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Sample records for hawkes rex horton

  1. Ivor Horton's Beginning Java

    CERN Document Server

    Horton, Ivor

    2011-01-01

    Find out why thousands have turned to Ivor Horton for learning Java Ivor Horton's approach is teaching Java is so effective and popular that he is one of the leading authors of introductory programming tutorials, with over 160,000 copies of his Java books sold. In this latest edition, whether you're a beginner or an experienced programmer switching to Java, you'll learn how to build real-world Java applications using Java SE 7. The author thoroughly covers the basics as well as new features such as extensions and classes; extended coverage of the Swing Application Framework; and he does it all

  2. 1982 Horton Medalist

    Science.gov (United States)

    Chapman, Thomas G.; Philip, J. R.

    The names of Horton and Philip occur together so frequently in any discussion of infiltration that it is particularly appropriate that John R. Philip should be the recipient of the Robert E. Horton Medal. In 1931, Horton emphasized the need for ‘research to provide connective tissue between related problems,’ and Philip's achievements have gone far toward satisfying that need.John R. Philip was born at Ballarat, some 70 miles from Melbourne, and attended Melbourne University, graduating as bachelor of civil engineering in 1946. After a few years of engineering experience with Queensland's Irrigation Commission, he took up a position as research scientist in the Commonwealth Scientific and Industrial Research Organization (CSIRO) in 1951. He moved rapidly from analysis of the hydraulics of border irrigation to the general problems of infiltration and soil water movement and found analytical solutions to a wide range of problems in homogeneous porous media. In 1957, Philip and his colleague D. A. de Vries were awarded the Horton prize of the AGU for their paper on moisture movement in porous materials under temperature gradients. In 1960, Melbourne University awarded John Philip his doctorate of science for a thesis, ‘Physical Contributions to Microhydrology,’ consisting of 19 published papers.

  3. Ivor Horton's beginning visual C++ 2013

    CERN Document Server

    Horton, Ivor

    2014-01-01

    Learn C++ with the best tutorial on the market! Horton's unique tutorial approach and step-by-step guidance have helped over 100,000 novice programmers learn C++. In Ivor Horton's Beginning Visual C++ 2013, Horton not only guides you through the fundamentals of the standard C++ language, but also teaches you how C++ is used in the latest Visual Studio 2013 environment. Visual Studio 2013 includes major changes to the IDE and expanded options for C++ coding. Ivor Horton's Beginning Visual C++ 2013 will teach you the latest techniques to take your Visual C++ coding to an all-new level.C++ langua

  4. Do You Hear What Horton Hears?

    Science.gov (United States)

    Snyder, Robert; Johnson, Jordan

    2010-01-01

    "I've never heard of a small speck of dust that is able to yell" says Horton of a sound he hears well (Geisel 1954). It is always valuable to connect science to student's interests and their everyday world--so what better way to teach concepts relating to sound than to read "Horton Hears a Who" by Dr. Seuss? Here the authors present several…

  5. Horton tõttab appi / Harro Puusild

    Index Scriptorium Estoniae

    Puusild, Harro

    2008-01-01

    Eesti kinodes esilinastub 14. märtsil üheaegselt maailma esilinastusega USA animafilm "Horton" (režissöörid Jimmy Hayward, Steve Martino). Eesti keelde dubleerimisest kõnelevad selle töö režissöör Veiko Anvelt ja Hortoni dubleerija Priit Võigemast

  6. Hawking radiation

    Science.gov (United States)

    Parentani, Renaud; Spindel, Philippe

    2011-12-01

    Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole horizon. It is named after the physicist Stephen Hawking who derived its existence in 1974. This radiation reduces the mass of black holes and is therefore also known as black hole evaporation.

  7. Horton Revisited: African Traditional Thought and Western Science ...

    African Journals Online (AJOL)

    Over the years Robin Horton has argued for what he refers to as the 'continuity thesis' according to which there are theoretical similarities between African traditional thought and modern Western science. Horton's thesis stands in contrast to the standard Western anthropological appraisal of traditional African thought.

  8. Ferruginous hawk

    Science.gov (United States)

    Hall, R.S.; Glinski, R.L.; Ellis, D.H.; Ramakka, J.M.; Base, D.L.; Glinski, Richard L.; Pendleton, Beth Giron; Moss, Mary Beth; LeFranc, Maurice N.=; Millsap, Brian A.; Hoffman, Stephen W.

    1988-01-01

    In the Southwest, the ferruginous hawk is a local and isolated breeder and an uncommon but consistent winter visitor. Apparently, the breeding range of this species in the Southwest was historically much greater than today. The ferruginous hawk is being considered for listing by the U.S. Fish and Wildlife Service but remains unclassified by the individual states comprising the Southwest region. Habitat and diet information is summarized. Nest location and structure, breeding, and wintering biology are also discussed. Long-term and seasonal monitoring is conducted annually at several nest locations in New Mexico, while documented reproductive efforts in Arizona, Texas and Oklahoma are extremely rare and isolated. Research and management recommendations include population and habitat surveys, dietary and reproductive investigations, and habitat protection.

  9. Cannibalism in Tyrannosaurus rex.

    Directory of Open Access Journals (Sweden)

    Nicholas R Longrich

    Full Text Available BACKGROUND: Tyrannosaurus rex was one of the largest terrestrial carnivores of all time, and consequently its ecology and diet have been the focus of much discussion. However, there is little direct evidence of diet or feeding habits in this species. METHODOLOGY/PRINCIPAL FINDINGS: Examination of museum collections has revealed four specimens of Tyrannosaurus rex that bear tooth marks made by large, carnivorous dinosaurs. Because Tyrannosaurus is the only large carnivore known from the Late Maastrichtian of western North America, we infer that Tyrannosaurus made these tooth marks. CONCLUSIONS/SIGNIFICANCE: The marks are interpreted as feeding traces and these fossils therefore record instances of cannibalism. Given that this behavior has a low preservation potential, cannibalism seems to have been a surprisingly common behavior in Tyrannosaurus, and this behavior may have been relatively common in carnivorous dinosaurs.

  10. Cannibalism in Tyrannosaurus rex

    Science.gov (United States)

    Longrich, Nicholas R.; Horner, John R.; Erickson, Gregory M.; Currie, Philip J.

    2010-01-01

    Background Tyrannosaurus rex was one of the largest terrestrial carnivores of all time, and consequently its ecology and diet have been the focus of much discussion. However, there is little direct evidence of diet or feeding habits in this species. Methodology/Principal Findings Examination of museum collections has revealed four specimens of Tyrannosaurus rex that bear tooth marks made by large, carnivorous dinosaurs. Because Tyrannosaurus is the only large carnivore known from the Late Maastrichtian of western North America, we infer that Tyrannosaurus made these tooth marks. Conclusions/Significance The marks are interpreted as feeding traces and these fossils therefore record instances of cannibalism. Given that this behavior has a low preservation potential, cannibalism seems to have been a surprisingly common behavior in Tyrannosaurus, and this behavior may have been relatively common in carnivorous dinosaurs. PMID:20976177

  11. Hawking's acting roles

    Science.gov (United States)

    Castell, Stephen

    2012-06-01

    In the wake of Stephen Hawking's appearance on the TV show The Big Bang Theory, last month's "Quanta" page (May p3), included a request: "If you think Hawking should appear in any other TV shows, then let us know".

  12. Horton slõshit slovo "matt!" / Nikolai Karajev

    Index Scriptorium Estoniae

    Karajev, Nikolai, 1978-

    2008-01-01

    USA animafilmi "Horton" (režissöörid Jimmy Hayward, Steve Martino) eesti keelde dubleerimisest. Artikli autori kriitika karakter Vlad Vladikoffile eestikeelses dublaazhis antud vene aktsendi kasutamise üle (originaalis rumeenia). Kommenteerib ka dublaazhi režissöör Veiko Anvelt

  13. Hawking, Stephen W (1942-)

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    Cosmologist and theoretical astrophysicist, born in Oxford, England, where he studied physics at University College. Moved to Cambridge to take up research in general relativity and cosmology, became Lucasian professor (an appointment earlier held by ISAAC NEWTON, with whom Hawking has been compared). Hawking worked to develop a valid mathematical treatment of the `singularities' in the theor...

  14. Cooper's Hawk (Accipiter cooperii)

    Science.gov (United States)

    Jean-Luc E. Cartron; Patricia L. Kennedy; Rob Yaksich; Scott H. Stoleson

    2010-01-01

    The Cooper's Hawk (Accipiter cooperii) is intermediate in size between the Northern Goshawk (Accipiter gentilis) and the Sharp-shinned Hawk (A. striatus), northern North America's other two accipiters. The two sexes are almost alike in plumage, but as in both of the other species, the female is noticeably larger. According to Wheeler and Clark (1995), a...

  15. Steven Hawking with Robert Aymar

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    Steven Hawking is seen meeting with CERN's Director-General, Robert Aymar. Hawking visited CERN between 24 September and 1 October 2006. During his stay he gave two lectures and toured the LHC, which may provide insights into Hawking's most famous area of study, black holes.

  16. Blocking the Hawking radiation

    DEFF Research Database (Denmark)

    Autzen, M.; Kouvaris, C.

    2014-01-01

    grows after its formation (and eventually destroys the star) instead of evaporating. The fate of the black hole is dictated by the two opposite mechanics, i.e., accretion of nuclear matter from the center of the star and Hawking radiation that tends to decrease the mass of the black hole. We study how...... the assumptions for the accretion rate can in fact affect the critical mass beyond which a black hole always grows. We also study to what extent degenerate nuclear matter can impede Hawking radiation due to the fact that emitted particles can be Pauli blocked at the core of the star....

  17. Fading Hawking Radiation

    CERN Document Server

    Sakalli, I; Pasaoglu, H

    2012-01-01

    In this study, we explore a particular type Hawking radiation which ends with zero temperature and entropy. The appropriate black holes for this purpose are the linear dilaton black holes. In addition to the black hole choice, a recent formalism in which the Parikh-Wilczek's tunneling formalism amalgamated with quantum corrections to all orders in \\hbar is considered. The adjustment of the coefficients of the quantum corrections plays a crucial role on this particular Hawking radiation. The obtained tunneling rate indicates that the radiation is not pure thermal anymore, and hence correlations of outgoing quanta are capable of carrying away information encoded within them. Finally, we show in detail that when the linear dilaton black hole completely evaporates through such a particular radiation, entropy of the radiation becomes identical with the entropy of the black hole, which corresponds to "no information loss".

  18. Canadian institute honours Hawking

    Science.gov (United States)

    Durrani, Matin

    2009-11-01

    The Perimeter Institute for Theoretical Physics in Waterloo, Canada, has announced that a major new extension to its campus will be known as the Stephen Hawking Centre. The extension, which is currently being built, is due to open in 2011 and will double the size of the institute. It will also provide a home for the institute's Masters students, the first of whom joined the Perimeter Institute this autumn as part of its Perimeter Scholars international programme.

  19. A consistent framework for Horton regression statistics that leads to a modified Hack's law

    Science.gov (United States)

    Furey, P.R.; Troutman, B.M.

    2008-01-01

    A statistical framework is introduced that resolves important problems with the interpretation and use of traditional Horton regression statistics. The framework is based on a univariate regression model that leads to an alternative expression for Horton ratio, connects Horton regression statistics to distributional simple scaling, and improves the accuracy in estimating Horton plot parameters. The model is used to examine data for drainage area A and mainstream length L from two groups of basins located in different physiographic settings. Results show that confidence intervals for the Horton plot regression statistics are quite wide. Nonetheless, an analysis of covariance shows that regression intercepts, but not regression slopes, can be used to distinguish between basin groups. The univariate model is generalized to include n > 1 dependent variables. For the case where the dependent variables represent ln A and ln L, the generalized model performs somewhat better at distinguishing between basin groups than two separate univariate models. The generalized model leads to a modification of Hack's law where L depends on both A and Strahler order ??. Data show that ?? plays a statistically significant role in the modified Hack's law expression. ?? 2008 Elsevier B.V.

  20. A consistent framework for Horton regression statistics that leads to a modified Hack's law

    Science.gov (United States)

    Furey, Peter R.; Troutman, Brent M.

    2008-12-01

    A statistical framework is introduced that resolves important problems with the interpretation and use of traditional Horton regression statistics. The framework is based on a univariate regression model that leads to an alternative expression for Horton ratio, connects Horton regression statistics to distributional simple scaling, and improves the accuracy in estimating Horton plot parameters. The model is used to examine data for drainage area A and mainstream length L from two groups of basins located in different physiographic settings. Results show that confidence intervals for the Horton plot regression statistics are quite wide. Nonetheless, an analysis of covariance shows that regression intercepts, but not regression slopes, can be used to distinguish between basin groups. The univariate model is generalized to include n > 1 dependent variables. For the case where the dependent variables represent ln A and ln L, the generalized model performs somewhat better at distinguishing between basin groups than two separate univariate models. The generalized model leads to a modification of Hack's law where L depends on both A and Strahler order ω. Data show that ω plays a statistically significant role in the modified Hack's law expression.

  1. Bayesian inference for Hawkes processes

    DEFF Research Database (Denmark)

    Rasmussen, Jakob Gulddahl

    intensity function, while the second approach is based on an underlying clustering and branching structure in the Hawkes process. For practical use, MCMC (Markov chain Monte Carlo) methods are employed. The two approaches are compared numerically using three examples of the Hawkes process....

  2. Bayesian inference for Hawkes processes

    DEFF Research Database (Denmark)

    Rasmussen, Jakob Gulddahl

    2013-01-01

    intensity function, while the second approach is based on an underlying clustering and branching structure in the Hawkes process. For practical use, MCMC (Markov chain Monte Carlo) methods are employed. The two approaches are compared numerically using three examples of the Hawkes process....

  3. Bayesian inference for Hawkes processes

    DEFF Research Database (Denmark)

    Rasmussen, Jakob Gulddahl

    The Hawkes process is a practically and theoretically important class of point processes, but parameter-estimation for such a process can pose various problems. In this paper we explore and compare two approaches to Bayesian inference. The first approach is based on the so-called conditional...... intensity function, while the second approach is based on an underlying clustering and branching structure in the Hawkes process. For practical use, MCMC (Markov chain Monte Carlo) methods are employed. The two approaches are compared numerically using three examples of the Hawkes process....

  4. Hawk and Handsaw

    Science.gov (United States)

    Usher, Peter D.

    2008-05-01

    In Shakespeare's Hamlet, Prince Hamlet states, "I am but mad north-north-west. When the wind is southerly, I know a hawk from a handsaw." This celebrated yet perennially baffling passage is readily understood in the context of the cosmic allegorical interpretation of the play (BAAS 28, 1305, 1996; Hamlet's Universe, 2006). The first direction points from Tycho Brahe's observatory on Hven to the fictional home of the geocentric Pyolemaic worldview at Elsinore, and the second from Hven to the home of Copernican heliocentricism at Wittenberg. The directions correspond to the two influences on Tycho's geo-heliocentric World model. Anyone at Elsinore who advocates the new organon of the New Philosophy is "mad," whereas sanity prevails at Wittenberg. "Hawk" refers to a bird of prey, the leonard, and to Leonard Digges, inventor of the world's first two-element telescope. "Handsaw" refers to the artistic tool necessary to sever the hands depicted in de Gheyn's two quasi-mirror-imaged portraits of Tycho at age 40, which show hands affixed to the wrong arms. Elsewhere in Hamlet, Shakespeare substantiates the New Astronomy through descriptions of planets and stars that could only have been determined telescopically. Therefore, the passage in question contrasts two modes of observing in the early modern era, viz. visual and telescopic. Shakespeare completed writing Hamlet in about 1601 and the Second Quarto appeared in 1604, so the first substantial account of astronomical telescopy is now over 400 years old. In addition, 432 years ago Thomas Digges published the first account of the New Astronomy in a popular almanac. These two means of presentation may seem odd by present standards, but contemporary culture was intolerant of 'natural magic,' and furthermore, it was prudent to minmize the risk of domestic persecution and threats from Continental armies and the European and Spanish Inquisitions.

  5. UAVSAR Global Hawk POLSAR Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Integrate the UAVSAR L-band radar to the Global Hawk UAV Bay 25 Provide long range (~ 9000 nmi) to enable data collection of distant areas of interest without...

  6. Entropy Budget for Hawking Evaporation

    National Research Council Canada - National Science Library

    Ana Alonso-Serrano; Matt Visser

    2017-01-01

    ...” in correlations between the photons. The importance of this result lies in the posterior extension of this argument to the Hawking radiation from black holes, demonstrating that the assumption of unitarity leads to a perfectly...

  7. Perfect simulation of Hawkes processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Rasmussen, Jakob Gulddahl

    their branching and conditional independence structure, useful approximations of the distribution function for the length of a cluster are derived. This is used to construct upper and lower processes for the perfect simulation algorithm. Examples of applications and empirical results are presented.......This article concerns a perfect simulation algorithm for unmarked and marked Hawkes processes. The usual stratihtforward simulation algorithm suffers from edge effects, whereas our perfect simulation algorithm does not. By viewing Hawkes processes as Poisson cluster processes and using...

  8. Status of the REX-ISOLDE project

    CERN Document Server

    Von Hahn, R; Podlech, H; Repnow, R; Schwalm, D; Bongers, H; Habs, D; Kester, O; Sieber, T; Rudolph, K; Thirolf, P G; Schempp, A; Smes, F; Bollen, G; Deloose, I; Ratzinger, U; Liljeby, L; Rensfelt, K G; Wenander, F; Van Duppen, P; Walter, G; Richter, A; Ostrowski, A N; Schotter, A; MacKay, W W

    1999-01-01

    The radioactive beam experiment REX-ISOLDE, a pilot experiment testing a new concept of post acceleration of radioactive ions at ISOLDE/CERN is in progress. Singly charged radioactive ions delivered by the online mass separator ISOLDE are accumulated in a Penning trap (REX trap), charge bred in an electron beam ion source (EBIS), separated from the residual gas in a mass separator and then accelerated in a linac with output energies between 0.8 and 2.2 MeV /u. The REX trap is in operation, a first test beam was already injected. The design phase of the EBIS is finished and the construction has been started. The superconducting magnet is delivered. The linac consists of a radiofrequency quadrupole (RFQ) accelerator, an interdigital IH-structure and 3 seven gap resonators to vary the final energy. (12 refs).

  9. Molecular phylogenetics of mastodon and Tyrannosaurus rex.

    Science.gov (United States)

    Organ, Chris L; Schweitzer, Mary H; Zheng, Wenxia; Freimark, Lisa M; Cantley, Lewis C; Asara, John M

    2008-04-25

    We report a molecular phylogeny for a nonavian dinosaur, extending our knowledge of trait evolution within nonavian dinosaurs into the macromolecular level of biological organization. Fragments of collagen alpha1(I) and alpha2(I) proteins extracted from fossil bones of Tyrannosaurus rex and Mammut americanum (mastodon) were analyzed with a variety of phylogenetic methods. Despite missing sequence data, the mastodon groups with elephant and the T. rex groups with birds, consistent with predictions based on genetic and morphological data for mastodon and on morphological data for T. rex. Our findings suggest that molecular data from long-extinct organisms may have the potential for resolving relationships at critical areas in the vertebrate evolutionary tree that have, so far, been phylogenetically intractable.

  10. Vacuum polarization and Hawking radiation

    Science.gov (United States)

    Rahmati, Shohreh

    Quantum gravity is one of the interesting fields in contemporary physics which is still in progress. The purpose of quantum gravity is to present a quantum description for spacetime at 10-33cm or find the 'quanta' of gravitational interaction.. At present, the most viable theory to describe gravitational interaction is general relativity which is a classical theory. Semi-classical quantum gravity or quantum field theory in curved spacetime is an approximation to a full quantum theory of gravity. This approximation considers gravity as a classical field and matter fields are quantized. One interesting phenomena in semi-classical quantum gravity is Hawking radiation. Hawking radiation was derived by Stephen Hawking as a thermal emission of particles from the black hole horizon. In this thesis we obtain the spectrum of Hawking radiation using a new method. Vacuum is defined as the possible lowest energy state which is filled with pairs of virtual particle-antiparticle. Vacuum polarization is a consequence of pair creation in the presence of an external field such as an electromagnetic or gravitational field. Vacuum polarization in the vicinity of a black hole horizon can be interpreted as the cause of the emission from black holes known as Hawking radiation. In this thesis we try to obtain the Hawking spectrum using this approach. We re-examine vacuum polarization of a scalar field in a quasi-local volume that includes the horizon. We study the interaction of a scalar field with the background gravitational field of the black hole in the desired quasi-local region. The quasi-local volume is a hollow cylinder enclosed by two membranes, one inside the horizon and one outside the horizon. The net rate of particle emission can be obtained as the difference of the vacuum polarization from the outer boundary and inner boundary of the cylinder. Thus we found a new method to derive Hawking emission which is unitary and well defined in quantum field theory.

  11. Maladie de Horton révélée par une dyspnée | Mahfoudhi | Pan ...

    African Journals Online (AJOL)

    Maladie de Horton révélée par une dyspnée. M Mahfoudhi, H Mamlouk, S Turki, A Kheder. Abstract. Les manifestations pleuro-pulmonaires de la maladie de Horton sont rares et peu connues. Elles peuvent être inaugurales, à l'origine d'un retard à la prise en charge si elles sont méconnues. Il s'agissait d'un patient âgé de ...

  12. Hawk migration over White Marsh, Maryland

    Science.gov (United States)

    Hackman, C.D.; Henny, C.J.

    1971-01-01

    The average number of hawks observed per hour in autumn migration between 1951-1954 and 1958-1961 at White Marsh, Maryland, was compared. The counts indicated that the status of the ten species observed may be divided into three categories: (1) relatively stable species (red-tailed hawk), (2) declining species (sparrow hawk, red-shouldered hawk, osprey, marsh hawk, and broad-winged hawk), and (3) rapidly declining species (peregrine falcon, Cooper?s hawk, bald eagle, and sharp-shinned hawk). The findings from this study are in agreement with the available literature and the status of the populations appears to be related to the food habits of the species.

  13. Stephen Hawking: An Unfettered Mind

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, Kitty

    2012-02-23

    Kitty Ferguson, biographer of physicist Stephen Hawking, will give an informal, nontechnical talk about the experience of writing her two books about the celebrated cosmologist and also of helping Hawking edit his own “The Universe in a Nutshell”. Hawking thinks and works somewhat differently from others because he must work almost entirely in his head, and he has a practice of pulling the rug out from under his own discoveries and assertions. As he has approached his recent 70th birthday, he has devoted an increasing amount of his time in efforts to share his science and particularly the adventure of it with people without a science background and young people who may be scientists of the future. Ferguson will discuss Hawking’s place in the science community (he is not and has never claimed to be on par with Einstein), the unique contributions he is able to make, and what his legacy might be.

  14. Important Milestone for REX-ISOLDE

    CERN Multimedia

    2001-01-01

    CERN's new nuclear physics facility, REX-ISOLDE, reached an important milestone on Thursday 23 August. Scheduled for full commissioning later this year, REX-ISOLDE will take beams of unstable ions from the ISOLDE facility and accelerate them, opening up a wide range of new research avenues. Members of the REX-ISOLDE team with REXEBIS - successfully tested last week. The key to REX-ISOLDE is the process of accumulating and cooling unstable ions in a trap and then stripping them of electrons in a so-called charge breeder before accelerating them in a linear accelerator. The first part of this process is the job of REXTRAP, the largest particle trap of its kind, which was successfully tested in 1999 (Bulletin 49/99). Last week it was the turn of REXEBIS (Electron Beam Ion Source), which strips the ions of electrons, to be put through its paces. By increasing the charge of the ions by removing electrons, the length of the linear accelerator needed to accelerate the ions can be reduced, since higher charge mean...

  15. Second order analysis for spatial Hawkes processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Torrisi, Giovanni Luca

    We derive summary statistics for stationary Hawkes processes which can be considered as spatial versions of classical Hawkes processes. Particularly, we derive the intensity, the pair correlation function and the Bartlett spectrum. Our results for Gaussian fertility rates and the extension...... to marked Hawkes processes are discussed....

  16. Perfect simulation of Hawkes processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Rasmussen, Jakob Gulddahl

    2005-01-01

    their branching and conditional independence structures, useful approximations of the distribution function for the length of a cluster are derived. This is used to construct upper and lower processes for the perfect simulation algorithm. A tail-lightness condition turns out to be of importance......Our objective is to construct a perfect simulation algorithm for unmarked and marked Hawkes processes. The usual straightforward simulation algorithm suffers from edge effects, whereas our perfect simulation algorithm does not. By viewing Hawkes processes as Poisson cluster processes and using...

  17. OSIRIS-REx Asterod Sample Return Mission

    Science.gov (United States)

    Nakamura-Messinger, Keiki; Connolly, Harold C. Jr.; Messenger, Scott; Lauretta, Dante S.

    2017-01-01

    OSIRIS-REx is NASA's third New Frontiers Program mission, following New Horizons that completed a flyby of Pluto in 2015 and the Juno mission to Jupiter that has just begun science operations. The OSIRIS-REx mission's primary objective is to collect pristine surface samples of a carbonaceous asteroid and return to Earth for analysis. Carbonaceous asteroids and comets are 'primitive' bodies that preserved remnants of the Solar System starting materials and through their study scientists can learn about the origin and the earliest evolution of the Solar System. The OSIRIS-REx spacecraft was successfully launched on September 8, 2016, beginning its seven year journey to asteroid 101955 Bennu. The robotic arm will collect 60-2000 grams of material from the surface of Bennu and will return to Earth in 2023 for worldwide distribution by the Astromaterials Curation Facility at NASA Johnson Space Center. The name OSIRIS-REx embodies the mission objectives (1) Origins: Return and analyze a sample of a carbonaceous asteroid, (2) Spectral Interpretation: Provide ground-truth for remote observation of asteroids, (3) Resource Identification: Determine the mineral and chemical makeup of a near-Earth asteroid (4) Security: Measure the non-gravitational that changes asteroidal orbits and (5) Regolith Explorer: Determine the properties of the material covering an asteroid surface. Asteroid Bennu may preserve remnants of stardust, interstellar materials and the first solids to form in the Solar System and the molecular precursors to the origin of life and the Earth's oceans. Bennu is a potentially hazardous asteroid, with an approximately 1 in 2700 chance of impacting the Earth late in the 22nd century. OSIRIS-REx collects from Bennu will help formulate the types of operations and identify mission activities that astronauts will perform during their expeditions. Such information is crucial in preparing for humanity's next steps beyond low Earthy orbit and on to deep space

  18. Timing and magnitude of Broad-winged Hawk migration at Montclair Hawk Lookout, New Jersey, and Hawk Mountain Sanctuary, Pennsylvania

    Science.gov (United States)

    Miller, M.W.; Greenstone, E.M.; Greenstone, W.; Bildstein, K.L.

    2002-01-01

    The Broad-winged Hawk (Buteo platypterus) breeds in eastern and central Canada and the United States, and winters in Central America and northern and central South America. Birders and ornithologists count migrating Broad-winged Hawks at dozens of traditional watch sites throughout the northeastern United States. We modeled counts of migrating Broad-winged Hawks from two raptor migration watch sites: Montclair Hawk Lookout, New Jersey, and Hawk Mountain Sanctuary, Pennsylvania, to determine whether annual abundance and trend estimates from individual sites within the mid-Atlantic states are representative of the region as a whole. We restricted ourselves to counts made between 10:00 and 16:00 EST during September to standardize count effort between sites. We created one model set for annual counts and another model set for daily counts. When modeling daily counts we incorporated weather and identity of individual observers. Akaike's Information Criteria were used to select the best model from an initial set of competing models. Annual counts declined at both sites during 1979-1998. Broad-winged Hawk migration began, peaked, and ended later at Montclair than at Hawk Mountain, even though Hawk Mountain is 155 km west-southwest of Montclair. Mean annual counts of hawks at Montclair were more than twice those at Hawk Mountain, but were not correlated. Broad-winged Hawks counted at Montclair may not be the same birds as those counted at Hawk Mountain. Rather, the two sites may be monitoring different regional subpopulations. Broad-winged Hawks counted at the two sites may use different migration tactics, with those counted at Hawk Mountain being more likely to slope soar, and those at Montclair more likely to use thermal soaring. A system of multiple watch sites is needed to monitor various breeding populations of this widely dispersed migrant.

  19. Hawking radiation and interacting fields

    Science.gov (United States)

    Frasca, Marco

    2017-11-01

    Hawking radiation is generally derived using a non-interacting field theory. Some time ago, Leahy and Unruh showed that, in two dimensions with a Schwarzschild geometry, a scalar field theory with a quartic interaction gets the coupling switched off near the horizon of the black hole. This would imply that interaction has no effect on Hawking radiation and free theory for particles can be used. Recently, a set of exact classical solutions for the quartic scalar field theory has been obtained. These solutions display a massive dispersion relation even if the starting theory is massless. When one considers the corresponding quantum field theory, this mass gap becomes a tower of massive excitations and, at the leading order, the theory is trivial. We apply these results to Hawking radiation for a Kerr geometry and prove that the Leahy-Unruh effect is at work. Approaching the horizon the scalar field theory has the mass gap going to zero. We devise a technique to study the interacting scalar theory very near the horizon increasing the coupling. As these solutions are represented by a Fourier series of plane waves, Hawking radiation can be immediately obtained with well-known techniques. These results open a question about the behavior of the Standard Model of particles very near the horizon of a black hole where the interactions turn out to be switched off and the electroweak symmetry could be restored.

  20. Stephen Hawking's Universe. Teacher's Guide.

    Science.gov (United States)

    Thompson, Malcolm H.; Rameau, Jonathan D.

    This program guide is meant to help teachers assist their students in viewing the six-part public television series, "Stephen Hawking's Universe." The guide features program summaries that give background information and brief synopses of the programs; previewing activities that familiarize students with the subject; vocabulary that…

  1. Hawking Colloquium Packed CERN Auditoriums

    CERN Multimedia

    2006-01-01

    Stephen Hawking's week long visit to CERN included an 'exceptional CERN colloquium' which filled six auditoriums. Stephen Hawking during his visit to the ATLAS experiment. Stephen Hawking, Lucasian Professor of Cambridge University, visited the Theory Unit of the Physics Department from 24 September to 1 October 2006. As part of his visit, he gave two lectures in the main auditorium - a theoretical seminar on 'The Semi-Classical Birth of The Universe', attended by about 120 specialists; and a colloquium titled 'The Origin of The Universe'. As a key public figure in theoretical physics, his presence was eagerly awaited on both occasions. Those who wanted to attend the colloquium had to arrive early and be equipped with plenty of patience. An hour before it was due to begin, the 400 capacity of the main auditorium was already full. The lecture, simultaneously broadcast to five other fully packed CERN auditoriums, was attended by an estimated total of 850. Stephen Hawking attracted a large CERN crowd, filling ...

  2. Approximate simulation of Hawkes processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Rasmussen, Jakob Gulddahl

    This article concerns a simulation algorithm for unmarked and marked Hawkes processes. The algorithm suffers from edge effects but is much faster than the perfect simulation algorithm introduced in our previous work. We derive various useful measures for the error committed when using the algorithm...

  3. Cranial mechanics and feeding in tyrannosaurus rex

    OpenAIRE

    Rayfield, Emily J.

    2009-01-01

    It has been suggested that the large theropod dinosaur Tyrannosaurus rex was capable of producing extremely powerful bite forces and resisting multi-directional loading generated during feeding. Contrary to this suggestion is the observation that the cranium is composed of often loosely articulated facial bones, although these bones may have performed a shock-absorption role. The structural analysis technique finite element analysis (FEA) is employed here to investigate the functional morphol...

  4. Delegating responsibility in digital systems: horton's 'who doneit?'

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Mark S.; Donnelley, Jed; Karp, Alan H.

    2007-06-01

    Delegation is a fundamental part of human society. If digital systems are to mediate ever more of our interactions, we must be able to delegate responsibility within them. While some systems support the controlled delegation of authority, and other systems support assignment of responsibility, today we have no means for delegating responsibility, that is, delegating authority coupled with assigning responsibility for using that authority. Horton demonstrates how delegation of responsibility can be added to systems that already support delegation of authority-object-capability systems.

  5. Cranial mechanics and feeding in Tyrannosaurus rex.

    Science.gov (United States)

    Rayfield, Emily J

    2004-07-22

    It has been suggested that the large theropod dinosaur Tyrannosaurus rex was capable of producing extremely powerful bite forces and resisting multi-directional loading generated during feeding. Contrary to this suggestion is the observation that the cranium is composed of often loosely articulated facial bones, although these bones may have performed a shock-absorption role. The structural analysis technique finite element analysis (FEA) is employed here to investigate the functional morphology and cranial mechanics of the T. rex skull. In particular, I test whether the skull is optimized for the resistance of large bi-directional feeding loads, whether mobile joints are adapted for the localized resistance of feeding-induced stress and strain, and whether mobile joints act to weaken or strengthen the skull overall. The results demonstrate that the cranium is equally adapted to resist biting or tearing forces and therefore the 'puncture-pull' feeding hypothesis is well supported. Finite-element-generated stress-strain patterns are consistent with T. rex cranial morphology: the maxilla-jugal suture provides a tensile shock-absorbing function that reduces localized tension yet 'weakens' the skull overall. Furthermore, peak compressive and shear stresses localize in the nasals rather than the fronto-parietal region as seen in Allosaurus, offering a reason why robusticity is commonplace in tyrannosaurid nasals. Copyright 2004 The Royal Society

  6. OSIRIS-REx Asteroid Sample Return Mission

    Science.gov (United States)

    Drake, M. J.; Lauretta, D. S.; Team, O.

    2011-12-01

    OSIRIS-REx is an asteroid sample return mission to organic-rich asteroid (101955) 1999 RQ36. The mission seeks to address deep questions: where did we come from; what is our destiny? Earth sterilized itself during its formation, yet here we are today. Where did the organics come from? To do so, we will return at least 60g of pristine, uncontaminated, organic-rich regolith for study on Earth by advanced analytical equipment. Because it is relatively easy for us to get the RQ36, it is relatively easy for it to get to us, making I the most potentially hazardous asteroid know to humanity with a 1:1800 probability of impacting the Earth in 2180. We will study the Yarkovsky effect, thermal forces that cause small objects to deviate from keplerian orbits, with the goal of understanding how to mitigate against a civilization-ending or species-ending impact catastrophe. The mission launches in September, 2016, arrives at RQ36 in November of 2019, and spends about a year conducting detailed studies of RQ36 in order to select the best sampling site. Sampling is achieved by approaching the surface ay 10 cm/sec and agitating the regolith with nitrogen gas on contact. The agitated regolith is collected in a sample head, which is stowed in the Sample return capsule for return to Earth at the UTTR Test range in Utah in September 2023. Two years of funded studies are carried out by the U.S. and world community before end of mission in 2025, after which samples will still be available through the NASA-JSC Curation Facility. OSIRIS-REx will return samples never before available for study on Earth, probably using some instruments yet to be invented. In addition, OSIRIS-REx will provide "ground truth" for telescope observations of airless bodies by returning a pristine sample of the surface of RQ36. OSIRIS-REx will evaluate resources available to future human missions, both materials and technologies such as proximity operations. And we will learn how to mitigate against impact

  7. Approximate simulation of Hawkes processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Rasmussen, Jakob Gulddahl

    2006-01-01

    Hawkes processes are important in point process theory and its applications, and simulation of such processes are often needed for various statistical purposes. This article concerns a simulation algorithm for unmarked and marked Hawkes processes, exploiting that the process can be constructed...... as a Poisson cluster process. The algorithm suffers from edge effects but is much faster than the perfect simulation algorithm introduced in our previous work Møller and Rasmussen (2004). We derive various useful measures for the error committed when using the algorithm, and we discuss various empirical...... results for the algorithm compared with perfect simulations. Extensions of the algorithm and the results to more general types of marked point processes are also discussed....

  8. Hawking Radiation and Classical Tunneling

    CERN Document Server

    Tracy, Eugene R

    2015-01-01

    Acoustic waves in fluids undergoing the transition from sub- to supersonic flow satisfy governing equations similar to those for light waves in the immediate vicinity of a black hole event horizon. This acoustic analogy has been used by Unruh and others as a conceptual model for `Hawking radiation.' Here we use variational methods, originally introduced by Brizard for the study of linearized MHD, and ray phase space methods, to analyze linearized acoustics in the presence of background flows. The variational formulation endows the evolution equations with natural Hermitian and symplectic structures that prove useful for later analysis. We derive a $2\\times 2$ normal form governing the wave evolution in the vicinity of the `event horizon.' This shows that the acoustic model can be reduced locally (in ray phase space) to a standard (scalar) tunneling process weakly coupled to a unidirectional non-dispersive wave (the `incoming wave'). Given the normal form, the Hawking `thermal spectrum' can be derived by invok...

  9. SURVIVAL AND CAUSES OF MORTALITY IN WINTERING SHARP-SHINNED HAWKS AND COOPER'S HAWKS

    National Research Council Canada - National Science Library

    TIMOTHY C. ROTH II; STEVEN L. LIMA; WILLIAM E. VETTER

    2005-01-01

    Abstract Sharp-shinned Hawks (Accipiter striatus) and Cooper's Hawks (A. cooperii) are important predators of birds in North America, but little is known about their natural history during the winter...

  10. OSIRIS-REx, Returning the Asteroid Sample

    Science.gov (United States)

    Ajluni, Thomas, M.; Everett, David F.; Linn, Timothy; Mink, Ronald; Willcockson, William; Wood, Joshua

    2015-01-01

    This paper addresses the technical aspects of the sample return system for the upcoming Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) asteroid sample return mission. The overall mission design and current implementation are presented as an overview to establish a context for the technical description of the reentry and landing segment of the mission.The prime objective of the OSIRIS-REx mission is to sample a primitive, carbonaceous asteroid and to return that sample to Earth in pristine condition for detailed laboratory analysis. Targeting the near-Earth asteroid Bennu, the mission launches in September 2016 with an Earth reentry date of September 24, 2023.OSIRIS-REx will thoroughly characterize asteroid Bennu providing knowledge of the nature of near-Earth asteroids that is fundamental to understanding planet formation and the origin of life. The return to Earth of pristine samples with known geologic context will enable precise analyses that cannot be duplicated by spacecraft-based instruments, revolutionizing our understanding of the early Solar System. Bennu is both the most accessible carbonaceous asteroid and one of the most potentially Earth-hazardous asteroids known. Study of Bennu addresses multiple NASA objectives to understand the origin of the Solar System and the origin of life and will provide a greater understanding of both the hazards and resources in near-Earth space, serving as a precursor to future human missions to asteroids.This paper focuses on the technical aspects of the Sample Return Capsule (SRC) design and concept of operations, including trajectory design and reentry retrieval. Highlights of the mission are included below.The OSIRIS-REx spacecraft provides the essential functions for an asteroid characterization and sample return mission: attitude control propulsion power thermal control telecommunications command and data handling structural support to ensure successful

  11. Stephen Hawking returns to CERN

    CERN Multimedia

    2009-01-01

    Stephen Hawking visiting the CERN Control Centre.If you happened to pass through Building 4 during the first weeks of September, you might have noticed the name of Stephen Hawking on one of the doors on the second floor, which hosts most of CERN theorists’ offices. Three years after his last visit to CERN, Stephen Hawking gladly accepted the invitation from the University of Geneva to hold a public lecture on the occasion of its 450th anniversary and requested an office at CERN for the length of his stay. The "master of the Universe", as the Geneva University journal dubbed him, attracted over 4000 people to his lecture on "The Creation of the Universe" held on 15 September in the Main Auditorium of Uni Dufour. His more technical colloquium on the same subject at CERN a week earlier, was no less popular and quite "provocative" according to some of the physicists in the audience. With his repeated reference to the "non-need" for a "creating agent" for the Universe, mo...

  12. Tilted foils polarization at REX-ISOLDE

    CERN Document Server

    Tornqvist, H; Yordanov, D T; Imai, N; Heinz, A; Nilsson, T; Sotty, C; Hass, M; Georgiev, G; Johansson, H; Dhal, A; Stuchbery, A; Wenander, F; Hirayama, Y; Kusoglu, A; Balabanski, D

    2013-01-01

    The tilted-foils nuclear-spin polarization method has been evaluated using the REX-ISOLDE linear accelerator at the ISOLDE facility, CERN. A beam of Li-8 delivered with an energy of 300 keV/u traversed through one Mylar foil to degrade the beam energy to 200 keV/u and consequently through 10 thin diamond-like carbon foils to polarize the nuclear spin. The attained nuclear spin polarization of 3.6 +/- 0.3% was measured with a beta-NMR setup. (C) 2013 Elsevier B.V. All rights reserved.

  13. Transverse Emittance Measurement at REX ISOLDE

    CERN Document Server

    Lanaia, D; Voulot, D

    2014-01-01

    The transverse emittance of REX-ISOLDE beams has been measured at 0.3 MeV/u (RFQ energy) and 2.85 MeV/u (maximum energy). This document compares RMS emittances measured with a slit-grid emittance meter (NTG emittance-meter) and RMS emittances measured with the quadrupole-scan method or three-gradient method. The results are compared with other measurements made with the slitgrid emittance meter in 2006 and 2008. The data treatment process is also described.

  14. Hawk: A Runtime System for Partitioned Objects

    NARCIS (Netherlands)

    Ben Hassen, S.; Bal, H.E.; Tanenbaum, A.S.

    1997-01-01

    Hawk is a language-independent runtime system for writing data-parallel programs using partitioned objects. A partitioned object is a multidimensional array of elements that can be partitioned and distributed by the programmer. The Hawk runtime system uses the user-defined partitioning of objects

  15. Hawking Temperature of Acoustic Black Hole

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Using a new tortoise coordinate transformation, the Hawking radiation of the acoustic black hole was discussed by studying the Klein–Gordon equation of scalar particles in the curve space-time. It was found that the Hawking temperature is connected with time and position on the event horizon.

  16. Zone-tailed Hawk (Buteo albonotatus)

    Science.gov (United States)

    Scott H. Stoleson; Giancarlo Sadoti

    2010-01-01

    The Zone-tailed Hawk (Buteo albonotatus) might well be dubbed "the Great Pretender" because it so closely resembles the ubiquitous Turkey Vulture (Cathartes aura) in appearance and behavior as to be frequently mistaken for it. In the border regions where it lives, it may be confused as well with another "Mexican" raptor, the Common Black-Hawk (...

  17. Longitudinal emittance measurements at REX-ISOLDE

    CERN Document Server

    Fraser, M A; Jones, R.M.; Jones, R M; Pasini, M; Posocco, P A; Voulot, D; Wenander, F

    2012-01-01

    We report on measurements of the longitudinal emittance at the Radioactive ion beam EXperiment (REX) at ISOLDE, CERN. The rms longitudinal emittance was measured as 0.34 ± 0.08 π ns keV/u at the output of the RFQ and as 0.36 ± 0.04π ns keV/u in front of the third 7-gap split-ring resonator (7G3) using the three-gradient technique; systematic errors are not included but are estimated at approximately 10%. The 86% emittance was measured a factor of approximately 4.4 times larger than the rms emittance at 1.48 ± 0.2 and 1.55 ± 0.12π ns keV/u at the RFQ and 7G3, respectively. The REX switchyard magnet was used as a spectrometer to analyse the energy spread of the beam as it was manipulated by varying the voltage of the rebuncher (ReB) and 7G3 cavities operating at non-accelerating phases. The transfer matrix for a multi-gap bunching cavity is derived and suitably truncated to allow for the accurate reconstruction of the beam parameters from measurement. The technique for measuring the energy spread was rig...

  18. Longitudinal Emittance Measurements at REX-ISOLDE

    CERN Document Server

    Fraser, MA; Piselli, E; Posocco, PA; Voulot, D; Wenander, F; Zocca, F

    2011-01-01

    The rms longitudinal emittance at output from the REX-ISOLDE RFQ was measured as 0.34 ± 0.08 π ns keV/u and at entry to the 7G3 as 0.36 ± 0.04 π ns keV/u using the three gradient technique; systematic errors are not included but are thought to be approximately 10%. The 86% emittance was measured a factor of approximately 4.4 times larger than the rms emittance at 1.48 ± 0.2 and 1.55 ± 0.12 π ns keV/u at the RFQ and 7G3, respectively. The REX-ISOLDE switchyard magnet was used as a spectrometer to analyse the energy spread as the beam was manipulated by changing the voltage of the ReB and 7G3 cavities operating at non-accelerating phases. The technique for measuring the energy spread was rigorously simulated and validated. A formalism was developed to accurately reconstruct the longitudinal beam parameters using a multi-gap constant-velocity bunching cavity when the voltage cannot be kept small. A silicon detector in its development phase was also exploited to measure the longitudinal beam properties. Th...

  19. Accelerated radioactive beams from REX-ISOLDE

    CERN Document Server

    Kester, O; Emhofer, S; Ames, F; Reisinger, K; Reiter, P; Thirolf, P G; Lutter, R; Habs, D; Wolf, B; Huber, G; Schmidt, P; Ostrowski, A N; Von Hahn, R; Repnow, R; Fitting, J; Lauer, M; Scheit, H; Schwalm, D; Podlech, H; Schempp, A; Ratzinger, U; Forstner, O; Wenander, F; Cederkäll, J; Nilsson, T; Lindroos, M; Fynbo, H O U; Franchoo, S; Bergmann, U C; Oinonen, M; Äystö, J; Van den Berg, P; Duppen, P V; Huyse, M; Warr, N; Weisshaar, D; Eberth, J; Jonson, B; Nyman, G H; Pantea, M; Simon, H; Shrieder, G; Richter, A; Tengblad, O; Davinson, T; Woods, P J; Bollen, G; Weissman, L; Liljeby, L; Rensfelt, K G

    2003-01-01

    In 2001 the linear accelerator of the Radioactive beam EXperiment (REX-ISOLDE) delivered for the first time accelerated radioactive ion beams, at a beam energy of 2 MeV/u. REX-ISOLDE uses the method of charge-state breeding, in order to enhance the charge state of the ions before injection into the LINAC. Radioactive singly-charged ions from the on-line mass separator ISOLDE are first accumulated in a Penning trap, then charge bred to an A/q<4.5 in an electron beam ion source (EBIS) and finally accelerated in a LINAC from 5 keV/u to energies between 0.8 and 2.2 MeV/u. Dedicated measurements with REXTRAP, the transfer line and the EBIS have been carried out in conjunction with the first commissioning of the accelerator. Thus the properties of the different elements could be determined for further optimization of the system. In two test beam times in 2001 stable and radioactive Na isotopes ( sup 2 sup 3 Na- sup 2 sup 6 Na) have been accelerated and transmitted to a preliminary target station. There sup 5 sup...

  20. Tunka-Rex: Status, Plans, and Recent Results

    Science.gov (United States)

    Schröder, F. G.; Bezyazeekov, P. A.; Budnev, N. M.; Fedorov, O.; Gress, O. A.; Haungs, A.; Hiller, R.; Huege, T.; Kazarina, Y.; Kleifges, M.; Korosteleva, E. E.; Kostunin, D.; Krömer, O.; Kungel, V.; Kuzmichev, L. A.; Lubsandorzhiev, N.; Mirgazov, R. R.; Monkhoev, R.; Osipova, E. A.; Pakhorukov, A.; Pankov, L.; Prosin, V. V.; Rubtsov, G. I.; Wischnewski, R.; Zagorodnikov, A.

    2017-03-01

    Tunka-Rex, the Tunka Radio extension at the TAIGA facility (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) in Siberia, has recently been expanded to a total number of 63 SALLA antennas, most of them distributed on an area of one square kilometer. In the first years of operation, Tunka-Rex was solely triggered by the co-located air-Cherenkov array Tunka-133. The correlation of the measurements by both detectors has provided direct experimental proof that radio arrays can measure the position of the shower maximum. The precision achieved so far is 40 g/cm2, and several methodical improvements are under study. Moreover, the cross-comparison of Tunka-Rex and Tunka-133 shows that the energy reconstruction of Tunka-Rex is precise to 15 %, with a total accuracy of 20 % including the absolute energy scale. By using exactly the same calibration source for Tunka-Rex and LOPES, the energy scale of their host experiments, Tunka-133 and KASCADE-Grande, respectively, can be compared even more accurately with a remaining uncertainty of about 10 %. The main goal of Tunka-Rex for the next years is a study of the cosmic-ray mass composition in the energy range above 100 PeV: For this purpose, Tunka-Rex now is triggered also during daytime by the particle detector array Tunka-Grande featuring surface and underground scintillators for electron and muon detection.

  1. Tunka-Rex: Status, Plans, and Recent Results

    Directory of Open Access Journals (Sweden)

    Schröder F. G.

    2017-01-01

    Full Text Available Tunka-Rex, the Tunka Radio extension at the TAIGA facility (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy in Siberia, has recently been expanded to a total number of 63 SALLA antennas, most of them distributed on an area of one square kilometer. In the first years of operation, Tunka-Rex was solely triggered by the co-located air-Cherenkov array Tunka-133. The correlation of the measurements by both detectors has provided direct experimental proof that radio arrays can measure the position of the shower maximum. The precision achieved so far is 40 g/cm2, and several methodical improvements are under study. Moreover, the cross-comparison of Tunka-Rex and Tunka-133 shows that the energy reconstruction of Tunka-Rex is precise to 15 %, with a total accuracy of 20 % including the absolute energy scale. By using exactly the same calibration source for Tunka-Rex and LOPES, the energy scale of their host experiments, Tunka-133 and KASCADE-Grande, respectively, can be compared even more accurately with a remaining uncertainty of about 10 %. The main goal of Tunka-Rex for the next years is a study of the cosmic-ray mass composition in the energy range above 100 PeV: For this purpose, Tunka-Rex now is triggered also during daytime by the particle detector array Tunka-Grande featuring surface and underground scintillators for electron and muon detection.

  2. The OSIRIS-REx Laser Altimeter (OLA) Investigation and Instrument

    Science.gov (United States)

    Daly, M. G.; Barnouin, O. S.; Dickinson, C.; Seabrook, J.; Johnson, C. L.; Cunningham, G.; Haltigin, T.; Gaudreau, D.; Brunet, C.; Aslam, I.; Taylor, A.; Bierhaus, E. B.; Boynton, W.; Nolan, M.; Lauretta, D. S.

    2017-10-01

    The Canadian Space Agency (CSA) has contributed to the Origins Spectral Interpretation Resource Identification Security-Regolith Explorer (OSIRIS-REx) spacecraft the OSIRIS-REx Laser Altimeter (OLA). The OSIRIS-REx mission will sample asteroid 101955 Bennu, the first B-type asteroid to be visited by a spacecraft. Bennu is thought to be primitive, carbonaceous, and spectrally most closely related to CI and/or CM meteorites. As a scanning laser altimeter, the OLA instrument will measure the range between the OSIRIS-REx spacecraft and the surface of Bennu to produce digital terrain maps of unprecedented spatial scales for a planetary mission. The digital terrain maps produced will measure ˜7 cm per pixel globally, and ˜3 cm per pixel at specific sample sites. In addition, OLA data will be used to constrain and refine the spacecraft trajectories. Global maps and highly accurate spacecraft trajectory estimates are critical to infer the internal structure of the asteroid. The global and regional maps also are key to gain new insights into the surface processes acting across Bennu, which inform the selection of the OSIRIS-REx sample site. These, in turn, are essential for understanding the provenance of the regolith sample collected by the OSIRIS-REx spacecraft. The OLA data also are important for quantifying any hazards near the selected OSIRIS-REx sample site and for evaluating the range of tilts at the sampling site for comparison against the capabilities of the sample acquisition device.

  3. Transcription factor Rex in regulation of pathophysiology in oral pathogens.

    Science.gov (United States)

    Bitoun, J P; Wen, Z T

    2016-04-01

    The NAD(+) and NADH-sensing transcriptional regulator Rex is widely conserved across gram-positive bacteria. Rex monitors cellular redox poise and controls the expression of genes/operons involved in diverse pathways including alternative fermentation, oxidative stress responses, and biofilm formation. The oral cavity undergoes frequent and drastic fluctuations in nutrient availability, pH, temperature, oxygen tension, saliva, and shear forces. The oral streptococci are major colonizers of oral mucosa and tooth surfaces and include commensals as well as opportunistic pathogens, including the primary etiological agent of dental caries, Streptococcus mutans. Current understanding of the Rex regulon in oral bacteria is mostly based on studies in S. mutans and endodontic pathogen Enterococcus faecalis. Indeed, other oral bacteria encode homologs of the Rex protein and much is to be gleaned from more in-depth studies. Our current understanding has Rex positioned at the interface of oxygen and energy metabolism. In biofilms, heterogeneous oxygen tension influences the ratio of intracellular NADH and NAD(+) , which is finely tuned through glycolysis and fermentation. In S. mutans, Rex regulates the expression of glycolytic enzyme NAD(+) -dependent glyceraldehyde 3-phosphate dehydrogenase, and NADH-dependent fermentation enzymes/complexes lactate dehydrogenase, pyruvate dehydrogenase, alcohol-acetaldehyde dehydrogenase, and fumarate reductase. In addition, Rex controls the expression of NADH oxidase, a major enzyme used to eliminate oxidative stress and regenerate NAD(+) . Here, we summarize recent studies carried out on the Rex regulators in S. mutans and E. faecalis. This research has important implications for understanding how Rex monitors redox balance and optimizes fermentation pathways for survival and subsequent pathogenicity. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. The pair correlation function of spatial Hawkes processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Torrisi, Giovanni Luca

    2007-01-01

    Spatial Hawkes processes can be considered as spatial versions of classical Hawkes processes. We derive the pair correlation function of stationary spatial Hawkes processes and discuss the connection to the Bartlett spectrum and other summary statistics. Particularly, results for Gaussian fertility...... rates and the extension to spatial Hawkes processes with random fertility rates are discussed....

  5. REXS : A financial risk diagnostic expert system

    Directory of Open Access Journals (Sweden)

    W. Richter

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Artificial intelligence techniques are rapidly emerging as important contributors to more effective management. One of the greatest growth areas probably lies in the use of Expert System methodology for supporting managerial decision processes.
    Existing Decision Support Systems often attempt to apply analytical techniques in combination with traditional data access and retrieval functions. One of the problems usually encountered while developing such decision support systems is the need to transform an unstructured problem environment into a structured analytical model. Using an expert system approach to strategic decision making in such unstructured problem environments may provide significant advantages.
    The financial Risk diagnostic EXpert System (REXS concentrates on Financial Risk Analysis. Based on a Forecasting Model the system will, with the support of several expert system knowledge bases, attempt to evaluate the financial risk of a business and provide guidelines for improvement.

    AFRIKAANSE OPSOMMING: Tegnieke gebaseer op Kunsmatige Intelligensie toon tans die belofte om belangrike bydraes te maak tot meerBestaande Besluitsteunstelsels poog dikwels om analitiese tegnieke en lradisionele datatoegang- en onttrekkingsfunksies te kombineer. Een van die probleme wat gewoonlik ondervind word gedurende die ontwikkeling van '0 besluitsteunstelsel bestaan uit die behoefte om 'n ongestruktueerde probleemomgewing te transformeer na 'n gestruktueerde analitiese model. 'n Ekspertstelselbenadering lot strategiese besluitneming in 'n ongeSlruktureerde probleemomgewing mag betekenisvolle voordele inhou.
    Die "financial Risk diagnostic EXpert System (REXS" konsentreer op fmansiele risiko-analise. Uitgaande vanaf 'n Vooruitskattingsmode~ en deur gebruik te maak van verskeie ekspertstelselkennisbasisse, poog die stelsel om die fmansiele risiko van 'n onderneming te evalueer en riglyne vir moontlike verbetering

  6. Entropy Budget for Hawking Evaporation

    Directory of Open Access Journals (Sweden)

    Ana Alonso-Serrano

    2017-07-01

    Full Text Available Blackbody radiation, emitted from a furnace and described by a Planck spectrum, contains (on average an entropy of 3 . 9 ± 2 . 5 bits per photon. Since normal physical burning is a unitary process, this amount of entropy is compensated by the same amount of “hidden information” in correlations between the photons. The importance of this result lies in the posterior extension of this argument to the Hawking radiation from black holes, demonstrating that the assumption of unitarity leads to a perfectly reasonable entropy/information budget for the evaporation process. In order to carry out this calculation, we adopt a variant of the “average subsystem” approach, but consider a tripartite pure system that includes the influence of the rest of the universe, and which allows “young” black holes to still have a non-zero entropy; which we identify with the standard Bekenstein entropy.

  7. OSIRIS-REx Contamination Control Strategy and Implementation

    Science.gov (United States)

    Dworkin, J. P.; Adelman, L. A.; Ajluni, T.; Andronikov, A. V.; Aponte, J. C.; Bartels, A. E.; Beshore, E.; Bierhaus, E. B.; Brucato, J. R.; Bryan, B. H.; Burton, A. S.; Callahan, M. P.; Castro-Wallace, S. L.; Clark, B. C.; Clemett, S. J.; Connolly, H. C.; Cutlip, W. E.; Daly, S. M.; Elliott, V. E.; Elsila, J. E.; Enos, H. L.; Everett, D. F.; Franchi, I. A.; Glavin, D. P.; Graham, H. V.; Hendershot, J. E.; Harris, J. W.; Hill, S. L.; Hildebrand, A. R.; Jayne, G. O.; Jenkens, R. W.; Johnson, K. S.; Kirsch, J. S.; Lauretta, D. S.; Lewis, A. S.; Loiacono, J. J.; Lorentson, C. C.; Marshall, J. R.; Martin, M. G.; Matthias, L. L.; McLain, H. L.; Messenger, S. R.; Mink, R. G.; Moore, J. L.; Nakamura-Messenger, K.; Nuth, J. A.; Owens, C. V.; Parish, C. L.; Perkins, B. D.; Pryzby, M. S.; Reigle, C. A.; Righter, K.; Rizk, B.; Russell, J. F.; Sandford, S. A.; Schepis, J. P.; Songer, J.; Sovinski, M. F.; Stahl, S. E.; Thomas-Keprta, K.; Vellinga, J. M.; Walker, M. S.

    2018-02-01

    OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This article describes how pristine was defined based on expectations of Bennu and on a realistic understanding of what is achievable with a constrained schedule and budget, and how that definition flowed to requirements and implementation. To return a pristine sample, the OSIRIS-REx spacecraft sampling hardware was maintained at level 100 A/2 and communication among scientists, engineers, managers, and technicians.

  8. Hawking's Israel boycott sparks heated response

    Science.gov (United States)

    Dacey, James

    2013-06-01

    The controversial decision by Stephen Hawking to boycott a prominent conference in Jerusalem in protest against the policies of the Israeli government has provoked strong responses from academics and commentators.

  9. Hawking radiation from quasilocal dynamical horizons

    Indian Academy of Sciences (India)

    2016-01-06

    Jan 6, 2016 ... Abstract. In completely local settings, we establish that a dynamically evolving spherically symmetric black hole horizon can be assigned a Hawking temperature and with the emission of flux, radius of the horizon shrinks.

  10. NASA 3D Models: Global Hawk

    Data.gov (United States)

    National Aeronautics and Space Administration — The ability of the Global Hawk air vehicle to autonomously fly long distances and remain aloft for extended periods of time means that measuring, monitoring, and...

  11. LVIS Integration onto Global Hawk Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Integrate LVIS lidar capability onto the Global Hawk (GH) to enable high altitude mapping of land, vegetation, and ice Provide operational capability and data...

  12. Amplifying the Hawking Signal in BECs

    Directory of Open Access Journals (Sweden)

    Roberto Balbinot

    2014-01-01

    Full Text Available We consider simple models of Bose-Einstein condensates to study analog pair-creation effects, namely, the Hawking effect from acoustic black holes and the dynamical Casimir effect in rapidly time-dependent backgrounds. We also focus on a proposal by Cornell to amplify the Hawking signal in density-density correlators by reducing the atoms’ interactions shortly before measurements are made.

  13. Ferruginous hawks on the Yakima Training Center

    Energy Technology Data Exchange (ETDEWEB)

    Mazaika, R.; Cadwell, L.L.

    1994-07-01

    Habitat quality for ferruginous hawks (Buteo regalis) is largely determined by availability of nest sites and adequate prey base. A limitation of one of these will limit the number of hawks in an area. In general, ferruginous hawks are adaptable to various nesting substrates and will nest in proximity to other closely related sympatric species (e.g., red-tailed hawk, Swainson`s hawk). This analysis focused on an assessment of prey base availability and habitat disturbance in the vicinity of historic nest sites and small mammal trap sites on the Yakima Training Center (YTC) in Washington State. The primary ground-disturbing activities on the YTC are associated with military training, fire, and grazing. In addition to the direct effect these activities can have on ferruginous hawks, indirect effects may result from changes in composition, density, and structure of vegetation that subsequently alter faunal population numbers and species diversity. A summary of results of small mammal trapping, population estimation, vegetative analysis and disturbance rating at seven trap sites during the time period of June through August of 1993 are presented.

  14. Horton Ratios Link Self-Similarity with Maximum Entropy of Eco-Geomorphological Properties in Stream Networks

    Directory of Open Access Journals (Sweden)

    Bruce T. Milne

    2017-05-01

    Full Text Available Stream networks are branched structures wherein water and energy move between land and atmosphere, modulated by evapotranspiration and its interaction with the gravitational dissipation of potential energy as runoff. These actions vary among climates characterized by Budyko theory, yet have not been integrated with Horton scaling, the ubiquitous pattern of eco-hydrological variation among Strahler streams that populate river basins. From Budyko theory, we reveal optimum entropy coincident with high biodiversity. Basins on either side of optimum respond in opposite ways to precipitation, which we evaluated for the classic Hubbard Brook experiment in New Hampshire and for the Whitewater River basin in Kansas. We demonstrate that Horton ratios are equivalent to Lagrange multipliers used in the extremum function leading to Shannon information entropy being maximal, subject to constraints. Properties of stream networks vary with constraints and inter-annual variation in water balance that challenge vegetation to match expected resource supply throughout the network. The entropy-Horton framework informs questions of biodiversity, resilience to perturbations in water supply, changes in potential evapotranspiration, and land use changes that move ecosystems away from optimal entropy with concomitant loss of productivity and biodiversity.

