaneous dynamical collapse of the wave function as a possible answer to that problem. In this work, we review briefly the difficulties facing the standard approach, as well as the answers provided by the above proposal and explore their relevance to the investigations concerning the characterization of the primordial spectrum and other statistical aspects of the cosmic microwave background and large-scale matter distribution. We will see that the new approach leads to novel ways of considering some of the relevant questions, and, in particular, to distinct characterizations of the non-Gaussianities that might have left imprints on the available data.

  11. Relic gravitational waves from light primordial black holes

    International Nuclear Information System (INIS)

    Dolgov, Alexander D.; Ejlli, Damian

    2011-01-01

    The energy density of relic gravitational waves (GWs) emitted by primordial black holes (PBHs) is calculated. We estimate the intensity of GWs produced at quantum and classical scattering of PBHs, the classical graviton emission from the PBH binaries in the early Universe, and the graviton emission due to PBH evaporation. If nonrelativistic PBHs dominated the cosmological energy density prior to their evaporation, the probability of formation of dense clusters of PBHs and their binaries in such clusters would be significant and the energy density of the generated gravitational waves in the present-day universe could exceed that produced by other known mechanisms. The intensity of these gravitational waves would be maximal in the GHz frequency band of the spectrum or higher and makes their observation very difficult by present detectors but also gives a rather good possibility to investigate it by present and future high-frequency gravitational waves electromagnetic detectors. However, the low-frequency part of the spectrum in the range f∼0.1-10 Hz may be detectable by the planned space interferometers DECIGO/BBO. For sufficiently long duration of the PBH matter-dominated stage, the cosmological energy fraction of GWs from inflation would be noticeably diluted.

  12. Planck 2015 results. XIX. Constraints on primordial magnetic fields

    CERN Document Server

    Ade, P.A.R.; Arnaud, M.; Arroja, F.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Ballardini, M.; Banday, A.J.; Barreiro, R.B.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Bucher, M.; Burigana, C.; Butler, R.C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chiang, H.C.; Chluba, J.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Diego, J.M.; Dolag, K.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T.A.; Eriksen, H.K.; Fergusson, J.; Finelli, F.; Florido, E.; Forni, O.; Frailis, M.; Fraisse, A.A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hansen, F.K.; Hanson, D.; Harrison, D.L.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Hurier, G.; Jaffe, A.H.; Jaffe, T.R.; Jones, W.C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kim, J.; Kisner, T.S.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C.R.; Leahy, J.P.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P.B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P.M.; Macías-Pérez, J.F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P.G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J.A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Nørgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Oppermann, N.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G.W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J.P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J.A.; Ruiz-Granados, B.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Shiraishi, M.; Spencer, L.D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J.A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L.A.; Wandelt, B.D.; Wehus, I.K.; Yvon, D.; Zacchei, A.

    2016-01-01

    We predict and investigate four types of imprint of a stochastic background of primordial magnetic fields (PMFs) on the cosmic microwave background (CMB) anisotropies: the impact of PMFs on the CMB spectra; the effect on CMB polarization induced by Faraday rotation; magnetically-induced non-Gaussianities; and the magnetically-induced breaking of statistical isotropy. Overall, Planck data constrain the amplitude of PMFs to less than a few nanogauss. In particular, individual limits coming from the analysis of the CMB angular power spectra, using the Planck likelihood, are $B_{1\\,\\mathrm{Mpc}}< 4.4$ nG (where $B_{1\\,\\mathrm{Mpc}}$ is the comoving field amplitude at a scale of 1 Mpc) at 95% confidence level, assuming zero helicity, and $B_{1\\,\\mathrm{Mpc}}< 5.6$ nG when we consider a maximally helical field. For nearly scale-invariant PMFs we obtain $B_{1\\,\\mathrm{Mpc}}<2.1$ nG and $B_{1\\,\\mathrm{Mpc}}<0.7$ nG if the impact of PMFs on the ionization history of the Universe is included in the analysis...

  13. Planck 2015 results. XVII. Constraints on primordial non-Gaussianity

    CERN Document Server

    Ade, P.A.R.; Arnaud, M.; Arroja, F.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Ballardini, M.; Banday, A.J.; Barreiro, R.B.; Bartolo, N.; Basak, S.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bock, J.J.; Bonaldi, A.; Bonavera, L.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R.C.; Calabrese, E.; Cardoso, J.F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, H.C.; Christensen, P.R.; Church, S.; Clements, D.L.; Colombi, S.; Colombo, L.P.L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B.P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; De Rosa, A.; De Zotti, G.; Delabrouille, J.; Désert, F.X.; Diego, J.M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T.A.; Eriksen, H.K.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A.A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Gauthier, C.; Ghosh, T.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K.M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J.E.; Hamann, J.; Hansen, F.K.; Hanson, D.; Harrison, D.L.; Heavens, A.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huang, Z.; Huffenberger, K.M.; Hurier, G.; Jaffe, A.H.; Jaffe, T.R.; Jones, W.C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kim, J.; Kisner, T.S.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lacasa, F.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.M.; Lasenby, A.; Lattanzi, M.; Lawrence, C.R.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Lewis, A.; Liguori, M.; Lilje, P.B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P.M.; Macías-Pérez, J.F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Marinucci, D.; Maris, M.; Martin, P.G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Münchmeyer, M.; Munshi, D.; Murphy, J.A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C.B.; Nørgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C.A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Peiris, H.V.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G.W.; Prézeau, G.; Prunet, S.; Puget, J.L.; Rachen, J.P.; Racine, B.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J.A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M.D.; Shellard, E.P.S.; Shiraishi, M.; Smith, K.; Spencer, L.D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutter, P.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Troja, A.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; van Tent, B.; Vielva, P.; Villa, F.; Wade, L.A.; Wandelt, B.D.; Wehus, I.K.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-01-01

    The Planck full mission cosmic microwave background(CMB) temperature and E-mode polarization maps are analysed to obtain constraints on primordial non-Gaussianity(NG). Using three classes of optimal bispectrum estimators - separable template-fitting (KSW), binned, and modal - we obtain consistent values for the local, equilateral, and orthogonal bispectrum amplitudes, quoting as our final result from temperature alone fNL^local=2.5+\\-5.7, fNL^equil=-16+\\-70 and fNL^ortho=-34+\\-33(68%CL). Combining temperature and polarization data we obtain fNL^local=0.8+\\-5.0, fNL^equil=-4+\\-43 and fNL^ortho=-26+\\-21 (68%CL). The results are based on cross-validation of these estimators on simulations, are stable across component separation techniques, pass an extensive suite of tests, and are consistent with Minkowski functionals based measurements. The effect of time-domain de-glitching systematics on the bispectrum is negligible. In spite of these test outcomes we conservatively label the results including polarization da...

  14. The origin and migration of primordial germ cells in sturgeons.

    Directory of Open Access Journals (Sweden)

    Taiju Saito

    Full Text Available Primordial germ cells (PGCs arise elsewhere in the embryo and migrate into developing gonadal ridges during embryonic development. In several model animals, formation and migration patterns of PGCs have been studied, and it is known that these patterns vary. Sturgeons (genus Acipenser have great potential for comparative and evolutionary studies of development. Sturgeons belong to the super class Actinoptergii, and their developmental pattern is similar to that of amphibians, although their phylogenetic position is an out-group to teleost fishes. Here, we reveal an injection technique for sturgeon eggs allowing visualization of germplasm and PGCs. Using this technique, we demonstrate that the PGCs are generated at the vegetal pole of the egg and they migrate on the yolky cell mass toward the gonadal ridge. We also provide evidence showing that PGCs are specified by inheritance of maternally supplied germplasm. Furthermore, we demonstrate that the migratory mechanism is well-conserved between sturgeon and other remotely related teleosts, such as goldfish, by a single PGCs transplantation (SPT assay. The mode of PGCs specification in sturgeon is similar to that of anurans, but the migration pattern resembles that of teleosts.

  15. On minimally parametric primordial power spectrum reconstruction and the evidence for a red tilt

    International Nuclear Information System (INIS)

    Verde, Licia; Peiris, Hiranya

    2008-01-01

    The latest cosmological data seem to indicate a significant deviation from scale invariance of the primordial power spectrum when parameterized either by a power law or by a spectral index with non-zero 'running'. This deviation, by itself, serves as a powerful tool for discriminating among theories for the origin of cosmological structures such as inflationary models. Here, we use a minimally parametric smoothing spline technique to reconstruct the shape of the primordial power spectrum. This technique is well suited to searching for smooth features in the primordial power spectrum such as deviations from scale invariance or a running spectral index, although it would recover sharp features of high statistical significance. We use the WMAP three-year results in combination with data from a suite of higher resolution cosmic microwave background experiments (including the latest ACBAR 2008 release), as well as large-scale structure data from SDSS and 2dFGRS. We employ cross-validation to assess, using the data themselves, the optimal amount of smoothness in the primordial power spectrum consistent with the data. This minimally parametric reconstruction supports the evidence for a power law primordial power spectrum with a red tilt, but not for deviations from a power law power spectrum. Smooth variations in the primordial power spectrum are not significantly degenerate with the other cosmological parameters

  16. Richard Rufus's theory of mixture: a medieval explanation of chemical combination.

    Science.gov (United States)

    Weisberg, Michael; Wood, Rega

    2003-05-01

    Richard Rufus of Cornwall offered a novel solution to the problem of mixture raised by Aristotle. The puzzle is that mixts or mixed bodies (blood, flesh, wood, etc.) seem to be unexplainable through logic, even though the world is full of them. Rufus's contribution to this long-standing theoretical debate is the development of a modal interpretation of certain Averroistic doctrines. Rufus's account, which posits that the elemental forms in a mixt are in accidental potential, avoids many of the problems that plagued non-atomistic medieval theories of mixture. This paper is an initial examination of Rufus' account.

  17. An experimental ‘Life’ for an experimental life : Richard Waller's biography of Robert Hooke (1705)

    OpenAIRE

    Moxham, Noah

    2016-01-01

    Richard Waller's ‘Life of Dr Robert Hooke’, prefixed to his edition of Hooke's Posthumous Works (1705), is an important source for the life of one of the most eminent members of the early Royal Society. It also has the distinction of being one of the earliest biographies of a man of science to be published in English. I argue that it is in fact the first biography to embrace the subject's natural-philosophical work as the centre of his life, and I investigate Waller's reasons for adopting thi...

  18. Of poetics and possibility: Richard Kearney’s post-metaphysical God

    Directory of Open Access Journals (Sweden)

    Yolande Steenkamp

    2017-11-01

    Full Text Available This article provides an overview of Richard Kearney’s attempt at re-imagining God post-metaphysically. In the context of a continental dialogue on the topic, Kearney has responded to onto-theology with a hermeneutic and phenomenologically informed attempt to rethink God post-metaphysically. This eschatological understanding of God is expounded in the article and is placed in relation to Kearney’s more recent concept of Anatheism. The article closes with a few remarks on what may be gained by Kearney’s work, as well as outlining a few critical questions.

  19. Popular science - common ground. A literary critique of Richard Dawkins's The Selfish Gene

    OpenAIRE

    Nilsen, Helene

    2012-01-01

    This thesis aims to perform a literary reading of Richard Dawkins's The Selfish Gene from a perspective situated outside of the 'battle of the two cultures'. Chapter 1 takes Foucault's article What is an author?" as its point of departure. After discussing how Dawkins may be seen as a reader of Darwin, I will go on to discuss Foucault's concept of the author-function, before I move on to consider some different readings of and approaches to The Selfish Gene. With reference to a polemic bet...

  20. Diagnosis and treatment of polycystic ovary syndrome (PCOS): an interview with Richard Legro.

    Science.gov (United States)

    Legro, Richard

    2015-03-27

    In this podcast, we talk to Professor Richard Legro about the recommendations for the diagnosis and treatment of polycystic ovary syndrome (PCOS) based on clinical practice guidelines and discuss the challenges of diagnosis PCOS at specific age groups. The controversies associated with treatment of PCOS, including therapies for infertility as this is a problem commonly observed in PCOS subjects, are highlighted together with future directions on the topic. The podcast for this interview is available at. http://www.biomedcentral.com/content/supplementary/s12916-015-0299-2-s1.mp3.

  1. Volatile inventories in clathrate hydrates formed in the primordial nebula.

    Science.gov (United States)

    Mousis, Olivier; Lunine, Jonathan I; Picaud, Sylvain; Cordier, Daniel

    2010-01-01

    The examination of ambient thermodynamic conditions suggests that clathrate hydrates could exist in the Martian permafrost, on the surface and in the interior of Titan, as well as in other icy satellites. Clathrate hydrates are probably formed in a significant fraction of planetesimals in the solar system. Thus, these crystalline solids may have been accreted in comets, in the forming giant planets and in their surrounding satellite systems. In this work, we use a statistical thermodynamic model to investigate the composition of clathrate hydrates that may have formed in the primordial nebula. In our approach, we consider the formation sequence of the different ices occurring during the cooling of the nebula, a reasonable idealization of the process by which volatiles are trapped in planetesimals. We then determine the fractional occupancies of guests in each clathrate hydrate formed at a given temperature. The major ingredient of our model is the description of the guest-clathrate hydrate interaction by a spherically averaged Kihara potential with a nominal set of parameters, most of which are fitted to experimental equilibrium data. Our model allows us to find that Kr, Ar and N2 can be efficiently encaged in clathrate hydrates formed at temperatures higher than approximately 48.5 K in the primitive nebula, instead of forming pure condensates below 30 K. However, we find at the same time that the determination of the relative abundances of guest species incorporated in these clathrate hydrates strongly depends on the choice of the parameters of the Kihara potential and also on the adopted size of cages. Indeed, by testing different potential parameters, we have noted that even minor dispersions between the different existing sets can lead to non-negligible variations in the determination of the volatiles trapped in clathrate hydrates formed in the primordial nebula. However, these variations are not found to be strong enough to reverse the relative abundances

  2. Probing Primordial Black Hole Dark Matter with Gravitational Waves.

    Science.gov (United States)

    Kovetz, Ely D

    2017-09-29

    Primordial black holes (PBHs) have long been suggested as a candidate for making up some or all of the dark matter in the Universe. Most of the theoretically possible mass range for PBH dark matter has been ruled out with various null observations of expected signatures of their interaction with standard astrophysical objects. However, current constraints are significantly less robust in the 20  M_{⊙}≲M_{PBH}≲100  M_{⊙} mass window, which has received much attention recently, following the detection of merging black holes with estimated masses of ∼30  M_{⊙} by LIGO and the suggestion that these could be black holes formed in the early Universe. We consider the potential of advanced LIGO (aLIGO) operating at design sensitivity to probe this mass range by looking for peaks in the mass spectrum of detected events. To quantify the background, which is due to black holes that are formed from dying stars, we model the shape of the stellar-black-hole mass function and calibrate its amplitude to match the O1 results. Adopting very conservative assumptions about the PBH and stellar-black-hole merger rates, we show that ∼5  yr of aLIGO data can be used to detect a contribution of >20  M_{⊙} PBHs to dark matter down to f_{PBH}99.9% confidence level. Combined with other probes that already suggest tension with f_{PBH}=1, the obtainable independent limits from aLIGO will thus enable a firm test of the scenario that PBHs make up all of dark matter.

  3. On the Maximum Mass of Accreting Primordial Supermassive Stars

    Energy Technology Data Exchange (ETDEWEB)

    Woods, T. E.; Heger, Alexander [Monash Centre for Astrophysics, School of Physics and Astronomy, Monash University, VIC 3800 (Australia); Whalen, Daniel J. [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Portsmouth PO1 3FX (United Kingdom); Haemmerlé, Lionel; Klessen, Ralf S. [Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische. Astrophysik, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany)

    2017-06-10

    Supermassive primordial stars are suspected to be the progenitors of the most massive quasars at z ∼ 6. Previous studies of such stars were either unable to resolve hydrodynamical timescales or considered stars in isolation, not in the extreme accretion flows in which they actually form. Therefore, they could not self-consistently predict their final masses at collapse, or those of the resulting supermassive black hole seeds, but rather invoked comparison to simple polytropic models. Here, we systematically examine the birth, evolution, and collapse of accreting, non-rotating supermassive stars under accretion rates of 0.01–10 M {sub ⊙} yr{sup −1} using the stellar evolution code Kepler . Our approach includes post-Newtonian corrections to the stellar structure and an adaptive nuclear network and can transition to following the hydrodynamic evolution of supermassive stars after they encounter the general relativistic instability. We find that this instability triggers the collapse of the star at masses of 150,000–330,000 M {sub ⊙} for accretion rates of 0.1–10 M {sub ⊙} yr{sup −1}, and that the final mass of the star scales roughly logarithmically with the rate. The structure of the star, and thus its stability against collapse, is sensitive to the treatment of convection and the heat content of the outer accreted envelope. Comparison with other codes suggests differences here may lead to small deviations in the evolutionary state of the star as a function of time, that worsen with accretion rate. Since the general relativistic instability leads to the immediate death of these stars, our models place an upper limit on the masses of the first quasars at birth.

  4. Mutations in the NHEJ component XRCC4 cause primordial dwarfism.

    Science.gov (United States)

    Murray, Jennie E; van der Burg, Mirjam; IJspeert, Hanna; Carroll, Paula; Wu, Qian; Ochi, Takashi; Leitch, Andrea; Miller, Edward S; Kysela, Boris; Jawad, Alireza; Bottani, Armand; Brancati, Francesco; Cappa, Marco; Cormier-Daire, Valerie; Deshpande, Charu; Faqeih, Eissa A; Graham, Gail E; Ranza, Emmanuelle; Blundell, Tom L; Jackson, Andrew P; Stewart, Grant S; Bicknell, Louise S

    2015-03-05

    Non-homologous end joining (NHEJ) is a key cellular process ensuring genome integrity. Mutations in several components of the NHEJ pathway have been identified, often associated with severe combined immunodeficiency (SCID), consistent with the requirement for NHEJ during V(D)J recombination to ensure diversity of the adaptive immune system. In contrast, we have recently found that biallelic mutations in LIG4 are a common cause of microcephalic primordial dwarfism (MPD), a phenotype characterized by prenatal-onset extreme global growth failure. Here we provide definitive molecular genetic evidence supported by biochemical, cellular, and immunological data for mutations in XRCC4, encoding the obligate binding partner of LIG4, causing MPD. We report the identification of biallelic mutations in XRCC4 in five families. Biochemical and cellular studies demonstrate that these alterations substantially decrease XRCC4 protein levels leading to reduced cellular ligase IV activity. Consequently, NHEJ-dependent repair of ionizing-radiation-induced DNA double-strand breaks is compromised in XRCC4 cells. Similarly, immunoglobulin junctional diversification is impaired in cells. However, immunoglobulin levels are normal, and individuals lack overt signs of immunodeficiency. Additionally, in contrast to individuals with LIG4 mutations, pancytopenia leading to bone marrow failure has not been observed. Hence, alterations that alter different NHEJ proteins give rise to a phenotypic spectrum, from SCID to extreme growth failure, with deficiencies in certain key components of this repair pathway predominantly exhibiting growth deficits, reflecting differential developmental requirements for NHEJ proteins to support growth and immune maturation. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  5. Primordial black holes in linear and non-linear regimes

    Energy Technology Data Exchange (ETDEWEB)

    Allahyari, Alireza; Abolhasani, Ali Akbar [Department of Physics, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Firouzjaee, Javad T., E-mail: allahyari@physics.sharif.edu, E-mail: j.taghizadeh.f@ipm.ir [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2017-06-01

    We revisit the formation of primordial black holes (PBHs) in the radiation-dominated era for both linear and non-linear regimes, elaborating on the concept of an apparent horizon. Contrary to the expectation from vacuum models, we argue that in a cosmological setting a density fluctuation with a high density does not always collapse to a black hole. To this end, we first elaborate on the perturbation theory for spherically symmetric space times in the linear regime. Thereby, we introduce two gauges. This allows to introduce a well defined gauge-invariant quantity for the expansion of null geodesics. Using this quantity, we argue that PBHs do not form in the linear regime irrespective of the density of the background. Finally, we consider the formation of PBHs in non-linear regimes, adopting the spherical collapse picture. In this picture, over-densities are modeled by closed FRW models in the radiation-dominated era. The difference of our approach is that we start by finding an exact solution for a closed radiation-dominated universe. This yields exact results for turn-around time and radius. It is important that we take the initial conditions from the linear perturbation theory. Additionally, instead of using uniform Hubble gauge condition, both density and velocity perturbations are admitted in this approach. Thereby, the matching condition will impose an important constraint on the initial velocity perturbations δ {sup h} {sub 0} = −δ{sub 0}/2. This can be extended to higher orders. Using this constraint, we find that the apparent horizon of a PBH forms when δ > 3 at turn-around time. The corrections also appear from the third order. Moreover, a PBH forms when its apparent horizon is outside the sound horizon at the re-entry time. Applying this condition, we infer that the threshold value of the density perturbations at horizon re-entry should be larger than δ {sub th} > 0.7.

  6. Hip pathology in Majewski osteodysplastic primordial dwarfism type II.

    Science.gov (United States)

    Karatas, Ali F; Bober, Michael B; Rogers, Kenneth; Duker, Angela L; Ditro, Colleen P; Mackenzie, William G

    2014-09-01

    Majewski osteodysplastic primordial dwarfism type II (MOPDII) is characterized by severe prenatal and postnatal growth failure with microcephaly, characteristic skeletal dysplasia, an increased risk for cerebrovascular disease, and insulin resistance. MOPDII is caused by mutations in the pericentrin (PCNT) gene and is inherited in an autosomal-recessive manner. This study aimed to determine the incidence of hip pathology in patients with molecularly confirmed MOPDII and to describe the functional outcomes of surgical treatment. Thirty-three enrolled patients had a clinical diagnosis of MOPDII. Biallelic PCNT mutations or absent pericentrin protein was confirmed in 25 of these patients. Twelve patients (7 female) had appropriate clinical and radiographic records at this institution and were included in this study. The data collected included age at presentation, age at surgery, sex, body weight and height, weight-bearing status at diagnosis, and the clinical examination. Four patients (31%) had coxa vara: 3 unilateral and 1 bilateral. Three unilateral patients had in situ pinning at a mean age 4 years. The patient with bilateral coxa vara had valgus osteotomy at the age of 5 years. Two children had bilateral hip dysplasia and subluxation with no surgery. One patient had bilateral developmental hip dislocations. The patient was treated by open reduction-spica cast and 2 years after surgery, coxa valga was noted. Another patient was diagnosed at an age of 12 years with bilateral avascular necrosis of the hips. Four patients did not have hip pathology. Hip pathology is common among children with MOPDII; coxa vara is the most frequent diagnosis. Routine clinical and radiographic hip evaluation is important. The capital femoral epiphysis appears to slip down along the shaft, giving the appearance of a proximal femoral epiphysiolysis. A hip diagnosed with slipped capital femoral epiphysis in early life may progress to severe coxa vara. Level IV.

  7. Merger rate of primordial black-hole binaries

    Science.gov (United States)

    Ali-Haïmoud, Yacine; Kovetz, Ely D.; Kamionkowski, Marc

    2017-12-01

    Primordial black holes (PBHs) have long been a candidate for the elusive dark matter (DM), and remain poorly constrained in the ˜20 - 100 M⊙ mass range. PBH binaries were recently suggested as the possible source of LIGO's first detections. In this paper, we thoroughly revisit existing estimates of the merger rate of PBH binaries. We compute the probability distribution of orbital parameters for PBH binaries formed in the early Universe, accounting for tidal torquing by all other PBHs, as well as standard large-scale adiabatic perturbations. We then check whether the orbital parameters of PBH binaries formed in the early Universe can be significantly affected between formation and merger. Our analytic estimates indicate that the tidal field of halos and interactions with other PBHs, as well as dynamical friction by unbound standard DM particles, do not do significant work on nor torque PBH binaries. We estimate the torque due to baryon accretion to be much weaker than previous calculations, albeit possibly large enough to significantly affect the eccentricity of typical PBH binaries. We also revisit the PBH-binary merger rate resulting from gravitational capture in present-day halos, accounting for Poisson fluctuations. If binaries formed in the early Universe survive to the present time, as suggested by our analytic estimates, they dominate the total PBH merger rate. Moreover, this merger rate would be orders of magnitude larger than LIGO's current upper limits if PBHs make a significant fraction of the dark matter. As a consequence, LIGO would constrain ˜10 - 300 M⊙ PBHs to constitute no more than ˜1 % of the dark matter. To make this conclusion fully robust, though, numerical study of several complex astrophysical processes—such as the formation of the first PBH halos and how they may affect PBH binaries, as well as the accretion of gas onto an extremely eccentric binary—is needed.

  8. Primordial black hole production in Critical Higgs Inflation

    Science.gov (United States)

    Ezquiaga, Jose María; García-Bellido, Juan; Ruiz Morales, Ester

    2018-01-01

    Primordial Black Holes (PBH) arise naturally from high peaks in the curvature power spectrum of near-inflection-point single-field inflation, and could constitute today the dominant component of the dark matter in the universe. In this letter we explore the possibility that a broad spectrum of PBH is formed in models of Critical Higgs Inflation (CHI), where the near-inflection point is related to the critical value of the RGE running of both the Higgs self-coupling λ (μ) and its non-minimal coupling to gravity ξ (μ). We show that, for a wide range of model parameters, a half-domed-shaped peak in the matter spectrum arises at sufficiently small scales that it passes all the constraints from large scale structure observations. The predicted cosmic microwave background spectrum at large scales is in agreement with Planck 2015 data, and has a relatively large tensor-to-scalar ratio that may soon be detected by B-mode polarization experiments. Moreover, the wide peak in the power spectrum gives an approximately lognormal PBH distribution in the range of masses 0.01- 100M⊙, which could explain the LIGO merger events, while passing all present PBH observational constraints. The stochastic background of gravitational waves coming from the unresolved black-hole-binary mergers could also be detected by LISA or PTA. Furthermore, the parameters of the CHI model are consistent, within 2σ, with the measured Higgs parameters at the LHC and their running. Future measurements of the PBH mass spectrum could allow us to obtain complementary information about the Higgs couplings at energies well above the EW scale, and thus constrain new physics beyond the Standard Model.

  9. Primordial black hole production in Critical Higgs Inflation

    Directory of Open Access Journals (Sweden)

    Jose María Ezquiaga

    2018-01-01

    Full Text Available Primordial Black Holes (PBH arise naturally from high peaks in the curvature power spectrum of near-inflection-point single-field inflation, and could constitute today the dominant component of the dark matter in the universe. In this letter we explore the possibility that a broad spectrum of PBH is formed in models of Critical Higgs Inflation (CHI, where the near-inflection point is related to the critical value of the RGE running of both the Higgs self-coupling λ(μ and its non-minimal coupling to gravity ξ(μ. We show that, for a wide range of model parameters, a half-domed-shaped peak in the matter spectrum arises at sufficiently small scales that it passes all the constraints from large scale structure observations. The predicted cosmic microwave background spectrum at large scales is in agreement with Planck 2015 data, and has a relatively large tensor-to-scalar ratio that may soon be detected by B-mode polarization experiments. Moreover, the wide peak in the power spectrum gives an approximately lognormal PBH distribution in the range of masses 0.01–100M⊙, which could explain the LIGO merger events, while passing all present PBH observational constraints. The stochastic background of gravitational waves coming from the unresolved black-hole-binary mergers could also be detected by LISA or PTA. Furthermore, the parameters of the CHI model are consistent, within 2σ, with the measured Higgs parameters at the LHC and their running. Future measurements of the PBH mass spectrum could allow us to obtain complementary information about the Higgs couplings at energies well above the EW scale, and thus constrain new physics beyond the Standard Model.

  10. Specification of primordial germ cells in medaka (Oryzias latipes

    Directory of Open Access Journals (Sweden)

    Raz Erez

    2007-01-01

    Full Text Available Abstract Background Primordial germ cells (PGCs give rise to gametes that are responsible for the development of a new organism in the next generation. Two modes of germ line specification have been described: the inheritance of asymmetrically-localized maternally provided cytoplasmic determinants and the induction of the PGC fate by other cell types. PGCs specification in zebrafish appears to depend on inheritance of germ plasm in which several RNA molecules such as vasa and nanos reside. Whether the specification mode of PGCs found in zebrafish is general for other fish species was brought into question upon analysis of olvas expression – the vasa homologue in another teleost, medaka (Oryzias latipes. Here, in contrast to the findings in zebrafish, the PGCs are found in a predictable position relative to a somatic structure, the embryonic shield. This finding, coupled with the fact that vasa mRNA, which is localized to the germ plasm of zebrafish but does not label a similar structure in medaka opened the possibility of fundamentally different mechanisms governing PGC specification in these two fish species. Results In this study we addressed the question concerning the mode of PGC specification in medaka using embryological experiments, analysis of RNA stability in the PGCs and electron microscopy observations. Dramatic alterations in the somatic environment, i.e. induction of a secondary axis or mesoderm formation alteration, did not affect the PGC number. Furthermore, the PGCs of medaka are capable of protecting specific RNA molecules from degradation and could therefore exhibit a specific mRNA expression pattern controlled by posttrancriptional mechanisms. Subsequent analysis of 4-cell stage medaka embryos using electron microscopy revealed germ plasm-like structures located at a region corresponding to that of zebrafish germ plasm. Conclusion Taken together, these results are consistent with the idea that in medaka the inheritance of

  11. Formation of primordial supermassive stars by rapid mass accretion

    Energy Technology Data Exchange (ETDEWEB)

    Hosokawa, Takashi; Yoshida, Naoki [Department of Physics and Research Center for the Early Universe, The University of Tokyo, Tokyo 113-0033 (Japan); Yorke, Harold W. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Inayoshi, Kohei; Omukai, Kazuyuki, E-mail: takashi.hosokawa@phys.s.u-tokyo.ac.jp, E-mail: hosokwtk@gmail.com [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)

    2013-12-01

    Supermassive stars (SMSs) forming via very rapid mass accretion ( M-dot {sub ∗}≳0.1 M{sub ⊙} yr{sup −1}) could be precursors of supermassive black holes observed beyond a redshift of about six. Extending our previous work, here we study the evolution of primordial stars growing under such rapid mass accretion until the stellar mass reaches 10{sup 4–5} M {sub ☉}. Our stellar evolution calculations show that a star becomes supermassive while passing through the 'supergiant protostar' stage, whereby the star has a very bloated envelope and a contracting inner core. The stellar radius increases monotonically with the stellar mass until ≅ 100 AU for M {sub *} ≳ 10{sup 4} M {sub ☉}, after which the star begins to slowly contract. Because of the large radius, the effective temperature is always less than 10{sup 4} K during rapid accretion. The accreting material is thus almost completely transparent to the stellar radiation. Only for M {sub *} ≳ 10{sup 5} M {sub ☉} can stellar UV feedback operate and disturb the mass accretion flow. We also examine the pulsation stability of accreting SMSs, showing that the pulsation-driven mass loss does not prevent stellar mass growth. Observational signatures of bloated SMSs should be detectable with future observational facilities such as the James Webb Space Telescope. Our results predict that an inner core of the accreting SMS should suffer from the general relativistic instability soon after the stellar mass exceeds 10{sup 5} M {sub ☉}. An extremely massive black hole should form after the collapse of the inner core.

  12. Funding Student Scholarships to the Richard Tapia Celebration of Diversity in Computing Conference 2013, February 7-10, 2013

    Energy Technology Data Exchange (ETDEWEB)

    Tapia, Richard

    2013-02-07

    This Basic Award allowed for the funding of student scholarships to the Richard Tapia Celebration of Diversity in Computing Conference which took place in Washington, D.C. from February 7-10, 2013. The conference was the seventh in a series and included a stellar array of invited speakers, compelling panel discussions, a student poster competition, a daylong Doctoral Consortium, a session featuring a choice of attractions unique to Washington, D.C., a gala banquet and dance, and many exciting networking opportunities. The conference created a welcoming environment for STEM students, especially underrepresented minority and female students, who were provided the highest quality of learning, networking, and social experiences to empower their educational experience and enhance their ability to succeed with a rigorous STEM degree. The networking and mentoring opportunities available at the conference were also designed to empower students to succeed in STEM careers and ultimately serve in leadership in industry and the professoriate. A key step in attracting underrepresented students into STEM fields and paving the way for their success in influential positions is to create a nurturing and supportive network and community for them to rely upon. It is also critical to educate leaders in corporations, government and academia about the benefits to be gained from increasing the percentage of STEM professionals from underrepresented groups. To this end, The Tapia Conference serves both functions, as it connects STEM students with STEM professionals, leaders, and academics who share the vision of a STEM workforce and community that is truly representative of the community in which we live.

  13. Leachate flow around a well in MSW landfill: Analysis of field tests using Richards model.

    Science.gov (United States)

    Slimani, R; Oxarango, L; Sbartai, B; Tinet, A-J; Olivier, F; Dias, D

    2017-05-01

    During the lifespan of a Municipal Solid Waste landfill, its leachate drainage system may get clogged. Then, as a consequence of rainfall, leachate generation and possibly leachate injection, the moisture content in the landfill increases to the point that a leachate mound could be created. Therefore, pumping the leachate becomes a necessary solution. This paper presents an original analysis of leachate pumping and injection in an instrumented well. The water table level around the well is monitored by nine piezometers which allow the leachate flow behaviour to be captured. A numerical model based on Richards equation and an exponential relationship between saturated hydraulic conductivity and depth is used to analyze the landfill response to pumping and injection. Decreasing permeability with depth appears to have a major influence on the behaviour of the leachate flow. It could have a drastic negative impact on the pumping efficiency with a maximum quasi-stationary pumping rate limited to approximately 1m 3 /h for the tested well and the radius of influence is less than 20m. The numerical model provides a reasonable description of both pumping and injection tests. However, an anomalous behaviour observed at the transition between pumping and recovery phases is observed. This could be due to a limitation of the Richards model in that it neglects the gas phase behaviour and other double porosity heterogeneous effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Wooing-Scenes in “Richard III”: A Parody of Courtliness?

    Directory of Open Access Journals (Sweden)

    Agnieszka Stępkowska

    2009-11-01

    Full Text Available In the famous opening soliloquy of Shakespeare’s Richard III, Richard mightily voices his repugnance to “fair well-spoken days” and their “idle pleasures”. He realizes his physical deformity and believes that it sets him apart from others. He openly admits that he is “not shaped for sportive tricks, nor made to court an amorous looking-glass”. Yet, his monstrosity constitutes more perhaps of his aggressive masculine exceptionality rather than of his deformity. Richard’s bullying masculinity manifests itself in his contempt for women. In the wooing scenes we clearly see his pugnacious pursuit of power over effeminate contentment by reducing women to mere objects. Additionally, those scenes are interesting from a psychological viewpoint as they brim over with conflicting emotions. Therefore, the paper explores two wooing encounters of the play, which belong the best examples of effective persuasion and also something we may refer to as ‘the power of eloquence’.

  15. Construction of Fluid - solid Coupling Model with Improved Richards - BP & Its Engineering Application

    Science.gov (United States)

    Xie, Chengyu; Jia, Nan; Shi, Dongping; Lu, Hao

    2017-10-01

    In order to study the slurry diffusion law during grouting, Richards unsaturated-saturated model was introduced, the definition of the grouting model is clear, the Richards model control equation was established, And the BP neural network was introduced, the improved fluid-solid coupling model was constructed, Through the use of saturated - unsaturated seepage flow model, As well as the overflow boundary iterative solution of the mixed boundary conditions, the free surface is calculated. Engineering practice for an example, with the aid of multi - field coupling analysis software, the diffusion law of slurry was simulated numerically. The results show that the slurry diffusion rule is affected by grouting material, initial pressure and other factors. When the slurry starts, it flows in the cracks along the upper side of the grouting hole, when the pressure gradient is reduced to the critical pressure, that is, to the lower side of the flow, when the slurry diffusion stability, and ultimately its shape like an 8. The slurry is spread evenly from the overall point of view, from the grouting mouth toward the surrounding evenly spread, it gradually reaches saturation by non-saturation, and it is not a purely saturated flow, when the slurry spread and reach a saturated state, the diffusion time is the engineering grouting time.

  16. Gamma radiation and radon concentration levels at the radioactive waste repositories 'Richard' and 'Bratrstvi'

    International Nuclear Information System (INIS)

    Berka, Z.; Sabol, J.; Janu, M.

    1998-01-01

    Owing to the fact that cosmic rays are shielded off, the photon equivalent dose rates in the corridors of the Richard repository are usually slightly lower than outside. However, in points close to barrels containing radioactive waste, the dose rates can reach values as high as tens of μSv/h. Because of high concentrations of natural radionuclides, the dose rates in the Bratrstvi repository is generally considerably higher, as much as 5 times the normal background value. Radon concentrations exhibit specific time variations which are modified by ventilation. Where ventilation is poor or absent, the radon concentrations are extremely high, viz. up to 30 and 300 kBq/m 3 in the Richard and Bratrstvi repositories, respectively. Personal exposure of workers depend on the total time spent underground and on the ventilation rate. While the contribution from photons can be kept below the relevant limits, the radon-related doses may be significant and even exceed the professional limits if no precautions are taken. (P.A.)

  17. The 1D Richards' equation in two layered soils: a Filippov approach to treat discontinuities

    Science.gov (United States)

    Berardi, Marco; Difonzo, Fabio; Vurro, Michele; Lopez, Luciano

    2018-05-01

    The infiltration process into the soil is generally modeled by the Richards' partial differential equation (PDE). In this paper a new approach for modeling the infiltration process through the interface of two different soils is proposed, where the interface is seen as a discontinuity surface defined by suitable state variables. Thus, the original 1D Richards' PDE, enriched by a particular choice of the boundary conditions, is first approximated by means of a time semidiscretization, that is by means of the transversal method of lines (TMOL). In such a way a sequence of discontinuous initial value problems, described by a sequence of second order differential systems in the space variable, is derived. Then, Filippov theory on discontinuous dynamical systems may be applied in order to study the relevant dynamics of the problem. The numerical integration of the semidiscretized differential system will be performed by using a one-step method, which employs an event driven procedure to locate the discontinuity surface and to adequately change the vector field.

  18. The Atacama Cosmology Telescope: A Measurement of the Primordial Power Spectrum

    Science.gov (United States)

    Hlozek, Renee; Dunkley, Joanna; Addison, Graeme; Appel, John William; Bond, J. Richard; Carvalho, C. Sofia; Das, Sudeep; Devlin, Mark J.; Duenner, Rolando; Essinger-Hileman, Thomas; hide

    2011-01-01

    We present constraints on the primordial power spectrum of adiabatic fluctuations using data from the 2008 Southern Survey of the Atacama Cosmology Telescope (ACT). The angular resolution of ACT provides sensitivity to scales beyond l = 1000 for resolution of multiple peaks in the primordial temperature power spectrum, which enables us to probe the primordial power spectrum of adiabatic scalar perturbations with wavenumbers up to k approx. = 0.2 Mp/c. We find no evidence for deviation from power-law fluctuations over two decades in scale. Matter fluctuations inferred from the primordial temperature power spectrum evolve over cosmic time and can be used to predict the matter power spectrum at late times; we illustrate the overlap of the matter power inferred from CMB measurements (which probe the power spectrum in thc linear regime) with existing probes of galaxy clustering, cluster abundances and weak lensing constraints on the primordial power. This highlights the range of scales probed by current measurement.s of the matter power spectrum.

  19. THE ATACAMA COSMOLOGY TELESCOPE: A MEASUREMENT OF THE PRIMORDIAL POWER SPECTRUM

    Energy Technology Data Exchange (ETDEWEB)

    Hlozek, Renee; Dunkley, Joanna; Addison, Graeme [Department of Astrophysics, Oxford University, Oxford OX1 3RH (United Kingdom); Appel, John William; Das, Sudeep; Essinger-Hileman, Thomas; Fowler, Joseph W.; Hajian, Amir; Hincks, Adam D. [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Bond, J. Richard [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Carvalho, C. Sofia [IPFN, IST, Av. RoviscoPais, 1049-001Lisboa, Portugal and RCAAM, Academy of Athens, Soranou Efessiou 4, 11-527 Athens (Greece); Devlin, Mark J.; Klein, Jeff [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Duenner, Rolando; Gallardo, Patricio [Departamento de Astronomia y Astrofisica, Facultad de Fisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Halpern, Mark; Hasselfield, Matthew [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Hilton, Matt [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Hughes, John P. [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854-8019 (United States); Irwin, Kent D. [NIST Quantum Devices Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305 (United States); and others

    2012-04-10

    We present constraints on the primordial power spectrum of adiabatic fluctuations using data from the 2008 Southern Survey of the Atacama Cosmology Telescope (ACT) in combination with measurements from the Wilkinson Microwave Anisotropy Probe and a prior on the Hubble constant. The angular resolution of ACT provides sensitivity to scales beyond l = 1000 for resolution of multiple peaks in the primordial temperature power spectrum, which enables us to probe the primordial power spectrum of adiabatic scalar perturbations with wavenumbers up to k {approx_equal} 0.2 Mpc{sup -1}. We find no evidence for deviation from power-law fluctuations over two decades in scale. Matter fluctuations inferred from the primordial temperature power spectrum evolve over cosmic time and can be used to predict the matter power spectrum at late times; we illustrate the overlap of the matter power inferred from cosmic microwave background measurements (which probe the power spectrum in the linear regime) with existing probes of galaxy clustering, cluster abundances, and weak-lensing constraints on the primordial power. This highlights the range of scales probed by current measurements of the matter power spectrum.

  20. Proteomic Analysis of Fetal Ovaries Reveals That Primordial Follicle Formation and Transition Are Differentially Regulated

    Directory of Open Access Journals (Sweden)

    Mengmeng Xu

    2017-01-01

    Full Text Available Primordial follicle formation represents a critical phase of the initiation of embryonic reproductive organ development, while the primordial follicle transition into primary follicle determines whether oestrus or ovulation will occur in female animals. To identify molecular mechanism of new proteins which are involved in ovarian development, we employed 2D-DIGE to compare the protein expression profiles of primordial follicles and primary follicles of fetal ovaries in pigs. Fetal ovaries were collected at distinct time-points of the gestation cycle (g55 and g90. The identified proteins at the g55 time-point are mainly involved in the development of anatomical structures [reticulocalbin-1 (RCN1, reticulocalbin-3 (RCN3], cell differentiation (actin, and stress response [heterogeneous nuclear ribonucleoprotein K (HNRNPK]. Meanwhile, at the g90 stage, the isolated proteins with altered expression levels were mainly associated with cell proliferation [major vault protein (MVP] and stress response [heat shock-related 70 kDa protein 2 (HSPA2]. In conclusion, our work revealed that primordial follicle formation is regulated by RCN1, RCN3, actin, and HNRNPK, while the primordial follicle transformation to primary follicle is regulated by MVP and HSPA2. Therefore, our results provide further information for the prospective understanding of the molecular mechanism(s involved in the regulation of the ovarian follicle development.

  1. Effects of rotation on the evolution of primordial stars

    Science.gov (United States)

    Ekström, S.; Meynet, G.; Chiappini, C.; Hirschi, R.; Maeder, A.

    2008-10-01

    Context: Although still beyond our observational abilities, Population III stars are interesting objects from many perspectives. They are responsible for the re-ionisation of the inter-galactic medium. They also left their chemical imprint in the early Universe, which can be deciphered in the most metal-poor stars in the halo of our Galaxy. Aims: Rotation has been shown to play a determinant role at very low metallicity, bringing heavy mass loss where almost none was expected. Is this still true when the metallicity strictly equals zero? The aim of our study is to answer this question, and to determine how rotation changes the evolution and the chemical signature of the primordial stars. Methods: We have calculated seven differentially-rotating stellar models at zero metallicity, with masses between 9 and 200 M⊙. For each mass, we also calculated a corresponding model without rotation. The evolution is followed up to the pre-supernova stage. Results: We find that Z=0 models rotate with an internal profile Ω(r) close to local angular momentum conservation, because of a very weak core-envelope coupling. Rotational mixing drives an H-shell boost due to a sudden onset of the CNO cycle in the shell. This boost leads to a high 14N production, which can be as much as 106 times higher than the production of the non-rotating models. Generally, the rotating models produce much more metal than their non-rotating counterparts. The mass loss is very low, even for the models that reach critical velocity during the main sequence. It may however have an impact on the chemical enrichment of the Universe, because some of the stars are supposed to collapse directly into black holes. They would contribute to the enrichment only through their winds. While in that case non-rotating stars would not contribute at all, rotating stars may leave an imprint on their surrounding. Due to the low mass loss and the weak coupling, the core retains a high angular momentum at the end of the

  2. Effect of accretion on primordial black holes in Brans-Dicke theory

    International Nuclear Information System (INIS)

    Nayak, B.; Singh, L. P.; Majumdar, A. S.

    2009-01-01

    We consider the effect of accretion of radiation in the early Universe on primordial black holes in Brans-Dicke theory. The rate of growth of a primordial black hole due to accretion of radiation in Brans-Dicke theory is considerably smaller than the rate of growth of the cosmological horizon, thus making available sufficient radiation density for the black hole to accrete causally. We show that accretion of radiation by Brans-Dicke black holes overrides the effect of Hawking evaporation during the radiation dominated era. The subsequent evaporation of the black holes in later eras is further modified due to the variable gravitational 'constant', and they could survive up to longer times compared to the case of standard cosmology. We estimate the impact of accretion on modification of the constraint on their initial mass fraction obtained from the γ-ray background limit from presently evaporating primordial black holes.

  3. arXiv Light Primordial Exotic Compact Objects as All Dark Matter

    CERN Document Server

    Raidal, Martti; Vaskonen, Ville; Veermäe, Hardi

    2018-06-13

    The radiation emitted by horizonless exotic compact objects (ECOs), such as wormholes, 2-2-holes, fuzzballs, gravastars, boson stars, collapsed polymers, superspinars etc., is expected to be strongly suppressed when compared to the radiation of black holes. If large primordial curvature fluctuations collapse into such objects instead of black holes, they do not evaporate or evaporate much slower than black holes and could thus constitute all of the dark matter with masses below $M < 10^{-16}M_\\odot.$ We reevaluate the relevant experimental constraints for light ECOs in this mass range and show that very large new parameter space down to ECO masses $M\\sim 10\\,{\\rm TeV}$ opens up for light primordial dark matter. A new dedicated experimental program is needed to test this mass range of primordial dark matter.