  15. The OSIRIS-REx Asteroid Sample Return Mission Operations Design

    Science.gov (United States)

    Gal-Edd, Jonathan S.; Cheuvront, Allan

    2015-01-01

    OSIRIS-REx is an acronym that captures the scientific objectives: Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer. OSIRIS-REx will thoroughly characterize near-Earth asteroid Bennu (Previously known as 1019551999 RQ36). The OSIRIS-REx Asteroid Sample Return Mission delivers its science using five instruments and radio science along with the Touch-And-Go Sample Acquisition Mechanism (TAGSAM). All of the instruments and data analysis techniques have direct heritage from flown planetary missions. The OSIRIS-REx mission employs a methodical, phased approach to ensure success in meeting the mission's science requirements. OSIRIS-REx launches in September 2016, with a backup launch period occurring one year later. Sampling occurs in 2019. The departure burn from Bennu occurs in March 2021. On September 24, 2023, the Sample Return Capsule (SRC) lands at the Utah Test and Training Range (UTTR). Stardust heritage procedures are followed to transport the SRC to Johnson Space Center, where the samples are removed and delivered to the OSIRIS-REx curation facility. After a six-month preliminary examination period the mission will produce a catalog of the returned sample, allowing the worldwide community to request samples for detailed analysis. Traveling and returning a sample from an Asteroid that has not been explored before requires unique operations consideration. The Design Reference Mission (DRM) ties together spacecraft, instrument and operations scenarios. Asteroid Touch and Go (TAG) has various options varying from ground only to fully automated (natural feature tracking). Spacecraft constraints such as thermo and high gain antenna pointing impact the timeline. The mission is sensitive to navigation errors, so a late command update has been implemented. The project implemented lessons learned from other "small body" missions. The key lesson learned was 'expect the unexpected' and implement planning tools early in the lifecycle

  16. GRIP GLOBAL HAWK NAVIGATION AND HOUSEKEEPING DATA V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP Global Hawk Navigation data was collected during the period Aug 15, 2010 to September 24, 2010 during the GRIP field campaign. The Global Hawk is an...

  17. Breeding ecology of ferruginous hawks, Swainson's hawks, and northern harriers in south-central North Dakota : Final report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Final report of research survey to document the breeding ecology of ferruginous hawks, Swainsons hawk, and northern harrier in Kulm Wetland Management District WMD...

  18. Breeding ecology of ferruginous hawks, Swainson’s hawks, and northern harriers in south-central North Dakota : Proposal

    Data.gov (United States)

    Department of the Interior — Project proposal for research survey to document the breeding ecology of ferruginous hawks, Swainson’s hawk, and northern harrier in Kulm Wetland Management District...

  19. Evidence of hawking (falconry) from bird and mammal bones

    NARCIS (Netherlands)

    Prummel, W.

    1997-01-01

    This paper deals with the archaeozoological and archaeological evidence for hawking, or falconry. The methods and history of hawking in Europe are described, after which five types of evidence for hawking are discussed. These are illustrated with material from the Slavonic stronghold of Oldenburg in

  20. Stephen Hawking a life in science

    CERN Document Server

    White, Michael

    1992-01-01

    This biography of the author of "A Brief History of Time", pays particular attention to Hawking's considerable scientific achievement, as well as to the tragic progress of his illnesss and his extraordinary will to survive and to continue working despite major progressive handicap.

  1. HH-60D night hawk helicopter

    Science.gov (United States)

    Richardson, C. S.

    1984-01-01

    Fundamental development issues, system requirements and improvements are reported for the HH-60D night hawk helicopter. The HH-60D mission requirements are for combat search and rescue (aerospace rescue and recovery service user based at Scott AFB) and special operations (special operations forces based at Hurlburt AFB). Cockpit design, computer architecture and software are described in detail.

  2. Hawking radiation power equations for black holes

    Directory of Open Access Journals (Sweden)

    Ravi Mistry

    2017-10-01

    Full Text Available We derive the Hawking radiation power equations for black holes in asymptotically flat, asymptotically Anti-de Sitter (AdS and asymptotically de Sitter (dS black holes. This is done by using the greybody factor for these black holes. We observe that the radiation power equation for asymptotically flat black holes, corresponding to greybody factor at low frequency, depends on both the Hawking temperature and the horizon radius. However, for the greybody factors at asymptotic frequency, it only depends on the Hawking temperature. We also obtain the power equation for asymptotically AdS black holes both below and above the critical frequency. The radiation power equation for at asymptotic frequency is same for both Schwarzschild AdS and Reissner–Nordström AdS solutions and only depends on the Hawking temperature. We also discuss the power equation for asymptotically dS black holes at low frequency, for both even or odd dimensions.

  3. On the stringy Hartle-Hawking state

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Israel, Roy [Physics Department, Tel-Aviv University,Ramat-Aviv, 69978 (Israel); Giveon, Amit [Racah Institute of Physics, The Hebrew University,Jerusalem, 91904 (Israel); Itzhaki, Nissan; Liram, Lior [Physics Department, Tel-Aviv University,Ramat-Aviv, 69978 (Israel)

    2016-03-03

    We argue that non-perturbative α{sup ′} stringy effects render the Hartle-Hawking state associated with the SL(2)/U(1) eternal black hole singular at the horizon. We discuss implications of this observation on firewalls in string theory.

  4. Tunka-Rex. Event reconstruction and effect of antenna alignment

    Energy Technology Data Exchange (ETDEWEB)

    Kazarina, Yulia [Institut fuer Kernphysik, Karlsruher Institut fuer Technologie (KIT) (Germany); Irkutsk State University (ISU) (Russian Federation)

    2015-07-01

    The Tunka-Rex experiment (Tunka Radio Extension) has been deployed in autumn 2012 at the territory of the Tunka-133 experiment (Tunka Valley, Republic of Buryatia, Russia), covering an area of approximately 1 km{sup 2}. Tunka-133 detects the Cherenkov radiation from air showers of cosmic rays at energies E >or similar 10{sup 16.5}-10{sup 18} eV, and 25 antennas of Tunka-Rex measure the radio emission of the same air showers. Unlike most radio experiments the Tunka-Rex antennas are not aligned along the north-south and east-west axis, but rotated by 45 {sup circle} with respect to the geomagnetic north-south axis. Using CoREAS simulations, we studied the effect of the antenna alignment on the efficiency of Tunka-Rex in the presence of noise. This report presents the results of this study as well as methods for the reconstruction of measured air shower events.

  5. Ophthalmologic and oculopathologic findings in red-tailed hawks and Cooper's hawks with naturally acquired West Nile virus infection.

    Science.gov (United States)

    Pauli, Amy M; Cruz-Martinez, Luis A; Ponder, Julia B; Redig, Patrick T; Glaser, Amy L; Klauss, Gia; Schoster, James V; Wünschmann, Arno

    2007-10-15

    To assess ophthalmologic features and ocular lesions in red-tailed hawks and Cooper's hawks naturally infected with West Nile virus (WNV). Original study. 13 hawks. All hawks underwent complete ophthalmic examinations including slit lamp biomicroscopy and binocular indirect ophthalmoscopy. Eleven hawks were euthanized because of a grave prognosis; complete necropsies were performed. Eyes, brain, heart, and kidneys were processed for histologic and immunohistochemical examinations. Pooled tissue homogenates and aqueous humor samples were assessed for WNV nucleic acid via PCR assay, and anti-WNV antibody titers in aqueous humor and plasma were determined. All birds had similar funduscopic abnormalities including exudative chorioretinal lesions and chorioretinal scarring in a geographic or linear pattern. Eleven birds were euthanized, and 2 birds were released. Plasma from both released hawks and plasma and aqueous humor of all euthanized hawks that were evaluated contained anti-WNV antibodies. Except for 1 hawk, all euthanized hawks had WNV-associated disease (determined via detection of WNV antigen or nucleic acid in at least 1 organ). Histopathologic ocular abnormalities, most commonly pectenitis, were detected in all euthanized birds; several birds had segmental choroiditis, often with corresponding segmental retinal atrophy. West Nile virus antigen was detected in the retinas of 9 of the euthanized birds. In 2 hawks, WNV antigen was detected in the retina only. Results indicated that funduscopically detectable chorioretinal lesions appear to be associated with WNV disease in hawks. Detection of ocular lesions may aid in antemortem or postmortem diagnosis of this condition.

  6. Computer Description of Black Hawk Helicopter

    Science.gov (United States)

    1979-06-01

    A RB8 •O/ lŔ/ ^ MUDO 667-668 ARB8 677 BOX Pi nnvfl 9 Q Solids Used to Describe the Pilot’s Seat of the Black Hawk. 46 L r I 752 / ARB8...F CI AM"£ AMMt G IN E CINE Y GINb Y C I N E G IM G I N E INE INE INE INE INE NG INE INE TAR TAR RAT RAT RAT R S R S R S

  7. Fatal pox infection in a rough-legged hawk

    Science.gov (United States)

    Pearson, G.L.; Pass, D.A.; Beggs, E.C.

    1975-01-01

    Natural pox infection occurred in a free-living rough-legged hawk (Buteo lagopus) in northeastern North Dakota. Gross, histological and electron microscopic findings were typical of pox infection, and characteristic lesions developed in red-tailed hawks (Buteo jamaicensis) but not in great horned owls (Bubo virginianus) following inoculation with case material. Death of the rough-legged hawk was attributed to starvation resulting from inability to capture prey and to blood loss from foot lesions.

  8. Estimation of recreational value of Horton Plains National Park in Sri Lanka: A decision making strategy for natural resourcemanagement

    Directory of Open Access Journals (Sweden)

    R. M. W. Rathnayake

    2011-10-01

    Full Text Available Horton Plains National Park (HPNP is an area of high biodiversity and exceptional endemism receiving high visitation (166,613 visitors in 2009, both by local and foreigners. Although, tourism causes negative impacts on the environment, environmental valuation could be used for taking decisions on natural resources management. The study shows that the recreational value of HPNP is Rs. 51.68 million rupees per year, but the total economic value could be many times higher than this. Calculations showed the maximum revenue from the park could be obtained if the entrance fee is raised to Rs. 472.00. This may however reduce the present visitor number by 65%, but it will improve the total revenue of the park by 314 %.  These differences strengthen the common argument by both officials and the public regarding insufficient allocation of man power and funds for natural resources management.Key words: wildlife, recreational value, travel cost method

  9. Minimizing Energy Spread In The REX/HIE-ISOLDE Linac

    CERN Document Server

    Yucemoz, Mert

    2017-01-01

    This report tries to minimize the energy spread of the beam at the end of the REX-HIE-ISOLDE Linac using the last RF cavity as a buncher. Beams with very low energy spread are often required by the users of the facility In addition, one of the main reason to have minimum energy spread in longitudinal phase space is that higher beam energy spread translates in to a position spread after interacting with target. This causes an overlap in the position of different particles that makes it difficult to distinguish them. Hence, in order to find the operation settings for minimum energy spread at the end of the REX-HIE-ISOLDE linac and to inspect the ongoing physics, several functions on Matlab were created that runs beam dynamics program called “TRACKV39” that provides some graphs and values as a result for analysis.

  10. Stable occupancy by breeding hawks (Buteospp.) over 25 years on a privately managed bunchgrass prairie in northeastern Oregon, USA

    National Research Council Canada - National Science Library

    Patricia L. Kennedy; Anne M. Bartuszevige; Marcy Houle; Ann B. Humphrey; Katie M. Dugger; John Williams

    2014-01-01

    ...–1980, high nesting densities of 3 species of hawks in the genus Buteo—Ferruginous Hawk ( ), Red-tailed Hawk ( ), and Swainson’s Hawk ( )—were documented on the Zumwalt Prairie and surrounding agricultural areas...

  11. NASA Global Hawk: A New Tool for Earth Science Research

    Science.gov (United States)

    Hall, Phill

    2009-01-01

    This slide presentation reviews the Global Hawk, a unmanned aerial vehicle (UAV) that NASA plans to use for Earth Sciences research. The Global Hawk is the world's first fully autonomous high-altitude, long-endurance aircraft, and is capable of conducting long duration missions. Plans are being made for the use of the aircraft on missions in the Arctic, Pacific and Western Atlantic Oceans. There are slides showing the Global Hawk Operations Center (GHOC), Flight Control and Air Traffic Control Communications Architecture, and Payload Integration and Accommodations on the Global Hawk. The first science campaign, planned for a study of the Pacific Ocean, is reviewed.

  12. Notes on breeding sharp-shinned hawks and Cooper’s hawks in Barnwell County, South Carolina.

    Energy Technology Data Exchange (ETDEWEB)

    Vukovich, Mark; Kilgo, John, C.

    2009-07-01

    Abstract - Breeding records of Accipiter striatus (Sharp-shinned Hawks) in the southeastern US are scattered and isolated. We documented a Sharp-shinned Hawk and Accipiter cooperii (Cooper’s Hawk) nest while conducting a telemetry study on Melanerpes erythrocephalus (Red-headed Woodpeckers) in Barnwell County, SC in 2006 and 2007. We report the first known nest of a Sharp-shinned Hawk in Barnwell County, SC and the first report of Sharp-shinned Hawks preying upon Red-headed Woodpeckers. Thirteen of 93 (13.9 %) woodpeckers were killed by accipiters in the summers of 2006 and 2007. Large, contiguous forests managed for Picoides borealis (Red-cockaded Woodpeckers) may be used by breeding Sharp-shinned Hawks. The bright plumage, loud calls, and behavior of Red-headed Woodpeckers, particularly during the nestling stage, may make them conspicuous prey for accipiters.

  13. The OSIRIS-Rex Asteroid Sample Return: Mission Operations Design

    Science.gov (United States)

    Gal-Edd, Jonathan; Cheuvront, Allan

    2014-01-01

    The OSIRIS-REx mission employs a methodical, phased approach to ensure success in meeting the missions science requirements. OSIRIS-REx launches in September 2016, with a backup launch period occurring one year later. Sampling occurs in 2019. The departure burn from Bennu occurs in March 2021. On September 24, 2023, the SRC lands at the Utah Test and Training Range (UTTR). Stardust heritage procedures are followed to transport the SRC to Johnson Space Center, where the samples are removed and delivered to the OSIRIS-REx curation facility. After a six-month preliminary examination period the mission will produce a catalog of the returned sample, allowing the worldwide community to request samples for detailed analysis.Traveling and returning a sample from an Asteroid that has not been explored before requires unique operations consideration. The Design Reference Mission (DRM) ties together space craft, instrument and operations scenarios. The project implemented lessons learned from other small body missions: APLNEAR, JPLDAWN and ESARosetta. The key lesson learned was expected the unexpected and implement planning tools early in the lifecycle. In preparation to PDR, the project changed the asteroid arrival date, to arrive one year earlier and provided additional time margin. STK is used for Mission Design and STKScheduler for instrument coverage analysis.

  14. Proteomic evidences for rex regulation of metabolism in toxin-producing Bacillus cereus ATCC 14579.

    Directory of Open Access Journals (Sweden)

    Sabrina Laouami

    Full Text Available The facultative anaerobe, Bacillus cereus, causes diarrheal diseases in humans. Its ability to deal with oxygen availability is recognized to be critical for pathogenesis. The B. cereus genome comprises a gene encoding a protein with high similarities to the redox regulator, Rex, which is a central regulator of anaerobic metabolism in Bacillus subtilis and other Gram-positive bacteria. Here, we showed that B. cereus rex is monocistronic and down-regulated in the absence of oxygen. The protein encoded by rex is an authentic Rex transcriptional factor since its DNA binding activity depends on the NADH/NAD+ ratio. Rex deletion compromised the ability of B. cereus to cope with external oxidative stress under anaerobiosis while increasing B. cereus resistance against such stress under aerobiosis. The deletion of rex affects anaerobic fermentative and aerobic respiratory metabolism of B. cereus by decreasing and increasing, respectively, the carbon flux through the NADH-recycling lactate pathway. We compared both the cellular proteome and exoproteome of the wild-type and Δrex cells using a high throughput shotgun label-free quantitation approach and identified proteins that are under control of Rex-mediated regulation. Proteomics data have been deposited to the ProteomeXchange with identifier PXD000886. The data suggest that Rex regulates both the cross-talk between metabolic pathways that produce NADH and NADPH and toxinogenesis, especially in oxic conditions.

  15. Thermophysical Analysis of 101955 Bennu with OSIRIS-REx

    Science.gov (United States)

    Emery, Joshua; Rozitis, Ben; Christensen, Philip R.; Thomas, Cristina A.; Hamilton, Victoria E.; Clark, Beth Ellen; Delbo, Marco; Lim, Lucy F.; Lauretta, Dante

    2017-10-01

    NASA’s OSIRIS-REx mission will approach its target asteroid, (101955) Bennu, in August 2018. The primary objective of the mission is to return a pristine sample from Bennu in order to address some of NASA’s (and humanity’s) fundamental questions: How did the Solar System form? How did life evolve in the Solar System? Are asteroids harbingers of life or death - or both? Prior to picking up the sample from the surface, OSIRIS-REx will spend more than a year characterizing the surface with cameras, spectrometers, and the laser altimeter that are on board the spacecraft. Global and local determination of thermophysical properties will inform maps of sampleability, spacecraft safety, and science value of the surface. The primary data set to be used for thermophysical analyses are thermal spectra from the OSIRIS-REx Thermal Emission Spectrometer (OTES). The long-wavelength end of spectra obtained by the OSIRIS-REx Visible and InfraRed Spectrometer (OVIRS) will also be dominated by thermal emission. Full-disk observations during Approach will provide hemispherically averaged, but rotationally resolved, properties. The Approach observations also enable direct comparisons to previous Spitzer space telescope observations of Bennu. During the Detailed Survey phase, OTES will measure the infrared radiation from the entire surface, enabling us to map temperatures over Bennu at seven different local times of day (3:20am, 6am, 10am, 12:30pm, 3pm, 6pm, and 8:40pm). The diurnal temperature curves will be used to map the thermal inertia of the surface at a ~40m spatial scale. The Orbital phase of the mission will enable higher spatial resolution thermal observations of up to twelve potential sample sites, and Reconnaissance phase will enable even higher spatial resolution observations of the two highest priority potential sample sites. Thermophysical analysis of these data will be carried out with a custom thermal model that is based on the Advanced Thermophysical Model of

  16. Hawking Temperature of Acoustic Black Hole Zhi Kun Xie

    Indian Academy of Sciences (India)

    Abstract. Using a new tortoise coordinate transformation, the Hawking radiation of the acoustic black hole was discussed by studying the Klein–. Gordon equation of scalar particles in the curve space-time. It was found that the Hawking temperature is connected with time and position on the event horizon. Key words.

  17. Hawking Temperature of an Arbitrarily Accelerating Black Hole Wei ...

    Indian Academy of Sciences (India)

    Introduction. In 1974, Hawking (1974) made a striking discovery that black holes could produce thermal radiation. In this paper, we will obtain Hawking temperature of an arbitrarily accelerating black hole based on the Klein–Gordon equation, which is identical to the one obtained by the Hamilton–Jacobi equation under the ...

  18. Teachers' Perception Of Street Hawking In Ilorin Metropolis ...

    African Journals Online (AJOL)

    This paper investigated the perception of teachers' on street hawking by children in Ilorin metropolis. Street Hawking as used in this study refers to children who sell goods or items on the streets of Ilorin. The study made use of one hundred and fifty participants. The data for the study was collected by means of a ...

  19. The death of Philosophy: A response to Stephen Hawking | Scott ...

    African Journals Online (AJOL)

    In his 2010 work, The Grand Design, Stephen Hawking, argues that '… philosophy is dead' (2010: 5). While not a Philosopher, Hawking provides strong argument for his thesis, principally that philosophers have not taken science sufficiently seriously and so Philosophy is no longer relevant to knowledge claims.

  20. Entropy/information flux in Hawking radiation

    Science.gov (United States)

    Alonso-Serrano, Ana; Visser, Matt

    2018-01-01

    Blackbody radiation contains (on average) an entropy of 3.9 ± 2.5 bits per photon. If the emission process is unitary, then this entropy is exactly compensated by "hidden information" in the correlations. We extend this argument to the Hawking radiation from GR black holes, demonstrating that the assumption of unitarity leads to a perfectly reasonable entropy/information budget. The key technical aspect of our calculation is a variant of the "average subsystem" approach developed by Page, which we extend beyond bipartite pure systems, to a tripartite pure system that considers the influence of the environment.

  1. Shin Clearance in the Hawk Mk115

    Science.gov (United States)

    2008-01-01

    represented by the Minister of National Defence, 2008 © Sa Majesté la Reine (en droit du Canada), telle que représentée par le ministre de la Défense...supplémentaires ont été effectués en utilisant le plus grand des sujets qui consistaient à effectuer des éjections simulées dans le simulateur... sujets qui consistaient à effectuer des éjections simulées dans le simulateur d’éjection du Hawk. L’objectif était double: 1) d’observer l’effet du

  2. Hawking radiation, the Stefan–Boltzmann law, and unitarization

    Energy Technology Data Exchange (ETDEWEB)

    Giddings, Steven B., E-mail: giddings@physics.ucsb.edu

    2016-03-10

    Where does Hawking radiation originate? A common picture is that it arises from excitations very near or at the horizon, and this viewpoint has supported the “firewall” argument and arguments for a key role for the UV-dependent entanglement entropy in describing the quantum mechanics of black holes. However, closer investigation of both the total emission rate and the stress tensor of Hawking radiation supports the statement that its source is a near-horizon quantum region, or “atmosphere,” whose radial extent is set by the horizon radius scale. This is potentially important, since Hawking radiation needs to be modified to restore unitarity, and a natural assumption is that the scales relevant to such modifications are comparable to those governing the Hawking radiation. Moreover, related discussion suggests a resolution to questions regarding extra energy flux in “nonviolent” scenarios, that does not spoil black hole thermodynamics as governed by the Bekenstein–Hawking entropy.

  3. Hawking radiation inside a Schwarzschild black hole

    CERN Document Server

    Hamilton, Andrew J S

    2016-01-01

    The boundary of any observer's spacetime is the boundary that divides what the observer can see from what they cannot see. The boundary of an observer's spacetime in the presence of a black hole is not the true (future event) horizon of the black hole, but rather the illusory horizon, the dimming, redshifting surface of the star that collapsed to the black hole long ago. The illusory horizon is the source of Hawking radiation seen by observers both outside and inside the true horizon. The perceived acceleration (gravity) on the illusory horizon sets the characteristic frequency scale of Hawking radiation, even if that acceleration varies dynamically, as it must do from the perspective of an infalling observer. The acceleration seen by a non-rotating free-faller both on the illusory horizon below and in the sky above is calculated for a Schwarzschild black hole. Remarkably, as an infaller approaches the singularity, the acceleration becomes isotropic, and diverging as a power law. The isotropic, power-law char...

  4. A red-tailed hawk at KSC

    Science.gov (United States)

    2000-01-01

    From the top of a utility pole, a red-tailed hawk launches into flight, perhaps after spotting prey, typically a small rodent. Ranging in height from 18 inches to 25 inches, the species has a stocky build with a whitish breast and rust-colored tail. It has a high-pitched descending scream with a hoarse quality. The hawk inhabits mainly deciduous forest and adjacent open country from Alaska and Nova Scotia south to Panama. KSC shares a boundary with the Merritt Island National Wildlife Refuge, which encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  5. Digital flexor musculotendinous contracture in two Devon Rex cats.

    Science.gov (United States)

    Thom, Leonie K; Pool, Roy R; Malik, Richard

    2017-03-01

    Clinical summary: A 13-year-old, spayed Devon Rex with unilateral digital flexor musculotendinous contracture of the forelimb was treated by surgical tenotomy. The condition improved transiently, but recurred rapidly and became bilateral. Histopathologic analysis of necropsy tissues resulted in a morphologic diagnosis of fibromyositis of the antebrachial muscles causing contracture and flexural deformity of the carpi and phalanges of both thoracic limbs. A search for similar cases yielded the clinical notes of a second cat, a 10-year-old, spayed Devon Rex, also with bilateral disease. This second case responded well to surgical tenotomy but tissue biopsies were not obtained to permit microscopic assessment of the underlying pathologic process. Relevance and novel information: Acquired and permanent contracture of the digital flexor muscles and/or tendons of the forelimbs is a rare and poorly described condition of cats. The very limited number of documented cases describing disease affecting one or more digits (but not the carpus) infers a causal link with onychectomy, but reported histopathologic changes have been limited to the tendons. The two cases described in this report suffered contracture of the carpus and all digits bilaterally, one without previous onychectomy and the other 9 years after onychectomy. There were novel histopathologic findings in the muscles of the one case for which biopsy material was available. Information gained from these two cases provides a new perspective for the investigation and treatment of future cases. Specifically, consideration should be given to an underlying immune-mediated myopathic process and a possible genetic predisposition in the Devon Rex breed. Currently, the poorly understood etiopathogenesis hinders our ability to definitively recommend treatment options, which might include corticosteroids and other forms of immunosuppressive therapy.

  6. Three-gradient Emittance Measurements at REX-ISOLDE

    CERN Document Server

    Olsson, T; Lanaia, D; Voulot, D

    2013-01-01

    The transverse emittance was measured using the three-gradient method (also known as the quadrupole scan method) and compared to the slit-grid method that is normally used at REX-ISOLDE. For a 2.85 MeV/u beam with A=q = 4 the rms normalised emittance was measured as 0:32 0:06 mm mrad with the three-gradient method, a factor of 5 larger than was measured by the NTG emittance meter. An investigation into the discrepancy and a hypothesis for its cause are detailed in this note.

  7. Benchmarking of the REX-ISOLDE RFQ Beam Dynamics Simulations

    CERN Document Server

    Fraser, MA; Posocco, PA

    2011-01-01

    The Institute of Applied Physics (IAP, Goethe-University, Frankfurt am Main) version of the PARMTEQM code used to design the REX-ISOLDE RFQ was benchmarked with PARMTEQM v3.07 in order to validate its beam dynamics design. IAP input files existing at CERN and thought to describe the RFQ were investigated. The RFQ was finally simulated in PARMTEQM v3.07 to provide an input particle distribution for end-to-end simulations of the HIE-ISOLDE linac. The simulation was found to be consistent with the IAP code and with recent beam measurements [4].

  8. The $^{9}$Li+d reaction at REX-ISOLDE

    CERN Document Server

    Jeppesen, H B

    2004-01-01

    With the completion of the post-accelerator REX-ISOLDE at ISOLDE (CERN) in the autumn of 2001 it has become possible to perform low energy (up to 2.3 MeV/u) reactions with a large fraction of the 700 radioactive isotopes presently available at ISOLDE. We here report on the $^{9}$Li + d reaction at 2.36 MeV/u. This reaction was used to search for information on the excited states in $^{10}$Li. We will here shortly review the experiment and show a few results from our first experiment with this new instrument.

  9. File list: ALL.Kid.20.AllAg.HEK293-T-REx [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  14. File list: His.Kid.20.AllAg.HEK293-T-REx [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  17. File list: ALL.Kid.50.AllAg.HEK293-T-REx [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  19. File list: InP.Kid.20.AllAg.HEK293-T-REx [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  20. File list: InP.Kid.50.AllAg.HEK293-T-REx [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  1. Presumed pluripotency markers UTF-1 and REX-1 are expressed in human adult testes and germ cell neoplasms

    DEFF Research Database (Denmark)

    Kristensen, D.M.; Nielsen, J.E.; Skakkebaek, N.E.

    2008-01-01

    NANOG and OCT-3/4, UTF-1 and REX-1 are expressed throughout human testes development. The expression pattern indicated that UTF-1 plays a possible role in spermatogonial self-renewal, whereas expression of REX-1 in meiotic cells from both testes and ovary indicate a role in meiosis. UFT-1 and REX-1...

  2. What the White "Squaws" Want from Black Hawk: Gendering the Fan-Celebrity Relationship

    Science.gov (United States)

    Helton, Tena L.

    2010-01-01

    Americans in the East were great fans of Black Hawk, whose popularity on tour overtook that of Andrew Jackson's parallel tour of the Northeast. Undoubtedly, then, Black Hawk was a celebrity. He remained popular even in 1837, when he attended Catlin's gallery opening in New York, which included his 1832 painting of Black Hawk. Black Hawk may also…

  3. Experimental vacuolar myelinopathy in red-tailed hawks.

    Science.gov (United States)

    Fischer, John R; Lewis-Weis, Lynn A; Tate, Cynthia M

    2003-04-01

    Avian vacuolar myelinopathy (AVM) was recognized in 1994 as a cause of wild bird mortality when 29 bald eagles (Haliaeetus leucocephalus) succumbed to the disease at DeGray Lake, Arkansas (USA). The cause of AVM and its source remain undetermined despite extensive diagnostic and research investigations. Two years later, when AVM killed 26 eagles in the same area in Arkansas, it became apparent that American coots (Fulica americana) had identical neurologic signs and lesions, and it was hypothesized that eagles acquired AVM via ingestion of affected coots. In order to test this hypothesis, we fed coot tissues (brain, liver, kidney, muscle, fat, and intestinal tract) to rehabilitated, non-releasable red-tailed hawks (Buteo jamaicensis). Five hawks received tissues from coots with AVM lesions, and one hawk received tissues from coots without brain lesions that had been collected at a site where AVM never has been documented. All hawks received 12-70 g/day (mean = 38 g) of coot tissues for 28 days. All six hawks remained clinically normal during the study. The birds were euthanatized on day 29 and microscopic lesions of AVM were found in all hawks that received tissues from affected coots, but not in the hawk that received tissues from unaffected coots. This marks the first time that AVM has been produced in birds under laboratory conditions and proves that birds of prey can acquire AVM via ingestion of tissues from affected coots.

  4. Studi Kapasitas Infiltrasi Metode Horton untuk Pemakaian Biopori di Kampus Universitas Bina Nusantara Berdasarkan Debit Limpasan Permukaan

    Directory of Open Access Journals (Sweden)

    Juliastuti Juliastuti

    2011-12-01

    Full Text Available Changes in land use due to the rapid growth of building construction leads to an increase in direct runoff, as well as declining water that seeped into the ground. Consequently, water distribution happens to be unequal of between the rainy and dry seasons. This phenomenon also occurs in the area of Kijang Campus - Bina Nusantara University which always comes up with puddles even though the rain falls with only a short duration. In this research the rainfall on the Kijang Campus - Bina Nusantara University is assessed based on the rainfall data record to obtain the rainfall intensity of various periods. Field survey is conducted to determine the existing infiltration capacity (with / without bio pore holes and on-site. It is concluded based on the research results using Horton method that the soil on the Kijang Campus - Bina Nusantara University is earth embankment that has the infiltration capacity ranging between 0.0867 - 0.2165 m3/hr. This illustrates that the soil infiltration capacity is relatively small and thus requires the installation of bio pore holes with distance by 0.5 meters. 

  5. P-REX1 amplification promotes progression of cutaneous melanoma via the PAK1/P38/MMP-2 pathway.

    Science.gov (United States)

    Wang, Jinhua; Hirose, Hajime; Du, Guanhua; Chong, Kelly; Kiyohara, Eiji; Witz, Isaac P; Hoon, Dave S B

    2017-10-28

    P-REX1 (PIP3-dependent Rac exchange factor-1) is a guanine nucleotide exchange factor that activates Rac by catalyzing exchange of GDP for GTP bound to Rac. Aberrant up-regulation of P-REX1 expression has a role in metastasis however, copy number (CN) and function of P-REX1 in cutaneous melanoma are unclear. To explore the role of P-REX1 in melanoma, SNP 6.0 and Exon 1.0 ST microarrays were assessed. There was a higher CN (2.82-fold change) of P-REX1 in melanoma cells than in melanocytes, and P-REX1 expression was significantly correlated with P-REX1 CN. When P-REX1 was knocked down in cells by P-REX1 shRNA, proliferation, colony formation, 3D matrigel growth, and migration/invasiveness were inhibited. Loss of P-REX1 inhibited cell proliferation by inhibiting cyclin D1, blocking cell cycle, and increased cell apoptosis by reducing expression of the protein survivin. Knockdown of P-REX1 expression inhibited cell migration/invasiveness by disrupting P-REX1/RAC1/PAK1/p38/MMP-2 pathway. Assessment of patient tumors and disease outcome demonstrated lower distant metastasis-free survival among AJCC stage I/II/III patients with high P-REX1 expression compared to patients with low P-REX1 expression. These results suggest P-REX1 plays an important role in tumor progression and a potential theranostic target. Copyright © 2017. Published by Elsevier B.V.

  6. OSIRIS-REx Touch-And-Go (TAG) Navigation Performance

    Science.gov (United States)

    Berry, Kevin; Antreasian, Peter; Moreau, Michael C.; May, Alex; Sutter, Brian

    2015-01-01

    The Origins Spectral Interpretation Resource identification Security Regolith Explorer (OSIRIS-REx) mission is a NASA New Frontiers mission launching in 2016 to rendezvous with the near-Earth asteroid (101955) Bennu in late 2018. Following an extensive campaign of proximity operations activities to characterize the properties of Bennu and select a suitable sample site, OSIRIES-REx will fly a Touch-And-Go (TAG) trajectory to the asteroid's surface to obtain a regolith sample. The paper summarizes the mission design of the TAG sequence, the propulsive required to achieve the trajectory, and the sequence of events leading up to the TAG event. The paper will summarize the Monte-Carlo simulation of the TAG sequence and present analysis results that demonstrate the ability to conduct the TAG within 25 meters of the selected sample site and +-2 cms of the targeted contact velocity. The paper will describe some of the challenges associated with conducting precision navigation operations and ultimately contacting a very small asteroid.

  7. OSIRI-REx Touch and Go (TAG) Navigation Performance

    Science.gov (United States)

    Berry, Kevin; Antreasian, Peter; Moreau, Michael C.; May, Alex; Sutter, Brian

    2015-01-01

    The Origins Spectral Interpretation Resource Identification Security Regolith Explorer (OSIRIS-REx) mission is a NASA New Frontiers mission launching in 2016 to rendezvous with the near-Earth asteroid (101955) Bennu in late 2018. Following an extensive campaign of proximity operations activities to characterize the properties of Bennu and select a suitable sample site, OSIRIS-REx will fly a Touch-And-Go (TAG) trajectory to the asteroid's surface to obtain a regolith sample. The paper summarizes the mission design of the TAG sequence, the propulsive maneuvers required to achieve the trajectory, and the sequence of events leading up to the TAG event. The paper also summarizes the Monte-Carlo simulation of the TAG sequence and presents analysis results that demonstrate the ability to conduct the TAG within 25 meters of the selected sample site and 2 cm/s of the targeted contact velocity. The paper describes some of the challenges associated with conducting precision navigation operations and ultimately contacting a very small asteroid.

  8. Transfer reactions in inverse kinematics at REX-ISOLDE

    CERN Document Server

    Tengborn, E

    Research on the structure of exotic nuclei is one of the most intriguing topics in present day nuclear physics. With the use of facilities for isotope separation on-line, such as ISOLDE at CERN, short-lived isotopes can be studied experimentally. Since 2002, the REX-ISOLDE facility enables radioactive ions produced by ISOLDE to be post-accelerated, increasing the energy of the ions enough to do nuclear transfer reactions in inverse kinematics. In this thesis, transfer reactions are used to study the structure of neutron-rich lithium isotopes through a series of experiments at REX-ISOLDE. The first experiment used a 9Li beam at 2.36 MeV/u impinging on a deuterated polyethylene target to study 10Li, 9Li and 8Li. For the (d,p)-channel the resonance ground state and a first excited state are observed and the results agree with theoretical calculations. The elastic channel agrees with Optical Model, OM, calculations. For the (d,t)-channel the shape of the angular distribution agrees with Distorted Wave Born Approx...

  9. Redox sensing by a Rex-family repressor is involved in the regulation of anaerobic gene expression in Staphylococcus aureus.

    Science.gov (United States)

    Pagels, Martin; Fuchs, Stephan; Pané-Farré, Jan; Kohler, Christian; Menschner, Leonhard; Hecker, Michael; McNamarra, Peter J; Bauer, Mikael C; von Wachenfeldt, Claes; Liebeke, Manuel; Lalk, Michael; Sander, Gunnar; von Eiff, Christof; Proctor, Richard A; Engelmann, Susanne

    2010-06-01

    An alignment of upstream regions of anaerobically induced genes in Staphylococcus aureus revealed the presence of an inverted repeat, corresponding to Rex binding sites in Streptomyces coelicolor. Gel shift experiments of selected upstream regions demonstrated that the redox-sensing regulator Rex of S. aureus binds to this inverted repeat. The binding sequence--TTGTGAAW(4)TTCACAA--is highly conserved in S. aureus. Rex binding to this sequence leads to the repression of genes located downstream. The binding activity of Rex is enhanced by NAD+ while NADH, which competes with NAD+ for Rex binding, decreases the activity of Rex. The impact of Rex on global protein synthesis and on the activity of fermentation pathways under aerobic and anaerobic conditions was analysed by using a rex-deficient strain. A direct regulatory effect of Rex on the expression of pathways that lead to anaerobic NAD+ regeneration, such as lactate, formate and ethanol formation, nitrate respiration, and ATP synthesis, is verified. Rex can be considered a central regulator of anaerobic metabolism in S. aureus. Since the activity of lactate dehydrogenase enables S. aureus to resist NO stress and thus the innate immune response, our data suggest that deactivation of Rex is a prerequisite for this phenomenon.

  10. Nesting habitat relationships of sympatric Crested Caracaras, Red-tailed Hawks, and White-tailed Hawks in South Texas

    Science.gov (United States)

    Actkinson, M.A.; Kuvlesky, W.P.; Boal, C.W.; Brennan, L.A.; Hernandez, F.

    2007-01-01

    We quantified nesting-site habitats for sympatric White-tailed Hawks (Buteo albicaudatus) (n = 40), Red-tailed Hawks (B. jamaicensis) (n = 39), and Crested Caracaras (Caracara cheriway) (n = 24) in the Coastal Sand Plain of south Texas. White-tailed Hawks and Crested Caracara nest sites occurred in savannas, whereas Red-tailed Hawk nest sites occurred in woodlands on the edge of savannas. White-tailed Hawk nest sites were in shrubs and trees that were shorter (3.5 ?? 1.0 m) and had smaller canopy diameters (5.5 ?? 2.1 m) than those of Red-tailed Hawks (10.1 ?? 2.0 m, 13.7 ?? 5.8 m) and Crested Caracaras (5.6 ?? 1.7 m, 8.5 ?? 3.5 m). Red-tailed Hawk nest sites had higher woody densities (15.7 ?? 9.6 plants) and more woody cover (84 ?? 19%) than those of White-tailed Hawks (5.6 ?? 5.8 plants, 20 ?? 21%) and Crested Caracaras (9.9 ?? 6.7 plants, 55 ?? 34%). Crested Caracara nest sites were in dense, multi-branched shrubs composed of more living material (97 ?? 3%) than those of White-tailed (88 ?? 18%) and Red-tailed hawks (88 ?? 18%). Nest sites of White-tailed Hawks, Red-tailed Hawks, and Crested Caracaras were similar to random samples from the surrounding habitat indicating that preferred nesting habitat was available for each of these species at least within 60 m of active nest sites. Nest tree height, along with woody plant and native grass cover best discriminated nest sites among the three raptor species. There was no overlap at Red-tailed and White-tailed hawk nest sites in vegetation structure, while Crested Caracara nests were in habitat intermediate between the two other species. Partitioning of nesting habitat may be how these raptor species co-exist at the broader landscape scale of our study area in the Coastal Sand Plain of Texas.

  11. Stephen Hawking ja tema kuulsad kihlveod / Andi Hektor

    Index Scriptorium Estoniae

    Hektor, Andi, 1975-

    2010-01-01

    Ratastooli aheldatud füüsikaikoon Hawking armastab sõlmida kihlvedusid. Viimane kihlvedu, mis puudutab gravitatsioonilainete ja inflatsiooni olemasolu, on taas päevakorda tõusnud, sest eelmisel aastal alustas mõõtmisi Plancki satelliit

  12. GRIP GLOBAL HAWK NAVIGATION AND HOUSEKEEPING DATA V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP Global Hawk Navigation and Housekeeping data was collected from August 15, 2010 to September 24, 2010 during the Genesis and Rapid Intensification Processes...

  13. Rotating embedded black holes: Entropy and Hawking's radiation

    OpenAIRE

    Ibohal, Ng.

    2004-01-01

    In this paper we derive a class of rotating embedded black holes. Then we study Hawking's radiation effects on these embedded black holes. The surface gravity, entropy and angular velocity are given for each of these black holes.

  14. Hawking Temperature of an Arbitrarily Accelerating Black Hole

    Indian Academy of Sciences (India)

    Abstract. Hawking temperature of an arbitrarily accelerating black hole with electric and magnetic charges are obtained based on the Klein–Gordon equation with a correct-dimension new tortoise coordinate transformation.

  15. Influence of poisoned prey on foraging behavior of ferruginous hawks

    Science.gov (United States)

    Vyas, Nimish B.; Kuncir, Frank; Clinton, Criss C.

    2017-01-01

    We recorded 19 visits by ferruginous hawks (Buteo regalis) over 6 d at two black–tailed prairie dog (Cynomys ludovicianus) subcolonies poisoned with the rodenticide Rozol® Prairie Dog Bait (0.005% chlorophacinone active ingredient) and at an adjacent untreated subcolony. Before Rozol® application ferruginous hawks foraged in the untreated and treated subcolonies but after Rozol® application predation by ferruginous hawks was only observed in the treated subcolonies. We suggest that ferruginous hawks' preference for hunting in the treated subcolonies after Rozol® application was influenced by the availability of easy-to-capture prey, presumably due to Rozol® poisoning. The energetically beneficial behavior of favoring substandard prey may increase raptor encounters with rodenticide exposed animals if prey vulnerability has resulted from poisoning.

  16. Hawking receives top US award at White House

    Science.gov (United States)

    Banks, Michael

    2009-09-01

    The Cambridge physicist Stephen Hawking has been awarded the highest US civilian honour - the presidential medal of freedom. At a ceremony at the White House last month, Hawking, together with 15 other recipients, received the 2009 award from President Barack Obama. The medal is given to individuals who make a contribution "to the security or national interests of the US, world peace, cultural or other significant public or private endeavours".

  17. Street Hawking: Oppressing the Girl Child or Family Economic Supplement?

    Science.gov (United States)

    Umar, Fatima M.

    2009-01-01

    Street hawking in its simplest form is the selling of things along the roads and from one place to the other. In Nigeria this is done almost all the time by young children both males and females. The girl hawkers come to the cities in groups and then go in different directions of the city to hawk their goods. They remain in the city from the early…

  18. Pitting, crevice and galvanic corrosion of REX stainless-steel/CoCr orthopedic implant material.

    Science.gov (United States)

    Reclaru, L; Lerf, R; Eschler, P Y; Blatter, A; Meyer, J M

    2002-08-01

    The corrosion behavior of surgical implant CoCr alloy and REX 734 steel has been investigated. The pitting or crevice corrosion potentials have been determined to reach values as high as 500 mV vs. SCE for CoCr and 450 mV vs. SCE for REX 734. The galvanic corrosion behavior of CoCr/REX 734 couples has been evaluated with various electrochemical techniques. The measurement of the corrosion current of the galvanic couple as well as its prediction by applying mixed potential theories on measured potentiodynamic polarization curves revealed low galvanic currents in the range of nanoamperes.

  19. Hélène Mialet, Hawking Incorporated. Stephen Hawking and the Anthropology of the Knowing subject

    OpenAIRE

    Popescu, Cristina

    2013-01-01

    Situé dans la tradition de recherche développée autour de la théorie de l’acteur-réseau (actor-network theory), le livre de Hélène Mialet choisit d’explorer la figure particulière du physicien anglais Stephen Hawking. À travers sept chapitres complémentaires, le lecteur découvre à la fois « Hawking l’individu » et « Hawking le génie en physique ». C’est une distinction qui ne paraît pas toute de suite évidente au non-initié, mais, nous allons le comprendre rapidement, le Hawking des médias, n...

  20. Tilted Foils Nuclear Spin Polarization at REX-ISOLDE

    CERN Document Server

    Törnqvist, Hans Toshihide

    2013-08-08

    This thesis will explain and summarize my work and involvement in experiments aimed at producing nuclear spin polarization of post-accelerated beams of ions with the tilted-foils technique at the REX-ISOLDE linear accelerator at CERN. Polarizing the nuclear spin of radioactive beams in particular may provide access to observables which may be difficult to obtain otherwise. Currently, the techniques commonly employed for nuclear spin polarization are restricted to specific nuclides and experimental measurement techniques. Tilted foils polarization may provide a new tool to extend the range of nuclides that can be polarized and the types of experiments that can be performed. The experiments rely not only on the production but also on the method to measure the degree of attained polarization. Two methods will be treated, based on particle scattering in Coulomb excitation that may be utilized for stable beams, and the $\\beta$-NMR that requires $\\beta$-decaying nuclei. The experimental setups and measurements will...

  1. The OSIRIS-REx Contamination Control and Witness Strategy

    Science.gov (United States)

    Dworkin, J. P.; Adelman, L.; Ajluni, T. M.; Andronikov, A. V.; Ballou, D. M.; Bartels, A. E.; Beshore, E.; Bierhaus, E. B.; Boynton, W. V.; Brucato, J. R.; hide

    2015-01-01

    The OSIRIS-REx mission (Origins, Spectral Interpretation, Resource Identification, and Security Regolith Explorer) is the third NASA New Frontiers mission. It is scheduled for launch in 2016. The primary objective of the mission is to return at least 60 g of "pristine" material from the B-type near- Earth asteroid (101955) Bennu, which is spectrally similar to organic-rich CI or CM meteorites [1]. The study of these samples will advance our understanding of materials available for the origin of life on Earth or elsewhere. The spacecraft will rendezvous with Bennu in 2018 and spend at least a year characterizing the asteroid before executing a maneuver to recover a sample of regolith in the touch-and-go sample acquisition mechanism (TAGSAM). The TAGSAM and sample is stowed in the sample return capsule (SRC) and returned to Earth in 2023.

  2. The OSIRIS-REx Radio Science Experiment at Bennu

    Science.gov (United States)

    McMahon, J. W.; Scheeres, D. J.; Hesar, S. G.; Farnocchia, D.; Chesley, S.; Lauretta, D.

    2018-02-01

    The OSIRIS-REx mission will conduct a Radio Science investigation of the asteroid Bennu with a primary goal of estimating the mass and gravity field of the asteroid. The spacecraft will conduct proximity operations around Bennu for over 1 year, during which time radiometric tracking data, optical landmark tracking images, and altimetry data will be obtained that can be used to make these estimates. Most significantly, the main Radio Science experiment will be a 9-day arc of quiescent operations in a 1-km nominally circular terminator orbit. The pristine data from this arc will allow the Radio Science team to determine the significant components of the gravity field up to the fourth spherical harmonic degree. The Radio Science team will also be responsible for estimating the surface accelerations, surface slopes, constraints on the internal density distribution of Bennu, the rotational state of Bennu to confirm YORP estimates, and the ephemeris of Bennu that incorporates a detailed model of the Yarkovsky effect.

  3. Ossifying fibroma in a miniature rex rabbit (Oryctolagus cuniculus).

    Science.gov (United States)

    Whitten, K A; Popielarczyk, M M; Belote, D A; McLeod, G C; Mense, M G

    2006-01-01

    In humans and animals, ossifying fibroma is a benign neoplasm that most frequently affects the mandible, often resulting in cosmetic deformities and malocclusion. It is considered rare in animals and most frequently affects young horses. A surgical biopsy of a solitary mass located beneath the gingiva in the right maxillary region, which had overgrown teeth and expanded the adjacent hard palate from a 6-year-old miniature Rex rabbit was submitted for light microscopic examination. The submitted incisional biopsy specimen was pale pink, firm, and nodular. Histopathologically, the neoplasm was composed of fibroblastic cells separated by abundant collagen. The neoplastic cells were interwoven with osteoblasts surrounding islands of mineralized, bony matrix containing few, widely spaced, often empty, lacunae. Minimal inflammation was present. Based on the histopathologic features, the tumor was diagnosed as an ossifying fibroma. To our knowledge, this is the first report of an ossifying fibroma in a rabbit.

  4. Hawking Incorporated Stephen Hawking and the Anthropology of the Knowing Subject

    CERN Document Server

    Mialet, Hélène

    2012-01-01

    These days, the idea of the cyborg is less the stuff of science fiction and more a reality, as we are all, in one way or another, constantly connected, extended, wired, and dispersed in and through technology. One wonders where the individual, the person, the human, and the body are-or, alternatively, where they stop. These are the kinds of questions Hélène Mialet explores in this fascinating volume, as she focuses on a man who is permanently attached to assemblages of machines, devices, and collectivities of people: Stephen Hawking. Drawing on an extensive and in-depth series of interviews wi

  5. P-Rex1 Expression in Invasive Breast Cancer in relation to Receptor Status and Distant Metastatic Site

    Directory of Open Access Journals (Sweden)

    Jonathan D. Marotti

    2017-01-01

    Full Text Available Background. Phosphatidylinositol-3,4,5-trisphosphate-dependent Rac exchange factor 1 (P-Rex1 has been implicated in cancer growth, metastasis, and response to phosphatidylinositol 3-kinase (PI3K inhibitor therapy. The aim of this study was to determine whether P-Rex1 expression differs between primary and metastatic human breast tumors and between breast cancer subtypes. Design. P-Rex1 expression was measured in 133 specimens by immunohistochemistry: 40 and 42 primary breast tumors from patients who did versus did not develop metastasis, respectively, and 51 breast-derived tumors from metastatic sites (36 of which had matching primary tumors available for analysis. Results. Primary breast tumors showed significant differences in P-Rex1 expression based on receptor subtype. ER+ and HER2+ primary tumors showed higher P-Rex1 expression than primary triple-negative tumors. HER2+ metastases from all sites showed significantly higher P-Rex1 expression compared to other metastatic receptor subtypes. Solid organ (i.e., brain, lung, and liver metastases showed higher P-Rex1 expression compared to bone metastases. Conclusions. P-Rex1 expression is increased in ER+ and HER2+ breast cancers compared to triple-negative tumors. P-Rex1 may be differentially expressed in metastatic tumors based on site and receptor status. The role of P-Rex1 in the development of breast cancer metastases and as a predictive biomarker of therapeutic response warrants further investigation.

  6. Comparison of Vegetation Water Use Using the Horton Index in a Sub-arctic, Alaskan Boreal Forest Environment Using Hydrograph Analysis

    Science.gov (United States)

    Bolton, W. R.; Cable, J.

    2012-12-01

    The sub-arctic environment is in the zone of discontinuous permafrost. The extreme energy influx from winter to summer has a strong influence on water storage and release processes at the watershed scale. For example, the seven months of snow accumulation are followed by a short 2-week period of snow ablation in which approximately 1/3 of the annual precipitation is released into the system. In permafrost soils, the soils begin to thaw immediately at the conclusion of snow melt, increasing the storage capacity of the soils. The storage capacity of the soils reaches a maximum in late summer then rapidly decreases during the freeze-back period in October. In permafrost-free soils dominated by deciduous vegetation, the trees appear to have a major role in taking up and transpiring liquid precipitation to back to the atmosphere. Conversely, in permafrost soils dominated by coniferous vegetation, the trees appear to have a more minor role in the cycling of liquid water during precipitation events. The overarching goal of our research is to quantify the relative roles of vegetation water use and soil storage dynamics associated with permafrost presence/absence in determining the magnitude and timing of water pathways in the sub-Arctic boreal forest. As part of this goal, we quantified the Horton Index - a metric used to describe vegetation water use relative to available soil water - in two small sub-basins of the Caribou-Poker Creeks Research Watershed, located near Fairbanks, Alaska. The C2 (5.2 km2) and C3 (5.7km2) sub-basins are underlain by approximately 2 and 53% permafrost, and are dominated by deciduous (Betula neoalaskana and Populus tremuloides) and coniferous vegetation (Picea mariana), respectively. Catchment scale calculations of the Horton Index are made using stream flow analysis and during snow-free precipitation events over an 11-year period. In each sub-basin, the Horton Index varies with time with the greatest variation occurring in the spring and fall

  7. Diagnosis performance of the positron computed tomography with {sup 18}F-F.D.G. in the Horton disease: meta-analysis; Performances diagnostiques de la tomographie par emission de positons au 18F-FDG dans la maladie de Horton: meta-analyse

    Energy Technology Data Exchange (ETDEWEB)

    Besson, F.; Costo, S.; Agostini, D. [CHU de Caen, Departement de medecine nucleaire, 14 (France); Dunet, V.; Prior, J. [CHU Vaudois, departement de medecine nucleaire, Lausanne (Switzerland); Hamon, M. [CHU de Caen, Departement de cardiologie, 14 (France); Parienti, J.J. [CHU de Caen, Departement de biostatiques, 14 (France)

    2010-07-01

    The PET with {sup 18}F-F.D.G. is a sensitive and specific technique to detect Horton disease. It could be used to invalidate the diagnosis among patients suffering of this disease, especially these ones presenting a negative or non contributive temporal artery biopsy or an atypical symptomatology. Furthermore, it should allow to better evaluate the extension of arteritis injuries. (N.C.)

  8. Hawking radiation, the Stefan–Boltzmann law, and unitarization

    Directory of Open Access Journals (Sweden)

    Steven B. Giddings

    2016-03-01

    Full Text Available Where does Hawking radiation originate? A common picture is that it arises from excitations very near or at the horizon, and this viewpoint has supported the “firewall” argument and arguments for a key role for the UV-dependent entanglement entropy in describing the quantum mechanics of black holes. However, closer investigation of both the total emission rate and the stress tensor of Hawking radiation supports the statement that its source is a near-horizon quantum region, or “atmosphere,” whose radial extent is set by the horizon radius scale. This is potentially important, since Hawking radiation needs to be modified to restore unitarity, and a natural assumption is that the scales relevant to such modifications are comparable to those governing the Hawking radiation. Moreover, related discussion suggests a resolution to questions regarding extra energy flux in “nonviolent” scenarios, that does not spoil black hole thermodynamics as governed by the Bekenstein–Hawking entropy.

  9. GRIP NOAA GLOBAL HAWK IN-FLIGHT TURBULENCE SENSOR (GHIS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP NOAA Global Hawk In-Flight Turbulence Sensor (GHIS) dataset was collected by the NOAA Global Hawk In-flight Turbulence Sensor (GHIS) instrument, which...

  10. Recent trends in counts of migrant hawks from northeastern North America

    Science.gov (United States)

    Titus, K.; Fuller, M.R.

    1990-01-01

    Using simple regression, pooled-sites route-regression, and nonparametric rank-trend analyses, we evaluated trends in counts of hawks migrating past 6 eastern hawk lookouts from 1972 to 1987. The indexing variable was the total count for a season. Bald eagle (Haliaeetus leucocephalus), peregrine falcon (Falco peregrinus), merlin (F. columbarius), osprey (Pandion haliaetus), and Cooper's hawk (Accipiter cooperii) counts increased using route-regression and nonparametric methods (P 0.10). We found no consistent trends (P > 0.10) in counts of sharp-shinned hawks (A. striatus), northern goshawks (A. gentilis) red-shouldered hawks (Buteo lineatus), red-tailed hawks (B. jamaicensis), rough-legged hawsk (B. lagopus), and American kestrels (F. sparverius). Broad-winged hawk (B. platypterus) counts declined (P migrant hawks are a useful and economical method for detecting long-term trends in species across regions, particularly for species that otherwise cannot be easily surveyed.

  11. File list: Oth.Kid.05.AllAg.HEK293-T-REx [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Kid.05.AllAg.HEK293-T-REx hg19 TFs and others Kidney HEK293-T-REx SRX1094520,SR...X1094512,SRX1094508,SRX1094521,SRX1094518,SRX1094516,SRX1094510,SRX1094514 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Kid.05.AllAg.HEK293-T-REx.bed ...

  12. File list: Oth.Kid.10.AllAg.HEK293-T-REx [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Kid.10.AllAg.HEK293-T-REx hg19 TFs and others Kidney HEK293-T-REx SRX1094520,SR...X1094521,SRX1094514,SRX1094510,SRX1094508,SRX1094518,SRX1094512,SRX1094516 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Kid.10.AllAg.HEK293-T-REx.bed ...

  13. File list: Oth.Kid.50.AllAg.HEK293-T-REx [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Kid.50.AllAg.HEK293-T-REx hg19 TFs and others Kidney HEK293-T-REx SRX1094520,SR...X1094521,SRX1094514,SRX1094510,SRX1094508,SRX1094518,SRX1094516,SRX1094512 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Kid.50.AllAg.HEK293-T-REx.bed ...

  14. HTLV-1 Rex: the courier of viral messages, making use of the host vehicle

    Directory of Open Access Journals (Sweden)

    Kazumi eNakano

    2012-09-01

    Full Text Available The human T-cell leukemia virus type 1 (HTLV-1 is a retrovirus causing an aggressive T-cell malignancy, adult T-cell leukemia (ATL. Although HTLV-1 has a compact RNA genome, it has evolved elaborate mechanisms to maximize its coding potential. The structural proteins Gag, Pro, and Pol are encoded in the unspliced form of viral mRNA, whereas the Env protein is encoded in singly spliced viral mRNA. Regulatory and accessory proteins, such as Tax, Rex, p30II, p12, and p13, are translated only from fully spliced mRNA. For effective viral replication, translation from all forms of HTLV-1 transcripts has to be achieved in concert, although unspliced mRNA are extremely unstable in mammalian cells. It has been well recognized that HTLV-1 Rex enhances the stability of unspliced and singly spliced HTLV-1 mRNA by promoting nuclear export and thereby, removing them from the splicing site. Rex specifically binds to the highly structured Rex responsive element (RxRE located at the 3′ end of all HTLV-1 mRNA. Rex then binds to the cellular nuclear exporter, CRM1, via its nuclear export signal domain and the Rex-viral transcript complex is selectively exported from the nucleus to the cytoplasm for effective translation of the viral proteins. Yet, the mechanisms by which Rex inhibits the cellular splicing machinery and utilizes the cellular pathways beneficial to viral survival in the host cell have not been fully explored. Furthermore, physiological impacts of Rex against homeostasis of the host cell via interactions with numerous cellular proteins have been largely left uninvestigated. In this review, we focus on the biological importance of HTLV-1 Rex in the HTLV-1 life cycle by following the historical path in the literature concerning this viral post-transcriptional regulator from its discovery to this day. In addition, for future studies, we discuss recently discovered aspects of HTLV-1 Rex as a post-transcriptional regulator and its use in host cellular

  15. OSIRIS-REx Asteroid Sample Return Mission Image Analysis

    Science.gov (United States)

    Chevres Fernandez, Lee Roger; Bos, Brent

    2018-01-01

    NASA’s Origins Spectral Interpretation Resource Identification Security-Regolith Explorer (OSIRIS-REx) mission constitutes the “first-of-its-kind” project to thoroughly characterize a near-Earth asteroid. The selected asteroid is (101955) 1999 RQ36 (a.k.a. Bennu). The mission launched in September 2016, and the spacecraft will reach its asteroid target in 2018 and return a sample to Earth in 2023. The spacecraft that will travel to, and collect a sample from, Bennu has five integrated instruments from national and international partners. NASA's OSIRIS-REx asteroid sample return mission spacecraft includes the Touch-And-Go Camera System (TAGCAMS) three camera-head instrument. The purpose of TAGCAMS is to provide imagery during the mission to facilitate navigation to the target asteroid, confirm acquisition of the asteroid sample and document asteroid sample stowage. Two of the TAGCAMS cameras, NavCam 1 and NavCam 2, serve as fully redundant navigation cameras to support optical navigation and natural feature tracking. The third TAGCAMS camera, StowCam, provides imagery to assist with and confirm proper stowage of the asteroid sample. Analysis of spacecraft imagery acquired by the TAGCAMS during cruise to the target asteroid Bennu was performed using custom codes developed in MATLAB. Assessment of the TAGCAMS in-flight performance using flight imagery was done to characterize camera performance. One specific area of investigation that was targeted was bad pixel mapping. A recent phase of the mission, known as the Earth Gravity Assist (EGA) maneuver, provided images that were used for the detection and confirmation of “questionable” pixels, possibly under responsive, using image segmentation analysis. Ongoing work on point spread function morphology and camera linearity and responsivity will also be used for calibration purposes and further analysis in preparation for proximity operations around Bennu. Said analyses will provide a broader understanding

  16. Hawking radiation of five-dimensional charged black holes with scalar fields

    Directory of Open Access Journals (Sweden)

    Yan-Gang Miao

    2017-09-01

    Full Text Available We investigate the Hawking radiation cascade from the five-dimensional charged black hole with a scalar field coupled to higher-order Euler densities in a conformally invariant manner. We give the semi-analytic calculation of greybody factors for the Hawking radiation. Our analysis shows that the Hawking radiation cascade from this five-dimensional black hole is extremely sparse. The charge enhances the sparsity of the Hawking radiation, while the conformally coupled scalar field reduces this sparsity.