  4. Imprint of primordial non-Gaussianity on dark matter halo profiles

    Energy Technology Data Exchange (ETDEWEB)

    Dizgah, Azadeh Moradinezhad; Dodelson, Scott; Riotto, Antonio

    2013-09-01

    We study the impact of primordial non-Gaussianity on the density profile of dark matter halos by using the semi-analytical model introduced recently by Dalal {\\it et al.} which relates the peaks of the initial linear density field to the final density profile of dark matter halos. Models with primordial non-Gaussianity typically produce an initial density field that differs from that produced in Gaussian models. We use the path-integral formulation of excursion set theory to calculate the non-Gaussian corrections to the peak profile and derive the statistics of the peaks of non-Gaussian density field. In the context of the semi-analytic model for halo profiles, currently allowed values for primordial non-Gaussianity would increase the shapes of the inner dark matter profiles, but only at the sub-percent level except in the very innermost regions.

  5. Relativistic effects and primordial non-Gaussianity in the galaxy bias

    International Nuclear Information System (INIS)

    Bartolo, Nicola; Matarrese, Sabino; Riotto, Antonio

    2011-01-01

    When dealing with observables, one needs to generalize the bias relation between the observed galaxy fluctuation field to the underlying matter distribution in a gauge-invariant way. We provide such relation at second-order in perturbation theory adopting the local Eulerian bias model and starting from the observationally motivated uniform-redshift gauge. Our computation includes the presence of primordial non-Gaussianity. We show that large scale-dependent relativistic effects in the Eulerian bias arise independently from the presence of some primordial non-Gaussianity. Furthermore, the Eulerian bias inherits from the primordial non-Gaussianity not only a scale-dependence, but also a modulation with the angle of observation when sources with different biases are correlated

  6. Searching for Primordial Black Holes in the Radio and X-Ray Sky.

    Science.gov (United States)

    Gaggero, Daniele; Bertone, Gianfranco; Calore, Francesca; Connors, Riley M T; Lovell, Mark; Markoff, Sera; Storm, Emma

    2017-06-16

    We model the accretion of gas onto a population of massive primordial black holes in the Milky Way and compare the predicted radio and x-ray emission with observational data. We show that, under conservative assumptions on the accretion process, the possibility that O(10)M_{⊙} primordial black holes can account for all of the dark matter in the Milky Way is excluded at 5σ by a comparison with a Very Large Array radio catalog at 1.4 GHz and at ≃40σ by a comparison with a Chandra x-ray catalog (0.5-8 keV). We argue that this method can be used to identify such a population of primordial black holes with more sensitive future radio and x-ray surveys.

  7. Pregnancy in a woman with proportionate (primordial) dwarfism: a case report and literature review.

    Science.gov (United States)

    Vance, C E; Desmond, M; Robinson, A; Johns, J; Zacharin, M; Savarirayan, R; König, K; Warrillow, S; Walker, S P

    2012-09-01

    Primordial dwarfism is a rare form of severe proportionate dwarfism which poses significant challenges in pregnancy. A 27-year-old with primordial dwarfism (height 97 cm, weight 22 kg) and coexisting morbidities of familial hypercholesterolaemia and hypertension presented to our unit. Early pregnancy was complicated by difficult blood pressure control, sinus tachycardia, biochemical hyperthyroidism and insulin-requiring gestational diabetes. Delivery was indicated at 24 weeks with uncontrollable hypertension, progressive renal impairment and intrauterine growth restriction. A caesarean section was performed under general anaesthesia, resulting in the delivery of a 486 g male infant. This case highlights the difficulties of managing pregnancy in a woman with primordial dwarfism. Her limited capacity to respond to the physiological demands of pregnancy created a life-threatening situation, culminating in profound preterm birth.

  8. SPRAI: coupling of radiative feedback and primordial chemistry in moving mesh hydrodynamics

    Science.gov (United States)

    Jaura, O.; Glover, S. C. O.; Klessen, R. S.; Paardekooper, J.-P.

    2018-04-01

    In this paper, we introduce a new radiative transfer code SPRAI (Simplex Photon Radiation in the Arepo Implementation) based on the SIMPLEX radiation transfer method. This method, originally used only for post-processing, is now directly integrated into the AREPO code and takes advantage of its adaptive unstructured mesh. Radiated photons are transferred from the sources through the series of Voronoi gas cells within a specific solid angle. From the photon attenuation, we derive corresponding photon fluxes and ionization rates and feed them to a primordial chemistry module. This gives us a self-consistent method for studying dynamical and chemical processes caused by ionizing sources in primordial gas. Since the computational cost of the SIMPLEX method does not scale directly with the number of sources, it is convenient for studying systems such as primordial star-forming haloes that may form multiple ionizing sources.

  9. Ultrastructure of sheep primordial follicles cultured in the presence of indol acetic acid, EGF, and FSH

    DEFF Research Database (Denmark)

    Andrade, Evelyn Rabelo; Hyttel, Poul; Landim-Alvarenga, Fernanda Da Cruz

    2011-01-01

    The aim of this study was to investigate the ultrastructural characteristics of primordial follicles after culturing of sheep ovarian cortical slices in the presence of indol acetic acid (IAA), Epidermal Growth Factor (EGF), and FSH. To evaluate ultrastructure of primordial follicles cultured...... in MEM (control) or in MEM containing IAA, EGF, and FSH, fragments of cultured tissue were processes for transmission electron microscopy. Except in the control, primordial follicles cultured in supplemented media for 6¿d were ultrastructurally normal. They had oocyte with intact nucleus...... and the cytoplasm contained heterogeneous-sized lipid droplets and numerous round or elongated mitochondria with intact parallel cristae were observed. Rough endoplasmic reticulum (RER) was rarely found. The granulosa cells cytoplasm contained a great number of mitochondria and abundant RER. In conclusion...

  10. Isotopic evidence for primordial molecular cloud material in metal-rich carbonaceous chondrites

    DEFF Research Database (Denmark)

    van Kooten, Elishevah M. M. E.; Wielandt, Daniel Kim Peel; Schiller, Martin

    2016-01-01

    product of (26)Al. This correlation is interpreted as reflecting progressive thermal processing of in-falling (26)Al-rich molecular cloud material in the inner Solar System. The thermally unprocessed molecular cloud matter reflecting the nucleosynthetic makeup of the molecular cloud before the last......)Mg*-depleted and (54)Cr-enriched component. This composition is consistent with that expected for thermally unprocessed primordial molecular cloud material before its pollution by stellar-derived (26)Al. The (26)Mg* and (54)Cr compositions of bulk metal-rich chondrites require significant amounts (25......-50%) of primordial molecular cloud matter in their precursor material. Given that such high fractions of primordial molecular cloud material are expected to survive only in the outer Solar System, we infer that, similarly to cometary bodies, metal-rich carbonaceous chondrites are samples of planetesimals...

  11. Features in the primordial power spectrum of double D-term inflation

    International Nuclear Information System (INIS)

    Lesgourgues, Julien

    2000-01-01

    Recently, there has been some interest for building supersymmetric models of double inflation. These models, realistic from a particle physics point of view, predict a broken-scale-invariant power spectrum of primordial cosmological perturbations, that may explain eventual nontrivial features in the present matter power spectrum. In previous works, the primordial spectrum was calculated using analytic slow-roll approximations. However, these models involve a fast second-order phase transition during inflation, with a stage of spinodal instability, and an interruption of slow-roll. For our previous model of double D-term inflation, we simulate numerically the evolution of quantum fluctuations, taking into account the spinodal modes, and we show that the semiclassical approximation can be employed even during the transition, due to the presence of a second inflaton field. The primordial power spectrum possesses a rich structure, and possibly, a non-Gaussian spike on observable scales

  12. Quantum mechanics in the cold war; Quantenmechanik im Kalten Krieg. David Bohm und Richard Feynman

    Energy Technology Data Exchange (ETDEWEB)

    Forstner, C.

    2007-07-01

    In the middle of the 20th century David Bohm and Richard Feynman developed two fundamentally different approaches of modern quantum mechanics: Bohm a realistic interpretation by means of hidden parameters and Feynman the path-integral formalism. This is by this more remarakable, because both physicists started from similar conditions and originated from similar connections. By its comparing approach this study presents more than a contribution to the history of the quantum theory. By the question for the social and cultural conditions of the formation of theories it is furthermore of science-sociological and science-theoretical interest. The in the beginning similar and later different binding of both scientists into the scientific community allows furthermore to study, which adapting pressure each group puts on the individual scientist and the fundamental parts of his research, and which new degrees of freedom in the formation of theories arise, when this constraint is cancelled.

  13. Richard Arwed Pfeifer - a pioneer of 'medical pedagogy' and an opponent of Paul Schroder.

    Science.gov (United States)

    Steinberg, Holger; Carius, Dirk; Himmerich, Hubertus

    2013-12-01

    Richard Arwed Pfeifer (1877-1957) was one of the initiators and foster fathers of the renowned child-psychiatric and special needs education workgroup at Leipzig University under Paul Schröder (1873-1941) in the 1920s and 1930s. This paper is an account of their dispute concerning the interrelations between child and adolescent psychiatry and special needs education, as well as their disagreement about whether adolescent psychopaths should be admitted to specialized child psychiatric wards or elsewhere. Moreover, Pfeifer questioned the practical relevance of the separation of constitutional and environmentally-based psychopathy and fought eugenic research, which he found incompatible with the ethics of his profession as a remedial teacher and child psychiatrist.

  14. Destruction of the Phoenix/Hibiscus and Barringtonia racemosa Communities at Richards Bay, Natal, South Africa

    Directory of Open Access Journals (Sweden)

    P. J. Weisser

    1982-10-01

    Full Text Available The destruction of the Phoenix!Hibiscus and Barringtonia racemosa Communities described by Venter in 1972 on the southern shores of Richards Bay is reported. The cause was the artificial openingof a new mouth about 5,5 km south of the original mouth, which increased tidal range and salinity. These swamp communities occupied a narrow band about 6 ha in area behind the Bruguiera gymnorrhiza Community. An estimated 95 % of the communities was affected and only on the landward border were some isolated remnants of species such as Acrostichum aureum, Hibiscus tiliaceus and Phoenix reclinata detected .Young stands of  Phragmites australis, seedlings of  Bruguiera gymnorrhiza and Avicennia marina and epipelic algae are recoIonizing the affected area.

  15. Marie-Christine Agosto. Richard Brautigan. Les fleurs de néant.

    Directory of Open Access Journals (Sweden)

    Jean-Bernard Basse

    2006-04-01

    Full Text Available Richard Brautigan, si on lui reconnaît un certain humour, est souvent associé avec condescendance au phénomène hippy et considéré comme un auteur démodé, superficiel. Celui qui écrivait dans Cahier d’un Retour de Troie : « Les mots sont des fleurs de néant » est pourtant l’un de ces écrivains que l’on pourrait qualifier de mineurs essentiels, et seuls ceux qui l’ont peu ou mal lu s’étonneront de ce que Marie-Christine Agosto ait choisi de donner comme sous-titre « Les fleurs de néant » au pet...

  16. Harmonic analysis, partial differential equations and applications in honor of Richard L. Wheeden

    CERN Document Server

    Franchi, Bruno; Lu, Guozhen; Perez, Carlos; Sawyer, Eric

    2017-01-01

    This is a collection of contributed papers by many eminent Harmonic Analysts and specialists of Partial Differential equations. The papers focus on weighted norm equalities for singular integrals, focusing wave equations, degenerate elliptic equations, Navier-Stokes flow in two dimensions and Poincare-Sobolev inequalities in the setting of metric spaces equipped with measures among others. Many topics considered in this volume stem from the interests of Richard L. Wheeden whose contributions to Potential Theory, singular integral theory and degenerate elliptic PDE theory this volume honors. Luis Caffarelli, Sagun Chanillo, Bruno Franchi, Cristian Guttierez, Xiaojun Huang, Carlos Kenig, Ermanno Lanconelli, Eric Sawyer and Alexander Volberg, are some of the many contributors to this volume. .

  17. A critical review of Richard Lynn's reports on reaction time and race.

    Science.gov (United States)

    Thomas, Drew M

    2011-01-01

    In the early 1990s, psychologist Richard Lynn published papers documenting average reaction times and decision times in samples of nine-year-olds taken from across the world. After summarizing these data, Lynn interpreted his results as evidence of national and racial differences in decision time and general intelligence. Others have also interpreted Lynn's data as evidence of racial differences in decision time and intelligence. However, comparing Lynn's summaries with his original reports shows that Lynn misreported and omitted some of his own data. Once these errors are fixed the rankings of nations in Lynn's datasets are unstable across different decision time measures. This instability, as well as within-race heterogeneity and between-race overlap in decision times, implies that Lynn's reaction time data do not permit generalizations about the decision times and intelligence of people of different races.

  18. Analytical and grid-free solutions to the Lighthill-Whitham-Richards traffic flow model

    KAUST Repository

    Mazaré , Pierre Emmanuel; Dehwah, Ahmad H.; Claudel, Christian G.; Bayen, Alexandre M.

    2011-01-01

    In this article, we propose a computational method for solving the Lighthill-Whitham-Richards (LWR) partial differential equation (PDE) semi-analytically for arbitrary piecewise-constant initial and boundary conditions, and for arbitrary concave fundamental diagrams. With these assumptions, we show that the solution to the LWR PDE at any location and time can be computed exactly and semi-analytically for a very low computational cost using the cumulative number of vehicles formulation of the problem. We implement the proposed computational method on a representative traffic flow scenario to illustrate the exactness of the analytical solution. We also show that the proposed scheme can handle more complex scenarios including traffic lights or moving bottlenecks. The computational cost of the method is very favorable, and is compared with existing algorithms. A toolbox implementation available for public download is briefly described, and posted at http://traffic.berkeley.edu/project/downloads/lwrsolver. © 2011 Elsevier Ltd.

  19. Richard Wrangham. Catching fire. How cooking made us Human. Basic Books (Perseus Books Group

    Directory of Open Access Journals (Sweden)

    Claude-Marcel Hladik

    2009-11-01

    Full Text Available L’histoire de l’émergence de l’homme est remise en cause par cet ouvrage puisque jusqu’à présent la plupart des anthropologues et des paléontologues s’accordaient pour faire remonter à environ 500.000 ans les premières utilisations du feu pour la cuisson des aliments par le genre Homo. Les arguments présentés par Richard Wrangham dans son dernier ouvrage nous font remonter aux deux derniers millions d’années. Wrangham et ses collègues avaient publié, dès 1999, les résultats de fouilles au cou...

  20. Analytical and grid-free solutions to the Lighthill-Whitham-Richards traffic flow model

    KAUST Repository

    Mazaré, Pierre Emmanuel

    2011-12-01

    In this article, we propose a computational method for solving the Lighthill-Whitham-Richards (LWR) partial differential equation (PDE) semi-analytically for arbitrary piecewise-constant initial and boundary conditions, and for arbitrary concave fundamental diagrams. With these assumptions, we show that the solution to the LWR PDE at any location and time can be computed exactly and semi-analytically for a very low computational cost using the cumulative number of vehicles formulation of the problem. We implement the proposed computational method on a representative traffic flow scenario to illustrate the exactness of the analytical solution. We also show that the proposed scheme can handle more complex scenarios including traffic lights or moving bottlenecks. The computational cost of the method is very favorable, and is compared with existing algorithms. A toolbox implementation available for public download is briefly described, and posted at http://traffic.berkeley.edu/project/downloads/lwrsolver. © 2011 Elsevier Ltd.

  1. Book review: Unholy trinity: The IMF, World Bank and WTO Richard Peet

    Directory of Open Access Journals (Sweden)

    M Breitenbach

    2014-05-01

    Full Text Available In this timely book Richard Peet and his team lay the foundation with an excellent analysis of the process of globalisation and the resultant emergence of the global economy. The authors are especially critical of the increasing influence of institutions like the International Monetary Fund (IMF, World Bank and World Trade Organisation (WTO on the economy and the consequences experienced by peoples, cultures and the environment. The single ideology of neo-liberalism is blamed for the undesirable outcomes. This book considers concepts of power, political interest, hegemony, discourse, responsibility and the power of practicality, in critically examining the IMF, World Bank and WTO. The conclusion is reached that “all three institutions play roles greatly different from those originally agreed to under the charters that set them up”.

  2. Femineidad y ficción en la obra operística de Richard Strauss

    Directory of Open Access Journals (Sweden)

    María José Sánchez Usón

    2014-01-01

    Full Text Available Tras la muerte de Wagner y Brahms, Richard Straussemergió como uno de los compositores más importantesy populares de la música del siglo XX. Su trayectoria vitaly profesional, azarosa y turbulenta, al igual que las décadasque vivió, estuvo marcada por la realidad femenina.Es innegable que las mujeres de la vida de Strauss, todasde fuerte y distintiva personalidad, dejaron en él huellastan hondas que fue necesario llevarlas a escena, no sólocomo una aportación valiosa a la tipología caracterológicafemenina, sino también como un ejercicio terapéuticopersonal. Así, mujeres reales y mujeres ficticias se confundenen sus obras en un proceso creativo único: el delhombre-artista.

  3. BACK TO THE ORIGINS OF THE REPUDIATION OF WUNDT: OSWALD KÜLPE AND RICHARD AVENARIUS.

    Science.gov (United States)

    Russo Krauss, Chiara

    2017-01-01

    This essay provides a fresh account of the break between Oswald Külpe and his master Wilhelm Wundt. Kurt Danziger's reconstruction of the "repudiation" of Wundt, which has become the canon for this significant episode of history of psychology, focused on the supposed influence of Ernst Mach on this set of events, overshadowing the other exponent of Empiriocriticism: Richard Avenarius. Analyzing archival documents and examining anew the primary sources, the paper shows that Avenarius was himself a member of Wundt's circle, and that his "repudiation" of the master paved the way for Külpe. The essay points out the original anti-Wundtian aspects of Avenarius' notion of psychology, thus showing how they were then adopted by Külpe. © 2016 Wiley Periodicals, Inc.

  4. Lucien Cuénot, Richard Goldschmidt y Miquel Crusafont Pairó

    Directory of Open Access Journals (Sweden)

    Casinos, Adrià

    2016-06-01

    Full Text Available An unpublished text, corresponding to a communication done by Crusafont Pairó is analysed. The communication is strongly critical with Cuénot’s necrology published previously by Goldschmidt, where he regrets the teleological ideas on evolution that Cuénot maintained in the last years of his life.Se analiza un texto inédito de Miquel Crusafont Pairó, correspondiente a comunicación que llevó a cabo en la Fundació Bosch i Cardellach, sobre la necrológica de Lucien Cuénot publicada por Richard Goldschmidt. La comunicación es un fuerte ataque a Goldschmidt por sus críticas a la deriva teleológica de Cuénot en los últimos años de su vida.

  5. On the non-Gaussian correlation of the primordial curvature perturbation with vector fields

    DEFF Research Database (Denmark)

    Kumar Jain, Rajeev; Sloth, Martin Snoager

    2013-01-01

    We compute the three-point cross-correlation function of the primordial curvature perturbation generated during inflation with two powers of a vector field in a model where conformal invariance is broken by a direct coupling of the vector field with the inflaton. If the vector field is identified...... with the electromagnetic field, this correlation would be a non-Gaussian signature of primordial magnetic fields generated during inflation. We find that the signal is maximized for the flattened configuration where the wave number of the curvature perturbation is twice that of the vector field and in this limit...

  6. Microcephalic osteodysplastic primordial dwarfism, with the fascinating history of "Mademoiselle Crachami".

    Science.gov (United States)

    Bozkaya, O Giray

    2013-01-01

    This review critically examines the findings which characterize the dysmorphic, radiologic and behavioral phenotype of Microcephalic Osteodysplastic Primordial Dwarfism (MOPD) and has an historical perspective on it. MOPD is a group of primordial dwarfism syndromes with prenatal onset growth retardation, a typical craniofacial appearance and behavioral phenotype. In 1959, Mann and Russell have described the first case in a detailed report, and named "microcephalic midget of extreme type". In their report; based on historical records and a small painting, they pointed "Mademoiselle Crachami" as the oldest known case.

  7. Implications of a primordial origin for the dispersion in D/H in quasar absorption systems.

    Science.gov (United States)

    Copi, C J; Olive, K A; Schramm, D N

    1998-03-17

    We explore the difficulties with a primordial origin of variations of D/H in quasar absorption systems. In particular we examine options such as a very large-scale inhomogeneity in the baryon content of the universe. We show that very large-scale (much larger than 1 Mpc) isocurvature perturbations are excluded by current cosmic microwave background observations. Smaller-scale ad hoc perturbations (approximately 1 Mpc) still may lead to a large dispersion in primordial abundances but are subject to other constraints.

  8. Laboratory approaches of nuclear reactions involved in primordial and stellar nucleosynthesis

    International Nuclear Information System (INIS)

    Rolfs, C.; California Inst. of Tech., Pasadena

    1986-01-01

    Laboratory-based studies of primordial and stellar nucleosynthesis are reviewed, with emphasis on the nuclear reactions induced by charged particles. The analytical approach used to investigate nuclear reactions associated with stellar reactions is described, as well as the experimental details and procedures used to investigate nuclear reactions induced by charged particles. The present knowledge of some of the key reactions involved in primordial nucleosynthesis is discussed, along with the progress and problems of nuclear reactions involved in the hydrogen and helium burning phases of a star. Finally, a description is given of new experimental techniques which might be useful for future experiments in the field of nuclear astrophysics. (U.K.)

  9. Digging Deeper: Observing Primordial Gravitational Waves below the Binary-Black-Hole-Produced Stochastic Background.

    Science.gov (United States)

    Regimbau, T; Evans, M; Christensen, N; Katsavounidis, E; Sathyaprakash, B; Vitale, S

    2017-04-14

    The merger rate of black hole binaries inferred from the detections in the first Advanced LIGO science run implies that a stochastic background produced by a cosmological population of mergers will likely mask the primordial gravitational wave background. Here we demonstrate that the next generation of ground-based detectors, such as the Einstein Telescope and Cosmic Explorer, will be able to observe binary black hole mergers throughout the Universe with sufficient efficiency that the confusion background can potentially be subtracted to observe the primordial background at the level of Ω_{GW}≃10^{-13} after 5 years of observation.

  10. Inflation with primordial broken power law spectrum as an alternative to the concordance cosmological model

    International Nuclear Information System (INIS)

    Pandolfi, Stefania; Giusarma, Elena; Lattanzi, Massimiliano; Melchiorri, Alessandro

    2010-01-01

    We consider cosmological models with a non-scale-invariant spectrum of primordial perturbations and assess whether they represent a viable alternative to the concordance ΛCDM model. We find that in the framework of a model selection analysis, the WMAP and 2dF data do not provide any conclusive evidence in favor of one or the other kind of model. However, when a marginalization over the entire space of nuisance parameters is performed, models with a modified primordial spectrum and Ω Λ =0 are strongly disfavored.

  11. Microwave background anisotropies and the primordial spectrum of cosmological density fluctuations

    International Nuclear Information System (INIS)

    Suto, Yasushi; Gouda, Naoteru; Sugiyama, Naoshi

    1990-01-01

    Microwave background anisotropies in various cosmological scenarios are studied. In particular, the extent to which nonscale-invariant spectra of the primordial density fluctuations are consistent with the observational upper limits is examined. The resultant constraints are summarized as contours on (n, Omega)-plane, where n is the power-law index of the primordial spectrum of density fuctuations and Omega is the cosmological density parameter. They are compared also with the constraints from the cosmic Mach number test, recently proposed by Ostriker and Suto (1990). The parameter regions which pass both tests are not consistent with the theoretical prejudice inspired by the inflationary model. 44 refs

  12. From electroweak theory to the primordial universe. A synthesis of some experimental results; De la theorie electrofaible a l'univers primordial. Synthese de quelques resultats experimentaux

    Energy Technology Data Exchange (ETDEWEB)

    Ealet, A

    2004-12-15

    Particle physic is based on a theory which can be tested on the current large colliders. Measurements are in a very good agreement with this electroweak theory and no deviation is observed to indicate new physics. What is surprising today is that none of its results agrees with what is known from our universe, neither to explain the primordial baryogenesis, neither to explain the acceleration of the expansion of the Universe. In this work, I come back on some results obtained in the Lep collider, to test the electroweak theory (Higgs and W boson production) and on some measurements of CP violation. I compare them with what can be extrapolated in term of primordial baryogenesis and dark energy density and show that there is no possible agreement in the Standard Model. I finish by some experimental and theoretical views to answer this fundamental question. (author)

  13. Nothing Risked, Nothing Gained: Richard Powers' Gain and the Horizon of Risk

    Directory of Open Access Journals (Sweden)

    Aaron Jaffe

    2010-02-01

    Full Text Available Cet article interprète Gain, sixième roman de Richard Powers, à la lumière du concept de « seconde modernité » proposé par le sociologue allemand Ulrich Beck. Ce concept souligne la dissémination du risque et la manière dont celle-ci invalide les marchés conclus par la « première modernité » entre l’avenir et le présent, entre l’intérieur du corps et l’extérieur. Cet article entend montrer que Beck fournit un cadre interprétatif utile à la compréhension de ces rapports, hors des impasses catégorielles que suscite l’opposition entre les deux régimes narratifs à l’œuvre dans le texte : le récit biographique, local et individuel, de la maladie de Laura Rowen Bodey, et l’histoire collective de l’entreprise Clare devenue conglomérat.This essay interprets Richard Powers' sixth novel Gain with reference to the German sociologist Ulrich Beck's concept of “second modernity.” The concept underscores the dispersal of risk and how it shreds promissory notes understood in “first modernity” between the future and present and the insides and outsides of the body. It argues that Beck supplies an apt interpretive framework for understanding these relationships and overcoming the categorical impasses between the two narrative words at work in Power's novel, the biographical situatedness of Laura Rowen Bodey's illness and the corporate history of the Clare conglomerate.

  14. Newtonian nudging for a Richards equation-based distributed hydrological model

    Science.gov (United States)

    Paniconi, Claudio; Marrocu, Marino; Putti, Mario; Verbunt, Mark

    The objective of data assimilation is to provide physically consistent estimates of spatially distributed environmental variables. In this study a relatively simple data assimilation method has been implemented in a relatively complex hydrological model. The data assimilation technique is Newtonian relaxation or nudging, in which model variables are driven towards observations by a forcing term added to the model equations. The forcing term is proportional to the difference between simulation and observation (relaxation component) and contains four-dimensional weighting functions that can incorporate prior knowledge about the spatial and temporal variability and characteristic scales of the state variable(s) being assimilated. The numerical model couples a three-dimensional finite element Richards equation solver for variably saturated porous media and a finite difference diffusion wave approximation based on digital elevation data for surface water dynamics. We describe the implementation of the data assimilation algorithm for the coupled model and report on the numerical and hydrological performance of the resulting assimilation scheme. Nudging is shown to be successful in improving the hydrological simulation results, and it introduces little computational cost, in terms of CPU and other numerical aspects of the model's behavior, in some cases even improving numerical performance compared to model runs without nudging. We also examine the sensitivity of the model to nudging term parameters including the spatio-temporal influence coefficients in the weighting functions. Overall the nudging algorithm is quite flexible, for instance in dealing with concurrent observation datasets, gridded or scattered data, and different state variables, and the implementation presented here can be readily extended to any of these features not already incorporated. Moreover the nudging code and tests can serve as a basis for implementation of more sophisticated data assimilation

  15. Preservation of primordial follicles from lions by slow freezing and xenotransplantation of ovarian cortex into an immunodeficient mouse

    DEFF Research Database (Denmark)

    Wiedemann, C; Hribal, R; Ringleb, J

    2012-01-01

    follicles within the ovarian cortex survived culture when the original sample was from a young healthy lion collected immediately after euthanasia. Within the xenotransplants, the number of primordial follicles decreased after 28 days by 20%, but the relation between primordial and growing follicles changed...

  16. Kitchenette: Hell or Home? Different"Kitchenette"Images Created by Richard Wright and Gwendolyn Brooks%Kitchenette:Hell or Home?Different"Kitchenette"Images Created by Richard Wright and Gwendolyn Brooks

    Institute of Scientific and Technical Information of China (English)

    肖志宏

    2017-01-01

    How the southern black migrants navigate and survive the northern urban space is a question profoundly explored and realistically documented in many migration narratives in African American literature. This paper concentrates on the image of Chicago"kitchenette"in the works of Richard Wright and Gwendolyn Brooks, in an attempt to demonstrate the different inter-pretations of migrant spaces on the urban landscape.

  17. Learning with leaders.

    Science.gov (United States)

    Bunkers, Sandra S

    2009-01-01

    This column focuses on ideas concerning leaders and leadership. The author proposes that leadership is about showing up and participating with others in doing something. "Mandela: His 8 Lessons of Leadership" by Richard Stengel is explored in light of selected philosophical writings, literature on nursing leadership, and nurse theorist Rosemarie Rizzo Parse's humanbecoming leading-following model. Teaching-learning questions are then posed to stimulate further reflection on the lessons of leadership.

  18. Richard J. Hill, Picturing Scotland through the Waverley Novels: Walter Scott and the Origins of the Victorian Illustrated Novel.

    Directory of Open Access Journals (Sweden)

    Jacqueline Irene Cannata

    2012-10-01

    Full Text Available Richard J. Hill, Picturing Scotland through the Waverley Novels: Walter Scott and the Origins of the Victorian Illustrated Novel . Farnham, Surrey, and Burlington, VT: Ashgate, 2010. Pp. 236. ISBN 978-0-7546-6806-0. US$99.99.

  19. Dr. Richard J. Whelan: Seeing the Field of Emotional and Behavior Disorders through the Lens of a Pioneer

    Science.gov (United States)

    Kaff, Marilyn S.; Teagarden, Jim; Zabel, Robert H.

    2011-01-01

    Dr. Richard J. Whelan is a distinguished professor emeritus at the University of Kansas. His earliest professional experiences were at the Children's Hospital (Southard School) of the Menninger Clinic, where he served as a recreational therapist, teacher, and director of education. During his career at the University of Kansas and the KU Medical…

  20. A soil moisture accounting-procedure with a Richards' equation-based soil texture-dependent parameterization

    Science.gov (United States)

    Given a time series of potential evapotranspiration and rainfall data, there are at least two approaches for estimating vertical percolation rates. One approach involves solving Richards' equation (RE) with a plant uptake model. An alternative approach involves applying a simple soil moisture accoun...

  1. Richards Bay Mesometeorological Data – Vertical profiles of air temperature and wind velocity and surface wind statistics.

    CSIR Research Space (South Africa)

    Scholtz, MT

    1978-03-01

    Full Text Available This report details the experimental methods and data obtained in the course of a study of the movement of stable air over a complex region. The field work was carried out in the Richards Bay area on the Natal Coast during the period May to August...

  2. Muusikamaailm : Suur klaveripidu Ruhrimaal. Kissingeni festival tippudega. Sulasoli 80. aastapäev. Richard Rodgers 100 / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    2002-01-01

    6. juuni-17. augustini Ruhrimaal toimuvast klaverifestivalist. Bad Kissingenis toimuvatest suvepidustustest. Soome Lauljate ja Mängijate Liit tähistab asutamise 80. aastapäeva. Helilooja Richard Rodgersi sünnist möödub 100 aastat

  3. Efficacy Quotient Tindakan ESWL Piezolith Richard Wolf 3000 pada Penderita Batu Ureter di RSUPN Dr. Cipto Mangunkusumo, 2008–2011

    Directory of Open Access Journals (Sweden)

    Vinny Verdini

    2017-01-01

    Full Text Available Extracorporeal shockwave lithotripsy (ESWL saat ini telah menjadi metode yang paling umum dalam tatalaksana aktif batu ureter. Sejak Maret 2008, RSCM telah menggunakan mesin ESWL piezolith 3000 richard wolf dan belum diketahui nilai efficacy quotient (EQ. Penelitian ini bertujuan untuk menentukan nilai EQ dari tindakan ESWL menggunakan mesin piezolith richard wolf 3000 pada batu ureter dan hubungan angka bebas batu dengan lokasi batu, jumlah batu, beban batu, opasitas batu, obstruksi, dan fungsi ginjal. Studi cross sectional ini dilakukan pada bulan Januari 2008-Desember 2011 dan data dianalisis dengan statistik multivariat. Terdapat 113 (95 % dari 119 pasien yang dinyatakan bebas batu setelah tindakan ESWL pertama. Didapatkan nilai EQ 0,89. Hanya ukuran batu yang mempengaruhi angka bebas batu dalam penelitian ini (p<0,05. Disimpulkan bahwa prosedur ESWL menggunakan mesin richard wolf piezolith 3000 memiliki nilai EQ dan angka bebas batu yang lebih baik daripada mesin-mesin sebelumnya dan mesin lain yang sejenis. Faktor yang mempengaruhi keberhasilan adalah ukuran batu ureter yang ditatalaksana.Kata Kunci: batu ureter, ESWL, efficacy quotient, angka bebas batu. Efficacy Quotient of ESWL Piezolith Richard Wolf 3000 Machine in Patientswith Ureteral Stones in Dr. Cipto MangunkusumoNational Hospital 2008 - 2011AbstractExtracorporeal shockwave lithotripsy (ESWL is the most common method of ureteral stone management. Since 2008, RSCM has ben using ESWL piezolith 3000 richard wolf and efficacy quotient (EQ value have not yet studied. The study aims was to determine the efficacy quotient (EQ of ESWL using piezolith richard wolf 3000 machine for ureteral stone by analyzing free-stone rate with location of stones, number of stones, stone burden, stone opacity, obstruction and kidney function. This cross sectional study was carried out in January 2008-December 2011, with multivariate analytical study. Ninety five percent (n=113 of 119 patients were

  4. The future of primordial features with large-scale structure surveys

    International Nuclear Information System (INIS)

    Chen, Xingang; Namjoo, Mohammad Hossein; Dvorkin, Cora; Huang, Zhiqi; Verde, Licia

    2016-01-01

    Primordial features are one of the most important extensions of the Standard Model of cosmology, providing a wealth of information on the primordial Universe, ranging from discrimination between inflation and alternative scenarios, new particle detection, to fine structures in the inflationary potential. We study the prospects of future large-scale structure (LSS) surveys on the detection and constraints of these features. We classify primordial feature models into several classes, and for each class we present a simple template of power spectrum that encodes the essential physics. We study how well the most ambitious LSS surveys proposed to date, including both spectroscopic and photometric surveys, will be able to improve the constraints with respect to the current Planck data. We find that these LSS surveys will significantly improve the experimental sensitivity on features signals that are oscillatory in scales, due to the 3D information. For a broad range of models, these surveys will be able to reduce the errors of the amplitudes of the features by a factor of 5 or more, including several interesting candidates identified in the recent Planck data. Therefore, LSS surveys offer an impressive opportunity for primordial feature discovery in the next decade or two. We also compare the advantages of both types of surveys.

  5. Meier-Gorlin syndrome: Growth and secondary sexual development of a microcephalic primordial dwarfism disorder

    NARCIS (Netherlands)

    de Munnik, Sonja A.; Otten, Barto J.; Schoots, Jeroen; Bicknell, Louise S.; Aftimos, Salim; Al-Aama, Jumana Y.; van Bever, Yolande; Bober, Michael B.; Borm, George F.; Clayton-Smith, Jill; Deal, Cheri L.; Edrees, Alaa Y.; Feingold, Murray; Fryer, Alan; van Hagen, Johanna M.; Hennekam, Raoul C.; Jansweijer, Maaike C. E.; Johnson, Diana; Kant, Sarina G.; Opitz, John M.; Ramadevi, A. Radha; Reardon, Willie; Ross, Alison; Sarda, Pierre; Schrander-Stumpel, Constance T. R. M.; Sluiter, A. Erik; Temple, I. Karen; Terhal, Paulien A.; Toutain, Annick; Wise, Carol A.; Wright, Michael; Skidmore, David L.; Samuels, Mark E.; Hoefsloot, Lies H.; Knoers, Nine V. A. M.; Brunner, Han G.; Jackson, Andrew P.; Bongers, Ernie M. H. F.

    2012-01-01

    MeierGorlin syndrome (MGS) is a rare autosomal recessive disorder characterized by primordial dwarfism, microtia, and patellar aplasia/hypoplasia. Recently, mutations in the ORC1, ORC4, ORC6, CDT1, and CDC6 genes, encoding components of the pre-replication complex, have been identified. This complex

  6. Meier-Gorlin syndrome: Growth and secondary sexual development of a microcephalic primordial dwarfism disorder

    NARCIS (Netherlands)

    de Munnik, S.A.; Otten, B.J.; Schoots, J.; Bicknell, L.S.; Aftimos, S.; Al-Aama, J.Y.; van Bever, Y.; Bober, M.B.; Borm, G.F.; Clayton-Smith, J.; Deal, C.L.; Edrees, A.Y.; Feingold, M.; Fryer, A.; van Hagen, J.M.; Hennekam, R.C.M.; Jansweijer, M.C.E.; Johnson, D.; Kant, S.G.; Opitz, J.M.; Ramadevi, A.R.; Reardon, W.; Ross, A.; Sarda, P.; Schrander-Stumpel, C.T.R.M.; Sluiter, A.E.; Temple, I.K.; Terhal, P.A.; Toutain, A.; Wise, C.A.; Wright, M.; Skidmore, D.L.; Samuels, M.E.; Hoefsloot, L.H.; Knoers, N.V.A.M.; Brunner, H.G.; Jackson, A.P.; Bongers, M.H.F.

    2012-01-01

    Meier-Gorlin syndrome (MGS) is a rare autosomal recessive disorder characterized by primordial dwarfism, microtia, and patellar aplasia/hypoplasia. Recently, mutations in the ORC1, ORC4, ORC6, CDT1, and CDC6 genes, encoding components of the pre-replication complex, have been identified. This

  7. The Primordial Soup Algorithm : a systematic approach to the specification of parallel parsers

    NARCIS (Netherlands)

    Janssen, Wil; Janssen, W.P.M.; Poel, Mannes; Sikkel, Nicolaas; Zwiers, Jakob

    1992-01-01

    A general framework for parallel parsing is presented, which allows for a unitied, systematic approach to parallel parsing. The Primordial Soup Algorithm creates trees by allowing partial parse trees to combine arbitrarily. By adding constraints to the general algorithm, a large, class of parallel

  8. Planck 2015 results: XVII. Constraints on primordial non-Gaussianity

    DEFF Research Database (Denmark)

    Ade, P. A R; Aghanim, N.; Arnaud, M.

    2016-01-01

    The Planck full mission cosmic microwave background (CMB) temperature and E-mode polarization maps are analysed to obtain constraints on primordial non-Gaussianity (NG). Using three classes of optimal bispectrum estimators – separable template-fitting (KSW), binned, and modal – we obtain consiste...

  9. The Observational Determination of the Primordial Helium Abundance: a Y2K Status Report

    Science.gov (United States)

    Skillman, Evan D.

    I review observational progress and assess the current state of the determination of the primordial helium abundance, Yp. At present there are two determinations with non-overlapping errors. My impression is that the errors have been under-estimated in both studies. I review recent work on errors assessment and give suggestions for decreasing systematic errors in future studies.

  10. Gravitational wave production by Hawking radiation from rotating primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Ruifeng; Kinney, William H.; Stojkovic, Dejan, E-mail: ruifengd@buffalo.edu, E-mail: whkinney@buffalo.edu, E-mail: ds77@buffalo.edu [HEPCOS, Department of Physics, SUNY, University at Buffalo, Buffalo, NY 14260-1500 (United States)

    2016-10-01

    In this paper we analyze in detail a rarely discussed question of gravity wave production from evaporating primordial black holes. These black holes emit gravitons which are, at classical level, registered as gravity waves. We use the latest constraints on their abundance, and calculate the power emitted in gravitons at the time of their evaporation. We then solve the coupled system of equations that gives us the evolution of the frequency and amplitude of gravity waves during the expansion of the universe. The spectrum of gravitational waves that can be detected today depends on multiple factors: fraction of the total energy density which was occupied by primordial black holes, the epoch in which they were formed, and quantities like their mass and angular momentum. We conclude that very small primordial black holes which evaporate before the big-bang nucleosynthesis emit gravitons whose spectral energy fraction today can be as large as 10{sup −7.5}. On the other hand, those which are massive enough so that they still exist now can yield a signal as high as 10{sup −6.5}. However, typical frequencies of the gravity waves from primordial black holes are still too high to be observed with the current and near future gravity wave observations.

  11. Genetic Testing for Type 2 Diabetes in High-Risk Children: the Case for Primordial Prevention

    Directory of Open Access Journals (Sweden)

    Jennifer Wessel

    2017-09-01

    Full Text Available Extensive research now demonstrates that lifestyle modification can significantly lower risk of developing type 2 diabetes (T2D in high-risk adults. In children, the evidence for lifestyle modification is not as robust, but the rapidly rising rate of obesity in children coupled with the substantial difficulty in changing behaviors later in life illuminates the need to implement prevention efforts early in the life course of children. Genetic data can now be used early in the life course to identify children at high-risk of developing T2D before traditional clinical measures can detect the presence of prediabetes; a metabolic condition associated with obesity that significantly increases risk for developing T2D.  Such early detection of risk may enable the promotion of “primordial prevention” in which parents implement behavior change for their at risk children.  Young children with genetic risk are a novel target population.  Here we review the literature on genetic testing for prevention as it relates to chronic diseases and specifically use T2D as a model. We discuss the history of primordial prevention, the need for primordial prevention of T2D and the role genetic testing has in primordial prevention of high-risk families.

  12. The atmospheric Cherenkov technique in searches for exploding primordial black holes

    International Nuclear Information System (INIS)

    Danaher, S.; Fegan, D.J.; Porter, N.A.; Weekes, T.C.

    1981-01-01

    The Cherenkov technique has been used with a number of detectors, ranging from 1.5 m 2 mirrors to the Central Receiver Test Facility of 8400 m 2 . Limits have been set to the flux of primordial black holes for various models of the evaporation process. (author)

  13. The future of primordial features with large-scale structure surveys

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xingang; Namjoo, Mohammad Hossein [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Dvorkin, Cora [Department of Physics, Harvard University, Cambridge, MA 02138 (United States); Huang, Zhiqi [School of Physics and Astronomy, Sun Yat-Sen University, 135 Xingang Xi Road, Guangzhou, 510275 (China); Verde, Licia, E-mail: xingang.chen@cfa.harvard.edu, E-mail: dvorkin@physics.harvard.edu, E-mail: huangzhq25@sysu.edu.cn, E-mail: mohammad.namjoo@cfa.harvard.edu, E-mail: liciaverde@icc.ub.edu [ICREA and ICC-UB, University of Barcelona (IEEC-UB), Marti i Franques, 1, Barcelona 08028 (Spain)

    2016-11-01

    Primordial features are one of the most important extensions of the Standard Model of cosmology, providing a wealth of information on the primordial Universe, ranging from discrimination between inflation and alternative scenarios, new particle detection, to fine structures in the inflationary potential. We study the prospects of future large-scale structure (LSS) surveys on the detection and constraints of these features. We classify primordial feature models into several classes, and for each class we present a simple template of power spectrum that encodes the essential physics. We study how well the most ambitious LSS surveys proposed to date, including both spectroscopic and photometric surveys, will be able to improve the constraints with respect to the current Planck data. We find that these LSS surveys will significantly improve the experimental sensitivity on features signals that are oscillatory in scales, due to the 3D information. For a broad range of models, these surveys will be able to reduce the errors of the amplitudes of the features by a factor of 5 or more, including several interesting candidates identified in the recent Planck data. Therefore, LSS surveys offer an impressive opportunity for primordial feature discovery in the next decade or two. We also compare the advantages of both types of surveys.

  14. Novel Microcephalic Primordial Dwarfism Disorder Associated with Variants in the Centrosomal Protein Ninein

    DEFF Research Database (Denmark)

    Dauber, Andrew; LaFranchi, Stephen H.; Maliga, Zoltan

    2012-01-01

    Context: Microcephalic primordial dwarfism (MPD) is a rare, severe form of human growth failure in which growth restriction is evident in utero and continues into postnatal life. Single causative gene defects have been identified in a number of patients with MPD, and all involve genes fundamental...

  15. PREFACE: Celebrating 20 years of Journal of Physics: Condensed Matter—in honour of Richard Palmer Celebrating 20 years of Journal of Physics: Condensed Matter—in honour of Richard Palmer

    Science.gov (United States)

    Ferry, David; Dowben, Peter; Inglesfield, John

    2009-11-01

    This year marks the 20th anniversary of the launch of Journal of Physics: Condensed Matter in 1989. The journal was formed from the merger of Journal of Physics C: Solid State Physics and Journal of Physics F: Metal Physics which had separated in 1971. In the 20 years since its launch, Journal of Physics: Condensed Matter has more than doubled in size, while raising standards. Indeed, Journal of Physics: Condensed Matter has become one of the leading scientific journals for our field. This could not have occurred without great leadership at the top. No one has been more responsible for this growth in both size and quality than our Senior Publisher, Richard Palmer. Richard first started work at IOP in March 1971 as an Editorial Assistant with J. Phys. B After a few months, he transferred to J. Phys.C The following year, the Assistant Editor of J. Phys. C, Malcolm Haines, left suddenly in order to work on his family vineyard in France, and Richard stepped into the breach. In those days, external editors had a much more hands-on role in IOP Publishing and he had to travel to Harwell to be interviewed by Alan Lidiard, the Honorary Editor of J. Phys. C, before being given the job of Assistant Editor permanently. Since J. Phys. C and J. Phys. F re-merged to form Journal of Physics: Condensed Matter, Richard gradually shed his other journal responsibilities, except for Reports on Progress in Physics, to build up Journal of Physics: Condensed Matter. He has worked closely with four Editors-in-Chief of J. Phys. C and five of Journal of Physics: Condensed Matter. When Richard announced his retirement this past winter, we met it with a great deal of both happiness and sadness. Of course, we are happy that he is going to be allowed to enjoy his retirement, but we remain very sad to lose such a valuable member of our team, especially the one who had provided the heart and soul of the journal over its 20 years. We will be able to rely upon the team which Richard ably trained as

  16. The role of primordial emotions in the evolutionary origin of consciousness.

    Science.gov (United States)

    Denton, D A; McKinley, M J; Farrell, M; Egan, G F

    2009-06-01

    Primordial emotions are the subjective element of the instincts which are the genetically programmed behaviour patterns which contrive homeostasis. They include thirst, hunger for air, hunger for food, pain and hunger for specific minerals etc. There are two constituents of a primordial emotion--the specific sensation which when severe may be imperious, and the compelling intention for gratification by a consummatory act. They may dominate the stream of consciousness, and can have plenipotentiary power over behaviour. It is hypothesized that early in animal evolution complex reflex mechanisms in the basal brain subserving homeostatic responses, in concert with elements of the reticular activating system subserving arousal, melded functionally with regions embodied in the progressive rostral development of the telencephalon. This included the emergent limbic and paralimbic areas, and the insula. This phylogenetically ancient organization subserved the origin of consciousness as the primordial emotion, which signalled that the organisms existence was immediately threatened. Neuroimaging confirms major activations in regions of the basal brain during primordial emotions in humans. The behaviour of decorticate humans and animals is discussed in relation to the possible existence of primitive awareness. Neuroimaging of the primordial emotions reveals that rapid gratification of intention by a consummatory act such as ingestion causes precipitate decline of both the initiating sensation and the intention. There is contemporaneous rapid disappearance of particular regions of brain activation which suggests they may be part of the jointly sufficient and severally necessary activations and deactivations which correlate with consciousness [Crick, F. & Koch, C. (2003). A framework for consciousness. NatureNeuroscience,6, 119-126].