  17. 'Tool' use by the red-tailed hawk (Buteo jamaicensis)

    Science.gov (United States)

    Ellis, David H.; Brunson, Shawn

    1993-01-01

    Perhaps the best documented example of regular tool use for a falconiform is the Egyptian Vulture (Neophron percnopterus) striking an Ostrich (Struthio camelus) egg with a stone (J. van Lawick-Goodall and H. van Lawick-Goodall 1966, Nature 212:1468-1469; R.K. Brooke 1979, Ostrich 50:257-258). Another species, the Lammergeier (Gypaetus barbatus), routinely drops bones on stone slabs to gain access to the marrow within (L. Brown and D Amadon 1968, Eagles, hawks and falcons of the world, McGraw-Hill, New York, NY U.S.A.). Some, however, would argue that, because the stone is not manipulated, the bone-dropping Lammergeier is not actually using a tool. Another reported example of tool use is the Ferruginous Hawk (Buteo regalis) that allegedly cast a stone at a human intruder near its nest (C.L. Blair 1981, Raptor Research 15:120).]The following may be yet another example of tool use by a raptor. On 5 June 1985, we observed an adult Red-tailed Hawk (Buteo jamaicensis) soaring low (ca 15 m) over the grass-covered slopes of the Galiuro Mountains in southern Arizona. The bird had, probably just moments before, captured a ca I m snake (probably a glossy snake, Arizona elegans, judging by size, shape and color). When the hawk passed near us, it was holding the snake by both feet near the snake's midpoint. With head elevated and mouth open, the snake appeared intent upon biting the hawk. When the hawk was ca 100 m distant from us, it made several shallow stoops over a scattered group of large boulders. On some (and perhaps all) passes, the bird swept sharply upward as it passed over and nearly collided with a boulder. The centrifugal force associated with this change in direction caused the snake to pendulate below the hawk's talons and strike the boulder. During one pass, we observed the snake's head and tail flipping up behind the hawk after slapping the boulder. Not all swoops were over the same boulder, but one particularly obtrusive (ca 1 m tall) boulder was used at least

  18. Atherosclerosis and ischemic cardiomyopathy in a captive, adult red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Shrubsole-Cockwill, Alana; Wojnarowicz, Chris; Parker, Dennilyn

    2008-09-01

    An adult, male, captive red-tailed hawk (Buteo jamaicensis) of at least 19 years of age presented in dorsal recumbency. The hawk was nonresponsive, and despite initial supportive care, died shortly after presentation. Gross postmortem revealed no abnormal findings. Histologic examination demonstrated atherosclerosis and ischemic cardiomyopathy. This is the first reported case of atherosclerosis in a red-tailed hawk.

  19. Toxoplasma gondii infections in red-tailed hawks inoculated orally with tissue cysts.

    Science.gov (United States)

    Lindsay, D S; Dubey, J P; Blagburn, B L

    1991-04-01

    The response to inoculation of Toxoplasma gondii tissue cysts was examined in 3 red-tailed hawks (Buteo jamaicensis). One hawk (hawk 1) was inoculated orally with 3.000 tissue cysts of the GT-1 isolate of T. gondii and 2 hawks (hawks 2 and 3) each were inoculated orally with 12,000 tissue cysts of a mixture of 8 isolates of T. gondii. None of the hawks developed clinical signs of toxoplasmosis. Serum antibodies were measured with the modified direct agglutination test using formalin-fixed tachyzoites. Hawk 1 had a titer of 1:40 prior to inoculation and did not have an increase in titer during the study. Hawks 2 and 3 had titers of 1:5 and 1:10, respectively, prior to inoculation, and both had increased titers (titers greater than or equal to 1:60) by 1 wk postinoculation and remained T. gondii antibody positive throughout the 10 wk of the study. Toxoplasma gondii was isolated from the heart and breast muscle of hawk 1. The biologic behavior of this T. gondii isolate was different from the 1 inoculated, and it probably represents a prior natural infection. Toxoplasma gondii was isolated from the brain, heart, breast muscle, and a mixture of gizzard and proventriculus from hawk 2 and from breast muscle of hawk 3. Toxoplasma gondii was not isolated from the eye, lung, liver, kidney, or spleen of any red-tailed hawk.

  20. Fairness and Reciprocity in the Hawk-Dove Game

    DEFF Research Database (Denmark)

    Poulsen, Anders; Neugebauer, Tibor; Schram, Arthur

    2002-01-01

    We study fairness and reciprocity in a Hawk-Dove game, using an experimental approach. This allows us to test various models in one framework. We observe a large extent of selfish and rational behavior. Our results are inconsistent with leading models in this field.......We study fairness and reciprocity in a Hawk-Dove game, using an experimental approach. This allows us to test various models in one framework. We observe a large extent of selfish and rational behavior. Our results are inconsistent with leading models in this field....

  1. Cyanide poisoning of a Cooper's hawk ( Accipiter cooperii).

    Science.gov (United States)

    Franson, J Christian

    2017-03-01

    A Cooper's hawk ( Accipiter cooperii) was found dead in a ditch leading from a heap leach pad at a gold mine in Nevada. Observations at autopsy included an absence of external lesions, traces of subcutaneous and coronary fat, no food in the upper gastrointestinal tract, and no lesions in the viscera. Cyanide concentrations (µg/g ww) were 5.04 in blood, 3.88 in liver, and 1.79 in brain. No bacteria or viruses were isolated from tissues, and brain cholinesterase activity was within the normal range for a Cooper's hawk.

  2. Cyanide poisoning of a Cooper’s hawk (Accipiter cooperii)

    Science.gov (United States)

    Franson, J. Christian

    2017-01-01

    A Cooper’s hawk (Accipiter cooperii) was found dead in a ditch leading from a heap leach pad at a gold mine in Nevada. Observations at autopsy included an absence of external lesions, traces of subcutaneous and coronary fat, no food in the upper gastrointestinal tract, and no lesions in the viscera. Cyanide concentrations (µg/g ww) were 5.04 in blood, 3.88 in liver, and 1.79 in brain. No bacteria or viruses were isolated from tissues, and brain cholinesterase activity was within the normal range for a Cooper’s hawk.

  3. The redox-sensing regulator Rex modulates central carbon metabolism, stress tolerance response and biofilm formation by Streptococcus mutans.

    Directory of Open Access Journals (Sweden)

    Jacob P Bitoun

    Full Text Available The Rex repressor has been implicated in regulation of central carbon and energy metabolism in gram-positive bacteria. We have previously shown that Streptococcus mutans, the primary causative agent of dental caries, alters its transcriptome upon Rex-deficiency and renders S. mutans to have increased susceptibility to oxidative stress, aberrations in glucan production, and poor biofilm formation. In this study, we showed that rex in S. mutans is co-transcribed as an operon with downstream guaA, encoding a putative glutamine amidotransferase. Electrophoretic mobility shift assays showed that recombinant Rex bound promoters of target genes avidly and specifically, including those down-regulated in response to Rex-deficiency, and that the ability of recombinant Rex to bind to selected promoters was modulated by NADH and NAD(+. Results suggest that Rex in S. mutans can function as an activator in response to intracellular NADH/NAD(+ level, although the exact binding site for activator Rex remains unclear. Consistent with a role in oxidative stress tolerance, hydrogen peroxide challenge assays showed that the Rex-deficient mutant, TW239, and the Rex/GuaA double mutant, JB314, were more susceptible to hydrogen peroxide killing than the wildtype, UA159. Relative to UA159, JB314 displayed major defects in biofilm formation, with a decrease of more than 50-fold in biomass after 48-hours. Collectively, these results further suggest that Rex in S. mutans regulates fermentation pathways, oxidative stress tolerance, and biofilm formation in response to intracellular NADH/NAD(+ level. Current effort is being directed to further investigation of the role of GuaA in S. mutans cellular physiology.

  4. Structural Basis for NADH/NAD+ Redox Sensing by a Rex Family Repressor

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, K.J.; Soares, A.; Strain-Damerell, C. M.; Xie, K.; Brekasis, D.; Pagent, M. S. B.; Kielkopf, C. L.

    2010-05-28

    Nicotinamide adenine dinucleotides have emerged as key signals of the cellular redox state. Yet the structural basis for allosteric gene regulation by the ratio of reduced NADH to oxidized NAD{sup +} is poorly understood. A key sensor among Gram-positive bacteria, Rex represses alternative respiratory gene expression until a limited oxygen supply elevates the intracellular NADH:NAD{sup +} ratio. Here we investigate the molecular mechanism for NADH/NAD{sup +} sensing among Rex family members by determining structures of Thermus aquaticus Rex bound to (1) NAD{sup +}, (2) DNA operator, and (3) without ligand. Comparison with the Rex/NADH complex reveals that NADH releases Rex from the DNA site following a 40{sup o} closure between the dimeric subunits. Complementary site-directed mutagenesis experiments implicate highly conserved residues in NAD-responsive DNA-binding activity. These rare views of a redox sensor in action establish a means for slight differences in the nicotinamide charge, pucker, and orientation to signal the redox state of the cell.

  5. Forelimbs of Tyrannosaurus Rex: A pathetic vestigial organ or an integral part of a fearsome predator?

    Science.gov (United States)

    Lee, Scott A.; Thomas, Joshua D.

    2014-12-01

    In this paper, we examine a first-year torque and angular acceleration problem to address a possible use of the forelimbs of Tyrannosaurus rex. A 1/40th-scale model (see Fig. 1) is brought to the classroom to introduce the students to the quandary: given that the forelimbs of T. rex were too short to reach its mouth, what function did the forelimbs serve? This issue crosses several scientific disciplines including paleontology, ecology, and physics, making it a great starting point for thinking "outside the box." Noted paleontologist Kenneth Carpenter has suggested that the forelimbs of T. rex were an integral part of its predatory behavior. Given the large teeth of T. rex, it is assumed that they killed with their teeth. Lipkin and Carpenter1 have suggested that the forelimbs were used to hold a struggling victim (which had not been dispatched with the first bite) while the final, lethal bite was applied. If that is the case, then the forelimbs must be capable of large angular accelerations α in order to grab the animal attempting to escape. The concepts of the typical first-year physics course are sufficient to test this hypothesis by solving α =τ /I . Naturally, students love solving any problem related to Tyrannosaurus rex!

  6. SBLOCA AND LOFW EXPERIMENTS IN A SCALED-DOWN IET FACILITY OF REX-10 REACTOR

    Directory of Open Access Journals (Sweden)

    YEON-GUN LEE

    2013-06-01

    Full Text Available This paper presents an experimental investigation of the small-break loss-of-coolant accident (SBLOCA and the loss-of-feedwater accident (LOFW in a scaled integral test facility of REX-10. REX-10 is a small integral-type PWR in which the coolant flow is driven by natural circulation, and the RCS is pressurized by the steam-gas pressurizer. The postulated accidents of REX-10 include the system depressurization initiated by the break of a nitrogen injection line connected to the steam-gas pressurizer and the complete loss of normal feedwater flow by the malfunction of control systems. The integral effect tests on SBLOCA and LOFW are conducted at the REX-10 Test Facility (RTF, a full-height full-pressure facility with reduced power by 1/50. The SBLOCA experiment is initiated by opening a flow passage out of the pressurizer vessel, and the LOFW experiment begins with the termination of the feedwater supply into the helical-coil steam generator. The experimental results reveal that the RTF can assure sufficient cooldown capability with the simulated PRHRS flow during these DBAs. In particular, the RTF exhibits faster pressurization during the LOFW test when employing the steam-gas pressurizer than the steam pressurizer. This experimental study can provide unique data to validate the thermal-hydraulic analysis code for REX-10.

  7. Surface gravity and Hawking temperature from entropic force viewpoint

    CERN Document Server

    Chang-Young, Ee; Kimm, Kyoungtae; Lee, Daeho

    2010-01-01

    We consider a freely falling holographic screen for the Schwarzschild and Reissner-Nordstr\\"om black holes and evaluate the entropic force \\`a la Verlinde. When the screen crosses the event horizon, the temperature of the screen agrees to the Hawking temperature and the entropic force gives rise to the surface gravity for both of the black holes.

  8. Stephen Hawking bags big new 3m physics prize

    Science.gov (United States)

    Johnston, Hamish

    2013-01-01

    A massive 3m in prize money has gone to the British cosmologist Stephen Hawking for his work on black holes, quantum gravity and the early universe. The award is one of two "special fundamental physics prizes" from the Fundamental Physics Prize Foundation, which was set up earlier this year by the Russian physicist-turned-entrepreneur Yuri Milner.

  9. The death of Philosophy: A response to Stephen Hawking | Scott ...

    African Journals Online (AJOL)

    Indeed, Hawking's appeal to multiverse theory and his core discussion of the metaphysical problem of being are philosophical. The question of the death of Philosophy has contemporary relevance for the discipline which is particularly under threat for its survival in the academy, oftentimes assumed to be irrelevant.

  10. Remarks on Hawking radiation as tunneling from a uniformly ...

    Indian Academy of Sciences (India)

    Abstract. Motivated by the Hamilton–Jacobi method of Angheben et al, we investigate the Hawking tunneling radiation from a uniformly accelerating rectilinear black hole for which the horizons and entropy are functions of θ. After several coordinate transforma- tions, we conclude that when the self-gravitational interaction ...

  11. Hawking Radiations from an Arbitrarily Accelerating Kerr Black Hole ...

    Indian Academy of Sciences (India)

    Introduction. In 1976, Damour & Ruffini (1976) presented a method proving Hawking radiation. Zhao et al. (1994) improved the method of Damour and Ruffini, and calculated the location of the event horizon and the temperature of the varying black holes at the same time. It is a pivotal step to introduce a tortoise coordinate ...

  12. Red-shouldered hawk nesting habitat preference in south Texas

    Science.gov (United States)

    Strobel, Bradley N.; Boal, Clint W.

    2010-01-01

    We examined nesting habitat preference by red-shouldered hawks Buteo lineatus using conditional logistic regression on characteristics measured at 27 occupied nest sites and 68 unused sites in 2005–2009 in south Texas. We measured vegetation characteristics of individual trees (nest trees and unused trees) and corresponding 0.04-ha plots. We evaluated the importance of tree and plot characteristics to nesting habitat selection by comparing a priori tree-specific and plot-specific models using Akaike's information criterion. Models with only plot variables carried 14% more weight than models with only center tree variables. The model-averaged odds ratios indicated red-shouldered hawks selected to nest in taller trees and in areas with higher average diameter at breast height than randomly available within the forest stand. Relative to randomly selected areas, each 1-m increase in nest tree height and 1-cm increase in the plot average diameter at breast height increased the probability of selection by 85% and 10%, respectively. Our results indicate that red-shouldered hawks select nesting habitat based on vegetation characteristics of individual trees as well as the 0.04-ha area surrounding the tree. Our results indicate forest management practices resulting in tall forest stands with large average diameter at breast height would benefit red-shouldered hawks in south Texas.

  13. Kas inimkond näeb aastat 2106? / Stephen Hawking

    Index Scriptorium Estoniae

    Hawking, Stephen W., 1942-

    2006-01-01

    Briti füüsik Stephen Hawking avas Yahoo! internetifoorumis debati, küsides foorumikasutajatelt: "Maailmas valitseb poliitiline, sotsiaalne ja ökoloogiline kaos - kuidas suudab inimkond järgmised sada aastat üle elada?". Kommenteerivad julgeolekuekspert Eerik-Niiles Kross, meditsiiniteaduste doktor Mari Järvelaid ja keskkonnaekspert Marek Strandberg

  14. Ambiguity of the equivalence principle and Hawking's temperature

    NARCIS (Netherlands)

    Hooft, G. 't

    1984-01-01

    There are two inequivalent ways in which the laws of physics in a gravitational field can be related to the laws in an inertial frame, when quantum mechanical effects are taken into account. This leads to an ambiguity in the derivation of Hawking's radiation temperature for a black hole: it could be

  15. Microbiological Qualities of Hawked Retted Cassava Fufu in Aba ...

    African Journals Online (AJOL)

    Retted cassava fufu samples obtained from five local government areas in Aba Metropolis were analyzed. Their microbial counts, chemical and organoleptic properties were determined from the day of preparation and every day for the eight days of hawking. There were increases in the microbial counts from initial average ...

  16. Comment on 'Hawking radiation from fluctuating black holes'

    NARCIS (Netherlands)

    Khavkine, I.

    2010-01-01

    Takahashi and Soda (2010 Class. Quantum Grav. 27 175008) have recently considered the effect (at lowest non-trivial order) of dynamical, quantized gravitational fluctuations on the spectrum of scalar Hawking radiation from a collapsing Schwarzschild black hole. However, due to an unfortunate choice

  17. Comparison of the breeding biology of sympatric red-tailed Hawks, White-tailed Hawks, and Crested Caracaras in south Texas

    Science.gov (United States)

    Actkinson, M.A.; Kuvlesky, W.P.; Boal, C.W.; Brennan, L.A.; Hernandez, F.

    2009-01-01

    We compared the breeding biology of sympatric nesting Red-tailed Hawks (Buteo jamaicensis), White-tailed Hawks (Buteo albicaudatus), and Crested Caracaras (Caracara cheriway) in south Texas during 2003 and 2004. We monitored 46 breeding attempts by Red-tailed Hawks, 56 by White-tailed Hawks, and 27 by Crested Caracaras. Observed nesting success was similar for Red-tailed Hawks (62%) and Crested Caracaras (61%), but lower for White-tailed Hawks (51%). Daily survival rates (0.99) were the same for all three species. Red-tailed Hawks and White-tailed Hawks both fledged 1.13 young per nesting pair and Crested Caracaras fledged 1.39 young per nesting pair. All three species nested earlier in 2004 than in 2003; in addition, the overall nesting density of these three species almost doubled from 2003 (1.45 pairs/km2) to 2004 (2.71 pairs/km2). Estimated productivity of all three species was within the ranges reported from other studies. Given extensive and progressive habitat alteration in some areas of south Texas, and the limited distributions of White-tailed Hawks and Crested Caracaras, the presence of large ranches managed for free-range cattle production and hunting leases likely provides important habitat and may be key areas for conservation of these two species. ?? 2009 The Raptor Research Foundation, Inc.

  18. OSIRIS-REx: Sample Return from Asteroid (101955) Bennu

    Science.gov (United States)

    Lauretta, D. S.; Balram-Knutson, S. S.; Beshore, E.; Boynton, W. V.; Drouet d'Aubigny, C.; DellaGiustina, D. N.; Enos, H. L.; Golish, D. R.; Hergenrother, C. W.; Howell, E. S.; Bennett, C. A.; Morton, E. T.; Nolan, M. C.; Rizk, B.; Roper, H. L.; Bartels, A. E.; Bos, B. J.; Dworkin, J. P.; Highsmith, D. E.; Lorenz, D. A.; Lim, L. F.; Mink, R.; Moreau, M. C.; Nuth, J. A.; Reuter, D. C.; Simon, A. A.; Bierhaus, E. B.; Bryan, B. H.; Ballouz, R.; Barnouin, O. S.; Binzel, R. P.; Bottke, W. F.; Hamilton, V. E.; Walsh, K. J.; Chesley, S. R.; Christensen, P. R.; Clark, B. E.; Connolly, H. C.; Crombie, M. K.; Daly, M. G.; Emery, J. P.; McCoy, T. J.; McMahon, J. W.; Scheeres, D. J.; Messenger, S.; Nakamura-Messenger, K.; Righter, K.; Sandford, S. A.

    2017-10-01

    In May of 2011, NASA selected the Origins, Spectral Interpretation, Resource Identification, and Security- Regolith Explorer (OSIRIS-REx) asteroid sample return mission as the third mission in the New Frontiers program. The other two New Frontiers missions are New Horizons, which explored Pluto during a flyby in July 2015 and is on its way for a flyby of Kuiper Belt object 2014 MU69 on January 1, 2019, and Juno, an orbiting mission that is studying the origin, evolution, and internal structure of Jupiter. The spacecraft departed for near-Earth asteroid (101955) Bennu aboard an United Launch Alliance Atlas V 411 evolved expendable launch vehicle at 7:05 p.m. EDT on September 8, 2016, on a seven-year journey to return samples from Bennu. The spacecraft is on an outbound-cruise trajectory that will result in a rendezvous with Bennu in November 2018. The science instruments on the spacecraft will survey Bennu to measure its physical, geological, and chemical properties, and the team will use these data to select a site on the surface to collect at least 60 g of asteroid regolith. The team will also analyze the remote-sensing data to perform a detailed study of the sample site for context, assess Bennu's resource potential, refine estimates of its impact probability with Earth, and provide ground-truth data for the extensive astronomical data set collected on this asteroid. The spacecraft will leave Bennu in 2021 and return the sample to the Utah Test and Training Range (UTTR) on September 24, 2023.

  19. Coupled vs. decoupled boundary layers in VOCALS-REx

    Directory of Open Access Journals (Sweden)

    C. R. Jones

    2011-07-01

    Full Text Available We analyze the extent of subtropical stratocumulus-capped boundary layer decoupling and its relation to other boundary-layer characteristics and forcings using aircraft observations from VOCALS-REx along a swath of the subtropical southeast Pacific Ocean running west 1600 km from the coast of Northern Chile. We develop two complementary and consistent measures of decoupling. The first is based on boundary layer moisture and temperature stratification in flight profiles from near the surface to above the capping inversion, and the second is based the difference between the lifted condensation level (LCL and a mean lidar-derived cloud base measured on flight legs at 150 m altitude. Most flights took place during early-mid morning, well before the peak in insolation-induced decoupling.

    We find that the boundary layer is typically shallower, drier, and well mixed near the shore, and tends to deepen, decouple, and produce more drizzle further offshore to the west. Decoupling is strongly correlated to the "mixed layer cloud thickness", defined as the difference between the capping inversion height and the LCL; other factors such as wind speed, cloud droplet concentration, and inversion thermodynamic jumps have little additional explanatory power. The results are broadly consistent with the deepening-warming theory of decoupling.

    In the deeper boundary layers observed well offshore, there was frequently nearly 100 % boundary-layer cloud cover despite pronounced decoupling. The cloud cover was more strongly correlated to a κ parameter related to the inversion jumps of humidity and temperature, though the exact functional relation is slightly different than found in prior large-eddy simulation studies.

  20. Presumed pluripotency markers UTF-1 and REX-1 are expressed in human adult testes and germ cell neoplasms

    DEFF Research Database (Denmark)

    Kristensen, David M; Nielsen, John E; Skakkebaek, Niels E

    2008-01-01

    UTF-1 and REX-1/ZFP42 are transcription factors involved in pluripotency. Because of phenotypic similarities between pluripotent embryonic stem cells and testicular germ cell tumours (TGCT) and the derivation of pluripotent cells from testes, we investigated the expression of UTF-1 and REX-1 duri...... human gonadal development and in TGCT....

  1. Calibration of the High Resolution Phase Shifter (HRPS) in Linac 3/Rex using a dedicated LabView program

    CERN Document Server

    Winsvold, D

    2013-01-01

    This is a document describing how to calibrate the High Resolution Phase Shifters of Linac 3 and REX. The document also describes how to do tests on the Delay Lines in Linac 2, 3 and REX, but these cannot be calibrated.

  2. Integrin activation by P-Rex1 is required for selectin-mediated slow leukocyte rolling and intravascular crawling.

    Science.gov (United States)

    Herter, Jan M; Rossaint, Jan; Block, Helena; Welch, Heidi; Zarbock, Alexander

    2013-03-21

    Integrin activation is essential for the function of leukocytes. Impaired integrin activation on leukocytes is the hallmark of the leukocyte adhesion deficiency syndrome in humans, characterized by impaired leukocyte recruitment and recurrent infections. In inflammation, leukocytes collect different signals during the contact with the microvasculature, which activate signaling pathways leading to integrin activation and leukocyte recruitment. We report the role of P-Rex1, a Rac-specific guanine nucleotide exchanging factor, in integrin activation and leukocyte recruitment. We find that P-Rex1 is required for inducing selectin-mediated lymphocyte function-associated antigen-1 (LFA-1) extension that corresponds to intermediate affinity and induces slow leukocyte rolling, whereas P-Rex1 is not involved in the induction of the high-affinity conformation of LFA-1 obligatory for leukocyte arrest. Furthermore, we demonstrate that P-Rex1 is involved in Mac-1-dependent intravascular crawling. In vivo, both LFA-1-dependent slow rolling and Mac-1-dependent crawling are defective in P-Rex1(-/-) leukocytes, whereas chemokine-induced arrest and postadhesion strengthening remain intact in P-Rex1-deficient leukocytes. Rac1 is involved in E-selectin-mediated slow rolling and crawling. In vivo, in an ischemia-reperfusion-induced model of acute kidney injury, abolished selectin-mediated integrin activation contributed to decreased neutrophil recruitment and reduced kidney damage in P-Rex1-deficient mice. We conclude that P-Rex1 serves distinct functions in LFA-1 and Mac-1 activation.

  3. OSIRIS-REx A NASA Mission to a Near Earth Asteroid!...and Other Recent Happenings in the Solar System

    Science.gov (United States)

    Moreau, Michael C.

    2015-01-01

    The OSIRIS-REx Mission launches in 2016 Arrives at Asteroid Bennu-2018 Returns a sample to Earth -2023 The mission, OSIRIS-REx, will visit an asteroid and return a sample from the early Solar System to help us understand how our Solar System formed.

  4. PREFACE: REXS 2013 - Workshop on Resonant Elastic X-ray Scattering in Condensed Matter

    Science.gov (United States)

    Beutier, G.; Mazzoli, C.; Yakhou, F.; Brown, S. D.; Bombardi, A.; Collins, S. P.

    2014-05-01

    The aim of this workshop was to bring together experts in experimental and theoretical aspects of resonant elastic x-ray scattering, along with researchers who are new to the field, to discuss important recent results and the fundamentals of the technique. The meeting was a great success, with the first day dedicated to students and new researchers in the field, who received introductory lectures and tutorials. All conference delegates were invited either to make an oral presentation or to present a poster, accompanied by a short talk. The first two papers selected for the REXS13 proceedings (Grenier & Joly and Helliwell) give a basic background to the theory of REXS and applications across a wide range of scientific areas. The remainder of the papers report on some of the latest scientific results obtained by applying the REXS technique to contemporary problems in condensed matter, materials and x-ray physics. It is hoped that these proceedings provide a snapshot of the current status of a vibrant and diverse scientific technique that will be of value not just to those who attended the workshop but also to any other reader with an interest in the subject. Local Scientific Committee REXS13 International Scientific Advisory Committee M Altarelli, European XFEL, Germany F de Bergevin, European Synchrotron Radiation Facility, France J Garcia-Ruiz, Universidad de Zaragoza, Spain A I Goldman, Iowa State University, USA M Goldmann, Institut Nanosciences, France T Schulli, European Synchrotron Radiation Facility, France C R Natoli, Laboratori Nazionali de Frascati, Italy G Materlik, Diamond Light Source, UK L Paolasini, European Synchrotron Radiation Facility, France U Staub, Paul Scherrer Institut, Switzerland K Finkelstein, Cornell University, USA Y Murakami, Photon Factory, Japan REXS13 Local Scientific Committee G Beutier, CNRS Grenoble, France C Mazzoli, Politecnico di Milano, Italy F Yakhou, European Synchrotron Radiation Facility, France S D Brown, XMaS UK CRG

  5. Communicating Science on YouTube and Beyond: OSIRIS-REx Presents 321Science!

    Science.gov (United States)

    Spitz, Anna H.; Dykhuis, Melissa; Platts, Symeon; Keane, James T.; Tanquary, Hannah E.; Zellem, Robert; Hawley, Tiffany; Lauretta, Dante; Beshore, Ed; Bottke, Bill; Hergenrother, Carl; Dworkin, Jason P.; Patchell, Rose; Spitz, Sarah E.; Bentley, Zoe

    2014-11-01

    NASA’s OSIRIS-REx asteroid sample return mission launched OSIRIS-REx Presents 321Science!, a series of short videos, in December 2013 at youtube.com/osirisrex. A multi-disciplinary team of communicators, film and graphic arts students, teens, scientists, and engineers produces one video per month on a science and engineering topic related to the OSIRIS-REx mission. The format is designed to engage all members of the public, but especially younger audiences with the science and engineering of the mission. The videos serve as a resource for team members and others, complementing more traditional formats such as formal video interviews, mission animations, and hands-on activities. In creating this new form of OSIRIS-REx engagement, we developed 321Science! as an umbrella program to encourage expansion of the concept and topics beyond the OSIRIS-REx mission through partnerships. Such an expansion strengthens and magnifies the reach of the OSIRIS-REx efforts.321Science! has a detailed proposed schedule of video production through launch in 2016. Production plans are categorized to coincide with the course of the mission beginning with Learning the basics - about asteroids and the mission - and proceeding to Building the spacecraft, Run up to launch, Cruising to Bennu, Run up to rendezvous, Mapping Bennu, Sampling, Analyzing data, Cruising home and Returning and analyzing the sample. The video library will host a combination of videos on broad science topics and short specialized concepts with an average length of 2-3 minutes. Video production also takes into account external events, such as other missions’ milestones, to draw attention to our videos. Production will remain flexible and responsive to audience interests and needs and to developments in the mission, science, and external events. As of August 2014, 321Science! videos have over 22,000 views. We use YouTube analytics to evaluate our success and we are investigating additional and more rigorous evaluation

  6. Preparación y caracterización de mezclas REX-PLA / ABS

    OpenAIRE

    Constans Solé, Nil

    2015-01-01

    El presente proyecto se centra en la producción y caracterización de mezclas de poli(ácido láctico) modificado mediante un extensor de cadena (REX-PLA) con Acrilonitrilo-Butadieno- Estireno (ABS), usando ABS injertado con ácido anhídrido maleico (ABS-g-MAH) como compatibilizante. La primera etapa de la preparación de las mezclas consiste en la obtención de REX-PLA por extrusión reactiva en una extrusora de doble husillo. Se llevan a cabo acciones de mejora del proceso produc...

  7. Spectral Characterization of Analog Samples in Anticipation of OSIRIS-REx's Arrival at Bennu

    Science.gov (United States)

    Donaldson Hanna, K. L.; Schrader, D. L.; Bowles, N. E.; Clark, B. E.; Cloutis, E. A.; Connolly, H. C., Jr.; Hamilton, V. E.; Keller, L. P.; Lauretta, D. S.; Lim, L. F.; hide

    2017-01-01

    NASA's Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission successfully launched on September 8th, 2016. During its rendezvous with near-Earth asteroid (101955) Bennu beginning in 2018, OSIRIS-REx will characterize the asteroid's physical, mineralogical, and chemical properties in an effort to globally map the properties of Bennu, a primitive carbonaceous asteroid, and choose a sampling location]. In preparation for these observations, analog samples were spectrally characterized across visible, near- and thermal-infrared wavelengths and were used in initial tests on mineral-phase-detection and abundance-determination software algorithms.

  8. Transverse beam profile measurements with slit scanner and Faraday cup at REX-ISOLDE

    CERN Document Server

    Cantero, E D; Lanaia, D; Sosa, A; Voulot, D

    2014-01-01

    The transverse profiles for the HIE-ISOLDE beams will be measured using a system composed of a scanning slit and a Faraday cup. A validation test of the proposed device was performed using the REX-ISOLDE stable beam and a prototype diagnostic box designed for HIE-ISOLDE. The slit used for this test was very thin (0.2 mm width), but still fairly good profiles could be obtained for beams with total current of around 20 pA (typical beam intensity during normal set-up procedures for REX-ISOLDE).

  9. Protein sequences from mastodon and Tyrannosaurus rex revealed by mass spectrometry.

    Science.gov (United States)

    Asara, John M; Schweitzer, Mary H; Freimark, Lisa M; Phillips, Matthew; Cantley, Lewis C

    2007-04-13

    Fossilized bones from extinct taxa harbor the potential for obtaining protein or DNA sequences that could reveal evolutionary links to extant species. We used mass spectrometry to obtain protein sequences from bones of a 160,000- to 600,000-year-old extinct mastodon (Mammut americanum) and a 68-million-year-old dinosaur (Tyrannosaurus rex). The presence of T. rex sequences indicates that their peptide bonds were remarkably stable. Mass spectrometry can thus be used to determine unique sequences from ancient organisms from peptide fragmentation patterns, a valuable tool to study the evolution and adaptation of ancient taxa from which genomic sequences are unlikely to be obtained.

  10. High-Resolution Energy and Intensity Measurements with CVD Diamond at REX-ISOLDE

    CERN Document Server

    Griesmayer, E; Dobos, D; Wenander, F; Bergoz, J; Bayle, H; Frais-Kölbl, H; Leinweber, J; Aumeyr, T; CERN. Geneva. BE Department

    2009-01-01

    A novel beam instrumentation device for the HIE-REX (High In-tensity and Energy REX) upgrade has been developed and tested at the On-Line Isotope Mass Separator ISOLDE, located at the European Laboratory for Particle Physics (CERN). This device is based on CVD diamond detector technology and is used for measuring the beam intensity, particle counting and measuring the energy spectrum of the beam. An energy resolution of 0.6% was measured at a carbon ion energy of 22.8 MeV. This corresponds to an energy spread of ± 140 keV.

  11. 3-minute Stephen Hawking. His life, theories and influence; Stephen Hawking im 3-Minuten-Takt. Sein Leben, sein Werk, sein Einfluss

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, Paul; Dixon, Gail

    2013-09-01

    3-minutes Stephen Hawking offers a compact introduction to life and work of this impressing scientist. This book is devided into three parts: Hawking's life, his theories, his influence. Each part offers fascinating reading material for one hour. The partial themes of this book are served up in practical 3-minute portions.

  12. Toxicity of gentamicin in red-tailed hawks.

    Science.gov (United States)

    Bird, J E; Walser, M M; Duke, G E

    1983-07-01

    Gentamicin sulfate at dosage levels of 10 and 20 mg/kg of body weight was administered twice daily IV to red-tailed hawks. Clinical signs, water consumption, and changes in blood chemical values were monitored. Tissues were examined grossly and ultrastructurally, using light and electron microscopy. Clinical signs of weakness and apnea were attributed to gentamicin-induced neuromuscular blockade in the 20-mg/kg group. Serum values of aspartate transaminase, alanine transaminase, cholesterol, inorganic phosphorus, total protein, albumin, and uric acid increased in some birds. There was a decrease in periodic acid-Schiff staining of proximal tubular brush borders. Increased numbers of cytoplasmic lysosomes, many of which contained myelin figures, in renal epithelial cells were seen at the ultrastructural level. All birds given 20 mg/kg died. Both dosage levels were considered toxic in red-tailed hawks.

  13. Conference | From Newton to Hawking and beyond | 28 May

    CERN Multimedia

    2013-01-01

    From Newton to Hawking and beyond: Why disability equality is relevant to the world of particle physics, Dr Tom Shakespeare.    Tuesday, 28 May 2013 - 11.30 am - 1 pm Main Auditorium – Room 500-1-001 Conference organised by the CERN Diversity Programme English with French interpretation According to the recent world report on disability, 15% of the world’s population is disabled.  Among that group could be numbered famous physicists such as Isaac Newton and Paul Dirac, neither of whom could be classed as “neuro-typical”, and Stephen Hawking.  This presentation will provide some basic data about global disability, and the socially imposed barriers which disabled people face.  It will also include some stories about high achieving people with disabilities.  Finally, some practical suggestions will be offered on how to respect and include people with disabilities in the workplace. Tom Shakespeare is a social sci...

  14. Investigation of the $^{9}$Li + $^{2}$H $\\to ^{8}$Li + t reaction at REX-ISOLDE

    CERN Document Server

    Jeppesen, H B; Nilsson, T; Ames, F

    2006-01-01

    The one-neutron transfer reaction has been investigated in an inverse kinematics experiment by bombarding a deuterated polypropylene target with a 2.36 MeV/u $^{9}$Li beam from the post-accelerator REX-ISOLDE at CERN. Excitation energies in $^{8}$Li as well as angular distributions of the tritons were obtained and spectroscopic factors deduced.

  15. Case studies on design, simulation and visualization of control and measurement applications using REX control system

    Science.gov (United States)

    Ozana, Stepan; Pies, Martin; Docekal, Tomas

    2016-06-01

    REX Control System is a professional advanced tool for design and implementation of complex control systems that belongs to softPLC category. It covers the entire process starting from simulation of functionality of the application before deployment, through implementation on real-time target, towards analysis, diagnostics and visualization. Basically it consists of two parts: the development tools and the runtime system. It is also compatible with Simulink environment, and the way of implementation of control algorithm is very similar. The control scheme is finally compiled (using RexDraw utility) and uploaded into a chosen real-time target (using RexView utility). There is a wide variety of hardware platforms and real-time operating systems supported by REX Control System such as for example Windows Embedded, Linux, Linux/Xenomai deployed on SBC, IPC, PAC, Raspberry Pi and others with many I/O interfaces. It is modern system designed both for measurement and control applications, offering a lot of additional functions concerning data archiving, visualization based on HTML5, and communication standards. The paper will sum up possibilities of its use in educational process, focused on control of case studies of physical models with classical and advanced control algorithms.

  16. Case studies on design, simulation and visualization of control and measurement applications using REX control system

    Energy Technology Data Exchange (ETDEWEB)

    Ozana, Stepan, E-mail: stepan.ozana@vsb.cz; Pies, Martin, E-mail: martin.pies@vsb.cz; Docekal, Tomas, E-mail: docekalt@email.cz [VSB-Technical University of Ostrava, Faculty of Electrical Engineering and Computer Science, Department of Cybernetics and Biomedical Engineering, 17. listopadu 15/2172, Ostrava-Poruba, 700 30 (Czech Republic)

    2016-06-08

    REX Control System is a professional advanced tool for design and implementation of complex control systems that belongs to softPLC category. It covers the entire process starting from simulation of functionality of the application before deployment, through implementation on real-time target, towards analysis, diagnostics and visualization. Basically it consists of two parts: the development tools and the runtime system. It is also compatible with Simulink environment, and the way of implementation of control algorithm is very similar. The control scheme is finally compiled (using RexDraw utility) and uploaded into a chosen real-time target (using RexView utility). There is a wide variety of hardware platforms and real-time operating systems supported by REX Control System such as for example Windows Embedded, Linux, Linux/Xenomai deployed on SBC, IPC, PAC, Raspberry Pi and others with many I/O interfaces. It is modern system designed both for measurement and control applications, offering a lot of additional functions concerning data archiving, visualization based on HTML5, and communication standards. The paper will sum up possibilities of its use in educational process, focused on control of case studies of physical models with classical and advanced control algorithms.

  17. Status, results and plans after 3 years of Tunka-Rex operation

    Energy Technology Data Exchange (ETDEWEB)

    Hiller, Roman [Karlsruher Institut fuer Technologie (Germany); Collaboration: Tunka-Rex-Collaboration

    2016-07-01

    The Tunka Radio Extension (Tunka-Rex) is a radio detector for air showers from cosmic rays around 10{sup 17} eV close to Lake Baikal in Russia. It currently consists of 44 antenna stations, distributed over 3 km{sup 2}, and will be extended by another 19 antenna stations this year. As most radio experiments, it is hosted by another air-showers detector, providing trigger and an independed reconstruction. This has been Tunka-133, an air-Cherenkov detector at the site, limited to operation during moonless nights. From winter 2015 on, Tunka-Rex also jointly operates with Tunka-Grande, a newly installed scintillator detector at the site, capable of 24 h operation. The goal of the first stage of Tunka-Rex was to develop methods for competitive air shower measurements and detemine the achievable precision for the most important air shower parameters, the energy and depth of the shower maximum. In the next stage, with the now available full duty cycle and powerful combination of radio and scintillator detector, the goal will be to contribute to measurements of the energy spectrum and mass composition of cosmic rays from 10{sup 17} eV to 10{sup 18} eV. Latest results and plans for Tunka-Rex are reported. This includes an energy reconstruction with a single antenna station and the comparison of the absolute energy scale via radio measurements.

  18. Kajian Kritis Terhadap Praanggapan Metafisis-Epistemologis Kosmologi Stephen Hawking

    Directory of Open Access Journals (Sweden)

    Sindung Tjahyadi

    2008-10-01

    Full Text Available Tulisan ini pada dasarnya merupakan kajian filosofis terhadap suatu "kosmologi ilmiah".Dengan demikian terdapat dua pendekatan yang digunakan,yakni,pertama,hampiran filsafatilmu, terkait dengan aspek-aspek metodologis dari kosmologi ilmiah;dan kedua, hampirankosmologi filsafat, terkait dengan evaluasi kritis atas kosmologi Hawking dalam dimensikosmologi filsafati, terutama berkenaan dengan posisi yang diambinya terhadap unsur hakikipembangun realitas dan peran pengkosmos di dalamnya khususnya terkait dengan konsepruang-wakru, prinsip determinisme, dan hukum kekekalan energi.

  19. Steven Hawking to visit Texas A&M in spring

    CERN Multimedia

    Xavier, D

    2002-01-01

    Stephen Hawking will visit Texas A&M University from Feb. 24 to March 21 2003 to participate in the inaugural meeting of the George P. and Cynthia W. Mitchell Institute for Fundamental Physics. This institute will bring several of the world's top physicists to A&M for a month-long exploration of the latest ideas on topics ranging from superstrings to M-theory and supergravity (1/2 page).

  20. Top scientists join Stephen Hawking at Perimeter Institute

    Science.gov (United States)

    Banks, Michael

    2009-03-01

    Nine leading researchers are to join Stephen Hawking as visiting fellows at the Perimeter Institute for Theoretical Physics in Ontario, Canada. The researchers, who include string theorists Leonard Susskind from Stanford University and Asoka Sen from the Harisch-Chandra Research Institute in India, will each spend a few months of the year at the institute as "distinguished research chairs". They will be joined by another 30 scientists to be announced at a later date.

  1. Numerical observation of Hawking radiation from acoustic black holes in atomic Bose-Einstein condensates

    Energy Technology Data Exchange (ETDEWEB)

    Carusotto, Iacopo; Recati, Alessio [CNR-INFM BEC Center and Dipartimento di Fisica, Universita di Trento, via Sommarive 14, I-38050 Povo, Trento (Italy); Fagnocchi, Serena [Centro Studi e Ricerche ' Enrico Fermi' , Compendio Viminale, 00184 Roma (Italy); Balbinot, Roberto [Dipartimento di Fisica dell' Universita di Bologna and INFN sezione di Bologna, Via Irnerio 46, 40126 Bologna (Italy); Fabbri, Alessandro [Departamento de Fisica Teorica and IFIC, Universidad de Valencia-CSIC, C. Dr Moliner 50, 46100 Burjassot (Spain)], E-mail: carusott@science.unitn.it

    2008-10-15

    We report numerical evidence of Hawking emission of Bogoliubov phonons from a sonic horizon in a flowing one-dimensional atomic Bose-Einstein condensate. The presence of Hawking radiation is revealed from peculiar long-range patterns in the density-density correlation function of the gas. Quantitative agreement between our fully microscopic calculations and the prediction of analog models is obtained in the hydrodynamic limit. New features are predicted and the robustness of the Hawking signal against a finite temperature discussed.

  2. Brachial plexus injury in two red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Shell, L; Richards, M; Saunders, G

    1993-01-01

    Two red-tailed hawks (Buteo jamaicensis), found near Deltaville, Virginia (USA), were evaluated because of inability to use a wing. Results of needle electromyographic studies of the affected wing muscles in both hawks were compatible with denervation. On euthanasia, one hawk had extensive axon and myelin loss with multifocal perivascular lymphocytic inflammation of its brachial plexus and radial nerve. Demyelination and axon loss in the dorsal white matter of the spinal cord on the affected side also were found at the origin of the brachial plexus. The other hawk's wing had not returned to functional status > 2 yr after injury.

  3. The Hawking evaporation process of rapidly-rotating black holes: an almost continuous cascade of gravitons

    Energy Technology Data Exchange (ETDEWEB)

    Hod, Shahar [The Ruppin Academic Center, Emek Hefer (Israel); The Hadassah Institute, Jerusalem (Israel)

    2015-07-15

    It is shown that rapidly-rotating Kerr black holes are characterized by the dimensionless ratio τ{sub gap}/τ{sub emission} = O(1), where τ{sub gap} is the average time gap between the emissions of successive Hawking quanta and τ{sub emission} is the characteristic timescale required for an individual Hawking quantum to be emitted from the black hole. This relation implies that the Hawking cascade from rapidly-rotating black holes has an almost continuous character. Our results correct some inaccurate claims that recently appeared in the literature regarding the nature of the Hawking black-hole evaporation process. (orig.)

  4. Manual Surface Feature Classification and Error Analysis for NASA's OSIRIS-Rex Asteroid Sample Return Mission Using QGIS

    Science.gov (United States)

    Westermann, M. M.

    2017-06-01

    Error mitigation for manual detection and classification of hazardous surface features for NASA's OSIRIS-REx asteroid sample return mission can be accomplished through the use of open-source GIS and standard land-cover change analysis methods.

  5. Comment on "Protein Sequences from Mastodon and Tyrannosaurus rex Revealed by Mass Spectrometry"

    DEFF Research Database (Denmark)

    Buckley, Mike; Walker, Angela; Ho, Simon Y W

    2008-01-01

    We used authentication tests developed for ancient DNA to evaluate claims by Asara et al. (Reports, 13 April 2007, p. 280) of collagen peptide sequences recovered from mastodon and Tyrannosaurus rex fossils. Although the mastodon samples pass these tests, absence of amino acid composition data, l......, lack of evidence for peptide deamidation, and association of alpha1(I) collagen sequences with amphibians rather than birds suggest that T. rex does not. Udgivelsesdato: 2008-Jan-4...

  6. Chromosomal Mapping of Transposable Elements of the Rex Family in the Bristlenose Catfish, Ancistrus (Siluriformes, Loricariidae), from the Amazonian Region.

    Science.gov (United States)

    Favarato, Ramon Marin; Ribeiro, Leila Braga; Feldberg, Eliana; Matoso, Daniele Aparecida

    2017-05-01

    Repetitive DNA sequences are present in the genome of basically every known organism, and transposable elements (TE) are one of the most representative sequences involved in chromosomal rearrangements and the genomic evolution of eukaryotes. In fish, the non-LTR retrotransposon TEs, Rex1, Rex3, and Rex6, are widely distributed in fish genomes and are the best-characterized TEs in several species. In the current study, three of these retroelements were physically mapped, through fluorescent in situ hybridization (FISH), in 7 species (71 specimens) of the genus Ancistrus, known as bristlenose catfish: Ancistrus ranunculus, Ancistrus sp. 1 "Purus," Ancistrus sp. 2 "Catalão," Ancistrus dolichopterus, Ancistrus maximus, Ancistrus aff. dolichopterus, and Ancistrus dubius. Rex1, Rex3, and Rex6 showed a cluster distribution, mainly in the terminal and pericentromeric portions, in heterochromatic and euchromatic regions, and did not occur in sexual chromosomes; however, the number and position of the clusters varied between species. This TE distribution suggests its implication in the karyotypic evolution of these species, without affecting the rise of sexual chromosome systems in Ancistrus, in view of their chromosomal variation. © The American Genetic Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Transcriptional repressor Rex is involved in regulation of oxidative stress response and biofilm formation by Streptococcus mutans.

    Science.gov (United States)

    Bitoun, Jacob P; Nguyen, Anne H; Fan, Yuwei; Burne, Robert A; Wen, Zezhang T

    2011-07-01

    The transcriptional repressor Rex has been implicated in the regulation of energy metabolism and fermentative growth in response to redox potential. Streptococcus mutans, the primary causative agent of human dental caries, possesses a gene that encodes a protein with high similarity to members of the Rex family of proteins. In this study, we showed that Rex-deficiency compromised the ability of S. mutans to cope with oxidative stress and to form biofilms. The Rex-deficient mutant also accumulated less biofilm after 3 days than the wild-type strain, especially when grown in sucrose-containing medium, but produced more extracellular glucans than the parental strain. Rex-deficiency caused substantial alterations in gene transcription, including those involved in heterofermentative metabolism, NAD(+) regeneration and oxidative stress. Among the upregulated genes was gtfC, which encodes glucosyltransferase C, an enzyme primarily responsible for synthesis of water-insoluble glucans. These results reveal that Rex plays an important role in oxidative stress responses and biofilm formation by S. mutans. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  8. Covariant anomalies and Hawking radiation from Kaluza–Klein AdS ...

    Indian Academy of Sciences (India)

    The KK-AdS black hole considered is a non-extremal charged rotating solution in the theory of 4D gauged supergravity. Its Hawking fluxes of electric charge, angular momentum and energy momentum tensor are derived here. Our results support the common view that Hawking radiation is the quantum effect arising at the ...

  9. Low prevalence of Trichomonas gallinae in urban and migratory Cooper's Hawks in northcentral North America

    Science.gov (United States)

    Rosenfield, Robert N.; Taft, Stephen J.; Stout, William E.; Driscoll, Timothy G.; Evans, David L.; Bozek, Michael A.

    2009-01-01

    Trichomoniasis is a digestive tract disease caused by ingestion of the protozoan Trichomonas gallinae. This disease can be a significant source of mortality. No deaths of nestlings could be attributed to trichomoniasis in Cooper's Hawks (Accipiter cooperii) breeding in urban and rural environs in Wisconsin, North Dakota, and British Columbia. We detected T. gallinae in four (5.2%) of 77 nestling Cooper's Hawks during 2006 and 2007 among 42 urban nests on new study areas in southeast Wisconsin and eastern North Dakota/western Minnesota. All four infected young fledged. We did not detect T. gallinae in 52 breeding adult Cooper's Hawks on two urban study sites, nor in 28 migrant hatching year (n  =  24) and adult (n  =  4) Cooper's Hawks at Hawk Ridge Nature Reserve, Duluth, Minnesota in 2006–2007. Overall, we detected T. gallinae in only 2.5% of 157 Cooper's Hawks in northcentral North America. These results suggest a low prevalence of T. gallinae in Cooper's Hawks in the northern part of this hawk's breeding range.

  10. Hawking radiation and black hole spectroscopy in Hořava–Lifshitz gravity

    National Research Council Canada - National Science Library

    Majhi, Bibhas Ranjan

    2010-01-01

    ...] . Surprisingly, however, there does not exist any detailed study of the Hawking effect [12] , except for some sporadic attempts [13,14] . The motivation of this Letter is to fill such a gap. We feel this study to be important since the Hawking radiation is crucial to give the black holes one of its thermodynamic properties making it consisten...

  11. Health evaluation of Galapagos Hawks (Buteo galapagoensis) on Santiago Island, Galapagos.

    Science.gov (United States)

    Deem, Sharon L; Rivera-Parra, Jose Luis; Parker, Patricia G

    2012-01-01

    Galapagos Hawks (Buteo galapagoensis), the only endemic, diurnal raptor species in Galapagos, are currently distributed on eight Galapagos Islands having been extirpated from three of the human-inhabited islands. In January 2009, we performed health assessments of 89 Galapagos Hawks on Santiago Island, Galapagos. Four of the 89 Galapagos Hawks (4%) evaluated had physical abnormalities. Blood parameters did not differ between males and females, except for aspartate transaminase values, which were significantly higher in females than males. No Galapagos Hawks tested positive for antibodies to avian encephalitis virus, Marek virus, and paramyxovirus-1 or to haemosporidian antigen. Chlamydophila psittaci antigen was detected in 2 of 86 Galapagos Hawks (2%), with 24 of 43 Galapagos Hawks (56%) antibody-positive for avian adenovirus-1 and 1 of 48 Galapagos Hawks (2%) antibody positive for Toxoplasma gondii. There were no significant differences in infectious disease results based on sex. This study contributes to the understanding of the health status of the Galapagos Hawk and to the establishment of baseline information for the species.

  12. Covariant anomalies and Hawking radiation from Kaluza–Klein AdS ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 80; Issue 2. Covariant anomalies and Hawking radiation from Kaluza–Klein AdS ... angular momentum and energy momentum tensor are derived here. Our results support the common view that Hawking radiation is the quantum effect arising at the event horizon.

  13. Spin One Hawking Radiation from Dirty Black Holes

    OpenAIRE

    Petarpa Boonserm; Tritos Ngampitipan; Matt Visser

    2013-01-01

    A “clean” black hole is a black hole in vacuum such as the Schwarzschild black hole. However in real physical systems, there are matter fields around a black hole. Such a black hole is called a “dirty black hole”. In this paper, the effect of matter fields on the black hole and the greybody factor is investigated. The results show that matter fields make a black hole smaller. They can increase the potential energy to a black hole to obstruct Hawking radiation to propagate. This causes the gre...

  14. Diabetes mellitus in a red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Wallner-Pendleton, E A; Rogers, D; Epple, A

    1993-09-01

    An adult, free-living female red-tailed hawk (Buteo jamaicensis) with clinical signs of generalized weakness, polyuria, and polydipsia, was killed and necropsied. An ante mortem serum sample taken from the bird contained 54.3 mmole/1 glucose, and large amounts of glucose were found in the urine. At necropsy, the pancreas was small, pale pink with multiple, round, approximately 0.5 mm white foci. Light and electron microscopic examination of the pancreas revealed markedly vacuolated islet cells. Histochemical examination of the tissue showed that the vacuolated cells were beta-cells. This is the first report of spontaneously occurring diabetes mellitus in a raptor.

  15. Lorentz Invariance Violation and Modified Hawking Fermions Tunneling Radiation

    Directory of Open Access Journals (Sweden)

    Shu-Zheng Yang

    2016-01-01

    Full Text Available Recently the modified Dirac equation with Lorentz invariance violation has been proposed, which would be helpful to resolve some issues in quantum gravity theory and high energy physics. In this paper, the modified Dirac equation has been generalized in curved spacetime, and then fermion tunneling of black holes is researched under this correctional Dirac field theory. We also use semiclassical approximation method to get correctional Hamilton-Jacobi equation, so that the correctional Hawking temperature and correctional black hole’s entropy are derived.

  16. OSIRIS-REx Touch-And-Go (TAG) Mission Design and Analysis

    Science.gov (United States)

    Berry, Kevin; Sutter, Brian; May, Alex; Williams, Ken; Barbee, Brent W.; Beckman, Mark; Williams, Bobby

    2013-01-01

    The Origins Spectral Interpretation Resource Identification Security Regolith Explorer (OSIRIS-REx) mission is a NASA New Frontiers mission launching in 2016 to rendezvous with the near-Earth asteroid (101955) 1999 RQ36 in late 2018. After several months in formation with and orbit about the asteroid, OSIRIS-REx will fly a Touch-And-Go (TAG) trajectory to the asteroid s surface to obtain a regolith sample. This paper describes the mission design of the TAG sequence and the propulsive maneuvers required to achieve the trajectory. This paper also shows preliminary results of orbit covariance analysis and Monte-Carlo analysis that demonstrate the ability to arrive at a targeted location on the surface of RQ36 within a 25 meter radius with 98.3% confidence.

  17. Coulomb Excitation of Neutron Deficient Sn-Isotopes using REX-ISOLDE

    CERN Multimedia

    Di julio, D D; Kownacki, J M; Marechal, F; Andreoiu, C; Siem, S; Perrot, F; Van duppen, P L E; Napiorkowski, P J; Iwanicki, J S

    2002-01-01

    It is proposed to study the evolution of the reduced transition probabilities, B(E2; 0$^{+} \\rightarrow$ 2$^{+}$), for neutron deficient Sn isotopes by Coulomb excitation in inverse kinematics using REX-ISOLDE and the MINIBALL detector array. Measurements of the reduced transition matrix element for the transition between the ground state and the first excited 2$^{+}$ state in light even-even Sn isotopes provide a means to study e.g. core polarization effects in the $^{100}$Sn core. Previous attempts to measure this quantity have been carried out using the decay of isomeric states populated in fusion evaporation reactions. We thus propose to utilize the unique opportunity provided by REX-ISOLDE, after the energy upgrade to 3.1 MeV/u, to use the more model-independent approach of Coulomb excitation to measure this quantity in a number of isotopes in this region.

  18. REX-ISOLDE post-accelerated radioactive BEAMS at CERN-ISOLDE

    CERN Document Server

    Nilsson, T; Forstner, O; Ravn, H L; Oinonen, M; Simon, H; Cederkäll, J; Weissman, L; Habs, D; Ames, F; Kester, O; Sieber, T; Bongers, H; Emhofer, S; Reiter, P; Thirolf, P G; Bollen, G; Schmidt, P; Huber, G; Liljeby, L; Rensfelt, K G; Skeppstedt, Ö; Wenander, F; Jonson, B; Nyman, G H; Von Hahn, R; Podlech, H; Repnow, R; Gund, C; Schwalm, D; Schempp, A; Kühnel, K U; Welsch, C P; Ratzinger, U; Walter, G; Huck, A; Kruglov, K; Huyse, M; Van den Bergh, P; Van Duppen, P; Shotter, A C; Ostrowski, A N; Davinson, T; Woods, P J; Moukha, I; Richter, A; Schrieder, G

    2001-01-01

    The ISOLDE RIB-facility at CERN has today been producing a vast range of radioactive beams since more than 30 years. The low-energy beams of ISOLDE will be complemented by a post-accelerator, REX-ISOLDE, currently being assembled. In order to convert the pseudo-DC, singly-charged beam from the ISOLDE mass separators into a cooled and bunched beam at higher charge states a novel scheme of trapping, cooling and charge-state breeding has been devised, using a linear Penning trap and an Electron Beam Ion Source (EBIS). This allows for subsequent acceleration by a short, cost-effective LINAC consisting of an RFQ, an IH-structure and three seven-gap resonators, reaching 0.8 - 2.2 MeV/u. The installation of REX-ISOLDE is well underway and the first post-accelerated radioactive beams are expected to be obtained during late 2000.

  19. Study of Neutron-Rich Be Isotopes with REX-ISOLDE

    CERN Multimedia

    Thiboud, J A; Riisager, K; Jonson, B N G; Koldste, G T

    2002-01-01

    We propose to perform a survey experiment with a $^{11}$Be beam reacting with a deuteron target at REX-ISOLDE at a beam energy of 3.1 MeV/u. The purpose of the experiment is to extract information on $^{10,11,12}$Be and $^{9}$Li via different nuclear reactions. Furthermore we suggest to explore the possibility to produce a $^{12}$Be beam.

  20. The albedo properties of four clean stratocumulus clouds studied during the VOCALS-REX field campaign

    OpenAIRE

    Parkes, B; Rosenberg, P; Gadian, A.; Blyth, A.; Latham, J

    2012-01-01

    The VOCALS-REx field campaign which took place in 2008 used several platforms to investigate the persistent marine stratocumulus cloud deck off the Chilean and Peruvian coasts. VOCALS-UK was the UK component of the experiment, during which the FAAM BAe-146 aircraft gathered data in the stratocumulus cloud. It flew 13 research flights including investigations along 20° S transects.

    In this paper, the shortwave cloud albedo derived from the Cloud Droplet Probe is compared ...

  1. Investigation of the $^{8}$Li($^{2}$H,p)$^{9}$Li Reaction at REX-ISOLDE

    CERN Multimedia

    2002-01-01

    We propose to investigate the $^{8}$Li($^{2}$H,p )$^{9}$Li reaction at REX-ISOLDE. The main aim is to test a recently found discrepancy in extracted spectroscopic factors for this reaction. As a byproduct we will obtain improved data relevant for predictions of the $^{8}$Li(n,$\\gamma$)$^{9}$Li rate in inhomogeneous nucleosynthesis. For the full experiment including beam tuning and background measurements we ask for 13 shifts.

  2. The Bekenstein-Hawking Corpuscular Cascading from the Back-Reacted Black Hole

    Directory of Open Access Journals (Sweden)

    Ali Övgün

    2017-01-01

    Full Text Available Exciting peculiarities of Planck-scale physics have immediate effects on the Bekenstein-Hawking radiation emitted from black holes (BHs. In this paper, using the tunneling formalism, we determine the Bekenstein-Hawking temperature for the vector particles from a back-reacted black hole (BBH constructed from a conformal scalar field surrounded by a BTZ (Banados-Teitelboim-Zanelli BH. Then, under the effect of the generalized uncertainty principle, we extend our calculations for scalar particles to understand the effects of quantum gravity. Then, we calculate an evaporation time for the BBH, the total number of Bekenstein-Hawking particles, and the quantum corrections of the number. We observe that remnants of the BH evaporation occur and that they affect the Bekenstein-Hawking temperature of the BBH as well as the total number of Bekenstein-Hawking particles.

  3. Caryospora uptoni and Frenkelia sp.-like coccidial infections in red-tailed hawks (Buteo borealis).

    Science.gov (United States)

    Lindsay, D S; Blagburn, B L

    1989-07-01

    The feces from 16 red-tailed hawks (Buteo borealis) were examined by fecal flotation for the presence of coccidial oocysts or sporocysts. Oocysts of Caryospora uptoni were found in five (31%), sporocysts of a Frenkelia sp.-like coccidium were found in eight (50%), and mixed infections with both species of coccidia were found in three (19%) red-tailed hawks. Neither oocysts nor sporocysts were found in six (38%) red-tailed hawks. Sexual stages of C. uptoni were found in the duodenum and jejunum of a naturally infected red-tailed hawk. Sexual stages were located in enterocytes on the distal three-fourths of the villi. This study shows that over 60% of red-tailed hawks may be passing coccidial oocysts/sporocysts in their feces and provides morphological information for diagnosing C. uptoni infections in histological sections.

  4. Scientific publications laboratory of remote experimentation - RExLab: a systematic review

    Directory of Open Access Journals (Sweden)

    Janine De Lavechia

    2017-10-01

    Full Text Available Introduction: The Information and Communication Technologies TICs are allowing day by day the improvement in all levels of the institutions, providing in a general context a greater communication, and enabling the creation of new knowledge. And with the emergence of the Remote Experimentation Laboratory - RExLab, which allows the student to perform experiments, makes possible the construction of new knowledge. Objective: Identify and present the NICT (New Information and Communication Technologies studied in the laboratory and explained in the publications of the members linked RExLab. Methodology: In this article a systematic research was done on the articles published in RExLab, and located at the Federal University of Santa Catarina, Araranguá. And the articles with the highest citations, the NICT used in each research were presented. Result: It was possible to identify that a great majority of articles published was related to questions of remote experimentation through the usage of mobile devices, and today it allows almost all the students to have a great access to it. Conclusion: It was possible to analyze that the greatest objective of published research is the achievement of democratization and the dissemination of knowledge through their experiments. These are projects that can be applied at all levels of education and also in public and private schools.With this, there are many ICTs that are inserted in the projects and that they have as purpose the aid to the education.

  5. Optimizing the production of suspension cells using the G-Rex “M” series

    Directory of Open Access Journals (Sweden)

    Pradip Bajgain

    2014-01-01

    Full Text Available Broader implementation of cell-based therapies has been hindered by the logistics associated with the expansion of clinically relevant cell numbers ex vivo. To overcome this limitation, Wilson Wolf Manufacturing developed the G-Rex, a cell culture flask with a gas-permeable membrane at the base that supports large media volumes without compromising gas exchange. Although this culture platform has recently gained traction with the scientific community due to its superior performance when compared with traditional culture systems, the limits of this technology have yet to be explored. In this study, we investigated multiple variables including optimal seeding density and media volume, as well as maximum cell output per unit of surface area. Additionally, we have identified a novel means of estimating culture growth kinetics. All of these parameters were subsequently integrated into a novel G-Rex “M” series, which can accommodate these optimal conditions. A multicenter study confirmed that this fully optimized cell culture system can reliably produce a 100-fold cell expansion in only 10 days using 1L of medium. The G-Rex M series is linearly scalable and adaptable as a closed system, allowing an easy translation of preclinical protocols into the good manufacturing practice.

  6. Beam-Preparation with REXTRAP for the REX-ISOLDE Experiment

    CERN Document Server

    Forstner, O; Oberhummer, Heinz; Bollen, Georg

    2001-01-01

    REX-ISOLDE is a post-accelerator for radioactive ions located at the ISOLDE facility at CERN. Its task is to accelerate the radioactive ions coming from the on-line mass separator ISOLDE from 60 keV to a final energy of 2.2 MeV/u. To achieve this goal with a compact and cost-efficient setup a new concept was proposed. First the ions are accumulated in a Penning trap (REXTRAP), then the ions are transported to an EBIS (Electron Beam Ion Source), where their charge-state will be increased. Due to the high charge-state of the ions the following linear accelerator can be built comparatively compactly. In the framework of this thesis the construction and commissioning phase of REX-TRAP is described. REXTRAP is a large, gas-filled Penning trap whose aim is to store and cool the radioactive ions coming from ISOLDE. After listing the physics motivation for building REX-ISOLDE and describing its elements, the theory of a Penning trap as well as the setup of REXTRAP is explained. Fi-nally test results for REXTRAP are p...

  7. Designing to Sample the Unknown: Lessons from OSIRIS-REx Project Systems Engineering

    Science.gov (United States)

    Everett, David; Mink, Ronald; Linn, Timothy; Wood, Joshua

    2017-01-01

    On September 8, 2016, the third NASA New Frontiers mission launched on an Atlas V 411. The Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) will rendezvous with asteroid Bennu in 2018, collect a sample in 2020, and return that sample to Earth in September 2023. The development team has overcome a number of challenges in order to design and build a system that will make contact with an unexplored, airless, low-gravity body. This paper will provide an overview of the mission, then focus in on the system-level challenges and some of the key system-level processes. Some of the lessons here are unique to the type of mission, like discussion of operating at a largely-unknown, low-gravity object. Other lessons, particularly from the build phase, have broad implications. The OSIRIS-REx risk management process was particularly effective in achieving an on-time and under-budget development effort. The systematic requirements management and verification and the system validation also helped identify numerous potential problems. The final assessment of the OSIRIS-REx performance will need to wait until the sample is returned in 2023, but this post-launch assessment will capture some of the key systems-engineering lessons from the development team.

  8. T-REX: software for the processing and analysis of T-RFLP data

    Directory of Open Access Journals (Sweden)

    Culman Steven W

    2009-06-01

    Full Text Available Abstract Background Despite increasing popularity and improvements in terminal restriction fragment length polymorphism (T-RFLP and other microbial community fingerprinting techniques, there are still numerous obstacles that hamper the analysis of these datasets. Many steps are required to process raw data into a format ready for analysis and interpretation. These steps can be time-intensive, error-prone, and can introduce unwanted variability into the analysis. Accordingly, we developed T-REX, free, online software for the processing and analysis of T-RFLP data. Results Analysis of T-RFLP data generated from a multiple-factorial study was performed with T-REX. With this software, we were able to i label raw data with attributes related to the experimental design of the samples, ii determine a baseline threshold for identification of true peaks over noise, iii align terminal restriction fragments (T-RFs in all samples (i.e., bin T-RFs, iv construct a two-way data matrix from labeled data and process the matrix in a variety of ways, v produce several measures of data matrix complexity, including the distribution of variance between main and interaction effects and sample heterogeneity, and vi analyze a data matrix with the additive main effects and multiplicative interaction (AMMI model. Conclusion T-REX provides a free, platform-independent tool to the research community that allows for an integrated, rapid, and more robust analysis of T-RFLP data.

  9. Investigating the running abilities of Tyrannosaurus rex using stress-constrained multibody dynamic analysis

    Directory of Open Access Journals (Sweden)

    William I. Sellers

    2017-07-01

    Full Text Available The running ability of Tyrannosaurus rex has been intensively studied due to its relevance to interpretations of feeding behaviour and the biomechanics of scaling in giant predatory dinosaurs. Different studies using differing methodologies have produced a very wide range of top speed estimates and there is therefore a need to develop techniques that can improve these predictions. Here we present a new approach that combines two separate biomechanical techniques (multibody dynamic analysis and skeletal stress analysis to demonstrate that true running gaits would probably lead to unacceptably high skeletal loads in T. rex. Combining these two approaches reduces the high-level of uncertainty in previous predictions associated with unknown soft tissue parameters in dinosaurs, and demonstrates that the relatively long limb segments of T. rex—long argued to indicate competent running ability—would actually have mechanically limited this species to walking gaits. Being limited to walking speeds contradicts arguments of high-speed pursuit predation for the largest bipedal dinosaurs like T. rex, and demonstrates the power of multiphysics approaches for locomotor reconstructions of extinct animals.

  10. Status and nesting of Ferruginous Hawks (Buteo regalis) in Washington

    Energy Technology Data Exchange (ETDEWEB)

    Fitzner, R.E.; Boyd, L.L.; Berry, D.; Rieck, C.

    1975-01-01

    Nesting of ferruginous hawks in Washington is confined to the shrubsteppe region in the eastern part of the state. The birds nest in two entirely different situations, either on outcroppings of basalt on the slopes of hillsides and canyons, or on the canopy of Juniper trees. Nests dimensions and materials are described. A nearly complete survey of all available nesting habitat in the state revealed that no fewer than 15 and perhaps 20 pair of adult birds breed in the state. Of these, we expect that 12 or 13 pairs will produce young each year. Dietary analysis revealed that small mammals (pocket gophers and ground squirrels) were the most frequently consumed prey items. Small birds, primarily meadowlarks, were frequently consumed prey by both ground and tree nesters. Insects and lagomorphs were fairly abundant as prey items at a ground nest, while snakes (yellow-bellied racer and bullsnake) seemed to replace them in importance at a Juniper nesting site. Dark phase ferruginous hawks are reported for the first time in Washington State.

  11. Nesting habitat and productivity of Swainson's Hawks in southeastern Arizona

    Science.gov (United States)

    Nishida, Catherine; Boal, Clint W.; DeStefano, Stephen; Hobbs, Royden J.

    2013-01-01

    We studied Swainson's Hawks (Buteo swainsoni) in southeastern Arizona to assess the status of the local breeding population. Nest success (≥1 young fledged) was 44.4% in 1999 with an average of 1.43 ± 0.09 (SE) young produced per successful pair. Productivity was similar in 2000, with 58.2% nesting success and 1.83 ± 0.09 fledglings per successful pair. Mesquite (Prosopis velutina) and cottonwood (Populus fremontii) accounted for >50% of 167 nest trees. Nest trees were taller than surrounding trees and random trees, and overall there was more vegetative cover at nest sites than random sites. This apparent requirement for cover around nest sites could be important for management of the species in Arizona. However, any need for cover at nest sites must be balanced with the need for open areas for foraging. Density of nesting Swainson's Hawks was higher in agriculture than in grasslands and desert scrub. Breeding pairs had similar success in agricultural and nonagricultural areas, but the effect of rapid and widespread land-use change on breeding distribution and productivity continues to be a concern throughout the range of the species.

  12. Tunneling method for Hawking radiation in the Nariai case

    Science.gov (United States)

    Belgiorno, F.; Cacciatori, S. L.; Dalla Piazza, F.

    2017-08-01

    We revisit the tunneling picture for the Hawking effect in light of the charged Nariai manifold, because this general relativistic solution, which displays two horizons, provides the bonus to allow the knowledge of exact solutions of the field equations. We first perform a revisitation of the tunneling ansatz in the framework of particle creation in external fields à la Nikishov, which corroborates the interpretation of the semiclassical emission rate Γ_{emission} as the conditional probability rate for the creation of a couple of particles from the vacuum. Then, particle creation associated with the Hawking effect on the Nariai manifold is calculated in two ways. On the one hand, we apply the Hamilton-Jacobi formalism for tunneling, in the case of a charged scalar field on the given background. On the other hand, the knowledge of the exact solutions for the Klein-Gordon equations on Nariai manifold, and their analytic properties on the extended manifold, allow us a direct computation of the flux of particles leaving the horizon, and, as a consequence, we obtain a further corroboration of the semiclassical tunneling picture from the side of S-matrix formalism.

  13. Predator pursuit strategies: how do falcons and hawks chase prey?

    Science.gov (United States)

    Kane, Suzanne Amador; Zamani, Marjon; Fulton, Andrew; Rosenthal, Lee

    2014-03-01

    This study reports on experiments on falcons, goshawks and red-tailed hawks wearing miniature videocameras mounted on their backs or heads while pursuing flying or ground-based prey. Videos of hunts recorded by the raptors were analyzed to determine apparent prey positions on their visual fields during pursuits. These video data then were interpreted using computer simulations of pursuit steering laws observed in insects and mammals. A comparison of the empirical and modeling data indicates that falcons use cues due to the apparent motion of prey on the falcon's visual field to track and capture flying prey via a form of motion camouflage. The falcons also were found to maintain their prey's image at visual angles consistent with using their shallow fovea. Results for goshawks and red-tailed hawks were analyzed for a comparative study of how pursuits of ground-based prey by accipeters and buteos differ from those used by falcons chasing flying prey. These results should prove relevant for understanding the coevolution of pursuit and evasion, as well as the development of computer models of predation on flocks,and the integration of sensory and locomotion systems in biomimetic robots.

  14. A COLQ Missense Mutation in Sphynx and Devon Rex Cats with Congenital Myasthenic Syndrome.

    Directory of Open Access Journals (Sweden)

    Marie Abitbol

    Full Text Available An autosomal recessive neuromuscular disorder characterized by skeletal muscle weakness, fatigability and variable electromyographic or muscular histopathological features has been described in the two related Sphynx and Devon Rex cat breeds (Felis catus. Collection of data from two affected Sphynx cats and their relatives pointed out a single disease candidate region on feline chromosome C2, identified following a genome-wide SNP-based homozygosity mapping strategy. In that region, we further identified COLQ (collagen-like tail subunit of asymmetric acetylcholinesterase as a good candidate gene, since COLQ mutations were identified in affected humans and dogs with endplate acetylcholinesterase deficiency leading to a synaptic form of congenital myasthenic syndrome (CMS. A homozygous c.1190G>A missense variant located in exon 15 of COLQ, leading to a C397Y substitution, was identified in the two affected cats. C397 is a highly-conserved residue from the C-terminal domain of the protein; its mutation was previously shown to produce CMS in humans, and here we confirmed in an affected Sphynx cat that it induces a loss of acetylcholinesterase clustering at the neuromuscular junction. Segregation of the c.1190G>A variant was 100% consistent with the autosomal recessive mode of inheritance of the disorder in our cat pedigree; in addition, an affected, unrelated Devon Rex cat recruited thereafter was also homozygous for the variant. Genotyping of a panel of 333 cats from 14 breeds failed to identify a single carrier in non-Sphynx and non-Devon Rex cats. Finally, the percentage of healthy carriers in a European subpanel of 81 genotyped Sphynx cats was estimated to be low (3.7% and 14 control Devon Rex cats were genotyped as wild-type individuals. Altogether, these results strongly support that the neuromuscular disorder reported in Sphynx and Devon Rex breeds is a CMS caused by a unique c.1190G>A missense mutation, presumably transmitted through a

  15. Basic Fibroblast Growth Factor Regulates REX1 Expression Via IL-6 In Stem Cells Isolated From Human Exfoliated Deciduous Teeth.

    Science.gov (United States)

    Nowwarote, Nunthawan; Sukarawan, Waleerat; Pavasant, Prasit; Osathanon, Thanaphum

    2017-06-01

    Basic fibroblast growth factor (bFGF) regulates pluripotent marker expression and cellular differentiation in various cell types. However, the mechanism by which bFGF regulates REX1 expression in stem cells, isolated from human exfoliated deciduous teeth (SHEDs) remains unclear. The aim of the present study was to investigate the regulation of REX1 expression by bFGF in SHEDs. SHEDs were isolated and characterized. Their mRNA and protein expression levels were determined using real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. In some experiments, chemical inhibitors were added to the culture medium to impede specific signaling pathways. Cells isolated from human exfoliated deciduous tooth dental pulp tissue expressed mesenchymal stem cell surface markers (CD44, CD73, CD90, and CD105). These cells differentiated into osteogenic and adipogenic lineages, when appropriately induced. Treating SHEDs with bFGF induced REX1 mRNA expression and this effect was attenuated by pretreatment with FGFR or Akt inhibitors. Cycloheximide pretreatment also inhibited the bFGF-induced REX1 expression, implying the involvement of intermediate molecule(s). Further, the addition of an IL-6 neutralizing antibody attenuated the bFGF-induced REX1 expression by SHEDs. In conclusion, bFGF enhanced REX1 expression by SHEDs via the FGFR and Akt signaling pathways. Moreover, IL-6 participated in the bFGF-induced REX1 expression in SHEDs. J. Cell. Biochem. 118: 1480-1488, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  16. Stephen Hawking's Community-Bound Voice A Functional Investigation of Self-Mentions in Stephen Hawking's Scientific Prose

    Directory of Open Access Journals (Sweden)

    Davud Kuhi

    2015-11-01

    Full Text Available Thanks to the development of the concept of metadiscourse, it is now widely acknowledged that academic/scientific writing is not only concerned with communicating purely propositional meanings: what is communicated through academic/scientific communication is seen to be intertwined with the negotiation of social and interpersonal meanings. While a large number of so called metadiscoursal resources contribute to the simultaneous negotiation of propositional and interpersonal meanings, the present study aimed at investigating the functions self-mention forms can fulfill in academic/scientific communication. Two of Stephen Hawking's scientific books were selected as the corpus of the research, and based on Tang and John's (1999 model, the constructed corpus was analyzed in terms of the functions self-mention forms can fulfill in academic/scientific writing. The findings revealed that from among the different roles identified by Tang and John, the representative role constituted the most frequent self-mention function in the corpus. The remarkably heavy presence of representative role in Hawking's scientific prose was interpreted as a further evidence for the claim that scientists are more likely to persuade readers of their ideas if they frame their messages in ways which appeal to appropriate community-recognized relationships.

  17. Effect of solute immobilization on the stability problem within the fractional model in the solute analog of the Horton-Rogers-Lapwood problem.

    Science.gov (United States)

    Klimenko, Lyudmila S; Maryshev, Boris S

    2017-11-24

    The paper is devoted to the linear stability analysis within the solute analogue of the Horton-Rogers-Lapwood (HRL) problem. The solid nanoparticles are treated as solute within the continuous approach. Therefore, we consider the infinite horizontal porous layer saturated with a mixture (carrier fluid and solute). Solute transport in porous media is very often complicated by solute immobilization on a solid matrix of porous media. Solute immobilization (solute sorption) is taken into account within the fractal model of the MIM approach. According to this model a solute in porous media immobilizes within random time intervals and the distribution of such random variable does not have a finite mean value, which has a good agreement with some experiments. The solute concentration difference between the layer boundaries is assumed as constant. We consider two cases of horizontal external filtration flux: constant and time-modulated. For the constant flux the system of equations that determines the frequency of neutral oscillations and the critical value of the Rayleigh-Darcy number is derived. Neutral curves of the critical parameters on the governing parameters are plotted. Stability maps are obtained numerically in a wide range of parameters of the system. We have found that taking immobilization into account leads to an increase in the critical value of the Rayleigh-Darcy number with an increase in the intensity of the external filtration flux. The case of weak time-dependent external flux is investigated analytically. We have shown that the modulated external flux leads to an increase in the critical value of the Rayleigh-Darcy number and a decrease in the critical wave number. For moderate time-dependent filtration flux the differential equation with Caputo fractional derivatives has been obtained for the description of the behavior near the convection instability threshold. This equation is analyzed numerically by the Floquet method; the parametric excitation of

  18. Backreaction of Hawking radiation on a gravitationally collapsing star I: Black holes?

    Directory of Open Access Journals (Sweden)

    Laura Mersini-Houghton

    2014-11-01

    Full Text Available Particle creation leading to Hawking radiation is produced by the changing gravitational field of the collapsing star. The two main initial conditions in the far past placed on the quantum field from which particles arise, are the Hartle–Hawking vacuum and the Unruh vacuum. The former leads to a time-symmetric thermal bath of radiation, while the latter to a flux of radiation coming out of the collapsing star. The energy of Hawking radiation in the interior of the collapsing star is negative and equal in magnitude to its value at future infinity. This work investigates the backreaction of Hawking radiation on the interior of a gravitationally collapsing star, in a Hartle–Hawking initial vacuum. It shows that due to the negative energy Hawking radiation in the interior, the collapse of the star stops at a finite radius, before the singularity and the event horizon of a black hole have a chance to form. That is, the star bounces instead of collapsing to a black hole. A trapped surface near the last stage of the star's collapse to its minimum size may still exist temporarily. Its formation depends on the details of collapse. Results for the case of Hawking flux of radiation with the Unruh initial state, will be given in a companion paper II.

  19. Nesting ecology and behavior of Broad-winged Hawks in moist karst forests of Puerto Rico

    Science.gov (United States)

    Hengstenberg, D.W.; Vilella, F.J.

    2005-01-01

    The Puerto Rican Broad-winged Hawk (Buteo platypterus brunnescens) is an endemic and endangered subspecies inhabiting upland montane forests of Puerto Rico. The reproductive ecology, behavior, and nesting habitat of the Broad-winged Hawk were studied in Ri??o Abajo Forest, Puerto Rico, from 2001-02. We observed 158 courtship displays by Broad-winged Hawks. Also, we recorded 25 territorial interactions between resident Broad-winged Hawks and intruding Red-tailed Hawks (Buteo jamaicensis jamaicensis). Broad-winged Hawks displaced intruding Red-tailed Hawks from occupied territories (P = 0.009). Mayfield nest survival was 0.67 across breeding seasons (0.81 in 2001, N = 6; 0.51 in 2002, N = 4), and pairs averaged 1.1 young per nest (years combined). The birds nested in mixed species timber plantations and mature secondary forest. Nests were placed in the upper reaches of large trees emerging from the canopy. Nest tree DBH, understory stem density, and distance to karst cliff wall correctly classified (77.8%) nest sites. ?? 2005 The Raptor Research Foundation, Inc.

  20. Hartle-Hawking wave function and large-scale power suppression of CMB

    Science.gov (United States)

    Yeom, Dong-han

    2018-01-01

    In this presentation, we first describe the Hartle-Hawking wave function in the Euclidean path integral approach. After we introduce perturbations to the background instanton solution, following the formalism developed by Halliwell-Hawking and Laflamme, one can obtain the scale-invariant power spectrum for small-scales. We further emphasize that the Hartle-Hawking wave function can explain the large-scale power suppression by choosing suitable potential parameters, where this will be a possible window to confirm or falsify models of quantum cosmology. Finally, we further comment on possible future applications, e.g., Euclidean wormholes, which can result in distinct signatures to the power spectrum.

  1. The hawk/goose story: the classical ethological experiments of Lorenz and Tinbergen, revisited.

    Science.gov (United States)

    Schleidt, Wolfgang; Shalter, Michael D; Moura-Neto, Humberto

    2011-05-01

    We present a historical account of the story behind the famous hawk/goose experiments of Lorenz and Tinbergen in a wider context of cognitive ethology. We discuss their significance, for ethological experimentation in general, and specifically for understanding innate constraints on cognition. As examples of the continuing significance of the hawk/goose paradigm of selective habituation, we discuss its relation to "exposure therapy" of human phobias and the use of hawk silhouettes as deterrents for songbirds. Finally we rephrase Uexküll's thesis of taxon-specific worlds ("Umwelten") as a "Theory of World." 2011 APA, all rights reserved

  2. The imprint of the Hawking effect in subcritical flows

    CERN Document Server

    Coutant, Antonin

    2016-01-01

    We study the propagation of low frequency shallow water waves on a one dimensional flow of varying depth. When taking into account dispersive effects, the linear propagation of long wavelength modes on uneven bottoms excites new solutions of the dispersion relation which possess a much shorter wavelength. The peculiarity is that one of these new solutions has a negative energy. When the flow becomes supercritical, this mode has been shown to be responsible for the (classical) analog of the Hawking effect. For subcritical flows, the production of this mode has been observed numerically and experimentally, but the precise physics governing the scattering remained unclear. In this work, we provide an analytic treatment of this effect in subcritical flows. We analyze the scattering of low frequency waves using a new perturbative series, derived from a generalization of the Bremmer series. We show that the production of short wavelength modes is governed by a complex value of the position: a complex turning point....

  3. Geometry of Nash Equilibrium in Quantum Hawk-Dove Games

    Directory of Open Access Journals (Sweden)

    Faisal Shah Khan

    2011-08-01

    Full Text Available A game is said to be “quantized" when the expected payoff to the player(s is computed via the higher order randomization notion of quantum superposition followed by measurement versus the randomization notion of probability distribution. A major motivation for quantizing a game is the potential manifestation of Nash equilibria that are superior to those already available in the game. Quantum superpositions are elements of a (projective Hilbert space which, among other things, is an inner product space. The inner product of the Hilbert space of quantum superpositions is used here to give a geometric characterization of Nash equilibrium in quantized versions of Hawk-Dove games, a class of games to which the well known game Prisoners

  4. Dark Spinors Hawking Radiation in String Theory Black Holes

    Directory of Open Access Journals (Sweden)

    R. T. Cavalcanti

    2016-01-01

    Full Text Available The Hawking radiation spectrum of Kerr-Sen axion-dilaton black holes is derived, in the context of dark spinors tunnelling across the horizon. Since a black hole has a well defined temperature, it should radiate in principle all the standard model particles, similar to a black body at that temperature. We investigate the tunnelling of mass dimension one spin-1/2 dark fermions, which are beyond the standard model and are prime candidates to the dark matter. Their interactions with the standard model matter and gauge fields are suppressed by at least one power of unification scale, being restricted just to the Higgs field and to the graviton likewise. The tunnelling method for the emission and absorption of mass dimension one particles across the event horizon of Kerr-Sen axion-dilaton black holes is shown here to provide further evidence for the universality of black hole radiation, further encompassing particles beyond the standard model.

  5. Mate replacement and alloparental care in Ferruginous Hawk (Buteo regalis)

    Science.gov (United States)

    Datta, Shubham; Inselman, Will M.; Jenks, Jonathan A.; Jensen, Kent C.; Swanson, Christopher C.; Klaver, Robert W.; Sasmal, Indrani; Grovenburg, Troy W.

    2015-01-01

    Alloparental care (i.e., care for unrelated offspring) has been documented in various avian species (Maxson 1978, Smith et al. 1996, Tella et al. 1997, Lislevand et al. 2001, Literak and Mraz 2011). A male replacement mate that encounters existing broods has options, which include alloparental care or infanticide. Infanticide may be beneficial in some species (Rohwer 1986, Kermott et al. 1990), but in long-lived avian species, like the ferruginous hawk (Buteo regalis) that do not renest within a season, infanticide might be detrimental. Adoption and rearing success likely provide direct evidence of competence of replacement mates as potential parents for future seasons, a benefit that might outweigh the investment of time and effort associated with adoption and rearing (after Rohwer 1986). Anticipated mating opportunity at the cost of adoption (Gori et al. 1996, Rohwer et al. 1999) may explain step-parental benevolence and therefore, in such a scenario would enhance individual fitness through subsequent recruitment of related young.

  6. Chlamydiosis in a red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Mirandé, L A; Howerth, E W; Poston, R P

    1992-04-01

    A red-tailed hawk (Buteo jamaicensis) with signs of respiratory distress and diarrhea was captured in the Manchac Wildlife Management Area, Louisiana (USA) and died the following day. At necropsy, the carcass was emaciated and there were splenomegaly, and fibrinous pericarditis, airsacculitis, and perihepatitis. Microscopically, there were fibrinous pericarditis and airsacculitis, myocardial necrosis, necrotizing hepatitis, splenic necrosis with reticuloendothelial cell hyperplasia, interstitial pneumonia and focal pancreatic necrosis. Intracytoplasmic chlamydial inclusion bodies were noticed in macrophages in the fibrinous exudate covering air sac and pericardium, and in spleen, liver, heart, lung, and pancreas. Schizonts compatible with a Sarcocystis sp.-like protozoon were present in the walls of air capillaries in the lung. A Chlamydia sp.-like organism was isolated in embryonating chicken eggs and cell culture and identified as C. psittaci with immunofluorescent staining.

  7. Comprehensive study of endurance for IAR-99 Hawk

    Directory of Open Access Journals (Sweden)

    Dorin LOZICI-BRINZEI

    2014-03-01

    Full Text Available The paper presents some methods of on-ground and in-flight calibration for strain gauges, intended to the development of complex programs which analyze the endurance phenomena for aerospace structures, with direct application to the IAR-99 Hawk. The strain gauges have the advantage of being sensitive to load and therefore to aerodynamic phenomena, thereby providing indications of the loads supported by the structure. The effects size of loads type phenomena caused by wind gusts or buffet can be measured only by strain gauges or accelerometres70 and they cannot be recorded by flight or fatigue parameters counters. The installation of a strain gauge is made using a pattern (its position and orientation are crucial and the strain gauge selected for installation should not be fragile or unstable. Routines should be established for periodic inspection of strain gauges and those which are defective should be replaced immediately.

  8. Some considerations about NS5 and LST Hawking radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lorente-Espin, Oscar, E-mail: oscar.lorente-espin@upc.edu [Departament de Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, Comte Urgell 187, E-08036 Barcelona (Spain)

    2011-09-26

    We have studied the Hawking radiation corresponding to the NS5 and Little String Theory (LST) black hole models using two semi-classical methods: the complex path method and a gravitational anomaly. After summarizing some known concepts about the thermodynamics of these theories, we have computed the emission rates for the two black hole models. The temperature calculated from, e.g. the well-known surface gravity expression, is shown to be identical to that obtained from both the computation of the gravitational anomaly and the complex path method. Moreover, the two semi-classical methods show that NS5 exhibits non-thermal behavior that contrasts with the thermal behavior of LST. We remark that energy conservation is the key factor leading to a non-thermal profile for NS5. In contrast, LST keeps a thermal profile even when energy conservation is considered because temperature in this model does not depend on energy.

  9. Christopher Hawkes and the International Summer Courses of Ampurias

    Directory of Open Access Journals (Sweden)

    Margarita Díaz-Andreu

    2007-05-01

    Full Text Available This article aims to provide an initial analysis of the early connections between Christopher Hawkes and Spanish archaeology in the context of his participation in two of the international summer courses in Ampurias in 1947 and 1950. The documentation used for this article comes mainly from the Pericot Archive in the Library of Catalonia, in which there are 43 letters from Hawkes to Pericot between 1940 and 1975. In addition, other correspondence in the British Museum and in the Ministry of Foreign Affairs will be mentioned. This study forms part of a larger project of recovering the memory of twentieth-century British-Spanish relations, of which a first phase has centred on the assessment of Gordon Childe’s contacts with Spain (Díaz-Andreu 1998; forthcoming–a; forthcoming–b. As in Gordon Childe’s case, all memory of Hawkes’ visits, and indeed of his relationships with Spanish archaeologists, has since been lost. Unfortunately, this situation is not exceptional: most of the links between Spanish archaeologists and British and American archaeologists in the twenty years around the Spanish Civil War have dropped out of archaeological memory. To the names mentioned in a recent seminar (Gordon Childe, Edward Thurlow Leeds, Eoin MacWhite, Hubert Savory (Armada Pita 2006, many others could be added. As this article will show, however, there were many contacts and these help to explain some developments in the archaeological thinking and practice of the participants involved in these exchanges, as well as some events in the international organisation of archaeology.

  10. PmiRExAt: plant miRNA expression atlas database and web applications.

    Science.gov (United States)

    Gurjar, Anoop Kishor Singh; Panwar, Abhijeet Singh; Gupta, Rajinder; Mantri, Shrikant S

    2016-01-01

    High-throughput small RNA (sRNA) sequencing technology enables an entirely new perspective for plant microRNA (miRNA) research and has immense potential to unravel regulatory networks. Novel insights gained through data mining in publically available rich resource of sRNA data will help in designing biotechnology-based approaches for crop improvement to enhance plant yield and nutritional value. Bioinformatics resources enabling meta-analysis of miRNA expression across multiple plant species are still evolving. Here, we report PmiRExAt, a new online database resource that caters plant miRNA expression atlas. The web-based repository comprises of miRNA expression profile and query tool for 1859 wheat, 2330 rice and 283 maize miRNA. The database interface offers open and easy access to miRNA expression profile and helps in identifying tissue preferential, differential and constitutively expressing miRNAs. A feature enabling expression study of conserved miRNA across multiple species is also implemented. Custom expression analysis feature enables expression analysis of novel miRNA in total 117 datasets. New sRNA dataset can also be uploaded for analysing miRNA expression profiles for 73 plant species. PmiRExAt application program interface, a simple object access protocol web service allows other programmers to remotely invoke the methods written for doing programmatic search operations on PmiRExAt database.Database URL:http://pmirexat.nabi.res.in. © The Author(s) 2016. Published by Oxford University Press.

  11. Development of system analysis code for thermal-hydraulic simulation of integral reactor, Rex-10

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-10-15

    Rex-10 is an environment-friendly and economical small-scale nuclear reactor to provide the energy for district heating as well as the electric power in micro-grid. This integral reactor comprises several innovative concepts supported by advanced primary circuit components, low coolant parameters and natural circulation cooling. To evaluate the system performance and thermal-hydraulic behavior of the reactor, a system analysis code is being developed so that the new designs and technologies adopted in Rex-10 can be reflected. The research efforts are absorbed in programming the simple and fast-running thermal-hydraulic analysis software. The details of hydrodynamic governing equations component models and numerical solution scheme used in this code are presented in this paper. On the basis of one-dimensional momentum integral model, the models of point reactor neutron kinetics for thorium-fueled core, physical processes in the steam-gas pressurizer, and heat transfers in helically coiled steam generator are implemented to the system code. Implicit numerical scheme is employed to momentum and energy equations to assure the numerical stability. The accuracy of simulation is validated by applying the solution method to the Rex-10 test facility. Calculated natural circulation flow rate and coolant temperature at steady-state are compared to the experimental data. The validation is also carried out for the transients in which the sudden reduction in the core power or the feedwater flow takes place. The code's capability to predict the steady-state flow by natural convection and the qualitative behaviour of the primary system in the transients is confirmed. (Author)

  12. T-REX on-demand redox targeting in live cells.

    Science.gov (United States)

    Parvez, Saba; Long, Marcus J C; Lin, Hong-Yu; Zhao, Yi; Haegele, Joseph A; Pham, Vanha N; Lee, Dustin K; Aye, Yimon

    2016-12-01

    This protocol describes targetable reactive electrophiles and oxidants (T-REX)-a live-cell-based tool designed to (i) interrogate the consequences of specific and time-resolved redox events, and (ii) screen for bona fide redox-sensor targets. A small-molecule toolset comprising photocaged precursors to specific reactive redox signals is constructed such that these inert precursors specifically and irreversibly tag any HaloTag-fused protein of interest (POI) in mammalian and Escherichia coli cells. Syntheses of the alkyne-functionalized endogenous reactive signal 4-hydroxynonenal (HNE(alkyne)) and the HaloTag-targetable photocaged precursor to HNE(alkyne) (also known as Ht-PreHNE or HtPHA) are described. Low-energy light prompts photo-uncaging (t1/2 <1-2 min) and target-specific modification. The targeted modification of the POI enables precisely timed and spatially controlled redox events with no off-target modification. Two independent pathways are described, along with a simple setup to functionally validate known targets or discover novel sensors. T-REX sidesteps mixed responses caused by uncontrolled whole-cell swamping with reactive signals. Modification and downstream response can be analyzed by in-gel fluorescence, proteomics, qRT-PCR, immunofluorescence, fluorescence resonance energy transfer (FRET)-based and dual-luciferase reporters, or flow cytometry assays. T-REX targeting takes 4 h from initial probe treatment. Analysis of targeted redox responses takes an additional 4-24 h, depending on the nature of the pathway and the type of readouts used.

  13. Touch And Go Camera System (TAGCAMS) for the OSIRIS-REx Asteroid Sample Return Mission

    Science.gov (United States)

    Bos, B. J.; Ravine, M. A.; Caplinger, M.; Schaffner, J. A.; Ladewig, J. V.; Olds, R. D.; Norman, C. D.; Huish, D.; Hughes, M.; Anderson, S. K.; Lorenz, D. A.; May, A.; Jackman, C. D.; Nelson, D.; Moreau, M.; Kubitschek, D.; Getzandanner, K.; Gordon, K. E.; Eberhardt, A.; Lauretta, D. S.

    2018-02-01

    NASA's OSIRIS-REx asteroid sample return mission spacecraft includes the Touch And Go Camera System (TAGCAMS) three camera-head instrument. The purpose of TAGCAMS is to provide imagery during the mission to facilitate navigation to the target asteroid, confirm acquisition of the asteroid sample, and document asteroid sample stowage. The cameras were designed and constructed by Malin Space Science Systems (MSSS) based on requirements developed by Lockheed Martin and NASA. All three of the cameras are mounted to the spacecraft nadir deck and provide images in the visible part of the spectrum, 400-700 nm. Two of the TAGCAMS cameras, NavCam 1 and NavCam 2, serve as fully redundant navigation cameras to support optical navigation and natural feature tracking. Their boresights are aligned in the nadir direction with small angular offsets for operational convenience. The third TAGCAMS camera, StowCam, provides imagery to assist with and confirm proper stowage of the asteroid sample. Its boresight is pointed at the OSIRIS-REx sample return capsule located on the spacecraft deck. All three cameras have at their heart a 2592 × 1944 pixel complementary metal oxide semiconductor (CMOS) detector array that provides up to 12-bit pixel depth. All cameras also share the same lens design and a camera field of view of roughly 44° × 32° with a pixel scale of 0.28 mrad/pixel. The StowCam lens is focused to image features on the spacecraft deck, while both NavCam lens focus positions are optimized for imaging at infinity. A brief description of the TAGCAMS instrument and how it is used to support critical OSIRIS-REx operations is provided.

  14. Combined Rex-bypass shunt with pericardial devascularization alleviated prehepatic portal hypertension caused by cavernomatous transformation of portal vein.

    Science.gov (United States)

    Wang, Ruo-Yi; Wang, Jun-Feng; Liu, Qian; Ma, Nan; Chen, Wei-Xiu; Li, Jin-Liang

    2017-09-01

    To evaluate the effects of combined Rex-bypass shunt and pericardial devascularization on prehepatic portal hypertension secondary to cavernomatous transformation of portal vein (CTPV). Forty-two patients aged from 3 years to 49 years (divided into 3 groups), 26 cases male and 16 female, with prehepatic vascular hepertention were treated with Rex-bypass shunt combined with pericardial devascularization. In each patient, preoperative assessment included ultrasound and computed tomographic angiography of the portal vein and blood analysis. The procedure was Rex-bypass shunt (with or without graft), and patients with moderate or severe gastroesophageal varices required additional paraesophagogastric devascularization. Splenectomy or subtotal splenectomy was performed if combined hypersplenism co-existed. All data were analyzed retrospectively. No intraoperative death occurred, blood routine analysis improved (P portal vein (LPV) significantly increased, the esophageal and gastric varices significantly relieved in 34 patients (P portal hypertension caused by CTPV.

  15. Use Of REX Control System For The Ball On Spool Model

    Science.gov (United States)

    Ožana, Štěpán; Pieš, Martin; Hájovský, Radovan; Dočekal, Tomáš

    2015-07-01

    This paper deals with the design and implementation of linear quadratic controller (LQR) for modeling of Ball on Spool. The paper presents the entire process, starting from mathematical model through control design towards application of controller with the use of given hardware platform. Proposed solution by means of REX Control System provides a high level of user comfort regarding implementation of control loop, diagnostics and automatically generated visualization based on HTML5. It represents an ideal example of a complex nonlinear mechatronic system with a lot of possibilities to apply other types of controllers.

  16. Asteroid Bennu Temperature Maps for OSIRIS-REx Spacecraft and Instrument Thermal Analyses

    Science.gov (United States)

    Choi, Michael K.; Emery, Josh; Delbo, Marco

    2014-01-01

    A thermophysical model has been developed to generate asteroid Bennu surface temperature maps for OSIRIS-REx spacecraft and instrument thermal design and analyses at the Critical Design Review (CDR). Two-dimensional temperature maps for worst hot and worst cold cases are used in Thermal Desktop to assure adequate thermal design margins. To minimize the complexity of the Bennu geometry in Thermal Desktop, it is modeled as a sphere instead of the radar shape. The post-CDR updated thermal inertia and a modified approach show that the new surface temperature predictions are more benign. Therefore the CDR Bennu surface temperature predictions are conservative.

  17. Study of Effect of Ion Source Energy Spread on RFQ Beam Dynamics at REX-ISOLDE

    CERN Document Server

    Fraser, M A

    2013-01-01

    With an upgrade to the Electron Beam Ion Source (EBIS) at REX under consideration a study was launched in order to understand the effect of an increased energy spread from the ion source on the beam dynamics of the RFQ. Due to the increased electron beam potential needed to achieve the upgrade’s charge breeding specification it is expected that the energy spread of the beam will increase from today’s estimated value of approximately +-0.1%. It is shown through beam dynamics simulations that the energy spread can be increased to +-1% without significant degradation of the beam quality output by the RFQ.

  18. Tau-REx: A new look at the retrieval of exoplanetary atmospheres

    Science.gov (United States)

    Waldmann, Ingo

    2014-11-01

    The field of exoplanetary spectroscopy is as fast moving as it is new. With an increasing amount of space and ground based instruments obtaining data on a large set of extrasolar planets we are indeed entering the era of exoplanetary characterisation. Permanently at the edge of instrument feasibility, it is as important as it is difficult to find the most optimal and objective methodologies to analysing and interpreting current data. This is particularly true for smaller and fainter Earth and Super-Earth type planets.For low to mid signal to noise (SNR) observations, we are prone to two sources of biases: 1) Prior selection in the data reduction and analysis; 2) Prior constraints on the spectral retrieval. In Waldmann et al. (2013), Morello et al. (2014) and Waldmann (2012, 2014) we have shown a prior-free approach to data analysis based on non-parametric machine learning techniques. Following these approaches we will present a new take on the spectral retrieval of extrasolar planets. Tau-REx (tau-retrieval of exoplanets) is a new line-by-line, atmospheric retrieval framework. In the past the decision on what opacity sources go into an atmospheric model were usually user defined. Manual input can lead to model biases and poor convergence of the atmospheric model to the data. In Tau-REx we have set out to solve this. Through custom built pattern recognition software, Tau-REx is able to rapidly identify the most likely atmospheric opacities from a large number of possible absorbers/emitters (ExoMol or HiTran data bases) and non-parametrically constrain the prior space for the Bayesian retrieval. Unlike other (MCMC based) techniques, Tau-REx is able to fully integrate high-dimensional log-likelihood spaces and to calculate the full Bayesian Evidence of the atmospheric models. We achieve this through a combination of Nested Sampling and a high degree of code parallelisation. This allows for an exact and unbiased Bayesian model selection and a fully mapping of potential

  19. Scale Invariant Power Laws Capture the 3-D Coupling Between Water, Energy and Carbon Budgets Across River Basins of Increasing Horton-Strahler Orders in the Andes-Amazon System

    Science.gov (United States)

    Poveda, G.; Zapata, A. F.

    2016-12-01

    The Andes-Amazon system exhibits complex interactions and feedbacks between hydrological, ecological, biogeochemical and climatic factors in a broad range of temporal and spatial scales. We aim to understand the coupling existing between water, energy and carbon budgets in the Andes-Amazon system, by performing a systematic study of the system for river basins of increasing Horton-Strahler orders, from the headwaters of the Amazon River basin along the Andes (order ω=1 river sub-basins) to the low-lying larger river sub-basins (order ω=10). To that end, this works introduces a 3-D generalization of the Budyko framework that aims to link the water, energy, and Carbon budgets in river basins. The newly proposed 3-D non-dimensional space is defined by: (1) the ratio between long-term mean values of Actual Evapotranspiration (AET) and Precipitation (P), α=AET/P, representing the water balance; (2) the ratio between AET and Potential Evapotranspiration (PET), β=AET/PET, representing the energy balance; and (3) the ratio between AET and Aboveground Net Primary Productivity, δ=AET/ANPP, representing the carbon budget. We use a 3" Digital Elevation Model (DEM), which allows defining river basins with Horton-Strahler orders from 1 to 10. The long-term water, energy, and carbon budgets are estimated for increasing values of the Horton-Strahler orders during the period 1987-2007. Data sets pertaining to the water balance come from ORE-HYBAM, potential evapotranspiration (PET) from GLEAM (Global Land-surface Evaporation: the Amsterdam Methodology). Data for the energy budget are from the Surface Radiation Budget (SRB). Data for the Carbon budget (annual mean net primary productivity, ANPP, gross primary productivity, GPP, and respiration rates, Rr, come from AMAZALERT and ORCHEDEE (Organizing Carbon and Hydrology In Dynamic EcosystEms), as well as from Flux Tower Data and the LBA project. Our results show that scale invariant power-laws emerge to capture the three 2-D

  20. The GUP effect on Hawking radiation of the 2 + 1 dimensional black hole

    Science.gov (United States)

    Gecim, Ganim; Sucu, Yusuf

    2017-10-01

    We investigate the Generalized Uncertainty Principle (GUP) effect on the Hawking radiation of the 2 + 1 dimensional Martinez-Zanelli black hole by using the Hamilton-Jacobi method. In this connection, we discuss the tunneling probabilities and Hawking temperature of the spin-1/2 and spin-0 particles for the black hole. Therefore, we use the modified Klein-Gordon and Dirac equations based on the GUP. Then, we observe that the Hawking temperature of the scalar and Dirac particles depend on not only the black hole properties, but also the properties of the tunneling particle, such as angular momentum, energy and mass. And, in this situation, we see that the tunneling probability and the Hawking radiation of the Dirac particle is different from that of the scalar particle.

  1. Information-carrying Hawking radiation and the number of microstate for a black hole

    Directory of Open Access Journals (Sweden)

    Qing-yu Cai

    2016-04-01

    Full Text Available We present a necessary and sufficient condition to falsify whether a Hawking radiation spectrum indicates unitary emission process or not from the perspective of information theory. With this condition, we show the precise values of Bekenstein–Hawking entropies for Schwarzschild black holes and Reissner–Nordström black holes can be calculated by counting the microstates of their Hawking radiations. In particular, for the extremal Reissner–Nordström black hole, its number of microstate and the corresponding entropy we obtain are found to be consistent with the string theory results. Our finding helps to refute the dispute about the Bekenstein–Hawking entropy of extremal black holes in the semiclassical limit.

  2. GRIP NOAA GLOBAL HAWK IN-FLIGHT TURBULENCE SENSOR (GHIS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NOAA Global Hawk In-flight Turbulence Sensor (GHIS) instrument measures acceleration at the location of the instrument. Two accelerometers (2g and 5g full scale)...

  3. Differential Migration between Discrete Populations of Juvenile Red-Tailed Hawks (Buteo jamaicensis)

    National Research Council Canada - National Science Library

    Joshua M. Hull; Holly B. Ernest; Jill A. Harley; Allen M. Fish; Angus C. Hull

    2009-01-01

    .... We used 24 years of banding data, 15 years of migration counts, and molecular genetic data from 17 microsatellite loci to describe the migration phenology, direction, and population connectivity of Red-tailed Hawks (Buteo jamaicensis...

  4. Information-carrying Hawking radiation and the number of microstate for a black hole

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Qing-yu, E-mail: qycai@wipm.ac.cn [State Key Laboratory of Magnetic Resonances and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Sun, Chang-pu, E-mail: cpsun@csrc.ac.cn [Beijing Computational Science Research Center, Beijing 100084 (China); Collaborative Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); You, Li, E-mail: lyou@mail.tsinghua.edu.cn [State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

    2016-04-15

    We present a necessary and sufficient condition to falsify whether a Hawking radiation spectrum indicates unitary emission process or not from the perspective of information theory. With this condition, we show the precise values of Bekenstein–Hawking entropies for Schwarzschild black holes and Reissner–Nordström black holes can be calculated by counting the microstates of their Hawking radiations. In particular, for the extremal Reissner–Nordström black hole, its number of microstate and the corresponding entropy we obtain are found to be consistent with the string theory results. Our finding helps to refute the dispute about the Bekenstein–Hawking entropy of extremal black holes in the semiclassical limit.

  5. Higgs v Hawking: a battle of the heavyweights that has shaken the world of theoretical physics

    CERN Multimedia

    Connor, S

    2002-01-01

    Stephen Hawking was accused yesterday of receiving instant credibility because of his celebrity status. His accuser was Professor Peter Higgs, who predicted the existence of the elementary particle, the Higgs Boson, in the 1960s (1 page).

  6. HURRICANE AND SEVERE STORM SENTINEL (HS3) GLOBAL HAWK NAVIGATION V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Hurricane and Severe Storm Sentinel (HS3) Global Hawk Navigation dataset consists of the real-time navigation and housekeeping data that was acquired from...

  7. Feeling the Hawks: Why an anti-corruption agency should not be in ...

    African Journals Online (AJOL)

    Hawks', is currently at a crossroads. The Constitutional Court judgment in Glenister vs the President of South Africa and Others has called into question the Directorate's continued existence in its current form. One of the most important questions ...

  8. HURRICANE AND SEVERE STORM SENTINEL (HS3) GLOBAL HAWK CLOUD PHYSICS LIDAR (CPL) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Hurricane and Severe Storm Sentinel (HS3) Global Hawk Cloud Physics Lidar (CPL) dataset includes measurements gathered by the CPL instrument during the HS3...

  9. A computational analysis of limb and body dimensions in Tyrannosaurus rex with implications for locomotion, ontogeny, and growth.

    Science.gov (United States)

    Hutchinson, John R; Bates, Karl T; Molnar, Julia; Allen, Vivian; Makovicky, Peter J

    2011-01-01

    The large theropod dinosaur Tyrannosaurus rex underwent remarkable changes during its growth from 6000 kg adults in muscle sizes as well as the body's centre of mass that could have influenced ontogenetic changes of locomotion in T. rex. Here we address these questions using three-dimensionally scanned computer models of four large, well-preserved fossil specimens as well as a putative juvenile individual. Furthermore we quantify the variations of estimated body mass, centre of mass and segment dimensions, to characterize inaccuracies in our reconstructions. These inaccuracies include not only subjectivity but also incomplete preservation and inconsistent articulations of museum skeletons. Although those problems cause ambiguity, we conclude that adult T. rex had body masses around 6000-8000 kg, with the largest known specimen ("Sue") perhaps ∼9500 kg. Our results show that during T. rex ontogeny, the torso became longer and heavier whereas the limbs became proportionately shorter and lighter. Our estimates of peak growth rates are about twice as rapid as previous ones but generally support previous methods, despite biases caused by the usage of scale models and equations that underestimate body masses. We tentatively infer that the hindlimb extensor muscles masses, including the large tail muscle M. caudofemoralis longus, may have decreased in their relative size as the centre of mass shifted craniodorsally during T. rex ontogeny. Such ontogenetic changes would have worsened any relative or absolute decline of maximal locomotor performance. Regardless, T. rex probably had hip and thigh muscles relatively larger than any extant animal's. Overall, the limb "antigravity" muscles may have been as large as or even larger than those of ratite birds, which themselves have the most muscular limbs of any living animal.

  10. A computational analysis of limb and body dimensions in Tyrannosaurus rex with implications for locomotion, ontogeny, and growth.

    Directory of Open Access Journals (Sweden)

    John R Hutchinson

    Full Text Available The large theropod dinosaur Tyrannosaurus rex underwent remarkable changes during its growth from 6000 kg adults in <20 years. These changes raise fascinating questions about the morphological transformations involved, peak growth rates, and scaling of limb muscle sizes as well as the body's centre of mass that could have influenced ontogenetic changes of locomotion in T. rex. Here we address these questions using three-dimensionally scanned computer models of four large, well-preserved fossil specimens as well as a putative juvenile individual. Furthermore we quantify the variations of estimated body mass, centre of mass and segment dimensions, to characterize inaccuracies in our reconstructions. These inaccuracies include not only subjectivity but also incomplete preservation and inconsistent articulations of museum skeletons. Although those problems cause ambiguity, we conclude that adult T. rex had body masses around 6000-8000 kg, with the largest known specimen ("Sue" perhaps ∼9500 kg. Our results show that during T. rex ontogeny, the torso became longer and heavier whereas the limbs became proportionately shorter and lighter. Our estimates of peak growth rates are about twice as rapid as previous ones but generally support previous methods, despite biases caused by the usage of scale models and equations that underestimate body masses. We tentatively infer that the hindlimb extensor muscles masses, including the large tail muscle M. caudofemoralis longus, may have decreased in their relative size as the centre of mass shifted craniodorsally during T. rex ontogeny. Such ontogenetic changes would have worsened any relative or absolute decline of maximal locomotor performance. Regardless, T. rex probably had hip and thigh muscles relatively larger than any extant animal's. Overall, the limb "antigravity" muscles may have been as large as or even larger than those of ratite birds, which themselves have the most muscular limbs of any living

  11. Comparative Studies on Bioactive Constituents in Hawk Tea Infusions with Different Maturity Degree and Their Antioxidant Activities

    Directory of Open Access Journals (Sweden)

    Ming Yuan

    2014-01-01

    Full Text Available Hawk tea (Litsea coreana var. lanuginose is a very popular herbal tea in the southwest of China. According to the maturity degree of raw materials, Hawk tea can usually be divided into three types: Hawk bud tea (HB, Hawk primary leaf tea (HP, and Hawk mature leaf tea (HM. In this study, some of the bioactive constituents and antioxidant properties of the three kinds of Hawk tea infusions were comparatively investigated. The results showed that the contents of total flavonoids, vitamin C, and carbohydrates in Hawk bud tea infusion (HBI were higher than those in Hawk primary leaf tea infusion (HPI and Hawk mature leaf tea infusion (HMI. HPI had higher contents of total polyphenols and exhibited better DPPH radical scavenging activity and ferric reducing activity power. HBI could provide more effective protection against erythrocyte hemolysis. As age is going from bud to mature leaf, the ability to inhibit the formation of low density lipoprotein (LDL conjugated diene and the loss of tryptophan fluorescence decreased. The bioactive constituents and antioxidant activities of Hawk tea infusions were significantly affected by the maturity degree of the raw material.

  12. Pathologic findings in red-tailed hawks (Buteo jamaicensis) and Cooper's hawks (Accipiter cooper) naturally infected with West Nile virus.

    Science.gov (United States)

    Wünschmann, Arno; Shivers, Jan; Bender, Jeff; Carroll, Larry; Fuller, Susan; Saggese, Miguel; van Wettere, Arnaud; Redig, Pat

    2004-09-01

    Carcasses of 13 red-tailed hawks (RTHAs) and 11 Cooper's hawks (COHAs) were tested for West Nile virus (WNV) using WNV-specific reverse transcriptase-polymerase chain reaction (RT-PCR) on fresh brain tissue and WNV-specific immunohistochemistry (IHC) on various organs. Ten COHAs (91%) and 11 RTHAs (85%) were positive for WNV RNA by RT-PCR. All 11 COHAs (100%) and 10 RTHAs (77%) were positive for WNV antigen by IHC. A triad of inflammatory lesions, including chronic lymphoplasmacytic and histiocytic encephalitis, endophthalmitis, and myocarditis, was common in both species. In COHAs, the heart (54%), cerebrum (50%), and eye (45%) were the organs that most commonly contained WNV antigen. The amount of WNV antigen was usually small. In RTHAs, the kidney (38%), cerebrum (38%), cerebellum (38%), and eye (36%) were the organs most commonly containing WNV antigen. Unlike COHAs, larger amounts of WNV antigen were present in the cerebrum of RTHAs. WNV antigen was detected in similar cell populations in both species, including neurons of brain, spinal cord, and retina, pigmented epithelial cells of the retina, epithelial cells of renal medullary tubules, cardiomyocytes, endothelial cells and smooth muscle cells of arteries, dendritic cells of splenic lymph follicles, exocrine pancreatic cells, adrenal cells, and keratinocytes of the skin. The study presents strong evidence that WNV can cause a chronic fatal disease in RTHAs and COHAs. The lesion distribution of WNV infection in both species is variable, but inflammatory lesions are common, and a triad of lesions including encephalitis, myocarditis, and endophthalmitis is indicative of WNV infection in both species.

  13. Pain-Suppressed Behaviors in the Red-tailed Hawk 1 (Buteo jamaicensis).

    Science.gov (United States)

    Mazor-Thomas, Jana E; Mann, Phyllis E; Karas, Alicia Z; Tseng, Flo

    2014-03-01

    Our ability to provide analgesia in wild and exotic patients is hampered by a lack of species-specific information on effective drugs and protocols. One contributing factor is the difficulty of applying data from traditional laboratory tests of nociception to clinical conditions frequently involving combinations of inflammatory, mechanical, and neuropathic pain. Pain-suppressed behaviors have become a valuable predictor of clinical utility in other species; in this study we extend this framework to red -tailed hawks in a wildlife hospital, in an attempt to develop a new, humane testing method for birds of prey. We scored six behaviors in hawks hospitalized either for orthopedic trauma or for non-painful conditions. These behaviors included: movement about the cage, grooming, head motions, foot shifts, beak clacks, and rouse. Movement, head motions, and beak clacks were all significantly reduced in hawks with recent orthopedic injury, but not in hawks with healed or minor injuries (Pred -tailed hawks with recent orthopedic trauma show consistent and marked red uctions in several normal maintenance behaviors. Head movements, reported for the first time in this study as a potential marker of pain in birds, in particular seem to be insensitive to sedative side effects of buprenorphine, while being a sensitive measu re of affective state in hawks with painful injuries. These behaviors can be scored humanely and with minimal expense, and should be considered for further research on pain and analgesia in avian species.

  14. Stephen Hawking, the Grand Design and the mass media communication: Philosophy, Science and Religion

    Directory of Open Access Journals (Sweden)

    Leandro Sequeiros

    2014-11-01

    Full Text Available The return of summer vacances 2010 coincide with the notice concerning the inminent publication of a provocative and scandalous book by the eminent Phisicist Stephen Hawking. The Grand Design came out on September 7 in EE.UU. and on 9 in United Kingdom. On November 15th, the Spanish edition have been issued. The Spanish newpapers have published some fragments, which apparently show Hawking intends to prove scientifically that God not exists. The communications media remark by different ways the scarce frangments of the text: «God is not necessary», «Hawking proves God not exists», «Creator God is a destroyed mith», «Hawking scientifically proves God not exists», «God expeled of the Universe»… We have tracked more than hundred web-pages in which the contents of Hawking book are comment. Rationalists and religious sectors have standed in the debate. But, what has Hawking really defended in The Grand Design?

  15. The REX-ISOLDE-project and the Munich Accelerator for Fission Fragments MAFF

    CERN Document Server

    Habs, D; Assmann, R W; Emhofer, S; Engels, O; Gross, M; Kester, O; Maier, H J; Reiter, P; Sieber, T; Thirolf, P G

    2001-01-01

    After a general discussion of ISOL-facilities in Europe we focus on the present status of the REX-ISOLDE facility at CERN and the Munich Accelerator for Fission Fragments MAFF. At REX-ISOLDE in 2001 radioactive beams of ISOLDE will be accelerated to (0.8-2.4) MeV/u. At the new Munich high-flux reactor FRM-II a production target of MAFF with 10$^{14}$ fissions/s is under design. Probably in 2003 intense low-energy beams ( approximately=10$^{11}$/s) of very neutron-rich fission fragments will be available. For MAFF a linac is being developed, which will accelerate the ions after charge breeding to energies between 3.7 and 5.9 MeV/u. In the long term a recycling ring with large momentum acceptance will further increase the radioactive beam intensities by a factor of 10$^{2}$-10$^{3}$ for specific experiments. (33 refs).

  16. OSIRIS-REx Touch-and-Go (TAG) Mission Design for Asteroid Sample Collection

    Science.gov (United States)

    May, Alexander; Sutter, Brian; Linn, Timothy; Bierhaus, Beau; Berry, Kevin; Mink, Ron

    2014-01-01

    The Origins Spectral Interpretation Resource Identification Security Regolith Explorer (OSIRIS-REx) mission is a NASA New Frontiers mission launching in September 2016 to rendezvous with the near-Earth asteroid Bennu in October 2018. After several months of proximity operations to characterize the asteroid, OSIRIS-REx flies a Touch-And-Go (TAG) trajectory to the asteroid's surface to collect at least 60 g of pristine regolith sample for Earth return. This paper provides mission and flight system overviews, with more details on the TAG mission design and key events that occur to safely and successfully collect the sample. An overview of the navigation performed relative to a chosen sample site, along with the maneuvers to reach the desired site is described. Safety monitoring during descent is performed with onboard sensors providing an option to abort, troubleshoot, and try again if necessary. Sample collection occurs using a collection device at the end of an articulating robotic arm during a brief five second contact period, while a constant force spring mechanism in the arm assists to rebound the spacecraft away from the surface. Finally, the sample is measured quantitatively utilizing the law of conservation of angular momentum, along with qualitative data from imagery of the sampling device. Upon sample mass verification, the arm places the sample into the Stardust-heritage Sample Return Capsule (SRC) for return to Earth in September 2023.

  17. Lessons Learned from Preparing OSIRIS-REx Spectral Analog Samples for Bennu

    Science.gov (United States)

    Schrader, D. L.; McCoy, T. J.; Cody, G. D.; King, A. J.; Schofield, P. F.; Russell, S. S.; Connolly, H. C., Jr.; Keller, L. P.; Donaldson Hanna, K.; Bowles, N.; hide

    2017-01-01

    NASA's OSIRIS-REx sample return mission launched on September 8th, 2016 to rendezvous with B-type asteroid (101955) Bennu in 2018. Type C and B asteroids have been linked to carbonaceous chondrites because of their similar visible - to - near infrared (VIS-NIR) spectral properties [e.g., 1,2]. The OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) and the Thermal Emission Spectrometer (OTES) will make spectroscopic observations of Bennu during the encounter. Constraining the presence or absence of hydrous minerals (e.g., Ca-carbonate, phyllosilicates) and organic molecules will be key to characterizing Bennu [3] prior to sample site selection. The goal of this study was to develop a suite of analog and meteorite samples and obtain their spectral properties over the wavelength ranges of OVIRS (0.4- 4.3 micrometer) and OTES (5.0-50 micrometer). These spectral data were used to validate the mission science-data processing system. We discuss the reasoning behind the study and share lessons learned.

  18. Integrated science and engineering for the OSIRIS-REx asteroid sample return mission

    Science.gov (United States)

    Lauretta, D.

    2014-07-01

    Introduction: The Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) asteroid sample return mission will survey near-Earth asteroid (101955) Bennu to understand its physical, mineralogical, and chemical properties, assess its resource potential, refine the impact hazard, and return a sample of this body to the Earth [1]. This mission is scheduled for launch in 2016 and will rendezvous with the asteroid in 2018. Sample return to the Earth follows in 2023. The OSIRIS-REx mission has the challenge of visiting asteroid Bennu, characterizing it at global and local scales, then selecting the best site on the asteroid surface to acquire a sample for return to the Earth. Minimizing the risk of exploring an unknown world requires a tight integration of science and engineering to inform flight system and mission design. Defining the Asteroid Environment: We have performed an extensive astronomical campaign in support of OSIRIS-REx. Lightcurve and phase function observations were obtained with UA Observatories telescopes located in southeastern Arizona during the 2005--2006 and 2011--2012 apparitions [2]. We observed Bennu using the 12.6-cm radar at the Arecibo Observatory in 1999, 2005, and 2011 and the 3.5-cm radar at the Goldstone tracking station in 1999 and 2005 [3]. We conducted near-infrared measurements using the NASA Infrared Telescope Facility at the Mauna Kea Observatory in Hawaii in September 2005 [4]. Additional spectral observations were obtained in July 2011 and May 2012 with the Magellan 6.5-m telescope [5]. We used the Spitzer space telescope to observe Bennu in May 2007 [6]. The extensive knowledge gained as a result of our telescopic characterization of Bennu was critical in the selection of this object as the OSIRIS-REx mission target. In addition, we use these data, combined with models of the asteroid, to constrain over 100 different asteroid parameters covering orbital, bulk, rotational, radar

  19. Stable occupancy by breeding hawks (Buteo spp.) over 25 years on a privately managed bunchgrass prairie in northeastern Oregon, USA

    Science.gov (United States)

    Kennedy, Patricia L.; Bartuszevige, Anne M.; Houle, Marcy; Humphrey, Ann B.; Dugger, Katie M.; Williams, John

    2014-01-01

    Potential for large prairie remnants to provide habitat for grassland-obligate wildlife may be compromised by nonsustainable range-management practices. In 1979–1980, high nesting densities of 3 species of hawks in the genus Buteo—Ferruginous Hawk (Buteo regalis), Red-tailed Hawk (B. jamaicensis), and Swainson's Hawk (B. swainsoni)—were documented on the Zumwalt Prairie and surrounding agricultural areas (34,361 ha) in northeastern Oregon, USA. This area has been managed primarily as livestock summer range since it was homesteaded. Unlike in other prairie remnants, land management on the Zumwalt Prairie was consistent over the past several decades; thus, we predicted that territory occupancy of these 3 species would be stable. We also predicted that territory occupancy would be positively related to local availability of nesting structures within territories. We evaluated these hypotheses using a historical dataset, current survey and habitat data, and occupancy models. In support of our predictions, territory occupancy of all 3 species has not changed over the study period of ∼25 yr, which suggests that local range-management practices are not negatively affecting these taxa. Probability of Ferruginous Hawk occupancy increased with increasing area of aspen, an important nest structure for this species in grasslands. Probability of Swainson's Hawk occupancy increased with increasing area of large shrubs, and probability of Red-tailed Hawk occupancy was weakly associated with area of conifers. In the study area, large shrubs and conifers are commonly used as nesting structures by Swainson's Hawks and Red-tailed Hawks, respectively. Availability of these woody species is changing (increases in conifers and large shrubs, and decline in aspen) throughout the west, and these changes may result in declines in Ferruginous Hawk occupancy and increases in Swainson's Hawk and Red-tailed Hawk occupancy in the future.