  17. Richards growth model and viability indicators for populations subject to interventions

    Directory of Open Access Journals (Sweden)

    Selene Loibel

    2010-12-01

    Full Text Available In this work we study the problem of modeling identification of a population employing a discrete dynamic model based on the Richards growth model. The population is subjected to interventions due to consumption, such as hunting or farming animals. The model identification allows us to estimate the probability or the average time for a population number to reach a certain level. The parameter inference for these models are obtained with the use of the likelihood profile technique as developed in this paper. The identification method here developed can be applied to evaluate the productivity of animal husbandry or to evaluate the risk of extinction of autochthon populations. It is applied to data of the Brazilian beef cattle herd population, and the the population number to reach a certain goal level is investigated.Neste trabalho estudamos o problema de identificação do modelo de uma população utilizando um modelo dinâmico discreto baseado no modelo de crescimento de Richards. A população é submetida a intervenções devido ao consumo, como no caso de caça ou na criação de animais. A identificação do modelo permite-nos estimar a probabilidade ou o tempo médio de ocorrência para que se atinja um certo número populacional. A inferência paramétrica dos modelos é obtida através da técnica de perfil de máxima verossimilhança como desenvolvida neste trabalho. O método de identificação desenvolvido pode ser aplicado para avaliar a produtividade de criação animal ou o risco de extinção de uma população autóctone. Ele foi aplicado aos dados da população global de gado de corte bovino brasileiro, e é utilizado na investigação de a população atingir um certo número desejado de cabeças.

  18. Who invented the dichotomous key? Richard Waller's watercolors of the herbs of Britain.

    Science.gov (United States)

    Griffing, Lawrence R

    2011-12-01

    On 27 March 1689, Richard Waller, Fellow and Secretary of the Royal Society presented his "Tables of the English Herbs reduced to such an order, as to find the name of them by their external figures and shapes" to his assembled colleagues at a meeting of the Royal Society. These tables were developed for the novice by being color images, composed in pencil and watercolor, of selected plants and their distinguishing characteristics. The botanical watercolors for the tables are now a Turning-the-Pages document online on the website of the Royal Society. However, for the past 320 years, the scientific context for the creation of these outstanding botanical watercolors has remained obscure. These tables were developed by Waller as an image-based dichotomous key, pre-dating by almost 100 years the text-based dichotomous keys in the first edition of Flora Française (1778) by Jean Baptiste Lamarck, who is generally given priority for the development of the dichotomous key. How these large folio images were arranged to illustrate a dichotomous key is unknown, but an arrangement based on Waller's description is illustrated here as leaf-ordering for the separate hierarchical clusters (tables). Although only 24 species of watercolored dicot herbs out of a total of 65 in the set of watercolors (the others being monocots) are used in these tables, they are a "proof of concept", serving as models upon which a method is based, that of using a key composed of dichotomous choices for aiding identification.

  19. Símbolo y forma: los hermanos Grimm en Richard Wagner

    Directory of Open Access Journals (Sweden)

    Miguel Salmerón Infante

    2015-05-01

    Full Text Available Este escrito estudia el cómo y el porqué de la presencia de los Cuentos de los Hermanos Grimm en la obra de Richard Wagner. Para dar un enfoque más concreto a esta reflexión el análisis se centra en Sigfrido, el drama musical de Wagner con más atmósfera de cuento, y las influencias y préstamos temáticos, formales y lingüísticos que le aportan los KHM. El artículo entiende que hay dos elementos que aprovecha Wagner de los Grimm para sus dramas musicales. El símbolo para su proyecto de tejido de la identidad alemana. Y la forma del cuento con sus temas y fórmulas recurrentes que el aplicó a su música y muy concretamente al Leitmotiv. Todo ello sin olvidar la muy frecuente presencia de la figura del huérfano tanto en Wagner como en los Grimm.  

  20. Staging Unincorporated Power: Richard Harding Davis and the Critique of Imperial News

    Directory of Open Access Journals (Sweden)

    Nirmal Trivedi

    2011-12-01

    Full Text Available This essay contextualizes the work of war correspondent Richard Harding Davis within an evolving “imperial news apparatus” that would culminate in his reporting of the Spanish-American War. Critics have conventionally framed Davis squarely within the imperial cause, associating him with his admirer Roosevelt and naval admiral Alfred T. Mahan. Contrary to readings of Davis as an apologist for US imperialism, Trivedi contends that Davis understood how US imperial power relied on an information apparatus to communicate to an increasingly media-conscious American public through culture, that is, via familiar narratives, symbols, and objects—what Trivedi calls “imperial news.” The essay follows Davis’s development from his fictional representation of the new war correspondent in “The Reporter Who Made Himself King” to his own war correspondence before and after the Spanish-American War as collected in the memoirs A Year from a Reporter’s Notebook (1897, Cuba in War Time (1897, and Notes of a War Correspondent (1912. Davis’s war correspondence and fictional work effectively stage US imperialism as “unincorporated power”: that is, as power reliant on a developing news-making apparatus that deploys particular discursive strategies to validate its political claims. This staging critiques strategies of US imperial sovereignty—specifically its “privatization of knowledge” and its promotion of the war correspondent as nothing more than a spectator and purveyor of massacres.

  1. Meeting to honor F. Richard Stephenson on his 70th birthday

    CERN Document Server

    Green, David; Strom, Richard

    2015-01-01

    This book contains papers from a conference held to celebrate the 70th birthday of one of the world’s foremost astronomical historians, Professor F. Richard Stephenson, the latest recipient of the American Astronomical Society’s highest award for research in astronomical history, the LeRoy Doggett Prize. Reflecting Professor Stephenson’s extensive research portfolio, this book brings together under one cover papers on four different areas of scholarship: applied historical astronomy (which Stephenson founded); Islamic astronomy; Oriental astronomy; and amateur astronomy.  These papers are penned by astronomers from Canada, China, England, France, Georgia, Iran, Japan, Lebanon, the Netherlands, Portugal, Thailand and the USA. Its diverse coverage represents a wide cross-section of the history of astronomy community.  Under discussion are ways in which recent research using historical data has provided new insights into auroral and solar activity, supernovae and changes in the rotation rate of the E...

  2. Against the Nihilism of Suffering and Death: Richard E. K. Kim and His Works

    Directory of Open Access Journals (Sweden)

    Jooyeon Rhee

    2016-03-01

    Full Text Available This article examines the life and works of Richard E. K. Kim (1932–2009, a first-generation Korean diasporic writer in the United States. It focuses on how Kim struggled to overcome the nihilism of suffering and death that derived from colonialism and the Korean War through his literary works. Kim witnessed firsthand these two major historical events, which caused irrevocable psychological and physical damage to many people of his generation. In his autobiographical fiction, he conveys painful memories of the events by reviving the voices of people in that era. What his works offer us goes beyond vivid memories of the past, however; they also present the power of forgiveness as a condition to overcome the nihilism of suffering and death. Remembrance and forgiveness are, therefore, two major thematic pillars of his works that enable us to connect to these difficult and traumatic times. These themes are portrayed in such a gripping way mainly because Kim tried to maintain a certain distance—an emotional and linguistic distance—from the familiar, in order to elucidate the reality of the human condition: an ontological position of the exile from which he produced his works. This article argues that Kim’s works provide us the possibility to transcend the nihilism of historical trauma through articulating the meaning of remembrance and forgiveness from his self-assumed position of exile.

  3. Providing the physical basis of SCS curve number method and its proportionality relationship from Richards' equation

    Science.gov (United States)

    Hooshyar, M.; Wang, D.

    2016-12-01

    The empirical proportionality relationship, which indicates that the ratio of cumulative surface runoff and infiltration to their corresponding potentials are equal, is the basis of the extensively used Soil Conservation Service Curve Number (SCS-CN) method. The objective of this paper is to provide the physical basis of the SCS-CN method and its proportionality hypothesis from the infiltration excess runoff generation perspective. To achieve this purpose, an analytical solution of Richards' equation is derived for ponded infiltration in shallow water table environment under the following boundary conditions: 1) the soil is saturated at the land surface; and 2) there is a no-flux boundary which moves downward. The solution is established based on the assumptions of negligible gravitational effect, constant soil water diffusivity, and hydrostatic soil moisture profile between the no-flux boundary and water table. Based on the derived analytical solution, the proportionality hypothesis is a reasonable approximation for rainfall partitioning at the early stage of ponded infiltration in areas with a shallow water table for coarse textured soils.

  4. Unreliability and the Animal Narrator in Richard Adams’s The Plague Dogs

    Directory of Open Access Journals (Sweden)

    Anja Höing

    2017-03-01

    Full Text Available Richard Adams’s talking animal story The Plague Dogs (1978, with its deeply genre-atypical mode of narration, offers a multiplicity of avenues to explore the literary animal as animal. The story draws much of its power from the psychological complexity and related unreliability of both canine narrators, two research lab escapees gone feral. Both the terrier Snitter and the black mongrel Rowf are mentally ill and experience a highly subjective, part-fantastic world. In episodes of zero focalization, a sarcastic voice comments on the plot from the off, aggressively attacking a thoroughly anthropocentric superstructure the protagonists themselves are oblivious of, and presenting all that is normally constructed as “rational” in the implied reader’s world as a carnivalesque farce. Combining these equally unreliable narratives, The Plague Dogs creates a unique mixture of what Phelan (2007 calls “estranging” and “bonding” unreliability and brings to light the devastating consequences of anthropocentrism. The Plague Dogs not only defamiliarizes a genre usually committed to conventional means of storytelling, but the dominant Western conception of the status of animals in the world, showing that once we start to read the animal as animal, this sets into motion an avalanche of other concepts in need of re-reading, among them the very ones making up the fundamental pillars of Western societies’ anthropocentric self-conception.

  5. Perbandingan antara Etika Jürgen Habermas dan Richard Rorty sebagai Prinsip Dasar Bertindak Manusia

    Directory of Open Access Journals (Sweden)

    Dominique Rio Adiwijaya

    2010-10-01

    Full Text Available Ethics without doubt is an issue in every scientific field. Questions on ethics are not merely questions on the responsibility of one or two specific individuals, but rather as what have been defined accurately by Immanuel Kant in Critique of Practical Reason – as question of all humanity as a thinking creature and the freedom of choice on, “what should I do”. From Kant’s definition, we may infer that if human can not think and not free in determining their choice, it would be almost impossible to hope for moral responsibility. However this article does not mean to give a full and historical description on ethics, but a sketch on discourse of contemporary ethics which is represented by two famous philosophers, Jürgen Habermas from the tradition of  Critical Theory from Frankfurt School, dan Richard Rorty with “Neo-Pragmatism”. Habermas proposes “discourse ethics” while Rorty proposes ethic concepts through his “liberal-ironists”. It is hoped that the assembly of readers may gain an insight of the unavoidable ethics problems since every ethical position must be theory laden and the theory itself has historical characteristics (the characteristics, origin and historical context of the schools behind it. Therefore ethics is a neverending reflection although it has been started from 2500 years ago. Ethics invites us from specific sciences to enter its general discourse which unavoidably all-encompassing in its nature. 

  6. Richard Rorty:From Anti-metaphysical Neo-Pragmatism to Rejection of Philosophy

    Directory of Open Access Journals (Sweden)

    M. Akrami

    2010-01-01

    Full Text Available Richard Rorty is a neo-Pragmatist philosopher. For three decades, he has attacked the traditional philosophy (from Plato to Kant as well as any other epistemology searching for truth or claiming to mirror the nature in his philosophical works. Rorty holds that, according to the history of philosophy in his reading, there is no final answer to the traditional questions concerning knowledge, truth, and representation. These questions, therefore, should be dissolved and denied. He maintains that knowledge is justified belief, justification, however, being not the consequence of some correspondence between the theory or the statement, but the consequence of conversation, social practice, group consensus, and social solidarity. Rorty also thinks that democracy has priority on philosophy, disagreeing with the thesis that philosophy is the foundation of the rest of culture.Despite of usefulness of some elements and implications of Rorty’s metaphilosophy (such as his emphasis on freedom, democracy, and pluralism as well as his insisting on philosophical humility and avoiding scientific pride, it is faced with several problems, including 1 ignoring the referential and realist features of language, 2 confusing interpretation and reality, 3 eliminating the border between objectivity and subjectivity, 4 interfering of public and private life, and 5 ignoring the need of science, culture, technology and, in particular, politics, in philosophy. The authors try to show and analyze some elements of these problems.

  7. Has David Howden Vindicated Richard von Mises’s Definition of Probability?

    Directory of Open Access Journals (Sweden)

    Mark R. Crovelli

    2009-11-01

    Full Text Available In my recent article on these pages (Crovelli 2009 I argued that members of the Austrian School of economics have adopted and defended a faulty definition of probability. I argued that the definition of probability necessarily depends upon the nature of the world in which we live. I claimed that if the nature of the world is such that every event and phenomenon which occurs has a cause of some sort, then probability must be defined subjectively; that is, “as a measure of our uncertainty about the likelihood of occurrence of some event or phenomenon, based upon evidence that need not derive solely from past frequencies of ‘collectives’ or ‘classes.’” I further claimed that the nature of the world is indeed such that all events and phenomena have prior causes, and that this fact compels us to adopt a subjective definition of probability.David Howden has recently published what he claims is a refutation of my argument in his article “Single Trial Probability Applications: Can Subjectivity Evade Frequency Limitations” (Howden 2009. Unfortunately, Mr. Howden appears to not have understood my argument, and his purported refutation of my subjective definition consequently amounts to nothing more than a concatenation of confused and fallacious ideas that are completely irrelevant to my argument. David Howden has thus failed in his attempt to vindicate Richard von Mises’s definition of probability.

  8. Blood, politics, and social science. Richard Titmuss and the Institute of Economic Affairs, 1957-1973.

    Science.gov (United States)

    Fontaine, Philippe

    2002-09-01

    Long before his last book, The Gift Relationship: From Human Blood to Social Policy, was published in early 1971, Richard M. Titmuss (1907-1973), a professor of social administration at the London School of Economics, had been a major figure in the debates over the welfare state. The Gift Relationship was the culmination of an eventful relationship with the Institute of Economic Affairs, a think tank that advocated the extension of rational pricing to social services. By arguing that the British system of blood procurement and distribution, based on free giving within the National Health Service, was more efficient than the partly commercialized American system, Titmuss intended to signal the dangers of the increasing commercialization of society. What made for the impact of his book, however, was not merely its argument that transfusion-transmitted infections were much more common with paid than with voluntary donors, but also its reflections on what it is that holds a society together. And here Titmuss argued that a "socialist" social policy, by encouraging the sense of community, played a central role. The eclecticism of Titmuss's work, together with its strong ethical and political flavor, makes it a rich and original account of the "social" at a time when heated debated over social policy, both in Britain and in the United States, raised the question of the division of labor among the social sciences.

  9. First record of the Asian diaptomid Neodiaptomus schmackeri (Poppe & Richard, 1892 (Crustacea: Copepoda: Calanoida in Europe

    Directory of Open Access Journals (Sweden)

    Giuseppe Alfonso

    2014-06-01

    Full Text Available Albania, as well as a great part of the Balkan area in general, still suffers a lack of environmental studies especially in limnological research. The Dumre plateau, in Central Albania, is characterized by an extraordinary high number of karst lakes in a small geographic area. Despite their environmental peculiarity, very few biological data are to date available for these lakes, none on the zooplankton. For this reason, 15 water bodies located in the central area of the plateau were selected for a preliminary limnological survey carried out in the years 2008-2011. Neodiaptomus schmackeri (Poppe & Richard, 1892, a diaptomid calanoid copepod characterized by a South-Eastern Palearctic - Oriental distribution, and the most widely spread Neodiaptomus species in Asia, was found in 8 lakes of the Dumre area. This finding represents the first record of the species, and of the entire genus Neodiaptomus, for Europe. Several environmental variables were measured to characterize the lakes, and the co-occurring planktonic crustaceans were also identified. Taxonomical drawings and descriptions of the main morphological features of both sexes are herein provided in order to compare the Albanian populations of N. schmackeri with those of the native distribution area of the species. The possible causes which determined the occurrence of this non-indigenous species in several Dumre lakes are discussed.

  10. Health Effects Due to Radionuclides Content of Solid Minerals within Port of Richards Bay, South Africa

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    Felix B. Masok

    2016-11-01

    Full Text Available This study assessed the radiological health hazards to various body organs of workers working within Transnet Precinct in Richards Bay in Kwazulu-Natal, South Africa due to radionuclide content of mineral ores often stored within the facility. Thirty samples were collected from five mineral ores (rock phosphate, rutile, zircon, coal and hematite and analyzed for 238U, 234U, 226Ra, 210Pb, 235U, 232Th, 228Ra, 228Th and 40K using delayed neutron activation analysis and low energy gamma spectroscopy. Rutile was found to be the most radioactive mineral ore within the facility with 210Pb concentration of 759.00 ± 106.00 Bq·kg−1. Effective annual dose rate in (mSv·y−1 delivered to different organs of the body: testes, bone marrow, whole body, lungs and ovaries from mineral ores were such that dose from mineral ores decreased in the order coal > rutile > rock phosphate > hematite > zircon. The organs with the highest received dose rate were the testes and this received dose was from coal. However, all of the calculated absorbed dose rates to organs of the body were below the maximum permissible safety limits.

  11. “This World Is Not My Home”: Richard Mouw and Christian Nationalism

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    Aaron Pattillo-Lunt

    2016-12-01

    Full Text Available American evangelicalism has often been punctuated by dual commitments to the United States and to God. Those commitments were strongest within politically conservative evangelicalism. Though representing a solid majority among professing evangelicals, conservatives could not speak for the movement as a whole. Politically progressive evangelicals, beginning in the 1960s, formed a dissenting opinion of the post-World War II revival of Christian nationalism. They dared to challenge American action abroad, noticeably during the Vietnam War. Their critique of Christian nationalism and conservative evangelicals’ close ties to the Republican Party led them to seek refuge in either progressive policies or the Democratic Party. A third, underexplored subgroup of evangelicalism rooted in reformed theology becomes important to consider in this regard. These reformed evangelicals sought to contextualize nationalism in biblical rather than partisan or political terms. This goal is championed well by Richard Mouw, resulting in a nuanced look at evangelical Christians’ difficult dual role as both citizens of the Kingdom of God and the United States.

  12. Poets/Trump/Philosophers: Reflections on Richard Rorty’s Liberalism, Ten Years after His Death

    Directory of Open Access Journals (Sweden)

    Giorgio Baruchello

    2017-08-01

    Full Text Available Starting with a prescient 1998 quote on the impending decline of US liberal democracy into right-wing, strong-man-based demagogy, this paper outlines Richard Rorty’s political philosophy, which I believe can help us understand perplexing political trends in today’s political reality well beyond the US alone. Specifically, I tackle three key-terms encapsulating the thrust of Rorty’s political philosophy, i.e. “liberalism of fear”, “bourgeois” and “postmodernism”. Also, I address a contraposition that explains how Rorty would approach and attempt to defend liberal democracy from contemporary right-wing, strong-man-based degenerations, namely the priority of “poetry” over “philosophy”. Essentially, if one wishes to win in the political arena, she must be armed with the most effective rhetorical weaponry, however good, solid and well-argued her political views may be. Finally, some remarks are offered on the role that “philosophy” can still play within the same arena.

  13. Arctic observers: Richard King, monogenism and the historicisation of Inuit through travel narratives.

    Science.gov (United States)

    Sera-Shriar, Efram

    2015-06-01

    In 1848 the ethnologist, surgeon and Arctic explorer Richard King (1810-1876) published a three-part series on Inuit in the Journal of the Ethnological Society of London. This series provided a detailed history of Inuit from the eleventh century to the early nineteenth century. It incorporated a mixture of King's personal observations from his experience travelling to the Arctic as a member of George Back's expedition (1833-1835), and the testimonies of other contemporary and historical actors who had written on the subject. The aim was to historicise Inuit through the use of travel reports and show persistent features among the race. King was a monogenist and his sensitive recasting of Inuit was influenced by his participation in a research community actively engaged in humanitarian and abolitionist causes. The physician and ethnologist Thomas Hodgkin (1798-1866) argued that King's research on Inuit was one of the best ethnological approaches to emulate and that it set the standard for the nascent discipline. If we are to take seriously Hodgkin's claim, we should look at how King constructed his depiction of Inuit. There is much to be gained by investigating the practices of nineteenth-century ethnologists because it strengthens our knowledge of the discipline's past and shows how modern understandings of races were formed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Tutorial Computer-Assisted Language Learning

    Science.gov (United States)

    Heift, Trude; Schulze, Mathias

    2015-01-01

    "Sometimes maligned for its allegedly behaviorist connotations but critical for success in many fields from music to sport to mathematics and language learning, 'practice' is undergoing something of a revival in the applied linguistics literature" (Long & Richards 2007, p. xi). This research timeline provides a systematic overview of…

  15. Multicollector High Precision Resolution of Primordial Kr and Xe in Mantle CO2 Well Gases

    Science.gov (United States)

    Holland, G.; Ballentine, C.; Cassidy, M.