  20. A Computational Analysis of Limb and Body Dimensions in Tyrannosaurus rex with Implications for Locomotion, Ontogeny, and Growth

    Science.gov (United States)

    Hutchinson, John R.; Bates, Karl T.; Molnar, Julia; Allen, Vivian; Makovicky, Peter J.

    2011-01-01

    The large theropod dinosaur Tyrannosaurus rex underwent remarkable changes during its growth from 6000 kg adults in antigravity” muscles may have been as large as or even larger than those of ratite birds, which themselves have the most muscular limbs of any living animal. PMID:22022500

  1. Hawking radiation as seen by an infalling observer

    Science.gov (United States)

    Greenwood, Eric; Stojkovic, Dejan

    2009-09-01

    We investigate an important question of Hawking-like radiation as seen by an infalling observer during gravitational collapse. Using the functional Schrodinger formalism we are able to probe the time dependent regime which is out of the reach of the standard approximations like the Bogolyubov method. We calculate the occupation number of particles whose frequencies are measured in the proper time of an infalling observer in two crucially different space-time foliations: Schwarzschild and Eddington-Finkelstein. We demonstrate that the distribution in Schwarzschild reference frame is not quite thermal, though it becomes thermal once the horizon is crossed. We approximately fit the temperature and find that the local temperature increases as the horizon is approached, and diverges exactly at the horizon. In Eddington-Finkelstein reference frame the temperature at the horizon is finite, since the observer in that frame is not accelerated. These results are in agreement with what is generically expected in the absence of backreaction. We also discuss some subtleties related to the physical interpretation of the infinite local temperature in Schwarzschild reference frame.

  2. A regularization of the Hartle–Hawking wave function

    Directory of Open Access Journals (Sweden)

    Nataliya N. Gorobey

    2017-06-01

    Full Text Available The paper puts forward a modification of the no-boundary Hartle–Hawking wave function in which, in the general case, the Euclidean functional integral can be described by an inhomogeneous universe. The regularization of this integral is achieved in arbitrary canonical calibration by abandoning integration over the lapse and shift functions. This makes it possible to ‘correct’ the sign of the Euclidean action corresponding to the scale factor of geometry. An additional time parameter associated with the canonical calibration condition then emerges. An additional condition for the stationary state of the wave function's phase after returning to the Lorentzian signature, serving as the quantum equivalent of the classical principle of the least action, was used to find this time parameter. We have substantiated the interpretation of the modified wave function as the amplitude of the universe's birth from ‘nothing’ with the additional parameter as the time of this process. A homogeneous model of the universe with a conformally invariant scalar field has been considered. In this case, two variants of the no-boundary wave function which are solutions of the Wheeler–DeWitt equation have been found.

  3. The three-body problem from Pythagoras to Hawking

    CERN Document Server

    Valtonen, Mauri; Kholshevnikov, Konstantin; Mylläri, Aleksandr; Orlov, Victor; Tanikawa, Kiyotaka

    2016-01-01

    This book, written for a general readership, reviews and explains the three-body problem in historical context reaching to latest developments in computational physics and gravitation theory. The three-body problem is one of the oldest problems in science and it is most relevant even in today’s physics and astronomy. The long history of the problem from Pythagoras to Hawking parallels the evolution of ideas about our physical universe, with a particular emphasis on understanding gravity and how it operates between astronomical bodies. The oldest astronomical three-body problem is the question how and when the moon and the sun line up with the earth to produce eclipses. Once the universal gravitation was discovered by Newton, it became immediately a problem to understand why these three-bodies form a stable system, in spite of the pull exerted from one to the other. In fact, it was a big question whether this system is stable at all in the long run. Leading mathematicians attacked this problem over more than...

  4. Migration patterns, use of stopover areas, and austral summer movements of Swainson's hawks

    Science.gov (United States)

    Kocher, Michael N.; Fuller, Mark R.; Schueck, Linda S.; Bond, Laura; Bechard, Marc J.; Woodbridge, Brian; Holroyd, Geoff L.; Martell, Mark S.; Banasch, Ursula

    2011-01-01

    from 1995 to 1998, we tracked movements of adult Swainson's Hawks (Buteo swainsoni), using satellite telemetry to characterize migration, important stopover areas, and movements in the austral summer. we tagged 46 hawks from July to September on their nesting grounds in seven U.S. states and two Canadian provinces. Swainson's Hawks followed three basic routes south on a broad front, converged along the east coast of cen-tral Mexico, and followed a concentrated corridor to a communal area in central Argentina for the austral summer. North of 20° N, southward and northward tracks differed little for individuals from east of the continental divide but differed greatly (up to 1700 km) for individuals from west of the continental divide. Hawks left the breeding grounds mid-August to mid-October; departure dates did not differ by location, year, or sex. Southbound migra-tion lasted 42 to 98 days, northbound migration 51 to 82 days. Southbound, 36% of the Swainson's Hawks departed the nesting grounds nearly 3 weeks earlier than the other radio-marked hawks and made stopovers 9.0–26.0 days long in seven separate areas, mainly in the southern great Plains, southern Arizona and New Mexico, and north-central Mexico. The birds stayed in their nonbreeding range for 76 to 128 days. All used a core area in central Ar-gentina within 23% of the 738 800-km2 austral summer range, where they frequently moved long distances (up to 1600 km). Conservation of Swainson's Hawks must be an international effort that considers habitats used during nesting and non-nesting seasons, including migration stopovers.

  5. Composition of the Rex Chert and associated rocks of the Permian Phosphoria Formation: Soda Springs area, SE Idaho

    Science.gov (United States)

    Hein, James R.; McIntyre, Brandie; Perkins, Robert B.; Piper, David Z.; Evans, James

    2002-01-01

    This study, one in a series, reports bulk chemical and mineralogical compositions, as well as petrographic and outcrop descriptions of rocks collected from three measured outcrop sections of the Rex Chert member of the Phosphoria Formation in SE Idaho. The three measured sections were chosen from ten outcrops of Rex Chert that were described in the field. The Rex Chert overlies the Meade Peak Phosphatic Shale Member of the Phosphoria Formation, the source of phosphate ore in the region. Rex Chert removed as overburden comprises part of the material disposed in waste-rock piles during phosphate mining. It has been proposed that the chert be used to cap and isolate waste piles, thereby inhibiting the leaching of potentially toxic elements into the environment. It is also used to surface roads in the mining district. The rock samples studied here constitute a set of individual chert beds that are representative of each stratigraphic section sampled. The informally named cherty shale member that overlies the Rex Chert in measured section 1 was also described and sampled. The upper Meade Peak and the transition zone to the Rex Chert were described and sampled in section 7. The cherts are predominantly spicularite composed of granular and mosaic quartz, and sponge spicules, with various but minor amounts of other fossils and detrital grains. The cherty shale member and transition rocks between the Meade Peak and Rex Chert are siliceous siltstones and argillaceous cherts with ghosts of sponge spicules and somewhat more detrital grains than the chert. The overwhelmingly dominant mineral is quartz, although carbonate beds are rare in each section and are composed predominantly of calcite and dolomite in addition to quartz. Feldspar, mica, clay minerals, calcite, dolomite, and carbonate fluorapatite are minor to trace minerals in the chert. The mean concentrations of oxides and elements in the Rex Chert and the cherty shale member are dominated by SiO2, which averages 94

  6. Code REX to fit experimental data to exponential functions and graphics plotting; Codigo REX para ajuste de datos experimentales a funciones exponenciales y su representacion grafica

    Energy Technology Data Exchange (ETDEWEB)

    Romero, L.; Travesi, A.

    1983-07-01

    The REX code, written in Fortran IV, performs the fitting a set of experimental data to different kind of functions as: straight-line (Y = A + BX) , and various exponential type (Y-A B{sup x}, Y=A X{sup B}; Y=A exp(BX) ) , using the Least Squares criterion. Such fitting could be done directly for one selected function of for the our simultaneously and allows to chose the function that best fitting to the data, since presents the statistics data of all the fitting. Further, it presents the graphics plotting, of the fitted function, in the appropriate coordinate axes system. An additional option allows also the Graphic plotting of experimental data used for the fitting. All the data necessary to execute this code are asked to the operator in the terminal screen, in the iterative way by screen-operator dialogue, and the values are introduced through the keyboard. This code could be executed with any computer provided with graphic screen and keyboard terminal, with a X-Y plotter serial connected to the graphics terminal. (Author) 5 refs.

  7. The VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx: goals, platforms, and field operations

    Directory of Open Access Journals (Sweden)

    R. Wood

    2011-01-01

    Full Text Available The VAMOS1 Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx was an international field program designed to make observations of poorly understood but critical components of the coupled climate system of the southeast Pacific. This region is characterized by strong coastal upwelling, the coolest SSTs in the tropical belt, and is home to the largest subtropical stratocumulus deck on Earth. The field intensive phase of VOCALS-REx took place during October and November 2008 and constitutes a critical part of a broader CLIVAR program (VOCALS designed to develop and promote scientific activities leading to improved understanding, model simulations, and predictions of the southeastern Pacific (SEP coupled ocean-atmosphere-land system, on diurnal to interannual timescales. The other major components of VOCALS are a modeling program with a model hierarchy ranging from the local to global scales, and a suite of extended observations from regular research cruises, instrumented moorings, and satellites. The two central themes of VOCALS-REx focus upon (a links between aerosols, clouds and precipitation and their impacts on marine stratocumulus radiative properties, and (b physical and chemical couplings between the upper ocean and the lower atmosphere, including the role that mesoscale ocean eddies play. A set of hypotheses designed to be tested with the combined field, monitoring and modeling work in VOCALS is presented here. A further goal of VOCALS-REx is to provide datasets for the evaluation and improvement of large-scale numerical models. VOCALS-REx involved five research aircraft, two ships and two surface sites in northern Chile. We describe the instrument payloads and key mission strategies for these platforms and give a summary of the missions conducted.

    1 Variability of the American Monsoon Systems, an international CLIVAR program.

  8. O{sub 2} depletion in granitic media. The Rex project

    Energy Technology Data Exchange (ETDEWEB)

    Puigdomenech, I. [Royal Inst. of Technology, Stockholm (Sweden); Ambrosi, J.P.; Eisenlohr, L.; Lartigue, J.E. [CNRS, Aix-en-Provence (France); Banwart, S.A. [Univ. of Sheffield (United Kingdom); Bateman, K.; Milodowski, A.E.; West, J.M. [British Geological Survey, Nottingham (United Kingdom); Griffault, L. [ANDRA (France); Gustafsson, E. [Geosigma AB, Uppsala (Sweden); Hama, K.; Yoshida, H. [JNC, Gifu (Japan). Tono Geoscience Centre; Kotelnikova, S.; Pedersen, K. [Goeteborg Univ. (Sweden); Michaud, V.; Trotignon, L. [CEA, Cadarache (France); Rivas Perez, J. [Univ. of Bradford (United Kingdom); Tullborg, E.L. [Terralogica AB, Graabo (Sweden)

    2001-02-01

    The redox conditions are of consequence for the performance of nuclear repositories. The presence of molecular oxygen (O{sub 2}) would affect the corrosion of canisters and the migration of radionuclides eventually released from a damaged canister. The rate of disappearance of O{sub 2} left in voids at repository closure is therefore an important information when evaluating repository designs. The REX project (Redox Experiment in Detailed Scale) has been carried out within the frame of SKB Aespoe Hard Rock Laboratory in Sweden. The aim was to determine how O{sub 2} trapped in the closed repository would react with the rock minerals in the tunnel and deposition holes and in the water conducting fractures. The REX project consisted of the following sections: Field investigations at Aespoe: Microbial O{sub 2} consumption at several sites in the Aespoe tunnel. The in situ experiment: Injection of oxygen and monitoring of O{sub 2} uptake in a confined fracture surface. The Replica Experiment: a laboratory study using the other half of the fracture surface used for the in situ experiment. Laboratory experiments: needed to support the interpretation of the field and replica experiments. Conducted with groundwaters, bacteria, and mineral samples from Aespoe. The results from the in-situ experiment were confirmed by those of the replica experiment performed in the CEA laboratory in France. Both were concordant in showing time scales for O{sub 2} uptake in the order of days. The agreement was remarkable when taking into account the differences in experimental conditions. For example, different microbial processes took place in the two experiments. Laboratory studies with rock samples demonstrated that microbial activity induced increased chemical weathering, with the formation of clay minerals. Rates of O{sub 2} uptake by fracture filling minerals were determined under laboratory conditions. These rates were faster than those reported in literature studies of pure mineral

  9. Behavioral ecology of the Swainson's Hawk (Buteo swainsoni) in Washington

    Energy Technology Data Exchange (ETDEWEB)

    Fitzner, R.E.

    1980-12-01

    This study examines the breeding ecology and behavior of the Swainson's Hawk (Buteo swainsoni) on its breeding ground in southeastern Washington. Seasonal movements and distribution of the buteo are also described. The birds were observed from blinds, or filmed by Super-8mm time-lapse cameras, during courtship, nest building, egg laying, incubation, and nestling and post-fledging development. Food habits were examined during the nestling and post-fledging periods. Snakes, especially the abundant Western Yellow-bellied racers, were a prey staple, and insects became an important food source during the post-fledging period. It was apparent that Swainson's Hawks feed on smaller and more diverse prey than sympatric buteos (Red-tailed and Ferruginous Hawks), thus reducing competition with neighboring congenerics. Interactions with buteos and other raptor genera were observed, and nearest neighbor distances measured. Organochlorine pesticides in prey species consumed by Swainson's Hawks are concentrated from prey to predator through the food chain. The hawk pellets (regurgitated castings) would contain those concentrations and could easily be monitored without sacrificing any part of the food chain.

  10. Red-tailed Hawk movements and use of habitat in the Luquillo Mountains of Puerto Rico

    Science.gov (United States)

    Vilella, Francisco; Nimitz, Wyatt F.

    2012-01-01

    The Red-tailed Hawk (Buteo jamaicensis) is a top predator of upland ecosystems in the Greater Antilles. Little information exists on the ecology of the insular forms of this widely distributed species. We studied movements and resource use of the Red-tailed Hawk from 2000 to 2002 in the montane forests of northeastern Puerto Rico. We captured 32 and used 21 radio-marked Red-tailed Hawks to delineate home range, core area shifts, and macrohabitat use in the Luquillo Mountains. Red-tailed Hawks in the Luquillo Mountains frequently perched near the top of canopy emergent trees and were characterized by wide-ranging capabilities and extensive spatial overlap. Home range size averaged 5,022.6 6 832.1 ha (305–11,288 ha) and core areas averaged 564.8 6 90.7 ha (150–1,230 ha). This species had large mean weekly movements (3,286.2 6 348.5 m) and a preference for roadside habitats. Our findings suggest fragmentation of contiguous forest outside protected areas in Puerto Rico may benefit the Red-tailed Hawk

  11. Comparison of transcoelomic, contrast transcoelomic, and transesophageal echocardiography in anesthetized red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Beaufrère, Hugues; Pariaut, Romain; Rodriguez, Daniel; Nevarez, Javier G; Tully, Thomas N

    2012-10-01

    To assess the agreement and reliability of cardiac measurements obtained with 3 echocardiographic techniques in anesthetized red-tailed hawks (Buteo jamaicensis). 10 red-tailed hawks. Transcoelomic, contrast transcoelomic, and transesophageal echocardiographic evaluations of the hawks were performed, and cineloops of imaging planes were recorded. Three observers performed echocardiographic measurements of cardiac variables 3 times on 3 days. The order in which hawks were assessed and echocardiographic techniques were used was randomized. Results were analyzed with linear mixed modeling, agreement was assessed with intraclass correlation coefficients, and variation was estimated with coefficients of variation. Significant differences were evident among the 3 echocardiographic methods for most measurements, and the agreement among findings was generally low. Interobserver agreement was generally low to medium. Intraobserver agreement was generally medium to high. Overall, better agreement was achieved for the left ventricular measurements and for the transesophageal approach than for other measurements and techniques. Echocardiographic measurements in hawks were not reliable, except when the left ventricle was measured by the same observer. Furthermore, cardiac morphometric measurements may not be clinically important. When measurements are required, one needs to consider that follow-up measurements should be performed by the same echocardiographer and should show at least a 20% difference from initial measurements to be confident that any difference is genuine.

  12. Exploring the Dipole Polarizability of $^{11}$Li at REX-ISOLDE

    CERN Multimedia

    2002-01-01

    Dipole polarizability refers to the effect of the excitation to negative parity states through the electric dipole interaction. In nuclear physics dipole polarizability has not yet played a major role. For nuclei close to the drip lines where the separation energies of neutrons (or protons) are small, a substantial part of the dipole strength function occurs at low excitation energies. We here propose to investigate this effect by measuring elastic scattering at energies close to the Coulomb barrier. REX-ISOLDE together with the new improved yields of $^{11}$Li provides the ideal setting for this experiment. We ask for a total of 24 shifts with proton beam plus 3 shifts of stable beam from a Ta-foil target.

  13. Energy and time of flight measurements of REX-ISOLDE stable beams using Si detectors

    CERN Document Server

    Cantero, E D; Fraser, M A; Lanaia, D; Sosa, A; Voulot, D; Zocca, F

    2014-01-01

    In this paper we present energy and time spectroscopy measurements for the stable beams of REX-ISOLDE obtained using Si detectors. By using an alpha source as a calibration reference, the absolute energy E of stable beam particles (A/q = 4) was determined in spectroscopy mode in the energy range 1 MeV < E < 8 MeV (0.30 MeV/u < E/A < 1.87 MeV/u). The time of flight of the beam particles (2.18 MeV/u < E/A < 2.27 MeV/u) was determined by installing identical Si detectors in two diagnostic boxes separated by 7.7 m. The results obtained with these two techniques are compared with the values obtained by dipole scans using a bending magnet. The measurements took place between January and February of 2013.

  14. Preliminary Beam Tests at REX for an Automatic Cavity Phasing Routine at HIE-ISOLDE

    CERN Document Server

    Fraser, M A; Broere, J; Lanaia, D; Valuch, D

    2013-01-01

    The HIE upgrade at ISOLDE will use 32 independently phased superconducting quarterwave cavities, which will impose new demands on the operation and set-up of the linac. The large range of different radioactive species and the broad experimental programme means that the same beam species and energy are rarely studied twice, and the accelerator must be re-tuned for each experimental run. In order to expedite machine set-up it is foreseen to calculate and set automatically the cavity phases when the operator inputs the desired beam energy and A/q of the beam species. In this note we explore our understanding of the REX rf system and test our beam dynamics calculations with two independently phased 7-gap split-ring cavities.

  15. The REX survey as a Tool to Test the Beaming Model for BL Lacs

    Science.gov (United States)

    Caccianiga, A.; della Ceca, R.; Gioia, I. M.; Maccacaro, T.; Wolter, A.

    We present the preliminary properties of the BL Lacs discovered in the REX survey (Caccianiga et al. 1998). In particular, we discuss a few sources with optical spectral properties ``intermediate'' between those of BL Lacs and those of elliptical galaxies. These objects could harbour weak (in the optical band) sources of non-thermal continuum in their nuclei and, if confirmed, they could represent the faint tail of the BL Lac population. The existence of such ``weak'' BL Lacs is matter of discussion in recent literature (e.g. Marcha et al. 1996) and could lead to a revision of the defining criteria of a BL Lac and, consequently, of their cosmological and statistical properties.

  16. Implementation and evaluation of tilted foils polarization at REX-ISOLDE

    CERN Document Server

    Tornqvist, H; Georgiev, G; Hass, M; Herlert, A; Kowalska, M; Nilsson, T; Pakarinen, J; Wenander, F

    2012-01-01

    The progress within atomic and nuclear physics relies on refining and adding new observables. One of these is the polarization of the nuclear spin, where there is a manifest interest in accessing a wide variety of polarized beams, e.g. at energies suitable for Coulomb excitation and transfer experiments. In particular, exotic nuclei with half-lives considerably less than one second are difficult to produce, but the issues present in traditional methods could be overcome by using the tilted foils technique. Two setups for measuring the degree of polarization of an ion beam after the REX-ISOLDE linear accelerator at CERN are being evaluated. An approach based on Coulomb excitation has been utilized in an experiment and preliminary results will be presented. Furthermore, a -NMR setup is currently under construction that will take radioactive beams soon.

  17. REX-ISOLDE RFQ Beam Dynamics Studies using CST EM Studio

    CERN Document Server

    Fraser, M A

    2014-01-01

    The original CNC milling files used to machine the electrodes of the REX-ISOLDE RFQ were acquired in late 2012 and electrostatic simulations were carried out using CST EM Studio in order to attain a 3D field map of the electric fields in the region around the beam axis. The objective was to construct a beam dynamics simulation tool that frees us from the constraints of the PARMTEQM code, which was used to design the RFQ, and that will afford us more flexibility in the studies needed for pre-bunching into the RFQ with an external multi-harmonic buncher. This note details the geometry of the electrodes and their simulation in CST EM Studio, the implementation of particle tracking in the computed field map using TRACK and benchmarking studies with PARMTEQM v3.09.

  18. ACES: The ASCENDS CarbonHawk Experiment Simulator

    Science.gov (United States)

    Obland, M. D.; Prasad, N. S.; Harrison, F. W.; Browell, E. V.; Ismail, S.; Dobler, J. T.; Moore, B.; Zaccheo, T.; Campbell, J.; Chen, S.; Cleckner, C. S.; DiJoseph, M.; Little, A.; Notari, A.; Refaat, T. F.; Rosenbaum, D.; Vanek, M. D.; Bender, J.; Braun, M.; Chavez-Pirson, A.; Neal, M.; Rayner, P. J.; Rosiewicz, A.; Shure, M.; Welch, W.

    2012-12-01

    The ASCENDS CarbonHawk Experiment Simulator (ACES) is a NASA Langley Research Center project funded by NASA's Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP) that seeks to advance technologies critical to measuring atmospheric column carbon dioxide (CO2) mixing ratios in support of the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The technologies being advanced are: (1) a high bandwidth detector, (2) a multi-aperture telescope assembly, (3) advanced algorithms for cloud and aerosol discrimination, and (4) high-efficiency, multiple-amplifier CO2 and O2 laser transmitters. The instrument architecture will be developed to operate on a high-altitude aircraft and will be directly scalable to meet the ASCENDS mission requirements. These technologies are viewed as critical towards developing an airborne simulator and eventual spaceborne instrument with lower size, mass, and power consumption, and improved performance. The detector effort will improve the existing detector subsystem by increasing its bandwidth to a goal of 5 MHz, reducing its overall mass from 18 lbs to 24 hrs. The development goals are to permit higher laser modulation rates, which provides greater flexibility for implementing thin-cloud discrimination algorithms as well as improving range resolution and error reduction, and to enable long flights on a high-altitude unmanned aerial vehicle (UAV). The telescope development consists of a three-telescope design built for the constraints of the Global Hawk aircraft. This task addresses the ability of multiple smaller telescopes to provide equal or greater collection efficiency compared with a single larger telescope with a reduced impact on launch mass and cost. The telescope assembly also integrates fiber-coupled transmit collimators for all of the laser transmitters and fiber-coupled optical signal output to the aft optics and detector package. The cloud/aerosol discrimination work features

  19. Pengaruh tingkat protein dan energi pakan terhadap kualitas kulit untuk atasan sepatu dari kelinci rex jantan

    Directory of Open Access Journals (Sweden)

    Sri Untari

    1995-06-01

    Full Text Available This research intends to know the effect of fodder protein and energy level on the physical test (i.e. the elasticity, tensile strength and tear strength of Rex rabbit leather, the raw material of shoe upper. The materials for research are 27 skin of dried 12-to-13-month-old male Rex rabbit. The complete random research design is used here with the factor pattern 3 X 3 = 9 kinds of combination of treatment factors,i.e. the factors or three levels of protein :15% n(P1, 17% (P2, and 19% (P3; the factors of three levels of digestible energy (D : 2,000 kcal/kg (D1, 2,250 kcal.kg (D2, and 2,500 kcal/kg; and three skins of dried rabbit leathers in each treatment as replication. The parameter of the physical test will be determined with the covariance analysis, with the thickness of the leathers as a coverable. When the F analysis gives the result that are perceptibly different, it is followed by the “Least Significant Difference (LSD analysis. The results of the research are that protein and ‘digestible energy’ have an imperceptibly different effect (P > 0.005 on the elasticity, tensile strength, and tear-trength of the charm tanned and than the thickness of the effect (P > 0.05 on the thickness of the leathers and a linear regression relation, but it does not it the physical-testing.

  20. Evaluating WRF-Chem aerosol indirect effects in Southeast Pacific marine stratocumulus during VOCALS-REx

    Directory of Open Access Journals (Sweden)

    P. E. Saide

    2012-03-01

    Full Text Available We evaluate a regional-scale simulation with the WRF-Chem model for the VAMOS (Variability of the American Monsoon Systems Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx, which sampled the Southeast Pacific's persistent stratocumulus deck. Evaluation of VOCALS-REx ship-based and three aircraft observations focuses on analyzing how aerosol loading affects marine boundary layer (MBL dynamics and cloud microphysics. We compare local time series and campaign-averaged longitudinal gradients, and highlight differences in model simulations with (W and without (NW wet deposition processes. The higher aerosol loadings in the NW case produce considerable changes in MBL dynamics and cloud microphysics, in accordance with the established conceptual model of aerosol indirect effects. These include increase in cloud albedo, increase in MBL and cloud heights, drizzle suppression, increase in liquid water content, and increase in cloud lifetime. Moreover, better statistical representation of aerosol mass and number concentration improves model fidelity in reproducing observed spatial and temporal variability in cloud properties, including top and base height, droplet concentration, water content, rain rate, optical depth (COD and liquid water path (LWP. Together, these help to quantify confidence in WRF-Chem's modeled aerosol-cloud interactions, especially in the activation parameterization, while identifying structural and parametric uncertainties including: irreversibility in rain wet removal; overestimation of marine DMS and sea salt emissions, and accelerated aqueous sulfate conversion. Our findings suggest that WRF-Chem simulates marine cloud-aerosol interactions at a level sufficient for applications in forecasting weather and air quality and studying aerosol climate forcing, and may do so with the reliability required for policy analysis.

  1. BOOK REVIEW: Meilensteine der Astronomie - Von Aristoteles bis Hawking

    Science.gov (United States)

    Duerbeck, H. W.; Hamel, J.

    2006-12-01

    A writer, more specific a writer on the history of astronomy, might from time to time look at the collected document folders with all the research material and reprints, and might wonder: has this been all? Especially at a time when recycling is in vogue? And, perhaps with a request or an invitation to submit something, he or she might consider re-using the material before its definitive disposal. Well, such are my feelings when I looked at Jurgen Hamel's new book Milestones of Astronomy - From Aristoteles to Hawking . A slight chance for survival of medium-sized publishers like Kosmos is to offer popular books, and a title must attract potential buyers: Aristoteles means the "old" times, and as concerns the "mad scientist" of modern times, Stephen Hawking has by now dethroned Einstein. In 1998, Hamel had published a Geschichte der Astronomie - Von den Anfangen bis zur Gegenwart (History of astronomy, from the beginnings to the present), which, of course, he could not simply copy. This time, he selected some stones from his research areas - milestones, touchstones, stumbling blocks in the long road of astronomical evolution - and put them between the covers of his new book. So let us look at these (mile)stones . The reader is informed about Aristoteles on 2 pages, but his medieval interpreter Johannes de Sacrobosco gets 8 pages! Copernicus' life and achievements are described on 9 pages, closely followed by his devotee and translator Rothmann with 8 pages; Copernicus' contemporary, Peter Apian, however, gets about 13! Bessel's and Herschel's lifes and works are described on well-deserved 13 and 15 pages, while the achievements of the two Lucasian professors, Isaac Newton and Stephen Hawking, are just outlined in a single paragraph! Thus, importance is sometimes inversely proportional to text length... But let us become serious now. Why should an active historian outline, for the hundreth time, the life of Copernicus, while there are so many interesting, and often

  2. The effect of the Gauss-Bonnet term on Hawking radiation from arbitrary dimensional black brane

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, Xiao-Mei [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Valparaiso (Chile); Yangzhou University, Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou (China); Saavedra, Joel [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Valparaiso (Chile); Oevguen, Ali [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Valparaiso (Chile); Eastern Mediterranean University, Physics Department, Famagusta, Northern Cyprus (Country Unknown)

    2017-09-15

    We investigate the probabilities of the tunneling and the radiation spectra of massive spin-1 particles from arbitrary dimensional Gauss-Bonnet-Axions (GBA) Anti-de Sitter (AdS) black branes, via using the WKB approximation to the Proca spin-1 field equation. The tunneling probabilities and Hawking temperature of the arbitrary dimensional GBA AdS black brane is calculated via the Hamilton-Jacobi approach. We also compute the Hawking temperature via the Parikh-Wilczek tunneling approach. The results obtained from the two methods are consistent. In our setup, the Gauss-Bonnet (GB) coupling affects the Hawking temperature if and only if the momentum of the axion fields is non-vanishing. (orig.)

  3. Hawking versus Unruh effects, or the difficulty of slowly crossing a black hole horizon

    Energy Technology Data Exchange (ETDEWEB)

    Barbado, Luis C. [Quantenoptik, Quantennanophysik und Quanteninformation, Fakultät für Physik,Universität Wien, Boltzmanngasse 5, 1090 Wien (Austria); Departamento de Astronomía Extragaláctica, Instituto de Astrofísica de Andalucía (CSIC),Glorieta de la Astronomía s/n, 18008 Granada (Spain); Barceló, Carlos [Departamento de Astronomía Extragaláctica, Instituto de Astrofísica de Andalucía (CSIC),Glorieta de la Astronomía s/n, 18008 Granada (Spain); Garay, Luis J. [Departamento de Física Teórica II, Facultad de Ciencias Fśicas,Universidad Complutense de Madrid, Ciudad Universitaria,Plaza Ciencias 1, 28040 Madrid (Spain); Departamento de Química y Física Teóricas, Instituto de Estructura de la Materia (CSIC),Serrano 121, 28006 Madrid (Spain); Jannes, Gil [Departamento de Ciencias y Tecnología, Universidad Europea de Madrid,Calle Tajo s/n, 28670 Villaviciosa de Odón, Madrid (Spain)

    2016-10-28

    When analyzing the perception of Hawking radiation by different observers, the Hawking effect becomes mixed with the Unruh effect. The separation of both effects is not always clear in the literature. Here we propose an inconsistency-free interpretation of what constitutes a Hawking effect and what an Unruh effect. An appropriate interpretation is important in order to elucidate what sort of effects a detector might experience depending on its trajectory and the state of the quantum field. Under simplifying assumptions we introduce an analytic formula that separates these two effects. Armed with the previous interpretation we argue that for a free-falling detector to cross the horizon without experiencing high-energy effects, it is necessary that the horizon crossing is not attempted at low velocities.

  4. Cardiomyopathy and right-sided congestive heart failure in a red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Knafo, S Emmanuelle; Rapoport, Gregg; Williams, Jamie; Brainard, Benjamin; Driskell, Elizabeth; Uhl, Elizabeth; Crochik, Sonia; Divers, Stephen J

    2011-03-01

    A 15-year-old female red-tailed hawk (Buteo jamaicensis) was evaluated because of dyspnea, anorexia, and coelomic distension. Diagnostic imaging results confirmed severe coelomic effusion and revealed a markedly dilated right ventricle. The diagnosis was right-sided congestive heart failure. Results of measurements of vitamin E, selenium, lead, zinc, and cardiac troponin levels were normal or nondiagnostic. The hawk was treated with furosemide, antifungal and antimicrobial agents, and supplemental fluids and oxygen, but euthanasia was elected because of the poor prognosis and the practical difficulties associated with intensive case management. To our knowledge, this is the first described case of cardiomyopathy and congestive heart failure in a captive red-tailed hawk.

  5. Hawking Radiation-Quasinormal Modes Correspondence for Large AdS Black Holes

    Directory of Open Access Journals (Sweden)

    Dao-Quan Sun

    2017-01-01

    Full Text Available It is well-known that the nonstrictly thermal character of the Hawking radiation spectrum generates a natural correspondence between Hawking radiation and black hole quasinormal modes. This main issue has been analyzed in the framework of Schwarzschild black holes, Kerr black holes, and nonextremal Reissner-Nordstrom black holes. In this paper, by introducing the effective temperature, we reanalyze the nonstrictly thermal character of large AdS black holes. The results show that the effective mass corresponding to the effective temperature is approximatively the average one in any dimension. And the other effective quantities can also be obtained. Based on the known forms of frequency in quasinormal modes, we reanalyze the asymptotic frequencies of the large AdS black hole in three and five dimensions. Then we get the formulas of the Bekenstein-Hawking entropy and the horizon’s area quantization with functions of the quantum “overtone” number n.

  6. More on the conformal mapping of quasi-local masses: The Hawking-Hayward case

    CERN Document Server

    Hammad, Fayçal

    2016-01-01

    The conformal transformation of the Hawking-Hayward quasi-local mass is reexamined. It has been found recently that the conformal transformation of the latter exhibits the 'wrong' conformal factor compared to the way usual masses transform under conformal transformations of spacetime. We show, in analogy with what was found recently for the Misner-Sharp mass, that unlike the purely geometric definition of the Hawking-Hayward mass, the latter exhibits the 'right' conformal factor whenever expressed in terms of its material content via the field equations. The case of conformally invariant scalar-tensor theories of gravity is also examined. The equivalence between the Misner-Sharp mass and the Hawking-Hayward mass for spherically symmetric spacetimes manifests itself by giving identical peculiar behaviors under conformal transformations.

  7. Pharmacokinetics of a single dose of voriconazole administered orally with and without food to red-tailed hawks (Buteo jamaicensus)

    NARCIS (Netherlands)

    Parsley, Ruth A; Tell, Lisa A; Gehring, Ronette

    OBJECTIVE To determine the pharmacokinetics of voriconazole administered PO with or without food to red-tailed hawks (Buteo jamaicensus) and whether any observed variability could be explained by measured covariates to inform dose adjustments. ANIMALS 7 adult red-tailed hawks. PROCEDURES In a

  8. Isolation of Erysipelothrix rhusiopathiae from a red-tailed hawk (Buteo jamaicensis) with a concurrent pox virus infection.

    Science.gov (United States)

    Pace, L W; Chengappa, M M; Greer, S; Alderson, C

    1987-10-01

    Erysipelothrix rhusiopathiae was isolated from the spleen, liver, lung, heart, kidney, and skin of a red-tailed hawk (Buteo jamaicensis) which had a concurrent avian pox virus infection. The hawk had been housed on a farm with domestic turkeys, providing a possible source of the E. rhusiopathiae.

  9. Breeding biology and nest-site selection of red-tailed hawks in an altered desert grassland

    Science.gov (United States)

    Hobbs, R.J.; DeStefano, S.; Halvorson, W.L.

    2006-01-01

    Red-tailed Hawks (Buteo jamaicensis) have expanded their range as trees have invaded formerly-open grasslands. Desert grasslands of southern Arizona have been invaded by mesquite trees (Prosopis velutina) since Anglo-American settlement and now support a large population of Red-tailed Hawks. We studied a population of Red-tailed Hawks in an altered desert grassland in southern Arizona. Our objectives were to determine what environmental characteristics influence Red-tailed Hawk habitat selection in mesquite-invaded desert grasslands and to evaluate the habitat quality of these grasslands for Red-tailed Hawks based on nesting density, nest success, and productivity. Red-tailed Hawks had 86% (95% C.I. = 73-99) nest success and 1.82 young per breeding pair (95% C.I. = 1.41-2.23). Nesting density was 0.15 (95% CI = 0.08-0.21) breeding pairs/km2 and the mean nearest-neighbor distance was 1.95 km (95% C.I. = 1.74-2.16). Red-tailed Hawks selected nest-sites with taller nest-trees and greater tree height and cover than were available at random. Mesquite trees in desert grasslands provide abundant potential nesting structures for Red-tailed Hawks. ?? 2006 The Raptor Research Foundation, Inc.

  10. DataHawk Flocks: Self-Contained sUAS Modules for High-Resolution Atmospheric Measurements

    Science.gov (United States)

    2015-08-25

    vehicle was covered in a thin laminating film using a special consolidating process at the surface to produce a smooth, weatherproof exterior on the...Navigation, who are interested in the DataHawk 2 design for a low-cost platform for photogrammetry applications. DataHawk Flocks Equipment and

  11. Comment on "Inflation with a graceful exit and entrance driven by Hawking radiation"

    OpenAIRE

    Firouzjaee, Javad T.

    2013-01-01

    Modak and Singleton [Phys. Rev. D 86, 123515 (2012)] have presented Hawking-like radiation for cosmological inflation which has a natural "turn on" and a natural "turn off" mechanism. This Hawking-like radiation results in an effective negative pressure "fluid" which leads to a rapid period of expansion in the very early Universe. We discuss that the turn on mechanism can not happen for FRW model in early universe because its horizon is apparent horizon not event horizon. Hence, we cannot app...

  12. Analytical solutions in rotating linear dilaton black holes: Hawking radiation of charged massive scalar particles

    CERN Document Server

    Sakalli, I

    2016-01-01

    Hawking radiation of charged massive spin-0 particles are studied in the gravitational, electromagnetic, dilaton, and axion fields of rotating linear dilaton black holes. In this geometry, we separate the covariant Klein--Gordon equation into radial and angular parts and obtain the exact solutions of both the equations in terms of the confluent Heun functions. Using the radial solution, we analyze the behavior of the wave solutions near the event horizon of the rotating linear dilaton black hole and derive its Hawking radiation spectrum via the Damour--Ruffini--Sannan method.

  13. Integral method for the calculation of Hawking radiation in dispersive media. II. Asymmetric asymptotics.

    Science.gov (United States)

    Robertson, Scott

    2014-11-01

    Analog gravity experiments make feasible the realization of black hole space-times in a laboratory setting and the observational verification of Hawking radiation. Since such analog systems are typically dominated by dispersion, efficient techniques for calculating the predicted Hawking spectrum in the presence of strong dispersion are required. In the preceding paper, an integral method in Fourier space is proposed for stationary 1+1-dimensional backgrounds which are asymptotically symmetric. Here, this method is generalized to backgrounds which are different in the asymptotic regions to the left and right of the scattering region.

  14. Frenkelia sp.-like infection in the small intestine of a red-tailed hawk.

    Science.gov (United States)

    Lindsay, D S; Ambrus, S I; Blagburn, B L

    1987-10-01

    Developmental stages of a Frenkelia sp.-like coccidium were observed in tissue sections of the duodenum, jejunum, and ileum of a naturally infected red-tailed hawk (Buteo jamaicensis borealis) that died and was examined at necropsy. Developmental stages were located in the lamina propria of these tissues. Thirty sporulated sporocysts measured 11.1 X 8.1 microns in tissue sections. Four sporozoites were present in each sporulated sporocyst. The coccidial infection was not a contributing factor in the death of this red-tailed hawk.

  15. Effect of Dietary Cysteine Supplementation on Growing Performance, Pelt Quality and Some Serum Biochemical Parameters of Young Rex Rabbit

    Directory of Open Access Journals (Sweden)

    Tossou Myrlene Carine B

    2013-01-01

    Full Text Available The present study was conducted to evaluate the effects of dietary cysteine, a sulphur containing amino acid supplementation on growth performance, pelt quality and a number of serum biochemical parameters of young Rex Rabbit. One hundred and twenty Rex Rabbits aged 45 days were divided into five dietary treatment groups including one control group and 4 experimental groups. Each group was composed of 24 animals and was fed with different diets for 56 days corresponding to the fattening period. Diet was incorporated with 0% of cysteine (control group and 0,10%, 0,20%, 0,30% and 0,40% respectively for the experimental groups. At the end of the experiment, results showed that cysteine supplementation to the diet affected average daily gain, live weight,skin length, skin area and pelt weight at the late phase of 42 to 56 days (P0.05

  16. Coulomb Excitation of Odd-Mass and Odd-Odd Cu Isotopes using REX-ISOLDE and Miniball

    CERN Multimedia

    Lauer, M; Iwanicki, J S

    2002-01-01

    We propose to study the properties of the odd-mass and the odd-odd neutron-rich Cu nuclei applying the Coulomb excitation technique and using the REX-ISOLDE facility coupled to the Miniball array. The results from the Coulex experiments accomplished at REX-ISOLDE after its upgrade to 3 MeV/u during the last year have shown the power of this method and its importance in order to obtain information on the collective properties of even-even nuclei. Performing an experiment on the odd-mass and on the odd-odd neutron-rich Cu isotopes in the vicinity of N=40 should allow us to determine and interpret the effective proton and neutron charges in the region and to unravel the lowest proton-neutron multiplets in $^{68,70}$Cu. This experiment can take the advantage of the unique opportunity to accelerate isomerically separated beams using the RILIS ion source at ISOLDE.

  17. Diamond fly cutting of aluminum thermal infrared flat mirrors for the OSIRIS-REx Thermal Emission Spectrometer (OTES) instrument

    Science.gov (United States)

    Groppi, Christopher E.; Underhill, Matthew; Farkas, Zoltan; Pelham, Daniel

    2016-07-01

    We present the fabrication and measurement of monolithic aluminum flat mirrors designed to operate in the thermal infrared for the OSIRIS-Rex Thermal Emission Spectrometer (OTES) space instrument. The mirrors were cut using a conventional fly cutter with a large radius diamond cutting tool on a high precision Kern Evo 3-axis CNC milling machine. The mirrors were measured to have less than 150 angstroms RMS surface error.

  18. South East Pacific atmospheric composition and variability sampled along 20° S during VOCALS-REx

    Directory of Open Access Journals (Sweden)

    G. Allen

    2011-06-01

    Full Text Available The VAMOS Ocean-Cloud-Atmosphere-Land Regional Experiment (VOCALS-REx was conducted from 15 October to 15 November 2008 in the South East Pacific (SEP region to investigate interactions between land, sea and atmosphere in this unique tropical eastern ocean environment and to improve the skill of global and regional models in representing the region. This study synthesises selected aircraft, ship and surface site observations from VOCALS-REx to statistically summarise and characterise the atmospheric composition and variability of the Marine Boundary Layer (MBL and Free Troposphere (FT along the 20° S parallel between 70° W and 85° W. Significant zonal gradients in mean MBL sub-micron aerosol particle size and composition, carbon monoxide, sulphur dioxide and ozone were seen over the campaign, with a generally more variable and polluted coastal environment and a less variable, more pristine remote maritime regime. Gradients in aerosol and trace gas concentrations were observed to be associated with strong gradients in cloud droplet number. The FT was often more polluted in terms of trace gases than the MBL in the mean; however increased variability in the FT composition suggests an episodic nature to elevated concentrations. This is consistent with a complex vertical interleaving of airmasses with diverse sources and hence pollutant concentrations as seen by generalised back trajectory analysis, which suggests contributions from both local and long-range sources. Furthermore, back trajectory analysis demonstrates that the observed zonal gradients both in the boundary layer and the free troposphere are characteristic of marked changes in airmass history with distance offshore – coastal boundary layer airmasses having been in recent contact with the local land surface and remote maritime airmasses having resided over ocean for in excess of ten days. Boundary layer composition to the east of 75° W was observed to be dominated by coastal

  19. P-REX1 creates a positive feedback loop to activate growth factor receptor, PI3K/AKT, and MEK/ERK signaling in breast cancer

    Science.gov (United States)

    Dillon, Lloye M.; Bean, Jennifer R.; Yang, Wei; Shee, Kevin; Symonds, Lynn K.; Balko, Justin M.; McDonald, W. Hayes; Liu, Shuying; Gonzalez-Angulo, Ana M.; Mills, Gordon B.; Arteaga, Carlos L.; Miller, Todd W.

    2014-01-01

    Phosphatidylinositol 3-kinase (PI3K) promotes cancer cell survival, migration, growth, and proliferation by generating phosphatidylinositol 3,4,5-trisphosphate (PIP3) in the inner leaflet of the plasma membrane. PIP3 recruits pleckstrin homology (PH) domain-containing proteins to the membrane to activate oncogenic signaling cascades. Anti-cancer therapeutics targeting the PI3K/AKT/mTOR pathway are in clinical development. In a mass spectrometric screen to identify PIP3-regulated proteins in breast cancer cells, levels of the Rac activator PIP3-dependent Rac exchange factor 1 (P-REX1) increased in response to PI3K inhibition, and decreased upon loss of the PI3K antagonist PTEN. P-REX1 mRNA and protein levels were positively correlated with ER expression, and inversely correlated with PI3K pathway activation in breast tumors as assessed by gene expression and phosphoproteomic analyses. P-REX1 increased activation of Rac1, PI3K/AKT, and MEK/ERK signaling in a PTEN-independent manner, and promoted cell and tumor viability. Loss of P-REX1 or inhibition of Rac suppressed PI3K/AKT and MEK/ERK, and decreased viability. P-REX1 also promoted insulin-like growth factor-1 receptor (IGF-1R) activation, suggesting that P-REX1 provides positive feedback to activators upstream of PI3K. In support of a model where PIP3-driven P-REX1 promotes both PI3K/AKT and MEK/ERK signaling, high levels of P-REX1 mRNA (but not phospho-AKT or a transcriptomic signature of PI3K activation) were predictive of sensitivity to PI3K inhibitors among breast cancer cell lines. P-REX1 expression was highest in ER+ breast tumors compared to many other cancer subtypes, suggesting that neutralizing the P-REX1/Rac axis may provide a novel therapeutic approach to selectively abrogate oncogenic signaling in breast cancer cells. PMID:25284585

  20. Lessons Learned from OSIRIS-Rex Autonomous Navigation Using Natural Feature Tracking

    Science.gov (United States)

    Lorenz, David A.; Olds, Ryan; May, Alexander; Mario, Courtney; Perry, Mark E.; Palmer, Eric E.; Daly, Michael

    2017-01-01

    The Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (Osiris-REx) spacecraft is scheduled to launch in September, 2016 to embark on an asteroid sample return mission. It is expected to rendezvous with the asteroid, Bennu, navigate to the surface, collect a sample (July 20), and return the sample to Earth (September 23). The original mission design called for using one of two Flash Lidar units to provide autonomous navigation to the surface. Following Preliminary design and initial development of the Lidars, reliability issues with the hardware and test program prompted the project to begin development of an alternative navigation technique to be used as a backup to the Lidar. At the critical design review, Natural Feature Tracking (NFT) was added to the mission. NFT is an onboard optical navigation system that compares observed images to a set of asteroid terrain models which are rendered in real-time from a catalog stored in memory on the flight computer. Onboard knowledge of the spacecraft state is then updated by a Kalman filter using the measured residuals between the rendered reference images and the actual observed images. The asteroid terrain models used by NFT are built from a shape model generated from observations collected during earlier phases of the mission and include both terrain shape and albedo information about the asteroid surface. As a result, the success of NFT is highly dependent on selecting a set of topographic features that can be both identified during descent as well as reliably rendered using the shape model data available. During development, the OSIRIS-REx team faced significant challenges in developing a process conducive to robust operation. This was especially true for terrain models to be used as the spacecraft gets close to the asteroid and higher fidelity models are required for reliable image correlation. This paper will present some of the challenges and lessons learned from the development

  1. Cassin\\'s hawk-eagle Spizaetus africanus in Ndundulu Forest: a first ...

    African Journals Online (AJOL)

    A single adult Cassin's hawk-eagle Spizaetus africanus was sighted on five occasions over three years in a highland forest in the Udzungwa Mountains, the first ever record of this species in Tanzania. This discovery has potentially significant biogeographical implications, strengthening ancient links between the forests of ...

  2. An analysis of Bat Hawk Macheiramphus alcinus diet in the Melaky ...

    African Journals Online (AJOL)

    We present information on the prey taken by the Bat Hawk Macheiramphus alcinus in two different areas of lowland western central Madagascar. These are the first dietary data from Madagascar for this widespread Old World species. The recovered remains were almost exclusively of bats and birds, with a few examples of ...

  3. Breaking the internet: making Stephen Hawking's PhD thesis available open access

    OpenAIRE

    Ammon, Matthias; Smith, Arthur

    2018-01-01

    Slides from a lightning talk (5 minute presentation) by Matthias Ammon (Research Support Librarian, MML Library, University of Cambridge) and Arthur Smith (Open Access Team, Office of Scholarly Communication, University of Cambridge). Presented at Cambridge Libraries Conference 2018. The talk discussed the process and impact of making Stephen Hawking's PhD thesis available as open access.

  4. Distribution and geographical variation of the White-tailed Hawk (Buteo albicaudatus)

    NARCIS (Netherlands)

    Voous, K.H.

    1968-01-01

    The present knowledge on infraspecific variation, distribution, and migration of the White-tailed Hawk ( Buteo albicaudatus Vieillot) is critically reviewed. In practically every aspect knowledge is highly inadequate. Size variation (tables I—IV) is in accordance with Bergmann’s Phenomenon, but does

  5. A note on a perfect simulation algorithm for marked Hawkes processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Rasmussen, Jakob Gulddahl

    2004-01-01

    The usual straightforward simulation algorithm for (marked or unmarked) Hawkes processes suffers from edge effect. In this note we describe a perfect simulation algorithm which is partly derived as in Brix and Kendall (2002) and partly using upper and lower processes as in the Propp-Wilson algori...

  6. Cooper’s hawk nest site characteristics in the Pineywoods Region

    Science.gov (United States)

    Richard R. Schaefer; D. Craig Rudolph; Jesse F. Fagan

    2011-01-01

    Early accounts describe the Cooper’s Hawk (Accipiter cooperi) as a species in decline in much of North America during the early twentieth century (Bent 1937), particularly when in close proximity to humans (Eaton 1914). This decreasing population trend continued to be recognized later in the century in both Texas (Oberholser 1974) and Louisiana (Lowery 1974). Shooting...

  7. The Hawkes process with different excitation functions and its asymptotoc behavior

    DEFF Research Database (Denmark)

    Fierro, Raúl; Leiva, Víctor; Møller, Jesper

    into account in a number of fields; e.g. in seismology, where main shocks produce aftershocks with possibly different intensities. The main results are devoted to the asymptotic behavior of this extension of the Hawkes process. Indeed, a law of large numbers and a central limit theorem are stated...

  8. Quantum transitions of minimum energy for Hawking quanta in highly excited black holes

    CERN Document Server

    Corda, Christian

    2012-01-01

    By adding an hypothesis of the locality of particle emission in a black hole, Yoon recently argued that, differently from previous literature, in loop quantum gravity the Hawking radiation spectrum is discrete even in the case that the allowed area is not simply the integer multiples of a single unit area. This looks consistent with our observation that the non-strictly thermal character of Hawking radiation implies that the spectrum is also not strictly continuous. Yoon also found that the Hawking radiation spectrum is truncated below a certain frequency, given a certain Hawking temperature of the black hole T_{H}, corresponding to a minimum energy of an emitted particle E_{min}\\approx\\alpha T_{H} where alpha is a constant which depends on the considered scenario (isolated horizon scenario, Tanaka-Tamaki scenario Kong-Yoon scenario). We match these results with our recent result that permits to find the frequency of emission for highly excited black hole's transitions between different levels if one interpre...

  9. Organophosphate insecticide (famphur) topically applied to cattle kills magpies and hawks

    Science.gov (United States)

    Henny, C.J.; Blus, L.J.; Kolbe, E.J.; Fitzner, R.E.

    1985-01-01

    A systematic field study of a black-billed magpie (P. pica) population revealed that magpies and red-tailed hawks (B. jamaicensis) were killed by famphur (= famophos, Warbex) used as a pour-on to control cattle warbles (Hypoderma sp.). Magpie mortality began on treatment day and continued for more than 3 mo. (38 found death); mortality peaked between Day 5 an Day 13. Estimates of magpie density (based on transects) decreased in both the control and treatment areas, but the decrease was greater in the treatment area. A red-tailed hawk found dead on Day 10 had eaten a famphur-contaminated magpie. Another red-tailed hawk was found alive but immobilized, and a 3rd died outside the study area. Brain cholinesterse (ChE) activity was 70-92% depressed in all dead birds examined; famphur residues were detected in all 17 magpies and the 2 hawks analyzed. The amount of famphur obtained by the dead magpies was estimated at 5.2-6.1 mg/kg (based on residue concentrations in the gizzard), which was above the acute oral LD50 for several bird species. The cow hair portion (12%) of the pooled gizzard contents from 13 other dead magpies produced extremely high famphur residues (4600 ppm). The residues persisted on cattle hair for more than 90 days post-treatment. Magpie populations in the far western states declined between 1968 and 1979, which corresponds with widespread use of famphur, although other factors may be involved.

  10. Are red-tailed hawks and great horned owls diurnal-nocturnal dietary counterparts?

    Science.gov (United States)

    Marti, C.D.; Kochert, Michael N.

    1995-01-01

    Red-tailed Hawks (Buteo jamaicensis) and Great Homed Owls (Bubo virginianus)are common in North America where they occupy a wide range of habitats, often sympatrically. The two species are similar in size and have been portrayed as ecological counterparts, eating the same prey by day and night. We tested the trophic similarity of the two species by comparing published dietary data from across the United States. Both species ate primarily mammals and birds, and mean proportions of those two prey types did not differ significantly between diets of the two raptors. Red-tailed Hawks ate significantly more reptiles, and Great Homed Owls significantly more invertebrates. Dietary diversity was not significantly different at the level of prey taxonomic class, and diet overlap between the two species averaged 91%. At the prey species level, dietary overlap averaged only 50%, and at that level Red-tailed Hawk dietary diversity was significantly greater than that of Great Horned Owls. Mean prey mass of Red-tailed Hawks was significantly greater than that of Great Homed Owls. Populations of the two species in the western United States differed trophically more than did eastern populations. We conclude that, although the two species are generalist predators, they take largely different prey species in the same localities resulting in distinctive trophic characteristics.

  11. Addendum: Hawking Radiation of Photons in a Variable-mass Kerr Black Hole

    OpenAIRE

    Wu, S. Q.; Cai, X.

    2001-01-01

    Hawking evaporation of photons in a variable-mass Kerr space-time is investigated by using a method of the generalized tortoise coordinate transformation. The blackbody radiant spectrum of photons displays a new spin-rotation coupling effect obviously dependent on different helicity states of photons.

  12. Gravitational instantons of type $D_k$ and a generalization of the Gibbons-Hawking Ansatz

    OpenAIRE

    Ionas, Radu A.

    2016-01-01

    We describe a quaternionic-based Ansatz generalizing the Gibbons-Hawking Ansatz to a class of hyperk\\"ahler metrics with hidden symmetries. We then apply it to obtain explicit expressions for gravitational instanton metrics of type $D_k$.

  13. Evaluating the release of a large store from the BAE Hawk Mk120

    CSIR Research Space (South Africa)

    Jamison, Kevin

    2010-11-01

    Full Text Available The analysis of the release of a large store from the outboard pylon of the BAE Hawk Mk120 is described as a case study. The process adopted to address this challenge included using both the ARUV panel code and the CFD-FASTRAN Navier...

  14. Notes on the breeding biology of Javan Hawk-eagle in West Java, Indonesia

    NARCIS (Netherlands)

    Nijman, V.; Balen, van S.; Sözer, R.

    2000-01-01

    The Javan Hawk-eagle Spizaetus bartelsi is one of the rarest and least known birds of prey, regarded as globally endangered and confined to the last remnants of forests left on the densely populated island of Java, Indonesia. Its biology is little-known and only a few cases of breeding have been

  15. "The Power of the Oral Tradition: Giving Life to Words:" Conversations with Virginia Driving Hawk Sneve

    Science.gov (United States)

    Young, Teresa; Henderson, Darwin L.

    2013-01-01

    Virginia Driving Hawk Sneve, a former English teacher and school counselor, is an award-winning author, best known for her children's books about the Rosebud Sioux life and culture, which combines history and legend to create culturally rich and authentic Native American stories. In this article, the authors share their conversations with Virginia…

  16. Behavioural ecology, distribution and conservation of the Javan Hawk-eagle Spizaetus bartelsi Stresemann, 1924

    NARCIS (Netherlands)

    Sözer, Resit; Nijman, Vincent

    1995-01-01

    In the period December 1993 – January 1995 research on the behavioural ecology, distribution and conservation of the Javan Hawk-eagle Spizaetus bartelsi was carried out by R. Sözer and V. Nijman, under supervision of BirdLife International / PHPA – Indonesia Programme. This research was part of the

  17. The potential role of oral pH in the persistence of Trichomonas gallinae in Cooper's Hawks (Accipiter cooperii).

    Science.gov (United States)

    Urban, Elizabeth H; Mannan, R William

    2014-01-01

    Trichomoniasis, caused by the protozoan Trichomonas gallinae, affects a variety of species worldwide including avivorious raptors. Existing information suggests that the disease is most prevalent in young birds, and differential susceptibility to trichomoniasis among individuals in different age groups was documented in Cooper's Hawks (Accipiter cooperii) nesting in Tucson, Arizona. In that population, 85% of nestling Cooper's Hawks had T. gallinae in their oral cavity, compared to only 1% of breeding-age hawks. Trichomonads generally are sensitive to environmental pH and we explored the possibility that differences in oral pH may contribute to the differential prevalence of infection between age groups. We measured the pH of the fluid in the oral cavity in 375 Cooper's Hawks from three age groups (nestlings, fledglings, and breeding age) in Tucson, Arizona, in 2010 and 2011 and clinically tested for T. gallinae in a subsample of hawks. Oral pH of nestlings (∼ 6.8) was 7.3 times less acidic than in fledgling or breeding Cooper's Hawks (∼ 6.1). The incidence of T. gallinae was higher in nestlings (16%) than in either fledglings or breeding hawks (0%). Our findings indicate that oral pH becomes more acidic in Cooper's Hawks soon after they leave the nest. Trichomonas gallinae thrives when pH is between 6.5 and 7.5 (optimum 7.2), but is less viable in more acidic conditions. Higher levels of acidity in the oral cavity of fledglings and breeding Cooper's Hawks may reduce their susceptibility to trichomoniasis, and play a role in the differential prevalence of infection among age groups.

  18. The red-tailed hawk, Buteo jamaicensis, a native definitive host of Frenkelia microti (Apicomplexa) in North America.

    Science.gov (United States)

    Upton, S J; McKown, R D

    1992-01-01

    Oral inoculation of prairie voles, Microtus ochrogaster, with coccidian sporocysts isolated from the feces of a red-tailed hawk, Buteo jamaicensis, in Kansas, USA, resulted in formation of Frenkelia microti (Apicomplexa: Sarcocystidae) tissue cysts in the brains of the voles. Five additional isolates of morphologically similar sporocysts collected from red-tailed hawks or other Buteo spp. in Kansas failed to result in detectable infections in rodents. These results are the first to verify that red-tailed hawks are natural definitive host in North America for F. microti.

  19. First radioactive ions charge bred in REXEBIS at the REX-ISOLDE accelerator

    CERN Document Server

    Wolf, B H; Fostner, O; Wenander, F; Ames, F; Reisinger, K; Liljeby, L; Skeppstedt, Ö; Jonson, B; Nyman, G H

    2003-01-01

    REXEBIS is the charge breeder of the REX-ISOLDE post accelerator. The radioactive 1$^{+}$ ions produced at ISOLDE are accumulated, phase-space cooled and bunched in the REXTRAP, and thereafter injected into the EBIS with an energy up to 60 keV. The REXEBIS produced the first charge bred ions in August 2001 and has been running nearly non-stop during September to December 2001. It has delivered stable $^{39}$K$^{10+}$ and $^{23}$Na$^{6+}$ beams generated in the ion source in front of REXTRAP with a Na$^{7+}$ current exceeding 70 pA (6x10$^{7}$ p/s). Stable $^{27}$Al$^{7+}$ and $^{23}$Na$^{6+}$ from ISOLDE and also the first radioactive $^{26}$Na$^{7+}$ and $^{24}$Na$^{7+}$ beams (just 5x10$^{5}$ p/s) have been charge bred and accelerated for tests of the experimental setup. Despite some problems with the electron gun, which had one breakdown after about 1500 hours of operation and displays slow changes of the emission conditions, the EBIS is working remarkably stable (24 hours / 7 days a week). We will report ...

  20. Potential and limitations of nucleon transfer experiments with radioactive beams at REX-ISOLDE

    CERN Document Server

    Gund, C.; Cub, J.; Dietrich, A.; Hartlein, T.; Lenske, H.; Pansegrau, D.; Richter, A.; Scheit, H.; Schrieder, G.; Schwalm, D.

    2001-01-01

    As a tool for studying the structure of nuclei far off stability the technique of $\\gamma$-ray spectroscopy after low-energy single-nucleon transfer reactions with radioactive nuclear beams in inverse kinematics was investigated. Modules of the MINIBALL germanium array and a thin position-sensitive parallel plate avalanche counter (PPAC) to be employed in future experiments at REX-ISOLDE were used in a test experiment performed with a stable $^{36}$S beam on deuteron and $^{9}$Be targets. It is demonstrated that the Doppler broadening of $\\gamma$ lines detected by the MINIBALL modules is considerably reduced by exploiting their segmentation, and that for beam intensities up to 10$^{6}$ particles/s the PPAC positioned around zero degrees with respect to the beam axis allows not only to significantly reduce the gamma background by requiring coincidences with the transfer products but also to control the beam and its intensity by single particle counting. The predicted large neutron pickup cross-sections of neut...

  1. REXEBIS the Electron Beam Ion Source for the REX-ISOLDE project

    CERN Document Server

    Wenander, F; Liljeby, L; Nyman, G H

    1998-01-01

    The REXEBIS is an Electron Beam Ion Source (EBIS) developed especially to trap and further ionise the sometimes rare and short-lived isotopes that are produced in the ISOLDE separator for the Radioactive beam EXperiment at ISOLDE (REX-ISOLDE). By promoting the single-charged ions to a high charge-state the ions are more efficiently accelerated in the following linear accelerator. The EBIS uses an electron gun capable of producing a 0.5 A electron beam. The electron gun is immersed in a magnetic field of 0.2 T, and the electron beam is compressed to a current density of >200 A/cm2 inside a 2 T superconducting solenoid. The EBIS is situated on a high voltage (HV) platform with an initial electric potential of 60 kV allowing cooled and bunched 60 keV ions extracted from a Penning trap to be captured. After a period of confinement in the electron beam (<20 ms), the single-charged ions have been ionised to a charge-to-mass ratio of approximately ¼. During this confinement period, the platform potential is decr...

  2. Beam Dynamics Simulations of the REX-ISOLDE A/q-separator

    CERN Document Server

    Fraser, M A; Wenander, F

    2014-01-01

    The REX-ISOLDE A=q-separator selects the radioactive species of interest from the background of residual gas ions coming from the EBIS ion source. In the context of the HIE-ISOLDE upgrade, including the implementation of a multi-harmonic buncher and an upgraded EBIS, the separator and the beam line between the EBIS and RFQ, which we will call the Low Energy Beam Transfer (LEBT) line, has been simulated by tracking particles through the field maps of each active element using the TRACK [4] code. The simulations were benchmarked with a COSY-1 model that was improved to take into account the fringe fields of the electrostatic quadrupoles, electrostatic deflector and magnetic bender; the model can be used to tune and optimise the separator with higher-order effects taken into account. In this note the beam dynamics simulations are documented and the transverse and longitudinal acceptance of the separator line studied to provide design constraints for the EBIS upgrade.

  3. Exploring halo effects in the scattering of $^{11}$Be on heavy targets at REX-ISOLDE

    CERN Multimedia

    2002-01-01

    We propose to measure the scattering of $^{11}$Be on heavy targets at energies around the Coulomb barrier with the aim to study the effect of the neutron halo on the reaction mechanisms. We expect to see deviations of the elastic cross sections with respect to Rutherford, even at energies below the barrier, due to the effect of dipole polarizability. We also expect to observe the inelastic excitation from the 1/2$^{+}$ ground state to the 1/2$^{-}$ excited state. One neutron transfer, as well as break-up cross sections will be obtained from the analysis of the $^{10}$Be fragments produced in the collision. We expect to obtain information on the B(E1) distribution in the low energy continuum of $^{11}$Be. \\\\ \\\\In a previous experiment, $^{11}$Be was produced and accelerated at REX-ISOLDE with an intensity of 10$^{5}$ pps. This beam intensity would allow us to measure the scattered fragments, at forward and backward angles, with a detector array based on silicon strip detectors. We ask for a total of 27 shift...

  4. Study of the Unbound Nuclei $^{10}$Li and $^{7}$He at REX ISOLDE

    CERN Multimedia

    2002-01-01

    % IS367\\\\ \\\\ We propose to study the two unbound nuclei $^{10}$Li and $^{7}$He produced in simple one-neutron pick-up reactions induced by intense beams of $^{9}$Li and $^{6}$He from REX ISOLDE in $^{9}$Be and CD$_{2}$ targets.\\\\ \\\\The unbound nucleus $^{10}$Li is a binary subsystem of the two-neutron halo nucleus $^{11}$Li and its structure is of key importance for theoretical investigations of the halo structure. We propose two different reactions, which together would give an unambiguous determination of lowest $\\textit{s-}$ and $\\textit{p-}$wave resonances in the ($^{9}$Li+n) system.\\\\ \\\\Similarly $^{7}$He plays an important role in the dissociation of $^{8}$He, a drip-line nucleus with an $\\alpha$+4n five-body structure. The aim of our investigation is to search for an excited 1/2$^{-}$ state above the $^{7}$He 3/2$^{-}$ ground state in order to investigate its cluster structure. \\\\ \\\\

  5. One nucleon transfer reactions around $^{68}$Ni at REX-ISOLDE

    CERN Multimedia

    Blazhev, A A; Kruecken, R; Mertzimekis, T; Darby, I G; Lagogiannis, A; Habs, D; Diriken, J V J; Patronis, N

    2008-01-01

    We intend to investigate the single particle properties of the neutron-rich Ni isotopes in the mass region around $^{68}$Ni and at a later stage towards the doubly-magic $^{78}$Ni. As a first experiment we propose to study the single particle character of the ground and first excited states of $^{67}$Ni. This nucleus will be the projectile-like reaction product for the one-neutron transfer reaction. A $^{66}$Ni beam at 3A MeV delivered from REX-ISOLDE will be directed on a CD$_{2}$ target. Protons produced from the (d,p) reaction will be detected either in singles or in coincidence with ${\\gamma}$-rays recorded by the MINIBALL array. The particles will be detected by the newly-built Si position-sensitive barrel configuration. The objectives of this work are the unambiguous determination of the spins and parities of the first excited states of $^{67}$Ni and measurement of the relative spectroscopic factors of those states as well as of the ground state. The experimental results will be compared with those from...

  6. Cleared for Launch - Lessons Learned from the OSIRIS-REx System Requirements Verification Program

    Science.gov (United States)

    Stevens, Craig; Adams, Angela; Williams, Bradley; Goodloe, Colby

    2017-01-01

    Requirements verification of a large flight system is a challenge. It is especially challenging for engineers taking on their first role in space systems engineering. This paper describes our approach to verification of the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) system requirements. It also captures lessons learned along the way from developing systems engineers embroiled in this process. We begin with an overview of the mission and science objectives as well as the project requirements verification program strategy. A description of the requirements flow down is presented including our implementation for managing the thousands of program and element level requirements and associated verification data. We discuss both successes and methods to improve the managing of this data across multiple organizational interfaces. Our approach to verifying system requirements at multiple levels of assembly is presented using examples from our work at instrument, spacecraft, and ground segment levels. We include a discussion of system end-to-end testing limitations and their impacts to the verification program. Finally, we describe lessons learned that are applicable to all emerging space systems engineers using our unique perspectives across multiple organizations of a large NASA program.

  7. HURRICANE AND SEVERE STORM SENTINEL (HS3) GLOBAL HAWK ADVANCED VERTICAL ATMOSPHERIC PROFILING SYSTEM (AVAPS) DROPSONDE SYSTEM V2

    Data.gov (United States)

    National Aeronautics and Space Administration — The Hurricane and Severe Storm Sentinel (HS3) Global Hawk Advanced Vertical Atmospheric Profiling System (AVAPS) Dropsonde System dataset was collected by the...

  8. Concentrations of environmental contaminants in blood samples collected from Sharp-shinned hawks (Accipiter striatus) from the Eastern Flyway

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Table 1 provides the results of organochlorine and mercury analysis on plasma and whole blood samples (respectively) collected from 20 sharp-shinned hawks at HMS...

  9. HURRICANE AND SEVERE STORM SENTINEL (HS3) GLOBAL HAWK HIGH ALTITUDE MMIC SOUNDING RADIOMETER (HAMSR) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Hurricane and Severe Storm Sentinel (HS3) Global Hawk High Altitude MMIC Sounding Radiometer (HAMSR) dataset includes measurements gathered by the HAMSR...

  10. How the Hawking radiation affect quantum Fisher information of Dirac particles in the background of a Schwarzschild black hole

    Science.gov (United States)

    Huang, ChunYu; Ma, Wen-chao; Wang, Dong; Ye, Liu

    2018-01-01

    In this work, the effect of Hawking radiation on the quantum Fisher information (QFI) of Dirac particles is investigated in the background of a Schwarzschild black hole. Interestingly, it has been verified that the QFI with respect to the weight parameter θ of a target state is always independent of the Hawking temperature T. This implies that if we encode the information on the weight parameter, then we can affirm that the corresponding accuracy of the parameter estimation will be immune to the Hawking effect. Besides, it reveals that the QFI with respect to the phase parameter φ exhibits a decay behavior with the increase in the Hawking temperature T and converges to a nonzero value in the limit of infinite Hawking temperature T. Remarkably, it turns out that the function F_φ on θ =π \\big /4 symmetry was broken by the influence of the Hawking radiation. Finally, we generalize the case of a three-qubit system to a case of a N-qubit system, i.e., |ψ > _{1,2,3,\\ldots ,N} =(cos θ | 0 > ^{⊗ N}+sin θ e^{iφ }| 1 > ^{⊗ N}) and obtain an interesting result: the number of particles in the initial state does not affect the QFI F_θ , nor the QFI F_φ . However, with the increasing number of particles located near the event horizon, F_φ will be affected by Hawking radiation to a large extent, while F_θ is still free from disturbance resulting from the Hawking effects.

  11. Solexa-Sequencing Based Transcriptome Study of Plaice Skin Phenotype in Rex Rabbits (Oryctolagus cuniculus.

    Directory of Open Access Journals (Sweden)

    Lei Pan

    Full Text Available Fur is an important genetically-determined characteristic of domestic rabbits; rabbit furs are of great economic value. We used the Solexa sequencing technology to assess gene expression in skin tissues from full-sib Rex rabbits of different phenotypes in order to explore the molecular mechanisms associated with fur determination.Transcriptome analysis included de novo assembly, gene function identification, and gene function classification and enrichment. We obtained 74,032,912 and 71,126,891 short reads of 100 nt, which were assembled into 377,618 unique sequences by Trinity strategy (N50=680 nt. Based on BLAST results with known proteins, 50,228 sequences were identified at a cut-off E-value ≥ 10-5. Using Blast to Gene Ontology (GO, Clusters of Orthologous Groups (KOG and Kyoto Encyclopedia of Genes and Genomes (KEGG, we obtained several genes with important protein functions. A total of 308 differentially expressed genes were obtained by transcriptome analysis of plaice and un-plaice phenotype animals; 209 additional differentially expressed genes were not found in any database. These genes included 49 that were only expressed in plaice skin rabbits. The novel genes may play important roles during skin growth and development. In addition, 99 known differentially expressed genes were assigned to PI3K-Akt signaling, focal adhesion, and ECM-receptor interactin, among others. Growth factors play a role in skin growth and development by regulating these signaling pathways. We confirmed the altered expression levels of seven target genes by qRT-PCR. And chosen a key gene for SNP to found the differentially between plaice and un-plaice phenotypes rabbit.The rabbit transcriptome profiling data provide new insights in understanding the molecular mechanisms underlying rabbit skin growth and development.

  12. Hawking radiation as tunneling in Schwarzschild anti-de Sitter black hole

    Science.gov (United States)

    Sefiedgar, A. S.; Ashrafinejad, A.

    2017-08-01

    The Hawking radiation from a (d+1) -dimensional Schwarzschild Anti-de Sitter (SAdS) black hole is investigated within rainbow gravity. Based on the method proposed by Kraus, Parikh and Wilczek, the Hawking radiation is considered as a tunneling process across the horizon. The emission rate of massless particles which are tunneling across the quantum-corrected horizon is calculated. Enforcing the energy conservation law leads to a dynamical geometry. Both the dynamical geometry and the quantum effects of space-time yield some corrections to the emission rate. The corrected radiation spectrum is not purely thermal. The emission rate is related to the changes of modified entropy in rainbow gravity and the corrected thermal spectrum may be consistent with an underlying unitary quantum theory. The correlations between emitted particles are also investigated in order to address the recovery of information.

  13. Regarding `Information Preservation and Weather Forecasting for Black Holes' by S. W. Hawking

    Science.gov (United States)

    Winterberg, Friedwardt

    2014-06-01

    It is proposed that the `apparent horizons' assumed by Hawking to resolve the black hole information paradox, are in reality the regions where in Lorentzian relativity the absolute velocity against a preferred reference system at rest with the zero point vacuum energy reaches the velocity of light, and where an elliptical differential equation holding matter in a stable equilibrium goes over a transluminal Euler-Tricomi equation into a hyperbolic differential equation where such an equilibrium is not more possible, with matter in approaching this region disintegrating into radiation. Hawking's proposal depends on the anti-de Sitter/conformal field theory (AdS/CFT) conjecture which in turn depends on string/M theory which in the absence of super-symmetry will not work.

  14. Violation of unitarity by Hawking radiation does not violate energy-momentum conservation

    Energy Technology Data Exchange (ETDEWEB)

    Nikolić, Hrvoje, E-mail: hnikolic@irb.hr [Theoretical Physics Division, Rudjer Bošković Institute, P.O.B. 180, HR-10002 Zagreb (Croatia)

    2015-04-01

    An argument by Banks, Susskind and Peskin (BSP), according to which violation of unitarity would violate either locality or energy-momentum conservation, is widely believed to be a strong argument against non-unitarity of Hawking radiation. We find that the whole BSP argument rests on the crucial assumption that the Hamiltonian is not highly degenerate, and point out that this assumption is not satisfied for systems with many degrees of freedom. Using Lindblad equation, we show that high degeneracy of the Hamiltonian allows local non-unitary evolution without violating energy-momentum conservation. Moreover, since energy-momentum is the source of gravity, we argue that energy-momentum is necessarily conserved for a large class of non-unitary systems with gravity. Finally, we explicitly calculate the Lindblad operators for non-unitary Hawking radiation and show that they conserve energy-momentum.

  15. Violation of unitarity by Hawking radiation does not violate energy-momentum conservation

    Energy Technology Data Exchange (ETDEWEB)

    Nikolić, Hrvoje [Theoretical Physics Division, Rudjer Bošković Institute, P.O.B. 180, HR-10002 Zagreb (Croatia)

    2015-04-02

    An argument by Banks, Susskind and Peskin (BSP), according to which violation of unitarity would violate either locality or energy-momentum conservation, is widely believed to be a strong argument against non-unitarity of Hawking radiation. We find that the whole BSP argument rests on the crucial assumption that the Hamiltonian is not highly degenerate, and point out that this assumption is not satisfied for systems with many degrees of freedom. Using Lindblad equation, we show that high degeneracy of the Hamiltonian allows local non-unitary evolution without violating energy-momentum conservation. Moreover, since energy-momentum is the source of gravity, we argue that energy-momentum is necessarily conserved for a large class of non-unitary systems with gravity. Finally, we explicitly calculate the Lindblad operators for non-unitary Hawking radiation and show that they conserve energy-momentum.

  16. Hawking temperature: an elementary approach based on Newtonian mechanics and quantum theory

    Science.gov (United States)

    Pinochet, Jorge

    2016-01-01

    In 1974, the British physicist Stephen Hawking discovered that black holes have a characteristic temperature and are therefore capable of emitting radiation. Given the scientific importance of this discovery, there is a profuse literature on the subject. Nevertheless, the available literature ends up being either too simple, which does not convey the true physical significance of the issue, or too technical, which excludes an ample segment of the audience interested in science, such as physics teachers and their students. The present article seeks to remedy this shortcoming. It develops a simple and plausible argument that provides insight into the fundamental aspects of Hawking’s discovery, which leads to an approximate equation for the so-called Hawking temperature. The exposition is mainly intended for physics teachers and their students, and it only requires elementary algebra, as well as basic notions of Newtonian mechanics and quantum theory.

  17. Maxwell’s Equal Area Law and the Hawking-Page Phase Transition

    Directory of Open Access Journals (Sweden)

    Euro Spallucci

    2013-01-01

    Full Text Available We study the phases of a Schwarzschild black hole in the Anti-deSitter background geometry. Exploiting fluid/gravity duality, we construct the Maxwell equal area isotherm   in the temperature-entropy plane, in order to eliminate negative heat capacity BHs. The construction we present here is reminiscent of the isobar cut in the pressure-volume plane which eliminates unphysical part of the Van der Walls curves below the critical temperature. Our construction also modifies the Hawking-Page phase transition. Stable BHs are formed at the temperature , while pure radiation persists for . turns out to be below the standard Hawking-Page temperature and there are no unstable BHs as in the usual scenario. Also, we show that, in order to reproduce the correct BH entropy , one has to write a black hole equation of state, that is, , in terms of the geometrical volume .

  18. A retrospective study of postmortem findings in red-tailed hawks

    Science.gov (United States)

    Franson, J.C.; Thomas, N.J.; Smith, M.R.; Robbins, A.H.; Newman, S.; McCartin, P.C.

    1996-01-01

    We studied necropsy results from carcasses of 163 red-tailed hawks (Buteo jamaicensis) submitted to the National Wildlife Health Center from 1975 through 1992. The most frequent postmortem finding was emaciation of unknown etiology, diagnosed in 33 (20%) carcasses. Proportionally more juveniles than adults were emaciated. Evidence of non-gunshot trauma, often suggestive of collision with vehicles or structures near roadways, was found in 29 (18%) birds. Of 25 (15%) toxicoses, 20 were attributed to agricultural pesticides, including famphur (4), fenthion (3), carbofuran (2), phosphamidon (2), endrin (1), and unidentified organophosphorus compounds (8). Lead and strychnine poisoning were diagnosed in two birds each, and selenium poisoning in one. Diseases, including aspergillosis, tuberculosis, pasteurellosis, and pox, were found in 21 (13%) hawks. Gunshot and electrocution were each diagnosed in six (4%) birds, one (0.6%) was trapped, miscellaneous conditions were found in 10 (6%), and no diagnosis could be determined for 32 (19%) of the carcasses.

  19. Hawking, fiducial, and free-fall temperature of black hole on gravity's rainbow

    Energy Technology Data Exchange (ETDEWEB)

    Gim, Yongwan; Kim, Wontae [Sogang University, Department of Physics, Seoul (Korea, Republic of)

    2016-03-15

    On gravity's rainbow, the energy of test particles deforms the geometry of a black hole in such a way that the corresponding Hawking temperature is expected to be modified. It means that the fiducial and free-fall temperatures on the black hole background should also be modified according to deformation of the geometry. In this work, the probing energy of test particles is assumed as the average energy of the Hawking particle in order to study the particle back reaction of the geometry by using the advantage of gravity's rainbow. We shall obtain the modified fiducial and free-fall temperatures, respectively. The behaviors of these two temperatures on the horizon tell us that black hole complementarity is still well defined on gravity's rainbow. (orig.)

  20. Analogy of QCD hadronization and Hawking-Unruh radiation at NICA

    Energy Technology Data Exchange (ETDEWEB)

    Nasser Tawfik, Abdel [Modern University for Technology and Information (MTI), Egyptian Center for Theoretical Physics (ECTP), Cairo (Egypt); World Laboratory for Cosmology And Particle Physics (WLCAPP), Cairo (Egypt); Academy for Scientific Research and Technology (ASRT), Network for Nuclear Sciences (NNS), Cairo (Egypt)

    2016-08-15

    The proposed analogy of particle production from high-energy collisions and Hawking-Unruh radiation from black holes is extended to finite density (collisions) and finite electric charge (black holes). Assuming that the electric charge is directly proportional to the density (or the chemical potential), it becomes clear that for at least two freezeout conditions; constant s/T{sup 3} and E/N, the proposed analogy works very well. Dependence of radiation (freezeout) temperature on finite electric charge leads to an excellent estimation for kaon-to-pion ratio, for instance, especially in the energy range covered by NICA. The precise and complete measurements for various light-flavored particle yields and ratios are essential in characterizing Hawking-Unruh radiation from charged black holes and the QCD hadronization at finite density, as well. (orig.)

  1. Probing the thermal character of analogue Hawking radiation for shallow water waves?

    CERN Document Server

    Michel, Florent

    2014-01-01

    We numerically compute the scattering coefficients of shallow water waves blocked by a stationary counterflow. When the flow is transcritical, these coefficients closely follow Hawking's prediction according to which black holes should emit a thermal spectrum. We then study how the spectrum deviates from thermality when reducing the maximal flow velocity, with a particular attention to subcritical flows since these have been recently used to test Hawking's prediction. For low frequencies, we show, first, that the scattering coefficients are dominated by hydrodynamical channels and, second, that the Planckianity of the spectrum is completely lost. Our numerical results reproduce rather well the observations made by S. Weinfurtner et al. in the Vancouver experiment. Nevertheless, we propose a new interpretation of what has been observed, as well as new experimental tests to validate our findings.

  2. Mechanism of stimulated Hawking radiation in a laboratory Bose-Einstein condensate

    Science.gov (United States)

    Wang, Yi-Hsieh; Jacobson, Ted; Edwards, Mark; Clark, Charles W.

    2017-08-01

    We model a sonic black-hole analog in a quasi-one-dimensional Bose-Einstein condensate, using a Gross-Pitaevskii equation matching the configuration of a recent experiment by Steinhauer [Nat. Phys. 10, 864 (2014), 10.1038/nphys3104]. The model agrees well with important features of the experimental observations, demonstrating their hydrodynamic nature. We find that a zero-frequency bow wave is generated at the inner (white-hole) horizon, which grows in proportion to the square of the background condensate density. The relative motion of the black- and white-hole horizons produces a Doppler shift of the bow wave at the black hole, where it stimulates the emission of monochromatic Hawking radiation. The mechanism is confirmed using temporal and spatial windowed Fourier spectra of the condensate. Mean field behavior similar to that in the experiment can thus be fully explained without the presence of self-amplifying Hawking radiation.

  3. An Energy Upgrade of REX-ISOLDE to 3.1 MeV/u and Acceleration of Heavier Masses up to $A$=150.

    CERN Multimedia

    Wenander, F J C

    2002-01-01

    With an additional 9-gap resonator, operated at 202.56 MHz, the maximum beam energy of REX-ISOLDE will be increased from 2.2 MeV/u to 3.1 MeV/u. This enlarges considerably the range of mass numbers of projectiles reaching the Coulomb barrier for nuclear reactions. Acceleration of heavier projectiles, however, requires longer charge breeding times leading to smaller pulse repetition rates. Thus EBIS developments aiming at shorter breeding times by using higher electron beam current densities are foreseen. Moreover, longer breeding times require longer accumulation times and larger ion storage capacities in REXTRAP to maintain the beam intensities, which will be reached by using new cooling techniques. Although various optimization steps can be performed with ion sources local to REX-ISOLDE, a commissioning of the modified REX-ISOLDE with ISOLDE beams of heavier masses with 15 shifts is requested.

  4. Loss of NADH Oxidase Activity in Streptococcus mutans Leads to Rex-Mediated Overcompensation in NAD+ Regeneration by Lactate Dehydrogenase.

    Science.gov (United States)

    Baker, J L; Derr, A M; Faustoferri, R C; Quivey, R G

    2015-12-01

    Previous studies of the oral pathogen Streptococcus mutans have determined that this Gram-positive facultative anaerobe mounts robust responses to both acid and oxidative stresses. The water-forming NADH oxidase (Nox; encoded by nox) is thought to be critical for the regeneration of NAD(+), for use in glycolysis, and for the reduction of oxygen, thereby preventing the formation of damaging reactive oxygen species. In this study, the free NAD(+)/NADH ratio in a nox deletion strain (Δnox) was discovered to be remarkably higher than that in the parent strain, UA159, when the strains were grown in continuous culture. This unanticipated result was explained by significantly elevated lactate dehydrogenase (Ldh; encoded by ldh) activity and ldh transcription in the Δnox strain, which was mediated in part by the redox-sensing regulator Rex. cDNA microarray analysis of S. mutans cultures exposed to simultaneous acid stress (growth at a low pH) and oxidative stress (generated through the deletion of nox or the addition of exogenous oxygen) revealed a stress response synergistically heightened over that with either stress alone. In the Δnox strain, this elevated stress response included increased glucose phosphoenolpyruvate phosphotransferase system (PTS) activity, which appeared to be due to elevated manL transcription, mediated in part, like elevated ldh transcription, by Rex. While the Δnox strain does possess a membrane composition different from that of the parent strain, it did not appear to have defects in either membrane permeability or ATPase activity. However, the altered transcriptome and metabolome of the Δnox strain were sufficient to impair its ability to compete with commensal peroxigenic oral streptococci during growth under aerobic conditions. Streptococcus mutans is an oral pathogen whose ability to outcompete commensal oral streptococci is strongly linked to the formation of dental caries. Previous work has demonstrated that the S. mutans water

  5. Hawk eyes I: diurnal raptors differ in visual fields and degree of eye movement.

    Directory of Open Access Journals (Sweden)

    Colleen T O'Rourke

    Full Text Available BACKGROUND: Different strategies to search and detect prey may place specific demands on sensory modalities. We studied visual field configuration, degree of eye movement, and orbit orientation in three diurnal raptors belonging to the Accipitridae and Falconidae families. METHODOLOGY/PRINCIPAL FINDINGS: We used an ophthalmoscopic reflex technique and an integrated 3D digitizer system. We found inter-specific variation in visual field configuration and degree of eye movement, but not in orbit orientation. Red-tailed Hawks have relatively small binocular areas (∼33° and wide blind areas (∼82°, but intermediate degree of eye movement (∼5°, which underscores the importance of lateral vision rather than binocular vision to scan for distant prey in open areas. Cooper's Hawks' have relatively wide binocular fields (∼36°, small blind areas (∼60°, and high degree of eye movement (∼8°, which may increase visual coverage and enhance prey detection in closed habitats. Additionally, we found that Cooper's Hawks can visually inspect the items held in the tip of the bill, which may facilitate food handling. American Kestrels have intermediate-sized binocular and lateral areas that may be used in prey detection at different distances through stereopsis and motion parallax; whereas the low degree eye movement (∼1° may help stabilize the image when hovering above prey before an attack. CONCLUSIONS: We conclude that: (a there are between-species differences in visual field configuration in these diurnal raptors; (b these differences are consistent with prey searching strategies and degree of visual obstruction in the environment (e.g., open and closed habitats; (c variations in the degree of eye movement between species appear associated with foraging strategies; and (d the size of the binocular and blind areas in hawks can vary substantially due to eye movements. Inter-specific variation in visual fields and eye movements can influence

  6. Hawk eyes II: diurnal raptors differ in head movement strategies when scanning from perches.

    Science.gov (United States)

    O'Rourke, Colleen T; Pitlik, Todd; Hoover, Melissa; Fernández-Juricic, Esteban

    2010-09-22

    Relatively little is known about the degree of inter-specific variability in visual scanning strategies in species with laterally placed eyes (e.g., birds). This is relevant because many species detect prey while perching; therefore, head movement behavior may be an indicator of prey detection rate, a central parameter in foraging models. We studied head movement strategies in three diurnal raptors belonging to the Accipitridae and Falconidae families. We used behavioral recording of individuals under field and captive conditions to calculate the rate of two types of head movements and the interval between consecutive head movements. Cooper's Hawks had the highest rate of regular head movements, which can facilitate tracking prey items in the visually cluttered environment they inhabit (e.g., forested habitats). On the other hand, Red-tailed Hawks showed long intervals between consecutive head movements, which is consistent with prey searching in less visually obstructed environments (e.g., open habitats) and with detecting prey movement from a distance with their central foveae. Finally, American Kestrels have the highest rates of translational head movements (vertical or frontal displacements of the head keeping the bill in the same direction), which have been associated with depth perception through motion parallax. Higher translational head movement rates may be a strategy to compensate for the reduced degree of eye movement of this species. Cooper's Hawks, Red-tailed Hawks, and American Kestrels use both regular and translational head movements, but to different extents. We conclude that these diurnal raptors have species-specific strategies to gather visual information while perching. These strategies may optimize prey search and detection with different visual systems in habitat types with different degrees of visual obstruction.

  7. Hawk eyes II: diurnal raptors differ in head movement strategies when scanning from perches.

    Directory of Open Access Journals (Sweden)

    Colleen T O'Rourke

    Full Text Available BACKGROUND: Relatively little is known about the degree of inter-specific variability in visual scanning strategies in species with laterally placed eyes (e.g., birds. This is relevant because many species detect prey while perching; therefore, head movement behavior may be an indicator of prey detection rate, a central parameter in foraging models. We studied head movement strategies in three diurnal raptors belonging to the Accipitridae and Falconidae families. METHODOLOGY/PRINCIPAL FINDINGS: We used behavioral recording of individuals under field and captive conditions to calculate the rate of two types of head movements and the interval between consecutive head movements. Cooper's Hawks had the highest rate of regular head movements, which can facilitate tracking prey items in the visually cluttered environment they inhabit (e.g., forested habitats. On the other hand, Red-tailed Hawks showed long intervals between consecutive head movements, which is consistent with prey searching in less visually obstructed environments (e.g., open habitats and with detecting prey movement from a distance with their central foveae. Finally, American Kestrels have the highest rates of translational head movements (vertical or frontal displacements of the head keeping the bill in the same direction, which have been associated with depth perception through motion parallax. Higher translational head movement rates may be a strategy to compensate for the reduced degree of eye movement of this species. CONCLUSIONS: Cooper's Hawks, Red-tailed Hawks, and American Kestrels use both regular and translational head movements, but to different extents. We conclude that these diurnal raptors have species-specific strategies to gather visual information while perching. These strategies may optimize prey search and detection with different visual systems in habitat types with different degrees of visual obstruction.

  8. Hawk eyes I: diurnal raptors differ in visual fields and degree of eye movement.

    Science.gov (United States)

    O'Rourke, Colleen T; Hall, Margaret I; Pitlik, Todd; Fernández-Juricic, Esteban

    2010-09-22

    Different strategies to search and detect prey may place specific demands on sensory modalities. We studied visual field configuration, degree of eye movement, and orbit orientation in three diurnal raptors belonging to the Accipitridae and Falconidae families. We used an ophthalmoscopic reflex technique and an integrated 3D digitizer system. We found inter-specific variation in visual field configuration and degree of eye movement, but not in orbit orientation. Red-tailed Hawks have relatively small binocular areas (∼33°) and wide blind areas (∼82°), but intermediate degree of eye movement (∼5°), which underscores the importance of lateral vision rather than binocular vision to scan for distant prey in open areas. Cooper's Hawks' have relatively wide binocular fields (∼36°), small blind areas (∼60°), and high degree of eye movement (∼8°), which may increase visual coverage and enhance prey detection in closed habitats. Additionally, we found that Cooper's Hawks can visually inspect the items held in the tip of the bill, which may facilitate food handling. American Kestrels have intermediate-sized binocular and lateral areas that may be used in prey detection at different distances through stereopsis and motion parallax; whereas the low degree eye movement (∼1°) may help stabilize the image when hovering above prey before an attack. We conclude that: (a) there are between-species differences in visual field configuration in these diurnal raptors; (b) these differences are consistent with prey searching strategies and degree of visual obstruction in the environment (e.g., open and closed habitats); (c) variations in the degree of eye movement between species appear associated with foraging strategies; and (d) the size of the binocular and blind areas in hawks can vary substantially due to eye movements. Inter-specific variation in visual fields and eye movements can influence behavioral strategies to visually search for and track prey while

  9. Dual brane pairs and the Bekenstein-Hawking entropy of non-Susy spacetimes

    CERN Document Server

    Krause, A

    2003-01-01

    A novel approach is described towards a microscopic understanding of the Bekenstein-Hawking entropy of non-supersymmetric spacetimes - including the Schwarzschild black hole. It is based at an intermediate step on the description of the event horizon in terms of dual Euclidean brane pairs of type-II string theory or M theory. By counting specific chain structures on the brane complex, it is shown that one can reproduce the exact Schwarzschild black hole entropy plus its logarithmic correction.

  10. NASA Global Hawk Project Update and Future Plans: A New Tool for Earth Science Research

    Science.gov (United States)

    Naftel, Chris

    2009-01-01

    Science objectives include: First demonstration of the Global Hawk unmanned aircraft system (UAS) for NASA and NOAA Earth science research and applications; Validation of instruments on-board the Aura satellite; Exploration of trace gases, aerosols, and dynamics of remote upper Troposphere/lower Stratosphere regions; Sample polar vortex fragments and atmospheric rivers; Risk reduction for future missions that will study hurricanes and atmospheric rivers.

  11. High frequency of extra-pair paternity in an urban population of Cooper's Hawks

    Science.gov (United States)

    Rosenfield, Robert N.; Sonsthagen, Sarah A.; Stout, William C.; Talbot, Sandra

    2015-01-01

    Raptors exhibit some of the highest rates of intra-pair copulations among birds, perhaps in an attempt by males to reduce the risk of being cuckolded. Indeed, the frequency of extra-pair fertilizations reported in studies of raptors to date is relatively low (0-11.2%). Socially monogamous Cooper's Hawks (Accipiter cooperii) exhibit one of the highest copulation rates among birds, yet there are no published accounts of extra-pair copulations (or paternity). We studied a population of Cooper's Hawks in Milwaukee, Wisconsin, during three breeding seasons (2003, 2004, and 2007), examining the possible effects of age (1 yr old vs. ≥ 2 yr old), adult mass, and brood size on the frequency of extra-pair paternity (EPP). We found that 19.3% of nestlings (N = 27/140) were extra-pair young (EPY), and 34% of all broods (N = 15/44) had at least one EPY. The sires of the EPY in our study were identified for only two broods, suggesting that floater males may have engaged in extra-pair copulations with territorial females. We found that brood size was a good predictor of the occurrence of EPP (EPP) in nests, but adult mass and female age were not. To our knowledge, these possible correlates of the occurrence of EPP in raptors had not previously been investigated. Male Cooper's Hawks provide food for females during the pre-nesting period, and delivery of food is, in contrast to other raptor species, typically followed by copulation. Thus, one possible explanation of the relatively high rates of EPP in our study is that females might accept or even solicit extra-pair copulations from males other than their mates as a means of maximizing energy intake for egg production. Such behavior might be particularly likely in our study area, i.e., a food-rich urban setting with a high breeding density of Cooper's Hawks.

  12. Hawking-like radiation and the density matrix for an infalling observer during gravitational collapse

    Science.gov (United States)

    Saini, Anshul; Stojkovic, Dejan

    2016-09-01

    We study time-dependent Hawking-like radiation as seen by an infalling observer during gravitational collapse of a thin shell. We calculate the occupation number of particles of which the frequencies are measured in the proper time of an infalling observer in Eddington-Finkelstein coordinates. We solve the equations for the whole process from the beginning of the collapse till the moment when the collapsing shell reaches zero radius. The radiation distribution is not thermal in the whole frequency regime, but it is approximately thermal for the wavelengths of the order of the Schwarzschild radius of the collapsing shell. After the Schwarzschild radius is crossed, the temperature increases without limits as the singularity is approached. We also calculate the density matrix associated with this radiation. It turns out that the off-diagonal correlation terms to the diagonal Hawking leading-order terms are very important. While the trace of the diagonal (Hawking) density matrix squared decreases during the evolution, the trace of the total density matrix squared remains unity at all times and all frequencies.

  13. Saturating the Bekenstein-Hawking entropy bound with initial data sets for gravitational collapse

    Science.gov (United States)

    Bahrami, Sina

    2017-01-01

    It is possible to find initial states for gravitational collapse whose entropy approximately saturates the Bekenstein-Hawking entropy of the final black hole. The prototypical example of such a state is that envisaged by Zurek and Thorne, and also by Susskind: for a black hole of mass M , a number ˜M2 of quanta with energies of order ˜M-1 are accreted on a time scale of order ˜M3 , an approximate time-reverse of Hawking evaporation. There is lore that all initial states which saturate the Bekenstein-Hawking entropy must involve a formation time scale of this order, ˜M3 , and not the much shorter dynamical time scale ˜M . Counterexamples to this lore have been found by Sorkin, Wald and Zhang, and also by Hsu and Reeb, in the form of semiclassical initial data sets. However, the spacetimes that correspond to these counterexamples possess white holes in the past, as well as black holes in the future, which casts doubt on their physical relevance. We modify the counterexamples to eliminate the white holes, yielding formation time scales of order ˜M2, and argue that the lore is unfounded.

  14. The High Altitude MMIC Sounding Radiometer on the GLOBAL HAWK: From Technology Development to Science Discovery

    Science.gov (United States)

    Brown, Shannon; Denning, Richard; Lambrigtsen, Bjorn; Lim, Boon; Tanabe, Jordan; Tanner, Alan

    2013-01-01

    This paper presents results from the High Altitude MMIC Sounding Radiometer (HAMSR) during three recent field campaigns on the Global Hawk Unmanned Ariel Vehicles (UAV), focusing on the enabling technology that led to unprecedented observations of significant weather phenomenon, such as thermodynamic evolution of the tropical cyclone core during rapid intensification and the high resolution three dimensional mapping of several atmospheric river events. HAMSR is a 25 channel cross-track scanning microwave sounder with channels near the 60 and 118 GHz oxygen lines and the 183 GHz water vapor line. HAMSR was originally designed and built at the Jet Propulsion Laboratory as a technology demonstrator in 1998. Subsequent to this, HAMSR participated in three NASA hurricane field campaigns, CAMEX-4, TCSP and NAMMA. Beginning in 2008, HAMSR was extensively upgraded to deploy on the NASA Global Hawk (GH) platform and serve as an asset to the NASA sub-orbital program. HAMSR has participated on the Global Hawk during the 2010 Genesis and Rapid Intensification (GRIP) campaign, the 2011 Winter Storms and Atmospheric Rivers (WISPAR) campaign and is currently participating in the NASA Ventures Hurricane and Severe Storm Sentinel (HS3) campaign (2011-2015).

  15. The Hawk-Dove game in phenotypically homogeneous and heterogeneous populations of finite dimension

    Science.gov (United States)

    Laruelle, Annick; da Silva Rocha, André Barreira; Escobedo, Ramón

    2018-02-01

    The Hawk-Dove game played between individuals in populations of finite dimension is analyzed by means of a stochastic model. We take into account both cases when all individuals in the population are either phenotypically homogeneous or heterogeneous. A strategy in the model is a gene representing the probability of playing the Hawk strategy. Individual interactions at the microscopic level are described by a genetic algorithm where evolution results from the interplay among selection, mutation, drift and cross-over of genes. We show that the behavioral patterns observed at the macroscopic level can be reproduced as the emergent result of individual interactions governed by the rules of the Hawk-Dove game at the microscopic level. We study how the results of the genetic algorithm compare with those obtained in evolutionary game theory, finding that, although genes continuously change both their presence and frequency in the population over time, the population average behavior always achieves stationarity and, when this happens, the final average strategy played in the population oscillates around the evolutionarily stable strategy in the homogeneous population case or the neutrally stable set in the heterogeneous population case.

  16. Red-shouldered hawk broadcast surveys: Factors affecting detection of responses and population trends

    Science.gov (United States)

    McLeod, M.A.; Andersen, D.E.

    1998-01-01

    Forest-nesting raptors are often difficult to detect and monitor because they can be secretive, and their nests can be difficult to locate. Some species, however, respond to broadcasts of taped calls, and these responses may be useful both in monitoring population trends and in locating nests. We conducted broadcast surveys on roads and at active red-shouldered hawk (Buteo lineatus) nests in northcentral Minnesota to determine effects of type of call (conspecific or great horned owl [Bubo virginianus]), time of day, and phase of the breeding cycle on red-shouldered hawk response behavior and to evaluate usefulness of broadcasts as a population monitoring tool using area occupied-probability-of-detection techniques. During the breeding seasons of 1994 and 1995, we surveyed 4 10-station road transects 59 times and conducted 76 surveys at 24 active nests. Results of these surveys indicated conspecific calls broadcast prior to hatch and early in the day were the most effective method of detecting red-shouldered hawks. Probability of detection via conspecific calls averaged 0.25, and area occupied was 100%. Computer simulations using these field data indicated broadcast surveys have the potential to be used as a population monitoring tool.

  17. Ocular Lesions in Red-Tailed Hawks ( Buteo jamaicensis) With Naturally Acquired West Nile Disease.

    Science.gov (United States)

    Wünschmann, A; Armién, A G; Khatri, M; Martinez, L C; Willette, M; Glaser, A; Alvarez, J; Redig, P

    2017-03-01

    Ocular lesions are common in red-tailed hawks with West Nile (WN) disease. These lesions consist of pectenitis, choroidal or retinal inflammation, or retinal necrosis, but detailed investigation of the ocular lesions is lacking. Postmortem examination of the eyes of 16 red-tailed hawks with naturally acquired WN disease and 3 red-tailed hawks without WN disease was performed using histopathology, immunohistochemistry for West Nile virus (WNV) antigen, glial fibrillary acid protein, cleaved caspase-3, and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling method. Retinal lesions were classified as type I or type II lesions. Type I lesions were characterized by lymphoplasmacytic infiltrates in the subjacent choroid with degeneration limited to the outer retina (type Ia lesion) or with degeneration and necrosis of the outer retina or outer and inner retina (type Ib lesion) while retinal collapse, atrophy, and scarring were hallmarks of type II lesions. Type II retinal lesions were associated with a more pronounced choroiditis. Although not statistically significant, WNV antigen tended to be present in larger quantity in type Ib lesions. Type I lesions are considered acute while type II lesions are chronic. The development of retinal lesions was associated with the presence of an inflammatory infiltrate in the choroid. A breakdown of the blood-retina barrier is suspected to be the main route of infection of the retina. Within the retina, virus appeared to spread via both neuronal and Müller cell processes.

  18. Effect of sublethal lead exposure on gastric motility of red-tailed hawks.

    Science.gov (United States)

    Lawler, E M; Duke, G E; Redig, P T

    1991-07-01

    In order to determine the effects of low level lead exposure on gastric motility in raptors, strain gage transducers were surgically implanted on the serosal surface of the muscular stomach of three red-tailed hawks. The frequency and amplitude of gastric contractions during ingestion and early digestion were monitored for 1 week under control conditions and for 3 weeks while the birds were fed 0.82 or 1.64 mg lead (as lead acetate) per kg body weight each day. Exposure to these doses did not appreciably affect either the frequency or amplitude of gastric contractions in these birds. This low level lead exposure also had no consistent effect on the regular egestion of pellets of undigested material by hawks. Daily exposure to doses up to 6.55 mg lead/kg body weight did not affect the frequency or timing of pellet egestion, and exposure to 1.64 mg lead/kg did not affect the gastric contractions associated with pellet egestion. Although gastrointestinal dysfunction is often associated with clinical cases of acute lead toxicity, chronic exposure to these low levels of lead acetate did not significantly alter gastric motility in red-tailed hawks.

  19. Hawk calls elicit alarm and defensive reactions in captive Geoffroy's marmosets (Callithrix geoffroyi).

    Science.gov (United States)

    Searcy, Yvonne M; Caine, Nancy G

    2003-01-01

    Most descriptions of callitrichid antipredator behavior have come from observations of visual encounters with predators, but there is also anecdotal evidence suggesting that callitrichids may use auditory cues associated with raptors for the early detection of potential danger. In the present study, Geoffroy's marmosets consistently reacted to the tape-recorded calls of a red-tailed hawk (Buteo jamaicensis) with high-intensity antipredator behaviors. Compared to the taped calls of a raven (Corvus corax) and the taped sound of a power drill, the hawk calls elicited more startle reactions, more alarm calls, longer freeze times, increased use of safe areas of their enclosure and greater disruption in ongoing behavior. Once in a relatively safe location in the enclosure, the marmosets visually monitored the site of origin of the calls for 10 min and minimized locomotion for 30 min, but resumed baseline levels of other activities that had been disrupted by the hawk calls. Marmosets may use the auditory cues associated with predators for early detection, and subsequent avoidance, of a potential predator in the vicinity.

  20. What is your diagnosis? Blood smear from an injured red-tailed hawk.

    Science.gov (United States)

    Johns, Jennifer L; Luff, Jennifer A; Shooshtari, Mahrokh P; Zehnder, Ashley M; Borjesson, Dori L

    2009-06-01

    An injured juvenile red-tailed hawk (Buteo jamaicensis) was evaluated at the Veterinary Medical Teaching Hospital at the University of California, Davis. The hawk was quiet, alert, and emaciated, and had a closed comminuted, mid-diaphyseal ulnar fracture. CBC results included heterophilia with a left shift, monocytosis, and increased plasma fibrinogen concentration. The blood smear included rare heterophils containing small, dark blue inclusions approximately 1-2 mum in diameter that ranged from round to coccobacillary in shape and formed variably shaped aggregates; the morphology of the inclusions was suspicious for Chlamydophila or Ehrlichia spp. pathogens. The hawk died, and histopathologic examination of tissues obtained at necropsy found severe multifocal histiocytic and heterophilic splenitis in addition to chronic hepatitis, myocarditis and epicarditis, meningoencephalitis, and airsacculitis. Using immunohistochemistry the presence of Chlamydia/Chlamydophila spp. antigen within multiple tissues was confirmed. Chlamydophila psittaci DNA was demonstrated in whole blood and fresh splenic tissue via real-time PCR. Direct fluorescent antibody staining of air-dried blood smears was positive in rare leukocytes for Chlamydia/Chlamydophila spp. antigen, and immunocytochemical staining of blood smears for Chlamydia/Chlamydophila spp. antigen was focally positive in rare heterophils. These findings may represent the first reported diagnosis of natural avian C. psittaci infection by visualization of organisms in peripheral blood heterophils. Immunocytochemical evaluation of blood smears was valuable in confirming the diagnosis and may be a useful antemortem test to discriminate between bacteria and other inclusions within heterophils.

  1. An aerial-hawking bat uses stealth echolocation to counter moth hearing.

    Science.gov (United States)

    Goerlitz, Holger R; ter Hofstede, Hannah M; Zeale, Matt R K; Jones, Gareth; Holderied, Marc W

    2010-09-14

    Ears evolved in many nocturnal insects, including some moths, to detect bat echolocation calls and evade capture [1, 2]. Although there is evidence that some bats emit echolocation calls that are inconspicuous to eared moths, it is difficult to determine whether this was an adaptation to moth hearing or originally evolved for a different purpose [2, 3]. Aerial-hawking bats generally emit high-amplitude echolocation calls to maximize detection range [4, 5]. Here we present the first example of an echolocation counterstrategy to overcome prey hearing at the cost of reduced detection distance. We combined comparative bat flight-path tracking and moth neurophysiology with fecal DNA analysis to show that the barbastelle, Barbastella barbastellus, emits calls that are 10 to 100 times lower in amplitude than those of other aerial-hawking bats, remains undetected by moths until close, and captures mainly eared moths. Model calculations demonstrate that only bats emitting such low-amplitude calls hear moth echoes before their calls are conspicuous to moths. This stealth echolocation allows the barbastelle to exploit food resources that are difficult to catch for other aerial-hawking bats emitting calls of greater amplitude. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Petrology, Palynology, and Geochemistry of Gray Hawk Coal (Early Pennsylvanian, Langsettian in Eastern Kentucky, USA

    Directory of Open Access Journals (Sweden)

    James C. Hower

    2015-09-01

    Full Text Available This study presents recently collected data examining the organic petrology, palynology, mineralogy and geochemistry of the Gray Hawk coal bed. From the Early Pennsylvanian, Langsettian substage, Gray Hawk coal has been mined near the western edge of the eastern Kentucky portion of the Central Appalachian coalfield. While the coal is thin, rarely more than 0.5-m thick, it has a low-ash yield and a low-S content, making it an important local resource. The Gray Hawk coal palynology is dominated by Lycospora spp., and contains a diverse spectrum of small lycopods, tree ferns, small ferns, calamites, and gymnosperms. The maceral assemblages show an abundance of collotelinite, telinite, vitrodetrinite, fusinite, and semifusinite. Fecal pellet-derived macrinite, albeit with more compaction than is typically seen in younger coals, was observed in the Gray Hawk coal. The minerals in the coal are dominated by clay minerals (e.g., kaolinite, mixed-layer illite/smectite, illite, and to a lesser extent, pyrite, quartz, and iron III hydroxyl-sulfate, along with traces of chlorite, and in some cases, jarosite, szomolnokite, anatase, and calcite. The clay minerals are of authigenic and detrital origins. The occurrence of anatase as cell-fillings also indicates an authigenic origin. With the exception of Ge and As, which are slightly enriched in the coals, the concentrations of other trace elements are either close to or much lower than the averages for world hard coals. Arsenic and Hg are also enriched in the top bench of the coal and probably occur in pyrite. The elemental associations (e.g., Al2O3/TiO2, Cr/Th-Sc/Th indicate a sediment-source region with intermediate and felsic compositions. Rare metals, including Ga, rare earth elements and Ge, are highly enriched in the coal ashes, and the Gray Hawk coals have a great potential for industrial use of these metals. The rare earth elements in the samples are weakly fractionated or are characterized by heavy

  3. Elastic scattering and cluster-transfer reactions of 98Rb on 7Li at REX-ISOLDE

    CERN Document Server

    Bouma, Jake

    Exotic nuclei are nuclei with unusual proton to neutron ratios that exist far away from stability. Due to their instability, these nuclei are only available for nuclear reactions as radioactive ion beams. Experiments must therefore be performed in inverse kinematics at advanced radioactive isotope separation and acceleration facilities. REX-ISOLDE at CERN is one such facility, capable of producing post-accelerated radioactive ion beams with energies up to 2.85 MeV/u. Cluster-transfer reactions in inverse kinematics with a $^{7}$Li target are proposed as a tool for the study of exotic nuclei at REX-ISOLDE. In these reactions, either the $\\alpha$ or triton clusters that make up the weakly bound $^{7}$Li nucleus can be transfered to the beam nucleus. The remaining cluster that is not transferred can be detected, and identifies the particular transfer channel. Through this mechanism it is possible to populate states of very high spin, which is useful for $\\gamma$-spectroscopy in poorly known exotic regions. Speci...

  4. Development of a Silicon Detector Monitor for the HIE-ISOLDE Superconducting Upgrade of the REX-ISOLDE Linac

    CERN Document Server

    Zocca, F; Bravin, E; Pasini, M; Voulot, D; Wenander, F

    2011-01-01

    A silicon detector monitor has been developed and tested at REX-ISOLDE in the framework of the R&D program for the HIE-ISOLDE superconducting (SC) linac upgrade. In the future setup the monitor is intended to be located downstream of the cryogenic SC modules, for beam energy and timing measurements and for the SC cavities phase scanning. In this very first test a passivated ion implanted silicon detector, suited for charge particle spectroscopy, was mounted inside a REX diagnostic box, downstream of the 9-gap resonator. A strongly attenuated stable ion beam with a mass-to-charge state (A/Q) of 4, mainly composed of 12C3+, 16O4+ and 20Ne5+, was used for the tests. The energy measurements carried out allowed for beam spectroscopy and ion identification with an energy resolution of ~ 3 % FWHM. The energy identification of the stable beam was suited for a rapid scan of the cavity; a procedure which could be demonstrated for the third 7-gap cavity. The time structure of the beam, characterized by a 9.87 ns per...

  5. Effects of Ni-5%RExOy Composite Additives on Electrochemical Hydrogen Storage Performances of Mg2Ni

    Directory of Open Access Journals (Sweden)

    ZHANG Guo-fang

    2017-11-01

    Full Text Available The Ni-5%RExOy (CeO2, La2O3, Eu2O3 as composite additives, Mg2Ni-Ni-5%RExOy composites were prepared by the ball milling method. The effects of different additives on the structure, morphology, electrochemistry and kinetic properties of Mg2Ni alloy were studied systematically. The results show that composite additives can improve the proportion of amorphous and nanocrystalline structure of Mg2Ni alloy. The particle size is homogeneous but the agglomeration is observed in the sample with Ni-5%CeO2 additives. The composites with additives show higher maximum discharge capacity and better cycle stabilities. All of these three kinds of composite additives can improve the kinetic properties of the composites effectively, including optimizing the charge-transfer ability, the reversibility of the electrochemical reaction on the alloy surface, and enhancing the diffusion coefficients of H atoms in the bulk of alloy. Among these three kinds of additives, Ni-5%CeO2 additive shows the best catalysis effect on promoting the kinetic properties of the composites.

  6. Evaluating MODIS cloud retrievals with in situ observations from VOCALS-REx

    Directory of Open Access Journals (Sweden)

    N. J. King

    2013-01-01

    Full Text Available Microphysical measurements collected during eleven profiles, by the UK BAe-146 aircraft, through marine stratocumulus as part of the Variability of the American Monsoon Systems (VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx are compared to collocated overpasses of the Moderate Resolution Imaging Spectroradiometer (MODIS aboard the Aqua and Terra satellite platforms. The full depth of the cloud is sampled in each case using a Cloud Droplet Probe (CDP and a Two-Dimensional Stereo Probe (2DS together sizing cloud and precipitation droplets in the diameter range 2–1260 μm. This allows the total optical depth (τc of the cloud and effective radius (re of the droplet size distribution to be compared to MODIS cloud retrievals of the same quantities along with the secondarily derived total liquid water path. When compared to the effective radius at cloud top, the MODIS retrieved re using the 2.1 μm wavelength channel overestimates the in situ measurements on average by 13% with the largest overestimations coinciding with the detection by the 2DS of drizzle sized droplets. We show through consideration of the full vertical profile and penetration depths of the wavelengths used in the retrieval that the expected retrieved values are less than those at cloud top thus increasing the apparent bias in re retrievals particularly when using the 1.6 and 2.1 μm channels, with the 3.7 μm channel retrievals displaying the best agreement with in situ values. Retrievals of τc also tend to overestimate in situ values which, coupled with a high bias in re retrievals, lead to an overestimation of liquid water path. There is little apparent correlation between the variation of the three near-infrared re retrievals and the vertical structure of the cloud observed in situ. Retrievals are performed using measured profiles of water

  7. Nature of low dimensional structural modulations and relative phase stability in RexMo(W)1-xS2 transition metal dichalcogenide alloys

    KAUST Repository

    Sahu, R.

    2017-03-08

    We report on the various types of Peierls like two dimensional structural modulations and relative phase stability of 2H and 1T poly-types in the RexMo1-xS2 and RexW1-xS2 alloy system. Theoretical calculation predicts a polytype phase transition cross over at ∼50 at. % of Mo and W in ReS2 in both monolayer and bulk form, respectively. Experimentally, two different types of structural modulations at 50% and a modulation corresponding to trimerization at 75% alloy composition are observed for RexMo1-xS2 and only one type of modulation is observed at the 50% RexW1-xS2 alloy system. The 50% alloy system is found to be a suitable monolithic candidate for metal semiconductor transition with minute external perturbation. ReS2 is known to be in the 2D Peierls distorted 1Td structure and forms a chain like superstructure. Incorporation of Mo and W atoms into the ReS2 lattice modifies the metal-metal hybridization between the cations and influences the structural modulation and electronic properties of the system. The results offer yet another effective way to tune the electronic structure and poly-type phases of this class of materials other than intercalation, strain, and vertical stacking arrangement.

  8. The 8Li + 2H reaction studied in inverse kinematics at 3.15 MeV/nucleon using the REX-ISOLDE post-accelerator

    DEFF Research Database (Denmark)

    Tengborn, E.; Moro, A.M.; Nilsson, T.

    2011-01-01

    The reaction 8Li + 2H has been studied in inverse kinematics at the incident energy of 3.15 MeV/nucleon, using the REX-ISOLDE post-accelerator. The reaction channels corresponding to (d,p), (d,d), and (d,t) reactions populating ground states and low-lying excited states in 7–9Li have been...

  9. Temporal and spatial stability of red-tailed hawk territories in the Luquillo Experimental Forest, Puerto Rico

    Science.gov (United States)

    Boal, C.W.; Snyder, H.A.; Bibles, Brent D.; Estabrook, T.S.

    2003-01-01

    We mapped Red-tailed Hawk (Buteo jamaicensis) territories in the Luquillo Experimental Forest (LEF) of Puerto Rico in 1998. We combined our 1998 data with that collected during previous studies of Red-tailed Hawks in the LEF to examine population numbers and spatial stability of territorial boundaries over a 26-yr period. We also investigated potential relationships between Red-tailed Hawk territory sizes and topographic and climatic factors. Mean size of 16 defended territories during 1998 was 124.3 ?? 12.0 ha, which was not significantly different from our calculations of mean territory sizes derived from data collected in 1974 and 1984. Aspect and slope influenced territory size with the smallest territories having high slope and easterly aspects. Territory size was small compared to that reported for other parts of the species' range. In addition, there was remarkably little temporal change in the spatial distribution, area, and boundaries of Red-tailed Hawk territories among the study periods. Further, there was substantial boundary overlap (21-27%) between defended territories among the different study periods. The temporal stability of the spatial distribution of Red-tailed Hawk territories in the study area leads us to believe the area might be at or near saturation.

  10. RExPrimer: an integrated primer designing tool increases PCR effectiveness by avoiding 3' SNP-in-primer and mis-priming from structural variation

    Directory of Open Access Journals (Sweden)

    Suwannasri Payiarat

    2009-12-01

    Full Text Available Abstract Background Polymerase chain reaction (PCR is very useful in many areas of molecular biology research. It is commonly observed that PCR success is critically dependent on design of an effective primer pair. Current tools for primer design do not adequately address the problem of PCR failure due to mis-priming on target-related sequences and structural variations in the genome. Methods We have developed an integrated graphical web-based application for primer design, called RExPrimer, which was written in Python language. The software uses Primer3 as the primer designing core algorithm. Locally stored sequence information and genomic variant information were hosted on MySQLv5.0 and were incorporated into RExPrimer. Results RExPrimer provides many functionalities for improved PCR primer design. Several databases, namely annotated human SNP databases, insertion/deletion (indel polymorphisms database, pseudogene database, and structural genomic variation databases were integrated into RExPrimer, enabling an effective without-leaving-the-website validation of the resulting primers. By incorporating these databases, the primers reported by RExPrimer avoid mis-priming to related sequences (e.g. pseudogene, segmental duplication as well as possible PCR failure because of structural polymorphisms (SNP, indel, and copy number variation (CNV. To prevent mismatching caused by unexpected SNPs in the designed primers, in particular the 3' end (SNP-in-Primer, several SNP databases covering the broad range of population-specific SNP information are utilized to report SNPs present in the primer sequences. Population-specific SNP information also helps customize primer design for a specific population. Furthermore, RExPrimer offers a graphical user-friendly interface through the use of scalable vector graphic image that intuitively presents resulting primers along with the corresponding gene structure. In this study, we demonstrated the program

  11. RExPrimer: an integrated primer designing tool increases PCR effectiveness by avoiding 3' SNP-in-primer and mis-priming from structural variation.

    Science.gov (United States)

    Piriyapongsa, Jittima; Ngamphiw, Chumpol; Assawamakin, Anunchai; Wangkumhang, Pongsakorn; Suwannasri, Payiarat; Ruangrit, Uttapong; Agavatpanitch, Gallissara; Tongsima, Sissades

    2009-12-03

    Polymerase chain reaction (PCR) is very useful in many areas of molecular biology research. It is commonly observed that PCR success is critically dependent on design of an effective primer pair. Current tools for primer design do not adequately address the problem of PCR failure due to mis-priming on target-related sequences and structural variations in the genome. We have developed an integrated graphical web-based application for primer design, called RExPrimer, which was written in Python language. The software uses Primer3 as the primer designing core algorithm. Locally stored sequence information and genomic variant information were hosted on MySQLv5.0 and were incorporated into RExPrimer. RExPrimer provides many functionalities for improved PCR primer design. Several databases, namely annotated human SNP databases, insertion/deletion (indel) polymorphisms database, pseudogene database, and structural genomic variation databases were integrated into RExPrimer, enabling an effective without-leaving-the-website validation of the resulting primers. By incorporating these databases, the primers reported by RExPrimer avoid mis-priming to related sequences (e.g. pseudogene, segmental duplication) as well as possible PCR failure because of structural polymorphisms (SNP, indel, and copy number variation (CNV)). To prevent mismatching caused by unexpected SNPs in the designed primers, in particular the 3' end (SNP-in-Primer), several SNP databases covering the broad range of population-specific SNP information are utilized to report SNPs present in the primer sequences. Population-specific SNP information also helps customize primer design for a specific population. Furthermore, RExPrimer offers a graphical user-friendly interface through the use of scalable vector graphic image that intuitively presents resulting primers along with the corresponding gene structure. In this study, we demonstrated the program effectiveness in successfully generating primers for strong

  12. Marine boundary layer over the subtropical southeast Pacific during VOCALS-REx – Part 2: Synoptic variability

    Directory of Open Access Journals (Sweden)

    D. A. Rahn

    2010-05-01

    Full Text Available In the second part of this work we study the day-to-day variability of the marine atmospheric boundary layer (MBL over the subtropical southeast Pacific using primarily results from a numerical simulation that covered the whole VOCALS-REx period (October–November 2008. In situ and satellite-derived observations of the MBL height in the offshore region indicate rapid, significant variations (from 500 m to 1700 m a.s.l. over a few days during October. These MBL changes are connected with the passage of midlatitude troughs that altered the large-scale environment over the VOCALS-REx region. In contrast, the synoptic forcing and MBL changes were less prominent during November. Modelled and observed MBL depth at Point Omega (20° S, 85° W compare quite well during October (but the simulation is on average 200 m lower while in November the simulation does not perform as well.