    2008-12-01

    Noble gas isotopes in magmatic CO2 well gases provide a unique insight into mantle volatile origin and dynamics [1-3]. Previous work has resolved mantle 20Ne/22Ne ratios consistent with a solar wind irradiated meteoritic source for mantle He and Ne [1]. This is distinct from Solar Wind values that might be expected if the primary mechanism of terrestrial mantle volatile acquisition was through the gravitational capture of solar nebula gases [see 4]. Within the CO2 well gases a primordial component has also been resolved in the non- radiogenic Xe isotopic composition [2,3]. Using multicollector mass spectrometry we have observed a 124Xe/130Xe excess of 1.85 percent over air plus/minus 0.17 percent for the least air contaminated samples. At this level of precision we are for the first time able to differentiate between a trapped meteoritic origin (average carbonaceous chondrite or Q Xe) rather than Solar Wind origin as the primordial Xe component. The well gases also contain Kr which, in the least air contaminated sample, have a correlated 86Kr/82Kr excess of 0.55 percent over air plus/minus 0.04 percent. Whilst mass dependent fractionation can theoretically produce correlated excesses in 124Xe-128Xe and 82Kr-86Kr isotopes, no fractionation from air is observed in 38Ar/36Ar [3] and the Kr excesses are in the opposite sense to that of Xe. From 136Xe excesses, Kr fission yield from Pu and U can be calculated and subtracted from the Kr isotopic signature. This fission-corrected signature is most reasonably explained as a primordial component. This is the first time that primordial Kr has ever been resolved in a terrestrial sample. The primordial Kr isotopic signature is distinct from Solar Wind Kr and is consistent with the primordial Kr also originating as a trapped component within meteorites. We are now able to demonstrate that both the light (He and Ne) and Heavy (Kr and Xe) noble gas origin in the terrestrial mantle is consistent with a trapped component during the

  16. El lugar del padre primordial en Moisés y la religión monoteísta: Algunas conclusiones The Place Of The Primordial Father In Moses And Monotheism: Some Conclusions

    Directory of Open Access Journals (Sweden)

    Laura Edith Raffaini

    2008-12-01

    Full Text Available En Moisés y la religión monoteísta Freud desarrolla su última versión del padre. En este trabajo, analizo el lugar que ocupa el padre primordial de Tótem y tabú a partir de dicha versión. Presento, asimismo, un movimiento teórico fundamental en la teoría freudiana sobre el padre: el pasaje del padre primordial a la religión del padre como producto de la neurosis.In "Moses and Monotheism" Freud's ultimate version of the father is described. In this paper, the place the primordial father in "Totem und Tabu" occupies is established based on such version. The transition from the primordial father to the religion of the father as a neurosis product is analysed.

  17. X-ray cross-sections and crossroads (The International Radiation Physics Society) - Richard Pratt's contributions to both

    International Nuclear Information System (INIS)

    Hubbell, J.H.

    2000-01-01

    Some examples of the impact of the theoretical contributions by Richard Pratt and his collaborators on photon cross section compilations at NBS/NIST and elsewhere over the past several decades are presented. Both the theoretical and measurement works which combine to provide this data base, and the contact with the varied user groups in medical applications, nuclear engineering, crystallography and X-ray astronomy, have formed a global crossroads of researchers now embodied in the International Radiation Physics Society (IRPS). Since the founding of the IRPS at the 3 rd International Symposium on Radiation Physics (ISRP-3) in Ferrara, Italy, in 1985, the Secretariat for this 'global radiation physics family' (the IRPS) has resided at the University of Pittsburgh under the direction of Richard Pratt. A brief account of the origins and history of the IRPS, beginning with ISRP-1 in Calcutta in 1974, is presented.

  18. X-ray cross-sections and crossroads (The International Radiation Physics Society) - Richard Pratt's contributions to both

    Science.gov (United States)

    Hubbell, J. H.

    2000-08-01

    Some examples of the impact of the theoretical contributions by Richard Pratt and his collaborators on photon cross section compilations at NBS/NIST and elsewhere over the past several decades are presented. Both the theoretical and measurement works which combine to provide this data base, and the contact with the varied user groups in medical applications, nuclear engineering, crystallography and X-ray astronomy, have formed a global crossroads of researchers now embodied in the International Radiation Physics Society (IRPS). Since the founding of the IRPS at the 3rd International Symposium on Radiation Physics (ISRP-3) in Ferrara, Italy, in 1985, the Secretariat for this ``global radiation physics family'' (the IRPS) has resided at the University of Pittsburgh under the direction of Richard Pratt. A brief account of the origins and history of the IRPS, beginning with ISRP-1 in Calcutta in 1974, is presented.

  19. Why Was General Richard O’Connor’s Command in Northwest Europe Less Effective Than Expected?

    Science.gov (United States)

    2011-03-01

    Commander of 7 Division and Military Governor of Jerusalem , September 1938- August 1939. ______. Papers of General Sir Richard O’Connor KT, GCB, DSO, MC...Montgomery, Brian. A Field Marshall in the Family: A Personal Biography of Montgomery of Alamein. New York: Taplinger, 1973. Montgomery, Field...Commanders: A Composite Biography . Combat Studies Institute publications, Fort Leavenworth, Kansas: U.S. Army Command and General Staff College, 1989

  20. Formation of primordial black holes from non-Gaussian perturbations produced in a waterfall transition

    Science.gov (United States)

    Bugaev, Edgar; Klimai, Peter

    2012-05-01

    We consider the process of primordial black hole (PBH) formation originated from primordial curvature perturbations produced during waterfall transition (with tachyonic instability), at the end of hybrid inflation. It is known that in such inflation models, rather large values of curvature perturbation amplitudes can be reached, which can potentially cause a significant PBH production in the early Universe. The probability distributions of density perturbation amplitudes in this case can be strongly non-Gaussian, which requires a special treatment. We calculated PBH abundances and PBH mass spectra for the model and analyzed their dependence on model parameters. We obtained the constraints on the parameters of the inflationary potential, using the available limits on βPBH.

  1. Stochastic Gravitational-Wave Background due to Primordial Binary Black Hole Mergers.

    Science.gov (United States)

    Mandic, Vuk; Bird, Simeon; Cholis, Ilias

    2016-11-11

    Recent Advanced LIGO detections of binary black hole mergers have prompted multiple studies investigating the possibility that the heavy GW150914 binary system was of primordial origin, and hence could be evidence for dark matter in the form of black holes. We compute the stochastic background arising from the incoherent superposition of such primordial binary black hole systems in the Universe and compare it to the similar background spectrum due to binary black hole systems of stellar origin. We investigate the possibility of detecting this background with future gravitational-wave detectors, and conclude that constraining the dark matter component in the form of black holes using stochastic gravitational-wave background measurements will be very challenging.

  2. Simultaneous effect of modified gravity and primordial non-Gaussianity in large scale structure observations

    International Nuclear Information System (INIS)

    Mirzatuny, Nareg; Khosravi, Shahram; Baghram, Shant; Moshafi, Hossein

    2014-01-01

    In this work we study the simultaneous effect of primordial non-Gaussianity and the modification of the gravity in f(R) framework on large scale structure observations. We show that non-Gaussianity and modified gravity introduce a scale dependent bias and growth rate functions. The deviation from ΛCDM in the case of primordial non-Gaussian models is in large scales, while the growth rate deviates from ΛCDM in small scales for modified gravity theories. We show that the redshift space distortion can be used to distinguish positive and negative f NL in standard background, while in f(R) theories they are not easily distinguishable. The galaxy power spectrum is generally enhanced in presence of non-Gaussianity and modified gravity. We also obtain the scale dependence of this enhancement. Finally we define galaxy growth rate and galaxy growth rate bias as new observational parameters to constrain cosmology

  3. Primordial soup was edible: abiotically produced Miller-Urey mixture supports bacterial growth.

    Science.gov (United States)

    Xie, Xueshu; Backman, Daniel; Lebedev, Albert T; Artaev, Viatcheslav B; Jiang, Liying; Ilag, Leopold L; Zubarev, Roman A

    2015-09-28

    Sixty years after the seminal Miller-Urey experiment that abiotically produced a mixture of racemized amino acids, we provide a definite proof that this primordial soup, when properly cooked, was edible for primitive organisms. Direct admixture of even small amounts of Miller-Urey mixture strongly inhibits E. coli bacteria growth due to the toxicity of abundant components, such as cyanides. However, these toxic compounds are both volatile and extremely reactive, while bacteria are highly capable of adaptation. Consequently, after bacterial adaptation to a mixture of the two most abundant abiotic amino acids, glycine and racemized alanine, dried and reconstituted MU soup was found to support bacterial growth and even accelerate it compared to a simple mixture of the two amino acids. Therefore, primordial Miller-Urey soup was perfectly suitable as a growth media for early life forms.

  4. Primordial Radionuclides Distribution and dose Evaluation in Udagamandalam Region of Nilgiris in India

    International Nuclear Information System (INIS)

    Manikandan, N. Muguntha; Selvasekarapandian, S.; Sivakumar, R.; Meenakshisundaram, V.; Raghunath, V. M.

    2001-01-01

    The activity concentration of primordial radionuclides i.e., 238 U series, 232 Th series and 40 K, in soil samples collected from Udagamandalam environment, have been measured by employing NaI (TI) Gamma ray Spectrometer. The absorbed gamma dose rate has also been simultaneously measured by using both environmental radiation dosimeter at each soil sampling location (ambient gamma dose) as well as from the gamma dose derived from the activity concentration of the primordial radionuclides. The results of activity concentration of each radionuclides in soil, absorbed dose rate in air due to soil activity and possible cosmic radiation at each location along with human effective dose equivalent for Udagamandalam environment are presented and discussed

  5. Primordial Radionuclides Distribution and dose Evaluation in Udagamandalam Region of Nilgiris in India

    Energy Technology Data Exchange (ETDEWEB)

    Manikandan, N. Muguntha; Selvasekarapandian, S.; Sivakumar, R.; Meenakshisundaram, V. [Bharathiar Univ., Coimbatore (India); Raghunath, V. M. [Indira Gandhi Center for Atomic Research, Kalpakkam (India)

    2001-09-15

    The activity concentration of primordial radionuclides i.e., {sup 238}U series, {sup 232}Th series and {sup 40}K, in soil samples collected from Udagamandalam environment, have been measured by employing NaI (TI) Gamma ray Spectrometer. The absorbed gamma dose rate has also been simultaneously measured by using both environmental radiation dosimeter at each soil sampling location (ambient gamma dose) as well as from the gamma dose derived from the activity concentration of the primordial radionuclides. The results of activity concentration of each radionuclides in soil, absorbed dose rate in air due to soil activity and possible cosmic radiation at each location along with human effective dose equivalent for Udagamandalam environment are presented and discussed.

  6. From electroweak theory to the primordial universe. A synthesis of some experimental results

    International Nuclear Information System (INIS)

    Ealet, A.

    2004-12-01

    Particle physic is based on a theory which can be tested on the current large colliders. Measurements are in a very good agreement with this electroweak theory and no deviation is observed to indicate new physics. What is surprising today is that none of its results agrees with what is known from our universe, neither to explain the primordial baryogenesis, neither to explain the acceleration of the expansion of the Universe. In this work, I come back on some results obtained in the Lep collider, to test the electroweak theory (Higgs and W boson production) and on some measurements of CP violation. I compare them with what can be extrapolated in term of primordial baryogenesis and dark energy density and show that there is no possible agreement in the Standard Model. I finish by some experimental and theoretical views to answer this fundamental question. (author)

  7. Primordial germ cell biology at the beginning of the XXI century.

    Science.gov (United States)

    De Felici, Massimo

    2009-01-01

    At the XIV Workshop on the Development and Function of the Reproductive Organs held at the Congress Centre of the University of Rome Tor Vergata, Monteporzio Catone, Rome, Italy, the introduction to the first session entitled Mammalian primordial germ cells dedicated to the memory of Anne McLaren, was the occasion for a concise review of the state of art of research on the biology of primordial germ cells (PGCs). This great, unforgettable scientist, who died in a car accident in July 2007, dedicated most of her studies to this field over the last 25 years. Topics briefly reviewed in this Meeting Report are: 1) how the germ line is determined; 2) what are the mechanisms underlying PGC migration; 3) to what extent PGC survival, proliferation and differentiation are cell autonomous or environmentally controlled processes and 4) how the potential for totipotency is retained in PGCs.

  8. Cosmic microwave background bispectrum from primordial magnetic fields on large angular scales.

    Science.gov (United States)

    Seshadri, T R; Subramanian, Kandaswamy

    2009-08-21

    Primordial magnetic fields lead to non-Gaussian signals in the cosmic microwave background (CMB) even at the lowest order, as magnetic stresses and the temperature anisotropy they induce depend quadratically on the magnetic field. In contrast, CMB non-Gaussianity due to inflationary scalar perturbations arises only as a higher-order effect. We propose a novel probe of stochastic primordial magnetic fields that exploits the characteristic CMB non-Gaussianity that they induce. We compute the CMB bispectrum (b(l1l2l3)) induced by such fields on large angular scales. We find a typical value of l1(l1 + 1)l3(l3 + 1)b(l1l2l3) approximately 10(-22), for magnetic fields of strength B0 approximately 3 nG and with a nearly scale invariant magnetic spectrum. Observational limits on the bispectrum allow us to set upper limits on B0 approximately 35 nG.

  9. Chiral primordial blue tensor spectra from the axion-gauge couplings

    Energy Technology Data Exchange (ETDEWEB)

    Obata, Ippei, E-mail: obata@tap.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, Kyoto, 606-8502 (Japan)

    2017-06-01

    We suggest the new feature of primordial gravitational waves sourced by the axion-gauge couplings, whose forms are motivated by the dimensional reduction of the form field in the string theory. In our inflationary model, as an inflaton we adopt two types of axion, dubbed the model-independent axion and the model-dependent axion, which couple with two gauge groups with different sign combination each other. Due to these forms both polarization modes of gauge fields are amplified and enhance both helicies of tensor modes during inflation. We point out the possibility that a primordial blue-tilted tensor power spectra with small chirality are provided by the combination of these axion-gauge couplings, intriguingly both amplitudes and chirality are potentially testable by future space-based gravitational wave interferometers such as DECIGO and BBO project.

  10. Search for gravitational waves from primordial black hole binary coalescences in the galactic halo

    International Nuclear Information System (INIS)

    Abbott, B.; Anderson, S.B.; Araya, M.; Armandula, H.; Asiri, F.; Barish, B.C.; Barnes, M.; Barton, M.A.; Bhawal, B.; Billingsley, G.; Black, E.; Blackburn, K.; Bogue, L.; Bork, R.; Brown, D.A.; Busby, D.; Cardenas, L.; Chandler, A.; Chapsky, J.; Charlton, P.

    2005-01-01

    We use data from the second science run of the LIGO gravitational-wave detectors to search for the gravitational waves from primordial black hole binary coalescence with component masses in the range 0.2-1.0M · . The analysis requires a signal to be found in the data from both LIGO observatories, according to a set of coincidence criteria. No inspiral signals were found. Assuming a spherical halo with core radius 5 kpc extending to 50 kpc containing nonspinning black holes with masses in the range 0.2-1.0M · , we place an observational upper limit on the rate of primordial black hole coalescence of 63 per year per Milky Way halo (MWH) with 90% confidence

  11. Non-Gaussian initial conditions in ΛCDM: Newtonian, relativistic, and primordial contributions

    International Nuclear Information System (INIS)

    Bruni, Marco; Hidalgo, Juan Carlos; Meures, Nikolai; Wands, David

    2014-01-01

    The goal of the present paper is to set initial conditions for structure formation at nonlinear order, consistent with general relativity, while also allowing for primordial non-Gaussianity. We use the nonlinear continuity and Raychaudhuri equations, which together with the nonlinear energy constraint, determine the evolution of the matter density fluctuation in general relativity. We solve this equations at first and second order in a perturbative expansion, recovering and extending previous results derived in the matter-dominated limit and in the Newtonian regime. We present a second-order solution for the comoving density contrast in a ΛCDM universe, identifying nonlinear contributions coming from the Newtonian growing mode, primordial non-Gaussianity and intrinsic non-Gaussianity, due to the essential nonlinearity of the relativistic constraint equations. We discuss the application of these results to initial conditions in N-body simulations, showing that relativistic corrections mimic a non-zero nonlinear parameter f NL

  12. Sufi, Christian or Buddhist? Richard Francis Burton’s “Parameters of Belief”

    Directory of Open Access Journals (Sweden)

    John Wallen

    2013-09-01

    Full Text Available Richard Burton has been interpreted and misinterpreted by literary critics as eminent as Edward Said and Louisa Pratt as well as by others such as Rana Kabbani and Reina Lewis. Biographers like Fawn Brody, Edward Rice, Mary Lovell and Jon Godsall have also had their say. Burton has been variously described as imperialist, sexist, gay, obssessed with pornography, racist, plagiarist, sexual libertine, scatologist, expert sociologist, profoundly deceitful and impotent. In spite of this negative press, interest in Burton is always high as his life and times are relevant to many scholars interested in the 19th century origins of modern thought and postcolonial ideas. In this paper presentation I will attempt to get beyond the confused and contradictory portrayals of Burton over the last 50 or so years by looking in some detail at Burton’s two long poems: Stone Talk and The Kasidah. In these works, published 15 years apart, Burton writes under pseudonyms and, as I will argue, is able to express many of his deepest beliefs, especially in The Kasidah where he is playing the part of Hadji Abu Al Yezid, a Sufi like-wise man who possesses some startling similarities to Burton himself. What emerges from this close examination of the texts is a sensitive relativist who, while adhering to the scientific method in all his practical dealings, is yet able to consider the possibility that everything we see around us and all our experience of the world might be, finally, nothing more than Maya and illusion.

  13. The Effect of Richard Wagner's Music and Beliefs on Hitler's Ideology

    Directory of Open Access Journals (Sweden)

    Carolyn S. Ticker

    2016-09-01

    Full Text Available The Holocaust will always be remembered as one of the most horrific and evil events in all of history. One question that has been so pervasive in regards to this historical event is the question of why. Why exactly did Hitler massacre the Jewish people? Why did he come to the conclusion that the Jews were somehow lesser than him, and that it was okay to kill them? What and who were his influences and how did they help form Hitler’s opinions leading up to the Holocaust? Although more than one situation or person influenced Hitler, I believe that one man in particular really helped contribute to Hitler’s ideas, especially about the Jewish people. This man is the famous musician Richard Wagner. While musicologists admit that Wagner was a musical genius, one aspect of his career that is hard to ignore is his strong antisemitism. In addition to speaking about his hatred for the Jews, he also wrote about it in his music, making it hard to glance over. Hitler had been close to the Wagner family, and had an obsessive, cult-like infatuation with Wagner’s music beginning in his childhood. This infatuation with Wagner’s music and his closeness to his later family helped facilitate and solidify his negative views about the Jewish people. In this paper I will explore the antisemitism that is within Wagner’s music and writing, and then I will discuss how Wagner’s antisemitism helped inform, influence, and shape Hitler’s ideas, indirectly assisting in the propagation of the Holocaust.

  14. Visiting Richard Serra’s Promenade sculpture improves postural control and judgment of subjective visual vertical.

    Directory of Open Access Journals (Sweden)

    Zoï eKapoula

    2014-12-01

    Full Text Available Body sway while maintaining an upright quiet stance reflects an active process of balance based on the integration of visual, vestibular, somatosensory and proprioceptive inputs. Richard Serra’s Promenade sculpture featured in the 2008 Monumenta exhibition at the Grand Palais in Paris, France is herein hypothesised to have stimulated the body’s vertical and longitudinal axes as it showcased 5 monumental rectangular solids pitched at a 1.69° angle.Using computerised dynamic posturography we measured the body sway of 23 visitors when fixating a cross, or when observing the artwork (fixating it or actively exploring it with eye movements before and after walking around and alongside the sculpture (i.e., before and after a promenade. A first fixation at the sculpture increased medio-lateral stability (in terms of spectral power of body sway. Eye movement exploration in the depth of the sculpture increased antero-posterior stability (in terms of spectral power and cancelling time of body sway at the expense of medio-lateral stability (in terms of cancelling time. Moreover, a medio-lateral instability associated with eye movement exploration before the promenade (in terms of body sway sensu stricto was cancelled after the promenade. Finally, the overall medio-lateral stability (in terms of spectral power increased after the promenade.Fourteen additional visitors were asked to sit in a dark room and adjust a luminous line to what they considered to be the earth-vertical axis. The promenade executed within the sculpted environment afforded by Serra’s monumental statuary works resulted in significantly improved performances on the subjective visual vertical test.We attribute these effects to the sculpted environment provided by the exhibition which may have acted as a kind of physiologic training ground thereby improving the visitors’ overall sense of visual perspective, equilibrium and gravity.

  15. Staging Unincorporated Power: Richard Harding Davis and the Critique of Imperial News

    Directory of Open Access Journals (Sweden)

    Nirmal Trivedi

    2011-12-01

    Full Text Available This essay contextualizes the work of war correspondent Richard Harding Davis within an evolving “imperial news apparatus” that would culminate in his reporting of the Spanish-American War. Critics have conventionally framed Davis squarely within the imperial cause, associating him with his admirer Roosevelt and naval admiral Alfred T. Mahan. Contrary to readings of Davis as an apologist for US imperialism, Trivedi contends that Davis understood how US imperial power relied on an information apparatus to communicate to an increasingly media-conscious American public through culture, that is, via familiar narratives, symbols, and objects—what Trivedi calls “imperial news.” The essay follows Davis’s development from his fictional representation of the new war correspondent in “The Reporter Who Made Himself King” to his own war correspondence before and after the Spanish-American War as collected in the memoirs A Year from a Reporter’s Notebook (1897, Cuba in War Time (1897, and Notes of a War Correspondent (1912. Davis’s war correspondence and fictional work effectively stage US imperialism as “unincorporated power”: that is, as power reliant on a developing news-making apparatus that deploys particular discursive strategies to validate its political claims. This staging critiques strategies of US imperial sovereignty—specifically its “privatization of knowledge” and its promotion of the war correspondent as nothing more than a spectator and purveyor of massacres.

  16. Charles Darwin, Richard Owen, and Natural Selection: A Question of Priority.

    Science.gov (United States)

    Johnson, Curtis N

    2018-05-03

    No single author presented Darwin with a more difficult question about his priority in discovering natural selection than the British comparative anatomist and paleontologist Richard Owen. Owen was arguably the most influential biologist in Great Britain in Darwin's time. Darwin wanted his approbation for what he believed to be his own theory of natural selection. Unfortunately for Darwin, when Owen first commented in publication about Darwin's theory of descent he was openly hostile (Edinb. Rev. vol. 111, Article VIII, 1860, pp. 487-533, anonymous). Darwin was taken off-guard. In private meetings and correspondence prior to 1860 Owen had been nothing but polite and friendly, even helping Darwin in cataloguing and analyzing Darwin's zoological specimens from the Beagle voyage. Every early indication predicted a life-long friendship and collaboration. But that was not to be. Owen followed his slashing review with a mounting campaign in the 1860s to denounce and discredit both Darwin and his small but ascendant circle of friends and supporters. But that was not enough for Owen. Starting in 1866, perhaps by now realizing Darwin had landed the big fish, Owen launched a new campaign, to claim the discovery of "Darwin's theory" for himself. Darwin naturally fought back, mainly in the "Historical Sketch" that he prefaced to Origin starting in 1861. But when we peel back the layers of personal animus and escalating vituperation we discover in fact their quarrel was generated more by mutual misunderstanding than scientific disagreement. The battle ended only when Darwin finally penetrated to the crux of the matter and put an end to the rivalry in 1872, in the final version of the Sketch.

  17. The reliability of the German version of the Richards Campbell Sleep Questionnaire.

    Science.gov (United States)

    Krotsetis, Susanne; Richards, Kathy C; Behncke, Anja; Köpke, Sascha

    2017-07-01

    The assessment of sleep quality in critically ill patients is a relevant factor of high-quality care. Despite the fact that sleep disturbances and insufficient sleep management contain an increased risk of severe morbidity for these patients, a translated and applicable instrument to evaluate sleep is not available for German-speaking intensive care settings. This study aimed to translate the Richards Campbell Sleep Questionnaire (RCSQ), a simple and validated instrument eligible for measuring sleep quality in critically ill patients, and subsequently to evaluate the internal consistency of the German version of the RCSQ. Furthermore, it also aimed to inquire into the perception of sleep in a sample of critically ill patients. The RCSQ was translated following established methodological standards. Data were collected cross-sectionally in a sample of 51 patients at 3 intensive care units at a university hospital in Germany. The German version of the RCSQ showed an overall internal consistency (Cronbach's alpha) of 0·88. The mean of the RSCQ in the sample was 47·00 (SD ± 27·57). Depth of sleep was rated the lowest and falling asleep again the highest of the RCSQ sleep items. The study demonstrated very good internal consistency of the German version of the RCSQ, allowing for its application in practice and research in German-speaking countries. Quality of sleep perception was generally low in this sample, emphasizing the need for enhanced care concepts regarding the sleep management of critically ill patients. Relevance to clinical practice Assessment of self-perception of sleep is crucial in order to plan an individually tailored care process. © 2017 British Association of Critical Care Nurses.

  18. An Enlightenment proposal for music therapy: Richard Brocklesby on music, spirit, and the passions.

    Science.gov (United States)

    Gouk, Penelope

    2015-01-01

    In 1749, the London physician Richard Brocklesby (1722-1797) published his Reflections on Antient [sic] and Modern Musick, an essay that not only sought to compare these practices in terms of their effects, but also to gather evidence supporting the use of music in treating mania and other mental diseases. As might be expected, Brocklesby's discussion of music therapy has already received attention by authors looking back to the origins of this practice, not least because he offers an account of a successful musical cure that took place in his own time (Rorke, 2001). My chapter, however, seeks to broaden the discussion of the Reflections, in order to show how Brocklesby's projected musical cures fit into his larger worldview, one that was influenced as much by Plato and other ancient philosophers as it was by modern thinkers such as Isaac Newton and his followers. Brocklesby's argument was essentially that music acted as a link between the mind and body and therefore could restore their intrinsic harmony, a connection that was mediated by the animal spirits, which also served as the vehicle of the passions. The movements and proportions of music could arouse or quell the passions by their effect on these (imaginary) spirits, which flowed through the nerves and brain and acted as the agent for the mind or soul. I show how his account of music in antiquity led him to reflect on the way that music was perceived and responded to in his own time, both as a stimulus to mental and bodily action, and as a source of esthetic pleasure through the cultivation of musical taste. © 2015 Elsevier B.V. All rights reserved.

  19. An experimental 'Life' for an experimental life: Richard Waller's biography of Robert Hooke (1705).

    Science.gov (United States)

    Moxham, Noah

    2016-03-01

    Richard Waller's 'Life of Dr Robert Hooke', prefixed to his edition of Hooke's Posthumous Works (1705), is an important source for the life of one of the most eminent members of the early Royal Society. It also has the distinction of being one of the earliest biographies of a man of science to be published in English. I argue that it is in fact the first biography to embrace the subject's natural-philosophical work as the centre of his life, and I investigate Waller's reasons for adopting this strategy and his struggle with the problem of how to represent an early experimental philosopher in print. I suggest that Waller eschews the 'Christian philosopher' tradition of contemporary biography - partly because of the unusually diverse and fragmentary nature of Hooke's intellectual output - and draws instead upon the structure of the Royal Society's archive as a means of organizing and understanding Hooke's life. The most quoted phrase from Waller's biography is that Hooke became 'to a crime close and reserved' in later life; this essay argues that Waller's biographical sketch was fashioned in order to undo the effects of that reserve. In modelling his approach very closely on the structure of the society's records he was principally concerned with making Hooke's work and biography accessible, intelligible and useful to the fellowship in a context familiar to them, a context which had provided the institutional framework for most of Hooke's adult life. I argue that Waller's 'Life' was also intended to make the largest claims for Hooke's intellectual standing that the author dared in the context of the enmity between Hooke and Isaac Newton once the latter became president of the Royal Society. However, I also adduce fresh manuscript evidence that Waller actually compiled, but did not publish, a defence of Hooke's claim to have discovered the inverse square law of gravity, allowing us to glimpse a much more assertive biography of Hooke than the published version.

  20. Timothy Leary, Richard Alpert (Ram Dass) and the changing definition of psilocybin.

    Science.gov (United States)

    Wark, Colin; Galliher, John F

    2010-05-01

    This research focuses on the events leading to the 1968 U.S. federal prohibition of psilocybin. It is a study of duelling moral entrepreneurs-Timothy Leary and Richard Alpert vs. the Harvard University Administration. The goal is to show how the primary active compound in an ostensibly harmless fungus (the psilocybin mushroom) became controversial in less than a decade. We used books, newspapers, magazine articles and previously unpublished materials (including documents from the Harvard Archives) to analyze Leary and Alpert's lives and careers through the early 1970s. The prohibition of psilocybin in the U.S. was largely a product of Leary and Alpert's involvement in the "Harvard drug scandal" and their transformation from Harvard professors to countercultural icons. They tested the substance on a variety of human subjects and in doing so piqued the interest of Harvard undergraduates while drawing condemnation from other faculty and Harvard administrators. This case is theoretically interesting because unlike most illegal drugs, psilocybin was never linked to a threatening minority group, but to some of the nation's most privileged youth. The Harvard administrators were not really moral entrepreneurs but Leary and Alpert clearly were. Although they were far from being prohibitionists, they were self-righteous crusaders on different but equally holy missions for the good of young and minority Americans. Ironically, due to their successes the possession of psilocybin was criminalized under United States federal law in 1968 (Pub. L. No. 90-639, Stat. 1361 1968 and Boire, 2002). This case study demonstrates that crusaders can be successful in changing culture even when laws are passed in futile attempts to control their behaviour, just as Leary predicted. Copyright 2009 Elsevier B.V. All rights reserved.

  1. Richard Doll and Alice Stewart: reputation and the shaping of scientific "truth".

    Science.gov (United States)

    Greene, Gayle

    2011-01-01

    As the world watched the Fukushima reactors release radionuclides into the ocean and atmosphere, the warnings of Dr. Alice Stewart about radiation risk and the reassurances of Sir Richard Doll assumed renewed relevance. Doll and Stewart, pioneer cancer epidemiologists who made major contributions in the 1950s-he by demonstrating the link between lung cancer and smoking, she by discovering that fetal X-rays double the chance of a childhood cancer-were locked into opposition about low-dose radiation risk. When she went public with the discovery that radiation at a fraction of the dose "known" to be dangerous could kill a child, her reputation plummeted, whereas Doll, foremost among her detractors, was knighted and lauded as "the world's most distinguished medical epidemiologist" for his work. Their lives and careers, so closely intertwined, took contrary courses, he becoming "more of the establishment" (as he said), while she became more oppositional. When it was discovered, after his death, that he'd been taking large sums of money from industries whose chemicals he was clearing of cancer risk, his reputation remained unscathed; it is now enshrined in the "Authorized Biography" (2009) commissioned by the Wellcome Institute, along with Doll's denigration of Stewart as an "embittered" woman and biased scientist. Stewart lived long enough to see radiation science move her way, to see international committees affirm, in the 1990s, that there is no threshold beneath which radiation ceases to be dangerous; recent evidence from Chernobyl is bearing out her warnings. But a look at the making and breaking of these reputations reveals the power of status, position, and image to shape scientific "knowledge" and social policy.

  2. Gravitational Waves from Primordial Black Holes and New Weak Scale Phenomena

    OpenAIRE

    Davoudiasl, Hooman; Giardino, Pier Paolo

    2016-01-01

    We entertain the possibility that primordialblack holes of mass $\\sim (10^{26}$--$10^{29})$~g, with Schwarzschild radii of $\\mathcal{O}{\\text{cm}}$, constitute $\\sim 10\\%$ or more of cosmic dark matter, as allowed by various constraints. These black holes would typically originate from cosmological eras corresponding to temperatures $\\mathcal{O}{10-100}$~GeV, and may be associated with first order phase transitions in the visible or hidden sectors. In case these small primordial black holes g...

  3. Low-Metallicity Blue Compact Dwarfs as Templates for Primordial Star Formation

    OpenAIRE

    Hunt, L. K.; Hirashita, H.; Thuan, T. X.; Izotov, Y. I.; Vanzi, L.

    2003-01-01

    Understanding how galaxies formed their first stars is a vital cosmological question, but the study of high-redshift objects, caught in the act of forming their first stars, is difficult. Here we argue that two extremely low-metallicity Blue Compact Dwarf galaxies (BCDs), IZw18 and SBS0335-052, could be local templates for primordial star formation, since both lack evolved ($> $1 Gyr) stellar populations; but they form stars differently.

  4. Cosmological Signature of the Standard Model Higgs Vacuum Instability: Primordial Black Holes as Dark Matter.

    Science.gov (United States)

    Espinosa, J R; Racco, D; Riotto, A

    2018-03-23

    For the current central values of the Higgs boson and top quark masses, the standard model Higgs potential develops an instability at a scale of the order of 10^{11}  GeV. We show that a cosmological signature of such instability could be dark matter in the form of primordial black holes seeded by Higgs fluctuations during inflation. The existence of dark matter might not require physics beyond the standard model.

  5. Neutrino burst of white dwarf being absorbed by a primordial black hole

    CERN Document Server

    Tikhomirov, V V

    2003-01-01

    Primordial black holes (PBHS) of masses M>=5x10 sup 4 g are able to absorb white dwarfs (WD), giving rise to formation of black holes of WD masses. The WD absorption is accomplained by up to 10 sup 5 sup 2 erg neutrino bursts which can be readily detected by modern neutrino detectors. We calculate time characteristics of such a burst in this paper. (authors)

  6. THE ROLE OF METHANOL IN THE CRYSTALLIZATION OF TITAN'S PRIMORDIAL OCEAN

    International Nuclear Information System (INIS)

    Deschamps, Frederic; Mousis, Olivier; Sanchez-Valle, Carmen; Lunine, Jonathan I.

    2010-01-01

    A key parameter that controls the crystallization of primordial oceans in large icy moons is the presence of anti-freeze compounds, which may have maintained primordial oceans over the age of the solar system. Here we investigate the influence of methanol, a possible anti-freeze candidate, on the crystallization of Titan's primordial ocean. Using a thermodynamic model of the solar nebula and assuming a plausible composition of its initial gas phase, we first calculate the condensation sequence of ices in Saturn's feeding zone, and show that in Titan's building blocks methanol can have a mass fraction of ∼4 wt% relative to water, i.e., methanol can be up to four times more abundant than ammonia. We then combine available data on the phase diagram of the water-methanol system and scaling laws derived from thermal convection to estimate the influence of methanol on the dynamics of the outer ice I shell and on the heat transfer through this layer. For a fraction of methanol consistent with the building blocks composition we determined, the vigor of convection in the ice I shell is strongly reduced. The effect of 5 wt% methanol is equivalent to that of 3 wt% ammonia. Thus, if methanol is present in the primordial ocean of Titan, the crystallization may stop, and a sub-surface ocean may be maintained between the ice I and high-pressure ice layers. A preliminary estimate indicates that the presence of 4 wt% methanol and 1 wt% ammonia may result in an ocean of thickness at least 90 km.

  7. Perchlorate Exposure Reduces Primordial Germ Cell Number in Female Threespine Stickleback.

    Directory of Open Access Journals (Sweden)

    Ann M Petersen

    Full Text Available Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14-18 days post fertilization (dpf. We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development.

  8. Exposure to Endocrine Disruptor Induces Transgenerational Epigenetic Deregulation of MicroRNAs in Primordial Germ Cells

    Czech Academy of Sciences Publication Activity Database

    Brieno-Enriguez, M. A.; García-López, J.; Cárdenas, D.B.; Guibert, S.; Cleroux, E.; Děd, Lukáš; de Dios Hourcade, J.; Pěknicová, Jana; Weber, M.; del Mazo, J.

    2015-01-01

    Roč. 10, č. 4 (2015) E-ISSN 1932-6203 R&D Projects: GA ČR(CZ) GAP503/12/1834; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : endocrine disruptor * epigenetic s * primordial germ cells * vinclozolin * TUNEL analysis * methylation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.057, year: 2015

  9. Microcephalic osteodysplastic primordial dwarfism type II (MOPD II) with multiple vascular complications misdiagnosed as Dubowitz syndrome

    OpenAIRE

    Dieks, Jana-Katharina; Baumer, Alessandra; Wilichowski, Ekkehard; Rauch, Anita; Sigler, Matthias

    2014-01-01

    To date, the genetic basis of Dubowitz syndrome (short stature, microcephaly, facial abnormalities, eczema) is unknown and vascular complications are not known to be associated with this syndrome. In microcephalic osteodysplastic primordial dwarfism type II (MOPD II; disproportionate short statue, microcephaly, facial abnormalities), however, cerebral aneurysms and other vascular abnormalities are frequent complications. MOPD II is a genetic disorder caused by mutations in the pericentrin (PC...

  10. Cosmological Signature of the Standard Model Higgs Vacuum Instability: Primordial Black Holes as Dark Matter

    Science.gov (United States)

    Espinosa, J. R.; Racco, D.; Riotto, A.

    2018-03-01

    For the current central values of the Higgs boson and top quark masses, the standard model Higgs potential develops an instability at a scale of the order of 1 011 GeV . We show that a cosmological signature of such instability could be dark matter in the form of primordial black holes seeded by Higgs fluctuations during inflation. The existence of dark matter might not require physics beyond the standard model.

  11. The safe use of a PTEN inhibitor for the activation of dormant mouse primordial follicles and generation of fertilizable eggs.

    Directory of Open Access Journals (Sweden)

    Deepak Adhikari

    Full Text Available Primordial ovarian follicles, which are often present in the ovaries of premature ovarian failure (POF patients or are cryopreserved from the ovaries of young cancer patients who are undergoing gonadotoxic anticancer therapies, cannot be used to generate mature oocytes for in vitro fertilization (IVF. There has been very little success in triggering growth of primordial follicles to obtain fertilizable oocytes due to the poor understanding of the biology of primordial follicle activation.We have recently reported that PTEN (phosphatase and tensin homolog deleted on chromosome ten prevents primordial follicle activation in mice, and deletion of Pten from the oocytes of primordial follicles leads to follicular activation. Consequently, the PTEN inhibitor has been successfully used in vitro to activate primordial follicles in both mouse and human ovaries. These results suggest that PTEN inhibitors could be used in ovarian culture medium to trigger the activation of primordial follicle. To study the safety and efficacy of the use of such inhibitors, we activated primordial follicles from neonatal mouse ovaries by transient treatment with a PTEN inhibitor bpV(HOpic. These ovaries were then transplanted under the kidney capsules of recipient mice to generate mature oocytes. The mature oocytes were fertilized in vitro and progeny mice were obtained after embryo transfer.Long-term monitoring up to the second generation of progeny mice showed that the mice were reproductively active and were free from any overt signs or symptoms of chronic illnesses. Our results indicate that the use of PTEN inhibitors could be a safe and effective way of generating mature human oocytes for use in novel IVF techniques.

  12. Gravitational wave signatures of inflationary models from Primordial Black Hole dark matter

    Energy Technology Data Exchange (ETDEWEB)

    García-Bellido, Juan [Instituto de Física Teórica UAM-CSIC, Universidad Autonóma de Madrid, Cantoblanco, Madrid, 28049 Spain (Spain); Peloso, Marco; Unal, Caner, E-mail: juan.garciabellido@uam.es, E-mail: peloso@physics.umn.edu, E-mail: unal@physics.umn.edu [School of Physics and Astronomy, and Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, Minnesota, 55455 (United States)

    2017-09-01

    Primordial Black Holes (PBH) could be the cold dark matter of the universe. They could have arisen from large (order one) curvature fluctuations produced during inflation that reentered the horizon in the radiation era. At reentry, these fluctuations source gravitational waves (GW) via second order anisotropic stresses. These GW, together with those (possibly) sourced during inflation by the same mechanism responsible for the large curvature fluctuations, constitute a primordial stochastic GW background (SGWB) that unavoidably accompanies the PBH formation. We study how the amplitude and the range of frequencies of this signal depend on the statistics (Gaussian versus χ{sup 2}) of the primordial curvature fluctuations, and on the evolution of the PBH mass function due to accretion and merging. We then compare this signal with the sensitivity of present and future detectors, at PTA and LISA scales. We find that this SGWB will help to probe, or strongly constrain, the early universe mechanism of PBH production. The comparison between the peak mass of the PBH distribution and the peak frequency of this SGWB will provide important information on the merging and accretion evolution of the PBH mass distribution from their formation to the present era. Different assumptions on the statistics and on the PBH evolution also result in different amounts of CMB μ-distortions. Therefore the above results can be complemented by the detection (or the absence) of μ-distortions with an experiment such as PIXIE.

  13. Primordial non-Gaussianity and power asymmetry with quantum gravitational effects in loop quantum cosmology

    Science.gov (United States)

    Zhu, Tao; Wang, Anzhong; Kirsten, Klaus; Cleaver, Gerald; Sheng, Qin

    2018-02-01

    Loop quantum cosmology provides a resolution of the classical big bang singularity in the deep Planck era. The evolution, prior to the usual slow-roll inflation, naturally generates excited states at the onset of the slow-roll inflation. It is expected that these quantum gravitational effects could leave its fingerprints on the primordial perturbation spectrum and non-Gaussianity, and lead to some observational evidences in the cosmic microwave background. While the impact of the quantum effects on the primordial perturbation spectrum has been already studied and constrained by current data, in this paper we continue to study such effects but now on the non-Gaussianity of the primordial curvature perturbations. We present detailed and analytical calculations of the non-Gaussianity and show explicitly that the corrections due to the quantum effects are at the same magnitude of the slow-roll parameters in the observable scales and thus are well within current observational constraints. Despite this, we show that the non-Gaussianity in the squeezed limit can be enhanced at superhorizon scales and it is these effects that can yield a large statistical anisotropy on the power spectrum through the Erickcek-Kamionkowski-Carroll mechanism.

  14. Reconstruction of the primordial power spectrum of curvature perturbations using multiple data sets

    DEFF Research Database (Denmark)

    Hunt, Paul; Sarkar, Subir

    2014-01-01

    Detailed knowledge of the primordial power spectrum of curvature perturbations is essential both in order to elucidate the physical mechanism (`inflation') which generated it, and for estimating the cosmological parameters from observations of the cosmic microwave background and large-scale struc......Detailed knowledge of the primordial power spectrum of curvature perturbations is essential both in order to elucidate the physical mechanism (`inflation') which generated it, and for estimating the cosmological parameters from observations of the cosmic microwave background and large...... content of the universe. Moreover the deconvolution problem is ill-conditioned so a regularisation scheme must be employed to control error propagation. We demonstrate that `Tikhonov regularisation' can robustly reconstruct the primordial spectrum from multiple cosmological data sets, a significant...... advantage being that both its uncertainty and resolution are then quantified. Using Monte Carlo simulations we investigate several regularisation parameter selection methods and find that generalised cross-validation and Mallow's Cp method give optimal results. We apply our inversion procedure to data from...

  15. Constraining Primordial Black Holes with the EDGES 21-cm Absorption Signal arXiv

    CERN Document Server

    Hektor, Andi; Marzola, Luca; Raidal, Martti; Vaskonen, Ville; Veermäe, Hardi

    The EDGES experiment has recently measured an anomalous global 21-cm spectrum due to hydrogen absorptions at redshifts of about $z\\sim 17$. Model independently, the unusually low temperature of baryons probed by this observable sets strong constraints on any physical process that transfers energy into the baryonic environment at such redshifts. Here we make use of the 21-cm spectrum to derive bounds on the energy injection due to a possible population of ${\\cal O}(1-100) M_\\odot$ primordial black holes, which induce a wide spectrum of radiation during the accretion of the surrounding gas. After calculating the total radiative intensity of a primordial black hole population, we estimate the amount of heat and ionisations produced in the baryonic gas and compute the resulting thermal history of the Universe with a modified version of RECFAST code. Finally, by imposing that the temperature of the gas at $z\\sim 17$ does not exceed the indications of EDGES, we constrain the possible abundance of primordial black h...

  16. Hunting for primordial non-Gaussianity in the cosmic microwave background

    International Nuclear Information System (INIS)

    Komatsu, Eiichiro

    2010-01-01

    Since the first limit on the (local) primordial non-Gaussianity parameter, f NL , was obtained from the Cosmic Background Explorer (COBE) data in 2002, observations of the cosmic microwave background (CMB) have been playing a central role in constraining the amplitudes of various forms of non-Gaussianity in primordial fluctuations. The current 68% limit from the 7-year data of the Wilkinson Microwave Anisotropy Probe (WMAP) is f NL = 32 ± 21, and the Planck satellite is expected to reduce the uncertainty by a factor of 4 in a few years from now. If f NL >> 1 is found by Planck with high statistical significance, all single-field models of inflation would be ruled out. Moreover, if the Planck satellite finds f NL ∼ 30, then it would be able to test a broad class of multi-field models using the 4-point function (trispectrum) test of τ NL ≥ (6f NL /5) 2 . In this paper, we review the methods (optimal estimator), results (WMAP 7-year) and challenges (secondary anisotropy, second-order effect and foreground) of measuring primordial non-Gaussianity from the CMB data, present a science case for the trispectrum and conclude with future prospects.

  17. Trojan Horse cross section measurements and their impact on primordial nucleosynthesis

    Science.gov (United States)

    Pizzone, R. G.; Spartá, R.; Bertulani, C.; Spitaleri, C.; La Cognata, M.; Lamia, L.; Mukhamedzhanov, A.; Tumino, A.

    2018-01-01

    Big Bang Nucleosynthesis (BBN) nucleosynthesis requires several nuclear physics inputs and, among them, an important role is played by nuclear reaction rates. They are among the most important input for a quantitative description of the early Universe. An up-to-date compilation of direct cross sections of d(d,p)t, d(d,n)3He and 3He(d,p)4He reactions is given, being these ones among the most uncertain bare-nucleus cross sections. An intense experimental effort has been carried on in the last decade to apply the Trojan Horse Method (THM) to study reactions of relevance for the BBN and measure their astrophysical S(E)-factor. The result of these recent measurements is reviewed and compared with the available direct data. The reaction rates and the relative error for the four reactions of interest are then numerically calculated in the temperature ranges of relevance for BBN (0.01primordial nucleosynthesis calculations in order to evaluate their impact on the calculated primordial abundances of D, 3,4He and 7Li. These ones were then compared with the observational primordial abundance estimates in different astrophysical sites. A comparison was also performed with calculations using other reaction rates compilations available in literature.

  18. Lyman-alpha clouds as a relic of primordial density fluctuations

    International Nuclear Information System (INIS)

    Bond, J.R.; Szalay, A.S.; Silk, J.