    In the prognostic local MBL height equation the height change, the horizontal MBL height advection, and the large scale vertical velocity at MBL top are calculated explicitly from the simulation. The entrainment velocity is calculated as the residual of the other terms in the equation. While the vertical velocity and residual terms are opposing and generally have the largest magnitude on average, it is the variability in the advection that explains most of the large changes in the MBL depth. Examination of several cases during VOCALS-REx suggests that the advective term is in turn largely controlled by changes in wind direction, driven by midlatitude activity, acting on a MBL that generally slopes down toward the coast. In one phase, the subtropical anticyclone is reinforced and extends toward the Chilean coast, leading to easterly wind that advects low MBL heights from the coast as far as Point Omega. The opposite phase occurs after the passage of an extratropical cyclone over southern Chile, leading to southwesterly wind that advects a deeper MBL towards subtropical

  13. Space Use by Swainson’s Hawk (Buteo swainsoni in the Natomas Basin, California

    Directory of Open Access Journals (Sweden)

    E. Fleishman

    2016-04-01

    Full Text Available We used satellite-based remote sensing to estimate home ranges for Swainson’s Hawk, a species listed as threatened in California (USA, on its breeding grounds in the Natomas Basin (northern Central Valley, California and to evaluate whether the species’ space-use intensity (statistically derived density of telemetry locations was associated with land cover, sex, reproductive success, or life stage of offspring. We differentiated seven classes of land cover—alfalfa, annually rotated irrigated crops, developed, grassland, orchard / vineyard, rice, and water. From 2011–2013, we fitted transmitters with global positioning systems to 23 adult Swainson’s Hawks. We recorded a minimum of six locations per day per bird from spring through early autumn of each year. We used a fixed, bivariate-normal kernel estimator to calculate a utilization distribution at 30-m resolution for each life stage of each individual within each year. We used a linear mixed model to estimate the associations between intensity of space use and land cover, sex, and reproductive status. The majority of adult Swainson’s Hawks traveled distances up to 8–10 km from the nest throughout the breeding season. Median seasonal home-range sizes in a given year ranged from 87–172 km2. The association between intensity of space use and grassland was 50–139% stronger, and the association between intensity of space use and alfalfa 23–59% stronger, than the associations between intensity of space use and any other land-cover type. Intensity of space use did not vary as a function of sex, reproductive status, or life stage. Given our results and additional knowledge of the species’ ecology, we suggest that reproductive success and, in turn, population-level recruitment may be associated equally if not more closely with availability of nesting sites than with the current distribution of land cover.

  14. Fluctuations of observed breeding Rough-legged Hawks and Gyrfalcons: regularity reconsidered.

    Science.gov (United States)

    Mindell, D P; White, C M

    1988-10-01

    We recently assessed regularity in fluctuation of annual numbers of breeding pairs observed for several raptor species, and found no indication of reputed regular or cyclic fluctuations in our Colville River, Alaska sample for Gyrfalcons (Falco rusticolus) or Rough-legged Hawks (Buteo lagopus) (Mindell et al. 1987). Discussions with colleagues have prompted us to expand our analysis and clarify key points. We present time series analyses, using the Colville River sample size and interval (13 surveys during a 27 year period) for a data set on lynx (Lynx canadensis) (Elton and Nicholson 1942) and for a hypothetical Gyrfalcon population. Indication of regular 10-year fluctuations (Pinterval in assessing a possible 10-year cycle for Gyrfalcons. We provide dates and methods used for the annual Colville River surveys in discussing applications and limitations of the survey findings. We use the annual Colville River surveys as an index of fluctuation in actual numbers of Gyrfalcons and Rough-legged Hawks present in the study area at the time, based on similarity in timing of surveys between years, use of boat surveys in 12 of 13 years, evidence indicating similarity in sampling error between years, and demonstration of the adequacy of the sample interval. Whether or not numbers of breeding Gyrfalcons and Rough-legged Hawks fluctuate regularly remains an open question. We have provided a first assessment of regularity in fluctuation of observed numbers of breeding pairs, and find regularity for this parameter unsupported considering the Colville River study area as a whole. If other researchersare stirred to test "conventional wisdom" presuming regularity, our study will have served its purpose.

  15. High-Altitude Laser Altimetry from the Global Hawk UAV for Regional Mapping of Surface Topography

    Science.gov (United States)

    Blair, J. B.; Rabine, D.; Wake, S.; Hofton, M. A.; Michell, S.

    2012-12-01

    NASA's Land, Vegetation, and Ice Sensor (LVIS) is a high-altitude, full-waveform, geodetic-imaging laser altimeter system of which a UAV-based version (LVIS-GH) is currently being tested. From 20 km above the surface in the Global Hawk UAV, LVIS-GH images surface topography and roughness (including forest height) across a 4 km wide swath using 15 m diameter footprints. In recent years, the LVIS has been flown at altitudes of up to 14 km over Greenland and Antarctica on flights up to 12 hours in duration, enabling the efficient and precise mapping of large areas from the air. The Global Hawk will extend this capability to up to 32 hours and altitudes approaching 20 km. In order to achieve decimeter level vertical precision and accuracy from high altitude, advanced parameter estimation techniques, based on those implemented in NASA's GEODYN software, are used to estimate the angular, spatial, and temporal biases required to accurately georeference the component lidar data sets. Data from specific in-air maneuvers are utilized in order to isolate the effects of different error sources and to break correlations between biases. Examples of high-altitude data and airborne/spaceborne sensor intercomparison and fusion will be shown. For example, the comparison of data from NASA's ICESat-1 mission with coincident LVIS data collected around 86S (the maximum extent of data collected during ICESat) to quantify inter-campaign biases in Icesat-1 elevation measurements and improve estimates of long -term elevation change rates of ice sheets will be shown. These results illustrate the utility of high-altitude wide swath imaging, particularly from platforms such as the Global-Hawk, for enhancing spacebased data sets.

  16. Flight initiation by Ferruginous Hawks depends on disturbance type, experience, and the anthropogenic landscape.

    Science.gov (United States)

    Nordell, Cameron J; Wellicome, Troy I; Bayne, Erin M

    2017-01-01

    The expansion of humans and their related infrastructure is increasing the likelihood that wildlife will interact with humans. When disturbed by humans, animals often change their behaviour, which can result in time and energetic costs to that animal. An animal's decision to change behaviour is likely related to the type of disturbance, the individual's past experience with disturbance, and the landscape in which the disturbance occurs. In southern Alberta and Saskatchewan, we quantified probability of flight initiation from the nest by Ferruginous Hawks (Buteo regalis) during approaches to nests by investigators. We tested if probability of flight was related to different disturbance types, previous experience, and the anthropogenic landscape in which individual Ferruginous Hawks nested. Probability of flight was related to the type of approach by the investigator, the number of previous visits by investigators, and the vehicular traffic around the nest. Approaches by humans on foot resulted in a greater probability of flight than those in a vehicle. Approaches in a vehicle via low traffic volume access roads were related to increased probability of flight relative to other road types. The number of previous investigator approaches to the nest increased the probability of flight. Overall, we found support that Ferruginous Hawks show habituation to vehicles and the positive reinforcement hypotheses as probability of flight was negatively related to an index of traffic activity near the nest. Our work emphasizes that complex, dynamic processes drive the decision to initiate flight from the nest, and contributes to the growing body of work explaining how responses to humans vary within species.

  17. Oceanic Weather Decision Support for Unmanned Global Hawk Science Missions into Hurricanes with Tailored Satellite Derived Products

    Science.gov (United States)

    Feltz, Wayne; Griffin, Sarah; Velden, Christopher; Zipser, Ed; Cecil, Daniel; Braun, Scott

    2017-04-01

    The purpose of this presentation is to identify in-flight hazards to high-altitude aircraft, namely the Global Hawk. The Global Hawk was used during Septembers 2012-2016 as part of two NASA funded Hurricane Sentinel-3 field campaigns to over-fly hurricanes in the Atlantic Ocean. This talk identifies the cause of severe turbulence experienced over Hurricane Emily (2005) and how a combination of NOAA funded GOES-R algorithm derived cloud top heights/tropical overshooting tops using GOES-13/SEVIRI imager radiances, and lightning information are used to identify areas of potential turbulence for near real-time navigation decision support. Several examples will demonstrate how the Global Hawk pilots remotely received and used real-time satellite derived cloud and lightning detection information to keep the aircraft safely above clouds and avoid regions of potential turbulence.

  18. INFLAMMATORY MARKERS ASSOCIATED WITH TRAUMA AND INFECTION IN RED-TAILED HAWKS (BUTEO JAMAICENSIS) IN THE USA.

    Science.gov (United States)

    Lee, Kelly A; Goetting, Valerie S; Tell, Lisa A

    2015-10-01

    Changes in inflammatory marker concentrations or activity can be used to monitor health and disease condition of domestic animals but have not been applied with the same frequency to wildlife. We measured concentrations or activity of six inflammatory markers (ceruloplasmin, haptoglobin, mannan-binding lectin-dependent complement [MBL/complement], unsaturated iron-binding capacity (UIBC) and total iron-binding capacity (TIBC), and plasma iron) in apparently healthy and sick or injured Red-tailed Hawks (Buteo jamaicensis). Haptoglobin and ceruloplasmin activities were consistently elevated in sick or injured hawks (2.1 and 2.5 times higher, respectively), and plasma iron concentrations decreased (0.46 times lower), relative to those of healthy birds. There were no differences between healthy and unhealthy hawks in TIBC and UIBC concentrations or MBL/complement activity. Therefore, haptoglobin, ceruloplasmin, and plasma iron would be useful inclusions in a panel of inflammatory markers for monitoring health in raptors.

  19. Probing the quantum correlation and Bell non-locality for Dirac particles with Hawking effect in the background of Schwarzschild black hole

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Shuai; Song, Xue-ke; Shi, Jia-dong; Ye, Liu, E-mail: yeliu@ahu.edu.cn

    2014-06-02

    In this Letter, we analytically explore the effect of the Hawking radiation on the quantum correlation and Bell non-locality for Dirac particles in the background of Schwarzschild black hole. It is shown that when the Hawking effect is almost nonexistent, corresponding to the case of an almost extreme black hole, the quantum properties of physically accessible state are the same for the initial situation. For finite Hawking temperature T, the accessible quantum correlation monotonously decreases along with increasing T owing to the thermal fields generated by the Hawking effect, and the accessible quantum non-locality will be disappeared when the Hawking temperature is more than a fixed value which increases with the parameter r of Werner state growing. Then we analyze the redistribution of quantum correlation, and find that for the case of the Hawking temperature being infinite, corresponding to the case of the black hole evaporating completely, the quantum correlation of physically accessible state is equal to the one of the inaccessible states. Moreover, due to the Pauli exclusion principle and the differences between Fermi–Dirac and Bose–Einstein statistics, for the Dirac fields the accessible classical correlation decreases with increase of the Hawking temperature, which is different for the scalar fields. For Bell non-locality, we also find that the quantum non-locality is always extinct for physically inaccessible states, and the strength of the non-locality decreases with enlarging intensity of Hawking effect when the non-locality is existent in physically accessible state.

  20. Extremal Black Holes in Supergravity and the Bekenstein-Hawking Entropy

    Directory of Open Access Journals (Sweden)

    R. D'Auria

    2002-03-01

    Full Text Available Abstract: We review some results on the connection among supergravity central charges, BPS states and Bekenstein-Hawking entropy. In particular, N = 2 super-gravity in four dimensions is studied in detail. For higher N supergravities we just give an account of the general theory specializing the discussion to the N = 8 case when one half of supersymmetry is preserved. We stress the fact that for extremal supergravity black holes the entropy formula is topological, that is the entropy turns out to be a moduli independent quantity and can be written in terms of invariants of the duality group of the supergravity theory.

  1. Klein-Gordon equation and Hawking radiation in the dyon black hole with a cosmic string

    CERN Document Server

    Vieira, H S; Silva, G V

    2015-01-01

    Charged massive scalar particles are considered in the gravitational and electromagnetic field produced by a dyonic black hole with a cosmic string along the axis of symmetry. Exact solutions of both angular and radial parts of the covariant Klein-Gordon equation in this background are obtained, and are given in terms of the confluent Heun functions. We emphasize the role of the presence of the cosmic string in these solutions. From the radial solution, we obtain the exact wave solutions near the exterior horizon of the black hole, and discuss the Hawking radiation spectrum and the energy flux.

  2. Generalized uncertainty principle impact onto the black holes information flux and the sparsity of Hawking radiation

    Science.gov (United States)

    Alonso-Serrano, Ana; DÄ browski, Mariusz P.; Gohar, Hussain

    2018-02-01

    We investigate the generalized uncertainty principle (GUP) corrections to the entropy content and the information flux of black holes, as well as the corrections to the sparsity of the Hawking radiation at the late stages of evaporation. We find that due to these quantum gravity motivated corrections, the entropy flow per particle reduces its value on the approach to the Planck scale due to a better accuracy in counting the number of microstates. We also show that the radiation flow is no longer sparse when the mass of a black hole approaches Planck mass which is not the case for non-GUP calculations.

  3. Integral method for the calculation of Hawking radiation in dispersive media. I. Symmetric asymptotics.

    Science.gov (United States)

    Robertson, Scott; Leonhardt, Ulf

    2014-11-01

    Hawking radiation has become experimentally testable thanks to the many analog systems which mimic the effects of the event horizon on wave propagation. These systems are typically dominated by dispersion and give rise to a numerically soluble and stable ordinary differential equation only if the rest-frame dispersion relation Ω^{2}(k) is a polynomial of relatively low degree. Here we present a new method for the calculation of wave scattering in a one-dimensional medium of arbitrary dispersion. It views the wave equation as an integral equation in Fourier space, which can be solved using standard and efficient numerical techniques.

  4. Newtonian black holes: Particle production, "Hawking" temperature, entropies and entropy field equations

    CERN Document Server

    Martínez-Merino, Aldo; Ryan, Michael P

    2016-01-01

    Newtonian gravitation with some slight modifications, along with some highly simplified ideas from quantum field theory allow us to reproduce, at least at the level of back-of-the-envelope calculations, many results of black hole physics. We consider particle production by a black hole, the Newtonian equivalent of the Hawking temperature, and the Bekenstein entropy. Also, we are able to deduce Newtonian field equations from entropy. We finally study higher-order Newtonian theories under the same assumptions used for ordinary Newtonian theory. In a companion article we will look at entropic forces for various entropies and make contact with our analysis of higher-order Newtonian theories.

  5. NEWTON, EINSTEIN AND HAWKING EXPLAIN DARK ENERGY, DARK MATTER AND COSMIC MYSTERIES.pdf

    OpenAIRE

    Bartlett, Rodney

    2016-01-01

    The idea of gravitational-electromagnetic coupling producing mass, first hinted at by Albert Einstein, allows Isaac Newton's laws of motion and gravitation to be looked at differently. In turn, this gives a new perspective on dark energy, dark matter and expansion of the universe. The work of Stephen Hawking also proved essential to writing this article, which grew out of a discussion I started on the vixra forums (Ramanujan/Einstein are lucky they lived b4 modern "science" - http://vixra.fre...

  6. High-Altitude MMIC Sounding Radiometer - From the IIP to the Global Hawk

    Science.gov (United States)

    Brown, Shannon; Denning, Richard; Lambrigtsen, Bjorn; Lim, Boon; Tanabe, Jordan; Tanner, Alan; Kangaslahti, Pekka; Gaier, Todd

    2011-01-01

    The HAMSR instrument is a 25 channel cross-track microwave sounder developed by the Jet Propulsion Laboratory under the IIP-98 program. The instrument was recently upgraded under the NASA AITT program in 2008 to deploy on the Global Hawk UAV. The instrument now has state-of-the-art radiometric performance and the capability to process and display both brightness temperature imagery and derived products in real time. The improved performance of the instrument is demonstrated through retrievals of temperature and water vapor.

  7. Recovery and Identification of West Nile Virus from a Hawk in Winter

    OpenAIRE

    Garmendia, Antonio E.; Van Kruiningen, Herbert J.; French, Richard A.; Anderson, John F.; Andreadis, Theodore G.; Kumar, Asok; West, A. Brian

    2000-01-01

    West Nile virus was recovered from the brain of a red-tailed hawk that died in Westchester County, N.Y., in February 2000. Multiple foci of glial cells, lymphocytes, and a few pyknotic nuclei were observed in the brain. Three to 4 days after inoculation of Vero cells with brain homogenates, cytopathic changes were detected. The presence of West Nile virus antigen in fixed cells or cell lysates was revealed by fluorescent antibody testing or enzyme-linked immunosorbent assay, respectively. Fur...

  8. Pansteatitis in a free-ranging red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Wong, E; Mikaelian, I; Desnoyers, M; Fitzgerald, G

    1999-12-01

    A free-ranging juvenile female red-tailed hawk (Buteo jamaicensis) that was unable to fly was admitted to a rehabilitation center and died 1 day later. Hematology and serum chemistry abnormalities included moderate regenerative anemia, elevated creatine kinase, and hyperphosphatemia. Necropsy revealed a generalized steatitis, and histology showed a necrotizing and granulomatous pansteatitis with intralesional pigment compatible with ceroid. There was also moderate diffuse myodegeneration, mild multifocal cardiomyopathy, and mild multifocal hepatic necrosis. These changes and lesions resemble those caused by vitamin E deficiency in mammals and fish-eating birds.

  9. Emerging Hawking-Like Radiation from Gravitational Bremsstrahlung Beyond the Planck Scale

    CERN Document Server

    Ciafaloni, Marcello; Veneziano, Gabriele

    2015-01-01

    We argue that, as a consequence of the graviton's spin-2, its bremsstrahlung in trans-planckian-energy ($E\\gg M_P$) gravitational scattering at small deflection angle can be nicely expressed in terms of helicity-transformation phases and their transfer within the scattering process. The resulting spectrum exhibits deeply sub-planckian characteristic energies of order $M_P^2/E \\ll M_P$ (reminiscent of Hawking radiation), a suppressed fragmentation region, and a reduced rapidity plateau, in broad agreement with recent classical estimates.

  10. Hawking radiation screening and Penrose process shielding in the Kerr black hole

    Energy Technology Data Exchange (ETDEWEB)

    Mc Caughey, Eamon [Dublin Institute of Technology, School of Mathematical Sciences, Dublin 8 (Ireland)

    2016-04-15

    The radial motion of massive particles in the equatorial plane of a Kerr black hole is considered. Screening of the Hawking radiation and shielding of the Penrose process are examined (both inside and outside the ergosphere) and their effect on the evaporation of the black hole is studied. In particular, the locus and width of a classically forbidden region and their dependence on the particle's angular momentum and energy is analysed. Tunneling of particles between the boundaries of this region is considered and the transmission coefficient determined. (orig.)

  11. A novel technique for prevention of self-mutilation in three Harris' hawks (Parabuteo unicinctus).

    Science.gov (United States)

    Smith, Stephen P; Forbes, Neil A

    2009-03-01

    Feather destructive behavior is an ever-increasing problem in captive birds of prey and any associated self-mutilation can be challenging to manage. This clinical report describes a noninvasive, nonpainful, temporary beak modification technique used to prevent self-mutilation in 3 Harris' hawks (Parabuteo unicinctus), when other methods and husbandry modifications had failed. The technique was successful in all 3 birds, and no adverse effects were observed. Further investigations are required to further evaluate if this beak modification technique causes any psychologic or physical stress to the avian patient.

  12. Susskind's challenge to the Hartle Hawking no-boundary proposal and possible resolutions

    Science.gov (United States)

    Page, Don N.

    2007-01-01

    Given the observed cosmic acceleration, Leonard Susskind has presented the following argument against the Hartle Hawking no-boundary proposal for the quantum state of the universe: it should most likely lead to a nearly empty large de Sitter universe, rather than to early rapid inflation. Even if one adds the condition of observers, they are most likely to form by quantum fluctuations in de Sitter and therefore not see the structure that we observe. Here I present my own amplified version of this argument and consider possible resolutions, one of which seems to imply that inflation expands the universe to be larger than 101010122 Mpc.

  13. Mechanism of stimulated Hawking radiation in a laboratory Bose-Einstein condensate

    CERN Document Server

    Wang, Yi-Hsieh; Edwards, Mark; Clark, Charles W

    2016-01-01

    We model a sonic black hole analog in a quasi one-dimensional Bose-Einstein condensate, using a Gross-Pitaevskii equation matching the configuration of a recent experiment by Steinhauer. The model agrees well with the experimental observations, with no adjustable parameters, demonstrating their hydrodynamic nature. With enhanced but experimentally feasible parameters we establish by spectral analysis that a growing bow wave is generated at the inner (white hole) horizon, stimulating the emission of Hawking radiation. The black hole laser effect plays no role.

  14. Routes and travel rates of migrating Peregrine Falcons Falco peregrinus and Swainson's Hawks Buteo swainsoni in the Western Hemisphere

    Science.gov (United States)

    Fuller, Mark R.; Seegar, William S.; Schueck, Linda S.

    1998-01-01

    We describe and compare the migration routes, length of migration, and duration of migration of Peregrine Falcons Falco peregrinus tundrius and Swainson's Hawks Buteo swainsoni in the Western Hemisphere. We radio tracked migrants using the Argos satellite system. Our initial samples were 34 Swainson's Hawks from representative areas of their breeding range, and 61 Peregrine Falcons captured at nest sites across the North American boreal forest and low Arctic or on the migration routes along the mid-Atlantic and Gulf of Mexico coasts. The average distance of migration for Peregrines was 8,624 km southward, and 8,247 km northward. Peregrines travelled at an average rate of 172 km/d southward and 198 km/d going north. Peregrine Falcons used at least three broad, general routes south from the breeding areas, and individuals stopped migrating as far north as the U.S.A. mid-Atlantic coast and as far south as central Argentina. The radiomarked Peregrine Falcons used coastal routes, mid-continental routes, and water-crossing routes: the Davis Strait and Caribbean Sea. During northward migration, Peregrines migrating through at Padre Island, Texas diverged for destinations from central Alaska across the continent to central West Greenland. Swainson's Hawks migrated an average of about 13,504 km southward and 11,952 km northward, and travelled 188 km/d southward and 150 km/d northward. Swainson's Hawks converged in eastern Mexico on the Gulf of Mexico coast. Southward, these hawks followed a narrow, well-defined path through Central America, across the Andes Mountains in Columbia, and east of the Andes to central Argentina where they all spent the austral summer. Swainson's Hawks northward migration largely retraced their southward route.

  15. Do nuclei go pear-shaped? Coulomb excitation of 220Rn and 224Ra at REX-ISOLDE (CERN

    Directory of Open Access Journals (Sweden)

    Scheck M.

    2015-01-01

    Full Text Available The IS475 collaboration conducted Coulomb-excitation experiments with post-accelerated radioactive 220Rn and 224Ra beams at the REX-ISOLDE facility. The beam particles (Ebeam: 2.83 MeV/u were Coulomb excited using 60Ni, 114Cd, and 120Sn scattering targets. De-excitation γ-rays were detected employing the Miniball array and scattered particles were detected in a silicon detector. Exploiting the Coulomb-excitation code GOSIA for each nucleus several matrix elements could be obtained from the measured γ-ray yields. The extracted ‹3−||E3||0+› matrix element allows for the conclusion that, while 220Rn represents an octupole vibrational system, 224Ra has already substantial octupole correlations in its ground state. This finding has implications for the search of CP-violating Schiff moments in the atomic systems of the adjacent odd-mass nuclei.

  16. Science-Grade Imaging Data for HAWK-I, VIMOS, and VIRCAM: The ESO-UK Pipeline Collaboration

    Science.gov (United States)

    Neeser, M.; Lewis, J.; Madsen, G.; Yoldas, A.; Irwin, M.; Gabasch, A.; Coccato, L.; García-Dabó, C. E.; Romaniello, M.; Freudling, W.; Ballester, P.

    2016-12-01

    A new chapter for ESO science-grade data has begun with the implementa-tion of three new pipelines developed for the HAWK-I, VIMOS and VIRCAM instruments. The HAWK-I and VIMOS image archives at ESO have been completely reprocessed using these new pipelines, and these data are now publicly available. This article introduces the work done to bring these pipelines to the level of science-grade, their use in reprocessing ESO archival data, and their dissemination into ESO science operations and to the ESO community.

  17. Dietary Iodine Affected the GSH-Px to Regulate the Thyroid Hormones in Thyroid Gland of Rex Rabbits.

    Science.gov (United States)

    Qin, Feng; Pan, Xiaoqing; Yang, Jie; Li, Sheng; Shao, Le; Zhang, Xia; Liu, Beiyi; Li, Jian

    2018-02-01

    Iodine (I) is an essential trace element that can influence animal health and productivity. In this study, we investigated the effects of dietary iodine on the antioxidant indices of organ (liver and thyroid gland) and messenger RNA (mRNA) expression of glutathione peroxidase (GSH-Px) in Rex rabbits. A total of 120 4-month-old Rex rabbits (2235.4 ± 13.04 g BW) were divided into four equal groups, and their diets were supplemented with iodine (0, 0.2, 2, or 4 mg/kg dry matter (DM)). The iodine concentration in basal diet (control group) was 0.36 mg/kg DM. In most of measured parameters, supplemental iodine exerted no significant effect. Growth and slaughter performance and organ weight were not influenced significantly by iodine supplementation. Serum T 3 was significantly lower in 2-mg I group than in 0.2 and 4-mg I groups (P  0.05). Conversely, serum catalase (CAT) was significantly reduced (P thyroid, GSH-Px was higher in the 2-mg I group than in the 0.2- and 4-mg I groups (P  0.05). In the thyroid gland, the mRNA expression level of GSH-Px was higher in the 2-mg I group than in the 4-mg I group (P thyroid gland. Thus, on the basis of serum T 3 and GSH-Px levels in the thyroid gland, we hypothesized that GSH-Px secretion was increased by adding dietary iodine in the thyroid, which may inhibit the H 2 O 2 generation and further influence the thyroid hormone synthesis.

  18. Recovery of Bennu's orientation for the OSIRIS-REx mission: implications for the spin state accuracy and geolocation errors

    Science.gov (United States)

    Mazarico, Erwan; Rowlands, David D.; Sabaka, Terence J.; Getzandanner, Kenneth M.; Rubincam, David P.; Nicholas, Joseph B.; Moreau, Michael C.

    2017-10-01

    The goal of the OSIRIS-REx mission is to return a sample of asteroid material from near-Earth asteroid (101955) Bennu. The role of the navigation and flight dynamics team is critical for the spacecraft to execute a precisely planned sampling maneuver over a specifically selected landing site. In particular, the orientation of Bennu needs to be recovered with good accuracy during orbital operations to contribute as small an error as possible to the landing error budget. Although Bennu is well characterized from Earth-based radar observations, its orientation dynamics are not sufficiently known to exclude the presence of a small wobble. To better understand this contingency and evaluate how well the orientation can be recovered in the presence of a large 1° wobble, we conduct a comprehensive simulation with the NASA GSFC GEODYN orbit determination and geodetic parameter estimation software. We describe the dynamic orientation modeling implemented in GEODYN in support of OSIRIS-REx operations and show how both altimetry and imagery data can be used as either undifferenced (landmark, direct altimetry) or differenced (image crossover, altimetry crossover) measurements. We find that these two different types of data contribute differently to the recovery of instrument pointing or planetary orientation. When upweighted, the absolute measurements help reduce the geolocation errors, despite poorer astrometric (inertial) performance. We find that with no wobble present, all the geolocation requirements are met. While the presence of a large wobble is detrimental, the recovery is still reliable thanks to the combined use of altimetry and imagery data.

  19. Power distribution in the hovering flight of the hawk moth Manduca sexta

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Liang; Deng Xinyan, E-mail: xdeng@purdue.ed [School of Mechanical Engineering, Purdue University, 500 Allison Rd., Chaffee Hall, West Lafayette, IN 47907 (United States)

    2009-12-15

    We investigated inertial and aerodynamic power consumption during hovering flight of the hawk moth Manduca sexta. The aerodynamic power was estimated based on the aerodynamic forces and torques measured on model hawk-moth wings and hovering kinematics. The inertial power was estimated based on the measured wing mass distribution and hovering kinematics. The results suggest that wing inertial power (without consideration of muscle efficiency and elastic energy storage) consumes about half of the total power expenditure. Wing areal mass density was measured to decrease sharply from the leading edge toward the trailing edge and from the wing base to the wing tip. Such a structural property helps to minimize the wing moment of inertia given a fixed amount of mass. We measured the aerodynamic forces on the rigid and flexible wings, which were made to approximate the flexural stiffness (EI) distribution and deformation of moth wings. It has been found that wings with the characteristic spanwise and chordwise decreasing EI (and mass density) are beneficial for power efficiency while generating aerodynamic forces comparative to rigid wings. Furthermore, negative work to aid pitching in stroke reversals from aerodynamic forces was found, and it showed that the aerodynamic force contributes partially to passive pitching of the wing

  20. Habitat Effects on the Breeding Performance of Three Forest-Dwelling Hawks.

    Directory of Open Access Journals (Sweden)

    Heidi Björklund

    Full Text Available Habitat loss causes population declines, but the mechanisms are rarely known. In the European Boreal Zone, loss of old forest due to intensive forestry is suspected to cause declines in forest-dwelling raptors by reducing their breeding performance. We studied the boreal breeding habitat and habitat-associated breeding performance of the northern goshawk (Accipiter gentilis, common buzzard (Buteo buteo and European honey buzzard (Pernis apivorus. We combined long-term Finnish bird-of-prey data with multi-source national forest inventory data at various distances (100-4000 m around the hawk nests. We found that breeding success of the goshawk was best explained by the habitat within a 2000-m radius around the nests; breeding was more successful with increasing proportions of old spruce forest and water, and decreasing proportions of young thinning forest. None of the habitat variables affected significantly the breeding success of the common buzzard or the honey buzzard, or the brood size of any of the species. The amount of old spruce forest decreased both around goshawk and common buzzard nests and throughout southern Finland in 1992-2010. In contrast, the area of young forest increased in southern Finland but not around hawk nests. We emphasize the importance of studying habitats at several spatial and temporal scales to determine the relevant species-specific scale and to detect environmental changes. Further effort is needed to reconcile the socioeconomic and ecological functions of forests and habitat requirements of old forest specialists.

  1. Gravitational Lensing Effect on the Hawking Radiation of Dyonic Black Holes

    CERN Document Server

    Sakalli, I; Mirekhtiary, S F

    2014-01-01

    In this paper, we analyze the Hawking radiation (HR) of a non-asymptotically flat (NAF) dyonic black hole (dBH) in four-dimensional (4D) Einstein-Maxwell-Dilaton (EMD) gravity by using one of the semiclassical approaches which is the so-called Hamilton-Jacobi (HJ) method. We particularly motivate on the isotropic coordinate system (ICS) of the dBH in order to highlight the ambiguity to be appeared in the derivation of the Hawking temperature (T_{H}) via the HJ method. Besides, it will be shown that the ICS allows us to write the metric of the dBH in form of the Fermat metric, which renders possible of identification of the refractive index (n) of the dBH. It is shown that the value of n and therefore the gravitational lensing effect is decisive on the the tunneling rate of the HR. We also uncloak how one can resolve the discrepancy about the T_{H} of the dBH in spite of that lensing effect.

  2. Emergent horizon, Hawking radiation and chaos in the collapsed polymer model of a black hole

    Energy Technology Data Exchange (ETDEWEB)

    Brustein, Ram [Department of Physics, Ben-Gurion University, Beer-Sheva (Israel); Medved, A.J.M. [Department of Physics and Electronics, Rhodes University, Grahamstown (South Africa); National Institute for Theoretical Physics (NITheP), Western Cape (South Africa)

    2017-02-15

    We have proposed that the interior of a macroscopic Schwarzschild black hole (BH) consists of highly excited, long, closed, interacting strings and, as such, can be modeled as a collapsed polymer. It was previously shown that the scaling relations of the collapsed-polymer model agree with those of the BH. The current paper further substantiates this proposal with an investigation into some of its dynamical consequences. In particular, we show that the model predicts, without relying on gravitational effects, an emergent horizon. We further show that the horizon fluctuates quantum mechanically as it should and that the strength of the fluctuations is inversely proportional to the BH entropy. It is then demonstrated that the emission of Hawking radiation is realized microscopically by the quantum-induced escape of small pieces of string, with the rate of escape and the energy per emitted piece both parametrically matching the Hawking temperature. We also show, using standard methods from statistical mechanics and chaos theory, how our model accounts for some other known properties of BHs. These include the accepted results for the scrambling time and the viscosity-to-entropy ratio, which in our model apply not only at the horizon but throughout the BH interior. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Pre-Hawking radiation may allow for reconstruction of the mass distribution of the collapsing object

    Science.gov (United States)

    Dai, De-Chang; Stojkovic, Dejan

    2016-07-01

    Hawking radiation explicitly depends only on the black hole's total mass, charge and angular momentum. It is therefore generally believed that one cannot reconstruct the information about the initial mass distribution of an object that made the black hole. However, instead of looking at radiation from a static black hole, we can study the whole time-dependent process of the gravitational collapse, and pre-Hawking radiation which is excited because of the time-dependent metric. We compare radiation emitted by a single collapsing shell with that emitted by two concentric shells of the equivalent total mass. We calculate the gravitational trajectory and the momentum energy tensor. We show that the flux of energy emitted during the collapse by a single shell is significantly different from the flux emitted by two concentric shells of the equivalent total mass. When the static black hole is formed, the fluxes become indistinguishable. This implies that an observer studying the flux of particles from a collapsing object could in principle reconstruct information not only about the total mass of the collapsing object, but also about the mass distribution.

  4. Ratio of critical quantities related to Hawking temperature–entanglement entropy criticality

    Directory of Open Access Journals (Sweden)

    Jie-Xiong Mo

    2017-10-01

    Full Text Available We revisit the Hawking temperature–entanglement entropy criticality of the d-dimensional charged AdS black hole with our attention concentrated on the ratio TcδSEcQc. Comparing the results of this paper with those of the ratio TcScQc, one can find both the similarities and differences. These two ratios are independent of the characteristic length scale l and dependent on the dimension d. These similarities further enhance the relation between the entanglement entropy and the Bekenstein–Hawking entropy. However, the ratio TcδSEcQc also relies on the size of the spherical entangling region. Moreover, these two ratios take different values even under the same choices of parameters. The differences between these two ratios can be attributed to the peculiar property of the entanglement entropy since the research in this paper is far from the regime where the behavior of the entanglement entropy is dominated by the thermal entropy.

  5. Pre-Hawking radiation may allow for reconstruction of the mass distribution of the collapsing object

    Directory of Open Access Journals (Sweden)

    De-Chang Dai

    2016-07-01

    Full Text Available Hawking radiation explicitly depends only on the black hole's total mass, charge and angular momentum. It is therefore generally believed that one cannot reconstruct the information about the initial mass distribution of an object that made the black hole. However, instead of looking at radiation from a static black hole, we can study the whole time-dependent process of the gravitational collapse, and pre-Hawking radiation which is excited because of the time-dependent metric. We compare radiation emitted by a single collapsing shell with that emitted by two concentric shells of the equivalent total mass. We calculate the gravitational trajectory and the momentum energy tensor. We show that the flux of energy emitted during the collapse by a single shell is significantly different from the flux emitted by two concentric shells of the equivalent total mass. When the static black hole is formed, the fluxes become indistinguishable. This implies that an observer studying the flux of particles from a collapsing object could in principle reconstruct information not only about the total mass of the collapsing object, but also about the mass distribution.

  6. Growing skull fracture in a red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Rush, E Marie; Shores, Andrew; Meintel, Sarah; Hathcock, John T

    2014-09-01

    Growing skull fractures have been reported in humans for many years, usually resulting from injury to the soft skull during the rapid growth period of an infant's life. Nestling raptors have thin, fragile skulls, a rapid growth rate, and compete aggressively for food items. Skull trauma may occur, which may lead to the development of a growing skull fracture. Growing skull fractures may be under-diagnosed in raptor rehabilitation facilities that do not have access to advanced technologic equipment. Three-dimensional (3-D) computed tomography was used to diagnose a growing skull fracture in a red-tailed hawk (Buteo jamaicensis). The lesion was surgically repaired and the animal was eventually returned to the wild. This is the first report of a growing skull fracture in an animal. In this case, 3-D computed topographic imaging was utilized to diagnose a growing skull fracture in a red-tailed hawk, surgical repair was performed, and the bird recovered completely and was ultimately released.

  7. Mechanism of stimulated Hawking radiation in a laboratory Bose-Einstein condensate

    Science.gov (United States)

    Jacobson, Ted; Wang, Yi-Hsieh; Edwards, Mark; Clark, Charles W.

    2017-01-01

    Analog black/white hole pairs have been achieved in recent experiment by J. Steinhauer, using an elongated Bose-Einstein condensate. He reported observations of self-amplifying Hawking radiation, via a lasing mechanism operating between the black and white hole horizons. Through the simulations using the 1D Gross-Pitaevskii equation, we find that the experimental observations should be attributed not to the black hole laser effect, but rather to a growing zero-frequency bow wave, generated at the white-hole horizon. The relative motion of the black and white hole horizons produces a Doppler shift of the bow wave at the black hole, where it stimulates the emission of monochromatic Hawking radiation. This mechanism is confirmed using temporal and spatial windowed Fourier spectra of the condensate. We also find that shot-to-shot atom number variations, of the type normally realized in ultracold-atom experiments, and quantum fluctuations of condensates, as computed in the Bogoliubov-De Gennes approximation, give density-density correlations consistent with those reported in the experiments. In particular, atom number variations can produce a spurious correlation signal.

  8. Parasite infections in nestling red-shouldered hawks (Buteo lineatus) in northeast Wisconsin.

    Science.gov (United States)

    King, Janet C; Dubay, Shelli A; Huspeni, Todd C; VanLanen, Andrew R; Gerhold, Richard W

    2010-06-01

    Red-shouldered hawks (Buteo lineatus) are threatened in Wisconsin and long-term data suggest that nest productivity is low in the state for unknown reasons. Our objective was to determine whether red-shouldered hawks in northeast Wisconsin were infected with parasites that could contribute to low nest productivity. We examined nestlings for the presence of Trichomonas gallinae, Protocalliphora avium, and blood parasites in June 2006 and 2007. We did not detect T. gallinae in throat swabs taken from 24 nestlings in 2007. Ear canals of nestlings were parasitized by P. avium larvae in 10 of 11 (91%) nests and in 22 of 24 (92%) nestlings. Larvae were found in higher intensity in 1 ear relative to the other. Leucocytozoon toddi was present in 90.5% (38/42) of the nestlings. At least 1 bird in each nest was infected. Intensity of L. toddi averaged 48.6 +/- 58.3 infected cells per 2,000 erythrocytes (2.4 +/- 2.9%). No other blood parasites were identified.

  9. A Red-Tailed Hawk perches on a stump at KSC.

    Science.gov (United States)

    2000-01-01

    This red-tailed hawk on the roadside at Kennedy Space Center appears to be eyeing the photographer. The red-tailed hawk has a stocky build and broad, rounded wings. Its wide range covers Alaska and Nova Scotia south to Panama. It can frequently be seen perched in a tree at the edge of a meadow, watching for movement in the grass below. It feeds mainly on small rodents. The Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects. Kennedy Space Center shares a boundary with the Merritt Island National Wildlife Refuge, encompassing 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  10. Ketamine-xylazine anesthesia in red-tailed hawks with antagonism by yohimbine.

    Science.gov (United States)

    Degernes, L A; Kreeger, T J; Mandsager, R; Redig, P T

    1988-04-01

    Five red-tailed hawks (Buteo jamaicensis) were anesthetized at weekly intervals with intravenous ketamine hydrochloride (KET, 4.4 mg/kg) and xylazine hydrochloride (XYL, 2.2 mg/kg). Twenty min after anesthesia, yohimbine hydrochloride (YOH, 0.05, 0.10, 0.20 and 0.40 mg/kg) or a control was administered. All doses of YOH significantly reduced the head-up times (F = 20.84, df = 1,24, P less than 0.0001) and the standing times (F = 12.30, df = 1,24, P less than 0.0001), compared to the control group. The heart and respiratory rates following YOH (all doses) were significantly greater (P less than 0.01) than the anesthetized rates, but were comparable to the rates observed in restrained, unanesthetized hawks. Yohimbine did not appear to have any significant effect on body temperature. Based upon administration of 4.4 mg/kg KET and 2.2 mg/kg XYL, a dose of 0.10 mg/kg YOH was recommended to achieve antagonism without causing profound cardiovascular or respiratory changes.

  11. Fine structure of the pecten oculi of the red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Braekevelt, C R

    1991-12-01

    The pecten oculi of the red-tailed hawk (Buteo jamaicensis) has been examined by light and electron microscopy. In this species the pecten is very large and of the pleated type. It consists of 17-18 accordion folds which are joined apically by a heavily pigmented bridge of tissue which holds the pecten in a fan-like shape, widest at its base. It is situated over the optic nerve head and extends into the vitreous. Within each fold are numerous capillaries, larger supply and drainage vessels and melanocytes. The capillaries are specialized and display extensive microfolds on both the luminal and abluminal borders. The endothelial cell bodies are thin with most organelles present in a paranuclear location. The capillaries are surrounded by thick fibrillar basal laminae which are probably structurally important and which often enclose pericytes. The melanocytes which are most plentiful in the bridge region and peripherally in the pecten, form an incomplete sheath around the capillaries and other blood vessels. These melanocytes are also felt to be fulfilling a structural role within the pecten. The morphology of the pecten of the red-tailed hawk is indicative of a heavy involvement in the transport of materials to the avascular avian retina.

  12. Dynamics of flexural gravity waves: from sea ice to Hawking radiation and analogue gravity

    Science.gov (United States)

    Das, S.; Sahoo, T.; Meylan, M. H.

    2018-01-01

    The propagation of flexural gravity waves, routinely used to model wave interaction with sea ice, is studied, including the effect of compression and current. A number of significant and surprising properties are shown to exist. The occurrence of blocking above a critical value of compression is illustrated. This is analogous to propagation of surface gravity waves in the presence of opposing current and light wave propagation in the curved space-time near a black hole, therefore providing a novel system for studying analogue gravity. Between the blocking and buckling limit of the compressive force, the dispersion relation possesses three positive real roots, contrary to an earlier observation of having a single positive real root. Negative energy waves, in which the phase and group velocity point in opposite directions, are also shown to exist. In the presence of an opposing current and certain critical ranges of compressive force, the second blocking point shifts from the positive to the negative branch of the dispersion relation. Such a shift is known as the Hawking effect from the analogous behaviour in the theory of relativity which leads to Hawking radiation. The theory we develop is illustrated with simulations of linear waves in the time domain.

  13. A self-consistency check for unitary propagation of Hawking quanta

    Science.gov (United States)

    Baker, Daniel; Kodwani, Darsh; Pen, Ue-Li; Yang, I.-Sheng

    2017-11-01

    The black hole information paradox presumes that quantum field theory in curved space-time can provide unitary propagation from a near-horizon mode to an asymptotic Hawking quantum. Instead of invoking conjectural quantum-gravity effects to modify such an assumption, we propose a self-consistency check. We establish an analogy to Feynman’s analysis of a double-slit experiment. Feynman showed that unitary propagation of the interfering particles, namely ignoring the entanglement with the double-slit, becomes an arbitrarily reliable assumption when the screen upon which the interference pattern is projected is infinitely far away. We argue for an analogous self-consistency check for quantum field theory in curved space-time. We apply it to the propagation of Hawking quanta and test whether ignoring the entanglement with the geometry also becomes arbitrarily reliable in the limit of a large black hole. We present curious results to suggest a negative answer, and we discuss how this loss of naive unitarity in QFT might be related to a solution of the paradox based on the soft-hair-memory effect.

  14. Pre-Hawking radiation may allow for reconstruction of the mass distribution of the collapsing object

    Energy Technology Data Exchange (ETDEWEB)

    Dai, De-Chang, E-mail: diedachung@gmail.com [Institute of Natural Sciences, Shanghai Key Lab for Particle Physics and Cosmology, and Center for Astrophysics and Astronomy, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Stojkovic, Dejan [HEPCOS, Department of Physics, SUNY, University at Buffalo, Buffalo, NY 14260-1500 (United States)

    2016-07-10

    Hawking radiation explicitly depends only on the black hole's total mass, charge and angular momentum. It is therefore generally believed that one cannot reconstruct the information about the initial mass distribution of an object that made the black hole. However, instead of looking at radiation from a static black hole, we can study the whole time-dependent process of the gravitational collapse, and pre-Hawking radiation which is excited because of the time-dependent metric. We compare radiation emitted by a single collapsing shell with that emitted by two concentric shells of the equivalent total mass. We calculate the gravitational trajectory and the momentum energy tensor. We show that the flux of energy emitted during the collapse by a single shell is significantly different from the flux emitted by two concentric shells of the equivalent total mass. When the static black hole is formed, the fluxes become indistinguishable. This implies that an observer studying the flux of particles from a collapsing object could in principle reconstruct information not only about the total mass of the collapsing object, but also about the mass distribution.

  15. Sample Curation in Support of the OSIRIS-REx Asteroid Sample Return Mission

    Science.gov (United States)

    Righter, Kevin; Nakamura-Messenger, Keiko

    2017-01-01

    The OSIRIS-REx asteroid sample return mission launched to asteroid Bennu Sept. 8, 2016. The spacecraft will arrive at Bennu in late 2019, orbit and map the asteroid, and perform a touch and go (TAG) sampling maneuver in July 2020. After sample is stowed and confirmed the spacecraft will return to Earth, and the sample return capsule (SRC) will land in Utah in September 2023. Samples will be recovered from Utah [2] and then transported and stored in a new sample cleanroom at NASA Johnson Space Center in Houston [3]. The materials curated for the mission are described here. a) Materials Archive and Witness Plate Collection: The SRC and TAGSAM were built between March 2014 and Summer of 2015, and instruments (OTES,OVIRS, OLA, OCAMS, REXIS) were integrated from Summer 2015 until May 2016. A total of 395 items were received for the materials archive at NASA-JSC, with archiving finishing 30 days after launch (with the final archived items being related to launch operations)[4]. The materials fall into several general categories including metals (stainless steel, aluminum, titanium alloys, brass and BeCu alloy), epoxies, paints, polymers, lubricants, non-volatile-residue samples (NVR), sapphire, and various miscellaneous materials. All through the ATLO process (from March 2015 until late August 2016) contamination knowledge witness plates (Si wafer and Al foil) were deployed in the various cleanrooms in Denver and KSC to provide an additional record of particle counts and volatiles that is archived for current and future scientific studies. These plates were deployed in roughly monthly increments with each unit containing 4 Si wafers and 4 Al foils. We archived 128 individual witness plates (64 Si wafers and 64 Al foils); one of each witness plate (Si and Al) was analyzed immediately by the science team after archiving, while the remaining 3 of each are archived indefinitely. Information about each material archived is stored in an extensive database at NASA-JSC, and key

  16. Declaration of the Javan hawk eagle Spizaetus bartelsi as Indonesia's National Rare Animal impedes conservation of the species

    NARCIS (Netherlands)

    Nijman, V.; Shepherd, C.R.; van Balen, S.

    2009-01-01

    The endangered Javan hawk eagle Spizaetus bartelsi is threatened in part by the illegal pet trade. In 1993 the species was declared Indonesia's National Rare/Precious Animal, by former President Soeharto. Trade in the species and keeping it as a pet are illegal. We consolidated data about the

  17. Hawking and Unruh Effects of a 5-Dimensional Minimal Gauged Supergravity Black Hole by a Global Embedding Approach

    Directory of Open Access Journals (Sweden)

    Li-Chun Zhang

    2013-03-01

    Full Text Available Using the new global embedding approach we investigate Unruh/Hawking temperature of the 5-dimensional minimal gauged supergravity black hole with double rotating parameters in a general (1 + 1 space-time. Our results verify that views of Banerjee and Majhi, and extend this approach to a higher dimension situation.

  18. Hawking radiation and the Stefan-Boltzmann law: The effective radius of the black-hole quantum atmosphere

    CERN Document Server

    Hod, Shahar

    2016-01-01

    It has recently been suggested [S. B. Giddings, Phys. Lett. B {\\bf 754}, 39 (2016)] that the Hawking black-hole radiation spectrum originates from an effective quantum "atmosphere" which extends well outside the black-hole horizon. In particular, comparing the Hawking radiation power of a $(3+1)$-dimensional Schwarzschild black hole of horizon radius $r_{\\text{H}}$ with the familiar Stefan-Boltzmann radiation power of a $(3+1)$-dimensional flat space perfect blackbody emitter, Giddings concluded that the source of the Hawking semi-classical black-hole radiation is a quantum region outside the Schwarzschild black-hole horizon whose effective radius $r_{\\text{A}}$ is characterized by the relation $\\Delta r\\equiv r_{\\text{A}}-r_{\\text{H}}\\sim r_{\\text{H}}$. It is of considerable physical interest to test the general validity of Giddings's intriguing conclusion. To this end, we study the Hawking radiation of $(D+1)$-dimensional Schwarzschild black holes. We find that the dimensionless radii $r_{\\text{A}}/r_{\\text...

  19. Valvular endocarditis and septic thrombosis associated with a radial fracture in a red-tailed hawk (Buteo jamaicensis)

    OpenAIRE

    Lemon, Matthew J.; Pack, LeeAnn; Forzán, María J.

    2012-01-01

    A free-ranging adult female red-tailed hawk died suddenly after 3 weeks in rehabilitation for a radial fracture. Cause of death was septic thrombosis from a chronic bacterial valvular endocarditis, probably associated with injury at the fracture site. The challenge of clinical diagnosis of sepsis in wild birds is emphasized.

  20. Distributions of choline acetyltransferase and acetylcholinesterase activities in the retinal layers of the red-tailed hawk and road runner.

    Science.gov (United States)

    White, L E; Ross, C D; Godfrey, D A

    1991-01-01

    The activities of choline acetyltransferase and acetylcholinesterase were assayed in submicrogram samples from layers of red-tailed hawk and road runner retina. Both enzyme activities were concentrated in and near the inner plexiform layer. Within the inner plexiform layers of both species, activities of each enzyme were concentrated in two bands, one in each half of this layer. Little choline acetyltransferase activity was found superficial to the middle third of the inner nuclear layer. The distributions of acetylcholinesterase activities corresponded well to those of choline acetyltransferase, except in the outer plexiform layer and the outer margin of the inner nuclear layer of the hawk. These distributions of enzyme activities indicate that populations of amacrine cells in the retinae of these species are cholinergic. In addition to these same cells and presumably cholinoceptive amacrine and ganglion cells, acetylcholinesterase activity in the hawk was associated with a population of horizontal cells that may be unrelated to synaptic cholinergic neurotransmission. Choline acetyltransferase activities associated with amacrine somata and processes were about four times greater in the hawk than in the road runner, suggesting important differences in the density and function of cholinergic elements between species. Possible synaptic relationships in the inner plexiform layer consistent with the interspecies differences in enzyme activities are considered.

  1. Pharmacokinetics of piperacillan after intramuscular injection in red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus).

    Science.gov (United States)

    Robbins, P K; Tell, L A; Needham, M L; Craigmill, A L

    2000-03-01

    This study characterized and compared the pharmacokinetics of piperacillin after single 100 mg/kg i.m. injections in nine red-tailed hawks (Buteo jamaicensis) and five great horned owls (Bubo virginianus) over 48 hr by a modified agar well diffusion microbial inhibition assay. The mean maximum plasma piperacillin concentrations were 204 microg/ml and 221 microg/ml for the hawks and owls, respectively, and times of maximum concentrations were 15 min and 30 min, respectively. The calculated mean terminal elimination half-lives were 77 min in the hawks and 118 min in the owls. Area-under-the-curve values were 218 +/- 52 microg x hr/ml in the hawks and 444 +/- 104 microg x hr/ml in the owls. On the basis of the most common minimal inhibitory concentration (90%) for various bacterial isolates from clinical samples of 8 microg/ml, analysis of the data suggests that the maximum dosing interval for piperacillin at 100 mg/kg in medium sized raptors should be 4-6 hr.

  2. Valvular endocarditis and septic thrombosis associated with a radial fracture in a red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Lemon, Matthew J; Pack, LeeAnn; Forzán, María J

    2012-01-01

    A free-ranging adult female red-tailed hawk died suddenly after 3 weeks in rehabilitation for a radial fracture. Cause of death was septic thrombosis from a chronic bacterial valvular endocarditis, probably associated with injury at the fracture site. The challenge of clinical diagnosis of sepsis in wild birds is emphasized.

  3. Using Autumn Hawk Watch to track raptor migration and to monitor populations of North American birds of prey

    Science.gov (United States)

    Kyle McCarty; Keith L. Bildstein

    2005-01-01

    Raptors are secretive, area-sensitive predators whose populations can be logistically difficult and financially prohibitive to monitor. Many North American populations of raptors are migratory however, and on migration raptors are frequently counted at traditional migration watchsites. Experiences at Hawk Mountain Sanctuary (HMS) and elsewhere suggest that long-term...

  4. The question of the existence of God in the book of Stephen Hawking: A brief history of time

    NARCIS (Netherlands)

    Driessen, A.; Driessen, A; Suarez, A.

    1997-01-01

    The continuing interest in the book of S. Hawking "A Brief History of Time" makes a philosophical evaluation of the content highly desirable. As will be shown, the genre of this work can be identified as a speciality in philosophy, namely the proof of the existence of God. In this study an attempt

  5. Property of various correlation measures of open Dirac system with Hawking effect in Schwarzschild space–time

    Energy Technology Data Exchange (ETDEWEB)

    He, Juan [School of Physics and Material Science, Anhui University, Hefei 230039 (China); School of Physics and Electronics Science, Fuyang Normal College, Fuyang 236037 (China); Xu, Shuai; Yu, Yang [School of Physics and Material Science, Anhui University, Hefei 230039 (China); Ye, Liu, E-mail: yeliu@ahu.edu.cn [School of Physics and Material Science, Anhui University, Hefei 230039 (China)

    2015-01-05

    We explore the performance of various correlation measures for open Dirac system with Hawking effect in Schwarzschild space–time. Our results indicate that the impact of Hawking effect on physical accessible entanglement is weaker than that of decoherence. For generalized amplitude damping (GAD) channel, the entanglement sudden death (ESD) is analyzed in detail, and the inequivalence of quantization for Dirac particles in the black hole and Kruskal space–time is verified via quantum discord measure. In addition, as an example for interpreting Bell non-locality, we study the GAD channel with Hawking effect. It can be noticed that there is a boundary line of Bell violation for physically accessible states. That is, quantum non-locality would disappear when Hawking temperature exceeds a certain value. This critical temperature increases as a decoherence parameter decreases. In the case of phase damping (PD) channel, the interaction between the particle and noise environment does not produce bipartite system–environment entanglement. Then we discuss entanglement distributions, and find that the reduced physically accessible entanglement can be redistributed to physical inaccessible region. At last, we extend our investigation to an N-qubit system, and obtain a universal expression of the physical accessible entanglement.

  6. Hawk Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Produces a high-current (750 kA) pulse with a microsecond rise time into a vacuum inductor. The energy stored in the inductor is transferred to a radiation...

  7. Weather Avoidance Guidelines for NASA Global Hawk High-Altitude Unmanned Aircraft Systems (UAS)

    Science.gov (United States)

    Cecil, Daniel J.; Zipser, Edward J.; Velden, Chris S.; Monette, Sarah A.; Heymsfield, Gerald M.; Braun, Scott A.; Newman, Paul A.; Black, Peter G.; Black, Michael L.; Dunion, Jason P.

    2014-01-01

    The current Global Hawk flight rules would probably not have been effective in the single event of greatest concern (the Emily encounter). The cloud top had not reached 50,000 ft until minutes before the encounter. The TOT and lightning data would not have been available until near the overflight time since this was a rapidly growing cell. This case would have required a last-minute diversion when lightning became frequent. Avoiding such a cell probably requires continual monitoring of the forward camera and storm scope, whether or not cloud tops have been exceeding specific limits. However, the current overflight rules as strictly interpreted would have prohibited significant fractions of the successful Global Hawk overpasses of Karl and Matthew that proved not to be hazardous. Many other high altitude aircraft (ER-2 and Global Hawk) flights in NASA tropical cyclone field programs have successfully overflown deep convective clouds without incident.The convective cell that caused serious concern about the safety of the ER-2 in Emily was especially strong for a tropical cyclone environment, probably as strong or stronger than any that was overflown by the ER-2 in 20 previous flights over tropical cyclones. Specifically, what made that cell a safety concern was the magnitude of the vertical velocity of the updraft, at least 20 m/s (4000 ft/minute) at the time the ER-2 overflew it. Such a strong updraft can generate strong gravity waves at and above the tropopause, posing a potential danger to aircraft far above the maximum altitude of the updraft itself or its associated cloud top. Indeed, the ER-2 was probably at least 9000 ft above that cloud top. Cloud-top height, by itself, is not an especially good indicator of the intensity of convection and the likelihood of turbulence. Nor is overflying high cloud tops (i.e. > 50,000 ft) of particular concern unless there is other evidence of very strong convective updrafts beneath those tops in the path of the aircraft

  8. Technology advancement for the ASCENDS mission using the ASCENDS CarbonHawk Experiment Simulator (ACES)

    Science.gov (United States)

    Obland, M. D.; Antill, C.; Browell, E. V.; Campbell, J. F.; CHEN, S.; Cleckner, C.; Dijoseph, M. S.; Harrison, F. W.; Ismail, S.; Lin, B.; Meadows, B. L.; Mills, C.; Nehrir, A. R.; Notari, A.; Prasad, N. S.; Kooi, S. A.; Vitullo, N.; Dobler, J. T.; Bender, J.; Blume, N.; Braun, M.; Horney, S.; McGregor, D.; Neal, M.; Shure, M.; Zaccheo, T.; Moore, B.; Crowell, S.; Rayner, P. J.; Welch, W.

    2013-12-01

    The ASCENDS CarbonHawk Experiment Simulator (ACES) is a NASA Langley Research Center project funded by NASA's Earth Science Technology Office that seeks to advance technologies critical to measuring atmospheric column carbon dioxide (CO2) mixing ratios in support of the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The technologies being advanced are: (1) multiple transmitter and telescope-aperture operations, (2) high-efficiency CO2 laser transmitters, (3) a high bandwidth detector and transimpedance amplifier (TIA), and (4) advanced algorithms for cloud and aerosol discrimination. The instrument architecture is being developed for ACES to operate on a high-altitude aircraft, and it will be directly scalable to meet the ASCENDS mission requirements. The above technologies are critical for developing an airborne simulator and spaceborne instrument with lower platform consumption of size, mass, and power, and with improved performance. This design employs several laser transmitters and telescope-apertures to demonstrate column CO2 retrievals with alignment of multiple laser beams in the far-field. ACES will transmit five laser beams: three from commercial lasers operating near 1.57-microns, and two from the Exelis atmospheric oxygen (O2) fiber laser amplifier system operating near 1.26-microns. The Master Oscillator Power Amplifier at 1.57-microns measures CO2 column concentrations using an Integrated-Path Differential Absorption (IPDA) lidar approach. O2 column amounts needed for calculating the CO2 mixing ratio will be retrieved using the Exelis laser system with a similar IPDA approach. The three aperture telescope design was built to meet the constraints of the Global Hawk high-altitude unmanned aerial vehicle (UAV). This assembly integrates fiber-coupled transmit collimators for all of the laser transmitters and fiber-coupled optical signals from the three telescopes to the aft optics and detector package. The detector

  9. Global Hawk dropsonde observations of the Arctic atmosphere obtained during the Winter Storms and Pacific Atmospheric Rivers (WISPAR field campaign

    Directory of Open Access Journals (Sweden)

    J. M. Intrieri

    2014-11-01

    Full Text Available In February and March of 2011, the Global Hawk unmanned aircraft system (UAS was deployed over the Pacific Ocean and the Arctic during the Winter Storms and Pacific Atmospheric Rivers (WISPAR field campaign. The WISPAR science missions were designed to (1 mprove our understanding of Pacific weather systems and the polar atmosphere; (2 evaluate operational use of unmanned aircraft for investigating these atmospheric events; and (3 demonstrate operational and research applications of a UAS dropsonde system at high latitudes. Dropsondes deployed from the Global Hawk successfully obtained high-resolution profiles of temperature, pressure, humidity, and wind information between the stratosphere and surface. The 35 m wingspan Global Hawk, which can soar for ~ 31 h at altitudes up to ~ 20 km, was remotely operated from NASA's Dryden Flight Research Center at Edwards Air Force Base (AFB in California. During the 25 h polar flight on 9–10 March 2011, the Global Hawk released 35 sondes between the North Slope of Alaska and 85° N latitude, marking the first UAS Arctic dropsonde mission of its kind. The polar flight transected an unusually cold polar vortex, notable for an associated record-level Arctic ozone loss, and documented polar boundary layer variations over a sizable ocean–ice lead feature. Comparison of dropsonde observations with atmospheric reanalyses reveal that, for this day, large-scale structures such as the polar vortex and air masses are captured by the reanalyses, while smaller-scale features, including low-level jets and inversion depths, are mischaracterized. The successful Arctic dropsonde deployment demonstrates the capability of the Global Hawk to conduct operations in harsh, remote regions. The limited comparison with other measurements and reanalyses highlights the potential value of Arctic atmospheric dropsonde observations where routine in situ measurements are practically nonexistent.

  10. A comparative study of the mechanics of the pectoralis muscle of the red-tailed hawk and the barred owl.

    Science.gov (United States)

    Peters, Susan E; Dobbins, Charles S

    2012-03-01

    A comparison of the isometric forces and levers of the pectoralis muscle in red-tailed hawks (Buteo jamaicensis) and barred owls (Strix varia) was done to identify differences that may correlate with their different flight styles. The pectoralis consists of two heads, the anterior m. sternobrachialis (SB) and the posterior m. thoracobrachialis (TB). These are joined at an intramuscular tendon and are supplied by separate primary nerve branches. As in other birds, the two heads have distinct fiber orientations in red-tailed hawks and barred owls. SB's fiber orientation (posterolateral and mediolateral from origin to insertion) provides pronation and protraction of the humerus during adduction. Electromyographic studies in pigeons show that it is active in early downstroke and during level flight. TB is more active during take-off and landing in pigeons. The anterolateral orientation (from origin to insertion) of its fibers provides a retractive component to humeral adduction used to control the wing during landing. In our study, the maximum isometric force produced by the combined pectoralis heads did not differ significantly between the hawk and owl, however, the forces were distributed differently between the two muscle heads. In the owl, SB and TB were capable of producing equal amounts of force, but in the hawk, SB produced significantly less force than did TB. This may reflect the need for a large TB to control landing in both birds during prey-strike, with the owl maintaining both protractive (using SB) and retractive (using TB) abilities. Pronation and protraction may be less important in the flight behavior of the hawk, but its prey-strike behavior may require the maintenance of a substantial TB for braking and controlled stalling, as it initiates strike behavior. Copyright © 2011 Wiley Periodicals, Inc.