    1988-01-01

    Primordial density fluctuations are studied using a CDM model and primordial clouds some of which are expanding, driven by pressure gradients created when the medium is photionized, and some of which are massive enough to continue collapsing in spite of the pressure. Normalization of CDM models to the clustering properties on large scales are used to predict the parameters of collapsing clouds of subgalactic mass at early epochs. It is shown that the abundance and dimensions of these clouds are comparable to those of the Lyman-alpha systems. The evolutionary history of the clouds is computed, utilizing a spherically symmetric hydrodynamics code with the dark matter treated as a collisionless fluid, and the H I column density distribution is evaluated as a function of N(H I) and redshift. The observed cloud parameters come out naturally in the CDM model and suggest that Lyman-alpha clouds are the missing link between primordial density fluctuations and the formation of galaxies. 31 references

  19. Constraints on dark matter particles charged under a hidden gauge group from primordial black holes

    International Nuclear Information System (INIS)

    Dai, De-Chang; Stojkovic, Dejan; Freese, Katherine

    2009-01-01

    In order to accommodate increasingly tighter observational constraints on dark matter, several models have been proposed recently in which dark matter particles are charged under some hidden gauge group. Hidden gauge charges are invisible for the standard model particles, hence such scenarios are very difficult to constrain directly. However black holes are sensitive to all gauge charges, whether they belong to the standard model or not. Here, we examine the constraints on the possible values of the dark matter particle mass and hidden gauge charge from the evolution of primordial black holes. We find that the existence of the primordial black holes with reasonable mass is incompatible with dark matter particles whose charge to mass ratio is of the order of one. For dark matter particles whose charge to mass ratio is much less than one, we are able to exclude only heavy dark matter in the mass range of 10 11 GeV–10 16 GeV. Finally, for dark matter particles whose charge to mass ratio is much greater than one, there are no useful limits coming from primordial black holes

  20. Influence of large local and non-local bispectra on primordial black hole abundance

    International Nuclear Information System (INIS)

    Young, Sam; Regan, Donough; Byrnes, Christian T.

    2016-01-01

    Primordial black holes represent a unique probe to constrain the early universe on small scales—providing the only constraints on the primordial power spectrum on the majority of scales. However, these constraints are strongly dependent on even small amounts of non-Gaussianity, which is unconstrained on scales significantly smaller than those visible in the CMB. This paper goes beyond previous considerations to consider the effects of a bispectrum of the equilateral, orthogonal and local shapes with arbitrary magnitude upon the abundance of primordial black holes. Non-Gaussian density maps of the early universe are generated from a given bispectrum and used to place constraints on the small scale power spectrum. When small, we show that the skewness provides an accurate estimate for how the constraint depends on non-Gaussianity, independently of the shape of the bispectrum. We show that the orthogonal template of non-Gaussianity has an order of magnitude weaker effect on the constraints than the local and equilateral templates

  1. Exact and grid-free solutions to the Lighthill-Whitham-Richards traffic flow model with bounded acceleration for a class of fundamental diagrams

    KAUST Repository

    Qiu, Shanwen; Abdelaziz, Mohamed Ewis; Abdel Latif, Fadl Hicham Fadl; Claudel, Christian G.

    2013-01-01

    In this article, we propose a new exact and grid-free numerical scheme for computing solutions associated with an hybrid traffic flow model based on the Lighthill-Whitham-Richards (LWR) partial differential equation, for a class of fundamental

  2. Süüme sundis vabrikujuhti palgatööliseks jääma / Richard Mutso ; interv. Jüri Saar

    Index Scriptorium Estoniae

    Mutso, Richard, 1933-

    2003-01-01

    Intervjuu Võru mööblitehase Wermo peadirektorina töötanud, praeguse tehase nõukogu liikme Richard Mutsoga tehase juhtimisest, euroreferendumist, eraelust. Kommenteerivad: Silva Mutso, Veljo Ipits

  3. Justiça e sociedade liberal em Richard Rorty: justiça como lealdade e o projeto social de uma utopia

    Directory of Open Access Journals (Sweden)

    Marcelo de Almeida Silva

    2014-07-01

    Full Text Available O presente texto pretende explorar o conceito de justiça de Richard Rorty e a proposta da Utopia Liberal que o autor apresenta. Para tanto, explora, dentro da obra de Richard Rorty e de alguns autores com quem dialoga, contribuições para o debate da concepção do termo Justiça como um senso de lealdade ampliada e de sua proposta para uma sociedade mais justa, igualitária e inclusiva.   Abstract: This paper aims to explore the concept of justice from Richard Rorty and his proposal about the idea of a Liberal Utopia. With this goal we seek, within the work of Richard Rorty, and some authors with whom he converses, contributions to the discussion of the conception of justice as an expanded sense of loyalty and his proposal for a fairer, equitable and inclusive society.   Resumen: Este trabajo se propone explorar el concepto de justicia de Richard Rorty y la propuesta de liberal utopía que el autor presenta. Con este objetivo, vamos a buscar en la obra de Richard Rorty, y algunos autores con los que conversa, contribuciones a la discusión sobre la concepción de la justicia como un sentido más amplio de la lealtad y su propuesta de una sociedad más justa, equitativa e incluyente.

  4. Learning

    Directory of Open Access Journals (Sweden)

    Mohsen Laabidi

    2014-01-01

    Full Text Available Nowadays learning technologies transformed educational systems with impressive progress of Information and Communication Technologies (ICT. Furthermore, when these technologies are available, affordable and accessible, they represent more than a transformation for people with disabilities. They represent real opportunities with access to an inclusive education and help to overcome the obstacles they met in classical educational systems. In this paper, we will cover basic concepts of e-accessibility, universal design and assistive technologies, with a special focus on accessible e-learning systems. Then, we will present recent research works conducted in our research Laboratory LaTICE toward the development of an accessible online learning environment for persons with disabilities from the design and specification step to the implementation. We will present, in particular, the accessible version “MoodleAcc+” of the well known e-learning platform Moodle as well as new elaborated generic models and a range of tools for authoring and evaluating accessible educational content.

  5. The effects of coal dust on photosynthetic performance of the mangrove, Avicennia marina in Richards Bay, South Africa

    International Nuclear Information System (INIS)

    Naidoo, G.; Chirkoot, D.

    2004-01-01

    Richards Bay, on the northern KwaZulu-Natal coast, is the largest coal exporting port in South Africa. The coal is stored at the Richards Bay Coal Terminal (RBCT) prior to export. Dust from coal operations is a major problem in the Richards Bay area. In this study, we tested the hypothesis that coal dust adversely affects photosynthetic performance of Avicennia marina (Forssk.) Vierh., the dominant mangrove species in the harbour. Photosynthetic performance was determined on 10 trees by measuring carbon dioxide uptake and chlorophyll fluorescence parameters at two elevation sites and on upper and lower leaf surfaces that were covered or uncovered with coal dust. Measurements were made on five clear, sunny days at saturating light (>1000 μmol m -2 s -1 ) and high temperature (28-30 deg. C). Coal dust significantly reduced carbon dioxide exchange of upper and lower leaf surfaces by 17-39%, the reduction being generally greater on the lower leaf surface that is covered by a dense mat of trichomes and salt glands. The reduction in carbon dioxide exchange by coal dust was higher at the high elevation site that supported isolated dwarfed trees. The chlorophyll fluorescence data indicated that leaves coated with dust exhibited significantly lower photosystem II (PS II) quantum yield, lower electron transport rate (ETR) through PSII and reduced quantum efficiency of PSII (F v F m ). The chlorophyll fluorescence data supported the gas exchange measurements and are consistent with reduced photosynthetic performance of leaves coated with coal dust. - Coal dust reduced photosynthetic performance of the mangrove, Avicennia marina

  6. O ateísmo de Richard Dawkins nas fronteiras da ciência evolucionista e do senso comum

    OpenAIRE

    Franco, Clarissa de

    2014-01-01

    O objeto de estudo consiste nas principais ideias ateístas de Richard Dawkins e na recepção destas por parte dos ateus inseridos na cultura brasileira. Dawkins é um dos principais divulgadores e militantes do movimento ateísta da atualidade, e a despeito de sua faceta pública divulgada em sites mundiais e em livros de reconhecido sucesso existem debates do autor, concernentes aos espaços acadêmicos e restritos a cientistas, que nem sempre se apresentam congruentes às suas e...

  7. Genetics and the origin of species: the continuing synthesis a symposium in honor of Richard G. Harrison

    Science.gov (United States)

    Grosberg, Richard K.; Rand, David M.; Normark, Benjamin B.

    2013-01-01

    This is a special issue of Genetica that has its origins in a symposium held in honor of Richard G. Harrison at Ithaca, New York on July 22–23. Former students of Rick Harrison organized the symposium and most of the speakers were former students, as well. The quality and breadth of the talks were a testament to Rick’s influence as a thinker, synthesizer, and mentor and it is only appropriate to reflect on Rick’s contributions to the fields of evolutionary ecology, systematics, and genetics in this preface to the symposium articles. PMID:21152955

  8. Development of steroid signaling pathways during primordial follicle formation in the human fetal ovary.

    Science.gov (United States)

    Fowler, Paul A; Anderson, Richard A; Saunders, Philippa T; Kinnell, Hazel; Mason, J Ian; Evans, Dean B; Bhattacharya, Siladitya; Flannigan, Samantha; Franks, Stephen; Monteiro, Ana; O'Shaughnessy, Peter J

    2011-06-01

    Ovarian primordial follicle formation is critical for subsequent human female fertility. It is likely that steroid, and especially estrogen, signaling is required for this process, but details of the pathways involved are currently lacking. The aim was to identify and characterize key members of the steroid-signaling pathway expressed in the second trimester human fetal ovary. We conducted an observational study of the female fetus, quantifying and localizing steroid-signaling pathway members. The study was conducted at the Universities of Aberdeen, Edinburgh, and Glasgow. Ovaries were collected from 43 morphologically normal human female fetuses from women undergoing elective termination of second trimester pregnancies. We measured mRNA transcript levels and immunolocalized key steroidogenic enzymes and steroid receptors, including those encoded by ESR2, AR, and CYP19A1. Levels of mRNA encoding the steroidogenic apparatus and steroid receptors increased across the second trimester. CYP19A1 transcript increased 4.7-fold during this period with intense immunostaining for CYP19A detected in pregranulosa cells around primordial follicles and somatic cells around oocyte nests. ESR2 was localized primarily to germ cells, but androgen receptor was exclusively expressed in somatic cells. CYP17A1 and HSD3B2 were also localized to oocytes, whereas CYP11A1 was detected in oocytes and some pregranulosa cells. The human fetal ovary expresses the machinery to produce and detect multiple steroid signaling pathways, including estrogenic signaling, with the oocyte acting as a key component. This study provides a step-change in our understanding of local dynamics of steroid hormone signaling during the key period of human primordial follicle formation.

  9. Extreme scenarios: the tightest possible constraints on the power spectrum due to primordial black holes

    Science.gov (United States)

    Cole, Philippa S.; Byrnes, Christian T.

    2018-02-01

    Observational constraints on the abundance of primordial black holes (PBHs) constrain the allowed amplitude of the primordial power spectrum on both the smallest and the largest ranges of scales, covering over 20 decades from 1‑1020/ Mpc. Despite tight constraints on the allowed fraction of PBHs at their time of formation near horizon entry in the early Universe, the corresponding constraints on the primordial power spectrum are quite weak, typically Script PRlesssim 10‑2 assuming Gaussian perturbations. Motivated by recent claims that the evaporation of just one PBH would destabilise the Higgs vacuum and collapse the Universe, we calculate the constraints which follow from assuming there are zero PBHs within the observable Universe. Even if evaporating PBHs do not collapse the Universe, this scenario represents the ultimate limit of observational constraints. Constraints can be extended on to smaller scales right down to the horizon scale at the end of inflation, but where power spectrum constraints already exist they do not tighten significantly, even though the constraint on PBH abundance can decrease by up to 46 orders of magnitude. This shows that no future improvement in observational constraints can ever lead to a significant tightening in constraints on inflation (via the power spectrum amplitude). The power spectrum constraints are weak because an order unity perturbation is required in order to overcome pressure forces. We therefore consider an early matter dominated era, during which exponentially more PBHs form for the same initial conditions. We show this leads to far tighter constraints, which approach Script PRlesssim10‑9, albeit over a smaller range of scales and are very sensitive to when the early matter dominated era ends. Finally, we show that an extended early matter era is incompatible with the argument that an evaporating PBH would destroy the Universe, unless the power spectrum amplitude decreases by up to ten orders of magnitude.

  10. Time evolution of primordial magnetic fields and present day extragalactic magnetism

    International Nuclear Information System (INIS)

    Saveliev, Andrey

    2014-05-01

    The topic of the present thesis is the time evolution of Primordial Magnetic Fields which have been generated in the Early Universe. Assuming this so-called Cosmological Scenario of magnetogenesis to be true, it is shown in the following that this would account for the present day Extragalactic Magnetic Fields. This is particularly important in light of recent gamma ray observations which are used to derive a lower limit for the corresponding magnetic field strength, even though also an alternative approach, claiming instead that these observations are due to interactions with the Intergalactic Medium, is possible and will be tested here with Monte Carlo simulations. In order to describe the aforementioned evolution of Primordial Magnetic Fields, a set of general Master Equations for the spectral magnetic, kinetic and helical components of the system are derived and then solved numerically for the Early Universe. This semianalytical method allows it to perform a full quantitative study for the time development of the power spectra, in particular by fully taking into account the backreaction of the turbulent medium onto the magnetic fields. Applying the formalism to non-helical Primordial Magnetic Fields created on some characteristic length measure, it is shown that on large scales L their spectrum 5 builds up a slope which behaves as B∝L -(5)/(2) and governs the evolution of the coherence (or integral) scale. In addition, the claim of equipartition between the magnetic and the kinetic energy is found to be true. Extending the analysis to helical magnetic fields, it is observed that the time evolution changes dramatically, hence confirming quantitatively that an Inverse Cascade, i.e. an efficient transport of energy from small to large scales, as predicted in previous works, indeed does take place.

  11. DEHP exposure impairs mouse oocyte cyst breakdown and primordial follicle assembly through estrogen receptor-dependent and independent mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Xinyi [Laboratory of Reproductive Biology, Chongqing Medical University, Chongqing 400016 (China); Department of Histology and Embryology, College of Basic Medicine, Chongqing Medical University, Chongqing 400016 (China); Liao, Xinggui; Chen, Xuemei; Li, Yanli; Wang, Meirong; Shen, Cha; Zhang, Xue; Wang, Yingxiong; Liu, Xueqing [Laboratory of Reproductive Biology, Chongqing Medical University, Chongqing 400016 (China); He, Junlin, E-mail: hejunlin_11@aliyun.com [Laboratory of Reproductive Biology, Chongqing Medical University, Chongqing 400016 (China)

    2015-11-15

    Highlights: • DEHP inhibits primordial folliculogenesis in vivo and in vitro. • Estrogen receptors participate in the effect of DEHP on early ovarian development. • DEHP exposure impairs the expression of Notch2 signaling components. • DEHP exposure disrupts the proliferation of pregranulosa precursor cells. - Abstract: Estrogen plays an essential role in the development of mammalian oocytes, and recent studies suggest that it also regulates primordial follicle assembly in the neonatal ovaries. During the last decade, potential exposure of humans and animals to estrogen-like endocrine disrupting chemicals has become a growing concern. In the present study, we focused on the effect of diethylhexyl phthalate (DEHP), a widespread plasticizer with estrogen-like activity, on germ-cell cyst breakdown and primordial follicle assembly in the early ovarian development of mouse. Neonatal mice injected with DEHP displayed impaired cyst breakdown. Using ovary organ cultures, we revealed that impairment was mediated through estrogen receptors (ERs), as ICI 182,780, an efficient antagonist of ER, reversed this DEHP-mediated effect. DEHP exposure reduced the expression of ERβ, progesterone receptor (PR), and Notch2 signaling components. Finally, DEHP reduced proliferation of pregranulosa precursor cells during the process of primordial folliculogenesis. Together, our results indicate that DEHP influences oocyte cyst breakdown and primordial follicle formation through several mechanisms. Therefore, exposure to estrogen-like chemicals during fetal or neonatal development may adversely influence early ovarian development.

  12. Primordial helium abundance from CMB: A constraint from recent observations and a forecast

    International Nuclear Information System (INIS)

    Ichikawa, Kazuhide; Sekiguchi, Toyokazu; Takahashi, Tomo

    2008-01-01

    We studied a constraint on the primordial helium abundance Y p from current and future observations of CMB. Using the currently available data from WMAP, ACBAR, CBI, and BOOMERANG, we obtained the constraint as Y p =0.25 -0.07 +0.10 at 68% confidence level. We also provide a forecast for the Planck experiment using the Markov chain Monte Carlo approach. In addition to forecasting the constraint on Y p , we investigate how assumptions for Y p affect constraints on the other cosmological parameters.

  13. Effective field theory of statistical anisotropies for primordial bispectrum and gravitational waves

    Energy Technology Data Exchange (ETDEWEB)

    Rostami, Tahereh; Karami, Asieh; Firouzjahi, Hassan, E-mail: t.rostami@ipm.ir, E-mail: karami@ipm.ir, E-mail: firouz@ipm.ir [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2017-06-01

    We present the effective field theory studies of primordial statistical anisotropies in models of anisotropic inflation. The general action in unitary gauge is presented to calculate the leading interactions between the gauge field fluctuations, the curvature perturbations and the tensor perturbations. The anisotropies in scalar power spectrum and bispectrum are calculated and the dependence of these anisotropies to EFT couplings are presented. In addition, we calculate the statistical anisotropy in tensor power spectrum and the scalar-tensor cross correlation. Our EFT approach incorporates anisotropies generated in models with non-trivial speed for the gauge field fluctuations and sound speed for scalar perturbations such as in DBI inflation.

  14. Search for a resonant enhancement of the 7Be + d reaction and primordial 7Li abundances

    International Nuclear Information System (INIS)

    O'Malley, Patrick; Adekola, A.S.; Cizewski, J.A.; Howard, M.E.; Strauss, S.; Bardayan, Daniel W.; Chae, Kyung Yuk; Nesaraja, Caroline D.; Pain, Steven D.; Smith, Michael Scott; Ahn, S.H.; Jones, K.L.; Pittman, S.T.; Schmitt, Kyle; Graves, S.; Kozub, R.L.; Shriner, J.F. Jr.; Wheeler, J.L.; Linhardt, Laura; Matos, M.; Moazen, B.M.; Peters, W.A.; Spassova, I.

    2011-01-01

    Big Bang nucleosynthesis calculations, constrained by the Wilkinson Microwave Anisotropy Probe results, produce 7 Li abundances almost a factor of four larger than those extrapolated from observations. Since primordial 7 Li is believed to be mostly produced by the beta decay of 7 Be, one proposed solution to this discrepancy is a resonant enhancement of the 7 Be(d,p)2α reaction rate through the 5/2 + 16.7-MeV state in 9 B. The 2 H( 7 Be,d) 7 Be reaction was used to search for such a resonance; none was observed. An upper limit on the width of the proposed resonance was deduced.

  15. New X-ray bound on density of primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Yoshiyuki [Institute of Space and Astronautical Science JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Kusenko, Alexander, E-mail: yinoue@astro.isas.jaxa.jp, E-mail: kusenko@ucla.edu [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States)

    2017-10-01

    We set a new upper limit on the abundance of primordial black holes (PBH) based on existing X-ray data. PBH interactions with interstellar medium should result in significant fluxes of X-ray photons, which would contribute to the observed number density of compact X-ray objects in galaxies. The data constrain PBH number density in the mass range from a few M {sub ⊙} to 2× 10{sup 7} M {sub ⊙}. PBH density needed to account for the origin of black holes detected by LIGO is marginally allowed.

  16. A new spin on primordial hydrogen recombination and a refined model for spinning dust radiation

    Science.gov (United States)

    Ali-Haimoud, Yacine

    2011-08-01

    This thesis describes theoretical calculations in two subjects: the primordial recombination of the electron-proton plasma about 400,000 years after the Big Bang and electric dipole radiation from spinning dust grains in the present-day interstellar medium. Primordial hydrogen recombination has recently been the subject of a renewed attention because of the impact of its theoretical uncertainties on predicted cosmic microwave background (CMB) anisotropy power spectra. The physics of the primordial recombination problem can be divided into two qualitatively different aspects. On the one hand, a detailed treatment of the non-thermal radiation field in the optically thick Lyman lines is required for an accurate recombination history near the peak of the visibility function. On the other hand, stimulated recombinations and out-of equilibrium effects are important at late times and a multilevel calculation is required to correctly compute the low-redshift end of the ionization history. Another facet of the problem is the requirement of computational efficiency, as a large number of recombination histories must be evaluated in Markov chains when analyzing CMB data. In this thesis, an effective multilevel atom method is presented, that speeds up multilevel atom computations by more than 5 orders of magnitude. The impact of previously ignored radiative transfer effects is quantified, and explicitly shown to be negligible. Finally, the numerical implementation of a fast and highly accurate primordial recombination code partly written by the author is described. The second part of this thesis is devoted to one of the potential galactic foregrounds for CMB experiments: the rotational emission from small dust grains. The rotational state of dust grains is described, first classically, and assuming that grains are rotating about their axis of greatest inertia. This assumption is then lifted, and a quantum-mechanical calculation is presented for disk-like grains with a

  17. Primordial Non-Gaussianity in the Large-Scale Structure of the Universe

    Directory of Open Access Journals (Sweden)

    Vincent Desjacques

    2010-01-01

    generated the cosmological fluctuations observed today. Any detection of significant non-Gaussianity would thus have profound implications for our understanding of cosmic structure formation. The large-scale mass distribution in the Universe is a sensitive probe of the nature of initial conditions. Recent theoretical progress together with rapid developments in observational techniques will enable us to critically confront predictions of inflationary scenarios and set constraints as competitive as those from the Cosmic Microwave Background. In this paper, we review past and current efforts in the search for primordial non-Gaussianity in the large-scale structure of the Universe.

  18. Berry phase of primordial scalar and tensor perturbations in single-field inflationary models

    Science.gov (United States)

    Balajany, Hamideh; Mehrafarin, Mohammad

    2018-06-01

    In the framework of the single-field slow-roll inflation, we derive the Hamiltonian of the linear primordial scalar and tensor perturbations in the form of time-dependent harmonic oscillator Hamiltonians. We find the invariant operators of the resulting Hamiltonians and use their eigenstates to calculate the adiabatic Berry phase for sub-horizon modes in terms of the Lewis-Riesenfeld phase. We conclude by discussing the discrepancy in the results of Pal et al. (2013) [21] for these Berry phases, which is resolved to yield agreement with our results.

  19. Observing trans-Planckian ripples in the primordial power spectrum with future large scale structure probes

    DEFF Research Database (Denmark)

    Hamann, Jan; Hannestad, Steen; Sloth, Martin Snoager

    2008-01-01

    We revisit the issue of ripples in the primordial power spectra caused by trans-Planckian physics, and the potential for their detection by future cosmological probes. We find that for reasonably large values of the first slow-roll parameter epsilon (> 0.001), a positive detection of trans......-Planckian ripples can be made even if the amplitude is as low as 10^-4. Data from the Large Synoptic Survey Telescope (LSST) and the proposed future 21 cm survey with the Fast Fourier Transform Telescope (FFTT) will be particularly useful in this regard. If the scale of inflation is close to its present upper bound...

  20. Primordial membranes

    DEFF Research Database (Denmark)

    Hanczyc, Martin M; Monnard, Pierre-Alain

    2017-01-01

    Cellular membranes, which are self-assembled bilayer structures mainly composed of lipids, proteins and conjugated polysaccharides, are the defining feature of cell physiology. It is likely that the complexity of contemporary cells was preceded by simpler chemical systems or protocells during...... the various evolutionary stages that led from inanimate to living matter. It is also likely that primitive membranes played a similar role in protocell 'physiology'. The composition of such ancestral membranes has been proposed as mixtures of single hydrocarbon chain amphiphiles, which are simpler versions...