  11. Predicted Antenna Temperatures Measured by REX/New Horizons During The Pluto’s FlybyProbing the sub-surface in Microwave

    Science.gov (United States)

    Leyrat, Cedric; Le Gall, Alice; Lorenz, Ralph; Boomi, Shadi

    2017-10-01

    The Pluto dwarf planet was observed in details in July 2015 by the New Horizons spacecraft (NASA) during a close-targeted flyby which reavealed surprising and fascinating landscapes with a variety of albedo and chemical composition over the surface. During the flyby, the REX microwave instrument was activated in order to measure the antenna temperature while the beam crossed Pluto’s surface. In particular, 3 scans were performed, the first two during few tens of seconds when both the day and night side of Pluto were observed, including the South pole ; and the last one during an occultation with Earth. We present here predited antenna temperatures considering the known and assumed variations of thermal and electrical properties of the Pluto’s sub-surface.. Each scan allow to observe thermal radiation at 4.2 cm wavelength of the surface and subsurface of Pluto, at different locations (latitudes / longitudes). Using a seasonnal thermal model that considers the measured Bond albedo and type of ice, we have modeled the Brightness temperatures that were measured by REX, for different amount of porosity (or thermal inertia). This modeling uses a seasonally-forced thermal model and an emissivity model in the case of circular polarized observations. An antenna temperature if then retrieved assuming a beam pattern for REX. We present here how the antenna temperatures vary with the porosity of the ices obseved.

  12. Modeling foreign exchange market activity around macroeconomic news: Hawkes-process approach

    Science.gov (United States)

    Rambaldi, Marcello; Pennesi, Paris; Lillo, Fabrizio

    2015-01-01

    We present a Hawkes-model approach to the foreign exchange market in which the high-frequency price dynamics is affected by a self-exciting mechanism and an exogenous component, generated by the pre-announced arrival of macroeconomic news. By focusing on time windows around the news announcement, we find that the model is able to capture the increase of trading activity after the news, both when the news has a sizable effect on volatility and when this effect is negligible, either because the news in not important or because the announcement is in line with the forecast by analysts. We extend the model by considering noncausal effects, due to the fact that the existence of the news (but not its content) is known by the market before the announcement.

  13. New holographic dark energy and the modified Bekenstein-Hawking entropy

    CERN Document Server

    Viaggiu, Stefano

    2013-01-01

    We show that in the standard derivation of the holographic dark energy some conceptual issues are present. In particular, the formula used in the literature to avoid black holes is not suitable in expanding universes. A more suitable expression for a holographic motivated dark energy must contain the energy density of the remaining matter content of the universe. However, we show that under some reasonable hypothesis, we can obtain a new physically motivated expression for the holographic dark energy. By considering an appropriate time-dependence of the saturation-level parameter, a de Sitter phase arises. Moreover, by adopting an argument similar to the original Bekenstein one, our approach justifies a correction of the Bekenstein-Hawking entropy for non-static isotropic expanding universes. Finally, we write down the equation of state of a black hole embedded in Friedmann spacetimes.

  14. $W_\\infty$ Algebras, Hawking Radiation and Information Retention by Stringy Black Holes

    CERN Document Server

    Ellis, John; Nanopoulos, Dimitri V

    2016-01-01

    We have argued previously, based on the analysis of two-dimensional stringy black holes, that information in stringy versions of four-dimensional Schwarzschild black holes (whose singular regions are represented by appropriate Wess-Zumino-Witten models) is retained by quantum $W$-symmetries when the horizon area is not preserved due to Hawking radiation. It is key that the exactly-marginal conformal world-sheet operator representing a massless stringy particle interacting with the black hole requires a contribution from $W_\\infty$ generators in its vertex function. The latter correspond to delocalised, non-propagating, string excitations that guarantee the transfer of information between the string black hole and external particles. When infalling matter crosses the horizon, these topological states are excited via a process: (Stringy black hole) + infalling matter $\\rightarrow $ (Stringy black hole)$^\\star$, where the black hole is viewed as a stringy state with a specific configuration of $W_\\infty$ charges...

  15. Schwarzschild-de Sitter spacetime: The role of temperature in the emission of Hawking radiation

    Science.gov (United States)

    Pappas, Thomas; Kanti, Panagiota

    2017-12-01

    We consider a Schwarzschild-de Sitter (SdS) black hole, and focus on the emission of massless scalar fields either minimally or non-minimally coupled to gravity. We use six different temperatures, two black-hole and four effective ones for the SdS spacetime, as the question of the proper temperature for such a background is still debated in the literature. We study their profiles under the variation of the cosmological constant, and derive the corresponding Hawking radiation spectra. We demonstrate that only few of these temperatures may support significant emission of radiation. We finally compute the total emissivities for each temperature, and show that the non-minimal coupling constant of the scalar field to gravity also affects the relative magnitudes of the energy emission rates.

  16. Caryospora uptoni n. sp. (Apicomplexa: Eimeriidae) from red-tailed hawks (Buteo jamaicensis borealis).

    Science.gov (United States)

    Lindsay, D S; Blagburn, B L

    1986-10-01

    Oocysts of Caryospora uptoni n. sp. were described from the feces of red-tailed hawks, Buteo jamaicensis borealis. Sporulated oocysts were spherical or subspherical and measured 28.1 by 26.4 micron. The oocyst wall was composed of a yellowish outer layer and brownish inner layer and was about 1.5 micron thick. Neither micropyle, polar granules, nor oocyst residuum were present. A single, spherical sporocyst 18.2 by 17.9 micron was present; a Stieda body was absent. A spherical eccentrically located sporocyst residuum was present in many sporocysts, but it degenerated to form a dispersed granular residuum in other sporocysts. Eight randomly arranged sporozoites, 12.6 by 4.2 micron, were present in each sporocyst; they contained a centrally or slightly posteriorly located nucleus.

  17. Variation in selected hematological parameters of captive red-tailed hawks.

    Science.gov (United States)

    Rehder, N B; Bird, D M; Laguë, P C; Mackay, C

    1982-01-01

    Diurnal and winter variations of four hematological parameters were examined in 10 red-tailed hawks (Buteo jamaicensis). The mean values obtained were: 39.4% packed cell volume (PCV); 2.45 X 10(6) erythrocytes (RBC) per mm3 of blood; 5.73 mg of calcium and 1.44 mg of magnesium per 100 ml of plasma. Only the PCV and RBC count showed significant diurnal variation. When the birds were sampled at a set time of day, from November through to February, no significant changes were detected in any of the four parameters. Variation among the birds in RBC count, PCV and calcium concentration was significant on a diurnal basis but over the four month period only the PCV varied significantly.

  18. Diagnosis and treatment of secondary anticoagulant rodenticide toxicosis in a red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Murray, Maureen; Tseng, Florina

    2008-03-01

    Anticoagulant rodenticides inhibit the activation of vitamin K-ependent clotting factors, resulting in fatal hemorrhage. Nontarget species are exposed to these rodenticides primarily by direct consumption of baits or secondarily by consumption of poisoned prey. The diagnosis of anticoagulant rodenticide toxicosis is more challenging in birds than in mammals because of the limited availability of laboratory tests to evaluate avian coagulation. In addition, the presenting signs in birds may differ from those commonly seen in mammals. Treatment for acute blood loss and therapy with vitamin K1 can result in a favorable outcome in birds. This report describes the presenting signs, diagnosis, and successful treatment of a red-tailed hawk (Buteo jamaicensis) with secondary anticoagulant rodenticide toxicosis.

  19. Scalar resonant frequencies and Hawking effect of an f(R) global monopole

    Science.gov (United States)

    Vieira, H. S.; Morais Graça, J. P.; Bezerra, V. B.

    2017-09-01

    Massive scalar fields are considered in the gravitational field produced by a Schwarzschild black hole with a global monopole in f(R) gravity. The exact solution of the radial part of the Klein-Gordon equation in this background is obtained and is given in terms of the general Heun functions. We apply the properties of the general Heun functions to study the Hawking radiation and the resonant frequencies of scalar particles. H.S.V. is funded by the Brazilian research agencies CNPq (research Project No. 140612/2014-9) and CAPES (PDSE Process No. 88881.133092/2016-01). J.P.M.G. is funded by the CNPq through the research Project No. 150565/2016-0. V.B.B. is partially supported by the CNPq through the research Project No. 304553/2010-7

  20. Phantom of the Hartle-Hawking instanton: connecting inflation with dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Pisin [National Taiwan University, Leung Center for Cosmology and Particle Astrophysics, Taipei (China); Stanford University, SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Stanford, CA (United States); Qiu, Taotao [Central China Normal University, Institute of Astrophysics, Wuhan (China); Yeom, Dong-han [National Taiwan University, Leung Center for Cosmology and Particle Astrophysics, Taipei (China)

    2016-02-15

    If the Hartle-Hawking wave function is the correct boundary condition of our universe, the history of our universe will be well approximated by an instanton. Although this instanton should be classicalized at infinity, as long as we are observing a process of each history, we may detect a non-classicalized part of field combinations. When we apply it to a dark energy model, this non-classicalized part of fields can be well embedded to a quintessence and a phantom model, i.e., a quintom model. Because of the property of complexified instantons, the phantomness will be naturally free from a big rip singularity. This phantomness does not cause perturbative instabilities, as it is an effect emergent from the entire wave function. Our work may thus provide a theoretical basis for the quintom models, whose equation of state can cross the cosmological constant boundary phenomenologically. (orig.)

  1. The third order correction on Hawking radiation and entropy conservation during black hole evaporation process

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Hao-Peng; Liu, Wen-Biao, E-mail: wbliu@bnu.edu.cn

    2016-08-10

    Using Parikh–Wilczek tunneling framework, we calculate the tunneling rate from a Schwarzschild black hole under the third order WKB approximation, and then obtain the expressions for emission spectrum and black hole entropy to the third order correction. The entropy contains four terms including the Bekenstein–Hawking entropy, the logarithmic term, the inverse area term, and the square of inverse area term. In addition, we analyse the correlation between sequential emissions under this approximation. It is shown that the entropy is conserved during the process of black hole evaporation, which consists with the request of quantum mechanics and implies the information is conserved during this process. We also compare the above result with that of pure thermal spectrum case, and find that the non-thermal correction played an important role.

  2. Mutation-selection equilibrium in finite populations playing a Hawk-Dove game

    Science.gov (United States)

    Catalán, Pablo; Seoane, Jesús M.; Sanjuán, Miguel A. F.

    2015-08-01

    We study the evolution of a finite population playing a Hawk-Dove game with mixed strategies. Players have a fixed strategy and their offspring inherit the parental strategy, with a probability u of mutating to another strategy. Payoff in the game is the only variation in fitness among individuals, and a selection coefficient δ measures the importance of the game in the overall fitness. Population evolution is carried out through a Moran process. We compare our numerical simulations with theoretical predictions in earlier work by Tarnita et al. (2009). Our results show that the effect of selection on the abundances of favored strategies is nonlinear, being less intense as δ increases. The mutation rate u has an opposite and stronger effect to that of selection. Heuristic theoretical arguments are given in order to explain this nonlinear relationship.

  3. An exact solution for the Hawking effect in a dispersive fluid

    CERN Document Server

    Philbin, T G

    2016-01-01

    We consider the wave equation for sound in a moving fluid with a fourth-order anomalous dispersion relation. The velocity of the fluid is a linear function of position, giving two points in the flow where the fluid velocity matches the group velocity of low-frequency waves. We find the exact scattering coefficients for wave propagation in the flow. The scattering shows amplification of classical waves, leading to spontaneous emission when the waves are quantized. In the dispersionless limit the system corresponds to a 1+1-dimensional black-hole or white-hole binary and there is a thermal spectrum of Hawking radiation from each horizon. Dispersion changes the scattering coefficients so that the quantum emission is no longer thermal.

  4. Image Analysis of OSIRIS-REx Touch-And-Go Camera System (TAGCAMS) Thermal Vacuum Test Images

    Science.gov (United States)

    Everett Gordon, Kenneth; Bos, Brent J.

    2017-01-01

    The objective of NASA’s OSIRIS-REx Asteroid Sample Return Mission, which launched in September 2016, is to travel to the near-Earth asteroid 101955 Bennu, survey and map the asteroid, and return a scientifically interesting sample to Earth in 2023. As a part of its suite of integrated sensors, the OSIRIS-REx spacecraft includes a Touch-And-Go Camera System (TAGCAMS). The purpose of TAGCAMS is to provide imagery during the mission to facilitate navigation to the target asteroid, acquisition of the asteroid sample, and confirmation of the asteroid sample stowage in the spacecraft’s Sample Return Capsule (SRC). After first being calibrated at Malin Space Science Systems (MSSS) at the instrument level, the TAGCAMS were then transferred to Lockheed Martin (LM), where they were put through a progressive series of spacecraft-level environmental tests. These tests culminated in a several-week long, spacecraft-level thermal vacuum (TVAC) test during which hundreds of images were recorded. To analyze the images, custom codes were developed using MATLAB R2016a programming software. For analyses of the TAGCAMS dark images, the codes observed the dark current level for each of the images as a function of the camera-head temperature. Results confirm that the detector dark current noise has not increased and follows similar trends to the results measured at the instrument-level by MSSS. This indicates that the electrical performance of the camera system is stable, even after integration with the spacecraft, and will provide imagery with the required signal-to-noise ratio during spaceflight operations. During the TVAC testing, the TAGCAMS were positioned to view optical dot targets suspended in the chamber. Results for the TAGCAMS light images using a centroid analysis on the positions of the optical target holes indicate that the boresight pointing of the two navigation cameras depend on spacecraft temperature, but will not change by more than ten pixels (approximately 2

  5. Fluorophotometric determination of aqueous humor flow rates in red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Jones, Michael P; Ward, Daniel A

    2012-04-01

    To determine aqueous humor flow rate (AHFR) in an avian species by use of anterior segment fluorophotometry. 9 healthy red-tailed hawks (Buteo jamaicensis; 4 males and 5 females) that ranged from 8 months to 8 years of age. A protocol was developed for fluorophotometric determination of AHFR. Topical administration of 10% fluorescein was used to load the corneas, and corneal and aqueous humor fluorescein concentrations were measured approximately 5, 6.5, and 8 hours later. Concentration-versus-time plots were generated, and slopes and cornea-to-aqueous humor concentration ratios from these plots were used to manually calculate flow rates. Mean ± SD AHFRs for the right eye, left eye, and both eyes were 3.17 ± 1.36 μL/min (range, 1.67 to 6.21 μL/min), 2.86 ± 0.88 μL/min (range, 2.04 to 4.30 μL/min), and 2.90 ± 0.90 μL/min (range, 1.67 to 4.42 μL/min), respectively. The AHFRs were similar for right and left eyes. These flow rates represented a mean aqueous humor transfer coefficient of 0.0082/min, which is similar to that of mammalian species. The AHFR in red-tailed hawks was similar to that of most mammalian species, and the fractional egress was almost identical to that of other species. This information will allow a greater understanding of aqueous humor flow in avian eyes, which is crucial when evaluating diseases that affect avian eyes as well as medications that alter aqueous humor flow.

  6. The pharmacokinetics of a single intramuscular dose of amikacin in red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Bloomfield, R B; Brooks, D; Vulliet, R

    1997-03-01

    The pharmacokinetic parameters of amikacin were determined in red-tailed hawks (Buteo jamaicensis) following the i.m. administration of a single 20 mg/kg dose. After a rapid absorption phase, mean amikacin serum concentrations peaked at 65 +/- 12 micrograms/ML 30-45 min following injection. The serum amikacin concentrations decreased to 2.3 +/- 2 micrograms/ml at 12 hr postinjection. Amikacin was eliminated with first-order kinetics characteristic of a single-compartment model with a half-life of 2.02 +/- 0.63 hr. The volume of distribution was estimated to be 0.28 +/- 0.03 L/kg. Forty-two isolates of gram-negative bacteria and coagulase-positive Staphylococcus species were cultured from birds of prey presented to the Veterinary Medical Teaching Hospital at the University of California-Davis. The minimum inhibitory concentration (MICs) of amikacin ranged from 0.5 to 8.0 micrograms/ml (mean = 2.5 micrograms/ml). The 20 mg/kg dose used in this study resulted in serum concentrations at or above the MICs for > 12 hr for most of the isolates examined. The heaviest birds had the lowest peak serum amikacin concentrations, and the lightest birds had the highest, despite exact volume replacement for each sample drawn. This observation suggests that doses should be based on factors other than weight alone. Amikacin administered at 15-20 mg/kg/day, either as a single dose or divided into two or three doses, is effective in treating sensitive pathogens of the red-tailed hawk.

  7. Beam Dynamics Feasibility Study for an RFQ Sub-harmonic Pre-buncher at REX-ISOLDE

    CERN Document Server

    Magdau, I B

    2013-01-01

    The feasibility of using an external multi-harmonic buncher placed before the existing RFQ at REX-ISOLDE to increase the bunch spacing of post-accelerated beams at HIE-ISOLDE was confirmed. It was found that with a pre-buncher operating at a subharmonic frequency of 10.128 MHz (a factor 10 below the fundamental frequency of the RFQ) transmissions as high as 80% could be achieved in the main bunches separated by 98.7 ns. Such a time-structure will allow particle identification employing time-offlight techniques to be carried out by the users at HIE-ISOLDE. The optimal effective voltage for a drift length of 1.4 m between the pre-buncher and RFQ was found to be Veff = 0:8 kV, without any deterioration in the simulated nominal rms longitudinal emittance of rms = 0:28 ns keV/u. Significant reduction in the rms longitudinal emittance formed inside the RFQ was observed as the drift distance between the pre-buncher and RFQ was increased and the energy spread imparted by the pre-buncher decreased; within the physica...

  8. Effects of hydroxyapatite/Zr and bioglass/Zr coatings on morphology and corrosion behaviour of Rex-734 alloy.

    Science.gov (United States)

    Say, Y; Aksakal, B

    2016-06-01

    To improve corrosion resistance of metallic implant surfaces, Rex-734 alloy was coated with two different bio-ceramics; single-Hydroxyapatite (HA), double-HA/Zirconia(Zr) and double-Bioglass (BG)/Zr by using sol-gel method. Porous surface morphologies at low crack density were obtained after coating and sintering processes. Corrosion characteristics of coatings were determined by Open circuit potential and Potentiodynamic polarization measurements during corrosion tests. Hardness and adhesion strength of coating layers were measured and their surface morphologies before and after corrosion were characterized by scanning electron microscope (SEM), XRD and EDX. Through the SEM analysis, it was observed that corrosion caused degradation and sphere-like formations appeared with dimples on the coated surfaces. The coated substrates that exhibit high crack density, the corrosion was more effective by disturbing and transmitting through the coating layer, produced CrO3 and Cr3O8 oxide formation. It was found that the addition of Zr provided an increase in adhesion strength and corrosion resistance of the coatings. However, BG/Zr coatings had lower adhesion strength than the HA/Zr coatings, but showed higher corrosion resistance.

  9. Anticoagulant rodenticides in red-tailed hawks, Buteo jamaicensis, and great horned owls, Bubo virginianus, from New Jersey, USA, 2008-2010.

    Science.gov (United States)

    Stansley, William; Cummings, Margaret; Vudathala, Daljit; Murphy, Lisa A

    2014-01-01

    Liver samples from red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus) were analyzed for anticoagulant rodenticides. Residues of one or more second generation anticoagulant rodenticides (SGARs) were detected in 81 % of red-tailed hawks and 82 % of great horned owls. The most frequently detected SGAR was brodifacoum, which was detected in 76 % of red-tailed hawks and 73 % of great horned owls. Bromadiolone was detected in 20 % of red-tailed hawks and 27 % of great horned owls. Difenacoum was detected in one great horned owl. No other ARs were detected. There were no significant differences between species in the frequency of detection or concentration of brodifacoum or bromadiolone. There was a marginally significant difference (p = 0.0497) between total SGAR residues in red-tailed hawks (0.117 mg/kg) and great horned owls (0.070 mg/kg). There were no seasonal differences in the frequency of detection or concentration of brodifacoum in red-tailed hawks. The data suggest that SGARs pose a significant risk of poisoning to predatory birds in New Jersey.

  10. Breeding biology and conservation of hawk-eagles (Spizaetus spp. (Aves, Accipitridae in southern Atlantic Forest, Brazil

    Directory of Open Access Journals (Sweden)

    Felipe Zilio

    2017-10-01

    Full Text Available ABSTRACT Neotropical hawk-eagles (Spizaetus spp. are large forest raptors, having low population densities and high sensitivity to human disturbance. The three species of Brazil’s Atlantic forest (S. ornatus, S. melanoleucus, S. tyrannus are threatened and little is known of many aspects of their biology, such habitat requirements, nesting behavior, and food habitats. Here I present data about the breeding biology, diet and behavior of the Ornate Hawk-Eagle (S. ornatus; OHE and the Black-and-white Hawk-Eagle (S. melanoleucus; BWHW, and estimations of distribution - extent of occurrence (EOO - and population sizes for the three hawk-eagles of the southern Atlantic Forest. I compiled data from nine years of field studies done in Rio Grande do Sul and Santa Catarina combined with data from the literature (n = 191 records. I calculated the total amount of forest available for each species by GIS analyses and estimated population sizes based on species density data from the literature. The EOO was 123,551 km² for BWHE, 92,512 km² for OHE, and 67,824 km² for Black Hawk-Eagle (S. tyrannus; BHE. All species experienced more than 30% shrinkage in their historical distribution (before the year 2000. Forest remnants comprise 32% of BHE’s EOO and around 20% for other hawk-eagle species. Population sizes estimated for the southern region were 869 pairs for BHE (1,684 individuals, 1,532 pairs for BWHE (2,849 individuals, and 2,020 pairs for OHE (1,192 individuals. Population size estimates based only on forest patches larger than 10 km² were 542 pairs for BHE (RS = 48 pairs; SC = 494 pairs, 818 pairs for BWHE (RS = 67 pairs; SC = 751 pairs, and 1,178 pairs for OHE (RS = 67 pairs; SC = 1,111 pairs. I recorded displays and copulation of BWHE in July; the nest was built in an inaccessible, emergent tree in the hillside of a valley. Two nests of OHE were found in emergent trees (20 m and 30 m height measured 138 x 115 x 45 cm and 132 x 100 x 100 cm; one

  11. Changes in Physiologic Parameters and Effects of Hooding in Red-tailed Hawks ( Buteo jamaicensis ) During Manual Restraint.

    Science.gov (United States)

    Doss, Grayson A; Mans, Christoph

    2016-06-01

    Manual restraint in birds of prey is required for many veterinary and research procedures. To investigate the effects of handling stress on physiologic parameters in raptorial birds, 8 red-tailed hawks ( Buteo jamaicensis ) were manually restrained over a 15-minute period. Respiratory rate (RR), heart rate (HR), and cloacal temperature were monitored over time and recorded at defined intervals during the experiment. The effect of hooding on physiologic variables was also evaluated in a complete crossover design. Both RR and HR decreased significantly during the 15-minute restraint period (HR, -80 ± 101.4 beats/min [bpm], [P red-tailed hawks, hooding versus nonhooding amplified the decrease in HR and RR but had no effect on stress-induced hyperthermia.

  12. Climbing performance of Harris' hawks (Parabuteo unicinctus) with added load: Implications for muscle mechanics and for radiotracking

    Science.gov (United States)

    Pennycuick, C.J.; Fuller, M.R.; McAllister, L.

    1989-01-01

    Two Harris' hawks were trained to fly along horizontal and climbing flight paths, while carrying loads of various masses, to provide data for estimating available muscle power during short flights. The body mass of both hawks was about 920 g, and they were able to carry loads up to 630 g in horizontal flight. The rate of climb decreased with increasing all-up mass, as also did the climbing power (product of weight and rate of climb). Various assumptions about the aerodynamic power in low-speed climbs led to estimates of the maximum power output of the flight muscles ranging from 41 to 46 W. This, in turn, would imply a stress during shortening of around 210 kPa. The effects of a radio package on a bird that is raising young should be considered in relation to the food load that the forager can normally carry, rather than in relation to its body mass.

  13. Stationing a U.S. Army Reserve Black Hawk Helicopter Company at Joint Forces Training Base Los Alamitos, California

    Science.gov (United States)

    2011-03-01

    21  Figure 3-5. Four Clusters of Households Complaining of Helicopter Noise Over a 5-Year Period ...the form of a FNSI or a NOI to complete an EIS will be issued upon completion of the 30-day review period . EA for Stationing a USAR Black Hawk...unconsolidated sediment and sedimentary rock, with a succession of Quaternary and Tertiary marine, lagoon, and fluvial sediments. Older Cretaceous and Jurassic

  14. Pharmacokinetics of a single dose of voriconazole administered orally with and without food to red-tailed hawks (Buteo jamaicensus).

    Science.gov (United States)

    Parsley, Ruth A; Tell, Lisa A; Gehring, Ronette

    2017-04-01

    OBJECTIVE To determine the pharmacokinetics of voriconazole administered PO with or without food to red-tailed hawks (Buteo jamaicensus) and whether any observed variability could be explained by measured covariates to inform dose adjustments. ANIMALS 7 adult red-tailed hawks. PROCEDURES In a crossover study design, hawks were randomly assigned to first receive voriconazole (15 mg/kg, PO) injected into a dead mouse (n = 3; fed birds) or without food (4; unfed birds). Sixteen days later, treatments were reversed. Blood samples were collected at various points to measure plasma voriconazole concentrations by ultraperformance liquid chromatography. Pharmacokinetic data were analyzed by noncompartmental methods and fit to a compartmental model through nonlinear mixed-effects regression, with feeding status and body weight investigated as covariates. RESULTS Voriconazole was well absorbed, with quantifiable plasma concentrations up to 24 hours after administration. Mean plasma half-life was approximately 2 hours in fed and unfed birds. Administration of the voriconazole in food delayed absorption, resulting in a significant delay in time to maximum plasma concentration. The final compartmental model included a categorical covariate to account for this lag in absorption as well as body weight as a covariate of total body clearance (relative to unknown bioavailability). CONCLUSIONS AND CLINICAL RELEVANCE A single dose of voriconazole (15 mg/kg) administered PO to red-tailed hawks resulted in mean plasma voriconazole concentrations greater than the targeted value (1 μg/mL). Additional studies with larger sample sizes and multidose regimens are required before the model developed here can be applied in clinical settings.

  15. Comparison of three different inhalant anesthetic agents (isoflurane, sevoflurane, desflurane) in red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Granone, Tiffany D; de Francisco, Olga N; Killos, Maria B; Quandt, Jane E; Mandsager, Ron E; Graham, Lynelle F

    2012-01-01

    To compare isoflurane, sevoflurane and desflurane for inhalant anesthesia in red-tailed hawks (Buteo jamaicensis) in terms of the speed and characteristics of induction; cardiovascular and respiratory parameters while anesthetized; and speed and quality of recovery. Prospective, cross over, randomized experimental study. 12 healthy adult red-tailed hawks. Anesthesia was induced with isoflurane, sevoflurane or desflurane in oxygen via face mask in a crossover, randomized design with a 1 week washout period between each treatment. Hawks were tracheally intubated, allowed to breathe spontaneously, and instrumented for cardiopulmonary monitoring. Data collected included heart rate, respiratory rate, end-tidal CO(2) , inspired and expired agent, SpO(2,) temperature, systolic blood pressure, time to intubation and time to recovery (tracking). Recovery was subjectively scored on a 4 point scale as well as a summary evaluation, by a single blinded observer. No significant difference in time to induction and time to extubation was noted with the administration of isoflurane, sevoflurane or desflurane. Time to the ability of the bird to follow a moving object with its eyes (tracking) was significantly faster with the administration of sevoflurane and desflurane. All recoveries were scored 1 or 2 and were assessed as good to excellent. No significant difference was noted in heart rate, blood pressure and temperature among the three inhalants. Administration of isoflurane resulted in lower respiratory rates. Overall, although isoflurane remains the most common inhaled anesthetic in avian practice, sevoflurane and desflurane both offer faster time to tracking, while similar changes in cardiopulmonary function were observed with each agent during anesthesia of healthy red-tailed hawks. © 2011 The Authors. Veterinary Anaesthesia and Analgesia. © 2011 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesiologists.

  16. Pharmacokinetics of a single intramuscular injection of ceftiofur crystalline-free acid in red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Sadar, Miranda J; Hawkins, Michelle G; Byrne, Barbara A; Cartoceti, Andrew N; Keel, Kevin; Drazenovich, Tracy L; Tell, Lisa A

    2015-12-01

    To determine the pharmacokinetics and adverse effects at the injection site of ceftiofur crystalline-free acid (CCFA) following IM administration of 1 dose to red-tailed hawks (Buteo jamaicensis). 7 adult nonreleasable healthy red-tailed hawks. In a randomized crossover study, CCFA (10 or 20 mg/kg) was administered IM to each hawk and blood samples were obtained. After a 2-month washout period, administration was repeated with the opposite dose. Muscle biopsy specimens were collected from the injection site 10 days after each sample collection period. Pharmacokinetic data were calculated. Minimum inhibitory concentrations of ceftiofur for various bacterial isolates were assessed. Mean peak plasma concentrations of ceftiofur-free acid equivalent were 6.8 and 15.1 μg/mL for the 10 and 20 mg/kg doses, respectively. Mean times to maximum plasma concentration were 6.4 and 6.7 hours, and mean terminal half-lives were 29 and 50 hours, respectively. Little to no muscle inflammation was identified. On the basis of a target MIC of 1 μg/mL and target plasma ceftiofur concentration of 4 μg/mL, dose administration frequencies for infections with gram-negative and gram-positive organisms were estimated as every 36 and 45 hours for the 10 mg/kg dose and every 96 and 120 hours for the 20 mg/kg dose, respectively. Study results suggested that CCFA could be administered IM to red-tailed hawks at 10 or 20 mg/kg to treat infections with ceftiofur-susceptible bacteria. Administration resulted in little to no inflammation at the injection site. Additional studies are needed to evaluate effects of repeated CCFA administration.

  17. Hazard Avoidance Products for Convectively-Induced Turbulence in Support of High-Altitude Global Hawk Aircraft Missions

    Science.gov (United States)

    Griffin, Sarah M.; Velden, Christopher S.

    2018-01-01

    A combination of satellite-based and ground-based information is used to identify regions of intense convection that may act as a hazard to high-altitude aircraft. Motivated by concerns that Global Hawk pilotless aircraft, flying near 60,000 feet, might encounter significant convectively-induced turbulence during research overflights of tropical cyclones, strict rules were put in place to avoid such hazards. However, these rules put constraints on science missions focused on sampling convection with onboard sensors. To address these concerns, three hazard avoidance tools to aid in real-time mission decision support are used to more precisely identify areas of potential turbulence: Satellite-derived Cloud-top height and tropical overshooting tops, and ground-based global network lightning flashes. These tools are used to compare an ER-2 aircraft overflight of tropical cyclone Emily in 2005, which experienced severe turbulence, to Global Hawk overflights of tropical cyclones Karl and Matthew in 2010 that experienced no turbulence. It is found that the ER-2 overflew the lowest cloud tops and had the largest vertical separation from them compared to the Global Hawk flights. Therefore, cold cloud tops alone cannot predict turbulence. Unlike the overflights of Matthew and Karl, Emily exhibited multiple lightning flashes and a distinct overshooting top coincident with the observed turbulence. Therefore, these tools in tandem can better assist in identifying likely regions/periods of intense active convection. The primary outcome of this study is an altering of the Global Hawk overflight rules to be more flexible based on the analyzed conditions.

  18. Confluent Heun functions and the physics of black holes: Resonant frequencies, Hawking radiation and scattering of scalar waves

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, H.S., E-mail: horacio.santana.vieira@hotmail.com [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, CEP 58051-970, João Pessoa, PB (Brazil); Centro de Ciências, Tecnologia e Saúde, Universidade Estadual da Paraíba, CEP 58233-000, Araruna, PB (Brazil); Bezerra, V.B., E-mail: valdir@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, CEP 58051-970, João Pessoa, PB (Brazil)

    2016-10-15

    We apply the confluent Heun functions to study the resonant frequencies (quasispectrum), the Hawking radiation and the scattering process of scalar waves, in a class of spacetimes, namely, the ones generated by a Kerr–Newman–Kasuya spacetime (dyon black hole) and a Reissner–Nordström black hole surrounded by a magnetic field (Ernst spacetime). In both spacetimes, the solutions for the angular and radial parts of the corresponding Klein–Gordon equations are obtained exactly, for massive and massless fields, respectively. The special cases of Kerr and Schwarzschild black holes are analyzed and the solutions obtained, as well as in the case of a Schwarzschild black hole surrounded by a magnetic field. In all these special situations, the resonant frequencies, Hawking radiation and scattering are studied. - Highlights: • Charged massive scalar field in the dyon black hole and massless scalar field in the Ernst spacetime are analyzed. • The confluent Heun functions are applied to obtain the solution of the Klein–Gordon equation. • The resonant frequencies are obtained. • The Hawking radiation and the scattering process of scalar waves are examined.

  19. HIWRAP Radar Development for High-Altitude Operation on the NASA Global Hawk and ER-2

    Science.gov (United States)

    Li, Lihua; Heymsfield, Gerlad; Careswell, James; Schaubert, Dan; Creticos, Justin

    2011-01-01

    The NASA High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) is a solid-state transmitter-based, dual-frequency (Ka- and Ku-band), dual-beam (30 degree and 40 degree incidence angle), conical scan Doppler radar system, designed for operation on the NASA high-altitude (20 km) aircrafts, such as the Global Hawk Unmanned Aerial System (UAS). Supported by the NASA Instrument Incubator Program (IIP), HIWRAP was developed to provide high spatial and temporal resolution 3D wind and reflectivity data for the research of tropical cyclone and severe storms. With the simultaneous measurements at both Ku- and Ka-band two different incidence angles, HIWRAP is capable of imaging Doppler winds and volume backscattering from clouds and precipitation associated with tropical storms. In addition, HIWRAP is able to obtain ocean surface backscatter measurements for surface wind retrieval using an approach similar to QuikScat. There are three key technology advances for HIWRAP. Firstly, a compact dual-frequency, dual-beam conical scan antenna system was designed to fit the tight size and weight constraints of the aircraft platform. Secondly, The use of solid state transmitters along with a novel transmit waveform and pulse compression scheme has resulted in a system with improved performance to size, weight, and power ratios compared to typical tube based Doppler radars currently in use for clouds and precipitation measurements. Tube based radars require high voltage power supply and pressurization of the transmitter and radar front end that complicates system design and implementation. Solid state technology also significantly improves system reliability. Finally, HIWRAP technology advances also include the development of a high-speed digital receiver and processor to handle the complex receiving pulse sequences and high data rates resulting from multi receiver channels and conical scanning. This paper describes HIWRAP technology development for dual-frequency operation at

  20. Thermal Assessment of Sunlight Impinging on OSIRIS-REx OCAMS PolyCam, OTES, and IMU-Sunshade MLI Blankets in Flight

    Science.gov (United States)

    Choi, Michael K.

    2017-01-01

    The NASA Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft was successfully launched into orbit on September 8, 2016. It is traveling to a near-Earth asteroid (101955) Bennu, study it in detail, and bring back a pristine sample to Earth for scientific analyses. At the Outbound Cruise nominal spacecraft attitude, with Sun on +X, sunlight impinges on the OSIRIS-REx camera suite (OCAMS) PolyCam sunshade multilayer insulation (MLI) with microporous black polytetrafluoroethylene (PTFE), a portion of the PolyCam optics support tube (MLI with germanium black Kapton (GBK)), a portion of the OSIRIS-REx Thermal Emission Spectrometer (OTES) sunshade (MLI with GBK), the Inertia Measurement Unit (IMU) sunshade (MLI with GBK), and the OSIRIS-REx Laser Altimeter (OLA) sunshade (MLI with GBK). Sunlight is reflected or scattered by the above MLIs to the other components on the forward (+Z) deck. It illuminates the forward deck. A detailed thermal assessment on the solar impingement has been performed for the Proximity Ops at the asteroid, Touch-and-Go (TAG) sample acquisition, and Return Cruise mission phases.The OSIRIS-REx Outbound Cruise flight temperature telemetry and USM_3_DPC_0_CURRENT flight currenttelemetry data have been analyzed. It is evident that at the nominal Outbound Cruise spacecraft Sun-pointing attitude(i.e., Sun on +X), sunlight impinging on the PolyCam, OTES, IMU-sunshade and OLA-sunshade MLIs is reflected orscattered to the forward deck and components on the forward deck. It illuminates the forward deck. The StowCam imageof Day 265 2016 also provided an evidence. The reflected or scattered sunlight cause warming to the forward deck andcomponents on its +Z side. It may also contribute to degradation of thermal coatings over the mission life. It is a factorthat the OVIRS detector operating temperature exceeds the 105K maximum AFT limit. The OVIRS PrincipalInvestigator indicated that it is not optimum

  1. Advanced MicroObserver UGS integration with and cueing of the BattleHawk squad level loitering munition and UAV

    Science.gov (United States)

    Steadman, Bob; Finklea, John; Kershaw, James; Loughman, Cathy; Shaffner, Patti; Frost, Dean; Deller, Sean

    2014-06-01

    Textron's Advanced MicroObserver(R) is a next generation remote unattended ground sensor system (UGS) for border security, infrastructure protection, and small combat unit security. The original MicroObserver(R) is a sophisticated seismic sensor system with multi-node fusion that supports target tracking. This system has been deployed in combat theaters. The system's seismic sensor nodes are uniquely able to be completely buried (including antennas) for optimal covertness. The advanced version adds a wireless day/night Electro-Optic Infrared (EOIR) system, cued by seismic tracking, with sophisticated target discrimination and automatic frame capture features. Also new is a field deployable Gateway configurable with a variety of radio systems and flexible networking, an important upgrade that enabled the research described herein. BattleHawkTM is a small tube launched Unmanned Air Vehicle (UAV) with a warhead. Using transmitted video from its EOIR subsystem an operator can search for and acquire a target day or night, select a target for attack, and execute terminal dive to destroy the target. It is designed as a lightweight squad level asset carried by an individual infantryman. Although BattleHawk has the best loiter time in its class, it's still relatively short compared to large UAVs. Also it's a one-shot asset in its munition configuration. Therefore Textron Defense Systems conducted research, funded internally, to determine if there was military utility in having the highly persistent MicroObserver(R) system cue BattleHawk's launch and vector it to beyond visual range targets for engagement. This paper describes that research; the system configuration implemented, and the results of field testing that was performed on a government range early in 2013. On the integrated system that was implemented, MicroObserver(R) seismic detections activated that system's camera which then automatically captured images of the target. The geo-referenced and time-tagged Micro

  2. Control of cerebellar long-term potentiation by P-Rex-family guanine-nucleotide exchange factors and phosphoinositide 3-kinase.

    Directory of Open Access Journals (Sweden)

    Claire Jackson

    2010-08-01

    Full Text Available Long-term potentiation (LTP at the parallel fibre-Purkinje cell synapse in the cerebellum is a recently described and poorly characterized form of synaptic plasticity. The induction mechanism for LTP at this synapse is considered reciprocal to "classical" LTP at hippocampal CA1 pyramidal neurons: kinases promote increased trafficking of AMPA receptors into the postsynaptic density in the hippocampus, whereas phosphatases decrease internalization of AMPA receptors in the cerebellum. In the hippocampus, LTP occurs in overlapping phases, with the transition from early to late phases requiring the consolidation of initial induction processes by structural re-arrangements at the synapse. Many signalling pathways have been implicated in this process, including PI3 kinases and Rho GTPases.We hypothesized that analogous phases are present in cerebellar LTP, and took as the starting point for investigation our recent discovery that P-Rex--a Rac guanine nucleotide exchange factor which is activated by PtdIns(3,4,5P(3--is highly expressed in mouse cerebellar Purkinje neurons and plays a role in motor coordination. We found that LTP evoked at parallel fibre synapses by 1 Hz stimulation or by NO donors was not sustained beyond 30 min when P-Rex was eliminated or Rac inhibited, suggesting that cerebellar LTP exhibits a late phase analogous to hippocampal LTP. In contrast, inhibition of PI3 kinase activity eliminated LTP at the induction stage.Our data suggest that a PI3K/P-Rex/Rac pathway is required for late phase LTP in the mouse cerebellum, and that other PI3K targets, which remain to be discovered, control LTP induction.

  3. Great Physicists - The Life and Times of Leading Physicists from Galileo to Hawking

    Science.gov (United States)

    Cropper, William H.

    2004-09-01

    Here is a lively history of modern physics, as seen through the lives of thirty men and women from the pantheon of physics. William H. Cropper vividly portrays the life and accomplishments of such giants as Galileo and Isaac Newton, Marie Curie and Ernest Rutherford, Albert Einstein and Niels Bohr, right up to contemporary figures such as Richard Feynman, Murray Gell-Mann, and Stephen Hawking. We meet scientists--all geniuses--who could be gregarious, aloof, unpretentious, friendly, dogged, imperious, generous to colleagues or contentious rivals. As Cropper captures their personalities, he also offers vivid portraits of their great moments of discovery, their bitter feuds, their relations with family and friends, their religious beliefs and education. In addition, Cropper has grouped these biographies by discipline--mechanics, thermodynamics, particle physics, and others--each section beginning with a historical overview. Thus in the section on quantum mechanics, readers can see how the work of Max Planck influenced Niels Bohr, and how Bohr in turn influenced Werner Heisenberg. Our understanding of the physical world has increased dramatically in the last four centuries. With Great Physicists , readers can retrace the footsteps of the men and women who led the way.

  4. Hawking Radiation from a (4+n)-dimensional Black Hole Exact Results for the Schwarzschild Phase

    CERN Document Server

    Harris, C M; Harris, Chris M.; Kanti, Panagiota

    2003-01-01

    We start our analysis by deriving a master equation that describes the motion of a field with arbitrary spin $s$ on a 3-brane embedded in a non-rotating, uncharged (4+n)-dimensional black hole background. By numerical analysis, we derive exact results for the greybody factors and emission rates for scalars, fermions and gauge bosons emitted directly on the brane, for all energy regimes and for an arbitrary number $n$ of extra dimensions. The relative emissivities on the brane for different types of particles are computed and their dependence on the dimensionality of spacetime is demonstrated -- we therefore conclude that both the amount and the type of radiation emitted can be used for the determination of $n$ if the Hawking radiation from these black holes is observed. The emission of scalar modes in the bulk from the same black holes is also studied and the relative bulk-to-brane energy emissivity is accurately computed. We demonstrate that this quantity varies considerably with $n$ but always remains small...

  5. Analytic explanation of the strong spin-dependent amplification in Hawking radiation from rotating black holes

    Science.gov (United States)

    Dai, De-Chang; Stojkovic, Dejan

    2010-08-01

    Numerical studies of black hole greybody factors indicate that Hawking emission from a highly rotating black hole is strongly spin dependent, with particles of highest spin (gravitons) dominating the energy spectrum. So far, there has been no analytic explanation or description of this effect. Using “gravitomagnetism”, or the formal analogy between the Maxwell’s field equations for electromagnetism and Einstein’s equations for gravity, we were able to establish a link between the spin of the rotating black hole and spin of an emitted particle. Namely, the intrinsic spin of the particle creates a “mass dipole moment” which interacts with external gravitomagnetic field whose source is the rotation of the black hole. We showed that a rotating black hole prefers to shed its spin, i.e. tends to emit particles with the spin parallel to its own. We also showed that the probability for emission grows with the increasing spin of the emitted particles. The amplification factors can be huge if a black hole is highly rotating, i.e. close to extremal. When applied to central galactic black holes, the same physical mechanism indicate that particles orbiting around these black holes should have spins strongly correlated with the spin of the black hole, which may have implications for cosmic rays believed to be coming from these regions of space.

  6. Dynamics of the echolocation beam during prey pursuit in aerial hawking bats.

    Science.gov (United States)

    Jakobsen, Lasse; Olsen, Mads Nedergaard; Surlykke, Annemarie

    2015-06-30

    In the evolutionary arms race between prey and predator, measures and countermeasures continuously evolve to increase survival on both sides. Bats and moths are prime examples. When exposed to intense ultrasound, eared moths perform dramatic escape behaviors. Vespertilionid and rhinolophid bats broaden their echolocation beam in the final stage of pursuit, presumably as a countermeasure to keep evading moths within their "acoustic field of view." In this study, we investigated if dynamic beam broadening is a general property of echolocation when catching moving prey. We recorded three species of emballonurid bats, Saccopteryx bilineata, Saccopteryx leptura, and Rhynchonycteris naso, catching airborne insects in the field. The study shows that S. bilineata and S. leptura maintain a constant beam shape during the entire prey pursuit, whereas R. naso broadens the beam by lowering the peak call frequency from 100 kHz during search and approach to 67 kHz in the buzz. Surprisingly, both Saccopteryx bats emit calls with very high energy throughout the pursuit, up to 60 times more than R. naso and Myotis daubentonii (a similar sized vespertilionid), providing them with as much, or more, peripheral "vision" than the vespertilionids, but ensonifying objects far ahead suggesting more clutter. Thus, beam broadening is not a fundamental property of the echolocation system. However, based on the results, we hypothesize that increased peripheral detection is crucial to all aerial hawking bats in the final stages of prey pursuit and speculate that beam broadening is a feature characterizing more advanced echolocation.

  7. Complete mitochondrial genome of the larch hawk moth, Sphinx morio (Lepidoptera: Sphingidae).

    Science.gov (United States)

    Kim, Min Jee; Choi, Sei-Woong; Kim, Iksoo

    2013-12-01

    The larch hawk moth, Sphinx morio, belongs to the lepidopteran family Sphingidae that has long been studied as a family of model insects in a diverse field. In this study, we describe the complete mitochondrial genome (mitogenome) sequences of the species in terms of general genomic features and characteristic short repetitive sequences found in the A + T-rich region. The 15,299-bp-long genome consisted of a typical set of genes (13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes) and one major non-coding A + T-rich region, with the typical arrangement found in Lepidoptera. The 316-bp-long A + T-rich region located between srRNA and tRNA(Met) harbored the conserved sequence blocks that are typically found in lepidopteran insects. Additionally, the A + T-rich region of S. morio contained three characteristic repeat sequences that are rarely found in Lepidoptera: two identical 12-bp repeat, three identical 5-bp-long tandem repeat, and six nearly identical 5-6 bp long repeat sequences.

  8. Multifocal respiratory and vertebral mycobacteriosis in a red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Sadar, Miranda J; McRuer, David; Hawkins, Michelle G; Armién, Aníbal G

    2015-03-01

    An adult, female, free-ranging red-tailed hawk (Buteo jamaicensis) was presented to a rehabilitation facility for an inability to stand. On examination, it displayed bilateral exaggeration of the pelvic limb reflexes with extensor muscle rigidity, intact superficial pain response, and positive withdrawal reflexes. A complete blood count identified moderate leukocytosis characterized by moderate heterophilia. No abnormalities were appreciable on radiographic evaluation. After initial improvement, it regressed and was euthanized 27 days after presentation. Necropsy and histologic investigation identified reduction in the diameter of the vertebral canal and spinal cord at cervical segments 8-9 with coalescing granulomas and intralesional acid-fast bacilli within the intertrabecular space, left side of the clavicular air sac, and cranial left lung. Bacterial culture and genetic sequencing from respiratory lesions identified Mycobacterium avium avium. Real time-polymerase chain reaction of paraffin-fixed spinal tissue tested positive for M. avium complex. Mycobacteriosis should be considered when peripheral neurologic deficits are present in raptors.

  9. Retinal photoreceptor fine structure in the red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Braekevelt, C R

    1993-09-01

    The retinal photoreceptors of the red-tailed hawk (Buteo jamaicensis) consist of rods, single cones and double (unequal) cones present in a ratio of about 2:1:5. In the light-adapted state, the rods are slender elongated cells with outer segments that reach to the retinal epithelial (RPE) cells. The inner segment displays an ellipsoid of mitochondria, plentiful polysomes, some rough ER and Golgi zones. The rod nucleus is located deep within the outer nuclear layer and the synaptic spherule displays both invaginated (ribbon) and superficial (conventional) synaptic sites. Single cones show a thin tapering outer segment, a large electron lucent oil droplet at the apex of the inner segment and an ellipsoid of mitochondria. Double cones consist of a larger chief member which displays a thin tapering outer segment and an electron dense oil droplet as well as a smaller accessory cone which shows no oil droplet, an ellipsoid and a paraboloid of glycogen. As in the single cone, polysomes, RER and Golgi zones are also noted in the inner segments of both members of the double cone. Near the external limiting membrane the chief and accessory cones show membrane specializations indicative of junctions on their contiguous surfaces. All cone photoreceptors are of a smaller diameter than is normally reported for avian species. Both single and double cones display several invaginated synapses as well as numerous superficial synaptic sites.

  10. Recovery and identification of West Nile virus from a hawk in winter.

    Science.gov (United States)

    Garmendia, A E; Van Kruiningen, H J; French, R A; Anderson, J F; Andreadis, T G; Kumar, A; West, A B

    2000-08-01

    West Nile virus was recovered from the brain of a red-tailed hawk that died in Westchester County, N.Y., in February 2000. Multiple foci of glial cells, lymphocytes, and a few pyknotic nuclei were observed in the brain. Three to 4 days after inoculation of Vero cells with brain homogenates, cytopathic changes were detected. The presence of West Nile virus antigen in fixed cells or cell lysates was revealed by fluorescent antibody testing or enzyme-linked immunosorbent assay, respectively. Furthermore, Reverse transcriptase-PCR with primers specific for the NS3 gene of West Nile virus resulted in an amplicon of the expected size (470 bp). Electron microscopy of thin sections of infected Vero cells revealed the presence of viral particles approximately 40 nm in diameter, within cytoplasmic vesicles. The demonstration of infection with the West Nile virus in the dead of the winter, long after mosquitoes ceased to be active, is significant in that it testifies to the survival of the virus in the region beyond mosquito season and suggests another route of transmission: in this case, prey to predator.

  11. Retinal pigment epithelial fine structure in the red-tailed hawk (Buto jamaicensis).

    Science.gov (United States)

    Braekevelt, C R

    1992-03-01

    As part of a comparative morphological study, the fine structure of the retinal epithelium (RPE), choriocapillaris and Bruch's membrane (complexus basalis) has been studied by electron microscopy in the red-tailed hawk (Buteo jamaicensis). In this species the RPE consists of a single layer of low cuboidal cells which display numerous basal (scleral) infoldings and extensive apical (vitreal) processes which interdigitate with photoreceptor outer segments. These epithelial cells are joined laterally by a series of basally located tight junctions. Internally SER is the most abundant cell organelle while only small amounts of RER are present. Polysomes are however abundant as are mitochondria. The RPE cell nucleus is large and vesicular. Melanosomes are mainly located in the apical processes of the RPE cells in light-adaptation. Myeloid bodies are large and numerous in light-adaptation and often show ribosomes on their outer border. Bruch's membrane (complexus basalis) shows the typical pentalaminate structure noted in most vertebrates but with only a poorly defined central elastic layer. The endothelium of the choriocapillaris is very thin facing the RPE but is only moderately fenestrated. The choriocapillaris in this species is unusual however in that many of the fenestrae show a double-layered diaphragm.

  12. Quasinormal modes of BTZ black hole and Hawking-like radiation in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Kandemir, B.S.; Ertem, Uemit [Department of Physics, Ankara University, Faculty of Sciences, 06100, Tandogan-Ankara (Turkey)

    2017-04-15

    The Banados-Teitelboim-Zanelli (BTZ) black hole model corresponds to a solution of (2+1)-dimensional Einstein gravity with negative cosmological constant, and by a conformal rescaling its metric can be mapped onto the hyperbolic pseudosphere surface (Beltrami trumpet) with negative curvature. Beltrami trumpet shaped graphene sheets have been predicted to emit Hawking radiation that is experimentally detectable by a scanning tunnelling microscope. Here, for the first time we present an analytical algorithm that allows variational solutions to the Dirac Hamiltonian of graphene pseudoparticles in BTZ black hole gravitational field by using an approach based on the formalism of pseudo-Hermitian Hamiltonians within a discrete-basis-set method. We show that our model not only reproduces the exact results for the real part of quasinormal mode frequencies of (2+1)-dimensional spinless BTZ black hole, but also provides analytical results for the real part of quasinormal modes of spinning BTZ black hole, and also offers some predictions for the observable effects with a view to gravity-like phenomena in a curved graphene sheet. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Universal Property of Quantum Gravity implied by Uniqueness Theorem of Bekenstein-Hawking Entropy

    Directory of Open Access Journals (Sweden)

    Hiromi Saida

    2011-09-01

    Full Text Available This paper consists of three parts. In the first part, we prove that the Bekenstein-Hawking entropy is the unique expression of black hole entropy. Our proof is constructed in the framework of thermodynamics without any statistical discussion. In the second part, intrinsic properties of quantum mechanics are shown, which justify the Boltzmann formula to yield a unique entropy in statistical mechanics. These properties clarify three conditions, one of which is necessary and others are sufficient for the validity of Boltzmann formula. In the third part, by combining the above results, we find a reasonable suggestion from the sufficient conditions that the potential of gravitational interaction among microstates of underlying quantum gravity may not diverge to negative infinity (such as Newtonian gravity but is bounded below at a finite length scale. In addition to that, from the necessary condition, the interaction has to be repulsive within the finite length scale. The length scale should be Planck size. Thus, quantum gravity may become repulsive at Planck length. Also, a relation of these suggestions with action integral of gravity at semi-classical level is given. These suggestions about quantum gravity are universal in the sense that they are independent of any existing model of quantum gravity.

  14. Hawking radiation of charged Einstein-aether black holes at both Killing and universal horizons

    Science.gov (United States)

    Ding, Chikun; Wang, Anzhong; Wang, Xinwen; Zhu, Tao

    2016-12-01

    We study analytically quantum tunneling of relativistic and non-relativistic particles at both Killing and universal horizons of Einstein-Maxwell-aether black holes, after high-order curvature corrections are taken into account, for which the dispersion relation of the particles becomes nonlinear. Our results at the Killing horizons confirm the previous ones, i.e., at high frequencies the corresponding radiation remains thermal and the nonlinearity of the dispersion does not alter the Hawking radiation significantly. In contrary, non-relativistic particles are created at universal horizons and are radiated out to infinity. The radiation also has a thermal spectrum, and the corresponding temperature takes the form, TUHz = 2κUH (z - 1) / (2 πz), where z (z ≥ 2) denotes the power of the leading term in the nonlinear dispersion relation, κUH is the surface gravity of the universal horizon, defined by peering behavior of ray trajectories at the universal horizon. We also study the Smarr formula by assuming that: (a) the entropy is proportional to the area of the universal horizon, and (b) the first law of black hole thermodynamics holds, whereby we derive the Smarr mass, which in general is different from the total mass obtained at infinity. This indicates that one or both of these assumptions must be modified.

  15. Finite width of the optical event horizon and enhancement of analog Hawking radiation

    Science.gov (United States)

    Vinish, Y.; Fleurov, V.

    2016-08-01

    Coherent light propagating in a bulk Kerr nonlinear defocusing medium obeys nonlinear Schrödinger (NLS) equation, which is similar to the Gross-Pitaevskii equation for Bose-Einstein condensates (BECs). An equivalent hydrodynamic approach allows one to consider propagation of light as a flow of an equivalent “luminous fluid.” An analog optical event horizon can be formed when the flow velocity of this fluid equals the local sound velocity, determined by the nonlinear term in the NLS equation. The analog event horizon is characterized by a finite width, also determined by the nonlinearity length, or by the healing length in Bose-Einstein condensates. The various eigenmodes of fluctuations are found in the immediate vicinity of the event horizon and the scattering matrix due to the finite width horizon is calculated to be within the leading order corrections in the nonlinearity length. The Hawking radiation is found to be enhanced with respect to that of a Planck’s black body spectrum and is characterized by the emissivity greater than one. A procedure of paraxial quantization of the fluctuation field is discussed and its connection to the conventional quantization of the electromagnetic field is demonstrated. Quantum fluctuations of the electric field energy and those of its flow are calculated.

  16. Hawkes-diffusion process and the conditional probability of defaults in the Eurozone

    Science.gov (United States)

    Kim, Jungmu; Park, Yuen Jung; Ryu, Doojin

    2016-05-01

    This study examines market information embedded in the European sovereign CDS (credit default swap) market by analyzing the sovereign CDSs of 13 Eurozone countries from January 1, 2008, to February 29, 2012, which includes the recent Eurozone debt crisis period. We design the conditional probability of defaults for the CDS prices based on the Hawkes-diffusion process and obtain the theoretical prices of CDS indexes. To estimate the model parameters, we calibrate the model prices to empirical prices obtained from individual sovereign CDS term structure data. The estimated parameters clearly explain both cross-sectional and time-series data. Our empirical results show that the probability of a huge loss event sharply increased during the Eurozone debt crisis, indicating a contagion effect. Even countries with strong and stable economies, such as Germany and France, suffered from the contagion effect. We also find that the probability of small events is sensitive to the state of the economy, spiking several times due to the global financial crisis and the Greek government debt crisis.

  17. Investigation of the Effectiveness of Dynamic Seat in a Black Hawk Flight Simulation

    Science.gov (United States)

    Chung, William W. Y.; Bengford, Norm; Perry, Chuck; Nicholson, Bob; Wilkinson, Colin

    2001-01-01

    Low cost alternatives have been sought to provide motion cues in ground-based flight simulators to meet mission objectives. The ability to provide high frequency vibrations makes the dynamic seat attractive to helicopter training applications. Previous studies have found that dynamic seat does enhance the realism of the cockpit and affect pilots' workload. This investigation, conducted under the auspices of the Joint Shipboard Helicopter Integration Process (JSHIP), is using a three degree-of-freedom dynamic seat, i.e., heave, surge, and sway, with limited travels in a research simulator configured as a UH-60 Black Hawk at NASA Ames Research Center. The seat's effectiveness is studied using hover, landing, pirouette, bob-up/bob-down, sidestep, and acceleration/deceleration maneuvers. Seat commands consist of constant vibrations in heave and sway which provide the fundamental vibratory cues. Pilot station accelerations and collective controls provide onset and sustained commands. In addition, transient effects due to translational-lift, collective; and normal acceleration are produced by regulating the magnitude and frequency that depend on the rotor rpm. Results are compared to flight test data and two other ground-based motion systems configurations, i.e., a motion condition with very large motion travels and a motion condition that is comparable with commercial simulator travels. Both subjective and objective data will be analyzed to determine the significance of the motion cueing effect in each system for selected maneuvers.

  18. Identification of Spurious Signals from Permeable Ffowcs Williams and Hawkings Surfaces

    Science.gov (United States)

    Lopes, Leonard V.; Boyd, David D., Jr.; Nark, Douglas M.; Wiedemann, Karl E.

    2017-01-01

    Integral forms of the permeable surface formulation of the Ffowcs Williams and Hawkings (FW-H) equation often require an input in the form of a near field Computational Fluid Dynamics (CFD) solution to predict noise in the near or far field from various types of geometries. The FW-H equation involves three source terms; two surface terms (monopole and dipole) and a volume term (quadrupole). Many solutions to the FW-H equation, such as several of Farassat's formulations, neglect the quadrupole term. Neglecting the quadrupole term in permeable surface formulations leads to inaccuracies called spurious signals. This paper explores the concept of spurious signals, explains how they are generated by specifying the acoustic and hydrodynamic surface properties individually, and provides methods to determine their presence, regardless of whether a correction algorithm is employed. A potential approach based on the equivalent sources method (ESM) and the sensitivity of Formulation 1A (Formulation S1A) is also discussed for the removal of spurious signals.

  19. Large-eddy simulation of mesoscale dynamics and entrainment around a pocket of open cells observed in VOCALS-REx RF06

    OpenAIRE

    Berner, A. H.; Bretherton, C. S.; Wood, R.

    2011-01-01

    Large-eddy simulations of a pocket of open cells (POC) based on VOCALS Regional Experiment (REx) NSF C-130 Research Flight 06 are analyzed and compared with aircraft observations. A doubly-periodic domain 192 km × 24 km with 125 m horizontal and 5 m vertical grid spacing near the capping inversion is used. The POC is realized in the model as a fixed 96 km wide region of reduced cloud droplet number concentration (Nc) based on observed values; initiali...

  20. Contrast fluoroscopic evaluation of gastrointestinal transit times with and without the use of falconry hoods in red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Doss, Grayson A; Williams, Jackie M; Mans, Christoph

    2017-11-01

    OBJECTIVE To evaluate gastrointestinal transit times in red-tailed hawks (Buteo jamaicensis) by use of contrast fluoroscopic imaging and investigate the effect of falconry hooding in these hawks on gastrointestinal transit time. DESIGN Prospective, randomized, blinded, complete crossover study. ANIMALS 9 healthy red-tailed hawks. PROCEDURES Hawks were gavage-fed a 30% weight-by-volume barium suspension (25 mL/kg [11.3 mL/lb]) into the crop. Fluoroscopic images were obtained at multiple time points after barium administration. Time to filling and emptying of various gastrointestinal tract organs and overall transit time were measured. The effect of hooding (hooded vs nonhooded) on these variables was assessed in a randomized complete crossover design. RESULTS In nonhooded birds, overall gastrointestinal transit time ranged from 30 to 180 minutes (mean ± SD, 100 ± 52 min). Time to complete crop emptying ranged from 30 to 180 minutes (83 ± 49 min). Contrast medium was present in the ventriculus in all birds within 5 minutes of administration and in the small intestines within 5 to 15 minutes (median, 5 min). Hooding of red-tailed hawks resulted in a significant delay of complete crop emptying (no hood, 83 ± 49 minutes; hood, 133 ± 48 minutes), but no significant effects of hooding were found on other measured variables. CONCLUSIONS AND CLINICAL RELEVANCE These results indicated that overall gastrointestinal transit times are faster in red-tailed hawks than has been reported for psittacines and that the use of a falconry hood in red-tailed hawks may result in delayed crop emptying. Hooding did not exert significant effects on overall gastrointestinal transit time in this raptorial species.